combine

Abstract

To detect the reaping height in a reliable manner in a combine harvester having a structure for detecting the reaping height by a reaping unit, by preventing malfunction due to contact with stocks broken by the reaping unit or their roots.SOLUTION: A combine harvester comprises: a reaping unit that is porvided to be raised and lowered in relation to a travel machine; and a reaping height detection device 40 for detecting the height of the reaping unit. The reaping height detection device 40 comprises a device body 41 that is vertically turnably installed; a grounding body 42 supported to be turnable relative to the device body 41; and a detection sensor 43 for detecting the quantity of rotation of the grounding body 42, and detects the height of the reaping unit on the basis of a detection signal by the detection sensor 43. The device body 41 is supported in relation to a grass divider support part 120 for supporting a grass dividing plate 21 provided on the front part of the reaping unit, and a unit supporter 44 for protecting the device body 41 from the front and both lateral sides is further provided.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a combine harvester having a height-adjustable cutting head. [Background technology]

[0002] Generally, a combine harvester is equipped with a reaping unit in front of the traveling body and a threshing unit on the traveling body, and while traveling, the reaping unit harvests stalks and the threshing unit threshes the stalks. Conventionally, some combine harvesters have a reaping unit that can be raised and lowered relative to the traveling body and a cutting height detection device to control the cutting height, which is the height of the reaping unit from the ground (see, for example, Patent Document 1). In such a configuration, the operation of a lifting device such as a hydraulic cylinder that raises and lowers the reaping unit is controlled based on a detection signal from the cutting height detection device, and the cutting height is automatically controlled.

[0003] Patent Document 1 discloses a configuration for a cutting height detection device that includes a sensor unit arranged below and behind a grass division body held by a cutting section. The sensor unit includes a unit body as a device body provided on a bracket attached to the grass division body, a potentiometer as a detection sensor that detects the rotational position of the unit body, and a grounding body provided rotatably with the left-right direction as an axial direction relative to the unit body.

[0004] The unit body is attached to the bracket so as to be rotatable up and down by a rotation shaft located at the front of the unit body and having an axial direction in the left-right direction. The grounding member extends downward from the rear of the unit body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5857987 Summary of the Invention [Problem to be solved by the invention]

[0006] The configuration of the sensor unit as disclosed in Patent Document 1 has the following problems. In the harvesting of culms, the stalk may be split into left and right halves by the grass splitter as the machine moves forward. In such cases, the split stalk or its roots may come into contact with the unit body or the grounding body located behind the grass splitter. Contact of the stalk or the like with the unit body or the grounding body may cause the sensor unit to malfunction, resulting in an unstable detection value of the cutting height. In particular, the action of the split stalk on the grounding body reduces the accuracy of the detection of the cutting height by the sensor unit.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a combine harvester that can detect the cutting height by the cutting unit in a configuration that can prevent malfunctions caused by contact with stumps split to the left and right by the grass body or their roots, and can stably detect the cutting height. [Means for solving the problem]

[0008] The combine harvester of the present invention is a combine harvester equipped with a cutting unit that is capable of being raised and lowered relative to the running body, and a cutting height detection device for detecting the height of the cutting unit, wherein the cutting height detection device has an apparatus main body that is capable of rotating up and down, a grounding body that is rotatably supported relative to the apparatus main body, and a detection sensor that detects the amount of rotation of the grounding body, and detects the height of the cutting unit based on a detection signal from the detection sensor, and further has a protective member that supports the apparatus main body relative to a grass dividing body support part that supports a grass dividing body provided in front of the cutting unit, and protects the apparatus main body from the front and both left and right sides.

[0009] In another aspect of the combine of the present invention, the protective member is arranged to be rotatable with the device main body relative to the grass body support part, with the forward / backward direction being the axial direction.

[0010] In another aspect of the combine of the present invention, the protective member includes left and right side plate portions which are plate-shaped portions with the plate thickness direction in the left-right direction as parts that protect the device main body from both the left and right sides, and the rear sides of the left and right side plate portions are provided with bent portions which are bent in directions facing each other so as to be located rearward of the device main body.

[0011] In another aspect of the combine of the present invention, in the combine described above, the grass body support section is provided with a front guide section which is located in front of the device main body and guides the stalks outward to the left and right as the machine body moves forward. Effect of the Invention

[0012] According to the present invention, in the configuration for detecting the cutting height by the cutting unit, it is possible to prevent malfunction due to contact with the stumps split to the left and right by the grass body and their bases, etc., and it is possible to stably detect the cutting height. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a left side view of a combine harvester according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a right side view of a combine harvester according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view showing the configuration of the reaping section of a combine harvester according to one embodiment of the present invention. [Figure 4] This is a left side view showing the configuration of a grass dividing section and a cutting height detection device according to one embodiment of the present invention. [Diagram 5] 1 is a left front perspective view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 6] 1 is a right front perspective view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 7] 1 is a left side view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 8]1 is a right side view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 9] 1 is a plan view of a cutting height detection device according to an embodiment of the present invention. [Figure 10] FIG. 2 is a bottom view of the cutting height detection device according to the embodiment of the present invention. [Figure 11] 1 is a front view showing a cutting height detection device and its support structure according to an embodiment of the present invention. [Figure 12] FIG. 2 is a front perspective view showing a sensor unit according to an embodiment of the present invention. [Figure 13] 2 is a plan sectional view showing a configuration of a shaft support part of the cutting height detection device according to one embodiment of the present invention. FIG. [Figure 14] FIG. 2 is a front view showing a schematic configuration of a cutting height detection device and its surroundings according to one embodiment of the present invention, and is an explanatory diagram of the action and effect of a combine harvester according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention relates to a cutting height detection device for detecting the height of a cutting part in a combine harvester having a height-adjustable cutting part, and aims to suppress malfunction of the device and improve the stability of the detection accuracy of the cutting height by devising a configuration of the cutting height detection device. The following describes an embodiment of the present invention.

[0015] The overall configuration of a combine harvester 1 according to this embodiment will be described with reference to Figures 1 and 2. In the following description, the left and right sides of the combine harvester 1 facing the front (left side in Figure 1) are the left and right sides of the combine harvester 1, respectively.

[0016] 1 and 2, the combine harvester 1 according to this embodiment includes a traveling section 2 configured as a crawler-type traveling device having a pair of left and right crawler sections 3, 3, and a traveling body 4 supported by the traveling section 2. The traveling 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 mounted on the traveling body 4 as a drive source.

[0017] A reaping unit 5 is provided at the front of the traveling body 4, which harvests and collects stalks of rice, wheat, etc. in the field. A threshing unit 6 which threshes the stalks harvested by the reaping unit 5, and a grain tank 7 which stores the grains removed from the threshing unit 6 are provided side by side on the traveling body 4. The threshing unit 6 is located on the left side of the body, and the grain tank 7 is located on the right side of the body. The combine harvester 1 travels on the traveling unit 2 while harvesting stalks with the reaping unit 5 and threshing with the threshing unit 6.

[0018] Each crawler unit 3 constituting the traveling unit 2 has a track frame 3a extending in the front-rear direction below the traveling body 4, various rotating bodies such as a drive sprocket 3b supported by the track frame 3a, and a track 3c wound around these rotating bodies. The crawler unit 3 is driven by the power of the engine 11 transmitted to the drive sprocket 3b.

[0019] The reaping unit 5 is driven by driving force from the engine 11, harvests the stalks, and transports the harvested stalks to the threshing unit 6, etc. The reaping unit 5 is provided in front of the traveling body 4 across substantially the entire width of the combine harvester 1. The reaping unit 5 is provided so as to be able to rise and fall relative to the traveling body 4. Note that Fig. 2 shows the reaping unit 5 in a state where it has been lowered from the state shown in Fig. 1.

[0020] The threshing section 6 has a threshing drum 6a with a rotation axis extending in the front-to-rear direction, and a stump supplying device provided to the left of the threshing drum 6a. The stump supplying device holds the base of the stump cut by the reaping section 5 and transports the stump rearward in a lying position with the ear tip facing the threshing drum 6a. The stump supplying device includes a feed chain 6b wound around multiple sprockets with a rotation axis extending in the left-to-right direction, and a stump supplying clamping body 6c that cooperates with the feed chain 6b to clamp the base of the stump.

[0021] Below the threshing section 6 on the traveling machine body 4, a sorting section 8 is provided which sorts the material threshed by the threshing section 6. The sorting section 8 has a rocking sorting device 8a, a wind sorting device and a grain conveying device. The sorting section 8 rocks and sorts the material that has fallen from the threshing section 6 using the rocking sorting device 8a, and wind sorts the material after rocking and sorting using the wind sorting device. The sorting section 8 conveys grains from the material after wind sorting to the right towards the grain tank 7 using the grain conveying device, and blows straw dust, dust and the like backwards using the wind sorting device and discharges them outside the machine body. The grains conveyed by the grain conveying device towards the grain tank 7 are stored in the grain tank 7.

[0022] A discharge auger 9 is rotatably provided at the rear right end of the traveling body 4 as a grain discharge device that discharges grains from the grain tank 7 to the outside. The discharge auger 9 has a discharge port 9a at its tip, and discharges grains stored in the grain tank 7 from the discharge port 9a. The grains discharged from the discharge port 9a are dumped into the bed of a truck, a container, or the like.

[0023] On the traveling machine body 4, behind the threshing section 6, there is provided a straw waste processing section 10 which processes the straw waste after threshing by the threshing section 6. The straw waste processing section 10 has a straw waste conveying device 10a and a straw waste cutting device 10b. The straw waste conveying device 10a conveys the threshed stump (stump) by the threshing section 6 rearward and discharges it outside the machine body or conveys it to the straw waste cutting device 10b. The straw waste cutting device 10b cuts the stump transported from the straw waste conveying device 10a and discharges it outside the machine body.

[0024] On the traveling body 4, to the right of the reaping unit 5 and in front of the grain tank 7, a driver's unit 14 covered by a cabin 13 is provided. A handle unit 15 serving as a steering operation unit is provided in front of the driver's unit 14, and a driver's seat 16 is provided behind the handle unit 15. Various operating tools are disposed to the sides of the driver's seat 16.

[0025] A prime mover unit including an engine 11 is provided below the driving unit 14. The engine 11 is, for example, a diesel engine. The power of the engine 11 is transmitted to various devices provided in each part of the combine 1 via a transmission or the like.

[0026] The reaping unit 5 will be described with reference to Figures 1 to 3. The reaping unit 5 has a reaping support machine frame 20 as a reaping frame, and is configured by supporting a grass dividing board 21, a lifting device 22, a raking device 23, a cutting blade device 24, a stalk transport device 25, etc. on the reaping support machine frame 20. Each device of the reaping unit 5 operates by transmitting power from the engine 11.

[0027] The grass dividing board 21 is an example of a grass dividing body constituting the grass dividing section 50 of the cutting unit 5, and is provided at the front of the cutting unit 5. The grass dividing board 21 has a tapered shape and divides the culms growing in the field. The lifting device 22 is provided at the rear of the grass dividing board 21, and lifts up fallen culms by operating multiple tines 22a connected by a chain.

[0028] The raking device 23 is provided behind the lifting device 22, and includes a chain-driven conveying mechanism 23a and a rotary packer 23b, and raks in the stalks. In addition, in Fig. 3, only the components of the raking device 23 provided at the left end are shown, and the other components are omitted.

[0029] The cutting blade device 24 is a clipper-type device that cuts the base of the raised culms. The culm transport device 25 is a device that transports the culms that have been cut, and it joins multiple culms together, clamps and transports them upward and rearward, and delivers them to the starting end of the feed chain 6b of the threshing section 6 in a horizontally lying position.

[0030] As shown in Fig. 1, the reaping support machine frame 20 is supported by a support frame 26 arranged in a downwardly-descending manner on the front side of the traveling machine body 4. The support frame 26 is provided in approximately the center in the left-right direction of the machine body, and the reaping support machine frame 20 is provided on the front side of the support frame 26.

[0031] As shown in Fig. 3, the reaping support machine frame 20 has a horizontal frame 31 extending in the left-right direction of the machine body, and a plurality of grass dividing frames 32, 34 extending forward from the horizontal frame 31. The reaping support machine frame 20 is supported by the support frame 26 at the horizontal frame 31.

[0032] The horizontal frame 31 is a straight frame part made of square pipe-shaped members. The grass division frames 32, 34 are frame parts made of round pipe-shaped members, have a predetermined bent or curved shape, and extend in the front-rear direction in a plan view. The grass division frames 32, 34 are supported in a cantilevered manner by fixing and supporting their rear ends or rear parts to the horizontal frame 31.

[0033] The multiple grass dividing frames 32, 34 are arranged in parallel at a predetermined interval in the left-right direction. The number of grass dividing frames 32, 34 is one more than the number of mowing rows of the combine harvester 1. The combine harvester 1 in this embodiment is a six-row mower, and seven grass dividing frames 32, 34 are provided. Of the seven grass dividing frames 32, 34, the grass dividing frames 34 located second and sixth from the left respectively have different shapes from the other multiple (five) grass dividing frames 32.

[0034] A lifting device 22 is arranged between adjacent grass dividing frames 32, 34 on the left and right, and a total of six lifting devices 22 are provided. The lower part of the lifting device 22 is connected and supported to the front of each grass dividing frame 32, 34 via a support stay or the like (not shown). A grass dividing board 21 is also attached to the front of each grass dividing frame 32, 34. The multiple grass dividing boards 21 include two types of grass dividing boards 21, one relatively large and one relatively small, which are provided in a predetermined arrangement. In this embodiment, four relatively large grass dividing boards 21 and three relatively small grass dividing boards 21 are arranged alternately in the left-right direction.

[0035] The reaping unit 5 having the above-mentioned configuration is attached to the traveling body 4 so as to be rotatable about a predetermined axis via a hydraulic cylinder 18 (see FIG. 1) serving as a lifting device. In other words, the reaping unit 5 is provided so as to be able to be raised and lowered relative to the traveling body 4 by a rotational motion due to the expansion and contraction of the hydraulic cylinder 18. The hydraulic cylinder 18 is provided between the traveling body 4 and the support frame 26. The rear end of the support frame 26 is supported so as to be rotatable about a left-right axis relative to the traveling body 4 as a rotation fulcrum for the lifting and lowering motion of the reaping unit 5.

[0036] As described above, the combine harvester 1 has the reaping unit 5 provided so as to be able to rise and fall relative to the traveling body 4. The combine harvester 1 is provided with a cutting height detection device 40 in order to control the cutting height (height above the ground), which is the height of the reaping unit 5 from the ground surface G1. In such a configuration, the operation of the hydraulic cylinder 18 that raises and lowers the reaping unit 5 is controlled based on a detection signal from the cutting height detection device 40, and the cutting height is automatically controlled.

[0037] The operation of the hydraulic cylinder 18 is controlled by controlling the operation of a solenoid valve, which is a control valve. A control device (not shown) constituting a control section provided in the combine harvester 1 controls the operation of the control valve of the hydraulic cylinder 18 based on a detection signal from the cutting height detection device 40, thereby controlling the cutting height.

[0038] The automatic control of the cutting height controls the operation of the control valve of the hydraulic cylinder 18 so as to maintain the cutting height of the cutting unit 5 at a set value based on the detection signal from the cutting height detection device 40, and automatically controls the elevation of the cutting unit 5. In the automatic control of the cutting height, the control device controls the height of the cutting unit 5 so that the cutting height detected by the cutting height detection device 40 becomes a preset target value (hereinafter referred to as the "target cutting height value").

[0039] That is, when the detected cutting height is below the target cutting height value, the control device raises the cutting unit 5, and when the detected cutting height is above the target cutting height value, the control device lowers the cutting unit 5, thereby controlling the elevation of the cutting unit 5 so that the height of the cutting unit 5 is maintained at a height corresponding to the target cutting height value. The driving unit 14 is provided with an operation unit for adjusting the cutting height, and for example, during automatic control of the cutting height, control is performed to prioritize adjustment of the cutting height by operating the operation unit. The target cutting height value is, for example, 10 mm, 30 mm, 50 mm, etc.

[0040] As described above, the combine 1 is equipped with a cutting unit 5 having a grass dividing section 50 including a grass dividing board 21 and arranged to be able to rise and fall relative to the running body 4, and a cutting height detection device 40 for detecting the cutting height, which is the height of the cutting unit 5.

[0041] In this embodiment, the cutting height detection device 40 is disposed behind the grass dividing boards 21A that are the second and sixth from the left among the seven grass dividing boards 21 (see FIG. 3). The grass dividing board 21A is supported by a grass dividing frame 34 that has a different shape from the other grass dividing frames 32. The grass dividing board 21A is the relatively smaller of the two types of grass dividing boards 21. Thus, the combine harvester 1 is equipped with two cutting height detection devices 40. However, the number of cutting height detection devices 40 equipped in the combine harvester 1 and the positions at which the cutting height detection devices 40 are provided are not limited. The cutting height detection device 40 may be provided, for example, in one location behind the leftmost or rightmost grass dividing board 21.

[0042] The configuration of the cutting height detection device 40 and the support configuration of the cutting height detection device 40 will be described with reference to Figures 4 to 14. The cutting height detection device 40 includes a device main body 41, a grounding body 42, a detection sensor 43 which is a cutting height sensor, and a unit support body 44 which is a member which supports the device main body 41.

[0043] In the cutting height detection device 40, the device body 41, the grounding body 42, and the detection sensor 43 form an integrated sensor unit 45 (see FIG. 12), and this sensor unit 45 is supported so as to be rotatable about an axis in the left-right direction relative to the unit support body 44. The unit support body 44 is supported so as to be rotatable about an axis in the front-rear direction relative to the grass dividing section 50.

[0044] The height-of-cutting detection device 40 as a whole is supported rotatably about an axis in the front-to-rear direction relative to the grass dividing section 50, and the sensor unit 45 is supported rotatably about an axis in the left-to-right direction relative to the unit support body 44. Rotation of the height-of-cutting detection device 40 about its front-to-rear axis and rotation of the sensor unit 45 about its left-to-right axis are performed in response to an external force acting on the height-of-cutting detection device 40. Below, a state in which no external force is acting on the height-of-cutting detection device 40 is defined as a reference state, and the height-of-cutting detection device 40 in its basic reference state will be described.

[0045] In the sensor unit 45, the device main body 41 has a configuration in which various gears, springs, etc. are supported on predetermined shafts within a case 51 made of, for example, a metal casting. The case 51 has a left-right two-part structure consisting of a right case body 52 forming the main body of the case 51 and a left case body 53 covering the left side of the right case body 52 like a lid. The right case body 52 and the left case body 53 are fixed to each other by fixing bolts 55 at four points around the periphery of the case 51 in a side view. The case 51 has a roughly rectangular outer shape with the longitudinal direction being the front-rear direction (the left-right direction in FIG. 7) in a side view. The upper side of the case 51 has a mountain-like shape that is convex upward in a side view.

[0046] In the sensor unit 45, the grounding body 42 extends downward from the rear side of the rear end of the case 51. The detection sensor 43 is provided in a manner such that it is attached to the right side surface of the case 51.

[0047] The unit support 44 is a member in the form of a narrow plate-like member that is bent to have a predetermined shape in a plan view, and extends in the front-rear direction. As shown in Figures 9 and 10, the unit support 44 has a first support 46 that mainly constitutes the left side of the unit support 44, and a second support 47 that mainly constitutes the right side of the unit support 44.

[0048] The unit support 44 has a left side surface portion 44a that is elongated in the front-rear direction, a front surface portion 44b that is formed to form a right angle from the front end portion of the left side surface portion 44a toward the right, and a right side surface portion 44c that is elongated in the front-rear direction and formed from the right end portion of the front surface portion 44b toward the rear. All of these surface portions that make up the unit support 44 are vertical surface portions.

[0049] That is, the first support 46 and the second support 47 are both plate-like members bent to have a predetermined shape in a plan view, and these supports form the left side surface portion 44a, the front surface portion 44b, and the right side surface portion 44c. The unit support 44 has a shape that positions the lower edge portion at a substantially constant height overall.

[0050] As shown in Figures 9 and 10, the first support 46 has an outer wall surface portion 46a forming the left side surface portion 44a of the unit support 44, a front wall surface portion 46b forming a part of the front surface portion 44b of the unit support 44, and an inner wall surface portion 46c formed so as to form a right angle from the right end portion of the front wall surface portion 46b toward the rear. The inner wall surface portion 46c is formed so as to face the front end portion of the outer wall surface portion 46a in the left-right direction. The outer wall surface portion 46a, the front wall surface portion 46b and the inner wall surface portion 46c form a bent shape that is approximately "J" shaped in a plan view (see Figure 9).

[0051] The second support 47 has a side wall portion 47a that forms the right side portion 44c of the unit support 44, a front wall portion 47b that forms part of the front surface portion 44b of the unit support 44, and a sloping wall portion 47c that is formed at the corner formed by the side wall portion 47a and the front wall portion 47b and has a chamfered shape when viewed from the bottom.

[0052] The left side surface portion 44a (outer wall surface portion 46a of the first support 46) of the unit support 44 is a plate-like portion that is elongated from front to rear with the plate thickness direction being the left-right direction. Approximately the front half of the left side surface portion 44a is a wide portion with a relatively large dimension (width) in the up-down direction, and approximately the rear half is a narrow portion having a width that is approximately 1 / 2 to 1 / 3 of the width of the front portion. The left side surface portion 44a has an oblique side portion that is inclined downward so as to gradually narrow from the front side to the rear side, above the center portion in the front-rear direction. The rear end position of the left side surface portion 44a extends rearward beyond the rear end of the case 51 in the front-rear direction.

[0053] The front portion 44b of the unit support 44 is a plate-like portion with the plate thickness direction being in the front-rear direction. The dimension of the front portion 44b in the up-down direction is approximately the same as the dimension of the front of the left side surface portion 44a in the up-down direction. The dimension of the front portion 44b in the left-right direction is approximately half the length of the left side surface portion 44a in the front-rear direction. The front portion 44b is formed by the front wall portion 46b of the first support 46 and the front wall portion 47b of the second support 47. Specifically, the front portion 44b is a portion where the front wall portion 47b of the second support 47 overlaps the right portion of the front wall portion 46b of the first support 46 from the front side.

[0054] The first support 46 and the second support 47 are connected to each other by being fastened and fixed by a screw body 48 and a nut 49 that penetrate the overlapping portion between the front wall surface portions 46b, 47b. The screw body 48 has a threaded portion that protrudes forward from the front wall surface portion 47b of the second support 47, and the nut 49 is screwed into this protruding portion. The fixing portions by the screw body 48 are provided at two locations, one above and one below.

[0055] The right side surface portion 44c (side wall surface portion 47a of the second support 47) of the unit support 44 is a plate-like portion that is elongated in the front-rear direction with the plate thickness direction being in the left-right direction, and is provided so as to face the left-right direction with respect to the left-right direction. The right side surface portion 44c has a relatively wide front portion and a narrow rear portion that is approximately 1 / 2 to 1 / 3 the width of the front portion. The right side surface portion 44c has a front vertical dimension that is approximately the same as the vertical dimension of the front surface portion 44b. The right side surface portion 44c has an oblique side portion that is inclined downward so as to gradually narrow from the front side to the rear side at the upper side of the front portion. The right side surface portion 44c has a rear end position that is approximately the same as the rear end position of the case 51 in the front-rear direction.

[0056] The unit support 44 is open at the top and bottom, and has a shape that, in plan view, is roughly rectangular with the longitudinal direction being the front-to-rear direction, with a left side surface portion 44a, a front surface portion 44b, and a right side surface portion 44c. The left side surface portion 44a, the front surface portion 44b, and the right side surface portion 44c of the unit support 44 are positioned respectively to the left, front, and right of the sensor unit 45 (see FIG. 12), forming a peripheral wall portion that surrounds the periphery of the sensor unit 45. In other words, the sensor unit 45 is positioned almost entirely in the space surrounded by the unit support 44 in plan view. Let It is designed to allow this.

[0057] The sensor unit 45 is positioned substantially entirely inside the unit support 44 in the front-rear and left-right directions. In particular, the sensor unit 45 has substantially the entire case 51 positioned between the outer wall surface portion 46a and the inner wall surface portion 46c of the first support 46 in the left-right direction. As a result, the sensor unit 45 has the front end portion of the case 51 positioned immediately behind the front surface portion 44b, between the front end portion of the outer wall surface portion 46a (left side surface portion 44a) and the inner wall surface portion 46c.

[0058] The sensor unit 45 is provided on both the left and right sides of the case 51 such that the left side surface portion 44a and the right side surface portion 44c are positioned in the vertical middle portion of the case 51. That is, the sensor unit 45 causes both the upper and lower sides of the case 51 to protrude from the unit support 44 relative to the left side surface portion 44a and the right side surface portion 44c in a side view (see FIG. 7).

[0059] The components of the sensor unit 45 will be described below. The device body 41 is provided on a front fixed shaft 61, which is a first shaft, so as to be rotatable up and down. The front fixed shaft 61 is a support shaft whose axial direction is in the left-right direction, and supports the sensor unit 45 so as to be rotatable around a first axis P1 (see FIGS. 7 and 9).

[0060] The front fixed shaft 61 is located in the device body 41 near the front end of the case 51. The front fixed shaft 61 extends leftward from the inner wall surface portion 46c with its right end fixed to the inner wall surface portion 46c of the first support 46 via a support plate 56. The front fixed shaft 61 is a fixed shaft supported in a cantilever manner by the inner wall surface portion 46c. The support plate 56 is fixed at two points, top and bottom, by bolts 57 in a state where it overlaps the inside (left side) of the inner wall surface portion 46c.

[0061] The front fixed shaft 61 may be any shaft that is fixed to the unit support 44. Therefore, the front fixed shaft 61 may be a shaft supported in a cantilevered manner by fixing its left end portion to the front end portion of the left side surface portion 44a of the unit support 44, or may be a shaft that is fixed to both the front end portion of the left side surface portion 44a and the inner wall surface portion 46c and spans between them.

[0062] The front fixed shaft 61 is supported so as to be rotatable relative to the case 51. In other words, the case 51 is supported so as to be rotatable relative to the front fixed shaft 61.

[0063] In this way, the sensor unit 45 is provided so as to be rotatable up and down in a cantilevered state with the left-right direction as the axial direction relative to the front fixed shaft 61, which is a fixed shaft fixed to the unit support 44 (see arrow A1 in FIG. 7). That is, the unit support 44 supports the device body 41 of the sensor unit 45 by the front fixed shaft 61 so as to be rotatable up and down about the first axis P1.

[0064] With respect to the rotation of the sensor unit 45 around the first axis P1 relative to the unit support 44, the sensor unit 45 is biased in a downward rotation direction (clockwise direction as viewed from the left side) by a case return member, which is an elastic member such as a spring provided in the case 51. The case return member is, for example, a torsion spring having linear extensions at both ends of a coil-shaped main body. In this case, the case return member is provided in a state in which the front fixed shaft 61 penetrates the main body, one extension is engaged with the front fixed shaft 61 side and the other extension is engaged with the case 51 side, and applies a force that presses the case 51 downward toward the front fixed shaft 61 side. As a result, the sensor unit 45 is biased in a direction of downward rotation around the axis of the front fixed shaft 61.

[0065] A case return spring 58 is provided on the portion of the front fixed shaft 61 protruding to the right from the case 51 to urge the sensor unit 45 in a downward rotation direction relative to the front fixed shaft 61. The case return spring 58 is a torsion spring having linear extensions 58a on both ends of a coil-shaped main body.

[0066] The case return spring 58 is provided with the front fixed shaft 61 penetrating the main body, one extension 58a inserted into and locked in a locking hole 52a (see FIG. 8) formed on the right side of the front part of the right case body 52 of the case 51, and the other extension 58a locked in a predetermined manner to the front surface 44b of the unit support 44, and exerts a force pressing the case 51 downward toward the front fixed shaft 61. This biases the sensor unit 45 in a direction to rotate downward around the axis of the front fixed shaft 61.

[0067] Meanwhile, with regard to rotation of the sensor unit 45 relative to the unit support 44, downward rotation of the sensor unit 45 is restricted to a reference position by a case stopper bolt 59 provided on the case 51. The case stopper bolt 59 is screwed from the left into the front-to-rear middle part of the upper edge of the left case body 53, with its head protruding leftward from the left case body 53. The case stopper bolt 59 is located near the rear side of the fixing bolt 55 that is located at the top front out of the four fixing bolts 55.

[0068] With this configuration, in the standard state, the head of the case stopper bolt 59 abuts against the upper edge of the left side surface portion 44a of the unit support 44, thereby preventing the sensor unit 45 from rotating downward relative to the unit support 44. Note that the locking portion of the sensor unit 45 with respect to the unit support 44 may be a protruding portion formed as a part of the left case body 53.

[0069] In this way, the sensor unit 45 is restricted from rotating downward from the reference state relative to the unit support 44 while being biased in the downward rotation direction with respect to rotation about the front fixed shaft 61. Therefore, when an external force from the ground G1 or the like acts on the sensor unit 45 to rotate the sensor unit 45 upward about the front fixed shaft 61, the sensor unit 45 rotates upward against the biasing forces of the case return member and the case return spring 58 in the case 51. When the action of the external force is released, the sensor unit 45 in the upward rotated state automatically rotates downward due to the biasing forces of the case return spring 58 and the like, and returns to the reference state position due to the locking action of the case stopper bolt 59 on the unit support 44.

[0070] The grounding body 42 is rotatably supported by a rear rotating shaft 62, which is a second shaft located behind the front fixed shaft 61 with respect to the device body 41. The rear rotating shaft 62 is a support shaft whose axial direction is in the left-right direction, and supports the grounding body 42 rotatably with respect to the case 51 of the device body 41 about the second axis P2.

[0071] The rear rotating shaft 62 is located near the rear end of the case 51, and is supported for relative rotation with respect to the case 51 via a bearing member such as a bush. The grounding body 42 is fixed to a portion of the rear rotating shaft 62 that protrudes to the right from the case 51. The grounding body 42 has a grounding body main body portion 42a that is a portion that extends downward from the device main body 41, and a support arm portion 42b that is a support portion for the rear rotating shaft 62. The grounding body main body portion 42a and the support arm portion 42b are both plate-like portions having a predetermined shape.

[0072] The grounding body main body 42a is a spatula-shaped portion that gradually widens in width (left-right dimension) from the top to the bottom. The grounding body main body 42a has an obtuse-angled bent shape with the front side convex in side view. The maximum width of the grounding body main body 42a is approximately the same as the left-right width of the case 51, and is located within the left-right width of the case 51 in the left-right direction.

[0073] The support arm portion 42b extends from the upper end of the grounding body main body portion 42a, which is located immediately behind the case 51, to the right front side along the case 51 and is fixed to the rear rotating shaft 62. The front portion of the support arm portion 42b serves as a fixed surface portion with the plate thickness direction being in the left-right direction, and the right end portion of the rear rotating shaft 62 passes through this fixed surface portion and is fastened and fixed to the rear rotating shaft 62 by a nut 68 or the like. A threaded portion into which the nut 68 is screwed is formed at the right end portion of the rear rotating shaft 62.

[0074] In this manner, the grounding body 42 is fixed to the rear rotating shaft 62 and rotates integrally with the rear rotating shaft 62 about the second axis P2. The grounding body 42 is provided so as not to interfere with the case 51 within its rotation range. With regard to the rotational position of the grounding body 42, the position of the grounding body 42 in the cutting height detection device 40 in the reference state is defined as the reference position.

[0075] The ground contact body 42 rotates as follows relative to the device body 41 around the rear rotation shaft 62. That is, with the tip of the ground contacting the ground G1, the ground contact body 42 rotates (rotates backward) to move the tip side backward due to drag resistance (ground sliding resistance) from the ground G1 caused by the combine harvester 1 moving forward (see arrow C1 in FIG. 7). On the other hand, the ground contact body 42 rotates (rotates forward) to move the tip side forward due to ground sliding resistance caused by the combine harvester 1 moving backward (see arrow C2 in FIG. 7).

[0076] The detection sensor 43 is a sensor that detects the amount of rotation of the grounding body 42 about the rear rotating shaft 62. The detection sensor 43 is provided for the intermediate rotating shaft 70, which is the third shaft provided in the cutting height detection device 40, and detects the amount of rotation of the grounding body 42 about the rear rotating shaft 62 from the amount of rotation of the intermediate rotating shaft 70.

[0077] The intermediate rotating shaft 70 is a support shaft whose axial direction is in the left-right direction, and is supported via a bearing member such as a bush to be relatively rotatable about a third axis P3 relative to the case 51 of the device body 41. The intermediate rotating shaft 70 is located midway between the front fixed shaft 61 and the rear rotating shaft 62 in the front-rear direction.

[0078] The detection sensor 43 is a rotary type potentiometer, and detects the rotational position of the grounding body 42 via the intermediate rotation shaft 70 and the rear rotation shaft 62. The detection sensor 43 is fixed to the right case body 52 at two points, the front and rear, with bolts 73 on the right side surface of the right case body 52.

[0079] The detection sensor 43 is connected to the right end of the intermediate rotating shaft 70 and directly detects the rotational position of the intermediate rotating shaft 70 about the third axis P3, using the intermediate rotating shaft 70 as a detection axis. The detection sensor 43 has a main body 43a and a connector 43b to which a signal line is connected in the main body 43a. One end of a wire harness 80 serving as a signal line is connected to the connector 43b (see FIG. 6). The detection sensor 43 is connected to a control device provided on the traveling body 4 side by the wire harness 80.

[0080] The connector portion 43b is a cylindrical portion protruding obliquely upward and rearward from the main body portion 43a. The wire harness 80, one end of which is connected to the connector portion 43b, extends obliquely upward and rearward from the detection sensor 43. Note that the detection sensor 43 may have a configuration in which a signal line extends directly from the main body portion as a connection configuration to the control device.

[0081] The intermediate rotating shaft 70 rotates by receiving the rotational power of the rear rotating shaft 62 accompanying the rotation of the grounding body 42. The intermediate rotating shaft 70 receives the rotational power of the rear rotating shaft 62 via gears or the like provided for each of the rear rotating shaft 62 and the intermediate rotating shaft 70. The rotation of the intermediate rotating shaft 70 is detected by the detection sensor 43. The grounding body 42 uses a grounding body returning member which is an elastic member such as a spring provided in the case 51, and is provided so that the grounding body 42 is positioned at a predetermined reference position in the absence of the action of an external force with respect to the rotation around the rear rotating shaft 62 by setting the biasing force (torque) of the grounding body returning member, the case returning member, etc.

[0082] In the height-of-cut detection device 40 having the above-described configuration, the grounding body 42 is arranged to rotate about the rear pivot shaft 62 with respect to the device body 41, which is in a state where rotation about the front fixed shaft 61 is stopped, when the grounding body 42 is located rearward of the reference position, for example, when the combine harvester 1 moves forward and the like, when the grounding body 42 is pressed from the front and rotates rearward from the reference position, the device body 41 does not rotate about the front fixed shaft 61, and only the grounding body 42 rotates about the rear pivot shaft 62 relative to the device body 41.

[0083] The detection sensor 43 detects the amount of rotation of the grounding body 42 backward from the reference position. That is, the detection sensor 43 detects the backward relative rotation of the grounding body 42 with respect to the device body 41 from a state in which the grounding body 42 is in the reference position as the rotation for detecting the mowing height.

[0084] On the other hand, with regard to the relative rotation of the grounding body 42 with respect to the device body 41, the rotation of the grounding body 42 forward from the reference position is accompanied by the upward rotation of the case 51. That is, when the grounding body 42 rotates forward from the reference position, the device body 41 as a whole rotates upward about the front fixed shaft 61 in conjunction with the rotation of the grounding body 42. Here, when the grounding body 42 rotates forward from the reference position relative to the device body 41, the intermediate rotation shaft 70 does not rotate, and the rotation of the intermediate rotation shaft 70 is not detected by the detection sensor 43.

[0085] As described above, the cutting height detection device 40 is configured so that the detection sensor 43 detects the amount of rotation of the grounding body 42 when the grounding body 42 is rotated rearward from the reference position relative to the device body 41.

[0086] By using the cutting height detection device 40 having the above-mentioned configuration, the combine harvester 1 detects the height (cutting height) of the cutting part 5 based on the detection signal from the detection sensor 43. As described above, the cutting height detection device 40 detects the rearward rotation of the ground contact body 42, and therefore detects the cutting height mainly when the body of the combine harvester 1 moves forward.

[0087] In the cutting height detection device 40, the detection sensor 43 detects the rotational position of the intermediate rotating shaft 70, which rotates in conjunction with the rotation of the ground contact body 42, to detect the height of the grass dividing board 21 from the ground G1, i.e., the cutting height. Detection sensor 43 The detection signal is sent to the control device by the wire harness 80. The control device receives the detection signal from the detection sensor 43, and operates the hydraulic cylinder 18 (see FIG. 1) based on the detection signal to adjust the mowing height so as to maintain the mowing height calculated from the detection results at a set value.

[0088] The cutting height detection device 40 is supported by the support structure of the unit support 44 relative to the grass dividing section 50 so as to be rotatable so as to swing left and right about an axis O1 (see FIGS. 7 and 9) that runs along the front-rear direction.

[0089] The configuration of the grass dividing section 50 will be described. The grass dividing section 50 includes a grass dividing frame 34 provided at the bottom of the cutting section 5, and a grass dividing board 21 provided in front of the grass dividing frame 34. Here, the grass dividing board 21 and grass dividing frame 34 related to supporting the cutting height detection device 40 are the grass dividing board 21A and grass dividing frame 34 located second and sixth from the left, respectively (see FIG. 3).

[0090] The grass dividing frame 34 has the following parts from the rear end to the front end. That is, as shown in FIG. 4, the grass dividing frame 34 has a rear inclined part 101 which is a part that slopes downward toward the front, a middle horizontal part 102 which is a horizontal part, and a front inclined part 103 which is a part that slopes upward toward the front and forms an obtuse-angled corner with the middle horizontal part 102. The rear inclined part 101 has a bent shape with a relatively steep slope at the front compared to the rear part. The middle horizontal part 102 and the front inclined part 103 form a curved corner 104. The rear end of the rear inclined part 101 is the base end of the grass dividing frame 34, and the front end of the front inclined part 103 is the tip end.

[0091] The grass dividing frame 34 has the rear end of the rear inclined portion 101 positioned above the horizontal frame 31, and the rear inclined portion 101 is fixed to the horizontal frame 31 via a support member 105 fixed to the horizontal frame 31 (see FIG. 4). The support member 105 is composed of multiple plate-shaped members fixed to the horizontal frame 31 and the grass dividing frame 34 by welding or the like.

[0092] The grass dividing board 21 has a grass dividing board main body 121 and a rib board portion 122 provided on the rear side of the grass dividing board main body 121. The grass dividing board main body 121 is a plate-shaped member with the front side being the convex side in a planar cross-sectional view, and has a pointed shape that gradually narrows from the rear side to the front side in a front view and plan view. The grass dividing board main body 121 has a curved shape with the front downward and the rear lower side being the convex side in a side view.

[0093] The rib plate portion 122 is a plate-shaped portion whose thickness direction is in the left-right direction, and is provided in the left-right center of the grass dividing board main body 121, behind the front plate portion of the grass dividing board main body 121. The rib plate portion 122 is provided as an integral part of the grass dividing board main body 121 by fixing a plate-shaped member to the grass dividing board main body 121 by welding or the like. The rib plate portion 122 is provided on the grass dividing board main body 121 in the range from approximately the center in the up-down direction to the lower end (tip).

[0094] The rib plate portion 122 has a shape that follows the curved shape of the grass dividing board body 121 in a side view, and is provided so as to protrude rearward from the grass dividing board body 121 so as to form an arrow shape together with the grass dividing board body 121 in a planar cross-sectional view. The configuration in which the rib plate portion 122 is provided on the grass dividing board body 121 has an approximately bilaterally symmetrical shape.

[0095] The grass dividing section 50 also includes a hitch 125 as a grass dividing board support member provided on the rear side of the grass dividing board 21. The hitch 125, together with the hitch support plate 124, constitutes the grass dividing body support section 120. The grass dividing body support section 120 receives the grass dividing board 21 and supports the grass dividing board 21 relative to the grass dividing frame 34 by being fixed to the grass dividing frame 34.

[0096] The hitch 125 is a longitudinal plate-like member, and is provided with a rearward-rising incline so that its longitudinal direction follows the rearward-rising incline of the grass dividing board 21. The hitch 125 has a length such that, in the extension direction of the grass dividing board main body 121, its rear end is positioned near the lower side of the rear end of the grass dividing board main body 121, and its front end is positioned approximately in the center between the front and rear of the rib board portion 122.

[0097] The hitch 125 has a rear part, the hitch rear part 125a, which is a relatively narrow plate-like part arranged in an inclined manner, and a part forward of the hitch rear part 125a is a hitch front part 125b which is wider than the hitch rear part 125a. The hitch front part 125b is a part of the hitch 125 located in front of the device body 41. The hitch front part 125b forms a straight upper edge part together with the hitch rear part 125a in the hitch 125, and forms a protruding part to the lower side along a substantially rectangular shape in a side view, partially increasing the vertical dimension of the front part of the hitch 125. The hitch front part 125b has a rear part protruding downward from the grass dividing board 21 in a side view. The hitch front part 125b forms a horizontal lower edge part 125c in the front part of the hitch 125.

[0098] The hitch 125 is fixed to the grass dividing frame 34 via a hitch support plate 124. The hitch support plate 124 is a plate-shaped member whose thickness direction is in the left-right direction, and is fixed to the front inclined part 103 of the grass dividing frame 34 by welding or the like. The hitch support plate 124 is provided so as to protrude downward toward the front from the front side of the upper part of the front inclined part 103 along the inclination of the grass dividing board 21.

[0099] The hitch support plate 124 has a generally triangular shape with the vertical dimension gradually decreasing from the rear side to the front side in a side view. The hitch support plate 124 is disposed in the generally central portion in the left-right direction with respect to the cylindrical front inclined portion 103. The hitch support plate 124 has a thickness greater than that of the hitch 125.

[0100] The hitch 125 is fastened to the hitch support plate 124 at two locations, front and rear, by bolts 127 and nuts 128 with the hitch rear portion 125a overlapping the hitch support plate 124 from the left side. The bolt 127 passes through the hitch 125 and the hitch support plate 124 and is screwed into the nut 128. The hitch support plate 124 has a downward exposed portion 124a at its rear that protrudes downward from the rear portion of the hitch 125 in a left side view. The downward exposed portion 124a is a portion of the hitch support plate 124 that is lower than the rear fixed portion of the two fixed portions by the bolt 127 in a left side view, and is a portion that is located between the rear end portion of the hitch 125 and the front inclined portion 103.

[0101] The grass dividing board 21 is attached to the hitch 125. The grass dividing board 21 is fastened to the hitch 125 at two points, the front and the back, by bolts 141 and nuts 142, with the rear part of the rib plate part 122 overlapping the hitch front part 125b from the right side. The bolts 141 pass through the hitch 125 and the rib plate part 122, and are screwed into the nuts 142.

[0102] In this way, the hitch 125 is fixed to the grass dividing frame 34, thereby supporting the grass dividing board 21 in front of the grass dividing frame 34. The grass dividing board 21 is attached so that its position can be adjusted relative to the grass dividing body support part 120. In this embodiment, the grass dividing board 21 is provided so that the attachment angle (tilt angle) relative to the hitch 125 that constitutes the grass dividing body support part 120 can be adjusted. In other words, the grass dividing board 21 is attached so that its angular position can be adjusted relative to the hitch 125.

[0103] 7, of the two front and rear fixing portions of the hitch 125 to the rib plate portion 122 by the bolts 141, the bolt hole 125d in the rear fixing portion through which the bolt 141 passes is an elongated hole whose longitudinal direction is the direction of the downward inclination to the rear. Also, the bolt hole 125e of the hitch 125 in the front fixing portion is a circular hole through which the bolt 141 passes.

[0104] Due to such a fixing structure of the hitch 125, the installation angle (tilt angle) of the grass dividing board 21 can be adjusted in the rotation direction with the center of the fixing part by the front bolt 141 as the rotation fulcrum B0 relative to the hitch 125 within the movable range of the long bolt hole 125d (see arrow B1 in FIG. 4). In other words, the grass dividing board 21 can be raised and lowered by raising and lowering the rear side within the rotation range with the lower fixing part as the fulcrum, as a position adjustment. In addition, in FIG. 7 and FIG. 8, the grass dividing board 21 in the lowered state is shown by a two-dot chain line, and the grass dividing board 21 in the raised state is shown by a one-dot chain line.

[0105] The cutting height detection device 40 is supported so as to be rotatable around a fore-aft axis relative to the grass dividing unit 50 having the above-mentioned configuration. The cutting height detection device 40 has a shaft support part 130 on its front side as a support part for the grass dividing unit 50, and is supported by this shaft support part 130 so as to be rotatable around a fore-aft axis O1 as a rotation axis.

[0106] The pivot support 130 is provided on the rear side of the grass dividing board 21. The pivot support 130 has a boss 132, which is a support provided on the rear side of the grass dividing board 21, and a support shaft 131 provided at the front end of the unit support 44 and supported by the boss 132. The pivot support 130 has a configuration in which the support shaft 131, which protrudes forward from the front wall surface 46b of the front surface 44b of the unit support 44, is supported by the boss 132 provided at the lower end of the hitch 125. In other words, the front end side of the cutting height detection device 40 is attached to the hitch 125 via the boss 132.

[0107] The support shaft portion 131 protrudes forward from the front wall surface portion 46b of the unit support body 44. The support shaft portion 131 is provided by fixing a pin-shaped shaft to the front surface portion 44b by welding or the like, with the axial direction being the front-rear direction. The support shaft portion 131 is an integral part of the unit support body 44, and its axis coincides with the axis line O1.

[0108] 13, the boss portion 132 is a hollow cylindrical portion that defines a shaft support space 132b by a cylindrical inner peripheral surface 132a, and has an open rear side and a tapered portion 132c that tapers toward the front side. The boss portion 132 is provided by fixing a cylindrical member to the lower end portion of the hitch 125.

[0109] Hitch 125 has, at its lower end, a notched recess 125f that is bent in a side view to match the side view shape of the front part of boss portion 132. The cylindrical member that forms boss portion 132 is fixed to hitch 125 by welding or the like with its front part fitted into recess 125f of hitch 125. Boss portion 132 has an outer diameter larger than the plate thickness of hitch 125, and positioning hitch 125 in the center in the left-right direction.

[0110] The support shaft 131 is supported rotatably by the boss 132 with its front portion inserted into the shaft support space 132b. End face , and is disposed close to the front surface of the front surface portion 44b of the unit support body 44. A cylindrical bush 134 and an O-ring 136 serving as bearing members through which the support shaft portion 131 penetrates are interposed between the support shaft portion 131 and an inner circumferential surface 132a of the boss portion 132. The O-ring 136 is located near the open end of the boss portion 132, and is fitted onto an outer circumferential groove 131c formed in the support shaft portion 131.

[0111] The support shaft portion 131 is prevented from coming off the boss portion 132 by a set screw 137 and a lock nut 138 which are screwed from the outside of the boss portion 132 toward the inside in the radial direction. The lock nut 138 is fixed to the outer circumferential surface of the boss portion 132 by welding or the like. The set screw 137 is screwed into the lock nut 138, passes through the peripheral wall of the boss portion 132, and engages with the support shaft portion 131. The set screw 137 engages with the support shaft portion 131 by positioning its tip portion in an outer circumferential groove formed by the reduced diameter portion 131a in a portion of the support shaft portion 131 forward of the bushing 134 (see FIG. 13).

[0112] In this way, the pivot support part 130 supports the support shaft part 131 provided on the front part of the unit support body 44 by the boss part 132 via the hitch 125 to the grass dividing board 21. As a result, the pivot support part 130 supports the front side of the cutting height detection device 40 rotatably with the front-to-rear direction as the rotation axis relative to the grass dividing part 50. The cutting height detection device 40 is supported in a cantilever manner relative to the grass dividing part 50 by the pivot support part 130.

[0113] As described above, the cutting height detection device 40 supports the unit support 44 so that it can rotate around the front-to-rear axis O1 relative to the grass dividing section 50, thereby supporting the sensor unit 45 supported by the unit support 44 so that it can swing left and right.

[0114] The cutting height detection device 40 is elastically positioned at a predetermined neutral position with respect to rotation about an axis in the front-rear direction by a return spring 147 provided on the shaft support portion 130. The return spring 147 is a so-called torsion spring, and has linear extensions 147a on both ends of a coiled portion. The return spring 147 is provided with its coiled portion passing through the rear portion of the boss portion 132, with the extensions 147a on both ends extending upward.

[0115] On the other hand, a locking pin 148 protrudes forward from the front wall surface portion 46b in the unit support body 44. The locking pin 148 protrudes forward from a semicircular protrusion 44g provided on the upper edge portion of the front wall surface portion 46b, and is located above the boss portion 132.

[0116] The return spring 147 has extensions 147a located on both the left and right sides of the locking pin 148, and the extensions 147a hold the locking pin 148 from both the left and right sides with elastic force. The return spring 147 also has extensions 147a located on both the left and right sides of the lower part of the hitch 125 located above the locking pin 148, and the left and right extensions 147a hold the hitch 125 with elastic force.

[0117] According to this configuration, when an external force of a predetermined magnitude or greater that rotates height-of-cutting detection device 40 about axis O1 acts on height-of-cutting detection device 40, height-of-cutting detection device 40 rotates against the elastic force of return spring 147 with one extension portion 147a pressed by locking pin 148 in accordance with the direction of rotation and the other extension portion 147a locked to hitch 125. Then, when the external force is no longer acting, height-of-cutting detection device 40 returns to the neutral position due to the elastic force of return spring 147.

[0118] In the height-cutting detection device 40 having the above-mentioned configuration, the unit support 44 functions as a protective member. The unit support 44 as a protective member supports the device body 41 with respect to the grass dividing body support part 120 that supports the grass dividing board 21 provided in front of the cutting part 5, and protects the device body 41 from the front side and both the left and right sides.

[0119] The unit support 44 is supported rotatably about a front-rear axis with respect to the hitch 125 via a support shaft portion 131 and a boss portion 132 that protrude forward from the front surface portion 44b. The unit support 44 also supports the device main body 41 rotatably about a left-right axis via a front fixed shaft 61 that protrudes leftward from the inner wall surface portion 46c.

[0120] In this way, the unit support 44 is interposed between the hitch 125 and the device body 41 as a support member that supports the device body 41 with respect to the hitch 125. In other words, the device body 41 is provided with respect to the hitch 125 via the unit support 44.

[0121] Further, the unit support 44 has the front surface 44b positioned in front of the device body 41, and the front surface 44b protects the device body 41 from the front side. The unit support 44 covers the case 51 of the device body 41 from the front side with most of the front surface 44b overlapping the case 51 of the device body 41 in a front view.

[0122] The unit support 44 has a left side surface portion 44a and a right side surface portion 44c located on the left and right sides of the device body 41, respectively, and protects the device body 41 from both the left and right sides with the left side surface portion 44a and the right side surface portion 44c. The unit support 44 covers the case 51 from the left side with most of the left side surface portion 44a overlapping the case 51 when viewed from the left side. The unit support 44 also covers the case 51 from the right side with most of the right side surface portion 44c overlapping the case 51 when viewed from the right side.

[0123] In this way, the unit support body 44 includes left side surface portion 44a and right side surface portion 44c, which are plate-shaped portions with the thickness direction in the left-right direction, and serve to protect the device main body 41 from both the left and right sides.

[0124] The unit support 44 is provided to be rotatable with the front-rear direction as an axial direction integrally with the device body 41 with respect to the grass dividing body support part 120. That is, by the configuration in which the cutting height detection device 40 is supported by the pivot support part 130 via the hitch 125 to the grass dividing board 21, the unit support 44 is supported integrally with the device body 41 connected via the front fixed shaft 61 and rotatably about the axis O1 with respect to the hitch 125.

[0125] In addition, the unit support 44 has left and right bent surface portions (151, 152) on the rear sides of the left side surface portion 44a and the right side surface portion 44c, which are bent in directions facing each other so as to be located at the rear of the device body 41.

[0126] The left side surface portion 44a extends rearward from the rear end of the device body 41 in the front-rear direction, and a left bent surface portion 151 is provided on the rear side of the left side surface portion 44a. The left bent surface portion 151 is a portion that is bent from the rear end of the left side surface portion 44a, which is a plate-shaped portion with the plate thickness direction in the left-right direction, toward the left-right inner side (right side) so as to form an obtuse angle with the left side surface portion 44a in a bottom view. The left bent surface portion 151 is formed at the rear end portion of the first support 46. In this embodiment, the angle formed between the left side surface portion 44a and the left bent surface portion 151 is approximately 130°.

[0127] Left bent surface portion 151 has a slightly tapered shape in which the dimension in the up-down direction gradually decreases from the left side surface portion 44a side toward the tip end. Left bent surface portion 151 is provided so that tip end portion 151a is located rearward of the left side portion of case 51. Left bent surface portion 151 has tip end portion 151a that is a circular arc-shaped rounded portion that forms a semi-cylindrical surface.

[0128] The right bent surface portion 152 on the rear side of the right side surface portion 44c is a portion that is bent from the rear end of the right side surface portion 44c, which is a plate-shaped portion with the plate thickness direction in the left-right direction, toward the left-right inner side (left side) so as to form an obtuse angle with the right side surface portion 44c in a bottom view. The right bent surface portion 152 is formed at the rear end portion of the second support body 47. In this embodiment, the angle formed between the left side surface portion 44a and the right bent surface portion 152 is approximately 120°.

[0129] Right bent surface portion 152 has a slightly tapered shape in which the dimension in the up-down direction gradually decreases from the right side surface portion 44c side toward the tip end. Right bent surface portion 152 is provided so that tip end portion 152a is located rearward of the right side portion of case 51. Right bent surface portion 152 has tip end portion 152a that is a circular arc-shaped rounded portion that forms a semi-cylindrical surface.

[0130] The left bent surface portion 151 and the right bent surface portion 152 are provided so that the tips 151a, 152a face each other. As shown in Fig. 10, the left and right bent surface portions 151, 152 are provided so that the tips 151a, 152a are located within the range D0 of the outer diameter of the grass dividing frame 34 located behind the cutting height detection device 40 in the left-right direction. That is, in the left-right direction, the tip 151a of the left bent surface portion 151 is located to the right of the position D1 of the left end of the grass dividing frame 34 (lower side in Fig. 10), and the tip 152a of the right bent surface portion 152 is located to the left of the position D2 of the right end of the grass dividing frame 34 (upper side in Fig. 10).

[0131] In the above-described configuration in which the unit support 44 has the left and right bent surface portions 151, 152, the unit support 44 covers the middle portion of the device body 41 in the vertical direction from both the left and right sides, and covers the entire front-rear direction of the case 51. The gap 153 between the tips 151a, 152a of the left bent surface portion 151 and the right bent surface portion 152 at the rear side of the unit support 44 is covered from the rear by the corner portion 104 of the grass dividing frame 34. The gap 153 is covered by the grass dividing frame 34 in a plan view. The magnitude of the bending angle of the left bent surface portion 151 and the right bent surface portion 152 with respect to the left side surface portion 44a or the right side surface portion 44c is not limited, and the bending angle may be an acute angle or a right angle.

[0132] In addition, the hitch front part 125b of the hitch 125 constituting the grass division support part 120 is provided with a horizontal guide plate part 160 located in front of the device main body 41 as a front guide part that guides the stalks outward to the left and right as the machine body moves forward. The horizontal guide plate part 160 is a horizontal plate-like part, and is provided by fixing a front guide plate, which is a plate-like member, to the underside of the hitch 125.

[0133] The horizontal guide plate 160 is provided by fixing a flat front guide plate to the horizontal lower surface of the lower edge 125c of the hitch 125 by welding or the like. The horizontal guide plate 160 has an approximately isosceles triangular shape with the apex side facing forward when viewed from the bottom. The horizontal guide plate 160 has guide edges 162 on both the left and right sides that correspond to the hypotenuses of the approximately isosceles triangular shape.

[0134] The horizontal guide plate portion 160 has the hitch 125 located approximately in the center in the left-right direction, and most of the left and right sides extend out to the left and right from the hitch 125. The horizontal guide plate portion 160 has an apex 163, which is the front end portion, protruding forward from the lower edge portion 125c of the hitch 125, and is located to the left of the rib plate portion 122. A right-angled notch 164 is formed on the apex 163 side of the horizontal guide plate portion 160 to avoid interference with the rib plate portion 122.

[0135] The rear edge of the horizontal guide plate 160 is positioned below the return spring 147. The rear surface 165 of the horizontal guide plate 160 is positioned slightly forward in the front-rear direction from the front surface 44b of the unit support 44. A substantially U-shaped notch 166 is formed in the rear edge of the horizontal guide plate 160 to avoid interference with the cutting height detection device 40, which rotates about an axis in the front-rear direction.

[0136] In addition, in the cutting height detection device 40, the detection sensor 43 is provided in a state of being attached to the outside of the case 51 of the device body 41. In this configuration in which the detection sensor 43 is disposed on the outside of the device body 41, the device body 41 is provided with a sensor cover 170 that covers the detection sensor 43.

[0137] The sensor cover 170 is provided to cover the detection sensor 43 attached to the right side of the case 51 mainly from the upper side, right side, and upper rear side. The sensor cover 170 is an integrated member formed into a substantially box-like shape with multiple surfaces, and by attaching it to the case 51, it forms a cover portion with the front side and lower rear side open. The sensor cover 170 is a member made of, for example, resin or metal.

[0138] Sensor cover 170 has a top surface portion 171, a right side surface portion 172, a rear upper surface portion 173, and a left side surface portion 174 facing right side surface portion 172. A fixing surface portion 175 for fixing sensor cover 170 to case 51 is provided on the left side of sensor cover 170. Sensor cover 170 covers the entire detection sensor 43 from above and from the right with top surface portion 171 and right side surface portion 172. A front opening 170a is formed together with right case body 52 on the right front side of right case body 52 by top surface portion 171 and right side surface portion 172.

[0139] Fixed surface portion 175 has a shape that follows the outer shape of the rear side of the upper side of case 51, which has a mountain shape in side view. Fixed surface portion 175 has a horizontal front portion that extends leftward from the front portion of upper surface portion 171, and a rear inclined surface portion that is rearward of the front portion and slopes downward toward the rear along the lower edge portion of left side surface portion 174.

[0140] Sensor cover 170 is fixed to case 51 at two locations on fixing surface 175, namely, the front portion and the front-rear middle portion of the rear inclined surface, by bolts 176. Bolt 176 passes through fixing surface 175 and is screwed into a screw hole 52b (see FIG. 12) formed in right case body 52 of case 51.

[0141] The positions of the front edges of the top surface portion 171 and the right side surface portion 172 of the sensor cover 170 are substantially aligned with the position of the front end of the detection sensor 43. A curved surface portion 177 having a quarter-cylindrical curved shape facing inwardly in the left and right directions is provided on the front edge of the right side surface portion 172 over the entire vertical direction.

[0142] The rear part of the sensor cover 170 is a protruding part 178 that protrudes rearward from the upper part of the case 51. The protruding part 178 is formed by the rear parts of the upper surface part 171 and the right side surface part 172, the rear upper surface part 173, and the left side surface part 174, and forms an internal space surrounded by the sensor cover 170 behind the connector part 43b of the detection sensor 43. This internal space forms an opening part 179 that opens toward the rear lower side of the sensor cover 170 by the right side surface part 172, the rear upper surface part 173, and the left side surface part 174. The internal space of the protruding part 178 becomes a space for arranging the connection part of the wire harness 80 to the detection sensor 43 and the vicinity thereof within the sensor cover 170.

[0143] In addition, the grass division support portion 120 has a portion located above the device main body 41, and is provided with a left front guide plate portion 201, a left rear guide plate portion 202, a right front guide plate portion 203 and a right rear guide plate portion 204 as upper guide portions that guide the stalks outward to the left and right as the machine body moves forward.

[0144] The left front guide plate portion 201 is a plate-like portion having a predetermined bent shape in a side view, and is provided by fixing a plate-like member to the left side surface 125g of the hitch 125 by welding or the like. The left front guide plate portion 201 is provided in an inclined manner so as to follow the downward inclination of the front of the hitch 125. The plate thickness direction of the left front guide plate portion 201 is a direction perpendicular to the direction of the downward inclination of the front in a side view.

[0145] The left front guide plate 201 has, from the front to the rear, a front inclined portion 201a, an intermediate inclined portion 201b that is gentler than the front inclined portion 201a, and a rear inclined portion 201c as a portion that forms a curved shape in a side view (see FIG. 7). The left front guide plate 201 is provided so that approximately the front half consisting of the front inclined portion 201a and the front part of the intermediate inclined portion 201b is covered by the left part of the grass dividing board 21 in a left side view. By rotating the grass dividing board 21 upward, the whole or almost the whole of the left front guide plate 201 becomes exposed (see FIG. 7).

[0146] Approximately the rear half of the left front guide plate portion 201, consisting of the rear part of the intermediate inclined portion 201b and the rear inclined portion 201c, is positioned below the lower edge of the grass dividing board 21 in a side view and is exposed from the grass dividing board 21. The left front guide plate portion 201 has the left-right width of the rear inclined portion 201c wider to the left than the other parts, and the left part of the rear inclined portion 201c protrudes outward to the left from the grass dividing board 21 in a front view.

[0147] The left front guide plate 201 has the left end of the rear inclined portion 201c positioned outside (left side) the case 51 in the left-right direction. In this embodiment, the side end surface 201d positioned at the left end of the rear inclined portion 201c is positioned at approximately the same position as the left side surface 44d of the left side surface portion 44a of the unit support 44 in the left-right direction (see FIG. 11). The side end surface 201d is a surface along the front-rear direction in a plan view. The rear inclined portion 201c has a side surface 201e at the front that is inclined in a direction that gradually narrows the width of the rear inclined portion 201c from the rear side to the front side. The inclined surface 201e is continuous with the side surface 201f of the intermediate inclined portion 201b (see FIG. 14).

[0148] The rear inclined portion 201c of the left front guide plate 201 extends in an inclined manner so as to follow the lower edge of the rear of the hitch 125 in a left side view. In the front-rear direction, the front end of the rear inclined portion 201c of the left front guide plate 201 is positioned above the vicinity of the front end of the case 51, and the rear end of the rear inclined portion 201c is positioned above the rear of the case 51. In this way, the left front guide plate 201 has the rear inclined portion 201c as a portion positioned above the device main body 41, and the rear inclined portion 201c covers the left side portion of the device main body 41 from above.

[0149] The front inclined portion 201a and the intermediate inclined portion 201b of the left front guide plate portion 201 are provided so as to cover most of the upper part of the left side portion of the case 51 in a front view. The front inclined portion 201a has a rear side surface that is flush with the side surface 201f of the intermediate inclined portion 201b, and a front side surface that is an inclined surface 201g that is inclined in a direction that gradually narrows the width of the front inclined portion 201a from the rear side to the front side. The left front guide plate portion 201 is extended so that its front end portion is located forward of the boss portion 132 in the front-rear direction.

[0150] A left rear guide plate 202 is provided on the rear side of the left front guide plate 201. The left rear guide plate 202 is a plate-shaped portion provided parallel to the left front guide plate 201 on the rear side of the left front guide plate 201. The left rear guide plate 202 is provided by fixing a plate-shaped member to the left side surface 124b of the hitch support plate 124 and the left outer peripheral surface of the front inclined portion 103 of the grass dividing frame 34 by welding or the like. The plate-shaped member forming the left rear guide plate 202 has an arc-shaped recess 202a into which the grass dividing frame 34 fits (see FIG. 5).

[0151] The left rear guide plate 202 has approximately the same width as the left front guide plate 201, and in the left-right direction, a side end face 202d located at the left end as a surface along the front-rear direction in a plan view is positioned at approximately the same position as the side end face 201d of the left front guide plate 201 (see FIG. 11). The left rear guide plate 202 has a front side surface that is an inclined face 202e that is inclined in a direction that gradually narrows the width of the left rear guide plate 202 from the rear side to the front side (see FIG. 5).

[0152] The left rear guide plate portion 202 has a front end portion located below the rear end portion of the left front guide plate portion 201, and is provided so as to be continuous with the left front guide plate portion 201 in the front-rear direction in a plan view. The left rear guide plate portion 202 has a front end portion located above the center portion of the case 51, and a rear end portion located rearward of the case 51 in the front-rear direction. In this manner, the left rear guide plate portion 202 is located above the device body 41, and covers the rear portion of the left side portion of the device body 41 from above.

[0153] The right front guide plate portion 203 is provided in a portion between the hitch support plate 124 and the rib plate portion 122 on the right side of the hitch 125. The right front guide plate portion 203 is provided by fixing a plate-shaped member to the right side surface 125h of the hitch 125 by welding or the like. The right front guide plate portion 203 is provided in an inclined manner so as to follow the downward inclination of the front of the hitch 125. The plate thickness direction of the right front guide plate portion 203 is a direction perpendicular to the direction of the downward inclination of the front in a side view.

[0154] The right front guide plate portion 203 is arranged so as to be entirely covered by the right part of the grass dividing board 21 when viewed from the right side. By rotating the grass dividing board 21 upward, the entire right front guide plate portion 203 becomes exposed (see FIG. 8). The right front guide plate portion 203 has a side end surface 203d located at the right end as a surface along the front-to-rear direction in a plan view, which is located inside (left side) of the right end of the grass dividing board 21. The right front guide plate portion 203 has a sloping surface 203e on the side surface of the front part that is sloping in a direction that gradually narrows the width of the right front guide plate portion 203 from the rear side to the front side.

[0155] In the front-rear direction, the front end of the right front guide plate 203 is located above the boss 132, and the rear end is located above the front part of the case 51. In this way, the right front guide plate 203 is located above the device body 41, and covers the front part of the right side part of the device body 41 from above.

[0156] A right rear guide plate 204 is provided above and behind the right front guide plate 203. The right rear guide plate 204 is provided on the right side of the hitch support plate 124 at a height position higher than the left rear guide plate 202, and is inclined to follow the forward downward inclination of the hitch 125. The right rear guide plate 204 is a plate-shaped portion provided so as to be parallel to the left rear guide plate 202 and to have an approximately symmetrical outer shape in a plan view. The right rear guide plate 204 is provided by fixing a plate-shaped member to the right side surface 124c of the hitch support plate 124 and the right outer peripheral surface of the front inclined portion 103 of the grass division frame 34 by welding or the like. The plate-shaped member forming the right rear guide plate 204 has an arc-shaped recess 204a into which the grass division frame 34 fits (see FIG. 11).

[0157] The right rear guide plate portion 204 has a side end surface 204d located at the right end as a surface along the front-rear direction in a plan view, which is located outside (on the right side) of the case 51 in the left-right direction. The front portion of the right rear guide plate portion 204 has a tapered shape that gradually narrows from the rear side to the front side. The right rear guide plate portion 204 has, as a right side surface, a side end surface 204d, a first inclined surface 204e in front of the side end surface 204d, and a second inclined surface 204f in front of the first inclined surface 204e. The inclination angle of the second inclined surface 204f with respect to the front-rear direction in a plan view is smaller than the inclination angle of the first inclined surface 204e.

[0158] The right rear guide plate portion 204 extends obliquely along the upper edge portion of the hitch support plate 124 when viewed from the right side. In the front-rear direction, the front end portion of the right rear guide plate portion 204 is located above the front portion of the case 51, and the rear end portion is located rearward of the case 51. In this manner, the right rear guide plate portion 204 is located above the device main body 41, and covers most of the rear side of the right portion of the device main body 41 from above.

[0159] Of the four upper guide parts described above, the right front guide plate part 203 and the right rear guide plate part 204 located on the right side are used as parts supporting the wire harness 80 extending from the detection sensor 43. As shown in Fig. 6, the right front guide plate part 203 and the right rear guide plate part 204 are support plate parts that support from below a part of the wire harness 80 arranged along the front downward slope of the divided grass body support part 120 on the right side of the divided grass body support part 120.

[0160] The right front guide plate portion 203 has an upper plate surface that is a flat inclined surface, and this upper plate surface serves as a support surface 203g for the wire harness 80. Similarly, the right rear guide plate portion 204 has an upper plate surface that is a flat inclined surface, and serves as a support surface 204g for the wire harness 80. The support surface 203g of the right front guide plate portion 203 is an inclined surface that is stepped down from the support surface 204g of the right rear guide plate portion 204.

[0161] The right front guide plate portion 203 and the right rear guide plate portion 204 support the wire harness 80 in a state in which a portion of the wire harness 80 is placed on the support surfaces 203g and 204g, respectively. Due to the supporting action of the right front guide plate portion 203 and the right rear guide plate portion 204 on the wire harness 80, the wire harness 80 is partially guided so as to assume a predetermined wiring form.

[0162] The portion of the wire harness 80 supported by the right front guide plate portion 203 and the right rear guide plate portion 204 is inclined so as to follow the downward inclination of the front of the grass division body support portion 120. In addition, most of the portion of the wire harness 80 supported by the right front guide plate portion 203 and the right rear guide plate portion 204 is covered by the right side of the grass division board 21 in the lowered state.

[0163] At the right front guide plate portion 203 and the right rear guide plate portion 204, the wire harness 80 is appropriately locked and fixed to the right front guide plate portion 203 and the right rear guide plate portion 204 by a stopper such as a band or a locking device such as a clamp (not shown). This prevents the wire harness 80 from being displaced relative to the right front guide plate portion 203 and the right rear guide plate portion 204.

[0164] The wire harness 80 has a connector (not shown) provided on one end thereof connected to the connector portion 43b of the detection sensor 43, extends from the detection sensor 43, and is wired to the traveling body 4 side where the control device is provided via a predetermined wiring path. Specifically, the wire harness 80 is folded back from the connector portion 43b, whose connection port is open toward the upper rear side, to the front side in the internal space of the protruding portion 178 of the sensor cover 170, and is disposed within the sensor cover 170 above the detection sensor 43 facing forward.

[0165] The wire harness 80 extends forward from the front opening 170a of the sensor cover 170, is folded back near the boss portion 132 in a right side view, and is arranged rearward on the right side of the grass body support portion 120 along the front downward (rear upward) slope of the grass body support portion 120. A locking guide 180 is provided above the boss portion 132 to lock the wire harness 80 folded back rearward.

[0166] The locking guide 180 is a part having a substantially plate-like outer shape having a predetermined bent or curved shape, and is fixed to the right side surface 122a of the rib plate portion 122 and protrudes rightward from the rear end of the rib plate portion 122. The locking guide 180 has an arm portion 181 along the left-right direction at the protruding portion from the rib plate portion 122, a bent portion 182 bent from the tip end of the arm portion 181 toward the front side, and a fixed portion 183 bent from the base end of the arm portion 181 toward the rear side. The locking guide 180 is provided on the rib plate portion 122 by fixing the fixed portion 183 to the right side surface 122a of the rib plate portion 122 by welding or the like. Note that an elongated hole-shaped opening is formed in the locking guide 180 in the middle portion in the width direction from the arm portion 181 to the bent portion 182.

[0167] The wire harness 80 folded back to the rear by the locking guide 180 is supported and guided by the right front guide plate 203 and the right rear guide plate 204 on the right side of the grass division body support part 120. The part of the wire harness 80 rearward of the part supported by the right rear guide plate 204 is stored in the grass division frame 34.

[0168] The grass dividing frame 34 is made of hollow pipes, and the internal space of the grass dividing frame 34 is the space for arranging the wire harness 80. A long hole 34a is formed in the right peripheral wall of the front inclined part 103 of the grass dividing frame 34, through which the wire harness 80 passes. The wire harness 80 arranged within the grass dividing frame 34 extends from a predetermined place at the rear of the grass dividing frame 34 to the outside of the grass dividing frame 34, and is connected to the control device on the main machine side via a predetermined wiring path. The tip opening of the hollow pipe constituting the grass dividing frame 34 is closed by a disk-shaped cover member 35.

[0169] 6 shows a resin cable tie 210 that fastens a portion of the wire harness 80 disposed inside the sensor cover 170 as a fastener for fastening the wire harness 80. In the example shown in Fig. 6, one side of the cable tie 210 is disposed outside the right side surface portion 172 of the sensor cover 170, and the other side is passed through a fastening hole 171a (see Figs. 5 and 12) that opens in the upper surface portion 171 of the sensor cover 170 between the detection sensor 43 and the right case body 52 inside the sensor cover 170, and is locked above the upper surface portion 171.

[0170] The cable tie 210, together with the detection sensor 43 and the right side surface portion 172 of the sensor cover 170, surrounds the wire harness 80 and fixes and holds the wire harness 80 disposed above the detection sensor 43 within the sensor cover 170. Not limited to the example shown in Fig. 6, the wire harness 80 is fixed and held at an appropriate location in its wiring path by a cable tie or the like.

[0171] The operation of the cutting height detection device 40 will now be described. During normal operation by the combine harvester 1, that is, when the machine body is in forward motion, the cutting height is controlled based on the cutting height detection value by the cutting height detection device 40 so that the cutting height is maintained at a set value. The cutting height is detected when the rotation position of the grounding body 42 relative to the device body 41 is rearward of the reference position.

[0172] When the machine body moves forward, the ground contact body 42, which slides with its tip in contact with the ground surface G1, rotates rearward from a reference position around the rear rotating shaft 62 relative to the case 51 of the machine body 41 due to ground sliding resistance (see arrow C1 in FIG. 7). The ground contact body 42 rotates integrally with the rear rotating shaft 62 around the second axis P2, and the rotation of the rear rotating shaft 62 is transmitted to the intermediate rotating shaft 70 via gears or the like. The rotation of the intermediate rotating shaft 70 is detected by the detection sensor 43, and the mowing height is detected based on the amount of rotation of the intermediate rotating shaft 70.

[0173] Furthermore, if a lateral external force acts on height-of-cutting detection device 40, for example when the machine is steered with grounding body 42 on the ground, height-of-cutting detection device 40 will rotate about axis O1 in the front-rear direction by pivot support 130 and escape (see arrow E1 in FIG. 11). When the lateral external force acting on height-of-cutting detection device 40 is no longer acting, the biasing structure of return spring 147 and locking pin 148 will return height-of-cutting detection device 40 to a predetermined neutral position.

[0174] According to the combine 1 having the above-described configuration, in the configuration for detecting the cutting height by the cutting section 5, malfunctions caused by contact with the stumps split to the left and right by the grass dividing board 21 and their bases, etc., can be prevented, and the cutting height can be detected stably.

[0175] As shown in FIG. 14, in the harvesting of culms, when horizontal cutting or the like is performed, the stalk 220 may be split into left and right culms 221 by the grass dividing plate 21 as the machine advances. In such a case, the split stalk 220 and its roots may come into contact with the device body 41 and the grounding body 42 located behind the grass dividing plate 21. The contact of the stalk 220 with the device body 41 and the grounding body 42 may cause the sensor unit 45 to malfunction, which may cause the detection value of the cutting height to become unstable. In particular, the action of the split stalk 220 on the grounding body 42 may cause the sensor unit 45 to detect the cutting height to be less accurate. FIG. 14 is a front view showing a schematic configuration of the cutting height detection device 40 and its surroundings.

[0176] Therefore, the cutting height detection device 40 has a unit support 44 as a protective member that supports the device body 41 on the grass dividing body support part 120 and protects the device body 41 from both the left and right sides. As a result, even if the stalk is divided into left and right parts by the grass dividing board 21 during culm harvesting work, the unit support 44 can protect the sensor unit 45.

[0177] That is, as the machine moves forward, the stalks, etc., that have been split to the left and right by the grass dividing board 21 can be guided to the left and right outside of the sensor unit 45 by the unit support 44 on the rear side of the grass dividing board 21, and can be knocked down to the left and right outside. In other words, the unit support 44 can continuously apply a grass dividing action to the stalks, etc., that have once been split to the left and right by the grass dividing board 21.

[0178] This makes it possible to prevent the stump split into left and right from coming into contact with the sensor unit 45. Specifically, for example, it is possible to prevent the stump split into left and right from falling inward to the left or right and coming into contact with the device body 41 or getting caught on the grounding body 42. Therefore, it is possible to prevent malfunction of the sensor unit 45 caused by, for example, the stump split into left and right getting caught on the grounding body 42, and it is possible to ensure the detection accuracy of the cutting height. As a result, it is possible to improve the operability of the combine harvester 1.

[0179] Furthermore, the unit support 44 is provided to be rotatable integrally with the device body 41 around an axis in the front-rear direction relative to the hitch 125 constituting the grass division support section 120. With this configuration, when a lateral external force acts on the cutting height detection device 40, the cutting height detection device 40 can be released by rolling around the axis O1, reducing the effect of the external force and allowing the unit support 44 to follow the rotating device body 41. As a result, regardless of the rotation position of the device body 41 around the axis in the front-rear direction, the device body 41 can be protected by the unit support 44, and the detection accuracy of the cutting height can be effectively stabilized.

[0180] Moreover, the unit support 44 has a left bent surface portion 151 and a right bent surface portion 152 bent in directions facing each other on the rear sides of the left side surface portion 44a and the right side surface portion 44c, respectively. With this configuration, the rear side of the unit support 44, which surrounds the periphery of the device main body 41 in a plan view, can be blocked or nearly blocked. This makes it possible to prevent stumps, uncut stumps, etc. from entering the inside of the unit support 44 when the machine is moving backwards, etc., and prevents the stumps, etc. from contacting the device main body 41, the ground body 42, etc., so that the detection accuracy of the cutting height can be effectively stabilized.

[0181] In particular, in this embodiment, the left and right bent surface portions 151, 152 are provided so that their respective tips 151a, 152a are positioned within the left and right width range of the grass dividing frame 34 located immediately behind them. With this configuration, the gap 153 between the left and right bent surface portions 151, 152 can be covered from the rear by the grass dividing frame 34, so that it is possible to effectively prevent stumps and the like from entering the inside of the unit support body 44 when the vehicle is moving backwards, etc.

[0182] In addition, a horizontal guide plate portion 160 is provided below the hitch 125 and located in front of the device body 41. With this configuration, the left and right guide edges 162 in the shape of a substantially isosceles triangle with the front side at the apex in a plan view mainly serve as guide portions, and can guide impurities such as stubble and weeds split to the left and right to the left and right outside of the sensor unit 45 as the machine moves forward. This improves the weed splitting effect in conjunction with the grass splitting plate 21, and can effectively prevent the stubble split to the left and right from coming into contact with the sensor unit 45.

[0183] Furthermore, according to the combine 1, in the configuration for detecting the cutting height by the cutting section 5, even if the position of the grass dividing board 21 is adjusted, there is no need to reset the target value for the cutting height, and good workability can be obtained.

[0184] As described above, the mowing height target value that is preset in the automatic control of the mowing height is a value related to the height of the device body 41 from the ground. For this reason, in a configuration in which the vertical position of the grass dividing board 21 can be adjusted, for example in a configuration in which the device body 41 is attached to the grass dividing board 21, the device body 41 moves up and down as the vertical position of the grass dividing board 21 is changed, and it becomes necessary to reset the mowing height target value, which reduces workability.

[0185] Therefore, as in this embodiment, by providing the device main body 41 to the grass dividing body support part 120 which supports the grass dividing board 21 so that its position can be adjusted up and down, it is possible to maintain the height position of the device main body 41 regardless of adjusting the position of the grass dividing board 21. In other words, because the grass dividing board 21 and the device main body 41 are provided to the grass dividing body support part 120 so that they can move independently, it is possible to change the height of only the grass dividing board 21.

[0186] This eliminates the need to reset the mowing height target value when adjusting the position of the grass dividing board 21, so that the position adjustment of the grass dividing board 21 can be smoothly performed according to the growing conditions of the crop, such as the state of lodging, and the field conditions, improving workability. Also, by ensuring the support strength of the mowing height detection device 40 in the hitch 125, the strength of the hitch 125 can be improved.

[0187] The grass division support section 120 is provided with a left front guide plate section 201, a left rear guide plate section 202, a right front guide plate section 203 and a right rear guide plate section 204 as upper guide sections located above the device main body 41. With this configuration, even if the grass division board 21 is rotated upward, for example, these guide plate sections can guide the stumps, etc., split to the left and right, to the outside of the sensor unit 45 to the left and right as the machine body moves forward.

[0188] This makes it possible to prevent the left and right split stubbles, etc. from coming into contact with the sensor unit 45 regardless of the position of the grass dividing board 21, and to stabilize the detection accuracy of the cutting height. In each guide plate portion, mainly the inclined surfaces 201e, 201g, 202e, 203e, the first inclined surface 204e, and the second inclined surface 204f act as guide surfaces for the left and right split stubbles, etc.

[0189] In addition, the right front guide plate portion 203 and the right rear guide plate portion 204 are used as support members for the wire harness 80. According to such a configuration, it is possible to eliminate the need to separately provide members for supporting and guiding the wire harness 80 around the grass division body support portion 120, so that the support structure for the wire harness 80 can be obtained at low cost.

[0190] Furthermore, in a configuration in which the position of the grass dividing board 21 can be adjusted, the horizontal guide plate section 160 is provided on the hitch 125 of the grass dividing body support section 120. With this configuration, the position of the horizontal guide plate section 160 is maintained without being affected by the position adjustment of the grass dividing board 21, so the grass dividing action of the horizontal guide plate section 160 can be obtained regardless of the position of the grass dividing board 21. As a result, even by adjusting the position of the grass dividing board 21, the grass dividing action of the horizontal guide plate section 160 can be prevented from causing stumps, etc., that have been split to the left and right to come into contact with the sensor unit 45, so work can be carried out with peace of mind.

[0191] Moreover, the cutting height detection device 40 has a sensor cover 170 that covers the detection sensor 43 attached to the device body 41. With this configuration, the detection sensor 43 and the connection part of the wire harness 80 to the detection sensor 43 can be protected from stumps, foreign objects, etc. that approach the device body 41 as the machine moves. This makes it possible to suppress malfunctions such as damage to the detection sensor 43 itself and the signal transmission path to the detection sensor 43.

[0192] The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, even if it is not the above-described embodiment, various modifications are possible according to the design, etc., as long as they do not deviate from the technical idea of ​​the present invention. In addition, the effects described in this disclosure are merely examples and are not limited, and other effects may be present.

[0193] In the above embodiment, the sensor cover 170 is provided on the right side of the device body 41, on the inside (left side) of the right side surface portion 44c of the unit support 44, which is a protective member, but the sensor cover 170 may also serve as a protective member according to the present invention. In the case of such a configuration, for example, the coverage area of ​​the device body 41 by the sensor cover 170 is expanded, or the right side surface portion 172 of the sensor cover 170 is positioned on the left and right outer side (right side) so as to be in the same position as the right side surface portion 44c of the unit support 44 with respect to the device body 41, thereby obtaining an action of guiding the stumps, etc., split to the left and right by the grass splitting board 21 to the right outer side by the sensor cover 170. According to such a configuration, the right side surface portion 44c can be omitted in the unit support 44. Specifically, the second support 47 can be omitted, and the unit support 44 can be composed of only the first support 46.

[0194] Furthermore, the unit support 44 may also function as the sensor cover 170. In other words, a cover portion equivalent to the sensor cover 170 may be provided by a part of the unit support 44. In such a configuration, for example, a cover portion that covers the detection sensor 43 is provided as part of the unit support 44 by enlarging the right side surface portion 44c of the unit support 44. With such a configuration, the unit support 44 functions as the protective member and the sensor cover according to the present invention, and it is possible to omit providing the sensor cover as a separate member from the unit support 44. [Explanation of symbols]

[0195] 1. Combine Harvester 4 Running body 5 Reaping section 21 Bunkusaita (branching board) 40 Cutting height detection device 41 Device body 42 Ground body 43 Detection sensor 44 Unit support (protective member) 44a Left side part (side plate part) 44c Right side part (side plate part) 45 Sensor unit 51 cases 80 Wire Harness 120 minute grass support section 121 Grass board body 122 Rib plate section 124 Hitch support plate 125 Hitch 151 Left bent surface section (bent section) 152 Right bent surface section (bent section) 160 Horizontal guide plate section (front guide section) 170 Sensor cover 201 Left front guide plate part (upper guide part) 202 Left rear guide plate part (upper guide part) 203 Right front guide plate part (upper guide part) 204 Right rear guide plate part (upper guide part)

Claims

1. A combine harvester comprising a reaping unit that is movably mounted on a traveling body and a cutting height detection device for detecting the height of the reaping unit, The cutting height detection device is A device main body that is provided so as to be vertically rotatable; a grounding body rotatably supported with respect to the device body; a detection sensor for detecting an amount of rotation of the grounding body, The height of the reaping unit is detected based on a detection signal from the detection sensor, The device body is supported on a grass cutting body support part that supports a grass cutting body provided in front of the cutting part, and further includes a protective member that protects the device body; the protective member includes left and right side portions that protect the device body from both the left and right sides, The left and right side portions are provided at the rear thereof with bent portions bent in directions facing each other so as to be located at the rear of the device body. A combine harvester characterized by the above.

2. The protective member is provided to be rotatable with the device body integrally with the grass body support portion with the front-rear direction being an axial direction. The combine harvester according to claim 1 .

3. The grass support part is provided with a front guide part which is located in front of the device body and guides the stalks outward to the left and right as the machine body moves forward. The combine harvester according to claim 1 or 2.

Images