Ridge height adjustment device and agricultural implement comprising ridge height adjustment device

Abstract

To provide a ridge height adjustment device that allows a worker to easily work while maintaining a positional relationship between an agricultural implement and a ridge.SOLUTION: A ridge height adjustment device includes: a sensor 36 which can detect a height of ridges U in a rear of a cover body G covering an upper part of a reap blade part F having a plurality of reap blades 23, the sensor being able to output ridge height information as information on the height of the current ridge U that has been detected; a tail wheel mechanism H provided in a rear of the cover body G, the mechanism being able to adjust the reap height of the reap blade part F by moving up and down with the grounding means 51 touching the ground; a lifting means 41 that drives the tail wheel mechanism H to move up and down; and a control unit P which, upon receiving the ridge height information, can vertically move the tail wheel mechanism H so as to maintain a set height, which is a distance between the preset reap blade part F and the ridge top surface, and output an H operation signal to the lifting means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a ridge height adjustment device and an agricultural work machine having the ridge height adjustment device. More specifically, the present invention relates to a ridge height adjustment device having a sensor capable of outputting ridge height information of a ridge and an imaging device capable of outputting a ridge image obtained by photographing the ridge after work has been done with a cutting blade unit, and an agricultural work machine having the ridge height adjustment device. [Background technology]

[0002] Patent Document 1 discloses a working machine capable of cutting the stalks and vines of crops growing above ground while maintaining the cutting blade height relative to the ridges. According to this machine, a sensor roller that rolls on the top surface of the ridges is provided behind the flail mower body attached to the rear of the tractor, and detection signals issued in response to the up and down movement of the sensor roller are fed back to a hydraulic control valve of a hydraulic cylinder device of the tractor to move the flail mower body up and down. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-287518 A Summary of the Invention [Problem to be solved by the invention]

[0004] When using the agricultural work machine described in Patent Document 1, the agricultural work machine attached to the rear of the traveling body is raised and lowered by a lifting device, typically a three-point link mechanism, of the traveling body. Therefore, the movement of raising and lowering the machine depends on the performance of the traveling body, and there is a problem that it is not possible to move the machine up and down satisfactorily along the ridges. There is also a problem that it is not easy to adjust the lifting and lowering of the agricultural work machine. Therefore, the present invention has been made with attention to the above-mentioned problems, and provides a ridge height adjustment device having a sensor capable of outputting ridge height information of the ridges, and an agricultural work machine having a ridge height adjustment device, which allows an operator to work easily while maintaining the positional relationship between the agricultural work machine and the ridges. [Means for solving the problem]

[0005] The present invention relates to a sensor capable of detecting the height of a ridge at the rear of a cover body that covers an upper portion of a cutting blade unit having a plurality of cutting blades and capable of outputting ridge height information that is information on the detected current ridge height; a tail wheel mechanism disposed at a rear portion of the cover body and capable of adjusting the cutting height of the cutting blade by raising and lowering the tail wheel mechanism while contacting a ground with a grounding means; A lifting means for driving the tail wheel mechanism to lift and lower; a control unit capable of raising and lowering the tail wheel mechanism to output an operation signal to the lifting means when the ridge height information is received, so as to maintain a preset height that is a distance between a cutting blade unit and a top surface of the ridge that is preset in advance; A ridge height adjustment device comprising: relates to.

[0006] The present invention further comprises: the set height includes a threshold range, and when the ridge height information falls outside the threshold range, the control unit operates the lifting means until the ridge height information falls within the threshold range. A ridge height adjustment device, relates to.

[0007] The present invention further comprises: The control unit operates the lifting means after a preset excess time, which is a preset excess time after receiving the ridge height information, even if the control unit receives the ridge height information other than the set height. A ridge height adjustment device, relates to.

[0008] The present invention further comprises: The control unit is provided to be switchable between an automatic mode in which the tail wheel mechanism is raised and lowered to automatically maintain the set height when the ridge height information is received, and a manual mode in which the mowing height can be adjusted to any desired height by manual operation by an operator regardless of whether the ridge height information is received. A ridge height adjustment device, relates to.

[0009] The present invention further comprises: a photographing device that photographs the ridges after work is performed using the cover body and the cutting blade unit at the rear of the cover body and outputs the photographed ridge image to the control unit; a display terminal having a display screen capable of simultaneously displaying the ridge image and the ridge height information by immediately outputting the ridge image and the ridge height information received by the control unit; A ridge height adjustment device comprising: relates to.

[0010] The present invention further comprises: A ridge height adjustment device, characterized in that the photographing device and the sensor are provided at different heights; relates to.

[0011] The present invention further comprises: A ridge height adjustment device, characterized in that the photographing device is provided behind the sensor; relates to.

[0012] The present invention relates to a ridge height adjustment device, characterized in that the photographing device is provided at a position higher than a position where the sensor is provided; relates to.

[0013] The present invention further comprises: a furrow height adjustment device, characterized in that the photographing device is attached to a part of the agricultural machine having strength greater than a part of the sensor attached to the agricultural machine; relates to.

[0014] The present invention further comprises: A ridge height adjustment device, characterized in that the tail wheel mechanism is made of a link; relates to.

[0015] The present invention further comprises: The display terminal has an operation unit that can be manually operated on the display screen; A ridge height adjustment device comprising: relates to.

[0016] The present invention further comprises: The operating unit is configured to be able to change the set height even when the cutting blade unit is moving on a ridge. A ridge height adjustment device, relates to.

[0017] The present invention further comprises: The operation unit is configured to be able to change the threshold range even when the cutting blade unit is moving on a ridge. A ridge height adjustment device, relates to.

[0018] The present invention further comprises: The operation unit is configured to be able to change the set excess time even when the cutting blade unit is moving on the furrow. A ridge height adjustment device, relates to.

[0019] The present invention relates to The operation unit is provided with a switching operation unit that causes the control unit to switch between and recognize either an automatic mode in which the tail wheel mechanism is raised and lowered to automatically maintain the set height when the ridge height information is received, or a manual mode in which the cutting height can be adjusted to any desired height by manual operation by an operator regardless of whether the ridge height information is received. A ridge height adjustment device, relates to.

[0020] The present invention further comprises: The operation unit includes a settable overtime adjustment operation unit that changes the set overtime so that the lifting means is operated after a set overtime time that is a preset overtime time after receiving the ridge height information even if the operation unit receives ridge height information other than the set height; and A ridge height adjustment device comprising: relates to.

[0021] The present invention further comprises: A vertical reference line is displayed along the traveling direction in the ridge image projected on the display screen, and a horizontal reference line is displayed along the traveling direction and in the width direction. A ridge height adjustment device, relates to.

[0022] The present invention further comprises: When the control unit operates the lifting means toward the set height, the control unit causes the display screen to display an operation status indicating an operation direction of the lifting means. A ridge height adjustment device, relates to.

[0023] The present invention further comprises: The ridge image displayed on the display screen can be manually enlarged or reduced to any desired magnification ratio. A ridge height adjustment device, relates to.

[0024] The present invention further comprises: The control unit is configured to operate the ridge image displayed on the display screen, so that the control unit can reattempt to receive the ridge image from the imaging device. A ridge height adjustment device, relates to.

[0025] The present invention further comprises: The display terminal operates the ridge image displayed on the display screen to request the control unit to re-output the ridge image. A ridge height adjustment device, relates to.

[0026] The present invention further comprises: a sensor capable of detecting the height of a ridge at the rear of a cover body that covers an upper portion of a cutting blade unit having a plurality of cutting blades and capable of outputting ridge height information that is information on the detected current ridge height; a tail wheel mechanism disposed at a rear portion of the cover body and capable of adjusting the cutting height of the cutting blade by raising and lowering the tail wheel mechanism while contacting a ground with a grounding means; A lifting means for driving the tail wheel mechanism to lift and lower; a control unit capable of raising and lowering the tail wheel mechanism to output an operation signal to the lifting means when the ridge height information is received, so as to maintain a preset height that is a distance between a cutting blade unit and a top surface of the ridge that is preset in advance; An agricultural machine having a ridge height adjustment device, relates to. Effect of the Invention

[0027] The present invention provides a ridge height adjustment device that enables an operator to work easily while maintaining the positional relationship between an agricultural machine and the ridge. [Brief description of the drawings]

[0028] [Figure 1] 1 is a side view of an agricultural machine according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a rear view of an agricultural machine according to a first embodiment of the present invention. [Diagram 3] 1 is a plan view of an agricultural machine according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a rear view showing the positional relationship between the cutting blade unit and the ridges of the agricultural machine according to the first embodiment of the present invention. [Diagram 5] 1 is a side cross-sectional view of a main part of an agricultural machine according to a first embodiment of the present invention, showing the right side of a pair of sides. [Figure 6] 1 is an enlarged rear view of a main portion of an agricultural machine according to a first embodiment of the present invention. [Figure 7]1 is an enlarged rear view of a main part of the agricultural work machine according to the first embodiment of the present invention, showing a case in which the cover body is slightly displaced from the left-right center of the ridge. [Figure 8] 1 is an enlarged rear view of a main part of the agricultural work machine according to the first embodiment of the present invention, showing a case in which the cover body is significantly displaced from the left-right center of the ridge. [Figure 9] FIG. 5 is a side cross-sectional view of a main part of an agricultural machine according to a second embodiment of the present invention. [Figure 10] 13 is an enlarged rear view of a main portion of an agricultural machine according to a second embodiment of the present invention. [Figure 11] Fig. 2 is a side view of the agricultural work machine according to the first embodiment of the present invention, showing the operating range of the tail wheel mechanism with the cutting blade unit in the lowest position. [Figure 12] Fig. 2 is a side view of the agricultural work machine according to the first embodiment of the present invention, showing the operating range of the tail wheel mechanism, with the cutting blade unit in the raised position. [Figure 13] 13 is a side view of an agricultural machine according to a third embodiment of the present invention, showing a third embodiment of a tail wheel mechanism lifting means. [Figure 14] 13 is a side view of an agricultural machine according to a fourth embodiment of the present invention, showing a fourth embodiment of a tail wheel mechanism lifting means. [Figure 15] 13 is a side view of an agricultural machine according to a fifth embodiment of the present invention, showing a fifth embodiment of a tail wheel mechanism lifting means. [Figure 16] FIG. 13 is a side view of an agricultural machine according to a sixth embodiment of the present invention. [Figure 17] FIG. 13 is a rear view of an agricultural machine according to a sixth embodiment of the present invention. [Figure 18] FIG. 13 is a plan view of an agricultural machine according to a sixth embodiment of the present invention. [Figure 19] Fig. 13 is a side view of an agricultural work machine according to a sixth embodiment of the present invention Fig. 14 is a diagram showing a photographing range Fig. 15 is a diagram showing a state in which the cutting blade is lowered to its lowest position. [Figure 20] Fig. 13 is a side view of an agricultural work machine according to a sixth embodiment of the present invention Fig. 14 is a diagram showing a photographing range Fig. 15 is a diagram showing a state in which the cutting blade is raised to the highest position. [Figure 21]FIG. 13 is a diagram showing the overall configuration of an agricultural machine according to a sixth embodiment of the present invention. [Figure 22] FIG. 13 is a block diagram of an agricultural machine according to a sixth embodiment of the present invention. [Figure 23] 13 is a display example (automatic mode) of a display terminal according to a sixth embodiment of the present invention. [Figure 24] 13 is a display example (setting display by setting operation) of a display terminal according to a sixth embodiment of the present invention. [Diagram 25] 13 is a display example (manual mode) of a display terminal according to a sixth embodiment of the present invention. [Figure 26] 13 is a display example of a display terminal according to a sixth embodiment of the present invention (when the mowing height is low). [Figure 27] 13 is a display example of a display terminal according to a sixth embodiment of the present invention (when the mowing height is high). [Figure 28] FIG. 13 is a flow chart showing an automatic operation (automatic mode) of a lifting means according to a sixth embodiment of the present invention. [Figure 29] FIG. 13 is a flow diagram showing the operation direction (automatic mode / manual mode) of the lifting means according to the sixth embodiment of the present invention. [Diagram 30] FIG. 13 is a flow chart for changing (automatic mode) the set height (reference distance) of the lifting means according to the sixth embodiment of the present invention. [Diagram 31] FIG. 13 is a flow chart for setting a threshold range (automatic mode) according to a sixth embodiment of the present invention. [Diagram 32] FIG. 13 is a flow chart for setting an overtime period (automatic mode) according to a sixth embodiment of the present invention. [Diagram 33] FIG. 13 is a flow chart showing a manual operation (manual mode) of a lifting means according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] A ridge height detecting device B according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 8. The agricultural work machine A to which the present invention is applied places the cutting blade unit F on the ridges, grounds the grounding means of the tail wheel mechanism H against the ridge bottom U2 on the side of the ridge, and moves forward while rotating the cutting blade 23 of the cutting blade unit F, thereby crushing the stalks and vines of sweet potato plants growing in the ridges. The ridges may or may not have mulch film laid on them, and the present invention is applicable to either form.

[0030] First, an overall outline of the ridge height detection device B of the agricultural machine A will be described. The agricultural machine A has a ridge height detection device B, a mounting section C, a speed change section D, a transmission device E, a cutting blade section F, a cover body G, and a tail wheel mechanism H. For the sake of expression, when written as left or right, it corresponds to the left and right in the width of the traveling direction, and when written as up or down, it is explained that the direction approaching the ground is down, and the direction away from the ground is up. Also, when written as front or rear, it is explained that it corresponds to the front and rear in the traveling direction. Also, regarding the symbols used, L or R may be added to the end of the symbols attached to similar parts to express them as a distinction. On the other hand, by not adding L or R, it may be expressed without distinguishing the parts. For example, in the case of parts XL and part XR, of the pair of left and right parts X, the left part is classified as XL and the right part is classified as XR, and when there is no distinction between left and right, it is expressed as part X.

[0031] The mounting part C will now be described. As shown in FIG. 1, the mounting part C is connected to a lifting device of the traveling body K to lift the agricultural work machine A. The transmission unit D is disposed approximately in the center of the mounting part C. The transmission unit D has an input shaft 11 that obtains power from a traveling machine body K such as a tractor, and the agricultural work machine A obtains driving force by rotating the input shaft 11 with the power of the traveling machine body K. The transmission unit D changes the speed of the driving force and outputs it to the transmission device E.

[0032] The transmission device E will now be described. 1 to 3, the transmission device E is disposed on the side of the agricultural work machine A. The transmission device E has a pulley (not shown) and a belt (not shown), and further changes the speed of the power obtained from the speed change unit D and transmits the rotational power to the cutting blade unit F.

[0033] The cutting blade F will now be described. 4, the cutting blade unit F has a rotor shaft 21, a holder 22, and a cutting blade 23, and is located between side plates G1 of a cover body G described below. The rotor shaft 21 is a cylindrical shaft located between the side plates G1 of the cover body G, arranged horizontally and parallel to the width direction of the moving direction, and is supported for free rotation. One end of the rotor shaft 21 is connected to a transmission device E, and can be rotated by power obtained from the traveling body K. Holders 22 are arranged on the rotor shaft 21 at intervals in the circumferential and axial directions of the rotor shaft 21. A cutting blade 23 capable of cutting vegetation is attached to the holder 22. The cutting blade 23 is rotatable relative to the holder 22, and as the rotor shaft 21 rotates, the cutting blade 23 is pulled in the radial direction by centrifugal force, and cuts vegetation with the blade at the tip. When the cutting blade 23 comes into contact with a foreign object such as an obstacle, the cutting blade 23 rotates backward in the rotational direction, preventing the impact from being transmitted to the rotor shaft 21 and the entire agricultural work machine A.

[0034] As shown in Fig. 4, the cutting blade unit F in this embodiment of the invention is arranged so that the rotational area F1 of the cutting blade 23 at the axial center of the rotor shaft 21 is smaller than the rotational area F1 of the other cutting blades 23. In other words, the cutting blade 23 located on the ridge top surface U1 has a smaller rotational radius, and the cutting blade 23 located outside the ridge top surface U1 has a larger rotational radius. This allows the cutting blade 23 to be aligned with the rotational area F1 from the top surface of the ridge through the shoulder portion U5 of the ridge to the upper portion of the ridge side surface U3. As a result, the stems and vines to be treated that grow from the top of the ridge to the bottom U2 of the ridge can be cut. Furthermore, by providing rotation areas with different rotation radii, it is possible to absorb some deviations of the stalks and vines of sweet potatoes growing from the ridges, even if they shift to the side from the center of the ridges U1. Also, the rotation area F1 does not have to completely match the shape of the ridges U. In this way, even if the cutting blade portion F shifts relatively to the left or right with respect to the traveling direction with respect to the ridges U, the cutting blade 23 is prevented from coming into contact with the upper surface U1 of the ridges.

[0035] The cover body G will be described. The cover body G is disposed so as to cover the upper part of the cutting blade part F, so that the cut vegetation or the cut stems and vines are not scattered around. Also, by guiding the cut stems and vines to the rear lower part, toward the bottom of the ridge U2, the cut stems and vines are not left on the ridge U. The cover body G is equipped with a divider G2. A pair of dividers G2 are provided on the left and right sides of the ridges, and are long members that protrude from the rear of the cover body G to the front of the cover body G. The lower end of the divider G2 moves forward while touching the bottom of the ridge U2 or being slightly buried in it, thereby raising up the stems and vines of vegetation that are growing on the ridges and on both sides of the bottom of the ridge U2, and collecting them while guiding them to the top of the ridge U. The stems and vines collected by the divider G2 are crushed by the cutting blade F.

[0036] The tail wheel mechanism H will now be described. A tail wheel mechanism H is disposed at the rear of the cover body G, and the tail wheel mechanism H is provided on the cover body G which covers the upper part of the cutting blade unit F having a plurality of cutting blades 23. The ground contact means 51, which is made up of wheels provided on the tail wheel mechanism H, comes into contact with the ground, and the ground contact means 51 rolls as the machine moves forward. The ground contact means 51 can be moved up and down relative to the cover body G by the lifting means 41. In other words, by moving the ground contact means 51 up and down while it is in contact with the ground, the cutting blade portion F moves up and down. That is, the cutting height can be adjusted by the ground contact means 51. A detailed description of the tail wheel mechanism H will be given later.

[0037] The ridge height detection device B will now be described. The ridge height detection device B is installed at the rear of the cover body G, as shown in Fig. 1. As shown in Fig. 2 and subsequent figures, the ridge height detection device B has a support base 31 having a slide rail 32, a sensor bracket 33 to which a sensor 36 is fixed, a first arm 34A connected to the support base 31, a second arm 34B connected to the first arm 34A, a third arm 34C connecting the support base 31, the sensor bracket 33 and the second arm 34B, and a guide arm 34D having a guide means 34E connected to the first arm 34A and in contact with the side of the ridge.

[0038] The support base 31 in the ridge height detection device B will be described. 2 and 5 to 10, the support base 31 in the ridge height detection device B is a member attached to the rear center of the cover body G. The support base 31 is fixed to the cover body G by a fixing member 37 located at the front. A slide rail 32, a first arm 34A, and a third arm 34C are attached to the portion of the support base 31 facing rearward. The support base 31 is attached to the rear of a cover body G that covers the upper part of the cutting blade unit F having a plurality of cutting blades 23, and has slide rails 32 fixed thereto with their longitudinal directions parallel to the left and right of the traveling direction. G3 is the rear lower end of the cover body. The rear lower end G3 of the cover body supports the divider G2 and increases the strength of the cover body G.

[0039] The slide rail 32 in the ridge height detection device B will be described. A slide rail 32 that enables a sensor bracket 33 (described later) to slide in the left-right direction is fixed to the support base 31. The slide rail 32 has a U-shaped cross section in a side view, and its long dimension is oriented horizontally to the left and right of the traveling direction.

[0040] The sensor bracket 33 in the ridge height detection device B will be described. 5 to 10, the sensor bracket 33 is made up of a plate-shaped mounting plate 331 attached to the slide rail 32 with its movable surface facing forward and backward, and a plate-shaped sensor fixing plate 35 attached to the lower part of the mounting plate 331 with its surface for mounting a sensor 36 facing left and right. The sensor bracket 33 is slidable horizontally left and right relative to the traveling direction by the slide rail 32. By attaching the sensor bracket 33 to the slide rail 32, the sensor 36 is movable in the width direction of the cover body G, which is the travel direction.

[0041] The sensor 36 in the ridge height detection device B will be described. A sensor 36 is attached to the sensor fixing plate 35 as shown in FIG. 5 and subsequent figures. The sensor 36 is capable of measuring the height from the underside of the sensor 36 to the ridge top surface U1 located directly below the sensor 36. In this embodiment of the invention, a photoelectric sensor is used. The photoelectric sensor is configured to be able to measure the distance to the target surface by projecting laser light toward the target surface and receiving the light reflected from the target surface. In this embodiment, the target surface is the ridge top surface U1. That is, the distance from the sensor 36 to the ridge top surface U1 can be measured by projecting light from the sensor 36 downward onto the ridge top surface U1 and receiving the laser light reflected from the ridge top surface U1. In this embodiment of the invention, the sensor 36 is capable of detecting the ridge height, and is fixed to the rear of the cover body G that covers the upper part of the cutting blade unit F having multiple cutting blades 23. Therefore, it is possible to know the state of the ridge U after it has been cut by the cutting blade unit F. Furthermore, the sensor 36 is provided close to the tail wheel mechanism H provided on the cover body G without contacting the tail wheel mechanism H. Therefore, it is possible to know the current state of the ridge U more accurately. Furthermore, since the relative height positional relationship between the sensor 36 and the cover body G and the relative positional relationship between the cover body G and the cutting blade unit F do not change, it is possible to directly measure the relative height between the lower end of the cutting blade unit F and the ridge top surface U1.

[0042] By integrating the sensor 36 with the cover body G, it is possible to directly measure the relative height between the cutting blade 23 and the ridge U. Although the sensor 36 can be installed on the tail wheel mechanism H (the tail wheel frame 45, the tail wheel arm 47, etc.), since a movable part is included between the tail wheel mechanism H and the cover body G, in order to grasp the relative height between the cutting blade 23 and the ridge U, it is necessary to accurately measure and calculate the positional relationship between the cover body G and the tail wheel mechanism H. That is, by integrating the sensor 36 with the cover body G, it is possible to configure the sensor 36 without increasing the number of measurement points. Although vibration of the cover body G is a concern, the cover body G is fixed to pipes (portions to which the fixing members 37 are attached) on the left and right sides of the rear end portion thereof. Therefore, the cover body G has a structure with a certain degree of strength.

[0043] The sensor 36 is movable on the slide rail 32 and is capable of detecting the ridge height. When the guide means 34E comes into contact with the ridge U, the sensor 36 moves along the longitudinal direction of the slide rail 32 so as to be positioned approximately at the center in the width direction of the ridge U. In other words, the sensor 36 can be positioned on the ridge upper surface U1 while moving left and right in the direction of travel by the slide rail 32, regardless of the relative positional relationship between the cover body G and the ridge U. A space is provided between the sensor 36 and the ridge U1 where no other components are placed. In other words, when the sensor continues to be positioned on the ridge top surface U1 while moving left and right, it is possible to prevent interference from other components that would make it impossible to measure. Also, because a space is provided below the non-contact type sensor 36 as in the embodiment where nothing is placed, it is possible to prevent malfunctions and erroneous measurements due to foreign matter scattered from the rear of the cover body G or the adhesion of such foreign matter, unlike sensors that physically contact the target object, such as arm-type sensors.

[0044] The type of the sensor 36 may be any type other than the photoelectric sensor shown as an example, as long as it can measure distance, and may be an optical type as in the embodiment, or a type using radio waves or ultrasonic waves. Also, other than the above, a type that measures distance by directly contacting the ridge U may be used as long as it can prevent malfunction and erroneous measurement due to foreign matter or the adhesion of such foreign matter. The sensor 36 is fixed in a vertical position relative to the cover body G and the cutting blade unit F. Therefore, by measuring the distance from the sensor 36 to the ridge top surface U1, it is possible to calculate the height from the lower end of the rotation area F1 of the cutting blade unit F to the ridge top surface U1. The sensor 36 is configured to be capable of outputting a measurement signal that is a measurement signal. The measurement signal can be transmitted to the control unit P.

[0045] The control unit P will now be described. The sensor 36 is connected to the control unit P. The control unit P can operate the lifting means 41 based on the measurement signal input from the sensor 36, and can automatically change the height of the cutting blade F from the ground by moving the ground contact means 51 of the tail wheel mechanism H up and down. The control unit P can also be configured to display the measurement signal input from the sensor 36 on the display terminal N as the height from the ground, and can be configured to enable the operator M, recognizing the displayed value, to manually operate the lifting means 41 to reach an arbitrary height.

[0046] The first elastic body 332 in the ridge height detection device B will be described. The sensor bracket 33 is biased by a first elastic body 332. The first elastic body 332 constantly biases the sensor bracket 33 toward the center in the width direction of the cover body G. In the embodiment, the first elastic body 332 has two tension springs disposed on the left and right of the sensor bracket 33, and constantly biases the sensor bracket 33 toward the center in the width direction of the cover body G. There are no limitations on the number, biasing direction, or installation method of the first elastic bodies 332, so long as they achieve the purpose of constantly biasing the sensor bracket 33 toward the center in the width direction of the cover body G. The first elastic body 332 biases the sensor bracket 33 toward the center of the slide rail 32. In other words, the sensor 36 is constantly biased toward the center of the cover body G in the left-right width direction.

[0047] The first arm 34A in the ridge height detection device B shown in FIG. 2 and subsequent figures will be described. The first arm 34A is attached to the rear-facing portion of the support base 31 below the slide rail 32. The first arm 34A is a vertically long member in rear view and is U-shaped in plan view. The upper end of the first arm 34A is rotatably connected to the support base 31. A pair of first arms 34A are provided symmetrically with the left and right central portions of the support base 31 as the axis. 34AL is the first left arm and 34AR is the first right arm. The first arm 34A is attached to the support base 31, and is a pair of first arms 34A, namely, a left first arm 34AL and a right first arm 34AR, which are rotatably connected to the support base 31.

[0048] The second arm 34B in the ridge height detection device B will be described. The second arm 34B is connected to the first arm 34A. The second arm 34B is a rectangular plate member that is long in the left-right direction when viewed from behind, and the outer end of the second arm 34B in the width direction in the traveling direction is rotatably connected to the middle part of the first arm 34A. Similar to the first arm 34A, the second arm 34B also has a pair of left second arms 34BL and right second arms 34BR that are symmetrical on the left and right sides, with their inner ends in the width direction of the traveling direction rotatably connected to each other by a connecting member 38. The second arm 34B consists of a pair that is rotatably connected to the first arm 34A. In the embodiment, the connecting member 38 is formed of a bolt and a nut, and in this case, by not completely fastening, the second arm 34B can rotate around the connecting member 38. Besides being formed of a bolt and a nut, the connecting member 38 may be formed of a pin-shaped member, and there is no limitation on its configuration as long as it can rotatably connect the second arms 34B to each other.

[0049] The third arm 34C in the ridge height detection device B will be described. The third arm 34C is provided at the bottom of the support base 31. The third arm 34C is a member that is long in the vertical direction. The lower end of the third arm 34C is inserted into a rotation shaft provided at the bottom of the support base 31, and the third arm 34C is freely rotatable around this rotation shaft as a fulcrum. The middle part of the third arm 34C in the longitudinal direction is connected to the connecting member 38. In other words, the middle part of the third arm 34C is commonly connected to the inner end of the second arm 34B by the connecting member 38. The third arm 34C is rotatably connected to the support base 31 and is also connected to the sensor bracket 33 and the second arm 34B.

[0050] With the above configuration, for example, when the lower end of the left first arm 34AL of the pair of arms rotates to the left in the traveling direction, the upper end of the third arm 34C rotates to the left in the traveling direction via the left second arm 34BL of the pair of arms. Then, in response to the rotation of the third arm 34C, the lower end of the right first arm 34AR of the pair of arms rotates to the left in the traveling direction via the right second arm 34BR of the pair of arms. That is, the pair of first arms 34A rotate in the same direction by being connected to the second arm 34B and the third arm 34C. Even if the left and right rotation directions of the first arms 34A are different, they rotate in the same direction in a similar manner in conjunction with each other according to the above action.

[0051] The upper end portion of the third arm 34C will now be described. The upper end of the third arm 34C reaches the front of the mounting plate 331 of the sensor bracket 33. As shown in Figs. 5 to 10, a long hole 39 is provided at the upper end of the third arm 34C. A guide pin 391 protruding forward from the mounting plate 331 is positioned in this long hole 39. On the other hand, the upper end side of the third arm 34C swings left and right as the third arm 34C rotates about the lower part of the support base 31 as a fulcrum. Therefore, as the third arm 34C swings left and right, it pushes the sensor bracket 33 toward the left and right in the longitudinal direction of the slide rail 32 via the long hole 39 and the guide pin 391, thereby moving it horizontally left and right. A guide pin 391 in an elongated hole 39 provided in the third arm 34C changes its position relatively in accordance with the amount of swing of the third arm 34C, thereby allowing the sensor bracket 33 to move smoothly along the slide rail 32.

[0052] The guide arm 34D in the ridge height detection device B will be described. The guide arm 34D is connected to the first arm 34A. The guide arm 34D is a vertically long member, with its upper end connected to the lower end of the first arm 34A and provided so as to be rotatable left and right. The guide arms 34D are attached to the first arms 34A arranged on the left and right sides as a pair of left guide arms 34DL and right guide arms 34DR, provided symmetrically to each other. The lower end of the guide arm 34D can swing left and right in the traveling direction. The guide arm 34D is rotatably connected to the lower end of the first arm 34A, and has a guide means 34E that contacts the side surface of the ridge U. The guide arm 34D is provided with a rotation restricting portion J that allows the guide arm 34D to rotate within a determined rotation range relative to the first arm 34A.

[0053] The rotation restricting portion J will now be described. A rotation restricting portion J is provided at the upper end of the guide arm 34D in a position close to the connection portion with the first arm 34A. The rotation restricting portion J is composed of an arc-shaped restricting hole J1 provided at the upper end of the guide arm 34D and a restricting pin J2 fixed to the lower end side of the first arm 34A. The restricting pin J2 is located in the restricting hole J1 and is provided so as to be relatively movable within the restricting hole J1. The guide arm 34D is freely rotatable within a range in which the restricting pin J2 can be located within the restricting hole J1. In other words, the rotation range of the guide arm 34D is limited by the rotation restricting portion J. In the illustration of FIG. 2, it is shown that the guide arm 34D and the guide means 34E can be rotated from the position indicated by the solid line to the position indicated by the two-dot chain line.

[0054] The second elastic body 333 in the ridge height detection device B will be described. A second elastic body 333 is disposed at the upper end of the guide arm 34D and at the middle of the first arm 34A. The second elastic body 333 biases the lower end side of the guide arm 34D inward in the width direction of the travel direction. In other words, it biases the lower end side of the guide arm 34D toward the center in the width direction of the ridge U. Also, in the embodiment, a tension spring is used as the second elastic body 333, but there are no limitations on the type of elastic body or the position where the elastic body is installed as long as the direction of biasing the guide arm 34D is the direction described above. The biasing force of the second elastic body 333 is set to be greater than the biasing force of the first elastic body 332. This will be described later. The second elastic body 333 biases the guide arm 34D so as to constantly press against the side surface of the ridge U.

[0055] The guide means 34E in the ridge height detection device B will be described. Guide means 34E is attached to the lower end of the guide arm 34D. The guide means 34E is a member that contacts the ridge side surface U3, and is fixed to each of the guide arms 34D arranged on the left and right in a symmetrical shape. The guide means 34E is composed of left guide means 34EL and right guide means 34ER. Guide means 34E in contact with ridge U swings guide arm 34D, thereby swinging sensor bracket 33 via first arm 34A, second arm 34B, and third arm 34C. In other words, guide means 34E in contact with ridge side surface U3 is configured to be able to swing sensor 36 left and right in the traveling direction.

[0056] In the first embodiment, the guide means 34E shown in Fig. 2 and subsequent figures is configured as a sled, and is configured so as to be able to come into contact with the ridge side U3. The sled-shaped guide means 34E is inclined relative to the contact surface so as it moves downward from the contact surface with the ridge U and widens outward in the width direction. In addition, the front end of the sled-shaped guide means 34E is inclined relative to the contact surface so as it moves forward from the contact surface and widens outward in the width direction in the traveling direction. This configuration prevents the guide means 34E from being buried in the ridge U when it is advanced while in contact with the ridge side U3. The guide means 34E contacts both sides of the ridge U as shown in Fig. 2. In this embodiment, the guide means 34E is positioned so as to contact the shoulder portion U5 of the ridge. Since it is sufficient for the guide means 34E to detect the position of the ridge U by abutting the left and right positions of the ridge, it may also be positioned so as to contact the ridge side surface U3 below the shoulder portion U5.

[0057] Illustrated in Figures 9 and 10 is a second embodiment of the guide means 34E. The guide means 34E is not limited to a sled shape as shown in FIG. 2, FIG. 5 to FIG. 9. For example, as in the second embodiment of the guide means 34E shown in FIG. 9 and FIG. 10, the guide means 34E may be configured as a cylindrical, rotatable roller. In this case, the guide means 34E may be formed as a roller that is long in the axial direction so as to extend in the direction of the rotation axis and suppress the ground pressure. In this case, the guide means 34E moves while rolling on the ridge side U3 and the ridge shoulder U5, so that friction with the ridge U can be reduced. This embodiment is particularly effective when the ridge U is covered with a mulch film (not shown). In other words, the friction when pressing against the ridge is reduced, so the risk of damage to the mulch film is reduced and the subsequent recovery work is facilitated. Of course, the second embodiment can also be used for the ridge U where no mulch film is laid.

[0058] The function and effect of each part during operation will be explained. First, the agricultural work machine A is positioned above the upper surface U1 of the ridge. At this time, as shown in Fig. 2, the cover body G is positioned so that its left-right central portion is located above the left-right central portion of the ridge U. In other words, the left-right central portion of the cutting blade portion F is located above the left-right central portion of the ridge U. At this time, the sensor bracket 33 is urged toward the left-right central portion of the cover body G by the first elastic body 332, and the sensor 36 located in the left-right central portion of the cover body G can also be positioned above the left-right central portion of the ridge U.

[0059] The height of the agricultural work machine A is adjusted by raising and lowering the lifting device of the traveling body K so that the cutting blade F located directly above the center of the ridge U is at a desired height. In this embodiment of the present invention, the cutting blade F is positioned so that it contacts the ridge U or is located slightly above it. More specifically, in the case of ridges U covered with mulch film, the cutting blade F is positioned slightly above the ridges U covered with the mulch film so as not to crush the mulch film. In the case of ridges U not covered with mulch film, the cutting blade F is positioned at a height that does not damage the harvested crop underground, so that the cutting blade F comes into contact with the ridge top surface U1 or is positioned slightly above the ridge top surface U1.

[0060] After the height of the agricultural work machine A is roughly determined by the lifting device of the traveling body K, the height is adjusted so that the ground contact means 51 of the tail wheel mechanism H is placed at the ridge bottom U2. By doing this, the height of the cutting blade F will not move below at least the height at which the ground contact means 51 of the tail wheel mechanism H touches the ground. After the adjustment, the tail wheel mechanism H is raised and lowered to move the main body of the agricultural work machine A up and down to adjust the cutting blade height. Also, by adjusting the tail wheel mechanism H during work, the ridge height, which is the relative distance between the cutting blade F and the ridge U, can be fine-tuned.

[0061] As the height of the agricultural work machine A is adjusted, the guide means 34E eventually comes into contact with the shoulder U5 of the ridge U from the side. In this embodiment of the invention, the cross-sectional shape of the ridge U is formed into a trapezoid, and the ridge side U3 is illustrated as inclining toward the center of the left-right width of the ridge U as it moves upward from the ridge bottom U2. As the height of the agricultural work machine A is gradually lowered, the guide means 34E is pushed outward in the width direction along the inclination of the side of the ridge U. In other words, the lower end of the guide arm 34D rotates outward in the width direction along the side of the ridge U.

[0062] The lower end side of the guide arm 34D is biased toward the center of the ridge U by the second elastic body 333. Therefore, in contrast to the above, when the height of the agricultural work machine A is raised with the guide means 34E in contact with the side surface of the ridge U, the guide arm 34D rotates toward the ridge side surface U3 until it is restricted by the rotation restricting part J. Therefore, even when the agricultural work machine A is raised or lowered relative to the ridge U, the guide means 34E can come into contact with the ridge side surface U3 until it is restricted by the rotation restricting portion J.

[0063] The movement of the agricultural work machine A will be described with reference to Figs. With the guide means 34E in contact with the side surface U3 of the ridge, the cutting blade section F is driven to rotate and move forward. The top of the ridge and the bottom U2 of the ridge are covered with vines growing from the harvested crop underground. The operator M who operates the traveling body K moves the traveling body K forward while predicting or estimating the ridge U covered with vines. Therefore, it is possible that the traveling body K and the agricultural work machine A may deviate relatively to the left or right in the direction of travel with respect to the ridge U. In the explanation, an example is shown in which the cover body G is shifted to the right in the direction of travel with respect to the ridge U, but if the cover body G is shifted to the left in the direction of travel with respect to the ridge U, the opposite operation will be performed and therefore this explanation will be omitted.

[0064] Fig. 7 shows a case where the cover body G is slightly deviated to the right in the direction of travel relative to the ridges U, and Fig. 8 shows a case where the cover body G is significantly deviated to the right in the direction of travel relative to the ridges U. Fig. 6 shows a state where the left-right center of the cover body G is not deviated at all from the left-right center of the ridges U.

[0065] The pressing side during operation will be described. When the agricultural work machine A deviates from the ridge U and the cover body G shifts relatively to the right side of the ridge U in the traveling direction, the ridge side U3 on the left side of the traveling direction or the left shoulder U5 of the ridge U presses the guide means 34E toward the left side of the traveling direction. The left guide arm 34DL arranged on the left side of the guide arm 34D tries to move relatively to the left side of the traveling direction with respect to the cover body G. In response to this, the lower end side of the first arm 34A also tries to move relatively to the left in the traveling direction with respect to the cover body G, and rotates about the support base 31 as a fulcrum. That is, the lower end side of the left first arm 34AL on the left side of the first arm 34A rotates so as to move relatively to the left with respect to the cover body G. At this time, the guide arm 34D is biased by the second elastic body 333, so that the guide means 34E continues to contact the ridge side U3 or the ridge shoulder U5.

[0066] By the rotation of the left first arm 34AL on the left side, the left second arm 34BL connected to the left first arm 34AL on the left side also moves to the left in the traveling direction. The upper end side of the third arm 34C connected to the second arm 34B rotates to the left in the traveling direction as shown in Fig. 7 which shows a case where the cover body is slightly displaced from the left-right center of the ridge, and Fig. 8 which shows a case where the cover body is significantly displaced from the left-right center of the ridge. In Figs. 7 and 8, 36A is a virtual line showing the position of the sensor, 36B is the amount of deviation of the position of the sensor 36 from the center position of the cover body G, and 36C is a virtual line showing the left-right center of the cover body G. That is, the long hole 39 at the upper end of the third arm 34C moves leftward in the traveling direction. The long hole 39 presses the guide pin 391 provided on the mounting plate 331 of the sensor bracket 33 leftward in the traveling direction, whereby the sensor bracket 33 moves leftward along the slide rail 32 relative to the cover body G. As a result, as shown in Figures 7 and 8, the sensor 36 mounted on the sensor bracket 33 moves leftward relative to the cover body G, but does not move relative to the ridge U, as can be seen by comparing with Figure 6. Alternatively, the sensor 36 moves leftward relative to the cover body G, but does not move significantly relative to the ridge U. The sensor 36 can always be positioned above the center of the left and right of the ridge U. In other words, the sensor 36 can remain positioned on the ridge top surface U1 regardless of the relative positional relationship of the cover body G to the ridge U in the width direction.

[0067] The non-pressing side during operation will be described. Of the pair of left and right second arms 34BL and 34BR, the third arm 34C is connected to the right second arm 34BR on the right side, which is the direction in which the machine is shifted. The right second arm 34BR on the right side also moves leftward in the traveling direction, like the left second arm 34BL on the left side, as shown in Figures 7 and 8. The right first arm 34AR on the right side connected to the right second arm 34BR on the right side rotates about the support base 31 side as a fulcrum so that the lower end side moves leftward in the traveling direction, similar to the left first arm 34AL on the left side.

[0068] Therefore, the right guide arm 34DR and the right guide means 34ER on the right side can move leftward in the traveling direction. As a result, as shown in Figures 7 and 8, the right guide means 34ER on the right side away from the ridge side surface U3 can move leftward in the traveling direction in the same way as the left guide means 34EL on the left side, and can be brought into contact with the right side surface of the ridge U. In other words, during operation, the left and right guide means 34E can always be in contact with the ridge side surface U3 regardless of the direction in which the sensor 36 swings left and right.

[0069] Therefore, even if the cover body G and the cutting blade section F move alternately left and right or randomly left and right from the ridge center U4 as the traveling body K advances in a zigzag pattern relative to the ridge U, the sensor 36 can immediately capture the ridge side surface U3 and move toward the ridge center U4 as shown in Figures 7 and 8. Therefore, the sensor 36 does not deviate significantly to the side from the ridge center U4, and can accurately measure the height of the ridge top surface U1.

[0070] The sensor 36, which is always positioned above the center U4 of the ridge, is connected to the control unit P. The sensor 36 can accurately measure the height of the ridge U and output a measurement signal of the measured ridge height. Therefore, when the tail wheel mechanism H is automatically raised and lowered by the control unit P, operation can be performed based on the measurement signal, which is information on the correct height of the ridge U, so that the tail wheel mechanism H can be raised and lowered with greater precision to adjust the height of the cutting blade 23.

[0071] Furthermore, even when the tail wheel mechanism H is raised and lowered manually, the control unit P displays the ridge height on the display terminal N based on the measurement signal, which is information on the correct height of the ridge U, so that the worker M can operate the lifting means 41 to raise and lower the tail wheel mechanism H based on the highly accurate and reliable display. The first arm 34A, the second arm 34B, and the guide arm 34D on the side moving away from the ridge side U3 so as to move from the ridge center U4 toward the outside in the width direction also swing in conjunction with the first arm 34A, the second arm 34B, and the guide arm 34D on the side approaching the ridge center U4 so as to move from the ridge side U3 toward the ridge center U4.

[0072] In this embodiment of the present invention, the biasing force of the second elastic body 333 is greater than that of the first elastic body 332. By providing a difference in the biasing forces, when the guide means 34E is pressed from the ridge side surface U3, the sensor bracket 33 can quickly swing against the biasing force of the first elastic body 332 without causing the guide arm 34D to rotate due to the biasing force of the second elastic body 333. Therefore, when the cover body G is shifted relatively in the left-right direction with respect to the ridge U, the sensor 36 can be quickly moved left-right with respect to the cover body G and positioned above the center of the ridge U.

[0073] The second elastic body 333 is effective when the sensor 36 reaches the limit of its left-right movement range but the cover body G attempts to deviate further in the left-right direction relative to the ridge U. Assuming that the guide arm 34D is fixed to the first arm 34A, when the cover body G deviates from the ridge U beyond the limit of the left-right movement range of the sensor 36, an abnormal state may occur in which the guide arm 34D and the guide means 34E pierce the ridge center U4 from the ridge side U3.

[0074] However, in this embodiment of the present invention, the guide arm 34D is freely rotatable relative to the first arm 34A and is biased toward the ridge U by the second elastic body 333, so that even if the above-mentioned abnormal condition occurs, the guide means 34E rotates while maintaining contact with the ridge U, thereby preventing damage to the ridge U. As the abnormal state is resolved, the guide arm 34D rotates so that the longitudinal direction of the guide arm 34D faces the vertical direction. After the abnormal state is resolved, the sensor 36 is again biased by the first elastic body 332, and the guide means 34E comes into contact with the ridge side surface U3 and moves left and right.

[0075] Therefore, by making the biasing force of the second elastic body 333 stronger than that of the first elastic body 332, it is possible to prevent damage to the ridges U without impeding the left-right movement of the sensor 36 relative to the cover body G. Furthermore, when the sensor 36 returns from the abnormal state to the normal state as shown in Figures 6 to 8, the sensor 36 can start moving left-right again as usual. Furthermore, it is assumed that the second elastic body 333 is such that the cover body G is not shifted left or right relative to the ridge U, and the cover body G approaches the ridge U. In this case, the sensor 36 does not move, and the left and right guide means 34E are pressed to spread along the slope of the ridge side surface U3 while resisting the biasing force of the second elastic body 333. When the cover body G is released from its proximity to the ridges U, the guide means 34E returns to its original position while in contact with the ridges U and is biased by the second elastic body 333. Even in a situation where the guide means 34E pierces the ridges U from above, it can return to its original position without damaging the ridges U. In addition, since the guide means 34E maintains a constant state of contact with the ridges U, immediate action can be taken if the cover body G and the ridges U are misaligned to the left or right.

[0076] The configuration of the tail wheel mechanism H and the agricultural machine A operated using the ridge height detection device B of the present invention is not limited to the form of the embodiment. Since the ridge height can be measured with high accuracy as the machine progresses, it is expected to be useful for the agricultural machine A working on the ridges U. In the embodiment described above, the first arm 34A, the second arm 34B, the guide arm 34D, and the guide means 34E are provided in pairs on the left and right sides, respectively. However, even if the first arm 34A, the second arm 34B, the guide arm 34D, and the guide means 34E are arranged on only one side, the sensor 36 can still follow the ridge top surface U1. When left-right misalignment occurs between the cover body G and the ridge U, the immediate response performance is slightly inferior to when a pair is provided, but the configuration of the ridge height detection device B can be simplified. Therefore, the number of processes related to manufacturing and machine maintenance can be reduced. Furthermore, the shape of the ridge U to which the ridge height detection device B of the present invention can be applied is not limited to that shown in the figure, and the shapes of each part of the ridge height detection device B can be appropriately changed depending on the shape of the ridge U.

[0077] The tail wheel mechanism H will now be further explained. The first link 43 will be described. The first link 43 is rotatable at a left-right intermediate portion of the upper portion of the cover body G in the width direction. A first link 43 is rotatably provided at the rear of the cover body G near the left-right center of the cover body G. The first link 43 is a member that is long in the front-to-rear direction, and its front end is rotatably provided relative to the cover body G. In this embodiment, two first links 43 are provided with a gap between them near the left-right center of the width of the cover body G. The first links 43 are positioned so that there is no ridge U below them. In other words, the first links 43 are positioned so that they are located on the ridge bottom U2. The rotation fulcrum of the first link 43 relative to the cover body G is positioned above the rear end of the cover body G.

[0078] The second link 44 will now be described. The second link 44 is provided at the lower part of the cover body G at the side of the cover body G so as to be rotatable. The second links 44 are rotatably provided at the left and right ends of the cover body G, at the rear of the cover body G. The second links 44 are members that are long in the front-to-rear direction, and their front ends are rotatably provided on side plates G1 located at the left and right ends of the cover body G. It can also be said that the second links 44 are located outside the working width of the cutting blade unit F. In the embodiment, two second links 44 are located at both outer ends of the cover body G. The longitudinal length of the second links 44 is set to be the same as that of the first links 43.

[0079] The tail wheel frame 45 will now be described. A tail wheel frame 45 is provided to connect the rear end of the first link 43 and the rear end of the second link 44. The tail wheel frame 45 has a frame that is long in the left-right direction, a first link connecting portion 431 that connects the first link 43, and a second link connecting portion 441 that connects the second link 44. In the embodiment, the first link connection portions 431 are provided at two locations near the left and right central portions of the frame to connect the respective rear ends of the two first links 43, and the second link connection portions 441 are provided at both left and right ends of the frame to connect the respective rear ends of the two second links 44.

[0080] The first link 43 and the second link 44 are connected to the cover body G and the tail wheel frame 45 to form parallel links in a side view. When the first link 43 and the second link 44 move up and down with the cover body G as a fulcrum, the tail wheel frame 45 located at the rear end moves up and down relative to the cover body G. As described above, the front-to-rear lengths, which are the lengths in the longitudinal direction of the first link 43 and the second link 44, are set to be the same, so when the tail wheel frame 45 moves up and down, it moves up and down without tilting, while maintaining an angle relative to the cover body G.

[0081] The advantages of the arrangement of the tail wheel mechanism H will now be explained. The first link 43, the second link 44 and the tail wheel frame 45, which move up and down, are cover body G and are not located below the lower end of the cover main body that covers the cutting blade F. Stems and vines cut or severed by the cutting blade F may fly backward from the lower end of the cover main body that does not cover the blade. However, the first link 43, the second link 44, and the tail wheel frame 45, which move up and down, are located above the rear lower end G3 of the cover body at any position, so that scattered stems and vines do not adhere to them. Fig. 11 shows the state in which the tail wheel frame 45 is located at the uppermost position relative to the cover body G, and Fig. 12 shows the state in which the tail wheel frame 45 is located at the lowermost position relative to the cover body G. As shown in the figures, the first link 43, the second link 44, and the tail wheel frame 45 rotate and move above the rear lower end G3 of the cover body. Moreover, the second link 44 is disposed further outboard than the working width of the cutting blade unit F, further reducing the possibility of scattered stems and vines adhering to them. Therefore, the first link 43, the second link 44, and the tail wheel frame 45 are disposed in a configuration that can prevent foreign objects from adhering to them, so that the operator M can be prevented from removing foreign objects from the first link 43, the second link 44, and the tail wheel frame 45. Also, although the first link 43 has been described as being disposed on the cover body G, it can also be rotatably mounted on the side plate G1, similar to the second link 44. In this case, the first link 43 can further reduce the possibility of scattered stems and vines attaching to it.

[0082] The holder 46 of the tail wheel frame 45 of the tail wheel mechanism H will be described. A holder 46 is provided on the tail wheel frame 45. The holder 46 can hold and fix a tail wheel arm 47, which will be described later. In this embodiment, the holder 46 is made of a square pipe with its elongated direction facing up and down.

[0083] The grounding means 51 includes a holder 46 fixed to the rear of the tail wheel frame 45. The tail wheel frame 45 is provided parallel to the cover body G on the left and right in the traveling direction, and connects the first link 43 and the second link 44. An explanation will be given of the tail wheel arm 47 of the tail wheel mechanism H. The tail wheel arm 47 of the tail wheel mechanism H is provided so as to be vertically movable relative to the holder 46 and so as to be able to be fixed in position relative to the holder 46. The tail wheel arm 47 is inserted into the holder 46. The tail wheel arm 47 is a vertically long member, and has multiple adjustment holes at its upper end. The adjustment holes can be aligned with the fixing holes 461 that penetrate the holder 46, and a fixing member 462 made of a pin-shaped member can be inserted into them. The tail wheel arm 47 and the holder 46 are fixed together by inserting the fixing member 462. Since multiple adjustment holes are provided in the vertical direction, the lower end position of the tail wheel arm 47 relative to the holder 46 can be selectively adjusted by selecting an adjustment hole at any position and inserting the fixing member 462 into the fixing hole 461. The tail wheel arm 47 can be adjusted in stages from the position represented by the solid line in FIG. 1 to the position represented by the two-dot chain line together with the grounding means 51 described later. Although it is difficult to change the position adjustment of the tail wheel arm 47 relative to the holder 46 during work, the tail wheel arm 47 can be moved up and down by the lifting means 41 during work. Also, as in this embodiment, the position of the tail wheel arm 47 can be adjusted relative to the holder 46, but it is also possible to omit the holder 46 and attach the tail wheel arm 47 directly to the tail wheel frame 45. In this case, the position adjustment between the tail wheel arm 47 and the holder 46 is omitted, but the configuration of the tail wheel mechanism H can be simplified, making it easier to manufacture and to inspect during operation.

[0084] Since the tail wheel frame 45 of the tail wheel mechanism H is configured to be able to rise and fall while maintaining a relative angle with respect to the cover body G, the tail wheel arm 47 is also able to rise and fall while maintaining a relative angle with respect to the cover body G. Therefore, the lower end of the tail wheel arm 47 does not move back and forth relative to the cover body G when it is raised and lowered, so the overall length of the agricultural work machine A does not change significantly. In other words, even when the tail wheel arm 47 moves up and down, the overall length of the agricultural work machine A can be almost maintained, so the worker M riding on the traveling body K can work without feeling any change in the sense of distance to the rear end of the agricultural work machine A.

[0085] The lifting means 41, which is the extension and contraction means of the tail wheel mechanism H, connects the upper part of the cover body G to the first link 43, and moves the tail wheel frame 45, the tail wheel arm 47, and the ground contact means 51 up and down by extending and contracting. The grounding means 51 of the tail wheel mechanism H will be described. A ground contact means 51 is provided at the lower end of the tail wheel arm 47. In this embodiment, the ground contact means 51 is a wheel, and while the wheel is in contact with and rolling on the ground at the ridge bottom U2, the tail wheel frame 45 is moved up and down by the lifting means 41, which is an extension means, so that the cutting height of the cutting blade portion F can be adjusted while working. The wheels, which are the ground contact means 51 shown in this embodiment, are provided on the tail wheel arm 47 so as not to be rotatable in the horizontal direction. Ground contact means 51 consisting of wheels provided on the tail wheel mechanism H is brought into contact with the ground, and the ground contact means 51 rolls as the machine moves forward. The ground contact means 51 can move up and down relative to the cover body G by the lifting means 41, which is an extension and contraction means. In other words, by moving the tail wheel frame 45 up and down with the ground contact means 51 in contact with the ground, the cutting blade section F moves up and down. In other words, the cutting height can be adjusted by the ground contact means 51.

[0086] The ground contact means 51 moves forward while in contact with the ridge bottom U2, thereby making it possible to maintain a constant mowing height, which is the height of the cover body G and the cutting blade F from the ridge bottom U2. In addition, the mowing height can be changed by moving the tail wheel arm 47 up and down. The ground contact means 51 is formed of wheels and is rotatably mounted on a horizontal axis at the lower end of the tail wheel arm 47. The wheels touch the ground on the ridge bottom U2 and move forward while rolling on the ridge bottom U2, allowing the agricultural work machine A located on the ridge U to move smoothly. The wheels may be made of any material, such as rubber, resin, or metal, and may be made of a composite of these materials. In the embodiment, the ground contact means 51 is formed of metal wheels. In the embodiment, the ground contact means 51 located at the ridge bottom U2 is located slightly inward in the vehicle width direction with respect to the cover body G from the side plate G1.

[0087] In the first embodiment of the present invention, the ground contact means 51 is configured with wheels, but as in the fourth embodiment shown in Fig. 14, the ground contact means 51 may be sled-shaped. In this case, the configurations of the ground contact means 51 and the lower end of the tail wheel arm 47 can be significantly simplified, thereby reducing the workload associated with maintenance.

[0088] The scraper 52 of the tail wheel mechanism H will now be described. The ground contact means 51 in the first embodiment comprises a scraper 52 arranged adjacent to the wheel. The grounding means 51 may have a scraper 52. The scraper 52 scrapes off the soil, stems, and vines adhering to the grounding portion of the wheel, which is the grounding means 51, so that the grounding means 51 can be grounded in an appropriate state. In other words, the rotational diameter of the wheel does not increase due to the adhesion of soil, stems, and vines, so the mowing height can be maintained at an appropriate height.

[0089] The lifting means 41 will now be described. Lifting means 41 is provided to lift and lower the grounding means 51. In this embodiment of the invention, a cylinder, which is an expandable means, is used as the lifting means 41. One end of the cylinder is connected to the cover body G, and the other end, which is a rod side, is connected to a connecting member 42 fixed to a first link 43. The extension and contraction of the cylinder causes the rear end side of the first link 43 to move up and down relative to the cover body G via the connecting member 42. As a result, the tail wheel frame 45 connected to the first link 43 also moves up and down, and the ground contact means 51 moves up and down relative to the cover body G. Since the ground contact means 51 can be raised and lowered by the cylinder, the operator M can easily adjust the mowing height.

[0090] The lower end of the connecting member 42 is fixed by a long member 421 such as a square pipe so as to be connected to the two first links 43. In other words, the thrust of the cylinder can be distributed to the two first links 43, so that the tail wheel arm 47 can move up and down smoothly without being subjected to an unbalanced load.

[0091] A third embodiment, which is another example of the lifting means 41 of the tail wheel mechanism H shown in FIG. 13, will be described. The lifting means 41 for lifting and lowering the grounding means 51 is not limited to a cylinder. As shown in FIG. 13, instead of a cylinder, it is also possible to move the grounding means 51 up and down by rotating a rod 411 having a thread. One end of the rod 411 is provided on the cover so as to rotatably hold the handle 412, and a male thread is formed on the other end. A female thread is provided on the upper part of the connecting member 42, and the other end of the rod 411 is inserted into the female thread. In this state, by rotating the rod 411 in either direction using the handle 412, the grounding means 51 can be lifted and lowered. By configuring the lifting means 41 with the rod 411, the lifting means 41 can be made extremely simple.

[0092] A fifth embodiment shown in FIG. 15, which is another example of the grounding means 51, will be described. It has been stated that the ground contact means 51 in the first embodiment of the present invention is configured with wheels. The wheels are configured so as not to rotate horizontally relative to the tail wheel arm 47, but as shown in the fifth embodiment, they can be configured so as to be freely rotatable horizontally. In this case, if the ground contact means 51 is in a situation where it meanders in the width direction of the traveling direction relative to the ground on which it is in contact, the wheels will rotate horizontally in response to the meandering while touching the ground and rolling, allowing the tail wheel mechanism H to move more smoothly relative to the ground. As a result, excessive load is not placed on the tail wheel mechanism H in the width direction, and damage to the tail wheel mechanism H including the ground contact means 51 can be reduced.

[0093] The agricultural work machine A according to the embodiment of the present invention crushes the stalks and vines of sweet potato plants growing in the ridges U. If mulch film has been laid on the ridges U, the mulch film is removed and the potatoes are dug up. For this reason, the stalks and vines of sweet potato plants growing in the ridges U need to be cut short, right up to the vines. If the sensor 36 is lower than the apex U4 of the ridge U, the measured value will be inaccurate. For example, if the sensor 36 is located at the shoulder U5 of the ridge or at the top of the side U3 of the ridge, the relative height between the cover body G and the ridge top surface U1, which is used to measure the height of the ridge U, cannot be accurately measured. Therefore, it is important that the sensor 36 is located above the apex U4 of the ridge U or above a position near the apex U4. The ridge height detection device B of the present invention allows the sensor 36 to be located above the apex U4 of the ridge U. In addition, when cutting the vines and stems of sweet potatoes with the agricultural machine A, vines and stems grow thickly on the ridge U and the ridge bottom U2 in front of the cover body G, and if the sensor 36 is placed in front of the cover body G, accurate measurement will not be possible. Therefore, the sensor 36 needs to be brought to the rear of the agricultural machine A, since the measurement will be inaccurate unless the stalks and vines of sweet potatoes are cut.

[0094] A ridge height adjusting device according to a sixth embodiment will be described mainly with reference to Figs. The outline of the sixth embodiment is similar to that of the first embodiment. However, the sensor 36 used in the sixth embodiment of the present invention may be installed using the ridge height detection device B of the first embodiment, or the sensor 36 may simply be fixed to the cover body G without using this. In addition, the tail wheel mechanism H may be the tail wheel mechanism H that moves in parallel as in the first embodiment, or may be configured to simply move the ground contact means 51 up and down by rotating (e.g., JP 2015-006146 Agricultural Machinery). In the illustrated example, the sensor 36 is directly fixed to the cover body G, and the tail wheel mechanism H employs a type using a parallel link.

[0095] The tail wheel mechanism H is raised and lowered by connecting the sensor 36, the photographing device 71, the display terminal N, and the lifting means 41 to the control unit P, and the lifting means 41 is operated by an operation signal from the control unit P. The display terminal N is arranged so that the ridge image Q photographed by the photographing device 71 can be displayed via the control unit P, and is provided with an operation unit N2 that can be operated by the worker M. 72 is the photographing range. The photographing device 71 photographs within the photographing range 72 to obtain an image. 23 to 25, the operating unit N2 allows the user to input necessary setting values ​​to the control unit P in order to put the agricultural work machine A into a desired working state. The control unit P is configured to perform calculations based on information obtained from the sensor 36 and operate the lifting means 41 based on the results of the calculations.

[0096] The sensor 36 will now be described. The rear of the cover body G covering the upper part of the cutting blade section F having multiple cutting blades 23 is capable of detecting the height of the ridges U, and has a sensor 36 capable of outputting ridge height information, which is information on the current height of the detected ridges U. The sensor 36 is disposed in the left-right center at the rear of the cover body G. The sensor 36 is fixed to the rear of a sensor fixing plate 35 disposed to protrude rearward from the rear of the cover body G, and measures the distance from the bottom of the sensor 36 to an object by emitting laser light from the bottom of the sensor 36 and receiving the reflected irradiated light. Since the left-right center of the cover body G and the cutting blade unit F is positioned above the ridge U during operation, the sensor 36 is able to measure the distance to the ridge top surface U1 located below. The sensor 36 is installed as close as possible to the ridges U in order to accurately grasp the state of the ridges U. For that reason, the sensor 36 is provided on the cover body G. By attaching the sensor 36 to the cover body G that is not driven and is close to the ridges U during the construction of the agricultural work machine A, it is possible to know the relative positional relationship between the ridges U after the current mowing height processing and the cover body G or the cutting blade section F.

[0097] Since the dimensions of each part of the cover body G and the rotational diameter of the cutting blade section F are known values, the distance from the lower end of the cover body G or the cutting blade section F to the top surface of the ridge can be calculated by calculation using the calculation section P3 of the control section P described below. That is, the sensor 36 does not necessarily have to be positioned at the same height as the bottom end of the cover body G or the bottom end of the rotational area of ​​the cutting blade unit F. In the embodiment, the sensor 36 is positioned slightly above the bottom end of the cover body G. The sensor unit is blocked by the cover body G from stems and vines flying off from the cutting blade unit F, so they do not collide with or adhere to the sensor unit.

[0098] When the sensor type of the embodiment is used to measure the distance to the ridge top surface U1, no other components are placed between the sensor 36 and the ridge top surface U1. While the sensor 36 can directly measure the distance to the ridge U, it is possible to eliminate the inconvenience that may occur when using a type using a physical arm or the like. For example, when a physical arm is grounded on the ridge top surface U1 for measurement, there is no erroneous measurement due to collision or adhesion of stems or vines scattered from the cutting blade F to the arms positioned below the sensor 36. In addition, it is possible to prevent the arms grounded on the ridge top surface U1 from getting caught on stems or vines and dragging them, thereby damaging the sensor 36 itself. In addition, the sensor 36 of the embodiment uses a sensor with a detection range of approximately 0 to 500 mm.

[0099] Ridge height information, which is information on the current height of the ridges U detected by the sensor 36, can be output to the control unit P. The detected ridge height information can be output immediately. The output may be wired or wireless, and is output to the control unit P, which is an external device. There are no limitations on the communication method used for output. In the case of wired communication, for example, it may be a serial bus standard represented by a universal serial bus or analog output. In the case of wireless communication, it may be output using a local area network or may be output using various short-range wireless communication standard methods. Of course, methods other than those exemplified may be used.

[0100] The control unit P will now be described. When the control unit P receives ridge height information, it can output an operation signal to the lifting means 41 by raising and lowering the tail wheel mechanism H to maintain a set height N10, which is the distance between the cutting blade section F and the ridge top surface U1 that has been preset. Even if the control unit P receives ridge height information other than the set height N10, it operates the lifting means 41 after a preset excess time, which is the excess time after receiving the preset ridge height information. The control unit P is switchable between an automatic mode in which, when ridge height information is received, the tail wheel mechanism H is raised and lowered to automatically maintain the set height N10, and a manual mode in which the cutting height can be adjusted to any desired height by manual operation by the operator M regardless of whether ridge height information has been received. When the control unit P operates the lifting means 41 toward the set height N10, the control unit P causes the display screen N1 to display an operating status indicating the operating direction of the lifting means 41. The control unit P is configured to be able to operate the ridge image Q displayed on the display screen N1, so that the control unit P can attempt to receive the ridge image Q from the photographing device 71 again.

[0101] The control unit P includes a communication unit P1, a memory unit P2, and a calculation unit P3, as shown in Fig. 22. The control unit P is connected to each of the sensor 36, the photographing device 71, the display terminal N, and the lifting means 41, as shown in Fig. 22, and is capable of inputting information from each device and outputting information to each device. The control unit P displays the ridge height on the display terminal N based on the information obtained from the sensor 36, and is also capable of operating the lifting means 41. The control unit P also receives a signal of the ridge image Q from the photographing device 71 and outputs the ridge image Q to the display terminal N. The set height N10 will now be described. The set height N10 includes the threshold range, and when the ridge height information falls outside the threshold range, the control unit P can operate the lifting means 41 until the ridge height information falls within the threshold range.

[0102] The photographing device 71 will now be described. The photographing device 71 can photograph the ridge U after work has been done with the cover body G and the cutting blade unit F at the rear of the cover body G and output the photographed image Q to the control unit P. The photographing device 71 is installed on the tail wheel mechanism H. The photographing device 71 is a camera capable of shooting moving images, and is installed so that information on the captured images can be output. The specific installation position and orientation are such that the photographing device 71 is installed in the center in the width direction of the tail wheel frame 45 of the tail wheel mechanism H, and the photographing device 71 is installed so that the area below the installation position becomes the shooting range 72. The photographing device 71 is installed so that no other members are placed directly below it.

[0103] Therefore, the photographing device 71 can photograph at least the rear end of the cover body G and the ridge U located below the cover body G. Even if the tail wheel frame 45 moves up and down, it is located above the lower end G3 of the cover body G in a side view. Therefore, the camera device 71 is blocked by the cover body G from the stems and vines flying off from the cutting blade F, so they do not collide with or adhere to it. Furthermore, the illustrated tail wheel frame 45 is configured so that it does not tilt in the front-to-rear direction relative to the cover body G even when it moves up and down, so the camera device 71 does not change its shooting direction. When attaching the camera device 71 to a type other than the illustrated tail wheel mechanism H, measures should be taken to prevent a change in the shooting direction of the shooting range 72. In other words, if the camera device 71 can be attached so that the shooting range 72 does not change even if the cutting height is adjusted by raising and lowering the tail wheel mechanism H, the object of the present invention can be achieved.

[0104] Since the photographing device 71 is fixed to the tail wheel frame 45, it moves up and down integrally with the tail wheel frame 45. That is, the photographing device 71 moves up and down relative to the cover body G in response to the up and down movement of the tail wheel frame 45. In actual use, the photographing device 71 is fixed in position relative to the grounding means 51 of the tail wheel frame 45, and therefore its position relative to the ridge bottom U2 where the grounding means 51 touches the ground is fixed. That is, when the lifting means 41 is operated with the grounding means 51 touching the ground, the cover body G moves up and down relative to the photographing device 71. Therefore, in the photographing range 72 of the photographing device 71, the apparent occupancy rate of the rear end of the cover body G photographed within the photographing range changes due to the elevation of the tail wheel mechanism H. In the photographing range 72 in this embodiment, the apparent occupancy rate of the rear end of the cover body G changes between zero and about 30% of the entire photographing range. Of course, this occupancy rate and the amount by which the occupancy rate increases or decreases can be freely changed depending on the configuration and specifications of the agricultural work machine A.

[0105] Since the position of the photographing device 71 is fixed with respect to the ridge bottom U2, the size of the ridge U itself contained in the ridge image Q photographed by the photographing device 71 does not vary significantly. Therefore, when the ridge image Q is displayed on the display screen N1 of the display terminal N described below, the worker M can easily recognize the ridge U.

[0106] The photographing device 71 is provided at the rear of the sensor 36. The sensor 36 is provided on the cover body G. By attaching the sensor 36 to the cover body G that is not driven while the agricultural work machine A is in close proximity to the ridges U, it is possible to measure the ridge height, which is the state of the ridges U immediately after the current harvesting process, and obtain ridge height information. The camera 71 is fixedly attached to the tail wheel mechanism H behind the sensor 36. The tail wheel mechanism H has a more stable attitude with respect to the ridges U and a more stable height relationship with respect to the ground compared to the cover body G. By providing it at the rear of the agricultural work machine A, it becomes possible to objectively grasp the condition of the ridges U after work is completed by the cutting blade unit F. In this embodiment of the invention, the tail wheel mechanism H is constructed of a parallel link, so the posture of the imaging device 71 installed on the tail wheel mechanism H is particularly stable. Since it is installed on the tail wheel mechanism H behind the sensor 36, the ridges U processed by the cutting blade F can be photographed over as wide a range as possible. If the imaging device 71 is attached to the cover body G, the shooting range 72 fluctuates and becomes unstable due to the up and down movement of the cover body G, making it difficult for the operator M to see the ridges U through the display screen N1. Since the imaging device 71 in this embodiment is provided on the tail wheel frame 45 of the tail wheel mechanism H, it is possible to photograph the ridges U over a wide shooting range 72 and transmit the photographed ridge image Q to the control unit P. The photographing device 71 is provided at a higher position than the sensor 36 so that a wider range can be photographed. On the other hand, the sensor 36 is provided on the cover body G as close as possible to the ridges U in order to accurately grasp the state of the ridges U, so that the relative distance between the cover body G, which moves up and down relative to the ridges U, and the ridges U can be measured directly and accurately. By effectively combining the photographing device 71 and the sensor 36 installed at different positions, the state of the ridge U can be accurately grasped.

[0107] The photographing device 71 can instantly output the photographed ridge image Q to the outside. The output can be wired or wireless, and is output by communicating with an external device. There is no limitation on the communication method. In the wired case, for example, a serial bus standard such as a universal serial bus or a multimedia interface standard can be used. Or, analog output can be used. In the wireless case, output can be made using a local area network or various short-distance wireless communication standards. Of course, methods other than those exemplified can be used.

[0108] The communication unit P1 will be described. The communication unit P1 is connected to the sensor 36, the photographing device 71, and the display terminal N, and can communicate with each other. Communication is performed with each device using the communication unit P1. Information from the sensor 36, the photographing device 71, and the display terminal N is input, and information is output to the sensor 36, the photographing device 71, and the display terminal N in return.

[0109] The memory unit P2 is provided so as to be capable of storing the setting values ​​input by the operator M to the display terminal N. The setting values ​​include a threshold range, which is a range of thresholds for the desired cutting height, a set overtime period for operating the lifting means 41 after the set overtime period, and a current operation mode. The memory unit P2 stores the input setting values, and provides the stored numerical values ​​for calculations in the calculation unit P3. The set height N10, threshold value display N11, threshold value operation section N12, excess time display N13, and excess time operation section N14 are each displayed on the setting display N4a of the display terminal N as shown in FIG.

[0110] The calculation unit P3 will now be described. The calculation unit P3 is capable of performing a comparative calculation between the current ridge height N9 based on the ridge height information shown in Figures 23 to 25 input from the sensor 36 and the set height N10, which is the reference distance of the ridge U set by the operator M. The calculation unit P3 also performs calculations based on the set height N10 for setting the desired mowing height, which is a set value stored in the memory unit P2, as well as a threshold range, which is a threshold range for the set height N10, and a set excess time for operating the lifting means 41 after a set excess time, to determine whether or not the lifting means 41 needs to operate. The control unit P sends an operation command to the lifting means 41 based on the result of the calculation unit P3, and operates the lifting means 41. The current ridge height N9 is sometimes called the current distance or ridge height information.

[0111] In the embodiment, the ridge height information used for calculation in the calculation unit P3 is the distance from directly below the sensor 36 to the ridge top surface U1. The ridge height information displayed on the display terminal N described below is the distance from directly below the sensor 36 to the ridge top surface U1.

[0112] In addition to the embodiment, the calculation unit P3 can correct the ridge height information inputted by the communication unit P1 and calculate the cutting height, which is the distance from the ridge top surface U1 to the lower end of the cutting blade unit F. It is also possible to calculate the corrected ridge height information and the set height N10, which is the set distance from the ridge top surface U1 to the lower end of the cutting blade unit F. In other words, the comparison between the corrected ridge height information and the reference distance may be performed by comparing the actual cutting height based on the ridge height information and the lower end of the cutting blade unit F with the actual cutting height calculated and set from the positional relationship between the ground contact means 51 and the sensor 36. In this case, since the calculation is performed based on the actual cutting height, when these values ​​are displayed on the display terminal N, the display can be made even easier for the operator M to understand.

[0113] The display terminal N will now be described. The control unit P is equipped with a display terminal N having a display screen N1 capable of simultaneously displaying the ridge image Q and the current ridge height N9, which is the ridge height information, by immediately outputting the ridge image Q and ridge height information received by the control unit P. The display terminal N is provided on the traveling body K. The display terminal N is preferably disposed in front of the worker M riding on the traveling body K, and more preferably, is disposed in a position within the field of view of the worker M or slightly out of the field of view of the worker M when the worker M operating the traveling body K faces forward in the direction of travel. Arranging in this manner makes it easy for the worker M to view the display terminal N. The display terminal N is provided with a display screen N1, which can be viewed by the worker M. The display screen N1 is also provided so that the worker M can touch it, and an operation unit N2 that can be operated by the worker M is displayed within the display screen N1. The worker M can change various settings and displays by operating the operation unit N2. In this embodiment, a tablet terminal is used as the display terminal N.

[0114] The display terminal N is capable of inputting and outputting information by communicating with the outside, similar to the photographing device 71. And, similar to the photographing device 71, the communication may be wired or wireless, and there is no limitation on the communication method. The display terminal N is capable of displaying an application that serves as an interface for operating the ridge height adjustment device, and the worker M can operate the ridge height adjustment device by operating the application.

[0115] The operation unit N2 will now be described. The display terminal N has a display screen N1 and an operation section N2 that can be operated manually. In this embodiment, the display screen N1 itself is configured to function as the operation section N2. The operating unit N2 is configured so that the set height N10 can be changed even when the cutting blade unit F is moving over the furrow. The operation unit N2 is configured so that the threshold range can be changed even when the cutting blade unit F is moving over the furrow. The operation unit N2 is configured so that the set excess time can be changed even when the cutting blade unit F is moving over the furrow. The operation unit N2 is provided with a switching operation unit N6 that causes the control unit P to switch and recognize either an automatic mode in which the tail wheel mechanism H is raised and lowered automatically to maintain the set height N10 when ridge height information is received from the sensor 36, or a manual mode in which the cutting height can be adjusted to any desired height by manual operation by the operator M regardless of whether ridge height information is received. The operation unit N2 is equipped with an overtime adjustment operation unit N14 that can change the set overtime so that even if ridge height information other than the set height N10 is received in automatic mode, the lifting means 41 is operated after the set overtime time, which is the overtime time from when the pre-set ridge height information is received.

[0116] The ridge image Q will be explained. Examples are shown in Fig. 23 showing a display example (automatic mode) of a display terminal N according to a sixth embodiment of the present invention, Fig. 25 showing a display example (manual mode) of the same display terminal N, Fig. 24 showing a display example (setting display N4a by setting operation) of the same display terminal N, Fig. 26 showing a display example (when the mowing height is low) of a ridge image Q displayed on the same display terminal N, and Fig. 27 showing a display example (when the mowing height is high) of a ridge image Q displayed on the same display terminal N. As shown in the display examples of the display terminal N shown above, the ridge image display section N3 which displays the ridge image Q on the display screen N1 of the display terminal N displays a vertical reference line Q1 displayed along the traveling direction and a horizontal reference line Q2 displayed in the width direction of the traveling direction. The ridge image Q displayed on the display screen N1 can be manually enlarged or reduced to any desired magnification ratio. The display terminal N requests the control unit P to re-output the ridge image Q by manipulating the ridge image Q displayed on the display screen N1.

[0117] The ridge image Q displayed on the ridge image display unit N3 includes, in addition to the vertical reference line Q1 and horizontal reference line Q2, the grounding means 51, the tail wheel arm 47, the holder 46, the tail wheel frame 45, the second link 44, the ridge bottom U2, the ridge top surface U1, the sensor 36, the cover body G, etc. In the automatic mode and manual mode shown in Figures 23 and 25, the display screen N1 of the display terminal N displays, in addition to the ridge image Q, an operation unit N2, a ridge image display unit N3, an operation mode display N4, a setting operation unit N5, a switching operation unit N6, a lifting operation unit N7, an operation icon N8, a current distance N9, which is the current ridge height based on ridge height information, and a reference distance N10, which is the set height. In the setting display N4a by the setting operation shown in FIG. 24, a threshold value display N11, a threshold value operation section N12, an excess time display N13, an excess time operation section N14, and a decision operation section N15 are displayed.

[0118] The display of the ridge image Q will now be described. The ridge image Q captured by the photographing device 71 can be displayed on the ridge image display section N3 within the display screen N1 as shown in Figures 23 to 25 via the control section P. The displayed ridge image Q is the ridge U as viewed from above the ridge, and the ridge U behind the cover body G is displayed. In this embodiment of the invention, the top of the display screen N1 is displayed so that it faces forward in the direction of travel. A part of the rear of the cover body G is displayed at the top of the ridge image Q. Since the position of the photographing device 71 is fixed relative to the grounding means 51 installed at the ridge bottom U2, the ridge U in the ridge image Q displayed on the display screen N1 does not appear to change significantly even when the lifting means 41 is operated. On the other hand, when the lifting means 41 is operated, the cover body G in the ridge image Q displayed on the display screen N1 appears to change in the area occupied by the cover body G. In other words, since the ridges U displayed on the display screen N1 do not change significantly, the worker M can easily visually recognize the state of the ridges U.

[0119] The ridge image Q displayed on the display screen N1 in the embodiment of the present invention is the ridge image Q captured by the imaging device 71, and is displayed distorted, since it is displayed without correction. Although not shown, it is also possible to correct the ridge image Q captured by the imaging device 71 and display the image after correcting the image distortion. When the image is displayed distorted as in the embodiment, the control unit P does not perform correction processing for the image distortion contained in the image acquired from the imaging device 71, and therefore the configuration of the control unit P can be simplified.

[0120] The display examples of the ridge image Q on the ridge image display unit N3 shown in Figure 26 and Figures 23 to 25 show a case where the mowing height is low. Specifically, the display shows a state where the ridge height from the ridge bottom U2 to the ridge top surface U1 is low and the cutting blade unit F is positioned near the ridge top surface U1. In this case, as shown in Figure 19, since the photographing device 71 and the lower end G3 of the cover body G are relatively far apart, the photographing range 72 includes the cover body G and the sensor 36, and the cover body G and the sensor 36 are also displayed in the ridge image Q displayed on the ridge image display unit N3. The display example of the ridge image Q on the ridge image display unit N3 shown in Figure 27 shows a case where the mowing height is higher than the state in Figure 26. Specifically, it shows a state where the ridge height from the ridge bottom U2 to the ridge top surface U1 is high and the cutting blade unit F is positioned near the ridge top surface U1. In this case, since the relative distance between the photographing device 71 and the lower end G3 of the cover body G is close as shown in Figure 20, the cover body G and the sensor 36 are outside the photographing range 72, and the cover body G and the sensor 36 are not displayed in the ridge image Q displayed on the ridge image display unit N3. The tail wheel mechanism H is configured to be able to rise and fall relative to the cover body G, so that when the tail wheel mechanism H is operated, the ridge image Q displayed on the ridge image display unit N3 can change from the state shown in Figure 26 to the state shown in Figure 27. In other words, the apparent occupancy rate of the cover body G displayed on the ridge image display unit N3 is displayed to change according to the mowing height. On the other hand, the display screen N1 also displays the current distance N9, which is the current ridge height, and the reference distance N10, which is the set height, together with the ridge image display section N3. However, since the worker M who drives the traveling machine body K wants to spend time watching the front, it is assumed that he / she may not be able to recognize and respond to the current distance N9 and reference distance N10, which are numerical information displayed on the display screen N1. In particular, since the display of the current distance N9 changes every certain period of time, it may be difficult to imagine the positional relationship between the ridge U and the cover body G from the displayed numerical value alone. In such a case, by displaying the cover body G together with the ridge U including the ridge top surface U1 and the ridge bottom U2 in the ridge image Q displayed on the ridge image display section N3, it is possible to easily imagine the positional relationship between the ridge U and the cover body G. Furthermore, by changing the occupancy rate of the cover body G of the ridge image Q displayed on the ridge image display unit N3 in accordance with the raising and lowering of the tail wheel mechanism H, it is possible to reliably confirm the positional relationship between the ridge U and the cover body G and the cutting height caused by the raising and lowering of the tail wheel mechanism H by simply visually checking the ridge image display unit N3 for a moment, for example, of about one second.

[0121] The video update will now be described. It is also possible to attempt to update the ridge image Q by operating the ridge image Q displayed on the display screen N1, which also serves as the operation unit N2, so as to reacquire the ridge image Q. When the worker M performs an update operation, the display terminal N requests the control unit P to re-output the ridge image Q. The control unit P, which has received a request for re-output, is configured to be able to try again to receive the ridge image Q output from the photographing device 71. This allows the control unit P to reacquire the ridge image Q from the photographing device 71 after operating the operating unit N2 and display it on the display terminal N if the image is no longer displayed properly on the display screen N1 due to a deterioration in communication conditions, etc.

[0122] This section explains how to enlarge and reduce an image. The ridge image Q displayed on the display screen N1 can be enlarged or reduced. By enlarging the image, the ridge portion can be enlarged, allowing the worker M to check the condition of the ridge U in detail. By reducing the image, the ridge U and its surroundings can be displayed including the cover body G, making it easier for the worker M to understand the positional relationship between the ridge U and the cover body G. In this embodiment, the enlarged and reduced image is achieved by touching the displayed ridge image Q, which is also the operation unit N2, with any two points and lengthening or shortening the distance between the two points.

[0123] The vertical reference line Q1 and the horizontal reference line Q2 will be described. The ridge image Q displayed on the display screen N1 has a vertical reference line Q1 and a horizontal reference line Q2. The vertical reference line Q1 is a reference line displayed along the direction of travel, and is displayed in the up-down direction by combining with the center of the width of the ridge image Q displayed on the display screen N1. The vertical reference line Q1 is a line that indicates the center of the working width, and the worker M can adjust the agricultural work machine A and the width direction of the ridge U without directly looking behind him / her by steering the traveling machine body K while viewing the display screen N1 so that the center of the width of the ridge U is aligned with the vertical reference line Q1.

[0124] The horizontal reference line Q2 is a reference line displayed along the width direction relative to the traveling direction, and is displayed in the left-right direction by combining it with the center of the vertical direction of the ridge image Q displayed on the display screen N1. The positional relationship of the horizontal reference line Q2 with the rear end of the displayed cover body G changes. In other words, since the rear end of the cover body G, which moves up and down by the lifting means 41, changes position within the display screen N1, the worker M can easily judge the relationship of the current lifted position of the cover body G in a sensory manner without relying on a numerical display. By displaying the horizontal reference line Q2, the worker M can steer the traveling machine body K while visually checking the vertical position of the cover body G relative to the ridge U on the display screen N1.

[0125] The display of distance information will now be described. At the bottom of the display screen N1, ridge height information N9, which is the height of the ridge U measured by the sensor 36, can be input from the control unit P and displayed. The current ridge height N9, which is the ridge height information to be displayed, is constantly updated as the control unit P receives the ridge height information from the sensor 36 and outputs it to the display terminal N in real time. Therefore, the operator M viewing the display screen N1 can recognize the current ridge height N9 in real time. As shown in Figures 23 to 25, the current ridge height N9 may also be referred to as the current distance. Adjacent to the ridge height information N9 displayed on the display screen N1, the operator M can display a reference distance N10, which is the relative height of the cutting blade part F with respect to the ridge U. The reference distance N10 is also called the set height, and is a numerical value that is set in advance to maintain the relative distance between the ridge top surface U1 and the cover body G in the automatic mode.

[0126] The operation mode display N4 and the operation mode switching operation will now be described. The display screen N1, which also serves as the operation unit N2, is provided with a switching operation unit N6 for switching the operation mode adjacent to the display of the ridge image Q. The operation modes include an automatic mode in which, when the control unit P receives ridge height information, the tail wheel mechanism H is automatically raised and lowered to maintain the set height N10, and a manual mode in which the operator M can manually adjust the cutting height to any desired value regardless of whether the control unit P has received ridge height information.

[0127] Either the automatic mode or the manual mode can be selected by operating the switching operation unit N6 displayed on the display screen N1. The display terminal N that receives the operation of the switching operation unit N6 transmits an instruction signal to the control unit P indicating which of the operation modes has been selected. The control unit P receives the instruction signal via the communication unit P1 of the control unit P and switches the control mode so as to operate according to the selected instruction signal. The display terminal N displays the currently selected operation mode on the display screen N1 so that the operator M can understand it. In this embodiment, it displays it in characters. The operation mode may also be called an operation mode or a control mode.

[0128] The automatic mode will now be described. When the control unit P recognizes that it is in the automatic mode, it receives ridge height information from the sensor 36, and operates the lifting means 41 to set the height N10 according to the result of comparison and calculation with the set height N10 by the calculation unit P3. Therefore, the tail wheel mechanism H is raised and lowered so that the mowing height is automatically maintained at the set height N10, allowing the operator M to work without adjusting the lifting means 41.

[0129] The change of the set height N10 in the automatic mode will be described. In the automatic mode, by operating the lift operation unit N7 shown in Fig. 23 among the operation units N2 displayed on the display screen N1, the reference distance, which is the set height N10, can be changed. The reference distance N10 can be changed at will by the worker M even during work. In other words, even if the height from the ridge bottom U2 to the ridge top surface U1, which is the condition of the ridge U, changes during work, the setting can be changed flexibly to deal with the situation. For example, if an operator M feels that the current height of the ridges U is higher than the height at the start of the work, the operator M can change the set height N10 by operating the lifting / lowering operation unit N7 to increase the reference distance, which is the set height N10. If the operator M feels that the height is lower, the operator performs the same operation as described above to lower the set height N10. When the set height N10 is changed, the changed set value is stored in the memory unit P2 of the control unit P, and the operation in the automatic mode thereafter is calculated by the calculation unit P3 with reference to the changed set value stored in the memory unit P2. The display of the set height N10, which is the reference distance, on the display screen N1 is also displayed as a value changed in response to the operation of the lifting / lowering operation unit N7.

[0130] The action icon N8 (visual confirmation of action status) shown in FIG. 23 to FIG. 25 will be described. When the lifting means 41 operates in the automatic mode, an operation icon N8 corresponding to the operating direction of the lifting means 41 is displayed. This makes it easier for the worker M to recognize whether the lifting means 41 is operating in the automatic mode, and by visually checking this together with the ridge image Q displayed on the display screen N1, the worker M can simultaneously recognize the current operating status of the tail wheel mechanism H along with the status of the ridge U. In the embodiment, the operation icon N8 is configured in the shape of an arrow, and is displayed as an animation that flashes in a chain manner along the direction of the arrow.

[0131] For example, when the lifting means 41, which is a lifting mechanism, is operated to lower the tail wheel mechanism H relative to the cover body G and the cutting blade F rises relative to the ridge top surface U1, an upward arrow is displayed as shown in Figures 23 and 25, and when the lifting means 41, which is a lifting mechanism, is operated to raise the tail wheel mechanism H relative to the cover body G and the cutting blade F falls relative to the ridge top surface, a downward arrow (not shown) is displayed. When the lifting means 41 is not operating, the display of the operation icon N8 is erased as shown in Figure 24, and when the lifting means 41 is operating, the operation icon N8 is displayed.

[0132] In the embodiment of the present invention, the operation icon N8 is displayed in the automatic mode, but it can also be displayed when the lifting means 41 is operated in the manual mode. Also, the operation icon N8 may be displayed as a single image only, not as an animation.

[0133] The condition change will be described. When operating the lifting means 41 in the automatic mode, detailed operating conditions can be specified by the control unit P. In this case, as shown in Fig. 23 and Fig. 24, the operating conditions can be changed by operating the setting operation unit N5 among the operation units N2 displayed on the display screen N1. By operating the setting operation unit N5, it is possible to change the threshold range, which is the range of thresholds for the set height N10, and the set overtime, which is the time for operating the lifting means 41 after the set overtime set after receiving the previously set ridge height information. When operating the lifting means 41 in automatic mode, the operating conditions of the lifting means 41 can be changed to those desired by the operator M by adjusting the detection conditions for the ridge height to be detected and the detection time. The set overtime can be controlled by selecting either the elapsed time after the lifting means 41 operates or the elapsed time after receiving the ridge height information from the sensor 36. In the embodiment, the operation is performed using the elapsed time after the control unit P receives the ridge height information from the sensor 36.

[0134] The setting display N4a will now be described. When the setting operation unit N5 is operated in the automatic mode, the display switches to the setting display N4a shown in Fig. 24. Instead of the operation mode display N4, the switching operation unit N6, and the lifting operation unit N7 displayed in the automatic mode of Fig. 23, the setting display N4a displays a threshold range display N11, a threshold range display N11 adjacent to the threshold range, an overtime display N13, an overtime operation unit N14 adjacent to the overtime display N13, and a decision operation unit N15, as shown in Fig. 24. Even when the setting display N4a is displayed, the ridge image Q, ridge height information N9, and set height N10 remain displayed in the ridge image display section N3 as shown in Fig. 24. Therefore, the worker M can adjust the detection conditions while visually checking the ridge image Q even during work.

[0135] The change in the threshold range will be described. As shown in Fig. 24, the threshold range can be increased or decreased by operating the threshold range operation section N12 displayed on the setting display N4a of the display terminal N. The changed threshold range is reflected in the changed numerical value and displayed in the threshold range display section N11. If the worker M agrees with the displayed numerical value, he or she transmits the changed numerical value to the control section P by operating the decision operation section N15. When the control unit P receives the changed threshold range value through the communication unit P1, the control unit P rewrites and stores this value in the memory unit P2. After the decision operation, the control unit P performs calculation processing in the calculation unit P3 based on the changed threshold range value stored in the memory unit P2, and operates the lifting means 41.

[0136] If the threshold range is set large, control unit P will not operate lifting means 41 unless the ridge height measured by sensor 36 deviates significantly from set height N10. In contrast, if the threshold range is set small, control unit P will operate lifting means 41 if the ridge height measured by sensor 36 deviates even slightly from set height N10. In other words, by freely changing the threshold range, it is possible to freely adjust whether lifting means 41 responds sensitively or insensitively to the detected ridge height when operating. In the embodiment, the adjustment amount of the threshold range can be adjusted for the upper and lower limit values ​​of the threshold range by operating the threshold range operation unit N12. Also, the adjustable range and adjustment amount in the embodiment are set to be adjustable in 1 mm increments from 0 to 20 mm, but the adjustable range and adjustment amount can be freely changed depending on the type of the agricultural work machine A and the work content.

[0137] After the operator M has determined the threshold range, he or she operates the determination operation unit N15 displayed on the setting display N4a of the display terminal N shown in Fig. 24, and transmits the range from the display terminal N to the control unit P. The control unit P stores the threshold range received by the communication unit P1 in the memory unit P2, updates the threshold range to be used in the automatic mode thereafter, performs calculations based on this value, and operates the lifting means 41.

[0138] Explain overtime. As shown in FIG. 24, by operating an overtime operation section N14 displayed on the setting display N4a of the display terminal N, it is possible to increase or decrease the overtime. As shown in Fig. 24, the changed overtime is displayed in the overtime display section N13 with the changed value reflected. If the worker M agrees with the displayed value, he / she transmits the changed value to the control section P by operating the decision operation section N15 shown in Fig. 24. When the control section P receives the changed overtime value through the communication section P1, it rewrites and stores this value in the memory section P2. After the decision operation, the control section P performs calculation processing in the calculation section P3 based on the changed overtime value stored in the memory section P2, and operates the lifting means 41.

[0139] The overtime is the time at which the control unit P updates the received ridge height information after a preset overtime has elapsed since receiving the ridge height information from the sensor 36. In other words, even if the control unit P receives ridge height information, it cannot operate the lifting means 41 until the preset overtime has elapsed since receiving the ridge height information. To set this overtime, the set overtime is adjusted by operating the overtime operation unit N14. Even if the control unit P sequentially receives ridge height information measured by the sensor 36, unless it determines that the overtime has been exceeded, it will not use this value to perform calculations in the calculation unit P3 and will not operate the lifting means 41.

[0140] If the set overtime is set to a large value, the time interval at which the control unit P receives the ridge height information and performs calculations based on this information will become larger. In other words, by lengthening the calculation interval for the ridge height information for the control unit P, the operation interval of the lifting means 41 will be lengthened, making it less sensitive to following the ridges U. On the other hand, if the set excess time is set to a small value, the time interval at which the control unit P receives the ridge height information and calculates based on this information becomes smaller. In other words, by shortening the calculation interval for the ridge height information for the control unit P, the operation interval of the lifting / lowering means 41 is shortened, making it more sensitive to following the ridges U. In this way, when the lifting / lowering means 41 is operated automatically in automatic mode, the operator M can freely change the set excess time to a desired value, thereby freely adjusting the degree of response of the operation of the lifting / lowering means 41 to the ridge height according to the calculated time interval.

[0141] Furthermore, by setting a set overtime, when the lifting means 41 is operated automatically, a chattering state in which the lifting means 41 constantly repeats operation toward the set ridge height can be avoided. The range and adjustment amount of the set overtime in the embodiment are set to be adjustable in 1 second increments within a range of 0 to 20 seconds, but the range and adjustment amount can be freely changed depending on the type of agricultural work machine A and the work content.

[0142] Since the detection range of sensor 36 is 0 to 500 mm, when the agricultural work machine A is raised above the ridge by the lifting device of the traveling body K, the distance from the top surface of the ridge to sensor 36 becomes larger than the distance of the detection range. Therefore, for example, when the traveling body K and the agricultural work machine A reach the end of the ridge U and the agricultural work machine A is raised by the lifting device of the traveling body K, control unit P will be unable to receive ridge height information from sensor 36, and the lifting means 41 will be unable to operate. As a result, even when the entire agricultural work machine A is raised, the tail wheel mechanism H does not move up and down, so that when work is started again on the ridges, the number of steps required to adjust the tail wheel mechanism H can be reduced.

[0143] The manual mode will now be described. When the operator M operates the switching operation unit N6 shown in Fig. 23, the operation mode can be switched from the automatic mode shown in Fig. 23 to the manual mode shown in Fig. 25. When switching from the manual mode to the automatic mode, the operator M operates the switching operation unit N6 shown in Fig. 25. When the control unit P recognizes that the mode is manual due to this switching operation, the cutting height can be adjusted to any desired height regardless of receipt of ridge height information from the control unit P. By operating the lifting / lowering operation unit N7 displayed on the display screen N1, the operator M can adjust the height of the tail wheel mechanism H to the desired height and position the cutting blade unit F at the desired cutting height. In the manual mode, the lifting / lowering operation unit N7 can operate the lifting means 41 in either direction to operate the tail wheel mechanism H in either the up or down direction.

[0144] In the embodiment, the set height N10 and ridge height information N9 are displayed in the same manner as in the automatic mode even in the manual mode. Therefore, the operator M can visually recognize the current ridge height N9 numerically. In addition, since the set set ridge height can be visually confirmed, when the operator M switches the operation mode to the automatic mode, he or she can determine how the control unit P will control the lifting means 41 in the initial stage after switching.

[0145] A description will now be given of FIG. 28, which is a flow chart showing the automatic operation (automatic mode) of the lifting means according to the sixth embodiment of the present invention. Upon starting, the sensor 36 measures the distance in S11. In S12, the communication unit P1 receives the ridge height information from the sensor 36. In S13, the current ridge height received by the calculation unit P3 is compared with the set height stored in the memory unit P2. In S14, it is determined whether the current ridge height received at P3 is within the threshold range stored in memory unit P2. In S15, if it is determined in S14 that the ridge height is not within the threshold range, that is, if the result is NO, the lifting means 41 is operated so that the current ridge height falls within the threshold range. In S16, if it is determined in S14 that the ridge height is within the threshold range, that is, if the result is YES, the process goes to standby. In S17, it is determined whether the overtime meets the set overtime. If it does, that is, if the answer is YES, the process returns to the start. If it does not meet the set overtime, that is, if the answer is NO, the process waits in S18 and the process is repeated in S17.

[0146] A description will now be given of FIG. 29, which is a flow chart showing the operation direction (automatic mode / manual mode) of the lifting means according to the sixth embodiment of the present invention. After starting, perform input operations using S21. In S22, it is determined whether the movement direction of the lifting means 41 is extension or contraction. If it is determined in S22 that the movement direction of the lifting means 41 is extension, a down arrow is displayed in S23 and the process returns to the start. If it is determined in S22 that the movement direction of the lifting means 41 is retraction, an up arrow is displayed in S24 and the process returns to the start.

[0147] A description will now be given of FIG. 30, which is a flow chart showing how to change (automatic mode) the set height N10 (reference distance) of the lifting means according to the sixth embodiment of the present invention. After starting, in S31, an input operation by the worker M is accepted via the lift operation unit N7 of the display terminal N. In S32, it is determined whether the operation of the lift operation unit N7 was an increase operation, a decrease operation, or no operation was performed. If it is determined in S32 that the lift operation unit N7 has not been operated, the process returns to the input operation in S31. If it is determined in S32 that the operation of the lift operation unit N7 is a decrease operation, the reference distance N10 is decreased in S33. If it is determined in S32 that the operation of the lift operation unit N7 is an increasing operation, the reference distance N10 is increased in S34. In S35, the changed reference distance N10 in both S33 and S34 is stored in the memory unit P2, and the process returns to the start.

[0148] A description will now be given of FIG. 31, which is a flow chart showing threshold range setting (automatic mode) according to the sixth embodiment of the present invention. In S41, the operator M performs an input operation to increase or decrease the threshold range in the threshold operation unit N12. In S42, it is determined whether or not a decision operation has been performed by decision operation unit N15. In S42, when a confirmation operation is performed, the determined threshold range is updated and stored in the storage unit P2, and the process ends. If no decision operation is performed in S42, the process returns to the start.

[0149] A description will now be given of FIG. 32, which is a flow chart showing the setting of the overtime period (automatic mode) according to the sixth embodiment of the present invention. In S51, the worker M performs an input operation to increase or decrease the overtime at the overtime operation unit N14. In S52, it is determined whether or not a decision operation has been performed by decision operation unit N15. In S52, when a confirmation operation is performed, the confirmed overtime time is updated and stored in the storage unit P2, and the process ends. If no decision operation is performed in S52, the process returns to the start.

[0150] FIG. 33 is a flow chart showing the manual operation (manual mode) of the lifting means according to the sixth embodiment of the present invention. In S61, the worker M performs an input operation to increase or decrease the lift operation unit N7. In S62, it is determined whether the movement direction of the lifting means 41 is extension, contraction, or no extension or contraction operation. If it is determined in S62 that the lifting means 41 is contracted, the lifting means 41 is contracted in S63. In the case of extension in S62, the lifting means 41 performs the extension operation in S64. If there is no operation in S62, the process returns to the start. [Explanation of symbols]

[0151] 23 cutting blade 36 Sensors 41 Lifting means 51 Grounding means F Cutting blade part G Cover body H Tail wheel mechanism P control section U ridge

Claims

1. a sensor capable of detecting the height of a ridge at the rear of a cover body that covers an upper portion of a cutting blade unit having a plurality of cutting blades and capable of outputting ridge height information that is information on the detected current ridge height; a tail wheel mechanism disposed at a rear portion of the cover body and capable of adjusting the cutting height of the cutting blade by raising and lowering the tail wheel mechanism while contacting a ground with a grounding means; A lifting means for driving the tail wheel mechanism to lift and lower; a control unit capable of raising and lowering the tail wheel mechanism to output an operation signal to the lifting means when the ridge height information is received, so as to maintain a preset height that is a distance between a cutting blade unit and a top surface of the ridge that is preset in advance; A ridge height adjustment device comprising:

2. the set height includes a threshold range, and when the ridge height information falls outside the threshold range, the control unit operates the lifting means until the ridge height information falls within the threshold range.

2. The device for adjusting ridge height according to claim 1.

3. The control unit operates the lifting means after a preset excess time, which is a preset excess time after receiving the ridge height information, even if the control unit receives the ridge height information other than the set height.

2. The device for adjusting ridge height according to claim 1.

4. The control unit is provided to be switchable between an automatic mode in which the tail wheel mechanism is raised and lowered to automatically maintain the set height when the ridge height information is received, and a manual mode in which the mowing height can be adjusted to any desired height by manual operation by an operator regardless of whether the ridge height information is received.

2. The device for adjusting ridge height according to claim 1.

5. a photographing device that photographs the ridges after work is performed using the cover body and the cutting blade unit at the rear of the cover body and outputs the photographed ridge image to the control unit; a display terminal having a display screen capable of simultaneously displaying the ridge image and the ridge height information by immediately outputting the ridge image and the ridge height information received by the control unit; The device for adjusting ridge height according to any one of claims 1 to 4, further comprising:

6. 6. The device for adjusting height relative to ridges according to claim 5, wherein the photographing device and the sensor are provided at different heights.

7. 6. The device for adjusting height relative to ridges according to claim 5, wherein the photographing device is provided behind the sensor.

8. 6. The device for adjusting height relative to ridges according to claim 5, wherein the photographing device is provided at a position higher than a position where the sensor is provided.

9. 6. The device for adjusting height relative to ridges according to claim 5, wherein the photographing device is attached to a part of the agricultural machine which is stronger than the part where the sensor is attached to the agricultural machine.

10. 6. The device for adjusting height relative to ridges according to claim 5, wherein the tail wheel mechanism comprises a link.

11. The display terminal has an operation unit that can be manually operated on the display screen; The device for adjusting ridge height according to claim 5, further comprising:

12. The operating unit is configured to be able to change the set height even when the cutting blade unit is moving on a ridge. The device for adjusting ridge height according to claim 11.

13. The operation unit is configured to be able to change the threshold range even when the cutting blade unit is moving on a ridge. The device for adjusting ridge height according to claim 11.

14. The operation unit is configured to be able to change the set excess time even when the cutting blade unit is moving on the furrow. The device for adjusting ridge height according to claim 11.

15. The operation unit is provided with a switching operation unit that causes the control unit to switch between and recognize either an automatic mode in which the tail wheel mechanism is raised and lowered to automatically maintain the set height when the ridge height information is received, or a manual mode in which the cutting height can be adjusted to any desired height by manual operation by an operator regardless of whether the ridge height information is received. The device for adjusting ridge height according to claim 11.

16. The operation unit includes a settable overtime adjustment operation unit that changes the set overtime so that the lifting means is operated after a set overtime time that is a preset overtime time after receiving the ridge height information even if the operation unit receives ridge height information other than the set height; and The device for adjusting height relative to ridges according to claim 11, further comprising:

17. A vertical reference line is displayed along the traveling direction in the ridge image projected on the display screen, and a horizontal reference line is displayed along the traveling direction and in the width direction.

6. The device for adjusting ridge height according to claim 5.

18. When the control unit operates the lifting means toward the set height, the control unit causes the display screen to display an operation status indicating an operation direction of the lifting means.

6. The device for adjusting ridge height according to claim 5.

19. The ridge image displayed on the display screen can be manually enlarged or reduced to any desired magnification ratio.

6. The device for adjusting ridge height according to claim 5.

20. The control unit is configured to operate the ridge image displayed on the display screen, so that the control unit can reattempt to receive the ridge image from the imaging device.

6. The device for adjusting ridge height according to claim 5.

21. The display terminal operates the ridge image displayed on the display screen to request the control unit to re-output the ridge image.

6. The device for adjusting ridge height according to claim 5.

22. a sensor capable of detecting the height of a ridge at the rear of a cover body that covers an upper portion of a cutting blade unit having a plurality of cutting blades and capable of outputting ridge height information that is information on the detected current ridge height; a tail wheel mechanism that is disposed at a rear portion of the cover body and that can adjust the cutting height of the cutting blade by raising and lowering the tail wheel mechanism while contacting a ground with a grounding means; A lifting means for driving the tail wheel mechanism to lift and lower; a control unit capable of raising and lowering the tail wheel mechanism to output an operation signal to the lifting means when the ridge height information is received, so as to maintain a preset height that is a distance between a cutting blade unit and a top surface of the ridge that is preset in advance; An agricultural machine having a ridge height adjustment device, comprising:

Images