Weeder

Abstract

To provide a technique to suppress the contact of right and left ends of a weeding device with a paddy field surface or the ground when the weeding device is greatly inclined while the weeding device is not performing weeding.SOLUTION: A weeder includes a traveling vehicle body, a weeding device 20 attached to the traveling vehicle body, a lifting device 30, an inclination adjusting device 40, and an electronic control part 100. The weeding device 20 has a plurality of weeding parts arranged in a right and left direction, and an inclination detection part 52 for detecting an inclination of the weeding device 20. The weeding device 20 is movable to an upper retreat position and a lower weeding position. The electronic control part 100 can execute horizontal control for operating the inclination adjustment device 40 based on a detection result of the inclination detection part 52. The electronic control part 100 automatically executes the horizontal control at the weeding position and can execute the horizontal control even at the retreat position. Thereby, the horizontal control can be performed when the weeding device is not performing weeding (when the weeding device is retreated), and right and left end parts of the weeding device can be prevented from coming into contact with the ground surface or a paddy field surface due to the inclination of the weeder.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a paddy field weeder for removing weeds growing around a plurality of seedlings planted in rows in a paddy field. [Background technology]

[0002] In farm machinery such as weeders and rice transplanters, which have a running body equipped with a work implement for working in fields, the running body and the work implement are connected by a connecting shaft such as a PTO shaft. The height of the work implement is controlled by adjusting the angle of this connecting shaft. In weeders, if the height of the weeding implement, which is the work implement, is not appropriate, sufficient weed control effect cannot be achieved, so height control is important.

[0003] For example, Patent Document 1 discloses a so-called rear-mounted weeder in which a weeding device is connected to the rear of a traveling vehicle body. In the weeder described in Patent Document 1, the up-and-down movement of the weeding device is controlled based on the height of a pair of left and right ground floats that receive ground pressure from the soil surface.

[0004] On the other hand, in the weeder described in Patent Document 1, a pair of left and right ground floats rotate around a support shaft, which is a connecting shaft, due to the ground pressure received from the soil surface, and horizontal control is performed to keep the weeding device horizontal by adding a corrective action from a pair of left and right balance springs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-343066 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, conventional mechanical horizontal control is based on the height of the float that contacts the rice field surface, and is therefore only possible when the weeding device is lowered to the weeding position. However, when the weeding device is retracted upward, there is a risk that the left and right ends of the weeding device may come into contact with the rice field surface if the weeding device tilts significantly during rotation, etc.

[0007] The present invention has been developed in consideration of these circumstances, and aims to provide a technology that prevents the left and right ends of a weeding device from coming into contact with the ground or the surface of a rice field when not weeding (when the weeding device is retracted). [Means for solving the problem]

[0008] In order to solve the above problems, the first invention of the present application is a self-propelled weeder for removing weeds that have grown in paddy fields where seedlings have been planted in rows, the weeding machine comprising: a traveling body having front and rear wheels; a weeding device attached to the traveling body and rotatable about a rotation axis extending in the front-rear direction; a lifting device for changing the height of the weeding device relative to the traveling body; an inclination adjusting device for adjusting the left-right inclination of the weeding device relative to the traveling body; and an electronic control unit for controlling the inclination adjusting device, wherein the weeding device comprises a plurality of weeding units arranged in the left-right direction; and an inclination detection unit that detects the left-right inclination of the weeding device relative to the horizontal direction, the weeding device being movable to an uppermost retracted position and a weeding position lower than the retracted position, the electronic control unit being capable of performing horizontal control that operates the inclination adjustment device so that the multiple weeding units are approximately horizontal based on the detection result of the inclination detection unit, the electronic control unit automatically performing the horizontal control when the weeding device is in the weeding position, and also being capable of performing the horizontal control when the weeding position is in the retracted position.

[0009] A second aspect of the present invention is the weeder of the first aspect of the present invention, further comprising an ON-OFF switch for inputting execution and stop of the horizontal control to the electronic control unit.

[0010] The third invention of the present application is a weeder according to the first invention, wherein the electronic control unit automatically stops the horizontal control when the operation of the tilt adjustment device, which is based on the detection result of the tilt detection unit, has elapsed for a predetermined time while the horizontal control is being performed and there is no change in the detection result of the tilt detection unit.

[0011] The fourth invention of the present application is a weeder according to the first invention, wherein the weeding device has an output section arranged at a distance from the pivot shaft in the left-right direction, and the tilt adjustment device has an input end that can change the height of the input end relative to the running vehicle body, and a damper spring having one end connected to the input end and the other end connected to the output section.

[0012] The fifth invention of the present application is a weeder of the fourth invention, wherein the damper spring comprises a coil spring, a rod having one end fixed to the input end of the input section and passing through the coil spring, an output member having the other end fixed to the output section of the weeding device, a first plate that contacts one end of the coil spring and moves to the other side relative to the output member when the damper spring contracts, and a second plate that contacts the other end of the coil spring and moves to one side relative to the output member when the damper spring expands.

[0013] The sixth invention of the present application is a weeder according to the fourth invention, wherein the input unit has a motor fixed to the running body and operated by a control signal from the electronic control unit, and a rotating member having the input end that rotates around a rotation axis fixed to the running body by the motor and moves up and down as it rotates.

[0014] The seventh invention of the present application is a weeder of the first invention, wherein the weeding device further has a float whose underside contacts the soil surface and a height detection unit that detects the height of the float, and the electronic control unit is capable of performing height control to operate the lifting device so that the height of the weeding device relative to the soil surface is within a predetermined range based on the detection result of the height detection unit.

[0015] The eighth invention of the present application is a weeder according to the seventh invention, wherein the lifting device has a link extending in the longitudinal direction and having a rear end rotatably fixed to the running body, an electromagnetic valve that operates in response to a control signal from the electronic control unit, and a hydraulic cylinder that expands and contracts in response to operation of the electromagnetic valve, thereby changing the angle of the link.

[0016] A ninth aspect of the present invention is the weeder of any one of the first to eighth aspects, wherein the weeding device is attached to the traveling vehicle body between the front wheels and the rear wheels. [Effects of the Invention]

[0017] According to the first to ninth inventions of the present application, horizontal control is enabled by electronic control when the weeding device is retracted, thereby preventing the left and right ends of the weeding device from coming into contact with the ground or the surface of the rice field if the weeding device tilts when the weeding device is retracted.

[0018] In particular, according to the second aspect of the present invention, horizontal control can be manually turned on or off.

[0019] In particular, according to the third aspect of the present invention, when the weeding device is tilted due to an unintended external factor and the tilt cannot be corrected by the tilt adjustment device, the tilt adjustment device can be prevented from continuing to operate.

[0020] In particular, the ninth aspect of the present invention is particularly useful in mid-mounted weeding devices, since the frame of the traveling vehicle body is located above the weeding device and the weeding device cannot be retracted to a very high position. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a perspective view of the weeding device as seen from the rear side. [Figure 6] 1A and 1B are front and rear views of a tilt adjustment device. [Figure 7] FIG. [Figure 8] FIG. 2 is a control block diagram relating to height control and horizontal control of the weeder. DETAILED DESCRIPTION OF THE INVENTION

[0022] Preferred embodiments of the present invention will be described below with reference to the drawings. In this application, the traveling direction of the weeding machine is referred to as the "forward direction," and the direction opposite to the traveling direction of the weeding machine is referred to as the "rearward direction." In this application, the up-down direction is defined according to the posture of the weeding machine when in use. In addition, the direction that is horizontal and perpendicular to the forward-backward direction when the weeding machine is in the posture of use is referred to as the left-right direction.

[0023] 1. First Embodiment <1-1. Overview of weeder> Fig. 1 is a side view of a weeder 1 according to this embodiment. Fig. 2 is a front view of a weeding device 20. This weeder 1 is a device for removing weeds that grow around seedlings planted in rows in paddy fields. As shown in Fig. 1, the weeder 1 has a traveling vehicle body 10, a weeding device 20, a lifting device 30, an inclination adjustment device 40, and an electronic control unit 100.

[0024] The traveling vehicle body 10 is a riding vehicle body including a main frame 11, front wheels 12, rear wheels 13, an operating unit 14, a driver's seat 15, and a traveling power mechanism 16. The main frame 11 is supported by the front wheels 12 and the rear wheels 13.

[0025] In this embodiment, the traveling body 10 is a tricycle having one front wheel 12 and two rear wheels 13. The front wheel 12 is located at the front center of the traveling body 10. The rear wheels 13 are located at the rear of the traveling body 10 with a gap between them on the left and right. The left-right distance between the front wheel 12 and the left rear wheel 13, and the left-right distance between the front wheel 12 and the right rear wheel 13, are each set to a distance that allows the weeder to straddle seedlings planted in rows in a field. The weeder of the present invention is not limited to a tricycle. For example, it may be a four-wheeled vehicle having two front wheels and two rear wheels.

[0026] An engine mechanism, for example, is used as the traveling power mechanism 16. The front wheels 12 and rear wheels 13 of this embodiment are each connected to the traveling power mechanism 16 via a power transmission mechanism (not shown). In other words, the weeder 1 of this embodiment is an all-wheel drive vehicle in which all wheels are driven by power. As a result, when the traveling power mechanism 16 operates, the front wheels 12 and rear wheels 13 rotate, causing the weeder 1 to travel.

[0027] The front wheels 12 are supported so as to be rotatable in the left and right directions relative to the traveling direction of the traveling vehicle body 10. The rotation direction of the front wheels 12 is controlled by operating an operating unit 14.

[0028] The operating unit 14 and the driver's seat 15 are provided in the center of the rear of the traveling body 10. The weeding machine 1 of this embodiment is a so-called mid-mounted weeding machine in which the weeding device 20 is disposed between the front wheels 12 and the rear wheels 13. Providing the driver's seat 15 at the rearmost part of the traveling body 10 makes it easy for the operator to monitor the traveling direction of the weeding machine 1 and the weeding work. While seated in the driver's seat 15, the operator operates each part of the operating unit 14 as needed to switch the traveling direction between forward and backward, switch the traveling speed, and perform the lifting and lowering operation of the lifting device 30, and performs the weeding work.

[0029] The weeding device 20 is a component that removes weeds that grow in the field. The weeding device 20 is attached to the traveling body 10 between the front wheels 12 and the rear wheels 13 via a lifting device 30. The weeding device 20 is rotatable about a rotation axis X1 that is provided near the center in the left-right direction and extends in the front-rear direction. When the weeding device 20 rotates about the rotation axis X1, the height of the right and left sides of the weeding device 20 changes. The detailed configuration of the weeding device 20 will be described later.

[0030] The lifting device 30 is a device for changing the vertical position (height) of the weeding device 20 relative to the traveling vehicle body 10. This allows the weeding device 20 to change its height relative to the field. When weeding is to be performed, the lifting device 30 moves the weeding device 20 downward and places it in the weeding position. When weeding is not to be performed, the lifting device 30 moves the weeding device 20 upward and places it in a retracted position above the weeding position. In Figures 1 and 2, the weeding device 20 is placed in the retracted position.

[0031] The inclination adjustment device 40 is a device for adjusting the left-right inclination of the weeding device 20 relative to the traveling body 10. Specifically, the inclination adjustment device 40 changes the angle of the weeding device 20 relative to the traveling body 10 in the horizontal direction by rotating the weeding device 20 about the rotation axis X1 relative to the traveling body 10. The detailed configuration of the inclination adjustment device 40 will be described later.

[0032] The electronic control unit 100 electrically controls the lifting device 30 and the inclination adjustment device 40. Specifically, the electronic control unit 100 operates the lifting device 30 and the inclination adjustment device based on operation commands input from the operation unit 14 and the detection results of the height detection unit 51 and the inclination detection unit 52 provided in the weeding device 20. The control of the height detection unit 51 and the inclination detection unit 52 by the electronic control unit will be described in detail later.

[0033] <1-2. Overview of the weeding device> The weeding device 20 is a device that removes weeds that grow in a field. Fig. 3 is a front view of the weeding device 20. Fig. 4 is a side view of the weeding device 20. Fig. 5 is a perspective view of the weeding device 20 as seen from the rear. As shown in Figs. 3 to 5, the weeding device 20 of this embodiment has a connection part 201, a frame 202, two floats 21, nine weed dividing plates 22, nine inter-row rotors 23, eight sets of oscillating teeth 24, and nine rotor mark leveling plates 25. In this weeding device 20, the inter-row rotors 23 weed between two adjacent rows of seedlings (between rows), and the oscillating teeth 24 weed around the seedlings (between plants).

[0034] The connection part 201 is connected to a parallel link 31 (described later) of the lifting device 30. Specifically, the front end part of the parallel link 31 supports the connection part 201. As a result, the weeding device 20 is supported by the lifting device 30 and attached to the traveling body 10.

[0035] The frame 202 is attached to the connecting part 201 so as to be rotatable about a rotation axis X1 located approximately in the center of the weeding device 20 in the left-right direction. The two floats 21 are attached so as to be movable in the height direction within a certain range relative to the frame 202. Furthermore, the nine grass dividing plates 22, nine row-to-row rotors 23, eight sets of oscillating teeth 24, and nine rotor mark leveling plates 25 do not move in the height direction relative to the frame 202 during weeding work. Furthermore, the weeding device 20 has a height detection unit 51 and an inclination detection unit 52.

[0036] The float 21 is a mechanism for detecting the height of the soil surface in the field. During weeding, the float 21 contacts its underside with the soil surface and receives pressure from the soil surface. The float 21 is mechanically connected to a height detection unit 51. In this embodiment, the height detection unit 51 is a potentiometer. By detecting the position of the float 21 relative to the frame 202, the height detection unit 51 can detect the positional relationship between the inter-row rotor 23 and oscillating teeth 24, which perform weeding in the weeding device 20, and the soil surface.

[0037] The detection result of the height detection unit 51 is input to the electronic control unit 100. As a result, the electronic control unit 100 operates the lifting device 30 according to the height of the field detected by the float 21, and positions the weeding device 20 at an appropriate height. In this embodiment, the two floats 21 are arranged in front of the two inter-row rotors 23 adjacent to the central inter-row rotor 23 on the left and right of the nine inter-row rotors 23 lined up on the left and right.

[0038] In this embodiment, the float 21 is positioned forward of the inter-row rotor 23 and the oscillating teeth 24. This allows the height of the soil surface in the field to be detected quickly and the height of the inter-row rotor 23 and the oscillating teeth 24 to be adjusted. Therefore, the depth at which the inter-row rotor 23 and the oscillating teeth 24 act on the field surface can be set to a desired depth, thereby improving the weed-killing effect of the inter-row rotor 23 and the oscillating teeth 24.

[0039] The grass dividing boards 22 are boards that prevent the leaves of seedlings planted in rows from spreading left and right. The grass dividing boards 22 are positioned in front of the nine row-to-row rotors 23 that are lined up in the left-right direction. Each grass dividing board 22 has a front board 221 that extends perpendicular to the front-to-rear direction, i.e., in the left-to-right and up-to-down directions, and two side boards 222 that extend diagonally rearward from the left and right ends of the front board 221. The side boards 222 are positioned so that they spread left and right from the front board 221 as they move rearward. Note that the grass dividing board 22 positioned at the extreme end in the left-to-right direction has only one side board 222 on the center side in the left-to-right direction. In other words, the rightmost grass dividing board 22 has a side board 222 only on the left side, and the leftmost grass dividing board 22 has a side board 222 only on the right side.

[0040] As a result, when the leaves of seedlings planted in the field are spread out in the left-right direction, the side plates 222 of the grass dividing board 22 come into contact with the leaves of the seedlings and gather the leaves toward the center of the seedlings. As a result, the leaves of the seedlings spread out in the left-right direction come into contact with the inter-row rotor 23, and the seedlings are prevented from being pulled out of the field.

[0041] The grass dividing board 22 has a water passage hole 223 at the bottom center of the front board 221. This reduces the resistance caused by the grass dividing board 22 and also prevents soil and algae from accumulating in front of the grass dividing board.

[0042] The inter-row rotors 23 weed between the rows of planted seedlings. The nine inter-row rotors 23 are arranged at equal intervals in the left-right direction so that they are positioned between the rows of planted seedlings. Each inter-row rotor 23 has multiple weeding claws 231.

[0043] When power is input from the traveling power mechanism 16 to the weeding device 20, the power is transmitted to the inter-row rotor 23, causing the inter-row rotor 23 to rotate. At this time, the inter-row rotor 23 is driven to rotate forward (in the same direction as the front wheels 12 and rear wheels 13 when moving forward) around a horizontal rotation axis extending left and right. The weeding claws 231 scrape the soil surface between the rows of the field, thereby scraping weeds that have grown between the rows from the soil. Weeds scraped by the inter-row rotor 23 and floating near the water surface can then be picked up or left alone. If left alone, the weeds will subsequently die.

[0044] The oscillating teeth 24 are a mechanism for weeding around the seedlings planted in rows. The weeding device 20 of this embodiment is an eight-row weeding device having eight sets of four oscillating teeth 24. The eight sets of oscillating teeth 24 are arranged at equal intervals in the left-right direction so as to act on the areas around the planted seedlings. The upper ends of each set of oscillating teeth 24 are fixed to a support part 241. Note that the weeding device 20 of this embodiment has four oscillating teeth 24 in one set for one row of plant spacing, but the number of oscillating teeth 24 for one row of plant spacing may be three or less, or five or more.

[0045] As shown in Fig. 3, each of the swing teeth 24 is formed of a wire-like member. The swing tooth 24 has a base 242 that is attached to a support part 241 in a cantilevered manner and extends downward, and an action part 243 that extends rearward while snaking in the vertical direction from the lower end of the base 242. The support part 241 is attached to the main body frame of the weeding device 20 so as to be able to swing.

[0046] The base 242 hangs vertically from the support 241, then bends slightly diagonally downward toward the front, and then further bends significantly diagonally downward toward the rear at the bottom. That is, the base 242 has a V-shape that is convex toward the front when viewed from the left and right. In this way, the oscillating tooth 24 extends in the up-down and front-to-back directions. Meanwhile, as shown in FIG. 4, because the oscillating tooth 24 does not extend in the left-to-right direction, the oscillating tooth 24 does not catch on seedlings growing in the field during weeding work and prevents the seedlings from being pulled out.

[0047] When power is input from the traveling power mechanism 16 to the weeding device 20, the power is converted into left and right reciprocating force and transmitted to the support part 241. This causes the oscillating teeth 24 to oscillate left and right together with the support part 241. As a result, the oscillating teeth 24 oscillate while contacting the soil surface around the seedlings growing in the field, thereby raking out and removing weeds that have grown between the plants and around the seedlings. Weeds raked out by the oscillating teeth 24 and floating near the water surface may be picked up or left, just like weeds raked out by the inter-row rotor 23.

[0048] Each rotor mark leveling plate 25 is disposed behind the inter-row rotor 23. The rotor mark leveling plate 25 is a plate-shaped member that slopes downward toward the rear. The lower surface of the rotor mark leveling plate 25 expands in the left-right direction and slopes downward toward the rear. The lower end of the rotor mark leveling plate 25 is disposed below the lower surface of the float 21. As a result, during weeding work, at least a portion of the lower surface, including the lower end of the rotor mark leveling plate 25, comes into contact with the soil surface of the field.

[0049] As the underside of the rotor mark leveling plate 25 moves forward while contacting the soil surface, the soil surface raked by the inter-row rotor 23 is leveled behind the inter-row rotor 23. This buries weeds that do not rise to the water surface and remain near the soil surface in the soil, thereby improving the weeding effect of the weeding device 20.

[0050] In this embodiment, the oscillating tooth 24 is disposed rearward of the inter-row rotor 23. As a result, the water flow from front to rear that is generated as the inter-row rotor 23 rotates acts on the periphery of the oscillating tooth 24. As a result, the weed-killing effect of the oscillating tooth 24 is enhanced and entanglement of algae and weeds in the oscillating tooth 24 is suppressed.

[0051] Next, the procedure for weeding work will be explained below. First, the operator seated in the driver's seat 15 of the weeder 1 operates the operating unit 14 to align the direction of travel of the weeder 1 with the rows of seedlings in the field, and adjusts the front wheels 12 and rear wheels 13 so that they are positioned between the rows. At this time, the weeding device 20 is positioned in the retracted position.

[0052] Next, the operator operates the operating unit 14 to lower the weeding device 20 and place it in a weeding position at a predetermined height. At this time, the height of the weeding device 20 is finely adjusted by height control using the electronic control unit 100 and the lifting device 30. This brings the inter-row rotor 23, the oscillating teeth 24, and the rotor mark leveling plate 25 into contact with the soil surface. Furthermore, at least while the weeding device 20 is placed in the weeding position, the electronic control unit 100 and the tilt adjustment device 40 control the leveling so that the weeding device 20 is kept level and the difference in height between the left and right sides is reduced.

[0053] After confirming the positions of the inter-row rotor 23 and the oscillating teeth 24 relative to the seedlings in the field, the operator drives the weeding device 20, causing the inter-row rotor 23 to rotate and the oscillating teeth 24 to begin oscillating. The weeder 1 is then moved forward to perform weeding work. In this way, the inter-row rotor 23, the oscillating teeth 24, and the rotor mark leveling plate 25 act to remove weeds that have grown in the field.

[0054] During weeding work, the rotation speed of the inter-row rotor 23, the oscillation speed of the oscillating teeth 24, and the height of the inter-row rotor 23 relative to the soil surface are adjusted taking into account the growth status of the seedlings, the occurrence of weeds and algae, and the depth of water in the field, etc.

[0055] When the weeding machine 1, which is moving forward while performing weeding work, reaches the edge of the field, the drive of the weeding device 20 is stopped and the weeding device 20 is raised to the retracted position. The direction of the weeding machine 1 is then turned and the weeding machine 1 is moved to align with the untreated shoots. At this time, even when the weeding device 20 is raised to the retracted position, horizontal control continues using the electronic control unit 100 and the tilt adjustment device 40. Once the position and direction of the weeding machine 1 are determined, the weeding device 20 is lowered to the weeding position and weeding work begins on the untreated shoots. Thereafter, the same work is repeated to perform weeding work in the field.

[0056] <1-3. Height control in lifting devices> The lifting device 30 has parallel links 31 extending in the front-rear direction, hydraulic cylinders 32, and electromagnetic valves 33. The parallel links 31 are made up of a plurality of plate- or rod-shaped members extending in the front-rear direction. The rear ends of the parallel links 31 are rotatably attached to a gear case 111. The gear case 111 is attached below the main frame 11. The gear case 111 holds the gears therein and also serves as a mounting frame for attaching the parallel links 31. Meanwhile, the weeding device 20 is attached to the front end of the parallel links 31.

[0057] The hydraulic cylinder 32 expands and contracts as oil flows in and out of the hydraulic cylinder 32 through switching operations of the electromagnetic valve 33 by the electronic control unit 100. The electromagnetic valve 33 operates in response to control signals from the electronic control unit 100. The upper end of the hydraulic cylinder 32 is rotatably attached to the main frame 11 of the traveling vehicle body 10. The lower end of the hydraulic cylinder 32 is rotatably attached to the parallel link 31.

[0058] When weeding is performed, the hydraulic cylinder 32 extends to move the weeding device 20 downward and place it in the weeding position. At the weeding position, the electronic control unit 100 adjusts the height of the weeding device 20 in accordance with the detection result of the height detection unit 51. When weeding is not performed, the hydraulic cylinder 32 retracts to move the weeding device 20 upward and place it in a retracted position above the weeding position. In FIG. 1, the weeding device 20 is placed in the retracted position.

[0059] The lifting device 30 of this embodiment also has a power transmission shaft (not shown) for transmitting part of the power of the traveling power mechanism 16 provided on the traveling body 10 to the weeding device 20. Part of the power of the traveling power mechanism 16 is output from an output end provided in the gear case 111 and input to the weeding device 20 via the power transmission shaft.

[0060] <1-4. Level control in tilt adjustment device> The inclination adjustment device 40 is a device that adjusts the left and right inclination of the weeding device 20 relative to the traveling vehicle body 10. The inclination adjustment device 40 operates under the control of the electronic control unit 100 based on the detection results of the inclination detection unit 52 provided in the weeding device 20. Figure 6 shows (a) a rear view and (b) a front view of the inclination adjustment device 40.

[0061] As shown in FIGS. 4 and 5, the tilt detection unit 52 and the tilt adjustment device 40 are attached to the upper part of the frame 202 of the weeding device 20.

[0062] The tilt detection unit 52 is attached along the left-right direction of the upper surface of the frame 202. The tilt detection unit 52 detects the degree to which the upper surface of the frame 202 is tilted relative to the horizontal direction. This detects the degree to which the entire weeding device 20 is tilted relative to the horizontal direction. The tilt detection unit 52 can be any of various horizontal sensors, such as a horizontal sensor that uses a fluid.

[0063] The inclination adjustment device 40 is disposed on one side in the left-right direction of the center of the weeding device 20. In this embodiment, the inclination adjustment device 40 is disposed on the left side of the center of the weeding device 20. As shown in FIG. 6 , the inclination adjustment device 40 has a motor 41, an input gear 42, and a damper spring 43.

[0064] The motor 41 operates in response to a control signal from the electronic control unit 100. The motor 41 has a rotor (not shown) that rotates in accordance with a command from the electronic control unit 100, and an internal gear (not shown) that rotates together with the rotor. The input gear 42 is an "input unit" that can rotate around a gear rotation axis X2. The input gear 42 has a gear portion 421 that extends in a fan shape from the gear rotation axis X2, and a transmission portion 422 that extends from the gear rotation axis X2 to the opposite side of the gear portion 421. The gear portion 421 has gear teeth on its outer edge that mesh with the internal gear of the motor 41. The tip of the transmission portion 422 forms an input end 420 that is connected to one end of the damper spring 43.

[0065] As a result, when the motor 41 rotates, the input gear 42 rotates about the gear rotation axis X2. Therefore, the input end 420 also rotates about the gear rotation axis X2, and the position of the input end 420 in the up-down direction moves. In other words, the height of the input end 420 relative to the traveling body 10 can be changed. Here, the motor 41 and the input gear 42 are fixed to the connection part 201 of the weeding device 20. Therefore, when the lifting device 30 is not operating, the motor 41 and the input gear 42 can change the height of the input end 420 relative to the traveling body 10.

[0066] The damper spring 43 connects the input end 420 of the input gear 42 and the output portion 203 of the frame 202. The output portion 203 is a portion of the frame 202 that is fixed to the output member 66. The output portion 203 is disposed at a distance in the left-right direction from the rotation axis X1.

[0067] One end of the damper spring 43 is rotatably connected to the input end 420 of the input gear 42. The other end of the damper spring 43 is connected to the output part 203. Therefore, the damper spring 43 transmits the up and down movement of the input end 420 of the input gear 42 to the output part 203. This causes the frame 202 to rotate around the rotation axis X1. Therefore, the left-right tilt of the entire weeding device 20 changes.

[0068] Based on the detection result of the tilt detection unit 52, the electronic control unit 100 controls the motor 41 to rotate so as to keep the weeding device 20 parallel. At this time, the elastic force of the damper spring 43 gently transmits the vertical movement of the input end 420 to the output unit 203, thereby preventing the weeding device 20 from rattling due to impact when adjusting the difference in height between the left and right sides of the weeding device 20.

[0069] Fig. 7 is a cross-sectional view of the damper spring 43. As shown in Fig. 7, the damper spring 43 has an outer cylinder 61, a rod 62, a coil spring 63, a first plate 64, a second plate 65, and an output member 66. Here, the outer cylinder 61, the rod 62, and the coil spring 63 are arranged around a central axis X3 indicated by a dashed line in Fig. 7. In the direction along this central axis X3, the side of an input connection portion 601 (described later) is referred to as one side, and the side of an output connection portion 602 is referred to as the other side.

[0070] The outer cylinder 61 is a cylindrical member extending along the central axis X3. A part of the rod 62, a coil spring 63, a first plate 64, and a second plate 65 are housed inside the outer cylinder 61. The outer surface on the other side of the outer cylinder 61 is fixed to an output member 66.

[0071] An annular first locking portion 611 is provided at the opening at one end of the outer tube 61. The first locking portion 611 prevents the first plate 64 from coming out from inside the outer tube 61 to one side. An annular second locking portion 612 is provided at the opening at the other end of the outer tube 61. The second locking portion 612 prevents the second plate 65 from coming out from inside the outer tube 61 to the other side.

[0072] The rod 62 is a generally columnar member extending along the central axis X3. One end of the rod 62 is an input connection portion 601. The input connection portion 601 is rotatably fixed to the input end 420 of the input gear 42, which is the input portion.

[0073] The rod 62 has a columnar main body 620 that penetrates the coil spring 63, a first protrusion 621 provided on one side of the main body 620, and a second protrusion 622 provided on the other side of the main body 620. Both the first protrusion 621 and the second protrusion 622 protrude radially outward from the main body 620.

[0074] Both the first plate 64 and the second plate 65 are disk-shaped members having a through-hole in the center. The through-hole of the first plate 64 is sized to allow the main body 620 of the rod 62 to pass through but not the first protrusion 621. The through-hole of the second plate 65 is sized to allow the main body 620 of the rod 62 to pass through but not the second protrusion 622.

[0075] Therefore, the first plate 64, the coil spring 63 and the second plate 65 are arranged in sequence from one side to the other between the first locking portion 611 and the second locking portion 612 of the outer tube 61 and between the first protrusion 621 and the second protrusion 622 of the rod 62.

[0076] 7 shows the damper spring 43 in an unloaded state where neither expansion nor contraction force is applied. When the damper spring 43 is in an unloaded state, the coil spring 63 is in a natural state or a slightly contracted state. When the damper spring 43 is in an unloaded state, the first plate 64 contacts one end of the coil spring 63, and the second plate 65 contacts the other end of the coil spring 63.

[0077] When the weeding device 20 is tilted with the left side up and the right side down relative to the horizontal, the electronic control unit 100 operates the motor 41 to move the input end 420 downward. At this time, as shown by the dashed arrow in Figure 6(a), the input gear 42 rotates counterclockwise as viewed from the rear in accordance with the rotation of the motor 41, and the input end 420 moves downward.

[0078] As a result, the input connection portion 601 of the damper spring 43 is pulled downward, the damper spring 43 contracts, and the rod 62 moves to the other side. As a result, the first plate 64 is moved to the other side by the first protrusion 621, and the coil spring 63 contracts. In other words, when the damper spring 43 contracts, the first plate 64 moves to the other side relative to the output member 66.

[0079] Thereafter, as the coil spring 63 expands toward its natural state, the coil spring 63 pushes the second plate 65 toward the other side, and the second plate 65 pushes the second locking portion 612 toward the other side, causing the outer cylinder 61 and the output member 66 to move toward the other side. As a result, the input connection portion 601 moves downward, and then the output connection portion 602 of the output member 66 moves downward gradually. That is, after the input end 420 moves downward, the output portion 203 of the frame 202 moves downward gradually, pushing down the left side of the weeding device 20 and easing the inclination.

[0080] When the weeding device 20 is tilted with the right side up and the left side down relative to the horizontal, the electronic control unit 100 operates the motor 41 to move the input end 420 upward. At this time, the input gear 42 rotates clockwise as viewed from the rear in accordance with the rotation of the motor 41, and the input end 420 moves upward.

[0081] As a result, the input connection portion 601 of the damper spring 43 is pulled upward, the damper spring 43 expands, and the rod 62 moves to one side. As a result, the second plate 65 is moved to one side by the second protrusion 622, and the coil spring 63 contracts. In other words, when the damper spring 43 expands, the second plate 65 moves to one side relative to the output member 66.

[0082] Thereafter, as the coil spring 63 expands toward its natural state, the coil spring 63 pushes the first plate 64 toward one side, and the first plate 64 pushes the first locking portion 611 toward one side, causing the outer cylinder 61 and the output member 66 to move toward one side. As a result, the input connection portion 601 moves upward, and then the output connection portion 602 of the output member 66 moves upward gently. That is, after the input end 420 moves upward, the output portion 203 of the frame 202 moves upward gently, the left side of the weeding device 20 is lifted, and the inclination is alleviated.

[0083] In conventional weeders, horizontal control generally uses two tension springs, one on the left and one on the right, as shock absorbing means provided between the travel unit and the weeding device. In this case, when one of the left and right sides of the weeding device is lifted, one of the tension springs is compressed and the other is extended. Furthermore, when the other of the left and right sides of the weeding device is lifted, the other tension spring is compressed and one of the tension springs is extended.

[0084] In contrast, in this embodiment, by using damper springs 43 that are compressed by both pushing and pulling loads, the coil spring 63, which is an internal elastic body, is compressed whether the damper spring 43 itself is compressed or stretched. Therefore, even if damper springs 43 are arranged on only one side, shock can be absorbed stably. As a result, by reducing the number of parts, costs can be reduced and the number of work processes during manufacturing can be reduced.

[0085] In addition, the electronic control unit 100 can perform horizontal control using the tilt adjustment device 40 not only when weeding and the weeding device 20 is placed in the weeding position, but also when not weeding and the weeding device 20 is placed in the retracted position.

[0086] The operation unit 14 is provided with an ON-OFF switch (not shown) that inputs execution and stop of horizontal control to the electronic control unit 100. Furthermore, during execution of horizontal control, the electronic control unit 100 automatically stops horizontal control if there is no change in the detection result of the tilt detection unit 52 after a predetermined time has elapsed since the operation of the tilt adjustment device 40, which is performed based on the detection result of the tilt detection unit 52.

[0087] When the weeding device 20 is in the weeding position, if one of the left or right ends of the weeding device 20 becomes buried in mud or runs up onto a ridge, or when the weeding device 20 is in the retracted position, if one of the left or right ends runs up onto an obstacle such as a rock or another device, it may be difficult to correct the tilt of the weeding device 20 even when level control is performed.

[0088] In such a case, if the horizontal control is continued, the inclination adjustment device 40 will continue to operate in an attempt to rotate the weeding device 20 in the same direction, which may actually cause a malfunction. In this way, when the weeding device 20 is tilted due to an unintended external factor and the inclination cannot be corrected by the inclination adjustment device, the horizontal control can be stopped manually with the ON-OFF switch or automatically, thereby preventing the inclination adjustment device 40 from continuing to operate.

[0089] <1-5. Effects of the weeder of this embodiment> The configuration of the weeder 1 according to this embodiment has been described above. The effects of the weeder 1 according to this embodiment will now be described.

[0090] In conventional mechanical height and level control, the float mechanically operates the lifting device, resulting in insufficient float tracking on the rice field surface. Specifically, if level control is performed using the ground pressure from the soil surface of components that come into contact with the soil, such as floats, when the load during weeding increases due to the resistance of mud in the field, the rotational reaction force of the connecting shaft to the weeding device also increases. This can cause one side of the weeding device to float up, making it unable to maintain sufficient levelness and reducing the weeding effect. In contrast, the weeder 1 uses electronic height and level control to improve paddy field tracking.

[0091] Furthermore, conventional mechanical level control is performed based on the height of the float that contacts the rice field surface, and is therefore only performed when the weeding device is lowered to the weeding position. In contrast, the weeder 1 performs level control electronically, allowing level control even when not weeding (when the weeding device is retracted). This prevents the left and right ends of the weeding device 20 from contacting the ground or the rice field surface if the weeder 1 tilts when not weeding. In particular, the weeder 1 of this embodiment is a so-called mid-mounted weeder 1 in which the weeding device 20 is located between the front wheels 12 and rear wheels 13 of the traveling body 10. This mid-mounted weeder 1 is particularly useful because the frame of the traveling body 10 is located above the weeding device 20, and the weeding device cannot be retracted to a very high position.

[0092] Furthermore, in the mid-mounted weeder 1, the length of the weeding device 20 in the front-to-rear direction is limited. However, the inter-row rotor 23 needs to have a certain width or more in the left-to-right direction to effectively weed between the rows. Furthermore, the float 21 needs to have a certain width or more in the left-to-right direction to stably detect the height of the soil surface. For this reason, it is difficult to arrange the float 21 and the inter-row rotor 23 so that they overlap in the left-to-right direction. Furthermore, the float 21 is preferably arranged in front of the inter-row rotor 23 and the oscillating tooth 24 to arrange the inter-row rotor 23 and the oscillating tooth 24 at an appropriate height.

[0093] Therefore, in this embodiment, the float 21, which has a relatively short length in the front-to-rear direction, is disposed in front of the inter-row rotor 23 and the oscillating teeth 24. Specifically, the length of the float 21 in the front-to-rear direction is shorter than the length of the inter-row rotor 23 in the front-to-rear direction. This allows the weeding device 20 to be mounted on a mid-mounted weeder 1 without excessively increasing the length of the weeding device 20 in the front-to-rear direction.

[0094] If the length of the float 21 in the front-to-rear direction is shortened, the contact area between the underside of the float 21 and the soil surface becomes smaller, making the weeding device 20 unstable and prone to tilting to the left or right. In particular, the stabilizing effect of the float 21 is small near the oscillating teeth 24, which are positioned away from the float 21. Therefore, in a mid-mounted weeding device 1 such as that of this embodiment, horizontal control by the electronic control unit 100 and the tilt adjustment device 40 is particularly useful.

[0095] Furthermore, the oscillating teeth 24 weed between plants by contacting the soil surface. Therefore, the lower end of the oscillating teeth 24 must be in contact with the soil surface. On the other hand, if the lower end of the oscillating teeth 24 reaches a certain depth below the soil surface, the oscillating teeth 24 become trapped in the soil and become difficult to move. In this case, the oscillating teeth 24 do not oscillate sufficiently, resulting in reduced inter-plant weeding effectiveness. When rolling occurs, the height of the oscillating teeth 24 becomes unstable, and the height of each set of oscillating teeth 24 varies. This results in inconsistent weeding effectiveness for each set of oscillating teeth 24, and the weeding effectiveness of each set also differs. The weeder 1 of this embodiment is an eight-row weeder and is long in the left-right direction. Therefore, compared to two-row or four-row weeders, the height difference between the left and right ends of the weeding device 20 due to rolling is greater. Therefore, horizontal control using the electronic control unit 100 and the tilt adjustment device 40 is particularly useful for multi-row weeders, such as six-row or eight-row weeders.

[0096] <2. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0097] The weeder in the above embodiment is a so-called mid-mounted weeder in which the weeding device is provided between the front and rear wheels, but the present invention is not limited to this. The weeder may be a so-called front-mounted weeder in which the weeding device is provided in front of the front wheels, or a so-called rear-mounted weeder in which the weeding device is provided behind the rear wheels.

[0098] Furthermore, although the weeding machine in the above embodiment is an eight-row weeding machine, the weeding device of the present invention is not limited to eight-row weeding machines. For example, the weeding device of the present invention may be installed in a two-row, four-row, or six-row weeding machine. In this case, the number of inter-row rotors, the number of oscillating teeth, and the number of rotor mark leveling plates may be appropriately changed depending on the number of rows of the weeding machine.

[0099] Furthermore, the detailed configuration of the weeding device may differ from the shape shown in each drawing of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0100] 1: Weeding machine 10: Running vehicle 11: Mainframe 12: Front wheel 13: Rear wheel 20: Weeding device 21: Float 23: Inter-row rotor 24: Oscillating tooth 30: Lifting device 31: Parallel link 32: Hydraulic cylinder 33: Electromagnetic valve 40:Tilt adjustment device 41: Motor 42: Input gear 43: Damper spring 51: Height detection unit 52: Tilt detection unit 61: Outer cylinder 62: Rod 63: Coil spring 64: 1st board 65: 2nd board 66: Output member 100: Electronic control unit 201: Connection part 202: Frame 203: Output section 420: Input terminal 601: Input connection 602: Output connection 611: First locking part 612: Second locking part 620: Main body 621: 1st protrusion 622: 2nd protrusion X1: Rotating axis X2: Gear rotation axis X3: Central axis

Claims

1. A self-propelled weeder that removes weeds that grow in paddy fields where seedlings are planted in rows, a traveling vehicle body having front and rear wheels; a weeding device attached to the traveling vehicle body and rotatable about a rotation axis extending in the front-rear direction; a lifting device for changing the height of the weeding device relative to the traveling vehicle body; an inclination adjustment device for adjusting the left and right inclination of the weeding device relative to the traveling vehicle body; an electronic control unit for controlling the tilt adjustment device; and The weeding device is Multiple weeding units lined up in the left and right direction, an inclination detection unit that detects the inclination of the weeding device in the left-right direction with respect to the horizontal direction; and The weeding device is an uppermost retracted position; a weeding position lower than the retracted position; It is movable to The electronic control unit A horizontal control that operates the inclination adjustment device so that the plurality of weeding units are approximately horizontal based on the detection result of the inclination detection unit. is executable, The electronic control unit When the weeding device is in the weeding position, the horizontal control is automatically performed; The weeder is capable of performing the horizontal control even when the weeding position is in the retracted position.

2. The weeder according to claim 1, An ON-OFF switch for inputting execution and stop of the horizontal control to the electronic control unit The weeder further comprises:

3. The weeder according to claim 1, The electronic control unit, while the horizontal control is being performed, automatically stops the horizontal control if the operation of the tilt adjustment device, which is performed based on the detection result of the tilt detection unit, has elapsed for a predetermined time and there is no change in the detection result of the tilt detection unit.

4. The weeder according to claim 1, The weeding device is an output section disposed at a distance in the left-right direction from the rotation axis; and The tilt adjustment device is an input unit having an input end and capable of changing the height of the input end relative to the traveling vehicle body; a damper spring having one end connected to the input end and the other end connected to the output end; A weeder having:

5. The weeder according to claim 4, The damper spring is A coil spring, a rod having one end fixed to the input end of the input portion and passing through the coil spring; an output member whose other end is fixed to the output portion of the weeding device; a first plate that contacts one end of the coil spring and moves toward the other side relative to the output member when the damper spring contracts; a second plate that contacts the other end of the coil spring and moves to one side relative to the output member when the damper spring is extended; A weeder having:

6. The weeder according to claim 4, The input unit a motor fixed to the vehicle body and operated by a control signal from the electronic control unit; a rotating member having the input end that rotates around a rotation axis fixed to the traveling vehicle body by the motor and moves up and down as the rotation occurs; A weeder having:

7. The weeder according to claim 1, The weeding device is a float whose underside contacts the soil surface; a height detection unit that detects the height of the float; and The electronic control unit a height control unit that operates the lifting device so that the height of the weeding device relative to the soil surface is within a predetermined range based on the detection result of the height detection unit; It is possible to do this with a weeder.

8. The weeder according to claim 7, The lifting device is a link extending in the front-rear direction and having a rear end rotatably fixed to the traveling vehicle body; an electromagnetic valve operated by a control signal from the electronic control unit; a hydraulic cylinder that expands and contracts in response to the operation of the electromagnetic valve to change the angle of the link; A weeder having:

9. A weeder according to any one of claims 1 to 6, The weeding device is attached to the traveling body between the front wheels and the rear wheels.

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