Agricultural implement

Abstract

To provide an agricultural implement capable of performing ground levelling work appropriately even when an advancing speed is increased though its ground levelling body is energized upward.SOLUTION: An agricultural implement includes: a ground levelling body capable of levelling a work surface by rotating up and down on a machine body rear side; a first link rotatably provided by connecting one end part to a turning fulcrum positioned above the ground levelling body; a second link rotatably connected to the other end of the first link, and turnably connected to the upper part of the ground levelling body; and an inter-link elastic body for giving energizing force to energize the ground levelling body upward by being laid on the first link and the second link. The inter-link elastic body gradually decreases the energizing force as the ground levelling body turns upward.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] The present invention relates to an agricultural work machine, and more particularly to an agricultural work machine capable of leveling mud, soil clods, etc. in a farm field. [Background technology]

[0002] Patent Document 1 discloses a leveling plate pressure adjustment device for a tilling machine. This tilling machine has a first leveling body and a second leveling body located at the rear of the shield cover, and the second leveling body is pivoted by a support arm pivoted to the machine body and a support rod pivoted to the support arm. Between the support arm and the support rod, there is an elastic body that urges the second leveling body in the pulling direction when it is in the leveling position. The above structure reduces the load on the leveling plate (second leveling body) without significantly changing the load on the leveling plate, thereby achieving the purpose of improving leveling performance even in light soil. In other words, it is a technology that does not allow the leveling plate to sink too deeply into the soil of the field. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Application No. 2001-231306 Summary of the Invention [Problem to be solved by the invention]

[0004] The leveling plate of the tilling machine levels the muddy water by moving forward while touching the muddy water, but as the moving speed increases, the relative speed between the leveling plate and the muddy water below the plate also increases. As the relative speed increases, the leveling plate, which acts as a soil leveling body, receives an upward repulsive force from the muddy water. At this time, the leveling plate of Patent Document 1 is biased upward, and the force with which it can hold down the field surface made of muddy water decreases, which causes a problem of reduced leveling.

[0005] The present invention has been made with the above-mentioned problems in mind, and aims to provide an agricultural working machine that can properly level the ground even when the traveling speed increases, while urging the leveling body upward. [Means for solving the problem]

[0006] One aspect of the present invention to achieve the objective is an agricultural machine comprising a leveling body capable of leveling a working surface by rotating up and down on the rear side of the machine body, a first link having one end connected to a pivot point located above the leveling body so as to be rotatable, a second link rotatably connected to the other end of the first link and also rotatably connected at the top of the leveling body, and an inter-link elastic body that spans the first link and second link to provide a biasing force to bias the leveling body upward, wherein the inter-link elastic body gradually reduces its biasing force as the leveling body rotates upward. Effect of the Invention

[0007] According to the present invention, it is possible to provide an agricultural work machine that can properly perform ground leveling even when the traveling speed increases, while urging the ground leveling body upward. [Brief description of the drawings]

[0008] [Figure 1] 1 is a front view showing an embodiment of an agricultural machine according to the present invention. [Diagram 2] FIG. 2 is a right side view of FIG. [Diagram 3] FIG. 2 is an enlarged plan view of a main part of FIG. [Figure 4] FIG. 4 is a front view of the main part of FIG. 3. [Figure 5A] FIG. 2 is an enlarged side view of the main part of FIG. 1, showing a state in which the swing arm is located in a regulated range. [Figure 5B] This is an enlarged side view of the main parts of Figure 1, showing the tilling preparation state in which the swing arm is positioned at the first posture maintenance point in the posture maintenance section. [Figure 5C]2 is an enlarged side view of the main part of FIG. 1, showing the state when the swing arm is located at the first attitude maintaining point in the attitude maintaining section and the soil leveling body is performing plowing work. [Figure 5D] This is an enlarged side view of the main parts of Figure 1, showing the tilling preparation state in which the swing arm is positioned at the second posture maintenance point in the posture maintenance section. [Figure 5E] 2 is an enlarged side view of a main portion of FIG. 1, showing the state in which the swing arm is located at the second attitude maintaining point in the attitude maintaining section and the soil leveling body is performing plowing work. [Figure 5F] This is an enlarged side view of the main parts of Figure 1, showing the state in which the swing arm is located at the second posture maintenance point in the posture maintenance section, the soil leveling body is performing plowing work, and the second soil leveling body has rotated upward. [Figure 5G] This is an enlarged side view of the main parts of Figure 1, showing the state in which the oscillating arm is located at the second posture maintenance point in the posture maintenance section, the first and second soil leveling bodies are rotating upward during plowing work on the soil leveling bodies. [Figure 6] FIG. 2 is a front view of the agricultural work machine of FIG. 1 in a folded state. [Figure 7] FIG. 11 is a side view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, the agricultural work machine according to the present invention showing an embodiment will be described in more detail. For convenience, parts having the same functions will be given the same reference numerals and their description will be omitted. Regarding the traveling direction, the left side of the page in Fig. 2, Fig. 5A to Fig. 5G, and Fig. 7 will be described as the forward traveling direction, and the back side of the page in Fig. 1, Fig. 4, and Fig. 6 will be described as the forward traveling direction.

[0010] As shown in Figures 1 to 7, an agricultural work machine 1 according to the present invention comprises a central work body 2, a side work body 3, and a posture control unit 17, and is mounted on the rear of a traveling machine body (not shown) such as a tractor and moves forward to perform work. Each of the work bodies 2, 3 has a machine frame 4 that supports the machine body, a cultivating unit 11 located below the machine frame 4, a cover body 35 that covers the upper part of the cultivating unit 11, land leveling units 31, 33 that can rotate up and down at the rear end of the cover body 35, and a posture control unit 17 that fixes and releases the posture of the land leveling units 31, 33. The posture control unit 17 is operated by remote control.

[0011] The machine frame 4 has a mounting part including top pin 8 and lower pin 9 that are mounted on the traveling body, a transmission unit 89 that obtains power from the traveling body via an input shaft 91 and changes the speed, and a pipe frame 85 that supports the mounting part and the transmission unit 89 and extends to the left and right from the transmission unit 89. In addition to the pipe frame 85, the machine frame 4 can also have a second pipe frame 93 that is positioned in front of the transmission unit 89 and secures support members 99 (described below) to each other. The cover body 35 covers the entire upper part of the tilling unit 11 from the front to the rear and prevents mud from scattering.

[0012] The side working bodies 3 are disposed on both sides of the central working body 2 which is provided in a direction perpendicular to the traveling direction indicated by the arrow, that is, on the left and right sides of the traveling direction of the central working body 2 shown in Fig. 1. The central working body 2 and the side working bodies 3 are attached to a three-point linkage device (not shown) of the traveling machine body by a top pin 8 and a lower pin 9 of a top mast 7. The central working body 2 and the side working bodies 3 have cultivating parts 11 attached below the machine frame 4 so as to be freely rotatable.

[0013] The tilling unit 11 has a rotor shaft 13 arranged to the left and right in the direction of travel, and multiple tines 15 fixed to the rotor shaft 13. The multiple tines 15 are arranged at intervals in both the circumferential and axial directions of the rotor shaft 13. The tilling unit 11 is rotatably supported by a support member 99 arranged at the end of the pipe frame 85, and a chain case provided on the support member 99 on the left side of the central working body 2 transmits rotational power output from the transmission unit 89 to the rotor shaft 13, driving it to rotate. The tilling unit 11 breaks up mud and soil clods with the rotating tines 15. Land leveling bodies 31, 33 are provided behind the tilling unit 11 via a posture control unit 17.

[0014] The cover body 35 covering the top of the tilling section 11 has a vertically rotatable land leveling body 30 at its rear end. The land leveling body 30 is composed of a first land leveling body 31 and a second land leveling body 33. The first land leveling body 31 is provided at the rear end of the cover body 35 so as to be vertically rotatable, and the second land leveling body 33 is provided at the rear end of the first land leveling body 31 so as to be vertically rotatable. The first land leveling body 31 and the second land leveling body 33 each press down the muddy soil after crushing from above, thereby leveling the muddy soil after crushing. The first land leveling body 31 rotates vertically together with the holding plate 32 by a pivot fulcrum 31a provided at the rear end of the cover body 35. The holding plate 32 is a pair of two plate members erected on the upper surface of the first land leveling body 31, and a holding member 69 is loosely fitted to the upper part. The holding member 69 is freely rotatable about a left-right axis relative to the direction of travel. A plurality of rotation fulcrums 31a are provided in the width direction of the first soil leveling body 31. The posture of the first soil leveling body 31 and the second soil leveling body 33 can be fixed and released by the posture control unit 17. The fixed posture state is also called the pile-up state, and the released posture state is also called the puddling state. A rotation fulcrum 33a of the second soil leveling body 33 is provided at the rear end of the first soil leveling body 31.

[0015] The posture control section 17 has a first link 18, a second link 19 and a swing arm 25, and controls the posture of each of the second ground leveling bodies 33 by controlling the posture of each of the first links 18 of the central working body 2 and the side working body 3 separately from the operation of the tilling section 11. As shown in FIG. 5A etc., the front end of the first link 18 is connected to a pivot fulcrum 18a at the top of a link support member 100 provided on the machine frame 4 so as to be vertically rotatable. The rear end of the first link 18 is connected to the second link 19 and is connected to be vertically movable. The upper end of the second link 19 is rotatably connected to the rear end of the first link 18, and the lower end is rotatably connected to the top of the second ground leveling body 33.

[0016] Furthermore, the posture control unit 17 includes an inter-link elastic body 20. The inter-link elastic body 20 biases the first link 18 and the second link 19 to rotate in a direction in which they approach each other, thereby biasing the second leveling body 33 in a direction to rotate upward.

[0017] A guide portion 21 is provided at the bottom of the first link 18. The guide portion 21 comprises a restriction hole 23, which is a hook-shaped hole provided at the bottom of the first link 18, and a posture maintaining portion 24, which is provided in a vertical concave arc or circular arc shape continuing from the restriction hole 23. A swing arm 25 that can rotate about a rotation fulcrum 25a is provided below the first link 18. The upper end of the swing arm 25 can move in the front-rear direction by the rotation fulcrum 25a located at the bottom. An engagement portion 27 that can slide on the guide portion 21 is provided at the upper end of the swing arm 25. The engagement portion 27 is an axis-shaped member that faces left and right in the traveling direction.

[0018] When the engaging portion 27 engages with the restricting hole 23, the rotation of the first link 18 is restricted, and a restricted range C is formed in which the rotation of the first leveling body 31 and the second leveling body 33 is fixed. On the other hand, when the engaging portion 27 engages with the posture maintaining portion 24, the restriction on the rotation of the first leveling body 31 and the second leveling body 33 is released, and a posture maintaining section R is formed in which the posture of the first link 18 does not change.

[0019] The position maintaining section R has a first position maintaining point 24a, which is a restriction release start point on the side closer to the restricted range C, and a second position maintaining point 24b, which is a restriction release end point on the side farther from the restricted range C. The center of the arc of the position maintaining section 24 coincides with the center of rotation of the swing arm 25. Therefore, whether the engaging section 27 is located at the first position maintaining point 24a or the second position maintaining point 24b, the effect of restriction release is basically the same. In other words, as long as the engaging section 27 is located within the range of the position maintaining section R, the position of the first link 18 with which the engaging section 27 abuts does not change within the position maintaining section R, so the second leveling body 33 does not rotate downward and the lower end, which is the operating end, does not fluctuate. This will be described later. The worker decides whether to move the swing arm 25 from the second position maintaining point 24b to the first position maintaining point 24a depending on the degree of unevenness of the field and the degree of crushing of the soil mass.

[0020] As shown in Figs. 5A to 5G, an inclined surface 23a is provided on the lower part of the guide portion 21 below the hook-shaped restriction hole 23. The inclined surface 23a is on the side of the posture maintaining section R of the restriction hole 23, and is a surface that inclines downward from the tip end 23b, which is the open side of the restriction hole 23, toward the rear side. The inclined surface 23a abuts against a stopper piece 28 provided on the swing arm 25. The inclined surface 23a and the stopper piece 28 abut against each other when the engagement portion 27 and the restriction hole 23 engage with each other. The stopper piece 28 is provided on the swing arm 25, and is located below the engagement portion 27.

[0021] When the engaging portion 27 is located in the restricted range C as shown in FIG. 5A, the inclined surface 23a is positioned so as to be sandwiched between the stopper piece 28 and the engaging portion 27. At this time, the stopper piece 28 acts to push up the inclined surface 23a, so that the engaging portion 27 is also pressed into the restricted range C, and the rotation of the first link 18 is fixed. The abutment of the inclined surface 23a with the stopper piece 28 and the engagement of the engaging portion 27 with the restricting hole 23 cooperate to further firmly fix the position of the first link 18. In other words, when the engaging portion 27 is located in the restricting hole 23, the movement of the first leveling body 31 and the second leveling body 33, which are the leveling body 30, is firmly fixed.

[0022] The swinging of the swing arm 25 is driven by an actuator 43. The actuator 43 is composed of a cylinder 43a and has a rod 43b which can move forward and backward. The engagement position between the engagement part 27 and the guide part 21 can be changed at any position in the posture maintaining section R. The actuator 43 is provided with a sensor which detects the stroke amount of the extending and retracting rod 43b. The source of operation of the actuator 43 is electric power in this embodiment, but it may also be hydraulic.

[0023] 5A to 5G, the cylinder 43a is provided with a sensor that detects a maximum value of the most protruding stroke amount of the rod 43b as a protruding position H, a minimum value of the most retracted stroke amount of the rod 43b as a retracted position L, and an intermediate position M that is a point intermediate between the protruding position and the retracted position. This sensor also detects the restricted range C, the first attitude maintaining point 24a that is the restriction release start point of the attitude maintaining section R, and the second attitude maintaining point 24b that is the restriction release end point.

[0024] A restricting protrusion 25b is provided near the pivot fulcrum 25a of the swing arm 25. The restricting protrusion 25b is engageable with a restricting edge 100d provided at the rear lower end of the link support member 100 that fixes the pivot fulcrum 25a. This engagement restricts the swing arm 25 from pivoting. Specifically, it restricts the engagement portion 27 of the swing arm 25 from moving rearward from a state in which the engagement portion 27 is positioned in the restricted range C. The restricting edge 100d can also be said to be located near the pivot fulcrum 31a of the first leveling body 31, and the arrangement of the members is efficient by concentrating the pivot fulcrum 25a, the pivot fulcrum 31a, the restricting edge 100d, and the restricting protrusion 25b.

[0025] In the figure, reference numeral 89 denotes a transmission portion, 91 denotes an input shaft, 93 denotes a second pipe frame, 95 denotes a chain case, 97 denotes a folding fulcrum portion, and 99 denotes a support member.

[0026] Here, the land leveling body 30 will be explained. The first land leveling body 31 and the second land leveling body 33 constituting the land leveling body 30 are provided on the central working body 2 and the side working body 3, respectively, and are provided so that even if the side working body 3 is folded, the land leveling body 30 will also be folded together with the cover body 35 and the tilling section 11. The central working body 2 is provided so that work can be performed in both a stored state in which the side working body 3 is folded, and an unfolded state in which it is unfolded. In the unfolded state, the land leveling performance is improved if the land leveling bodies 31, 33 are connected and move up and down as a unit. When unfolded, the land leveling bodies 31, 33 are connected and integrated by fitting the fitting parts of the respective land leveling bodies 31, 33 together.

[0027] Next, the operation and effects of the above embodiment will be described. In the agricultural work machine 1, rotational power output from a drive source (not shown) via a speed change unit 89 is transmitted to a rotor shaft 13 (shown in FIG. 2, etc.) via a chain case 95 provided on support members 99 (shown in FIG. 1) on both sides of the central working body 2, thereby rotating and driving the tilling unit 11. The tilling unit 11 breaks up mud and soil clods with rotating tines 15. In this embodiment, a chain case 95 is provided on each of the central working body 2 and the side working bodies 3 to drive the tilling unit 11 provided thereon. Alternatively, the chain case 95 may be provided only on the central working body 2, and the tilling unit 11 of the side working body 3 may be driven from the chain case 95 of the central working body 2.

[0028] (Attitude control) The attitude control unit 17 will be described. First, the swing arm 25 of the attitude control unit 17 of the central working body 2 and each side working body 3 is operated to engage the engagement part 27 in the restriction hole 23 of the first link 18 (Fig. 5A). Then, the rear end of the first link 18 is rotated downward, but the rotation is restricted, and the second leveling body 33, which is pushed downward by the second link 19, becomes upright as shown in Fig. 5A. Since the rotation of the first link 18 is restricted and fixed, the second link cannot move either, and the rotation of both the first leveling body 31 and the second leveling body 33, which are freely rotatable, is restricted, and the contact position between the second leveling body 33 and the field is fixed. In this state, the machine travels to perform soil piling work. 5A also shows the position of the engaging part 27 when the side working body 3 is folded or unfolded in this embodiment, and it is possible to fold the side working body 3 having the posture control part 17 and prevent the rotation of the upside-down ground leveling bodies 31, 33. Plowing work is performed after the engaging part 27 is moved from the restricted range C to the unrestricted range R.

[0029] The work performed by the agricultural work machine 1 consists of piling and plowing. Piling is the work of roughly piling up and leveling the soil by moving the agricultural work machine forward while it is inserted into the soil or mud, while plowing is the work of leveling the top surface of the mud in the field. In other words, plowing is the finishing work of leveling the ground.

[0030] The soil piling work is performed when the first soil leveling body 31 and the second soil leveling body 33 are rotated downward and the second soil leveling body 33 reaches the lower end of the rotation direction and is fixed so that it cannot rotate (FIG. 5A). During the soil piling work, the first link 18 is fixed, so that the second soil leveling body 33 and the first soil leveling body 31 are prevented from rotating up and down, and each soil leveling body can work while maintaining its posture. The soil piling work is performed by moving the piled up muddy soil to the sunken field by the soil leveling bodies 31 and 33, and roughly flattening the field. In many cases, the soil piling work is performed before the plowing work using the tilling unit 11, and after the soil piling work, the tilling work is set for the plowing work, and the soil is crushed by the tilling unit 11 and the land is leveled by the soil leveling body 30.

[0031] During the piling work, that is, when the engaging portion 27 is located in the regulated range C, the first link 18 is prevented from rotating, so that the second leveling body 33 is prevented from rotating around the first leveling body 31 side as a fulcrum via the second link 19. At this time, the first leveling body 31 connected to the cover body 35 and the second leveling body 33 is also prevented from rotating up and down. Since the second leveling body 33 and the first leveling body 31 in the regulated range state are fixed with the rear end side facing downward, it becomes easy for the rear end of the second leveling body 33 to be stuck in the soil or mud. If the work machine is moved forward while stuck in the soil or mud, the muddy soil arranged in front of the leveling body can be moved. Even during the piling work, the second leveling body 33 and the first leveling body 31 are prevented from rotating up and down, so that each leveling body can maintain its posture.

[0032] The effects of the inclined surface 23a and the stopper piece 28 will be described in detail. When the engaging portion 27 is moved from the restriction release range R to the restriction range C, the tip 23B is located between the engaging portion 27 and the stopper piece 28. As shown in Figs. 5A to 5G, the vertical width of the tip 23B is smaller than the distance between the engaging portion 27 and the stopper piece 28. Therefore, without adjusting the position of the tip 23B, the engaging portion 27 can be positioned in the restriction range C and the tip 23B can be positioned between the engaging portion 27 and the stopper piece 28 at the same time. Then, as the engaging portion 27 is moved to the restriction range C by the actuator 43, for example, from the state shown in Fig. 5B or Fig. 5D to the state shown in Fig. 5A, the stopper piece 28 pushes up the inclined surface 23a formed continuously from the tip 23B. Then, when the engaging portion 27 moves to the restriction range C, the inclined surface 23a is pressed from both the restriction hole 23 and the stopper piece 28 in the restriction range C so as to be completely sandwiched between them. The first link 18, which is pressed by the engaging portion 27 and the stopper piece 28, is strongly prevented from rotating. The engagement portion 27 moves between the unrestricted range R and the restricted range C while sliding between the unrestricted range R and the restricted range C. That is, the first link 18 moves up and down depending on the swing position of the engagement portion 27.

[0033] The second leveling body 33 in the piled-up state shown in Figure 5A receives a load that rotates it upward. However, because the first link 18 is strongly prevented from rotating, the second link 19 located between the first link 18 and the second leveling body 33 cannot rotate or move either. Therefore, the second leveling body 33 can perform work without slight movement at the rotation fulcrum 33a or the connection with the second link 19. This slight movement is also called "wobble" and can cause wear and vibration, but the inclined surface 23a and the stopper piece 28 can eliminate this wobble.

[0034] The effects of the folding operation, unfolding operation, and the storage position after folding operation will be described below. As described above, the leveling body 30 of the side working body 3 takes the storage position upside down by folding operation. The transition to the storage position is performed by putting the leveling body 30 in a piled-up state, but since the leveling body 30 is fixed integrally with the side working body 3 by the inclined surface 23a and the stopper piece 28, there is no slight movement (wobble) of the connecting part of the second leveling body. Therefore, the causes of wear and vibration during folding and unfolding operations can be eliminated.

[0035] In addition, in the stored position, the leveling body 30 is maintained in the piled-up state. When moving using the traveling body, the inclined surface 23a and the stopper piece 28 prevent slight movement (wobble) of the connecting part. Even if vibrations are generated due to the movement of the traveling body in the stored position, there is no slight movement (wobble) of the connecting part of the second leveling body. In other words, causes of wear and vibration can be eliminated even in the stored position.

[0036] The effects of the restricting protrusion 25b and the restricting edge 100d will be described in detail. During pile-up work in the deployed position, the engaging portion 27 of the swing arm 25 is located in the restricting range C (FIG. 5A). At this time, the upper end of the swing arm 25 in a side view is located rearward of the pivot fulcrum 25a, and the swing arm 25 itself is slightly inclined rearward. The restricting edge 100d engages with the restricting protrusion 25b.

[0037] Consider a case where the traveling machine body moves backwards due to an operator's mistake in operation when performing soil piling work in the soil piling state. At this time, the leveling body 30 including the second leveling body 33 is pushed forward and downward, and the second link 19 is also pulled downward. In conjunction with this, the first link 18 also receives a load that rotates downward. The downward load of the first link 18 is transmitted to the swing arm 25 via the engagement part 27, and the swing arm 25 receives a load that rotates backward. At this time, since the regulating edge part 100d is engaged with the regulating protrusion 25b, the swing arm 25 does not actually rotate backward in the traveling direction. As a result, the rod 43b of the actuator 43 is not subjected to a load in a direction that forcibly extends it, so the actuator 43 can be protected from unintended loads. And the actuator 43 can operate without any influence even after a load that rotates the swing arm 25 backward is applied.

[0038] Also, consider the case where the attitude control unit 17 is arranged on the side working body 3. In the stored attitude of the side working body 3, the leveling body 30 of the side working body 3 moves by the traveling machine body in an upside-down state with soil piled up. At this time, among the vibrations and inertial forces caused by the traveling machine body, the restricting protrusion 25b and the restricting edge portion 100d can prevent the leveling body 30 of the side working body 3 from moving in the direction toward the tilling section 11 of the side working body 3. Therefore, when the attitude control unit 17 is arranged on the side working body 3, the actuator 43 can be protected from unintended loads even in the stored state. Furthermore, the above-mentioned inclined surface 23a and the stopper piece 28 cooperate to suppress the movement of the first link 18, so that the actuator 43 can be further protected.

[0039] The plowing operation will now be described. The swing arms 25 of the central working body 2 and each side working body 3 are operated, and the engagement parts 27 are moved to the position maintaining parts 24 of the first links 18 shown in Fig. 5B. The second leveling body 33 is in a state where its rear end is lifted upward by the first links being pushed up by the engagement parts 27. This state is called the plowing preparation state, and preparations for the plowing operation are made.

[0040] Next, when the agricultural work machine 1 is lowered to insert the tilling unit 11 into the soil, the leveling bodies 31, 33 that are in contact with the field are pushed by the mud and soil and rotate upward, causing the unrestricted first link 18 to rotate further and rise to the position shown in Fig. 5C. Then, the second link 19 rises and changes from an upright state to an inclined state, so that the attitude of the second leveling body 33 becomes horizontal. In this attitude, the machine travels and performs plowing work. In plowing work, the tilling unit 11 is rotated to crush the muddy soil, while the leveling body 30 levels the soil. The crushed muddy soil is prevented from scattering because the cover body 35 covers the upper side to the rear of the tilling unit 11.

[0041] When the engaging portion 27 is located in the position maintaining portion 24, that is, when the engaging portion 27 is in the position maintaining section R, the first link 18 is only prevented from rotating downward, and is not restricted from rotating upward (FIG. 5B). In this plowing state, the second leveling body 33 is prevented from rotating downward around the first leveling body 31 side as a fulcrum. The second leveling body 33 is not prevented from moving upward or rotating around the first leveling body 31 side as a fulcrum. Therefore, the first leveling body 31 can also rotate upward, so the first leveling body 31 and the second leveling body 33 can freely rotate upward. The first leveling body 31 and the second leveling body 33 rotate to press down the top surface of the muddy soil, and the top surface of the muddy soil can be leveled.

[0042] In addition, the rear end of the second soil leveling body 33 in the plowing preparation state is raised higher than the rear end of the second soil leveling body 33 in the soil piling state, and downward rotation is prevented. This position makes it possible to prevent the second soil leveling body 33 from sticking into the soil when the working machine is positioned in the soil to perform plowing work. Therefore, the muddy soil at the beginning of plowing work is not dug up, and the soil can be leveled even more evenly.

[0043] In addition, the inter-link elastic body 20 biases the rear end side of the second soil leveling body 33 upward, so that when the machine body is lowered from the plowing preparation state to start plowing work, the second soil leveling body 33 is biased upward, so that the soil leveling section can be prevented from sinking. Therefore, the inter-link elastic body 20 can contribute to more appropriate soil leveling in the soil leveling section 30.

[0044] In this embodiment, the inter-link elastic body 20 uses a tension spring, and is arranged so as to span the first link 18 behind the guide portion 21 and the middle portion of the resilient 2 link 19. By arranging it in this manner, the first link 18 and the resilient 2 link 19 are biased so as to attract each other, and as a result, the second land leveling body 33 in the plowing state is biased upward. The biasing of the inter-link elastic body 20 will be described in detail later.

[0045] Since the position maintaining portion 24 of the first link 18 is formed in a concave arc shape so that the center of the arc coincides with the center of rotation of the swing arm 25, the relative position of the leveling bodies 31, 33, such as the angle and position, which have reached the lower end in the rotation direction, does not change depending on the engagement position of the engagement portion 27 and the position maintaining portion 24. In other words, regardless of the engagement position of the engagement portion 27 and the position maintaining portion 24, the leveling bodies 31, 33 can be prevented from sticking into the ground. Furthermore, since the second leveling body 33 is biased by the inter-link elastic body 20, it can be prevented from sticking into the ground.

[0046] During plowing work, the engagement portion 27 of the swing arm 25 is positioned at the first attitude maintaining point 24a in the attitude maintaining section R.

[0047] 5D and 5E show a case where the engagement portion 27 of the swing arm 25 moves from the first position maintaining point 24a in the position maintaining section R to the second position maintaining point 24b.

[0048] The downward rotation of the first link 18 is restricted by the engaging portion 27, so the position of the rotation fulcrum 33a when the first ground leveling body 31 rotates downward is also the same, and the posture when it reaches below the second ground leveling body 33 can be formed in the same way. In other words, when the ground leveling bodies 31, 33 are located at the lower end in the rotation direction, the first ground leveling body 31 and the second ground leveling body 33 can always maintain the same position, so that when the ground leveling bodies 31, 33 are grounded on the farmland, a stable grounding state can be created.

[0049] The posture of the first link 18 does not change when it reaches the lower end in the rotation direction while the engaging portion 27 of the swing arm 25 is engaged with the posture maintaining section R, that is, the entire section from the first posture maintaining point 24a to the second posture maintaining point 24b of the posture maintaining section 24. When the engaging portion 27 is in the position where it is engaged with the posture maintaining section R, the first link 18 does not rotate downward from the bottom dead center D.

[0050] The position maintaining portion 24 is formed in a concave arc shape, and the center of the arc coincides with the pivot point of the swinging arm 25. In other words, as long as the engaging portion 27 is located in the position maintaining section R, the position of the first link 18 in the plowing preparation state does not change, and as a result, the lower end of the second soil leveling body 33 that rotates downward does not fluctuate. Therefore, in the plowing preparation state, the magnitude of the force that the second soil leveling body 33 receives from the inter-link elastic body 20 does not change.

[0051] Here, the movement of the first leveling body 31 and the second leveling body 33 will be described when the engaging portion 27 is moved from the restricting hole 23 where the restricted range C is formed to the posture maintaining portion 24 where the unrestricted range, i.e., the posture maintaining section R, is formed. As it moves to the posture maintaining section R, the rear end side of the first link 18 rotates upward, and the second leveling body 33 also rotates upward via the second link 19. When the engaging portion 27 reaches the posture maintaining section R, the restriction on the upward rotation of the first link 18 is released, and the restriction on the rotation of the second leveling body 33 is also released.

[0052] When the swing arm 25 is moved from the restriction release range of the first link 18 to the restriction range C (Fig. 5A), the rear end of the second land leveling body 33 moves downward from the position of the plow preparation state. Conversely, when the swing arm 25 is moved from the restriction range C of the first link 18 to the restriction release range (Figs. 5B, 5D), the rear end of the second land leveling body 33 moves upward from the position of the piled-up state and enters the plow preparation state. As described above, when the second land leveling body 33 is moved up and down, the thrust of the actuator 43 is transmitted to the second land leveling body 33 via the swing arm 25, but the biasing force of the inter-link elastic body 20 can reduce the required thrust of the actuator 43.

[0053] The operation of the soil leveling body 30 in the plowing operation and the effect of the inter-link elastic body 20 will be further explained. As explained above, for example, as shown in Fig. 5C and Fig. 5E, the first soil leveling body 31 and the second soil leveling body 33, which are the soil leveling body 30 in the plowing operation, contact the field surface, which is the work surface, and perform the soil leveling operation by moving up and down while moving forward. In other words, the soil leveling body 30 moves relative to the field surface located below. The field surface in the plowing operation is muddy soil, and the greater the relative speed between the soil leveling body 30 and the field surface, the more the soil leveling body 30 in contact with the field surface receives a repulsive force from the field surface in the upward direction. As the soil leveling body 30 moves up and down, the first link 18 rotates so that the engagement portion 27 of the swing arm 25 moves away from the restriction release range at the bottom of the guide portion 21, and the soil is leveled while moving up and down.

[0054] Using FIG. 5F, the explanation will be given based on the pivot fulcrum 33a of the second ground leveling body 33. The higher the relative speed of the second ground leveling body 33 with respect to the field surface, which is the working surface, the higher the rear end side rises around the pivot fulcrum 33a. In this case, it is considered that the second ground leveling body 33 will not be able to land properly on the ground. At this time, the angle α1 between the second ground leveling body 33 and the first ground leveling body 31 will tend to become smaller than the originally desired angle α0 as shown in FIG. 5E. Then, the second link 19 also rises in conjunction with the first link 18 and pushes up the first link 18. Then, the angle between the first link 18 and the second link 19 becomes smaller, and at the same time, the installation distance of the inter-link elastic body 20 also becomes smaller. In other words, the spring length L1 of the inter-link elastic body 20 shown in FIG. 5F becomes smaller than the spring length L0 of the inter-link elastic body 20 shown in FIG. 5E. Then, the biasing force of the inter-link elastic body 20 weakens, and the upward biasing force of the second ground leveling body 33 also weakens. As a result, the second link 19 rotates downward and can properly touch the ground.

[0055] Using FIG. 5G, the explanation will be given based on the pivot fulcrum 31a of the first leveling body 31. As in the above, the greater the relative speed between the leveling body 30 and the field, the greater the rear end side of the first leveling body 31 rises around the pivot fulcrum 33a as shown in FIG. 5G. The angle α2 between the second leveling body 33 and the first leveling body 31 becomes larger than the originally desired angle α0 as shown in FIG. 5E. On the other hand, since the first leveling body 31 is rising, the second leveling body 33 also rises with respect to the posture control unit 17, and the second link 19 also rises in conjunction with it. Furthermore, the first link 18 connected to the second link 19 is also pushed up. As a result, the angle between the first link 18 and the second link 19 becomes smaller, and the installation distance of the inter-link elastic body 20 also becomes smaller. In other words, the spring length L2 of the inter-link elastic body 20 shown in FIG. 5G becomes smaller than the spring length L0 of the inter-link elastic body 20 shown in FIG. 5E. Then, the biasing force of the inter-link elastic body 20 weakens, and the upward biasing force of the second ground leveling body 33 also weakens. As a result, the second link 19 rotates downward, pressing against the field surface and enabling the ground to be properly leveled.

[0056] In summary, the inter-link elastic body 20 is arranged so that the biasing force gradually decreases as the soil leveling body 30 rises. Therefore, the soil leveling body 30 can be properly grounded on the field surface according to the relative speed between the soil leveling body 30 and the field surface, and the soil leveling work can be properly performed. On the other hand, when the tilling work is started in which the tilling section 11 is gradually buried from the tilling preparation state and the soil leveling body 30 is grounded on the field surface, the second soil leveling body 33, which receives the biasing force of the inter-link elastic body 20, can be properly grounded on the field surface without being buried in the field surface.

[0057] The effect of the inter-link elastic body 20 has been described with the engaging portion 27 shown in Fig. 5E positioned at the second posture maintaining point 24. However, if the engaging portion 27 is positioned within the posture maintaining section R (e.g. Fig. 5B or Fig. 5C), the effect of the reduction in the biasing force accompanying the rise of the leveling body 30 described above remains unchanged.

[0058] In order for the inter-link elastic body 20 to function properly, the positional relationship between the first link 18 and the first leveling body 31 is important. The rotation fulcrum 18a of the first link 18 is located between the machine frame 4 and the rotation fulcrum 31a of the first leveling body 31. It can also be said that the rotation fulcrum 18a is located between the pipe frame 85 and the rotation fulcrum 31a.

[0059] The distance from the pivot 18a of the first link 18 to the pivot 31a of the first leveling body 31 is preferably about 70 to 85% of the distance from the pivot 18a of the first link 18 to the connection point of the first link 18 and the second link 19. In the embodiment, a preferable value of 77% is adopted. In the side view shown in Figs. 5A to 5G, the horizontal distance from the pivot 18a to the pivot 31a is preferably 15 to 35% of the distance from the pivot 18a of the first link 18 to the connection point of the first link 18 and the second link 19. In the embodiment, a preferable value of 25% is adopted. The vertical distance from the pivot 18a to the pivot 31a is preferably 60 to 85% of the distance from the pivot 18a of the first link 18 to the connection point of the first link 18 and the second link 19. In the embodiment, a preferable value of 73% is adopted.

[0060] That is, by arranging the pivot point 18a of the first link 18 close to the pivot point 31a of the first soil cultivating body 31, while biasing the second soil cultivating body 33 upward, the biasing force can be decreased as the soil cultivating body 30 ascends. As a result, regardless of the traveling speed, the soil cultivating body 30 can perform proper soil cultivation, thus further improving the working efficiency.

[0061] The present embodiment has a foldable structure. When the soil cultivating bodies 31 and 33 are rotated downward (Fig. 5A), or when the side working bodies are deployed between the positions shown in Figs. 5B to 5D of the swing arm, it is necessary to align the soil cultivating bodies of the respective working bodies (the first soil cultivating bodies 31 with each other and the second soil cultivating bodies 33 with each other). That is, it is necessary to align the respective soil cultivating bodies 31 and 33 at the same angle and position. In this case, since the positions of the lower ends of rotation of the soil cultivating bodies 31 and 33 formed by the first posture maintaining point 24a and the second posture maintaining point 24b are determined, the inconvenience of alignment caused by the displacement of the positions of the soil cultivating bodies 31 and 33 does not occur. Here, alignment means that in the deployed posture, the first soil cultivating body 31 and the second soil cultivating body 33 of each working body 2 and 3 are joined and aligned at their respective ends so that they can operate integrally.

[0062] Fig. 5C shows that the engaging portion 27 is not at the first posture maintaining point 24a, which represents a state where the second soil cultivating body 33 hits a convex portion of the field and the second soil cultivating body 33 is pushed upward. Also, the lower part of the rotating tilling portion 11 enters the soil to stir and crush the soil, and the first soil cultivating body 31 and the second soil cultivating body 33 are positioned on the soil surface after crushing the soil (in a state of floating on the soil surface, so to speak). In such a case, the first soil cultivating body 31 and the second soil cultivating body 33 are in a pushed-up state, and in conjunction with the movement of each soil cultivating body 31 and 33, the first link 18 performs a rotational movement.

[0063] Fig. 5E shows that the engaging portion 27 is not at the second posture maintaining point 24b, and this is the same as what was described in Fig. 5C.

[0064] Furthermore, comparing Figures 5B and 5D, these figures show that the plowing work can be performed in the same way whether the first attitude is maintained (Figure 5B) or the second attitude is maintained (Figure 5D). In this embodiment, the lower end positions of the ground leveling bodies 31 and 33 in the rotation direction can be made the same, so that the alignment of the ground leveling bodies 31 and 33 when folded can be easily performed.

[0065] The first leveling body 31 and the second leveling body 33, which are arranged as separate bodies on the central working body 2 and the side working body 3, respectively, can operate integrally when they are fitted together so that the second leveling bodies 33 cannot move back and forth or rotate about each other's rotation axis. This means the following. Let us consider a case where the rotation position of the first link 18 is different in the restriction release range depending on the engagement position at the first posture maintaining point 24a and the second posture maintaining point 24b. That is, even if one first link 18 is at the first posture maintaining point 24a and the other is at the second posture maintaining point 24b, the angle of the second ground leveling body 33 is constant, which means that the second ground leveling bodies 33 can be engaged with each other at the same angle and orientation. In other words, the first leveling body 31 and the second leveling body 33 on the side working body 3 and the central working body 2 cannot be interlocked unless they are at the same angle and positional relationship with each other, and if they cannot be interlocked, the leveling performance will decrease.However, in this embodiment, the leveling bodies 31, 33 can be in the same posture (rotation angle) when positioned downward.

[0066] Even if the engaging portion 27 is moved from the first attitude maintaining point 24a to the second attitude maintaining point 24b, the attitude at the bottom dead center D (shown by two-dot chain lines in Figs. 5A, 5C, and 5D) where the first link 18 rotates does not change. Therefore, the attitude of the second soil leveling body 33 before it touches the field surface is constant, and the upward rotation of the soil leveling body is stabilized. Therefore, the soil leveling body 30 can be touched down without damaging the field surface, which is the working surface.

[0067] In this embodiment, the movement of the swing arm 25, that is, the movement from the regulated range C to the position maintaining section R including the first position maintaining point 24a and the second position maintaining point 24b, can be performed by remote control without manual operation by the operator, because the actuator 43 is used. When the swing arm 25 is moved from the position maintaining section R of the first link 18 to the regulated range C, the first link 18 rotates so as to lower downward relative to the position of the bottom dead center D. Therefore, when moving from the plowing preparation state to the soil piling state, only the second soil leveling body 33 rotates downward relative to the first soil leveling body 31. When moving from the soil piling state to the plowing preparation state, the opposite operation is performed, and only the second soil leveling body 33 rotates upward.

[0068] In this embodiment, the folding and unfolding operations shown in Figs. 10 and 11 are possible in the restricted position. The above-mentioned operations can be performed in the folded state. This is because the positions of the first leveling body 31 and the second leveling body 33 are stable even if the side working body 3 is folded upside down. In the above-mentioned embodiment, the engaging portion 27 is positioned in the restricted range C when the side working body 3 is folded or unfolded. However, if a mechanism for preventing the first link 18 from turning is added, the side working body 3 may be folded or unfolded with the engaging portion 27 positioned in the unrestricted range R. In the stored state in this embodiment, the leveling body of the side working body 3 is in a soil-pile state, and the central working body 2 is controlled to be in a plow-preparation position after folding is completed. This prevents the minimum ground clearance from being such that only the leveling body 30 protrudes significantly downward. Furthermore, by setting the soil leveling body 30 in the plowing preparation state, even if the lower part of the soil leveling body 30 unexpectedly comes into contact with an obstacle or the like, the soil leveling body 30 can be prevented from being damaged because the soil leveling body 30 is in a state where it can be rotated upward.

[0069] The manner of installation of the attitude control units 17 and the number of them are arbitrary. As in the above embodiment, the attitude control units 17 may be provided on all the working bodies, or the attitude control units 17 equipped with the actuators 43 may be provided only on the central working body 2 or only on the side working body 3, and the other working bodies may not have the actuators 43. In this case, by providing a linking member that connects the swing arm 25 to which the actuator 43 is connected with a swing arm 25 to which the actuator 43 is not connected with a swing arm 25 by a wire, cable, link device, or the like, it is also possible to operate all the swing arms 25 in the same way with one actuator. In this case, the drive source and the machine body configuration can be simplified.

[0070] Furthermore, the operation of the swing arm 25 of the posture control unit 17 can be linked to other members. For example, the operation of the swing arm 25 within the posture maintaining section R can be used to link with a pressure adjusting unit (not shown). The pressure adjusting unit is a part that adjusts the pressing force of the soil leveling body 30 against the field surface, and by adjusting this, further improvement in soil leveling performance can be expected.

[0071] There is no limit to the number of posture control units 17 that can be installed, and they may be installed only on the central working body 2, or may be grounded only on the side working body 3. Alternatively, they may be grounded on both.

[0072] The actuator may be a motor. By connecting the rotating shaft of the motor so as to drive the swing arm 25 to swing, it becomes possible to move the engaging portion 27 from the restricted range C of the guide portion 21 to abut against the position maintaining section R. Also, by detecting the rotation angle of the rotating shaft of the motor using a sensor, the abutment position of the engaging portion 27 can be detected and grasped. [Industrial Applicability]

[0073] The present invention can be used in agricultural work. [Explanation of symbols]

[0074] 1: agricultural work machine, 2: central work body, 3: side work body, 4: machine frame, 17: attitude control unit, 18: first link, 18a: pivot fulcrum, 19: second link, 20: inter-link elastic body, 21: guide portion, 23: restriction hole, 23a: inclined surface, 23b: tip portion, 24b: attitude maintaining point, 24a: attitude maintaining point, 24: attitude maintaining portion, 25: swing arm, 25a: pivot fulcrum, 25b: restriction protrusion, 27: engagement portion, 28: stopper piece, 30: ground leveling body, 31: first ground leveling body, 31a: pivot fulcrum, 33: second ground leveling body, 33a: pivot fulcrum, 35: cover body, 100: link support member, 100d: restriction edge portion, D: Bottom dead center, L0: Spring length, L1: Spring length, L2: Spring length, α0: Angle, α1: Angle, α2: Angle,

Claims

1. A leveling body that can level the work surface by rotating up and down at the rear of the machine body, A first link is provided rotatably with one end connected to a pivot point located above the leveling body; a second link rotatably connected to the other end of the first link and rotatably connected to an upper portion of the leveling body; and an inter-link elastic body that spans the first link and the second link to provide a biasing force that biases the ground leveling body upward, the inter-link elastic body gradually reduces the biasing force as the leveling body rotates upward; Agricultural machinery characterized by:

2. The leveling body is a first leveling body that is vertically rotatable on the rear side of the machine body and is capable of leveling a work surface; 2. The agricultural machine according to claim 1, further comprising: a second leveling body that is vertically rotatably connected to a rear end of the first leveling body and is capable of leveling a work surface.

3. The pivot point of the first link is located between a machine frame supporting the machine body and a pivot point of the leveling body.

3. The agricultural machine according to claim 1 or 2.

4. The distance between the pivot point of the first link and the pivot point of the leveling body is shorter than the length of the first link.

3. The agricultural machine according to claim 1 or 2.

5. A distance in a front-rear direction between a pivot point of the first link and a pivot point of the leveling body is shorter than a length of the first link.

3. The agricultural machine according to claim 1 or 2.

6. The distance in the vertical direction between the pivot point of the first link and the pivot point of the ground leveling body is shorter than the length of the first link.

3. The agricultural machine according to claim 1 or 2.

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