Disc harrow type tilling machine

Abstract

To improve the work efficiency of tillage depth adjustment work. [Solution] A disc harrow type tilling implement 3 that tills the soil in accordance with the movement of a tractor 1, comprising: a front disc row 5 and a rear disc row 6 that crush soil in accordance with the movement of the tractor 1; a roller 7 positioned behind the rear disc row 6 that rolls on the soil surface to regulate the tilling depth of the front disc row 5 and the rear disc row 6; a hydraulic cylinder 32 that raises and lowers the roller 7 between a lower limit position that regulates the tilling depth and a storage position that is retracted upward from the lower limit position; a mechanical stopper 55 that mechanically regulates the lower limit position of the roller 7; and a lower limit position adjustment unit 56 that can move and fix the position of the mechanical stopper 55 in accordance with manual operation, thereby changing the tilling depth of the front disc row 5 and the rear disc row 6 based on the position movement of the mechanical stopper 55.

Description

Technical Field

[0001] The present invention relates to a disk harrow type tillage working machine used by being connected to the rear part of a traveling body.

Background Art

[0002] A disk harrow type tillage working machine that is connected to the rear part of a traveling body via a lift link mechanism and tills the soil according to the traveling of the traveling body is known (for example, see Patent Document 1). This type of disk harrow type tillage working machine has the advantage that, since the disk pierces the soil while rotating itself as the traveling body travels, not only can the fuel consumption of the traveling body be reduced, but the work can be speeded up compared to a rotary type tillage working machine that rotates tillage claws with the PTO power of the traveling body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, this type of disk harrow type tillage working machine has a roller for regulating the tillage depth of the disk by rolling on the soil surface behind the disk, and the tillage depth amount of the disk can be changed based on the vertical position adjustment of the roller. However, when changing the tillage depth amount, since it is necessary to move the roller itself up and down by turning the handle, there is a problem in workability.

Means for Solving the Problems

[0005] The present invention was created in view of the above circumstances and with the aim of solving these problems, and the invention of claim 1 is a disc harrow type tilling work machine connected to the rear of a traveling machine via a lifting link mechanism and tilling the soil in accordance with the movement of the traveling machine, comprising: a work machine frame connected to the rear of the traveling machine via the lifting link mechanism; a front row of discs arranged at predetermined intervals in the left-right direction below the front side of the work machine frame and crushing soil in accordance with the movement of the traveling machine; and a mechanism arranged at predetermined intervals in the left-right direction below the rear side of the work machine frame and in accordance with the movement of the traveling machine The system comprises a rear disc row that breaks up soil accordingly, a roller positioned behind the rear disc row that rolls across the soil surface to regulate the tilling depth of the front disc row and the rear disc row, an actuator that raises and lowers the roller between a lower limit position that regulates the tilling depth and a storage position that retracts upward from the lower limit position, a mechanical stopper that mechanically restricts the lower limit position of the roller, and a lower limit position adjustment unit that can move and fix the position of the mechanical stopper in accordance with manual operation, wherein the tilling depth of the front disc row and the rear disc row is changed based on the position movement of the mechanical stopper. Furthermore, the invention of claim 2 is a disc harrow type tilling machine as described in claim 1, wherein the lower limit position adjustment unit comprises a handle that is manually rotated, and a screw mechanism that moves the mechanical stopper forward and backward in accordance with the rotation operation of the handle, and further comprises a handle rotation restricting means for restricting the rotation of the handle when not in operation. Furthermore, the invention of claim 3 is a disc harrow type tilling machine as described in claim 1, characterized in that the machine frame supports the roller so that it can be raised and lowered via a link mechanism, and the mechanical stopper and the lower limit position adjustment unit are attached to the link mechanism. Furthermore, the invention of claim 4 is a disc harrow type tilling machine as described in claim 2, characterized in that the handle protrudes toward the rear or upward of the machine. Furthermore, the invention of claim 5 is a disc harrow type tilling machine as described in claim 3, wherein the lower limit position adjustment unit is provided with an indicator that shows the tilling depth of the front disc row and the rear disc row corresponding to the current position of the mechanical stopper, and the indicator is covered on the side by the link mechanism and is visible through a hole formed in the link mechanism. [Effects of the Invention]

[0006] According to the invention of claim 1, by raising the roller from its lower limit position using an actuator, the tilling depth can be changed by moving the mechanical stopper without the roller's own weight acting on it. As a result, there is no need to move the roller itself up and down when changing the tilling depth, as in the conventional method, and work efficiency when changing the tilling depth can be improved. In addition, since the roller can be raised to the storage position by the actuator, the disc harrow type tilling implement can be made more compact when not in use, improving its transportability and storage. Furthermore, complex electrical control of the actuator is unnecessary, so electrical control-related problems can be avoided. Furthermore, according to the invention of claim 2, not only can the tilling depth be changed by rotating the handle, but the rotation of the handle when not in operation can be restricted to prevent damage to the handle and unintended fluctuations in the tilling depth. Furthermore, according to the invention of claim 3, the mechanical stopper and the lower limit position adjustment unit are attached to a link mechanism that supports the roller so that it can move up and down. Therefore, the link mechanism can be used as both the mounting part for the mechanical stopper and the lower limit position adjustment unit, which makes it possible to reduce the number of parts and simplify the structure. Furthermore, according to the invention of claim 4, since the handle protrudes toward the rear or upward of the work machine, the handle can be easily operated from the rear of the work machine. Furthermore, according to the invention of claim 5, the lower limit position adjustment unit is provided with indicators that show the tilling depth of the front and rear disc rows corresponding to the current position of the mechanical stopper, making it easier to change the tilling depth by moving the mechanical stopper. In addition, the indicators are covered on the sides by a link mechanism and are visible through holes formed in the link mechanism, so the indicators can be protected by the link mechanism while being visible through the holes. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of a disc harrow-type tilling implement attached to a tractor. [Figure 2] This is a side view of a disc harrow-type tilling machine attached to a tractor. [Figure 3] This is a plan view of a disc harrow-type tilling machine attached to a tractor. [Figure 4] This is a perspective view of a disc harrow type tilling machine. [Figure 5] This is a side view of a disc harrow type tilling machine. [Figure 6] This is a plan view of a disc harrow type tilling machine. [Figure 7] This is a front view of a disc harrow type tilling machine. [Figure 8] This is a rear view of a disc harrow type tilling machine. [Figure 9] This is a side view of a disc harrow type tilling machine with the rollers raised. [Figure 10] This is a rear view of a disc harrow type tilling machine with the rollers raised. [Figure 11] This is a side view of a disc harrow-type tilling machine with the chisel stored away. [Figure 12] This is a side view of the main parts of a disc harrow type tilling machine with the rollers in their shallowest position. [Figure 13] This is a side view of the main parts of a disc harrow type tilling machine, showing the rollers slightly raised from the state shown in Figure 12. [Figure 14]It is a side view of the main part of a disk harrow type tillage implement showing the case where the mechanical stopper is adjusted from the shallowest position to the deepest position in the state of FIG. 13. [Figure 15] It is a side view of the main part of a disk harrow type tillage implement in the state where the roller is lowered to the lower limit after adjustment shown in FIG. 14. [Figure 16] It is a side view of a disk harrow type tillage implement with the roller in the shallowest position. [Figure 17] It is a side view of a disk harrow type tillage implement with the roller in the middle position. [Figure 18] It is a side view of a disk harrow type tillage implement with the roller in the deepest position. [Figure 19] It is a perspective view of the main part showing the state of restricting the rotation of the handle. [Figure 20] It is a side view of the first link. [Figure 21] It is a front view of the scale sheet.

Mode for Carrying Out the Invention

[0008] [Disk Harrow Type Tillage Implement] Embodiments of the present invention will be described based on the drawings. In FIGS. 1 to FIG. 3, reference numeral 1 denotes a small or medium-sized tractor (traveling body) with a relatively small output horsepower of the engine. A disk harrow type tillage implement 3 (hereinafter sometimes referred to as the tillage implement 3) is connected to the rear part of the tractor 1 via a lift link mechanism 2 (top link 2a, left and right lower links 2b, 2b). The tillage implement 3 does not require the PTO power of the tractor 1 and tills the soil according to the forward travel of the tractor 1.

[0009] Hereinafter, the tillage implement 3 will be described with reference to FIGS. 1 to FIG. 11. [[ID=3​​The tilling implement 3 comprises an implement frame 4 connected to the rear of the tractor 1 via a lifting link mechanism 2; a front row of discs 5 arranged at predetermined intervals in the left-right direction below the front of the implement frame 4, which crushes soil in accordance with the movement of the tractor 1; a rear row of discs 6 arranged at predetermined intervals in the left-right direction below the rear of the implement frame 4, which crushes soil in accordance with the movement of the tractor 1; rollers 7 (tooth rollers) positioned behind the rear row of discs 6 so as to be vertically adjustable; a chisel 8 positioned in front of the front row of discs 5; and a weight mounting section 10 to which a weight 9 can be attached and detached.

[0011] [Working equipment frame] The tilling implement 3 is equipped with a lightweight implement frame 4 made of lightweight square steel pipes. Specifically, the implement frame 4 is constructed by connecting a pair of left and right main frames 4a, a front disc support frame 4b, a front reinforcing lateral frame 4c, a rear disc support frame 4d, a rear reinforcing lateral frame 4e, and a pair of left and right reinforcing vertical frames 4f.

[0012] A pair of left and right main frames 4a are arranged along the front-rear direction and connected to the rear of the tractor 1 via a lifting link mechanism 2. The front disc support frame 4b is arranged along the left-right direction and supports the front disc row 5. The front reinforcing transverse frame 4c is arranged along the left-right direction behind the front disc support frame 4b. The rear disc support frame 4d is arranged along the left-right direction behind the front reinforcing transverse frame 4c and supports the rear disc row 6. The rear reinforcing transverse frame 4e is arranged along the left-right direction behind the rear disc support frame 4d and supports the rollers 7. A pair of left and right reinforcing longitudinal frames 4f are arranged facing the front-rear direction on the outside of the main frame 4a.

[0013] Furthermore, the front disc support frame 4b, the front reinforcing lateral frame 4c, the rear disc support frame 4d, and the rear reinforcing lateral frame 4e are connected to the upper surfaces of a pair of left and right main frames 4a, and the pair of left and right reinforcing vertical frames 4f are connected to the upper surfaces of the front disc support frame 4b, the front reinforcing lateral frame 4c, the rear disc support frame 4d, and the rear reinforcing lateral frame 4e.

[0014] A top link mast 11 and support plate 12, formed by bending steel plates, are fixed to the front of a pair of left and right main frames 4a, and a top link pin 13 for connecting to the top link 2a is provided on the upper part of the top link mast 11. In addition, U-shaped link brackets 14 are fixed to the front ends of the pair of left and right main frames 4a, and each link bracket 14 is provided with a lower link pin 15 for connecting to the left and right lower links 2b.

[0015] [disk] Both the front disc row 5 and the rear disc row 6 have multiple soil-crushing discs 16, which are arranged at predetermined intervals in the left-right direction. The soil-crushing discs 16 are dish-shaped discs with a concave curved surface, and have sharp cutting blades formed on their outer edges, which cut crop residue and other materials. The outer edges of the soil-crushing discs 16 also have numerous arc-shaped notches and are sometimes called flower-shaped discs. Due to their flower-shaped disc shape, the soil-crushing discs 16 rotate on their own while penetrating the soil, thereby crushing the soil.

[0016] When tilling the soil with such a flower-shaped soil-crushing disc 16, the soil clumps scraped off by the soil-crushing disc 16 accumulate in the concave, curved surface near the bottom of the disc 16. These accumulated soil clumps are then lifted upward as the soil-crushing disc 16 rotates, and then thrown out to the side from the open side of the curved surface.

[0017] Therefore, when arranging a large number of soil-crushing discs 16 at predetermined intervals in the left-right direction, if their concave curved surfaces are oriented in the same direction, the soil clumps tilled by the numerous soil-crushing discs 16 will be thrown and moved to one side in the left-right direction perpendicular to the forward travel direction of the tractor 1. To address this, the number of soil-crushing discs 16 constituting the front disc row 5 and the rear disc row 6 are made the same, and the orientation of the curved surfaces of the soil-crushing discs 16 constituting each row is made different from each other, for example, the front row facing left and the rear row facing right.

[0018] With this type of disc arrangement, the rear disc row 6 can return soil clumps moved to one side by the front disc row 5 to the other side, thereby leveling the tilled surface in the left-right direction. Furthermore, if the front disc row 5 and the rear disc row 6 are offset by a predetermined distance in the left-right direction, the rear disc row 6 can till any uncultivated land that the front disc row 5 could not till, thereby reducing the unevenness of the tilled surface.

[0019] The individual soil-crushing disc 16 is attached to the front disc support frame 4b and the rear disc support frame 4d via a disc support mechanism 17. The disc support mechanism 17 includes a disc bracket 18, a disc arm 19, and a spring 20.

[0020] The disc bracket 18 is attached to the front disc support frame 4b and the rear disc support frame 4d at predetermined intervals in the left-right direction. The disc arm 19 extends downward and rearward from the disc bracket 18, and its tip rotatably supports the soil-crushing disc 16 via the disc support shaft 21.

[0021] The disc bracket 18 supports the base end of the disc arm 19 via the disc arm support shaft 22 so that it can rotate up and down. The disc bracket 18 also includes a rotation restricting bolt 23 that is parallel to the rear of the disc arm support shaft 22. The rotation restricting bolt 23 passes through an arc-shaped (arc shape centered on the disc arm support shaft 22) elongated hole (not shown) formed in the disc arm 19, allowing the disc arm 19 to rotate up and down within the range of the elongated hole.

[0022] The spring 20 is interposed between the spring receiving portion 18a of the disc bracket 18 and the spring receiving portion 19a of the disc arm 19, biasing the disc arm 19 downward. The spring 20 is, for example, a compression coil spring with adjustable biasing force, and the biasing force is adjusted so that under normal tilling conditions the disc arm 19 is positioned at the lower limit of its swing range, and if the soil-crushing disc 16 comes into contact with an obstacle, the disc arm 19 is allowed to rotate upward to avoid it. This prevents the soil-crushing disc 16 from being damaged by contact with an obstacle.

[0023] [Laura] Roller 7 is located behind the rear disc row 6 and has a first function of finely crushing and cutting soil, soil clumps, or crop residue tilled by the front disc row 5 and rear disc row 6, and a second function of adjusting the tilling depth (hereinafter sometimes referred to as tilling depth or tilling depth amount) of the front disc row 5 and rear disc row 6. The first function is achieved by making roller 7 a cage-type roller.

[0024] The second function is achieved by supporting the roller 7 so that its vertical position can be adjusted via a roller support mechanism 24. The roller support mechanism 24 comprises a plurality of roller brackets 25, a roller arm support shaft 26, a pair of left and right roller arms 27, a cylinder connecting arm 28, a cylinder bracket 29, a first link 30, a second link 31, a hydraulic cylinder 32, and a tilling depth adjustment mechanism 33.

[0025] Multiple roller brackets 25 are attached to the rear ends of the rear reinforcing transverse frame 4e or the left and right reinforcing longitudinal frames 4f. The roller arm support shaft 26 is arranged in parallel above the rear reinforcing transverse frame 4e and is rotatably supported by the multiple roller brackets 25. A pair of left and right roller arms 27 are integrally rotatably connected to both ends of the roller arm support shaft 26, and their ends rotatably support the rollers 7 via the roller support shaft 34.

[0026] The cylinder connecting arm 28 is integrally and rotatably connected to the center of the roller arm support shaft 26. The cylinder bracket 29 is fixed in a bridge-like manner along the front-rear direction between the center of the front reinforcing transverse frame 4c and the center of the rear disc support frame 4d. The first link 30 and the second link 31 are rotatably connected to each other at one end via a connecting shaft 35. The other end of the first link 30 is rotatably connected to the tip of the cylinder connecting arm 28, and the other end of the second link 31 is rotatably connected to the rear end of the cylinder bracket 29.

[0027] One end of the hydraulic cylinder 32 is rotatably connected to the front end of the cylinder bracket 29, and the other end is rotatably connected to the connecting shaft 35. When the hydraulic cylinder 32 is extended or retracted, the roller arm support shaft 26 rotates via the first link 30 and the cylinder connecting arm 28, and as a result the pair of left and right roller arms 27 rotate up and down, causing the roller 7 to be raised and lowered. Figures 1 to 8 show the working state with the hydraulic cylinder 32 extended and the roller 7 lowered, while Figures 9 and 10 show the non-working state (storage state) with the hydraulic cylinder 32 retracted and the roller 7 raised.

[0028] The tillage depth adjustment mechanism 33 is a key component of the present invention, and its details will be described later.

[0029] [Chisel] The chisel 8 penetrates the soil in front of the front disc row 5, thereby breaking up the soil and assisting in the penetration of the front disc row 5 and the rear disc row 6. The chisel 8 may be a pair, left and right, as in this embodiment, but there may be one or two or more.

[0030] The chisel 8 comprises a chisel bracket 36, a first chisel arm 37, a second chisel arm 38, a soil-crushing blade 39, and a resistance plate 40.

[0031] The chisel bracket 36 is attached to the front disc support frame 4b at a predetermined distance in the left-right direction. The first chisel arm 37 is supported by the chisel bracket 36 so as to be vertically slidable and is fixed to the chisel bracket 36 via bolts B1. In addition, a second chisel arm 38 is detachably fixed to the tip of the first chisel arm 37 via a plurality of bolts B2. Since the second chisel arm 38 is pre-integrated with the soil-crushing blade 39 and resistance plate 40, if the soil-crushing blade 39 and resistance plate 40 wear out or are damaged, the soil-crushing blade 39 and resistance plate 40 can be replaced by attaching and detaching the second chisel arm 38 to the first chisel arm 37.

[0032] Furthermore, the first chisel arm 37 is provided with a plurality of fixing holes 37a arranged in the longitudinal direction. When the first chisel arm 37 is fixed to the chisel bracket 36 so that the bolt B1 passes through the fixing hole 37a on the base end, the soil-crushing blade 39 is in an operational state where it is positioned at the same depth as the front disc row 5, as shown in Figure 5. When the first chisel arm 37 is fixed to the chisel bracket 36 so that the bolt B1 passes through the fixing hole 37a on the tip end, the soil-crushing blade 39 is in a retracted state where it is moved upward, as shown in Figure 11. The chisel 8 of this embodiment can be switched between an operational state where it is driven into the field and a retracted state where it is moved upward and does not act on the soil.

[0033] The soil-crushing blade 39 and the resistance plate 40 are integrally fixed to the second chisel arm 38 by welding or the like. The soil-crushing blade 39 has a sharp, sled-like shape at its front end and penetrates the soil as the machine moves. In addition, the soil-crushing blade 39 is inclined so that it is lower towards the front. This allows the soil-crushing blade 39 to exert a downward vector on the chisel 8 as it moves through the soil, promoting penetration of the front disc row 5 and the rear disc row 6.

[0034] [Weight mounting section] The weight mounting section 10 is configured to allow the weight 9 to be attached and detached. For example, the weight mounting section 10 in this embodiment is integrally configured to include a frame fixing section 10a fixed to the upper surface of the work machine frame 4, a pair of legs 10b rising from both ends of the frame fixing section 10a, and a hanger section 10c connecting the upper ends of the pair of legs 10b, and multiple (for example, three) weights 9 can be attached and detached from the hanger section 10c by hooking them.

[0035] Specifically, the weight 9 has a hook portion 9a, and is attached to the weight mounting portion 10 by hooking this hook portion 9a onto the hanger portion 10c. A fixing bolt B3 is screwed into the hook portion 9a of the weight 9, and by tightening this fixing bolt B3, the hook portion 9a of the weight 9 is tightly pressed against the hanger portion 10c, preventing the weight 9 from falling off. In this embodiment, the weight 9 is a repurposed front weight attached to the front end of the tractor 1, but the weight and shape of the weight 9 can be changed as desired.

[0036] Multiple weight mounting sections 10 are provided, distributed to the front and rear and left and right sides of the implement frame 4. Specifically, the weight mounting section 10 includes a left front weight mounting section 10FL located on the left front of the implement frame 4, a right front weight mounting section 10FR located on the right front of the implement frame 4, a left rear weight mounting section 10RL located on the left rear of the implement frame 4, and a right rear weight mounting section 10RR located on the right rear of the implement frame 4. In this way, the weights 9 can be distributed to the left and right and front and rear of the implement frame 4, thereby reducing the behavior of the tilling implement 3 when subjected to external forces from the field surface and lifting due to bending of the implement frame 4, and stabilizing the penetration of the front disc row 5 and rear disc row 6 into the soil. On the other hand, if the weight 9 is concentrated in the center of the tilling implement 3, and the tilling implement 3 receives an external force biased to one corner due to unevenness in the field, the weight 9 cannot receive the external force. This can cause the tilling implement 3 to shake or wobble, or the implement frame 4 to bend due to the external force, potentially preventing proper tilling. However, the tilling implement 3 of this embodiment can resolve these problems.

[0037] The left front weight mounting section 10FL is provided on the upper surface of the front end of the left reinforcing vertical frame 4f, and the left rear weight mounting section 10RL is provided on the upper surface of the rear end of the left reinforcing vertical frame 4f. The right front weight mounting section 10FR is provided on the upper surface of the front end of the right reinforcing vertical frame 4f, and the right rear weight mounting section 10RR is provided on the upper surface of the rear end of the right reinforcing vertical frame 4f. In this way, the weight mounting sections 10 can be positioned near the four corners of the work machine frame 4, allowing the weight load to be applied in a well-balanced manner. In addition, since the weight mounting sections 10 are positioned as high as possible on the work machine frame 4 (on the upper surface of the reinforcing vertical frame 4f), the possibility of grass and mud accumulating on the weights 9 attached to the weight mounting sections 10 can be reduced.

[0038] Furthermore, as shown in Figure 5, the weight mounting portion 10 (weight 9) is positioned above the disc support shaft 21 in a side view. In this configuration, the weight 9 absorbs the upward load received by the front disc row 5 and the rear disc row 6 from the soil, thereby promoting penetration of the front disc row 5 and the rear disc row 6 into the soil.

[0039] Furthermore, as shown in Figure 5, the weight mounting portion 10 (weight 9) is positioned on a virtual line L passing through the disc support shaft 21 and the spring 20 in a side view. In this configuration, when the spring 20 contracts due to the upward load received by the front disc row 5 and the rear disc row 6 from the soil, the weight 9 supports the spring 20, thereby promoting the penetration of the front disc row 5 and the rear disc row 6 into the soil.

[0040] Furthermore, since the weight attachment portion 10 (weight 9) is positioned near the chisel 8 in a plan view, the load of the weight 9 attached to the weight attachment portion 10 can promote the penetration of the chisel 8.

[0041] Furthermore, the weight mounting section 10 allows for the selection of the number of weights 9 to be attached, and the chisel 8 can be selectively switched between the working state and the retracted state. Based on the selection of these two states, the adaptability to the field can be further improved.

[0042] Furthermore, as shown in Figures 3 and 6, a space S is formed on both the left and right sides of the tilling implement 3, allowing a person to enter. This space S is located between the front disc row 5 and the rear disc row 6, and is situated outside the reinforcing vertical frame 4f. With such a space S, the person can get close to the weight mounting section 10 when attaching or detaching the weight 9, making the attachment and detachment of the weight 9 easier.

[0043] [Configuration of the tillage depth adjustment mechanism] Next, the configuration of the tillage depth adjustment mechanism 33, which is the main part of the present invention, will be described with reference to Figure 12 and subsequent figures.

[0044] The tilling depth adjustment mechanism 33 is located between the first link 30 and the cylinder connecting arm 28. The first link 30 comprises left and right link plates 51 arranged in parallel with a gap between them, and a guide plate 52 integrally provided between the left and right link plates 51. The cylinder connecting arm 28 comprises left and right arm plates 53 arranged in parallel with a gap between them, and a stopper plate 54 integrally provided between the left and right arm plates 53.

[0045] The tilling depth adjustment mechanism 33 includes a mechanical stopper 55 that mechanically restricts the lower limit position of the roller 7, and a lower limit position adjustment unit 56 that can move and fix the position of the mechanical stopper 55 in response to manual operation. The tilling depth of the front disc row 5 and the rear disc row 6 can be changed based on the position movement of the mechanical stopper 55.

[0046] The lower limit position adjustment unit 56 includes a handle 57 that is manually rotated, and a screw mechanism 58 that moves the mechanical stopper 55 forward and backward in response to the rotation of the handle 57. The screw mechanism 58 includes a rod 59 to which the handle 57 is foldably connected at its upper end and to which the mechanical stopper 55 is integrally connected at its lower end, and a screw shaft 60 that is provided in a spanner-like manner between the left and right link plates 51.

[0047] The screw shaft 60 has a through hole 60a through which the rod 59 passes. The inner circumference of the through hole 60a and the outer circumference of the rod 59 have screw grooves (not shown) that mesh with each other, and when the rod 59 rotates in response to the rotational operation of the handle 57, the rod 59 moves up and down by a so-called feed screw action. This makes it possible to adjust the position of the mechanical stopper 55 provided at the lower end of the rod 59.

[0048] The mechanical stopper 55 restricts the lower limit position of the roller 7 by contacting a stopper plate 54 provided on the cylinder connecting arm 28 when the hydraulic cylinder 32 lowers the roller 7. In this embodiment, the mechanical stopper 55 is made of a washer having a diameter sufficiently larger than the diameter of the rod 59 and is integrally welded to the lower end of the rod 59. This increases the contact area between the mechanical stopper 55 and the stopper plate 54, enabling stable restriction of the lower limit of the roller 7.

[0049] Furthermore, the screw shaft 60 is rotatable around its axis relative to the left and right link plates 51, allowing the rod 59 to swing back and forth around the screw shaft 60. Therefore, even if the position of the mechanical stopper 55 is changed, it is possible to bring the mechanical stopper 55 and the stopper plate 54 into parallel contact based on the back and forth swing of the rod 59. As a result, not only can the lower limit of the roller 7 be stably restricted, but wear on the mechanical stopper 55 and the stopper plate 54 can also be suppressed.

[0050] The rod 59 and screw shaft 60 that constitute the screw mechanism 58 are positioned between the left and right link plates 51. This allows the left and right link plates 51 to protect the screw mechanism 58, preventing the accumulation of mud and other debris, and also eliminates the need for a dedicated cover, thereby reducing the number of parts and lowering costs.

[0051] Furthermore, the lower limit position adjustment section 56 is provided with an indicator 61 that shows the tilling depth of the front disc row 5 and the rear disc row 6 corresponding to the current position of the mechanical stopper 55. The indicator 61 is composed of a washer welded to the rod 59, for example, as shown in Figure 14. The indicator 61 is covered on both sides by the left and right link plates 51 and is visible through the holes 51a formed in the link plates 51.

[0052] As shown in Figures 20 and 21, a scale sheet 62 indicating the approximate tillage depth is provided around the hole 51a. The scale sheet 62 has scales and numerical values ​​printed on it that show the relationship between the position of the indicator 61 and the tillage depth.

[0053] As shown in Figure 19, the guide plate 52 is provided so as to cover the screw mechanism 58 from above and behind, and includes a through hole 52a through which the rod 59 passes, and an engagement groove 52b (handle rotation restricting means) that restricts the rotation of the handle 57 when not in operation.

[0054] The through hole 52a is an elongated hole that is long in the front-rear direction. This allows for the forward and backward swinging of the rod 59 described above, while restricting excessive swinging. In addition, the engagement groove 52b engages with the handle 57 when the handle 57 is folded forward, thereby restricting the rotation of the handle 57. For example, the handle 57 in this embodiment protrudes toward the rear or above the work machine to facilitate operation from the rear of the work machine, but when not in operation, it can be folded forward and stored inside the first link 30 (between the left and right link plates 51). When stored, rotation is restricted by engagement with the engagement groove 52b.

[0055] As shown in Figures 9 and 11, an upper limit stopper 63 is integrally provided at the rear end of the cylinder bracket 29, which restricts the upper limit of the roller 7 by contacting the second link 31. As a result, the pivot points of the hydraulic cylinder 32 and the second link 31, as well as the upper limit stopper 63, are integrated into the cylinder bracket 29, thus simplifying the structure while ensuring strength.

[0056] [Operating Procedure for the Tillage Depth Adjustment Mechanism] Next, the operating procedure for the tillage depth adjustment mechanism 33 will be explained with reference to Figures 12 to 18. Figures 12 to 15 show the operating procedure when changing the position of the roller 7 from the shallowest position to the deepest position.

[0057] Figure 12 is a side view of the main parts of the disc harrow type tilling machine 3 with the roller 7 in its shallowest position. In the shallowest position shown in Figure 12, the hydraulic cylinder 32 is fully extended, and the mechanical stopper 55 bears the entire load of the roller 7. Therefore, in this state, it is difficult to turn the handle 57.

[0058] Figure 13 is a side view of the main parts of the disc harrow type tilling machine 3, with the roller 7 slightly raised from the state shown in Figure 12. As shown in Figure 13, when the roller 7 is slightly lifted by the hydraulic cylinder 32, the mechanical stopper 55 separates from the stopper plate 54. In this state, since the load of the roller 7 is not acting on the mechanical stopper 55, the handle 27 can be easily turned.

[0059] Figure 14 is a side view of the main parts of the disc harrow type tilling machine 3, showing the state in Figure 13 when the mechanical stopper 55 is adjusted from the shallowest position to the deepest position. As shown in Figure 14, the position of the mechanical stopper 55 is adjusted by turning the handle 57. In this embodiment, the tilling depth is set to change by a predetermined amount with one rotation of the handle 57. Therefore, to change the mechanical stopper 55 from the shallowest position to the deepest position, the handle 57 is rotated a number of times equal to the amount of change divided by the predetermined amount.

[0060] Figure 15 is a side view of the main parts of the disc harrow type tilling machine 3 after the adjustments shown in Figure 14, with the roller 7 lowered to its lowest limit. After adjusting the position of the mechanical stopper 55, the hydraulic cylinder 32 is fully extended as shown in Figure 15. This causes the roller 7 to stop at its deepest position due to the lower limit restriction by the mechanical stopper 55.

[0061] According to the operation procedure of this tilling depth adjustment mechanism 33, if the roller 7 is raised from its lower limit position by the hydraulic cylinder 32, the tilling depth can be easily changed by moving the mechanical stopper 55 while the weight of the roller 7 is not acting on it. The amount of change in tilling depth per rotation of the handle 57 can be set arbitrarily. Based on the movement of the mechanical stopper 55 by the handle 57, it becomes possible to adjust the tilling depth from shallowest to intermediate to deepest as shown in Figures 16 to 18.

[0062] [Effects of the Embodiment] According to this embodiment configured as described above, a disc harrow type tilling implement 3 is connected to the rear of a tractor 1 via a lifting link mechanism 2 and tills the soil in accordance with the movement of the tractor 1, comprising: an implement frame 4 connected to the rear of the tractor 1 via a lifting link mechanism 2; a front row of discs 5 arranged at predetermined intervals in the left-right direction below the front of the implement frame 4 and crushing the soil in accordance with the movement of the tractor 1; a rear row of discs 6 arranged at predetermined intervals in the left-right direction below the rear of the implement frame 4 and crushing the soil in accordance with the movement of the tractor 1; and a mechanism positioned behind the rear row of discs 6 that rolls across the soil surface to till the front discs The system includes a roller 7 that regulates the tilling depth of the front disc row 5 and the rear disc row 6, a hydraulic cylinder 32 that raises and lowers the roller 7 between a lower limit position that regulates the tilling depth and a storage position that is retracted upward from the lower limit position, a mechanical stopper 55 that mechanically regulates the lower limit position of the roller 7, and a lower limit position adjustment unit 56 that can move and fix the position of the mechanical stopper 55 according to manual operation. Since the tilling depth of the front disc row 5 and the rear disc row 6 is changed based on the position movement of the mechanical stopper 55, if the roller 7 is raised from the lower limit position by the hydraulic cylinder 32, the tilling depth can be changed by moving the mechanical stopper 55 without the weight of the roller 7 acting on it. In other words, there is no need to move the roller 7 itself up and down when changing the tilling depth as in the conventional system, so the workability when changing the tilling depth can be improved. In addition, since the roller 7 can be raised to the storage position by the hydraulic cylinder 32, the disc harrow type tilling implement 3 can be made more compact when not in use, improving its transportability and storage. Furthermore, since complex electrical control of the hydraulic cylinder 32 is unnecessary, electrical control-related problems can be avoided.

[0063] Furthermore, the lower limit position adjustment unit 56 is configured to include a handle 57 that is manually rotated, and a screw mechanism 58 that moves a mechanical stopper 55 forward and backward in response to the rotation of the handle 57. It also includes a handle rotation restricting means that restricts the rotation of the handle 57 when not in operation. This allows the tilling depth to be changed by rotating the handle 57, and also prevents damage to the handle 57 and unintended fluctuations in the tilling depth by restricting the rotation of the handle 57 when not in operation.

[0064] Furthermore, the work machine frame 4 supports the roller 7 so that it can be raised and lowered via the first link 30, and the mechanical stopper 55 and the lower limit position adjustment part 56 are attached to the first link 30. Therefore, the first link 30 can also be used as the mounting part for the mechanical stopper 55 and the lower limit position adjustment part 56, which makes it possible to reduce the number of parts and simplify the structure.

[0065] Furthermore, since the handle 57 protrudes towards the rear or above the work machine, the handle 57 can be easily operated from the rear of the work machine.

[0066] Furthermore, the lower limit position adjustment unit 56 is provided with an indicator 61 that shows the tilling depth of the front disc row 5 and rear disc row 6 corresponding to the current position of the mechanical stopper 55. The indicator 61 is covered on the side by the first link 30 and can be seen through the hole 51a formed in the first link 30. This not only makes it easy to change the tilling depth by moving the position of the mechanical stopper 55, but also allows the indicator 61 to be seen through the hole 51a while being protected by the first link 30.

[0067] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the claims. [Explanation of symbols]

[0068] 1 tractor 2. Lifting link mechanism 2a Top Link 2b Lower Link 3. Disc harrow type tilling machine 4. Work machine frame 4a Mainframe 4b Front disc support frame 4c Front reinforced horizontal frame 4d Rear disc support frame 4e Rear reinforcing lateral frame 4F Reinforcement vertical frame 5 Front disk row 6. Rear disk row 7 Laura 8 Chisels 9 weights 9a Hook part 10 Weight mounting section 10FL Left front weight mounting area 10FR Right front weight mounting area 10RL Left rear weight mounting area 10RR Right rear weight mounting area 10a Frame fixing part 10b Legs 10c Hanger section 11. Top link mast 12 support plates 13 Top Link Pins 14 Link Bracket 15 Lower Link Pins 16 Soil-crushing discs 17. Disk support mechanism 18 Disc Bracket 18a Spring support 19 Disc Arm 19a Spring support 20 springs 21 Disk support axis 22 Disc arm support shaft 23 Rotation regulating bolts 24 Roller support mechanism 25 Roller Bracket 26 Roller arm support shaft 27 Roller Arm 28 Cylinder connecting arm 29 Cylinder bracket 30. First link (linkage mechanism) 31. Second Link 32 Hydraulic cylinder (actuator) 33 Tillage depth adjustment mechanism 34 Roller support shaft 35 Connecting shaft 36 Chisel Bracket 37. First Chisel Arm 37a Fixing hole 38. Second Chisel Arm 39 Soil-crushing blade 40 Resistance plate 51 Link Plate 51a hole 52 Guide Plate 52a through hole 52b Engagement groove 53 Arm Plate 54 Stopper Plate 55 Mecha Stopper 56 Lower limit position adjustment section 57 Handle 58 Screw mechanism 59 Rods 60 Screw shaft 60a Through hole 61 indicators 62 seats 63 Upper limit stopper

Claims

1. A disc harrow type tilling machine is connected to the rear of a traveling machine via a lifting link mechanism and tills the soil in accordance with the movement of the traveling machine, A work machine frame connected to the rear of the aforementioned traveling machine body via the aforementioned lifting link mechanism, The front row of discs is arranged at predetermined intervals in the left-right direction on the lower front side of the work machine frame, and crushes soil in accordance with the movement of the traveling machine, The rear disc row is arranged at predetermined intervals in the left-right direction below the rear side of the work machine frame, and crushes soil in accordance with the movement of the traveling machine, A roller positioned behind the rear disc row and rolling across the soil surface to regulate the tillage depth of the front disc row and the rear disc row, An actuator that raises and lowers the roller between a lower limit position that restricts the tilling depth and a storage position that is retracted upward from the lower limit position, A mechanical stopper that mechanically restricts the lower limit position of the roller, It includes a lower limit position adjustment unit that can move and fix the position of the mechanical stopper in response to manual operation, A disc harrow type tilling machine characterized by changing the tilling depth of the front disc row and the rear disc row based on the positional movement of the mechanical stopper.

2. The lower limit position adjustment unit is, A handle that is operated by manual rotation, It is configured to include a screw mechanism that moves the mechanical stopper forward and backward in response to the rotational operation of the handle, The disc harrow type tilling machine according to claim 1, further comprising a handle rotation restricting means for restricting the rotation of the handle when not in operation.

3. The aforementioned work machine frame supports the roller so that it can be raised and lowered via a link mechanism. The disc harrow type tilling machine according to claim 1, characterized in that the mechanical stopper and the lower limit position adjustment unit are attached to the link mechanism.

4. The disc harrow type tilling machine according to claim 2, characterized in that the handle protrudes toward the rear or upward of the work machine.

5. The lower limit position adjustment unit is provided with an indicator that shows the tilling depth of the front disc row and the rear disc row corresponding to the current position of the mechanical stopper. The disc harrow type tilling machine according to claim 3, characterized in that the indicator is covered on the side by the link mechanism and is visible through a hole formed in the link mechanism.

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