Agricultural machinery

Abstract

The objective is to provide an agricultural implement that prevents unnecessary lifting and lowering control of the implement from occurring even when the pressurization state, such as turning the apron pressurization device ON / OFF, is changed during operation. [Solution] An agricultural implement connected to a vehicle body that raises and lowers the agricultural implement based on tillage depth information, comprising tillage depth detection means 5, a leveling body 35L, and a leveling body pressurizing device 4L, wherein the leveling body 35L is mounted so as to be vertically rotatable behind a work rotor 31 having a plurality of work tines to level the work surface MS, the leveling body pressurizing device 4L pressurizes the leveling body 35L toward the work surface MS, and comprising a changing means 54 that changes the operation of the tillage depth detection means 5 by the operation of the leveling body pressurizing device 4L, wherein the tillage depth information is the detection result of the tillage depth detection means 5.

Description

Technical Field

[0001] The present invention relates to an agricultural working machine having a leveling body (apron) for leveling the field surface (mud surface of paddy field).

Background Art

[0002] Conventionally, there is known an agricultural working machine provided with a leveling body (apron) provided at the rear of a tillage body for leveling the unevenness of the field surface, and further having an apron pressing device capable of pressing the apron against the field surface, and capable of turning on / off the pressing by this apron pressing device. (Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional agricultural working machine, means for detecting the tillage depth of the agricultural working machine is provided according to the (rotational) position etc. of an apron that moves up and down, and the detected tillage depth information is transmitted to a traveling vehicle body such as a tractor to which the agricultural working machine is connected. And the traveling vehicle body such as a tractor is provided with a tillage depth control device for raising and lowering the agricultural working machine based on the tillage depth information of the agricultural working machine transmitted from the agricultural working machine to make the tillage depth constant. In an agricultural working machine provided with both the apron pressing device and the means for detecting the tillage depth as described above, switching on / off the apron pressing device during operation may affect the detection of the tillage depth. Specifically, when the apron pressure device is switched from OFF to ON during operation, a downward force is applied to the apron, causing it to lower even if there is no change in the tilling depth of the agricultural implement. When the means for detecting the apron's position detects that the apron has lowered, the tilling depth control device on the tractor or other vehicle determines that the tilling depth has become shallower and lowers the agricultural implement to increase the tilling depth. Conversely, when the apron pressure device is switched from ON to OFF during operation, the downward force applied to the apron is removed, causing the apron to rise even if there is no change in the tilling depth of the agricultural implement. When the means for detecting the apron's position detects that the apron has risen, the tilling depth control device on the tractor or other vehicle determines that the tilling depth has increased and raises the agricultural implement to decrease the tilling depth.

[0005] As described above, switching the apron pressure device ON / OFF during operation changes the position of the apron. This causes the tillage depth control device to detect a change in tillage depth even though the tillage depth has not actually changed, resulting in unnecessary lifting and lowering control of the agricultural machinery. When the moving vehicle controls the lifting and lowering of such agricultural machinery, it can cause unevenness in the field surface or pull up soil, making it impossible to sufficiently level the field surface.

[0006] Therefore, the present invention aims to solve the above problems and provide an agricultural implement that prevents unnecessary lifting and lowering control of the agricultural implement by the vehicle body when the pressurization state, such as turning the apron pressurization device ON / OFF, is changed during operation. [Means for solving the problem]

[0007] To solve these problems, the present invention has the following configuration. An agricultural implement connected to a vehicle body that raises and lowers the agricultural implement based on tillage depth information, It has a tillage depth detection means, a leveling body, and a means for pressurizing the leveling body. The aforementioned leveling body is mounted so as to be vertically rotatable behind a work rotor having multiple working claws, and is used to level the work surface. The aforementioned ground leveling pressurizing device applies pressure to the ground leveling body toward the work surface, The system includes a modification means for changing the operation of the tillage depth detection means based on the operation of the soil leveling pressurization device, The agricultural implement is characterized in that the tillage depth information is the detection result of the tillage depth detection means. [Effects of the Invention]

[0008] By switching the apron pressurizing device ON / OFF, it is possible to provide an agricultural implement that can level the field surface without unnecessary lifting and lowering control of the agricultural implement by the tillage depth control device of the traveling vehicle body such as a tractor. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows Halo A according to Embodiment 1 of the present invention. [Figure 2] This figure shows the apron pressurizing device and apron detection means of Halo A according to Embodiment 1 of the present invention. [Figure 3] This figure shows an apron pressurizing device and apron detection means of a modified example 1 of Halo A according to Embodiment 1 of the present invention. [Figure 4] This figure shows the apron pressurizing device and apron detection means of Halo A according to Embodiment 2 of the present invention. [Figure 5] This figure shows an apron pressurizing device and apron detection means for a modified example 5 of Halo A according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0010] [Embodiment 1] Hereinafter, with reference to the drawings, a first embodiment of the present invention, Halo A, will be described. Furthermore, the agricultural machinery used is not limited to harrows; other agricultural machinery such as rotary tillers can also be used. In the following explanation, the same symbols in different figures indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate. Furthermore, for the sake of explanation, we will use terms indicating direction such as up, down, forward, backward, right, and left. However, the direction in which gravity acts is down, and the opposite is up. Also, the direction in which a moving vehicle is moving is forward, and the opposite is backward. In addition, looking forward, the right side is right, and the left side is left.

[0011] [Overall structure] Figure 1 is a three-view drawing (view from above (upper right), view from the rear (lower right), and view from the left (lower left)) of Halo A according to Embodiment 1 of the present invention. Note that the apron detection means 5, which will be described later, is omitted in Figure 1.

[0012] As shown in Figure 1, the harrow A in this embodiment 1 is an agricultural machine used for tasks such as puddling, and comprises a mounting section 1, a frame 2, and a working section 3. Harrow A is connected to a vehicle body (not shown) such as a tractor by a mounting part 1. A frame 2 is connected to the mounting part 1, and a working part 3 is connected to the frame 2. As a result, harrow A is towed as the vehicle moves, and the working part 3 performs tasks such as puddling.

[0013] In this embodiment 1, the harrow A has a width (width in the left-right direction) that is wider than the width of the vehicle body, and both the left and right sides of the harrow A protrude from the vehicle body to the left and right. Therefore, in order to narrow the width when moving from the garage to the field, or when moving between fields, the working sections 3 on both the left and right sides are configured to be foldable (openable and foldable) toward the center. The working section 3 is divided into three parts: a central working section 3C which is slightly wider than the distance between the rear tires of the vehicle body, and a left working section 3L and a right working section 3R which are narrower in width than the central working section 3C. The left working section 3L and the right working section 3R are almost symmetrical and have almost the same configuration. The central work section 3C, the left work section 3L, and the right work section 3R are all equipped with a work rotor 31 having a rotating shaft (not shown) to which a work claw (not shown) is fixed. In the first embodiment, the working part configured to be foldable on the central part side is connected to both the left and right sides. However, the present invention can also be applied to a configuration in which the working part configured to be foldable (openable and closable) on the central part side is connected to only one of the left and right sides, or a configuration without a foldable working part.

[0014] [Mounting part] The mounting part 1 is connected to a three-point link mechanism (lifting means: not shown) provided at the rear of the traveling vehicle body. The three-point link mechanism is usually composed of a top link, a lift rod, a lower link, etc. Since the three-point link mechanism is a known mechanism, detailed description thereof is omitted. The mounting part 1 has a top mast 11 connected to the top link and a lower link connecting part (not shown) connected to the lower link. The harrow A can be lifted and lowered by a three-point link mechanism via the mounting part 1.

[0015] [Frame] The frame 2 has a gearbox 21 connected to the mounting part 1, a support frame connected to the gearbox 21, and a chain case 23. The gearbox 21 is disposed at the center of a left support frame 22L and a right support frame 22R of the support frame to be described later. The gearbox 21 has a power input shaft 211. The power from the PTO shaft (not shown) of the traveling vehicle body is transmitted to the power input shaft 211 via a universal joint (not shown). The support frame is the main body frame of the harrow A and supports the working part 3. The support frame is divided into a left support frame 22L extending to the left and a right support frame 22R extending to the right with the gearbox 21 interposed therebetween. Both the left support frame 22L and the right support frame 22R are cylindrical, and a power transmission shaft for transmitting the power from the gearbox 21 can be housed therein. A bevel gear (not shown) is housed in the gearbox 21, and transmits the power from the power input shaft 211 to the power transmission shaft. In this embodiment 1, a power transmission shaft (not shown) is housed within the left support frame 22L, and power from the bevel gear in the gearbox 21 is transmitted to a chain (not shown) in a chain case 23 located at the left end of the left support frame 22L.

[0016] Left support parts and right support parts (neither of which are shown in the figure) are attached to the outer ends of the left support frame 22L and the right support frame 22R, respectively, connecting the left support frame 22L and the right support frame 22R to the central work section 3C. A chain case 23, capable of storing a chain inside, is located on the left side of the left support section.

[0017] The output shaft of the chain inside the chain case 23 is the rotation shaft (not shown) of the work rotor 31 of the central work section 3C, and the chain inside the chain case 23 transmits power from the power transmission shaft inside the left support frame 22L to the work rotor 31. A clutch (not shown in the diagram) is installed between the left end of the rotation axis of the work rotor 31 of the central work section 3C and the right end of the rotation axis of the work rotor 31 of the left work section 3L, and between the right end of the rotation axis of the work rotor 31 of the central work section 3C and the left end of the rotation axis of the work rotor 31 of the left work section 3L. This clutch allows for the switching of power transmission from the rotation axis of the central work unit 3C to the rotation axis of the left work unit 3L and the right work unit 3R when opening and closing the left work unit 3L and the right work unit 3R. In other words, when the left work section 3L and the right work section 3R are in the closed (folded) state, the clutches are disengaged, and power is not transmitted from the rotation axis of the central work section 3C to the rotation axes of the left work section 3L and the right work section 3R. Conversely, when the left work section 3L and the right work section 3R are in the open (unfolded) state, the clutches are engaged, and power is transmitted from the rotation axis of the central work section 3C to the rotation axes of the left work section 3L and the right work section 3R.

[0018] In this embodiment 1, the chain case 23 is positioned on the left side of the left support section, and power is transmitted from the gearbox 21 to the work section 3 via the power transmission shaft in the left support frame 22L and the chain in the chain case 23. However, the chain case may be positioned on the right side of the right support section, and power may be transmitted from the gearbox 21 to the work section 3 via the power transmission shaft in the right support frame 22R and the chain in the chain case. Furthermore, the power transmission from the power transmission shaft to the rotation shaft of the work rotor 31 is not limited to a chain; other known transmission means such as belts and gears may also be used.

[0019] [Working Department] As described above, the work section 3 is divided into three parts: the central work section 3C, the left work section 3L, and the right work section 3R. The left work section 3L and the right work section 3R are configured to be able to be opened and closed relative to the central work section 3C, either folded upwards (closed state) or unfolded to the side (open state). The front and top of the work rotor 31 of the central work section 3C are covered by the central shield cover 32C, the left side by the left support, the right side by the right support, and the rear by the central apron 35C. The front and top of the work rotor 31 of the left work section 3L are covered by the left shield cover 32L, the left side by the left plate 33L, the right side by the right support section, and the rear by the left apron 35L. The front and top of the work rotor 31 of the right work section 3R are covered by the right shield cover 32R, the left side by the left support section, the right side by the right plate 33R, and the rear by the right apron 35R.

[0020] The central shield cover 32C and the left shield cover 32L are connected by a left-rotating support part 34L, the central shield cover 32C and the right shield cover 32R are connected by a right-rotating support part 34R, and the left work section 3L and the right work section 3R are rotatably supported relative to the central work section 3C and are configured to be openable and closable. Furthermore, a left work section opening / closing hydraulic cylinder 24L and a right work section opening / closing hydraulic cylinder 24R are interposed between the central shield cover 32C and the left work section 3L side member of the left rotation support 34L, and between the central shield cover 32C and the right work section 3R side member of the right rotation support 34R, respectively. The left work section opening / closing hydraulic cylinder 24L and the right work section opening / closing hydraulic cylinder 24R are driven independently, and the left work section 3L and the right work section 3R can be opened and closed independently, respectively.

[0021] The central apron 35C, left apron 35L, and right apron 35R are supported at the rear ends of the central shield cover 32C, left shield cover 32L, and right shield cover 32R, respectively. The central leveler 36C, left leveler 36L, and right leveler 36R are supported at the lower ends of the central apron 35C, left apron 35L, and right apron 35R, respectively, so as to be able to rotate vertically. The left apron 35L and right apron 35R, and the left leveler 36L and right leveler 36R are configured to connect to the central apron 35C and central leveler 36C when the left work section 3L and right work section 3R are in the open position, respectively.

[0022] The left end of the left leveler 36L and the right end of the right leveler 36R are rotatably supported by the left extension leveler 37L and the right extension leveler 37R, respectively, and can be opened and closed outwards to the left and right, respectively. The left extension leveler 37L and the right extension leveler 37R are used to pull soil and mud from the side of the work area 3 inwards and to level the soil on the side of the work area 3. The left extension leveler 37L and the right extension leveler 37R are configured to be opened and closed by a motor and wire, and this opening and closing can be operated by remote control.

[0023] The working rotor 31 is provided in the central working section 3C, the left working section 3L, and the right working section 3R, and has working claws for tilling the rice paddy and a rotating shaft (neither of which is shown in the figure) to which the working claws are fixed. The rotation axis of the central work unit 3C is supported by the left support and the right support of the central work unit 3C. The rotation axis of the left work section 3L is supported by the left plate 33L and the support on the right side of the left work section 3L, while the rotation axis of the right work section 3R is supported by the right plate 33R and the support on the left side of the right work section 3R. The working rotor 31 receives power from the power input shaft 211, which is transmitted to the rotating shaft, causing the rotating shaft to rotate. As the rotating shaft rotates, the working claws rotate, performing the puddling operation. In this embodiment 1, the working rotor 31 rotates counterclockwise when viewed from the left side.

[0024] [apron] The central apron 35C, left apron 35L, and right apron 35R (hereinafter collectively referred to as the aprons (ground leveling bodies)) are pivotally supported at the rear ends of the central shield cover 32C, left shield cover 32L, and right shield cover 32R so as to be rotatable in the vertical direction. The apron, located behind the working rotor 31, presses against the mud surface MS, thereby contributing to soil pulverization, leveling of the mud surface MS, and incorporation of straw and other materials into the soil. The left apron 35L and the right apron 35R are each fitted with a left apron pressurizing device 4L and a right apron pressurizing device 4R (hereinafter collectively referred to as apron pressurizing devices (ground leveling pressurizing devices)) between them and the left shield cover 32L and the right shield cover 32R, respectively, to pressurize the aprons downward. As described above, the central apron 35C is configured to connect with the left apron 35L and the right apron 35R when the left work section 3L and the right work section 3R are open. When the left apron pressurizing device 4L and the right apron pressurizing device 4R pressurize the left apron 35L and the right apron 35R, the central apron 35C is also pressurized. Details of the apron pressurizing devices will be described later. Furthermore, the apron pressurizing device is not limited to being interposed between the left shield cover 32L and the left apron 35L, or between the right shield cover 32R and the right apron 35R, but may also be interposed between the central shield cover 32C and the central apron 35C, or it may be interposed only between the central shield cover 32C and the central apron 35C.

[0025] In this embodiment 1, an apron detection means 5 (agricultural machine detection means) for detecting the vertical position of the central apron 35C is installed between the central shield cover 32C and the central apron 35C. Details of the apron detection means will be described later. Note that the apron detection means 5 is not limited to being located in the central work section 3C, but may be located in either the left work section 3L or the right work section 3R, or it may be located in all three: the central work section 3C, the left work section 3L, and the right work section 3R. A rake (not shown in the diagram) is attached to the inner surface of the apron. The rake is located behind the working rotor 31 and, in addition to the action of the apron, further contributes to the pulverization of the field soil and the incorporation of straw and other materials into the field soil.

[0026] [Apron pressurizing device] Figure 2 shows the left apron pressurizing device 4L and apron detection means 5 of Halo A according to Embodiment 1 of the present invention, where (a) shows the apron pressurizing device in the ON state and (b) shows the apron pressurizing device in the OFF state. Note that other components besides the left apron pressurizing device 4L and apron detection means 5 have been omitted as appropriate. The apron pressurizing device is a device that applies downward rotational force to the apron, and acts to press the apron downward, that is, against the mud surface MS (work surface) of the field, by the force of an elastic force-generating member (a coil spring in this embodiment 1). Furthermore, the apron pressurizing device of this embodiment 1 is configured to allow the pressurizing action of the apron to be turned ON / OFF, and the operator turns it ON / OFF considering the field conditions, the desired degree of leveling, etc. The ON / OFF of the apron pressurizing device can be controlled by remote control.

[0027] The apron pressurizing device will be described in detail using the left apron pressurizing device 4L. As shown in Figures 2(a) and 2(b), the left apron pressurizing device 4L includes a left support arm 4L1, a left pressurizing rod 4L2, a left biasing means 4L3, a left pressurizing operating member 4L4, and a left driving means 4L5. The left support arm 4L1 and the left pressurizing operating member 4L4 are rotatably supported on a common left shaft 32L1, which is provided on a bracket (not shown) installed on the left shield cover 32L. The left support arm 4L1 has one end (front end) pivotally supported on the left shaft 32L1, and the other end (rear end) pivotally supports the upper end of the left pressure rod 4L2 by the left shaft 4L6. The upper end of the left pressure rod 4L2 is pivotally supported on the left shaft 4L6 at the rear end of the left support arm 4L1. The lower end of the left pressure rod 4L2 is supported on the left support member 35L2, which is attached to the left pressure bracket 35L1 provided on the left apron 35L. The left support member 35L2 is pivotally supported on the left pressure bracket 35L1 and supports the left pressure rod 4L2 so that it can slide in the longitudinal direction.

[0028] The left biasing means 4L3 is a coil spring. The left biasing means 4L3 is inserted through the left pressure rod 4L2 and mounted so as to fit over the left pressure rod 4L2. The lower end of the left biasing means 4L3 abuts against the left support member 35L2 and is configured to apply a downward force to the left apron 35L via the left pressure bracket 35L1. The upper end of the left biasing means 4L3 abuts against a pin attached to the upper part of the left pressure rod 4L2. This pin is detachable from multiple pin holes provided in the axial direction of the left pressure rod 4L2, and the elastic force applied by the left biasing means 4L3 can be adjusted by selecting the pin hole into which the pin is inserted. Note that other biasing means such as a gas spring or an electric cylinder may be used instead of a coil spring as the left biasing means 4L3.

[0029] The left pressurizing operating member 4L4 is configured in a substantially fan shape and has a left gear portion 4L41 with a gear formed on its outer edge. The gear of the left gear portion 4L41 is configured to mesh with a drive gear (not shown) driven by the left drive means 4L5. The left pressurizing operating member 4L4 has a left contact arm 4L42 that extends to the rear. The left contact arm 4L42 has a left contact portion 4L43 at its rear lower end (see Figure 2(b)). The left pressurizing operating member 4L4 is configured to come into contact with or separate from the left shaft 4L6 of the left support arm 4L1 by the forward and reverse rotation of the left pressurizing operating member 4L4 driven by the left driving means 4L5. In order to prevent displacement when in contact with the left shaft 4L6, a recess is formed in the left contact portion 4L43 that conforms to the shape of the left shaft 4L6. The left drive means 4L5 is an actuator for switching the left apron pressurizing device 4L ON / OFF, and in this embodiment, it is configured as an electric motor. The left apron pressurizing device 4L is turned ON / OFF by the rotational drive of the left drive means 4L5. As shown in Figure 2(a), when the left drive means 4L5 rotates the left pressurizing operating member 4L4 clockwise when viewed from the left, the left contact portion 4L43 contacts the left shaft 4L6 of the left support arm 4L1, pushing the left pressurizing rod 4L2 downward. As a result, the left biasing means 4L3 retracts, and the elastic force of the left biasing means 4L3 strongly presses the left apron 35L downward. As described above, when the left work section 3L and the right work section 3R are in the open position, the left apron 35L and the right apron 35R are configured to be connected to the central apron 35C. Therefore, when the left apron 35L is strongly pressed downward, the central apron 35C is also pressed downward.

[0030] As shown in Figure 2(b), when the left drive means 4L5 rotates the left pressurizing member 4L4 counterclockwise when viewed from the left, the left contact portion 4L43 separates from the left axis 4L6 of the left support arm 4L1. As a result, the left biasing means 4L3 extends, and the pressure on the left apron 35L due to the elastic force of the left biasing means 4L3 is released. Furthermore, in addition to switching the apron pressurization ON / OFF, the strength of the apron pressurization pressure can also be adjusted by adjusting the amount of drive by the left drive means 4L5 when the apron pressurization is ON. In other words, by controlling the drive by the left drive means 4L5 and adjusting the amount of rotation of the left support arm 4L1 within the range in which the left contact portion 4L43 can maintain contact with the left shaft 4L6 of the left support arm 4L1, the strength of the apron pressurization pressure can be adjusted. Furthermore, the right apron pressurizing device 4R is configured in the same way as the left apron pressurizing device 4L.

[0031] [Apron detection means] The apron detection means 5 is a means for detecting the vertical rotation position of the apron. The detected result is transmitted to the tillage depth control device of the vehicle body via the lifting operation lever 53, which will be described later. The tillage depth control device of the vehicle body raises or lowers the harrow A based on the transmitted vertical rotation position (tillage depth information) of the apron, and tillage depth control is performed. In this embodiment 1, the apron detection means 5 is positioned near the left side of the gearbox 21 so as to be interposed between the central shield cover 32C and the central apron 35C of the central work section 3C, and transmits the detection result of the vertical rotation of the apron to the tilling depth control device of the vehicle body via the lifting operation lever 53. The operation of the apron detection means 5 will be changed depending on the operating state of the apron pressurizing device, as will be described in detail later.

[0032] The apron detection means 5 will be described in detail. As shown in Figures 2(a) and 2(b), the apron detection means 5 includes a detection arm 51, a detection rod 52, and a lifting operation lever 53 (lifting operation member). The detection arm 51 is rotatably supported by a detection bracket 35C3 located on the central apron 35C. The detection rod 52 is a component that transmits the movement of the detection arm 51 to the lifting operation lever 53. One end (rear end) is connected to the upper end of the detection arm 51, and the other end (front end) is connected to the lifting operation lever 53. The lifting operation lever 53 is pivotally supported on the left shaft 22L1, and a detection rod 52 is connected to its lower end. The left shaft 22L1 is supported by a mounting part 1, to which a left support frame 22L is connected at the rear and a lower link connecting part is provided at the front. The lifting operation lever 53 also has an engagement part to which a lifting operation rod (not shown), which is provided on the vehicle body and is used to drive (lift) the three-point linkage mechanism of the vehicle body, can be detachably connected.

[0033] In the apron detection means 5 having the structure described above, when the central apron 35C rotates up and down, the detection rod 52 is displaced in the front-rear direction, and the lifting operation lever 53 rotates in the front-rear direction. The detection arm 51 is biased in a direction that pulls the detection rod 52 backward by a coil spring 511 provided on the opposite side from the detection rod 52. One end of the coil spring 511 is connected to the detection arm 51, and the other end is connected to a bracket 35C4 provided on the upper surface of the central apron 35C. Furthermore, the detection bracket 35C3 has a contact portion 35C31 formed therein that restricts the detection arm 51 from rotating backward beyond a predetermined angle. The detection arm 51, which is pulled backward by the coil spring 511, is configured so that it cannot rotate backward beyond a predetermined angle at which it contacts the contact portion 35C31. Therefore, the detection arm 51 maintains a predetermined angle with respect to the central apron 35C by the coil spring 511 and the contact portion 35C31. As a result, while the detection arm 51 maintains a predetermined angle with respect to the central apron 35C, it is possible to displace the detection rod 52 in the front-rear direction in response to the rotation of the central apron 35C.

[0034] When the tilling depth becomes shallow, the central apron 35C is displaced (rotated) downward. When the central apron 35C is displaced (rotated) downward, the detection arm 51 pulls the detection rod 52 backward, causing the lifting operation lever 53 to rotate backward. Conversely, as the tilling depth increases, the central apron 35C is displaced (rotated) upward. When the central apron 35C is displaced (rotated) upward, the detection arm 51 pushes the detection rod 52 forward, causing the lifting operation lever 53 to rotate forward. Thus, the apron detection means 5 is configured to rotate the lifting operation lever 53 back and forth in response to the vertical rotation of the central apron 35C. In other words, the apron detection means 5 detects the vertical rotation of the central apron 35C, outputs the detection result (tilling depth information) as the rotation position of the lifting operation lever 53, and transmits the detection result (tilling depth information) to the tilling depth control device of the vehicle body via the lifting operation rod.

[0035] [Coordination between apron pressurizing device and apron detection means] The left apron pressurizing device 4L and the apron detection means 5 are configured to operate in conjunction, that is, to work in conjunction, via an interlocking wire 54 (modification means) that connects the left pressurizing operating member 4L4 of the left apron pressurizing device 4L and the detection arm 51 of the apron detection means 5. The interlocking wire 54 has one end connected to the left pressurizing operating member 4L4 and the other end connected to the detection arm 51, and transmits the displacement of the left pressurizing operating member 4L4 to the detection arm 51. In the apron detection means 5 having the structure described above, when the left apron pressurizing device 4L turns the apron pressurizing ON / OFF, the left apron 35L rotates up and down, and the central apron 35C connected to the left apron 35L also rotates up and down. As a result, the detection rod 52 is displaced in the front-rear direction in conjunction with the up-and-down rotation of the central apron. More specifically, as shown in Figure 2(a), when the apron pressurization is switched ON, the left pressurization operating member 4L4 rotates clockwise. When the left pressurization operating member 4L4 rotates clockwise, the interlocking wire 54 connected to the left pressurization operating member 4L4 pulls the detection arm 51 against the biasing force of the coil spring 511. This causes the detection arm 51 to push the detection rod 52 forward, rotating the lifting operation lever 53 forward. Conversely, as shown in Figure 2(b), when the apron pressurization is switched to OFF, the left pressurization operating member 4L4 rotates counterclockwise. When the left pressurization operating member 4L4 rotates counterclockwise, the tension on the detection arm 51 by the interlocking wire 54 connected to the left pressurization operating member 4L4 is released. As a result, the detection arm 51 is pulled backward by the coil spring 511, pulling the detection rod 52 backward and causing the lifting operation lever 53 to rotate backward.

[0036] [Tillage depth control] As described above, the detection result of the apron detection means 5 (the rotation state of the lifting operation lever 53 (tilling depth information)) is transmitted to the tilling depth control device of the vehicle body, and the tilling depth of harrow A is controlled. In other words, when the apron detection means 5 detects a downward displacement of the apron by rotating the lifting operation lever 53 backward, the tillage depth control device of the vehicle body, which receives the detection result, determines that the tillage depth has become shallower and drives the lifting means of the vehicle body's three-point linkage mechanism to lower the harrow A and deepen the tillage depth. Conversely, when the apron detection means 5 detects an upward displacement of the apron by rotating the lifting operation lever 53 forward, the tillage depth control device of the vehicle body, which receives the detection result, determines that the tillage depth has become deeper and drives the lifting means of the vehicle body's three-point linkage mechanism to raise the harrow A and shallow the tillage depth. In this manner, the lifting mechanism of the three-point linkage mechanism of the vehicle body is driven based on the detection result of the apron detection means 5. As a result, the lifting and lowering of harrow A is controlled, and the tilling depth of harrow A is adjusted to an appropriate state.

[0037] If the apron pressurizing device and the apron detection means 5 are not coordinated, and the apron pressurizing device is turned ON / OFF while tillage depth control is being performed based on the detection results of the apron detection means 5, it will affect the detection results of the apron detection means, resulting in unnecessary tillage depth control. This will be explained in detail using the left apron pressurizing device 4L and the apron detection means 5. Note that in this explanation, it will be assumed that the interlocking wire 54 is not provided. As shown in Figure 2(a), when the left pressurizing operating member 4L4 rotates clockwise to turn on the apron pressurization, the left contact portion 4L43 of the left contact arm 4L42 contacts the left shaft 4L6 and presses downward. As a result, the left pressurizing rod 4L2 is pressed downward, and the left biasing means 4L3 presses the left apron 35L downward via the left support member 35L2 and the left pressurizing bracket 35L1. When the left apron 35L is pressed downward and rotates downward, the central apron 35C, which is connected to the left apron 35L, also rotates downward. When the apron detection means 5 detects this downward rotation of the central apron 35C, the tillage depth control device of the vehicle body determines that the tillage depth has become shallower and performs control to deepen the tillage depth. However, in reality, the tillage depth has not changed, as only the central apron 35C has rotated downward due to the change in the left apron pressurizing device 4L from a non-operating state to an operating state, resulting in unnecessary tillage depth control.

[0038] Conversely, as shown in Figure 2(b), when the left pressurizing operating member 4L4 rotates counterclockwise to turn off the apron pressurization, the left contact portion 4L43 of the left contact arm 4L42 moves away from the left shaft 4L6, which was in contact with the left shaft 4L6 and pressing downwards. As a result, the left pressurizing rod 4L2, which was being pressed downwards, returns to its upward position, and the left biasing means 4L3 is released from the state in which it was pressing the left apron 35L downwards via the left support member 35L2 and the left pressurizing bracket 35L1. When the left apron 35L is released from the left apron pressurizing device 4L and rotates upward, the central apron 35C, which is connected to the left apron 35L, also rotates upward. When the apron detection means 5 detects this upward rotation of the central apron 35C, the tillage depth control device of the vehicle body determines that the tillage depth has increased and performs control to reduce the tillage depth. However, in reality, the tillage depth has not changed, as only the central apron 35C has rotated upward due to the left apron pressurizing device 4L switching from activated to deactivated, resulting in incorrect tillage depth control.

[0039] Therefore, in this embodiment 1, the left apron pressurizing device 4L and the apron detection means 5 are linked by an interlocking wire 54, thereby preventing unnecessary control of the tillage depth control device of the vehicle body based on the detection results of the apron detection means 5. As described above, when the apron pressurization is turned ON, the left apron 35L is pressed downward and rotates downward, and the central apron 35C, which is connected to the left apron 35L, also rotates downward. This downward rotation of the central apron 35C has the effect of moving the detection rod 52 backward. To turn on the apron pressurization, rotating the left pressurization operating member 4L4 to one side, i.e., clockwise, causes the interlocking wire 54, to which the left pressurization operating member 4L4 is connected, to pull the detection arm 51, moving the detection rod 52 forward. In other words, when the apron pressurization is turned on, the interlocking wire 54 acts to move the detection rod 52 forward. Therefore, the effect of moving the detection rod 52 backward due to the downward rotation of the central apron 35C caused by turning on the apron pressurization, and the effect of moving the detection rod 52 forward via the detection arm 51 by the interlocking wire 54 cancel each other out (cancel each other out), and the detection rod 52 does not move. For this reason, the apron detection means 5 can be prevented from detecting the downward rotation of the central apron 35C caused by turning on the apron pressurization. When the apron pressurization is turned on, the detection arm 51 is maintained at a predetermined angle with respect to the central apron 35C by the interlocking wire 54 and the coil spring 511. Therefore, the detection arm 51 maintains a predetermined angle with respect to the central apron 35C, and in response to the rotation of the central apron 35C, it is possible to displace the detection rod 52 in the front-rear direction.

[0040] Conversely, when the apron pressurization is turned OFF, the left apron 35L rotates upward, and the central apron 35C, which is connected to the left apron 35L, also rotates upward. This upward rotation of the central apron 35C causes the detection rod 52 to move forward. To turn off the apron pressure, the left pressure operating member 4L4 is rotated counterclockwise, to the opposite side from when the apron pressure is turned ON. This loosens the interlocking wire 54 to which the left pressure operating member 4L4 is connected. As the interlocking wire 54 loosens, the detection arm 51 moves (rotates) backward due to the tensile force of the coil spring 511, and moves the detection rod 52 backward. In other words, when the apron pressure is turned OFF, the tensile force of the coil spring 511 acts to move the detection rod 52 backward. Therefore, the forward movement of the detection rod 52 due to the upward rotation of the central apron 35C caused by turning off the apron pressure and the backward movement of the detection rod 52 via the detection arm 51 by the coil spring 511 cancel each other out, and the detection rod 52 does not move. Therefore, the apron detection means 5 can be prevented from detecting the upward rotation of the central apron 35C due to the apron pressurization being turned OFF. In other words, in the harrow A of this embodiment 1, the movement of the detection rod 52 caused by the ON / OFF switching of the left apron pressurizing device, which occurred in conventional harrows, is eliminated. In other words, the operation of the detection arm 51 (apron detection means 5) is changed so that the detection result of the apron detection means 5 does not change before and after the ON / OFF switching of the left apron pressurizing device. This prevents unnecessary tillage depth control by the tillage depth control device of the vehicle body caused by the ON / OFF switching of the apron pressurizing device during operation, and ensures that the tillage depth of harrow A does not change.

[0041] In this embodiment 1, the apron detection means 5 is located in the central work area 3C, but the apron detection means 5 may also be located near the left apron pressurizing device 4L or near the right apron pressurizing device 4R. Furthermore, the apron detection means 5 can be placed in two locations, near the left apron pressurizing device 4L and near the right apron pressurizing device 4R. In this case, the two apron detection means 5 are configured to be connectable to the lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 of the left apron 35L and the detection results of the apron detection means 5 of the right apron 35R.

[0042] Furthermore, the apron detection means 5 can also be placed in three locations: near the central work section 3C, near the left apron pressurizing device 4L, and near the right apron pressurizing device 4R. The three apron detection means 5 are configured to be connectable to the lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 located in the central work section 3C, the apron detection means 5 located near the left apron pressurizing device 4L, and the apron detection means 5 located near the right apron pressurizing device 4R.

[0043] Furthermore, the configuration for linking the left apron pressurizing device 4L and the apron detection means 5 is not limited to a configuration in which the left pressurizing operating member 4L4 and the detection arm 51 are connected by an interlocking wire 54. Alternatively, a member may be provided that operates in conjunction with the operation of the left apron pressurizing device 4L, or together with the operation of the left apron pressurizing device 4L, and this member may be connected to the detection arm 51 by a wire or the like. Furthermore, as described above, if the apron pressurization can be switched ON / OFF, and the strength of the apron pressurization pressure can be adjusted when the apron pressurization is ON, the amount that the interlocking wire 54 pulls the detection arm 51 will change according to the strength of the pressurization pressure, and the detection result of the apron detection means 5 will not change depending on the strength of the pressurization pressure of the left apron pressurization device 4L.

[0044] [Example 1] Figure 3 shows the left apron pressurizing device 4L and apron detection means 5 of Halo A in Modification 1 of Embodiment 1 of the present invention, with the apron pressurizing device in the ON state. Other components other than the left apron pressurizing device 4L and apron detection means 5 have been omitted as appropriate. In the above-described embodiment 1, the apron pressurizing device and the apron detection means 5 were linked by a wire to adjust the movement of the detection rod 52 based on the ON / OFF state of the apron pressurizing device, thereby changing the operation of the detection arm 51 before and after the ON / OFF switching of the apron pressurizing device so that the detection result of the apron detection means 5 does not change due to the ON / OFF switching of the apron pressurizing device. However, in this modified example 1, the detection result of the apron detection means 5 is corrected based on the electrical detection of the ON / OFF state of the apron pressurizing device, thereby preventing unnecessary tillage depth control of the harrow A by the tillage depth control device of the vehicle body caused by the ON / OFF switching of the apron pressurizing device. Specifically, in a vehicle body tillage depth control device that raises and lowers a three-point linkage mechanism based on the detection result of an apron detection means, the vehicle body tillage depth control device corrects the detection result (tillage depth information) of the apron detection means 5 by detecting the ON / OFF status of the apron pressurizing device, and raises and lowers the three-point linkage mechanism based on the corrected detection result.

[0045] The tillage depth control of Modification 1 will be explained in detail using the left apron pressurizing device 4L and the apron detection means 5. In this modified example 1, the ON / OFF status of the left apron pressurizing device 4L is detected by a pressurizing detection means 55 that detects the relative rotational angle displacement between the left support arm 4L1 and the left pressurizing operating member 4L4. When the left apron pressurizing device 4L is switched ON or OFF, the rotational drive of the left drive means 4L5 causes the angle between the left support arm 4L1 and the left pressurizing operating member 4L4 to change by a predetermined angle. Therefore, the pressurizing detection means 55 is composed of a rotational position detection sensor such as a potentiometer or rotary encoder, and the ON / OFF status of the left apron pressurizing device 4L can be detected by detecting the relative angle change of the left pressurizing operating member 4L4 with respect to the left support arm 4L1. Alternatively, instead of a rotational position detection sensor, two switches may be provided to detect the position of the left pressurizing operating member 4L4 when the left apron pressurizing device 4L is turned ON or OFF, thereby detecting the ON / OFF status of the left apron pressurizing device 4L. The two switches are arranged such that when the left apron pressurizing device 4L is switched ON and the left pressurizing operating member 4L4 changes angle to a predetermined position, one of the two switches turns ON by the left pressurizing operating member 4L4 or a member that displaces in conjunction with the rotation of the left pressurizing operating member 4L4. When the left apron pressurizing device 4L is switched OFF and the left pressurizing operating member 4L4 changes angle to a predetermined position, the other of the two switches turns ON by the left pressurizing operating member 4L4 or a member that displaces in conjunction with the rotation of the left pressurizing operating member 4L4. By detecting the ON / OFF status of the two switches arranged in this way, it is possible to detect the ON / OFF status of the left apron pressurizing device 4L.

[0046] Furthermore, in this modified example 1, as in Embodiment 1, the apron detection means 5 is displaced in the front-rear direction by the vertical movement of the central apron 35C, causing the lifting operation lever 53 to rotate back and forth. In this modified example 1, the detection rod 52 is directly connected to the detection bracket 35C3 provided on the central apron 35C, without going through the detection arm 51. In this modified example 1, the tillage depth control device of the vehicle body is configured to receive not only the detection result of the apron detection means 5, but also the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55. Based on this received information, the tillage depth control device of the vehicle body controls the tillage depth of harrow A. More specifically, the tillage depth control device of the vehicle body corrects the detection result of the apron detection means 5, which has been transmitted, based on the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55. Here, the detection result of the pressure detection means 55 refers to the detection result of the rotation position detection sensor in this modified example 1, and is information regarding the rotation position or rotation angle detected by the rotation position detection sensor. If the pressure detection means 55 is configured as a switch, the ON / OFF information of the switch corresponds to the detection result of the pressure detection means 55. The information based on the detection result of the pressure detection means 55 is information calculated (created) by the agricultural machinery control device based on the detection result of the pressure detection means 55, and includes, for example, information indicating the ON / OFF status of the left apron pressurizing device 4L.

[0047] Furthermore, the transmission of the detection result of the apron detection means 5 to the tilling depth control device of the vehicle body is performed via a lifting operation rod connected to the lifting operation lever 53, as in Embodiment 1. The detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, is transmitted to the tillage depth control device of the vehicle body via the agricultural implement control device (transmission means) mounted on the harrow A. Alternatively, the detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, may be transmitted from the pressure detection means 55 to the tillage depth control device of the vehicle body without going through the agricultural implement control device. The transmission of the detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, may be done by wireless or wired communication.

[0048] The following describes in detail the operation of the vehicle's tillage depth control device to prevent unnecessary tillage depth control. When the left apron pressurizing device 4L is turned ON, the apron detection means 5 detects the downward rotation of the central apron 35C connected to the left apron 35L. At the same time, the pressurizing detection means 55 detects a predetermined amount of displacement in the relative rotation angle between the left support arm 4L1 and the left pressurizing operating member 4L4. When the agricultural implement control device transmits the detection result of the pressurizing detection means 55, or information based on the detection result of the pressurizing detection means 55, to the vehicle's tillage depth control device, the vehicle's tillage depth control device cancels the detection result of the apron detection means 5 that the central apron 35C has rotated downward. Specifically, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the memory device of the tillage depth control device of the vehicle body stores a correction table in which a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF are set for the detection result of the pressure detection means 55 transmitted. Based on the detection result of the pressure detection means 55 transmitted and the correction table, the tillage depth control device of the vehicle body determines whether the left apron pressure device 4L is ON or OFF.

[0049] Furthermore, when information based on the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle, the storage device of the agricultural implement control device stores a correction table in which a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF are set for the detection result of the pressure detection means 55. When the agricultural implement control device transmits information regarding the ON / OFF status of the left apron pressure device 4L determined by the correction table, the tillage depth control device of the vehicle determines whether the left apron pressure device 4L is ON or OFF from the transmitted information based on the detection result of the pressure detection means 55. Then, when the tillage depth control device of the vehicle body determines that the left apron pressurizing device 4L has been switched from OFF to ON, the detection result by the apron detection means 5 that the central apron 35C has rotated downward is assumed to be due to the left apron pressurizing device 4L being turned ON, and therefore the detection result by the apron detection means 5 that the central apron 35C has rotated downward is canceled. In other words, the tillage depth control device of the vehicle body receives information from the agricultural implement control device based on the detection result of the pressure detection means 55, or the detection result that the left apron pressure device 4L of the pressure detection means 55 has applied pressure. When it determines that the left apron pressure device 4L has switched from OFF to ON, even if the apron detection means 5 transmits a detection result that the central apron 35C has rotated downward, it does not perform control to raise the three-point linkage mechanism (lifting means), and the tillage depth control device of the vehicle body does not perform unnecessary tillage depth control. In this case, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotation direction and amount of rotation of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod.

[0050] To prevent unnecessary tillage depth control, the tillage depth control device of the vehicle body is not limited to a configuration that cancels the detection result of the apron detection means 5, as described above. For example, if the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the tillage depth control device of the vehicle body can take into account the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and control the drive of the lifting means to raise and lower the three-point linkage mechanism, thereby preventing the tillage depth control device of the vehicle body from performing unnecessary tillage depth control. In a configuration in which the drive control of the lifting means prevents unnecessary configuration control of the tillage depth control device of the traveling vehicle, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the traveling vehicle, the storage device of the tillage depth control device of the traveling vehicle stores a correction table that sets a threshold for determining whether the left apron pressure device 4L is ON, a threshold for determining whether the left apron pressure device 4L is OFF, the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON, and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, based on the detection result of the pressure detection means 55 transmitted from the agricultural implement control device. Note that the correction table is not limited to setting both the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, but may also be set only for the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON.

[0051] The tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is ON or OFF based on the detection result of the pressurizing detection means 55 and a correction table. If the left apron pressurizing device 4L is ON, it corrects the detection result of the apron detection means 5 based on the correction table and adjusts the drive amount of the lifting means (lifting amount of the three-point linkage mechanism). In this case, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotational position of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod. Furthermore, in a configuration that prevents unnecessary tillage depth control of the vehicle body's tillage depth control device, i.e., unnecessary drive control of the lifting means, when information based on the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the vehicle body's tillage depth control device, the storage device of the vehicle body's tillage depth control device stores a correction table that sets the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON, and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF. Note that the correction table is not limited to setting both the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON, and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, but may also be set only for the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON. The tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is ON or ON based on the information obtained from the detection result of the pressurizing detection means 55. If the left apron pressurizing device 4L is ON, the detection result of the apron detection means 5 is corrected based on the correction table, and the drive amount of the lifting means (lifting amount of the three-point linkage mechanism) is adjusted. In this case as well, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotational position of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod. The correction data for correcting the detection result of the apron detection means 5 can be any data that can be used to correct the detection result of the apron detection means 5. For example, it may be data indicating the amount of rotation of the apron, data relating to the amount of movement (rotation) of the lifting operation lever 53, or data relating to the amount of drive of the lifting means of the apron detection means 5.

[0052] Conversely, when the left apron pressurizing device 4L is turned OFF, just as when the left apron pressurizing device 4L is turned ON, control can be performed based on the detection result of the apron detection means 5 and the detection result of the pressurizing detection means 55, or information based on the detection result of the pressurizing detection means 55, thereby preventing the tillage depth control device of the vehicle from performing unnecessary tillage depth control. When the left apron pressurizing device 4L is turned OFF, the apron detection means 5 detects the upward rotation of the central apron 35C connected to the left apron 35L, and at the same time, the pressurizing detection means 55 detects a predetermined amount of displacement in the relative rotation angle between the left support arm 4L1 and the left pressurizing operating member 4L4. When the agricultural implement control device transmits the detection result of the pressurizing detection means 55, the tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is OFF or OFF based on the transmitted detection result of the pressurizing detection means 55 and the correction table. When the tillage depth control device of the vehicle body transmits information regarding the ON / OFF status of the left apron pressurizing device 4L, which the agricultural implement control device determined based on the correction table, as information based on the detection result of the pressurizing detection means 55, the tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is ON or OFF from the transmitted information. Then, when the tillage depth control device of the vehicle determines that the left apron pressurizing device 4L has been switched from ON to OFF, it cancels the detection result from the apron detection means 5 that the central apron 35C has rotated upward. As a result, even if the tillage depth control device of the vehicle receives a detection result from the apron detection means 5 that the central apron 35C has rotated upward, it does not perform the control to lower the three-point linkage mechanism. Furthermore, even when the left apron pressurizing device 4L is turned OFF, the vehicle body's tillage depth control device may use a correction table stored in the vehicle body's tillage depth control device to add the detection result of the pressurizing detection device 55 to the detection result of the apron detection device 5, and then perform drive control of the lifting device. In this way, by adding the detection result of the pressure detection means 55 to the detection result of the apron detection means 5, unnecessary tillage depth control of the tillage depth control device of the vehicle body, which may be performed due to the ON / OFF switching of the apron pressure device, is prevented.

[0053] Furthermore, since the amount of rotation of the central apron 35C when the left apron pressurizing device 4L is turned ON / OFF varies depending on the soil type, when using the correction table as described above, it is possible to store a correction table corresponding to each soil type. In this case, it becomes possible to select a correction table according to the soil type of the field being worked on, enabling more accurate tillage depth control. The user can select the correction table directly from multiple options, or the field and correction table can be associated and stored, and the tillage depth control device can select the correction table corresponding to the field being worked on. Furthermore, in this modified example 1, the pressure detection means 55 is installed to detect the relative rotational angle displacement between the left support arm 4L1 and the left pressure operating member 4L4, but it can also be installed to detect the rotational angle of the left pressure operating member 4L4 with respect to the work section 3.

[0054] Furthermore, in this modified example 1, the apron detection means 5 is located in the central work section 3C, similar to Embodiment 1. However, the apron detection means 5 may be located near the left apron pressurizing device 4L or near the right apron pressurizing device 4R. Also, although the pressurizing detection means 55 is configured to detect the relative rotational angle displacement between the left support arm 4L1 of the left apron pressurizing device 4L and the left pressurizing operating member 4L4, it may be configured to detect the relative rotational angle displacement between the right support arm and the right pressurizing operating member of the right apron pressurizing device 4R. Furthermore, it is also possible to place the apron detection means 5 in two locations, near the left apron pressurizing device 4L and near the right apron pressurizing device 4R, and install two pressurizing detection means 55: one that detects the relative rotational angle displacement between the left support arm 4L1 of the left apron pressurizing device 4L and the left pressurizing operating member 4L4, and another that detects the relative rotational angle displacement between the right support arm and the right pressurizing operating member of the right apron pressurizing device 4R. In this case, the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 of the left apron 35L and the detection results of the apron detection means 5 of the right apron 35R.

[0055] Furthermore, the apron detection means 5 can also be placed in three locations: near the central work section 3C, near the left apron pressurizing device 4L, and near the right apron pressurizing device 4R. The three apron detection means 5 are configured to be connectable to the lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means placed in the central work section 3C, the detection results of the apron detection means 5 placed near the left apron pressurizing device 4L, and the detection results of the apron detection means 5 placed near the right apron pressurizing device 4R.

[0056] Furthermore, in Embodiment 1, instead of the interlocking wire 54, a drive device capable of rotatable detection arm 51 may be provided, and a pressure detection means 55 may be provided to detect the relative rotational angle displacement between the left support arm 4L1 and the left pressure operating member 4L4, and the detection arm 51 may be rotated by an actuator or the like based on the detection result of the pressure detection means 55. In addition, instead of the configuration in which the detection arm 51 is rotated, a configuration in which the detection rod 52 is moved or a configuration in which the lifting operation lever 53 is rotated may also be used.

[0057] [Differentiation 2] In the above-described modification 1, the detection result of the apron detection means 5 is transmitted to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body receives the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and corrects the detection result of the apron detection means 5. This modification 2, like modification 1, corrects the detection result of the apron detection means 5 based on the electrical detection of the ON / OFF state of the apron pressure device, and prevents unnecessary tillage depth control of the harrow A by the tillage depth control device of the vehicle body caused by the ON / OFF switching of the apron pressure device. However, the configuration in which the tillage depth control device of the vehicle body acquires the detection result of the apron detection means 5 differs from that of modification 1. Specifically, in a configuration in which the agricultural implement control device mounted on Harrow A receives the detection result of the apron detection means 5 and transmits (transmits) the detection result of the apron detection means 5 to the tillage depth control device of the vehicle body, the agricultural implement control device receives the detection result of the pressure detection means 55 and transmits (transmits) the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, to the tillage depth control device of the vehicle body.

[0058] In this modified example 2, the lifting operation lever 53 and the lifting operation rod are not connected. Instead, the apron detection means 5 is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. The agricultural implement control device in this modified example 2 receives the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53 and transmits the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53, or information based on the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53, to the tillage depth control device of the vehicle. The detection result of the sensor that detects the amount of rotation of the lifting operation lever 53 may be transmitted to the tillage depth control device of the vehicle without going through the agricultural implement control device. The transmission of the detection result of the apron detection means 5 to the tillage depth control device of the vehicle can be done by wireless or wired communication. The apron detection means 5 is not limited to a configuration that is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53, but can be configured to detect the direction and amount of rotation of the vertical rotation of the central apron 35C. Furthermore, in this modified example 2, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, similar to modified example 1, a correction table is stored in the memory of the tillage depth control device of the vehicle body, which sets a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF, based on the detection result of the pressure detection means 55 transmitted. The tillage depth control device of the vehicle body determines whether the left apron pressure device 4L is ON or OFF based on the detection result of the pressure detection means 55 transmitted and the correction table. Furthermore, in this modified example 2, when the ON / OFF information of the left apron pressurizing device 4L, determined by the agricultural implement control device based on the correction table, is transmitted to the tillage depth control device of the vehicle body as information based on the detection result of the pressurization detection means 55, the tillage depth control device of the vehicle body determines whether the transmitted information based on the detection result of the pressurization detection means 55 is ON or OFF information for the left apron pressurizing device 4L, similar to modified example 1.

[0059] Then, when the tillage depth control device of the vehicle body determines that the left apron pressurizing device 4L has switched from OFF to ON, the detection result by the apron detection means 5 that the central apron 35C has rotated downward is assumed to be due to the left apron pressurizing device 4L being turned ON, and therefore the detection result by the apron detection means 5 that the central apron 35C has rotated downward is canceled. In other words, the tillage depth control device of the vehicle body receives information from the agricultural implement control device based on the detection result of the pressure detection means 55, or the detection result that the left apron pressurizing device 4L of the pressure detection means 55 has applied pressure. When it determines that the left apron pressurizing device 4L has transitioned from OFF to ON, even if the apron detection means 5 transmits a detection result that the central apron 35C has rotated downward, it does not perform control to raise the three-point linkage mechanism (lifting means), and the tillage depth control device of the vehicle body does not perform unnecessary tillage depth control. In this case, the agricultural implement control device may detect the rotation direction and amount of the central apron 35C from the detection result of the apron detection means 5 and transmit it to the tillage depth control device of the vehicle body, or, as in the modified example 1, the tillage depth control device of the vehicle body may be equipped with a sensor that detects the rotation direction and amount of the central apron 35C from the received detection result of the apron detection means 5. In addition, in this modified version 2, similar to modified version 1, the agricultural implement control device may store a threshold value for the detection result of the pressure detection means 55 for determining whether the apron pressurizing device is ON or OFF, or the storage device of the tillage depth control device of the traveling vehicle body may store a threshold value for the detection result of the pressure detection means 55 for determining whether the apron pressurizing device is ON or OFF. Furthermore, in this modified example 2, similar to modified example 1, the tillage depth control device of the vehicle body may correct the detection result of the apron detection means 5 so as to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF of the apron pressurizing device. In this way, by adding the detection result of the pressure detection means 55 to the detection result of the apron detection means 5, unnecessary tillage depth control of the tillage depth control device of the vehicle body, which may be performed due to the ON / OFF switching of the apron pressure device, is prevented.

[0060] [Difference 3] In the above-described modification 1, the detection result of the apron detection means 5 is transmitted to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body receives the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and the tillage depth control device of the vehicle body corrects the detection result of the apron detection means 5. However, in this modification 3, the agricultural implement control device (correction means) mounted on the harrow A corrects the detection result of the apron detection means 5, and the tillage depth control device of the vehicle body raises and lowers the three-point linkage mechanism based on the corrected detection result transmitted from the agricultural implement control device (correction means). Specifically, the agricultural machine control device receives the detection results from the apron detection means 5 and the pressure detection means 55, and the agricultural machine control device corrects the detection results from the apron detection means 5 by taking into account the detection results from the pressure detection means 55. That is, if the agricultural machine control device determines, based on the detection results from the pressure detection means 55, that the apron pressure device has been turned ON (switched from OFF to ON), it corrects the detection results from the apron detection means 5 so as to cancel the detection result that the central apron 35C has rotated downward, or to offset the amount of downward rotation of the central apron 35C that occurs when the apron pressure device is turned ON. If the agricultural machine control device determines, based on the detection results from the pressure detection means 55, that the apron pressure device has been turned OFF (switched from ON to OFF), it corrects the detection results from the apron detection means 5 so as to cancel the detection result that the central apron 35C has rotated upward, or to offset the amount of upward rotation of the central apron 35C that occurs when the apron pressure device is turned OFF. The agricultural implement control device then transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. Based on the detection result of the apron detection means 5 corrected by the apron detection means 5, the tillage depth control device drives the lifting mechanism of the vehicle body's three-point linkage mechanism to control the tillage depth of the harrow A. The transmission of the detection result of the apron detection means 5 (including the corrected detection result) to the tillage depth control device of the vehicle body can be done by wireless or wired communication. In this modified example 3, the lifting operation lever 53 and the lifting operation rod are not connected. Instead, the apron detection means 5 is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. The apron detection means 5 is not limited to a configuration that is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. It is acceptable as long as it is a configuration that can detect the direction and amount of rotation of the vertical rotation of the central apron 35C, or a configuration that can detect the rotational position of the central apron 35C.

[0061] Similar to Modification 1, the storage device of the agricultural machinery control device in Modification 3 stores a threshold value for the detection result of the pressure detection means 55, which is used to determine whether the apron pressurizing device is ON or OFF. When correcting the detection result of the apron detection means 5 to cancel it, a correction table is used in which a threshold value for determining whether the apron pressurizing device is ON or OFF is set for the detection result of the pressurizing detection means 55. The agricultural implement control device determines whether the apron pressurizing device is ON or OFF based on the transmitted detection result of the pressurizing detection means 55 and the correction table stored in the storage device. When it determines that the apron pressurizing device is ON or OFF, it corrects the detection result of the apron detection means 5 to cancel it and transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. Furthermore, in this modified example 3, the agricultural machinery control device may correct the detection result of the apron detection means 5 so as to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF of the apron pressurizing device. In this case, the storage device of the agricultural machinery control device stores a threshold value for the detection result of the pressurizing detection means 55 for determining whether the apron pressurizing device is ON or OFF, similar to modified example 1. It also stores correction data for correcting the detection result of the apron detection means 5 when it is determined that the apron pressurizing device is ON, and correction data for correcting the detection result of the apron detection means 5 when it is determined that the apron pressurizing device is OFF. The correction data for correcting the detection result of the apron detection means 5 only needs to be usable to correct the detection result of the apron detection means 5. For example, it may be data indicating the amount of rotation of the apron, data relating to the amount of movement (rotation) of the lifting operation lever 53, or data relating to the amount of drive of the lifting means of the apron detection means 5.

[0062] When correcting the detection result of the apron detection means 5 to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF state of the apron pressurizing device, the agricultural implement control device uses a threshold value stored in the memory device for determining whether the left apron pressurizing device 4L is ON or OFF, correction data to be applied when the left apron pressurizing device 4L is determined to be ON, and correction data to be applied when the left apron pressurizing device 4L is determined to be OFF, to determine whether the apron pressurizing device is ON or OFF. When the ON or OFF state of the apron pressurizing device is determined, the control device corrects the detection result from the apron detection means 5 using the corresponding correction data. The agricultural implement control device then transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. In this way, the agricultural implement control device corrects the detection result from the apron detection means 5 to counteract the upward or downward rotation of the central apron 35C caused by the ON / OFF switching of the apron pressurizing device, and transmits the corrected detection result from the apron detection means 5 to the tillage depth control device of the vehicle body, thereby preventing unnecessary tillage depth control by the tillage depth control device of the vehicle body that may be performed due to the ON / OFF switching of the apron pressurizing device during operation.

[0063] [Differentiation Example 4] In the above-described modification 3, the detection result (including the corrected detection result) of the apron detection means 5 was transmitted to the tillage depth control device of the vehicle body. However, in this modification 4, the agricultural implement control device creates tillage depth control information for controlling the tillage depth control device of the vehicle body based on the detection result of the pressure detection means 55 and transmits this to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body raises and lowers the three-point linkage mechanism based on the transmitted tillage depth control information. In this case, the storage device of the agricultural implement control device stores a correction table that sets a threshold for determining whether the left apron pressurizing device 4L is ON or OFF, the amount of drive for the lifting means of the three-point linkage mechanism to be driven when the left apron pressurizing device 4L is determined to be ON, and the amount of drive for the lifting means of the three-point linkage mechanism to be driven when the left apron pressurizing device 4L is determined to be OFF. Based on the detection result (rotation amount) of the pressurizing detection means 55 and the correction table, the agricultural implement control device determines whether the left apron pressurizing device 4L is ON or OFF and calculates the amount of drive for the lifting means corresponding to that determination result. Then, when the agricultural implement control device transmits the calculated information regarding the amount of drive for the lifting means as tillage depth control information to the tillage depth control device of the vehicle body, the tillage depth control device of the vehicle body controls the driving of the lifting means of the three-point linkage mechanism based on the transmitted tillage depth control information. Thus, if the tillage depth control device of the vehicle body controls the drive of the lifting mechanism based on tillage depth control information transmitted from the agricultural implement control device, unnecessary tillage depth control by the tillage depth control device of the vehicle body, which may be performed due to the ON / OFF switching of the apron pressurizing device, can be prevented.

[0064] [Embodiment 2] Figure 4 shows the left apron pressurizing device 4L and apron detection means 5 of Halo A according to Embodiment 2 of the present invention, where (a) shows the apron pressurizing device in the ON state and (b) shows the apron pressurizing device in the OFF state. Note that other components besides the apron pressurizing device and apron detection means 5 have been omitted as appropriate. The apron pressurizing device is a device that applies downward rotational force to the apron, and acts to press the apron against the mud surface MS of the field by the force of an elastic force-generating member (a gas spring in this embodiment 2). Furthermore, the apron pressurizing device in this second embodiment is configured to allow the pressurizing action of the apron to be turned ON / OFF, similar to the first embodiment, and the operator turns it ON / OFF considering the field conditions, the desired degree of leveling, etc. The apron pressurizing device can be turned ON / OFF by remote control. In addition, although not shown in the figures, in the second embodiment, unlike the first embodiment, the apron pressurizing devices 4L and 4R (hereinafter collectively referred to as the apron pressurizing devices (ground leveling pressurizing devices)) of the harrow A are interposed between the central shield cover 32C and the central apron 35C, respectively, on the left and right sides of the central work section 3C.

[0065] [Apron pressurizing device] As shown in Figures 4(a) and 4(b), the left apron pressurizing device 4L includes a left support arm 4L1, a left pressurizing rod 4L2, a left biasing means 4L3, a left pressurizing operating member 4L4, a left driving means 4L5, and a left biasing means support member 4L7. The left support arm 4L1 is a roughly triangular member, and its front end is rotatably supported on a left shaft 32C1 provided on a bracket installed on the central shield cover 32C. The rear end of the left support arm 4L1 rotatably supports the upper end of the left pressure rod 4L2 by a left shaft 4L6. Furthermore, the upper end of the left support arm 4L1 rotatably supports the rear end of the left biasing means 4L3. The upper end of the left pressure rod 4L2 is pivotally supported on the left shaft 4L6 at the rear end of the left support arm 4L1. The lower end of the left pressure rod 4L2 is supported on a shaft attached to the left pressure bracket 35C1, which is provided on the central apron 35C. The left biasing means 4L3 is a gas spring. The rear end of the left biasing means 4L3 is rotatably supported by the upper end of the left support arm 4L1, and the front end of the left biasing means 4L3 is rotatably supported by the left biasing means support member 4L7. Note that a biasing means other than a gas spring, such as a coil spring, may be used as the left biasing means 4L3.

[0066] The left pressurizing operating member 4L4 and the left biasing means support member 4L7 are rotatably supported on a common left shaft 22L2 installed on the left support frame 22L. A left drive means 4L5 is interposed between the left pressurizing operating member 4L4 and the central shield cover 32C. The left drive means 4L5 functions as an actuator for the left apron pressurizing device 4L, and in this embodiment, it is composed of an electric hydraulic cylinder. The left pressurizing operating member 4L4 has an elongated hole 4L44 formed in an arc shape centered on the left shaft 22L2. The left biasing means support member 4L7 has a projection 4L71 formed to engage with the elongated hole 4L44. As a result, the left pressurizing operating member 4L4 and the left biasing means support member 4L7 can rotate relative to each other within the range in which the elongated hole 4L44 and the projection 4L71 engage. The left pressurizing operating member 4L4 is configured to rotate in the front-rear direction by the extension and retraction of the left driving means 4L5, thereby adjusting the rotational position of the left biasing means support member 4L7. The left biasing means support member 4L7 defines the position of the front end of the left biasing means 4L3 and switches the left apron pressurizing device 4L on and off using the left biasing means 4L3.

[0067] To explain in detail, as shown in Figure 4(a), when the left drive means 4L5 contracts, the left pressurizing operating member 4L4 rotates in the rearward direction (counterclockwise). Then, the upper end of the elongated hole 4L44 of the left pressurizing operating member 4L4 comes into contact with the projection 4L71 of the left biasing means support member 4L7, and the left biasing means support member 4L7 also rotates in the rearward direction (counterclockwise). Due to the rotation of the left biasing means support member 4L7, the front end of the left biasing means 4L3 moves rearward, and the left biasing means 4L3 contracts. The elastic force caused by the contraction of the left biasing means 4L3 is transmitted to the left pressure rod 4L2 via the left support arm 4L1, and the left pressure rod 4L2 strongly presses against the left pressure bracket 35C1. As shown in Figure 4(b), when the left drive mechanism 4L5 extends, the left pressurizing operating member 4L4 rotates forward (clockwise). As a result, the upper end of the elongated hole 4L44 of the left pressurizing operating member 4L4 separates from the projection 4L71 of the left biasing mechanism support member 4L7. When the upper end of the elongated hole 4L44 of the left pressurizing operating member 4L4 separates from the protrusion 4L71 of the left biasing means support member 4L7, the elastic force of the left biasing means 4L3 is no longer transmitted to the left pressurizing rod 4L2, and the pressure on the central apron 35C is released. In addition to switching the apron pressurization ON / OFF, it is also possible to adjust the strength of the apron pressurization pressure when the ON state is achieved by controlling the drive amount (expansion / contraction amount) of the left drive means 4L5. Furthermore, the right apron pressurizing device 4R is configured in the same way as the left apron pressurizing device 4L.

[0068] [Apron detection means] The apron detection means 5 in this second embodiment is configured in the same way as the apron detection means 5 in the first embodiment. As shown in Figures 4(a) and 4(b), the apron detection means 5 includes a detection arm 51, a detection rod 52, and a lifting / lowering operation lever 53. In the apron detection means having the structure described above, when the central apron 35C moves up and down, the detection rod 52 is displaced in the front-rear direction. The detection arm 51 is biased in a direction that pulls the detection rod 52 backward by a coil spring 511 provided on the opposite side from the detection rod 52. One end of the coil spring 511 is connected to the detection arm 51, and the other end is connected to a bracket 35C4 provided on the upper surface of the central apron 35C. Furthermore, the detection bracket 35C3 has a contact portion 35C31 formed therein that restricts the detection arm 51 from rotating backward beyond a predetermined angle. The detection arm 51, which is pulled backward by the coil spring 511, is configured so that it cannot rotate backward beyond a predetermined angle at which it contacts the contact portion 35C31. Therefore, the detection arm 51 maintains a predetermined angle with respect to the central apron 35C by the coil spring 511 and the contact portion 35C31. As a result, while the detection arm 51 maintains a predetermined angle with respect to the central apron 35C, it is possible to displace the detection rod 52 in the front-rear direction in response to the rotation of the central apron 35C.

[0069] When the tilling depth becomes shallow, the central apron 35C is displaced (rotated) downward. When the central apron 35C is displaced (rotated) downward, the detection arm 51 pulls the detection rod 52 backward, causing the lifting operation lever 53 to rotate backward. Conversely, as the tilling depth increases, the central apron 35C is displaced (rotated) upward. When the central apron 35C is displaced (rotated) upward, the detection arm 51 pushes the detection rod 52 forward, causing the lifting operation lever 53 to rotate forward. In this manner, the apron detection means 5 detects the vertical rotation of the central apron 35C, outputs the detection result (tillage depth information) as the rotation position of the lifting operation lever 53, and transmits the detection result (tillage depth information) to the tillage depth control device of the vehicle body.

[0070] [Coordination between apron pressurizing device and apron detection means] The left apron pressurizing device 4L and the apron detection means 5 are configured to operate in conjunction, that is, to work in conjunction, via an interlocking wire 54 (modification means) that connects the left pressurizing operating member 4L4 of the left apron pressurizing device 4L and the detection arm 51 of the apron detection means 5. The interlocking wire 54 has one end connected to the left pressurizing operating member 4L4 and the other end connected to the detection arm 51, and transmits the displacement of the left pressurizing operating member 4L4 to the detection arm 51. In the apron detection means 5 having the structure described above, when the left apron pressurizing device 4L turns the apron pressurizing ON / OFF, the central apron 35C rotates up and down. As a result, the detection rod 52 is displaced in the front-rear direction in conjunction with the up-and-down rotation of the central apron 35C. More specifically, as shown in Figure 4(a), when the apron pressurization is switched ON, the left pressurization operating member 4L4 rotates counterclockwise. When the left pressurization operating member 4L4 rotates counterclockwise, the interlocking wire 54 connected to the left pressurization operating member 4L4 pulls the detection arm 51 against the biasing force of the coil spring 511. This causes the detection arm 51 to push the detection rod 52 forward, rotating the lifting operation lever 53 forward. Conversely, as shown in Figure 4(b), when the apron pressurization is switched to OFF, the left pressurization operating member 4L4 rotates clockwise. When the left pressurization operating member 4L4 rotates clockwise, the tension on the detection arm 51 by the interlocking wire 54 connected to the left pressurization operating member 4L4 is released. As a result, the detection arm 51 is pulled backward by the coil spring 511, pulling the detection rod 52 backward and causing the lifting operation lever 53 to rotate backward.

[0071] [Tillage depth control] The tillage depth control by the apron detection means 5 in this second embodiment is performed in the same manner as in the first embodiment. In this second embodiment, the left apron pressurizing device 4L and the apron detection means 5 are linked by an interlocking wire 54, thereby preventing unnecessary tillage depth control of the tillage depth control device of the vehicle body based on the detection results of the apron detection means 5. As described above, when the apron pressurization is turned ON, the central apron 35C also rotates downward. This downward rotation of the central apron 35C causes the detection rod 52 to move backward. When the left biasing means support member 4L7 is rotated backward to turn on the apron pressurization, the interlocking wire 54 to which the left pressurization operating member 4L4 is connected pulls the detection arm 51, moving the detection rod 52 forward. In other words, when the apron pressurization is turned on, the interlocking wire 54 acts to move the detection rod 52 forward. Therefore, the effect of the detection rod 52 moving backward due to the downward rotation of the central apron 35C caused by turning on the apron pressurization cancels out (cancels out) the effect of the interlocking wire 54 moving the detection rod 52 forward via the detection arm 51, and the detection rod 52 does not move. For this reason, it is possible to prevent the apron detection means 5 from erroneously detecting the downward rotation of the central apron 35C due to the turning on the apron pressurization. When the apron pressurization is turned on, the detection arm 51 is maintained at a predetermined angle with respect to the central apron 35C by the interlocking wire 54 and the coil spring 511. Therefore, the detection arm 51 maintains a predetermined angle with respect to the central apron 35C, and in response to the rotation of the central apron 35C, it is possible to displace the detection rod 52 in the front-rear direction.

[0072] Conversely, when the apron pressure is turned OFF, the central apron 35C rotates upward. This upward rotation of the central apron 35C causes the detection rod 52 to move forward. When the left pressurizing operating member 4L4 is rotated counterclockwise to turn off the apron pressurization, the interlocking wire 54 to which the left pressurizing operating member 4L4 is connected loosens. As the interlocking wire 54 loosens, the detection arm 51 moves the detection rod 52 backward due to the tensile force of the coil spring 511. In other words, when the apron pressurization is turned off, the tensile force of the coil spring 511 acts to move the detection rod 52 backward. Therefore, the forward movement of the detection rod 52 due to the upward rotation of the central apron 35C caused by turning off the apron pressurization and the backward movement of the detection rod 52 via the detection arm 51 by the coil spring 511 cancel each other out (cancel each other out), and the detection rod 52 does not move. For this reason, it is possible to prevent the apron detection means 5 from detecting the upward rotation of the central apron 35C caused by turning off the apron pressurization. In other words, in the harrow A of this second embodiment, the movement of the detection rod 52 caused by the ON / OFF switching of the left apron pressurizing device 4L, which occurred in conventional harrows, is eliminated by adjusting the operation of the detection arm 51 (apron detection means 5) so that the detection result of the apron detection means 5 does not change before and after the ON / OFF switching of the left apron pressurizing device 4L. This prevents the tilling depth control by the tilling depth control device of the vehicle from being performed due to the ON / OFF switching of the apron pressurizing device during operation, and prevents the tilling depth of harrow A from changing.

[0073] In this embodiment 2, the left apron pressurizing device 4L and the right apron pressurizing device 4R are located in the central work area 3C, but they may also be located in the left work area 3L and the right work area 3R, as in embodiment 1. In this case, the apron detection means 5 can be located in the central work area 3C, or it can be located near the left apron pressurizing device 4L or near the right apron pressurizing device 4R, or it can be located in two locations, near the left apron pressurizing device 4L and near the right apron pressurizing device 4R. In this case, the two apron detection means 5 are configured to be connectable to a lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 of the left apron 35L and the detection results of the apron detection means 5 of the right apron 35R.

[0074] Furthermore, in this second embodiment, the left apron pressurizing device 4L and the right apron pressurizing device 4R are located in the central work area 3C, but they may also be located in the left work area 3L and the right work area 3R, as in the first embodiment. In this case, the apron detection means 5 can be located in three places: in the central work area 3C, near the left apron pressurizing device 4L, and near the right apron pressurizing device 4R. The three apron detection means 5 are configured to be connectable to the lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 located in the central work area 3C, the apron detection means 5 located near the left apron pressurizing device 4L, and the apron detection means 5 located near the right apron pressurizing device 4R.

[0075] Furthermore, the configuration for linking the left apron pressurizing device 4L and the apron detection means 5 is not limited to a configuration in which the left pressurizing operating member 4L4 and the detection arm 51 are connected by an interlocking wire 54. Alternatively, a member may be provided that operates in conjunction with the operation of the left apron pressurizing device 4L, or together with the operation of the left apron pressurizing device 4L, and this member may be connected to the detection arm 51 by a wire or the like. Furthermore, as described above, if the apron pressurization can be switched ON / OFF, and the strength of the apron pressurization pressure can be adjusted when the apron pressurization is ON, the amount that the interlocking wire 54 pulls the detection arm 51 will change according to the strength of the pressurization pressure, and the detection result of the apron detection means 5 will not change depending on the strength of the pressurization pressure of the left apron pressurization device 4L.

[0076] [Difference 5] Figure 5 shows the left apron pressurizing device 4L and apron detection means 5 of Halo A in a modified example 5 of Embodiment 2 of the present invention, with the apron pressurizing device in the ON state. Other components besides the left apron pressurizing device 4L and apron detection means 5 have been omitted as appropriate. In the above-described embodiment 2, the apron pressurizing device and the apron detection means 5 were linked by a wire to adjust the movement of the detection rod 52 based on the ON / OFF state of the apron pressurizing device, thereby changing the operation of the detection arm 51 before and after the ON / OFF switching of the apron pressurizing device so that the detection result of the apron detection means 5 does not change due to the ON / OFF switching of the apron pressurizing device. In this modified example 5, the detection result of the apron detection means 5 is corrected based on the electrical detection of the ON / OFF state of the apron pressurizing device, thereby preventing unnecessary tillage depth control of the harrow A caused by the ON / OFF switching of the apron pressurizing device. Specifically, in a tilling depth control device for a vehicle body that raises and lowers a three-point linkage mechanism based on the detection result of an apron detection means, the detection result (tilling depth information) of the apron detection means 5 is corrected by detecting the ON / OFF status of the apron pressurizing device, and the three-point linkage mechanism is raised and lowered based on the corrected detection result.

[0077] The tillage depth control of Modification 5 will be explained in detail using the left apron pressurizing device 4L and the apron detection means 5. In this modified example 5, the ON / OFF status of the left apron pressurizing device 4L is detected by a pressurizing detection means 55 that detects the relative rotational angle displacement between the left pressurizing operating member 4L4 and the left biasing means support member 4L7. When the left apron pressurizing device 4L is switched ON or OFF, the rotational drive of the left driving means 4L5 causes the angle between the left biasing means support member 4L7 and the left pressurizing operating member 4L4 to change by a predetermined angle. Therefore, the pressurizing detection means 55 is composed of a rotational position detection sensor such as a potentiometer or rotary encoder, and the ON / OFF status of the left apron pressurizing device 4L can be detected by detecting the relative angle change of the left pressurizing operating member 4L4 with respect to the left biasing means support member 4L7. Alternatively, instead of a rotational position detection sensor, two switches may be provided to detect the ON / OFF state of the left apron pressurizing device 4L by detecting the position of the left pressurizing operating member 4L4 when the left apron pressurizing device 4L is ON or OFF. When the left apron pressurizing device 4L is switched ON and the left pressurizing operating member 4L4 changes angle to a predetermined position, one of the two switches is turned ON by the left pressurizing operating member 4L4 or a member that is displaced in conjunction with the rotation of the left pressurizing operating member 4L4. When the left apron pressurizing device 4L is switched OFF and the left pressurizing operating member 4L4 changes angle to a predetermined position, the other switch is turned ON by the left pressurizing operating member 4L4 or a member that is displaced in conjunction with the rotation of the left pressurizing operating member 4L4. Therefore, by detecting the ON / OFF state of the two switches, it is possible to detect the ON / OFF state of the left apron pressurizing device 4L.

[0078] Furthermore, in this modified example 5, as in Embodiment 2, the apron detection means 5 is displaced in the front-rear direction by the vertical movement of the central apron 35C, causing the lifting operation lever 53 to rotate back and forth. In this modified example 5, the detection rod 52 is directly connected to the detection bracket 35C3 provided on the central apron 35C, without going through the detection arm 51. In this modified example 5, the tillage depth control device of the vehicle body is configured to receive not only the detection result of the apron detection means 5, but also the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55. Based on this received information, the tillage depth control device of the vehicle body controls the tillage depth of the harrow A. More specifically, the tillage depth control device of the vehicle body corrects the detection result of the apron detection means 5, which has been transmitted, based on the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55. Here, the detection result of the pressure detection means 55 refers to the detection result of the rotation position detection sensor in this modified example 5, and is information regarding the rotation position or rotation angle detected by the rotation position detection sensor. If the pressure detection means 55 is configured as a switch, the ON / OFF information of the switch corresponds to the detection result of the pressure detection means 55. The information based on the detection result of the pressure detection means 55 is information calculated (created) by the agricultural machinery control device based on the detection result of the pressure detection means 55, and includes, for example, information indicating the ON / OFF status of the left apron pressurizing device 4L.

[0079] The detection results of the apron detection means 5 are transmitted to the tilling depth control device of the vehicle body via the lifting operation rod, as in Embodiment 2. Furthermore, the detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, is transmitted to the tillage depth control device of the vehicle body via the agricultural implement control device (transmission means) mounted on the harrow A. Alternatively, the detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, may be transmitted from the pressure detection means 55 to the tillage depth control device of the vehicle body without going through the agricultural implement control device. The transmission of the detection result of the pressure detection means 55, or the information based on the detection result of the pressure detection means 55, may be done by wireless or wired communication.

[0080] The following describes in detail the operation of the vehicle's tillage depth control device to prevent unnecessary tillage depth control. When the left apron pressurizing device 4L is turned ON, the apron detection means 5 detects the downward rotation of the central apron 35C. At the same time, the pressurizing detection means 55 detects a predetermined amount of displacement in the relative rotation angle between the left support arm 4L1 and the left pressurizing operating member 4L4. When the agricultural implement control device transmits the detection result of the pressurizing detection means 55, or information based on the detection result of the pressurizing detection means 55, to the vehicle's tillage depth control device, the vehicle's tillage depth control device cancels the detection result of the apron detection means 5 that the central apron 35C has rotated downward. Specifically, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the memory device of the tillage depth control device of the vehicle body stores a correction table in which a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF are set for the detection result of the pressure detection means 55 transmitted. Based on the detection result of the pressure detection means 55 transmitted and the correction table, the tillage depth control device of the vehicle body determines whether the left apron pressure device 4L is ON or OFF. Furthermore, when information based on the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the storage device of the agricultural implement control device stores a correction table in which a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF are set for the detection result of the pressure detection means 55. The agricultural implement control device generates information regarding the ON / OFF status of the left apron pressure device 4L based on the correction table and transmits it to the tillage control device of the vehicle body. The tillage depth control device of the vehicle body then determines whether the left apron pressure device 4L is ON or OFF from the transmitted information based on the detection result of the pressure detection means 55.

[0081] Then, when the tillage depth control device of the vehicle body determines that the left apron pressurizing device 4L has switched from OFF to ON, the detection result by the apron detection means 5 that the central apron 35C has rotated downward is assumed to be due to the left apron pressurizing device 4L being turned ON, and therefore the detection result by the apron detection means 5 that the central apron 35C has rotated downward is canceled. In other words, the tillage depth control device of the vehicle body receives information from the agricultural implement control device based on the detection result of the pressure detection means 55, or the detection result that the left apron pressure device 4L of the pressure detection means 55 has applied pressure. When it determines that the left apron pressure device 4L has transitioned from OFF to ON, even if the apron detection means 5 transmits a detection result that the central apron 35C has rotated downward, it does not perform control to raise the three-point linkage mechanism (lifting means), and the tillage depth control device of the vehicle body does not perform unnecessary tillage depth control. In this case, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotation direction and amount of rotation of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod. To prevent unnecessary tillage depth control, the tillage depth control device of the vehicle body is not limited to a configuration that cancels the detection result of the apron detection means 5, as described above. For example, if the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the tillage depth control device of the vehicle body can take into account the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and control the drive of the lifting means to raise and lower the three-point linkage mechanism, thereby preventing the tillage depth control device from performing unnecessary tillage depth control.

[0082] In a configuration in which the drive control of the lifting means prevents unnecessary configuration control of the tillage depth control device of the traveling vehicle, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the traveling vehicle, the storage device of the tillage depth control device of the traveling vehicle stores a correction table that sets a threshold for determining whether the left apron pressure device 4L is ON, a threshold for determining whether the left apron pressure device 4L is OFF, the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON, and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, based on the detection result of the pressure detection means 55 transmitted from the agricultural implement control device. Note that the correction table is not limited to setting both the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, but may also be set only for the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON. The tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is ON or OFF based on the detection result of the pressurizing detection means 55 and a correction table. If the left apron pressurizing device 4L is ON, it corrects the detection result of the apron detection means 5 based on the correction table and adjusts the drive amount of the lifting means (lifting amount of the three-point linkage mechanism). In this case, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotational position of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod.

[0083] Furthermore, in a configuration in which the drive control of the lifting means prevents unnecessary configuration control of the tillage depth control device of the vehicle body, when information based on the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, the storage device of the tillage depth control device of the vehicle body stores a correction table that sets the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF. Note that the correction table is not limited to setting both the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON and the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is OFF, but may also be set only for the amount of drive of the lifting means to be corrected when it is determined that the left apron pressure device 4L is ON. The tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is ON or ON based on the information obtained from the detection result of the pressurizing detection means 55. If the left apron pressurizing device 4L is ON, the detection result of the apron detection means 5 is corrected based on the correction table, and the drive amount of the lifting means (lifting amount of the three-point linkage mechanism) is adjusted. In this case as well, the tillage depth control device of the vehicle body is equipped with a sensor that detects the rotational position of the central apron 35C from the detection result of the apron detection means 5 transmitted via the lifting operation rod. The correction data for correcting the detection result of the apron detection means 5 can be any data that can be used to correct the detection result of the apron detection means 5. For example, it may be data indicating the amount of rotation of the apron, data relating to the amount of movement (rotation) of the lifting operation lever 53, or data relating to the amount of drive of the lifting means of the apron detection means 5.

[0084] Conversely, when the left apron pressurizing device 4L is turned OFF, just as when the left apron pressurizing device 4L is turned ON, control can be performed based on the detection result of the apron detection means 5 and the detection result of the pressurizing detection means 55, or information based on the detection result of the pressurizing detection means 55, thereby preventing the tillage depth control device of the vehicle from performing unnecessary tillage depth control. When the left apron pressurizing device 4L is turned OFF, the apron detection means 5 detects the upward rotation of the central apron 35C, and at the same time, the pressurizing detection means 55 detects a predetermined amount of displacement in the relative rotation angle between the left support arm 4L1 and the left pressurizing operating member 4L4. When the agricultural implement control device transmits the detection result of the pressurizing detection means 55, the tillage depth control device of the vehicle body determines whether the left apron pressurizing device 4L is OFF or OFF based on the transmitted detection result of the pressurizing detection means 55 and the correction table. When the agricultural implement control device transmits ON / OFF information of the left apron pressurizing device 4L, which it has determined based on the correction table, to the tillage depth control device of the vehicle body as information based on the detection result of the pressurizing detection means 55, the tillage depth control device of the vehicle body determines from the transmitted information whether the left apron pressurizing device 4L is OFF or OFF. Then, when the tillage depth control device of the vehicle body determines that the left apron pressurizing device 4L has switched from ON to OFF, it cancels the detection result from the apron detection means 5 that the central apron 35C has rotated upward. As a result, even if the tillage depth control device of the vehicle body receives a detection result from the apron detection means 5 that the central apron 35C has rotated upward, it does not perform the control to lower the three-point linkage mechanism. Furthermore, even when the left apron pressurizing device 4L is turned OFF, the vehicle body's tillage depth control device may use a correction table stored in the vehicle body's tillage depth control device to add the detection result of the pressurizing detection device 55 to the detection result of the apron detection device 5, and then perform drive control of the lifting device. In this way, by adding the detection result of the pressure detection means 55 to the detection result of the apron detection means 5, unnecessary tillage depth control of the tillage depth control device of the vehicle body, which may be performed due to the ON / OFF switching of the apron pressure device, is prevented.

[0085] Furthermore, since the amount of rotation of the central apron 35C when the left apron pressurizing device 4L is turned ON / OFF varies depending on the soil type, when using the correction table as described above, it is possible to store a correction table corresponding to each soil type. In this case, it becomes possible to select a correction table according to the soil type of the field being worked on, enabling more accurate tillage depth control. The user can select the correction table directly from multiple options, or the field and correction table can be associated and stored, and the tillage depth control device can select the correction table corresponding to the field being worked on. Furthermore, in this modified example 5, the pressure detection means 55 is installed to detect the relative rotational angle displacement between the left pressure operating member 4L4 and the left biasing means support member 4L7, but it can also be installed to detect the rotational angle of the left biasing means support member 4L7 with respect to the work section 3. Furthermore, the pressure detection means 55 is configured to detect the relative rotational angle displacement between the left pressure operating member 4L4 and the left biasing means support member 4L7, but it may also be configured to detect the amount of expansion and contraction of the left drive means 4L5 to detect the ON / OFF state of the apron pressurizing device.

[0086] Furthermore, in this modified example 5, similar to embodiment 2, the pressure detection means 55 is configured to detect the relative rotational angle displacement between the left support arm 4L1 of the left apron pressurizing device 4L and the left pressurizing operating member 4L4. However, it may also be configured to detect the relative rotational angle displacement between the right support arm and the right pressurizing operating member of the right apron pressurizing device 4R. Furthermore, in this modified example 5, the left apron pressurizing device 4L and the right apron pressurizing device 4R are arranged in the central work area 3C, similar to Embodiment 2. However, they may also be arranged in the left work area 3L and the right work area 3R, similar to Embodiment 1. In this case, the apron detection means 5 can be arranged in the central work area 3C, but it can also be arranged near the left apron pressurizing device 4L or near the right apron pressurizing device 4R. Alternatively, the apron detection means 5 can be arranged in two locations, near the left apron pressurizing device 4L and near the right apron pressurizing device 4R, and two pressurizing detection means 55 can be installed: one that detects the relative rotation angle displacement between the left support arm 4L1 of the left apron pressurizing device 4L and the left pressurizing operating member 4L4, and another that detects the relative rotation angle displacement between the right support arm and the right pressurizing operating member of the right apron pressurizing device 4R. In this case, the tilling depth of harrow A is controlled by a combination of the detection results of the apron detection means 5 on the left apron 35L and the detection results of the apron detection means 5 on the right apron 35R.

[0087] Furthermore, in this second embodiment, the left apron pressurizing device 4L and the right apron pressurizing device 4R are located in the central work area 3C, but they may also be located in the left work area 3L and the right work area 3R, as in the first embodiment. In this case, the apron detection means 5 can be located in three places: in the central work area 3C, near the left apron pressurizing device 4L, and near the right apron pressurizing device 4R. The three apron detection means 5 are configured to be connectable to the lifting operation rod for driving (raising and lowering) the three-point linkage mechanism of the vehicle body, and the tilling depth of the harrow A is controlled by a combination of the detection results of the apron detection means 5 located in the central work area 3C, the apron detection means 5 located near the left apron pressurizing device 4L, and the apron detection means 5 located near the right apron pressurizing device 4R.

[0088] Furthermore, in Embodiment 2, instead of the interlocking wire 54, a drive device capable of rotatable detection arm 51 may be provided, and a pressure detection means 55 may be provided to detect the relative rotation angle displacement between the left pressure operating member 4L4 and the left biasing means support member 4L7, and the detection arm 51 may be rotated by an actuator or the like based on the detection result of the pressure detection means 55. In addition, instead of the configuration in which the detection arm 51 is rotated, a configuration in which the detection rod 52 is moved or a configuration in which the lifting operation lever 53 is rotated may also be used.

[0089] [Modification 6] In the modified version 5 described above, the detection result of the apron detection means 5 is transmitted to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body receives the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and corrects the detection result of the apron detection means 5. This modified version 6, like modified version 5, corrects the detection result of the apron detection means 5 based on the electrical detection of the ON / OFF state of the apron pressure device, and prevents unnecessary tillage depth control of the harrow A by the tillage depth control device of the vehicle body caused by the ON / OFF switching of the apron pressure device. However, the configuration in which the tillage depth control device of the vehicle body acquires the detection result of the apron detection means 5 differs from that of modified version 5. Specifically, in a configuration in which the agricultural implement control device mounted on Harrow A receives the detection result of the apron detection means 5 and transmits (transmits) the detection result of the apron detection means 5 to the tillage depth control device of the vehicle body, the agricultural implement control device receives the detection result of the pressure detection means 55 and transmits (transmits) the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, to the tillage depth control device of the vehicle body. In this modified example 6, the lifting operation lever 53 and the lifting operation rod are not connected, and instead, the apron detection means 5 is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. The agricultural implement control device in this modified example 6 receives the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53 and transmits the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53, or information based on the detection result of the sensor that detects the amount of rotation of the lifting operation lever 53, to the tillage depth control device of the vehicle body. The detection result of the sensor that detects the amount of rotation of the lifting operation lever 53 may be transmitted to the tillage depth control device of the vehicle body without going through the agricultural implement control device. The detection results of the apron detection means 5 to the tilling depth control device of the vehicle body can be transmitted wirelessly or via wired communication. The apron detection means 5 is not limited to a configuration that includes a sensor for detecting the amount of rotation of the lifting operation lever 53, but can be configured to detect the direction and amount of rotation of the vertical rotation of the central apron 35C.

[0090] Furthermore, in this modified example 6, when the detection result of the pressure detection means 55 is transmitted from the agricultural implement control device to the tillage depth control device of the vehicle body, similar to modified example 5, a correction table is stored in the memory of the tillage depth control device of the vehicle body, which sets a threshold value for determining whether the left apron pressure device 4L has been switched ON and a threshold value for determining whether the left apron pressure device 4L has been switched OFF, based on the detection result of the pressure detection means 55 transmitted. The tillage depth control device of the vehicle body determines whether the left apron pressure device 4L is ON or OFF based on the detection result of the pressure detection means 55 transmitted and the correction table.

[0091] Furthermore, in this modified example 6, when the ON / OFF information of the left apron pressurizing device 4L, determined by the agricultural implement control device based on the correction table, is transmitted to the tillage depth control device of the vehicle body as information based on the detection result of the pressurization detection means 55, the tillage depth control device of the vehicle body determines whether the transmitted information based on the detection result of the pressurization detection means 55 is ON or OFF information for the left apron pressurizing device 4L, similar to modified example 1. Then, when the tillage depth control device of the vehicle body determines that the left apron pressurizing device 4L has switched from OFF to ON, the detection result by the apron detection means 5 that the central apron 35C has rotated downward is assumed to be due to the left apron pressurizing device 4L being turned ON, and therefore the detection result by the apron detection means 5 that the central apron 35C has rotated downward is canceled. In other words, the tillage depth control device of the vehicle body receives information from the agricultural implement control device based on the detection result of the pressure detection means 55, or the detection result that the left apron pressurizing device 4L of the pressure detection means 55 has applied pressure. When it determines that the left apron pressurizing device 4L has transitioned from OFF to ON, even if the apron detection means 5 transmits a detection result that the central apron 35C has rotated downward, it does not perform control to raise the three-point linkage mechanism (lifting means), and the tillage depth control device of the vehicle body does not perform unnecessary tillage depth control. In this case, the agricultural implement control device may detect the rotation direction and amount of the central apron 35C from the detection result of the apron detection means 5 and transmit it to the tillage depth control device of the vehicle body, or, as in the modified example 5, the tillage depth control device of the vehicle body may be equipped with a sensor that detects the rotation direction and amount of the central apron 35C from the received detection result of the apron detection means 5.

[0092] In addition, in this modified version 6, similar to modified version 5, the agricultural implement control device may store a threshold value for the detection result of the pressure detection means 55 for determining whether the apron pressurizing device is ON or OFF, or the storage device of the tillage depth control device of the traveling vehicle body may store a threshold value for the detection result of the pressure detection means 55 for determining whether the apron pressurizing device is ON or OFF. Furthermore, in this modified example 6, similar to modified example 5, the tillage depth control device of the traveling vehicle body may correct the detection result of the apron detection means 5 so as to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF of the apron pressurizing device. In this way, by adding the detection result of the pressure detection means 55 to the detection result of the apron detection means 5, unnecessary tillage depth control of the tillage depth control device of the vehicle body, which may be performed due to the ON / OFF switching of the apron pressure device, is prevented.

[0093] [Difference 7] In the above-described modification 6, the detection result of the apron detection means 5 is transmitted to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body receives the detection result of the pressure detection means 55, or information based on the detection result of the pressure detection means 55, and corrects the detection result of the apron detection means 5. However, in this modification 7, the agricultural implement control device (correction means) mounted on the harrow A corrects the detection result of the apron detection means 5, and the tillage depth control device of the vehicle body raises and lowers the three-point linkage mechanism based on the corrected detection result transmitted from the agricultural implement control device (correction means). Specifically, the agricultural machine control device receives the detection results from the apron detection means 5 and the pressure detection means 55, and the agricultural machine control device corrects the detection results from the apron detection means 5 by taking into account the detection results from the pressure detection means 55. That is, if the agricultural machine control device determines that the apron pressure device has been turned ON (switched from OFF to ON) based on the detection results from the pressure detection means 55, it corrects the detection results from the apron detection means 5 so as to cancel the detection result that the central apron 35C has rotated downward, or to offset the amount of downward rotation of the central apron 35C that occurs when the apron pressure device is turned ON. If the agricultural machine control device determines that the apron pressure device has been turned OFF (switched from ON to OFF), it corrects the detection results from the apron detection means 5 so as to cancel the detection result that the central apron 35C has rotated upward, or to offset the amount of upward rotation of the central apron 35C that occurs when the apron pressure device is turned OFF. The agricultural implement control device then transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. The tillage depth control device of the vehicle body controls the tillage depth of the harrow A by driving the lifting mechanism of the vehicle body's three-point linkage mechanism based on the detection result of the apron detection means 5, which has been corrected by the apron detection means 5. The transmission of the detection result of the apron detection means 5 (including the corrected detection result) to the tillage depth control device of the vehicle body can be done by wireless or wired communication. In this modified example 7, the lifting operation lever 53 and the lifting operation rod are not connected. Instead, the apron detection means 5 is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. However, the apron detection means 5 is not limited to a configuration that is equipped with a sensor that detects the amount of rotation of the lifting operation lever 53. It may be configured to detect the direction and amount of rotation of the vertical rotation of the central apron 35C, or to detect the rotational position of the central apron 35C.

[0094] Similar to Modification 5, the storage device of the agricultural machinery control device in this Modification 7 stores a threshold value for the detection result of the pressure detection means 55 for determining whether the apron pressurizing device is ON or OFF. When correcting the detection result of the apron detection means 5 to cancel it, a correction table is used in which a threshold value for determining whether the apron pressurizing device is ON or OFF is set for the detection result of the pressurizing detection means 55. The agricultural implement control device determines whether the apron pressurizing device is ON or OFF based on the transmitted detection result of the pressurizing detection means 55 and the correction table stored in the storage device. When it determines that the apron pressurizing device is ON or OFF, it corrects the detection result of the apron detection means 5 to cancel it and transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. Furthermore, in this modified example 7, the agricultural machine control device may correct the detection result of the apron detection means 5 so as to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF of the apron pressurizing device. In this case, the storage device of the agricultural machine control device stores a threshold value for the detection result of the pressurizing detection means 55 for determining whether the apron pressurizing device is ON or OFF, similar to modified example 5. It also stores correction data for correcting the detection result of the apron detection means 5 when it is determined that the apron pressurizing device is ON, and correction data for correcting the detection result of the apron detection means 5 when it is determined that the apron pressurizing device is OFF. The correction data for correcting the detection result of the apron detection means 5 only needs to be usable to correct the detection result of the apron detection means 5. For example, it may be data indicating the amount of rotation of the apron, data relating to the amount of movement (rotation) of the lifting operation lever 53, or data relating to the amount of drive of the lifting means of the apron detection means 5.

[0095] When correcting the detection result of the apron detection means 5 to compensate for the upward or downward rotation of the central apron 35C caused by the ON or OFF state of the apron pressurizing device, the agricultural implement control device uses a threshold value stored in the memory device for determining whether the left apron pressurizing device 4L is ON or OFF, correction data to be applied when the left apron pressurizing device 4L is determined to be ON, and correction data to be applied when the left apron pressurizing device 4L is determined to be OFF, to determine whether the apron pressurizing device is ON or OFF. When the ON or OFF state of the apron pressurizing device is determined, the control device corrects the detection result from the apron detection means 5 using the corresponding correction data. The agricultural implement control device then transmits the corrected detection result of the apron detection means 5 to the tillage depth control device of the vehicle body. In this way, the agricultural implement control device corrects the detection result from the apron detection means 5 to counteract the upward or downward rotation of the central apron 35C caused by the ON / OFF switching of the apron pressurizing device, and transmits the corrected detection result from the apron detection means 5 to the tillage depth control device of the vehicle body, thereby preventing unnecessary tillage depth control by the tillage depth control device of the vehicle body that may be performed due to the ON / OFF switching of the apron pressurizing device during operation.

[0096] [Differentiation 8] In the above-described modification 7, the detection result (including the corrected detection result) of the apron detection means 5 was transmitted to the tillage depth control device of the vehicle body. However, in this modification 8, the agricultural implement control device creates tillage depth control information for controlling the tillage depth control device of the vehicle body based on the detection result of the pressure detection means 55 and transmits this to the tillage depth control device of the vehicle body, and the tillage depth control device of the vehicle body raises and lowers the three-point linkage mechanism based on the transmitted tillage depth control information. In this case, the storage device of the agricultural implement control device stores a correction table that sets a threshold for determining whether the left apron pressurizing device 4L is ON or OFF, the amount of drive for the lifting means of the three-point linkage mechanism to be driven when the left apron pressurizing device 4L is determined to be ON, and the amount of drive for the lifting means of the three-point linkage mechanism to be driven when the left apron pressurizing device 4L is determined to be OFF. Based on the detection result (rotation amount) of the pressurizing detection means 55 and the correction table, the agricultural implement control device determines whether the left apron pressurizing device 4L is ON or OFF and calculates the amount of drive for the lifting means corresponding to that determination result. Then, when the agricultural implement control device transmits the calculated information regarding the amount of drive for the lifting means as tillage depth control information to the tillage depth control device of the vehicle body, the tillage depth control device of the vehicle body controls the driving of the lifting means of the three-point linkage mechanism based on the transmitted tillage depth control information. In this way, if the tillage depth control device of the vehicle body controls the drive of the lifting mechanism based on tillage depth control information transmitted from the agricultural implement control device, unnecessary tillage depth control by the tillage depth control device of the vehicle body that may be performed due to the ON / OFF switching of the apron pressurizing device can be prevented.

[0097] In Embodiment 1, Modifications 1-4, Embodiment 2, and Modifications 5-8, the tillage depth was detected by the vertical rotation position of the apron. However, the system is not limited to this configuration. The tillage depth may be calculated by measuring the distance to the field using an ultrasonic sensor or infrared sensor, or by using a tilt sensor to detect the tilt of the harrow A in the front-rear direction and performing tillage depth control based on the detected tilt. Alternatively, the tillage depth may be calculated from the detected tilt. The tillage depth may also be detected by the vertical position of the leveler, or the tillage depth may be calculated from the height (vertical) position of the harrow A using a Global Navigation Satellite System (GNSS). Furthermore, in Embodiment 1, Modification 1, Modification 2, Embodiment 2, Modification 5, and Modification 6, the tilling depth of harrow A was transmitted to the vehicle body via a lifting operation rod (not shown). However, the configuration is not limited to this, and the detection result of the apron detection means 5 and information based on the detection result of the apron detection means 5 may be transmitted to the tilling depth control device of the vehicle body by communication (whether wired or wireless).

[0098] Furthermore, in Embodiment 1, Modifications 1-4, Embodiment 2, and Modifications 5-8, information regarding the operating status of the apron pressurizing device (ON / OFF, or ON / OFF and pressurizing force (amount)) may be transmitted via communication (whether wired or wireless, direct or indirect) to a mobile terminal such as a smartphone or to the tillage depth control device of the vehicle, and displayed on the mobile terminal such as a smartphone or to the display device of the vehicle. Furthermore, in Modifications 1-4, Embodiment 2, and Modifications 5-8, the lifting and lowering means of the three-point linkage mechanism of the vehicle body was controlled based on the corrected detection results and information based on the corrected detection results. However, the system is not limited to this configuration. Based on the operating state of the apron pressurizing device (ON / OFF, or ON / OFF and pressurizing force (amount)), notifications (display, voice) may be provided via a remote control, a mobile terminal such as a smartphone, or a display device on the vehicle body to prompt the operator to operate the vehicle body's operating means for controlling the lifting and lowering amount of harrow A by the tillage depth control device so that the tillage depth remains constant. In this case, the notification prompting the operation of the vehicle's control means may be something like, "The apron pressurizing device has been turned ON," or "The pressure (amount) applied to the apron by the apron pressurizing device is XX (XX may be a numerical value or represent a relative degree such as large, medium, or small)," which would prompt the operation of the vehicle's control means by notifying that the pressurizing state of Harrow A has changed or the degree of change in the pressurizing state. Alternatively, if the control means is a dial type, it may be something like, "Turn the control dial to the right," or "Set the control dial to the XX mark," which would notify the specific operation or amount (position) of the vehicle's control means.

[0099] As described above, Embodiment 1, Modifications 1-4, Embodiment 2, and Modifications 5-8 of the harrow A, including the soil-piling machine according to the present invention, have been described in detail with reference to the drawings. However, the specific configuration is not limited to Embodiment 1, Modifications 1-4, Embodiment 2, and Modifications 5-8, and any design changes, etc., that do not depart from the gist of the present invention are also included. Furthermore, Embodiment 1, Modifications 1-4, Embodiment 2, and Modifications 5-8 can be combined by utilizing each other's technologies, as long as there are no particular contradictions or problems in their purpose and configuration. [Explanation of symbols]

[0100] A Hello 1. Mounting part 11 Topmast 2 frames 21 Gearbox 211 Power input shaft 22L Left Support Frame 22L1, 22L2 Left axis 22R Right support frame 23 Chain Case 24L Left work section opening / closing hydraulic cylinder 24R Right work section opening / closing hydraulic cylinder 3. Work area 3C Central working section 3L Left work area 3R Right work area 31 Working rotor 32C Central Shield Cover 32C1 Left axis 32L Left Shield Cover 32L1 Left Axis 32R Right Shield Cover 33L left side plate 33R Right side plate 34L Left-rotating support section 34R Right-hand rotation support section 35C Central Apron 35C1 Left Pressure Bracket 35C3 detection bracket 35C31 Contact part 35C4 Bracket 35L Left apron 35L1 Left Pressure Bracket 35L2 Left support member 35R Right Apron 36C Central Level 36L Left Leveler 36R Right Level 37L Left Extension Leveler 37R Right extension level 4L Left Apron Pressurizing Device 4L1 Left support arm 4L2 Left pressure rod 4L3 Left biasing means 4L4 Left pressurizing operating member 4L41 Left gear section 4L42 Left contact arm 4L43 Left contact part 4L44 long hole 4L5 Left drive mechanism 4L6 Left Axis 4L7 Left biasing means support member 4L71 Protrusion 4R Right apron pressurizing device 5. Apron detection means 51 detection arm 511 Coil spring 52 detection rods 53 Lifting / Lowering Lever 54 Interlocking wire 55 Pressure detection means MS mud face WS water surface

Claims

1. An agricultural implement connected to a vehicle body that raises and lowers the agricultural implement based on tillage depth information, It has a tillage depth detection means, a leveling body, and a leveling body pressurizing device. The aforementioned leveling body is mounted so as to be vertically rotatable behind a work rotor having multiple working claws, and is used to level the work surface. The aforementioned ground leveling pressurizing device applies pressure to the ground leveling body toward the work surface, The system includes a modification means for changing the operation of the tillage depth detection means based on the operation of the soil leveling pressurization device, The agricultural implement is characterized in that the tillage depth information is the detection result of the tillage depth detection means.

2. An agricultural implement connected to a vehicle body that raises and lowers the agricultural implement based on tillage depth information, It has a tillage depth detection means, a leveling body, and a leveling body pressurizing device. The aforementioned leveling body is mounted so as to be vertically rotatable behind a work rotor having multiple working claws, and is used to level the work surface. The aforementioned ground leveling pressurizing device applies pressure to the ground leveling body toward the work surface, The system includes a correction means for correcting the detection result of the tillage depth detection means by the operation of the soil leveling body pressurizing device, The agricultural implement is characterized in that the tillage depth information is generated based on the detection result of the tillage depth detection means corrected by the correction means.

3. An agricultural implement connected to a vehicle body that raises and lowers the agricultural implement based on tillage depth information, It has a tillage depth detection means, a leveling body, and a leveling body pressurizing device. The aforementioned leveling body is mounted so as to be vertically rotatable behind a work rotor having multiple working claws, and is used to level the work surface. The aforementioned ground leveling pressurizing device applies pressure to the ground leveling body toward the work surface, An agricultural implement characterized by comprising a transmission means for transmitting information relating to the operating state of the soil-leveling pressurizing device to the traveling vehicle body that generates the tillage depth information.

4. The agricultural implement according to claim 3, characterized in that the transmitting means transmits the detection result of the tillage depth detection means to the traveling vehicle body that generates the tillage depth information.

5. The agricultural implement according to any one of claims 1 to 4, characterized in that the tillage depth detection means detects the vertical rotation position of the soil leveling body.

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