JPH08214612A - Controller for power tiller - Google Patents

Abstract

PURPOSE: To enable the obtaining of a good tillage state in spite of the rapid practicable operations to lift a rotary power tiller by controlling operations of a forced lifting and lowering controlling means. CONSTITUTION: A power takeoff(PTO) rotation controlling means 18G capable of reducing the rotational frequency of a PTO shaft to a prescribed one during a period to the lifting of a rotary tilling device to a lifting limit position when a lifting command of a rotary tilling device is issued from a lifting and lowering command switch 24 in a controller for a power tiller equipped with an automatic plowing depth controlling means 18B capable of lifting and lowering the rotary tilling device based on sensed information from a ground height sensing means S3 so that the sensed information may coincide with the target ground height of the rotary tilting device preset with a plowing depth setting means 21 and a forced lifting and lowering controlling means 18D capable of forcedly lifting the rotary tilling device to a prescribed lifting limit position in preference to the controlling operation of the automatic plowing depth controlling means 18B based on the lifting command from the lifting and lowering command switch 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tiller which is driven by power from an engine via a PTO shaft,
Based on the detection information from the ground height detecting means for detecting the ground height of the rotary tilling device while being connected to the traveling body so as to be vertically movable, the detection information and the plowing depth setting means are set in advance. The automatic plowing depth control means for raising and lowering the rotary tilling device so that the target ground height of the rotary tilling device matches, and the control operation of the automatic plowing depth controlling means based on the rising command from the raising / lowering command switch. The invention relates to a control device for a cultivator, comprising: a forced lifting control means for forcibly lifting the rotary cultivating device to a predetermined rising limit position.

[0002]

2. Description of the Related Art Since the control operation by the automatic tilling depth control means in the control device for a tiller as described above is to keep the tillage during the tilling work accurately and constantly, the ground height detecting means If the ground height of the rotary tiller detected by the and the target ground height of the rotary tiller preset by the tiller setting means do not match, it is necessary to immediately correct the rotary tiller to the target ground height. There is. Therefore, it is necessary to set the lifting speed of the rotary tiller to a relatively high speed so that the lifting operation of the rotary tiller can be performed quickly. on the other hand,
Since the control operation by the forced lifting control means is performed when the headland is turning during the tillage work, the lifting speed of the rotary tiller is set to a relatively high speed, and the lifting operation of the rotary tiller is quickly performed. It is desirable to be able to do so. That is, in the control device for a tiller as described above, the raising operation of the rotary tiller by the control operation of the automatic tilling depth control means and the raising operation of the rotary tiller by the control operation of the forced lifting control means are respectively compared. It is configured to be performed at the same speed set to a relatively high speed.

By the way, conventionally, the control device for a tiller as described above is also designed to forcibly raise the rotary tiller from the target ground height to a predetermined rising limit position by the control operation of the forcible lifting control means. The PTO shaft for transmitting the power from the engine to the rotary tiller is rotated at high speed in the same manner as when the soil is tilled at a constant tillage by the rotary tiller by the control operation of the automatic tiller control means. Was there.

[0004]

However, even when the rotary tiller is raised by the control operation of the forced lifting control means as in the above-mentioned prior art, the PTO shaft is cultivated in the same manner as when the soil is tilled by the rotary tiller. When the rotary cultivator is rotated at a high speed and the rotary cultivator is raised all at once with a high lifting speed, in the soil part where the raising operation is started, the soil in that part is vigorously splashed backward by the rotary cultivator. There was an inconvenience that a large hole was formed without being covered with soil while being blown off.

An object of the present invention is to provide a control device for a cultivator capable of quickly raising the rotary cultivating device by the control operation of the forcible lifting control means, while obtaining a good cultivating state. It is in.

[0006]

In order to achieve the above object, in the first aspect of the present invention, a rotary tiller driven by power from an engine via a PTO shaft is connected to a traveling machine body so as to be vertically movable. With, based on the detection information from the ground height detection means for detecting the ground height of the rotary tiller, the detection information, and the target ground height of the rotary tiller preset by the tilling depth setting means and In accordance with the automatic tilling depth control means for raising and lowering the rotary tiller, and the rising command from the raising / lowering command switch, the rotary tiller is given a predetermined priority over the control operation of the automatic tiller controlling means. In the control device of the tiller forcibly raising to the upper limit position of the rotary tiller by the raising / lowering command switch. When a command is issued, until the rotary plow is raised to the raised limit position, PT decreasing the rotational speed of the PTO shaft to a predetermined rotational speed
An O rotation control means was provided.

According to the second invention, in the first invention,
The rising speed control means for adjusting the rising speed of the rotary tiller when the rotary tiller is forcibly lifted by the control operation of the forced lift control means so that the first half side in the moving range is slower and the second half side is faster .

According to a third aspect of the present invention, in the first or second aspect of the invention, the PTO rotation control means rotates the PTO shaft by accelerator control for operating a speed control lever of a speed governor provided in the engine. The number of rotations is reduced to the predetermined number of rotations.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, a friction type PTO clutch for intermittently transmitting the power from the engine to the PTO shaft is provided, and the PTO rotation control means is the PTO rotation control means. The rotational speed of the PTO shaft is reduced to the predetermined rotational speed by clutch control that controls the operation of the clutch.

According to a fifth aspect of the present invention, in the first or second aspect of the invention, a PTO speed change mechanism for changing the rotational speed of the PTO shaft is provided, and the PTO rotation control means controls the operation of the PTO speed change mechanism. The PTO shift control is configured to reduce the rotation speed of the PTO shaft to the predetermined rotation speed.

[0011]

According to the first aspect of the present invention, when the ascending command is issued from the ascending / descending command switch and the forcible ascending operation of the rotary tiller is performed by the control operation of the forcible ascending / descending control means, the control operation of the PTO rotation control means is performed. , The rotation speed of the PTO shaft is increased until the rotary tiller reaches the upper limit position, in other words, the tillage claw of the rotary tiller enters the soil and becomes far away from the soil to cultivate the soil. Until then, it will be reduced to a predetermined number of revolutions set in advance. That is, when the forcible raising operation of the rotary cultivator is performed by the control operation of the forcible lifting control means, the rotational speed of the rotary cultivator also decreases as the rotational speed of the PTO shaft decreases. There is no inconvenience that the soil in the soil portion where the forced raising operation of the device is started is not covered with the rotary tilling device while being bounced back vigorously and a large hole is formed. By the way, by lowering the rising speed of the rotary tiller during the forced raising operation, and gradually raising the rotary tiller as the aircraft travels, the soil tilling operation of the rotary tiller was started. Although it is possible to avoid the inconvenience of forming a large hole, in this case, an inconvenience arises in that the raising operation of the rotary tiller cannot be performed quickly. However, in the first invention, the PTO
By lowering the rotation speed of the shaft, it avoids the inconvenience that a large hole is formed in the soil part where the compulsory lifting operation of the rotary tiller is started. Since it is not necessary to reduce the speed, the inconvenience that the forced raising operation of the rotary tiller cannot be performed quickly does not occur. Therefore, the raising operation of the rotary tilling device by the control operation of the forced raising / lowering control means can be quickly performed without inconvenience that a large hole is formed in the soil portion where the raising operation is started.

According to the second aspect of the present invention, when the ascending / descending command is issued from the ascending / descending command switch and the forcible ascending operation of the rotary tiller is performed by the control operation of the forcible ascending / descending control means, the control operation of the PTO rotation control means is performed. , PT
The rotation speed of the O-axis decreases to a predetermined rotation speed set in advance until the rotary tiller reaches the upper limit position, and the moving speed of the rotary tiller is controlled by the control operation of the ascending speed control means. The first half side, in other words, the rising speed of the rotary tiller on the side where the tilling claws of the rotary tiller enter the soil to cultivate the soil, and the rising speed of the rotary tiller slows down. In other words, the rising speed of the rotary tiller on the side where the tilling claws of the rotary tiller are separated from the soil is adjusted to be high. In other words, in addition to the operation of the first invention, in the first half of the range of movement of the rotary tiller, the rotary tiller gradually rises as the vehicle travels, so a constant high speed from the start of raising. As compared with the case where the rotary tiller is raised all at once, it is possible to more suitably avoid the inconvenience that a large hole is formed in the soil portion where the forcible raising operation of the rotary tiller is started. Further, in the second half of the range of movement of the rotary tiller, the rotary tiller is already separated from the soil, so even if the raising speed is increased, it does not adversely affect the soil. Can be set to speed. As a result, the raising operation of the rotary tiller by the control operation of the forced raising / lowering control means is performed relatively quickly while avoiding the inconvenience of forming a large hole in the soil portion where the raising operation is started. You will be able to do it.

According to the third aspect of the present invention, when the ascending / descending command is issued from the ascending / descending command switch and the forcible ascending operation of the rotary tiller is performed by the control operation of the forcible ascending / descending control means, the control operation of the PTO rotation control means is performed. , Until the rotary tiller reaches the upper limit position, the speed governor of the speed governor equipped in the engine is operated to the low speed side so that the engine speed drops to the preset speed. By doing so, the rotation speed of the PTO shaft is reduced to a predetermined rotation speed set in advance. In other words, a simple structure is provided only by providing a mechanism for operating the existing speed governing lever to the low speed side until the rotary tiller is raised to the ascending limit position as the ascending command is issued from the ascending / descending command switch. Thus, it becomes possible to avoid the inconvenience that a large hole is formed in the soil portion where the raising operation of the rotary tiller is started.

According to the fourth aspect of the present invention, when the ascending / descending command is issued from the ascending / descending command switch and the forcible ascending operation of the rotary tiller is performed by the control operation of the forcible ascending / descending control means, the control operation of the PTO rotation control means is performed. , PT until the rotary tiller reaches the upper limit position.
The operation (intermittent state) of the friction type PTO clutch, which intermittently transmits the power from the engine to the O-axis, is controlled so that the rotational speed of the PTO shaft is reduced to a predetermined rotational speed set in advance. become. That is, as in the case of operating the speed control lever to the low speed side based on the ascending command from the ascending / descending command switch, along with the operation, the rotational speed of the PTO shaft decreases to a predetermined rotational speed set in advance. Therefore, there is no inconvenience that the traveling speed of the machine body is switched to a predetermined low speed state and the work efficiency is reduced.

According to the fifth aspect of the present invention, when the ascending command is issued from the ascending / descending command switch and the forcible ascending operation of the rotary tiller is performed by the control operation of the forcible ascending / descending control means, the control operation of the PTO rotation control means is performed. , PT until the rotary tiller reaches the upper limit position.
The operation (shift state) of the PTO speed change mechanism that changes the rotation speed of the O-axis is controlled so that the rotation speed of the PTO shaft is reduced to a predetermined rotation speed set in advance. That is, as in the case of operating the speed control lever to the low speed side based on the ascending command from the ascending / descending command switch, along with the operation, the rotational speed of the PTO shaft decreases to a predetermined rotational speed set in advance. In the case of controlling the operation (intermittent state) of the PTO clutch on the basis of an ascending command from the ascending / descending command switch, there is no inconvenience that the traveling speed of the machine body is switched to a predetermined low speed state and work efficiency is reduced. As described above, frequent switching of the discontinuous state of the PTO clutch for maintaining the rotational speed of the PTO shaft at a predetermined rotational speed does not cause the inconvenience of premature wear of the PTO clutch.

[0016]

Therefore, according to the first aspect of the present invention, the soil portion where the raising operation of the rotary tiller is started while the raising operation of the rotary tiller can be quickly performed by the control operation of the forced lifting control means. It has become possible to provide a control device for a cultivator that can obtain a good cultivated state without inconvenience that a large hole is formed in the cultivator.

According to the second aspect of the present invention, by slowing the rising speed of the rotary tiller on the first half side in the moving range of the rotary tiller, a large hole is formed in the soil portion where the raising operation of the rotary tiller is started. Since it is possible to more appropriately avoid the inconvenience caused, it is possible to relatively quickly perform the raising operation of the rotary tiller by the control operation of the forcible lifting control means while obtaining a better tilling state. It was

According to the third aspect of the present invention, while simplifying the structure, the rotary tiller can be quickly raised by the control operation of the forcible lifting control means, and a good tilling state can be obtained. It was

According to the fourth aspect of the present invention, while suppressing the decrease in work efficiency, the raising operation of the rotary tiller by the control operation of the forcible lifting control means can be performed quickly and a good tilling state can be obtained. became.

According to the fifth aspect of the present invention, while lowering the work efficiency is suppressed and the durability of the PTO clutch is improved, the raising operation of the rotary tiller can be quickly performed by the control operation of the forced lifting control means. At the same time, it became possible to obtain a good tilling condition.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the entire side surface of a riding-type cultivator. This riding-type cultivator is equipped with a rotary mechanism via a three-point link mechanism 2 at the rear of a riding-type traveling machine body 1 that constitutes an agricultural tractor. It is configured by connecting the tilling device 3 so as to be able to move up and down. At the rear part of the traveling machine body 1, a mission case 6 having a pair of left and right lift arms 5 that swing up and down about the horizontal axis by the operation of the lift cylinder 4 is provided. A PTO shaft 7 for extracting power is provided on the rear surface of the mission case 6 so as to project rearward.
The three-point link mechanism 2 is composed of a pair of left and right lower links 2A pivotally supported on the lower portion of the mission case 6, a top link 2B disposed in the upper center of the pair of left and right lower links 2A, and the like. . Lift arm 5
The swinging end of and the intermediate portion of the lower link 2A are connected by a lift rod 8. In other words, the rotary tiller 3,
It is suspended and supported by a lift arm 5 via a lift rod 8, and is lifted and lowered by the operation of a lift cylinder 4.

The rotary tiller 3 includes a gear case 10 in which a bevel gear mechanism (not shown) is connected to the PTO shaft 7 via a transmission shaft 9, and a relay transmission shaft connected to the bevel gear mechanism (see FIG. A horizontal frame 11 in which a not shown) is installed, a transmission case 12 in which a chain type transmission mechanism (not shown) is connected to a relay transmission shaft, and a rotary tiller 13 having a plurality of tillage claws 13a, and a rotary tiller. 13, a rotary cover 14 that covers the upper side of the rotary cover 13, and a rear cover 15 that is pivotally supported around the horizontal axis at the rear end of the rotary cover 14 so as to cover the rear of the tilling rotary 13 and the like. There is. That is, in the rotary cultivator 3, the power from the engine E taken out by the PTO shaft 7 is transmitted to the cultivating rotary 13 through the transmission shaft 9, the bevel gear mechanism, the relay transmission shaft, and the chain type transmission mechanism, and the cultivating tiller 13 is cultivated. By rotatably driving the rotary 13 around the horizontal axis, the cultivating work can be performed.

As shown in FIG. 1, on the right side of the driver's seat 16 mounted on the control section of the traveling machine body 1, the target height of the rotary tiller 3 with respect to the traveling machine body 1, that is, the target height of the machine body is set. A control lever 17 for manually setting is provided so as to be swingable back and forth. As shown in FIG. 2, the pivotal support portion of the control lever 17 is provided with a lever sensor S1 which is a potentiometer for detecting the operation angle of the control lever 17. Lever sensor S1
Outputs the detected operation angle of the control lever 17 to the control device 18 equipped with the microcomputer mounted on the traveling machine body 1 as the target height of the rotary tiller 3 with respect to the machine body. On the other hand, at the swing fulcrum of the lift arm 5, an arm sensor S including a potentiometer for detecting an operation angle of the lift arm 5 with respect to the traveling machine body 1.
2 is provided. The arm sensor S2 outputs the detected operation angle of the lift arm 5 to the controller 18 as the height of the rotary tiller 3 with respect to the body. The control device 18 operates the hydraulic oil for the lift cylinder 4 so that the target height of the rotary tiller 3 output from the lever sensor S1 and the height of the rotary tiller 3 output from the arm sensor S2 match. The operation of the electromagnetic control valve 19 for switching the flow state of the solenoid valve is controlled. That is, the control device 18 is provided with the position control means 18A as a control program for controlling the raising and lowering of the rotary cultivating device 3 based on an arbitrary target height of the body set manually by operating the control lever 17. . By executing the control operation by the position control means 18A, the rotary cultivating device 3 can be held at an arbitrary body height set by the operation of the control lever 17.

As shown in FIG. 1, an operation box 20 is arranged on the right side of the driver's seat 16. The operation box 20 is equipped with a tilling depth setting device 21 as a tilling depth setting means that is operated to manually set the target ground height (tilt depth setting position) of the rotary tiller 3. As shown in FIG. 2, the plowing depth setting device 21 is configured as a dial type consisting of a potentiometer, and outputs its operating angle to the control device 18 as the target ground height of the rotary tilling device 3. . On the other hand, the rotary cover 14 of the rotary tiller 3 is provided with a cover sensor S3 including a potentiometer that detects a swing angle of the rear cover 15 with respect to the rotary cover 14. Cover sensor S3
Outputs the detected swing angle of the cover 15 to the control device 18 as the ground height of the rotary tiller 3. That is, the cover sensor S3 functions as a ground-height detecting unit that detects the ground-height of the rotary tiller 3 as detection information. Control device 18
Is the rotary tiller 3 output from the tiller depth setting device 21.
The operation of the electromagnetic control valve 19 for switching the flow state of the hydraulic oil to the lift cylinder 4 is controlled so that the target ground height of the above and the ground height of the rotary tiller 3 output from the cover sensor S3 match. There is. That is, the control device 18 is provided with the automatic plowing depth control means 18B as a control program for controlling the raising and lowering of the rotary tilling device 3 based on an arbitrary target ground height set manually by operating the plowing depth setting device 21. Has been. By performing the control operation by the automatic tilling depth control means 18B, a constant tilling depth can be always obtained during the tilling work.

As shown in FIG. 2, the operation box 20 is equipped with a mode setter 22 for switching the control mode executed by the controller 18 to either the "normal mode" or the "automatic mode". The mode setter 22 is composed of a two-position switchable dial-type switch, and instructs the control device 18 to execute a control mode according to the operation position. The control device 18 executes the control operation by the position control means 18A when the mode setter 22 is set to the "normal mode", and the automatic working depth control means when the mode setter 22 is set to the "automatic mode". The control operation by 18B is executed. That is, the control device 18 is provided with the execution mode switching means 18C for switching the execution mode based on the set position of the mode setting device 22 as a control program.

As shown in FIG. 1, on the lower left side of the steering handle 23 provided in the control section of the traveling machine body 1, there is provided an operation lever 25 for switching operation of a two-position changeable lift command switch 24. . As shown in FIG. 2, when the mode setter 22 is set to the “automatic mode”, when the operation lever 25 is switched to the upward posture, a lift command for lifting the rotary tiller 3 is controlled by the lift command switch 24. The device 18 is instructed. Further, when the operation lever 25 is switched to the downward posture, the descending command for descending the rotary tilling device 3 is instructed from the ascending / descending command switch 24 to the control device 18. When the raising command is issued from the raising / lowering command switch 24, the control device 18 automatically feeds the plowing depth control means 1.
The operation of the electromagnetic control valve 19 that switches the flow state of the hydraulic oil to the lift cylinder 4 is controlled in preference to the control operation of 8B, and the rotary tiller 3 is forcibly lifted to a predetermined lift limit position. . Further, when the descending command is issued from the elevating command switch 24, the operation of the electromagnetic control valve 19 which switches the flow state of the hydraulic oil to the lift cylinder 4 is controlled, and the target ground clearance set manually by the plowing depth setting device 21. The rotary tiller 3 is lowered to the depth (set position for plowing). That is, the control device 18 has a forced elevating control means 18 for elevating the rotary tilling device 3 in preference to the control operation of the automatic tilling depth control means 18B based on the elevating command from the elevating command switch 24.
D is provided as a control program. Then, by operating the operation lever 25 to execute the control operation by the forcible lifting control means 18D, the lifting and lowering of the rotary tilling device 3 between the tilling depth setting position and the ascending limit position at the time of headland turning during the tilling work can be performed quickly. It can be done.

As shown in FIG. 2, the control device 18 controls the rotary tiller 3 in the case where the rotary tiller 3 is forcibly lifted from the tilling depth setting position to the ascending limit position by the control operation of the forced lift control means 18D. Rise rate of
As shown in FIG. 3, ascending speed control means 18E that adjusts based on the detection information from the cover sensor S3 is provided as a control program. Ascending speed control means 18E
If the cover sensor S3 detects that the rear cover 15 is not in the hanging posture (the rear cover 15 is in the grounded state) regardless of the working depth setting position set by the working depth setting device 21. , The rising speed of the rotary tiller 3 is slowed by reducing the duty cycle of the pulse signal for controlling the operation of the electromagnetic control valve 19 for switching the flow state of the hydraulic oil to the lift cylinder 4, and the cover sensor S3 is used to cover the rear cover. 15 is in a suspended posture (rear cover 15 is in a non-grounded state)
When it is detected, the rising speed of the rotary tiller 3 is increased by increasing the duty cycle of the pulse signal that controls the operation of the electromagnetic control valve 19. That is, the rising speed control means 1
8E shows that, in the first half side of the moving range of the rotary tiller 3 (the side where the tilling claw 13a of the rotary tiller 3 enters the soil to cultivate the soil), the traveling vehicle 1 travels in the forward direction and the rotary 8E. In the second half of the range of movement of the rotary tiller 3 (the side where the tilling claw 13a of the rotary tiller 3 is separated from the soil), the rotary tiller 3 is gradually raised from the soil. The rotary tiller 3 is raised at a high speed all at once from the time of separation to the rising limit position. As a result, when the rotary tiller 3 is raised at a constant high speed from the tilling depth setting position to the ascending limit position, the soil of the soil portion where the raising operation is started is moved backward by the rotary tiller 3. While avoiding the inconvenience that a large hole is formed without being covered with soil while being bounced off, the raising operation of the rotary tiller 3 can be performed relatively quickly.

As shown in FIG. 2, the control device 18 detects a target engine speed and a rotation sensor S4 according to the set value based on the set value set by the setter 26 including a potentiometer. An engine that controls the operation of the DC motor 27 with a speed reducer to operate the speed control lever 28a of the speed governor 28 provided in the engine E, so-called accelerator control, so that the engine speed matches. The rotation control means 18F is provided as a control program. Further, when the raising / lowering command switch 24 issues a raising command for forcibly raising the rotary tiller 3 to the control device 18, as shown in FIG.
By controlling the operation of the motor 27 and reducing the engine speed to a predetermined speed set in advance by accelerator control for operating the speed control lever 28a, the rotary tiller 3 is controlled by the control operation of the forced lifting control means 18D. Decrease the rotation speed of the PTO shaft 7 to a predetermined rotation speed until it rises from the plowing depth setting position to a predetermined rising limit position (until the arm sensor S2 detects that the reaching limit position is reached). A PTO rotation control means 18G is provided as a control program. That is, the PTO rotation control means 18G is controlled by the control till the rotary tiller 3 is raised from the tilling depth setting position to the ascending limit position, in other words, the tiller claw 13a of the rotary tiller 3 is operated.
During the period in which the soil penetrates into the soil and plunges the soil into a state in which it is separated from the soil by a large amount, the rotation speed of the PTO shaft 7 is reduced to a predetermined rotation speed, and the forced raising operation is performed. The splashing of the soil to the rear by the rotary tilling device 3 in the soil portion to be covered is suppressed. As a result, it is more preferable that the soil in the soil portion on which the rotary tiller 3 has been forcedly lifted is not covered with the rotary tiller 3 while being swept backwards and a large hole is formed. It can be avoided.

[Other Embodiments] Other embodiments of the present invention will be listed below. In the above embodiment, the control device 18 is provided with the ascending speed control means 18E and the PTO rotation control means 18G, and when the ascending / descending command switch 24 issues the ascending command of the rotary tiller 3, the ascending speed control means 18E controls. Although it is configured to execute the operation and the control operation by the PTO rotation control means 18G, the elevating command switch 24 issues an elevating command of the rotary tiller 3 without providing the elevating speed controlling means 18E in the control device 18. Alternatively, only the control operation by the PTO rotation control means 18G may be executed. That is, when the raising / lowering command switch 24 issues a command to raise the rotary tiller 3, the rotation speed of the PTO shaft 7 is set to a predetermined value until the rotary tiller 3 moves from the tilling depth setting position to the ascent limit position. The rotary tiller 3 is raised at a normal ascending / descending speed while being lowered to a certain number. As shown in FIG. 5, the PTO rotation control means 18G includes a friction type PTO clutch 29 for intermittently transmitting the power from the engine E to the PTO shaft 7, and a clutch for controlling the operation of the PTO clutch 29. It may be configured to reduce the rotation speed of the PTO shaft 7 to a predetermined rotation speed by control. The configuration will be described in detail. A hydraulic braking mechanism 30 that applies a braking action to the clutch pack 29A of the PTO clutch 29, and a rotation sensor S that detects the number of rotations of the PTO shaft 7.
5, and an electromagnetic control valve 31 for switching the flow state of the hydraulic oil to the PTO clutch 29 and the braking mechanism 30 is provided, and the PTO rotation control means 18G sends an instruction to raise the rotary tiller 3 by the elevation command switch 24. When instructed, the operation of the electromagnetic control valve 31 is controlled by controlling the operation of the electromagnetic control valve 31 so that the target rotation speed of the PTO shaft 7 set low in advance and the rotation speed of the PTO shaft 7 detected by the rotation sensor S5 match. It is configured to reduce the rotation speed of the PTO shaft 7 to a predetermined rotation speed until the tilling device 3 moves up from the tilling depth setting position to the rising limit position. Although not shown in the drawings as the PTO rotation control means 18G, in the one provided with the PTO speed change mechanism for changing the rotation speed of the PTO shaft 7, when the raising / lowering command switch 24 issues an instruction to raise the rotary tiller 3, Even if the PTO speed change mechanism is switched to a low speed state by the PTO speed change control for controlling the operation of the PTO speed change mechanism, the rotation speed of the PTO shaft 7 may be reduced to a preset predetermined speed. Good. As the ascending speed control means 18E, as shown in FIG. 6, the rotary tilling device 3 is moved (moved from the start of the ascending operation until a preset predetermined body height H is detected by the arm sensor S2). It may be configured such that the first half side in the range is raised at a slow speed, and the range from the detection to the rising limit position (the second half side in the movement range) is raised at a fast speed. As shown in (a) of FIG. 7, as the ascending speed control means 18E, regardless of the plowing depth setting position, the rotary tilling device 3 is armed so that the predetermined ground distance L rises from the start of the ascent. It is configured to increase at a slow speed until it is detected by the sensor S2 (the first half side in the moving range), and at a high speed from the time after the detection until the rising limit position (the second half side in the moving range). It may be one. Further, as shown in FIG. 7B, the predetermined ground distance L may be changed according to the plow depth setting position. As the ascending speed control means 18E, as shown in (a) of FIG. 8, the rotary tiller 3 is operated regardless of the plowing depth setting position until the preset predetermined time T elapses from the ascending start time. It may be configured such that the interval (the first half side in the moving range) is increased at a slow speed, and the interval from the predetermined time after that to the rising limit position (the latter half side in the moving range) is increased at a high speed. Also, FIG.
As shown in (B) of No., the predetermined time T may be changed in accordance with the plow depth setting position. As shown in FIG. 9, the ascending speed control means 18E may be configured to increase the ascending speed on the first half side in the moving range of the rotary tiller 3 as the plowing depth setting position becomes deeper. .

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

1] Overall side view of a riding-type cultivator

FIG. 2 is a block diagram showing a control configuration of a riding-type cultivator.

FIG. 3 is a diagram showing changes in the rising speed of the rotary tiller.

FIG. 4 is a diagram showing the relationship between the height of the rotary cultivator and the PTO rotation speed at the time of forced ascent.

FIG. 5 is a diagram showing a control configuration of PTO rotation control means in another embodiment.

FIG. 6 is a diagram showing changes in the ascending speed of the rotary tiller in another embodiment.

FIG. 7 is a diagram showing changes in the ascending speed of the rotary tiller according to another embodiment.

FIG. 8 is a diagram showing changes in the ascending speed of the rotary tiller according to another embodiment.

FIG. 9 is a diagram showing changes in the ascending speed of the rotary tiller in another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling vehicle 3 Rotary tiller 7 PTO shaft 18B Automatic tilling depth control means 18D Forced elevation control means 18E Ascent speed control means 18G PTO rotation control means 21 Tillage depth setting means 24 Lift command switch 28 Speed governor 28a Speed control lever 29 PTO Clutch E Engine S3 Ground height detection means

Claims (5)

[Claims] 1. An engine (E) via a PTO shaft (7)
Rotary tiller (3) driven by power from
Is connected to the traveling machine body (1) so as to be movable up and down, and based on the detection information from the ground height detecting means (S3) for detecting the ground height of the rotary tiller (3), the detection is performed. Automatic plowing depth control means (18B) for raising and lowering the rotary tilling device (3) so that the information matches the target ground height of the rotary tilling device (3) preset by the tilling depth setting means (21). ), And an ascending command from the ascending / descending command switch (24),
Control of a tiller equipped with a forced raising / lowering control means (18D) for forcibly raising the rotary tiller (3) to a predetermined raising limit position in preference to the control operation of the automatic tilling depth control means (18B). A device, wherein when the raising / lowering command switch (24) issues a command to raise the rotary tiller (3), the rotary tiller (3) is raised to the raising limit position.
A control device for a cultivator comprising PTO rotation control means (18G) for reducing the rotation speed of the PTO shaft (7) to a predetermined rotation speed. 2. The rising speed of the rotary tiller (3) when the rotary tiller (3) is forcibly lifted by the control operation of the forced lift control means (18D) is such that the first half side in the moving range is slow and the second half is slow. The control device for a cultivator according to claim 1, further comprising an ascending speed control means (18E) for adjusting so that the side becomes faster. 3. The PTO rotation control means (18G),
The rotational speed of the PTO shaft (7) is reduced to the predetermined rotational speed by accelerator control that operates a speed control lever (28a) of a speed governor (28) provided in the engine (E). The control device for a tiller according to claim 1 or 2. 4. A friction type PTO clutch (29) for intermittently transmitting power from the engine (E) to the PTO shaft (7) is provided, and the PTO rotation control means (18G) is provided with the PTO clutch. The control device for a cultivator according to claim 1, wherein the rotation speed of the PTO shaft (7) is reduced to the predetermined rotation speed by clutch control for controlling the operation of (29). 5. The PTO speed change mechanism for changing the rotation speed of the PTO shaft (7) is provided, and the PTO rotation control means (18G) controls the PT by the PTO speed change control for controlling the operation of the PTO speed change mechanism.
The control device for a tiller according to claim 1 or 2, wherein the rotation speed of the O-axis (7) is configured to be reduced to the predetermined rotation speed.