JP3053053B2 - Work device attitude change structure of work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for supporting a working device with respect to a machine body so as to be capable of changing its posture, and for changing the posture of the working device relative to the machine body, and a posture for detecting the posture of the working device relative to the machine body. The present invention relates to a working device posture changing structure of a working vehicle including a sensor and configured to operate an actuator so that a detection value of the posture sensor coincides with a set target value.

[0002]

2. Description of the Related Art An agricultural tractor is an example of the work vehicle described above. In the agricultural tractor, a rotary tilling device (corresponding to a working device) is supported by a hydraulic cylinder (corresponding to an actuator) at a rear portion of the fuselage so as to be able to freely move up and down. doing.
And a height sensor (corresponding to a posture sensor) that detects the height (corresponding to posture) of the rotary tilling device with respect to the aircraft
The rotary tilling device is configured to be operated by a hydraulic cylinder so as to move up and down such that the detection value C ′ of the height sensor matches the set target value A ′ as shown in FIG. 4, for example.

[0003] A dead zone B1 ', B2' is set on one and the other side of the set target value A 'so that the hydraulic cylinder operates even if the detected value C' of the height sensor deviates from the target value A '. No, the detection value C 'of the height sensor is dead zone B
The hydraulic cylinder is operated so that the detected value C 'of the height sensor coincides with the target value A' when it goes outside from 1 'and B2'. In this case, the detection value C 'of the height sensor goes out of the dead zones B1' and B2 ', and the detection value C' (height of the rotary tilling device) of the height sensor is set to the target value A 'by the hydraulic cylinder. When returning, the detection value C 'of the height sensor
The operating speed of the hydraulic cylinder is set based on a difference D3 between the hydraulic cylinder and the target value A '.

[0004]

As described above, when returning the detection value (height of the rotary tilling device) of the height sensor which has come out of the dead zone to the target value, the detection value of the height sensor and the target value When the operating speed of the hydraulic cylinder is set on the basis of the difference (D3 in FIG. 4), the greater the difference between the detected value of the height sensor and the target value, the sooner the detected value of the height sensor is returned to the target value. From this point, the operating speed of the hydraulic cylinder is set to be high.

[0005] However, when the detected value of the height sensor suddenly goes out of the dead zone due to a large vibration of the body or the like, the difference between the detected value of the height sensor and the target value is determined as described above. If the operating speed of the hydraulic cylinder is set to a high speed, the hydraulic cylinder may suddenly operate and the rotary tilling apparatus may be operated to move up and down, causing a shock. An object of the present invention is to suppress a shock when the detection value of the posture sensor (the posture of the work device) is returned to a target value in the working device posture changing structure of the work vehicle as described above.

[0006]

A feature of the present invention resides in the following structure of the working device posture changing structure of the working vehicle as described above. In other words, the working device is supported so as to be able to change the attitude of the working device with respect to the airframe, and an actuator that changes the attitude of the working device with respect to the airframe is provided with an attitude sensor that detects the attitude of the working device with respect to the airframe. A first control means for operating the actuator so that when the detected value of the attitude sensor goes outside the dead zone by setting a dead zone on one and the other sides of the value, the detected value of the attitude sensor coincides with a target value; When the detected value of the attitude sensor goes out of the dead zone, based on a value obtained by subtracting the dead zone on the side where the detected value comes out from the difference between the target value and the detected value, the operation of the actuator by the first control means is performed. Second control means for setting the speed.

[0007]

According to the present invention, as shown in FIG. 3, for example, as shown in FIG.
The detection value C of the attitude sensor deviates from the target value A and the dead zone B
1 and B2, the value D2 is obtained by subtracting the dead zone B1 on the side from which the detected value C is output from the difference D1 between the detected value C of the attitude sensor and the target value A at that time. Then, the operation speed of the actuator is set based on the obtained value D2, and the posture changing operation of the working device is performed.

In this case, as in the prior art shown in FIG. 4, the difference D3 between the detected value C 'of the height sensor and the target value A' is determined.
3, the operating speed of the actuator is set based on the value D2 obtained by subtracting the dead zone B1 from the difference D1 between the detected value C of the attitude sensor and the target value A, as shown in FIG. Even if the operation speed of the actuator is set to be higher as D2 is larger, it is unlikely that the actuator is suddenly operated, the posture of the working device is changed, and a shock occurs. Also in the present invention, it is maintained that the larger the difference between the detected value of the attitude sensor and the target value, the sooner the detected value of the attitude sensor is returned to the target value.

[0009]

As described above, when the detected value of the height sensor suddenly goes out of the dead zone due to a large vibration of the body or the like, the operation speed of the actuator is slightly suppressed. The posture of the working device can be returned to the original position with less shock, and the function of changing the posture of the working device in the working vehicle can be enhanced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a rear part of an agricultural tractor, which is an example of a working vehicle. A rotary tilling device 4 (for a working device) is mounted on a transmission case 3 via a top link 1 and a pair of left and right lower links 2 that can swing vertically. Equivalent). A pair of lift arms 6 which are vertically driven by a hydraulic cylinder 5 (corresponding to an actuator) are provided on the upper part of the transmission case 3, and the pair of lift arms 6 and the lower link 2 are connected to a lift rod 7 and a double-acting type. Hydraulic cylinder 8
Are connected via

As a result, as shown in FIG. 2, the three-position switching type lifting / lowering control valve 16 for the hydraulic cylinder 5 is switched to operate the hydraulic cylinder 5 and the lift arm 6 to raise / lower the entire rotary plow 4. Then, the rolling control valve 17 of a three-position switching type with respect to the hydraulic cylinder 8 is switched, and the rotary cultivator 4 is rolled around the connection point with the lift rod 7 by the expansion and contraction of the hydraulic cylinder 8.

[0012] The agricultural tractor includes a rotary tilling device 4.
Depth control means for maintaining the tilling depth at a set height from the ground and a constant tilling depth, position control means (corresponding to first control means) for maintaining the height of the rotary tilling device 4 with respect to the body at a set position, and And a rolling control means for maintaining the left and right inclinations of the rotary tilling device 4 at a set posture. As shown in FIG. 2 and FIG. 1, a tillage depth sensor 10 for detecting a vertical swinging angle of a rear cover 9 that is vertically swingably provided on the rotary tillage device 4 is provided. Thereby, the automatic plowing depth control means switches the lifting / lowering control valve 16 so that the detected value of the plowing depth sensor 10 becomes the set plowing depth of the potentiometer type plowing depth setting device 11 provided on the machine body, The rotary plow 4 is automatically raised and lowered by the cylinder 5 and the lift cylinder 6.

At the base of the lift arm 6, an angle sensor 13 (corresponding to an attitude sensor) for detecting the vertical angle of the lift arm 6 with respect to the body is provided. Accordingly, the position control means operates the lifting / lowering control valve 16 by switching the hydraulic cylinder 5 so that the detection value of the angle sensor 13 becomes the target value set by the position setting device 12 provided on the body.
To swing the lift arm 6 up and down. Therefore,
When the rotary tilling device 4 is located above the ground, the operator operates the position setting device 12 to arbitrarily change the position of the rotary tilling device 4 with respect to the body up and down by the position control means. can do. When the rotary tilling device 4 is moved down to a position in contact with the ground by the position setting device 12, the state automatically switches to a state in which the automatic cultivation depth control means is activated, and the detection value of the cultivation depth sensor 10 is changed to the cultivation depth setting device. The rotary tillage device 4 is automatically moved up and down so as to have the set tillage depth of 11.

An elevating switch 18 (push-on push-off type) for raising the rotary tilling device 4 to a predetermined height with respect to the body at a stretch is provided. This allows
When the raising / lowering switch 18 is pressed and turned on, the lifting / lowering control valve 16 is operated in preference to the above-mentioned position control means and automatic plowing depth control means, and the rotary plow 4 is raised at a stroke to a predetermined height with respect to the body. When the lifting switch 18 is pressed again to turn off, the rotary tillage device 4 is lowered to the original position, and returns to the position control means or the automatic plowing depth control means. In this case, a height setting device 19 is provided which adjusts a predetermined height at which the rotary tilling device 4 is raised when the lifting switch 18 is pressed and turned on.

As shown in FIGS. 2 and 1, a stroke sensor 14 for detecting the amount of expansion and contraction of the hydraulic cylinder 8 and a weight type tilt sensor 15 for detecting the right and left inclination of the body are provided. Accordingly, the rolling control means uses the inclination sensor 15 to detect the inclination of the body and the stroke sensor 1.
4, the rolling control valve 17 is switched so that the inclination setting device 20 provided on the fuselage is in the set posture while detecting the inclination of the rotary tillage device 4 with respect to the fuselage by the
The rotary tilling device 4 is automatically rolled by the hydraulic cylinder 8.

Further, a changeover switch 21 for manually rolling the rotary tilling apparatus 4 is provided, and the changeover switch 21 is biased toward a neutral position by a three-position changeover type. Thus, when the changeover switch 21 is operated to the neutral position, the rolling control valve 17 is operated to the neutral position and the hydraulic cylinder 8 stops, and when the changeover switch 21 is operated to the lower right position, the hydraulic cylinder 8 is controlled by the rolling control valve 17. When the extension operation is performed, the posture of the rotary tilling device 4 is operated to the lower right side, and when the changeover switch 21 is operated to the lower left position, the hydraulic cylinder 8 is contracted by the rolling control valve 17, and the posture of the rotary tilling device 4 is changed. Is operated to the left.

Next, the state of control by the position control means (corresponding to the first control means) will be described. As shown in FIG. 3 and FIG. 2, when the operator operates the position setting device 12 in order to operate the rotary tilling device 4 to move up and down to a desired height, an upper side of the target value A set by the position setting device 12 is sandwiched. (One) and the lower side (the other), dead zone B
1 and B2 are set, and the hydraulic cylinder 5 is operated by the lifting / lowering control valve 16 and the rotary tilling device 4 is raised / lowered so that the detection value C of the angle sensor 13 matches the set target value A. . The elevating control valve 16 is capable of controlling the flow rate, and by changing the flow rate of supply and discharge of the hydraulic oil to and from the hydraulic cylinder 5 by the elevating control valve 16,
The operation speed of the expansion and contraction of the hydraulic cylinder 5 can be changed.

In this case, in a state where the rotary tilling device 4 is maintained at the height of the target value A without operating the position setting device 12, the rotary tilling device 4 moves up and down due to vibration of the body and the like, and the angle sensor 13 is the target value A
, The hydraulic cylinder 5 is not operated unless the detected value C falls outside the dead zones B1 and B2.

Conversely, when the rotary tiller 4 moves up and down due to large vibrations of the body and the like, the detected value C of the angle sensor 13 deviates from the target value A and goes out of the dead zones B1 and B2. 13 detected value C and target value A
Is obtained by subtracting the dead zone B1 on the side from which the detection value C is output from the difference D1 from the difference D1. Then, the obtained value D2
(The operation speed is high when the difference D2 is large, and the operation speed is low when the difference D2 is small)
The lifting / lowering control valve 16 changes the flow rate of supply and discharge of hydraulic oil to and from the hydraulic cylinder 5 so that the hydraulic cylinder 5 expands and contracts, and the detection value C of the angle sensor 13 matches the set target value A. The rotary tilling device 4 is moved up and down (corresponding to the second control means).

[Alternative Embodiment] The control shown in FIG. 3 is not limited to the position control means, but also the automatic plowing depth control means and the height setting device 1 using the above-described plowing depth sensor 10 and plowing depth setting device 11.
Alternatively, the present invention may be applied to a lifting operation using the lifting switch 9 and the lifting switch 18, a rolling control means using the inclination sensor 15 and the inclination setting device 20, and a manual rolling operation using the changeover switch 21. The present invention is not only for agricultural tractors,
The present invention can also be applied to a raising and lowering operation and a rolling operation of a seedling planting device (corresponding to a working device) in a riding type rice transplanter, and a raising and lowering operation of a cutting unit (corresponding to a working device) in a combine.

[0021] In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rear part of a agricultural tractor and a rotary tillage device.

FIG. 2 is a circuit diagram of a hydraulic cylinder for lifting and lowering and rolling operations.

FIG. 3 is a diagram showing a control state when a detection value of an angle sensor deviates from a target value and a dead zone in the present invention.

FIG. 4 is a diagram showing a state of control when a detection value of a height sensor deviates from a target value and a dead zone in the related art.

[Explanation of symbols]

4 Working device 5 Actuator 13 Attitude sensor A Target value C Detection value of attitude sensor D1 Difference between target value and detection value D2 Value obtained by subtracting dead zone from difference between target value and detection value B1, B2 Dead zone

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-163002 (JP, A) JP-A-62-130603 (JP, A) JP-A-61-136809 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) A01B 63/10-63/114

Claims (1)

(57) [Claims] An actuator (5) that supports a working device (4) with respect to a machine body so as to be capable of changing its posture, and that changes the posture of the working device (4) with respect to the machine body; 4) An attitude sensor (1) that detects the attitude
3), and dead zones (B1) and (B2) are set on one and the other sides of the set target value (A), and the posture sensor (1) is set.
When the detection value (C) of 3) goes out of the dead zones (B1) and (B2), the actuator is adjusted so that the detection value (C) of the attitude sensor (13) matches the target value (A). (5) a first control means for operating and operating the target value (A) when a detection value (C) of the attitude sensor (13) comes out of the dead zones (B1) and (B2). The difference (D1) obtained by subtracting the dead zone (B1) on the side where the detection value (C) comes out from the difference (D1) from the detection value (C).
A second control means for setting an operation speed of the actuator (5) by the first control means based on 2);