JPH0715370Y2 - Tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tractor, and more particularly, to lifting and posture control of a working machine such as a rotary and a plow mounted on a rear portion of the tractor.

The work machine is required to control its height and posture, for example, for controlling the working depth. However, heretofore, these control modes have not been able to correspond to the overall situation of the field or the difference in the situation depending on the location of the field, and fine tillage depth control has been impossible.

The present invention has been made in view of such a problem, and an object thereof is to provide a tractor capable of controlling the speed thereof and performing fine control corresponding to the situation of a field.

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 is a partially cutaway left side view of a tractor according to the present invention in which a rotary 2 is mounted as a working machine in the rear part (hereinafter referred to as the present invention machine), and FIG. In the figure, reference numeral 1 is a tractor body, and a rotary 2 is mounted to be vertically movable via a three-point link mechanism composed of a left and right pair of lower links 12 and a double link hydraulic cylinder 11 and a top link. There is.

The top link composed of the hydraulic cylinder 11 supports the cylinder tube 11a on the top arm 23 of the rotary 2 by a trunnion, and the tip of its piston rod 11b is pivotally supported on the top link hinge 17 at the rear part of the tractor body 1. The left and right lower links 12,12 are connected and supported at their front ends to the lower corners on both sides of the mission case 3 via the lower link pins 16,16, and the lower links 12,12 can be expanded and contracted by turnback. It is connected to a pair of left and right lift arms 14 and 14 via 13 and 13 respectively, and the front ends of the lift arms 14 and 14 are interlocked and connected to a hydraulic lift 15 provided on the upper side of the mission case 3, and on the upper side thereof. By operating an elevating lever 19 provided, the hydraulic lift 15 is driven to cause the lift arms 14 and 14 to cooperate with each other to elevate and lower the entire rotary 2. Reference numeral 18 denotes a flexible pipe for feeding pressure oil to the hydraulic cylinder 11.

At the center of the upper surface of the rotary cover 22 of the rotary 2, the rotary 2
A tilt angle sensor 40 having a cylindrical shape for detecting the tilt angle in the front-back direction is provided. On the upper surface of the rotary cover 22, a tilting depth sensor 50 that detects the tilting angle of the rear cover 21 rotatably supported on the rear side of the rotary cover 22 and thereby obtains the working depth of the rotary 2 is provided. It is mounted on the rear side.

FIG. 3 is a schematic perspective view showing the internal structure of the housing of the tilt angle sensor 40. In the figure, 44,44 ... Are light receiving elements made of phototransistors, 45,45 ... Are light emitting elements made of LEDs, Five of each are arranged vertically at equal pitches and are fixed to the inner surface of the cylindrical case so as to face each other in the left-right direction of the machine body. A light shield plate 42 is provided between the emitting and receiving element facing gaps.
Is pivotally supported at its upper end so that it can swing back and forth. An oil damper 43 is attached to the pivot shaft 41 of the light shield plate 42, so that when the tilt angle sensor 40 or the tilt angle of the front-rear direction of the rotary 2 changes, the light shield plate 42 becomes vertical and immediately stops. The swing of the light shielding plate 42 is suppressed. Light shield
Reference numeral 42 indicates light receiving elements 44, 44 ..., Light emitting elements 45, 45 ... Light shielding elements 42a, 42b, 42c, 42d, 42e for 5 bits are provided at the opposite height positions. The circumference and phase of each light shielding window are set so that the light receiving and light shielding states are gray code. As a result, the 5-bit output of the light receiving elements 44, 44 ... Outputs a gray code signal representing the tilt angle of the tilt angle sensor 40.

FIG. 4 schematically shows a control system of the proposed machine together with a connecting portion between the tractor body 1 and the rotary 2. The working depth sensor 50 provided behind the tilt angle sensor 40 is attached to the upper surface of the rotary cover 22, and an operating rod 51 that rotates up and down is extended rearward and bent downward, and the tip thereof is rear cover 21. The working rod 51 is mounted on the upper surface and follows the vertical movement of the rear cover 21 to rotate up and down, and the working angle is detected by detecting the rotation angle of the base end of the operating rod 51 as an electric signal using, for example, a potentiometer. It is supposed to do. The output signal of the plowing depth sensor 50 and the output signal of the tilt angle sensor 40 are controlled by the control unit.
It is entered in 60.

The hydraulic cylinder 11 forming the top link has a piston rod.
Cylinder sensor 6 that outputs a voltage corresponding to the amount of advance / retreat of 11b
1 is provided, and this output is input to the control unit 60. In addition, the hydraulic lift 15 that raises and lowers the rotary 2
A lift lever 19 for advancing and retracting the rod of the hydraulic lift 15 is provided above, and the base end of the lift lever 19 is used when the lift lever 19 is operated to raise and lower the rotary 2. Limit switches 62 and 63 which are turned on respectively are provided, and outputs of the limit switches 62 and 63 are given to the control unit 60. Further, the control unit 60 is provided on the operation panel 5 in front of the driver's seat 4 and is provided with the output of a tilling depth instruction switch 64 for instructing the setting of the tilling depth.

Further, the control unit 60 is provided on the operation panel 5 and is used to set the drive speed of the hydraulic cylinder 11 forming the top link.
The output of the top link speed setting switch 65, which is the speed setting unit, and the lift arm speed setting switch 66, which is the first speed setting unit that sets the lifting drive speed of the hydraulic lift 15, is given. The control unit 60 intermittently excites each solenoid 84, 85, 82, 83 of the solenoid valves 74, 73 described later with a pulse signal of a predetermined duty ratio so that the set drive speed is achieved. Therefore, the drive speeds of the hydraulic cylinder 11 and the hydraulic lift 15 are changed by the change of the duty ratio of the pulse signal generated by the control unit 60. When the limit switch 62 for raising is turned on, the control unit 60 continuously excites the solenoid 83 of the solenoid valve 73.

Each speed setting switch 65, 66 takes in the value set by the respective independent operation into the control unit 60, but the value set by the operation of one speed setting switch 65 is changed by the other speed setting switch 66. It is also possible to perform an interlocking operation that takes in the control unit 60 as a set value, and in the vicinity of both speed setting switches 65 and 66, an independent and interlocking operation changeover switch 67, which is an independent and interlocking changeover unit, is provided. The output of the changeover switch 67 is also input to the control unit 60. Note that the setting value of the speed setting switch 66 may be prioritized during the interlocking operation.

Further, the detection result of the speed sensor 68 that detects the vehicle speed of the tractor body 1 is input to the control unit 60, and it is also possible to automatically control the ascending drive speed of the hydraulic lift 15 in accordance with the vehicle speed. The automatic switch 69 for performing this automatic control is also input to the control unit 60, and the automatic switch 69
Is operated to the automatic side, the ascending drive speed of the hydraulic lift 15 is changed according to the detection result of the speed sensor 68.
The descending drive speed is the value set by the speed setting switch 66. On the contrary, when the automatic switch 69 is operated to the manual side, the hydraulic lift 15 is controlled up and down at the speed set by the speed setting switch 66.

Drive control of the hydraulic lift 15 and hydraulic cylinder 11 is controlled by solenoid valves 73 and 74.
Etc. That is, the pressure oil of the hydraulic pump 71 driven by the engine is given to the hydraulic cylinder 11 via the solenoid valve 74 and to the hydraulic lift 15 via the sequence valve 75 and the solenoid valve 73. The solenoid valve 74 connected to the hydraulic cylinder 11 is a 4-port 3-position switching type directional control valve. When one solenoid 84 is excited, pressure oil is supplied to the rod retraction side oil chamber of the hydraulic cylinder 11, and The pressure oil in the rod advancing side oil chamber is returned to the tank and the piston rod 11b
Retreats, and the rotary 2 leans forward. On the contrary, when the other solenoid 85 is excited, pressure oil is supplied to the rod advancing side oil chamber of the hydraulic cylinder 11, and the pressure oil in the rod retreating side oil chamber is returned to the tank and the piston rod 11b advances, The rotary 2 tilts backward. At the neutral position where both solenoids 84 and 85 are demagnetized, all ports of the solenoid valve 74 are closed, the piston rod 11b of the hydraulic cylinder 11 holds its advanced position, and the rotary 2 is held in the front-back tilted posture.

On the other hand, the solenoid valve 73 that controls the hydraulic lift 15 and the hydraulic pump
A sequence valve 75 is interposed between the solenoid valve 71 and the valve 71, and the relief pressure of the sequence valve 75 is obtained from the oil passage between the solenoid valve 74 and the hydraulic pump 71. When the internal pressure rises, the sequence valve 75 operates to send pressure oil to the solenoid valve 73 side.

The solenoid valve 73 connected to the hydraulic lift 15 is a three-port three-position switching type directional control valve, and when one solenoid 82 is excited, pressure oil is sent to the hydraulic lift 15 so that its piston rod advances and the rotary valve moves. 2 rises. When the other solenoid 83 is excited, the pressure oil of the hydraulic lift 15 is returned to the tank, and the piston rod of the hydraulic lift 15 retracts and descends due to its own weight such as the rotary 2. Both solenoids 8
When 2,83 are demagnetized, the port connected to the hydraulic lift 15 is closed, and the piston rod of the hydraulic lift 15 holds its advanced position and the height position of the rotary 2. The solenoids 82, 83, 84, 85 of the solenoid valves 73, 74 are controlled by the output signals of the control unit 60.

When the rotary plowing work is performed so that the plowing depth is constant in the above-described construction machine, first, the plowing depth is set by the plowing depth instruction switch 64, and the speed setting switch 6
5, 66 are operated to set the drive speeds of the hydraulic cylinder 11 and the hydraulic lift 15 in correspondence with the field conditions and the like. In this case, both speed setting switches 65 and 66 can be switched between the independent operation of each speed setting switch and the interlocking operation in which the operation of one speed setting switch is linked to the operation of the other speed setting switch by the changeover switch 67. When the changeover switch 67 is operated to the interlocking side, if one speed setting switch 65 is operated, the setting value of the speed setting switch 65 becomes the setting value of the other speed setting switch 66, and it is operated to the independent side. In this case, the speed setting switches 65 and 66 are controlled by respective set values obtained by operating them independently. Therefore, when the rotary is installed as the working machine as in the present embodiment, the workability can be improved by simultaneously controlling the hydraulic cylinder 11 and the hydraulic lift 15 that form the top link.
By making 5,66 interlockable, the operability is significantly improved, and work equipment such as plows or hydraulic lifts that require control of only the hydraulic cylinder 11 that forms the top link.
When a working machine such as a digging machine that requires control of only 15 is mounted, each speed setting switch 65, 66 may be operated independently.

Now, in order to automatically change the ascending drive speed of the hydraulic lift 15 to the vehicle speed, operate the automatic switch 69 to the automatic side,
Next, when the lift lever 19 is operated to the rotary lower side, the limit switch 63 is turned on, the control unit 60 continuously excites the solenoid 83 of the solenoid valve 73, communicates the hydraulic lift 15 and the tank, and lowers the rotary 2. Is at a predetermined height position with respect to the tractor body 1. In such a state, when the rotary tilling work is performed so that the plowing depth becomes constant, the tilt angle sensor 40 detects the tilt angle of the rotary 2 in the front-rear direction and inputs the detection result to the control unit 60. The 60 controls so that the tilt angle of the rotary 2 in the front-rear direction is always horizontal. That is, when the tractor body 1 is tilted due to the unevenness of the field surface and the rotary 2 is tilted forward (or backward), the tilt angle sensor 40 detects this state, and the control unit 60 causes the solenoid 85 of the solenoid valve 74 to move.
(Or 84) is intermittently excited by a predetermined pulse signal set by the speed setting switch 65, and the piston rod 11b of the hydraulic cylinder 11 is advanced (or retracted) to move the rotary 2 forward or backward. Also keep it in a horizontal position without tilting.

On the other hand, the tilling depth sensor 50 detects the tilling depth by the angle between the rear cover 21 slidingly contacting the field surface cultivated by the rotary 2 and the rotary cover 22, and the control unit 60 controls the tilling depth switch.
The tilling depth set at 64 is compared with the actual tilling depth detected by the tilling depth sensor 50. If there is a difference between the two, the hydraulic lift 15 is set so that the tilling depth becomes the set value. To change the height position of the rotary 2. That is, when the working depth is larger (or smaller) than the set position, the solenoid of the solenoid valve 73
82 (or 83) is intermittently excited to supply the pressure oil to the hydraulic cylinder 15 (or the pressure oil of the hydraulic cylinder 15 is returned to the tank),
The rotary 2 is raised (or lowered) so that a predetermined working depth is reached.

In this case, since the automatic switch 69 is operated to the automatic side, the rising speed of the rotary 2 is controlled based on the detection result of the speed sensor 68. That is, when the traveling speed of the tractor main body 1 is slow, the solenoid 82 is intermittently excited by a pulse signal having a small duty ratio so that the rising speed of the rotary 2 becomes slow, and conversely when the traveling speed of the tractor main body 1 is high. In order to increase the rising speed of the rotary 2, the solenoid 82 is intermittently excited by a pulse signal having a large duty ratio. Therefore, the tilled state of the field becomes constant regardless of the vehicle speed.

The lowering of the rotary 2 is controlled at the speed set by the speed setting switch 66, and the control unit 60 outputs a predetermined pulse signal so as to reach the speed set by the speed setting switch 66. The solenoid 83 is excited intermittently to lower the rotary 2 at a predetermined speed.

When the automatic switch 69 is operated to the manual side, the rotary 2 is moved up and down at the speed set by the speed setting switch 66.

In this way, the speed for controlling the raising and lowering of the rotary 2 is determined by the speed setting switch 66. Therefore, by setting this speed according to the situation in the field, a desired control response can be obtained.

Furthermore, the rotary 2 is tilted in the front-rear direction,
When the working depth is not the predetermined depth, the sequence valve 75 first controls the hydraulic cylinder 11 to bring the rotary 2 into a horizontal state, and when the pressure in the control circuit of the hydraulic cylinder 11 increases, the hydraulic lift is performed. Since 15 is controlled to a predetermined working depth, the working depth control is performed based on the working depth detected by the working depth sensor 50 in a horizontal state in which the rotary 2 is not tilted in any of the front and rear directions, and erroneous control is performed. There is no fear of this, and a predetermined working depth can be obtained with certainty.

Since the speed of controlling the tilting posture of the rotary 2 at this time is determined by the speed setting switch 65, a desired control response can be obtained by setting this speed according to the situation of the field.

When the elevator lever 19 is operated to raise the rotary 2 as in the case where the one-step tilling work is completed, the limit switch 62 is turned on, and the control unit 60 causes the cylinder provided in the hydraulic cylinder 11 forming the top link. The tilt angle of the rotary 2 in the front-rear direction is controlled based on the sensor 61, and the rotary 2 is raised. That is, the control unit 60 controls the solenoid valve so that the amount of advance of the piston rod 11b is approximately half of its total length.
The solenoid 84 or 85 of 74 is continuously excited, and the solenoid 82 of the solenoid valve 73 is continuously excited. As a result, the piston rod 11b is controlled and the amount of advance of the piston rod 11b is approximately
When the cylinder sensor 61 detects that the number has become 1/2, the control unit 60 terminates the excitation of the solenoid 84 or 85, and the rotary 2
Is in a horizontal state in which it is not tilted in either direction.

When the rotary 2 becomes horizontal, the pressure in the oil passage between the hydraulic pump 71 and the solenoid valve 74 rises, the sequence valve 75 operates, and the pressure oil of the hydraulic pump 71 is fed to the solenoid valve 73 side. Hydraulic lift due to continuous excitation of solenoid 82
15 is driven promptly and the rotary 2 rises. Therefore, when the lift lever 19 is operated to raise the rotary 2, the limit switch 62 is turned on, and the rotary 2 is placed in a horizontal state in which it is not tilted in any of the front and rear directions, and then the rotary 2 is moved.
However, since the rotary 2 is continuously raised so as to have the highest speed in preference to the speed set by the lift arm speed setting switch 66, the rotary 2 is immediately moved to the upper retracted position. .

As described in detail above, the tractor according to the present invention includes a first speed setting unit for setting, a unit for tilting the working machine in the front-rear direction, a second speed setting unit for setting the front-rear direction tilting speed of the working machine, By the respective speeds set in the first speed setting unit and the second speed setting unit, respectively, the individual control for controlling the vertical movement of the working machine and the tilting in the front-rear direction, or the speed set in any of the speed setting units, It is provided with an individual and interlocking switching section for selecting interlocking control for controlling the lifting and lowering of the working machine and the tilting in the front-rear direction. The lifting speed of the working machine and the tilting speed in the front-rear direction are respectively set to the first speed setting section and the second speed. It is characterized in that the individual control by the speed set in the setting unit and the interlocking control by the speed set in any one of the speed setting units are selectable, so that the overall situation of the field to be worked is 1st speed setting according to And it can be individually controlled in the longitudinal direction tilting speed of the elevator and working machine of the working machine by the second speed setting unit,
In addition, it is possible to control the raising and lowering of the working machine and the tilting speed in the front-rear direction at a speed related to the speeds set in the first speed setting unit and the second speed setting unit in response to the partial situation change in the field, so that the desired speed can be obtained. The control response speed can be obtained, and the effect that fine work corresponding to the situation in the field becomes possible is obtained.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a partially cutaway left side view of the machine of the present invention, FIG.
FIG. 4 is a schematic diagram of the inside of the tilt angle sensor, and FIG. 4 is a schematic diagram of the control system of the proposed machine. 1 ... tractor body, 2 ... rotary, 11 ... hydraulic cylinder,
12 ... Lower link, 15 ... Hydraulic lift, 19 ... Lift lever, 21 ...
Rear cover, 22 ... Rotary cover, 40 ... Tilt angle sensor, 50 ...
Plowing depth sensor, 60 ... Control unit, 61 ... Cylinder sensor, 62, 63
… Limit switch, 64… Tillage depth instruction switch, 65… Top link speed setting switch, 66… Lift arm speed setting switch, 67… Changeover switch, 68… Speed sensor, 73, 74
…solenoid valve

Claims (1)

[Scope of utility model registration request] 1. A means for raising and lowering a working machine, a first speed setting section for setting a raising and lowering speed of the working machine, a means for tilting the working machine in the front-rear direction, and a first speed setting section for setting a forward-backward tilting speed of the working machine. 2 speed setting unit, individual speed control of each of the first speed setting unit and the second speed setting unit and the speed set respectively in the first speed setting unit and the second speed setting unit. It is equipped with an individual and interlocking switching section that selects interlocking control for controlling the lifting and lowering of the working machine according to the set speed, and sets the lifting speed and the forward and backward tilting speed of the working machine to the first speed setting, respectively. Unit and the second speed setting unit, the individual control according to the speed set, and the interlocking control according to the speed set in any one of the speed setting units are configured to be selectable.