JP2000342011A - Tractor lift control device - Google Patents

Abstract

(57) [Summary] (With correction) [Problem] For a device that changes the throttle position in conjunction with lifting and lowering of a work machine, this changed position is always set to the same position. In a tractor equipped with both the throttle adjusting device and a device that reduces the descending speed before the work machine lands, in the process of landing from one work machine descent, the change in the descending speed can be minimized and the operator's Makes it easy to perform the alignment operation. SOLUTION: In a tractor 10 that adjusts a throttle position in conjunction with lifting and lowering of a work machine 1, a drive speed of a hydraulic cylinder 2 for lifting and lowering the work machine is changed by an amount of electricity supplied to a solenoid of a proportional pressure control valve. And setting device 6
The lowering speed of the work machine 1 is switched from the normal speed to the low speed at the height with respect to the vehicle body set in the above, and the throttle position is returned at the same position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor lifting / lowering control device for a working machine.

[0002]

2. Description of the Related Art Conventionally, as shown in JP-A-8-21268, a hydraulic lift device for a ground work machine connected to a rear portion of a vehicle body and an actuator for changing a throttle position of an engine are provided. There is known a tractor that sometimes changes the throttle position to the low engine speed side by operating the actuator, and returns the throttle position changed to the low engine speed side when the work machine is lowered. On the other hand, there is also known a work implement lifting / lowering control device which slows down the descending speed when the work implement connected to the vehicle body descends and gently lands the work implement.

[0003]

Generally, these tractors transmit the rotational power of the engine to the drive wheels and the working machine, and also drive a hydraulic pump that sends pressurized oil to a hydraulic cylinder or the like provided on the vehicle body. It has a configuration. For this reason, especially when the throttle position is changed from the state where the throttle position is set to the low engine rotation state, the supply amount of the pressure oil to the hydraulic actuator is changed and the driving speed is changed. ing.

However, the throttle position is changed at the time of lifting and lowering of the work machine, so that the throttle position is always changed at the same position in order to set the changed position at the time of factory shipment. Therefore, in a tractor equipped with both the same device and a device for reducing the descending speed before the work machine lands, in the process of landing from one descent of the work machine, when the throttle position returns, When the aircraft descends and lands, the descending speed is changed, and there is a problem that it is difficult for the operator to perform alignment at the field end.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a work implement elevating control device for a tractor as follows. That is, a hydraulic lifting device 2 for a ground working machine 1 connected to the rear of the vehicle body, and an actuator 3 for changing the throttle position of the engine are provided. And the driving speed of the hydraulic lifting device 2 is changed in the tractor which returns the throttle position changed to the low rotation side when the work machine 1 descends. 5u, 5d, and setting means 6 for setting the height with respect to the vehicle body for changing the driving speed, and setting the height with respect to the vehicle body for returning the throttle position when the work implement 1 descends. Control means 7A, 7B for changing in accordance with the height of work implement 1 with respect to body set in step
And a tractor work machine lifting / lowering control device.

[0006]

In the tractor constructed as described above, the height of the vehicle body for returning the throttle position when the work machine 1 is lowered is determined by the setting means 7 for setting the height of the vehicle body for changing the driving speed. Since it was changed according to the set position,
The speed change at the time of descent can be minimized, and the alignment operation in the field can be easily performed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, the overall configuration of the tractor 10 will be described. As shown in FIG. 1, the tractor 10 includes an engine 12 inside a hood 11, and transmits the rotational power of the engine 12 to the rear wheel 1 via various transmissions.
3 or the front and rear wheels 14 and 13 to travel, and also transmits power to a rotary work machine 1 which is a ground work machine to be described later to rotate and drive the tilling claws 47.

A steering handle 18 for steering the front wheel 14 is provided in front of the cockpit 17, and a work implement elevating one-touch lever 15 and an accelerator lever 16 are provided below the handle 18 to provide a work implement elevating one-touch lever 15. The rotation base is provided with a limit switch 15S for detecting the operation of the lever 15 in the vertical direction. A brake mechanism is provided at the rotation base of the accelerator lever 16 to hold the lever set position, that is, the throttle position.

An accelerator pedal 19 is provided on the floor 23 below the handle 18 and the throttle position is changed from the set position of the accelerator lever 19 to the high engine rotation side only when the pedal 19 is depressed. . Further, on the side of the cockpit 17, there are provided a shift lever 20 for switching the transmission, a working machine elevating lever 21 for changing the height of the working machine 1, and the like.
A potentiometer 21P for detecting an operation position is provided at one rotation base.

Further, a dial-type plowing depth setting device 25 and a means for setting a height for lowering the descending speed when the working machine is lowered according to the present invention are provided near the guide of the working machine raising / lowering lever 21. A certain descending speed deceleration position setting device 6, a rolling control mode setting device 26, and the like are provided. The lowering speed deceleration position setting device 6 is a setting device for arbitrarily setting the height of the work implement for performing the so-called “desera control”, and the lowering speed of the work implement is switched from the normal speed to the low speed at this set height. Take the place. Further, the rolling control mode setting unit 26 maintains the work machine 1 in a parallel state with the vehicle body of the tractor 10 in a “parallel mode”.
And a "horizontal mode" for maintaining a horizontal state, and a "off" position for locking the pressure oil communicating with the rolling hydraulic cylinder 32 without performing these controls.

The detectors 15S, 21P... And setting devices 6, 25... Are connected to various controllers 7A, 7B as control means provided below the cockpit 17. At the rear of the vehicle body of the tractor 10, there is provided a cylinder case 29 in which a working machine lifting hydraulic cylinder 2 serving as a lifting and lowering device of the working machine 1 is provided. It is configured to rotate up and down. Further, a three-point link mechanism 31 including a top link 31a and left and right lower links 31b, 31b is connected to the lift arms 30, 30, and the working machine 1 is connected to the link mechanism 31. .

The three-point link mechanism 31 connects the left and right lower links 31b (right side in FIG. 2) and the lift arm 30 via a rolling hydraulic cylinder 32, which is an actuator for changing the left / right tilting posture of the entire work machine. And the lower link 31b and the lift arm 3 on the other side (the left side in FIG. 2).
0 is connected by a fixed length rod 33.

Thus, when the switching control valve 8 in the hydraulic circuit is switched to extend the piston of the rolling hydraulic cylinder 32, the right side of the work machine 1 is lowered. Conversely, when the piston is shortened, the right side of the work machine 1 is raised and the right and left tilts. You can change your posture. As shown in FIG. 3, near the lift arm 30 on one side to which the fixed length rod 33 is connected,
The cylinder case 29 is provided with a bracket 35 having an “L” shape as viewed from the front. The bracket 35 is provided with a lift arm angle sensor 4 as a means for detecting the height of the working machine 1 with respect to the vehicle body, and a rolling control of the working machine 1 described later. A horizontal sensor 40 for detecting the left and right inclination posture of the vehicle body and an angular velocity sensor 41 for detecting the vertical and horizontal angular velocities of the vehicle body are provided.

The horizontal sensor 40 and the angular velocity sensor 41
Is disposed on the lift arm side to which the fixed length rod 33 is connected with respect to the center position of the vehicle body, so that the cylinder 32
As compared with the configuration in which the vehicle body is disposed, even if the vehicle body shakes due to this reaction during rolling of the work machine 1, the detection values of the sensors 40 and 41 are not affected as much as possible.

Reference numeral 34 in FIG. 3 denotes a sensor for detecting the amount of piston expansion / contraction of the hydraulic cylinder 7 for rolling on the link side via a wire. In the lifting device of the tractor 10 described above, the following position control of the working machine is performed by the controller 7A described later. That is, the detection angle of the working machine elevating lever 21 and the lift arm 30 (30)
For lifting the working machine of the hydraulic circuit to match the set angle of
Or, the solenoids 5u, 5 of the proportional pressure control valve for descending
d as needed, and the one-touch lever 1
5 is operated once in the up and down direction.
The working machine 1 is configured to energize the solenoids 5u and 5d of the proportional pressure control valve so as to continuously raise or lower the work implement 1 from the work position set in the step (1) to a separately determined ascent position.

The controller 7A can change the lifting speed of the work implement 1 by appropriately changing the amount of current supplied to the solenoids 5u and 5d of the proportional pressure control valve. Next, the rotary working machine 1 will be described. The rotary work machine 1 transmits the rotational power of the PTO shaft 45 protruding to the rear of the tractor 10 to a power transmission mechanism in the main beam via a universal joint, transmits the rotational power to a rotary shaft 46 via a reduction mechanism, etc. Tillage claw 4
7 are rotated. And tilling nail 47 ...
Above the chain case 4 that houses the speed reduction mechanism, etc.
A rotary cover 49 fixed to the rotary cover 8 is provided, and a rear cover 50 that rotates vertically while following the ground surface is provided at the rear end of the rotary cover 49. On the rotary cover 49, a potentiometer type cultivation depth sensor 28 is provided.
, And the rotation state of the rear cover 50 is detected via a link mechanism.

The throttle adjusting mechanism 52 of the tractor engine 2 will be described with reference to FIG. The throttle adjusting mechanism 52 is provided on the governor device 53 side of the engine 11, and rotates the throttle adjusting shaft 54 that protrudes the control rack position in the governor mechanism 53 toward the governor side, thereby allowing the accelerator lever 16 to operate. The throttle position that has been set and held is changed to adjust the amount of fuel supplied to the engine combustion chamber. An arm member 55 is integrally formed with the coaxial 54 on the adjusting shaft 54, and a wire 56 connected to the accelerator pedal 19 and a wire 57 connected to the accelerator lever 16 are connected to the arm member 55 from behind. It has a configuration.

From the front of the arm member 55,
A stepping type electric motor 3 as an actuator for changing the throttle position of the engine 12 is connected to a wire 58.
And an accelerator position sensor 59 for detecting the rotational position of the arm member 55 via a rod 60. The electric motor 3 includes a bonnet 1
The radiator 61 is mounted on an upper part of a radiator net mounting frame 62 disposed in front of the radiator 61 inside the radiator 61. The accelerator position sensor 59 is configured to be mounted on a side of the radiator net mounting frame 62. Thus, when the arm member 55 is rotated rightward in FIG. 4, the rotation speed of the engine 12 is changed to a low speed side,
When it is turned to the middle left side, it changes to the high speed side.

Next, a control system of the tractor 10 will be described with reference to FIG. The tractor 10 includes, as control means, a main controller 7A for performing various controls relating to lifting and lowering and rolling of the working machine, and an engine control controller 7B for performing various controls relating to the engine 12, and various signals are internally provided, respectively. It has a CPU for processing, a RAM for temporarily storing these signal information, an EEPROM for storing these various control programs, and the like. The two controllers 7A and 7B communicate with each other necessary information via a communication line.

The input portion of the main controller 7A has a potentiometer 21
P, limit switch 15S of the work machine elevating one-touch lever 15, lift arm angle sensor 4, descent speed deceleration position setting device 6, plowing depth setting device 25, plowing depth sensor 28, rolling control mode setting device 26, horizontal sensor 40, angular speed The sensor 41 and the stroke sensor 34 are connected and provided.

The output unit includes solenoids 5u and 5d of proportional pressure control valves for raising and lowering the working machine for connecting an oil passage to the hydraulic cylinder 32 for lifting and lowering the working machine, and hydraulic pressure for working machine rolling. Solenoids 8u and 8d of a switching control valve that expands and contracts the piston of the cylinder 32 are connected and provided. The proportional pressure control valve 5 and the switching control valve 8 are
The configuration is such that the hydraulic oil of a hydraulic pump driven by the rotational power of the engine 12 is communicated to hydraulic cylinders respectively connected thereto.

An input portion of the engine control controller 7B is provided with an engine rotation sensor 65, an accelerator position sensor 59, a battery remaining amount sensor 66, and the like connected thereto. The output unit is provided with the electric motor 3 and the electromagnetic clutch 67 connected thereto. The electromagnetic clutch 67 is provided with two alternators 6 provided on the engine 12.
A clutch for turning on and off the power transmission of the power transmission shaft between the power transmission shafts 8A and 68B. This clutch is used when the preset engine torque has a margin based on the detection values of the accelerator position sensor 59 and the engine rotation sensor 65, or When the remaining amount is equal to or less than a predetermined value, the power is turned on to generate a large amount of power and charge the battery.

In the tractor 10 configured as described above,
The work implement lifting / lowering control is performed as in the flowchart showing the outline of the program shown in FIG. 6 and FIG. The flowchart shown in FIG. 6 is a flowchart showing the entire processing of the main controller 8A. In addition to turning on the engine key switch of the tractor 10, the connection state and the detection state of various sensors and switches are read, and then the position control, the tillage depth control, Rolling control and the like are sequentially performed.

The work implement lifting / lowering control device of the present invention is a part of the position control and is executed according to the flow shown in FIG. First, in STEP 1, it is determined whether or not the operation of the working machine elevating one-touch lever 15 has been performed.
If this is YES, the process proceeds to STEP 2 and it is determined whether or not the current height of the work machine is a low position that is assumed to be the work position. If this is YES, the work machine 1 at the work position is continuously raised to a separately-specified height, and during this ascent, for example, when the rear cover 50 is lowered, the electric motor 3 is energized. The throttle position is changed by a predetermined amount to the low engine speed side.
Thereby, the vehicle speed of the tractor 10 is reduced.

If the determination in STEP 2 is NO,
Since the work machine 1 is in the current ascending position, the work machine 1 is continuously lowered to the plowing depth set value at which the work state is attained, and the height determined by the descent speed deceleration position setting device 6 during the descent is used. Then, the amount of current supplied to the solenoids 5u and 5d of the proportional pressure control valve is changed to reduce the degree of opening of the oil passage of the control valve, and the electric motor 3 is supplied with power to increase the throttle position by a predetermined amount. That is, the throttle position changed to the deceleration side is changed to the original position (accelerator lever 16).
To the set position).

Thus, the position at which the throttle position is returned when the work machine 1 is lowered is changed so as to match the position set by the descent speed deceleration position setting device 6, so that, for example, the throttle return position As compared with a configuration in which the speed is always constant or a case in which the speed is set at a position having no relation to the deceleration position, the speed change when the work machine 1 is lowered is reduced as much as possible, so that the alignment operation in the field can be easily performed.

In the above-described embodiment, the return height of the throttle position is changed while being matched with the set value of the descending speed deceleration position setting device 6, but one of them is taken into account in consideration of the response delay of the link mechanism and the hydraulic mechanism. It is also possible to adopt a configuration in which the time difference before and after or the height is shifted and adjusted. Further, the rolling control in the flowchart will be described with reference to FIG.

In the rolling control of the tractor 10, the inclination is maintained horizontally or parallel to the vehicle body by the horizontal sensor 40 and the angular velocity sensor 41. More specifically, the control program of the controller 7A sets an angular velocity at which the detection of the horizontal sensor 40 is assumed to be delayed. The configuration is such that switching from the rolling control to the rolling control of the work implement 1 by the angular velocity sensor 41 is performed.

However, the angular velocity sensor 41 is
When the power is turned on after the engine key switch is turned on, the detected voltage rises, which is determined to be rolling of the vehicle body, and there is a problem that the solenoids 8u and 8d of the switching control valve are energized. Therefore, in the rolling control of the tractor 10, the energization output is stopped until a certain voltage decreases from the detection of the peak voltage of the sensor signal or until a certain time elapses. Thus, it is possible to prevent a rolling malfunction of the work implement 1 at the time of starting the engine.

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is a rear view of the tractor.

FIG. 3A is a partial top view of a cylinder case. (B) Partial left side view of the cylinder case.

FIG. 4A is a side view showing a throttle adjustment mechanism. (B) The top view which shows a throttle adjustment mechanism.

FIG. 5 is a diagram showing a connection state of a controller.

FIG. 6 is a flowchart showing the overall control flow of a main controller.

FIG. 7 is a flowchart showing an outline of position control.

FIG. 8 is a flowchart showing an outline of rolling control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary work machine 2 Hydraulic cylinder for raising and lowering work machine 3 Electric motor 4 Lift arm angle sensor 5u Solenoid for proportional control valve for raising work machine 5d Solenoid for proportional control valve for lowering work machine 6 Lowering speed deceleration position setting device 7A Main Controller 7B Engine control controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinji Ninomiya 1st Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. Within the department (72) Inventor Toshiyuki Hori 1-tower Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. 2B304 KA08 LA02 LA05 LB05 LB15 MA03 MB02 MC02 MC08 PB02 PB06 QA11 QA22 QB13 RA27

Claims (1)

[Claims] 1. A hydraulic lift device 2 for a ground working machine 1 connected to a rear portion of a vehicle body, and an actuator 3 for changing a throttle position of an engine. Means 4 for detecting the height of the working machine 1 with respect to the vehicle body, and driving of the hydraulic lifting device 2 in a tractor that changes to a low rotation side and returns the throttle position changed to the low rotation side when the working machine 1 descends. Speed change means 5u and 5d, and setting means 6 for setting the height with respect to the vehicle body for changing the drive speed are provided. Control means 7A, 7B for changing in accordance with the height of work implement 1 with respect to the vehicle body set by setting means 6
A tractor work machine lifting / lowering control device comprising: