JPS595245B2 - tillage machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a tillage device 1 is mounted on the front and back ends of a machine body so as to be able to be raised and lowered, and an actual rotation speed detector is provided for a reference engine rotation speed set by a rotation speed setting device 8. The variation amount of the engine load is detected based on the amount of decrease in the actual engine rotational speed detected in step 7. This invention relates to a tillage work machine equipped with an automatic elevation control mechanism for lowering the machine.

The above-mentioned riding tillage machine, which has a rotary tillage device, plow, etc. connected to the rear of the tractor so that it can be raised and lowered, has a tendency to sink (or tilt) when working in extremely wet fields or fields with strong clay. As a result, the tillage equipment tends to sink further into the soil, resulting in an increased workload and a greater load on the engine.If the engine speed decreases significantly during work, the control mechanism However, under these conditions, the tillage device that has bitten into the soil receives a large resistance from the soil, so the tillage device does not rise and is controlled against the aircraft by the climb control. As the support angle changes, the front of the fuselage relatively floats around the rear wheels of the fuselage as a fulcrum, and the ground pressure of the wheels at the rear of the fuselage equipped with the tillage device increases, making them more likely to sink into the ground. Therefore, if the rear of the aircraft were to sink rapidly, the plowing load would increase rapidly, and the overload could even cause the engine to stop.

The present invention aims to solve this problem based on the finding that the workload stabilization control as described above actually has the opposite effect.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 shows a tillage work machine in which a rotary tillage device 1 as a tillage work device is attached to the rear of a tractor 2 so as to be able to rise and fall freely.The rear propulsion wheels 4, 4 and the A single-acting type lifting mechanism for the tilling device 1 is operated by a hydraulic control valve (described later) which drives the tilling device 1 and also drives a hydraulic pump (not shown) and is appropriately switched and activated by an electric control signal. The hydraulic cylinder 5 is telescopically operated to cause a lift arm 6 connected to the cylinder 5 to swing up and down, thereby driving the tilling device 1 suspended and supported by the lift arm 6 up and down.

The hydraulic cylinder 5 is configured to be automatically controlled based on changes in the load of the engine 3 and changes in the relative height of the tilling device 1 with respect to the tractor 2, the details of which will be explained in the block diagram of FIG. 2. .

A signal E from a detector 7 that detects the actual rotational speed of the engine 3 and a signal A from a rotational speed setter 8 that sets a reference engine rotational speed are applied to a first subtractor 9 to reduce the engine load to the engine. The configuration is such that the amount of decrease in rotational speed is detected as A-E.

Further, the signals A-E from the first subtractor 9 and the tilling device 1
The signal H from the plowing depth setter 10 for changing the target plowing depth by adjusting the relative level with respect to the tractor is sent to the adder 11.
The signal A- from this adder 11 is applied to
The signals from the level detector 12 which detects the relative level of E+H and the tiller 1 with respect to the tractor 2 are applied to a second subtractor 13, which balances the signals from the respective detectors and setters 7, 8, 10 and 12. Accordingly, the automatic lift control mechanism is configured such that a signal for determining whether to raise or lower the tilling device 1 is taken out from the second subtractor 13 in view of changes in engine load and set plowing depth value.

That is, the signal A-E from the first subtractor 9 increases as the engine speed decreases, and the signals H and L from the plowing depth setter 10 and level detector 12 decrease as the plowing depth increases. If the tilling device 1 is located shallower than the set plowing depth position while the rotational speed is decreasing, the amount of rotational speed reduction (engine load) A-E>
0 and the deviation value H-L<0 to the set tilling depth of the rotary device 1, the output from the second subtractor 13 becomes zero, and the tilling device 1
It is determined that raising and lowering of the tilling device 1 is not necessary, and when the engine speed reduction amount A-E increases from this state, the output from the second subtractor 13 becomes positive, and it is determined that raising and lowering of the tilling device 1 is necessary. Conversely, when the engine speed reduction amount A-E decreases, the output from the second subtractor 13 becomes negative, and it is determined that the tilling device 1 needs to be lowered.

Then, the raising and lowering of the tilling device 1 is controlled so that the above-mentioned balanced relationship is established based on the change in the amount of decrease in engine rotational speed and the change in the signal from the level detector 12 as the tilling device 1 is raised and lowered.

That is, when the output from the second subtractor 13 is positive, this is determined by the discriminator 14, and the lifting valve 15 of the hydraulic cylinder 5 is opened so as to drive the lift arm 6 in an upward swinging manner, and vice versa. If the output is negative, this is determined by the discriminator 16, and the lowering valve 17 of the hydraulic cylinder 5 is opened so that the lift arm 6 and the tilling device 1 are lowered by their own weight.

Furthermore, if only the elevation discrimination control is performed by the second subtractor 13, the balanced relationship will be established even when the engine rotational speed is greatly reduced, and the low-speed running state or high-load state will be stably maintained, resulting in a decrease in work efficiency and a problem with the engine. Since there is a risk of a stoppage, this problem is solved by the following control.

That is, the signal from the first subtractor 13 is applied to three comparators 18, 19, 20, each of which has been manually set with different reference values a, b, and c (where a<b<c). , when the engine speed decreases significantly due to an increase in engine load and the signal from the first subtractor 9 increases, exceeding the second reference value C and becoming smaller than the third reference value C, the second comparator 19
is activated, a descending prohibition command signal is input to the driving circuit 21 of the descending valve 17, and even if there is a descending command from the second subtractor 13, the descending operation is prohibited and the engine rotational speed is further reduced. Accordingly, when the signal from the first subtractor 9 exceeds the third reference value C, the third comparator 20 is activated to issue a forced rise command signal, and the intermittent signal generator 22 is activated based on this signal. , the first drive circuit 23 of the lifting valve 15 is operated intermittently regardless of the lifting control command from the second subtractor 13.

As a result, the tilling device 1 is controlled to rise and fall based on the command from the second subtractor 13 in a range where the amount of decrease in the engine speed is smaller than the second reference value, and the second reference value is lower than the third reference value. In the range between C, the tilling device 1 is raised only when there is a rising command from the second subtractor 13, and descending is prohibited, and when it becomes larger than the third reference value C, the third reference value C
The load is reduced by forcibly raising the tilling device 1 until it drops below .

Further, the operation of the third comparator 20 is controlled according to the actual engine rotation speed as follows.

That is, the detection signal from the engine rotational speed detector 7 is preset to the signal E' corresponding to the engine idle link rotational speed or a constant rotational speed slightly lower than this to the setting device 24.
When the actual engine speed decreases to below the set signal E, the increase control blocking circuit 26 is activated, and the signal from the first subtractor 9 is applied to the third reference signal E. Even if it is larger than the value C, the operation of the third comparator 20 is stopped, the forced raising control of the tilling device 10 is blocked, and from this blocked state, the actual engine rotational speed becomes the rotation corresponding to the setting signal E'. When the speed recovers and becomes faster, the system is configured so that the forced raising control of the tilling device 1 is released and the tilling device 1 is forcibly raised.

Therefore, even when the tillage equipment sinks deeply into the ground during tillage work in ultra-wet fields or clay fields, resulting in an increased workload and the above-mentioned forced intermittent raising control is performed, it is still possible to When the engine rotational speed has fallen to near the idling rotational speed, the above-mentioned forced rise control is inhibited, the tilling device 1 is maintained at a constant depth in the ground, and the N tilling operation continues.

As a result, the relative floating of the front part of the machine body (backward tilting of the machine body) caused by raising the tilling device 1, which is strongly held in the soil, is prevented.

Then, it maintains a load state that is large but without sudden fluctuations and waits for the natural recovery of engine output, and if the engine speed becomes lower than the constant low rotation speed set by the setting device 24, forced increase control is performed to This is to reduce the load.

The first comparator 18 is used to control the descending speed, and operates as follows based on the signal from the first subtractor 9.

In other words, while the load is sufficiently small and the signal from the first subtractor 9 is smaller than the first reference value a, as in the case where the tiller 1 is lowered from the ground floating position, the continuous lowering command from the discriminator 16 is The signal is directly input to the 1 drive circuit 21, and the tilling device 1 is continuously lowered.

In this case, the intermittent signal generator 27 operates based on the descending command signal from the discriminator 16 and issues a descending control signal intermittently, but since the direct signal from the discriminator 16 has priority, continuous descending control is performed. becomes.

When the signal from the first subtractor 9 exceeds the first reference value a, the first comparator 18 operates to prevent the downward control signal from the discriminator 16 from being directly transmitted to the drive circuit 21. , the valve 17 is controlled by a signal from the intermittent signal generator 27, and the tilling device 1 is controlled to descend intermittently.

In other words, when the load is low, the depth is lowered continuously and quickly to quickly approach the target depth, and when the load increases to a certain extent, the depth is lowered intermittently at a low speed to prevent a sudden increase in load.

As described above, the present invention is configured to attach the tilling work device 1 to the longitudinal end of the machine body so as to be able to move up and down, and to detect the actual rotational speed detected by the actual rotational speed detector 7 relative to the standard engine rotational speed set by the rotational speed setting device 8. configured to detect the amount of variation in engine load based on the amount of decrease in engine rotational speed,
In a tillage work machine equipped with an automatic lift control mechanism that raises the tillage work apparatus 1 as the engine load increases and lowers it as the engine load decreases, the actual rotational speed detected by the actual rotation speed detector 7 is Based on the detection that the engine rotation speed of the plowing device 1 has decreased below a certain low engine rotation speed set by the low rotation speed setting device 24, the increase control of the plowing work device 1 is prevented, and the actual engine rotation speed is It is characterized by being equipped with a rise prevention control mechanism 26 that releases the rise prevention of the tillage work device 1 when the engine rotation speed becomes faster than a low engine speed, so it is easy to use when working in ultra-wet fields or strong clay. Even if lifting control is attempted in a state where the lifting device 1 is deeply sunk and is dug into the soil and is difficult to lift, the engine rotational speed will be kept at a constant low engine speed set by the low rotational speed setting device 24 due to an increase in the work load. When the rotation speed is lower than the rotational speed, the lifting control of the tillage work device 1 is blocked, so that a situation in which the machine body is relatively lifted and tilted in the front-back direction due to unreasonable lifting control, which causes an increase in load on the engine, is avoided. Since the tilling work device 1 is raised after waiting for the rotational speed to recover, it is possible to reduce the number of engine stoppages, and it has become possible to prevent engine stoppage caused by raising control.

[Brief explanation of the drawing]

The drawings show an embodiment of the tillage work machine according to the present invention, with FIG. 1 being a side view of the riding tiller, and FIG. 2 being a block diagram of the control mechanism. 1...Plowing work device, 7...- Actual rotation speed detector, 8...Rotation speed setting device, 24...
. . . Low rotation speed setting device, 26 . . . Rise prevention control mechanism.

Claims (1)

[Claims] 1 The tilling work device 1 is attached to the longitudinal end of the machine body so as to be able to be raised and lowered, and the actual engine rotation speed detected by the actual rotation speed detector 7 is compared to the reference engine rotation speed set by the rotation speed setting device 8. The tiller is configured to detect the amount of variation in engine load based on the amount of decrease, and is equipped with an automatic lifting control mechanism that raises the tilling device 1 as the engine load increases and lowers it as the engine load decreases. In the plowing work machine, the plowing operation is performed based on the detection that the actual engine rotation speed detected by the actual rotation speed detector 7 has decreased below a certain low engine rotation speed set by the low rotation speed setting device 24. It is characterized by being equipped with a rise prevention control mechanism 26 that prevents the rise control of the device 1 and releases the rise prevention of the tilling work device 1 when the actual engine rotation speed becomes higher than the low engine rotation speed. Plowing machine.