JPS5849126B2 - ground work equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects engine load fluctuations based on the deviation between a set engine rotation speed and an actual engine rotation speed, and detects engine load fluctuations based on the deviation between a set engine rotation speed and an actual engine rotation speed. The present invention relates to a ground working machine equipped with a control mechanism that detects a positional deviation and automatically controls the lifting and lowering of the ground working machine based on the detection results.

In the above-mentioned ground-working machines, such as power tillers with a rotary tiller attached to the rear of the tractor, the machine sinks into the ground and the working depth changes9, and the work load increases due to local changes in soil quality. In order to prevent the work load from increasing and causing engine stoppage, the work load fluctuation is detected as a fluctuation in the engine load, and the deviation of the height position of the ground working device attached to the machine body from the target setting plowing depth is detected.
The elevating and lowering of the tilling device is controlled based on both of the detection results.

Conventionally, the control gain (sensitivity) that affects the vertical control amount of the tiller based on the unit engine load fluctuation was kept constant in advance, so when the ground working depth is set to a deeper side, the tiller lowers. When controlling,
The rate of change in the increase in workload increases, making it easy for engine stoppage to occur, and in the case of upward control, the amount of engine load recovery is small, which may be insufficient as a means to avoid engine stoppage.

The present invention prevents the engine from stopping when descending by pressing the button at a deep point by rationally changing the control sensitivity.
This was designed to ensure sufficient engine load recovery when ascending in deep places.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 1 shows a ground working machine in which a rotary tilling device 1 as a ground working device is attached to the rear of a tractor 2 as a machine body so that it can be raised and lowered, and the rear propulsion wheels 4, 4 and In addition to driving the tilling device 1, a hydraulic pump (not shown) is operated, and a hydraulic control valve (described later) which is appropriately switched and activated by an electric control signal is actuated to operate the tilling device 1 as a single-acting lifting mechanism. A hydraulic cylinder 5 is telescopically operated to vertically swing a lift arm 6 connected to the cylinder 5, 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 are explained in the block diagram of FIG. do.

A signal E1 from the detector 7 that detects the actual rotational speed of the engine 3 and a signal A from the rotational speed setter 8 that sets the maximum engine rotational speed according to the accelerator setting are applied to the first subtractor 9 to load the engine. is configured to be detected as the amount of decrease in engine rotational speed (A-E).

Further, the signal from the first subtractor 9 and the signal H from the plowing depth setting device 10 for adjusting the relative level of the tilling device 1 with respect to the tractor to change the target plowing depth are applied to the adder 11. , the signal from this adder 11 (A-E+
D and the signal L from the level detector 12 that detects the relative level of the tiller 1 with respect to the tractor 2 is sent to the second subtractor 13
is applied to each of the detection and setting devices 7, 8, 10 and 12.
Based on the balance of the signals from the second subtractor 13, a signal for determining whether to raise or lower the tilling device 1 is taken out from the second subtractor 13 in view of an increase or decrease in engine load and a set plowing depth value.

Therefore, 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 increase as the plowing depth increases. If the tilling device 1 is located shallower than the set plowing depth position while the engine rotation speed is decreasing, the rotation speed decrease amount (engine load) (A
-E>O) and the amount of deviation from the set tilling depth of tilling device 1 (H-L
<O) are equal, the output from the second subtractor 13 (G=A-
E+H-L) becomes zero, and it is determined that there is no need to raise or lower the tilling device 1. From this state, the amount of engine rotational speed reduction (A
-E) increases, the output G from the second subtractor 13 becomes positive, and it is determined that the tilling device 1 needs to be raised;
Conversely, when the engine speed reduction amount (A-E) decreases, the output G from the second subtractor 13 becomes negative, and the tilling device 1
It is determined that it is necessary to lower the

The tilling device 1 is adjusted so that the balance relationship based on the change in engine speed reduction as the tilling device 1 is raised and lowered and the change in the signal from the level detector 12 is maintained.
Elevation control is performed.

Therefore, when the output G from the second subtractor 13 is positive, the hydraulic cylinder 5 is activated so as to drive the lift arm 6 in an upward swinging manner.
The lifting valve 14 of the hydraulic cylinder 5 is opened, and conversely, when the output G is negative, the lowering valve 15 of the hydraulic cylinder 5 is opened so that the lift arm 6 and the tilling device 1 are lowered by their own weight.

Between the first subtracter 9 and the adder 11, there are first and second amplifiers 1 connected in parallel as a control sensitivity adjustment mechanism.
6.17 is interposed, and the first amplifier 16 is connected to the second subtractor 13.
It is configured to operate only when the signal G from is positive (ascent finger 4>), and by changing the amplification factor, it is possible to increase the amount of ascending control relative to the unit engine speed fluctuation amount and increase the control sensitivity. , and the second amplifier 17 and the second subtracter 13
It operates only when the signal G from It has been.

The tilling depth setting device 10II'i, as shown in FIG.
A control sensitivity changing volume 19 for changing the amplification factor of each of the amplifiers 16 and 17 is integrally attached to the a, and the control sensitivity changing volume 19 changes the amplification factor of each of the amplifiers 16 and 17 in conjunction with changing the plowing depth setting.
The amplification factor can be changed.

According to this structure, when the plowing depth setting is changed to a deeper side, the control sensitivity on the ascending side is changed to be high, while the control sensitivity on the descending side is changed to be low, and in a deep place, the unit engine rotation speed The upward control amount is large relative to the fluctuation amount, so that the engine load can be recovered quickly, and the downward control amount is small, preventing a sudden increase in load.

Note that the second subtractor 13 is used as a means for changing the control sensitivity.
Hydraulic control valve 1 based on the subtracted signal G by
4,15. The hydraulic cylinder 5 and the lift arm 6 are operated respectively, and each of these operations has operating characteristics set, and these operating characteristics (response characteristics) can be changed to change the control sensitivity. can also be considered.

Also, when increasing either the quick load recovery function during ascending control or the function to avoid sudden load increases during descending control, only the ascending control sensitivity or descending control sensitivity may be changed by changing the working depth setting. You can change it as described above.

As described above, the ground work equipment of the present invention detects engine load fluctuations based on the deviation between the set engine rotation speed and the actual engine rotation speed, and also detects the height position of the ground work equipment 1 attached to the machine body with respect to the target setting plowing depth. detect the deviation of
In a ground work machine equipped with a control limit mechanism that automatically controls the elevation of the ground work device 1 based on the detection results, as the setting depth of the ground work device 1 increases, the height of the ground work device 1 increases when the ground work device is raised and lowered. It is characterized in that the control sensitivity for the engine load is automatically and reversibly higher than the control sensitivity during descent, so that the control sensitivity can be changed by changing the control sensitivity when the working depth setting is changed. ,
The deeper the work becomes, the more likely sudden changes in load will occur.
It has become possible to perform stable control by enhancing the function to avoid sudden load increases during downward control, or the quick load recovery function during upward control, or by enhancing both of these functions.

[Brief explanation of the drawing]

The drawings show an embodiment of the ground work machine according to the present invention, with FIG. 1 being an overall survey view, FIG. 2 being a circuit diagram, and FIG. 3 being a perspective view of the main parts. 1...Ground work equipment.

Claims (1)

[Claims] 1. Engine load fluctuation is detected based on the deviation between the set engine rotation speed and the actual engine rotation speed, and the deviation of the height position of the ground working device 1 attached to the machine body with respect to the target plowing depth is detected. In the ground work machine equipped with a control mechanism that automatically controls the elevation of the ground work device 1 based on the detection results, the ground work device 1 is raised and lowered as the set depth of the ground work device 1 increases. A ground-based working machine characterized in that the control sensitivity to the engine load during control is automatically and reversibly made higher than the control sensitivity when the button is pressed during descent. 2. Ground work according to claim 1, wherein as the setting depth of the ground work device 1 is increased, the control sensitivity of the button to be pressed during ascending control is automatically and reversibly increased. Machine. 3. The ground working machine according to claim 1, which is configured to automatically and reversibly reduce the control sensitivity during descending control as the set depth of the ground working machine 1 increases. . 4. As the set depth of the ground work device 1 increases, the control sensitivity during ascending control is automatically and reversibly increased, and the control sensitivity during descending control is automatically and reversibly reduced. A ground-based working machine according to claim 1.