JPS597284B2 - earthmoving vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an earthmoving vehicle in which a ground working device is automatically raised and lowered by a lifting mechanism driven by the engine as the rotational speed of the engine changes.

The above-mentioned earthmoving vehicle tIζ is mainly configured to keep the level of the ground working equipment as constant as possible, but if the lifting mechanism is simply driven by the engine, the lifting mechanism will rise due to fluctuations in engine speed. Drive speed fluctuates.

As a result, when the ground work equipment is raised with relatively high ground/engine rotational speeds, the control response and delay cause the ground work equipment to be lifted more than necessary, resulting in a situation where ground work cannot be performed. This can easily lead to inconvenient situations.

If the lifting drive speed of the lifting mechanism is set to be relatively low in order to correct this drawback, the followability will be extremely degraded, especially when lifting and lowering the ground work equipment at a relatively low engine speed. This is inconvenient for stabilizing the level of ground work equipment.

In particular, when the ground is extremely uneven, the followability of the control becomes inappropriate, and there are likely to be locations where ground work is not performed at all or where ground work is performed more deeply than necessary.

The present invention enables the lifting and lowering of the ground working device of an earthmoving vehicle to be performed without being affected only by changes in engine load, and by suppressing the lifting and lowering of the ground working device in response to changes in engine load, thereby allowing ground work to be performed at a substantially constant level of °C. However, by making the lifting drive speed of the lifting mechanism constant, it is possible to always maintain an appropriate lifting speed of the ground working equipment, and the purpose is to further ensure that the level of the ground working equipment is constant.

The feature of the present invention is an earthmoving vehicle in which a ground work device is connected to the vehicle body so that it can be driven up and down, and includes a mechanism for detecting the engine speed and setting the maximum engine speed according to the accelerator set. A load fluctuation detection device is provided that detects the amount of rotational drop of the engine based on the deviation of the output from the mechanism that detects the output from the mechanism that sets the level of the aircraft relative to the ground work equipment and the mechanism that detects the level of the aircraft relative to the aircraft. A position deviation detection device is provided for detecting the amount of variation in the vertical position of the ground work device relative to the aircraft body with respect to a set level based on the deviation of the position, and an output deviation indicating the rotational drop amount of the engine and an output indicating the amount of vertical position variation of the ground work device. With the correlation with the deviation set in advance, the elevating mechanism of the ground work equipment is driven by the engine so that the sum of the detection results by the two detection devices becomes a constant force value, and the ground work equipment is automatically raised and lowered. In addition to being equipped with a control mechanism to control
A mechanism is provided to automatically control the upward driving speed of the lifting mechanism in accordance with the engine rotational speed fluctuation, and the controlling mechanism automatically controls the upward driving speed fluctuation of the lifting mechanism due to the engine rotational speed fluctuation. The following effects can be obtained from the configuration that is designed to be used.

In other words, during ground work, the amount of engine rotation drop and slop caused by the deviation of the output from the mechanism that detects the engine speed and the mechanism that sets the maximum engine speed, and the level of the ground work device relative to the aircraft. The addition value of the detection results by the load fluctuation detection device and the position deviation detection device in a state where the correlation between the vertical position fluctuation amount due to the deviation of the output from the mechanism for setting the level and the mechanism for detecting the level of the counter body is set in advance. By configuring this so that It is stably located near the level set by the setting mechanism and can always perform ground work at a constant level, and if the work load unexpectedly increases and the engine speed decreases. When the ground work equipment rises, the engine speed increases due to the rise, and the deviation due to the engine speed becomes smaller. However, on the other hand, the deviation from the aircraft level increases, so the output deviation by the load fluctuation detection device and the position deviation detection device Due to the balance relationship with the output deviation due to It has the advantage of being able to perform ground work at a certain level.

Furthermore, by providing a mechanism that automatically controls the lifting drive speed of the lifting mechanism of the ground work equipment, it is possible to automatically control the rise drive speed fluctuation of the ground work equipment in accordance with fluctuations in engine speed. As the speed decreases, the lifting drive speed of the lifting mechanism can be kept constant without reducing it, and even if a sudden increase in work load occurs, the engine will not stop, and control followability can be improved. There are advantages.

Then, as the engine speed recovers due to the rise of the ground work equipment, the ground work equipment, the speed of which is controlled by the automatic control mechanism, increases due to the balanced relationship between the output deviation with respect to load fluctuation and the output deviation with respect to position deviation. It is possible to avoid the most inconvenient situation where the amount of ground work is suppressed and there are places where ground work cannot be performed due to unexpectedly rising too much, and it is possible to more reliably achieve a constant level of ground work equipment as a whole. It's arrived.

Next, embodiments of the present invention will be described with reference to the drawings.

The rotary tilling device 4, which is detachably attached to the tow vehicle 1 via a coupling device, is raised and lowered by a lift arm 3 provided at the rear of the passenger tow vehicle 1 so as to be able to swing up and down by a hydraulic cylinder 2. , drive wheels 5 of the tractor 1
The engine 6 and the rotary tilling device 4 are interlocked and connected via a power take-off shaft provided in the traveling transmission 7, and the tilling device 4, which is rotatably driven while traveling, is configured to till the field. There is.

The hydraulic cylinder 2 is configured to be automatically controlled based on changes in the load of the engine 6 and changes in the level of the tiller 40 relative to the machine body, and the details thereof will be explained with reference to FIG. 2.

Signals are sent to the rotation drop detector 10 from the mechanism 8 that detects the engine 60 rotation speed and the mechanism 9 that sets the maximum rotation speed of the engine 6 according to the accelerator set, to prevent the engine rotation speed from decreasing due to the work load. The engine load fluctuation detection device is configured to be detected, and the rotation drop detector 10, the tilling device 40 to machine level setting mechanism 11, and the tilling device 4 to the machine body level detecting mechanism 13 to the total deviation detector 14, respectively. A signal is sent, and the target plowing depth can be changed by adjusting the level setting mechanism 11, and the balance of the signals from the four mechanisms 8, 9, 11, and 13 allows the target plowing depth to be changed in consideration of the set target plowing depth value. The automatic lifting control mechanism is configured so that it is determined whether the tilling device 4 should be raised or lowered.

In other words, the signal voltage from the rotation drop detector 10 increases as the engine speed decreases, and the signal voltage from the level setting mechanism 11 and level detection mechanism 13 that constitute the position deviation detection device increases as the plowing depth decreases. When the load is such that the actual engine speed does not drop much, the tiller is stably located near the set level, and the total deviation detector 14 indicates The output voltage of the total deviation detector 14 becomes zero, and it is determined that there is no need to raise or lower the tilling device 4. If the engine speed decreases from that state, the output voltage from the total deviation detector 14 will change in the positive direction, and vice versa. When the rotational speed increases, the output voltage from the total deviation detector 14 becomes negative, and it is determined that the tilling device 4 needs to be raised or lowered.

If the output voltage from the level setting mechanism 11 is changed, the above-mentioned balanced relationship will be disrupted, and a signal will be transmitted from the total deviation detector 14 so that the balanced relationship will be established again, and the actual plowing depth will be changed. It can be changed.

That is, when the output voltage from the total deviation detector 14 is positive, the up valve for controlling the hydraulic cylinder 2 is opened to raise the tilling device 4, and when it is negative, the tilling device is lowered. When the down valve is opened, a signal is sent from the total deviation detector 14 to the descending valve controller 11 via the descending comparator 15 and to the ascending valve controller 18 via the ascending comparator 16, respectively. It is configured as much as possible.

The signal from the rotational drop detector 10 is sent to a continuous drive prohibition comparator 19 for controlling continuous operation prohibition circuits 7a and 7b provided in the input systems of both the valve controllers 17 and 18;
It is also configured to be sent to the modulation circuit 20 for controlling the intermittent operation command device 12a provided in the input system of the rising side valve controller 18, and also sent to the continuous drive prohibition comparator 19. is the set value (e.g. 2
00 rpm), and if so, activates the interlock operation prohibition circuits 7a and 7b, and also activates the cylinder 2 by pulse signals from the intermittent operation command devices 12a and 12b. The tilling device 4 should be operated intermittently, and the tilling device 4 should be moved up and down intermittently. C. is automatically changed as the engine speed changes, thereby suppressing fluctuations in the operating speed of the cylinder 2 as a result of fluctuations in engine speed.

In other words, when the engine 60 rotation speed decreases, the intermittent operation command device 12a is activated based on the command from the modulation circuit 20, so that the amount of oil sent per hour to the cylinder 2 decreases, and the rising speed of the tilling device 4 increases. However, by increasing the pulse width and the pulse period, the tiller 4 is configured to be raised at a constant speed, with little change in speed, and sometimes at an increased speed.

In addition, there are various types of ground work such as binding, trench digging, and ground leveling, and the equipment used for these purposes is called Ground Work Equipment 4.
Furthermore, since the configuration and operating state for raising and lowering the ground work device 4 can be modified in various ways, they are collectively referred to as the lifting mechanism 2.

The work vehicles equipped with these ground work devices 4 are collectively referred to as earthmoving vehicles.

In order to automatically control the ascending driving speed of the elevating mechanism 2 in accordance with fluctuations in engine speed, various modifications such as adjusting the oil passage opening are possible, and these are collectively referred to as the control mechanism 20.

[Brief explanation of drawings]

The drawings show an embodiment of the earthmoving vehicle according to the present invention, and FIG. 1 is a side view of the tractor, and FIG. 2 is a block diagram of the control system. 2... Lifting mechanism, 4... Ground work device, 6... Engine, 8... Engine rotation speed detection mechanism, 9... Engine maximum rotation speed setting mechanism, 11... Aircraft level setting mechanism, 13.
... Aircraft level detection mechanism, 20 ... Control mechanism.

Claims (1)

[Claims] 1. An earthmoving vehicle in which a ground work device 4 is connected to the vehicle body so that it can be driven up and down, and includes a mechanism 8 that detects the engine 60 rotation speed, and a mechanism 9 that sets the maximum rotation speed of the engine 6 according to the accelerator set. A load fluctuation detection device is provided to detect the amount of rotational drop of the engine based on the deviation of the output of the output from a mechanism 11 for setting the aircraft-to-aircraft level of the ground work load 4 and a mechanism 13 for detecting the aircraft-to-aircraft level. A positional deviation detection device is provided for detecting the amount of variation in the vertical position of the ground work device 10 relative to the aircraft body with respect to a set level based on the deviation of With the correlation with the output deviation set in advance, the elevating mechanism 2 of the ground work device 4 is driven by the engine 6 so that the sum of the detection results by both the detection devices becomes a constant value. Equipped with a control mechanism that automatically controls the lifting and lowering of the device 4, and a mechanism 20 that automatically controls the rising drive speed of the lifting mechanism 2 in accordance with fluctuations in the rotational speed of the engine 6. The lifting mechanism 2
An earthmoving vehicle characterized in that said control mechanism 20 automatically controls fluctuations in the upward drive speed of said earthmoving vehicle.