JPH0781461A - Driving control mechanism for working vehicle - Google Patents

Abstract

PURPOSE:To provide a highly accurate vehicle speed controlling characteristic by computing a lower limit value for speed reduction and an upper limit value for speed increase respectively within a preset range in vehicle speed control based on the rotational speed of an engine under a no-load condition corresponding to the preset value for an accelerator and the pre-determined power characteristic of the engine, and performing vehicle speed control based on the preset range. CONSTITUTION:A rotational speed detecting sensor 15 for an engine 3, an accelerator sensor 17 for detecting the operating position of an accelerator lever 16, a clutch switch SW1 for detecting the stepping operation of a clutch pedal 18, and a vehicle speed control on/off switch SW2 are mounted, whose respective signals are fed into a controller 14. When the rotational speed detecting sensor 15 detects that the rotational speed of the engine has decreased to the lower limit value of the preset range while running through a speed setter 13, driving of the electrically-driven cylinder 10 is controlled toward the speed reduction side by a vehicle speed controlling means A based on the results of computation by the computing means of the electrically- driven cylinder 10. When the rotational speed of the engine has returned to the upper limit value of the preset range, driving of the electrically-driven cylinder 10 is controlled to increase the rotational speed to the original preset value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a speed change device interposed in an airframe traveling system is configured to be capable of speed change operation by driving an actuator, and is provided with a rotation speed detecting means for detecting the rotation speed of an engine. The present invention relates to a traveling control mechanism for a work vehicle including vehicle speed control means for driving and controlling the actuator so as to decelerate when a value falls below a lower limit value of a set region and to accelerate when a value exceeds an upper limit value of the set region.

[0002]

2. Description of the Related Art Conventionally, in the traveling control mechanism for a work vehicle described above, only when it is detected that the accelerator lever for the engine is at the fully open position of the accelerator, as disclosed in, for example, Japanese Patent Laid-Open No. 3-56760. It was configured to perform the vehicle speed control operation.

[0003]

In the above-mentioned conventional structure, for example, even in a field where traveling load is comparatively small and sufficient work traveling is possible without setting the accelerator of the engine to the fully open position, Unless the accelerator is set to full open, the vehicle speed control will not be executed, and if the traveling load is small, the engine noise will become unnecessarily large.
When the accelerator setting is changed, vehicle speed control is not performed, and depending on the field conditions, the load on the engine becomes excessive and the engine frequently stops. The present invention aims to eliminate the above-mentioned problems.

[0004]

According to a characteristic configuration of the present invention, in the traveling control mechanism for a working vehicle described at the beginning, accelerator position detecting means for detecting an operating position of an accelerator setting device with respect to the engine, and And a calculating means for calculating a lower limit value and an upper limit value of the setting region corresponding to the accelerator setting value, based on a detection value of the rotation speed detecting means corresponding to a change operation position of the accelerator setting device in a no-load state. And the vehicle speed control means is configured to perform vehicle speed control based on the calculation result of the calculation means.

[0005]

[Operation] Even when the accelerator set value is changed from the fully open position to the closed side depending on the hardness and softness of the mud in the field and the surrounding environment, the engine in the unloaded state corresponding to the changed accelerator set value The rotation speed is detected, and the lower limit value for deceleration and the upper limit value for speed increase in the set region in vehicle speed control are calculated based on the unloaded engine rotation speed and the predetermined engine power characteristic, and the calculated value is calculated. The vehicle speed control is executed according to the set area.

[0006]

Therefore, even when the accelerator setting is changed according to the working conditions, the vehicle speed is always controlled so that the engine load is maintained in an appropriate set rotational speed range adapted to the accelerator set value. , The problem of frequent engine stoppages has been eliminated. The control characteristics of the vehicle speed control (rotation speed setting area) are detected based on the map data based on the detection result of the operation position of the accelerator operation tool.
However, if this is done, an error may occur in the correlation between the initial engine speed and accelerator operation position due to a malfunction in the accelerator operation system, installation error, etc. However, in the present invention, by directly detecting the no-load engine speed corresponding to the accelerator set value, it is possible to always obtain an accurate vehicle speed control characteristic that matches the power characteristic of the engine.

[0007]

Embodiments will be described below with reference to the drawings. Figure 4
Fig. 1 shows a passenger type rice transplanter which is an example of a work vehicle. In this rice transplanter, the seedling planting device 2 is connected to the rear portion of the riding type traveling body 1 so as to be able to move up and down as well as left and right, and
The engine 3 is mounted on the front part of the machine body, and the power of the engine 3 is supplied to the front and rear wheels 7 and 8 via the transmission case 6 having the belt type continuously variable transmission 5 and the main clutch 4 therein. The seedlings are supplied to the seedling planting device 2 so that the seedlings can be planted as the machine runs.

As shown in FIG. 1, the continuously variable transmission 5 includes an output pulley 3a of the engine 3 and a transmission case 6 as shown in FIG.
The transmission belt 9 is wound around the input pulley 6a, and each of the pulleys 3a and 6a is of a split pulley type, and the pulley spacing is provided via a cam mechanism 11 operated by an electric cylinder 10 [an example of an actuator]. Is configured so that the speed change operation can be continuously performed. The electric cylinder 10 is controlled by a control device 14 equipped with a microcomputer so that a detection value of a feedback sensor 12 for detecting an actual operation amount of the electric cylinder 10 matches a speed set by a potentiometer-type speed setter 13 provided in a body control section. It is configured to be controlled and driven. In addition, the control device 14
Is provided with a vehicle speed control means A for automatically controlling the electric cylinder 10 according to the load state of the engine 3 in a control program format regardless of the set value by the speed setter 13. That is, when the electric cylinder 10 is traveling with the speed set by the speed setter 13 and the engine speed falls to the lower limit value of the set range, the electric cylinder 10 is decelerated regardless of the set speed. Drive control is performed, and when the engine speed returns to the upper limit value of the set region by this deceleration operation, the electric cylinder 10 is drive-controlled so as to increase and return to the original set speed.

The engine speed setting area in the vehicle speed control is configured to detect the actual engine speed according to the change in the accelerator setting for the engine 3 and obtain the result based on the result. More specifically, as shown in FIG. 1, a rotation speed detection sensor 15 for detecting the output rotation speed of the engine 3 and an accelerator lever 16 for the engine 3 are provided.
Potentiometer-type accelerator sensor 17 [an example of accelerator position detecting means] for detecting the operation position of [an example of accelerator setting device], clutch pedal 1 for operating the main clutch 4.
A clutch switch SW1 and a vehicle speed control ON / OFF switch SW2 for detecting the depression operation (clutch disengagement operation) of the vehicle 8 are provided, and respective signals are given to the control device 14.

The relationship between the operating position of the accelerator lever 16 and the actual engine speed prior to the original traveling control is the adjustment error of the accelerator operating system, the accelerator sensor 17
Since there is a possibility that each work vehicle may differ due to an installation error of the vehicle or an individual difference in the characteristics of the speed governor 20 [governor], the characteristics of the accelerator set value and the engine speed are used as actual measurement data. Based on the measurement, it is stored. That is, based on the detection value of the rotation speed detection sensor 15 corresponding to the changing operation position of the accelerator lever 16 in the no-load state with respect to the engine 3, the lower limit value of the setting region for vehicle speed control corresponding to the accelerator setting value. And a computing means B for computing the upper limit value in the control device in the form of a control program.

The control operation of the controller will be described below. As shown in FIG. 2, when the clutch pedal 18 is turned off and the vehicle body is stopped, the vehicle speed control on / off switch SW2 is turned on and operated [Step 1
2] The accelerator lever 16 is sequentially changed between the closed position and the open position [step 3]. At this time, the output Va of the accelerator sensor 17 is sequentially read [step 4]. The operation of the accelerator lever 16 is stopped at an appropriate position, and after a certain time has elapsed in consideration of the timing delay between the accelerator operation and the change of the engine speed, the engine speed N0 and the accelerator sensor 17 of the engine 3 when the engine 3 is in a no-load state. The output Va is read [steps 5-7].
Here, from the change situation of the detection value of the accelerator sensor 17,
It is determined whether or not the accelerator lever 16 is operated from the closed side to the open side, and if so, the no-load engine speed N0 and the detected value Va of the accelerator sensor 16 read in step 7 are set to the open side. To the closing side [steps 8 to 11]. That is, there is a hysteresis in the change characteristic due to the difference in the operating direction of the accelerator lever 16, and the values have different values. And
When the control ON / OFF switch SW2 is turned off after the data reading operation is repeated at appropriate operation points and the reciprocating operation is repeated a plurality of times to store the data, the change characteristic data detected a plurality of times is changed. An averaging process is performed to specify one change characteristic of the no-load engine speed with respect to the accelerator set value in each of the reciprocating directions [steps 12 and 1].
3]. Also, from this change characteristic of the no-load engine speed,
From the predetermined power characteristic of the engine 3, the characteristics of the lower limit value and the upper limit value for controlling the vehicle speed are calculated and stored [step 14].

Then, as shown in FIG. 3, during work traveling in which the main clutch pedal 18 is turned on and operated, the outputs of the speed setter 13 and the feedback sensor 12 are read,
The electric cylinder 10 is drive-controlled so that the vehicle speed is maintained at the set speed [steps 15 to 17]. When the vehicle speed control on / off switch SW2 is turned on, the output of the accelerator sensor 17 at that time is read, and the lower limit value N1 and the upper limit value for vehicle speed control are read based on the change characteristics obtained as described above. Find N2 [steps 18-20].
Thereafter, the engine speed N is sequentially read, and when the engine speed N becomes equal to or lower than the lower limit value, the electric cylinder 10 is decelerated regardless of the set speed, and when the engine speed N recovers to the upper limit value N2, the engine speed N is increased to the set speed. The speed of the electric cylinder 10 is increased so as to recover quickly [steps 21 to 25].

As the continuously variable transmission, a hydraulic continuously variable transmission may be used instead of the belt type.

It should be noted that reference numerals are added to the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a control block diagram.

[Fig. 2] Control flowchart

FIG. 3 is a control flowchart.

[Figure 4] Side view of rice transplanter

[Explanation of symbols]

 3 Engine 5 Transmission 10 Actuator 15 Rotational Speed Detection Means 16 Accelerator Setting Device 17 Accelerator Position Detection Means A Vehicle Speed Control Means B Computing Means

Claims (1)

[Claims] 1. A speed change means (15) for detecting a rotation speed of an engine (3), wherein a speed change device (5) interposed in an airframe traveling system is configured to be operable by a drive of an actuator (10). A vehicle speed control means (A) is provided for driving and controlling the actuator (10) so as to decelerate when the engine speed falls below a lower limit value of the set range and accelerate the speed when the engine speed exceeds an upper limit value of the set range. A travel control mechanism for a working vehicle, comprising accelerator position detecting means (17) for detecting an operation position of an accelerator setting device (16) with respect to the engine (3), and the engine (3) in a no-load state. Based on the detection value of the rotation speed detection means (15) corresponding to the change operation position of the accelerator setting device (16), the lower limit value and the upper limit value of the setting region corresponding to the accelerator setting value are calculated. A traveling control mechanism for a work vehicle, comprising: a calculating means (B) for calculating, wherein the vehicle speed control means (A) is configured to perform vehicle speed control based on a calculation result by the calculating means (B).