JP2944376B2 - Work vehicle travel control mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device interposed in an airframe traveling system, which is configured to be capable of performing a shift operation by driving an actuator, and is provided with a rotation speed detecting means for detecting an engine rotation speed. The present invention relates to a traveling control mechanism for a work vehicle including a vehicle speed control unit that controls the driving of the actuator so as to reduce the speed when the value falls below a lower limit value of the setting region and to increase the speed when exceeding the upper limit value of the setting region.

[0002]

2. Description of the Related Art In a traveling control mechanism for a work vehicle, conventionally, as disclosed in Japanese Patent Application Laid-Open No. 3-56760, for example, only when it is detected that an accelerator lever for an engine is at an accelerator fully open position, The vehicle speed control operation is performed.

[0003]

In the above-mentioned conventional structure, for example, even in a field where the traveling load is relatively small and the traveling of the work can be sufficiently performed without setting the accelerator of the engine to the fully open position, Unless the accelerator setting is always set to full open, vehicle speed control will not be executed, and if the running load is small, the engine noise will be unnecessarily loud,
When the accelerator setting is changed, the vehicle speed control is not performed, and depending on field conditions, the load on the engine becomes excessive and the engine is frequently stopped. An object of the present invention is to eliminate the above disadvantages.

[0004]

According to a feature of the present invention, in the traveling control mechanism for a working vehicle described at the beginning, an accelerator position detecting means for detecting an operation position of an accelerator setting device with respect to the engine; Calculating means for calculating a lower limit value and an upper limit value of the setting area 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 a calculation result by the calculation means.

[0005]

According to the present invention, even when the accelerator set value is changed from the fully open position to the closed side depending on the degree of hardness of the mud in the field and the surrounding environment, the engine in a no-load state corresponding to the changed accelerator set value. The engine speed is detected, and the lower limit value for deceleration and the upper limit value for speed increase in the set area in the vehicle speed control are calculated based on the no-load engine speed and a predetermined power characteristic of the engine. The vehicle speed control is executed according to the set area.

[0006]

Therefore, even when the accelerator setting is changed in accordance with the working conditions, the vehicle speed is controlled such that the engine load is always maintained in an appropriate set rotation speed region suitable for the accelerator setting value. The disadvantage of frequently stopping the engine has been eliminated. In addition, the operation position of the accelerator operation tool is detected, and the control characteristic of the vehicle speed control based on the map data based on the detection result [rotation speed setting area]
However, if this is done, errors may occur in the correlation between the initially set engine speed and the accelerator operation position due to malfunctions in the adjustment of the accelerator operation system or mounting errors. However, in the present invention, by directly detecting the no-load engine speed corresponding to the accelerator setting value, it is possible to always obtain accurate vehicle speed control characteristics that match the engine power characteristics.

[0007]

Embodiments will be described below with reference to the drawings. FIG.
2 shows a riding type rice transplanter which is an example of a working vehicle. In this rice transplanter, the seedling planting device 2 is connected to the rear part of the riding type traveling machine 1 so as to be able to move up and down as well as to roll left and right.
The engine 3 is mounted on the front of the fuselage, and the power of the engine 3 is supplied to the front and rear wheels 7, 8 via a transmission case 6 equipped with a belt-type continuously variable transmission 5 and a main clutch 4. It is supplied to the seedling planting apparatus 2 and is configured so that the seedling planting operation can be performed with the machine running.

As shown in FIG. 1, the continuously variable transmission 5 includes an output pulley 3 a of the engine 3 and a transmission case 6.
The transmission belt 9 is wound around the input pulley 6a, and each of the pulleys 3a, 6a is configured as a split pulley type. Is changed so that the speed change operation can be performed steplessly. The electric cylinder 10 is controlled by a control device 14 including a microcomputer so that a detection value of a feedback sensor 12 for detecting an actual operation amount thereof matches a speed set by a potentiometer type speed setting device 13 provided in the aircraft operation unit. It is configured to control and drive. The control device 14
Has a vehicle speed control means A for automatically controlling the electric cylinder 10 in accordance with the load state of the engine 3 irrespective of the value set by the speed setting unit 13 in the form of a control program. That is, when the electric cylinder 10 is traveling with the speed set by the speed setting device 13 and the engine speed falls to the lower limit value of the set area, the electric cylinder 10 is moved to the deceleration side regardless of the set speed. The drive control is performed, and when the engine speed returns to the upper limit value of the set area by this deceleration operation, the drive control of the electric cylinder 10 is performed so that the speed is restored to the original set speed.

The setting range of the engine speed in the vehicle speed control is configured to detect the actual engine speed in accordance with a change in the accelerator setting for the engine 3 and obtain the engine speed 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
A potentiometer-type accelerator sensor 17 [an example of an accelerator position detecting means] for detecting an operation position of [an example of an accelerator setting device], a clutch pedal 1 for operating the main clutch 4
A clutch switch SW1 and a vehicle speed control on / off switch SW2 for detecting that the step 8 is depressed (clutch disengagement operation) are provided, and respective signals are given to the control device 14.

Prior to the actual traveling control, the relationship between the operation position of the accelerator lever 16 and the actual engine speed is determined by the adjustment error of the accelerator operation system and the accelerator sensor 17.
There is a possibility that the characteristics of the accelerator setting value and the engine speed may be different from each other due to the mounting error of the vehicle or individual differences in the characteristics of the governing device 20 [governor]. It is measured based on the information and stored. That is, based on the detection value of the rotation speed detection sensor 15 corresponding to the change operation position of the accelerator lever 16 when the engine 3 is not loaded, the lower limit value of the vehicle speed control setting area corresponding to the accelerator setting value And a calculating means B for calculating the upper limit value is provided in the control device in the form of a control program.

Hereinafter, the control operation of the control device will be described. As shown in FIG. 2, when the clutch pedal 18 is disengaged and the vehicle body is stopped, and the vehicle 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 most closed position and the most opened position [Step 3]. At this time, the output Va of the accelerator sensor 17 is sequentially read (step 4). After the operation of the accelerator lever 16 is stopped at an appropriate position and a certain period of time has elapsed in consideration of the timing delay between the accelerator operation and the change in the engine speed, the engine speed N0 and the acceleration sensor 17 when the engine 3 is in a no-load state. The output Va is read [Steps 5 to 7].
Here, from the state of change in the detection value of the accelerator sensor 17,
It is determined whether or not the accelerator lever 16 has been operated from the closed side to the open side. If so, the no-load engine speed N0 read in step 7 and the detection value Va of the accelerator sensor 16 are set to the open side. , And if the operation is in the reverse direction, it is stored as the change characteristic data to the closing side [steps 8 to 11]. That is, there is a hysteresis in the change characteristic due to a difference in the operation direction of the accelerator lever 16, and the change characteristic has a different value. And
When such a data reading operation is appropriately performed at an operation location and the reciprocating operation is repeated a plurality of times to store the data, when the control ON / OFF switch SW2 is turned OFF, the change characteristic data detected a plurality of times is read. An averaging process is performed to specify a single change characteristic of the no-load engine speed with respect to the accelerator setting value in each of the reciprocating directions [Steps 12 and 1].
3]. Also, from the characteristics of the change of the no-load engine speed,
From the power characteristics of the engine 3 determined in advance, the characteristics of the lower limit value and the upper limit value for vehicle speed control are calculated and stored [step 14].

As shown in FIG. 3, when the main clutch pedal 18 is engaged and operated, the output of the speed setting unit 13 and the feedback sensor 12 is read.
The drive of the electric cylinder 10 is 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 determined based on the change characteristics obtained as described above. N2 is obtained [steps 18 to 20].
Thereafter, the engine speed N is sequentially read, and when the engine speed N falls below 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 electric cylinder 10 increases to the set speed. The speed of the electric cylinder 10 is increased so as to return to the high speed [Steps 21 to 25].

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

In the claims, the reference numerals are used to facilitate comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a control flowchart.

FIG. 3 is a control flowchart.

FIG. 4 is a side view of the rice transplanter.

[Explanation of symbols]

 Reference Signs List 3 engine 5 transmission 10 actuator 15 rotation speed detecting means 16 accelerator setting device 17 accelerator position detecting means A vehicle speed controlling means B calculating means

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-56760 (JP, A) JP-A-59-200852 (JP, A) JP-A-61-132436 (JP, A) JP-A-1- 141132 (JP, A) JP-A-1-160426 (JP, A) JP-A-2-237828 (JP, A) JP-A 5-260826 (JP, A) (58) Fields investigated (Int. ⁶ , DB name) B60K 41/04

Claims (1)

(57) [Claims] A transmission (5) interposed in an airframe traveling system is configured to be capable of performing a shift operation by driving an actuator (10), and a rotation speed detecting means (15) for detecting a rotation speed of the engine (3). A vehicle speed control means (A) for controlling the drive of the actuator (10) so that the engine speed is reduced when the engine speed falls below a lower limit value of the set area and increased when the engine speed exceeds the upper limit value of the set area. A travel control mechanism for a working vehicle, wherein: an accelerator position detection means (17) for detecting an operation position of an accelerator setting device (16) with respect to the engine (3); Based on the detection value of the rotation speed detecting 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 area corresponding to the accelerator setting value are calculated. A vehicle speed control means (A) for performing vehicle speed control based on a result of calculation by the calculation means (B).