JPH06201031A - Travel control device for working machine - Google Patents

Abstract

PURPOSE:To prevent excessive load from being applied to an engine while suppressing the lowering of work efficiency and making travel smooth. CONSTITUTION:A continuously variable transmission 4 interposed in a machine body travel system is constituted in such a way as to be speed-change operated by the driving of a motor-driven cylinder CY. When the engine speed is lowered to the first set value, the motor-driven cylinder CY is automatically reduction- operated until the continuously variable transmission 4 reaches the specified medium speed regardless of the set value set by a speed setter 12. When the engine speed is further lowered to the second set value lower than the first set value, the motor-driven cylinder CY is automatically reduction-operated until the continuously variable transmission 4 reaches the lowest speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a continuously variable transmission arranged in a machine running system so as to be able to perform a gear shift 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 device for a working machine, which is provided with a vehicle speed control means for controlling a set value of a setting device and a speed change speed by the actuator to match.

[0002]

2. Description of the Related Art Conventionally, in a traveling control device for a work machine described above, a belt-type continuously variable transmission, which is freely shiftable by an electric cylinder, is provided in an aircraft traveling system, as disclosed in, for example, Japanese Patent Laid-Open No. 4-222508. There is a structure in which the electric cylinder is decelerated to a minimum speed when the engine speed becomes equal to or lower than a predetermined value as the vehicle travels.

[0003]

In the above structure, the continuously variable transmission is driven by the actuator so that the gear shifting operation can be performed lightly to improve the maneuverability, and the speed set value manually set can be improved. When the engine is relatively high, the load on the engine may become too great during work traveling depending on the working conditions such as the viscosity and hardness of the field, and the engine may be stopped. When the number of revolutions becomes a predetermined value or less, the continuously variable transmission is automatically decelerated to reduce the load on the engine regardless of the set speed. However, in the above-described conventional structure, when the engine speed becomes equal to or lower than a predetermined value, the deceleration operation is always performed to the minimum speed. In such a case, the traveling load fluctuates and the above-mentioned automatic deceleration operation frequently occurs, and even if it is not necessary to decelerate to the lowest speed, the vehicle will always decelerate to the lowest speed. There was room for improvement because there was a risk that the efficiency would rather decline. The present invention aims to eliminate the above-mentioned problems.

[0004]

According to the characteristic configuration of the present invention, in the traveling control device for a working machine described at the beginning, regardless of the set value by the speed setter when the engine speed falls to the first set value. If the continuously variable transmission decelerates the actuator until the intermediate speed reaches a predetermined intermediate speed and the engine speed drops to a second set value that is lower than the first set value, the continuously variable transmission becomes minimum. An automatic deceleration control means for decelerating the actuator until the speed is reached is provided.

[0005]

When the operation speed is maintained at the speed set by the speed setting device and the work travels, the load on the engine fluctuates, and the engine speed drops below the first set value. Regardless, the continuously variable transmission decelerates the actuator until it reaches a predetermined intermediate speed that is lower than the set speed but higher than the minimum speed. Even after the automatic deceleration to the intermediate speed in this way, when the engine load is large and the engine speed further decreases to the second set value, the continuously variable transmission starts to operate at the minimum speed for the first time. The actuator is decelerated until it becomes.

[0006]

Therefore, even if the load on the engine increases as the work is run, the intermediate speed of the load does not need to be reduced to the minimum speed. Try to slow it down
As in the case of suddenly decelerating from the set speed to the minimum speed, the amount of deceleration with respect to the working conditions is not wasted, and the reduction in working efficiency can be suppressed. Moreover, if the load is so heavy that the engine will stop, deceleration to the minimum speed can prevent a large decrease in efficiency due to engine stop, and improve the overall work efficiency. Further, since the automatic deceleration operation by the control of the actuator is performed only in two steps of high and low, compared to the multi-step control, the traveling state of the airframe becomes unstable as if the vehicle is decelerated every short time. Can be suppressed.

[0007]

Embodiments will be described below with reference to the drawings. Figure 5
Fig. 1 shows a riding-type rice transplanter, which is an example of a working machine. In this rice transplanter, a seedling planting device 2 is connected to a rear portion of a riding type traveling body via a link mechanism 1 so as to be vertically movable and to be freely rolled around a front-rear axis. The traveling aircraft has the engine 3 installed in the hood at the front of the aircraft.
Is transmitted to the mission case 5 via the belt type continuously variable transmission 4, and the front and rear wheels 6, 7 are transmitted from the mission case 5.
On the other hand, the transmission system is configured to supply the seedling planting device 2 to the seedling planting device 2, and the seedling planting work can be performed while the machine body is running.

As shown in FIG. 1, the belt type continuously variable transmission 4 extends over a drive pulley 8 mounted on the output shaft 3a of the engine 3 and a driven pulley 9 mounted on the input shaft 5a of the transmission case 5. While the transmission belt 10 is wound, the pulleys 8 and 9 are provided in a split pulley type in which the pulley intervals can be changed, and the pulley intervals are integrally operated by an electric cylinder CY [an example of an actuator]. By changing it upside down by the rising cam mechanism 11,
The belt winding diameters of the respective pulleys 8 and 9 are changed so that the speed change operation can be continuously performed.

A speed setter 1 in which the electric cylinder CY in the continuously variable transmission 4 has a speed change speed arranged in the body control section
Vehicle speed control means A for controlling to match the speed set by 2
Is equipped with. That is, the electric cylinder CY is driven and controlled by the control device 13 including a microcomputer,
The control device 13 feedback-controls the electric cylinder CY so that the input value from the speed setter 12 including a potentiometer and the detection value of the stroke sensor 14 that detects the actual operating stroke of the electric cylinder CY match. That is, the vehicle speed control means A is provided in the control device 13 in the form of a control program, and the operating stroke of the electric cylinder CY is set so that the machine traveling speed and the set speed correspond to each other. Therefore, the operator can arbitrarily set the machine body traveling speed by operating the speed setting device 12.

Then, the continuously variable transmission 4 is operated at a predetermined speed V.
When the engine speed N drops to a predetermined first set value N1 while the vehicle is traveling in the state of being set to 0, the continuously variable transmission 4 operates at a predetermined intermediate speed regardless of the set value by the speed setter 12. When the electric cylinder CY is decelerated to V1 and the engine speed N drops to the second set value N2 lower than the first set value N1, the electric cylinder CY is set until the continuously variable transmission 4 reaches the minimum speed. The automatic deceleration control means B for decelerating the vehicle is provided. That is, the output shaft 3a of the engine 3 is provided with an engine rotation speed detection sensor 15 [rotation speed detection means] for detecting the rotation speed.
The detected value is input to the control device 13, and the control device 13 drives and controls the electric cylinder CY while monitoring the engine speed N. The automatic deceleration control means B is provided in the control device 13 in a control program format, and the control device 1
3 executes control as follows.

FIG. 4 shows a vehicle speed control flowchart during work traveling. First, the output of each of the speed setter 12, the stroke sensor 14, and the engine speed detection sensor 15 is read [step 1], and the set speed VS by the speed setter 12 and the shift speed V0 [actual speed] by the electric cylinder CY match. The drive control of the electric cylinder CY is performed [steps 2 to 4]. Then, the mode switch SW
Is set to the automatic deceleration mode, when the engine speed N becomes equal to or lower than the predetermined first set value N1 as a result of work traveling, as shown in FIG.
The electric cylinder CY is decelerated until the intermediate speed V1 between the minimum speed V2 and the minimum speed V2 is reached [steps 5 to 7]. afterwards,
When the engine speed N recovers to a first return value N12 that is larger than the first set value N1, the speed change speed is set by the speed setter 12.
The electric cylinder CY so that it will return to the set speed V0
Is accelerated [steps 8 and 9]. Further, despite the deceleration operation to the intermediate speed V1, the engine speed N is further decreased to the second set value N2 smaller than the first set value N1.
If it is decreased to 0, the load on the engine 3 becomes excessive and the engine may be stopped. Therefore, the electric cylinder CY is decelerated so that the speed change speed of the continuously variable transmission 4 becomes the minimum speed V2 [steps 10 and 11]. After that, when the engine speed N recovers to the first return value V12, the speed is returned to the intermediate speed V1 by acceleration, and when the engine speed N recovers to the second return value N22 which is larger than the first return value N12, the setting by the speed setter 12 is performed. The electric cylinder CY is accelerated to return to the speed V0 [steps 12 to 14]. Since such automatic deceleration control is performed regardless of the intention of the operator, when such automatic deceleration control is performed, the status is displayed by the indicator 16 provided on the control panel. That is, as shown in FIG. 3, when the mode changeover switch SW is operated to be set to the automatic deceleration mode, the central load-sensitive deceleration display lamp L1 [green] is turned on, and as the engine speed N decreases. The level meter display lamps L2, L3 on both the left and right sides are sequentially turned on, and when deceleration control is performed, the display color changes from green (L2) to red (L3) for easy identification. I am doing it. The steps 2 to 4 constitute the vehicle speed control means A, and the steps 6 to 14 constitute the automatic deceleration control means B.

It should be noted that although reference numerals are given in the claims for facilitating the comparison with the drawings, 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 characteristic diagram

FIG. 3 is a plan view of the indicator.

FIG. 4 is a control flowchart.

[Figure 5] Overall side view of rice transplanter

[Explanation of symbols]

 3 Engine 4 Continuously Variable Transmission 12 Speed Setting Device 15 Rotation Speed Detection Means A Vehicle Speed Control Means B Automatic Deceleration Control Means CY Actuator N1 First Set Value N2 Second Set Value

Claims (1)

[Claims] 1. A continuously variable transmission (4) interposed in an airframe traveling system is configured to be capable of gear shifting operation by driving an actuator (CY), and rotational speed detection means (for detecting the rotational speed of an engine (3) ( 15) equipped with a speed setting device (1
A traveling control device for a working machine, comprising: a vehicle speed control means (A) for controlling such that a set value of 2) and a shift speed of the actuator (CY) match each other, wherein an engine speed is a first set value ( N1), regardless of the value set by the speed setter (12), the actuator (CY) is decelerated until the continuously variable transmission (4) reaches a predetermined intermediate speed, and the engine speed is reduced. When the number drops to a second set value (N2) lower than the first set value (N1), automatic deceleration control for decelerating the actuator (CY) until the continuously variable transmission (4) reaches the minimum speed. A traveling control device for a working machine, which is provided with means (B).