JPH04140559A - Agricultural working vehicle - Google Patents

Abstract

PURPOSE:To maintain constantly appropriate load to an engine by providing a change operating means for changing/adjusting the rotating speed characteristic value for performing the automatic deceleration of speed change mechanism, by human-initiated operation. CONSTITUTION:A continuously variable transmission 3 is provided with a deceleration control means A for performing the automatic deceleration control of the continuously variable transmission 3 regardless of the operation of a speed change lever 10 when the output rotating speed of an engine 2 is lowered below the specified characteristic value due to work load during planting travel with the engine 2 set into the maximum output state. The first set rotating speed is changed by operating a first rotating speed setter 15, and effective automatic deceleration control can be performed without generating an engine stalling even on such soil of high viscosity as to cause the sudden lowering of engine speed immediately after the start of its operation. The second set rotating speed is changed by operating a second rotating speed setter 16, and appropriate speed change control to engine load is performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a rotation speed detection system that configures a transmission system to transmit the power of an engine to traveling wheels via a transmission mechanism, and detects the output rotation speed of the engine. deceleration control means for automatically decelerating the transmission mechanism when the detected value by the rotation speed detection means decreases to a predetermined rotation speed characteristic value corresponding to the operation of the accelerator lever as the work travels; Regarding agricultural vehicles equipped with

[Conventional technology]

Conventionally, in the agricultural vehicle mentioned above, when the accelerator lever is set at the maximum output position and the engine output decreases from the no-load maximum output rotation speed to a predetermined level due to the work load, the transmission mechanism is activated. A structure configured to automatically decelerate has been considered (see, for example, Japanese Patent Application No. 19240/1999 filed by the present applicant).

[Problem to be solved by the invention]

However, in the conventional structure described above, since the rotational speed level at which automatic deceleration is started is constant, the following problems occur depending on the working conditions.

For example, in cases where the work depth is large in heavy viscosity soil, when work is started while the machine is moving, an excessive load is suddenly applied, and the engine There was a risk that it would stop. In addition, if the rotation speed level is set high in consideration of such an overload condition, automatic deceleration will be performed unnecessarily when working on soil where the work load is relatively light, reducing work efficiency. There was a drawback.

The present invention aims to eliminate the above-mentioned disadvantages through rational improvements.

[Means to solve the problem]

A characteristic configuration of the present invention resides in that the agricultural vehicle described at the beginning is provided with a changing operation means that allows the predetermined rotational speed characteristic value to be changed and adjusted by manual operation.

[For production]

For example, in the case of work conditions such as soil with a heavy viscosity value, where a large work load is applied almost at the same time as the start of work, setting the rotation speed characteristic value, which is the control standard for automatic deceleration, to a relatively high level will reduce the engine speed. Since the traveling speed of the aircraft is reduced before an excessive load is applied to the engine, the risk of engine stalling is reduced.

In addition, under work conditions where the workload is relatively light during normal work, but where there is a risk of sudden overload due to the presence of foreign objects, it is recommended that the characteristic values be set to a relatively low level. Since deceleration control is not activated during operation, work efficiency is improved.

〔Effect of the invention〕

Therefore, since the start level of automatic deceleration can be artificially changed in advance according to field conditions, it is possible to maintain an appropriate load on the engine at all times, and as a result, it is possible to prevent work driving from stalling or frequent deceleration. This prevents the harmful effects of this and further improves work efficiency.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 4 shows a riding rice transplanter which is an example of an agricultural vehicle according to the present invention. This rice transplanter is constructed by connecting a seedling planting device (1) to the rear of a riding-type traveling body, and the traveling body is equipped with an engine (2) at the front, and the power of this engine (2) is The front and rear wheels (5) and (6) are connected to the front and rear wheels (5) and (6) through a transmission case (4) containing a split-pulley type belt-type continuously variable transmission (3) and a gear-type main transmission (not shown).
) and the seedling planting device (1), so that the seedling planting work can be carried out while traveling.

Next, the speed change control mechanism of the traveling aircraft will be explained.

As shown in FIG. 1, the belt type continuously variable transmission (3)
The split pulley interval is configured to be changed and adjusted by the telescopic drive of an electric cylinder (7) via a rising cam mechanism (8) to perform a changing operation. Moreover, the electric cylinder (
7) is configured to be driven in accordance with the amount of operation of a speed change lever (10) provided on a control panel (9) of the aircraft.

In other words, the detection setting amount of the first potentiometer (PMI) that detects the operation amount of the gear shift lever (10), and the detection setting amount of the second potentiometer (PMI) that detects the amount of expansion and contraction of the electric cylinder (7).
A servo operation system is configured such that the control device (11) drives and controls the electric cylinder (7) so that the feedback detection amount of M2) coincides with the detected amount of feedback.

Further, the continuously variable transmission device (3) is configured such that when the engine (2) is set to the maximum output state and traveling for planting, the output rotation speed of the engine (2) is set to a predetermined value due to the work load. A deceleration control means (A) is provided which automatically decelerates the continuously variable transmission (3) when the speed decreases below the characteristic value, regardless of the operation of the speed change lever (10). In detail, engine (2)
Equipped with an electromagnetic rotation speed sensor (S) [an example of rotation speed detection means] that detects the output rotation speed of the engine, and an accelerator switch (SWI) that detects when the accelerator lever (12) is operated to the maximum output position. and main clutch pedal (13
) is turned off.
W, ), and each of the switches (SWI), (S
W2) and the outputs of the rotational speed sensor (S) are provided to the control device (11) containing a microcomputer, and the control device (11) executes control operations as described below.

That is, as shown in Fig. 2, after the engine (2) is started, when the accelerator switch (SW, ) is in the detection state, that is, in the clutch disengaged state, the gear type main transmission mechanism is in the forward mode for planting. 1st speed switch that detects that it is in 1st speed (
(not shown) is in a non-detection state and the forced deceleration switch (SWs) is operated, and
When the operation switch (14) for raising and lowering the seedling planting device (1) is not in the planting work position, the continuously variable transmission (3) is maintained at the lowest speed operation state (steps 81 to 8). Ss).

When the first speed switch is in the detection state, the rotation speed sensor (S), the first and second potentiometers (PMI)
) and (PMz) are read (step Ss), and the electric cylinder (7) is slowly increased in speed until the outputs of each potentiometer (PMI) and (PM2) match (step S7). Next, press the accelerator switch (
SWI) is in the detection state (step Ss), and if the forced mode change switch (SW4) is not in the ON state (step S,), the engine speed will increase to the predetermined first set speed (N1) due to the work load. When it decreases (see line 11 in Figure 3), the continuously variable transmission (3) is automatically operated to decelerate (steps S and O).

511). Then, when the engine speed returns to the second set speed (N2), which is higher than the first set speed, the automatic deceleration operation of the continuously variable transmission (3) is stopped (
Step Sl! , 513). Accelerator lever (12)
If the engine speed is not set to the maximum output position, or if the engine speed decreases little due to the work load, as described above, the first and second potentiometers (PMI
), (PM!) Execute speed change operation control to drive the electric cylinder (7) until their respective outputs match (step S1.).

S's, S+s).

This rice transplanter includes a potentiometer-type rotation speed setting device (15) that allows manual adjustment of the first set rotation speed and the second set rotation speed according to work conditions such as soil conditions.
(16).

That is, the first rotation speed setting device (15) [: changing operation means]
By operating , the first set rotation speed (N1) is changed to (N+') as shown in line 12 in Figure 3, for example, and the engine rotation speed suddenly decreases at the same time as work starts. In clay-like soil, effective automatic deceleration control can be performed without stalling the engine. Similarly, by operating the second rotation speed setter (16), the second set rotation speed (N2) is changed, and appropriate speed change control for the engine load is executed.

In addition, if a malfunction occurs in the rotation speed sensor (S) and the engine rotation speed cannot be detected, turning on the forced mode change switch (SW) allows the rotation speed sensor (S) to be detected. ) The above-mentioned speed change operation control can be executed regardless of the output from (step Ss). Incidentally, steps S1° to SI3 constitute a deceleration control means (A).

[Another example]

The first rotation speed setting device (15) may be of a multi-stage switching type instead of a potentiometer type.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the agricultural vehicle according to the present invention, in which Fig. 1 is a control system diagram, Fig. 2 is a control flowchart, Fig. 3 is a rotation speed characteristic diagram, and Fig. 4 is an overall side view of the rice transplanter. . (2)...Engine, (3)...Transmission mechanism, (5), (6)...Wheels, (14)...
... Accelerator lever 1 (15) ... Change operation means, (A) ... Deceleration control means, (S) ...
...Detection means.

Claims (1)

[Claims] A transmission system is configured to transmit the power of the engine (2) to the running wheels (5) and (6) via the transmission mechanism (3), and the output rotation speed of the engine (2) is detected. rotation speed detection means (
S), and as the work travels, the detected value by the rotation speed detection means (S) is detected by the accelerator lever (12).
), the agricultural vehicle is equipped with a deceleration control means (A) that automatically decelerates the transmission mechanism (3) when the rotation speed decreases below a predetermined rotation speed characteristic value corresponding to the operation of A farm vehicle equipped with a changing operation means (15) that can be changed and adjusted by human operation.