JP2531848B2 - Work vehicle shift control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shift control device for a work vehicle such as a rice transplanter, and more specifically, to a transmission for transmitting power of an engine to traveling wheels via a transmission mechanism. The system is provided with a rotation speed detection means for detecting the output rotation speed of the engine, and the detected value by the rotation speed detection means is accompanied by the maximum output characteristic value corresponding to the operation of the accelerator lever as the work travels. The present invention relates to a work vehicle shift control device including deceleration control means for automatically decelerating the speed change mechanism when the speed is reduced to a predetermined ratio or less.

[Conventional technology]

In the above shift control device, conventionally, in a state where the accelerator lever is set to the maximum engine output position, the engine speed becomes a predetermined value due to the work load from the maximum no-load speed of the engine corresponding to the set position. In some cases, when the rotational speed is reduced to a value lower than a set speed, the transmission mechanism interposed in the transmission system is automatically decelerated, and the set speed is constant (for example, Japanese Patent Application No.
See 192406).

[Problems to be Solved by the Invention]

Generally, engines mounted on farming vehicles such as rice transplanters include gasoline engines and diesel engines, but these two have different speed characteristics, and the maximum no-load speeds have different values. Is. As a result, in the case of the above-mentioned conventional technique, it is necessary to prepare control devices of different specifications depending on the type of the engine described above, and it is necessary to prepare two types of control devices that control substantially the same control operation. However, there is a disadvantage that the manufacturing cost is increased.

An object of the present invention is to eliminate the above-mentioned inconveniences by improving the rational configuration.

[Means for solving the problem]

A characteristic configuration of the present invention is, in the work vehicle shift control device described at the beginning, a storage unit that stores a detection value by the rotation speed detection unit during no-load operation corresponding to each operation position of the accelerator lever of the engine. The deceleration control means is configured to execute the control based on the stored value of the storage means.

[Action]

When the onboard engine is operated without load and the accelerator lever is changed from the minimum output position to the maximum output position prior to work traveling, the maximum engine speed of each engine output corresponding to each operation position of the accelerator lever is stored in the storage means. Remembered. Then, in the subsequent work traveling, when the engine speed decreases to a value of a predetermined ratio of the maximum output characteristic value stored as described above due to the work load, the speed change mechanism is automatically decelerated. .

〔The invention's effect〕

Therefore, the shift control device according to the present invention does not need to determine in advance the control characteristic value at which the deceleration control is started, and therefore can be used regardless of the type of the mounted engine.
There is no need to bother with separate specifications, and it is possible to reduce costs by sharing.

Further, since the control characteristic values are individually based on the actual measurement data of the mounted engines, it is possible to perform highly accurate control without variations due to individual differences.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows a riding type rice transplanter which is an example of the agricultural work vehicle according to the present invention. This rice transplanter is configured by connecting a seedling planting device (1) to a rear portion of a riding type traveling body so as to be able to move up and down, and the traveling body has an engine (2) mounted on a front portion thereof and the engine (2). ) Power via a split pulley type belt type continuously variable transmission (3) and a gear type main transmission mechanism (not shown) inside a front and rear wheels (5), (6) and It is configured so that it can be supplied to the seedling planting device (1) to perform seedling planting work while running.

 Next, the traveling speed change control mechanism will be described.

As shown in FIG. 1, in the belt type continuously variable transmission (3), the interval between the split pulleys is changed by the ride-on cam mechanism (8) based on the expansion / contraction drive of the electric cylinder (7) to perform the gear shift operation. Configured, electric cylinder (7)
Is a gearshift lever (10) arranged on the aircraft control panel (9)
The control device (11) is configured to perform drive control based on the operation amount of.

Further, the main speed change mechanism has a forward first speed (F ₁ ) for work traveling, a second forward speed (F ₂ ) and reverse (R) for road traveling, which are planted by operating the main speed change lever (12). It is configured so that switching operation can be freely performed in three positions.

Further, the control panel (9) is provided with a liquid crystal display bar graph type speedometer (13) for selectively displaying the output speed or vehicle speed of the engine (2).

That is, an electromagnetic rotation speed sensor (S) for detecting the output rotation speed of the engine (2) is provided, and a main gear shift position detection switch (SW ₁ ) for detecting the gear shift position of the main gear shift lever (12) and display contents. A changeover switch (SW ₂ ) and a first potentiometer (PM ₁ ) for detecting the drive stroke amount of the electric cylinder (7) are provided, and the control device (11) switches the changeover switch (SW ₂ ) to the engine speed display position. And the detected rotation speed is displayed on the speedometer (13) based on the output value of the rotation speed sensor (S), and the changeover switch (SW ₂ )
When is switched to the vehicle speed display position, the control device (11) calculates the vehicle speed from the engine speed, the main gear shift position and the continuously variable gear shift position and displays it on the speed meter (13).

Next, the shift control mechanism of the continuously variable transmission (3) will be described.

The electric cylinder (7) in the continuously variable transmission (3) is
The control device (11) is controlled and driven so that the detection value of the second potentiometer (PM ₂ ) for detecting the operation amount of the speed change lever (10) and the feedback detection value of the first potentiometer (PM ₁ ) match. Gear lever (10)
The gear shift operation can be performed according to the operation amount of.

Then, when the engine speed decreases to a predetermined ratio or less of the maximum output characteristic value corresponding to the operation of the accelerator lever (14) due to the work load, the deceleration control means (A) for automatically decelerating the speed change mechanism (3). ) Is provided. More specifically, a third potentiometer (PM ₃ ) for detecting the operation amount of the accelerator lever (14) is provided, and as shown in FIG. 3, the maximum output of the engine (2) with respect to each operation position of the accelerator lever (14). When the engine speed decreases to a predetermined ratio (Nx) of a predetermined value, for example, 0.8 times the rotational speed characteristic value (Nmax), the continuously variable transmission (3) is moved to the operation position of the speed change lever (10). It reduces the engine load by automatically decelerating regardless. Further, a non-volatile memory (15) [an example of storage means] for storing the detection value of the rotation speed sensor (S) corresponding to each operation position of the accelerator lever (14) when the engine (2) is under no-load operation is provided. The automatic deceleration control is executed based on the value stored in the memory (15).

The deceleration control means (A) is provided in the control device (11) in the form of a control program, and the control is executed in the following procedure.

As shown in FIG. 2, first, the characteristic value setting switch (SW
₃ ) is operated, the accelerator lever (14) is changed from the minimum output position to the maximum output position in the engine unloaded state, and the operation position of the accelerator lever (14) and the engine speed are read (step S ₁ , S ₂ ) and the maximum engine output speed characteristic value (Nmax) corresponding to each operating position of the accelerator lever (14) are fetched and stored in the memory (15) (step S ₃ ). Further, a predetermined ratio of the maximum output characteristic value, for example, a value (Nx) of 0.8 times is calculated (step S ₄ ). When the aircraft is running, the clutch switch (SW) that detects that the clutch pedal (16) is in the clutch disengaged state.
_{When 7} ) is in the detection state, when the main speed change lever (12) is not in the first forward speed (F ₁ ) and the deceleration switch (SW ₄ ) is in the ON state, the seedling planting device (1) is operated. In each case where the operation switch (17) is not in the planting position, the electric cylinder (7) is operated and held at the lowest speed position (step S ₅
~S _9). If it becomes a planting running state, a rotation speed sensor (S),
1st thru | or 3rd potentiometer (PM ₁ ), (PM ₂ ),
Each detected value of (PM ₃ ) is read (step S ₁₀ ), and the electric cylinder (7) is slowly accelerated to the speed set by the second potentiometer (PM ₂ ) (step S ₁₁ ).

Then, if the automatic deceleration on-off selection switch (SW ₅₎ that are configured as ON state, (step S _12), corresponding to the operating position of the accelerator lever (14) engine speed, due to the workload When the calculated value (Nx) is decreased, the electric cylinder (7) is automatically decelerated and driven regardless of the operation amount of the speed change lever (10) (steps S ₁₃ and S ₁₄ ). If the selection switch (SW ₅ ) is off, the shift control corresponding to the shift lever (10) as described above is executed (step
S ₁₅ ).

In step S ₁ , the characteristic value setting switch (S
If W ₃ ) is off, the process proceeds to step S ₅ and control is executed. Deceleration control means in step S _13, S ₁₄ (A)
Is configured.

Further, the calculated value (Nx) is configured so that it can be finely adjusted and changed by an adjuster (not shown), and the control device (11) operates the electric cylinder (7) and the rotation speed sensor (S). In order to ensure safety in the event of an abnormality, a means (not shown) is provided to stop the above shift control, but if the release switch (SW ₆ ) is turned on, even if an abnormality occurs The shift control is configured to be executed.

The memory (15) may be a volatile memory having a backup power source, instead of the nonvolatile type.

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

[Brief description of drawings]

The drawings show an embodiment of a shift control device for a work vehicle according to the present invention. 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 the entire rice transplanter. It is a side view. (2) ... Engine, (3) ... Transmission mechanism, (5),
(6) …… Wheels, (14) …… Accelerator lever, (15)…
... storage means (A) ... deceleration control means, (S) ... detection means.

Claims (1)

(57) [Claims] 1. A transmission system is configured to transmit the power of an engine (2) to traveling wheels (5), (6) via a speed change mechanism (3), and the output speed of the engine (2) is detected. The rotation speed detecting means (S) is provided, and the value detected by the rotation speed detecting means (S) is equal to or less than a predetermined ratio of the maximum output characteristic value corresponding to the operation of the accelerator lever (14) as the work travels. A work vehicle gear shift control device comprising deceleration control means (A) for automatically decelerating the gear shift mechanism (3) when the number of gears is reduced, which corresponds to each operation position of an accelerator lever (14) of the engine (2). A storage means (15) for storing a value detected by the rotation speed detection means (S) during no-load operation,
A work vehicle shift control device configured such that the deceleration control means (A) executes control based on the stored value of the storage means (15).