JP2755847B2 - Automatic transmission structure of work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission structure for a work vehicle such as a ride-type rice transplanter or a combine which automatically shifts the traveling speed of the body of the work vehicle.

[0002]

2. Description of the Related Art In a work vehicle as described above, a change in load applied to an engine is detected as a change in engine speed by a rotation speed sensor, and the load applied to the engine is maintained at a set value. That is, there is a vehicle equipped with a control means for automatically shifting the speed of the traveling transmission so that the engine speed is maintained at the set value. Thus, efficient use of engine power and prevention of engine stoppage are achieved.

[0003]

The above-mentioned work vehicle rarely travels on a flat place such as a pavement road, and often travels on a work place with severe irregularities such as a field. Therefore, when the vehicle travels on a work surface with severe irregularities, the load on the engine may be large.Therefore, as described above, the conventional control means for reducing the load on the engine by operating the transmission at a low speed side as described above. It will be effective. However, for example, in a downhill work place having irregularities, the load applied to the engine may be reduced even if there is irregularity. In such a case, the transmission is operated to a higher speed side by the control means. Therefore, if the transmission is operated to the high speed side in a work place having unevenness, the unevenness causes the body to sway violently, which makes the rider's riding comfort worse. Planting, etc.) is not performed accurately.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of cases in which the detection of the load applied to the engine alone is not sufficient as described above when automatically shifting the transmission for traveling.

[0005]

A first feature of the present invention (claim 1) is to provide a rolling sensor for detecting a rolling operation of the aircraft with respect to the ground, and that the rolling angular velocity of the aircraft detected by the rolling sensor is reduced. The control means for reducing the traveling speed of the aircraft when the speed is equal to or more than the set value is provided. The operation and effect are as follows.

A second feature of the present invention (claim 2) is that according to claim 1, further comprising a load sensor for detecting a load applied to the engine, and adjusting a load value detected by the load sensor by adjusting the traveling speed. The operation and effect of the control operation of the control means are set as follows.

[0007]

According to the first feature, when the rolling sensor detects that the rolling angular velocity of the aircraft is equal to or higher than the set value, the control means reduces the traveling speed of the traveling aircraft. In other words, the control of the traveling speed in this type of work vehicle is sometimes performed based on the load and the running load of the working device provided in the work vehicle. Could not be avoided. When traveling in a rough field scene, the amount of rolling of the aircraft is likely to be large, but in addition to this, if the aircraft travels at a relatively high speed,
The aircraft tends to roll more easily in proportion to the unevenness of the ground and the traveling speed, and the rolling angular velocity tends to increase. At this time, if the deceleration control is performed based on the detection of the rolling amount, the influence of the unevenness of the running surface can be reduced to some extent and the degree of rolling can be suppressed. However, in this type of work vehicle, work travel is often performed on uneven terrain, so when performing control based on the detection result of the rolling amount as described above, if the control is too sensitive, Hunting may be caused. Therefore, the result is that the dead zone must be relatively widened and the result that the rolling state continues to some extent must be observed, so that the control response delay is liable to occur. Therefore, in the present invention, by performing the control configured to reduce the traveling speed based on the rolling angular velocity of the aircraft, it is possible to perform the control with good responsiveness and to reduce the rolling amount due to the traveling by configuring as described above. Becomes

According to the second feature, the control for reducing the running speed during the rolling of the body is performed as described above, and the control means is operated so that the engine load detected by the load sensor is maintained at the set value. Will be adjusted. In other words, when the load on the engine increases during work, the running speed is reduced, and when the load on the engine is reduced, the running speed is increased to reduce the load on the engine and avoid engine stop, Even in a situation where the engine load is small and high-speed traveling is possible, in a situation where the aircraft is largely rolled, the running speed is reduced to reduce the shaking of the aircraft.

[0009]

As described above, by performing the deceleration control based on the rolling angular velocity, it is possible to reduce the shaking of the airframe and make it comfortable to ride, and to perform ground work on the ground (e.g., cutting of planted culms and planting of seedlings). It can be performed with high accuracy (claim 1). Further, it is possible to perform the work in which the vibration of the body is reduced as in the first aspect, and also to perform the operation at an appropriate traveling speed by avoiding the engine stop (the second aspect).

[0010]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a seedling planting device 3 is connected to a rear portion of the machine body supported by a front wheel 1 and a rear wheel 2 so as to be able to move up and down by a link mechanism 4 so as to be a riding type rice transplanter which is an example of a working vehicle. Is composed.

As shown in FIGS. 1 and 2, the power from the engine 9 is transmitted to a front wheel 1 and a rear wheel 2 via a belt-type continuously variable transmission 10, a main clutch 5, and a stepped gear transmission 14. It is transmitted to the seedling planting device 3. The continuously variable transmission 10 is configured to perform a shift operation by an electric cylinder 16, and a control device 1 as a control unit is configured to be in a shift state corresponding to an operation position of a shift lever 17 provided in a control unit.
3, the electric cylinder 16 is operated to expand and contract.

Next, a description will be given of an automatic transmission state in which the continuously variable transmission 10 is automatically shifted to perform the planting run in contrast to the manual transmission state by the transmission lever 17 as described above. As shown in FIG. 1, a rotation speed sensor 15 (corresponding to a load sensor) for detecting the rotation speed of the engine 9 is provided. A rolling sensor 6 (optical fiber gyro type, piezoelectric vibration gyro type, etc.) for detecting the rolling angular velocity of the body with respect to the rice field surface is provided at the rear of the body.

As shown in FIG. 3, when the planting traveling by automatic transmission is started, first, the rotation speed of the engine 9 is detected by the rotation speed sensor 15 (step S1), and the rolling angular velocity of the body in the left-right direction is determined. It is detected by the sensor 6 (step S2). If the rotation speed of the engine 9 is equal to or less than the set range (corresponding to the set value), it is determined that a large load is applied to the engine 9 (step S3), and the operation of the electric cylinder 16 is performed by an operation signal from the control device 13. Operates the continuously variable transmission 10 to the low speed side (step S4).

Conversely, if the rotation speed of the engine 9 is equal to or greater than the set range (corresponding to the set value), it is determined that the load on the engine 9 is small (step S3). In this case, if the detected rolling angular velocity is equal to or higher than the set value, it is determined that the machine body is rolling relatively intensely due to the unevenness of the cultivator on which the front wheel 1 and the rear wheel 2 travel (step S5). In step S4, the continuously variable transmission 10 is operated to the lower speed side in the same manner as described above.

When it is determined that the load on the engine 9 is small (step S3), if the detected rolling angular velocity is less than the set value, it is determined that the body is not rolling much (step S3).
5). In such a case, the electric cylinder 16 operates the continuously variable transmission 10 to the high-speed side according to the operation signal from the control device 13 (step S6).

[Another Embodiment] In the above-described embodiment, a yawing sensor (not shown) for detecting the swinging (yawing operation) of the body around the vertical axis is provided, and the yaw angular velocity is determined in step S5 in FIG. May be configured to operate the continuously variable transmission 10 to the low speed side when the value is equal to or more than the set value, and to operate the continuously variable transmission 10 to the high speed side when the yawing angular velocity is less than the set value. Then, instead of detecting the rotation speed of the engine 9 as a load, a transmission torque applied to a transmission shaft on the way from the engine 9 to the front wheel 1 and the rear wheel 2 is detected by a torque sensor (not shown) (corresponding to a load sensor). The transmission torque may be detected and used as the load applied to the engine 9.

Further, the frequency of the rolling operation or the frequency of the yawing operation is detected instead of the rolling angular velocity and the yawing angular velocity, and if the frequency is equal to or more than a set value, the continuously variable transmission 10 is operated to the low speed side. If is less than the set value, the continuously variable transmission 10 may be configured to operate at a higher speed. Furthermore, the automatic shifting operation of the continuously variable transmission 10 may be performed by taking into account the pitching operation of the aircraft in addition to the rolling operation and the yawing operation.

In the claims, reference numerals are provided for convenience of 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 diagram showing a relationship between a shift lever, a transmission for traveling, an electric cylinder, a rolling sensor, and the like.

FIG. 2 is an overall side view of a riding rice transplanter.

FIG. 3 is a flowchart showing a control flow;

[Explanation of symbols]

 6 Rolling sensor 9 Engine 13 Control means 15 Load sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 59/00-63/48 A01B 63/10 B60K 28/14

Claims (2)

(57) [Claims] 1. A method for detecting a rolling operation of an aircraft with respect to the ground.
With a rolling sensor (6)
Rollin of the aircraft detected by the rolling sensor (6)
If the angular speed is higher than the set value, reduce the traveling speed of the aircraft.
An automatic transmission structure of a work vehicle including a control means (13) . 2. A load sensor (15) for detecting a load applied to an engine (9) .
Set the load value detected by the load sensor (15) to the set value
The control operation of the control means (13) is set to maintain
The automatic transmission structure for a working vehicle according to claim 1, wherein