JP3114231B2 - Throttle upper limit setting device for combine speed 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 an improvement of a combine speed control mechanism.

[0002]

2. Description of the Related Art Conventionally, when a throttle valve is automatically opened and closed to maintain the number of revolutions of an engine of a combine at a predetermined value, the opening operation of the throttle valve is performed despite the output of a throttle opening command signal from a controller. The tilt position of the throttle lever at the time of stop is stored as a throttle upper limit value. Thereafter, when the throttle lever tilts to the throttle upper limit value, this is detected by a throttle position sensor and the vehicle speed of the combine is automatically reduced to thereby reduce the engine speed. There is known a vehicle speed control mechanism for eliminating overload on the vehicle.

[0003]

In the above-mentioned vehicle speed control mechanism, the opening and closing of the throttle valve is manually or automatically operated, and when both operations are overlapped, the manual operation has priority over the automatic operation. For this reason, if the operator tilts the throttle lever and performs an operation to close the throttle valve even though the controller outputs the throttle open command signal, the throttle valve closes. As a result, when the manual operation is performed, the throttle valve does not open even though the throttle open command signal of the controller is issued, and the maximum tilt position of the throttle lever when the throttle valve is manually closed is changed. This will be stored as the throttle upper limit value.

In this case, since the throttle upper limit value is not updated thereafter, the vehicle speed control is performed at the erroneously lower upper limit value. Since the engine speed is proportional to the tilt angle of the throttle lever, if the throttle lever cannot be tilted too much, the engine speed will not increase, and the vehicle speed of the combine will be reduced unnecessarily, reducing the work efficiency. .

[0005] It is an object of the present invention to solve the above-mentioned drawbacks and to provide an apparatus for correcting a throttle to a correct upper limit value.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, when a throttle valve is automatically opened and closed to maintain the engine speed of a combine at a predetermined value, a throttle opening command signal of a controller is provided. The tilting position of the throttle lever when the opening operation of the throttle valve stops despite the output is stored as a throttle upper limit value. When the throttle valve is opened to the throttle upper limit value and opened to the throttle upper limit value, the throttle position is stored. In a vehicle speed automatic control mechanism of a combine which eliminates an engine overload by detecting a sensor and automatically reducing the vehicle speed, a throttle which compares a detected value of the throttle position sensor with a previously stored throttle upper limit value. Position comparing / determining means is provided; If it is determined that the actual throttle position value is larger than the already stored throttle upper limit value, reset means for resetting the already stored throttle upper limit value is provided, and a value larger than the reset throttle upper limit value is set to a new value. An upper limit value updating means for storing the throttle upper limit value is provided.

[0007]

When the tilt position of the throttle lever is larger than the previously stored throttle upper limit value, a new value is updated and stored as the throttle upper limit value.

[0008]

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

FIG. 1 is a side view of a combine, wherein 1 is a power steering lever, 2 is a throttle lever for changing the vehicle speed, 3 is a crawler, and 4 is a mowing section.

The operator operates the throttle lever 2 to
Set the required engine speed according to vehicle speed and work load. Normally, the rotation speed of this engine (not shown) is set to about 2600 rpm, which is a proper rotation speed (rated rotation speed). After that, the vehicle speed control mechanism automatically works,
Unless the throttle lever 2 is manually operated, the engine speed is maintained at this rated speed.

FIG. 2 is a block diagram showing a device configuration of the throttle upper limit position setting device of the present invention. The throttle upper limit position setting device includes a throttle position sensor 7 for detecting a tilt position of the throttle lever 2 on an input interface 6 of a microcomputer 5 as a controller.
A throttle opening relay 10 and a throttle closing relay 11 for automatically opening and closing a throttle to an output interface 9 and an HST speed-up relay 12 for automatically changing a vehicle speed are connected to an output interface 9. And the HST deceleration relay 13 are connected. From the engine speed measured by the engine speed sensor 8 input via the input interface 6, the microcomputer 5 provides a throttle opening relay 10 when the engine speed decreases and a throttle closing relay when the engine speed increases. 11 is operated to maintain the engine speed constant. Thus, when the engine speed drops abnormally, the throttle is opened by the throttle opening relay 10, and when the engine speed does not reach the rated speed even when the engine speed reaches the upper limit, the HST deceleration relay 13 automatically controls the vehicle speed. Slow down. As a result, the load caused by the harvesting and threshing work of the combine is reduced, and the overload state is eliminated.

In the above operation, since the throttle lever 2 and the throttle valve are mechanically linked, the opening position of the throttle valve corresponds to the tilt position of the throttle lever 2. Although the upper limit value of the throttle can be mechanically determined as the maximum tilt position of the throttle lever 2, it cannot be determined uniformly because it differs for each vehicle due to an error in the assembling work of the combine. Therefore, if the value of the throttle position sensor 7 does not change at the time of outputting the throttle opening command signal, it is more reasonable to determine the throttle upper limit value at which the throttle valve cannot be opened any more for each model. . Thus, the throttle upper limit value is the tilt position of the throttle lever when the value of the throttle position sensor 7 does not change despite the output of the throttle opening command signal. The tilt position of the throttle lever 2 detected by the throttle position sensor 7 is stored in the microcomputer 5 and is set as a throttle upper limit value in vehicle speed control at the time of overload.

In this case, for example, if an operator performs an operation to close the throttle valve even though the microcomputer 5 has issued a throttle opening command signal, the manual operation has priority, and the throttle valve has priority over automatic control. Close. As a result, when the manual operation is performed, the rotation speed of the engine decreases even though the throttle opening command signal of the microcomputer 5 is issued, and the throttle lever 2 when the throttle valve is manually closed is reduced. The microcomputer 5 stores the tilt position as the throttle upper limit value.

Thereafter, the throttle lever 2 does not become larger than the erroneously stored throttle upper limit value by the automatic control. However, when the throttle position sensor 7 detects that the tilt has been manually erroneously increased more than the stored value, the storage of the throttle upper limit value up to now is canceled, and the microcomputer 5 sets the newly detected position as the throttle upper limit value and sets the throttle position as the throttle upper limit value. Remember. By this update work, it is possible to automatically control with the throttle upper limit value higher than the lower throttle upper limit value erroneously stored,
The engine speed can be increased as before. As a result, the number of rotations of the engine does not reach the rated number of rotations, and the number of operations by automatic control to reduce the vehicle speed unnecessarily is reduced, thereby preventing a delay in the harvesting operation due to the reduction in the vehicle speed.

When the engine speed does not increase even though the microcomputer 5 has issued the throttle opening command signal for a predetermined time, the microcomputer 5 operates the HST deceleration relay 13 to reduce the vehicle speed. By performing the control, the vehicle speed can be automatically controlled without providing the means for storing the throttle upper limit value as described above.

FIG. 3 shows a hydraulic circuit for crawler control of the combine according to the present invention. A proportional pressure reducing valve 15 which is a constant pressure reducing valve for changing the oil pressure via a filter is connected to a pump 14 for sending hydraulic oil. The proportional pressure reducing valve 15 changes the solenoid current by manual operation to change the oil pressure on the output side. Further, this hydraulic circuit is connected to the left and right cylinders 1 through a directional control valve 16 for controlling the direction in which the hydraulic pressure is applied.
7, 18 are connected. Reference numeral 19 denotes a direction switching valve for returning the hydraulic oil to the tank 20, and is connected to the pump 14 in parallel.

The directional control valve 1 is operated by manually operating the proportional pressure reducing valve 15 to change the hydraulic pressure of the hydraulic oil.
The hydraulic pressure of the right and left cylinders 17 and 18 is changed through the cylinder 6, and the rotation and stop of the crawler 3 are controlled by connecting and disconnecting the clutch by the cylinders 17 and 18. The direction control valve 16 controls which of the left and right cylinders is to be subjected to hydraulic pressure.
When hydraulic pressure is applied to 7, the clutch is disengaged, the power transmission of the left crawler is cut off, and the combine turns significantly to the left. Further, when the hydraulic pressure of the left cylinder 17 is increased by increasing the current value of the proportional pressure reducing valve solenoid, the brake is applied, the rotation of the left crawler is stopped, and the combine turns slightly to the left. Conversely, when the hydraulic pressure of the right cylinder 18 is changed, the braking of the right crawler is controlled as in the case of the left crawler.

Thus, current detecting means for detecting a current flowing through the coil of the proportional pressure reducing valve is provided, and a difference between the current value detected by the current detecting means and a set current value is obtained to change the coil current value of the proportional pressure reducing valve. The current value correction means
The correct pressure is applied to the left and right cylinders irrespective of the change in temperature, so operations such as connecting and disconnecting the clutch are performed reliably, the crawler moves correctly according to the operator's operation, and the combine operates safely. FIG. 2 is a block diagram illustrating a device configuration of an embodiment of the clutch hydraulic pressure control device. The clutch hydraulic pressure control device of the present invention includes a coil current detection sensor 23 as a proportional pressure reducing valve coil current detecting means for detecting a coil current of the proportional pressure reducing valve 15 at the input interface 22 of the microcomputer 21, and rotation / stop of the left and right crawlers. Angle detection sensor 24 and direction control sensor 25 for detecting the operation angle of power steering lever 1 performing the operation of
And a left solenoid 27 and a right solenoid 28 of the direction control valve 16 and a proportional pressure reducing valve solenoid 29 of the proportional pressure reducing valve 15 are connected to the output interface 26. And
Since the coil current flowing through the proportional pressure reducing valve solenoid 29 fluctuates due to a temperature change, as shown in FIG. 5, the microcomputer compares the actual current value of the coil current of the proportional pressure reducing valve with the set current value, and The on-time correction is controlled so that the current value of the coil current of FIG. Accordingly, the hydraulic pressure generated by the proportional pressure reducing valve 15 is not affected by the temperature change, and the crawler is correctly controlled in response to the operation of the power steering lever by the operator.

In the above case, the current value of the coil current of the proportional pressure-reducing valve 15 is fluctuating manually during the operation of the power steering lever 1, for example, in which the left and right braking outputs fluctuate. Do not adjust the time. That is, while the value of the operation angle detection sensor 24 fluctuates, the on-time correction of the current value by the automatic control is not performed. Then, when the current value at which neither the left direction output nor the right direction output is output is stabilized, the current value is measured several times, the average value is calculated, and the on-time correction is performed according to the average value. Thereby, the correction of the coil current of the proportional pressure reducing valve is completed before the braking output, and an accurate braking force of the crawler can be obtained.

Further, as shown in FIG. 6, a standard line curve (solid line) showing a set current value at a certain on-time.
And a curve (dotted line) of an actual measurement line indicating the actual value of the coil current of the proportional pressure reducing valve has a certain correlation. Thus, the actual current value I1 'at the on-time T1, the set current value I1 at this time, the set current value I0 at the on-time T0, and the actual current value I0' are: IO ': I0 =
I1 ': I1. From this equation, the rate of change between the set current value and the detected measured current value is the same at any time, so that the on-time correction at a certain on-time is corrected in accordance with the above-mentioned constant rate, By performing the control while comparing the values, the number of feedbacks can be reduced and the correction can be performed quickly.

On the other hand, when the temperature of the proportional pressure reducing valve solenoid 29 rises for some reason and the detected actual current value greatly deviates from a certain range or cannot be accurately measured, on-time correction is performed. Since the correction value cannot be corrected with a normal value or a correct correction value cannot be obtained, the microcomputer 21 controls the on-time correction not to be performed in this case. As a result, it is possible to avoid a danger in operation caused by an abnormally large correction of the hydraulic pressure of the hydraulic oil for braking the crawler or an abnormally small correction of the hydraulic pressure.

[0022]

According to the present invention, as described above, the means for resetting the stored upper limit value when the value of the throttle position sensor becomes larger than the upper limit value and storing the newly increased value is provided. In addition, there is an effect that the overload can be eliminated and the harvesting and threshing operation can be performed smoothly without unnecessarily lowering the vehicle speed.

[Brief description of the drawings]

FIG. 1 is a side view showing an entire self-removing combine according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a device configuration of an embodiment of a throttle upper limit position setting device.

FIG. 3 is a hydraulic circuit diagram for crawler control.

FIG. 4 is a block diagram showing a device configuration of an embodiment of the clutch hydraulic pressure control device.

FIG. 5 is a block diagram showing a procedure of on-time correction of a current value of a proportional pressure reducing valve.

FIG. 6 is a diagram showing a state of a change between a set current value of a proportional pressure reducing valve and an actual current value at a certain on-time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power steering lever 2 Throttle lever 3 Crawler 5 Microcomputer 7 Throttle position sensor 15 Proportional pressure reducing valve 23 Coil current detection sensor

Claims (1)

(57) [Claims] When a throttle valve is automatically opened and closed to maintain the engine speed of a combine engine at a predetermined value, the opening operation of the throttle valve is stopped even though a throttle opening command signal of a controller is output. The tilt position of the throttle lever at the time of the release is stored as a throttle upper limit value, and when the throttle valve is opened to the throttle upper limit value and opened to the throttle upper limit value, this is detected by a throttle position sensor and the vehicle speed is automatically reduced to thereby reduce the engine speed. In the automatic vehicle speed control mechanism of the combine that eliminates the overload of the throttle position, a throttle position comparison determination means for comparing the detected value of the throttle position sensor with the throttle upper limit value already stored is provided.
If the comparison and determination means determines that the value of the actual throttle position is larger than the already stored throttle upper limit value, reset means for resetting the already stored throttle upper limit value is provided. A throttle upper limit value setting device comprising upper limit value updating means for storing a larger value as a new throttle upper limit value.