JPS6340918A - Driving device for actuator - Google Patents

Abstract

PURPOSE:To operate a member to be operated, as desired, by increasing a driving time per unit time of a control valve, in case a detected position by a sensor is not varied. CONSTITUTION:A sensor 6 for detecting an operating position of a reaping part 2 operated by an actuator 7 of a fluid pressure type is provided, and a control valve 11 of the actuator 7 is driven intermittently by controlling a driving time per unit time, based on detected information by the sensor 6, so that operating speed of the reaping part 2 becomes lower as it approaches a target position H0. Also, in case detected ground height by the sensor 6 for detecting an operating position of the reaping part 2 is not varied, even if a solenoid valve 11 is driven, in a state that a flow rate of an operating fluid to the actuator 7 has been reduced, the driving time per unit time of solenoid valve 11 is increased automatically.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a sensor for detecting the operating position of an operated member operated by a fluid pressure actuator, and the operating speed of the operated member is adjusted to a target level. The present invention relates to an actuator drive device configured to drive a control valve of the actuator intermittently while adjusting drive time per unit time based on information detected by the sensor so that the drive speed becomes slower as the sensor approaches the position.

[Conventional technology]

The drive device for this type of actuator described above detects the height above the ground that is the operating position of the reaping section as an operated member, for example, in order to maintain the height above the ground of the reaping section of the combine at a set height. This is used as a means for controlling the operation of a control valve of a hydraulic cylinder, which is a fluid pressure actuator that raises and lowers the reaping section, based on the information detected by the sensor for detecting the height. When raising and lowering the reaping section, if the actual height of the reaping section is far from the target position π, the reaping section is raised and lowered at high speed, and when it is close to the target position, it is raised and lowered at a low speed. Thus, in order to both speed up the control response and prevent overshoot near the target position, the control valve is driven intermittently while adjusting the driving time per unit time. .

[Problem that the invention seeks to solve]

By the way, if the above-mentioned combine harvester is used as an example, the pump for the hydraulic actuator will be driven by an engine that supplies power to each part of the combine harvester. However, since this engine simultaneously drives various parts of the combine, such as the reaping device, the threshing device, and the crawler traveling device, the output fluctuates in response to load fluctuations.

Therefore, when the engine output decreases in a state where the driving time of the control valve per unit time is short, that is, in a state where the operating speed of the operated member is slowed down, the control valve is driven to raise the reaping section, for example. However, there is a possibility that the hydraulic cylinder may not operate and the reaping section may not be raised as desired. In addition, even if the output of the engine is not low, the drive time per unit time may be reduced even if foreign matter such as field mud or straw is attached to the cutting section and its own weight increases. If the distance is short, there is a possibility that the reaping section cannot be raised as desired.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a fluid pressure actuator that is controlled to slow down its operating speed in a range where the operating position of the operated member is close to the target position. , to prevent it from malfunctioning.

[Means for solving problems]

The characteristic configuration of the actuator drive device according to the present invention is as follows:
Even if the control valve is driven, if there is no change in the position detected by the sensor, a driving time correction means is provided that increases the driving time per unit time of the control valve, and its operation and effects are as follows. It is as follows.

[Created/Used]

In other words, even if the control valve is driven to change the operating position of the operated member, if the detection position of the sensor that detects the operating position of the operated member does not change, the driving time of the control valve per unit time is This increases the flow rate of the working fluid supplied to the actuator.

〔Effect of the invention〕

Therefore, even if the operating fluid supply pressure to the control valve decreases or the load on the actuator becomes heavy and the operated member stops moving, the control valve will automatically increase the drive time per unit time. Since the correction is made, it has become possible to operate the operated member as desired.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a cutting height control means for automatically raising and lowering the cutting part of a combine harvester to maintain the cutting height at a set cutting height will be described based on the drawings. .

As shown in Figure 5, the planted stem culms of rice, wheat, etc. in the field are raised and harvested, and while the harvested stem culms are being conveyed, the posture is changed to a sideways posture, and the threshing feed chain (1) is reaped. The passing reaping section (2) and the threshing feed chain (1
A threshing device (3) that threshes the stem culms that are pinched and conveyed by the wheels (3) and sorts and collects the grains is combined with a pair of left and right crawler traveling devices (4).
), (4) is installed on the aircraft (V) equipped with.

An ultrasonic sensor (6) as a sensor for detecting the height above the ground (H) as an operating position of the reaping section (2) as the operated member is provided at the tip of the reaping section (2). It is provided on the back of the weeding tool (5).

The ultrasonic sensor (6) includes a transmitter (6a) that transmits ultrasonic waves toward the ground, and a transmitter (6a) that transmits ultrasonic waves toward the ground.
6a) includes a receiving section (6b) that receives the reflected waves of the ultrasonic waves reflected by the ground, and measures the elapsed time from the point of transmitting the ultrasonic waves to the point of receiving the ultrasonic waves.
It is configured to detect the height above the ground (11), that is, the operating position of the reaping section (2).

To explain the structure of the mechanism for adjusting the height of the reaping section (2) above the ground, as shown in FIGS. The reaping part (2) is pivoted around the core (P) so as to be able to swing freely, and is operated by a hydraulic cylinder (7) serving as a fluid pressure actuator.
The height above the ground is adjusted by swinging the entire unit around the horizontal axis (P).

The configuration for adjusting the flow rate of working fluid to the hydraulic cylinder (7) will be explained as shown in FIG.
The hydraulic cylinder (7) is extended to open the reaping section (2).
), the first solenoid valve (10) that adjusts the flow rate of hydraulic oil sent from the hydraulic pump (9) driven by the engine (E) and the hydraulic cylinder (7) are expanded and contracted. Two solenoid valves are provided, a second solenoid valve (11) for adjusting the flow rate when the reaping part (2) is lowered.

However, the first solenoid valve (10) is always ON when the reaping section (2) is raised, and is always OFF when lowered.
F, and only the second electromagnetic valve (11) is intermittently driven to reduce the flow of hydraulic fluid to the hydraulic cylinder (7). This is to adjust Affl. That is, when the reaping part (2) is at its upper limit, the second solenoid valve (11) is driven intermittently while the first solenoid valve (10) is always kept in the ON state. ), the extension speed of the hydraulic cylinder (7) is adjusted, and the first solenoid valve (10) is always maintained in the FF state when descending. At the same time, the expansion and contraction speed of the hydraulic cylinder (7) can be adjusted by intermittently driving the second solenoid valve (11) and adjusting the flow rate of the hydraulic oil discharged through the second solenoid valve (11). Adjust it.

When the reaping section (2) is raised and lowered, the target height above the ground (11°) set by a potentiometer (1?) serving as a target mowing height setting means and the ultrasonic sensor (6) are set. The detection height above the ground (I) is compared so that the larger the deviation, the faster the vertical speed of the reaping section (2), and the smaller the deviation, the slower the vertical speed of the reaping section (2).
Based on the deviation between the target height above the ground (1°) and the detected height above the ground H), the first solenoid valve (10) is turned on.
The second solenoid valve (11) is configured to control 08 hours per unit time of the second solenoid valve (11).

However, the detection height above the ground by the ultrasonic sensor (6) is H.
) is lower than the target ground height +10), and in order to extend the hydraulic cylinder (7), the solenoid valve (10),
If the detected height above the ground 11) does not change even after driving (11), the driving time per unit time of the second solenoid valve (11), that is, 08 hours, is automatically increased from the set value. Then, the driving time should be corrected.

Next, while explaining the operation of the control device (8) based on the flowchart shown in FIG.
0), (11) to automatically adjust the cutting height, and a drive time correction means (A) to correct the drive time per unit time of the second solenoid valve (11). The configuration of is explained in detail.

That is, the control device (8) controls the ultrasonic sensor (
The detected height above ground 11) obtained in 6) is repeatedly read at predetermined time intervals, and compared with the target height above ground Ho), it is determined that the detected height above ground H) is the target height above ground ■. ).

When the detected height above the ground H) is higher than the target height above the ground Ho), as shown in Fig. 3, the descending speed becomes faster as the deviation (h) from the target height above the ground +1°) becomes larger. In addition, the first
While maintaining the solenoid valve (10) in the OFF state, the second solenoid valve (11) is operated for 08 hours (1+) per unit time.
~(+5) is made to be sequentially shortened in five steps according to the deviation (h), and the cutting part (2) at the beginning of cutting etc.
The height above the ground is larger than the target height above the ground (Ho) (when the reaping section (2) is continuously lowered when it is far away from the top, the reaping section (2) reaches the target height above the ground Ho). It is designed to descend in a short period of time and to reduce the shock when it stops descending. However, 08 hours is approximately 15
When the driving time is less than ma, the second solenoid valve (11)
Since it becomes difficult for the 0N10 FF to follow the drive signal, the flow rate per writing time is reduced by fixing the 08 time to 15 ms and gradually increasing the OFF time.

On the other hand, the detected height above the ground 1 is the target height above the ground +10
), as shown in FIG. Based on the table below, the second solenoid valve is adjusted so that the rising speed of the reaping section (2) with a small deviation (h) is slowed down at a speed corresponding to the zone. (11) The ON time is automatically set. However, the zone where the deviation (h) is less than or equal to the setting (i (Ul) closest to the target height above the ground Ho) is set as a control refractory zone, and the deviation (h)
h) is below this set value (Ul), both electromagnetic valves (10
) and (11) are to be stopped.

However, when the deviation (h) from the target ground height Ho) is in the small zone (υ1~UZ), the second solenoid valve (always ON) is
11) If the detected height above the ground (H) does not change even after driving 11), the driving time is changed to the driving time (ON=40+na) when the deviation (h) is one step lower.

OFF-=lQms), thereby forming a driving time correction means (A).

That is, the deviation (h) is in the first zone (U+~U2)
If so, the state of a flag for determining whether or not the first solenoid valve (10) is driven is determined, and if this flag is set, the second solenoid valve (11) is driven. After the set time (Td) has elapsed, it is determined whether or not the set time (Td) has elapsed, and if the set time (Td) has not elapsed and the flag is not set, after setting the flag,
Drive with the set drive time based on the table above. On the other hand, if the flag is set and the set time (Td) has elapsed, the hydraulic cylinder (7 ) has not operated, and the second solenoid valve (11
), the deviation (h) is the driving time of the first zone (U, ~
The second zone (U, ~[13
).

Therefore, even if the solenoid valve (11) that operates the hydraulic cylinder (7) is driven when the flow rate of the working fluid to the hydraulic cylinder (7) is restricted, the sensor detects the operating position of the operated member. If the height above the ground (I) detected by the ultrasonic sensor (6) does not change, the solenoid valve (11)
The drive time per unit time will be automatically increased.

[Another example]

In the above embodiment, the driving time per unit time of the second electromagnetic valve (11) is corrected only when the reaping section (2) is raised, but also when the reaping section (2) is lowered. It may be configured to correct. Also, rising
In either case, the correction may be sequentially changed over multiple stages.

Furthermore, in the above embodiment, two solenoid valves, the ascending solenoid valve (10) and the descending solenoid valve (11), are used, and the descending solenoid valve (11) is configured to be driven intermittently. However, for example, it may be configured using a single solenoid valve that can be freely switched to three positions: ascending, descending, and stopping (the specific configuration of the control valve for expanding and contracting the hydraulic cylinder (7) may vary). Can be changed.

Further, in the above embodiments, the case where the present invention is applied to a cutting height control means in a combine harvester is illustrated, but the present invention can be applied to various devices using a fluid pressure actuator, and is limited only to the above embodiments. It's not a thing.

[Brief explanation of drawings]

The drawings show an embodiment of the actuator drive device according to the present invention, FIG. 1 is a block diagram showing the configuration of the control system, FIG. 2 is a flow chart showing the operation of the control device, and FIG.
The figure is an explanatory diagram showing the change in operating speed when the reaping part is lowered.
The figure is an explanatory diagram of the deviation from the target ground height when the reaping part is above the limit, and FIG. 5 is a front side view of the combine harvester. (2)...Operated member, (6)...Sensor, (7)...Actuator, (11)...
...Control valve, (A) ...Driving time correction means.

Claims (1)

[Claims] A sensor (6) is provided to detect the operating position of the operated member (2) operated by the fluid pressure actuator (7), and the operating speed of the operated member (2) is adjusted to the target position (II).
The control valve (11) of the actuator (7) is driven intermittently while adjusting the driving time per unit time based on the information detected by the sensor (6) so that the speed becomes slower as it approaches _0). In the case where there is no change in the position detected by the sensor (6) even if the control valve (11) is driven,
An actuator drive device comprising drive time correction means (A) for increasing the drive time per unit time of the control valve (11).