JPS644723B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a ground height detection sensor in a reaping pre-processing section connected to a traveling machine body so as to be able to be driven up and down, and raises and lowers the reaping processing section based on the detection result of this sensor. The grain culm is equipped with an automatic lifting control mechanism for maintaining a target height above the ground arbitrarily set by a cutting height setting means, and a manual lifting switch that operates preferentially with respect to the sensor, and the grain culm is provided in the pre-harvesting processing section. The present invention relates to a cutting height control device for a combine harvester configured to operate the automatic elevation control mechanism only when a presence/absence detection sensor detects the presence of a grain culm. Conventionally, in such a cutting height control device, it has been considered to set the raising and lowering speed of the cutting pre-processing section as follows. Set the lifting speed during automatic control to be slower than that during manual operation. The area where the height of the pre-reaping treatment section from the ground is lower than the preset height is the automatic control operation area, and the area higher than this is the non-automatic control area, and the vertical speed of the automatic control operation area is that of the non-automatic control area. Set it to a slower speed. Both of the above methods are designed to suppress hunting and provide stable control during automatic operation, and to enable rapid lifting and lowering during manual operation. When adjusting the elevation, a manual elevation switch or the like must be operated by inching, which is difficult for an unskilled person. In addition, in the case of the latter, the lifting speed is set depending on the height of the pre-reaping processing section, and the speed is always low at a low position (within the automatic control operating range), so it is easy to make fine adjustments even when adjusting manually. It has its advantages, but when it comes to the headland after one stroke of reaping and when the pre-reaping section is manually raised to turn the machine, it only rises at a slow speed up to a certain height, and it does not rise sufficiently. There was a risk that it would turn around and get caught on a stump. The purpose of the present invention is to solve this problem, and in the cutting height control device having the above-mentioned configuration, the height of the cutting pre-processing section above the ground is set in advance in order to set the range in which the cutting height is to be controlled. The area lower than the set height is set as the automatic control operating area, and the area higher than this set height is set as the non-automatic control area, and when the grain culm presence/absence detection sensor detects the presence of grain culms, the reaping In both manual and automatic control for raising and lowering the pre-treatment section, the raising and lowering speeds of the reaping pre-treatment section in an area lower than the set height are set to be lower than those in the area above the set height. However, in a state where the grain culm presence/absence detection sensor does not detect the presence of grain culms, the raising speed of the reaping pre-processing section is increased in the entire area, and the raising speed of the reaping pre-processing section is increased in the area lower than the set height. The characteristic configuration is that the descending speed of the area is set to be lower than that of the area above the set height. In other words, during the reaping operation when the grain culm is introduced into the pre-reaping processing section, the above-mentioned method is used, which enables stable control with less hunting, and
If you want to temporarily change the cutting height manually from the target height during automatic operation, you can finely adjust it at low speed. As the raising can be done at high speed over the entire area, it is possible to manually raise quickly and turn immediately without touching the stump. Moreover, when the next cutting starts after going to the headland, the pre-cutting processing section is at high speed. While the position is in the non-automatic control range, it descends at high speed, and when it enters the low-position automatic control operating range, the speed decreases, making it possible to stably approach the target cutting height. In other words, by rationally combining the judgment of whether or not reaping work is in progress and the switching of the lifting speed, we were able to achieve stable automatic control and improve the operability of manual lifting adjustment at the headland or at the beginning of cutting. be. Embodiments of the present invention will be described below based on the drawings. FIG. 1 shows the front part of the combine harvester, and the front part of the traveling machine body 4 is equipped with a crawler traveling device 1, a threshing device 2, and a control section 3. A frame 9 of a reaping pre-processing section 8 equipped with a device 7 and the like is connected to be able to swing vertically around a fulcrum P, and is connected to a hydraulic cylinder 10.
It is configured to be driven up and down by. The reaping pre-processing section 8 can be manually raised and lowered as desired, and can also be automatically maintained at a set cutting height.The configuration thereof will be explained below. FIG. 2 shows an outline of the elevating control mechanism of the reaping pre-processing section, in which the electromagnetic control valve 11 that controls the operation of the hydraulic cylinder 10 is placed in the ascending control position when the transistor Tu is energized, or is in the descending control position when the transistor Td is energized. position, such that both transistors Tu, Td are held in a neutral lock position in a de-energized state. A ground height detection sensor 12 consisting of an ultrasonic transmitter and a receiver is provided above the reaping device 6 of the reaping pre-processing section 8 , and transmits a signal toward the ground at regular intervals. The reception time of the ultrasonic waves is detected, and the measurement circuit 13 calculates and measures this to obtain the height h above the ground. The detected height h above the ground is then input to the first and second subtractors 14 and 15, and the deviation from the target cutting height H from the cutting height setting device 16 consisting of a variable resistor is calculated. height h
is lower than the target height H, the deviation is the first
It is taken out as the output of the subtractor 14, and the detected height h
is higher than the target height H, the deviation is the second
It is taken out as the output from the subtractor 15. The outputs of each subtractor 14, 15 are input to comparison/discrimination circuits 17, 18, respectively, and compared with the output from dead zone setter 19. Only when the output of each subtracter 14, 15 is larger than the dead zone setting value, "High" output is taken out from each discrimination circuit 17, 18, and each "high"
The output becomes a rise control signal and a fall control signal. In other words, the vertical setting range (△
h) is defined as a dead zone, the area below it is a rise control area, and the area above it is a fall control area. Further, the detected height h is inputted to a third comparison/discrimination circuit 20, and is compared with an output indicating the value of the set height _H0 from a setter 21 for setting a cutting height control range,
While the detected height h is lower than this set height Ho, a "high" output is output from the discrimination circuit 20, and the detected height h
is configured such that the output of the discrimination circuit 20 becomes "low" when the height becomes higher than the set height Ho, and the "high" output of the discrimination circuit 20 causes the intermittent signal generator 2 to
2 is now activated. The set height Ho is set to a value higher than the cutting height used for normal work, and therefore the target height H is arbitrarily adjusted within a range lower than the set height Ho. Further, a switch 23 for manual lifting is provided near the control section 3, and a switch 24 is provided at the bottom of the lifting device 5, which is closed by contact with the base of the planted grain culm introduced. , is provided as a grain culm presence/absence detecting sensor, and both of these switches 23 and 24 are incorporated into a logic circuit as shown in FIG. In FIG. 2, the symbol An is an AND circuit, Rn is an OR circuit, and I is an inverter. The present invention is constructed as described above.
Next, the elevating and lowering operations in various modes will be explained. (A) Automatic elevation control during reaping work In this case, both the up contact u and the down contact d of the manual switch 23 are opened, and the grain culm presence/absence detection switch 24 is closed. Therefore, AND circuits _A5 to _A9 are inactive. Furthermore, since the detection height h is lower than the set height Ho, the intermittent signal generator 22 is operating. (a-) Neutral state When the detection height h is within the dead zone, the outputs of the first and second comparison and discrimination circuits 17 and 18 are both "low", and the AND circuits A ₁ to A ₄ and the OR circuit R ₁ and _R2 are all stopped, and the reaping pre-processing section 8 is in a state where the vertical movement is stopped. (a-) Ascent control When the detected height h falls below the dead zone, only the output of the comparison/discrimination circuit 17 becomes "high" and the output of the AND circuit _A1 becomes "high". and,
Only when the output of the intermittent signal generation circuit 22 is "high", the output of the AND circuit _A3 becomes "high",
As a result, the first transistor Tu is intermittently energized to drive the control valve 11, and the reaping pre-processing section 8 is intermittently controlled to rise until the detected height h enters the dead zone. (a-) Lowering operation When the detection height h exceeds the dead zone, only the output of the comparison/discrimination circuit ₁₈ becomes " _high ", and the _second transistor Td is It is energized intermittently, and intermittent lowering control is performed by lowering its own weight. (B) Manual lifting and lowering during reaping work Switch 2 during reaping work under automatic control
If you switch to 3, you can preferentially move up and down. (b-) When the lift switch 23 is switched to the lift contact u in the area lower than the set height Ho,
Since one input of the AND circuit A ₅ is "high" and the other input is switched to "high-low" by the output from the intermittent signal generation circuit 22, the OR circuit R ₁ operates intermittently and becomes an intermittent rising operation. . Mata switch 2
When the contact 3 is switched to the lowering contact d, the AND circuit _A6 similarly operates intermittently, and the lowering operation is performed intermittently. (b-) Lifting and lowering in the area above the set height Ho In this case, the output of the comparison discrimination circuit 20 is "low" and the intermittent signal generation circuit 22 is also inactive, so the switch 23 is set to the rising contact u. When switched, the output of the AND circuit A ₇ will be "high" continuously, so that a continuous raising operation, ie a faster raising compared to an intermittent raising, will occur. Also, the switch 23 is at the lowering contact d
When switched to , the AND circuit _A8 continuously becomes a "high" output, and a continuous downward operation is performed. (C) Lifting and lowering during non-reaping work In this case, since the grain culm presence/absence detection sensor 24 is open, both AND circuits A ₁ and A ₂ have a "low" output, and the automatic cutting height control operation is checked. It operates only by a command from the manual switch 23. (c-) When the rising operation switch 23 is switched to the rising contact u,
AND circuit A ₉ has a "high" output and a continuous rise is performed. This raising operation is performed continuously in the entire lifting range, regardless of the area divided by the set height Ho. Therefore, when one stroke of reaping travel is completed and the machine reaches the headland, the above-mentioned automatic control is checked and prevented, and if the switch 23 is operated to ascend, the aircraft will ascend at a high speed (compared to the automatic control), and the aircraft will immediately start moving. Even when turning, the lower part of the pre-reaping treatment section 8 will not get caught on the stump. (c-) Lowering operation Switch 2 is activated in the area above the set height Ho.
When the lowering operation according to 3 is performed, the above (b-)
As explained in the section above, the AND circuit _A8 continuously outputs a "high" output, and a continuous fall occurs. Furthermore, if the lowering operation is performed using the switch 23 in an area lower than the set height Ho, the above-mentioned (b-
), the output of the AND circuit A ₆ is intermittently switched between "high and low" and is intermittently lowered. Therefore, at the beginning of the first cutting in the field or at the start of the next process after going to the headland, the lowering by the switch 23 before the grain culm has been introduced into the pre-harvesting treatment section is performed at the set height Ho. It is possible to rapidly lower it continuously up to that point, and then lower it intermittently at a low speed after that, making it easy to lower it to approximately the target height H before reaching automatic control. In the above embodiment, a non-contact type height sensor is used as the ground height sensor, but a contact type sensor capable of analog detection may also be used. In addition, when using a contact type on/off type sensor, the height of the reaping pre-processing section 8 relative to the traveling machine body 4 is detected in order to detect whether the cutting height is lower than or equal to the set height Ho. It is necessary to take In addition to the continuous lifting and intermittent lifting methods, the lifting speed can be switched by using two types of intermittent signals with the same period but different ON times, or by using two types of intermittent signals with the same ON time and different cycles. Various modifications are possible, such as a method in which the absolute lifting speed itself is changed by switching the amount of oil supplied and discharged from the hydraulic cylinder 10. Note that 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]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cutting height control device for a combine harvester according to the present invention is shown, with FIG. 1 being a side view showing the front part of the combine, and FIG. 2 being a schematic configuration diagram of the control mechanism. 4... Traveling machine body, 8 ... Reaping pre-processing section, 12...
...Ground height detection sensor, 23...Manual lifting switch, 24...Grain culm presence/absence detection sensor, h...Detection height, H...Target height, Ho...Setting height.

Claims (1)

[Claims] 1. A ground height detection sensor 12 is provided in the pre-reaping processing section 8 which is connected to the traveling machine body 4 so as to be able to be driven up and down, and based on the detection result of this sensor 12, the reaping processing section 8 is raised and lowered, and the cutting height setting means Equipped with an automatic lift control mechanism for maintaining an arbitrarily set target height H above the ground, and a manual lift switch 23 configured to operate with priority over the automatic lift control based on the detection result of the sensor 12, and A cutting height control device for a combine harvester configured to operate the automatic elevation control mechanism only when a grain culm presence/absence detection sensor 24 provided in a pre-harvesting processing section 8 detects the presence of a grain culm, Height above ground h of processing unit 8
In order to set the cutting height control range, an area lower than a set height Ho set in advance is set as an automatic control operation area, and an area higher than this set height Ho is set as a non-automatic control area. In a state where the culm presence/absence detection sensor 24 detects the presence of a grain culm, both manual and automatic control for raising and lowering the pre-harvesting processing section 8 prevents the pre-harvesting within a region lower than the set height _H0 . setting the ascending and descending speeds of the processing section 8 to be slower than those in the area above the set height Ho;
In a state where the grain culm presence/absence detection sensor 24 does not detect the presence of grain culms, the reaping pre-processing section 8 in the entire area
The rising speed of the pre-reaping processing unit 8 is set to a high speed, and the descending speed of the reaping pre-processing section 8 in an area lower than the set height Ho is set to be lower than that in an area above the set height Ho. Cutting height control device for combine harvesters.