JPH11168935A - Reaping height controller of combine harvester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reaping height controller of a combine harvester properly using results of detection by an ultrasonic sensor and a ground contact type reaping height sensor and further employing a noncontact type sensor device and a ground contact type sensor device in combination. SOLUTION: This reaping height controller of a combine harvester is capable of judging whether or not a reflected wave from an ultrasonic sensor is returned (S4) during the reaping height control, making a decision about whether or not the reflected wave is present (S4: yes) or the results of detection by the ultrasonic sensor are stabilized by a stability judging means (S5), returning the operation to S3 when the results of detection by the ultrasonic sensor are stabilized (S5: no), performing the reaping height control based on the moving average and, on the other hand, further carrying out the lifting and lowering control of a reaping pretreatment device based on the results of detection by a ground contact type ground height sensor installed at the lower end of the reaping pretreatment device (S6) when the reflected wave is not returned (S4: no) and the results of detection by the ultrasonic sensor are unstable (S5: yes).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type cutting height sensor, and a detection signal of a ground type cutting height sensor. The present invention relates to a technique for automatically adjusting a cutting height from a field scene in consideration of both.

[0002]

2. Description of the Related Art Conventionally, as a cutting height sensor device in this type of combine, Japanese Utility Model Laid-Open Publication No. 51-153227 and Japanese Patent Laid-Open Publication No. 7-274650 disclose the structure of a grounding type cutting height sensor device. ing. On the other hand, JP-A-6-30
No. 0833 discloses a configuration of an ultrasonic non-contact type cutting height sensor device.

[0003]

However, in the grounding-type sensor device, a sensing lever associated with a sensor body such as a limit switch is extended rearward and downward, and a grounding portion (sled portion) is disposed at the rear end. The limit switch was turned on within a certain range of vertical movement of the sled part →
It is only possible to detect the height position where OFF or OFF → ON, and to change and adjust this detected height position,
The only option is to change the length of the sensing lever or to change the installation height of the grounded sensor device, which is extremely troublesome.

On the other hand, an ultrasonic sensor, which is a non-contact type sensor device, can set a wide detection range of the height of the ground relative to a field scene. There is a problem that hunting is easy to sense and lacks stability. Therefore, an object of the present invention is to provide a cutting height control device in a combine using a non-contact type sensor device and a grounding type sensor device in combination.

[0005]

According to a first aspect of the present invention, there is provided a cutting height control device for a combine according to the present invention. A combine configured to be able to move up and down, and configured to drive the up and down driving means up and down by a detection signal of a non-contact type cutting height sensor and a grounding type cutting height sensor for detecting a ground height of the cutting pretreatment device. In the cutting height control device, the non-contact cutting height sensor is provided with a stability determining means for detecting the cutting height, while the ground contact type cutting height sensor is constituted by a displacement meter capable of measuring the amount of elevation of the ground contact portion. When it is determined that the detection result of the non-contact type cutting height sensor is unstable, when it is determined that the detection result of the non-contact type cutting height sensor is unstable, Of the sensor In accordance with the detected value later, which is constituted so as to lift controls the lifting drive means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. FIG. 1 is a side view of a traveling body 1 of a combine having a pair of right and left traveling devices 2 provided with traveling crawlers 2a. FIG. 2 is a plan view of the traveling body 1, and FIG.
FIG. 6 is a side view of a vertical position sensor for detecting a vertical position of the machine body between the cutting pre-processing device and the traveling body, FIG. 6 is a skeleton diagram of power transmission, and FIG. 7 is a functional block diagram of a hydraulic circuit and a control device.

As shown in FIGS. 1 and 2, a threshing device 3 having a conventionally known configuration is mounted on the left side in the traveling direction of the traveling machine body 1, and a single-acting type is mounted on the front of the traveling machine body 1. A cutting pretreatment device 4 that can be moved up and down by a hydraulic cylinder 9 is arranged. A clipper-type cutting blade device 5 is disposed below the lower frame of the pre-cutting device 4, and a grain stem raising device 6 for six rows is disposed in front of the clipping blade device 5. A grain stalk transport device 8 is arranged between the feed chain 3 and the front end of the feed chain 7 for supplying the grain stalk to the grain stalk raising device 6.
In the lower front part of the tree, a weeding body 10 for six rows protrudes. A driver's cab 11 is arranged at the front right side of the traveling machine body 1, and a grain tank 12 is arranged at the rear side. In the cereal stalk transport device 8, the stalk root raised by the cereal stalk raising device 6 is conveyed while pinching the root portion of the cereal stem, and the root portion of the feed chain 7 is inherited by the feed chain 7.

As shown in FIGS. 4 and 5, the base of a vertically downwardly inclined lifting / lowering cylinder frame 14 having a front end attached to a cutting pretreatment device 4 is fixed to a horizontal cylinder 15, and the horizontal cylinder 15 is mounted on a traveling machine body. 1 is rotatably supported by a plurality of bearing brackets 16 (one of which is not shown) provided at a front portion of the vehicle body 1 and receives power from an engine 35 on the traveling machine body 1 in each of the horizontal cylinder 15 and the lifting cylinder frame 14. Transmission shafts 17 and 19 arranged in the inner diameter portion,
Power is transmitted to each part of the pre-cutting device 4 via the bevel gear pair 18 and the like. The lifting pre-processing device 8 is driven up and down by a lifting hydraulic cylinder 9 mounted between the middle part of the lifting cylinder frame 14 and the traveling machine body 1.

As shown in a skeleton diagram (FIG. 6) showing the power transmission system of the combine, one of the outputs from the engine 35 is transmitted to a bottom conveyor 37 and a vertical conveyor 38 in the grain tank 12 via a clutch 36. And then to a screw conveyor (not shown) in the discharge auger 28. The other output from the engine 35 is transmitted via the power branching mission 39 to the handling cylinder drive shaft 40 and the sorting drive shaft 4.
1. A hydraulic pump for traveling The power is transmitted to a drive shaft 43 to a hydraulic motor type (HST type) traveling drive unit 42 and to a constant speed rotation drive shaft 44 to a pre-cutting device 4. The other output from the engine 35 turns ON / OFF the power transmission via the threshing clutch 48a in the power branching mission 39, and the handling cylinder 13 via the handling cylinder drive shaft 40 or the sorting drive shaft 41. And the processing cylinder 29, the first gutter screw conveyor 26 a, Karan Juan, the second gutter screw conveyor 26 b and the second reduction conveyor 25, the straw chain 31,
It is transmitted to the suction fan 30 and the straw cutter 33.

On the other hand, a cutting and tuning drive shaft 45 output from the (HST type) traveling drive unit 42 receives a cutting shaft 47 via a one-way clutch 45a (which can be transmitted only when the traveling drive unit rotates forward) and a tuning clutch 46. Power to
It is transmitted directly to the feed chain 7. The power transmission to the pre-cutting device 4 is turned ON / OFF via a cutting clutch 49 provided on the cutting shaft 47. In order to turn on / off the threshing clutch 48a, the tuning clutch 46, the inflow clutch 48, and the reaping clutch 49, respectively, a clutch actuator such as an electromagnetic solenoid corresponding to each clutch is turned on / off. . The tuning clutch 46 may be a tension clutch that cuts off the power by tensioning and relaxing the tension of the belt. Therefore, as described later, when the vehicle speed tuning control is prohibited (stopped) or the like, power is transmitted to the reaping shaft 47 via the constant-speed rotation drive shaft 44 of the power branching mission 39, and the HST traveling drive unit 42 The one-way clutch 45a idles when the output rotation speed of the cutting synchronization drive shaft 45 is lower than the rotation speed from the constant speed rotation drive shaft 44 or when the cutting synchronization drive shaft 45 rotates in the retreating direction of the combine. .

The swash plate of each hydraulic pump of the traveling drive unit 42 is adjusted by adjusting the swash plate of the HST type (in which a mechanical speed change mechanism is incorporated in a stepless speed change mechanism using two hydraulic motors and two hydraulic pumps). Main shift lever 85 for step shifting
Is a seat 11a in the cab 11 as shown in FIG.
Is turned forward and backward by the side operation unit, and when it is tilted forward with respect to the neutral position (stop position) in a substantially vertical posture, it is the forward position. The larger the inclination angle with respect to the vertical, the higher the vehicle speed. When the vehicle is tilted backward, the vehicle retreats, and the vehicle speed increases as the angle of inclination increases.

A sub-transmission lever 86 also disposed on the side operation portion of the seat 11a controls an actuator such as a transmission motor for operating a mechanical transmission mechanism (not shown) provided in the HST-type traveling drive unit 42. When the sub-transmission lever 86 is switched to each of the road traveling mode, the standard operation mode, and the low-speed operation mode, the microcomputer-based control unit (controller unit) 70 mounted on the combine unit issues a command. The output (horsepower) and the number of revolutions of the traveling drive unit 42 adapted in the work mode can be set and maintained in a predetermined range.

When a normal harvesting and threshing operation is performed while the traveling body 1 is traveling forward (in the low-speed operation mode and the standard operation mode), the power branching mission 39 is used.
OFF (power cutoff) the inflow clutch 48 at
The threshing clutch 48a, the tuning clutch 46, and the reaping clutch 49 are turned on (power connection), and while monitoring the detection values of the fuel injection amount sensor and the vehicle speed sensor, the reaping of the rotational speed tuned to the output of the traveling drive unit 42 is performed. The mowing shaft 47 is driven via the tuning drive shaft 45 to drive the cutting pre-processing device 4 and the feed chain 7 in synchronism, while driving the handling drum drive shaft 40 and the sorting drive shaft 41 to handle the handling drum 11 and the processing drum 2.
9, the blower fan, the Karaoke fan 27, the swing sorting mechanism 15 and the like are driven.

Further, when the traveling body is to be turned or retreated in the course of harvesting and threshing work in the field, when the traveling body 1 is stopped or retracted, and when the drive of the pre-cutting device 4 and the feed chain 7 is stopped. The tuning clutch 46 and the inflow clutch 48 are turned off. To drive only the feed chain 7, the reaping clutch 49 must be turned off.
Change to F. In this case, power is not transmitted to the pre-cutting device 4, but is transmitted only from the power branching mission 39 to the feed chain 7 via the cutting shaft 47.

An ultrasonic sensor 20 as a non-contact type of cutting height sensor for detecting the cutting height by detecting the height of the ground between the cutting pre-processing device 4 and the field scene is located on the side close to the cab 11. Is arranged on a bracket (not shown) provided on the back side of the grain stalk raising device 6, and the transmitting part (horn part) of the transmitter 20 a and the receiving part of the receiver 20 b in the ultrasonic sensor 20 are arranged in a field scene. Place it so that it faces. Ultrasonic sensor 20
When the installation height of the cutting blade 5 is different from the installation height of the cutting blade 5, the detection value of the cutting height is obtained by a predetermined conversion from the detection value of the ultrasonic sensor 20.

Next, the configuration of the grounding type cutting height sensor 90 will be described with reference to FIGS. In the present embodiment, among the plurality of weeding bodies 10 protruding from the lower front end of the pre-cutting device 4, the location of the rotary weeding body 10a disposed at the rightmost end in the forward direction (FIG. 2). And FIG. 3) is provided with a ground-type cutting height sensor 90, and the other weeding bodies 10 are fixed to the lower frame 4a and the like. The ground contact type cutting height sensor 90 includes a sled body 91 which is always in contact with the field scene, and a displacement gauge 92 such as a rotary encoder which detects an amount of vertical movement of the sled body 91 with respect to a reference position such as a horizontal line.

A mounting bracket 93 on the back side of a weeding plate 93 having a substantially triangular shape in a front view of the rotary weeding body 10a.
A slidable body 91 of the field scene 100 which can be slid and contacted is fixed to a. Further, the mounting bracket 93a and a horizontal portion 95a, which is a front portion of the interlocking arm 95, are connected via a pivot pin 96 behind the sled body 91. And the horizontal part 95a
The bracket 97 erected from the bottom is fixed to a bolt 99 through an arcuate groove 98 formed in the mounting bracket 93a, so that the vertical inclination of the weeding board 93 can be adjusted. As shown in FIG. 8, the proximal end of the interlocking arm 95 has a short horizontal portion 95a close to the field scene 100, and is inclined rearward and upward from the horizontal portion 95a to be a pivot shaft 101 serving as a rotation fulcrum. The length of the inclined portion extending in the direction is set to be large.

The pivot shaft 101 is rotatably supported by a support frame 102 attached to the lower frame 4a of the pre-cutting device 4. The pivot shaft 101 and a fitted cylindrical portion 95c at the base of an interlocking arm 95 are provided. And are vertically rotatably supported via a key 103. The displacement meter 92 attached to the support frame 102 is configured to detect the rotation angle of the pivot 101 and the vertical movement of the sled body 91 with respect to the reference height.

The sled body 91 is always urged downward by an urging spring such as a torsion spring (not shown). Further, in order to regulate the lower limit position when the tip end side of the sled body 91 rotates downward due to its own weight of the weeding board 93, the sled body 91, the interlocking arm 95, and the like, and to change the position, the regulating pieces are bolts and nuts. There is provided a suspension type regulating means 104 which can be executed by position adjustment. In a normal case, the height position of the sled body 91 in the rotary-type weeding body 10a is set to be a position lower by an appropriate dimension (a reference height position) than the fixed-type weeding body 10,
The ground contact is made to the field scene 100 earlier than the fixed type herbaceous body 10, and the ground contact state is adjusted so as to be detected.

Therefore, in the displacement meter 92, the reference height position of the sled body 91 (the height position at which the sled body 91 is stationary below due to its own weight or the like, where the field scene 100 is not in contact with the sled body 91). ) Can be measured, in other words, the amount of pushing up from the field scene 100 or the pushing up strength can be measured. When a linear potentiometer (differential transformer method) is used as the displacement meter, a configuration is employed in which a sensor rod for moving the linear potentiometer forward and backward is pressed against an arm for increasing the amount of rotation of the pivot 101. .

The elevation position sensor 22 is for detecting the relative height between the traveling machine body 1 and the pre-cutting device 4, and in the present embodiment, as shown in FIGS. The rotation arm 23 of the rotation position sensor 22 of the rotation potentiometer type fixed to the bearing bracket 16 is brought into contact with a sensor shaft 24 fixed to the outer surface of the horizontal cylinder 15 to detect the rotation angle θ of the horizontal cylinder 15. Thereby, the rotation angle of the elevating cylinder frame 14 and, consequently, the relative elevating position of the pre-cutting device 4 with respect to the traveling machine 1 (the elevating position of the machine body) can be detected. The value set by the cutting height setting unit 73, which will be described later,
It corresponds to a predetermined value in the detected value of 0.

FIG. 7 shows a functional block diagram of a control device 70 for executing the cutting height control.
An electronic control device such as a microcomputer, not shown, a central processing unit (CPU) for executing various arithmetic processing and control, a read-only memory (ROM) storing a control program, various detected values, Read / write memory (RAM) for temporarily storing data etc.,
A nonvolatile memory (flash memory) for holding stored data even when the power of the control device is turned off, a clock as a timer function, an interface, a bus, and the like are provided.

An ultrasonic wave is transmitted to the transmitter 20a of the ultrasonic sensor 20 at an appropriate time interval T1 through a transmission drive circuit 71 in accordance with a command from the control device 70, and a reflected wave reflected from an object or the like is reflected. Is received by the receiver 20b, and the detection signal is input to the control device 70 via the reception amplifier circuit 72. The detection signal of the displacement meter 92 in the elevation position sensor 22 and the grounding-type cutting height sensor 90 is also input to the control device 70 via the A / D converter at each time interval T1.

A variable resistance type (volume type) cutting height setting device 73, a three-position detection type manual switch 76 for performing the harvesting and threshing operation in a manual mode, and an automatic operation for setting the same operation to an automatic control mode. In order to change the lifting amount and / or the lifting speed of the pre-cutting device 4 to a smaller side when the manual operation is performed by the switch 75, each signal of the foot switch 74 which is turned on and off by the operator by the foot is also controlled. It is input to the device 70. A display unit such as a liquid crystal panel operated by an output from the control device 70 is provided on an operation panel unit which can be viewed by an operator sitting on a seat in the cab 11 so that the cutting height detection value of the ultrasonic sensor 20 can be displayed as a numerical value. is set up.

The control device 70 outputs a predetermined elevating command signal to the first driving circuit 77 and the second driving circuit 78 in accordance with a predetermined calculation result, and responds to the output from the first driving circuit 77. To operate the electromagnetic solenoids 80a and 80b of the hydraulic switching valve 80 in the hydraulic circuit 79, while operating the electromagnetic solenoid 50a of the electromagnetic proportional pressure reducing valve 50 which is an example of a high-speed response electromagnetic valve in response to the output from the second drive circuit 78. Thus, the single-acting hydraulic cylinder 9 for raising and lowering the pre-cutting device 4 is operated.

In the hydraulic circuit 79 shown in FIG. 7, a pair of left and right rolling control hydraulic cylinders for controlling the relative left and right vehicle heights of the single-acting lifting hydraulic cylinder 9 and the right and left traveling devices 3 and the traveling body 1 are provided. Pressure oil is also supplied to a hydraulic control valve 51 and the like (not shown). In this case, the hydraulic circuit 79
A relief valve 54 is inserted in the oil supply passage 53 from the hydraulic pump 52 to the hydraulic switching valve 49. A check valve 55 and a slow return check valve 56 are connected in the middle of the hydraulic pipe from the output port of the 4-port 3-position switching electromagnetic hydraulic switching valve 80 to the single-acting hydraulic cylinder 9. The hydraulic switching valve 80
The other output ports are configured to supply oil to the other hydraulic control valves 51 at the same time.

A return throttle pipe 57 connected between the check valve 55 of the hydraulic pipe and the slow return check valve 56 has a variable throttle valve 58 for lowering the piston rod of the single-acting hydraulic cylinder 9 and an emergency lowering valve 59. And are connected in parallel. The variable throttle valve 58 is a two-port two-position switching type valve.
The pilot port has one of the aforementioned high-speed response solenoid valves.
The output port of the electromagnetic proportional pressure reducing valve 50 is connected as an example.

The operation control of the lifting hydraulic cylinder 9 of the pre-cutting device 4 is executed as follows. That is, when the hydraulic hydraulic pressure switching valve 80 is switched to extend the hydraulic cylinder 9 (when the pre-cutting device 4 is driven upward).
, The electromagnetic solenoid 80a is controlled by pulse width modulation (PW
M), the pilot pressure appropriately adjusted to the hydraulic pressure by the electromagnetic proportional pressure reducing valve 50 acts on the variable throttle valve 58, the degree of throttle of the variable throttle valve 58 is arbitrarily changed, and the return oil pipe 57 is connected to the oil tank. Drained to 60. In that case,
The operating speed of the hydraulic cylinder 9 is adjusted according to the degree of throttle of the variable throttle valve 58.

When the hydraulic cylinder 9 is reduced (when the pre-cutting device 4 is driven downward), the hydraulic switching valve 80 is set to neutral, and the electromagnetic proportional pressure reducing valve 50 is controlled in the same manner as described above. The operation is performed by a PWM (PWM) method, and the throttle opening of the variable throttle valve 58 is adjusted by adjusting the pilot pressure, whereby the operating speed of the hydraulic cylinder 9 is adjusted.

Next, the cutting height control of the present invention will be described. The cutting height setting unit 73 for determining the target cutting height set value Hsm may be an analog type such as a variable resistor,
It may be a digital type. In the first embodiment of the present invention, when raising and lowering the cutting pre-processing device 4 based on the detection value of the ultrasonic sensor 20 so as to approach the target cutting height set value Hsm, it is shown in the main flowchart of FIG. Thus, following the start of the control, the target cutting height set value Hsm is read in S1, and the ultrasonic sensor 20 is read in S2.
Then, a plurality of cutting height detection values Hsx are read and stored in a memory (RAM), and then at S3, cutting height control based on a so-called moving average value is executed. That is, as shown in FIG. 8, the ultrasonic sensor 20 sampled every ΔT1
Extraction of multiple cutting height detection values Hsx (input and storage)
Then, the arithmetic unit of the control device 70 calculates the average value. When the next average value is obtained, a moving average value is obtained by sequentially extracting newly extracted detection values that are older by the number of additionally input cutting height detection values. This moving average value is set at a preset cutting height (a target cutting height set value Hs).
m) is determined to be out of the range of ± ΔHf (dead zone width), and if the target cutting height set value Hsm is deviated from the range of the dead zone ± ΔHf, the pre-cutting processing is performed. When the moving average value Him is within the dead zone width, the cutting height control based on the moving average value Him is performed, in which the raising and lowering of the cutting pre-processing device 4 is not performed (S3). .

Then, during the cutting height control, it is determined whether or not the reflected wave from the ultrasonic sensor 20 has returned (S4). If there is a reflected wave (S4: yes), stability determination means to be described later is used. It is determined whether the detection result of the ultrasonic sensor 20 is stable or not (S5).
When the detection result of 0 is stable (S5: no), S
3, the cutting height control based on the moving average value is executed. In this case, when the deviation between the cutting height setting value and the moving average value is large, the hydraulic cylinder 9
Is increased, the lifting speed of the pre-cutting device 4 is increased, and if the deviation is reduced, the pulse width modulation control (PW
The driving speed of the hydraulic cylinder 9 is reduced by the M) method, and the vertical movement speed of the pre-cutting device 4 is reduced to enable fine adjustment of the cutting height.

On the other hand, when the reflected wave does not return (S4:
no) and if the detection result of the ultrasonic sensor 20 is unstable (S5: yes), the detection result of the grounding type ground height sensor 90 provided at the lower end of the pre-cutting device 4 is prioritized and the pre-cutting process is performed. The device 4 is moved up and down (S6). If the detection result of the grounding type ground height sensor 90 is used, it is possible to reliably prevent the lower end (tip) of the pre-cutting device 4 from sticking into the ground.

The stability determination means for determining whether the cutting height detection result of the ultrasonic sensor 20 is unstable or stable,
A control program (FIG. 11) stored in the control device 70 in advance
(Refer to the subroutine flowchart shown in (1)). In this subroutine flowchart, following the start, initial values of Lc = 0, tc = 0, and Z = 0 are set (S10). Here, Lc is the cutting height travel distance of the combine (in millimeters), tc is the duration of the phenomenon described below (in milliseconds), and Z is the number of occurrences of the phenomenon described below. A plurality of cut height detection values Hsx after the start of the harvesting and threshing work of the combine are read (S11). Next, a moving average value calculation is executed (S12). Then, the first one of the calculated moving average values Him is stored in the memory (RAM) as the reference value Hstao (S13).

Next, it is determined whether or not the subsequently calculated moving average value Him has increased or decreased with respect to the (initial) reference value Hstao by a predetermined variation amount ΔHi or more (S14).
When | Hsta−Him | ≧ ΔHi, that is, the moving average value Him is a predetermined variation Δ with respect to the reference value Hstao.
If it has increased or decreased more than Hi (S14: yes), then it is determined whether or not the fluctuation state has continued for a predetermined time tco or more (S15). This is shown in FIG.

When the above two conditions are satisfied (S1
4: yes, and S15: yes), the reference value is updated and stored (S16). That is, the updated reference value Hsta
Is the cutting height detection value Hsx of the ultrasonic sensor 20 immediately after satisfying the above two conditions (S14: yes and S15: yes). Then, the updated reference value Hsta is compared with the target cutting height set value Hsm, and the cutting height control in S3 is executed (S17). Each time this state occurs, Z is incremented by one (S19). When the number Z is equal to or more than the predetermined number Zo (S20: yes)
), Measurement distance Lc is set value Lo (unit: millimeter,
When it is within the range of 200 mm to 400 mm in the embodiment (S21: yes), it is determined that the detection result of the ultrasonic sensor 20 is unstable (flag P = 1) (S2).
2). In other conditions, the detection result is stable (flag P = 0) (S23).

That is, the combine is at a predetermined distance (set value L
o) When the reference value Hsta is updated more than the number of times Zo during traveling, the latest moving average value Him is updated when the moving average value changes in a simple increasing trend as shown in FIG. 12, for example. Based on the deviation between the updated reference value Hsta and the target cutting height set value Hsm,
When this deviation is large, when the cutting height control of increasing the elevation control speed of the pre-cutting device is executed, the descending speed of the pre-cutting device is sequentially increased, and the lower end of the pre-cutting device 4 may be pushed into the field scene. Will be higher. Therefore, the above state is defined as unstable, and the cutting height detection value Hsx of the ultrasonic sensor 20 immediately after the predetermined time tco is updated to the reference value Hs.
sta.

When the fluctuation state does not continue for the predetermined time tco or longer (S15: no), the moving average value H (calculated latest) is set as the updated reference value Hsta.
im is adopted (S18). When the height of the ultrasonic sensor 20 above the ground is high, irregularities in the field, undergrowth (weeds), irregular reflection of ultrasonic waves by straw chips, and the like increase, the fluctuation of the moving average value increases. Such a state is caused by the ultrasonic sensor 2
The detection result of 0 is called unstable.

When such an unstable state is determined,
As another embodiment, the automatic raising and lowering control of the pre-cutting device 4 is interrupted, and the set position (the height position of the pre-cutting device 4) immediately before the unstable state is maintained for a certain period of time. You may do it. In this case, in order to notify the operator of the interruption (stop) of the automatic lifting / lowering control, control is performed to activate a notification means such as sounding of an alarm buzzer and blinking of an alarm lamp.

When the operator confirms the operation of this notifying means and lowers the target cutting height set value Hsm of the cutting height setting device 73, the height of the ultrasonic sensor 20 above the ground is also reduced, and the ultrasonic sensor 20 The probability that the detection result becomes stable increases. Further, if the auto set button is pressed, the automatic elevating control using the original target cutting height set value Hsm as a reference value is restarted from the beginning.

In each case, the ultrasonic sensor 20
It is preferable to continue to determine whether the detection result is stable or unstable, and to return to the normal automatic elevating control when it is determined that the detection result is stable. As another example, when the detection result of the ultrasonic sensor 20 is determined to be unstable,
As the target cutting height set value is larger, the number of samples for the moving average (or time for sampling) is increased, or the width of the dead zone for raising and lowering control of the above-described pre-cutting device 4 is increased. Control may be performed.

As described above, when the detection result of the ultrasonic sensor 20 is unstable, the sled 91 travels while sliding on the field scene 100, and the displacement meter measures the lower end of the field scene 100 and the cutting preprocessing device 4. And the cutting height (the cutting blade 5
And the height of the field scene 100)
If the pre-cutting device 4 is controlled to move up and down, there is no danger that the lower end of the pre-cutting device 4 will plunge into the field scene 100.

Next, a description will be given of a mode of lifting control of the pre-cutting device 4 in the manual mode. Manual switch 7
The operation lever 76a is tiltable back and forth and is urged to automatically return to a neutral position. While the operation lever 76a is tilted forward, a predetermined elevating speed Vo (for example, the electromagnetic solenoid is continuously excited) (Operating speed in the state), and continues to rise at a predetermined elevating speed Vo while tilting backward.

In the manual mode, as a fine adjustment switching means for finely raising and lowering the raising and lowering speed of the pre-cutting device 4 at the fine speed V2 lower than the predetermined speed Vo, ON / OFF of the foot switch 74 is used. As shown in FIG. 8, a step-up petal 87 projects upward from a floor plate below the left front side of the seat 11a. A pouring petal 88 for turning on / off the pouring clutch 48 is disposed so as to protrude from a floor plate below the round handle 89.

When the foot switch 74 is ON,
That is, assuming that the operator operates the fine adjustment switching means, when the depressed petal 87 is depressed, the mowing pre-processing device 4 is raised or lowered at the slow speed V2 only during the depression (the raising or lowering is performed manually. Switch 76
Corresponding to the raised position or the lowered position). The very low speed V2 is executed by operating the hydraulic cylinder 9 by the pulse width modulation control (PWM) method.

During a few hundred milliseconds after the manual switch 76 is turned on to the descending side, the direct drive in the descending direction by the solenoid valve 58 is prohibited, and the flow rate is controlled by the pulse width modulation control (PWM) method. Then, when the manual switch 76 remains ON on the descending side, the continuous descending drive is executed. Similarly, for several hundred milliseconds after the manual switch 76 is turned on to the ascending side, direct drive in the ascending direction by the solenoid valve 58 is prohibited, and pulse width modulation control (PWM) is performed.
When the manual switch 76 is kept ON on the ascending side after that, the fine ascending is executed by the flow control in the method, and the continuous ascending drive is executed.

[0046]

As described above, the cutting height control device in the combine according to the first aspect of the present invention is configured such that the cutting pretreatment device can be raised and lowered with respect to the front portion of the traveling machine body by the lifting drive means. Cutting height control in a combine configured to drive the elevating drive unit up and down by a detection signal of a non-contact type cutting height sensor and a grounding type cutting height sensor for detecting the ground height of the cutting pre-processing device. In the device,
The non-contact type cutting height sensor comprises a non-contact type cutting height sensor, and the ground contact type cutting height sensor comprises a displacement meter capable of measuring an amount of elevation of a ground contact portion. When the detection result of the contact sensor is determined to be unstable, it is determined that the detection result of the non-contact type cutting height sensor is unstable. Accordingly, the elevation drive means is configured to perform elevation control.

Therefore, when the detection result of the non-contact type cutting height sensor such as the ultrasonic sensor is unstable, the value of the field scene and the value before the cutting are determined by the detection value of the contact type cutting height sensor which is in direct contact with the field scene. If the pre-cutting device is controlled to move up and down based on the height of the lower end of the processing device and, consequently, the cutting height, the contact of the lower end of the pre-cutting device is not likely to plunge into the field scene. This has the effect of compensating for the instability of the detection result of the cutting height sensor.

[Brief description of the drawings]

FIG. 1 is a side view of a combine.

FIG. 2 is a plan view of the combine.

FIG. 3 is a front view of the combine.

FIG. 4 is a side view showing a mounting position of a position sensor.

FIG. 5 is a plan view showing a mounting position of a position sensor.

FIG. 6 is a skeleton diagram of a power transmission system.

FIG. 7 is a functional block diagram of a hydraulic circuit and control means.

FIG. 8 is a side view of the grounding type sensor.

FIG. 9 is a partially cutaway front view taken along line IX-IX of FIG. 8;

FIG. 10 is a main flowchart of cutting height control.

FIG. 11 is a flowchart of determining whether the cutting height is stable or unstable.

FIG. 12 is a diagram showing an unstable state of a cutting height detection result.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling body 4 Cutting pretreatment device 9 Elevating hydraulic cylinder 4a Lower frame 10 Weeding body 10a Rotating weeding body 20 Ultrasonic sensor 70 Control unit 73 Cutting height setting device 90 Grounding cutting height sensor 91 Sledge body 92 Displacement meter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Taiji Mizukura 1-32 Chaya-cho, Kita-ku, Osaka-shi Yanmar Agricultural Machinery Co., Ltd. Inside

Claims (1)

[Claims] 1. A non-contact type cutting height sensor for detecting a height of the pre-cutting device with respect to the ground, wherein the cutting pre-processing device is configured to be able to move up and down with respect to a front portion of a traveling machine body by a lifting drive means. A cutting height control device in a combine which is configured to drive the lifting drive unit up and down by a detection signal of a cutting height sensor, comprising: a non-contact type cutting height sensor for determining stability of cutting height detection, The contact type cutting height sensor is constituted by a displacement meter capable of measuring the amount of elevation of the contact portion, and when the detection result of the non-contact type cutting height sensor is determined to be unstable, the contact type cutting height is determined. A cutting height control device for a combine, wherein the lifting drive unit is controlled to move up and down in accordance with a value detected by a height sensor.