JPH0974816A - Plowing depth control for electronic governor-type tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deal with such unfavorableness that, when a plowing depth control is to be made by the rear cover sensor of a rotary tilting device in a tractor, the control goes into no actuation in case the rear cover is embedded in soil in e.g. an ill-drained paddy field. SOLUTION: This plowing depth control is made by using an engine load detective means in an electronic governor, and in case the rate of load is high, it is judged that the tractor stands in a deep-plowing state, and a hydraulic: lift is controlled for rising. In this constitution, a rack position sensor RS is used as the engine load detective means and a controller is divided into an engine controller EC and a hydraulic lift controller LC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to tillage depth control in a tractor of a type in which an electronic governor controls speed of an engine.

[0002]

2. Description of the Related Art A tractor for towing an agricultural working machine such as a tilling device has a lift angle corresponding to the plowing depth when the plowing depth is set to a certain plowing depth, as shown in JP-A-63-123305. It keeps a hydraulic lift while traveling to perform plowing work. However, if the tractor tilts due to the tilting of the tiller or the like, the hydraulic lift angle held at the set angle causes a deviation from the actual target working depth. At this time, the plowing depth control detects the deviation from the working depth set by the working machine, corrects the hydraulic lift angle, and controls the working machine to reach the target working depth. With the recent demand for high-speed work, it is desired that the plowing depth control be performed more accurately and quickly.

Conventionally, the working means for detecting the working depth control has been attached to a working machine, and in the case of a rotary tilling device, it has become publicly known that it is attached to a rear cover as disclosed in JP-A-6-141606. There is.

[0004]

However, when the working depth detecting means is provided on the working machine side, particularly in the case of the rear cover of the rotary tiller, the rear cover sinks into the mud during the tilling work in the wetland. However, at this time, the sensor does not work, and in the end, the rear cover will cultivate in a deeper cultivated state than the sinking target cultivating depth, and it will not be possible to cultivate evenly and deep cultivating. The area marked with is in an unsuitable field condition for growing seedlings whose surface is hardened. The present invention provides a device capable of leveling tillage control even during tillage work in a wet field.

The present invention uses the following means in order to solve the above problems. That is, in the tractor in which the electronic governor controls the engine speed as described in claim 1, the plowing depth control is performed using the load detection means of the engine control controller.

In the tractor for controlling the working depth by using the engine load detecting means of the electronic governor as described in claim 2, a rack position sensor is used as the engine load detecting means.

Further, in the tractor for controlling the working depth using the engine load detecting means of the electronic governor, the controller of the electronic governor is divided into one for engine control and one for hydraulic lift control.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of a tractor showing an arrangement configuration of respective members related to an electronic governor and a working depth control mechanism, FIG. 2 is a block diagram of an engine control and a working depth control mechanism of the electronic governor, and FIG. 3 is an engine control block of the electronic governor. Figure,
FIG. 4 is an engine control flowchart for the electronic governor, FIG. 5 is a tilling depth control flowchart for detecting the engine load of the electronic governor, and FIG. 6 is a tilling depth control flowchart for detecting the engine load of the electronic governor and the rear cover angle.

The structures of the engine control mechanism and the working depth control mechanism based on the electronic governor of the present invention will be described with reference to FIGS. 1 to 3. First, the arrangement structure in the tractor of each part related to the engine control mechanism in the electronic governor will be described with reference to FIG. An engine E, which is a diesel engine, is installed inside the hood of the tractor, and a fuel injection pump P is attached to the engine E. The fuel injection pump P is internally provided with a rack for adjusting speed (a rack R described later), a rack position sensor RS for detecting the rack position is additionally provided, and a fuel tuned to the engine speed is attached. An engine speed sensor ES for detecting the speed of the plunger drive shaft of the injection pump P is additionally provided.

Further, an accelerator lever AL is arranged in the front column formed at the rear of the bonnet,
An accelerator sensor AS for detecting the operation angle of the accelerator lever AL is provided inside the front column. An engine control controller EC is arranged at the forefront of the hood.

The engine control mechanism in the electrified governor will be described with reference to FIGS. 2 and 3. As the detecting means, an accelerator sensor AS, which is a detecting means of a target set rotational speed,
An engine speed sensor ES for detecting an actual engine speed, and a rack position sensor R for detecting a rack position which is an actuator for controlling the actual fuel injection amount.
S, and these detection signals are input to the engine control controller EC to drive and control the solenoid S (which may be the motor M), which is an actuator for driving the rack R shown in FIG. 3, to detect the accelerator sensor AS. The actual engine speed is held at the target engine speed to be set.

Conventionally, an accelerator sensor AS and an engine speed sensor E have been used as detection means for engine speed control.
Using S and S, the actual engine speed detected by the engine speed sensor ES is controlled to approach the engine speed set by the accelerator sensor AS. In the present invention, by further providing the rack position sensor RS, the actual fuel injection amount can be detected, and by using this, more accurate and speedy control of the fuel injection amount, that is, speed control can be performed. It has become.

Next, the arrangement and linkage structure of each part for controlling the working depth will be described with reference to FIGS. 1 and 2. A hydraulic lift L that is raised and lowered by electromagnetic valve control is provided at the rear of the tractor so as to project rearward, and a working machine such as the rotary tiller R shown in FIG. 1 is towed by the hydraulic lift L. As a controller for transmitting a control signal to this electromagnetic valve to control the hydraulic lift L up and down, the hydraulic lift controller L is used.
C is installed inside the tractor body on the side of the driver's seat separately from the engine control controller EC. In addition to the lifting / lowering electromagnetic valve of the hydraulic lift L, an electromagnetic valve for controlling the left / right inclination of the hydraulic lift L is also provided, which can be used to horizontally control the working machine. This is also controlled by the hydraulic lift controller LC, and therefore, the hydraulic lift controller LC can perform lifting control and horizontal control of the working machine.

As the control mode relating to the elevation control, in addition to the plowing depth control according to the present invention, control for raising the working machine during turning (this control is performed when turning mode switch SW4 is turned on), and There are controls such as raising the working machine when the vehicle is moving backward (this control is performed when the back switch SW5 is turned on).

As the input means in the working depth control according to the present invention, first, a working depth setting dial D for setting the working depth is provided. A lift angle sensor LS, which detects the angle of the hydraulic lift L, is provided near the rotation axis of the hydraulic lift L as a detection unit for controlling the working depth, and the rear cover R of the rotary tiller R is also provided.
The "a" is provided with a detection unit that synchronizes with the inclination of the rear cover Ra, and a rear cover sensor CS that detects the inclination angle of the rear cover Ra by detecting the movement of the detection unit is provided at the rear portion of the tractor body. There is. Furthermore, the height of the rotary in the rotary tiller R,
That is, a position sensor PS for detecting the actual working depth is provided in the tractor body.
The rotary tiller R is connected to a detecting means provided in the rotary so that the cultivation depth can be detected.

In the working depth control of the present invention, a working depth control mechanism based on engine load detection is provided, assuming that the rear cover sensor CS does not work. That is, it is the plowing depth control for performing the elevation control of the hydraulic lift L using the accelerator sensor AS, which is the detection sensor of the electronic governor, the engine speed sensor ES, the rack position sensor RS, and the lift angle sensor LS as the detection means. Load tillage depth control setting switch SW2 for selecting to perform tillage depth control (load tillage depth control) by this electronic governor
And the rear cover sensor C described above.
Combined with the plowing depth control based on the detection of S, the rear cover R is placed in an area where the rear cover sensor CS does not work, that is, in the dead zone.
A mixed tillage depth control SW3 is provided for selecting to perform load tillage depth control only when a is located.

As described above, although the tilling depth control mechanism by the electronic governor is provided, as shown in FIGS. 1 and 2, the engine control controller EC and the hydraulic lift controller LS are separate. When a failure occurs in the control mechanism related to the hydraulic lift system, only the hydraulic lift controller LC needs to be replaced, and the failure does not affect the engine control system. On the contrary, even if a failure occurs in the engine control system, the hydraulic lift controller LC can be left as it is. That is, between the engine control system and the hydraulic lift control system, either of the failures is prevented from affecting one side,
This contributes to improved maintainability and cost reduction.

In the structure in which the engine control controller EC and the hydraulic lift controller LC are separated as described above, the control signal transmitted from the engine control controller EC to the hydraulic lift controller LC is for controlling the engine. Electronic governor detection means (accelerator sensor AS, engine speed sensor E
S, the rack position sensor RS), the load factor (the ratio of the actual engine speed to the set engine speed detected by the accelerator sensor AS) V _L is transmitted as a load factor signal. It is used for such plowing depth control.

In addition to the control of the working depth, the vehicle travels as the hydraulic lift L moves up and down, such as deceleration at the time of turning, deceleration at the working depth, and speed control accompanying the operation of the hydraulic lift switch SW1. The speed is controlled, and the turning signal S _S , the back signal S _B , and the engine speed increase / decrease signal S _UD based on the operation of the hydraulic lift switch SW1 are transmitted from the hydraulic lift control controller LS. .

Next, the flow of engine control and plowing depth control will be described with reference to FIGS. 4 to 6. First, the load factor V _{L of the} engine control system, which is the detection value in the tilling depth control by the electronic governor.
Calculation of will be described with reference to FIG. In this engine control system, partition values a and b (a <b) of the load factor are set as a guide for load factor detection. Then, first, the detected value N _RS in the rack position sensor _RS is the maximum value MA.
It is detected whether or not it is X, that is, whether or not the fuel injection amount is the limit, and if it does not reach the maximum value, it is considered that the engine output has a margin and the load is light, and the input for the plowing depth control is set. The load factor V _L as means is uniformly B%
(For example, 70%) is set. It can be said that this is a state in which the rotary tiller R is only being towed or is being cultivated smoothly with an extremely slight tilling load.

Then, the detected value N_RSHas reached the maximum value
If so, the engine speed detected by the accelerator sensor AS
Turn setting N_ESETAnd the actual engine speed N_ECompare with
Then, the load factor is detected. In this case, use the previous
The partition values a and b described above are used. First, the actual speed N
_EIs the set speed N_ESETIf a% or less of (N_E≦ N_{ES ET}
Xa / 100) indicates that the actual rotation speed is lower than the set rotation speed.
Very low load above the limit that can control the rotation speed
Load factor V_LIs 100%.
And the actual rotation speed N_EIs a little faster than that N
_ESETClose to, but N_ESETB% or less of (N_ESET× a /
100 <N_E≦ N_ESET× b / 100), a little load
As a high state, the load factor V_LTo A% (eg 90%)
It is set. Furthermore, the actual speed N_EIs the set speed N
_ESETHigher than b% of (N_E> N _ESETXb / 100)
If so, it means that the engine E is rotating at about the set speed.
Then, as described above, the load factor V_LB% (for example 70
%).

The value of the load factor V _L thus calculated by the engine control controller EC is transmitted to the hydraulic lift controller LC as a load factor signal as described above. As described above, the load factor V _l is 100%.
Alternatively, when it is 90%, it is considered that the rotary tilling apparatus R is depressed and the tilling load is increased.
Based on such a determination, when the load factor V _L has such a value, the hydraulic lift controller LC calculates the hydraulic lift correction value V _L 'for controlling the working depth. 5 and 6, the flow of the tilling depth control will be described based on this.

In FIG. 5, the load plowing depth control switch S described above is used.
It shows a case where W2 is turned on to perform the plowing depth control based on the load factor signal from the engine control controller EC of the electronic governor, and the turning on of the load plowing depth control switch SW2 indicates that the mixed plowing depth will be described later. ON of control switch SW3
Is selected as an alternative. Load tillage depth control switch S
If W2 is OFF and the later-described mixed tilling depth control switch SW3 is also OFF, tilling depth control based on the rear cover sensor CS is performed. When the moisturizing property of the field is low and there is not much concern that the rotary tiller R will sink, the control by the rear cover sensor CS can also handle it.

In FIG. 5, assuming that the load control switch SW2 is turned on, first, the detection value V _S of the position sensor PS indicating the actual tilling depth of the rotary tiller R is set to the tilling depth setting dial D. It is determined below the set value V _r , that is, whether it is deep, and if deep, the plowing depth control is performed. In addition, above the plowing depth set value V _r ,
That is, when it is shallow, position control is performed.

In the working depth control, in order to avoid the extremely small lifting control of the hydraulic lift L in the vicinity of the set working depth, a certain working depth width is set as a dead zone up and down from the set working depth, and within the dead zone, The hydraulic lift L is kept stopped. The dead zone value c (> 0) is the width from the plowing depth set value V _r to the upper and lower dead zone boundaries, and V _P is the actual lift angle value detected by the lift angle sensor LS. When the hydraulic lift L is the highest, the actual lift angle value V _P is the minimum (MIN),
When the actual lift angle value V _P is maximum (MAX) at the lowest position (that is, when the lower side is +), if the working depth set value V _r is not corrected, V _r − c ≦ V _P
When ≦ V _r + c, the hydraulic lift L stops, and V _r + c <V
When the _P, increase control the hydraulic lift L, when the V _r -c> V _P, lowered control the hydraulic lift L.

In the working depth control shown in FIG. 5,
Based on the load factor signal transmitted from the engine control controller EC, tilling depth correction value to calculate the V _L 'of the set value V _r, hydraulic lift L of the lift match the height tilling depth of the target value V _r + V _L '(The lower part is +, V _L '<0 or V
_L '≧ 0). For a certain tilling depth, the engine load commensurate with the tilling depth, that is, the load factor is determined. If the actual load factor is higher than the set tilling depth, the deep tilling state will be more than necessary. Is set to V _r + V _L ′ (V _L ′ <0), the target value of plowing depth is corrected above the set value of plowing depth. Further, if the actual load factor is lower than the set load factor corresponding to the set plowing depth, it is determined that the shallow plowing state is more than necessary, and the plowing depth target value is set to V _r +.
Set V _L '(V _L '> 0), and correct below the plowing depth set value.

Thus, based on the load factor signal, the working depth target
The value is the plowing depth setting value V_rTo V_r+ V _LMove to '
And the dead zone moves with it. That is, the above-mentioned working depth
Set value V_rSimilarly to, the working depth target value V_r+ V_L'
A dead zone having a dead zone value of ± c is defined around This
Based on this, the above-mentioned plowing depth set value V_rAnd for
Similarly, V_r+ V_L'+ C <V_PWhen the hydraulic lift L
Lift control, V_r+ V_L'-C> V_PWhen the hydraulic lift L
To lower the V_r+ V_L'-C≤V_P≤
V_r+ V_L'+ C stops the hydraulic lift L
You.

Next, the mixed plowing depth control of FIG. 6 will be described. This is to control the cultivation depth control and the load cultivation depth control by the rear cover sensor CS in a mixed manner, and is performed when the mixed cultivation depth control switch SW3 is turned on. (As described above, the load tilling depth control switch SW2 is OFF at this time.) The load tilling depth control is performed only when the load factor is high, that is, when the deep tilling state is more than necessary.

In FIG. 6, in addition to the plowing depth set value V _r , the lift angle sensor value V _P , and the dead zone value c, the rear cover sensor value is V _d . Mix plowing control SW3 O
Assuming N, first, load factor detection in the engine controller is used to detect whether the load factor _VL is greater than a constant value C (%) that is a reference value for load factor tillage depth control. If V _L > C, the load factor is quite high,
It is judged that the condition is deeper than necessary. Also, V _L ≤C
Even if this is the case, it is detected whether or not this lasts for a fixed time t (seconds), and if the duration is t or less, it is similarly determined that the state is in a deep plowing state in which the engine load is applied more than necessary.

Next, in order to determine whether or not the rear cover sensor CS can control the working depth, the difference between the working depth set value V _r and the rear cover sensor value V _d is compared (both V _r and V _d are + And). If the rear cover sensor CS is functioning, the actual working depth and the rear cover sensor CS have a fixed relationship, and the engine load does not become excessive. However, when the rear cover Ra submerges in soil such as a wetland and the rear cover sensor CS behaves as if it were the actual plowing depth, the difference between the plowing depth set value V _r and the rear cover sensor value V _d enters the dead zone. Despite being
Since the actual tillage depth is deep, the load becomes excessive. As a criterion for this judgment, when the difference between the two exceeds a certain value Δθ (| V
_d− V _r |> Δθ), the normal rear cover sensor CS described below is used for plowing depth control, and if it is within a certain value Δθ, the lift angle correction value β is calculated based on the load factor signal, The target lift angle is V _P '(= V _P + Δθ). In this way, the hydraulic lift L is raised until the actual lift angle value V _P falls within the dead zone of the target lift angle value V _P ′.

On the other hand, when the load factor V _L ≤C (%) and the state continues for t hours or longer, _VL > C and the load factor is high, but | V _d −V _r |> Δθ Then, if it is determined that the rear cover sensor CS is functioning,
Cultivation depth is controlled by the rear cover sensor CS. That is,
The plowing depth set value V _r and the rear cover sensor value V _d are compared, and when the distance between them is larger than the dead zone value c,
If the plowing depth setting value V _r is larger than the rear cover sensor value V _d , the hydraulic lift L is raised, if it is smaller, the hydraulic lift L is lowered, and if the difference between them is within the dead zone value c, the hydraulic lift L is set. It will stop.

In the working depth control, the rear cover sensor CS which directly detects the working depth of the working machine is a load based on the judgment that the working machine is in the deep working condition jointly due to the increased engine load. More accurate than plowing depth control. Therefore, if possible, the cultivation depth control by the rear cover sensor CS can maintain a more accurate cultivation depth. In the case of mixed tillage depth control, tillage depth control based on the rear cover sensor CS is performed as long as the rear cover sensor CS functions.
The precision of the tillage depth control is improved in that the load tillage depth control is performed only when the rear cover sensor CS is in the deep tillage state where the function does not work.

[0033]

Since the present invention is configured as described above, it has the following effects. That is, since it is configured as in claim 1, by controlling the hydraulic lift up and down by setting the deep load state when the engine load increases and the shallow load state when the engine load decreases, a rear cover or the like with a rear cover sensor of the rotary tiller is provided. It is possible to control the working depth even when it is buried in the soil of the wetland and does not function as the actual working depth.

Further, as described in claim 2, since the rack position sensor for detecting the rack position for directly adjusting the fuel injection amount of the fuel injection pump is used, the engine load can be detected more accurately and the plow depth control can be performed. The control signal value for is also more accurate, and more accurate plowing depth control can be obtained.

Further, in the control mechanism for controlling the working depth based on the engine load, the controller for controlling the engine and the controller for controlling the hydraulic lift are separate from each other. At the time of failure, the tilling depth control system is not affected by the failure and can be replaced separately, contributing to maintainability and cost reduction.

[Brief description of drawings]

FIG. 1 is a plan view of a tractor showing an arrangement configuration of respective members related to an electronic governor and a working depth control mechanism.

FIG. 2 is a block diagram of an engine control and plowing depth control mechanism of the electronic governor.

FIG. 3 is an engine control block diagram of the electronic governor.

FIG. 4 is a flowchart of engine control by an electronic governor.

FIG. 5 is a flowchart of tilling depth control by detecting an engine load of the electronic governor.

FIG. 6 is a flowchart of tilling depth control by detecting an engine load of an electronic governor and detecting a rear cover angle.

[Explanation of symbols]

 E engine P fuel injection pump L hydraulic lift R rotary tiller Ra rear cover EC engine control controller LS hydraulic lift controller AS accelerator sensor ES engine speed sensor RS rack position sensor CS rear cover sensor D plowing depth setting dial SW2 load plowing depth control Switch SW3 Mix plowing control switch

Claims (3)

[Claims] 1. A tillage depth control for an electronic governor type tractor, wherein the tiller depth control is performed by using a load detecting means of an engine control controller in a tractor that performs engine speed control by an electronic governor. 2. A tillage depth control for an electronic governor type tractor, wherein a rack position sensor is used as the engine load detection means in a tractor for performing tillage depth control using the engine load detection means of the electronic governor. 3. A tractor for controlling tillage depth using engine load detection means of an electronic governor, wherein the controller of the electronic governor is divided into one for engine control and one for hydraulic lift control. Depth control.