JPH09224408A - Work machine lifting control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently operate by eliminating troublesomeness on operation and ascending a working machine comparatively fast even at the time of stoppage in the state of idling or at the time of working and traveling at a very low speed. SOLUTION: The controller is provided with a lift cylinder 10 freely driving and ascending/descending the working machine connected to a machine body, a vehicle speed sensor 28 detecting the traveling speed of the machine body, a revolution/speed detecting means 20 detecting the speed of the revolution of an engine and a governor freely adjusting the speed of the revolution of the engine. Then the controller is provided with a rotating and ascending control means K connecting an ascending/descending lever 41, the revolution speed detecting means 20, the vehicle speed sensor 28 and the governor 40 so as to increase the speed of the revolution of the engine by a prescribed quantity when the working machine is ascending-operated at the time of being in a nearly idling state and traveling at the speed of zero or very slowly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work device connected to a work machine such as a tractor, which is relatively fast even when the vehicle is stopped at idling or when the vehicle is running at a slight speed slightly above the idling speed. The present invention relates to a technique that enables the user to ascend and adjust the height well.

[0002]

2. Description of the Related Art Normally, in a working machine such as a tractor, plow or plowing work is carried out in a state where the accelerator lever is fully operated and the engine is set at the maximum rotation speed (the rotation speed at which the maximum output is generated). For example, as shown in Japanese Unexamined Patent Publication No. 5-292803, even if automatic raising / lowering control is performed to maintain the tilling device at the target plowing depth, it is premised that the engine output has a surplus state by the full accelerator. There is.

[0003]

In the tractor, as described above, the engine speed is raised during the work traveling. However, during warm-up operation immediately after the engine is started, the work equipment is inspected and a short break is performed. Therefore, in a situation such as when traveling in the field is stopped or when moving at an extremely low speed on the side of a private house, the hand accelerator lever is operated to reduce the engine speed to an idling speed or an extremely low speed rotation state close to the idling speed. And in such a situation, the height of the working device is often adjusted, but the pump discharge amount is small in the vicinity of idling, so that the rising speed of the working device is very slow and inefficient. There was a specific aspect.

For example, even if an attempt is made to raise the work device so as to start after the warm-up operation is finished, the work device does not come up easily. In such a case, it is irritated and waits unavoidably, or the hand accelerator lever is operated to rotate the engine speed. There is room for improvement because it is a cumbersome operation of raising the work device to raise the work device quickly, and then operating the hand accelerator lever to a position where the engine speed drops to a value suitable for the subsequent traveling. An object of the present invention is to enable efficient and efficient maneuvering by allowing the work device to move up and down relatively quickly without any inconvenience in operation, such as when stopped in an idling state or when traveling at low speed. There is a point to.

[0005]

[Means for Solving the Problems]

[Configuration] In order to achieve the above object, the present invention provides, in an elevator control device for a work machine, a hydraulic actuator that drives a work device connected to the machine body and is capable of moving up and down, and a vehicle speed detection unit that detects a traveling speed of the machine body. The engine is equipped with an engine speed detecting means capable of detecting the engine speed and an accelerator device capable of adjusting the engine speed.When the idling state and the traveling speed is zero or very low, the work device can be lifted. A raising / lowering operation tool capable of operating the hydraulic actuator, a rotation speed detection means, a vehicle speed detection means, and a rotation increase control means for coordinating the accelerator device are provided so as to increase the engine rotation speed by a predetermined amount when performed. It is characterized by

[Operation] According to the above characteristic configuration, when the working device is raised in the idling state and the traveling speed is zero or very low, the engine speed automatically increases by a predetermined amount. The pump discharge amount increases and the working device rises quickly. For example, when the work device is raised to prepare for start-up during idling immediately after the engine is started in the warehouse, the engine speed increases by, for example, 500 rpm and the work device rises relatively quickly with the raising operation. , The traveling start state is revealed without waiting. Also, when traveling at idling state or at a slightly higher rotation speed,
In other words, when traveling at a very low speed, in the case where the work device is raised to the upper limit and moved to a rapid moving speed, when the work device is raised, the work device rises quickly and the traveling speed also increases, but the predetermined increase in the number of revolutions Is, for example, 4 to 5 km /
It is possible to suppress the increase of the traveling speed to such an extent that the traveling speed is increased to the traveling speed of h within a low speed range where there is no practical problem. That is, even when the engine speed is low, if the traveling speed is low, the work device can be quickly raised by simply performing the raising operation.

[Effect] As a result, the running state at low speed,
Also, by knowing the height adjustment state of the work device when the machine is stopped, so to speak, it is possible to speed up by simply raising the operation even when the vehicle is idling and the traveling speed is zero or very slow, by devising it like an automatic accelerator. It was possible to provide a lifting control device capable of raising the working device and further improving working efficiency.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cultivator, 1 is a front wheel, 2 is a rear wheel, 3 is an engine, 4 is a main clutch, 5 is a mission, 6 is a control panel, 7 is a three-point unequal side lifting link mechanism, and 8 is A rotary tiller, 9 is a body, and 10 is a lift cylinder. The up-and-down link mechanism 7 is a known one including a lift arm 11, a top link 12, a lower link 13, a lift rod 14, and the like,
The cultivating device 8 is a known device including a cultivating claw 17, a rotary cover 15, a rear cover 16 pivotally supported by the rotary cover 15, and the like.

The structure of each part will be briefly described with reference to FIGS. 1 and 2. First, the power passing through the main clutch 4 is passed through a main transmission mechanism a, an auxiliary transmission mechanism (not shown), and a differential mechanism b. It is transmitted to the rear wheels 2 and also transmitted to the PTO shaft 23 via the PTO speed change mechanism c. The main speed change mechanism a includes a hydraulic cylinder (not shown) for drive shift operation, a first geared motor 24 for operating a rotary type speed change operation valve (may be an electromagnetic valve type) 25, and a traveling hydraulic clutch (not shown). Which has a first potentiometer 26a and is driven and operated by operating the traveling speed change lever 26,
It has a so-called known power shift structure (Japanese Patent Laid-Open No. 5-10493, etc.).

Further, a vehicle speed sensor (an example of vehicle speed detecting means) 28 for detecting the number of revolutions of the pinion shaft 27 which transmits power to the differential mechanism b is provided, and the traveling speed is calculated from the detected information and the traveling speed is calculated. I try to figure it out. It is convenient to provide a display device 35 that indicates the current gear and the automatic mode or the manual mode. In this cultivator, automatic raising / lowering control for raising and lowering the cultivating device 8 to keep the cultivating depth constant based on the vertical swing amount of the rear cover 16, and
The vehicle speed control for increasing / decreasing the traveling speed during the automatic raising / lowering control is performed in combination, which will be described below.

Automatic Elevating Control Means A An automatic elevating control means A for maintaining the tilling depth by the tiller 8 at a set value is provided. That is, a cover sensor 18, which is a potentiometer that detects the amount of vertical swing of the rear cover 16 that can swing vertically following ground contact, is provided in the tiller 8 and the tilling depth for setting the target tillage depth of the tiller 8 is provided. A plowing depth setting dial 19 which is a setting means is provided. The control valve V1 of the lift cylinder 10, which is a lifting drive mechanism, is switched so that the detected value by the cover sensor 18 matches the value set by the working depth setting dial 19, so that the automatic operation is performed. Elevating control means A is configured.

Tillage Depth Correction Control Means B The tillage depth correction control means B is provided with an engine rotation sensor (an example of a rotation speed detection means) 20, and the change amount of the engine rotation speed during the operation of the automatic lifting control means A is previously set. When it becomes larger than the allowable change amount range set by the range setting means 22 in the rotational speed decreasing direction, the target value is corrected to a shallow side, and
The target value is controlled to be corrected to a deeper side when the rotational speed increases in the rotational speed increasing direction beyond the allowable rotational speed range. In actual operation, when the rotation speed is too low, the tiller is raised, and when the rotation speed is too high, the tiller is lowered, and the engine rotation sensor 20 and the lift cylinder 10 are linked by the control device 31. ing.

In practice, the target value of the cover sensor 18 is corrected by fuzzy control based on the change amount of the engine speed and the change rate of the engine speed. That is,
The engine speed at a stable tilling load after the start of the tilling work with the accelerator lever 21 set is detected, and the reference load at that time is obtained and stored from the difference from the engine speed at no load. Then, the fluctuating engine speed is detected at any time, the load predicted from the difference between the actual speed and the no-load speed is compared with the reference load, and the working depth value is corrected according to the difference. . That is, the correction amount of the tilling depth value based on the difference between the reference load and the predicted load is stored in the form of map data or the like, and the control amount is finally determined based on the fuzzy inference.

As the control operation, the plowing depth correction control is activated by the soil change during the automatic raising / lowering control, and when the engine speed returns after the target plowing depth value is changed, the original automatic raising / lowering control state is restored. Will come back. For example, if the actual plowing depth becomes deep and the rotation speed falls too low due to the soft ground, the target plowing depth will be made shallow, so the rotation speed will recover quickly, but it will return to the original standard field condition in that state. Since the plowing depth becomes shallow and the number of rotations increases this time, the plowing depth correction control works again to shift the plowing depth value to the deep side, that is, the original standard plowing depth value by the automatic raising / lowering control. It will come back. The automatic lifting control for keeping the tilling depth value within a predetermined range by the automatic lifting control means A is called cover auto.
Further, as described above, the control in which the automatic lifting control means A and the working depth correction control means B are combined will be referred to as mixing control. Mixing control is covered MC Auto (MC is Mix
(Abbreviation of Control).

The vehicle speed control means C increases the engine speed by increasing the running speed of the machine body 9 when the engine speed increases and slows the running speed of the machine body 9 when the engine speed decreases. Is a control for operating the geared motor 24 based on the detection information of the engine rotation sensor 20 so as to maintain the rotation speed within a predetermined rotation speed range determined by the operation position.
The first geared motor 24, which operates the shift operation valve 25,
The main transmission mechanism a corresponds to a vehicle speed adjusting means capable of shifting.

That is, when the accelerator lever 21 is appropriately operated, the no-load engine speed and the maximum torque at the operation position are determined, and the rated torque (about 80% of the maximum torque is determined.
Is set), the vehicle speed is controlled so that the load torque becomes a value near the rated torque. For example, if the vehicle speed is controlled so that the load torque is 110% or less of the rated torque, and the detected load torque is 50% of the rated torque, then 50% <1.
Since it is 10%, the load torque when shifting from that state to the one-speed higher speed side is predicted. Then, if the predicted load torque is 110% or less of the rated torque, the gear shifts to the first speed, and if it exceeds 110%, the gear shift is not performed. The rated torque is set with a margin in mind, and the maximum load torque is about 125% of the rated torque.

That is, when there is a surplus in engine output, the vehicle speed is increased to increase the efficiency of plowing work, and the output torque becomes insufficient due to changes in soil properties such as the load torque actually exceeding α times the rated torque (eg, 1.1 times). When it becomes, the vehicle speed is reduced to increase the torque. Actually, the allowable setting range of the engine speed determined by the operating position of the accelerator lever 21 (the proper torque range, that is, the engine speed corresponding to 110% or less of the rated torque is The engine speed is controlled so that the engine speed closest to the allowable lower limit value, that is, the value closest to 110% at 110% or less of the rated torque appears. This is equivalent to providing a dead zone in the torque range, and has an advantage that hunting due to frequent up and down shifts can be avoided. By this control, the generated torque in the set engine speed range can be utilized to the maximum extent, and the plowing work can be always exerted in the maximum efficiency range.

Coordination Control Means E However, there are some conditions for applying the vehicle speed control means C. That is, the vehicle speed control means C is executed in a state where the engine speed fluctuates gently, and the plowing depth correction control means B is executed in a state where the engine speed changes abruptly and largely (that is, the cover MC auto Works)
Coordination control means E is provided to perform the control. That is, the first computing means D1 for obtaining the moving average of the engine speed in a state where the number of samplings of the detection value by the rotation speed detecting means 20 is relatively small, and the state where the number of samplings of the detection value by the rotation speed detecting means 20 is relatively large. A second calculating means D2 for obtaining the moving average of the engine speed is provided, and the working depth correction control means B is based on the calculating result of the first calculating means D1 and is based on the calculating result of the second calculating means D2. The linkage control means E is configured so that the vehicle speed control means C is executed respectively.

Supposing that there is a graph (solid line) of the engine speed with time shown in FIG. 4, the first computing means D1
The detection value per unit time is detected, for example, by the second computing means D2, by operating the tilling depth correction control means B based on a graph (single-dotted line) based on a moving average calculated by sampling three pieces. The vehicle speed control means C is operated based on a graph (two-dotted broken line) obtained by sampling six values, for example, and calculating a moving average. In the case where the number of samplings is 3, a rotational speed fluctuation state that is close to the raw data appears while the extreme peak is alleviated, which is suitable as the data of the plowing depth correction control means B, and when the number of samplings is 6. In the above, the rotational speed fluctuation is remarkably alleviated, and the rapid and large fluctuation degree is replaced with the gentle and small fluctuation degree, which is suitable as the data of the vehicle speed control means C. Note that the plowing depth correction control means B may be controlled with the sampling number set to 1, that is, based on the raw data of the engine speed.

Highest speed control means F When the traveling speed is changed by the operation of the first geared motor 24, the traveling speed is reduced when an uncontrollable state in which the actual tillage depth does not match the target tillage depth occurs. There is provided a maximum speed regulation means F that links the geared motor 24 and the automatic lifting control means A. That is, the maximum vehicle speed controlled by the vehicle speed is regulated depending on whether or not it reaches the target plowing depth.

That is, when the traveling speed is gradually increased by the vehicle speed control means C, it is considered that the tilling ability of the tiller 8 cannot be caught up at last and the tiller rotary is rebounded on the ground and becomes floating. Then, the cover sensor outputs false information that the rear cover hangs down and the plowing depth becomes shallow, even though the plowing is not actually performed till the plowing depth by the automatic lifting control means A. More and more, the tilling rotary is bounced back to the ground, and it becomes impossible to control the tilling depth within the set depth. Therefore, if the automatic traveling control is disabled after the traveling speed is changed, the traveling speed is reduced so that the floating phenomenon of the tiller 8 is suppressed and the automatic traveling control can be returned to the normal operating state. That is, the maximum vehicle speed at that time is determined depending on whether or not the automatic lifting control is established.

Labor-saving control means G This is to reduce wasteful engine output to improve fuel efficiency and reduce noise. That is, the traveling speed developed by the operation of the vehicle speed control means C is previously set to the vehicle speed setter 29.
When the vehicle goes out of the traveling speed range set in step 1, the governor 40, the vehicle speed setter 29, and the vehicle speed sensor 28 are arranged so that the engine speed is changed in preference to the operation of the vehicle speed control means C.
It is the labor saving control means G that links the and. actually,
A potentiometer 21a for detecting the operation amount of the accelerator lever 21 and a second geared motor 30 for driving and operating the governor 40 are also linked.

In short, when the traveling speed exceeds the set value of the vehicle speed setting device 29 while the accelerator lever 21 is appropriately operated, the accelerator (governor 40) is narrowed down to reduce the engine speed so as to be within the set vehicle speed range. On the contrary, when the value is below the set value, the accelerator (governor 40) is opened to control the engine speed so as to increase the engine speed, and the vehicle speed is also controlled. In other words, if there is extra capacity, throttle the accelerator, and if the output is insufficient, open the accelerator,
This is to control to the minimum output state for expressing the set vehicle speed, and waste of engine output can be eliminated. However, the limit of the accelerator throttle amount is regulated by whether or not the rotation speed of the PTO shaft 23 is secured.

Next, the actual tillage control operation will be described. As shown in FIG. 2, each control unit A to G is a control device 3.
The control device 31 is associated with various levers, setting devices, sensors, operation motors, and the like. Further, FIG. 3 and FIG. 5 to FIG. 9 show various flowcharts of the tilling control, which will be described below with reference to these flowcharts.

First, as shown in FIG. 3, the mode changeover switch 32 is operated to select the maximum efficiency vehicle speed control mode (automatic operation mode), the energy-saving tilling vehicle speed control mode (automatic operation mode), or the manual operation mode. . When the maximum efficiency vehicle speed control mode or the energy-saving tilling vehicle speed control mode is selected and the control is being executed, when the non-tilling work state is entered, the control is locked in the state at that time. For example, when the steering sensor is O
The main clutch for operating the compulsory ascending switch (pumper switch) 36 and the position lever to the ascending side in order to make the tilling device 8 float above the ground when turning to N, and forcibly raising the compulsory ascending switch 36 and the position lever when not turning. When the (clutch switch 37) is turned off, the switching lever 34 of the forward / reverse switching mechanism is neutrally operated, and the forcible raising switch 36 and the position lever are operated to the raising side in a state where the switching lever 34 of the forward / backward switching mechanism is operated in reverse. And so on.

Then, when the maximum efficiency vehicle speed control mode or the energy-saving tilling vehicle speed control mode is being executed, if a speed change (moving the speed change lever 26) is manually performed,
As a result, the automatic control mode is released and the mode is switched to the manual operation mode. When the mode is switched to the manual operation mode, the control of the vehicle speed control is canceled (becomes manual), but the mixing control is continued. The automatic control mode may be released by a brake operation (depressing the brake pedal 38). Next, each automatic control mode will be described.

When the maximum efficiency vehicle speed control mode is selected (FIGS. 5 and 6) First, the initial characteristics are set, and the initial traveling speed (vehicle speed) during work, the target plowing depth value, the PTO gear speed, and the engine speed. The (accelerator lever position) and the like are appropriately set in advance in consideration of the field conditions and the like (step # 1), and then the cultivating work is started by operating the position lever and the like (step # 2).

After the start of the plowing work, based on the detection information of the engine rotation sensor 20, the fluctuation of the engine speed in a state where the set plowing depth is maintained is a predetermined level (for example, ± 10).
(step # 3), the rated engine speed at that time is determined from the operating position of the accelerator lever 21 (usually full accelerator is often used), and the range of speeds to be controlled is determined. It is decided (step # 4). That is, map data of the no-load rotational speed corresponding to the accelerator lever setting is stored in advance in the control device 31, and the maximum efficiency is calculated from the no-load rotational speed and the maximum horsepower rotational speed at the accelerator setting. The range of the proper engine speed to be achieved (set speed range) is automatically determined.

For example, if the maximum horsepower rotation speed is 2600 rpm when the no-load rotation speed is 2800 rpm due to the accelerator lever setting, the upper limit is set to 2620 rpm and the lower limit is set to 2400 rpm, and the no-load rotation speed is 2400 rpm. When the maximum horsepower is 22
If it is 00 rpm, the upper limit is 2220 rpm and the lower limit is 2.
It is set to 000 rpm respectively.

Then, a moving average is obtained by each of the first calculating means D1 and the second calculating means D2 (step # 5).
6) The plowing load calculated from the difference between the actual engine speed by the second calculating means D2 and the no-load speed at the set accelerator lever position is detected in a certain section (step # 7).

When the engine speed range is determined, the mixing control based on the detection result of the first calculating means D1 is started (step # 8). The mixing control is performed by the automatic lifting control means A and the plowing depth correction control means B,
It operates according to the flowchart shown in FIG. That is, the target plowing depth value and the engine speed are initially set (step # 01).
Is being processed by. Therefore, it is determined whether the engine speed is higher than the set range (step # 02), and if it is higher, the target plowing depth value is corrected to the deep side based on the fuzzy theory (step # 03), and step # 03 Proceed to 06. If it is not high, it is judged whether the engine speed is lower than the set range (step # 04), and if it is low, the target plowing depth value is corrected to the shallow side based on the fuzzy theory (step # 05). ), The process proceeds to step # 06, and even if the value is not low and is within the set range, the process proceeds to step # 06. These steps # 02 to # 05 correspond to the control operation by the plowing depth correction control means B.

In step # 06, it is judged whether the working depth value is within the set range, and if it is within the set range, step # 0.
If it is outside the range, it is judged whether it is deeper than the target plowing depth value (step # 07). If it is deep, the tiller 8 is raised (step # 08), and if it is not deep, that is, shallow. Lower the tiller 8 (step # 0
After 9), the process returns to step # 02. These steps # 06 to # 09 correspond to the control operation by the automatic lifting control means A.

Then, in step # 9, it is judged whether or not the engine speed obtained from the second calculating means D2 is higher than the set range. Of the plowing load from various conditions (PTO gear, engine speed, traveling gear, etc.), and whether the predicted value is less than α times the rated load (rated torque) determined by the operating position of the accelerator lever 21 Ask for it (step # 13). When the speed is α times or less, the speed is increased by one to increase the vehicle speed (step # 15), and when the speed is more than α, the current speed is maintained (step # 15).
14) and returns to step # 4, respectively.

If the determination in step # 9 is No, the process proceeds to step # 10 to determine whether the engine speed obtained from the second computing means D2 is lower than the set range. It is determined whether or not (step # 16). When the vehicle speed has not fallen to the minimum vehicle speed, the gear is set to one step in order to increase the torque (step # 12), and then the process returns to step # 4. If the vehicle speed is the lowest, it is then judged whether or not the maximum correction value on the ascending side of the tilling device 8 by the mixed control (the limit correction amount of the plowing depth predetermined in the mixed control) is exceeded (step # 17) If it exceeds, it is no longer possible to recover the engine speed by mixing control and vehicle speed control. Therefore, a warning device such as a lamp or buzzer is activated (step # 18), and the operator is instructed. Prompt for other measures Step # 4
Return to As a countermeasure, it is conceivable to change the PTO stage or the target tillage depth value to the load reduction side. If not,
It can be dealt with by mixed control, and just step #
Return to 4.

If the determination in step # 10 is No, it is determined whether or not the automatic lifting control by the maximum speed control means F is established (step # 11), and if it is established, the process directly returns to step # 4 and is established. If it is not, the cause is that the vehicle speed is high as described above. Therefore, the gear position is set to one paragraph (step # 12), and then the process returns to step # 4. Actually, in step # 11, the ratio of the lowering command for a certain period of time is determined. When the vehicle speed is the lowest in step # 16, the plowing depth correction control means B is made to correspond (the plowing depth value is corrected to a shallow side) in step # 17, and the correction value exceeds the limit (that is, ,
When the engine drop is severe), the driver is informed that it is an alarm device because the accelerator setting at the beginning is low or the target working depth value is deep.

That is, if there is a margin in the initial engine speed setting, the gear speed is raised by the operation of the vehicle speed control means C in a state where the mixture control is operating normally, and the actual vehicle speed is initially set. Although it may exceed the vehicle speed, it does not matter that the speed increases because the efficiency of the plowing work improves.
In the maximum efficiency vehicle speed control mode, it is possible to exceed the set vehicle speed on the speed increasing side. However, whether or not the automatic lifting control is established with the speed increased is step # 1
The determination is made in step 1 and the countermeasure is taken, and the idea of whether or not the automatic control is established is as described in the section of the maximum speed control means F.

Ii When the energy-saving plowing vehicle speed control mode is selected (FIGS. 7 and 8), the control method in this mode is the same as that in the maximum efficiency vehicle speed control mode described above, but the difference is the same. explain. First, step # 1 to step # 3 and step # 5 to step # 8 are the same as the maximum efficiency vehicle speed control mode, but in step # 20, the target control of the traveling speed is performed instead of the engine speed range. It is clearly different in that it determines the range (target vehicle speed range). Hereinafter, step # 21 and subsequent steps will be described.

At step # 21, the load factor (described later) is β.
(For example, if it is less than 0.8), if it is less than 0.8, the output margin is sufficient, so the policy is to increase the gear by one step, and predict the load factor when the gear is increased by one (step #
25) If the predicted value is larger than α (for example, 1.1), the gear position at that time is maintained and the process returns to step # 20. If the predicted value is less than or equal to α, it is judged whether or not it is the maximum speed at the set vehicle speed (step # 27). If the maximum speed is already reached, the process returns to step # 20. If so, the accelerator target position is calculated (step # 28). In other words, when the vehicle speed is increased by one step, the accelerator position is predicted and calculated so as to fall within the target vehicle speed range (a means for predicting and calculating the accelerator position where the load factor is 0.8 or more and 1.1 or less is also conceivable). The load factor is defined as a value obtained by dividing the load torque by the rated torque at the accelerator position at that time.

Whether or not the accelerator target position obtained in step # 28 is appropriate is judged from the PTO rotation constraint conditions and the like (step # 29), and if appropriate, step # 31.
In step # 32, the gear position is increased by one, and then the accelerator position is actually throttled to the target position determined in step # 28 (step # 32). When it is not appropriate in step # 29, in step # 30, the accelerator target position is set to the allowable lower limit value (the lower limit of the engine speed is predetermined from the lowest tilling pitch), and then step #
Then, the process proceeds to step 31, in which the gear position is increased by one, and then the accelerator position is actually throttled to the target position obtained in step # 30 (step # 32).

When the determination in step # 21 is No, the process proceeds to step # 22, this time it is determined whether or not the load factor is larger than α (1.1), and if it is larger than the set minimum vehicle speed is determined. (Step # 33) If the vehicle speed is the lowest, the accelerator is opened (step # 34) and the process returns to step # 20. That is, the accelerator is opened when the set vehicle speed range is exceeded. When the vehicle speed is not the lowest, it is determined whether the accelerator is fully opened (step # 35), and when it is not fully opened, the target accelerator position when the gear is lowered by one gear is calculated (step # 36).
In other words, when the vehicle speed is reduced by one step, the accelerator position is predicted and calculated so that the vehicle speed falls within the target vehicle speed range (the load factor is 0.
A method of predicting and calculating the accelerator position where 8 or more and 1.1 or less is also possible).

Next, the gear is lowered by one (step # 3
7) Then, the accelerator position is actually throttled to the target position determined in step # 36 (step # 3
8) and then return to step # 20. If it is determined in step # 35 that the accelerator is fully opened, the accelerator cannot be opened any further, so the process immediately proceeds to step # 37, and the shift speed is lowered by one gear. Then, in step # 38, the accelerator is moved to the target position. In this case, the accelerator remains fully open, and in that state, the process returns to step # 20.

The fact that the load factor is less than α in step # 22 is, in short, an appropriate load factor, and the maximum speed control means F
It is determined whether or not the automatic raising / lowering control by is established (step # 23), and when it is established, step # 20 is directly performed.
If not established, the gear position is lowered by one (step # 24), and then the process returns to step # 20.

As described above, the maximum efficiency vehicle speed control is
The engine speed is controlled so as to be maintained within the set speed range determined by the accelerator lever position, and the maximum work efficiency is achieved by increasing the vehicle speed as much as possible within the set speed range. . On the other hand, the energy-saving plowing vehicle speed control is to first set a vehicle speed range and control the engine speed to the lowest engine speed sufficient to bring out the vehicle speed in that range, that is, to the accelerator position, and to control the intended work traveling speed. By demonstrating the minimum amount of accelerator required, fuel efficiency and noise can be improved while plowing work efficiently.

This tractor is provided with a rotation raising control means K in addition to the above-mentioned controls. That is, the rotation increasing control means K raises the engine speed by a predetermined amount when the raising operation of the tilling device 8 is performed in the idling state and when the traveling speed is zero or very low. Example of hydraulic actuator) 10 control valves V
Lifting lever that can operate 1 (an example of lifting operation tool) 41
The engine rotation sensor 20, the vehicle speed sensor 28, and the governor (an example of an accelerator device) 40 are linked together. A throttle may be used as the accelerator device.

Actually, the clutch switch 37 of the main clutch 4 and the switch 34a of the forward / reverse switching lever 34 are linked to each other as means for judging the stop of running, and the main clutch is disengaged or the forward / reverse switching mechanism. When (not shown) is neutrally operated, that is, when the traveling transmission system is neutrally operated, the rotation increase control means K is irrespective of the information from the vehicle speed sensor 28.
Operates. Also, an extremely low speed such as 1000 rpm when 700 rpm is the idling speed is defined to be included in the “idling” state in the claims. That is, it means an idling state or an almost idling state (see FIG. 10).
Although not shown in FIG. 10, “start” is placed above “elevation lever raising operation”, and “rotation raising control means is activated” and “rotation raising control means is not activated”. There is a "return".

The rotation increasing control means K operates in the following cases. When raising the work equipment for easy inspection when the engine is idling and the vehicle is temporarily stopped during work for checking work equipment such as a tiller and plow in a field. 1000 rpm for light load work such as scraping work
When raising the tilling device 8 to make a turn in a headland when the engine speed is around idling. When the machine is stopped after the work is finished and the work equipment is washed to raise the position so that it is easy to wash. When raising the work equipment in preparation for traveling while warming up. In addition to the above, various states such as inspection of the working device are conceivable.

Incidentally, reference numerals are provided in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of drawings]

Fig. 1 Side view of a cultivator

FIG. 2 is a block diagram showing a functional system of the tillage control device.

FIG. 3 is a flowchart for selecting a control mode.

[Fig. 4] Various fluctuation graphs of engine speed

FIG. 5 is a flowchart of maximum efficiency vehicle speed control mode 1

FIG. 6 is a flowchart 2 of the maximum efficiency vehicle speed control mode.

FIG. 7: Flowchart of energy-saving tilling vehicle speed control mode 1

FIG. 8: Flowchart 2 of energy-saving tilling vehicle speed control mode

FIG. 9 is a flowchart of mixing control (cover MC auto).

FIG. 10 is a flowchart of rotation increase control.

[Explanation of symbols]

 8 Tillage device 9 Airframe 10 Hydraulic actuator 20 Rotation speed detection means 28 Vehicle speed detection means 40 Accelerator device 41 Elevating operation tool K Rotation rise control means

Claims (1)

[Claims] 1. A working device (8) connected to an airframe (9)
And a hydraulic actuator (10) capable of moving up and down and a vehicle speed detecting means (28) for detecting the traveling speed of the machine body (9).
And an engine speed detecting means (2
0) and an accelerator device (40) whose engine speed can be freely adjusted, and when the vehicle is idling and the traveling speed is zero or very low, the work device (8) is lifted. And a lifting operation tool (41) capable of operating the hydraulic actuator (10) so as to increase the engine speed by a predetermined amount.
An elevator control device for a working machine, comprising: a rotation speed detecting means (20); a vehicle speed detecting means (28); and a rotation increasing control means (K) for linking the accelerator device (40).