JP7206176B2 - agricultural vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to an agricultural vehicle equipped with an engine and equipped with various devices driven by the power of the engine.

A combine harvester, which is an example of an agricultural vehicle, has conventionally been configured as follows. Equipped with an engine rotation control unit that can change and adjust engine rotation, and a mode switch that switches the control mode. When the mode switch is in the off state, the engine rotation speed is adjusted to the rotation speed set with the accelerator setting dial. be done. When the mode switch is in the ON state, the engine is idling in the non-working state, and when the vehicle is running or the work clutch is engaged for mowing work, the engine speed is controlled so that the engine operates at rated speed. is performed (see, for example, Patent Document 1). In the configuration disclosed in Patent Document 1, various devices mounted on the airframe are mechanically driven by power from the engine.

JP 2012-90606 A

In the above-described conventional configuration, wasteful consumption of fuel is suppressed by idling when the machine is not working, and the engine is operated at rated speed during harvesting. That is, since the engine operates at a high rotational speed close to the maximum output, for example, crops such as rice can be efficiently harvested.

Crops to be harvested include various crops other than rice, such as soybeans, buckwheat, and corn. Depending on the type of crop, operating the engine at rated operation may damage the crop.

Agricultural vehicles are equipped with hydraulic actuators such as hydraulic cylinders and hydraulic motors as devices operated by the power of the engine. In some cases, such hydraulic actuators are configured to move an object to be operated. When operating such a hydraulic actuator, if the engine is running at rated speed, the hydraulic actuator may operate too fast, and if the engine is idling, the hydraulic actuator may operate too slowly.

Therefore, while it is possible to suppress wasteful consumption of fuel and efficiently perform harvesting work, even when harvesting a type of crop that is easily damaged or when a hydraulic actuator is provided, it is preferable. There was a demand to be able to perform such work.

The agricultural work vehicle according to the present invention is characterized by an engine, a speed governor that adjusts the rotation speed of the engine, a rotation speed control unit that controls the rotation speed of the engine, and a target rotation speed of the engine that is manually operated . a target rotation speed setting means for commanding, a mode switching means capable of switching the control mode of the rotation speed control unit between a first control mode and a second control mode, and switching power transmission to a working device mounted on the machine body. and a hydraulic actuator that can be operated based on the power of the engine. In the second control mode, if a predetermined condition is satisfied, the normal control is executed, and if the predetermined condition is not satisfied For example, idling control is executed to control the operation of the speed governor so that the number of revolutions of the engine becomes the idling number of revolutions ; , that the hydraulic actuator is operating.

According to the present invention, if a condition is set as a predetermined condition to operate various devices associated with the harvesting work, switching to the second control mode during the harvesting work will result in a non-working state, i.e., a running state. When the machine is stopped and no harvesting work is being performed, the engine speed is the idling speed. As a result, wasteful fuel consumption can be suppressed.

During harvesting work, a predetermined condition is established and the speed governor is controlled so that the engine speed reaches the target speed. At this time, since the target rotation speed is manually set by the target rotation speed setting means, the rotation speed suitable for the work at that time can be set. When harvesting a kind of crop that is easily damaged, the rotation speed suitable for it is set. As a result, it becomes possible to perform harvesting work efficiently. When traveling on a road or on a ridge, switching to the first control mode and setting the target rotation speed to a rotation speed suitable for traveling, for example, the maximum rotation speed, allows good road travel.

A hydraulic actuator operated by the power of the engine is provided, and when the hydraulic actuator is operating, a predetermined condition is established, so the engine is driven at an appropriate engine speed set by the target speed setting means. , the operation by the hydraulic actuator takes place in the proper conditions.

Therefore, while it is possible to suppress wasteful consumption of fuel and efficiently perform harvesting work, it is possible to perform good work even when harvesting fragile crops or when a hydraulic actuator is provided. has become possible.

In the present invention, there is provided a storage device capable of switching between an action posture in which the crops can be stored and a discharge posture in which the stored crops are discharged to the outside, and the hydraulic actuator moves the storage device to the action position. It is preferable that a switching operation is possible between the attitude and the discharge attitude.

According to this configuration, the hydraulic actuator changes the attitude of the storage device to discharge the stored crops to the outside. When the hydraulic actuator operates, a predetermined condition is established and the engine is driven at an appropriate engine speed set by the target engine speed setting means, so that the hydraulic actuator operates in an appropriate state.

In the present invention, in the second control mode, when the state in which the predetermined condition is not satisfied is switched to the state in which the predetermined condition is satisfied, the rotation speed control unit is configured to operate for the first set time from the time of switching. After elapses, when the normal control is executed and the state in which the predetermined condition is satisfied is switched to the state in which the predetermined condition is not satisfied, the first set time from the time of the switching It is preferable that the idling control is executed after a second set time that is too long has elapsed.

According to this configuration, when the predetermined condition is not satisfied, the idling control is executed, and when the predetermined condition is satisfied from this state, the rotation speed control unit is operated after the short first set time elapses. , the speed governor is controlled so that the engine speed changes from the idling speed to the target set speed.

When the state in which the predetermined condition is satisfied is switched to the state in which the predetermined condition is not satisfied, the engine speed control unit reduces the engine speed from the target set speed to idling after a second longer set time has elapsed. A governor is controlled so that the number of revolutions is reached.

When the engine speed increases, it is possible to respond as quickly as possible and prepare for subsequent work. On the other hand, when the engine speed decreases, it is possible to wait for a longer period of time so that it is possible to avoid the determination that the predetermined condition is not satisfied due to an erroneous operation.

In the present invention, as the hydraulic actuator, an automatic operation hydraulic actuator for automatically moving the operation object to the target operation position based on the operation command, and a manual operation hydraulic actuator that is operated only while the operation command is issued. A hydraulic actuator for manual operation for moving an object is provided, and the rotation speed control unit controls the first set time when switching to a state where the predetermined condition is satisfied by the operation of the hydraulic actuator for manual operation. and the first set time when switching to the state in which the predetermined condition is satisfied by the operation of the hydraulic actuator for automatic operation is set to the same time, and the operation of the hydraulic actuator for manual operation is completed. The second set time when switching to the state in which the predetermined condition is not satisfied is the second set time when switching to the state in which the predetermined condition is not satisfied after the operation of the hydraulic actuator for automatic operation is completed. It is preferable to set the time longer than the two set times.

According to this configuration, the first set time, which is the waiting time from switching to the state where the predetermined condition is satisfied until the normal control is executed, is set for the hydraulic actuator for manual operation and for the hydraulic actuator for automatic operation. In both cases, the same time is set so that when the engine speed increases, it can respond as quickly as possible to prepare for subsequent work.

As the second set time, which is the waiting time from when the predetermined condition is satisfied to when the predetermined condition is not satisfied until the idling control is executed, in the case of the hydraulic actuator for manual operation, the automatic A longer time is set than in the case of hydraulic actuators for operation.

When the hydraulic actuator is manually operated, the command operation may be repeated at short intervals, so the waiting time (second set time) should be set longer to avoid switching the control state due to erroneous operation. can be made

In the present invention, a speed change operation tool capable of changing the traveling speed of the vehicle body by manual operation and a neutral detection sensor for detecting a neutral state in which the speed change operation tool is in a traveling neutral position are provided, and the predetermined condition includes: It is preferable that the neutral state is not detected by the neutral detection sensor.

According to this configuration, if the speed change operation tool is not in the neutral running state, the vehicle body is in a running state, so a running load is applied to the engine. Therefore, normal control is executed to rotate the engine at the target rotation speed, thereby enabling smooth driving.

In the present invention, the rotational speed control unit, in the second control mode, sets the first set time when switching to a state in which the predetermined condition is satisfied by switching to a state in which the work clutch is engaged . It is preferable to set the time to be longer than the first set time when the neutral state is not detected by the neutral detection sensor and the predetermined condition is satisfied.

According to this configuration, the first set time, which is the waiting time when the speed change operation device is switched from the neutral running state to the vehicle body running state, is set to a relatively short time. When the shift operating tool is operated, it may be operated quickly by manual operation, so the engine speed can be increased as quickly as possible.

On the other hand, when the work clutch is switched to the engaged state, if the engine speed is increased at the same time as the work clutch is engaged and the working device starts to be driven, the load on the engine may become excessive. Therefore, by setting the first set time, which is the waiting time, to a longer time, the engine is driven at a low speed at first, and then after a short period of time, the engine speed is increased. can be avoided.

In the present invention, the rotational speed control unit, in the second control mode, sets the first set time when switching to the state in which the predetermined condition is satisfied by switching to the engaged state of the work clutch. It is preferable to set the time longer than the second set time when switching to the state where the predetermined condition is not satisfied by switching the work clutch to the disengaged state.

According to this configuration, when the work clutch is switched to the disengaged state, unlike when the working device is started, there is no risk of an excessive load being generated, so the first set time, which is the waiting time, is set to a relatively short time. be done. As a result, the engine speed can be reduced to the idling speed as early as possible.

In the present invention, it is preferable to provide alarm means for activating an alarm when the rotational speed of the engine falls below a lower limit set to a value lower than a reference rotational speed corresponding to a no-load condition by a predetermined amount. be.

According to this configuration, when work is performed while the vehicle body is running, the driving load on the engine increases, and accordingly the engine speed decreases from the speed in the no-load state. The amount of reduction in engine speed corresponds to the magnitude of the load applied to the engine.

Therefore, when the engine speed falls below a lower limit value set to a value lower than the reference speed corresponding to the no-load state by a predetermined amount, there is a possibility that the load on the engine is excessive. Alarm activated. As a result, the driver can be prompted to take countermeasures.

It is the whole combine side view. It is the whole combine top view. It is a rear view which shows the raising/lowering state of a grain tank. It is a side view of an operation panel. It is a top view of an operation panel. It is a top view of an engine information display operation part. It is a control block diagram. 4 is a flow chart of control operation; 4 is a flow chart of control operation; 4 is a flow chart of control operation; 4 is a flow chart of control operation;

An embodiment of the present invention will be described based on the drawings. In the following explanation, the direction of the arrow "F" is the "front side of the aircraft" (see FIGS. 1 and 2), the direction of the arrow "B" is the "back side of the aircraft" (see FIGS. 1 and 2), and the direction of the arrow " The direction of the arrow "L" is defined as the "left side of the fuselage" (see FIG. 2), and the direction of the arrow "R" is defined as the "right side of the fuselage" (see FIG. 2).

(Overall configuration of combine harvester)
1 and 2 show a common combine as an example of a harvester. This combine harvester has a running body 1 equipped with a pair of left and right front wheels 2 and a pair of left and right rear wheels 3 as a running device. That is, this combine is a wheel type combine. The front wheels 2 are configured to be driven by power from the engine 4 . The power of the engine 4 is converted into forward power and reverse power by a main transmission 5 consisting of a hydrostatic continuously variable transmission (HST), and the rotational speeds of the forward power and reverse power are changed steplessly. It is transmitted to the wheels 2. The rear wheels 3 are configured to be steerable. In the vicinity of the engine 4, although not shown, various devices related to the engine 4, such as a radiator and an air cleaner, are provided. An exhaust gas treatment device 6 for purifying exhaust gas from the engine 4 is provided above the engine 4 .

The exhaust gas treatment device 6 includes a well-known DPF (Diesel Particulate Filter) that collects and removes PM (Particulate Matter) contained in the exhaust gas. The exhaust gas treatment device 6 is configured to be switchable between an automatic mode in which a regeneration process for burning and removing the collected particulate matter is automatically performed, and a prohibition mode in which the regeneration process is prohibited. If the engine 4 continues to collect particulate matter while the engine 4 is switched to the prohibition mode, clogging will occur, so it is necessary to manually perform the regeneration process periodically.

A driving unit 7 is provided in the front part of the traveling machine body 1 . The operating part 7 is covered by a cabin 8 . The driving section 7 is provided with a driver's seat 9 and a steering wheel 10 in front of the driver's seat 9 . By rotating the steering wheel 10, the rear wheels 3 are steered by a power steering device (not shown).

A harvesting and conveying unit 12 is provided in the front part of the body frame 11 . The reaping and conveying unit 12 has a reaping unit 13 for reaping planted grain culms and a feeder 14 for conveying the harvested reaping grain culms rearward. The reaping part 13 is supported by the machine body so as to be able to move up and down. The feeder 14 is supported by the machine body at its rear end so as to be vertically swingable about the horizontal axis.

The entire reaping and conveying unit 12 including the feeder 14 and the reaping unit 13 is configured to be swingable and vertically movable by a lifting hydraulic cylinder 18 . The reaping part 13 moves up and down between a lowered working state in which the reaping and conveying part 12 is lowered close to the ground and a raised non-working state in which the reaping and conveying part 12 is raised to a high position from the ground. manipulated. A reaping elevation sensor 19 (see FIG. 7) capable of detecting the elevation height of the reaping unit 13 based on the relative angle of the feeder 14 with respect to the machine body is provided. The reaping/lifting sensor 19 makes it possible to determine whether the reaping/conveying unit 12 is in a lowering working state or in a non-raising state.

Planted stalks in a field are raked into the rear part of the reaping unit 13 by a reel 15 and cut by a reaping blade 16 having a clipper-type cutting blade. The harvested grain culms that have been cut by the cutting blade 16 are collected by the auger 17 at the position of the inlet of the feeder 14 and sent out to the feeder 14 .

A threshing device 20 as a working device for threshing the reaping grain culms conveyed by the feeder 14 is provided at the rear portion of the traveling machine body 1 . The feeder 14 is connected to the front part of the threshing device 20 so as to be vertically swingable around the horizontal axis. All culms of harvested grain culms after harvesting are conveyed from the harvesting section 13 to the threshing device 20 via the feeder 14 . As shown in FIGS. 2 and 3, the threshing device 20 is mounted on the machine body frame 11 in a state of being biased to the left lateral side of the traveling machine body 1 with respect to the center of the traveling machine body 1 in the width direction. supported in a fixed state. Above the threshing device 20, a grain tank 21 for storing grains obtained by threshing is provided.

(Grain discharging device)
A grain discharging device 22 for discharging grains stored in the grain tank 21 to the outside of the machine body is provided. A discharge screw 23 extending in the front-rear direction is provided at the bottom of the grain tank 21, and a grain discharge device 22 capable of conveying grains to the outside of the machine body is connected to the front of the discharge screw 23 via a connection case 24. there is The grain discharging device 22 includes a screw conveyor type vertical conveying unit 25 that conveys the grains upward from the terminal end of the discharge screw 23, and a screw conveyor type that conveys the grains in the horizontal direction from the upper end of the vertical conveying unit 25. and a horizontal conveying section 26 of.

The grain discharging device 22 is driven by power of a hydraulic motor 27 for discharging. The operation of the discharge hydraulic motor 27 is controlled by a control device 28, and ON/OFF is controlled based on the operation of a discharge command switch 29 (see FIG. 7) provided in the operation section 7. FIG.

The grain discharging device 22 is moved to a retracted posture (posture indicated by a solid line in FIG. 2) and a discharging posture (posture indicated by a solid line in FIG. 2) can be swiveled. A turning angle sensor 31 (see FIG. 7) capable of detecting a turning angle is provided near the center of turning of the grain discharging device 22 .

The turning operation by the turning hydraulic cylinder 30 is automatically performed by the control device 28 based on the command operation of the turning command switch 32 (see FIG. 7) provided in the operating section 7 . That is, when the turning command switch 32 is turned on, the turning hydraulic cylinder 30 is operated from the retracted posture to the discharged posture based on the detection result of the turning angle sensor 31 . After that, when the turning command switch 32 is turned on again, the turning operation is automatically performed from the discharge posture to the storage posture in the same manner. Therefore, the turning hydraulic cylinder 30 corresponds to a hydraulic actuator for automatic operation.

The grain tank 21 can be stored directly from the right side by swinging the entire grain tank 21 around the rotation axis of the discharge screw 23, in addition to the grain discharge form by the grain discharge device 22. It is configured so that the grains in it can be discharged to the outside.

As shown in FIG. 3 , the tank frame body 33 is erected around the grain tank 21 in the body frame 11 . The tank frame body 33 is connected with the grain tank 21 . The grain tank 21 is supported by the tank frame body 33 so as to be vertically swingable about the horizontal axis P of the discharge screw 23 extending in the longitudinal direction of the vehicle body. A tank lifting hydraulic cylinder 34 is connected across the tank frame body 33 and the lower part of the grain tank 21 . The grain tank 21 is moved to a lowered position (see FIGS. 1 and 2) to create a lowered posture and a raised position (see FIG. 3) to create a raised posture with the horizontal axis P as the swing axis by the tank lifting hydraulic cylinder 34. , and swings up and down. When rocked to the raised position, the lower side wall is opened and the stored grains can be discharged laterally outward.

The rocking and raising/lowering operation of the grain tank 21 is performed by the control device 28 based on command operations of a tank raising switch 35 and a tank lowering switch 36 (see FIG. 7) provided in the operation section 7 . When the tank lift switch 35 is operated, the grain tank 21 swings upward only while it is being operated. When the tank lowering switch 36 is operated, the grain tank 21 swings downward only while it is being operated. Therefore, the tank lifting hydraulic cylinder 34 corresponds to a hydraulic actuator for manual operation.

(Driver)
As shown in FIG. 2 , the operation section 7 is provided with an operation panel section 38 located on the lateral side of the driver's seat 9 . As shown in FIGS. 4 and 5, on the operation panel section 38, a main transmission lever 39 for shifting the main transmission 5 and a threshing clutch 40, which is an example of a work clutch for turning on and off power transmission to the threshing device 20, can be turned on and off. A threshing clutch lever 41, a reaping clutch lever 42 capable of turning on and off a reaping clutch (not shown) for turning power transmission to the reaping unit 13 on and off, information on the engine 4, and an engine information display for performing operations related to the information. An operation unit 43 and the like are provided.

The main transmission lever 39 can be swung in the front-rear direction, and the further forward the main transmission lever 39 is swung from the neutral position, the more the main transmission 5 moves forward and the traveling speed is steplessly increased. The more the main transmission lever 39 is swung rearward from the neutral position, the more the main transmission 5 is in the reverse traveling state and the traveling speed is steplessly increased. The threshing clutch lever 41 and the reaping clutch lever 42 can be pivoted in the front-rear direction, and are configured to engage the clutch by being operated to the front side.

In the vicinity of the main shift lever 39, there are a neutral detection sensor 46 for detecting that the main shift lever 39 is in the neutral position, and a reverse detection sensor 47 for detecting that the main shift lever 39 is operated in reverse. are provided. A threshing sensor 48 is provided in the vicinity of the threshing clutch lever 41 for detecting that the threshing clutch lever 41 is engaged.

The engine information display operation section 43 will be described.
As shown in FIG. 6, in front of the engine information display operation unit 43, a rotation speed setting device 49 as target rotation speed setting means for setting a target rotation speed of the engine 4 and an output rotation speed of the engine 4 are provided. An automatic ON/OFF switch 50 for commanding turning on/off of the rotation speed control which automatically adjusts so as to achieve the target rotation speed set by the number setter 49, and an automatic on/off switch 50 which lights up when the rotation speed control is turned on and turns off when turning off the rotation speed control. An on/off display lamp 51 is provided. Rotational speed control will be described later.

Between the front and rear of the engine information display operation unit 43, there is a manual operation unit 52 for performing manual operation related to the exhaust gas processing device 6, and a state in which the state of the exhaust gas processing device 6 is indicated by being positioned adjacent to the manual operation unit 52. A display unit 53 is provided. The manual operation unit 52 includes a prohibition switch 54 for switching the exhaust gas treatment device 6 to a prohibition mode, and a regeneration switch 55 for forcibly executing regeneration processing. The prohibition switch 54 is provided with a prohibition state display lamp 56 which lights up when the exhaust gas treatment device 6 is switched to the prohibition mode and which is extinguished when the prohibition mode is released. The regeneration switch 55 is provided with a regeneration status indicator lamp 57 which lights up when execution of the regeneration process is commanded and turns off when execution of the regeneration process is not commanded.

The state display section 53 is provided with an operating state display lamp 58 which is lit when the exhaust gas treatment device 6 is performing the regeneration process and turned off when the regeneration process is not being performed. The exhaust gas treatment device 6 is in the automatic mode in the initial setting state, and is always set to the automatic mode when the prohibition switch 54 is not operated.

At the rear of the engine information display operation section 43, there is a first abnormality display section 59 for displaying an abnormality (system abnormality) in each part around the engine for operating the engine 4, A second abnormality display portion 60 for displaying an abnormality and a fuel abnormality display portion 61 for displaying an abnormal state in which water is intruded into the fuel supplied to the engine 4 are provided.

(engine speed control)
Next, rotation control of the engine 4 will be described.
As shown in FIG. 7, an engine rotation sensor 62 for detecting the rotation speed of the engine 4 and a speed governor 63 for adjusting the rotation speed of the engine 4 are provided. It is configured to be controlled by Therefore, the control device 28 is provided with a rotation speed control section 64 that controls the rotation speed of the engine 4 .

A mode switch 65 is provided as mode switching means capable of switching the control mode of the rotational speed control section 64 between a first control mode and a second control mode. In the first control mode, the rotation speed control unit 64 performs normal control to control the operation of the speed governor 63 so that the rotation speed of the engine 4 reaches the target rotation speed set by the rotation speed setting device 49. do. In the second control mode, if a predetermined condition is satisfied, the normal control is executed. is configured to perform idling control that controls the operation of The predetermined condition includes a condition that either the turning hydraulic cylinder 30 or the tank lifting hydraulic cylinder 34 is operating.

A specific control operation will be described based on the control flow charts of the rotational speed control section 64 shown in FIGS. The rotational speed control unit 64 operates on the precondition that the automatic on/off switch 50 is turned on.

When the mode switch 65 is set to the first control mode, normal control is executed regardless of various conditions to be described later (steps 1 and 7). When the second control mode is set, the traveling neutral condition is that the main transmission lever 39 is operated to a position other than the neutral position, the threshing work condition is that the threshing clutch lever 41 is in the engaged state, and the grain discharging device 22 is discharged. At least one of a discharge work condition that the grain discharging device 22 is in operation, a turning operation condition that the grain discharging device 22 is in a turning operation, and a tank lifting operation condition that the grain tank 21 is being moved up and down is established. If so, normal control is executed, and if none of the conditions are met, idling control is executed (steps 1-6, 8).

The neutral traveling condition is detected by the neutral detection sensor 46, the threshing work condition is detected by the threshing sensor 48, the discharge work condition is detected by the operation state of the discharge command switch 29, and the swing operation condition is detected by the swing command switch 32. The operation state is detected, and the tank lifting operation condition is detected by the operation state of the tank raising switch 35 and the tank lowering switch 36 .

Normal control executes the control shown in FIG.
In normal control, when the condition is established from the state where the condition is not established, the engine speed is adjusted so that the engine speed reaches the target speed. The waiting time (an example of the first set time) until is different depending on the difference in conditions that are established.

That is, the waiting time is zero under the traveling neutral condition, the first waiting time (T1) is set under the threshing work condition, the second waiting time (T2) is set as the waiting time under the discharging work condition, and the turning operation condition is set. A third waiting time (T3) is set, and a fourth waiting time (T4) is set under the tank lifting operation condition. That is, when the running neutral condition is satisfied, the engine speed is adjusted to the target speed without delay (steps 11 and 20). When the threshing work conditions are met, the engine speed is adjusted to the target speed after the first waiting time (T1) has passed (steps 12 and 13). Thereafter, similarly, after the set waiting time has elapsed, the engine speed is adjusted to the target speed (steps 14 to 19).

The waiting time under the threshing conditions, that is, the second waiting time (T2) is set longer than the waiting time (zero) under the neutral traveling condition. The same time is set for the third waiting time (T3) and the fourth waiting time (T4). The third standby time (T3) corresponds to the first set time when switching to a state in which the conditions are satisfied by the operation of the tank lifting hydraulic cylinder 34 . The fourth standby time (T4) corresponds to the first set time when switching to the state where the conditions are satisfied by the operation of the hydraulic cylinder 30 for turning.

The idling control executes the control shown in FIG.
In idling control, when the conditions change from satisfied to none of the conditions, the engine speed is adjusted to the idling speed. The waiting time (an example of the second set time) from when the engine speed is changed and adjusted differs depending on the difference in the conditions that are established.

That is, a fifth waiting time (T5) is set as the waiting time under the traveling neutral condition, a sixth waiting time (T6) is set as the waiting time under the threshing work condition, and a seventh waiting time (T6) is set as the waiting time under the discharging work condition. T7) is set, an eighth standby time (T8) is set under the turning operation condition, and a ninth standby time (T9) is set under the tank lifting operation condition. As in normal control, the engine speed is adjusted to the idling speed after the set waiting time has passed since each condition is satisfied (steps 21 to 31).

The ninth waiting time (T9) is set longer than the eighth waiting time (T8). A fifth waiting time (T5) is set under the running neutral condition, and this fifth waiting time (T5) is the waiting time ( 0) longer time is set.

The first waiting time (T1) in normal control is set longer than the sixth waiting time (T6) in idling control. The first waiting time (T1) corresponds to the waiting time (first set time) when the threshing clutch 40 is switched to the engaged state to switch to the state where the predetermined condition is satisfied. The sixth waiting time (T6) corresponds to the waiting time (second set time) when the threshing clutch 40 is switched to the disengaged state to switch to a state in which the predetermined condition is not satisfied.

Next, engine load control will be described with reference to FIG.
The condition that the threshing clutch lever 41 is in the engaged state, the condition that the main transmission lever 39 is neither in the neutral position nor in the reverse position, and the lifting height of the reaping unit 13 is below the set height (reaping work state). Furthermore, if the condition that the engine speed is equal to or lower than the reference speed if the reference speed is set in advance, then the engine speed at that time is used as the reference speed. Set (steps 41 to 46). That is, the no-load rotation speed at which the machine starts reaping work while traveling forward is set as the reference rotation speed.

After that, when the reaping work is executed, if the engine speed becomes equal to or lower than the lower limit set to a value lower than the reference speed by a predetermined amount, the engine 4 is assumed to be overloaded, and the operating section 7 prepares for it. The warning device 66 as the warning means is activated (steps 47 and 48).

The alarm device 66 is composed of a buzzer and an indicator lamp (not shown) provided on the operation panel section 38, and notifies the driver that the engine 4 is overloaded by sounding the buzzer and lighting the indicator lamp. .

[Another embodiment]
(1) In the above embodiment, in the normal control, the waiting time (second waiting time) under the threshing condition is set longer than the waiting time (zero) under the neutral running condition. Each waiting time described above may be set to the same time.

(2) In the above embodiment, the same time is set for the third standby time (T3) and the fourth standby time (T4) in normal control, but they may be set to different times. In that case, the third waiting time (T3) may be set longer than the fourth waiting time (T4), or the third waiting time (T3) may be set shorter than the fourth waiting time (T4).

(3) In the above embodiment, in the idling control, the ninth standby time (T9) is set longer than the eighth standby time (T8). The 9 waiting time (T9) may be set to be shorter than the 8th waiting time (T8).

(4) In the above embodiment, as hydraulic actuators, the turning hydraulic cylinder 30 for turning the grain discharging device 22 and the tank lifting hydraulic cylinder 34 for lifting and lowering the grain tank 21 are provided. Alternatively, it may be a hydraulic cylinder operating another device, a hydraulic motor, or the like.

INDUSTRIAL APPLICABILITY The present invention can be applied to agricultural vehicles equipped with various devices such as combine harvesters, rice transplanters, tractors, etc., which are equipped with an engine and driven by the power of the engine.

4 engine 20 threshing device (working device)
21 grain tank (storage device)
30, 34 hydraulic cylinder (hydraulic actuator)
40 threshing clutch (work clutch)
46 neutral detection sensor 49 rotation speed setting device (target rotation speed setting means)
63 speed governor 64 rotation speed control unit 65 mode switching means 66 alarm device (alarm means)

Claims (8)

an engine, a speed governor for adjusting the speed of the engine, a speed controller for controlling the speed of the engine, a target speed setting means for commanding a target speed of the engine by manual operation , Mode switching means for switching the control mode of the rotation speed control unit between a first control mode and a second control mode, a work clutch for turning on and off power transmission to a working device mounted on the machine body, a hydraulic actuator operable by
The rotation speed control unit is
In the first control mode, normal control is performed to control the operation of the speed governor so that the rotation speed of the engine becomes the target rotation speed,
In the second control mode, if a predetermined condition is satisfied, the normal control is executed. configured to perform idling control that controls the operation of the speed governor;
The agricultural vehicle, wherein the predetermined conditions include a condition that the work clutch is engaged and a condition that the hydraulic actuator is operating. Equipped with a storage device capable of switching between an operating posture in which the crops can be stored and a discharge posture in which the stored crops are discharged to the outside,
The agricultural vehicle according to claim 1, wherein the hydraulic actuator is operable to switch the storage device between the working posture and the discharge posture. The rotation speed control unit, in the second control mode,
When the state in which the predetermined condition is not satisfied is switched to the state in which the predetermined condition is satisfied, the normal control is executed after a first set time has elapsed from the switching point, and
When the state in which the predetermined condition is satisfied is switched to the state in which the predetermined condition is not satisfied, the idling control is performed after a second set time longer than the first set time has passed since the switching time. 3. A farm vehicle according to claim 1 or 2, configured to perform As the hydraulic actuator,
A hydraulic actuator for automatic operation that automatically moves the operation target to the target operation position based on the operation command, and a hydraulic actuator for manual operation that moves the operation target only while the manual operation command is issued. an actuator,
The rotation speed control unit is
The first set time when the operation of the hydraulic actuator for manual operation switches to the state in which the predetermined condition is satisfied, and the time when the operation of the hydraulic actuator for automatic operation switches to the state in which the predetermined condition is satisfied. is set to the same time as the first set time of
The second set time when the operation of the hydraulic actuator for manual operation is completed and the predetermined condition is not satisfied is set to the second set time when the operation of the hydraulic actuator for automatic operation is completed and the predetermined condition is satisfied. The agricultural vehicle according to claim 3, wherein the time is set to be longer than the second set time when switching to a state in which is not established. A speed change operation tool capable of changing the traveling speed of the vehicle body by manual operation, and a neutral detection sensor for detecting a neutral state in which the speed change operation tool is in a traveling neutral position,
5. The agricultural vehicle according to claim 3, wherein said predetermined condition includes that said neutral state is not detected by said neutral detection sensor. In the second control mode, the rotation speed control unit is configured to:
The predetermined condition is satisfied when the neutral state is not detected by the neutral detection sensor for the first set time when switching to the state in which the predetermined condition is satisfied by switching the work clutch to the engaged state. 6. The agricultural vehicle according to claim 5, wherein the time is set to be longer than the first set time when switching to the state of turning on. In the second control mode, the rotation speed control unit is configured to:
The state in which the predetermined condition is not satisfied by switching the work clutch to the disengaged state is changed from the first set time when the work clutch is switched to the engaged state to the state in which the predetermined condition is satisfied. The agricultural vehicle according to any one of claims 3 to 6, wherein the time is set to be longer than the second set time when switching to . 8. An alarm means for activating an alarm when the number of revolutions of said engine falls below a lower limit set to a value lower than a reference number of revolutions corresponding to a no-load condition by a predetermined amount. 1. Agricultural vehicle according to item 1.

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