JP2003267254A - Swing control device of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swing control device of a working vehicle capable of properly performing a gentle swing with a fine adjustment while a large swing force can be provided without a troublesome swing operation. <P>SOLUTION: In a small side operating area W1 where the amount of movement of a swing operation means from a forward movement directive position by a swing directive means is small, the swing operation means capable of changing a swing force by differentiating the traveling speeds of a pair of right and left traveling devices is brought into an insensitive operating state where the amount of variation of the swing force to the variation of the operating position for each unit is small. In a large side operating area W2, the means is brought into a sensitive operation state where the amount of variation of the swing force to the variation of the operating position for each unit is large. The means is formed so as to differentiate the traveling speeds of the pair of the traveling device so that a target swing force can be obtained and the target swing force can be provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of switching the traveling state of a pair of left and right traveling devices between a straight traveling state and a turning state, and in the turning state, the traveling speed of each of the pair of traveling devices is made to differ. A turning operation means configured to change the force, a straight movement command position for instructing the straight traveling state, and a movement operation over the entire range of a turning command operation region for instructing the turning state, and as the turning state. The present invention relates to a turning control device for a working vehicle, comprising: a turning command means for instructing a turning state in which a larger turning force results in a larger turning force in a direction away from a straight-ahead command position in the turning command operation area.

[0002]

2. Description of the Related Art Conventionally, as a turning control device for a work vehicle having the above-mentioned structure, there has been a structure shown in, for example, Japanese Patent Laid-Open No. 10-84749. That is, as the turning operation means, a pair of hydrostatic continuously variable transmissions (HSTs) for individually driving a pair of left and right traveling devices are provided, and the left and right traveling devices by the pair of hydrostatic continuously variable transmissions. By changing the traveling speed of the same to the straight traveling state,
A configuration is provided in which the traveling speeds of the left and right traveling devices are given a speed difference to switch to a turning state, and the following operating mechanism for turning is provided. In other words, a turning command means (steering handle) that can be freely turned is provided, and the turning command means and the pair of hydrostatic continuously variable transmissions to be operated (trunnion shafts) for shifting are mechanically interlocked. A pair of hydrostatic continuously variable transmissions are provided by rotating the turning command means in the turning command operation region from the straight-ahead command position toward the left and right turning directions. The configuration is such that the speed difference between the left and right traveling devices that are changed in speed is continuously changed according to a predetermined specific correlation, in other words, the turning force is changed to be larger as the operation amount is larger. Moreover,
The amount of change in the turning force with respect to the change in the operation position of the turning command means per unit amount is such that the turning operation is performed in the same state over the entire turning command operation region. Specifically, the traveling device on the turning side is driven in the same direction as the traveling device on the opposite side as the turning command means is moved from the straight-ahead command position in the operation region for the turning command, In addition, the turning state in which the speed of the turning side traveling device is lower than the speed of the opposite side traveling device and the speed difference gradually increases, the turning state in which the turning side traveling device is in the rotation stop state, and the turning side traveling device Was sequentially switched to the traveling device on the opposite side and the turning state driven in the opposite direction.

[0003]

In the above-mentioned conventional configuration, the turning state can be expressed by an arbitrary turning force by moving the turning command means and changing the operation position thereof. Since the amount of change in the turning force with respect to the change in the operation position per unit amount is such that the turning operation is performed over the entire turning command operation region, there is still room for improvement in the following aspects. there were.

In the above-mentioned conventional structure, the traveling device on the turning side is opposite when the turning command means is operated to the maximum operating position where the movement amount in the direction away from the straight-ahead command position in the turning command operating region is the largest. It is driven in the opposite direction of the traveling device on the side and switches to a swivel state in which a large turning force can be obtained, so it is convenient when such a large turning force is required. When performing an operation, such a large turning force is not always required, and a turning operation with a small turning force may be required. For example, in the case of harvesting planted crops such as combine harvesters, when performing a turning operation to align the vehicle body with the planting row of crops, a gentle turning force may be used while finely adjusting. You need to make a turn.

However, in the above-mentioned conventional structure, the amount of change in the turning force with respect to the change in the operating position of the turning command means per unit amount is the same over the entire operating region for the turning command, and moreover, the maximum operating position. Since a large turning force is obtained in the above, when performing the above-described gentle turning operation, the turning command means should be operated to move slightly in a direction away from the straight-ahead command position in the turning command operation area. However, there is a disadvantage that the turning force changes greatly, and it becomes impossible to properly turn while finely adjusting with a small turning force.

As one method for avoiding such a disadvantage, it is conceivable to suppress the target turning force when the turning command means is operated to the maximum operation position to a small one. With such a configuration, for example, when a large turning force is required, such as when the traveling direction of the vehicle body is greatly changed, even if the turning command means is operated to the maximum operating position, only a small turning force is obtained at that time. There is an inconvenience that you cannot do it.

As another method for avoiding the above disadvantage, the range in which the turning command means can be moved in the turning command operation area is widened to change the operating position of the turning command means per unit amount. It is possible to reduce the amount of change in the turning force with respect to the entire turning command operation region, but with this configuration, a large turning force is applied in order to greatly change the traveling direction of the vehicle body from the straight traveling state as described above. In the case of changing to a required state, it is necessary to greatly move the turning command means, which is disadvantageous in that the operation for turning becomes troublesome.

The present invention has been made by paying attention to such a point, and an object thereof is to avoid a disadvantage that the operation range of the turning command means is unnecessarily widened to make the operation troublesome, and a large turning force is exerted. It is an object of the present invention to provide a turning control device for a working vehicle, which is capable of appropriately performing a gentle turning while finely adjusting the turning amount.

[0009]

According to a first aspect of the present invention, there is provided a turning control device for a working vehicle, wherein the running state of a pair of left and right traveling devices can be switched between a straight traveling state and a turning state, and the pair of traveling devices can be operated in the turning state. Of the traveling devices, the turning operation means is configured to be able to change the turning force by changing the traveling speed of each of the traveling devices, and the entire range of the straight-ahead command position for instructing the straight-ahead state and the operation area for a turn-command for instructing the turning state. And a swing command means for commanding a swing state in which the larger the amount of movement in a direction away from the straight ahead command position in the swing command operation area is, the larger the swing force becomes. The small-side operation in which the turning operation means has a small movement amount in the turning command operation area in a direction away from the straight-ahead command position by the turning command means. In the insensitive operation state in which the amount of change in the turning force with respect to the change in the operation position of the turning command unit per unit amount is small, and the movement amount in the turning command operation region is smaller than the small side operation region. In the large-side operation area, which is also large, the amount of change in the turning force with respect to the change in the operating position of the turning command unit per unit amount is
In the form of a sensitive operation state that is larger than the change amount of the turning force with respect to the change in the operating position of the turning command unit in the small side operation area per unit amount, the target turning force is obtained and the turning command unit is obtained. On the basis of the command information of 1., the speed difference between the traveling speeds of the pair of traveling devices is made different so that the target turning force is obtained.

That is, the turning command means commands a turning state in which a larger turning force is obtained as the amount of movement in the direction in which the vehicle moves in a direction away from the straight-ahead command position in the turning command operation area becomes larger. Based on the command information of the command means, the turning operation is performed in a state in which the speed difference between the traveling speeds of the pair of traveling devices is different so that the target turning force is obtained. The traveling speed is a speed at which the traveling device drives to travel. Then, the turning operation means is in the insensitive operation state when the turning command means is moved within the small-side operation area to change and adjust the turning force, and the turning operation means becomes a target for a change in the operating position of the turning command means per unit amount. The amount of change in the turning force is small. Therefore, even if the turning command means is operated to move in a direction away from the straight-ahead command position, the change in the target turning force is small with respect to the change in the operating position. It becomes easy to properly perform the turning.

Further, the turning operation means is in the sensitive operation state when the turning command means is moved in the large-side operation area in which the movement amount is larger than the small-side operation area to change and adjust the turning force. The change amount of the target turning force with respect to the change of the operation position of the command unit per unit amount is the change amount of the target turning force with respect to the change of the operation position of the turn command unit in the small side operation area per unit amount. Will be greater than. That is, when the turning command means is moved beyond the small-side operation area to the large-side operation area and is moved within the large-side operation area, the change in the target turning force with respect to the change in the operation position is changed. Since it becomes large, the target turning force in the state where the turning command means is operated to the maximum operation position in which the amount of movement in the direction away from the straight-ahead command position in the turning command operation region is the largest can be swung, for example. Even if it is set to a large one, it is not necessary to widen the movement operation range of the turning command means in the large side operation area, and the movement operation range for moving the turning command means in the turning command operation area becomes unnecessary. It doesn't make it wide.

Therefore, there is no disadvantage that the operation range of the turning command means is unnecessarily widened to make the operation troublesome, and a large turning force can be obtained in a state in which the turning operation means is operated to the maximum operation position, but a small turning force is required. It has become possible to provide a turning control device for a work vehicle capable of appropriately performing a gentle turning while adjusting.

According to a second aspect of the present invention, there is provided a turning control device for a working vehicle according to the first aspect, in which the turning operation means is adapted to a change per unit amount of an operation position of the turning command means in the small side operation area. The amount of change in the turning force is maintained constant at a small set value, and in the large operation range, the amount of change in the turning force with respect to the change in the operating position of the turning command unit per unit amount is , In a form in which the set value on the large side, which is larger than the set value on the small side, is constantly maintained,
It is characterized in that it is configured to obtain the target turning force.

That is, in the small-side operation area, the amount of change in the turning force with respect to the change in the operating position of the turning command means per unit amount is maintained constant at the small-side set value. In the region, the change of the turning force is small with respect to the change of the operation position of the turning command means, and changes at a constant rate, which is desirable when performing a gentle turning while finely adjusting with a small turning force. Therefore, it is easy to adjust the turning force and to perform the turning operation properly. In the large-side operation area, since the amount of change in the turning force with respect to the change in the operating position of the turning command unit per unit amount is kept constant at the set value on the large side, it is large for a sharp turn or the like. When the operation is performed toward the target turning force, since the change of the target turning force with respect to the operation position is constant, it is easy to adjust to a desired turning force, and it is easy to properly perform the turning operation.

Further, in the connecting portion between the small-side operation area and the large-side operation area, the target amount of change in the turning force with respect to the change in the operating position of the turning command means changes in that portion, so that In the connecting portion, the changing state of the turning force suddenly changes with the movement operation of the turning command means. As a result, the operator who operates the turn command means moves,
It is possible to recognize that the degree of change in the turning force has changed when passing through this connecting portion, and it is possible to easily recognize whether the operation position is in the small-side operation area or the large-side operation area.

Therefore, while it is easy to properly perform the turning operation over the entire range of the turning command operation area, it is possible to easily recognize whether it is in the small side operation area or the large side operation area, and there are few operation errors. Good operation can be performed, and a suitable means for carrying out claim 1 can be obtained.

A turning control device for a work vehicle according to a third aspect of the present invention is
In Claim 1 or 2, the said turning operation means WHEREIN: In each of the said small side operation area and the said large side operation area, as the amount of movement to the direction away from the said straight advance command position by the said turning instruction means becomes large, the said In a configuration in which the amount of change in the turning force with respect to a change in the operating position of the turning commanding unit per unit amount gradually changes to the large side, and also in the connecting portion between the small side operation area and the large side operation area. The target turning force is such that the change amount of the turning force with respect to the change in the operating position of the turning command unit per unit amount gradually changes to the larger side as the movement amount by the turning command unit increases. It is characterized in that it is configured to seek.

That is, in the entire range of the turning command operation area including not only the small side operation area and the large side operation area but also the connecting portion thereof, the larger the movement amount by the turning command means is, the more the turning is performed. The target turning force is obtained in a form in which the change amount of the turning force with respect to the change in the operation position of the command means per unit amount gradually changes to the larger side.

Therefore, in the entire range of the operation area for turning command, the turning force changes smoothly with the moving operation of the turning command means, and the changing degree of the turning force changes rapidly during the moving operation. As a result, there is no disadvantage that the user feels uncomfortable in operation, and the suitable means for carrying out claim 1 can be obtained.

A turn control device for a work vehicle according to a fourth aspect of the present invention is
The operation position of the turning command means and the target according to any one of claims 1 to 3, wherein the insensitive operation state is set in the small side operation area and the sensitive operation state is set in the large side operation area. A turning force setting means for setting a correlation with the turning force to be set and for changing the correlation based on an artificial operation command. The target turning force is obtained based on the setting information of the force setting means.

That is, the turning force setting means for setting the correlation between the operating position of the turning command means and the target turning force is configured to be able to change and set the correlation based on the manual operation command. It is possible to change the correlation to an appropriate correlation according to the difference in the work situation at that time and the difference in the skill of the operator for the turning operation. Then, when the turning command means instructs the turning operation, the turning operation means commands a turning state in which a larger turning force is obtained as the amount of movement in a direction away from the straight-ahead command position in the turning command operation area is increased. At this time, the turning operation is performed by making the speed difference of the traveling speeds of the pair of traveling devices different so that the target turning force is obtained by the correlation set by the turning force setting hand. Become.

Therefore, it is possible to set the target turning force with respect to the operation position of the turning command means in an appropriate state according to the difference in the work situation at that time and the difference in the skill of the operator in the turning operation. Therefore, a suitable means for carrying out any one of claims 1 to 3 can be obtained.

A turning control device for a work vehicle according to claim 5 is
5. The turning force setting means according to claim 4, wherein the turning force when the turning command means is operated to a maximum operation position in which the movement amount is the largest in the operation area for turning command is based on an artificial operation command. It is characterized in that the correlation can be changed and set freely in a state of being increased or decreased.

That is, the turning force setting means increases or decreases the turning force when the turning command means is operated to the maximum operation position where the movement amount is the largest in the turning command range based on the human operation command, The correlation between the operating position of the turning command means and the target turning force is set.

Therefore, even when the operator feels that a large turning force is required and operates the turning command means to the maximum operating position, the turning force when the turning command means is operated to the maximum operating position is set. Is a turning force which is arbitrarily changed and set by the operator by the turning force setting means, so that the turning operation can be performed with an appropriate turning force. Suitable means are available.

A turning control device for a work vehicle according to a sixth aspect of the present invention is
The pair of continuously variable transmissions according to any one of claims 1 to 5, wherein the turning operation means continuously changes the traveling speed of each of the pair of left and right traveling devices, and the pair of continuously variable transmissions. And a control means for controlling the operation of the actuator. The control means controls the pair of actuators to change the turning force. It is characterized by being configured.

That is, by operating the pair of continuously variable transmissions individually by the pair of actuators, respectively,
It is possible to continuously change the traveling speed of each of the pair of left and right traveling devices. Therefore, by continuously changing the speed difference between the traveling speeds of the pair of left and right traveling devices,
The turning force can be changed steplessly, and the turning operation can be performed as smoothly as possible and the target turning force can be changed steplessly as compared with the structure in which the turning force is switched stepwise. Since it can be changed, it becomes possible to perform the turning operation with the most appropriate turning force that matches the operation feeling of the operator, and a means suitable for carrying out any one of claims 1 to 5 can be obtained.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] A case in which a first embodiment of a turning control device for a work vehicle according to the present invention is applied to a combine as an example of the work vehicle will be described with reference to the drawings. .

FIG. 1 shows an overall side surface of a combine, which is an example of a work vehicle. This combine has a traveling body 2 that is driven by a pair of left and right crawler type traveling devices 1R and 1L, which is an example of a traveling device. The harvesting and conveying device 3 that cuts the planted culm and conveys it to the rear is vertically connected to the front part of the, and the traveling machine body 2 receives the harvested culm from the harvesting and conveying device 3 to perform threshing / sorting processing. The threshing device 4 for carrying out the above and the grain tank 5 for storing the grain from the threshing device 4 are mounted, and the boarding operation part 6 is formed at a front portion of the grain tank 5.

As shown in FIG. 2, this combiner transmits the power from the engine 7 to the input shaft 10 of the transmission case 9 via the belt tension type main clutch 8, and the input shaft 10 is used for traveling. Distributing and transmitting to the pair of hydrostatic continuously variable transmissions 11R and 11L (an example of the continuously variable transmission), and the power after shifting by one of the hydrostatic continuously variable transmissions 11L for traveling is shifted to the left gear type auxiliary gearshift. The power after shifting by the other hydrostatic continuously variable transmission 11R for traveling is transmitted to the left crawler type traveling device 1L via the device 13L and is transmitted to the right crawler via the right gear type auxiliary transmission device 13R. The transmission mechanism for traveling drive is configured so as to be transmitted to the traveling device 1R. On the other hand, the power from the engine 7 is also supplied to the working hydrostatic stepless transmission 12, and the power after shifting by the working hydrostatic stepless transmission 12 is supplied to the belt tension type cutting clutch 14. A transmission mechanism for the reaping work is configured so as to be transmitted to the reaping and conveying device 3 via.

Left and right gear type auxiliary transmissions 13R, 13L
Is configured as a sub-transmission mechanism that is capable of switching the power of each of the hydrostatic stepless transmissions 11R and 11L after shifting to high and low two stages and switching to a power cut-off state.
Further, by connecting and disconnecting the transmission shafts 15R and 15L, the left and right crawler type traveling devices 1R and 1L are integrally connected to each other and driven at a constant speed, and the left and right crawler type traveling devices 1R and 1L are respectively connected. In addition, a multi-plate hydraulic clutch 16 that switches to a state in which a shift operation is permitted is provided.

Then, as shown in FIG. 3, a hydraulic traveling operating mechanism 30 for individually shifting the traveling hydrostatic continuously variable transmissions 11R and 11L, and a working hydrostatic continuously variable transmission. A hydraulic operation mechanism 36 for shifting the transmission 12 and an electromagnetic switching valve 32 for switching the flow state of the hydraulic oil to the hydraulic clutch 16 are provided. The traveling operation mechanism 30 includes a trunnion shaft 29 in each of the hydrostatic continuously variable transmissions 11R and 11L for traveling.
A pair of double-acting hydraulic cylinders 33 linked to 29
R, 33L (an example of an actuator) and a state in which hydraulic oil is supplied to a pair of oil chambers corresponding to operations of the hydraulic cylinders 33R, 33L in forward and reverse directions, respectively, and a state in which supply of hydraulic oil is stopped can be switched freely. A pair of two-position switching type hydraulic electromagnetic valves 34A for oil supply, and a pair of two-position switching type oil discharging oils that can be switched between a state in which hydraulic oil is discharged from the pair of oil chambers and a state in which discharge is stopped. And a hydraulic solenoid valve 34B. Each of the hydraulic cylinders 33R,
33L is configured to be urged to return to the neutral position by the urging force of a spring installed therein.

Similarly, the work operating mechanism 36 also has a trunnion shaft 37 in the hydrostatic continuously variable transmission 12 for work.
And a pair of hydraulic cylinders 40 of a double-acting type configured to be urged to return to a neutral position by an urging force of a spring installed inside, and a pair of hydraulic cylinders 40 corresponding to respective operations in forward and reverse directions. A pair of two-position switching hydraulic solenoid valves 41A for refueling, which can be switched between a state in which the working oil is supplied to the oil chamber and a state in which the working oil is stopped, and a state in which the working oil is discharged from the pair of oil chambers. And a pair of two-position switching type hydraulic electromagnetic valves 41B for oil discharge that can be switched to a state in which the oil is stopped.

Hydraulic solenoid valves 34A, 41A for refueling
Is configured to move and urge the spool to the oil supply stop state by the urging force of the spring, and the solenoid is moved by electromagnetic force against the urging force of the spring to switch the spool to a state in which hydraulic oil is supplied. It is configured,
Further, each of the hydraulic electromagnetic valves 34B and 41B for draining oil is configured to move and urge the spool to the discharge state by the urging force of the spring, and resist the urging force of the spring by the electromagnetic force of the solenoid. The spool is moved to switch to a state in which the discharge of hydraulic oil is stopped. or,
The boarding operation unit 6 is provided with a single sub-transmission lever 25 that can be rocked in the front-rear direction.
It is linked to the gear type auxiliary transmissions 13R and 13L, and by operating the auxiliary transmission lever 25, the power after shifting by each of the hydrostatic stepless transmissions 11R and 11L for traveling is controlled to a high or low level.
It is possible to shift gears.

The hydrostatic continuously variable transmission 11 as described above.
If the shift operation of R and 11L is added, for example, as shown in FIG. 4, when the shift position of the trunnion shaft 29 is in the neutral range having a predetermined width including the neutral position N, the shift output (running speed) becomes zero. When the gear shift position of the trunnion shaft 29 is rotated in a predetermined direction from its neutral position, the traveling speed in the forward direction is continuously increased, and the trunnion shaft 2
When 9 is rotated from the neutral region in the direction opposite to the predetermined direction, the traveling speed in the reverse direction is continuously increased.

The boarding operation unit 6 has a main gear shift lever 2 which can be rocked over a predetermined front and rear operation range along the front and rear direction.
4 and a swiveling lever 26 as a swiveling command means capable of swinging over a predetermined left and right operating range along the left and right direction.
Are equipped with. As shown in FIG. 3, a shift lever sensor 27 for detecting the operating position of the main shift lever 24 and a swing lever sensor 28 for detecting the operating position of the swing lever 26 are provided respectively, both of which are rotary type. It consists of a potentiometer.

A pair of hydrostatic continuously variable transmissions 11R,
11L includes rotation speed sensors 44 and 45 as shift output detecting means for individually detecting the output rotation speeds thereof,
Shift position sensors 46 and 47 as shift position detecting means for detecting shift positions of the respective hydrostatic stepless transmissions 11R and 11L, that is, operating angles of the trunnion shafts 29 by the pair of hydraulic cylinders 33R and 33L. Are provided respectively.

Then, the hydraulic cylinders 33R, 33
A control device 31 using a microcomputer for controlling the operations of the L and 40 is provided, and the control device 31 is based on the detection information of the speed change lever sensor 27 and the turning lever sensor 28, and a pair of hydrostatic stepless. Transmission 11
The respective target rotation speeds of R and 11L are calculated, and the target shift positions of the trunnion shafts 29 corresponding to the calculated target rotation speeds are set, and the shift position sensors 46 and 47 are set.
It is configured to execute traveling control for controlling the operation of the pair of hydraulic cylinders 33R and 33L so that the detected value of 1 is the target shift position.

That is, in the state where the turning lever 26 is operated to the straight-ahead command position and the straight-ahead command is issued, the main gearshift lever 24 is moved to the neutral position (corresponding to the stop command position) which is located substantially in the middle of the operable range. When it is operated, the vehicle stops running, and when it is rocked from the neutral position to the forward side, the traveling speed to the forward side is continuously increased accordingly, and when it is operated from the neutral position to the reverse side, it is accompanied by it. The operation of the pair of hydraulic cylinders 33R and 33L is controlled so that the traveling speed to the reverse side is continuously increased, and when the main transmission lever 24 is fixed at a predetermined position, The operation of the pair of hydraulic cylinders 33R and 33L is controlled so that the vehicle body travels straight at the target traveling speed commanded by the position. Further, the control device 31 controls the main shift lever 2
4 is operated and is traveling at a predetermined speed, when the turning lever 26 is oscillated in any one of the left and right turning command operation regions from the straight ahead command position, it is operated to the side away from the straight ahead command position. The smaller the turning radius,
In other words, a turning state that gives a large turning force is commanded, and each hydraulic cylinder 33R,
It is configured to control the operation of the 33L.

Then, the control unit 31 is a unit of the operation position of the turning lever 26 in the small operation area in which the amount of movement of the turning lever 26 in the direction away from the straight-ahead command position is small in the turning command operation area. The target amount of change in the turning force with respect to the change per amount is in the insensitive operation state, and the turning lever 26 is included in the turning command operation region.
In the large-side operation range in which the amount of movement in the direction away from the straight-ahead command position due to is larger than the small-side operation range, the change amount of the target turning force with respect to the change in the operation position of the turning lever 26 per unit amount is The target turning force is determined in a sensitive operation state in which the change amount of the target turning force is larger than the change amount of the turning lever 26 per unit amount in the small operation area. .

In the small side operation area, the amount of change in the turning force with respect to the change in the operating position of the turning lever 26 per unit amount is maintained constant at the small side set value, and the large side operation is performed. In the range, the change amount of the turning force with respect to the change in the operation position of the turning lever 26 per unit amount is kept constant at the set value on the large side which is larger than the set value on the small side. It is configured to obtain a turning force to rotate, and further, the correlation between the operating position of the turning lever 26 and the target turning force can be changed and set based on an artificial operation command. The target turning force is obtained based on the information on the correlation between the set operation position of the turning lever 26 and the target turning force. Then, the hydraulic cylinders 33R, 3R, 3R, 3R, 3R, 3L, 3R, 3R, 3R, 3R, 3R, 3L, 3L, 3L, 3L, 3L, 3L, 3L are configured so that the traveling speeds of the pair of crawler traveling devices 1R, 1L are different from each other so as to obtain the target turning force.
It is configured to control the operation of the 3L.

In addition, the magnitude of the turning force due to the speed difference between the left and right crawler traveling devices 1R and 1L with respect to the operation position of the turning lever 26, specifically, the crawler on the side opposite to the speed of the crawler traveling device on the turning side. The correlation of the speed ratio to the speed of the traveling device is set. That is, FIG.
As shown in, in the small-side operation range W1 in which the amount of movement by the turning lever 26 in the direction away from the straight-ahead command position is small, the target turning force with respect to the change in the operating position of the turning lever 26 per unit amount is The turning lever 2 becomes a linear state in which the amount of change is kept constant at the small setting value.
In the large-side operation range W2 in which the amount of movement by 6 in the direction away from the straight-ahead command position is larger than the small-side operation range, the target amount of change in the turning force with respect to the change in the operation position of the turning lever 26 per unit amount. Is in a linear state so as to be constantly maintained at a large set value that is larger than the small set value, and has a target turning force, specifically, a pair of crawler traveling devices 1R, 1L. The speed ratio of is set.

Further, the above-mentioned correlation can be freely changed and set based on an artificial operation command. That is, in a state where the turning lever 26 increases or decreases the turning force when the turning lever 26 is operated to the maximum operation position where the movement amount is the largest in the turning command operation area, the correlation in the large operation area is basically changed. It is possible to switch to three different types of turning modes, and moreover, the target amount of change in turning force with respect to the change in the operating position of the turning lever 26 per unit amount in the small side operation area W1, and the small side. The width of the operation area in the operation area can be adjusted to be increased or decreased.

First, switching of the turning mode will be described. In the boarding operation unit 6, the correlation as described above in the large-side operation area W2 is displayed in the gentle turning mode indicated by the line L2 in FIG. 6, the ground turning mode indicated by the line L3 in FIG.
A three-contact type mode changeover switch 42 for changing over to the three turning modes of the super-trust turning mode shown by line L4 in FIG. 6 is provided, and a changeover command by this mode changeover switch 42 is given to the control device 31. Control device 3
1 is configured to switch the turning mode as follows based on the switching command. However, even if the mode changeover switch 42 is switched, the correlation of the small side operation area W1 does not change.

A line L1 in the figure shows the speed of the crawler traveling device on the side opposite to the turning side. A line L2 shows a change in traveling speed of the crawler traveling device on the turning side in the gentle turning mode. That is, as the operation position of the turning lever 26 moves away from the straight ahead command position to the turning side, the traveling speed of the crawler traveling device on the turning side is gradually reduced, and when the turning lever 26 is operated to the maximum operation position, the opposite side is reached. The change characteristics of the speed ratios of the left and right crawler traveling devices 1R and 1L with respect to the operation position of the turning lever 26 are preset so that the speed is reduced to about 1/3 of the traveling speed V of the crawler traveling device. There is. Further, in the solid turning mode indicated by the line L3, when the turning lever 26 is operated to the maximum operation position, the turning lever 26 is decelerated so that the running speed of the crawler running device on the turning side becomes zero. The speed ratios of the left and right crawler traveling devices 1R and 1L with respect to the operating position of are set in advance. Further, in the super-trust turning mode indicated by the line L4, when the turning lever 26 is operated to the maximum operation position, the traveling speed of the crawler traveling device on the turning side is different from the driving rotation direction of the crawler traveling device on the opposite side. The speed ratio of the left and right crawler traveling devices with respect to the operation position of the turning lever 26 is preset so that the speed is about 1/3 of the speed of the crawler traveling device on the opposite side in the reverse rotation direction.

The boarding operation unit 6 has two potentiometer-type manually operated adjustment operation tools 43a and 43b.
Is provided, and these pieces of information are also input to the control device 31. Then, when the adjustment operation tool 43a for adjusting the deceleration amount is operated, the control device 31 changes the target turning force with respect to the change in the operating position of the turning lever 26 in the small-side operation area W1 per unit amount. Is configured to be changed. Specifically, the configuration is such that the end point position (point P in FIG. 6) of the small side operation area W1 can be moved and adjusted in the vehicle speed increasing / decreasing direction (Y direction).
When the adjustment operation tool 43b for changing the operation width is operated,
It is configured to increase or decrease the width of the operation area in the small-side operation area W1. Specifically, it is configured such that the end point position (point P) of the small side operation area W1 can be moved and adjusted in the operation position changing direction (X direction). However, even if the adjustment operation using these adjustment operation tools 43a and 43b is performed,
The change amount of the target turning force with respect to the change in the operation position of the turning lever 26 per unit amount in the small side operation area W1 is maintained smaller than that in the large side operation area W2.

Therefore, by operating the mode changeover switch 42 and the adjusting operation tools 43a and 43b, the correlation between the operating position of the turning lever 26 in the turning command operation area and the target turning force, that is, Swivel lever 26
One line is specified as the characteristic of the speed ratio of the left and right crawler traveling devices 1R and 1L by the operation of. In the above correlation, the straight-ahead command position of the turning lever 26 includes the dead band set to a predetermined width, and the fact that the turning state is in the operation position where no command is given is called the straight-ahead command position.

Therefore, the controller 31 is used to change and set the correlation between the operation position of the turning command in the turning command operation area and the desired turning force as described above, based on the manual operation command. A free turning force setting means 100,
Based on the command information of the turning command means and the setting information of the turning force setting means, obtain the target turning force,
The traveling control means 101 as a control means for controlling the operation of the hydraulic cylinders 33R and 33L is configured so that the speed difference between the traveling speeds of the pair of crawler traveling devices is made different so that the target turning force is obtained. Has been done.

On the other hand, as shown in FIG.
The characteristic of the change of the target vehicle speed with respect to the operation position of No. 4 is preset and stored, and the control device 31 controls the characteristic of the speed ratio of the left and right crawler traveling devices 1R and 1L by the operation of the turning lever 26 as described above. , The target rotational speeds of the hydrostatic stepless transmissions 11R and 11L for the pair of left and right crawler traveling devices 1R and 1L are determined based on the target vehicle speed determined by the operation position of the main transmission lever 24 shown in FIG. Perform the desired process. Then, as shown in FIG. 7, the trunnion shafts 29, 29 corresponding to the respective target rotation speeds are provided.
The target shift positions of the trunnion shafts 29, 29 that correspond to the target rotational speeds obtained as described above are set based on the reference information set to obtain the target shift positions of The corresponding hydraulic cylinders 33 are arranged so that the gear shift positions of the pair of trunnion shafts 29, 29 detected by the sensors 46, 47 become the respective target gear shift positions.
Controls R and 33L. That is, the pair of left and right hydrostatic continuously variable transmissions 11R,
Control is performed so that the speed difference between the traveling speeds of the 11Ls is different.

The traveling control operation by the control device 31 will be specifically described below with reference to the control flowchart. That is, as shown in FIG. 8, the control device 31 controls the operation position of the main speed change lever 24 detected by the speed change lever sensor 27 and the operation position of the turning lever 26 detected by the turning lever 26 sensor 28. Based on the detection result,
The target rotational speeds of the left and right hydrostatic continuously variable transmissions 11R and 11L are obtained (steps 1 and 2). And
The respective target shift positions for the pair of trunnion shafts 29, 29 are set in correspondence with the obtained respective target rotation speeds (step 3). Next, the shift position sensors 46 and 47
The hydraulic solenoid valves 3 are adjusted so that the gear shift positions of the trunnion shafts 29, 29 detected by the above are the target gear shift positions.
4A and 34B are controlled to execute a gear shift operation to operate the traveling hydraulic cylinders 33R and 33L (step 4). That is, the feedback control is executed based on the shift position detection information. In this way, the traveling speed of each of the pair of left and right hydrostatic continuously variable transmissions 11R and 11L is set to a speed corresponding to the command state at that time so that the target turning force is obtained in the turning operation state. In addition, the pair of left and right hydrostatic continuously variable transmissions 11R and 11L are controlled so that the speed difference between the traveling speeds thereof is different.

The above-mentioned pair of left and right hydrostatic continuously variable transmissions 11
Each of the R and 11L, the pair of hydraulic cylinders 33R and 33L, the traveling operation mechanism 30, and the control device 31 constitutes a turning operation means.

[Second Embodiment] A second embodiment of the turning control apparatus for a work vehicle according to the present invention will be described below with reference to the drawings. This embodiment is the same as the first embodiment except for the configuration related to the setting of the correlation between the operation position of the turning lever 26 in the turning command operation region and the target turning force. Therefore, only different parts will be described, and description of the same parts will be omitted.

In this embodiment, in each of the small-side operation area and the large-side operation area, the operating position of the turning lever 26 increases as the amount of movement of the turning lever 26 in the direction away from the straight-ahead command position increases. Is a form in which the amount of change in the turning force with respect to a change per unit amount gradually changes to the large side, and the turning lever 26 also moves at the connecting portion between the small side operation region and the large side operation region. As the amount increases, the target turning force is obtained in a form in which the amount of change in the turning force with respect to the change in the operating position of the turning lever 26 per unit amount gradually changes to the larger side.

That is, as shown in FIG. 9, the target amount of change in the turning force with respect to the change in the operating position of the turning lever 26 per unit amount in the small-side operating area W1 is larger than that in the large-side operating area W2. While maintaining the small state, the left and right crawler traveling devices 1 with respect to the operation position of the turning lever 26.
The magnitude of the turning force due to the speed difference between R and 1L gradually changes to the larger side with respect to the change in the operating position of the turning lever 26 per unit amount as the amount of movement of the turning lever 26 increases. It is set as a form that smoothly changes while drawing a quadratic curve.

Further, there is a structure in which three different kinds of turning modes can be switched based on the switching operation of the mode switch 42 having the same structure as in the first embodiment. In addition, in the slow turning mode shown by the line L5 in FIG. 9, when the turning lever 26 is operated to the maximum operating position, the crawler running device on the turning side changes the running speed V of the crawler running device on the opposite side. The change characteristic of the speed ratio of the left and right crawler traveling devices 1R and 1L with respect to the operation position of the turning lever 26 is preset so that the speed is reduced to about 1/3. In the solid turning mode indicated by line L6, when the turning lever 26 is operated to the maximum operation position, the turning lever 26 is operated so that the running speed of the turning side crawler running device is reduced to zero. The speed ratio of the left and right crawler traveling devices 1R and 1L with respect to the position is preset. Further, in the super-trust turning mode indicated by line L7, when the turning lever 26 is operated to the maximum operation position, the traveling speed of the crawler traveling device on the turning side is the driving rotation direction of the crawler traveling device on the opposite side. With respect to the operation position of the turning lever 26, so that the speed becomes the same as the speed of the crawler traveling device on the opposite side in the reverse rotation direction,
The speed ratio of the left and right crawler traveling devices is preset.

In the second embodiment, the large side operation area W
Not only 2 but also in the small side operation area W1, a different line is formed for each of the modes, and a turning command including the small side operation area W1 and the large side operation area W2, and a connecting portion thereof. A quadratic curve is drawn over the entire range of the operation area for use to smoothly change the turning force. The configuration of the traveling control for the pair of crawler traveling devices 1R and 1L is the same as that of the first embodiment.

[Other Embodiments] Other embodiments will be listed below.

(1) In the above-described first embodiment, as a changeable total range in which the turning force when the turning lever 26 is operated to the maximum operation position is increased / decreased, a pair of crawlers from the state where the speed difference is zero is set. An example is shown in which the traveling devices are rotationally driven in the opposite directions at the same speed so that the vehicle body can be changed and adjusted to the maximum speed difference state in which the vehicle makes a spin turn. As
When the swiveling lever 26 is operated to the maximum operation position, the crawler traveling device on the swiveling side is set to be driven at a speed of about 1/3 in the opposite direction to the speed of the crawler traveling device on the opposite side. Alternatively, the crawler traveling device on the turning side may be set to a zero speed state when the turning lever 26 is operated to the maximum operation position.

(2) In the first embodiment, as the switching of the turning mode, the three lines L2, L3 of FIG.
Although the three modes shown by L4 are illustrated, the turning mode is not limited to such a configuration and may have any configuration. For example, when the turning lever 26 is operated to the maximum operation position, the running speed of the crawler running device on the turning side is the reverse rotation direction to the drive rotation direction of the crawler running device on the opposite side, and the crawler running device on the opposite side is running. To the same position as the speed of
A turning mode in which the speed ratio of the left and right crawler traveling devices is preset may be set, and the setting of the correlation can be changed to various states. In the first embodiment, the correlation in the small-side operation area W1 does not change even when the turning mode is switched. However, instead of such a configuration, for example, as shown in FIG. The correlation in the small-side operation area W1 may change as the turning mode is switched.

(3) In the first embodiment, the target amount of change in the turning force with respect to the change in the operation position of the turning lever 26 per unit amount in the small side operation area W1 and the small side operation area. Although the configuration is such that the width of the operation region can be adjusted to be increased or decreased, only one of them may be adjustable, or such change adjustment may not be performed.

(4) In the second embodiment, different lines are formed for each of the modes not only in the large side operation area W2 but also in the small side operation area W1, and the small side operation area W1 is formed. An example is shown in which the turning force is smoothly changed by drawing a quadratic curve over the entire range of the turning command operation area including the large side operation area W2 and the connecting portion thereof. Instead of such a configuration, the following configuration may be adopted. For example, as shown in FIG. 11, even if the turning mode is switched, the correlation does not change in the small-side operation area W1, but the correlation may change only in the large-side operation area W2. However, in this case, the connecting portion between the small-side operation area W1 and the large-side operation area W2 is not a smooth quadratic curve but is in a refraction state.

(5) In each of the above embodiments, the correlation can be switched to a plurality of modes, but the invention is not limited to such a configuration and only one line is set in advance as the correlation. The turning operation may be performed only on that line.

(6) In each of the above embodiments, the swing command type swing lever 26 is illustrated as the swing command means, but the invention is not limited to such a configuration, and a swingable steering wheel handle may be used. Good.

(7) In the above embodiment, when a turning operation is performed, the speed of the traveling device on the turning side is gradually decelerated while maintaining the speed of the traveling device on the opposite side to the turning side constant. However, the present invention is not limited to such a configuration, and the speed of the traveling device located on the side opposite to the turning side is gradually increased while the speed of the traveling device on the turning side is kept constant, and The present invention can be implemented in various forms, such as a configuration in which the speed of the traveling device is gradually reduced and the speed of the traveling device located on the side opposite to the turning side is gradually increased.

(8) In each of the above-mentioned embodiments, as the turning operation means, a hydrostatic stepless transmission that continuously changes the traveling speed of each of a pair of left and right traveling devices, and a speed change gear for each of them. An example is shown in which a hydraulic cylinder as a pair of actuators to be operated and control means for controlling the operation of the hydraulic cylinder are provided, but instead of such a configuration, the following (a) to (d) ). (A) As the pair of continuously variable transmissions, for example, instead of a hydrostatic continuously variable transmission, for example, a belt type continuously variable transmission or a taper cone type continuously variable transmission, and for switching the traveling direction back and forth It may be configured to include a forward / reverse switching mechanism or the like. (B) As the actuator, another actuator such as an electric motor or a hydraulic motor may be used instead of the hydraulic cylinder. (C) Instead of using the actuator and the control means, by operating a turning lever as a turning command means, the pair of continuously variable transmissions are integrally formed in a state in which a speed-changing operated body is provided with a speed difference. Of the turning lever within the turning command operation area and the target turning force by changing the mechanical link ratio of the link mechanism, etc. It may be configured to change and set the relationship. (D) Instead of the above-described structure in which the continuously variable transmission is provided, the left and right sides are changed by a so-called pulse width modulation control, which electrically turns on and off the clutch interposed in the transmission system for each crawler traveling device in a short time. It may be configured to change and adjust the speed difference of the crawler traveling device. in short,
The turning operation means may be any structure that can change the turning force by changing the running speeds of the pair of running devices.

(9) In the above embodiment, the combine vehicle is exemplified as the work vehicle, but the present invention is not limited to the combine vehicle.
Other farm work vehicles such as carrot harvesters and radish harvesters may also be used,
Further, the work vehicle is not limited to an agricultural work vehicle and may be a work vehicle such as a construction machine.

[Brief description of drawings]

1] Overall side view of combine

FIG. 2 is a schematic configuration diagram showing a transmission structure.

FIG. 3 is a control block diagram.

FIG. 4 is a diagram showing a relationship between a shift position and a shift output.

FIG. 5 is a diagram showing a relationship between a main shift lever operation position and a target vehicle speed.

FIG. 6 is a diagram showing a relationship between an operation position of a turning lever and a speed ratio of a left and right traveling device.

FIG. 7 is a diagram showing a relationship between a target rotation speed and a target shift position.

FIG. 8 is a flowchart of control operation

FIG. 9 is a diagram showing the relationship between the operating position of the turning lever and the speed ratio of the left and right traveling devices according to the second embodiment.

FIG. 10 is a diagram showing the relationship between the operating position of the turning lever and the speed ratio of the left and right traveling devices according to another embodiment.

FIG. 11 is a diagram showing the relationship between the operating position of the turning lever and the speed ratio of the left and right traveling devices according to another embodiment.

[Explanation of symbols]

1R, 1L traveling device 11R, 11L continuously variable transmission 26 Turning command means 33R, 33L actuator 100 Turning force setting means 101 control means W1 small side operation area W2 Large side operation area

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2B043 AA04 AB08 BA02 BA05 BB14                       DA05 DA07 DA13 DB17 DB18                       DB20 DB21                 2B076 AA03 CC02 DA03 DA15 DB08                       DC01 EA01 EA06 EC16                 3D052 AA05 BB08 DD03 DD04 EE01                       FF02 GG04 GG05 JJ02 JJ03                       JJ12 JJ14 JJ21 JJ22 JJ23                       JJ35 JJ37

Claims (6)

[Claims] 1. A configuration in which the traveling state of a pair of left and right traveling devices can be switched between a straight traveling state and a turning state, and the turning force can be changed by changing the traveling speed of each of the pair of traveling devices in the turning state. The turning operation means, the straight-moving command position for instructing the straight-ahead traveling state, and the entire range of the turning-command operating area for instructing the turning state. In the turning control device for a working vehicle, the turning control means includes a turning command means for instructing a turning state in which a larger turning force results in a larger turning force in a direction away from the straight ahead command position. In the operation area, in the small-side operation area in which the amount of movement by the turning command means in the direction away from the straight-ahead command position is small, the operating position of the turning command means is small. The change amount of the turning force with respect to the change per unit amount of the operation is in the insensitive operation state, and in the turning command operation region, the movement amount is larger than the small side operation region, in the large side operation region, The amount of change in the turning force with respect to the change in the operating position of the turning command unit per unit amount is larger than the amount of change in the turning force with respect to the change in the operating position of the turning command unit in the small-side operation area per unit amount. In the form of a large sensitive operation state, the target turning force is obtained, and based on the command information of the turning command means, the traveling speed of each of the pair of traveling devices is adjusted so as to become the target turning force. A turning control device for a work vehicle configured to have different speed differences. 2. The turning operation means maintains a constant change amount of the turning force with respect to a change in the operation position of the turning command means per unit amount in the small-side operation range at a small-side set value. Further, in the large-side operation range, the change amount of the turning force with respect to the change per unit amount of the operation position of the turning instruction means is set to a large-side set value that is larger than the small-side set value. The turning control device for a work vehicle according to claim 1, wherein the turning control device is configured to obtain the target turning force in a form of being maintained constant. 3. The turning command is provided by the turning operation means in each of the small-side operation area and the large-side operation area, as the amount of movement in a direction away from the straight-ahead instruction position by the turning instruction means increases. In a form in which the amount of change in the turning force with respect to a change in the operation position of the means per unit amount gradually changes to the large side, and also in the connecting portion between the small side operation area and the large side operation area, The target turning force is obtained in such a manner that the change amount of the turning force with respect to the change in the operation position of the turning command unit per unit amount gradually changes to the larger side as the amount of movement by the turning command unit increases. The turning control device for a work vehicle according to claim 1, wherein the turning control device is configured as described above. 4. The operation position of the turning command means and the target turning force are set such that the insensitive operation state is set in the small side operation area and the sensitive operation state is set in the large side operation area. A turning force setting means for setting the correlation and changing and setting the correlation based on an artificial operation command is provided, and the turning operation means sets the command information of the turning command means and the turning force setting means. The turning control device for a working vehicle according to any one of claims 1 to 3, wherein the turning control device is configured to obtain the target turning force based on information. 5. The turning force setting means sets a turning force when the turning command means is operated to a maximum operation position where the movement amount is the largest in the turning command operation area based on an artificial operation command. The turning control device for a work vehicle according to claim 4, wherein the correlation is freely changeable and set in a state where the correlation is increased or decreased. 6. A pair of continuously variable transmissions for continuously changing the traveling speed of each of the pair of left and right traveling devices by the turning operation means, and a pair of continuously variable transmissions for individually changing the traveling speeds respectively. A pair of actuators to be operated and a control means for controlling the operation of the actuators are provided, and the control means is configured to change the turning force by controlling the pair of actuators. Item 7. A turning control device for a work vehicle according to any one of items 1 to 5.