JP5385618B2 - Work vehicle turning control device - Google Patents

Description

The present invention provides an index value command means for commanding an index value corresponding to the magnitude of the operating pressure;
Operating pressure adjusting means for adjusting the operating pressure on the operated device;
An actual operating pressure detecting means for detecting an actual operating pressure of the operating pressure adjusting means;
Control means for operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure,
As the relationship between the index value of the index value command means and the target operation pressure, an operation for storing a plurality of operation relationships in which the target operation pressure is increased as the operation pressure is larger and the target operation pressure at the same index value is different. Relationship storage means;
As the operated device, a plurality of frictions that adjust the traveling speed of the traveling device on the inner side of the turning of the pair of left and right traveling devices for turning and that show different turning radii when the same hydraulic pressure is applied. Type hydraulic clutch,
An operation relationship selecting means for selecting any one of a plurality of operation relationships,
The control means is
An index value commanded by the index value command means, a target operating pressure calculation process for obtaining a target operating pressure based on the operating relation selected by the operating relation selecting means, and
An operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure detected by the actual operation pressure detection means becomes the target operation pressure obtained in the target operation pressure calculation process. The present invention relates to a turning control device for a work vehicle .

The work vehicle turning control device is, for example, a friction hydraulic clutch for turning operation in a work vehicle such as a combine, and the like, and is used to adjust the operation pressure on the operated device. In this type of work vehicle, the control means is configured to control the operating pressure for the frictional hydraulic clutch by changing the current value energized to the electromagnetic proportional valve as the operating pressure adjusting means, and the index value command As a relation between the operation position (index value) of the turning lever as a means and the target operation pressure, the operation relation in which the target operation pressure becomes larger as the movement amount of the turning lever in the direction away from the rectilinear command position is larger. Is set based on the index value of the turning lever as the index value command means and the operation relationship selected by the mode changeover switch as the operation relationship selection means. Is configured to determine the target operating pressure for operating the operation device (e.g., see Patent Document 1.).

  By the way, Patent Document 1 discloses that when the index value of the index value command means is changed to the maximum value when the hydraulic clutch for turning operation is operated as the operated device as the turning mode, the turning side of the pair of left and right traveling devices If the index value of the index value command means is changed to the maximum value when the driving speed of the traveling apparatus is made slower than the driving speed of the traveling apparatus on the opposite side and the vehicle turns slowly, the traveling speed of the traveling apparatus on the turning side When the index value of the index value command means is changed to the maximum value, the traveling speed of the turning-side traveling device is opposite to the traveling speed of the opposite-side traveling device. A reverse turning mode (super turning mode) that is driven in the direction opposite to the drive rotation direction of the traveling device on the side is set, and as a hydraulic clutch for turning operation, a hydraulic clutch for slow turning, In order to simplify the configuration, instead of such a configuration, a hydraulic clutch for turning the brake and a hydraulic clutch for reverse rotation are provided. A configuration has been considered in which both the hydraulic clutch and the hydraulic clutch for the turning operation corresponding to the reverse turning mode are used.

  That is, in order to use the hydraulic clutch for the turning operation corresponding to the reverse turning mode as the hydraulic clutch for the turning operation corresponding to the brake turning mode, the fuselage with respect to the traveling device inside the turning of the pair of left and right traveling devices. By changing the operating pressure of the friction type hydraulic clutch that transmits the propulsive force that travels in the direction opposite to the traveling direction, it is possible to switch between the brake turning state and the reverse turning state, and the operation pressure adjusting means is configured to be friction type. In this configuration, the operation pressure of the hydraulic clutch is adjusted. In this configuration, in the reverse rotation mode, when the index value of the index value command means is changed to the maximum value, the operating pressure of the friction type hydraulic clutch is adjusted to the operating pressure that drives the swing side travel device in the reverse direction. In the brake turning mode, when the index value of the index value command means is changed to the maximum value, the operation pressure of the friction hydraulic clutch is decelerated until the running speed of the running device on the turning side becomes zero. It is necessary to adjust the pressure.

  As a result, since it is necessary to make the target operating pressures different at the same index value, as the relationship between the index value of the index value command means and the target operating pressure, the larger the operating pressure is, the higher the target operating pressure is and the same index It is necessary to provide two types of operation relationships in which the target operation pressure in the value is changed to a smaller value in the brake turning mode than in the reverse turning mode.

  In the configuration in which a plurality of operation relationships are provided as described above, even when the turning lever as the index value command means is moved in a direction away from the straight-ahead command position and the turning travel is being performed, the operation relation selection means It is possible to change the operation relationship to a different operation relationship with the operation relationship selection means, and when the operation relationship is changed to a different operation relationship with the operation relationship selection means, the target operation pressure is changed based on the operation relationship until the change. The target operating pressure is changed from the target operating pressure before the change to the target operating pressure after the change obtained based on the changed operation relation, and the target operating pressure after the change becomes the target operating pressure after the change. The operating pressure adjusting means is operated in such a manner that the value is immediately changed.

JP 2000-264243 A

  As described above, a plurality of operation relations are provided, and the operation relation selection means is used even when the turning lever as the index value instruction means is moved in the direction away from the straight-ahead instruction position and turning is in progress. In the operation pressure control device configured to be able to change the operation relationship to a different operation relationship, the target operation pressure is immediately switched according to the change of the operation relationship, so that the actual operation pressure becomes the target operation pressure. There is a risk that the amount of overshoot or undershoot of the operation amount when operating the operation pressure adjusting means will increase, and as a result, the amount of overshoot or undershoot of the operation pressure for the operated device may increase. .

  That is, when the control means obtains the target operation pressure based on the index value of the index value command means and the operation relation selected by the operation relation selection means and executes the operation pressure adjustment process, the actual operation pressure and the target In general, the operation pressure adjusting means is configured to operate so that the actual operation pressure becomes the target operation pressure by PID (proportional integral derivative) control based on the deviation from the operation pressure. In performing such PID control, when the index value by the index value command means is changed by manual operation, control is performed so that the operating pressure can be quickly changed following the change of the index value. A constant is generally set.

  However, when configured in this way, the operation relationship is different in the operation relationship selection means while the turning lever as the index value command means is moved in the direction away from the rectilinear command position to perform the turning travel. If the operating pressure is changed to, the target operating pressure will be large and change suddenly. Therefore, when operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure, the overshoot amount and undershoot of the operation amount The amount may increase.

  As a result, for example, when operating the hydraulic clutch for turning operation in a work vehicle such as a combiner as the operated device, the operating pressure of the frictional hydraulic clutch for slow turning acting when the slow turning mode is selected When the index value of the index value command means is the same as the operation pressure of the brake-type friction hydraulic clutch that acts when the brake-turn mode is selected, the operation of the friction-type hydraulic clutch for slow-turn When the pressure has a larger relationship than the operating pressure of the frictional hydraulic clutch for turning the brake, the turning lever as the index value command means moves from the straight running command position in the state where the slow turning mode is selected. When the vehicle is turning while moving away from the vehicle, it feels that the turning force is insufficient, and the operation relationship is changed by the operation relationship selection means. For example, as shown in FIG. 13, the actual operating force for the frictional hydraulic clutch for turning the brake may be temporarily reduced, so that the vehicle turns slowly even though it wants to make a sudden turn. There is a disadvantage that the user feels uncomfortable.

The object of the present invention is to increase the overshoot amount and undershoot amount of the operation pressure of the operation target even when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship. It is in the point which provides the turning control apparatus of the working vehicle which can avoid and can adjust the operating pressure with respect to a to-be-operated apparatus smoothly.

The turning control device for a work vehicle according to the present invention includes an index value command means for commanding an index value corresponding to the magnitude of the operation pressure,
Operating pressure adjusting means for adjusting the operating pressure on the operated device;
An actual operating pressure detecting means for detecting an actual operating pressure of the operating pressure adjusting means;
Control means for operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure,
As the relationship between the index value of the index value command means and the target operation pressure, an operation for storing a plurality of operation relationships in which the target operation pressure is increased as the operation pressure is larger and the target operation pressure at the same index value is different. Relationship storage means;
As the operated device, a plurality of frictions that adjust the traveling speed of the traveling device on the inner side of the turning of the pair of left and right traveling devices for turning and that show different turning radii when the same hydraulic pressure is applied. Type hydraulic clutch,
An operation relationship selecting means for selecting any one of a plurality of operation relationships,
The control means is
An index value commanded by the index value command means, a target operating pressure calculation process for obtaining a target operating pressure based on the operating relation selected by the operating relation selecting means, and
An operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure detected by the actual operation pressure detection means becomes the target operation pressure obtained in the target operation pressure calculation process. The first characteristic configuration is configured.
A hydraulic pressure supply target changing means for changing a target for supplying the hydraulic pressure to be adjusted by the operation pressure adjusting means is provided;
The index value command means is configured to include a swing lever that is swingable over a rectilinear command position and a swing command operation region that is linked thereto, and a swing lever sensor that detects an operation position of the swing lever,
The operation relationship selection means is provided in a swing mode switch for commanding switching to one of a plurality of swing modes as a plurality of operation relationships, and a gripping portion of the swing lever so as to be operated by a finger, and is operated at the time of a turn to operate a turning force. And a turning state changeover switch for improving
The control means operates the hydraulic pressure supply object changing means based on clutch selection information that defines a relationship between a plurality of operation relations selected by the operation relation selection means and the plurality of friction hydraulic clutches. Configured,
An operation relationship in which the clutch selection information has a large target operation pressure when the index value of the index value command means is the same among the plurality of operation relationships when the clutch selection information is a slowly turning side among a plurality of friction type hydraulic clutches Of the plurality of friction-type hydraulic clutches in the operation relationship that becomes a small target operation pressure when the index value of the index value command means is the same among the plurality of operation relationships. To be operated,
The control means is
In the operation pressure adjustment process, the operation relationship selected by the operation relationship selection means is different when the turning state changeover switch is operated while the turning lever is operated in the turning command operation region. Until the change is made when the operation relationship becomes a large target operation pressure when the index value of the index value command means is the same, and the operation relationship becomes a small target operation pressure. The operation pressure adjusting means is configured to gradually change the target operation pressure to a state where the target operation pressure after change is obtained based on the operation relation changed from the target operation pressure before change obtained based on the operation relation. Execute target operation pressure gradual change processing to be activated , and
This is when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship by operating the turning state changeover switch while the swing lever is operated in the turn command operation area. When the index value of the index value command means is the same, the target operation pressure after the change is changed from the target operation pressure before the change to the operation relation where the target operation pressure becomes a large target operation pressure. The target operation pressure rapid change processing for operating the operation pressure adjusting means is executed in such a manner that the target operation pressure is immediately changed to a state where the target operation pressure is obtained.

  That is, the control means obtains the target operation pressure for the operated device based on the index value commanded by the index value command means and the operation relation selected by the operation relation selection means, and the actual operation pressure detection means The operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure of the operation pressure adjustment means detected at step S becomes the target operation pressure. In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection unit is changed to a different operation relationship, the target operation pressure before the change obtained based on the operation relationship until the change is changed. The target operation pressure gradual change processing is executed in which the operation pressure adjusting means is operated in such a manner that the target operation pressure is gradually changed to a state where the target operation pressure after the change is obtained based on the operated relation.

  Since the operation pressure adjusting means is operated in such a manner that the target operation pressure is gradually changed in this way, the operation relation selected by the operation relation selecting means is changed to a different operation relation, and the target before the operation relation is changed. Even if the target operating pressure changes greatly from the operating pressure, when the operating pressure adjustment process is executed, the operating pressure adjusting means is operated in such a manner that the operating target pressure is gradually changed, and then the operating pressure adjusting means is gradually changed. The deviation between the target operating pressure and the actual operating pressure becomes a small value, and the control means can quickly change the operating pressure based on the small deviation, for example, following the change of the index value by the index value command means. Even if the operation pressure adjusting means is operated by PID control in a state where the control constant is set as described above, the PID control is performed based on a small deviation at that time, so that the operation amount of the operation pressure adjusting means is small. To become. As a result, the operation amount of the operation pressure adjusting means gradually changes by repeatedly operating with a small operation amount, but when operating the operation pressure adjusting means when operated with a small operation amount, The overshoot amount and undershoot amount of the operation amount are small values, and it is possible to avoid an increase in the overshoot amount and undershoot amount of the operation pressure of the operation target.

Therefore, according to the first characteristic configuration, even when the operation relationship selected by the operation relationship selection unit is changed to a different operation relationship, the overshoot amount and the undershoot amount of the operation pressure of the operation target are not reduced. It has become possible to provide a turning control device for a work vehicle that can avoid the increase and smoothly adjust the operation pressure on the operated device.
Further, according to the first characteristic configuration, the control means changes the hydraulic supply target changing means based on the clutch selection information that defines the relation between the plurality of operation relations selected by the operation relation selection means and the plurality of friction hydraulic clutches. The target to be supplied with the hydraulic pressure adjusted by the operating pressure adjusting means, that is, the frictional hydraulic clutch for supplying the hydraulic pressure is changed. Then, by adjusting the hydraulic pressure supplied to the friction type hydraulic clutch changed by the hydraulic pressure supply object changing means so as to vary the operation pressure by commanding different index values by the index value command means, The traveling speed of the traveling device on the inner side of the turning of the pair of traveling devices can be adjusted for turning, and different turning radii can appear when the same hydraulic pressure is applied.
That is, the plurality of friction hydraulic clutches and the plurality of operation relationships are set in association with each other so that different turning radii appear when the same hydraulic pressure is applied to each of the plurality of friction hydraulic clutches. If the operation relationship selected by the operation relationship selection means is different by changing the target friction type hydraulic clutch, the turning radius when the index value commanded by the index value command means is the same is obtained. It can be different.
Therefore, according to the first feature configuration, when the operation relationship selected by the operation relationship selection unit is different, the turning radius when the index value commanded by the index value command unit is the same can be varied. It will be a thing.
Further, according to the first characteristic configuration, when the operation relationship selected by the operation relationship selection unit is selected from the plurality of friction hydraulic clutches on the slow turning side, the index value of the index value command unit Are operated with an operation relationship that results in a large target operation pressure at the same time, and the operation relationship selected by the operation relationship selection means is selected from the plurality of friction-type hydraulic clutches on the sudden turn side. When the index value of the index value command means is the same, the operation is performed with an operation relationship that provides a small target operation pressure.
By the way, when the operation relationship of a large target operation pressure is changed to the operation relationship of a small target operation pressure when the index values of the index value command means are the same, the operation pressure of the friction hydraulic clutch is reduced (turning) At that time, the turning state of the work vehicle changes so that the driving force is reduced, so the amount of undershoot of the operating pressure tends to increase and the operator feels uncomfortable. The risk of doing this is great. On the other hand, when the operation relationship of a small target operation pressure is changed to the operation relationship of a large target operation pressure when the index values of the index value command means are the same, the operation pressure of the friction hydraulic clutch is increased. That is, since the turning force changes so as to increase, the behavior delay of the vehicle body of the work vehicle accompanying the change in the turning state is large, and the overshoot amount of the operation pressure does not become so large.
Therefore, the first characteristic configuration executes the target operation pressure gradual change processing when the operation relationship that becomes a large target operation pressure is changed to the operation relationship that becomes a small target operation pressure when the index values of the index value command means are the same. By doing so, it is possible to suppress the overshoot amount and undershoot amount of the operation pressure of the operation target to be small. On the other hand, when the operation relationship of a small target operation pressure is changed to an operation relationship of a large target operation pressure when the index value of the index value command means is the same, the target operation pressure before the change is changed to the target operation pressure after the change. By immediately changing the target operation pressure to the state, the turning state can be changed as quickly as possible.
Therefore, according to the first feature configuration, when the operation relationship selected by the operation relationship selection unit is changed to a different operation relationship, the amount of overshoot or the amount of undershoot of the operation pressure of the operation target is reduced. However, the turning state of the vehicle body can be changed in accordance with the fluctuation of the index value of the index value command means while the operating pressure can be adjusted to the desired value as quickly as possible.
The second characteristic configuration of the present invention includes an index value command means for commanding an index value corresponding to the magnitude of the operating pressure,
Operating pressure adjusting means for adjusting the operating pressure on the operated device;
An actual operating pressure detecting means for detecting an actual operating pressure of the operating pressure adjusting means;
Control means for operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure,
As the relationship between the index value of the index value command means and the target operation pressure, an operation for storing a plurality of operation relationships in which the target operation pressure is increased as the operation pressure is larger and the target operation pressure at the same index value is different. Relationship storage means;
As the operated device, a plurality of frictions that adjust the traveling speed of the traveling device on the inner side of the turning of the pair of left and right traveling devices for turning and that show different turning radii when the same hydraulic pressure is applied. Type hydraulic clutch,
An operation relationship selecting means for selecting any one of a plurality of operation relationships,
The control means is
An index value commanded by the index value command means, a target operating pressure calculation process for obtaining a target operating pressure based on the operating relation selected by the operating relation selecting means, and
An operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure detected by the actual operation pressure detection means becomes the target operation pressure obtained in the target operation pressure calculation process. A work vehicle turning control device comprising :
The plurality of friction-type hydraulic clutches make a slow turning clutch that makes the running device on the inner side of the turn slower than the running device on the outer side of the turn at the maximum operating pressure, and travels on the inner side of the turn at the maximum operating pressure. A reverse clutch that reverses the device with respect to the traveling device on the outer side of the turning,
The operating pressure adjusting means is configured to adjust the hydraulic pressure supplied to the two frictional hydraulic clutches;
A hydraulic pressure supply target changing means for changing a target for supplying the hydraulic pressure to be adjusted by the operation pressure adjusting means is provided;
The index value command means is configured to include a swing lever that is swingable over a rectilinear command position and a swing command operation region that is linked thereto, and a swing lever sensor that detects an operation position of the swing lever,
The operation relationship selection means includes, as the plurality of operation relationships, a slow turning mode in which the traveling device on the inner side of the turning is slower than the traveling device on the outer side of the turning, and a brake that sets the traveling device on the inner side of the turning to a braking state. It is configured to select any one of a turning mode and a reverse rotation mode for reversing the traveling device on the inner side of the turning with respect to the traveling device on the outer side of the turning,
The control means operates the hydraulic pressure supply target changing means based on clutch selection information that defines a relation between a plurality of operation relations selected by the operation relation selection means and the two friction hydraulic clutches. Configured,
In the slow turning mode, the clutch selection information operates the slow turning clutch with a large-side operation relationship that becomes a large target operating pressure when the index value of the index value command means is the same. The reverse clutch is operated with a small side operation relationship that results in a small target operating pressure when the index value of the index value command means is the same, and the reverse clutch is operated in the slow turning mode in the reverse rotation mode. It is determined to operate in the same large-side operation relationship as the relationship,
The control means is
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the operation pressure is changed from the target operation pressure before the change obtained based on the operation relationship until the change. The target operation pressure gradual change process for operating the operation pressure adjusting means is executed in such a manner that the target operation pressure is gradually changed to the target operation pressure after change obtained based on the operation relation. In the point.
In addition to the second feature configuration, the third feature configuration of the present invention includes the control means,
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, and when the large-side operation relationship is changed to the small-side operation relationship. , When the target operation pressure gradual change processing is executed and the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, from the small side operation relationship to the large side When the operation relation is changed, a target operation pressure rapid change process is performed in which the operation pressure adjusting means is operated in such a manner that the target operation pressure is immediately changed from the target operation pressure before the change to the target operation pressure after the change. The point is that it is configured to do.

In addition to any one of the first feature configuration to the third feature configuration , the fourth feature configuration of the present invention includes:
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the target operation pressure before the change and the change obtained based on the operation relationship until the change is changed When the difference from the changed target operating pressure obtained based on the operated relation is equal to or larger than the set amount, the target operating pressure gradual change processing is executed and obtained based on the operating relation until the change is made. When the difference between the target operation pressure before change and the target operation pressure after change obtained based on the changed operation relationship is less than the set amount, the target operation pressure after change is changed to the target operation pressure after change. A target operation pressure rapid change process is performed in which the operation pressure adjusting means is operated in such a manner that the target operation pressure is immediately changed.

According to the fourth feature configuration, when the operation relation selected by the operation relation selection means is changed to a different operation relation, the control means determines the difference between the target operation pressure before the change and the target operation pressure after the change. If the difference between the target operation pressure before the change and the target operation pressure after the change is less than the set amount, the target operation pressure after the change is changed from the target operation pressure before the change. The operating pressure adjusting means is operated in such a manner that the target operating pressure is immediately changed to a state where the operating pressure is reached.

  In other words, when the difference between the target operation pressure before the change of the operation relationship and the target operation pressure after the change is equal to or greater than the set amount, the fluctuation range is large, so the pre-change obtained based on the operation relationship until the change is made When the control is executed in such a manner that the target operating pressure is suddenly changed to the target operating pressure after change obtained based on the operation relation changed from the target operating pressure of the operating pressure, the overshoot amount or the undershoot of the operating pressure of the operating pressure adjusting means In such cases, the amount of chute is large, but in such cases, the target pressure gradually changing process is executed to suppress the amount of overshoot and undershoot of the operating pressure of the operating pressure adjusting means to be small. Is possible.

  On the other hand, when the difference between the target operation pressure before the change and the target operation pressure after the change is less than the set amount, even if the operation pressure adjustment means is operated so as to immediately change the operation pressure, the operation pressure adjustment means Since the amount of overshoot and undershoot of the operating pressure is small, in this case, the target operating pressure is changed immediately by executing the target operating pressure rapid change process. The adjustment can be quickly performed, and the operability is improved.

Therefore, according to the fourth feature configuration, even when the operation relationship selected by the operation relationship selection unit is changed to a different operation relationship, the overshoot amount or the undershoot amount of the operation pressure of the operation target is not increased. While avoiding an increase in size, the operation target can be operated smoothly and as quickly as possible, and a turning control device for a work vehicle with good operability can be provided.

According to a fifth feature configuration of the present invention, in addition to any of the first feature configuration to the third feature configuration , the control means includes:
In the target operation pressure gradual change processing, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the target operation pressure before the change obtained based on the operation relationship until the change is made The target operation pressure is gradually increased from the target operation pressure before the change to the target operation pressure after the change in a state where the speed becomes higher as the difference between the target operation pressure after the change and the target operation pressure after the change obtained based on the changed operation relationship is smaller. The operating pressure adjusting means is configured to be operated in a form that changes.

  That is, when the difference between the target operation pressure before the change of the operation relationship and the target operation pressure after the change is large, the operation pressure adjustment means is configured to change the target operation pressure at a high speed when the target operation pressure is gradually changed. When activated, the greater the difference in the target operating pressure, the larger the amount of overshoot and undershoot of the operating pressure of the operating pressure adjusting means, but the target operating pressure before the change and the target operating pressure after the change When the target operating pressure is gradually changed, even if the operating pressure adjusting means is operated in a form that changes the target operating pressure at a high speed, the overshoot amount or undershoot amount of the operating pressure of the operating pressure adjusting means In addition, the smaller the difference in the target operating pressure, the smaller the overshoot amount and the undershoot amount.

Therefore, in the fifth characteristic configuration, the control means increases the speed from the target operation pressure before the change in a state where the speed is higher as the difference between the target operation pressure before the change of the operation relation and the target operation pressure after the change is smaller. The target operation pressure is gradually changed to a state where the target operation pressure is reached. With this configuration, when the difference in the target operation pressure is large, the target operation pressure is gradually changed at a low speed, so that the amount of overshoot and the amount of undershoot of the operation pressure of the operation pressure adjusting means increases. If the difference in target operating pressure is small, the target operating pressure is gradually changed at high speed, so that the overshoot amount and undershoot amount of the operating pressure of the operating pressure adjusting means are small. It becomes possible to perform the operation of the operation target as quickly as possible. In other words, the operation target can be operated as quickly as possible while avoiding an increase in the overshoot amount or undershoot amount of the operation pressure of the operation pressure adjusting means.

Therefore, according to the fifth feature configuration, even when the operation relationship selected by the operation relationship selecting means is changed to a different operation relationship, the overshoot amount and the undershoot amount of the operation pressure of the operation target are not reduced. While avoiding an increase in size, the operation target can be operated smoothly and as quickly as possible, and a turning control device for a work vehicle with good operability can be provided.

In addition to any of the first characteristic configuration to the fifth characteristic configuration, the sixth characteristic configuration of the present invention is that the operating pressure adjusting means is an electromagnetic proportional valve,
The actual operation pressure detecting means is configured to detect a current value energized to the electromagnetic proportional valve as an actual operation pressure,
The operation relationship storage means is configured to store a relationship between the index value and a target current value for energizing the electromagnetic proportional valve as a relationship between the index value of the index value command means and a target operation pressure,
The control means is
In the target operation pressure calculation process, the target current value as the target operation pressure is obtained,
In the target operation pressure adjustment processing, the electromagnetic proportional valve is energized so that the current value as the actual operation pressure detected by the actual operation pressure detection means becomes the target current value. In the point.

According to the sixth characteristic configuration, the operation pressure to the operated device is adjusted by the electromagnetic proportional valve, and the control means obtains the target current value as the target operation pressure, and the electromagnetic proportional valve detected as the actual operation pressure The solenoid proportional valve is actuated by energizing so that the energized current value becomes the target current value.

  For example, a pressure sensor may be used as the actual operation pressure detection means. However, the detection means for detecting the current value is generally simpler than the pressure sensor, which is generally a complicated and expensive detection means. Since the sensor is configured and inexpensive, by using such a simple and inexpensive sensor, it is possible to simplify and reduce the configuration of the entire apparatus.

Therefore, according to the sixth feature configuration, it is possible to provide a turning control device for a work vehicle capable of simplifying the device configuration and reducing the cost by using the actual operation pressure detecting means having a simple configuration. .

It is a whole side view of a combine. It is a figure which shows a transmission structure. It is a figure which shows a transmission structure. It is a hydraulic circuit diagram. It is a control block diagram. It is a figure which shows the relationship between a turning lever operation position and a target speed ratio. It is a figure which shows the relationship between a turning lever operation position and target operation pressure. It is a flowchart of control operation. It is a flowchart of control operation. It is a timing chart. It is a flowchart of control operation. It is a timing chart. It is a timing chart.

Hereinafter, the case where the embodiment of the 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.

  As shown in FIG. 1, a cutting unit 4 is supported at a front portion of a vehicle body supported by right and left crawler travel devices 1 and 1 by a lifting cylinder 3 so as to be driven up and down around a horizontal axis P1. A driving unit 5 is provided on the right side of the front part of the vehicle, an engine 7 is provided on the lower side of the driving seat 6 of the driving unit 5, a threshing device 8 is provided on the left side of the rear part of the vehicle body, and a glen on the right side of the rear part of the vehicle body. A tank 9 is provided to constitute a self-removing combine that is an example of a work vehicle.

  As shown in FIG. 2, the power of the engine 7 is transmitted to the input shaft of the hydrostatic continuously variable transmission 11 for traveling speed change via the transmission belt 19, the input pulley 17, and the input shaft 16. Is transmitted to the cutting unit 4 via the transmission belt 20 and the hydrostatic continuously variable transmission 21 for cutting and shifting.

Next, the transmission mechanism inside the mission case will be described with reference to FIG.
An input shaft 22 is supported on the upper part of the transmission case 10, and transmission gears 23 and 24 are fixed to the input shaft 22 by a spline structure. An output shaft 11c of the hydrostatic continuously variable transmission 11 is inserted into the transmission case 10 and connected to the transmission gear 24 (input shaft 22) by a spline structure. Further, a high-speed gear 25 and a low-speed gear 26 are externally fitted to the sub-transmission transmission shaft 27 supported on the upper portion of the transmission case 10 so as to be relatively rotatable, and the transmission gear 23 and the high-speed gear 25, the transmission gear 24 and the low-speed gear 26 are fitted. The shift member 28 is externally fitted to the sub-transmission transmission shaft 27 so as to be integrally rotatable and slidable by a spline structure. The transmission gear 23 and the high-speed gear 25, the transmission gear 24 and the low-speed gear 26, and the shift member 28 constitute an auxiliary transmission, and the input shaft 22 is engaged by engaging the shift member 28 with the high-speed and low-speed gears 25 and 26. Is transmitted to the sub-transmission transmission shaft 27 after being shifted to high and low two stages (low speed and high speed).
The auxiliary transmission is normally slid to a position where the shift member 28 meshes with the high speed gear 25 to set the high speed position.

  A linear transmission shaft 29 is supported at the lower part of the transmission case 10, and a transmission gear 31 is fixed to the linear transmission shaft 29. The transmission gear 31 is engaged with a transmission gear 30 fixed to the auxiliary transmission transmission shaft 27. Yes. Further, a pair of left and right output gears 32R and 32L are externally fitted to the linear transmission shaft 29 so as to be relatively rotatable, and a pair of left and right occlusion portions 33R and 33L are integrally rotated with the linear transmission shaft 29 by a spline structure. It is slidably fitted outside. And the right side clutch 34 is comprised between the right output gear 32R and the right occlusion part 33R, and the left side clutch 34 is comprised between the left output gear 32L and the left occlusion part 33L.

Next, the right and left side clutches 34 will be described.
Spline portions are formed on the outer surfaces of the right and left side portions of the straight transmission shaft 29, and the right occlusion portion 33R and the left occlusion portion 33L are externally fitted to the spline portion of the straight movement transmission shaft 29 so as to be integrally rotatable and slidable. The receiving member 40 is externally fitted to the spline portion of the linear transmission shaft 29 so as to be integrally rotatable. The right and left occlusal portions 33R and 33L are urged by the receiving member 40 and the spring 41 to the occlusal side of the right and left output gears 32R and 32L. The right and left occlusal portions 33R and 33L are engaged with the right and left output gears 32R and 32L, so that the right and left side clutches 34 are in a transmission state. And transmitted to the right and left crawler travel devices 1 via the left side clutch 34.
Further, by supplying hydraulic oil into the oil chambers formed between the right and left output gears 32R and 32L and the right and left occlusion portions 33R and 33L, the right and left occlusion portions 33R and 33L The right and left occlusal portions 33R and 33L are slid to the side where they are separated against the biasing force of the spring 41, and the right and left side clutches 34 are in a clutch disengaged state (disengaged state). When the hydraulic oil is discharged, the right and left side clutches 34 are engaged (transmission state) by the biasing force of the spring 41.

  The left and right transmission shafts 35 are supported on the same axis so as to be arranged side by side on the same axis, and the left and right transmission gears 36 fixed to the left and right transmission shafts 35 are connected to the right output gear 32R and the left. The left and right transmission gears 37 fixed to the left and right transmission shafts 35 are engaged with the transmission gears 39 fixed to the right and left axles 38, respectively. The right and left axles 38 are connected to the right and left crawler travel device 1 sprockets.

  If both the left and right side clutches 34 are engaged, the power of the input shaft 22 is transmitted to the sub-transmission transmission shaft 27, the transmission gears 30 and 31, the straight transmission shaft 29, the right and left side clutches 34, When the right and left output gears 32R and 32L, the transmission gear 36, the transmission shaft 35, the transmission gears 37 and 39, and the right and left axles 38 are transmitted to the right and left crawler travel devices 1, the aircraft goes straight. It becomes the transmission state which runs in the state.

Next, the structure of the turning transmission system for turning the vehicle body will be described.
A transmission shaft 44 is supported in the transmission case 10, and a transmission gear 45 fitted on the transmission shaft 44 so as to be relatively rotatable is engaged with a gear portion on the outer periphery of the right occlusion portion 33 </ b> R. A slow turning clutch 46 is provided between the gear 45. The slow swing clutch 46 is configured as a friction multi-plate type, and is operated to a transmission state (on state) when hydraulic oil is supplied, and is operated to a cut-off state (off state) when the hydraulic oil is discharged. .

  A revolving clutch case 47 is fitted on the linear transmission shaft 29 so as to be relatively rotatable, and a transmission gear 48 fixed to the transmission shaft 44 and a transmission gear 47 a on the outer periphery of the revolving clutch case 47 are engaged with each other. The turning clutch case 47 is configured to be bilaterally symmetrical, and a right and left turning clutch 49 is formed between the turning clutch case 47 and the right and left output gears 32R and 32L. The right and left turning clutch 49 is configured as a friction multi-plate type, and is operated in a transmission state by supplying hydraulic oil. The right and left turning clutches 49 are arranged so that the friction plates are dense with each other, and the right and left turning clutches 49 are in a semi-transmission state even when the hydraulic oil is discharged. .

  When the slow swing clutch 46 is operated in the transmission state, the power of the straight drive shaft 29 is used for the straight drive via the right occlusal portion 33R, the transmission gear 45, the slow swing clutch 46, the transmission shaft 44, and the transmission gear 48. Rotation in the same direction as the transmission shaft 29 is transmitted to the turning clutch case 47 as power lower than that of the linear transmission shaft 29. When one of the right and left side clutches 34 is operated in a disconnected state and the one of the right or left turning clutch 49 on the side where the side clutch 34 is disconnected is operated in a transmission state, a transmission state is established. Through the turning clutch 49, the power in the same direction as that of the straight transmission shaft 29 is transmitted to one of the right and left output gears 32R and 32L by the rotation in the same direction as that of the straight transmission shaft 29. Low speed power is transmitted to the traveling device 1. At that time, the power of the straight drive shaft 29 is transmitted as it is to the other of the right or left output gears 32R, 32L.

  A transmission gear 52 is fitted on the transmission shaft 44 so as to be relatively rotatable. The transmission gear 52 is engaged with a transmission gear 51 provided on the auxiliary transmission transmission shaft 27 so as to be integrally rotatable. A reverse clutch 53 as a friction type hydraulic clutch is provided between the transmission shaft 44 and the transmission gear 52. The reverse clutch 53 is configured as a frictional multi-plate type, and is operated to a transmission state (ON state) when hydraulic oil is supplied, and is operated to a cutoff state (OFF state) when the hydraulic oil is discharged. The reverse clutch 53 can be operated in a braking state as will be described later by adjusting the supply pressure of the hydraulic oil.

  When the reverse clutch 53 is operated in the transmission state, the power of the sub-transmission transmission shaft 27 is reverse to the linear transmission shaft 29 via the transmission gears 51 and 52, the reverse clutch 53, the transmission shaft 44 and the transmission gear 48. It is transmitted to the turning clutch case 47 as directional rotation power. When one of the right and left side clutches 34 is operated in a disconnected state and the one of the right or left turning clutch 49 on the side where the side clutch 34 is disconnected is operated in a transmission state, a transmission state is established. The rotational power in the direction opposite to that of the straight transmission shaft 29 is transmitted to one of the right or left output gears 32R and 32L via the turning clutch 49, and the reverse rotation is transmitted to the traveling device 1 on the corresponding side. Power is transmitted. At that time, the power of the straight drive shaft 29 is transmitted as it is to the other of the right or left output gears 32R, 32L.

  Further, by adjusting the supply pressure of the hydraulic oil to the reverse clutch 53, the brake can be brought into a braking state by adjusting the operation pressure so as to prevent the transmission shaft 44 from rotating. In this braking state, the transmission shaft can be set. The turning clutch case 47 is brought into a braking state via 44 and the transmission gear 48. When one of the right and left side clutches 34 is operated to the disconnected state, and the one of the right or left turning clutch 49 on the side where the side clutch 34 is disconnected is operated to the transmission state, the right or left side clutch 34 is operated. Of the output gears 32R and 32L, the side where the side clutch 34 is not disengaged is in a braking state, and the power on the opposite side transmits the power of the straight transmission shaft 29 as it is.

  Therefore, the transmission as described above includes the slow turning clutch 46, the reverse clutch 53, and the left and right side clutches 34 for switching the driving state of the pair of left and right traveling devices 1 between the straight traveling state and the turning state. A transmission mechanism provided in the case 10 corresponds to the travel drive means 100.

Next, the operation of the hydrostatic continuously variable transmission 11 for traveling speed change will be described with reference to FIG.
The pump 11P of the hydrostatic continuously variable transmission 11 is configured to be continuously variable from the neutral position N and the neutral position N to the high speed side of the forward F and the high speed side of the reverse R. The hydrostatic continuously variable transmission Eleven motors 11M are configured to be variable in two levels. A hydraulic cylinder 59 for operating the swash plate of the pump 11P of the hydrostatic continuously variable transmission 11 and a control valve 60 for supplying / discharging hydraulic oil to / from the hydraulic cylinder 59 are provided, and a shift lever 61 provided in the operating unit 5 is provided. And the control valve 60 are mechanically linked. Thus, by operating the speed change lever 61, the control valve 60 is operated and the hydraulic cylinder 59 is operated, and the pump 11P of the hydrostatic continuously variable transmission 11 is tilted to a position corresponding to the operation position of the speed change lever 61. Operate the board.

  A hydraulic cylinder 62 that operates the swash plate of the motor 11M of the hydrostatic continuously variable transmission 11 and an electromagnetically operated control valve 63 that supplies and discharges hydraulic oil to and from the hydraulic cylinder 62 are provided. A shift switch 61a is provided in the unit, and an operation signal of the shift switch 61a of the shift lever 61 is input to a control device 64 including a microcomputer. Thus, by operating the speed change switch 61a of the speed change lever 61, the control valve 63 is operated by the control device 64, the hydraulic cylinder 62 is operated, and the swash plate of the motor 11M of the hydrostatic continuously variable transmission 11 is operated at high speed. And it is the structure operated to a low-speed position.

  An operation position sensor 65 for detecting the operation position of the shift lever 61 is provided, and left and right axle rotation sensors 66R and 66L as traveling speed detecting means for detecting the rotational speeds of the left and right axles for detecting the traveling speed of the airframe. , And the detection values of the operation position sensor 65 and the left and right axle rotation sensors 66R and 66L are input to the control device 64. Detection of whether the swash plate of the motor 11M of the hydrostatic continuously variable transmission 11 is at the high speed position or the low speed position is recognized by the control device 64 based on the operation signal of the speed change switch 61a of the speed change lever 61.

Next, the hydraulic unit 57 that supplies and discharges hydraulic oil to and from the right and left side clutches 34 (the right and left occlusion portions 33R and 33L), the right and left turning clutch 49, the slow turning clutch 46, and the reverse rotation clutch 53. explain.
As shown in FIG. 4, the hydraulic unit 57 includes a right turn control valve 67, a left turn control valve 68, a relief valve 69, an unload valve 70, a proportional control valve 71, a turn switching control valve 72, and a reverse turn turn valve. A pilot valve 74 is provided. The external pipe 58 from the hydraulic pump 56 driven by the output shaft 11 c of the hydrostatic continuously variable transmission 11 is connected to the hydraulic unit 57, and the right turning control valve 67 is the oil path 29 b of the straight transmission shaft 29. Are connected to the right side clutch 34 and the right turning clutch 49, and the left turning control valve 68 is connected to the left side clutch 34 and the left turning clutch 49 via the oil passage 29b of the straight transmission shaft 29. ing.

  The right turn control valve 67 and the left turn control valve 68 are configured by electromagnetic operation that can be switched to two positions of supply positions 67a and 68a and discharge positions 67b and 68b, respectively. The return is energized. The unload valve 70 is configured in an electromagnetic operation type that can be switched between two positions of a blocking position 70a and a discharging position 70b, and is urged to return to the blocking position 70a. A proportional control valve 71 and a turning switching control valve 72 are connected in series to an oil passage 75 branched from between the right and left turning control valves 67 and 68 and the oil passage 29b of the transmission shaft 29 for straight travel. A switching control valve 72 is connected to the slow swing clutch 46 and the reverse clutch 53 via an oil passage 44 a of the transmission shaft 44.

  The proportional control valve 71 is composed of an electromagnetic proportional pressure reducing valve, and as will be described later, the slow swing clutch 46 and the reverse clutch 53 on the lower side of the hydraulic fluid flow path are adjusted by changing and adjusting the control current supplied from the control device 64. The supply pressure can be changed and adjusted. Therefore, the proportional control valve 71 constitutes an operating pressure adjusting means for adjusting the operating pressure of the reverse clutch 53 by changing and adjusting the supply pressure of the pressure oil supplied from the hydraulic source.

  The turning switching control valve 72 is configured as a pilot operated type that can be operated to a slow turning position 72a and a reverse turning position 72c, and is urged to return to the slow turning position 72a. A reverse turning pilot valve 74 is configured so that the pilot hydraulic oil branched from the oil passage 75 is supplied to the turning switching control valve 72 and operated to the reverse turning position 72c. The reverse turning pilot valve 74 has a supply position for supplying pilot hydraulic oil to the turning switching control valve 72 and a stop position for stopping the supply of pilot hydraulic oil and returning the turning switching control valve 72 to the slow turning position 72a. It is configured as an electromagnetic operation type that can be switched to a position and is urged to return to a stop position. Therefore, this turning switching control valve 72 constitutes a hydraulic pressure supply target changing means for changing the target for supplying the hydraulic pressure adjusted by the proportional control valve 71.

  The right turning control valve 67, the left turning control valve 68, the unload valve 70, the proportional control valve 71, and the reverse turning pilot valve 74 are controlled by a control device 64 as described later.

  Then, as shown in FIG. 5, the return command is urged to return to the straight command position N, and the turn command operation region extends from the straight command position N to the maximum operation position Rm on the right side and the maximum operation position Lm on the left side. A swing lever 77 capable of swinging operation is provided in the operation unit 5, and a swing lever sensor 80 is provided as a turn command position detecting means for detecting an operation position of the swing lever 77. It is input to the control device 64.

  The swivel lever 77 can be freely moved over the straight command position N and the swivel command operation area connected thereto, and the swivel lever sensor 80 has a maximum operation position (Rm, Lm), a command value corresponding to a larger target turning force, in other words, a smaller turning radius is commanded to the control device 64, and an index value command means is constituted by the turning lever 77 and the turning lever sensor 80. 200 is configured. Accordingly, the index value command means 200 is switchable between a straight command state for commanding straight travel and a swing command state for commanding turning, and commands an index value corresponding to the turning radius in the turn command state. It is configured.

  Further, a turning mode switch 78 for instructing switching to a slow turning mode, a brake turning mode, and a reverse turning mode is provided in the operation unit 5, and the operation position of the turning mode switch 78 is input to the control device 64. The switch 78 is configured to be freely switchable between a slow turning position for instructing a slow turning mode, a brake turning position for instructing a brake turning mode, and a reverse turning position instructing a reverse turning mode. The driving state of the travel driving means 100 is switched so as to correspond to the operation position.

  When the turning lever 77 is operated to the rectilinear command position N, the right and left turning control valves 67 and 68 are operated to the discharge positions 67b and 68b, the unload valve 70 is operated to the discharge position 70b, and the right and left The hydraulic oil is discharged from the side clutch 34 and the right and left turning clutch 49, the right and left side clutch 34 are operated to the transmission state, and the right and left turning clutch 49 are operated to the half transmission state. Since the right and left turning control valves 67 and 68 are operated to the discharge positions 67b and 68b and the unload valve 70 is operated to the discharge position 70b, the hydraulic oil from the hydraulic pump 56 passes to the transmission case 10 through the unload valve 70. Returned.

  As a result, the power of the input shaft 22 is transmitted to the sub-transmission transmission shaft 27, the transmission gears 30, 31, the linear transmission transmission shaft 29, the right and left side clutches 34 (the right and left occlusion portions 33R, 33L), the right and The aircraft is transmitted straight to the right and left crawler travel devices 1 via the left output gears 32R and 32L, the transmission gear 36, the transmission shaft 35, the transmission gears 37 and 39, and the right and left axles 38.

Next, the case where the turning lever 77 is operated to the turning command operation area when the turning mode switch 78 is operated to the slow turning position will be described.
When the turning mode switch 78 is operated to the slow turning position and the turning lever 77 is operated to the right from the straight command position N to move out of the dead zone, the right turning control valve 67 is operated to the supply position 67a to unload. The valve 70 is switched to the shut-off position 70a, hydraulic oil is supplied to the right side clutch 34 (right occlusion portion 33R) and the right turning clutch 49, and the right side clutch 34 (right occlusion portion 33R) is shut off. The hydraulic oil is supplied to the right turning clutch 49 and is operated to the transmission state.

In this case, since the left turning clutch 49 is in a semi-transmission state, the power of the left side clutch 34 is transmitted from the left output gear 32L and the left turning clutch 49 to the right output gear 32R via the right turning clutch 49. The power slightly lower than that of the linear transmission shaft 29 is transmitted to the right output gear 32R by rotation in the same direction as the linear transmission shaft 29. As a result, the aircraft gently turns to the right.
When the swivel lever 77 is operated rightward from the rectilinear command position N and moves out of the dead zone, the proportional control valve 71 and swivel switching are almost simultaneously with the right swivel control valve 67 being operated to the supply position 67a as described above. The hydraulic oil begins to be supplied to the slow swing clutch 46 via the control valve 72, and as the swing lever 77 is moved to the right in a direction away from the straight advance command position after moving out of the dead zone, the proportional control valve 71 becomes slower. The operation pressure of the swing clutch 46 is increased.

  As the operation pressure of the slow swing clutch 46 is increased by the proportional control valve 71 based on the operation position of the swing lever 77, the power of the straight drive shaft 29 is changed to the right occlusal portion 33R, the transmission gear 45, Through the turning clutch 46, the transmission shaft 44, the transmission gear 48, the turning clutch case 47 and the right turning clutch 49, the motive power at a lower speed than the straight traveling transmission shaft 29 is rotated in the same direction as the straight traveling transmission shaft 29. It is transmitted to the output gear 32R.

  In this case, the power from the left side clutch 34 (the left occlusal portion 33L) and the power from the slow turning clutch 46 are transmitted to the right output gear 32R at the same time. In the range where the operation pressure is low, the power from the left side clutch 34 (the left occlusion portion 33L) overcomes the power from the slow swing clutch 46, and the power from the left side clutch 34 (the left occlusion portion 33L). As a result, the right output gear 32R is driven. As a result, when the operating pressure of the gentle turning clutch 46 is low, the aircraft gradually turns to the right.

  When the amount of movement of the turning lever 77 to the right increases and the operating pressure of the slow turning clutch 46 increases, the power from the slow turning clutch 46 overcomes the power from the left side clutch 34 (left occlusal portion 33L). Thus, the right output gear 32R is driven by the power from the slow turning clutch 46. In this state, the right output gear is driven by the power from the slow turning clutch 46 rather than the left output gear 32L driven by the power of the straight transmission shaft 29 via the left side clutch 34 (the left engagement portion 33L). 32R will be driven at low speed and the aircraft will turn to the right.

  When the swivel lever 77 is operated to the left from the rectilinear command position N and moves out of the dead zone, the left swivel control valve 68 is operated to the supply position 68a, the unload valve 70 is held at the shut-off position 70a, and the left side The hydraulic oil is supplied to the clutch 34 (the left occlusion portion 33L) and the left turning clutch 49, the left side clutch 34 (the left occlusion portion 33L) is operated to be disconnected, and the left turning clutch 49 is operated with the hydraulic oil. Is operated in the transmission state. At the same time, the same operation as the left turn described above is performed, and the aircraft gradually turns to the left. Further, when the operation amount to the right side of the turning lever 77 increases and the operation pressure of the slow turning clutch 46 becomes high, the same operation as the right turning operation is performed, and the aircraft turns to the left.

Next, the case where the turning lever 77 is operated to the turning command operation area when the turning mode switch 78 is operated to the brake turning position will be described.
When the turning mode switch 78 is operated to the brake turning position and the turning lever 77 is operated rightward from the straight travel command position N to move out of the dead zone, the right turning control valve 67 is operated to the supply position 67a and the unload valve 70 is switched to the cut-off position 70a, and hydraulic oil is supplied to the right side clutch 34 (right occlusion portion 33R) and the right turning clutch 49, and the right side clutch 34 (right occlusion portion 33R) is cut off. The hydraulic oil is operated to the right turning clutch 49 in the transmission state. In this case, since the left turning clutch 49 is in a semi-transmission state, the aircraft gradually turns to the right.

  When the swivel lever 77 is operated rightward from the rectilinear command position N and moves out of the dead zone, the proportional control valve 71 and swivel switching are almost simultaneously with the right swivel control valve 67 being operated to the supply position 67a as described above. The hydraulic oil begins to be supplied to the reverse rotation clutch 53 via the control valve 72 (reverse rotation position 72c), and is proportional as the rotation lever 77 is moved to the right in the direction away from the straight command position after leaving the dead zone. The operating pressure of the reverse clutch 53 is increased by the control valve 71. However, even if the turning lever 77 is operated rightward to the maximum operation position Rm at this time, the operation pressure of the reverse clutch 53 does not reverse the transmission shaft 44 but stops the rotation of the transmission shaft 44 or substantially. The operating pressure is adjusted so as to stop.

  In this case, the power from the left side clutch 34 (left occlusal portion 33L) and the braking force of the transmission shaft 44 braked via the reverse clutch 53 are simultaneously transmitted to the right output gear 32R. Therefore, in the range where the operating pressure of the reverse clutch 53 is low, the power from the left side clutch 34 (left occlusion portion 33L) overcomes the braking force of the reverse clutch 53 and the left side clutch 34 (left occlusion) The right output gear 32R is driven by the power from the portion 33L). As a result, when the operating pressure of the reverse clutch 53 is in a low pressure range, the aircraft gradually turns to the right.

  When the amount of movement of the swivel lever 77 to the right increases and the operating pressure of the reverse clutch 53 reaches an operating pressure set to act as a brake, the braking force is applied to the left side clutch 34 (the left occlusal portion 33L). ), The right output gear 32R enters the braking state, and the aircraft turns to the right. The turning state at this time corresponds to a brake turning state in which the rotation of the traveling device inside the turning is stopped or substantially stopped.

  Accordingly, as the operation pressure of the reverse clutch 53 is increased by the proportional control valve 71 in accordance with the operation of the turning lever 77, the transmission shaft 44, the transmission gear 48, the turning clutch case 47, and the right turning clutch 49 are moved. Thus, a braking force is applied to the right output gear 32R. That is, the pseudo brake state is equal to the state in which the transmission shaft 44 is braked by the brake.

  When the turning lever 77 is operated to the left from the rectilinear command position N to move out of the dead zone, the left turning control valve 68 is operated to the supply position 68a, the unload valve 70 is operated to the cutoff position 70a, and the left side clutch 34 (the left occlusion portion 33L) and the left turning clutch 49 are supplied with hydraulic oil, the left side clutch 34 (the left occlusion portion 33L) is operated to be disconnected, and the left turning clutch 49 is supplied with hydraulic oil. Operated in transmission state. At the same time, the same operation as described above is performed, and the aircraft gradually turns to the left. When the amount of movement of the turning lever 77 to the left increases and the operating pressure of the reverse clutch 52 becomes high, the same operation as the right turning operation is performed, and the aircraft turns to the left.

Next, the case where the turning lever 77 is operated to the turning command operation area when the turning mode switch 78 is operated to the reverse turning position will be described.
When the turning mode switch 78 is operated to the reverse turning position and the turning lever 77 is operated to the right from the rectilinear command position N to move out of the dead zone, the right turning control valve 67 is operated to the supply position 67a, and the unload valve 70 is switched to the cut-off position 70a, and hydraulic oil is supplied to the right side clutch 34 (right occlusion portion 33R) and the right turning clutch 49, and the right side clutch 34 (right occlusion portion 33R) is cut off. And the right turning clutch 49 is operated to the transmission state. In this case, since the left turning clutch 49 is in a semi-transmission state, the aircraft gradually turns to the right.

  When the swivel lever 77 is operated rightward from the rectilinear command position N and moves out of the dead zone, the proportional control valve 71 and swivel switching are almost simultaneously with the right swivel control valve 67 being operated to the supply position 67a as described above. The hydraulic oil begins to be supplied to the reverse rotation clutch 53 via the control valve 72 (reverse rotation position 72c). The proportional control valve 71 moves the rotation lever 77 away from the dead zone command position and moves to the right side. The operating pressure of the reverse clutch 53 is increased. In this reverse turning state, when the turning lever 77 is operated rightward to the maximum operating position Rm, the operating pressure of the reverse clutch 53 causes the reverse rotation clutch 53 to be completely engaged and the transmission shaft 44 to move straightly to the transmission shaft 29. And adjusted to rotate in the opposite direction.

  As the operation pressure of the reverse clutch 53 is increased by the proportional control valve 71 in accordance with the operation of the turning lever 77, the power of the subtransmission transmission shaft 27 is transmitted to the transmission gears 51, 52, the reverse clutch 53, the transmission shaft. 44, the transmission gear 48, the turning clutch case 47, and the right turning clutch 49 are transmitted to the right output gear 32R as the rotational power in the direction opposite to that of the straight drive shaft 29.

  In this case, since the power from the left side clutch 34 (the left occlusal portion 33L) and the power from the reverse clutch 53 are simultaneously transmitted to the right output gear 32R, the operation pressure of the reverse clutch 53 is reached. In the low pressure range, the power from the left side clutch 34 (the left occlusion portion 33L) overcomes the power from the reverse clutch 53, and the power from the left side clutch 34 (the left occlusion portion 33L) The output gear 32R is driven. As a result, when the operating pressure of the reverse clutch 53 is in a low pressure range, the aircraft gradually turns to the right.

  Then, when the amount of movement of the turning lever 77 to the right increases and the operating pressure of the reverse clutch 53 becomes high, the power from the reverse clutch 53 becomes the power from the left side clutch 34 (the left occlusal portion 33L). The right output gear 32R is driven by the power from the reverse clutch 53 by overcoming it. In this state, the right output gear 32R is driven in the reverse direction with respect to the left output gear 32L, and the aircraft turns to the right. The turning state at this time corresponds to a reverse turning state in which the traveling device inside the turning is driven so as to advance in the direction opposite to the aircraft traveling direction.

  Next, when the turning lever 77 is operated leftward from the rectilinear command position N, when the dead zone is removed, the left turning control valve 68 is operated to the supply position 68a, and the unload valve 70 is moved to the cutoff position 70a. The hydraulic oil is supplied to the left side clutch 34 (left occlusion portion 33L) and the left turning clutch 49, and the left side clutch 34 (left occlusion portion 33L) is operated to be disconnected, The hydraulic oil is operated in the transmission state to the swing clutch 49. At the same time, the same operation as described above is performed, and the aircraft gradually turns to the left. When the amount of movement of the turning lever 77 to the left increases and the operating pressure of the reverse clutch 53 becomes high, the same operation as in the case of turning right is performed, and the aircraft turns to the left.

  As shown in FIG. 5, the turning state changeover switch 81 is provided in the grip portion of the turning lever 77, and in the case of the gentle turning mode, the turning state changeover switch 81 is operated in a state where the turning lever 77 is operated to make a turn. When the push operation is performed, the turning switching control valve 72 is operated from the slow turning position 72a to the brake turning position 72b, and the above-described brake turning mode can be switched. This brake turning mode is only while the turning state changeover switch 81 of the turning lever 77 is being pressed, and when the release operation is performed by releasing the turning state changeover switch 81 of the turning lever 77, the mode returns to the gentle turning mode.

  In the case of the brake turning mode, if the turning state changeover switch 81 of the turning lever 77 is pushed while the turning lever 77 is operated to turn, the operation pressure to the reverse clutch 53 is changed and adjusted. Reversing turning mode is entered and the aircraft turns. This reverse turning mode is only while the turning state changeover switch 81 of the turning lever 77 is being pressed. When the turning state release switch 81 of the turning lever 77 is released and returned, the brake turning mode is restored.

  Therefore, in this embodiment, the turning mode switch 78 and the turning state changeover switch 81 correspond to the turning mode command means 300 as the operation relation selecting means.

  Then, current detection as actual operation pressure detecting means for detecting a current value supplied to the proportional control valve 71 as actual operation pressures for the slow swing clutch 46 and the reverse clutch 53, which are a plurality of friction type hydraulic clutches as operated devices. A sensor 82 is provided, and the control device 64 determines a target current value (target operation value) based on the index value commanded by the index value command unit 200 and the operation relationship selected by the turning mode command unit 300. Pressure) and the current detection value (actual operation pressure) of the current detection sensor 82 is proportional to the target current value (target operation pressure) obtained in the target operation pressure calculation process. An operation pressure adjustment process for operating the control valve 71 is executed.

  In other words, the control device 64 detects the operation pressure of the slow swing clutch 46, specifically the current when the slow swing mode is instructed by the swing mode command means 300 and the swing is instructed by the swing lever 77. The current value to be supplied to the proportional control valve 71 is adjusted so that the current detection value (operating pressure of the gentle turning clutch 46) detected by the sensor 82 becomes the target current value corresponding to the commanded turning state, When the brake turning state is commanded and the turning lever 77 is commanded to turn, the current detection value (operating pressure of the reverse clutch 53) detected by the current detection sensor 82 is proportional to the target current value. When the value of the current supplied to the control valve 71 is adjusted, and the reverse rotation mode is commanded by the swing mode command means 300 and the swing lever 77 is commanded to rotate, the current detection sensor 82 is detected. Current detection value detected (operation pressure of the reverse clutch 53) is configured to adjust the current value to be supplied to the proportional control valve 71 so that the target current value corresponding to the turning state commanded Te.

  More specifically, the relationship between the operation position and the target operation pressure in the turning command operation area of the turning lever 77 constituting the index value command means 200 is expressed as the amount of movement in the direction away from the straight-ahead command position in the turning command operation area. The larger the amount is, and the larger the amount of movement in the direction away from the rectilinear command position in the turn command operation region over the entire range of the turn command operation region, the greater the per unit amount of the operation position of the turn lever 77. It is determined as a relationship corresponding to a quadratic function that changes the amount of change in the target operation pressure with respect to the change to the large side, and in a direction away from the rectilinear command position in the turning command operation region defined as a relationship corresponding to this quadratic function Based on the relationship between the amount of movement and the target operating pressure, and the operating position of the turning lever 77, the target corresponding to the operating position of the turning lever 77 Seeking Saku圧, it is configured to control the proportional control valve 71 to be the target operating pressures.

  As shown in FIG. 6, in the gentle turning mode, when the turning lever 77 is operated to the maximum operation position, the traveling device with the output rotational speed of the traveling device inside the turning of the pair of left and right traveling devices is on the opposite side. A turning state is set in which the speed is reduced to about 1/3 of the output rotation speed (see line L1 in FIG. 6). In the brake turning mode, the turning lever 77 is operated to the maximum operating position. The target speed ratio is set so that the output rotational speed of the traveling device on the turning center side becomes zero (see the line L2 in FIG. 6), and the turning lever 77 is operated to the maximum operation position in the reverse turning mode. Sometimes, the target speed is such that the output rotational speed of the traveling device on the inside of the turn is the rotational direction opposite to the drive rotational direction of the opposite traveling device and is about 1/3 of the output rotational speed of the opposite traveling device. Ratio set Are (see line L3 in FIG. 6).

  As shown in FIG. 7, the operation position of the turning lever 77 (hereinafter sometimes referred to as a lever operating position), the slow turning clutch 46 and the reverse clutch 53 so as to obtain the target speed ratio as described above through experiments and the like in advance. The target operating pressure (specifically, the target current value to be supplied to the proportional control valve 71), that is, the higher the operating pressure, the higher the target operating pressure and the same lever operating position. A plurality of operation relationships with different target operation pressures in the operation relationship storage unit are defined as a relationship corresponding to a quadratic function that changes the change amount of the target operation pressure to the larger side with respect to a change per unit amount of the operation position. Is stored in the non-volatile memory M.

  In other words, the line L4 in FIG. 7 indicates the operation position of the turning lever 77 and the target operating pressures of the slow turning clutch 46 and the reverse clutch 53 (the target to be supplied to the proportional control valve 71) in the slow turning mode and the reverse turning mode. The line L5 in FIG. 7 shows the correlation between the operation position of the turning lever 77 and the target operating pressure (target current to be supplied to the proportional control valve 71) in the brake turning mode. Value).

  In the line L4, when the turning lever 77 is operated to the maximum operating positions Lm and Rm, the slow turning clutch 46 is operated in a completely engaged state by a strong pressure in the slow turning mode, and the reverse turning mode is set. In this case, the operation pressure is set so that the reverse clutch 53 is operated to a fully engaged state by a strong pressure contact force. However, in the line L5, when the turning lever 77 is operated to the maximum operating positions Lm and Rm, the transmission shaft 44 is not driven in reverse rotation, but the turning of the traveling device 1 inside the turning is stopped or substantially stopped. The operating pressure in the reverse clutch 53 is set so as to be in a state.

Accordingly, as the clutch selection information for defining the relationship between the plurality of operation relationships selected in accordance with the selection of the turning mode by the turning mode command means 300 and the plurality of friction type hydraulic clutches, the slow turning of the plurality of friction type hydraulic clutches is performed. Of the plurality of operation relations (the gentle turning clutch 46), the operation relation (line L4) that becomes a large target operation pressure (target current value) when the index value of the index value command means 200 is the same. The target operating pressure (small target operating pressure) when the index value of the index value command means 200 is the same among the plurality of operating relationships is operated by operating the sudden turning side (reverse clutch 53) of the plurality of friction type hydraulic clutches. Re et set to operate at the target current value) and a manipulation relationship (line L5) becomes Rukoto.

  And the control apparatus 64 is a change calculated | required based on the operation relationship until it is changed when the operation relationship selected by the turning mode command means 300 is changed to a different operation relationship in the operation pressure adjustment process. When the difference between the previous target operation pressure and the target operation pressure after change obtained based on the changed operation relationship is greater than or equal to the set amount, the target operation pressure before change obtained based on the operation relationship until the change is made The target operation pressure gradual change process for operating the proportional control valve 71 in a form in which the gradual target operation pressure is changed to a state where the target operation pressure after the change is obtained based on the operation relation changed from Change when the difference between the target operation pressure before change obtained based on the operation relationship until the change is made and the target operation pressure after change obtained based on the changed operation relationship is less than the set amount. And a target operating pressure to perform the desired operation 圧急 speed change processing for activating the operating pressure regulating means immediately form changing the target operating pressure condition to be the target operating pressure after the change.

  Specifically, in the operation pressure adjustment process, when the operation relationship selected by the turning mode command unit 300 is changed to a different operation relationship, and the index value of the index value command unit 200 is the same. When the operation relationship (line L4) having a large target current value (target operation pressure) is changed to the operation relationship (line L5) having a small target current value (target operation pressure), a target operation pressure gradual change process is executed. When the operation relationship selected by the turning mode command means 300 is changed to a different operation relationship, and the index value of the index value command means 200 is the same, a small target current value (target operation pressure) ) Is changed from the operation relationship (line L5) to a large target current value (target operation pressure) to the operation relationship (line L4). It is configured to execute immediately the target operating 圧急 speed change processing for operating the proportional control valve 71 in the form of changing the target current value to the state a value.

Hereinafter, the turning control of the control device 64 will be described with reference to the flowcharts shown in FIGS. This process is repeated every unit time (for example, 5 msec).
If the turning lever 77 is within the dead zone of the straight travel command position N, the unload valve 70 is switched to the discharge position 70a (steps 1 and 2). Further, both the left turn control valve 68 and the right turn control valve 67 are held in the shut-off state (steps 3 and 4). When the turning lever 77 deviates from the dead zone from the straight travel command position N, the left turn control valve 68 is switched to the supply position 68a if the operation direction is the left direction, and the right turn control valve 67 is turned if the operation direction is the right direction. Switching to the supply position 67a (steps 5, 6 and 7), the unload valve 70 is switched to the shut-off position 70a (step 8).

  Next, a target current value (corresponding to a target operating pressure) is obtained based on the index value commanded by the index value command means 200 and the operation relationship selected by the turning mode command means 300 (step 9). ). For example, if the slow turning mode is commanded by the turning mode command means 300, based on the operation relationship set in the line L4 in FIG. 7 corresponding to the slow turning mode and the detection information of the turning lever sensor 80, A target operation pressure at the operation position of the turning lever 77, specifically, a target current value for the proportional control valve 71 is obtained. When the brake turning mode is commanded by the turning mode command means 300, the turning lever is determined based on the operation relationship set in the line L5 in FIG. 7 corresponding to the brake turning mode and the detection information of the turning lever sensor 80. A target current value for the proportional control valve 71 at the operation position 77 is obtained. Similarly, in the reverse turning mode, the proportional control valve at the operation position of the turning lever 77 based on the operation relationship set in the line L4 of FIG. 7 corresponding to the slow turning mode and the detection information of the turning lever sensor 80. A target current value for 71 is obtained.

Then, the operation pressure adjustment process is executed (step 10).
As shown in FIG. 9, this operation pressure adjustment process is performed when the turning mode is changed by operating the turning state changeover switch 81 with a finger in a state where turning is instructed by the turning lever 77. If the currently commanded turning mode is the brake turning mode (step 101), it is within the set time after changing from the slow turning mode to the brake turning mode (step 102), and is obtained before the turning mode is changed. If the difference between the target current value I ₁ and the target current value I ₂ obtained after changing the turning mode is greater than or equal to the set amount A (step 103), the target current value I ₁ obtained before changing the turning mode is determined. until reduced to the target current value I ₂ obtained after the change of the swivel mode so as to be changed to follow the current detection value is energized proportional control valve 71, the passage of set interval time Setting a control target current value Im for outputting to the proportional control valve 71 in the form of reducing one by unit amount ΔI (step 104-109). Therefore, for example, as shown in FIG. 10, the control target current value Im gradually decreases from the target current value I ₁ obtained before the turning mode is changed to the target current value I ₂ obtained after the turning mode is changed. become.

When not in the brake turn mode, even when in the brake turn mode, when the set time has elapsed since the change from the slow turn mode, or when the set time has not passed since the change from the slow turn mode to the brake turn mode Even if the difference between the target current value I ₁ obtained before the change of the turning mode and the target current value I ₂ obtained after the change of the turning mode is less than the set amount, the change of the turning mode is immediately performed. The target current value obtained later is set as a control target current value Im for outputting to the proportional control valve 71 (step 110).
Then, by PID control based on the deviation between the current detection value and the control target current value Im so that the current detection value (corresponding to the actual operation pressure) detected by the current detection sensor 82 becomes the control target current value Im. The output current value for energizing the proportional control valve 71 is changed and adjusted (step 111).

  Steps 104 to 108 and step 111 correspond to the target operation pressure gradual change process, and steps 110 and 111 correspond to the target operation pressure rapid change process.

  By controlling in this way, as shown in FIG. 10, the actual operating pressure with respect to the reverse clutch 53 gradually decreases with the passage of time, and an overshoot due to a sudden fluctuation in operating pressure occurs. Can be avoided. For example, there is a difference in hydraulic operation characteristics between the slow swing clutch 46 and the reverse clutch 53. For example, the swing lever 77 is turned from the state where the swing lever 77 is operated to the maximum operation position in the slow swing mode. When switching to the brake turning mode by operating the state switch 81, if the calculated target current value is immediately set as the control target current value Im, the operating pressure is temporarily insufficient, and the brake turning is commanded. Nevertheless, the turning force may temporarily decrease in the turning state, but even in such a case, the turning state can be smoothly switched by controlling as described above.

[Second Embodiment]
Next, a second embodiment of the turning control device for a work vehicle according to the present invention will be described.
This embodiment is the same as the configuration of the first embodiment except that the configuration of the control processing of the control device is different, so only the different configuration will be described, and the description of the same configuration will be omitted.

  That is, in the second embodiment, the control device 64 as the control unit changes the operation relationship selected by the turning mode command unit 300 as the operation relationship selection unit to a different operation relationship as the target operation pressure gradual change process. When the target operation pressure before the change obtained based on the operation relationship until the change is made and the target operation pressure after the change obtained based on the changed operation relationship is smaller, the speed is increased. Thus, the proportional control valve 71 as the operation pressure adjusting means is operated in such a manner that the target operation pressure is gradually changed from the target operation pressure before the change to the target operation pressure after the change.

Hereinafter, the turning control of the control device 64 will be described with reference to the flowchart of the operation pressure adjustment process shown in FIG. The processes other than the operation pressure adjustment process, that is, the processes from Step 1 to Step 9 of the first embodiment are the same as those of the first embodiment.
When the turning mode is changed by a finger operation on the turning state changeover switch 81 in a state in which turning is commanded by the turning lever 77, the currently commanded turning mode is the brake turning mode. The difference between the target current value I ₁ obtained before the change of the turning mode and the target current value I ₂ obtained after the change of the turning mode is within the set time after the change from the slow turning mode to the brake turning mode ( The target current value decrease value ΔIm is set so as to increase as I ₁ −I ₂ ) increases. Then, every time the set interval time elapses, the process is executed until the target current value I ₁ obtained before the change of the turning mode is decreased to the target current value I ₂ obtained after the change of the turning mode. A control target current value Im to be output to the proportional control valve 71 is set in such a manner that the target current value decrease value ΔIm obtained in step 103 is sequentially decreased every time (steps 104 to 109).

  In other words, the difference between the target operation pressure before change (target current value) obtained based on the operation relationship until the change and the target operation pressure (target current value) after change obtained based on the changed operation relationship The target operation pressure is gradually changed from the target operation pressure (target current value) before the change to the target operation pressure (target current value) after the change in a state where the speed is increased as the value becomes smaller.

If not brake the turning mode, also, the brake when passed a turning mode from being changed from slow turning mode setting time or immediately, the target current value I ₂ proportional control valve determined after changing the turning mode It is set as a control target current value Im for output to 71 (step 110).
Then, by PID control based on the deviation between the current detection value and the control target current value Im so that the current detection value (corresponding to the actual operation pressure) detected by the current detection sensor 82 becomes the control target current value Im. The output current value for energizing the proportional control valve 71 is changed and adjusted (step 111).

By controlling in this way, as shown in FIG. 12, the control target current value Im reaches from the target current value I ₁ obtained before the change of the turning mode to the target current value I ₂ obtained after the change of the turning mode. At this time, the control target current value Im decreases rapidly and rapidly as the difference (I ₁ −I ₂ ) is small, and gradually decreases as the difference (I ₁ −I ₂ ) is large, The undershoot amount of the operating pressure can be reduced.

[Other Embodiments] Other embodiments are listed below.

  (1) In the above-described embodiment, when the operation pressure adjustment processing is changed from an operation relationship that results in a large target operation pressure when the index value of the index value command means is the same to an operation relationship that results in a small target operation pressure. , When the target operation pressure gradual change processing is executed and the operation relationship of a small target operation pressure is changed to the operation relationship of a large target operation pressure when the index value of the index value command means is the same, The target operation pressure rapid change processing is executed, but instead of such a configuration, an operation that results in a small target operation pressure from an operation relationship that results in a large target operation pressure when the index value of the index value command means is the same. Not only when the relationship is changed to a relationship, but also when the operation relationship is changed from a small target operation pressure to a large target operation pressure when the index value of the index value command means is the same, It may be executed a serial control input 圧漸 following modifications.

(2) In the above embodiment, as the target operation pressure gradual change processing, the target operation pressure is changed by gradually decreasing the control target value of the current value for the control means to output to the proportional control valve. The operation pressure adjusting means is configured to operate, but instead of such a configuration, the target operation pressure is gradually changed by sequentially changing the control constant when executing the target operation pressure gradual change processing. The operation pressure gradual change process may be executed.
For example, when the difference between the target current value obtained before the change of the turning mode and the target current value obtained after the change of the turning mode is a set amount or more, the target current value obtained after the change of the turning mode is set to the control target. It is also possible to set the control gain when controlling the proportional control valve 71 to a value smaller than a preset standard value so as to control the actual output current value to gradually decrease. . When the difference between the target current value obtained before the change of the turning mode and the target current value obtained after the change of the turning mode is less than the set amount, the control gain is set to the standard value.

  In addition to such a configuration, the control gain is changed to a smaller value as the difference between the target current value obtained before changing the turning mode and the target current value obtained after changing the turning mode is larger. The proportional control valve may be controlled by the above.

(3) In the above embodiment has been described as applied to a work vehicle combine, the present invention can be applied to work vehicles other than combine.

1 Traveling device 46 Slow turn clutch (friction type hydraulic clutch)
53 Reverse clutch (friction type hydraulic clutch)
64 Control means 71 Operating pressure adjusting means 72 Hydraulic pressure supply object changing means
77 Swivel lever
78 Turning mode switch
80 Rotating lever sensor
81 turning state changeover switch 82 actual operation pressure detection means 200 index value command means 300 operation relation selection means M operation relation storage means

Claims (6)

Index value command means for commanding an index value corresponding to the magnitude of the operating pressure;
Operating pressure adjusting means for adjusting the operating pressure on the operated device;
An actual operating pressure detecting means for detecting an actual operating pressure of the operating pressure adjusting means;
Control means for operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure,
As the relationship between the index value of the index value command means and the target operation pressure, an operation for storing a plurality of operation relationships in which the target operation pressure is increased as the operation pressure is larger and the target operation pressure at the same index value is different. Relationship storage means;
As the operated device, a plurality of frictions that adjust the traveling speed of the traveling device on the inner side of the turning of the pair of left and right traveling devices for turning and that show different turning radii when the same hydraulic pressure is applied. Type hydraulic clutch,
An operation relationship selecting means for selecting any one of a plurality of operation relationships,
The control means is
An index value commanded by the index value command means, a target operating pressure calculation process for obtaining a target operating pressure based on the operating relation selected by the operating relation selecting means, and
An operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure detected by the actual operation pressure detection means becomes the target operation pressure obtained in the target operation pressure calculation process. A work vehicle turning control device comprising :
A hydraulic pressure supply target changing means for changing a target for supplying the hydraulic pressure to be adjusted by the operation pressure adjusting means is provided;
The index value command means is configured to include a swing lever that is swingable over a rectilinear command position and a swing command operation region that is linked thereto, and a swing lever sensor that detects an operation position of the swing lever,
The operation relationship selection means is provided in a swing mode switch for commanding switching to one of a plurality of swing modes as a plurality of operation relationships, and a gripping portion of the swing lever so as to be operated by a finger, and is operated at the time of a turn to operate a turning force. And a turning state changeover switch for improving
The control means operates the hydraulic pressure supply object changing means based on clutch selection information that defines a relationship between a plurality of operation relations selected by the operation relation selection means and the plurality of friction hydraulic clutches. Configured,
An operation relationship in which the clutch selection information has a large target operation pressure when the index value of the index value command means is the same among the plurality of operation relationships when the clutch selection information is a slowly turning side among a plurality of friction type hydraulic clutches Of the plurality of friction-type hydraulic clutches in the operation relationship that becomes a small target operation pressure when the index value of the index value command means is the same among the plurality of operation relationships. To be operated,
The control means is
In the operation pressure adjustment process, the operation relationship selected by the operation relationship selection means is different when the turning state changeover switch is operated while the turning lever is operated in the turning command operation region. Until the change is made when the operation relationship becomes a large target operation pressure when the index value of the index value command means is the same, and the operation relationship becomes a small target operation pressure. The operation pressure adjusting means is configured to gradually change the target operation pressure to a state where the target operation pressure after change is obtained based on the operation relation changed from the target operation pressure before change obtained based on the operation relation. Execute target operation pressure gradual change processing to be activated , and
This is when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship by operating the turning state changeover switch while the swing lever is operated in the turn command operation area. When the index value of the index value command means is the same, the target operation pressure after the change is changed from the target operation pressure before the change to the operation relation where the target operation pressure becomes a large target operation pressure. A turn control device for a work vehicle configured to execute a target operation pressure rapid change process for operating the operation pressure adjusting means in such a manner that the target operation pressure is immediately changed to a state of becoming . Index value command means for commanding an index value corresponding to the magnitude of the operating pressure;
Operating pressure adjusting means for adjusting the operating pressure on the operated device;
An actual operating pressure detecting means for detecting an actual operating pressure of the operating pressure adjusting means;
Control means for operating the operating pressure adjusting means so that the actual operating pressure becomes the target operating pressure,
As the relationship between the index value of the index value command means and the target operation pressure, an operation for storing a plurality of operation relationships in which the target operation pressure is increased as the operation pressure is larger and the target operation pressure at the same index value is different. Relationship storage means;
As the operated device, a plurality of frictions that adjust the traveling speed of the traveling device on the inner side of the turning of the pair of left and right traveling devices for turning and that show different turning radii when the same hydraulic pressure is applied. Type hydraulic clutch,
An operation relationship selecting means for selecting any one of a plurality of operation relationships,
The control means is
An index value commanded by the index value command means, a target operating pressure calculation process for obtaining a target operating pressure based on the operating relation selected by the operating relation selecting means, and
An operation pressure adjustment process for operating the operation pressure adjustment means is executed so that the actual operation pressure detected by the actual operation pressure detection means becomes the target operation pressure obtained in the target operation pressure calculation process. A work vehicle turning control device comprising:
The plurality of friction-type hydraulic clutches make a slow turning clutch that makes the running device on the inner side of the turn slower than the running device on the outer side of the turn at the maximum operating pressure, and travels on the inner side of the turn at the maximum operating pressure. A reverse clutch that reverses the device with respect to the traveling device on the outer side of the turning,
The operating pressure adjusting means is configured to adjust the hydraulic pressure supplied to the two frictional hydraulic clutches;
A hydraulic pressure supply target changing means for changing a target for supplying the hydraulic pressure to be adjusted by the operation pressure adjusting means is provided;
The index value command means is configured to include a swing lever that is swingable over a rectilinear command position and a swing command operation region that is linked thereto, and a swing lever sensor that detects an operation position of the swing lever,
The operation relationship selection means includes, as the plurality of operation relationships, a slow turning mode in which the traveling device on the inner side of the turning is slower than the traveling device on the outer side of the turning, and a brake that sets the traveling device on the inner side of the turning to a braking state. It is configured to select any one of a turning mode and a reverse rotation mode for reversing the traveling device on the inner side of the turning with respect to the traveling device on the outer side of the turning,
The control means operates the hydraulic pressure supply target changing means based on clutch selection information that defines a relation between a plurality of operation relations selected by the operation relation selection means and the two friction hydraulic clutches. Configured,
In the slow turning mode, the clutch selection information operates the slow turning clutch with a large-side operation relationship that becomes a large target operating pressure when the index value of the index value command means is the same. The reverse clutch is operated with a small side operation relationship that results in a small target operating pressure when the index value of the index value command means is the same, and the reverse clutch is operated in the slow turning mode in the reverse rotation mode. It is determined to operate in the same large-side operation relationship as the relationship,
The control means is
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the operation pressure is changed from the target operation pressure before the change obtained based on the operation relationship until the change. The target operation pressure gradual change process for operating the operation pressure adjusting means is executed in such a manner that the target operation pressure is gradually changed to the target operation pressure after change obtained based on the operation relation. A turning control device for work vehicles. The control means is
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, and when the large-side operation relationship is changed to the small-side operation relationship. , When the target operation pressure gradual change processing is executed and the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, from the small side operation relationship to the large side When the operation relation is changed, a target operation pressure rapid change process is performed in which the operation pressure adjusting means is operated in such a manner that the target operation pressure is immediately changed from the target operation pressure before the change to the target operation pressure after the change. The turning control device for a work vehicle according to claim 2, wherein the turning control device is configured to do so. The control means is
In the operation pressure adjustment process, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the target operation pressure before the change and the change obtained based on the operation relationship until the change is changed When the difference from the changed target operating pressure obtained based on the operated relation is equal to or larger than the set amount, the target operating pressure gradual change processing is executed and obtained based on the operating relation until the change is made. When the difference between the target operation pressure before change and the target operation pressure after change obtained based on the changed operation relationship is less than the set amount, the target operation pressure after change is changed to the target operation pressure after change. The turning control of the work vehicle according to any one of claims 1 to 3 , wherein a target operation pressure rapid change process for operating the operation pressure adjusting means in a form in which the target operation pressure is immediately changed is executed. Dress . The control means is
In the target operation pressure gradual change processing, when the operation relationship selected by the operation relationship selection means is changed to a different operation relationship, the target operation pressure before the change obtained based on the operation relationship until the change is made The target operation pressure is gradually increased from the target operation pressure before the change to the target operation pressure after the change in a state where the speed becomes higher as the difference between the target operation pressure after the change and the target operation pressure after the change obtained based on the changed operation relationship is smaller. The turning control device for a work vehicle according to any one of claims 1 to 3 , wherein the operation pressure adjusting means is configured to be operated in a form in which the operating pressure is changed. The operating pressure adjusting means is an electromagnetic proportional valve,
The actual operation pressure detecting means is configured to detect a current value energized to the electromagnetic proportional valve as an actual operation pressure,
The operation relationship storage means is configured to store a relationship between the index value and a target current value for energizing the electromagnetic proportional valve as a relationship between the index value of the index value command means and a target operation pressure,
The control means is
In the target operation pressure calculation process, the target current value as the target operation pressure is obtained, and in the operation pressure adjustment process, the current value as the actual operation pressure detected by the actual operation pressure detection means is the target. The turning control device for a work vehicle according to any one of claims 1 to 5 , wherein the electromagnetic proportional valve is energized so as to have a current value.

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