JP4901667B2 - Work vehicle attitude control device - Google Patents

Description

  The present invention relates to a posture control device for a work vehicle, and more particularly, a posture change operation means that can freely change a front / rear inclination angle of a vehicle body with respect to a grounding portion of a traveling device in a front downward inclination direction and a rear downward inclination direction, The front / rear inclination angle detecting means for detecting the front / rear inclination angle with respect to the horizontal reference plane, and the posture changing operation so that the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes a set inclination angle based on detection information of the front / rear inclination angle detection means A posture control means for performing front and rear posture control for controlling the operation of the means, and the posture changing operation means is capable of changing and adjusting the height of the front end side portion of the vehicle body relative to the grounding portion of the traveling device. And a rear drive means that can change and adjust the height of the rear end side portion of the vehicle body relative to the grounding portion of the traveling device in an adjustable state, and In the case where the control means changes the front / rear inclination angle of the vehicle body with respect to the ground contact portion of the traveling device to either the front lower inclination direction or the rear lower inclination direction as the front / rear posture control, If the height of the portion located on the lower side of the inclination direction to be changed among the rear end side portions with respect to the ground contact portion of the traveling device is not the lower limit position, of the front drive means and the rear drive means A downward tilting operation is performed in which the driving means positioned on the inclined lower side is operated in the vehicle lowering direction in a state where the operation of the driving means positioned on the opposite side to the lowering side of the tilt direction is stopped, and the front end of the vehicle body is If the height with respect to the ground contact portion of the traveling device of the side portion and the rear end side portion located on the lower side of the inclination direction to be changed is the lower limit position, the front side The drive means that operates the drive means located on the opposite side to the tilt-down side in the state of stopping the operation of the drive means that is located on the tilt-down side among the moving means and the drive means on the rear side is moved upward The height with respect to the grounding portion of the traveling device is a lower limit in a form in which the tilting operation is performed and in the position located on the tilting-down side of the front end side portion and the rear end side portion in the vehicle body by executing the descending tilt operation. Even when the vehicle is in the position, if the forward / backward inclination angle with respect to the horizontal reference plane of the vehicle body is not the set inclination angle, the upward inclination operation is executed following the downward inclination operation. The present invention relates to a posture control device for a work vehicle configured to execute posture change operation processing for controlling operation.

  The work vehicle attitude control device executes the attitude change operation process to thereby increase the height of the front end side portion of the vehicle body relative to the grounding portion of the traveling device and the rear end portion of the vehicle body relative to the grounding portion of the traveling device. The vehicle's front / rear tilt angle is changed so that either one of the heights is always at the lower limit position, and the position of the center of gravity of the fuselage is low, so the posture is easy to stabilize and driving stability is improved. In this type of work vehicle attitude control device, there has been conventionally configured as follows.

  That is, the front-rear inclination angle detecting means is constituted by a gravity-type inclination angle sensor that detects the front-rear inclination angle of the vehicle body by the action of gravity, and based on the detection value of the gravity-type inclination angle sensor, It is configured to obtain an inclination angle, and as the posture changing operation means, the height with respect to the grounding portion of the traveling device is individually changed at each of the left front portion, left rear portion, right front portion, and right rear portion of the vehicle body. Comprising four hydraulic cylinders as adjustable drive means, and among the four hydraulic cylinders, two hydraulic cylinders located at the left front and right front are operated as front drive means, Two hydraulic cylinders located at the left rear and right rear are actuated as rear drive means, and when changing the front-rear tilt angle of the vehicle body, the attitude control means There is one configured to perform serial posture changing operation processing (for example, see Patent Document 1.).

  More specifically, the gravitational tilt sensor includes a pair of electrodes that store a liquid of a predetermined viscosity in a container provided in the vehicle body and is immersed in the liquid. As the liquid is inclined, the liquid level is inclined with respect to the container, the amount of immersion of the pair of electrodes is changed, and the capacitance between the pair of electrodes is changed. It is configured to electrically detect a change in capacity as information on the front and rear inclination angle of the vehicle body.

JP 2002-204613 A

  The gravitational tilt angle sensor used in the above-described conventional configuration has a configuration in which the liquid has a predetermined viscosity so that the liquid does not sway due to fine vibration accompanying the traveling of the vehicle body and erroneous information is detected. In addition, since the liquid has a predetermined viscosity, the followability with respect to a quick change in the posture of the vehicle body deteriorates.

  In other words, the gravitational tilt angle sensor accurately detects the front / rear tilt angle of the vehicle body when the longitudinal tilt angle of the vehicle body is not changing or when the vehicle body is tilted at a slow speed. However, when the vehicle body is tilted back and forth rapidly, the tilt angle sensor cannot follow the vehicle body tilt, causing a response delay and accurately detecting the vehicle body front / back tilt angle. There is a possibility that the posture change operation process cannot be performed satisfactorily.

  Therefore, as an improved configuration, an angular velocity sensor that detects the angular velocity in the vehicle body inclination angle detection direction, for example, a vibration gyro type angular velocity sensor, is provided separately from the gravity type inclination angle sensor, and the detected value of this angular velocity sensor is integrated. There has also been proposed a configuration in which the inclination angle of the vehicle body is detected by obtaining the inclination angle and supplementing the detection value of the inclination angle sensor. In other words, using a highly responsive angular velocity sensor, even when the vehicle body tilts rapidly, the inclination angle of the vehicle body is detected by the detected value of the angular velocity sensor, resulting in a response delay of the inclination angle sensor. It is intended to eliminate the error.

  However, when the angular velocity sensor as described above is arranged so as to detect the angular velocity in the longitudinal tilt direction of the vehicle body, the angular velocity sensor is used when the vehicle body tilts back and forth with its own detection axis when detecting the angular velocity. Although it is necessary to attach the shaft core along the shaft core along the left and right direction of the vehicle body, the detection shaft core may be provided in a state slightly deviated from the shaft core along the left and right direction of the vehicle body due to an assembly error or the like. is there. In addition, this type of work vehicle often travels on rough terrain such as a farm field, and the vehicle body may travel with the vehicle tilted to the left and right. The detection axis may be slightly displaced from the axis along the left-right direction of the vehicle body. And if the vehicle turns while the axis of its own detection when detecting the angular velocity is slightly deviated from the axis along the left and right direction of the vehicle body, the front and back around the axis along the left and right direction of the vehicle body In addition to the angular velocity in the tilt direction, an angular velocity component around the vertical axis perpendicular to the axis along the left-right direction of the vehicle body may be detected.

  As a result, during the turning of the vehicle body, even if the longitudinal inclination angle with respect to the horizontal reference plane of the vehicle body is the set inclination angle, an error is included in the detected angular velocity, and the error is accumulated by integration. The posture change operation in the front / rear tilt direction of the vehicle body by the posture change operation means, such as erroneously determining that the vehicle body is tilted in the front / rear direction and changing the posture in the front / rear tilt angle direction. There was a possibility that it could not be carried out satisfactorily.

  Therefore, the detection by the angular velocity sensor during turning is performed as described above, in which the inclination angle of the vehicle body is detected based on the detection value of the angular velocity sensor to eliminate the error caused by the response delay of the inclination angle sensor. In order to eliminate the error, a configuration in which the operation of the posture changing operation means is stopped during turning is considered, but with such a configuration, for example, the height of the front end side portion of the vehicle body with respect to the grounding portion of the traveling device, or , There is a risk that the vehicle will continue to turn while any of the heights of the rear end side of the vehicle body with respect to the grounding portion of the traveling device is higher than the lower limit position, and the vehicle body running stability is reduced. There are disadvantages to doing.

  The object of the present invention is to avoid unnecessary posture change due to detection error of the front / rear inclination angle detection means and reduce the possibility that the running stability is lowered while the vehicle body is turning. In a state where the vehicle is not turning, the posture control device for a work vehicle that can accurately detect the front / rear inclination angle of the vehicle body and perform the operation control in the vehicle front / rear inclination direction by the posture change operation means. Is to provide

A posture control device for a work vehicle according to the present invention includes a posture change operation means that can freely change a front / rear inclination angle of a vehicle body with respect to a grounding portion of a traveling device in each of a forward and downward inclination direction, and a horizontal reference plane of the vehicle body The front / rear inclination angle detecting means for detecting the front / rear inclination angle with respect to the vehicle, and the posture changing operation means operating so that the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes a set inclination angle based on detection information of the front / rear inclination angle detection means Posture control means for performing front-rear posture control for controlling
The posture changing operation means is
A front drive means that can change and adjust the height of the front end side portion of the vehicle body relative to the grounding portion of the traveling device, and a rear side that can change and adjust the height of the rear end portion of the vehicle body relative to the grounding portion of the traveling device. The drive means are provided in a state where they can be operated separately,
The posture control means, as the front and rear posture control,
When changing the front / rear inclination angle of the vehicle body with respect to the grounding portion of the traveling device to either the front lower inclination direction or the rear lower inclination direction, the change operation of the front end side position and the rear end side position of the vehicle body is performed. If the height of the portion located on the descending side in the tilt direction with respect to the ground contact portion of the traveling device is not the lower limit position, it is opposite to the descending side in the tilt direction of the front driving means and the rear driving means. The driving means positioned on the side is stopped and the driving means positioned on the inclined side is operated in the downward direction of the vehicle body. If the height with respect to the grounding portion of the traveling device at the position on the lower side of the tilt direction to be changed is the lower limit position, of the front drive means and the rear drive means The said inclined downward side in a state where the stopping operation of the driving means located on serial inclined downward side in a form to perform the rising slope operation for operating the drive means located on the opposite side of the vehicle body upward direction, and,
Even after the descending and tilting operation is executed and the height of the traveling device with respect to the ground contact portion at the position located on the inclined downward side of the front end side position and the rear end side position on the vehicle body becomes the lower limit position, If the forward / backward inclination angle with respect to the reference plane is not the set inclination angle, the posture change operation process for controlling the operation of the posture change operation means is executed in a form in which the upward inclination operation is executed following the downward inclination operation. Is configured to, and
The first characteristic configuration is that the front and rear inclination angle detecting means is
Among the detection values of the gravitational front / rear tilt angle sensor for detecting the front / rear tilt angle with respect to the horizontal reference plane of the vehicle body by the action of gravity, the angular velocity sensor for detecting the angular velocity in the front / rear tilt direction of the vehicle body, and the front / rear tilt angle sensor Inclination angle for obtaining the front-rear inclination angle of the vehicle body by adding the detected value after removing the high frequency component of the vehicle and the integrated value after removing the low frequency component of the integrated value obtained by integrating the detected value of the angular velocity sensor And a calculation means,
A turning state detecting means for detecting whether or not the vehicle body is in a turning running state is provided;
The posture control means, as the front and rear posture control,
When the turning state detecting means detects that the vehicle body is in a turning traveling state, the forward / backward inclination angle with respect to the horizontal reference plane of the vehicle body is determined so as to execute the downward inclination operation and not execute the upward inclination operation. The lowering operation limiting process for controlling the operation of the posture changing operation means so as to become the set inclination angle is executed, and when the turning state detecting means detects that the vehicle is not in the turning running state, the posture changing operation process is executed. In that it is configured to run.

According to the first characteristic configuration, the front / rear inclination angle detecting means detects a front / rear inclination angle of the vehicle body by the action of gravity, an angular velocity sensor that detects an angular velocity in the front / rear inclination direction of the vehicle body, The detection value after removing the high frequency component of the detection value of the front / rear inclination angle sensor and the integration value after removing the low frequency component of the integration value obtained by integrating the detection value of the angular velocity sensor are added. For example, a state in which the front-rear tilt angle of the vehicle body has not changed or the vehicle body is tilted back and forth at a slow speed. In the state, the angle change appears as a low-frequency component, so it is possible to accurately detect the front-rear tilt angle of the vehicle body mainly by the detection value after removing the high-frequency component of the gravitational tilt angle sensor. And the car body is Since the angle change appears as a high-frequency component when the vehicle is tilted extremely back and forth, the low-frequency component of the integrated value obtained by integrating the detected value of the angular velocity sensor that detects the angular velocity in the longitudinal tilt direction of the vehicle body It is possible to accurately detect the front-rear inclination angle of the vehicle body by the integrated value after removing the.
In this way, it is possible to accurately detect the front-rear inclination angle of the vehicle body, regardless of whether the vehicle body inclination direction changes slowly or rapidly.

  Then, it is detected by the turning state detecting means whether or not the vehicle body is in a turning traveling state, and when the turning state detecting means detects that the vehicle body is in a turning traveling state, the lowering operation is performed. Perform limited processing. That is, when the vehicle body is turning, the operation of the posture changing operation means is controlled so that the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes the set inclination angle. Only the operation is performed and the ascending tilt operation is not performed.

  In addition, when the vehicle body is turning, not only the angular velocity component around the axis along the left and right direction of the vehicle body, but also due to factors such as assembly error of the angular velocity sensor and traveling with the vehicle body tilted left and right, etc. The angular velocity component around the vertical axis may also be detected. However, when the angular velocity around the vertical axis is detected in this way, when the vehicle turns, the vertical axis associated with the turning is detected. There is a possibility that the angular velocity around is detected as an error.

  Therefore, in a state where the vehicle body is turning, only the descending tilt operation is performed and the ascending tilt operation is not performed so that the vehicle body is positioned as low as possible, while the vehicle body is in a low position. The posture is changed so that the front / rear inclination angle approaches the set inclination angle, and it is possible to reduce the possibility that the running stability is lowered while avoiding an unnecessary posture change due to the detection error of the angular velocity sensor.

  On the other hand, since the posture control means executes the posture change operation process when the turning state detecting means detects that the turning state is not in the turning state, the posture control means executes the posture changing operation process accurately. By detecting the front / rear inclination angle of the vehicle body, it is possible to satisfactorily control the operation of the vehicle body in the front / rear inclination direction by the posture changing operation means.

  Therefore, according to the first characteristic configuration, in the state where the vehicle body is turning, it is possible to avoid unnecessary posture change due to the detection error of the front / rear inclination angle detecting means and to reduce the risk of lowering the running stability. However, in a state where the vehicle body is not turning, the work vehicle can accurately detect the vehicle body front-rear inclination angle and perform good operation control in the vehicle body front-rear inclination direction by the posture change operation means. The attitude control device can be provided.

  According to a second characteristic configuration of the present invention, in addition to the first characteristic configuration, the posture control means performs the turning movement of the vehicle body by the turning state detection means as the front-rear posture control based on a command from the mode switching command means. A process mode change type control mode that executes the lowering operation limiting process when it is detected that the state is detected, and executes the posture change operation process when it is detected that the vehicle is not in the turning traveling state; The attitude control is configured to be switchable to a processing mode invariant control mode that always executes the attitude changing operation process regardless of the detection information of the turning state detecting means.

  According to the second characteristic configuration, when the posture control means is switched to the processing mode change type control mode based on the command from the mode switching command means, the turning state detection means is used as the front-rear posture control. When it is detected that the vehicle is in the turning state, the lowering operation limiting process is executed, and when it is detected that the vehicle is not in the turning state, the posture changing operation process is executed. In such a state, while avoiding unnecessary posture changes due to detection errors of the front and rear inclination angle detection means, there is little risk of lowering the running stability, but it does not turn, for example, it runs straight. In this case, it is possible to accurately detect the vehicle front / rear tilt angle with little detection error, and to perform good operation control in the vehicle front / rear tilt direction by the posture change operation means. It is possible.

  For example, when working on a hard field where the work vehicle is dry, the vehicle body is not tilted back and forth during turning while switching to this processing mode change type control mode. Nevertheless, if the forward / backward inclination angle is changed due to the measurement error of the angular velocity sensor, there is a risk that a working device such as a mowing device provided at the front of the vehicle body may thrust into the ground. According to the configuration, it is easy to avoid such disadvantages. By the way, in the case of a solid field, there is little possibility that the front / rear inclination angle of the work vehicle will change greatly, and the front / rear posture of the work vehicle becomes unstable even if the posture change operation process is not executed during turning. There is little risk of damage.

  On the other hand, when the attitude control means is switched to the processing mode invariable control mode based on a command from the mode switching command means, the attitude control means always performs the attitude as the front / rear attitude control regardless of the detection information of the turning state detection means. The change operation process is executed. In this processing mode change type control mode, for example, even when the vehicle body is turning, an attitude change operation process is executed, so that a detection error of the front / rear tilt angle has occurred due to turning. However, the posture change operation is performed so that the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes the set inclination angle.

  For example, when a work vehicle runs on a soft field such as a paddy field, if acceleration occurs in the longitudinal direction of the vehicle body when the work vehicle travels, the vehicle body is buried in the soft field and tilted forward and backward. Since the posture may change greatly, it is necessary to perform posture correction operation as soon as possible.In such a case, the vehicle body is turning by switching to the processing mode invariant control mode. Even in the case, the posture changing operation can be performed so that the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes the set inclination angle, which is easy to use.

  Therefore, according to the second feature configuration, by switching the control mode based on the operator's command, the posture changing operation means can be controlled in an appropriate control state according to a difference in work situation such as a difference in the degree of softness of the field. It has become possible to provide an easy-to-use work vehicle that can control the operation.

  According to a third feature configuration of the present invention, in addition to the second feature configuration, the posture change operation process is performed when the posture control unit is executing the lowering operation restriction process in the processing mode change type control mode. The operation speed for posture change at the time of changing the processing mode when operating the posture change operation means so that the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes the set inclination angle when the state is switched to In a state where the processing mode is not changed, the posture changing operation means is set to be slower than the normal posture changing operation speed when the posture changing operation means is operated so that the forward / backward inclination angle with respect to the horizontal reference plane of the vehicle body becomes the set inclination angle. In this state, the operation of the posture changing operation means is controlled.

  According to the third characteristic configuration, in the state where the lowering operation limiting process is being executed in the processing mode changing type control mode, the state may be switched from such a state to the state where the posture changing operation process is executed. If so, the operation of the posture changing operation means is controlled in a state where the posture changing operation speed is set lower than the normal posture changing operation speed.

  In the state in which the lowering operation limiting process is being performed, it is conceivable that the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body has changed greatly due to, for example, unevenness on the traveling road surface. When switching to a state in which the posture change operation process is executed and the posture correction operation is performed at the normal posture change operation speed, the driver changes the posture in the forward and backward direction and the rider is riding on the work vehicle. Although it may be uncomfortable, as described above, the operation of the posture changing operation means is controlled in a state in which the posture changing operation speed is set lower than the normal posture changing operation speed. As a result, the forward / backward posture does not change abruptly, and there is little risk of poor ride comfort.

  Therefore, according to the third characteristic configuration, it is possible to provide a work vehicle that can improve the running stability without causing the rider on the work vehicle to have a poor ride comfort.

In addition to any one of the first feature configuration to the third feature configuration, the fourth feature configuration of the present invention is provided with a pair of left and right traveling devices capable of changing the driving speed individually as the traveling device,
The vehicle body is configured to turn while varying the driving speed of each of the pair of left and right traveling devices,
The turning state detecting means is
A pair of traveling speed detecting means for detecting the respective driving speeds of the pair of left and right traveling apparatuses, and a calculating means for obtaining a turning angular speed when the vehicle body turns based on a difference between the respective driving speeds of the pair of left and right traveling apparatuses. , An integrating means for integrating the turning angular velocity, a high-pass filter for detecting a turning state that removes a low frequency component of the integrated value integrated by the integrating means, and an output value of the high-pass filter for detecting the turning state And a discriminating means for discriminating whether or not the vehicle is in a turning traveling state.

  According to the fourth characteristic configuration, the work vehicle turns the vehicle body by changing the driving speeds of the pair of left and right traveling devices, but each of the pair of left and right traveling devices detected by the pair of traveling speed detecting means. Based on the difference in the driving speeds, the turning angular speed when the vehicle body turns by the calculating means is obtained. Then, the turning angular velocity obtained by the computing means is integrated by the integrating means, and the low frequency component of the integrated value integrated by the integrating means is removed by the high-pass filter for detecting the turning state. Based on the output value, the determination means determines whether or not the vehicle is in the turning traveling state.

  Thus, the turning angular velocity is obtained based on the difference between the driving speeds of the pair of left and right traveling devices, the turning angular velocity is integrated to obtain the turning angle, and the low frequency component of the integrated value is Since it is determined whether or not the vehicle is in the turning state based on the output value after being removed, in the case of turning at a higher speed, it is appropriately determined that the vehicle is in the turning state. In the case where the lowering operation limiting process is executed and the vehicle slowly turns at a low speed, the low frequency component is removed, so that it is determined that the vehicle is not in a turning state, and the posture changing operation process is executed. .

  As a result, for example, when turning while working, the lowering operation limiting process is executed because the vehicle is turning at a higher speed. However, when the work vehicle enters the field from the fence, the lower speed is reduced. In such a case, there is an advantage that the approaching operation can be easily performed by executing the posture changing operation process.

  Therefore, according to the fourth feature configuration, it is possible to appropriately determine whether or not the vehicle is in the turning traveling state necessary for executing the lowering operation limiting process, and execute the front-rear posture control suitable for the work situation. We were able to provide a work vehicle that could do this.

Hereinafter, a case where an embodiment of the present invention is applied to a combine as an example of a work vehicle will be described with reference to the drawings.
As shown in FIG. 1, the combine includes a pair of left and right crawler type traveling devices 1 </ b> L and 1 </ b> R, a threshing device 3 that threshs the harvested cereal, a grain tank 4 that stores the threshed grain, and a boarding operation unit 2. The harvesting part 10 which harvests planted cereals such as rice and wheat and supplies it to the threshing device 3 with respect to the vehicle body V provided with the above and the like is configured to be movable up and down.

  The cutting unit 10 includes a weeding tool 6 provided at the tip part, a trigger device 5 that causes a planted culm that has been weeded by the weeding tool 6, and a clipper type that cuts the stock side of the induced culm. The cutting blade 7 and a vertical conveying device 8 that conveys the harvested cereal rice cake to the rear side while gradually changing to a laterally inclined posture are configured, and a hydraulic cutting cylinder C1 around the horizontal axis P1 at the front of the vehicle body V. Is provided so as to be swingable up and down.

  An ultrasonic cutting height sensor 9 that detects the height of the cutting unit 10 with respect to the ground is provided at a location on the rear side of the weeding tool 6. Although not described in detail, the cutting height sensor 9 detects the height of the cutting unit 10 with respect to the ground by measuring the time from when the ultrasonic wave is transmitted downward to when it is received. It is configured in a non-contact manner.

The combine is provided with posture changing operation means 100 that can freely change the front-rear inclination angle and the left-right inclination angle of the vehicle body V with respect to the grounding portions of the left and right traveling apparatuses 1L, 1R. Hereinafter, the configuration will be described.
First, a structure for attaching the left and right traveling devices 1L and 1R to the vehicle body V will be described. Since the left and right traveling apparatuses 1L and 1R have the same configuration, the left traveling apparatus 1L will be described below, and the description of the right traveling apparatus 1R will be omitted.

  As shown in FIG. 2, a drive sprocket 13 is rotatably supported on the front end side of the support frame 12 fixed to the main frame 11 that constitutes the vehicle body V in the front-rear-facing posture, and a plurality of idle rotations. A track frame 16 that pivots in a state where the ring bodies 14 are arranged in the front-rear direction and supports a tension ring body 15 at the rear end portion is mounted on the support frame 12 so as to be movable up and down. A crawler belt B, which is an endless rotating body, is wound around the drive sprocket 13, the tension ring body 15, and each idler ring body 14.

A front bell crank 17a configured to be substantially L-shaped in a side view so as to be rotatable around a horizontal axis P2 is pivotally supported on the front side of the support frame 12, and a horizontal axis is provided on the rear side of the support frame 12. A rear bell crank 17b configured to be substantially L-shaped in a side view so as to be rotatable around P3 is pivotally supported. The lower end portion of the front bell crank 17a is pivotally connected to the front portion of the track frame 16, and the lower end portion of the rear bell crank 17b is connected to the track frame 16 via an auxiliary link 17b1 for absorbing the stroke. It is pivotally connected to the rear part.
On the other hand, the cylinder rods of the hydraulic cylinders C2 and C3 are connected to the upper end portions of the front and rear bell cranks 17a and 17b, respectively. The cylinder main body side of each of the hydraulic cylinders C2 and C3 is pivotally connected to the horizontal frame portion of the main frame 11, and each of the hydraulic cylinders C2 and C3 is constituted by a double-acting hydraulic cylinder.

  When the hydraulic cylinder C2 (hereinafter referred to as the left front cylinder) corresponding to the front bell crank 17a is most extended and the hydraulic cylinder C3 (hereinafter referred to as the left rear cylinder) corresponding to the rear bell crank 17b is most shortened, FIG. As shown, the track frame 16 is received and supported by the support frame 12, and the track frame 16 comes closest to the main frame 11 and becomes substantially parallel.

Then, from the state shown in FIG. 2, when the left front cylinder C2 is shortened while maintaining the left rear cylinder C3 as it is, the front side of the vehicle body V is separated from the grounding portion as shown in FIG. The posture will be changed in the direction to do.
When the left rear cylinder C3 is extended while maintaining the left front cylinder C2 as it is from the state shown in FIG. 2, the rear side of the vehicle body V is moved away from the grounding portion as shown in FIG. The posture will be changed.
In addition, when the left front cylinder C2 is shortened and the left rear cylinder C3 is extended from the state shown in FIG. 2, the vehicle body V is separated from the grounding portion in a parallel posture as shown in FIG. The posture will change in the direction.

  Similarly to the left traveling device 1L, the right traveling device 1R includes a right front cylinder C4 located on the front side of the fuselage and a right rear cylinder C5 located on the rear side of the fuselage. A similar operation is performed. When the left and right traveling apparatuses 1L and 1R are in the state shown in FIG. 2, the longitudinal inclination angle and the lateral inclination angle of the vehicle body V with respect to the grounding portions of the traveling apparatuses 1L and 1R are zero or substantially zero, respectively. It becomes a lower limit reference posture as a reference state.

  As described above, the posture changing operation means 100 changes and adjusts the height of the left and right traveling devices 1L and 1R with respect to the grounding portions at the left front, left rear, right front, and right rear in the vehicle body V, respectively. The four hydraulic cylinders C2 to C5 for changing the posture of the body as four flexible driving means are provided.

In a state where the left and right rear cylinders C3 and C5 are deactivated, when the left and right front cylinders C2 and C4 are shortened, the front side of the vehicle body V moves away from the grounding portions of the traveling devices 1L and 1R. When the posture is changed (front ascending operation) and the left and right front cylinders C2 and C4 are extended, the front side of the vehicle body V is changed in the direction closer to the grounding portion of the traveling devices 1L and 1R (forward downward operation). It will be. Further, when the left and right front cylinders C2 and C4 are deactivated, when the left and right rear cylinders C3 and C5 are extended, the rear side of the vehicle body V is positioned in a direction away from the grounding portion of the traveling devices 1L and 1R. When the left and right rear cylinders C3 and C5 are shortened by changing (rearward raising operation), the posture of the rear side of the vehicle body V is changed (rearward lowering operation) in a direction approaching the grounding portion of the traveling devices 1L and 1R. Become.
Therefore, the left front cylinder C2 and the right front cylinder C4 correspond to the front drive means, and the left front cylinder C2 and the left rear cylinder C3 correspond to the rear drive means.

  Based on the amount of rotation of the four hydraulic cylinders C2, C3, C4, C5 corresponding to the rotation fulcrums of the bell cranks 17a, 17b in the left and right traveling devices 1L, 1R. In addition, potentiometer-type stroke sensors 18, 19, 20, and 21 are provided for detecting the operation amounts of the hydraulic cylinders C2, C3, C4, and C5 (that is, the stroke amount that has been expanded and contracted) (see FIG. 9).

  Next, the power transmission system is shown in FIG. The power output from the engine E mounted on the vehicle body V is transmitted to the threshing device 3 via the threshing clutch 45 and travels to the left and right via the traveling clutch 46 and the continuously variable transmission 47 as the traveling transmission device. The power transmitted to the transmission unit 48 of the devices 1L and 1R and transmitted to the transmission unit 48 is transmitted to the traveling devices 1L and 1R, while being transmitted to the cutting unit 10 via the cutting clutch 49. Although not described in detail, a turning transmission mechanism 55 is provided for turning the power transmitted to the transmission unit 48 with a difference in driving speed between the left and right traveling apparatuses 1L and 1R. The vehicle body V can be caused to turn by switching the turning transmission mechanism 55 based on the left / right swinging operation of the operation lever 28 that can be swung in the left / right direction and the front / rear direction provided in the driving unit 2. It can be done. The continuously variable transmission 47 is configured to be shifted by a shift lever 51 provided in the boarding operation unit 2. Further, a pair of rotational speed sensors 65 and 66 are provided as a traveling speed detection means for separately detecting the driving speeds of the output shafts of the left and right traveling apparatuses 1L and 1R.

The combine is provided with a gravity-type front / rear inclination angle sensor 24 for detecting the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body V by the action of gravity. It is configured as follows.
That is, as shown in FIG. 7, a liquid 42 having a predetermined viscosity made of silicon oil or the like is accommodated in a rectangular container 41 fixed to the vehicle body V, and metal plates having the same shape are arranged in parallel at the same intervals. Two pairs of the detection electrodes 43 provided are arranged in a state of being fixed to the container 41 with an interval in the inclination angle detection direction (left-right direction in FIG. 7). When the liquid 42 is returned to the initial posture (liquid level horizontal state) due to gravity, when the vehicle body V is not inclined, the two sets of detection electrodes 43 are in the same immersion state (the state of FIG. 7). In the state where the vehicle body V is inclined, the immersion state of the two sets of detection electrodes 43 is different. The capacitance of each detection electrode 43 is measured, and the difference between the measured values (the vehicle body V is inclined). The conversion circuit unit 44 converts the detection value corresponding to the inclination angle information into zero. Further, an angular velocity sensor 25 for detecting the angular velocity of the vehicle body V in the front-rear inclination direction is provided, and the inclination for obtaining the front-rear inclination angle of the vehicle body V based on the detection value of the front-rear inclination angle sensor 24 and the detection value of the angular velocity sensor 25 is provided. The angle calculation means 300 is configured using a control device 22 described later.

  In addition, a gravity-type left / right inclination angle sensor 23 for detecting the right / left inclination angle with respect to the horizontal reference plane of the vehicle body V by the action of gravity is provided. The configuration is the same as that of the front / rear inclination angle sensor 24.

  As shown in FIG. 9, a microcomputer-based control device 22 is provided. The control device 22 includes the stroke sensors 18 to 21, a cutting height sensor 9, a left / right tilt angle sensor 23, a front / rear tilt angle sensor 24, Each detection information of the angular velocity sensor 25 is input. In addition, on the operation panel of the boarding operation unit 2, a left / right automatic switch 26 for commanding on / off of left / right posture control for changing the posture in the left / right direction, and a command for turning on / off of front / rear posture control for changing the posture in the front / rear direction. A front / rear automatic switch 27 and a mode changeover switch 67 as a mode changeover command means for changing over the control mode are provided, and each operation information thereof is also input to the control device 22. Further, there are a volume-type cutting height setting device 39 for setting the height of the cutting unit 10 with respect to the vehicle body V relative to the ground, that is, a cutting height, a raising switch SW1 for instructing the raising of the cutting unit, a lowering switch SW2 for instructing the lowering of the cutting unit, and the like. These pieces of information are also input to the control device 22.

  The ascending switch SW1 and the descending switch SW2 are configured to be turned on and off by a back and forth swinging operation of a cross swinging operation lever 28 provided on the operation panel of the boarding operation unit 2. That is, when the operation lever 28 is swung backward by a set amount or more, the raising switch SW1 is turned on, and when the operation lever 28 is swung forward by a set amount or more, the lowering switch SW2 is turned on.

  As shown in FIG. 8, on the upper part of the grip portion 28 a of the operation lever 28, a left tilt switch 60 for instructing a left tilt command for changing the left-right tilt posture of the vehicle body V in the left-down direction, A right tilt switch 61 for instructing a right tilt command for changing the right / left tilt posture in a right lowering direction, a front tilt switch 62 for instructing a front tilt operation for changing the front / rear tilt posture of the vehicle body V in a forward lowering direction, A rear tilt switch 63 for commanding a rear tilt command for changing the posture of the front / rear tilt posture in the rear lowering direction and a horizontal switch 64 for commanding the horizontal posture of the vehicle body V are provided so as to be operable with fingers. Detection information of these switches 60 to 64 is also input to the control device 22.

  Each of the switches 60 to 64 is composed of a push-push type push operation switch that is turned on (commanded state) by a push operation and turned off (non-commanded state) when the push operation is released, and when the left tilt switch 60 is turned on. A left tilt command is issued to tilt the vehicle body V so that the left side is lowered and the right side is raised. When the right tilt switch 61 is turned on, a right tilt command is issued so that the right side of the vehicle body V is lowered and the left side is raised. When the tilt switch 62 is turned on, a front tilt command is issued to tilt the vehicle body V so that the front side is lowered and the rear side is raised. When the rear tilt switch 63 is turned on, the vehicle body V is tilted so that the rear side is lowered and the front side is raised. A right tilt command is issued.

  Further, by using the control device 22, the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body V is calculated based on the detection information of the front-rear inclination angle sensor 24 and the angular velocity sensor 25, and the front-rear inclination angle becomes the set inclination angle. Posture control means 200 is configured to perform front-rear posture control for controlling the operation of the posture change operation means 100 so as to be maintained. The posture control means 200 controls the operation of the posture change operation means 100 based on the detection information of the left / right tilt angle sensor 23 so that the left / right tilt angle with respect to the horizontal reference plane of the vehicle body V is maintained at the set tilt angle. It is configured.

  In the front-rear posture control, the posture control means 200 includes two hydraulic cylinders (a left front cylinder C2 and a right front cylinder C4) positioned at the left front part and the right front part among the four hydraulic cylinders C2 to C5. The other two hydraulic cylinders in a state where one of the two hydraulic cylinders (the left rear cylinder C3 and the right rear cylinder C5) located at the left rear part and the right rear part is stopped. In the rolling control, two hydraulic cylinders (the left front cylinder C2 and the left rear cylinder C3) that are positioned at the left front part and the left rear part among the four hydraulic cylinders C2 to C5 in the rolling control. ) And two hydraulic cylinders (right front cylinder C4 and right rear cylinder C5) located at the right front part and right rear part are driven. In a state in which sealed, and is configured to drive the operation of the other two hydraulic cylinders.

  The control device 22 outputs drive signals for the hydraulic control solenoid valves 29 to 33 for hydraulic control of the cutting cylinder C1 and the four body posture changing hydraulic cylinders C2 to C5. Although not described in detail, the control device 22 is configured so that, during the cutting operation, the cutting value sensor 9 keeps the detected value of the cutting height sensor 9 at the set cutting height set by the cutting height setting device 39. The cutting height control for operating C1 is executed.

  In addition, an inclination angle calculation means 300 for determining the longitudinal inclination angle of the vehicle body V based on the detection value of the longitudinal inclination angle sensor 24 and the detection value of the angular velocity sensor 25 is configured using the control device 22. In other words, as shown in FIG. 10, the control device 22 integrates the detection value of the angular velocity sensor 25, the low-pass filter processing for removing the high frequency component from the detection values of the front and rear inclination angle sensor 24 that are sequentially detected. The integration process and the high-pass filter process that removes the low-frequency component of the integrated integral value are executed by software processing, and the output value and the high-pass filter process after the low-pass filter process are performed. After that, the output value is added to the vehicle body V to obtain the front-rear inclination angle of the vehicle body V.

  That is, a low-pass filter 301, an integration unit 302, a high-pass filter 303, and the like are configured using the control device 22, and the tilt angle calculation unit 300 is configured by these, and the longitudinal tilt angle sensor 24, the angular velocity sensor 25, and the like. The tilt angle calculation means 300 constitutes the front / rear tilt angle detection means 400 for detecting the front / rear tilt angle with respect to the horizontal reference plane of the vehicle body. The control device 22 is configured to repeatedly execute the above-described forward / backward inclination angle calculation processing every set unit time.

  In this embodiment, the turning state is detected by using the control device 22 to detect whether the vehicle body V is in the turning running state based on the difference between the driving speeds of the pair of left and right traveling devices 1L, 1R. The detection means SK is configured.

  That is, as shown in FIG. 11, the turning state detecting means SK detects the vehicle body V based on the difference between the driving speeds of the pair of left and right rotational speed sensors 65 and 66 and the pair of left and right traveling devices 1L and 1R. Calculating means 500 for obtaining a turning angular velocity when the vehicle turns, integrating means 501 for integrating the turning angular speed, and a high-pass for detecting a turning state that removes a low frequency component of the integrated value integrated by the integrating means 501. The filter 502 and a determination unit 503 for determining whether or not the vehicle is in a turning traveling state based on the output value of the turning state detection high-pass filter 502 are provided.

  Specifically, the control device 22 performs calculation processing for obtaining a turning angular velocity when the vehicle body V turns based on detection information of the pair of left and right rotational speed sensors 65 and 66, integration processing for integrating the turning angular velocity, and integration. High-pass filter processing that removes low-frequency components from the integrated value, and discrimination processing that determines whether or not the vehicle is turning based on the output value of the high-pass filter processing are executed by software processing. The device 22 is used to configure the calculation means 500, the integration means 501, the turning state detection high-pass filter 502, and the discrimination means 503.

  Further, the posture control means 200 performs the vehicle body V in the case of changing the front / rear inclination angle of the vehicle body V with respect to the ground contact portions of the traveling devices 1L and 1R to either the front lowering inclination direction or the rear lowering inclination direction. If the height with respect to the grounding portion of the traveling devices 1L and 1R located on the lower side of the inclination direction to be changed among the front end side location and the rear end side location is not the lower limit position, the front drive means (the left front cylinder C2 and the right front cylinder C4) and the drive means located on the opposite side to the lower side in the inclination direction of the drive means (left rear cylinder C3 and right rear cylinder C5) of the rear side are stopped in the state where the operation of the drive means is stopped. A downward tilting operation is performed in which the driving means positioned on the lower side is operated in the vehicle body lowering direction. If the height with respect to the grounding portion of the traveling devices 1L and 1R at the position located on the beam side is the lower limit position, the driving means located on the inclined lower side of the front driving means and the rear driving means. In a state in which the driving means located on the side opposite to the inclined lowering side is operated in the vehicle ascending direction while the operation of the vehicle is stopped, and the front end of the vehicle body is executed by executing the descending inclined operation. Even after the height of the traveling devices 1L, 1R with respect to the ground contact portion at the position located on the inclined downward side of the side portion and the rear end side portion becomes the lower limit position, the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body is If it is not the set inclination angle, the posture changing operation process for controlling the operation of the posture changing operation means 100 is executed in such a manner that the rising inclination operation is executed following the downward inclination operation. It is configured to.

  When the turning state detecting means SK detects that the vehicle body V is in a turning running state, the posture control means 200 executes the downward inclination operation and does not execute the upward inclination operation as the forward / backward attitude control. In the embodiment, a descent operation limiting process for controlling the operation of the posture changing operation means 100 is executed so that the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body V becomes the set inclination angle, and the turning state detection means SK performs the turning When it is detected that the vehicle is not in the running state, the posture changing operation process is executed.

  More specifically, the attitude control means 200 is lowered when the turning state detecting means SK detects that the vehicle body V is in a turning traveling state as the front and rear attitude control based on the command from the mode changeover switch 67. When the operation limiting process is executed and it is detected that the vehicle is not in the turning traveling state, the dry state mode as a processing mode change type control mode for executing the posture changing operation processing, and the turning state detection as the front / rear posture control. Regardless of the detection information of the means SK, it is configured to be switchable to a wetland mode as a processing mode invariant control mode that always executes the posture changing operation processing. That is, in this embodiment, the control mode is switched according to the state of the field such as a dry paddy or a wet paddy field.

  Further, in the dry paddy mode, the vehicle body V has a longitudinal inclination angle that is the set inclination angle when the state is changed from the state in which the lowering operation limiting process is executed to the state in which the posture change operation process is executed. The posture change operation means is set so that the posture change operation speed when changing the processing form when the posture change operation means 100 is operated is such that the front-rear inclination angle of the vehicle body V becomes the set inclination angle without changing the processing form. The operation of the posture changing operation means 100 is controlled in a state where the operation speed is set to be lower than the normal posture changing operation speed when the 100 is operated.

  The control sensitivity in the wet paddy mode is set to a control sensitivity that is more sensitive than the control sensitivity in the dry paddy mode. That is, if the deviation between the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body detected by the front / rear inclination angle detection means and the set inclination angle is out of the dead zone for posture control, the deviation is included in the dead zone. In the dry rice field mode, the dead zone for the dry rice field is used as the dead zone for the posture control, and in the wet rice field mode, the dead zone for the dry rice field is used as the dead zone for the posture control. By using a dead zone for a wet paddy that is narrower than the width of the dead zone, the control sensitivity is set to be more sensitive than in the dry paddy mode.

Next, the front / rear posture control by the control device 22 will be specifically described based on the flowchart of FIG.
If the front / rear automatic switch 27 is turned on, it is determined whether the control mode switched according to the operation state of the mode changeover switch 67 is the wet paddy mode or the dry paddy mode. And if it is wet field mode, the following attitude | position change operation processes will be performed. Note that, as the set inclination angle with respect to the horizontal reference plane, a value corresponding to zero degrees, that is, a horizontal state is preset.

  If the deviation between the detected value of the front / rear inclination angle sensor 24 and the signal value (control target value) corresponding to the set inclination angle being zero deviates from the dead zone for the wet field to the front inclination side of the vehicle body V, Post-tilt processing is executed to change the tilt posture in the downward direction. That is, the standard value is set as the normal operation speed for the attitude change operation speed when operating the attitude change operation means 100 including the four cylinders C2 to C5. Based on the detection information of the left and right stroke sensors 19 and 21 located at the rear of the machine body, it is determined whether either the left rear cylinder C3 or the right rear cylinder C5 is operated to the lower limit position, and both cylinders C3 , C5 are not operated to the lower limit position, the operation of the left front cylinder C2 and the right front cylinder C4 as driving means located on the side opposite to the descending side in the tilt direction is stopped, and the left rear cylinder C3 and the right Until either one of the rear cylinders C5 reaches the lower limit position, a downward tilting operation is performed to shorten the left rear cylinder C3 and the right rear cylinder C5 as driving means located on the lower side in the tilt direction.

  Even if one of the left rear cylinder C3 and the right rear cylinder C5 is operated to the lower limit position, if the deviation deviates from the dead zone for the wet paddy to the rear slope side of the vehicle body V, the left rear cylinder C3 continues. Then, the right rear cylinder C5 is deactivated and the ascending tilting operation is performed to shorten the left front cylinder C2 and the right front cylinder C4 until either the left front cylinder C2 or the right front cylinder C4 reaches the upper limit position.

  Further, if the deviation between the detected value of the front / rear inclination angle sensor 24 and the signal value corresponding to the horizontal state deviates from the dead zone for the wet field to the rear inclination side of the vehicle body V, the front / rear inclination posture of the vehicle body V is lowered in the forward direction. Execute pre-tilt processing to change the posture. That is, based on the detection information of the left and right stroke sensors 18 and 20 located at the front of the machine body, it is determined whether either the left front cylinder C2 or the right front cylinder C4 is operated to the lower limit position, and both cylinders C2, If neither C4 is operated to the lower limit position, the left front cylinder C2 and the right front cylinder C4 are extended until either one of the cylinders C2 and C4 reaches the lower limit position. Even if either the left front cylinder C2 or the right front cylinder C4 is operated to the lower limit position, if the deviation deviates from the dead zone for the wet field to the rear slope side of the vehicle body V, either the left rear cylinder C3 or the right rear cylinder C5 Until the upper limit position is reached, the left rear cylinder C3 and the right rear cylinder C5 are extended.

  Although not shown in the figure, when a manual front / rear posture change operation command is issued during the front / rear posture control, the manual posture change operation based on the command is preferentially executed. That is, when the front tilt switch 62 is turned on, the front tilt process is executed only when the front tilt switch 62 is turned on, regardless of the magnitude of the deviation, and when the rear tilt switch 63 is turned on, the deviation only occurs. The post-tilt process is executed regardless of the size of the image.

If the control mode is the dry rice field mode, the following processing is executed.
If the deviation between the detected value of the front / rear inclination angle sensor 24 and the signal value corresponding to the horizontal state is out of the dead zone for the dry rice field, then whether or not the determination result of the turning state detecting means SK is the turning state. If it is determined that the vehicle is not in the turning state, the posture changing operation process as described above is executed. However, immediately after switching from the turning state to the non-turning state, the posture changing operation speed when operating the posture changing operation means 100 is the normal posture changing operation speed. The posture change operation process is executed by setting an operation speed that is lower than the standard value by a set amount.

However, if it is determined that the turning state is detected by the turning state detecting means SK, the following lowering operation limiting process is executed.
If the deviation deviates from the dead zone for the dry rice pad to the front tilt side, a post-tilt process for changing the front-back tilt posture of the vehicle body V in the rear-lowering direction is executed. That is, based on the detection information of the left and right stroke sensors 19 and 21 located at the rear of the machine body, it is determined whether either the left rear cylinder C3 or the right rear cylinder C5 is operated to the lower limit position, and both cylinders C3 , C5 are not operated to the lower limit position, the operation of the left front cylinder C2 and the right front cylinder C4 as driving means located on the side opposite to the descending side in the tilt direction is stopped, and the left rear cylinder C3 and the right Until either one of the rear cylinders C5 reaches the lower limit position, a downward inclination operation is performed to shorten the left rear cylinder C3 and the right rear cylinder C5.

  If the deviation deviates from the dead zone for the dry rice pad to the rear tilt side, a pre-tilt process for changing the front-back tilt posture of the vehicle body V in the front-down direction is executed. That is, based on the detection information of the left and right stroke sensors 18 and 20 located at the front of the machine body, it is determined whether either the left front cylinder C2 or the right front cylinder C4 is operated to the lower limit position, and both cylinders C2, If neither C4 is operated to the lower limit position, the operation of the left rear cylinder C3 and the right rear cylinder C5 is stopped, and the left front cylinder C2 and the right front cylinder until either one of the cylinders C2 and C4 reaches the lower limit position. A downward inclination operation for extending C4 is executed.

  As described above, in the dry paddy mode, when it is determined that the vehicle is in the turning state, only the downward tilt operation is performed without performing the upward tilt operation, which may cause a detection error of the angular velocity sensor 25. During cornering, it is possible to avoid a decrease in traveling stability due to an unnecessary posture change caused by the detection error of the angular velocity sensor 25.

[Another embodiment]
Hereinafter, other embodiments are listed.

(1) In the above embodiment, when the posture control means switches from the state in which the lowering operation limiting processing is executed to the state in which the posture changing operation processing is executed in the processing mode change type control mode. In addition, the operation of the posture changing operation means is controlled in a state where the operation speed for posture change is set to be lower than the operation speed for normal posture change. It is good also as a structure which act | operates at the operation speed for this attitude | position change.

(2) In the above-described embodiment, the configuration in which the turning state detection unit determines whether or not the turning state is in a turning state based on the difference between the driving speeds of the pair of traveling devices is exemplified. The present invention is not limited to this, and it may be detected whether or not the vehicle is in a turning state based on the presence / absence of a command from a manually operated turning command means that commands turning of the vehicle body.

(3) In the above embodiment, based on a command from the mode switching command means, it is possible to switch between a dry paddy mode as the processing mode change type control mode and a wet paddy mode as the processing mode invariant control mode. It is configured to illustrate switching according to the state of a farm such as a dry paddy or a wet paddy, but the posture control means may be configured to include only the processing mode change type control mode, and the difference in the state of the field Instead, it may be configured to select according to the preference of the operator.

(4) In the above embodiment, the traveling device is configured by a pair of left and right crawler type traveling devices, but is not limited thereto, and may be a single traveling device, for example, or a wheel type instead of a crawler type. The traveling device may be used.

(5) In the above embodiment, the posture changing operation means 100 is configured by the four hydraulic cylinders C2 to C5 located at four positions on the front and rear, left and right of the vehicle body V. However, in addition to the hydraulic cylinder, an electric motor and screw feed You may comprise by the other drive means which consists of mechanisms. In addition, the traveling device may be configured to change the front-rear inclination angle of the vehicle body with respect to the grounding portion by a single driving unit.

(6) In the above embodiment, the combine is exemplified as the work vehicle. However, for example, a work vehicle other than the combine such as an agricultural tractor or a rice planting machine may be used.

Side view showing the front of the combine Side view showing the lifting / lowering configuration of the traveling device Side view showing the lifting / lowering configuration of the traveling device Side view showing the lifting / lowering configuration of the traveling device Side view showing the lifting / lowering configuration of the traveling device Combine power transmission diagram A perspective view showing a configuration of an inclination angle sensor Operation lever perspective view Control block diagram Block diagram of front / rear inclination angle detection means Block diagram of turning state detection means Flow chart showing control operation

Explanation of symbols

1L, 1R Traveling device 24 Front / rear inclination angle sensor 25 Angular speed sensor 65, 66 Traveling speed detection means 67 Mode switching command means 100 Attitude change operation means 200 Attitude control means 300 Inclination angle calculation means 400 Front / rear inclination angle detection means 500 Arithmetic means 501 Integration Means 502 High-pass filter 503 Discrimination means C2, C4 Front drive means C3, C5 Rear drive means SK Turning state detection means V Vehicle body

Claims (4)

Attitude change operation means capable of changing the front / rear inclination angle of the vehicle body with respect to the grounding portion of the traveling device in both the forward and backward inclination directions and the front / rear inclination angle detection means for detecting the front / rear inclination angle with respect to the horizontal reference plane of the vehicle body And attitude control means for performing front and back attitude control for controlling the operation of the attitude changing operation means so that the front and rear inclination angle with respect to the horizontal reference plane of the vehicle body becomes a set inclination angle based on detection information of the front and rear inclination angle detection means And
The posture changing operation means is
A front drive means that can change and adjust the height of the front end side portion of the vehicle body relative to the grounding portion of the traveling device, and a rear side that can change and adjust the height of the rear end portion of the vehicle body relative to the grounding portion of the traveling device. The drive means are provided in a state where they can be operated separately,
The posture control means, as the front and rear posture control,
When changing the front / rear inclination angle of the vehicle body with respect to the grounding portion of the traveling device to either the front lower inclination direction or the rear lower inclination direction, the change operation of the front end side position and the rear end side position of the vehicle body is performed. If the height of the portion located on the descending side in the tilt direction with respect to the ground contact portion of the traveling device is not the lower limit position, it is opposite to the descending side in the tilt direction of the front driving means and the rear driving means. The driving means positioned on the side is stopped and the driving means positioned on the inclined side is operated in the downward direction of the vehicle body. If the height with respect to the grounding portion of the traveling device at the position on the lower side of the tilt direction to be changed is the lower limit position, of the front drive means and the rear drive means The said inclined downward side in a state where the stopping operation of the driving means located on serial inclined downward side in a form to perform the rising slope operation for operating the drive means located on the opposite side of the vehicle body upward direction, and,
Even after the descending and tilting operation is executed and the height of the traveling device with respect to the ground contact portion at the position located on the inclined downward side of the front end side position and the rear end side position on the vehicle body becomes the lower limit position, If the forward / backward inclination angle with respect to the reference plane is not the set inclination angle, the posture change operation process for controlling the operation of the posture change operation means is executed in a form in which the upward inclination operation is executed following the downward inclination operation. A work vehicle attitude control device configured to:
The front and rear inclination angle detecting means is
Among the detection values of the gravitational front / rear tilt angle sensor for detecting the front / rear tilt angle with respect to the horizontal reference plane of the vehicle body by the action of gravity, the angular velocity sensor for detecting the angular velocity in the front / rear tilt direction of the vehicle body, and the front / rear tilt angle sensor Inclination angle for obtaining the front-rear inclination angle of the vehicle body by adding the detected value after removing the high frequency component of the vehicle and the integrated value after removing the low frequency component of the integrated value obtained by integrating the detected value of the angular velocity sensor And a calculation means,
A turning state detecting means for detecting whether or not the vehicle body is in a turning running state is provided;
The posture control means, as the front and rear posture control,
When the turning state detecting means detects that the vehicle body is in a turning traveling state, the forward / backward inclination angle with respect to the horizontal reference plane of the vehicle body is determined so as to execute the downward inclination operation and not execute the upward inclination operation. The lowering operation limiting process for controlling the operation of the posture changing operation means so as to become the set inclination angle is executed, and when the turning state detecting means detects that the vehicle is not in the turning running state, the posture changing operation process is executed. An attitude control device for a work vehicle configured to execute. The attitude control means is based on a command from the mode switching command means,
As the front / rear posture control, when the turning state detecting means detects that the vehicle body is in a turning state, the lowering operation limiting process is executed, and when it is detected that the vehicle is not in the turning state, the posture is determined. A processing mode change type control mode for executing a change operation process;
2. The work vehicle according to claim 1, wherein the front-rear posture control is configured to be switchable to a processing mode invariant control mode in which the posture change operation processing is always executed regardless of detection information of the turning state detection unit. Attitude control device. The posture control means is
In the processing mode change type control mode, the front-rear inclination angle with respect to the horizontal reference plane of the vehicle body is the set inclination when the state in which the lowering operation limiting process is executed is switched to the state in which the attitude changing operation process is executed. The operation speed for changing the posture when changing the processing mode when operating the posture changing operation means so as to be a corner, the front / rear tilt angle with respect to the horizontal reference plane of the vehicle body is the set tilt angle without changing the processing mode. The operation of the posture changing operation means is controlled in a state set to be lower than a normal posture changing operation speed when the posture changing operation means is operated. Attitude control device for work vehicles. As the traveling device, a pair of left and right traveling devices that can freely change the driving speed are provided,
The vehicle body is configured to turn while varying the driving speed of each of the pair of left and right traveling devices,
The turning state detecting means is
A pair of traveling speed detecting means for detecting the respective driving speeds of the pair of left and right traveling apparatuses, and a calculating means for obtaining a turning angular speed when the vehicle body turns based on a difference between the respective driving speeds of the pair of left and right traveling apparatuses. , An integrating means for integrating the turning angular velocity, a high-pass filter for detecting a turning state that removes a low frequency component of the integrated value integrated by the integrating means, and an output value of the high-pass filter for detecting the turning state The work vehicle attitude control device according to any one of claims 1 to 3, further comprising: discrimination means for discriminating whether or not the vehicle is in a turning traveling state.

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