JP2007238056A - Attitude controller of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an attitude controller for a working vehicle capable of sensing the left-right inclination angle of the vehicle body properly whether the vehicle is in the straight running condition or in turning and able to perform proper control of an attitude changing means so that the left-right inclination angle of the vehicle body is maintained at the set inclination angle. <P>SOLUTION: A left-right inclination angle sensing means SK to sense the left-right inclination angle of the vehicle body includes a gravity type inclination angle sensor 45 to sense the left-right inclination angle of the vehicle body on the basis of acting of the gravitational force and an angular velocity sensor 46 to sense the angular velocity in the left-right inclining direction of the vehicle body, and is further equipped with an inclination angle calculating means 300 which determines the left-right inclination angle of the vehicle body on the basis of the sensing values of the two sensors 45 and 46 when such a sensing is made that running is not in the turning condition, and when such a sensing is made that running is in turning, it determines the left-right inclination angle of the vehicle body on the basis of the sensing value of the angle sensor 45. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a posture changing operation means capable of changing a left and right inclination angle of a vehicle body with respect to a grounding portion of a traveling device, a left and right inclination angle detecting means for detecting a left and right inclination angle of the vehicle body, and detection information of the left and right inclination angle detecting means And a posture control means for controlling the operation of the posture change operation means so that the left-right inclination angle of the vehicle body is maintained at the set inclination angle.

  In the work vehicle attitude control device, conventionally, the left / right inclination angle detecting means is constituted by a gravity type inclination angle sensor that detects the right / left inclination angle of the vehicle body by the action of gravity, and the gravity type inclination angle sensor. The left and right inclination angles of the vehicle body are obtained based on the detected value (see, for example, Patent Document 1).

  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, and as the vehicle body tilts from the horizontal reference plane. The liquid level is inclined with respect to the container, the amount of immersion of the pair of electrodes changes, and the capacitance between the pair of electrodes changes. It is configured to detect electrically as information on the right and left tilt angles of the vehicle body.

JP 2001-270475 A

  The gravitational tilt angle sensor used in the above-described conventional configuration properly detects the tilt of the vehicle body in the left-right direction without detecting erroneous information due to the liquid shaking due to fine vibrations associated with the travel of the vehicle body. Since the liquid has a predetermined viscosity and the liquid has the predetermined viscosity as described above, the followability with respect to a quick posture change of the vehicle body is deteriorated.

  In other words, the gravitational tilt angle sensor accurately detects the left / right tilt angle of the vehicle body when the lateral 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 rapidly left and right, the tilt angle sensor cannot follow the left and right tilt of the vehicle body and a response delay occurs, so that the right and left tilt angle of the vehicle body can be accurately detected. There is a possibility that the posture change operation means cannot be controlled favorably so that the left / right inclination angle of the vehicle body is maintained at the set inclination angle.

  Therefore, as an improved configuration, an angular velocity sensor that detects the angular velocity in the left-right inclination direction of the vehicle body, for example, a vibration gyro type angular velocity sensor, is provided separately from the inclination angle sensor, and the detected value of the angular velocity sensor is integrated to obtain an inclination angle. A configuration is also proposed in which the right and left inclination angles of the vehicle body are detected by correcting the inclination angle with the detection value of the inclination angle sensor. In other words, using a highly responsive angular velocity sensor, even if the vehicle body is rapidly tilting left and right, the left and right tilt angle of the vehicle body is detected based on the detected value of the angular velocity sensor, so that the response of the tilt angle sensor is delayed. It is intended to eliminate the error caused.

  However, the angular velocity sensor as described above needs to be attached along the axis when the vehicle body tilts left and right, that is, along the axis along the longitudinal direction of the vehicle body, when detecting the angular velocity. Due to an assembly error or the like, the detection axis may be attached with a slight deviation from the axis along the longitudinal direction of the vehicle body. Then, not only the angular velocity in the left-right tilt direction around the axis along the longitudinal direction of the vehicle body, but also the axis velocity orthogonal to the axial center along the longitudinal direction of the vehicle, for example, the angular velocity component around the vertical axis may be detected. There is.

Thus, when the angular velocity sensor also detects the angular velocity around the vertical axis, there are the following disadvantages.
That is, when the vehicle body turns, an angular velocity around the vertical axis is generated along with the turning. However, when the angular velocity sensor is configured to detect the angular velocity around the vertical axis, Accordingly, the angular velocity around the vertical axis that occurs with this is detected. As a result, the angular velocity sensor may output an erroneous detection value of angular velocity on the assumption that the vehicle body is tilted in the left-right direction even though the vehicle body is not tilted left and right. Therefore, it may not be possible to satisfactorily control the posture changing operation means so that the left / right inclination angle of the vehicle body is maintained at the set inclination angle.

  By the way, in a work vehicle such as a combine, when the vehicle body travels straight, various operations such as a mowing operation are performed, and the turning travel is performed toward the travel route for the next work. When traveling straight ahead, when the left / right tilt angle of the vehicle body changes rapidly, the left / right tilt angle of the vehicle body must be adjusted in order to keep the left / right tilt angle of the vehicle body at the set tilt angle as quickly as possible. It is necessary to accurately detect the angular velocity of the vehicle, but when turning, the need for angular velocity in the horizontal direction of the vehicle body is much higher than when traveling straight, even if the vehicle body angle changes rapidly. There is nothing. In addition, when the vehicle body travels straight, the posture of the vehicle body may change due to unevenness of the traveling road surface, but for example, it does not rotate significantly around the vertical axis, so There is little possibility that the angular velocity sensor erroneously detects the angular velocity component.

  The present invention has been made paying attention to this point, and the object of the present invention is to be able to appropriately detect the left-right inclination angle of the vehicle body in both the straight traveling state and the turning traveling state. The object is to provide a posture control device for a work vehicle that can appropriately control the posture change operation means so that the left-right inclination angle is maintained at the set inclination angle.

An attitude control device for a work vehicle according to the present invention includes an attitude change operation unit that can freely change a left and right inclination angle of a vehicle body with respect to a grounding portion of a traveling device, a left and right inclination angle detection unit that detects a left and right inclination angle of the vehicle body, Posture control means for controlling the operation of the posture change operation means so that the left and right inclination angle of the vehicle body is maintained at the set inclination angle based on the detection information of the right and left inclination angle detection means, The first characteristic configuration is
A turning state detecting means for detecting whether or not the vehicle body is in a turning running state is provided;
The left / right inclination angle detecting means is
A gravity-type tilt angle sensor that detects the left-right tilt angle of the vehicle body by the action of gravity, and an angular velocity sensor that detects an angular velocity in the left-right tilt direction of the vehicle body, and
When the turning state detecting means detects that the vehicle is not in a turning state, the left and right inclination angles of the vehicle body are obtained based on the detected values of the inclination angle sensor and the angular velocity sensor, and the turning state detection means When it is detected that the vehicle is in a turning state, the vehicle is configured to include an inclination angle calculating means for obtaining a left and right inclination angle of the vehicle body based on a detection value of the inclination angle sensor.

  According to the first characteristic configuration, the turning state detecting means includes a gravity-type tilt angle sensor that detects a left-right tilt angle of the vehicle body by the action of gravity, and an angular velocity sensor that detects an angular velocity in the left-right tilt direction of the vehicle body. When the turning state detecting means detects that the vehicle is not turning, in other words, when the vehicle is traveling straight, the left and right sides of the vehicle are detected based on the detected values of the inclination angle sensor and the angular velocity sensor. The inclination angle is obtained.

  In this way, if the left and right inclination angles of the vehicle body are obtained based on the detection values of the inclination angle sensor and the angular velocity sensor, for example, the state in which the inclination angle in the left and right direction of the vehicle body has not changed or the vehicle body is slow. In a state where the vehicle is tilted left and right, it is possible to accurately detect the left and right tilt angle of the vehicle body by a gravitational tilt angle sensor that detects the left and right tilt angle of the vehicle body by the action of gravity. In the state of tilting left and right, the detection value of the angular velocity sensor that detects the angular velocity in the horizontal tilt direction of the vehicle body is integrated to compensate for the detection value of the tilt angle sensor, or the detection value of the angular velocity sensor is integrated Is used as the right / left inclination angle and is corrected by the detection value of the inclination angle sensor, etc., so that the right / left inclination angle of the vehicle body can be detected with high accuracy.

  When the turning state detecting means detects that the vehicle is turning, the left / right inclination angle of the vehicle body is obtained based on the detected value of the inclination angle sensor. In other words, even if the angular velocity sensor may erroneously detect the angular velocity of the vehicle body around the vertical axis due to an assembly error or the like, the detected value of the angular velocity sensor is used during turning. Therefore, the left and right inclination angles of the vehicle body are obtained based on the detection value of the inclination angle sensor.

  The posture control means is either in the case where the turning state detecting means detects that the turning state is not in the turning state, or in the case where the turning state detection means detects that the turning state is in the turning state. As described above, the operation of the posture changing operation means is controlled so that the left / right inclination angle of the vehicle body detected by the right / left inclination angle detecting means is maintained at the set inclination angle.

  Therefore, in either the straight traveling state or the turning traveling state, the right / left inclination angle of the vehicle body can be detected appropriately, and the posture changing operation means is provided so that the left / right inclination angle of the vehicle body is maintained at the set inclination angle. Thus, it has become possible to provide an attitude control device for a work vehicle that can be appropriately controlled.

In addition to the first feature configuration, the second feature configuration of the present invention is provided with a centrifugal force detection means for detecting the centrifugal force applied to the vehicle body when the vehicle body is turning.
The tilt angle calculation means is
When the turning state detecting means detects that the vehicle is in a turning state, the amount of change in the inclination angle in the inclination angle sensor that changes due to the centrifugal force detected by the centrifugal force detection means is calculated. In addition, the left and right inclination angles of the vehicle body are obtained by correcting the detected value of the inclination angle sensor with the amount of change in inclination angle.

  According to the second characteristic configuration, the centrifugal force applied to the vehicle body when the vehicle body turns by the centrifugal force detection means is detected. The inclination angle calculation means is an inclination angle sensor that changes due to the centrifugal force detected by the centrifugal force detection means when the turning state detection means detects that the vehicle is turning. The tilt angle change amount is calculated, and the detected value of the tilt angle sensor is corrected with the tilt angle change amount to obtain the left and right tilt angles of the vehicle body.

  In other words, the gravity-type tilt angle sensor can detect the tilt angle in the horizontal direction of the vehicle body properly when there is no horizontal movement and only gravity is applied. In the case of traveling, centrifugal force to the outside of the turn is generated due to the turning of the vehicle body. When such a centrifugal force is generated, the gravity-type tilt angle sensor erroneously states that the vehicle body is tilted left and right by the set angle even if the vehicle body is not tilted in the left-right direction. The detection result may be output.

  Therefore, the centrifugal force applied to the vehicle body when the vehicle body turns is detected, the amount of change in the inclination angle in the inclination angle sensor that changes due to the centrifugal force is calculated, and the detected value is corrected.

  Therefore, when the vehicle body is turning, the detection error of the inclination angle sensor generated due to centrifugal force can be reduced, and the left and right inclination angles of the vehicle body can be detected with high accuracy.

  In addition to the first feature configuration or the second feature configuration, the third feature configuration of the present invention is characterized in that the centrifugal force detecting means is configured to turn the travel device when the vehicle body is turning, and to turn the travel device. The centrifugal force is calculated based on the traveling speed.

  According to the third characteristic configuration, the centrifugal force detection means calculates the centrifugal force based on the turning state of the traveling device when the vehicle body makes a turn and the turning traveling speed of the traveling device. The centrifugal force generated when the vehicle body turns is determined by the difference in the turning state of the traveling device. For example, the centrifugal force is larger when the turning radius is larger than when the turning radius is small. Moreover, even if the turning state is the same, if the turning traveling speed is high, the centrifugal force is larger than when the turning speed is low.

  Therefore, based on the turning state of the traveling device and the turning traveling speed of the traveling device, the centrifugal force applied to the vehicle body when the vehicle body turns is calculated.

In addition to the third feature configuration, the fourth feature configuration of the present invention is configured such that the traveling device includes a pair of left and right traveling devices, and is configured to turn by a speed difference between the pair of left and right traveling devices. And
A pair of traveling speed detection means for detecting the driving speed of each of the pair of traveling devices,
The centrifugal force detection means is
The turning state of the traveling device and the turning traveling speed of the traveling device are obtained based on the detection values of the pair of traveling speed detecting means, and the centrifugal force is calculated based on the turning state and the turning traveling speed. The point is that it is configured to do.

  According to the fourth characteristic configuration, a pair of left and right traveling devices are provided, and the vehicle is configured to turn by a speed difference between the pair of left and right traveling devices. The driving speed is detected separately, and the turning state of the traveling device and the turning traveling speed of the traveling device are obtained based on the detection values of the pair of traveling speed detecting means.

  In other words, since it is configured to turn by the speed difference between the pair of left and right traveling devices, for example, the vehicle travels by the ratio or speed difference between the driving speeds of the pair of traveling devices detected by the pair of traveling speed detecting means. The turning state of the device can be determined. Further, the turning traveling speed of the traveling device can be obtained from the average value of the driving speeds of the pair of traveling devices. Then, based on the turning state and the turning speed, the centrifugal force applied to the vehicle body when the vehicle body turns is calculated.

  As described above, the driving speeds of the left and right traveling devices are detected by the pair of traveling speed detecting means, so that the turning state and the turning traveling speed are accurately detected based on the actual traveling state of the left and right traveling devices. The centrifugal force can be detected with high accuracy.

In addition to the third feature configuration, the fifth feature configuration of the present invention is a manually operated turning state command means for instructing a turning state of the traveling device when the vehicle body is turning, and when the vehicle body is turning. A manually operated speed command means for commanding the turning traveling speed of the traveling device;
The centrifugal force detection means is
The centrifugal force is calculated based on the command information of the turning command means and the command information of the speed command means.

  According to the fifth characteristic configuration, when the vehicle body turns, the turning state of the traveling device is commanded by the manually operated turning state command means, and the turning device turns by the manually operated speed command means. Although the speed is commanded, the centrifugal force applied to the vehicle body when the vehicle body turns based on the command information of the turning command means and the command information of the speed command means is calculated. By effectively using the command information of the command means and the speed command means, it is possible to detect the centrifugal force applied to the vehicle body when the vehicle body is turning without providing a special centrifugal force detection means.

  According to a sixth feature configuration of the present invention, in addition to any one of the first feature configuration to the fifth feature configuration, when the turning state detecting means detects that the vehicle is not in a turning running state, the angular velocity sensor detects The reference value of the angular velocity corresponding to the state where the angular velocity is zero is updated on the basis of a value obtained by averaging a plurality of detection values obtained by sampling the values, and the turning state detecting means is in a turning traveling state. Is detected, reference value updating means configured not to update the reference value is provided.

  According to the sixth feature, when the turning state detecting means detects that the vehicle is not in the turning state, the angular velocity is calculated based on a value obtained by averaging a plurality of detection values obtained by sampling the detection values of the angular velocity sensor. The reference value of the angular velocity corresponding to the state where is zero is updated. However, when the turning state detecting means detects that the vehicle is turning, the reference value is not updated.

  In addition, in the angular velocity sensor as described above, the reference value corresponding to the state where the angular velocity is zero may deviate from an appropriate value due to various factors such as temperature fluctuation. If detection is continued in a state where the value deviates from an appropriate value, errors may be accumulated and a large detection error may occur.

  Therefore, when it is detected by the turning state detection means that the vehicle is not in a turning state, in other words, when the vehicle is in a straight traveling state, a plurality of detected values obtained by sampling the detected values of the angular velocity sensor are averaged. Based on this, since the reference value of the angular velocity corresponding to the state where the angular velocity is zero is updated, it is possible to prevent the reference value from deviating from an appropriate value and appropriately detect the angular velocity.

  As described above, when the vehicle is in the turning state, the angular velocity sensor may erroneously detect the angular velocity of the vehicle body around the vertical axis due to an assembly error or the like. When it is detected that the vehicle is turning, the reference value is not updated.

  Therefore, the reference value is not updated during turning, which may cause erroneous detection of the angular velocity of the vehicle body. Therefore, the reference value is maintained at an appropriate value, and the turning is finished and straight running is executed. In this case, the detection of the subsequent inclination angle can be started with an appropriate reference value, and the angular velocity sensor is updated to an appropriate value by updating the reference value of the angular velocity corresponding to the state where the angular velocity is zero. The angular velocity in the left-right tilt direction can be detected as accurately as possible with little error.

[First Embodiment]
Hereinafter, a case where the first 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, a pulling 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 the vertical conveying device 8 that conveys the harvested cereal grains to the rear side while gradually changing the posture to the horizontal position, and the hydraulic cutting cylinder around the horizontal axis P1 at the front of the vehicle body V It is provided to be swingable up and down by C1.

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 via a stroke absorbing auxiliary link 17b1. 16 is pivotally connected to a rear side portion.
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, the hydraulic cylinder C3 (hereinafter referred to as the left rear cylinder) corresponding to the rear bell crank 17b is most shortened. As shown in FIG. 2, 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. This state is called the lower limit reference posture.

When the left front cylinder C2 is shortened while maintaining the left rear cylinder C3 as it is from the lower limit reference posture, as shown in FIG. Therefore, the posture is changed in the direction of separating (i.e., a forward ascending operation).
When the left rear cylinder C3 is extended from the state where the lower left reference posture is maintained while the left front cylinder C2 is maintained as it is, as shown in FIG. The posture is changed (backward raising operation) in the direction of separation.
Further, when the left front cylinder C2 is shortened and the left rear cylinder C3 is extended from the lower limit reference posture, as shown in FIG. 5, the vehicle body V remains parallel to the grounding portion. The posture is changed (raising operation) in the direction of separation.

  Similarly, the right traveling apparatus 1R includes a right front cylinder C4 positioned on the front side of the fuselage and a right rear cylinder C5 positioned on the rear side of the fuselage, and operates in the same manner as the left traveling apparatus 1L. Do.

  Accordingly, the posture changing operation means 100 can change and adjust the height of the left and right traveling devices 1L and 1R with respect to the grounding portion at the left front, left rear, right front, and right rear in the vehicle body V, respectively. And four hydraulic cylinders C2 to C5 for changing the body posture.

  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. The potentiometer type stroke sensors 18, 19, 20, 21 are provided for detecting the operation amount of each of the hydraulic cylinders C2, C3, C4, C5 (that is, the stroke amount of the expansion / contraction operation) (see FIG. 10). .

Next, the transmission structure of this combine is demonstrated.
As shown in FIG. 6, the continuously variable transmission 70 for straight traveling that can freely change the traveling speed in the straight traveling state, and the turning speed that allows the traveling speed of the traveling device positioned on the turning side during turning to be turned at high and low speeds. A continuously variable transmission 80 is provided, and the transmission system is configured such that power from the continuously variable transmissions 70, 80 is output to the left and right traveling devices 1R, 1L. The continuously variable transmission 70 for straight travel and the continuously variable transmission 80 for turning are respectively rotated by variable hydraulic pumps 70A and 80A to which power from the engine E is input and oil supplied from the variable hydraulic pumps 70A and 80A. It is constituted by a hydrostatic continuously variable transmission (HST) having a known structure constituted by a pair of driven hydraulic motors 70B and 80B.

  More specifically, the output of the linearly variable continuously variable transmission 70 is transmitted to the pair of left and right traveling apparatuses 1R and 1L via the high and low two-stage switching type auxiliary transmission 22, while the linearly variable continuously variable continuously variable transmission 22 is transmitted. The power of the transmission 70 is transmitted to the cutting unit 10. An output gear 22b is fixed to the output shaft 22a of the auxiliary transmission, and a center gear 24 provided integrally with the support shaft 23 is provided in a state where the output gear 22b is always meshed with the output gear 22b.

  As a pair of left and right linear transmission clutches that can be switched between a transmission state and a cut-off state so that power transmission from the continuously variable transmission 70 for straight traveling to each of the pair of left and right traveling devices 1R and 1L can be interrupted separately. A pair of left and right meshing clutches 27, 27 and a left and right switchable between a transmission state and a cut-off state so that power transmission from the continuously variable transmission 80 for turning to each of the pair of left and right traveling devices 1R, 1L can be interrupted separately. A pair of left and right multi-plate friction clutches 25, 25 as a pair of turning transmission clutches are provided.

  That is, a pair of left and right as a pair of left and right linear transmission clutches formed on both sides of the support shaft 23 around the center gear 24 and between the both side surfaces of the center gear 24 and the shift gear 26 opposed thereto. A pair of left and right multi-plate frictions as the pair of left and right turning transmission clutches including the meshing clutches 27 and 27 and outer peripheral gear portions 25a and 25b linked to the transmission system of the continuously variable transmission 80 for turning on the outer peripheral portion. Clutches 25 and 25 are provided.

  The left and right shift gears 26 can be shifted in the direction of the rotation axis in a state where they are engaged with the center gear 24 and in a state where they are not engaged with each other. When the right shift gear 26 is engaged with the center gear 24, the right engagement clutch 27 is configured to be switched so that the right engagement gear 27 is switched to the engagement state. Both shift gears 26 are engaged with the center gear 24, and the left and right traveling apparatuses 1 </ b> R, 1 </ b> L are driven straight through the shift gear 26 in the same direction at the same speed.

  More specifically, the left and right shift gears 26, 26 are urged into the engaged state in which the meshing clutches 27, 27 are engaged by the pressing force of the pressure springs 29, 29, respectively. The meshing clutches 27 and 27 are disengaged by supplying pressure oil to the hydraulic cylinders 31L and 31R, which are single acting hydraulic cylinders, against the pressing force of the pressing springs 29 and 29 and performing a shift operation. Switching operation is possible. As shown in FIG. 7, the shut-off hydraulic cylinders 31L and 31R are operated by switching the shut-off solenoid valves 63 and 64 between a pressure oil supply state and an oil discharge state. By the way, the shut-off solenoid valves 63 and 64 are configured to be urged to return to the pressure oil supply state by the springs 63a and 64a. By energizing and energizing the solenoids 63b and 64b, the urging forces of the springs 63a and 64a are applied. Accordingly, the valve body is operated to switch to the drained state.

  Operation state detection for detecting whether the hydraulic oil is supplied to the hydraulic cylinders 31L and 31R for shutoff or whether the hydraulic oil is discharged or the hydraulic oil is discharged. Pressure sensors 68 and 69 are provided as means. In other words, the left meshing clutch 27 is disengaged when the shutoff hydraulic cylinder 31L is in the pressure oil supply state, and the left meshing clutch 27 is engaged when the oil is exhausted. Further, when the hydraulic cylinder 31R for shutoff is in the pressure oil supply state, the right meshing clutch 27 is in a disengaged state, and when it is in an oil exhausted state, the right meshing clutch 27 is in an engaged state. Therefore, the pressure sensors 68 and 69 can detect whether the engagement clutches 27 and 27 are in the engaged state or the disconnected state based on the pressure of the oil chambers in the cutoff hydraulic cylinders 31L and 31R.

  Further, by supplying pressure oil to the left steering hydraulic cylinder 30L of the left and right steering hydraulic cylinders 30L, 30R composed of a single-acting hydraulic cylinder, the friction plate in the shift gear 26 is shifted. The left friction clutch 25 is configured to be able to be switched to a transmission state where the friction clutch 25 is in pressure contact. On the other hand, by supplying pressure oil to the right steering hydraulic cylinder 30R and shifting the friction plate in the shift gear 26, the right friction is achieved. The clutch 25 is configured to be able to be switched to a transmission state where the clutch 25 is in pressure contact. As shown in FIG. 7, the pair of steering hydraulic cylinders 30L and 30R are configured to be operated by switching the shut-off solenoid valves 32 and 33 between the pressure oil supply state and the oil discharge state. .

  The power from the shift gear 26 is transmitted to the pair of left and right traveling devices 1R and 1L via the final gear 35. The shift gear 26 is always in the engaged state even when the meshing clutch 27 is engaged or not engaged. It is configured to mesh with the relay gear 34 of the transmission system to the traveling device.

  That is, when the left and right meshing clutches 27 and 27 are respectively engaged and the left and right friction clutches 25 and 25 are respectively disengaged, the straight transmission state is established, and the left meshing clutch 27 is disengaged from the straight transmission state. When the left friction clutch 25 is in the engaged state, a left-turn transmission state is established, and when the right engagement clutch 27 is disengaged and the right friction clutch 25 is engaged from the straight-ahead transmission state, the right-turn transmission state is established. Become.

  In other words, transmission gears 80b1 and 80b2 are fixed to both ends of the output shaft 80b of the continuously variable transmission 80 for turning, and the friction clutches 25 and 25 are connected to the transmission gears 80b1 and 80b2, respectively. The outer peripheral gear portions 25a and 25a are engaged with each other. Then, one of the left and right shift gears 26, 26 is shifted by operating either one of the shutoff hydraulic cylinders 31L, 31R to shift to the side where the meshing with the center gear 24 is disengaged. When the friction plate in the shift gear 26 is shifted by either one of the hydraulic cylinders 30L, 30R, the friction clutch 25 on the side to which the shift gear 26 has moved is brought into a pressure contact state, and the friction clutch 25 is engaged. The power of the continuously variable transmission 80 for turning is transmitted to the shift gear 26 via the relay gear 34 and the final gear 35 from the shift gear 26, and the vehicle turns. Further, the shift gear 26 is engaged with the relay gear 34 of the transmission system to the traveling device both when engaged with the center gear 24 and when operated on the clutch engagement side of the friction clutch 25. It is configured.

  The linearly variable continuously variable transmission device 70 is configured to be able to perform a stepless speed change operation from the neutral position in each of the forward rotation direction and the reverse rotation direction, and the riding operation unit 2 has a predetermined direction along the front-rear direction. A main speed change lever 40 is provided as speed command means that can be swung by manual operation over the front and rear operation range. As shown in FIG. 7, the swash plate 41 of the variable hydraulic pump 70A is linked to the main transmission lever 40 via the hydraulic servo mechanism SV, and the angle of the swash plate 41 is changed based on an operation command of the main transmission lever 40. By doing so, the output state on the hydraulic motor 70B side is changed steplessly. In other words, when the main transmission lever 40 is manually operated, the shift operation can be lightly operated by performing an assist operation with a hydraulic operation force by the action of the hydraulic servo mechanism SV. It has become. Since the hydraulic servo mechanism SV has a well-known configuration, detailed description thereof is omitted here.

Next, the speed change operation configuration of the continuously variable transmission 70 for straight travel will be described.
As shown in FIG. 8, when the main transmission lever 40 is in the neutral range and the neutral state is commanded, the swash plate 41 is in the neutral state, the hydraulic motor 70B is not rotated and is maintained in the stopped state, and the main transmission lever 40 Is a shift command to the forward speed increasing side or the reverse speed increasing side, the angle of the swash plate 41 is set in the forward rotation direction (by the hydraulic servo mechanism SV as described above in accordance with the operation command of the main shift lever 40 ( The speed change operation is performed so that the hydraulic motor 70B is driven to rotate in the forward direction or the reverse direction at a speed corresponding to the command position by an assist operation by a hydraulic operation force in the forward speed direction) or in the reverse direction (reverse speed direction). It becomes the composition which is done.

  On the other hand, similarly to the continuously variable continuously variable transmission device 70, the turning continuously variable transmission device 80 is configured to be capable of shifting operation in a stepless manner in each of the forward rotation direction and the reverse rotation direction. However, the turning continuously variable transmission 80 does not shift manually, but the swash plate 42 of the variable hydraulic pump 80A is linked to the hydraulic turning operation mechanism 43. The output state on the hydraulic motor 80B side is changed by changing the swash plate angle. As shown in FIG. 7, the turning operation mechanism 43 includes a double-acting shift hydraulic cylinder 44 as an actuator linked to the swash plate 15 in the continuously variable transmission 80 for turning, and the shifting hydraulic pressure. A hydraulic control unit VU that performs hydraulic control on the cylinder 44 is provided. The shifting hydraulic cylinder 44 is configured to be urged to return to the neutral position by the urging force of a pair of left and right springs 44a and 44b provided therein.

  Although not described in detail, the hydraulic control unit VU moves the swash plate 42 in the continuously variable transmission 80 for turning in the forward speed increasing direction and the reverse speed increasing direction based on a control command from the control device H. The shift hydraulic cylinder 44 is controlled so as to move and hold the swash plate 42 at an arbitrary shift position.

  The shifting operation of the continuously variable transmissions 70 and 80 as described above will be described. If the shifting positions of the swash plates 41 and 42 are in a neutral region having a predetermined width including the neutral position N, as shown in FIG. The speed change output (output rotation speed) becomes zero, and when the speed change position of the swash plates 41 and 42 is rotated in a predetermined direction from the neutral range, the speed change output in the forward direction is steplessly increased. When 41 and 42 are operated in the direction opposite to the predetermined direction from the neutral range, the shift output in the reverse direction is increased steplessly.

  The boarding operation unit 2 is provided with a potentiometer type shift lever sensor 65 that detects a shift command position by detecting a swing operation amount of the main shift lever 40. In addition to the main shift lever 40, a neutral operation area for a straight advance command having a predetermined width including the neutral position N, a left turn operation area for a left turn command operated in the forward direction from the neutral operation area, and A turn lever 56 is provided as a turn command means that can be moved and operated in the right turn operation range for the right turn command operated in the reverse direction from the neutral operation range. Turn as command information so that it can be moved over the entire range of the predetermined operation area in each of the operation area and the right turn operation area, and the smaller the movement amount in the direction away from the neutral operation area, the smaller the movement amount. Is configured to command a target speed ratio.

  In other words, a turning lever sensor 57 is provided as a turning state detecting means comprising a rotary potentiometer for detecting the operation position of the turning lever 56, and the amount of movement in a direction away from the neutral area in the turning command operation area. Is larger, in other words, for example, the greater the tilting angle from the neutral position N to the left or right, the greater is the command of the speed ratio of the left and right traveling devices 1L, 1R that results in a greater turning force. . Accordingly, the turning lever 56 constitutes a manually operated turning state command means for instructing the turning state of the traveling devices 1L and 1R.

  FIG. 9 shows changes in the target speed ratio of the left and right traveling apparatuses 1L and 1R when the turning lever 56 is operated. Line L1 indicates the speed X of the traveling device located outside the turn, and lines L2, L3, and L4 indicate the ratio of the speed of the traveling device inside the turn to the speed X of the traveling device located outside the turn (target speed ratio). This shows the change. That is, the turning-side traveling device changes to the lower speed side as the amount of movement in the direction away from the neutral region of the turning lever 56 increases, and the line L2 is 1/3 of the speed X of the traveling device located outside the turning. Shows the change in the target speed ratio in the slow turning mode decelerated to line 0, line L3 shows the change in the target speed ratio in the reliable turning mode decelerated to zero speed, and line L4 exceeds the zero speed in the reverse direction. The change of the target speed ratio in the super-trust turn mode in which the speed increases is shown. The mode can be switched to one of the lines L2 to L4 by operating the mode switch 62.

  A linear shift position sensor 60 for detecting the operation position of the swash plate 41 in the continuously variable transmission 70 for straight travel, and a turning sensor for detecting the operation position of the swash plate 15 in the continuously variable transmission 80 for turning. A shift position detection sensor 61 is provided. On the other hand, the output rotational speed of the continuously variable transmission 70 for straight traveling is detected by counting the number of teeth of the output gear 22b, and the output rotational speed of the continuously variable transmission 80 for turning is determined. A traveling speed sensor 59 for turning which is detected by counting the number of teeth of the transmission gear 80b1 is provided.

  Based on the input information of various sensors as described above, the operation of the shifting hydraulic cylinder 44 is controlled to control the shifting of the continuously variable transmission 80 for turning, and the solenoid valves 32, 33 for shutoff, and By switching the solenoid valves 63 and 64 for shutting off and controlling the operation of the steering hydraulic cylinders 30R and 30L and the shutting hydraulic cylinders 31L and 31R, the left and right meshing clutches 27 and 27, the left and right friction clutches 25, A microcomputer-based travel drive control device H that switches between 25 transmission states is provided.

  When the rectilinear drive is commanded by the turning lever 56, the traveling drive control device H receives a pair of left and right meshing gears so as to transmit the shift output of the continuously variable continuously variable transmission 70 to the pair of left and right traveling devices 1R and 1L. The clutches 27 and 27 are respectively set in the transmission state, and the pair of left and right friction clutches 25 and 25 are respectively disconnected and switched to the straight traveling state.

  When the turning to the right is commanded by the turning lever 56, the shift output of the continuously variable continuously variable transmission 70 is transmitted to the left traveling device 1L, and the shift output of the continuously variable transmission 80 for turning is transmitted to the right. In order to transmit to the traveling device 1R, the left meshing clutch 27 and the right friction clutch 25 are set in a transmission state, and the right meshing clutch 27 and the left friction clutch 25 are set in a shut-off state so as to turn right. Switch to driving mode.

  Further, when a left turn is commanded by the turning lever 56, the shift output of the continuously variable transmission 70 for straight travel is transmitted to the right traveling device 1R, and the shift output of the continuously variable transmission 80 for turning is transmitted. In order to transmit to the left traveling device 1L, the right mesh clutch 27 and the left friction clutch 25 are switched to the transmission state, the left mesh clutch 27 and the right friction clutch 25 are disconnected, and the left turn is turned. Switch to driving mode.

  In both of the right turn turning state and the left turn turning state, the turning state of the pair of left and right traveling devices 1L and 1R, that is, the turning radius is changed in accordance with the change in the operation position of the turning lever 56. It will change corresponding to the target speed ratio.

Next, a configuration for controlling the left-right inclined posture of the vehicle body V will be described.
That is, in this combine, the left / right inclination angle detection means SK for detecting the right / left inclination angle of the vehicle body V and the left / right inclination angle of the vehicle body V are maintained at the set inclination angle based on the detection information of the left / right inclination angle detection means SK. As described above, posture control means 200 for controlling the operation of the posture change operation means 100 is provided.

  As shown in FIGS. 10 and 18, the left / right inclination angle detecting means SK includes a gravity-type right / left inclination angle sensor 45 that detects the right / left inclination angle from the horizontal reference plane of the vehicle body V by the action of gravity, An angular velocity sensor 46 that detects an angular velocity in the left-right inclination direction, and an inclination angle calculation means 300 that obtains a left-right inclination angle of the vehicle body V based on a detection value of the left-right inclination angle sensor 45 and a detection value of the angular velocity sensor 46 are provided. It is configured.

  When it is detected that the inclination angle calculation means 300 is not in the turning traveling state based on the detection information of the turning lever sensor 57 as the turning state detection means, the left and right inclination angle sensors 45 and the angular velocity sensor 46 detect each of them. The left / right inclination angle of the vehicle body V is obtained based on the value (see FIG. 18 (a)), and when it is detected that the vehicle is turning based on the detection information of the turning lever sensor 57, the left / right inclination angle sensor 45 is detected. Based on the detected value, the left / right inclination angle of the vehicle body is obtained (see FIG. 18B).

  Further, as shown in FIG. 18 (a), the inclination angle calculation means 300 integrates the detection value of the angular velocity sensor 46 with the low-pass filter LPF that removes the high-frequency component from the detection value of the left / right inclination angle sensor 45. An integration unit 400 and a high-pass filter HPF that removes a low-frequency component of the integration value integrated by the integration unit 400 are provided, and the vehicle body is based on the detection values of the left and right inclination angle sensors 45 and the angular velocity sensor 46. When obtaining the left-right inclination angle of V, the output value of the low-pass filter LPF and the output value of the high-pass filter HPF are added to obtain the left-right inclination angle of the vehicle body V.

  In other words, the gravitational left / right tilt angle sensor 45 is positioned on the main frame 11 in a state where it is located at the center position in the left / right direction of the vehicle body V and slightly ahead of the vehicle body in the front / rear direction. It is provided in a fixed state, and is specifically configured as follows.

  As shown in FIG. 13, a liquid 42 having a predetermined viscosity made of silicon oil or the like is placed in a rectangular container 45a fixed to the vehicle body V, and metal plates having the same shape are erected in parallel at the same interval. Two pairs of the detection electrodes 45c are arranged in a state where they are fixed to the container 41 with an interval in the inclination angle detection direction (left and right direction in FIG. 13). When the liquid 42 returns to the initial posture (liquid level horizontal state) due to gravity, the two detection electrodes 45c are in the same immersion state (state shown in FIG. 13) when the vehicle body V is not inclined. In the state where the vehicle body V is inclined, the immersion state of the two sets of detection electrodes 45c is different (the state shown in FIG. 14 (a)), and the capacitance of each detection electrode 45c is measured and measured. A conversion circuit unit 45d is provided for converting a difference in values (zero when the vehicle body V is not inclined) into a detection value corresponding to the inclination angle information.

  Although not described in detail, the angular velocity sensor 46 is composed of a vibration gyro-type angular velocity sensor, and is located at the center position in the left-right direction of the vehicle body V and substantially at the center position in the front-rear direction of the vehicle body V. 11 is provided in a fixed state, and can detect an angular velocity when the vehicle body V tilts in the left-right direction.

  Then, based on the command information of the turning lever 56 detected by the turning lever sensor 57 and the command information of the main transmission lever 40 detected by the transmission lever sensor 65, the vehicle body V is applied to the vehicle body V when turning. Centrifugal force detecting means 600 for detecting centrifugal force is provided, and when it is detected that the tilt angle calculating means 300 is in the turning traveling state based on the detection information of the turning lever sensor 57, the centrifugal force detecting means. An inclination angle change amount in the inclination angle sensor 45 that changes due to the centrifugal force detected at 600, that is, a correction inclination angle is calculated, and a detection value of the inclination angle sensor 45 is corrected by the correction inclination angle. The left / right inclination angle of the vehicle body V is obtained.

  As shown in FIG. 10, a control device H1 using a microcomputer is provided. In addition to the stroke sensors 18 to 21, the left / right tilt angle sensor 45, the angular velocity sensor 46, and the attitude change switch unit SU, the control device H1 is provided. Information of the shift lever sensor 52 and the turning lever sensor 57 is input.

  As shown in FIG. 11, the posture change switch unit SU is turned on and off by a left / right inclination angle setting unit 47 that sets a target right / left inclination angle (set inclination angle) of the vehicle body V and horizontal control (rolling control described later). A horizontal automatic switch 48, a horizontal lamp 48a indicating the on state of horizontal control, and a manual command right raising switch 50a, a left raising switch 50b, an aircraft raising switch 50c and an aircraft lowering which are operated by a cross lever type operation tool 50. A switch 50d is provided.

  The left / right tilt angle setting unit 47 includes a horizontal switch 47a, a left tilt switch 47b, and a right tilt switch 47c. That is, when the horizontal switch 47a is pressed, a tilt angle corresponding to the horizontal state is set as the set tilt angle, and when the left tilt switch 47b is pressed, the currently set tilt angle is corrected in the left tilt direction by the set angle. When the right tilt switch 47c is pressed, the currently set tilt angle is corrected to the right tilt direction by the set angle. And about the left-right inclination angle set by the left-right inclination-angle setting device 47, as shown in FIG. 12, 7 of 1-7 shown in the display apparatus (not shown) provided in the front side of the boarding operation part 2. It is displayed whether it is a stage (stage 4 with an angle of 0 represents a horizontal state, a positive angle represents a right tilt direction, and a negative angle represents a left tilt direction).

  On the other hand, the control device H1 outputs drive signals to the hydraulic control electromagnetic valves 29 to 32 for hydraulic control of the four body posture changing hydraulic cylinders C2 to C5.

  Using the control device H1, the tilt angle calculating means 300 for determining the left / right tilt angle with respect to the horizontal reference plane of the vehicle body V based on the detected value of the left / right tilt angle sensor 45 and the detected value of the angular velocity sensor 46 is configured. Yes. That is, the control device H1 includes a low-pass filter process that removes a high-frequency component from the detection value of the left / right inclination angle sensor 45, an integration process that integrates the detection value of the angular velocity sensor 46, and the integrated value that is integrated. Each of the high-pass filter processing that removes low-frequency components is executed by software processing, and the output value after low-pass filter processing and the output value after high-pass filter processing are added together to tilt the vehicle left and right It is configured to execute processing for obtaining a corner. That is, the low-pass filter LPF, the integrating unit 400, and the high-pass filter HPF are configured using the control device H1.

  Further, reference value updating means 500 is configured to update the reference value (zero point) of the angular velocity corresponding to the state where the angular velocity is zero by using the control device H1, and the vehicle is turned based on the detection information of the turning lever sensor 57. When it is detected that the vehicle is not in a state, in other words, when the vehicle is running straight, the reference value is updated based on a value obtained by averaging a plurality of detection values obtained by sampling the detection values of the angular velocity sensor 46, and The reference value is not updated when it is detected that the vehicle is in the turning traveling state based on the detection information of the turning lever sensor 57.

In other words, when the vehicle body V changes its posture in the left-right direction, it does not rotate in one direction (rolls over), but it always repeats the left-right inclination while returning to the horizontal posture. Even so, if sampling and averaging for a time sufficiently longer than the field undulations and irregularities cycle, the output value due to left and right inclination is canceled out, and an almost accurate reference value (zero point) can be obtained. .

  Then, when it is detected that the vehicle is in the turning traveling state based on the detection information of the turning lever sensor 57, the control device H1 receives the command information of the turning lever 56 detected by the turning lever sensor 57 and the speed change lever. Based on the command information of the main shift lever 40 detected by the sensor 65, the turning radius and the turning traveling speed as the turning state of the traveling devices 1L and 1R are calculated, and the vehicle body turns from the turning radius and the turning traveling speed. The centrifugal force applied to the vehicle body V when traveling is calculated, the amount of change in the tilt angle in the left / right tilt angle sensor 45 that changes due to the centrifugal force is calculated, and the detected value of the left / right tilt angle sensor 45 is calculated. Is corrected by a correction inclination angle corresponding to the amount of change in inclination angle, and the right and left inclination angles of the vehicle body V are obtained. That is, the centrifugal force detection means 600 is configured using the control device H1.

  That is, when the vehicle body V is turning, as shown in FIG. 14 (b), the vehicle body V is not tilted by acting on the centrifugal force laterally with respect to the gravity-type left / right inclination angle sensor 45. Nevertheless, since the liquid level of the liquid 45b is in an inclined state and a detection error occurs, an error caused by such centrifugal force is removed and an accurate left-right inclination angle of the vehicle body V is detected.

  Further, by using the control device H 1, the left / right tilt angle of the vehicle body V is maintained at the set tilt angle set by the left / right tilt angle setting unit 47 based on the detection information of the left / right tilt angle sensor 45. The attitude control means 200 is configured to execute rolling control for controlling the operation of the attitude change operation means 100.

  In other words, the calculation corresponding to a model representing the relationship of the turning radius of the vehicle body V to the command information (target speed ratio) of the turning lever 56 detected by the turning lever sensor 57 from each mechanical element of the vehicle body V. An expression is obtained in advance. Further, in the arithmetic expression corresponding to the model representing the relationship of the centrifugal force applied to the vehicle body V with respect to the turning radius and the turning speed of the vehicle body V, how the liquid 45b appears when the centrifugal force is actually applied. , An equation corresponding to a model representing a behavior of whether the liquid is tilted, the relationship between the tilt angle of the liquid 45b in the left / right tilt angle sensor 45 and the value corresponding to the detected value output from the left / right tilt angle sensor 45, that is, the liquid Based on a model that represents the relationship between the tilt angle from the horizontal state of 45b and the detection value that is actually output with respect to the tilt angle, the respective operation equations representing the relationship are obtained in advance. Note that the turning speed at the time of turning can be obtained from the detection value of the shift lever sensor 65.

  And the control apparatus 22 memorize | stores the various arithmetic expressions as mentioned above in memory, and based on the detected value of the turning lever sensor 57 and the detected value of the shift lever sensor 65 using these various arithmetic expressions. Thus, an error caused by centrifugal force is removed, and an accurate left-right inclination angle of the vehicle body V can be detected.

  Next, a specific control operation of the rolling control by the control device H1 will be described based on the flowchart of FIG.

  That is, first, based on the detection information of the turning lever sensor 57, it is determined whether or not a turning command for turning the vehicle body V by the turning lever 56 is instructed. If it is determined that the straight traveling state is commanded instead of the turning traveling state, the angular velocity sensor 46 updates the reference value (zero point) of the angular velocity corresponding to the state where the angular velocity is zero. That is, a set number of detected values obtained by sampling the detected values of the angular velocity sensor 46 at a set time interval are averaged, and the reference value is updated based on the averaged average value. Incidentally, the time for sampling the set number of detection values is set to a time sufficiently longer than the ups and downs of the field and the period of unevenness, for example, a time as long as several seconds.

Then, the difference between the reference value (zero point) updated as described above and the actual detection value detected by the angular velocity sensor 46 is calculated as the angular velocity, and further, the detection value of the angular velocity sensor 46 is thus calculated. Based on the angular velocity obtained from the above and the detected value of the left / right inclination angle sensor 45, processing for obtaining the right / left inclination angle of the vehicle body V is executed.

  Specifically, as shown in FIG. 18A, low-pass filter processing for removing high-frequency components from the detection value of the left / right tilt angle sensor 45, the angular velocity obtained from the detection value of the angular velocity sensor 46 (the reference The difference between the value and the actual detection value detected by the angular velocity sensor 46), and the high-pass filter process for removing the low frequency component of the integrated value, and The left and right tilt angles of the vehicle body V are obtained by adding the output value after the low-pass filter processing and the output value after the high-pass filter processing.

  FIG. 19 shows the signal processing of control for obtaining the left / right tilt angle as a transfer function. The actual left / right inclination angle θ of the vehicle body is detected by the inclination angle sensor, and the detected inclination angle value is output. The left / right inclination angle sensor 45 includes a first-order lag element (1 / (T1S + 1)) (T1 is a coefficient). ing. Then, the detected tilt angle value is generated due to fine vibration of the vehicle body in the left / right tilt angle sensor 45 by performing a low-pass filter process having a first-order lag element (1 / (T2S + 1)) (T2 is a coefficient). High frequency noise can be effectively removed, and the detection value is stabilized.

  On the other hand, the detected value of the angular velocity sensor 46 is a value obtained by differentiating the actual left-right inclination angle θ of the vehicle body V, and after integrating the detected value, the first-order lag element possessed by the inclination angle sensor and the lag element by low-pass filter processing By performing a high-pass filter process with a reverse characteristic (1-1 / (T1S + 1) × 1 / (T2S + 1)) of the combined characteristics, a detection value including a high-frequency component can be obtained in a state where the integration error is effectively removed. it can.

By adding the output value after performing the low-pass filter processing and the output value after performing the high-pass filter processing, the left / right inclination angle of the vehicle body V is detected in a state with little error, and thus obtained. Based on the left / right inclination angle of the vehicle body V, a posture changing operation process as described later is executed.

  When it is determined that the vehicle is in a turning state based on the detection information of the turning lever sensor 57, as shown in FIG. 18 (b), the process for updating the reference value as described above is not executed. In addition, the left and right inclination angles of the vehicle body V are obtained based on the detection values of the left and right inclination angle sensors 45 without using the detection values of the angular velocity sensor 46. Further, when it is determined that the vehicle is in a turning state, a centrifugal force calculation process is performed to calculate a centrifugal force applied to the vehicle body when the vehicle body V turns.

  The centrifugal force calculation process will be described. As shown in FIG. 16, the detection value of the turning lever sensor 57 and the detection value of the transmission lever sensor 65 are read, and the target speed ratio as the turning state commanded by the turning lever 56 is obtained. Further, the turning radius is calculated from the map data indicating the relationship between the target speed ratio and the turning radius that are measured and stored in advance. Further, the turning traveling speed is calculated based on the target vehicle speed by the main transmission lever 40 detected by the transmission lever sensor 65, and the centrifugal force applied to the vehicle body V by the turning traveling is calculated from the turning radius and the turning traveling speed. .

  In other words, what is commanded by the main transmission lever 40 is the traveling speed of the traveling device located outside the turning, and what is commanded by the turning lever 56 is the traveling of the pair of traveling devices 1L and 1R. Since it is the ratio of the speeds, the respective traveling speeds of the left and right traveling apparatuses 1L, 1R are obtained from the information, and the average value of the traveling speeds of the left and right traveling apparatuses 1L, 1R becomes the turning traveling speed.

A tilt angle change amount (corrected tilt angle) corresponding to an electrical output value output when the liquid 45b of the left / right tilt angle sensor 45 tilts due to the centrifugal force is obtained. That is, the change amount of the tilt angle is a value corresponding to an error generated in the tilt angle sensor 45 due to the centrifugal force (see FIG. 14B). From the inclination angle change amount (corrected inclination angle) and the actual detection value of the left / right inclination angle sensor 45, an accurate detection value of the left / right inclination angle of the vehicle body V based on the detection value of the left / right inclination angle sensor 45 is calculated. Based on the left and right inclination angles of the vehicle body V thus obtained, posture change operation processing as described later is executed.

Next, posture change operation processing will be described.
As shown in FIG. 17, the deviation between the detected value of the left / right tilt angle detected as described above and the set tilt angle set by the left / right tilt angle setting unit 47 passes through the dead zone for rolling to the left of the traveling vehicle body V. If it is off to the tilt side, it is determined whether one of the right front cylinder C4 and the right rear cylinder C5 is operated to the lower limit position based on the detection information of the stroke sensors 20 and 21 positioned on the front and rear of the right side of the aircraft. If both the cylinders C4 and C5 are not operated to the lower limit position, the right front cylinder C4 is extended and the right rear cylinder C5 is shortened until either of the cylinders C4 and C5 reaches the lower limit position. Operate. If either the right front cylinder C4 or the right rear cylinder C5 is operated to the lower limit position, the left front cylinder C2 is shortened and the left rear cylinder C3 is operated until either the left front cylinder C2 or the left rear cylinder C3 reaches the upper limit position. Is extended.

  If the deviation deviates from the rolling dead zone to the right inclination side of the traveling vehicle body V, the left front cylinder C2 and the left rear cylinder C3 are detected based on the detection information of the stroke sensors 18 and 19 positioned on the front and rear of the left side of the vehicle body. It is determined whether or not any of the cylinders C2 and C3 is operated to the lower limit position, and if both of the cylinders C2 and C3 are not operated to the lower limit position, the front left The cylinder C2 is extended and the left rear cylinder C3 is shortened. When either the left front cylinder C2 or the left rear cylinder C3 is operated to the lower limit position, the right front cylinder C4 is shortened and the right rear cylinder C5 is operated until either the right front cylinder C4 or the right rear cylinder C5 reaches the upper limit position. Is extended.

  In this way, while the height of the traveling machine body V is made as low as possible, the angular deviation between the left / right inclination angle of the traveling machine body V and the set left / right inclination angle set by the left / right inclination angle setting device 25 is within the dead zone F. The rolling control is executed so as to fall within the range. When driving two hydraulic cylinders as described above, if there is a difference in the change speed of the operation amount (cylinder expansion / contraction amount) by the two hydraulic cylinders to be driven, for example, the slower one The two hydraulic cylinders that are driven by adjusting the operating state of the two hydraulic cylinders, such as intermittently driving the hydraulic cylinder with the higher speed while continuously driving the hydraulic cylinder The operation is controlled so that the amount difference falls within the set value.

[Second Embodiment]
Next, a second embodiment will be described. In this embodiment, the configuration of the centrifugal force calculation means is different, but the other configuration is the same as that of the first embodiment, so only the different configuration will be described and the description of the same configuration will be omitted.

  That is, in this embodiment, in the centrifugal force calculation process, as in the first embodiment, the driving speeds of the left and right traveling devices are detected separately in the turning state, instead of the command information of the shift lever and the turning lever. The centrifugal force is calculated based on the detection values of the pair of traveling speed sensors 58 and 59.

  That is, as shown in FIGS. 20 and 21, a control device H2 using a microcomputer similar to the control device H1 in the first embodiment is provided, and when this control device H2 executes a centrifugal force calculation process, FIG. As shown in FIG. 6, the detection values of the pair of traveling speed sensors 58 and 59 provided in the transmission mechanism for the left and right traveling apparatuses 1L and 1R are used, and the detection information of the pair of traveling speed sensors 58 and 59 is used. The turning radius is calculated from the speed ratio of the left and right traveling apparatuses 1L and 1R, the turning traveling speed is calculated from the average value of the speeds of the left and right traveling apparatuses 1L and 1R, and the information as well as these are measured and stored in advance. The centrifugal force is calculated from the mechanical characteristics of the vehicle body V.

[Another embodiment]
Next, another embodiment will be listed.

  In each of the above embodiments, the tilt angle calculation means includes a low-pass filter that removes a high-frequency component from the detection values of the left and right tilt angle sensors, an integration means that integrates the detection values of the angular velocity sensor, and an integration means thereof. And a high-pass filter that removes a low-frequency component of the integrated value integrated in step S, and the left-right inclination angle of the vehicle body is obtained by adding the output value of the low-pass filter and the output value of the high-pass filter. However, instead of such a configuration, the configuration may be such that the left and right tilt angles of the vehicle body are obtained by adding the output value of the tilt angle sensor and the output value of the integrating means without providing the low pass filter and the high pass filter. Good.

  In each of the above embodiments, an arithmetic expression corresponding to a model representing the relationship of the turning radius of the vehicle body with respect to the command information (target speed ratio) of the turning lever, and a model representing the relationship between the turning radius of the vehicle body and the centrifugal force applied to the vehicle body with respect to the turning speed. In the left and right tilt angle sensor, the calculation formula corresponding to the model representing the behavior of how the liquid tilts when a centrifugal force is actually applied, the tilt of the liquid in the left and right tilt angle sensor This is a model that represents the relationship between the angle and the value corresponding to the detection value output from the left / right tilt angle sensor, that is, the relationship between the tilt angle from the horizontal state of the liquid and the actually output detection value for that tilt angle. On the basis of the above, each arithmetic expression representing the relation is obtained and stored in advance, and the corrected inclination angle as the inclination angle change amount is obtained using these arithmetic expressions. But the may be configured as follows: Instead of such a configuration.

  That is, in a model that represents the relationship of the turning radius of the vehicle body to the command information (target speed ratio) of the turning lever, a model that represents the relationship of the centrifugal force applied to the vehicle body V to the turning radius and turning speed of the vehicle body, Model expressing the behavior of how the liquid tilts when centrifugal force is applied to it, the tilt angle of the liquid in the left / right tilt angle sensor and the value corresponding to the detection value output from the left / right tilt angle sensor By using a model representing the relationship and the like by simulation by software processing, detected values of the turning lever sensor and the shift lever sensor, and tilt angle correction information corresponding to the error of the left and right tilt angle sensor generated due to centrifugal force, The map data is stored in association with each other, and the map lever data is stored. At a stroke from the detection value of the lever sensor may be configured to obtain a correction slope angle corresponding to error of lateral inclination angle sensor.

  In each of the embodiments described above, the centrifugal force detection means is configured to be obtained by calculation using the control device, but instead of such a configuration, the centrifugal force applied to the vehicle body is directly detected and output as a signal value. You may comprise with a centrifugal-force detection apparatus.

  In each of the above embodiments, the traveling device is configured by a pair of left and right crawler type traveling devices, but is not limited thereto, and for example, a single traveling device may be used, and a wheel type instead of a crawler type may be used. A traveling device may be used.

  In each of the above embodiments, the turning state command means is constituted by a turning lever, and the speed command means is constituted by a shift lever. However, the invention is not limited to such a configuration, and the turning state command means is a circular handle. The speed command means may be a foot pedal.

  In each of the above-described embodiments, the posture changing operation means 100 is configured by the four hydraulic cylinders C2 to C5 positioned at the four positions on the front, rear, left and right of the machine body V. However, in addition to the hydraulic cylinders, an electric motor and a screw feed mechanism are provided. You may comprise by the other drive means which consists of etc. Further, the traveling device may be configured to change the left / right inclination angle of the vehicle body with respect to the grounding portion by one driving means.

  In the above embodiment, the combine is exemplified as the work vehicle. However, various harvesters or constructions such as an rush harvester or an onion harvester may be used as long as the vehicle body is configured to change the left / right inclination angle of the vehicle body with respect to the grounding portion of the traveling device. A work vehicle other than a combine such as a 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 Control block diagram for travel drive The figure which shows the shift output of the continuously variable transmission for straight travel The figure which shows the target speed ratio of turning state Control block diagram for posture change The figure which shows the switch unit for posture change Diagram showing set tilt angle A perspective view showing a configuration of an inclination angle sensor Side view showing detection operation of tilt angle sensor Flow chart showing control operation Flow chart showing control operation Flow chart showing control operation Block diagram of posture change operation means Diagram showing transfer function Control block diagram for posture change of the second embodiment The flowchart which shows the control action of 2nd Embodiment.

Explanation of symbols

1L, 1R Traveling device 40 Speed command means 45 Inclination angle sensor 46 Angular speed sensor 56 Turning state command means 57 Turning state detection means 58, 59 Traveling speed detection means 100 Attitude change operation means 200 Attitude control means 300 Inclination angle calculation means 500 Reference value Update means 600 Centrifugal force detection means SK Left / right tilt angle detection means V Car body

Claims (6)

Based on the detection information of the right / left inclination angle detection means, the right / left inclination angle detection means for detecting the right / left inclination angle of the vehicle body, and the detection information of the left / right inclination angle detection means. Attitude control means for controlling the operation of the attitude change operation means so that the right and left inclination angle is maintained at the set inclination angle, and a work vehicle attitude control device comprising:
A turning state detecting means for detecting whether or not the vehicle body is in a turning running state is provided;
The left / right inclination angle detecting means is
A gravity-type tilt angle sensor that detects the left-right tilt angle of the vehicle body by the action of gravity, and an angular velocity sensor that detects an angular velocity in the left-right tilt direction of the vehicle body, and
When the turning state detecting means detects that the vehicle is not in a turning state, the left and right inclination angles of the vehicle body are obtained based on the detected values of the inclination angle sensor and the angular velocity sensor, and the turning state detection means When the vehicle is detected to be in a turning state, the work vehicle attitude control device is configured to include an inclination angle calculation means for obtaining a right and left inclination angle of the vehicle body based on a detection value of the inclination angle sensor. Centrifugal force detecting means for detecting the centrifugal force applied to the vehicle body when the vehicle body turns is provided,
The tilt angle calculation means is
When the turning state detecting means detects that the vehicle is in a turning state, the amount of change in the inclination angle in the inclination angle sensor that changes due to the centrifugal force detected by the centrifugal force detection means is calculated. 2. The work vehicle attitude control device according to claim 1, wherein the left and right inclination angles of the vehicle body are obtained by correcting a detection value of the inclination angle sensor with the amount of change in inclination angle.   The centrifugal force detection means is configured to calculate the centrifugal force based on a turning state of the traveling device when the vehicle body makes a turn and a turning traveling speed of the traveling device. The work vehicle attitude control device described. The travel device is configured to include a pair of left and right travel devices, and is configured to turn by a speed difference between the pair of left and right travel devices,
A pair of traveling speed detection means for detecting the driving speed of each of the pair of traveling devices,
The centrifugal force detection means is
The turning state of the traveling device and the turning traveling speed of the traveling device are obtained based on the detection values of the pair of traveling speed detecting means, and the centrifugal force is calculated based on the turning state and the turning traveling speed. The attitude control device for a work vehicle according to claim 3, which is configured to do so. Manual operation type turning state command means for instructing the turning state of the traveling device when the vehicle body makes a turn traveling, and manual operation type speed command means for instructing the turning traveling speed of the traveling device when the vehicle body makes a turn traveling And
The centrifugal force detection means is
The work vehicle attitude control device according to claim 3, wherein the centrifugal force is calculated based on command information of the turning command means and command information of the speed command means.   When the turning state detection means detects that the vehicle is not in a turning state, it corresponds to a state in which the angular velocity is zero based on a value obtained by averaging a plurality of detection values obtained by sampling the detection values of the angular velocity sensor. A reference value updating unit configured to update the reference value when the reference value of the angular velocity is updated and the turning state detecting unit detects that the vehicle is in a turning state. The work vehicle attitude control device according to any one of claims 1 to 5.

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