KR100609791B1 - Work vehicle - Google Patents

Abstract

Right and left traveling apparatuses 1R and 1L, engine 3, a speedless continuous transmission 7 and a continuously variable transmission 8 for shifting power from the engine, and a speed command for commanding a traveling speed of the aircraft. A work vehicle comprising a means 14 and a turning command means 56 for commanding the turning of either the straight or the left or right side of the body, wherein the straight continuously variable transmission 7 or the turning continuously variable transmission 8 is provided. When the speed detecting means for obtaining the speed of one continuously variable transmission and the control device H for controlling the shift operation of the one continuously variable transmission are provided, and when the turning command means is instructed to switch straight from the turning, Said one continuously variable transmission is shifted on the basis of the instruction speed from said speed command means 14, and said other continuously variable transmission is obtained by said control device H at said detection output speed. A shift operation is performed so as to be equal to the speed of one continuously variable transmission, and the shift operation is performed at a speed larger than the speed of shifting the continuously variable transmission at the commanded speed.

Swing command means, continuously variable transmission, speed command means, control device, engine

Description

WORK VEHICLE}

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the work vehicle which concerns on this invention, and is the whole side view of the combine illustrated as an example of a work vehicle.

Fig. 2 is a schematic configuration diagram showing the transmission structure in the first embodiment.

Fig. 3 is a control block diagram in the first embodiment.

4 is a diagram showing a configuration of a hydraulic control unit in the first embodiment.

Fig. 5 is a graph showing a relationship between a shift position and a shift output in the first embodiment.

6 is a flowchart of a control operation in the first embodiment;

Fig. 7 is a graph showing the relationship between the operating position of the swing lever and the speed ratio in the first embodiment.

8 is a control block diagram according to a second embodiment;

9 is a graph showing a relationship between a shift position and a shift output in the second embodiment.

Fig. 10 is a graph showing a relationship between a shift position and a shift output in the second embodiment.

Fig. 11 is a graph showing a relationship between a shift position and a shift output in the second embodiment.

12 is a control block diagram according to a third embodiment;

Fig. 13 is a graph showing a relationship between a shift position and a shift output in the third embodiment.

Fig. 14 is a graph showing a relationship between a shift position and a shift output in the third embodiment.

Fig. 15 is a graph showing a relationship between a shift position and a shift output in the third embodiment.

Fig. 16 is a control block diagram in the fourth embodiment.

Fig. 17 is a graph showing a relationship between a shift position and a shift output in the fourth embodiment.

Fig. 18 is a control block diagram according to the fifth embodiment.

Fig. 19 is a graph showing a relationship between a shift position and a shift output in the fifth embodiment.

20 is a graph showing a relationship between a target rotational speed and a target shift position in the fifth embodiment;

Fig. 21 is a flowchart of the control operation in the fifth embodiment.

Fig. 22 is a flowchart of the control operation in the fifth embodiment.

Fig. 23 is a flowchart of a control operation in the fifth embodiment.

FIG. 24 is a diagram showing the configuration of the hydraulic control unit in the sixth embodiment, and corresponding to FIG. 4; FIG.

<Explanation of symbols for the main parts of the drawings>

1R, 1L: Traveling device

2: driving body

3: mowing and returning device

4: threshing device

5: grain tank

6: boarding driver

7, 8: continuously variable transmission

7A: Variable Hydraulic Pump

9: mission case

10: electric belt

11: electric pulley

13: straight slope plate

14: shift operation tool

15: Turning Slope Plate

16: hydraulic swing operation mechanism

17: hydraulic cylinder for shifting

20, 21: output shaft

20a, 20b, 21a, 21b, 22e: output gear

22: sub-shift shaft

22d, 26: shift gear

23: support shaft

24: center gear

25: friction clutch

27: engagement clutch

29: compression spring

30L, 30R, 31L. 31R: Hydraulic Cylinder

34: relay gear

35: final gear

36: control valve

37: spool

38, 39: coil spring

40, 41: pressure control unit

42, 43: solenoid valve

44: drainage

47, 48: solenoid

49: relief valve

56: turning lever

57: pivot lever sensor

58, 59: rotation sensor

60: Shift position sensor for straight ahead

61: variable speed position sensor

62: mode switching volume

63, 64: solenoid valve

71: mode switch

72: turning state setter

73a, 73b: Articulated control mechanism

74: turning force setting means

74a: area select switch

100: calculation means

101: driving control means

OP1, OP2: output port

[Document 1]

Japanese Patent No. 3153515

[Document 2]

JP-A-10-157650

[Document 3]

KR-A-1998-63749

[Document 4]

CN-A-1191816

[Document 5]

JP-A-2002-362403

The present invention relates to a work vehicle. More specifically, the present invention relates primarily to techniques for improving the straightness and turning operability of agricultural machinery, including harvesting machinery (such as combines).

The prior art of such a work vehicle is disclosed, for example in Japanese Patent No. 3153515 (or the corresponding public publication: JP-A-10-157650, KR-A-1998-63749 or CN-A-1191816). Reference). In this conventional configuration, a speed command means, a swing command means, mechanical command linkage means for linking both command means, a linear continuously variable transmission and a swing continuously variable transmission device are provided. When the straight forward is commanded from the turning command means, the straight continuously variable transmission is shifted at the commanded speed from the speed command means, and the output is transmitted to the left and right traveling devices. At that time, the swing continuously variable transmission is also shifted to follow this command speed via the mechanical operation linkage means.

On the other hand, when the turning is commanded from the turning command means, the output of the straight continuously variable transmission is transmitted to the traveling apparatus outside the swing, and the output of the swing continuously variable transmission is transmitted to the traveling apparatus inside the swing. At that time, the speed change operation is performed to the command speed from the speed command means for the linear continuously variable transmission, and the speed change operation is performed to the target speed according to the operation position of the swing command means via the mechanical operation linkage means for the swing variable speed transmission. Thus, one traveling device ("slow turn" or "grand turn") which is driven by driving one (rear turning) traveling device in the same direction at a lower speed than the other (revolving outside) traveling device. Pivot turn ("pivot turn"), which is carried out by stopping the engine and driving only the other travel device, and "spin turn" by driving one travel device in a reverse direction to the driving direction of the other travel device. Various turning patterns may be represented by a stepless shift (these terms are used in the same meaning in the claims and the following description).

The above-mentioned conventional work vehicle is excellent in that various turning patterns can be performed by simple operation by cooperation of a single turning command means, a linear continuously variable transmission and a continuously variable transmission, but there is room for improvement in the following points.

That is, in the above conventional work vehicle, when returning from turning to straight, due to the time lug until the rotational speed of the continuously variable transmission becomes the same rotational speed as the continuous continuously variable transmission, between the fixed time and both rotational speeds There is a case that a difference occurs. This difference is large when the turning angle before returning straight is large.

In this way, if the turning operation is performed rapidly from one direction to the opposite direction while the difference is generated between both rotational speeds, the following problem may occur. For example, when the vehicle is fully turned to the right, the swing continuously variable transmission driving the right (turning inside) traveling device is considerably decelerated than the swing continuously variable transmission driving the left (turning outside) traveling device. There is a large difference between the rotational speeds. In this state, when the vehicle is turned in the opposite direction (left side) while the speeds of both the continuously variable transmissions are not the same yet, the rotational speed of the left (slewing outside) continuously variable transmission is right (swing inside). The body starts turning to the left while greater than the rotational speeds of both continuously variable transmissions. At this time, even if the turning command means commands the left turn, the turn is turned to the right. There was room for improvement in terms of operability such as useless turning operation required.

Also in JP-A-2002-362403, there is the same problem caused by the time lugs caused by the delay of the control system.

An object of the present invention is to solve such a problem and to provide a work vehicle with improved operability.

In order to achieve the above object, a feature configuration of the present invention includes a left and right traveling apparatus, an engine, a straight continuously variable transmission and a swing continuously variable transmission for shifting power from the engine, and a speed command means for instructing a traveling speed of the aircraft. And a work vehicle provided with a turning command means for instructing turning of either the straight or the left or right side of the body,

A speed detecting means for obtaining a speed of either the continuously variable transmission or the continuously variable transmission, and a control device for controlling a shifting operation of the continuously variable transmission;

When the turning command means is commanded to switch straight from the turning,

The one continuously variable transmission is shifted on the basis of the command speed from the speed command means;

The other continuously variable transmission is shifted by the control device so as to be equal to the speed of the one continuously variable transmission obtained by the speed detecting means, and this shift operation causes the one continuously variable transmission to operate at the commanded speed. It is characterized in that it is performed at a speed larger than the speed of shifting to

According to this configuration, since the time lug until the rotation speed of the other continuously variable transmission becomes the same as the rotation speed of the one continuously variable transmission is greatly reduced, the rotation speed of the swing continuously variable transmission and the straight continuously variable transmission The deviation of the rotational speed is prevented as much as possible. Problems such as turning once in the direction opposite to the desired turning direction can be accurately avoided.

Therefore, even when turning sharply in one direction and turning in the opposite direction via a straight state, it came to provide the working vehicle which can accurately avoid the fall of operability.

In a preferred embodiment of the present invention, the one continuously variable transmission is the straight continuously variable transmission and the other continuously variable transmission is the swing continuously variable transmission, and a power transmission system between each continuously variable transmission and each traveling device. The motorized state switching means is provided in the motor vehicle, and the motorized state switching means transmits the power from the linear continuously variable transmission to the respective traveling devices by the control device in response to the straight command of the turning command means. And, in response to the turning command of the turning command means, the control device transmits the power from the straight continuously variable transmission to the traveling device outside the swing, and further transfers the power from the turning continuously variable transmission to the turning inside traveling device. It is comprised so that switching is possible between the turning electric states to transmit to.

According to the above feature configuration, when turning the body from straight to left or right side, turning preliminary control processing is performed in which the linear continuously variable transmission and the swing continuously variable transmission are electrically operated by the electric state switching means in advance. This processing causes the high speed side continuously variable transmission to slip to the low speed side, or the low speed side continuously variable transmission becomes the high speed side by the driving force of the high speed side continuously variable transmission, so that both continuously variable transmissions are at about the same speed. Therefore, it is possible to accurately avoid giving a sense of discomfort by the occurrence of shock due to the speed difference between the two continuously variable transmissions when turning. Therefore, it is possible to suppress the occurrence of discomfort when switching from a straight line to a turning line. As a suitable aspect for realizing the said structure, the said drive state switching means is a linear clutch which interrupts the power from the said linear continuously variable transmission, a linear actuator which performs the operation which disconnects this linear clutch, and the said turning continuously variable speed It is advantageous to have a swing clutch that intercepts power from the apparatus and a swing actuator that operates to disconnect the swing clutch.

In a preferred embodiment, each of the continuously variable transmissions is a hydrostatic continuously variable transmission including a hydraulic pump and a hydraulic motor, and the output of the corresponding hydraulic motor is changed by steplessly changing the position of the inclined plate of the hydraulic pump of each hydrostatic continuously variable transmission. It is configured to be changed steplessly. In this way, when the hydrostatic stepless speed transmission device (HST) is employed as the continuously variable transmission, minute speed adjustment from zero speed can be performed, and optimum speed selection (particularly deceleration) can be performed for turning. Similarly, the speed increase operation after completion of turning can be easily performed by employing HST.

In a preferred embodiment, mode command means for switching a relationship between the amount of movement from the straight command position of the swing command means and the speed of each traveling device via the control device is provided, and the swing command means provides the swing command. When the amount of movement of the command means is maximum (MAX), the complete turning mode for decelerating the traveling device on the inside of the swing and traveling in the same direction by decelerating the traveling device on the outside of the turning, the pivot turning mode for stopping the traveling device on the inside of the turning, and both traveling devices The driving state of each said traveling apparatus is comprised so that switching is possible between the spin turning modes which drive | move the driving direction to the opposite direction. According to this structure, the turning pattern is diversified by the synergistic effect with any one of the above structures, and the operation for diversifying in this way can also be easily performed. Moreover, it becomes easy for an operator to know the relationship between the target turning state and the operation position of a turning instruction means.

As an advantageous means for obtaining the above characteristics, the speed of the traveling device inside the swing is increased by the control device when the speed of the traveling device outside the swing is constant once the mode command means is switched to the respective swing modes. It is conceivable that the reduction amount of the speed is increased as the movement amount becomes larger as the relation is a quadratic function with respect to the movement amount from the straight command position of the turning command means. Alternatively, when the second mode is switched to the spin swing mode by the mode command means, swing mode change means is provided for changing the change characteristic of the speed ratio between both traveling devices with respect to the swing operation position of the swing command means. I can think of it. Or, when switching to each said turning mode by the said mode command means, the control apparatus has the larger movement amount from the straight instruction | operation range of the said turning instruction means than the smaller operation range than the small operation range with which the said movement command means is larger. It is conceivable that an amount of reduction in the speed ratio between the two traveling devices with respect to the unit moving amount is set to be large, and an adjustment control device is provided for setting the moving amount at the boundary between the two operating ranges and the speed of the traveling device inside the swing. have.

In any configuration, the speed ratio between the two traveling devices with respect to the swing operation position of the swing command means can be arbitrarily set. In particular, according to the first and the third means, since the turning angle becomes large due to a slight increase in the moving amount of the turning command means in a large range of the moving amount of the turning command means, it is possible to obtain a large turning force especially necessary for sharp turning with a relatively small operating force. Become.

In one suitable embodiment, a pair of shift position sensors for detecting the position of each inclined plate and a rotational speed sensor for detecting the rotational speed of the respective hydraulic motors are provided, and the control device is provided at a target value of the respective rotational speeds. The correlation between the target positions of the respective inclined plates is stored as reference information, and a calibration process for correcting the reference information based on the detected values of the shift position sensor and the rotational speed sensor is configured to be executable.

That is, by switching the control device to the calibration processing mode and performing the calibration process of the detected values, the correlation between the target rotational speed and the inclination plate angle of each hydrostatic stepless speed change device is corrected. Therefore, even if a detection error occurs due to the assembling error of each hydrostatic stepless speed change device and the sensor, or a change over time, the detection accuracy can be maintained satisfactorily, thereby maintaining the shifting accuracy of the work vehicle accurately. Can be.

Other features and advantages and effects of the features will be apparent from reading the following description with reference to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a work vehicle according to the present invention will be described below with reference to the drawings on the basis of a combine as an example of a farm worker.

[First Embodiment]

Overall configuration and transmission structure of combine

1 shows the entire side of the combine. This combine combines the harvesting conveying apparatus 3 which harvests the crop planted in the front part of the traveling body 2 which drives by a pair of left and right crawler-type traveling apparatuses 1R, 1L, and conveys it toward the rear. It is constructed by connecting to the elevator. The traveling body 2 includes a threshing apparatus 4 for receiving harvested crops from the harvesting conveying apparatus 3 and performing threshing and sorting treatment, and a grain tank 5 for storing grains from the threshing apparatus 4. Is mounted. The boarding driving part 6 is formed in the front part of the grain tank 5.

As shown in Fig. 2 and Fig. 3, the combine's electric system includes a linear continuously variable transmission 7 capable of high and low speed shifting in a straight traveling state, and a traveling device positioned on the turning center side at the time of turning driving. The swing continuously variable transmission 8 which can shift the traveling speed at a high and low speed, and the mission case 9 which inputs the power from each of these continuously variable transmissions 7 and 8 and outputs the power to the left and right traveling devices 1R and 1L are outputted. Equipped.

The linear continuously variable transmission 7 and the swing continuously variable transmission 8 are variable hydraulic pumps 7A, 8A driven by power from an engine mounted on a vehicle body of a combine, and the variable hydraulic pumps 7A, 8A. It is comprised by the hydrostatic continuously variable transmission HST of the well-known structure comprised by the pair with the hydraulic motors 7B and 8B which are rotationally driven by the supply oil from (). In addition, the power of the engine is transmitted to the transmission shaft 12 of the variable hydraulic pumps 7A and 8A via the transmission belt 10 and the transmission pulley 11.

In the mission case 9, an output shaft 20 of the straight continuously variable transmission 7 and an output shaft 21 of the swing continuously variable transmission 8 are inserted therein, and both output shafts 20 are inserted therein. 21 is transmitted to the left and right pair of traveling devices 1R and 1L, while the power from the output shaft 20 of the linear continuously variable transmission 7 is transmitted to the mowing conveying device 3. It is. Further, the left output gear 21a and the right output gear 21b are fixed to the output shaft 21 of the swing continuously variable transmission 8.

A pair of output gears 20a and 20b for sub-shifting and an output gear 20c for harvesting section drive are fixedly attached to the output shaft 20 of the linear continuously variable transmission 7. The small transmission gear 22a and the large diameter gear 22b, which are always engaged with the output gears 20a and 20b, are supported by the secondary transmission shaft 22 so as to be rotatable relative to each other. The sub transmission shift gear 22d which integrally rotates with the sub transmission shaft 22 in the intermediate position is externally fitted so as to be slidable in the axial center direction. By sliding the sub gear shift gear 22d, a sub transmission device capable of shifting operation in two stages is provided. In addition, the output gear 22e is fixedly attached to the sub transmission shaft 22, and the center gear 24 integrally provided on the support shaft 23 with respect to the output gear 22e is always engaged. It is installed.

In the support shaft 23, the transmission-driven state for the straight line which transmits the shift output of the continuously variable transmission 7 straight to both sides to which the center gear 24 is fitted to each of the pair of left and right traveling devices 1L and 1R, the straight endless The transmission state of the left turning which transmits the transmission output of the transmission to the traveling device on the right side, and the transmission output of the swinging continuously variable transmission to the traveling device on the left side, and the transmission output of the straight continuously variable transmission to the traveling device on the left side. Transmission state switching means (A) which is transmitted, and which can switch to the transmission state of the right turning which transmits the speed change output of the said continuously variable transmission to the right traveling device is provided.

This electric state switching means A is provided in the power transmission system between each continuously variable transmission 7 and 8 and each traveling apparatus 1L and 1R. In response to the straight command of the turning lever 56 (an example of the turning command means), the motorized state switching means A transmits the power from the straight continuously variable transmission 7 by the control device H to each traveling device 1L. , In response to the straight-line transmission state to be transmitted to 1R and the turning command from the turning lever 56, transmits the power from the straight endless transmission 7 to the traveling device outside of the turning by the control device H, Moreover, it is comprised so that switching is possible between the turning electric states which transmit the power from the said turning continuously variable transmission 8 to the traveling apparatus of a turning inside.

This electric state switching means (A) is provided with the left outer peripheral gear part 25a which always engaged with the left output gear 21a, and the right outer peripheral gear part 25b which always engaged with the right output gear 21b. Left and right pair of left and right pair of multi-plate friction clutches (an example of swing clutch) 25 and 25 and a pair of left and right engagement clutches formed between both side surfaces of the center gear 24 and the shift gears 26 opposed thereto. (An example of a straight clutch) 27 and 27 are comprised. And the left clutch which can be switched in the state which interrupts the transmission between the turning continuously variable transmission 8 and the left traveling apparatus 1L by the left friction clutch 25 is comprised, and the turning endless clutch 25 is comprised by the right friction clutch 25 The right clutch which can be switched in the state which interrupts the transmission between the transmission 8 and the right traveling apparatus 1R is comprised.

The left and right shift gears 26 can be shifted in the direction of the rotational axis, and can be switched to a state in which the engagement clutch 27 is engaged and transmission is engaged and the engagement clutch 27 is not engaged so that the transmission is interrupted. It is composed. Moreover, the friction plate in the shift gear 26 is comprised so that shifting movement is possible with respect to the main-body part of the shift gear 26, The multi-plate friction clutch 25 is carried out in the electrically interrupted state of the engagement clutch 27. It is comprised so that switching can be carried out by the state which the pressure contact enters and the transmission which the multiplate friction clutch 25 does not press-contact.

That is, the power transmission to the pair of right and left traveling apparatuses 1L and 1R transmits the power from the straight endless speed change apparatus 7 in the state where transmission is engaged with the engagement clutch 27. On the other hand, the power from the turning continuously variable transmission 8 is transmitted in the state where the electric transmission which the friction clutch 25 pressed-in entered. If both the engagement clutch 27 and the friction clutch 25 are in an electrically shut off state, power is not transmitted from any of the straight continuously variable transmission 7 and the turning continuously variable transmission 8.

The left and right shift gears 26 and 26 are pressed in a state where transmission is engaged with the engagement clutches 27 and 27 engaged by the pressing force by the pressing springs 29 and 29, respectively. The engagement clutches 27 and 27 are operated by shifting each of the left and right shift gears 26 and 26 to the shutoff hydraulic cylinders (an example of a straight actuator) 31L and 31R against the pressing force by the pressing springs 29 and 29. The switch is configured to be switched to a state in which the motor is not engaged. And the operation | movement of this hydraulic cylinder 31L, 31R for interruption | blocking is performed by switching operation of the solenoid valve 63,64 for blocking as shown in FIG. In this electric shut-off state, the friction clutches 25 and 25 press-contact by shifting the friction plates in the shift gear 26 with steering hydraulic cylinders (an example of the turning actuator) 30L and 30R. Switching operation becomes possible in this state. The power is transmitted from the shift gear 26 to the pair of left and right traveling devices via the final gear 35. The shift gear 26 is configured to mesh with the relay gear 34 of the electric system to the traveling device at all times even when the engagement clutch 27 is engaged or not engaged.

The linear continuously variable transmission device 7 is configured to be steplessly shifted from the neutral position in each of the forward rotation direction and the reverse rotation direction. The boarding driver 6 is provided with a manually operated shift operation tool 14 (an example of speed command means) for operating the straight continuously variable transmission 7. The shift operation tool 14 is configured to be able to swing by manual operation over a predetermined front and rear operation range in the front and rear directions. Then, as shown in Fig. 3, the straight inclination plate for the variable hydraulic pump 7A (an example of the workpiece of the linear continuously variable transmission 7) 13 is a hydraulic servo mechanism SV (an example of the servo means). It is connected to the shift operation tool 14 via the following. And it is comprised so that the output state of the hydraulic-motor 7B side may be changed steplessly by changing the position (angle) of the straight inclination plate 13 based on the operation instruction | movement of the shifting operation tool 14. That is, if there is a manual operation with respect to the shift operation tool 14, it is set as the structure which can operate a shift operation lightly by the assist by the action of the hydraulic servo mechanism SV with respect to the operation.

In addition, the servo mechanism includes two types of servo mechanisms, a mechanically controlled servo mechanism and an electronically controlled servo mechanism, but the hydraulic servo mechanism SV as described above is a kind of a mechanically controlled servo mechanism. Such mechanical control has an advantage that, for example, even when the control device breaks down, at least a gas stop is possible if the linear continuously variable transmission is shifted to neutral by a mechanical servo means.

Then, as shown in Fig. 5, when the shift operation tool 14 is in the neutral region and the neutral state is instructed, the straight inclination plate 13 is in the neutral state, and the hydraulic motor 7B does not rotate but is stopped. maintain. If the command from the shift operation tool 14 is a shift command to the forward speed increasing side or the reverse speed increasing side, the angle of the straight inclination plate 13 is moved by the hydraulic servo mechanism SV according to this command in the forward rotation direction (forward speed increasing direction). ) Or in the reverse rotation direction (reverse speed increasing direction) in accordance with the command amount by the shift operation tool 14 in a stepless manner by hydraulic pressure, and the hydraulic motor 7B is rotated in the forward direction or at the speed according to the command. The gear shifting operation is configured to rotate in the reverse rotation direction.

On the other hand, the swing continuously variable transmission device 8 is also configured to be steplessly shifted in each of the forward rotation direction and the reverse rotation direction in the same manner as the straight continuously variable transmission device 7. However, the swing continuously variable transmission 8 is not shifted by manual operation, and the swinging inclination plate 15 of the variable hydraulic pump 8A (an example of the work piece of the swing continuously variable transmission 8) is hydraulic. It is linked with the turning operation mechanism 16 (an example of a shift control means). The swing operation mechanism 16 is configured to change the output speed of the hydraulic motor 8B by changing the position (angle) of the inclined plate 15 steplessly. As shown in Fig. 3, the swing operation mechanism 16 is an example of a reciprocating type hydraulic cylinder 17 (shift actuator) which is linked to a swing inclined plate 15 in the swing continuously variable transmission device 8 (as shown in Fig. 3). ) And a hydraulic control unit (VU) for switching and operating the supply / discharge state of the hydraulic oil for the transmission hydraulic cylinder (17). The shift hydraulic cylinder 17 is constituted of a reciprocating type which can be operated in a forward direction and a reverse direction from a neutral position, and is pressed back to a neutral position by a pressing force of a pair of left and right springs 17a and 17b to be built in. It is composed.

Configuration of Hydraulic Control Unit (UV)

As shown in Fig. 4, the hydraulic control unit VU uses a hydraulic pilot control valve 36 for controlling the hydraulic pressure supply state in order to drive the transmission hydraulic cylinder 17 in the forward or reverse direction from the neutral shift position. Equipped. The control valve 36 includes a spool 37 operable to move to a forward output position moved forward from a neutral position and a reverse output position moved backward from the neutral shift position, and the spool 37 is moved to the neutral position. It consists of a pair of coil springs 38 and 39 as pressurization means for return pressurization, and the relief valve 49 for pilot flow paths.

In addition, the control valve 36 is a pressure-only rotary unit 40 for supplying hydraulic oil for moving the spool 37 in the forward direction and a reverse rotational pressure for supplying hydraulic oil for moving the spool 37 in the reverse direction. The operation part 41 is provided. The control valve 36 further includes a pilot pressure control solenoid solenoid valve 42 for controlling the supply state of the hydraulic oil to the pressure regulating unit 40 for rotation, and a supply state of the hydraulic oil to the pressure regulating unit 41 for reverse rotation. The reverse pressure solenoid valve 43 for controlling the pilot pressure to be controlled is provided so as to be switchable to a supply state for supplying hydraulic oil and to a discharge state for discharging the hydraulic oil, and to return to the discharged state.

That is, the pair of pilot pressure control solenoid valves 42 and 43 stop the supply state of supplying the hydraulic oil supplied from the hydraulic pump (not shown) to the respective pressure operation units 40 and 41 and the supply from the hydraulic pump. It is comprised by the 2-position switch type solenoid valve which can switch to the 2 position of the discharge state which connects the pressure operation parts 40 and 41 to the drain path 44. These pilot pressure control solenoid valves 42 and 43 are configured to be pressurized to the discharged state by the springs 45 and 46, and are energized by the solenoids 47 and 48 to excite the springs 45, In response to the pressing force of 46), the valve body is operated to switch to the supply state. Therefore, these pilot pressure control solenoid valves 42 and 43 are always in the discharged state when the energization is stopped, and maintains the state.

In addition, the control valve 36 is provided with a pair of output ports OP1 and OP2 which are separately connected to a pair of hydraulic oil chambers 17A and 17B of the transmission hydraulic cylinder 17, respectively. In the neutral position as described above, each of the pair of output ports OP1 and OP2 is configured such that it is not connected to any one of the input port IP and the discharge port DP. Therefore, the shift hydraulic cylinder 17 will be in the state which maintains the shift position at that time as it is.

Then, when the spool 37 is in the forward output position, one forward output connected to the forward operating hydraulic oil chamber 17A of the speed change hydraulic cylinder 17 among the pair of output ports OP1 and OP2. The port 0P1 is connected to the input port IP, and the reverse output port OP2 connected to the hydraulic oil chamber 17B for reverse operation of the transmission hydraulic cylinder 17 is connected to the discharge port DP. Becomes Therefore, the shift hydraulic cylinder 17 is moved and operated in the forward direction (forward speed increasing direction).

Further, when the spool 37 is in the reverse output position, the forward output port OP1 is connected to the discharge port DP, and the reverse output port OP2 is connected to the input port IP. It becomes a state. Therefore, the shift hydraulic cylinder 17 is moved and operated in the reverse direction (reverse speed increasing direction).

As illustrated in Fig. 5, in the continuously variable transmissions 7 and 8, when the shift positions of the inclined plates 13 and 15 are in a neutral region having a predetermined width including the straight command position N, the shift output (Running Speed) becomes 0. When the shift positions of the inclined plates 13 and 15 are rotated in the predetermined direction from the neutral region, the traveling speed in the forward direction is increased steplessly. When the inclined plates 13 and 15 are operated in a direction opposite to the predetermined direction from the neutral region, the traveling speed in the reverse direction is increased in stepless speed.

The boarding driver 6 commands a left turn adjacent to the straight command position where the turning lever 56 commands the straight and the straight command position, and is set in the perspective direction with respect to the straight command position. Moving to the range and moving away from the straight command position, the left turn command range commanding the lower target speed and the right turn command adjacent to the straight command position are commanded, and the setting range is set in the perspective direction to the straight command position. It is provided so that movement operation is possible over the right turning command range which instructs a low target speed as it moves and moves away from a straight command position.

As shown in FIG. 3, the turning lever sensor 57 (operation position detection means) which consists of a rotary potentiometer which detects the straight operation position of the swing lever 56, and the swing operation position (the amount of movement from a straight command position). As an example, a rotation sensor 58 for detecting the output rotational speed of each of the pair of continuously variable transmissions 7 and 8 by counting the number of teeth of the output gear 22e and the left output gear 21a. 59) (an example of the speed detecting means) and the potentiometer type linear shift position sensor 60 (an example of the shift position detecting means) for detecting the inclined plate angle of the straight inclined plate 13 of the straight continuously variable transmission 7 ), A potentiometer-type swing position sensor 61 (an example of the shift position detecting means) for detecting the inclination plate angle of the swing continuously variable transmission device 8, and a mode for steplessly switching to the three modes to describe the swing mode described later. Switching volume (an example of mode command means) 62 It is provided. Moreover, the control apparatus H using a microcomputer which controls the operation | movement of the turning operation mechanism 16, the steering hydraulic cylinders 30R, 30L, and the shutoff hydraulic cylinders 30R, 31L based on these input information. (An example of the speed control means and the control means for switching the running state) is provided. In addition, although the rotation sensor 59 is provided in the left output gear 21a in FIG. 2, you may install in the right output gear 21b and count this number instead.

The linear shift position sensor 60 outputs a voltage corresponding to the angle (hardness position) of the straight inclination plate 13 in the straight endless speed changer 7, and the voltage is A / D converted to detect the straight line. Value is input to the control device H. The swing shift position sensor 61 outputs a voltage corresponding to the angle (hardness position) of the swing inclined plate 15 in the swing continuously variable transmission device 8. The voltage is A / D converted to detect the swing. It is configured to be input to the control device H as a value.

Traveling device by the control device H

As shown in the flowchart of Fig. 6, when the swing lever 56 is in the neutral position (YES branch in step # 1), it is configured to execute the straight control process for traveling straight (step # 5). That is, the rotation sensor which shifts the linear continuously variable transmission 7 so that it may become the traveling speed commanded by the speed change operation tool 14, and also detects the speed of the rotary continuously variable transmission 8 to the continuous continuously variable transmission 7. It is comprised so that the straight-line control process of shifting operation may be performed so that it may become the same speed as the detection speed of 58, 59.

At this time, the continuously variable speed control apparatus so that the speed change operation speed for shifting the swing continuously variable transmission device 8 so as to be the same speed as the detection speed of the rotation sensors 58 and 59 becomes the traveling speed commanded from the shift operation port 14. In the state which makes (7) shift larger than the shift operation speed which shift-shifts, it is comprised so that the swing continuously variable transmission device 8 may be shifted. That is, when the turning lever 56 is commanded to switch from turning to straight, the straight endless speed change gear 7 is shifted on the basis of the command speed from the shift operation tool 14, but is turned by the straight control process. The continuously variable transmission 8 is shifted so as to be the same as the detection speed of the straight continuously variable transmission 7 obtained by the rotation sensor 58, and this shifting operation causes the swing continuously variable transmission 8 to operate at the commanded speed. The speed is higher than the speed of shifting.

On the other hand, when the turning lever 56 is rotated to either of the left and right sides from the neutral position (No branch in step # 1), and the turning direction is right (No branch in step # 2), the electric state switching means ( A) operates the right shutoff hydraulic cylinder 31R and the right turning hydraulic cylinder 30R to operate the right steering hydraulic cylinder to transmit the shifting power of the turning continuously variable transmission 8 to the right traveling device 1R. Switch to the electric transmission state (step # 3). On the contrary, if the turning direction is left (the "Yes" branch in step # 2), the electric state switching means A activates the left shut hydraulic cylinder 31L and the left steering hydraulic cylinder 30L, It is comprised so that it may be switched to the left turning transmission state which transmits the shifting power of the turning continuously variable transmission 8 to the left traveling apparatus 1R (step # 4).

Then, the target of the swing continuously variable transmission apparatus is such that the speed ratio of both rotational speeds when the rotational directions of the left and right traveling apparatuses 1R and 1L are the same is the speed ratio corresponding to the turning radius commanded by the turning lever 56. It is configured to execute the swing control process for obtaining the shift position.

As shown in Fig. 7, the relationship between the amount of movement in the direction away from the straight command position in the swing command operating region of the swing lever 56 and the speed ratio corresponding to the swing radius corresponds to the quadratic function. It is memorized in (H). On the other hand, the target shift position, i.e., the target inclined plate position, of the swing continuously variable transmission 8 is obtained from the function of the linear detection value from the linear shift position sensor 60 and the relationship as shown in FIG. Then, the shift operation is performed by controlling the operation of the swing operation mechanism 16 so that the swing detection value from the swing shift position sensor 61 becomes the target shift value. In addition, the speed change position of the straight continuously variable transmission 7 is adjusted by manual operation with respect to the shift lever 14.

A mode switching volume 62 is provided for switching the relationship between the amount of movement from the straight command position of the swing lever 56 and the speed of each traveling device 1R, 1L via the control device H. When the moving amount is the maximum amount MAX, the switching volume 62 stops the traveling device on the inside of the swing inside, in the "turning mode", which causes the traveling device on the inside of the swing to decelerate than the traveling device on the outside of the swing and runs in the same direction. The driving state of each of the traveling devices 1R and 1L can be switched between the &quot; pivot swing mode &quot; and the &quot; spin swing mode &quot; for driving the traveling directions of both traveling devices 1R and 1L in opposite directions. have. When the mode switching volume 62 switches the respective turning modes, when the speed of the traveling device on the outside of the turning is constant, the speed of the traveling device on the inside of the turning is controlled by the control device H. It becomes a relation of a quadratic function with respect to the movement amount from a straight command position, and it is comprised so that the decrease amount of the said speed may become large as said movement amount becomes large.

The line L1 in Fig. 7 represents the speed of the straight-side continuously variable transmission as a reference, the line L2 represents the change in the target rotational speed in the "full swing mode", and the line L3 is the target in the "pivot swing mode". The change in the rotational speed is shown, and the line L4 represents the change in the target rotational speed in the &quot; spin turning mode &quot;, so that the turning mode designated by the mode switching volume 62 is selected. In the "full swing mode" indicated by the line L2, when the swing lever 56 is operated to the maximum operating position, the swing inside traveling device decelerates to about 1/3 of the travel speed V of the opposite travel device. The change characteristic of the speed ratio of the left and right traveling apparatuses 1R and 1L with respect to the operation position of the lever 56 is preset. In the "pivot swing mode" indicated by the line L3, when the swing lever 56 is operated to the maximum operating position, the swing lever 56 is operated with respect to the operating position of the swing lever 56 so as to decelerate until the traveling speed of the traveling device inside the swing becomes zero. The speed ratios of the left and right traveling apparatuses 1R and 1L are preset. In addition, in the "spin turning mode" shown by the line L4, when the turning lever 56 is operated to the maximum operation position, the traveling speed of the traveling device of the turning inside is opposite to the driving rotation direction of the opposite traveling device, on the opposite side. The speed ratio of the left and right traveling apparatuses 1R and 1L to the operating position of the swing lever 56 is set in advance so as to be the same speed as the traveling apparatus.

When shifting the swing continuously variable transmission 8, the operation of the swing operation mechanism 16 is controlled as follows. For example, when shifting the continuously variable transmission 8 in the forward speed increasing direction with the operation of the turning lever 56, the operation of moving the spool 37 in the control valve 36 to the forward output position is performed. Let's do it. Specifically, the pulse current which turns on and off at every set period is supplied to the solenoid 47 in the pilot pressure control solenoid valve 42 with respect to the pressure exclusive operation part 40 for rotation, and the duty ratio Therefore, the solenoid valve 42 is switched to supply state and discharge state. As a result, the spool 37 is moved and manipulated against the pressing force of the spring 39 by the electromagnetic force, and moves to the forward output position. When the swing continuously variable transmission 8 is shifted in the reverse speed increasing direction, the spool 37 in the control valve 36 is moved to the reverse output position, but at this time, the pilot for the reverse rotation pressure operating unit 41 is operated. The pressure control solenoid valve 43 is controlled in the same manner.

When the output rotational speed of the swing continuously variable transmission 8 becomes the target rotational speed by the speed increasing operation, the spool 37 is moved to the neutral position. As a result, the hydraulic oil is not discharged from the shift hydraulic cylinder 17, and the shift hydraulic cylinder 17 maintains the shift position at that time. In addition, even in the case of holding in the reverse holding position, the same processing is performed in this forward holding position.

Second Embodiment

Hereinafter, although 2nd Embodiment of the turning control apparatus of the work vehicle which concerns on this invention is described, since the basic structure is the same as that of the said 1st Embodiment, the same code | symbol is attached | subjected to 1st Embodiment about the same structure, and description is abbreviate | omitted.

As shown in Fig. 8, in the present embodiment, a three-contact mode switching switch (mode command) for switching to three different turning modes ("full swing mode", "pivot swing mode" and "spin swing mode"). One example of the means) 71 and when the mode switching switch 71 is switched to the "spin swing mode", the relationship between the operating position of the swing lever 56 and the target swing state can be artificially changed and set. The turning state setter (an example of turning form changing means) 72 which is present is provided.

That is, in this embodiment, instead of the mode switching volume 62 of 1st Embodiment, when the movement amount from the straight command position of the turning lever 56 is the maximum amount MAX by the mode switching switch 71, it is the inside of a turning inside. "Turn-turn mode" to decelerate the traveling device from the outside of the turning device and run in the same direction, "Pivot turning mode" to stop the turning device inside the turning direction, and the driving directions of the both traveling devices 1R and 1L to be reversed. The driving state of each said traveling apparatus 1R, 1L is switchable between the "spin turning modes" which are made to drive | running by speed. When switching to the "spin turning mode" by this mode switching switch 71, the speed between both traveling apparatuses 1R and 1L with respect to the turning operation position of the turning lever 56 by the turning state setter 72 is carried out. Change the nature of the rate change.

In this embodiment, the process of obtaining a target speed change position is performed as follows. As shown in Fig. 9, the line L1 in Fig. 9 represents the speed of the straight-side continuously variable transmission as a reference, the line L2 represents the change in the target rotational speed in the "full swing mode", and the line L3 represents the "pivot". Change in the target rotational speed in the &quot; turning mode &quot;, and the line L4 shows a change in the target rotational speed in the &quot; spin turning mode &quot;, and the turning mode designated by the turning mode switching switch 71 is selected. . In addition, in the "slewing mode" indicated by the line L2, when the turning lever 56 is operated to the maximum operating position, the traveling device inside the swing is about 1/3 the speed of the traveling speed V of the opposite traveling device. The change characteristic of the speed ratio of the left-right traveling apparatuses 1R and 1L with respect to the operation position of the turning lever 56 is preset before it decelerates to In the "pivot swing mode" indicated by the line L3, when the swing lever 56 is operated to the maximum operating position, the swing lever 56 is operated with respect to the operating position of the swing lever 56 so as to decelerate until the traveling speed of the traveling device inside the swing becomes zero. The speed ratios of the left and right traveling apparatuses 1R and 1L are preset. In addition, in the "spin turning mode" shown by the line L4, when the turning lever 56 is operated to the maximum operation position, the traveling speed of the traveling device of the turning inside will be opposite to the drive rotation direction of the opposite traveling device in the reverse rotation direction. The speed ratio of the left and right traveling apparatuses 1R and 1L to the operating position of the turning lever 56 is set in advance so as to decelerate to a speed of about 1/3 of the traveling speed V of the traveling apparatus.

As shown in Fig. 10, the swing state setter 72 maintains the change in the deceleration amount of the traveling speed of the swing-side crawler traveling device with respect to the amount of operation of the swing lever 56 in a straight state by adjusting the volume or the like. In addition, it is possible to change and adjust the operation position (point P in Fig. 10) of the swing lever 56 at the time of the second swing state to an arbitrary position, and to control the amount of operation of the swing lever 56. The change in the deceleration amount of the traveling speed of the swing-side crawler traveling device may be switched from a linear state to an arc shape as shown in FIG.

[Third Embodiment]

Hereinafter, although 3rd Embodiment of the work vehicle turning control apparatus which concerns on this invention is described, since the basic structure is the same as that of the said 1st Embodiment, the same code | symbol is attached | subjected to 1st Embodiment about the same structure, and description is abbreviate | omitted.

As shown in Fig. 12, in the present embodiment, as in the second embodiment, the mode switching switch 71 of the three contact points is used to change the "slewing mode", "pivot turning mode" and "spin turning mode". You can switch to the swing mode. In addition, in this embodiment, the change amount of the turning force made into the target with respect to the change per unit amount of the operation position of the turning lever 56 in the small side operating range W1, and the width | variety of the operating area in the said small side operating range W1. Two potentiometer-type artificially operated adjustment operation knobs 73a and 73b, which are configured to perform the increase and decrease adjustment for each of the two, are provided.

In the present embodiment, a process for obtaining the target shift position is performed as follows. In Fig. 13, the line L1 represents the speed of the straight-side continuously variable transmission as a reference, the line L2 represents the change of the target rotational speed in the "turning mode", and the line L3 represents the "pivot turning mode". The change in the target rotational speed in Fig. 2 shows a change in the target rotational speed in the &quot; spin turning mode &quot;, and the turning mode designated by the mode switching switch 71 is selected. However, even if this mode switching switch is operated for switching, the correlation of the said small side operating range W1 does not change. Then, when the deceleration amount adjusting operation knob 73a is operated, the end position (point P in Fig. 13) of the small-side operating range W1 can be moved and adjusted in the vehicle speed increasing / decreasing direction (Y direction), and the adjusting operation for changing the operation width is performed. When the sphere 73b is operated, it is set as the structure which can move and adjust the end position (point P of FIG. 13) of the small side operation range W1 to an operation position change direction (X direction).

Each line shown in FIG. 14 is different from that in FIG. 13 by switching the mode switching switch 71 so as to correlate the small-side operation range W1 in a state having a width of a predetermined interval in the vehicle speed increasing / decreasing direction (Y direction). It is configured to change the relationship.

As shown in Fig. 15, in the small side operating range W1 and the contralateral operating range W2, different lines are formed for each mode, and the small side operating range W1, the contralateral operating range W2, and the joint portion thereof are formed. It is comprised so that it may change smoothly, drawing a secondary curve in the form which changes gradually with respect to the change per unit amount of the operation position of the turning lever 56, as the movement amount of the turning lever 56 over the whole range included. .

As described above, in the present embodiment, when the mode switching switch 7l is switched to each turning mode, the small-side operation range W1 having a small amount of movement from the straight command position of the turning lever 56 by the control device H is shown. Is set such that the amount of reduction in the speed ratio between the two traveling devices with respect to the unit movement amount is greater in the contrary operation range W2 than in the movement. The movement amount on the boundary between the two operation ranges W1 and W2 and the speed of the traveling device on the inside of the swing are configured to be changeable by the adjustment operation ports 73a and 73b.

[4th Embodiment]

Hereinafter, although 4th Embodiment of the turning control apparatus of the work vehicle which concerns on this invention is described, since the basic structure is the same as that of said 1st Embodiment, the same code | symbol is attached | subjected to 1st Embodiment about the same structure, and description is abbreviate | omitted.

Referring to FIG. 16, the turning force setting means 74 in this embodiment is comprised by the area | region selection switch 74a and the adjustment operation tool 74b.

In the present embodiment, a process for obtaining the target shift position is performed as follows. As shown in Fig. 17, the maximum adjustable speed range indicated by the line L5 from the state of speed difference 0 indicated by the line L1 as the entire adjustable adjustable range for increasing and decreasing the turning force when the turning lever 56 is operated to the maximum operating position. It is configured to be change-adjustable to a state, and such a characteristic is set in advance, and this whole adjustable range is divided into three areas A, B, and C, and any one of these areas A, B, and C It is comprised so that an area may be switched by the three-contact type area | region selection switch 74 to switch. And the adjustment operation tool 74b is comprised so that the turning force at the time of being operated to the maximum operation position in the area | region selected by the area | region selection switch 74 is changeable and adjustable.

[Fifth Embodiment]

Hereinafter, although 5th Embodiment of the turning control apparatus of the work vehicle which concerns on this invention is described, since the basic structure is the same as that of the said 1st Embodiment, the same code | symbol is attached | subjected to 1st Embodiment about the same structure, and description is abbreviate | omitted.

In this embodiment, as shown in Fig. 18, rotation speed sensors 83 and 84 (both of shift output detecting means) for detecting rotation speeds of the respective hydraulic motors 7B and 8B are provided, and the hydraulic cylinder ( The control device H using a microcomputer for controlling the operations of the 17 and 81 stores the correlation between the target positions of the inclined plates 13 and 15 with respect to the target values of the respective rotational speeds as reference information, and the straight shift position On the basis of the detected values of the sensor 60, the swing shift position sensor 61 (all examples of the shift position detecting means), and the rotational speed sensors 83 and 84, a calibration process for correcting this reference information can be executed. It is composed. Hereinafter, this calibration process is explained in full detail.

Moreover, the shift lever sensor 82 which detects the operation position of the shift operation tool 14, and the swing lever sensor 57 which detects the operation position of the swing lever 56 are provided, respectively, and they are all a rotary potentiometer. Consists of.

Moving operation is possible within the predetermined operation range including the stop command position for commanding the travel stop by the shift operation tool 14 and the shift lever sensor 82, and the straight travel is carried out as the movement operation amount from the stop command position increases. The vehicle speed command means S1 that commands the target vehicle speed in the state is configured. Further, the turning lever 56 and the turning lever sensor 57 can be changed into a straight command state for moving the vehicle body straight and a turning command state for turning the vehicle body, and in the turning command state, the turning direction and turning of the vehicle body. The turning state command means S2 which instructs a radius is comprised.

Then, the control device H calculates the target rotational speeds of the linear and swing continuously variable transmissions 7, 8 based on the detection information of the shift lever sensor 82 and the swing lever sensor 57. And set the target shift positions corresponding to the respective target rotational speeds thus obtained, and set the hydraulic pressure for each shift so that the detected values of the straight forward and swing shift position sensors 60 and 61 become the respective target shift positions. It is configured to execute travel control for controlling the operation of the cylinders 17 and 81.

Therefore, using the control device H, the straight forward and swing continuously variable transmissions are adapted to correspond to the traveling state commanded based on the respective instruction information of the vehicle speed command means S1 and the swing state command means S2. Computation means 100 for obtaining target rotational speeds of 7, 8 and 8 and travel control means 101 for executing the travel control are configured. Moreover, target rotational speed instruction means M0 which instructs each target rotational speed of a pair of continuously variable transmissions by the said vehicle speed instruction means S1, the said turning state instruction means S2, and the said calculation means 100. This is made up.

That is, the control device H is operated to a neutral position in which the shift operation tool 14 is positioned almost in the middle of the operable range while the turning lever 56 is operated to the straight command position and straight is commanded. When the vehicle is stopped, the driving speed from the neutral position to the forward side is increased steplessly, and the operation speed from the neutral position to the reverse side is increased steplessly. In addition, when the shift operation tool 14 is fixed at a predetermined position, the operation of the straight hydraulic cylinder 81 is controlled so that the vehicle body travels straight at the target traveling speed commanded at the position.

Then, the speed change control device 7 is shifted so as to be the speed commanded by the speed change operation tool 14, and the turning stepless speed change device 8 is made to be the same speed as the speed of the speed control device 7. It is configured to operate shifting.

At this time, the traveling operation speed commanded by the shift operation tool 14 is a shift operation speed for shifting the swing inclined plate 15 of the swing continuously variable transmission 8 so as to be the same speed as the speed of the continuous continuously variable transmission 7. The swing continuously variable transmission 8 is shifted in a state in which the speed of the straight inclination plate 13 of the linear continuously variable transmission 7 is made larger than the shift operation speed for shifting the speed.

When the shift lever 56 is operated at a predetermined speed while the shift operation tool 14 is operated, the control device H swings the swing lever 56 from one of the straight command positions to one of the swing command ranges. The operation of each of the hydraulic cylinders 17 and 81 is controlled so that the turning radius becomes smaller as it is operated toward the side away from the straight command position.

When the turning run is commanded, the control is executed so that the turning lever 56 is in a turning state of decreasing the turning radius as the turning lever 56 is operated toward the side away from the straight command position in the turning command range, but the turning lever 56 at the time of performing the turning operation. Basically, the relationship between the operation position in the said turning command range and the target turning state is changed into three types of different turning modes. That is, a three-contact mode switching switch 71 is provided for switching the swing mode as described above into three swing modes of "full swing mode", "pivot swing mode", and "spin swing mode". The switching instruction by the mode switching switch 71 is given to the control apparatus H, and the control apparatus H is comprised so that the turning mode may be switched based on the switching instruction.

On the other hand, the characteristic of the target vehicle speed change with respect to the operation position of the shift operation tool 14 is preset and stored, and the control device H is the speed of the left and right traveling apparatuses by the operation of the turning lever 56 as described above. Based on the characteristics of the ratio and the target vehicle speed determined at the operation position of the shift operation tool 14, a process for obtaining the target rotational speeds of the straight and swing continuously variable transmissions 7 and 8 is executed. Then, as shown in Fig. 20, the target rotational speed obtained as described above on the basis of the reference information set for obtaining the target shift positions of the straight and turning inclined plates 13 and 15 corresponding to each target rotational speed. The target shift positions of the straight and swing inclined plates 13 and 15 respectively corresponding to the straight and swing inclined plates 13 and 15 detected by the straight and swing shift position sensors 60 and 61, respectively. The corresponding hydraulic cylinders 17 and 81 are controlled so that the shift position of the respective target shift positions becomes. The existence of two characteristic lines in Fig. 20 is set separately by correcting on the basis of the measured values of the straight position and swing shift position sensors 60 and 61, respectively. The detection value correction processing will be described later in detail.

The control apparatus H is comprised so that switching can be made into the "normal control mode" which performs a running control as the control mode, and the "adjustment mode" which performs a detection value correction process, and turns on the switching command switch which is not shown in figure. The control mode can be commanded by turning on the power supply while the power supply is turned on. This switching command switch cannot be operated by an ordinary user, and the &quot; normal control mode &quot; is commanded during normal use.

On the basis of the detection information of the respective rotational speed sensors 83 and 84 as the detection value correction process, the straight and the turning hydraulic pressure are applied so that each of the linear and the swing continuously variable transmissions 7 and 8 becomes the reference rotation state. The cylinders 17 and 81 are automatically operated and based on the detected values of the linear and swing shifting position sensors 60 and 61 when the straight and swing continuously variable transmissions respectively become the reference rotation state. 20, the correlation (reference information) of the target shift position with respect to the target rotational speed as shown in FIG. Further, in the detection value correcting process, each of the straight forward and swing continuously variable transmissions as the reference rotation state is a high speed reference rotation state which is the maximum speed or a speed close thereto and a low speed reference rotation which is the zero speed or the speed close thereto. In each of the states, the detection values of the straight forward and swing shift position sensors 13 and 15 are obtained, and the reference information is corrected based on the detected values of the respective states. In addition, such a detection value correction process is performed by the inspector or the maintenance worker of an inspection process in the step before shipment in a combine manufacturing process, or when the shift position sensors 46 and 47 are broken or replaced with a new one. It is not an ordinary user performing farm work.

Hereinafter, the specific control operation in "adjustment mode" is demonstrated. As shown in Fig. 21, in the &quot; normal control mode &quot;, the running control is executed when there is a start command (steps # 20, 21, 22, 23). Then, when the power is turned on while the switching command switch is turned on, the adjustment mode is set. When the preset starting condition is established, the detection value correction process is executed (steps # 24, 25, 26). As the above starting conditions, the respective conditions of starting the engine, operating the accelerator set value to the maximum value, and switching the sub transmission to the neutral state are satisfied. Therefore, if these conditions are not satisfied, the control apparatus H will not switch to adjustment mode.

Next, the detection value correction process at the time of calculating | requiring two detection values for correcting the correlation at the time of changing from a neutral position in one shift position sensor to a forward direction is demonstrated as an example.

In addition, these processes are respectively performed four times in total separately in correspondence with the operation in each of the forward direction and the reverse direction for each of the straight forward and swing shifting position sensors 46 and 47. As shown in FIG. 22 and FIG. 23, if the detected value (neutral value) of the neutral position in the target shift position sensor is not read, the value is read (step # 31, 32). Incidentally, in the state where the shift operation is not performed, the inclined plates 13 and 15 are always pressed back to the neutral position by the return pressing force. After reading the neutral value, the shift hydraulic cylinder 17 (or 81) is driven to automatically move and operate the inclined plate 13 (or 15) in the forward direction at the maximum speed (step # 33, 34).

In addition, the output speed is monitored by the rotational speed sensor 83 (or 84) every set unit time to monitor the output change, and the shifting output detected by the rotational speed sensor 83 (or 84) is When the state which does not change for 1 second is detected, it judges that the forward side shown by the point P1 in FIG. 19 is a value corresponding to the maximum change position which can be mechanically displaced, and stops the movement operation along a forward direction, and the hydraulic cylinder 17 ( Or 81 to automatically move and operate the inclined plate 13 (or 15) toward the reverse direction at the minimum speed (steps # 35, 36). At this time, on the basis of the detected value of the rotational speed sensor 83 (or 84), it is detected whether the shift output is changed, and the pulses of the respective solenoid valves 42 and 43 of the hydraulic cylinder 17 (or 81) are detected. If it is judged that the duty ratio is too small and shifting is not performed, the duty ratio is changed to a slightly larger value (steps # 37, 38). Then, when the speed change output (rotational speed) detected by the rotational speed sensor 83 (or 84) becomes the maximum output (maximum rotational speed) (point P2 in Fig. 19) in the speed change adjustable range, the shift position at that time The detection value of the sensor 60 (or 61) is read out as a maximum output value (step # 39, 40). The state at this time corresponds to the high speed side reference rotation state.

Next, if the detection value (0 speed value) of the 0 speed position in the shift position sensor 60 (or 61) is not read (step # 41), the inclined plate 13 (or 15) is reversed at the minimum speed. An operation to automatically move and move toward the direction is executed, but if the detected value is greater than or equal to the setting and the difference to the zero speed position is large, the operation is moved to the maximum speed (steps # 42, 43, 44). Also at this time, it is detected based on the detected value of the rotational speed sensor 83 (or 84), and it is detected whether the shift ratio is too small and the duty ratio is set to a slightly larger value if it is determined that the shift is not performed. (Step # 45, 46). When zero speed is detected as the shift output (rotation speed) detected by the rotation speed sensor (at point P3 in Fig. 19), the detected value of the shift position sensor 60 (or 61) at that time is read as the zero speed value. The process ends (steps # 47, 48). The read state of the zero speed value corresponds to the low speed side reference rotation state.

Then, the reference information is corrected to an appropriate value so as to correspond to the detected values of the two points P2 and P3 thus detected, and the reference information is stored. In addition, the value of the intermediate position between each said 2 points is prescribed | regulated by linear interpolation. Such processing is performed four times in total separately in correspondence to the operation in each of the forward direction and the backward direction for each of the shift position sensors 60 and 61, respectively, and the two lines L1 and L2 in FIG. As shown in the figure, corresponding to different actual detection values, the left and right pairs of shift position sensors 60 and 61 are set as different calibration information, respectively, so that they are stored.

[Sixth Embodiment]

Hereinafter, although 6th Embodiment of the swing control apparatus of the work vehicle which concerns on this invention is described, since the basic structure is the same as that of the said 1st Embodiment, the same code | symbol is attached | subjected to 1st Embodiment about the same structure, and description is abbreviate | omitted.

In this embodiment, when the spool 37 of the control valve 36 in the said hydraulic control unit VU moves to a neutral position as shown in FIG. 8, a pair of output ports OP1 and OP2 will be made. Since all are comprised so that it may be connected to discharge port DP, it differs from the structure of 1st Embodiment which is not connected to discharge port DP in the neutral position. This configuration will be described in more detail below.

In the neutral position of the control valve 36 as described above, each of the pair of output ports OP1 and OP2 is connected to the discharge port DP, and the transmission hydraulic cylinder 17 returns to the neutral position.

When shifting the swing continuously variable transmission 8, the operation of the swing operation mechanism 16 is controlled as follows. For example, when shifting the continuously variable transmission 8 in the forward speed-up direction with the operation of the turning lever 56, the spool 37 in the control valve 36 is moved to a forward output position. . Specifically, the solenoid 47 of the pilot pressure control solenoid valve 42 to the pressure exclusive operation section 40 is supplied with a pulse current of repeating on and off at every set cycle, and the duty ratio is adjusted. Adjust the value to a larger value than the set value. As a result, the spool 37 is moved by the electromagnetic force against the pressing force of the spring 39 and moved to the forward output position. When the swing continuously variable transmission 8 is shifted in the reverse speed increasing direction, the spool 37 in the control valve 36 is moved to the reverse output position, but at this time, the pilot for the reverse rotational pressure operating portion 41 is operated. The pressure control solenoid valve 43 is controlled in the same manner.

When the output rotational speed of the swing continuously variable transmission 8 becomes the target rotational speed by the speed increasing operation, the spool 37 is moved to the forward holding position. That is, the duty ratio of the pulse current with respect to the solenoid 47 is changed and adjusted so that it may become a maintenance duty ratio smaller than the said set value. As a result, the electromagnetic force of the solenoid 47 and the pressing force of the spring 39 are balanced so that the spool 37 is held at the position. As a result, the shift hydraulic cylinder 17 maintains the shift position at that time as it is. In addition, also in the case of holding at the reverse holding position, the same processing is performed at this forward holding position.

When the swing continuously variable transmission 8 is returned to the neutral position, the solenoids 47 and 48 for the respective pilot pressure control solenoid valves 42 and 43 are switched to the energized state, respectively, and the spool 37 is spring-loaded. Return to the neutral position by the pressing force of 38 and 39). In this neutral position, all the hydraulic oil chambers 17A and 17B of the transmission hydraulic cylinder 17 are in an oil drainage state, and the transmission hydraulic cylinder 17 is pressed against the springs 17a and 17b and swings. The neutral restoring force of the straight inclination plate 15 of the continuously variable transmission 8 is returned to the neutral position.

As mentioned above, although each embodiment of the work vehicle which concerns on this invention was described, this invention is not limited to these structures.

For example, the mode switching volume 62 as the mode command means and the mode switching switch 71 at the three contact points may be applied to other embodiments, and other mode command means capable of switching a turning mode such as a dial to three modes. May be employed. Moreover, the control apparatus H is used using the turning state setter 72 of 2nd Embodiment, the adjustment operation tool 73a, 73b of 3rd Embodiment, or the turning force setting means 74 of 4th Embodiment. By this means, other speed change characteristics such as those shown in addition to the above embodiments may be set.

[Other Embodiments]

Moreover, the following forms can also be employ | adopted for the work vehicle which concerns on this invention.

(1) In the first to fourth and sixth embodiments, the speed control means is exemplified as including a speed control means for shifting operation by operating a mechanical servo means and a shift actuator. Instead of this, the speed control means may be provided with shift control means for shifting operation by operating two shift actuators. In this case, the speed change operation is performed so that the swing continuously variable transmission 8 becomes the speed commanded by the speed change operation tool 14, and the straight continuously variable transmission 7 has the same speed as that of the swing continuously variable transmission 8. The shifting operation may be configured as much as possible.

(2) In the fifth embodiment, the continuously variable transmission device 7 is operated such that the swing continuously variable transmission device 8 is shifted so as to shift at a speed commanded by the shift operation tool 14. Although it is comprised so that a speed change operation may be made to be the same speed as the speed of (5), the speed change control apparatus will be made so that a shifting speed change control apparatus 8 may change speed so that it may become the speed commanded by the speed change operation tool 14 as described above (1). You may comprise (7) so that a speed change operation may be made so that it may become the same speed as the speed of the turning continuously variable transmission 8.

(3) In the above embodiment, the control valve is configured to be hydraulic pilot operated in a state in which the spool is moved and operated by pilot hydraulic pressure, and the hydraulic oil as a working fluid is supplied to the pressure control unit for forward rotation or the pressure control unit for reverse rotation. Illustrated. Instead, it may be operated by using another fluid such as operated by air pressure. The spool may be moved and operated by electromagnetic force using a solenoid or the like, without being limited to using an operating fluid.

(4) In the said embodiment, it was set as the structure which detects the moving operation amount of a turning lever by a potentiometer, and performs a stepless speed change operation of a turning continuously variable transmission apparatus with operation of a turning lever. Instead of this, for example, the displacement of the swing operation amount of the swing lever may be detected step by step with a plurality of switches, or may be implemented in various forms such as a configuration in which the swing radius is changed at a time of pressing the swing command switch. .

(5) Although the above embodiment has exemplified that the control valve is applied to a shift operation apparatus for shifting the swing continuously variable transmission device, the control valve is used for switching control of a reciprocating controlled object to be controlled, for example, a hydraulic cylinder. If it is, it is not limited to a shift control apparatus, It can apply to any apparatus.

(6) In the said embodiment, the left and right pair of engagement clutches 27 and 27 were illustrated as a straight clutch. Instead of this, the straight clutch may be constituted by a multi-plate friction clutch. Further, the engagement clutch may be configured as a single unit, and the connection clutch may be configured to be disconnected from the right and left in conjunction with the operation of the friction clutches (orbiting clutches) 25 and 25.

(7) In the said embodiment, the target speed was calculated | required from the inclination plate position of the turning inclination plate 15 as a process which controls the operation | movement of the turning operation mechanism 16 so that the turning continuously variable transmission 8 may become a turning target speed. Although the example is illustrated, instead, the target speed may be obtained from the output rotational speed of the rotation sensor 59.

(8) In the said embodiment, the combine was illustrated as a vehicle with a shift control apparatus. However, the work vehicle of the present invention is not limited to a combine, and may be a tractor or other agricultural work machine or a construction work vehicle.

According to the present invention, a work vehicle with improved operability can be provided.

Claims (9)

Left and right traveling device (1R, 1L), Engine 3, A linear continuously variable transmission 7 and a swing continuously variable transmission 8 for shifting power from the engine, A speed command means 14 for commanding a traveling speed of the aircraft, It is a work vehicle provided with the turning instruction means 56 which instructs turning to either the straight or left and right sides of a base body, Speed detecting means for obtaining the speed of either the continuously variable transmission 7 or the continuously variable transmission 8 and the continuously variable transmission 8, and a control device H for controlling the shift operation of the continuously variable transmission. Become, When the turning command means is commanded to switch straight from the turning, The one continuously variable transmission is shifted on the basis of the command speed from the speed command means 14, The other continuously variable transmission is shifted so as to be equal to the speed of the one continuously variable transmission obtained by the speed detecting means by the control device H, and this shift operation causes the one continuously variable transmission to A work vehicle characterized by being carried out at a speed larger than the speed shifted to the command speed. The method of claim 1, wherein the one continuously variable transmission is the straight continuously variable transmission (7), the other continuously variable transmission is the pivoting continuously variable transmission (8), An electric state switching means (A) is provided in the power transmission system between each continuously variable transmission and each traveling device, and this electric state switching means is provided. In response to the straight line command of the turning command means 56, a straight forward electric state for transmitting power from the straight endless speed change device 7 to the respective traveling devices by the control device H, and the turning command means. In response to the turning command of the control device H, the power from the straight continuously variable transmission is transmitted to the traveling device outside the swing, and the power from the swing continuously variable transmission 8 is transferred to the inside of the swing. A work vehicle, wherein the work vehicle is configured to be switchable between an electric state for swing to be transmitted to the vehicle. The linear clutch 27 which controls the power from the said linear continuously variable transmission, and the linear actuators 31R and 31L which operate the operation | movement which disconnects this linear clutch. And a swing clutch (25) for regulating power from the swing continuously variable transmission device, and a swing actuator (30R, 30L) for operating to disconnect the swing clutch. 2. The hydraulic continuously variable transmission as claimed in claim 1, wherein the continuously variable transmission includes hydraulic pumps 7A and 8A and hydraulic motors 7B and 8B. A work vehicle characterized in that the output of a corresponding hydraulic motor can be changed steplessly by changing the positions of the inclined plates (13, 15) steplessly. The mode according to any one of claims 1 to 4, wherein the relationship between the amount of movement from the straight command position of the turning command means 56 and the speed of each traveling device is switched via the control device H. Command means 62, 71 are further provided, When the movement amount is the maximum amount MAX by the mode command means, the full swing mode in which the traveling device inside the swing is decelerated from the traveling device outside the swing and traveling in the same direction, and the pivot swing mode in which the traveling device inside the swing is stopped. And a driving state of each of the traveling devices can be switched between the spin turning modes for driving the traveling directions of both traveling devices in opposite directions. The speed of the traveling device on the inside of the turning is controlled by the control device H when the speed of the traveling device on the outside of the turning is constant when switching to the respective turning modes by the mode command means. And a reduction function of the speed as the movement amount becomes larger as the relation of the quadratic function with respect to the movement amount from the straight command position of the means (56). The swing mode change means according to claim 5, wherein the swing mode change means for changing the change characteristic of the speed ratio between the two traveling devices with respect to the swing operation position of the swing command means 56 when the mode command means is switched to the spin swing mode. A work vehicle, characterized in that 72 are provided. The small-side operation range W1 according to claim 5, wherein the amount of movement from the straight command position of the swing command means 56 is small by the control device H when the mode command means is switched to the respective swing modes. Is set such that the amount of reduction in the speed ratio between the two traveling devices with respect to the unit movement amount is greater in the contralateral operation range W2 where the movement amount is larger than And a control operation mechanism (73a, 73b) for setting the movement amount at the boundary between the two operation ranges and the speed of the traveling device inside the swing. A pair of shift position sensors (60, 61) for detecting the position of each of said inclined plates (13, 15), and rotational speed sensors (83, 84) for detecting the rotational speed of said hydraulic motors. Is installed, The control device H stores the correlation of the target position of each inclined plate with the target value of the respective rotational speeds as reference information, and corrects the reference information based on the detected values of the shift position sensor and the rotational speed sensor. A work vehicle, characterized by being configured to be capable of performing a calibration process.

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