JP5368129B2 - Work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working vehicle performing a turn excellent in improved work efficiency and work uniformity. <P>SOLUTION: The working vehicle includes an angle detection means 51 detecting a rotation angle of a steering wheel 7 making a straight motion direction as reference, an angle-threshold setting means 61 setting a threshold A of the rotation angle of the steering wheel 7 that is the reference of the start and/or end of control of working speed and turning speed, a turning-vehicle-speed setting means 62 setting the set-turning-vehicle speed V when the steering wheel 7 is positioned at the threshold A of the rotation angle or more, a transmission actuator 24 of a hydraulic continuously variable transmission 23, and a control means 81. The control means 81 operates the transmission actuator 24 to make the speed the set-turning-vehicle speed V when the value detected by the angle detection means 51 becomes the threshold A of the rotation angle or more, and controls the transmission actuator 24 to make the speed the working speed when the value detected by the angle detection means 51 is less than the threshold A of the rotation angle. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle speed control technique for a work vehicle.

  A conventional work vehicle such as a tractor is connected to a work machine that performs a desired work at the rear of the vehicle body, and works while traveling on a farm field. Therefore, the operator must travel the work vehicle while confirming the work and performing various operations. Further, when the work vehicle reaches the end of the field, the work machine turns and turns without turning the work machine to turn.

  The work vehicle shown in Patent Document 1 includes switching means for decelerating the vehicle speed based on the detection result of the steering wheel turning angle. When the riding tractor reaches the headland in the field, the tilling device (working machine) detects the turning operation of the steering handle by performing the turning operation with the steering handle, and the switching means detects the riding tractor. The vehicle speed is automatically reduced. In other words, when changing the direction at the field headland where the tillage work is carried out by reciprocating, if the turning angle (rotation angle) of the handle exceeds the set rotation, the work implement is raised to decrease the vehicle speed, The vehicle speed of the passenger tractor is decelerated at substantially the same timing, and the direction change operation in the high speed tillage work and the simplification of the headland tillage process can be easily performed. However, even if it is effective in the case of high-speed tillage work, the work speed varies depending on the work type, the ability and preference of the operator. Also, normally, in work with a low work speed, such as ditching work and tilling work, it is more efficient to turn faster than the work speed and turn faster. Further, in a work having a high work speed such as a roll baler work, a fertilizer work, and a mower, a stable turn can be performed by lowering the turn speed than the work speed.

  In other words, in a work vehicle that performs various operations, in order to obtain a desired turning speed when turning on a headland or the like, it is necessary to perform a specific operation like a general work vehicle, which is inefficient. There was a problem of being correct.

JP 2003-225004 A

  The present invention has been made in view of the above-described problems, and a problem to be solved is to reduce a specific operation during turning, and to easily achieve a desired turning speed and / or engine speed. It is an object of the present invention to provide a work vehicle that can turn and control with excellent work efficiency and uniform work.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, a work vehicle comprising an engine, a hydraulic continuously variable transmission that shifts and transmits rotational power generated by the engine to drive wheels, and a steering handle that performs a turning operation. The angle detection means for detecting the rotation angle of the steering handle with reference to the straight traveling direction, and the threshold value of the rotation angle of the steering handle for starting and / or ending the control of the working speed and the turning speed are set. An angle threshold setting means, a turning vehicle speed setting means for setting a setting turning vehicle speed when the steering handle is turned to be equal to or greater than the turning angle threshold, a speed change actuator of the hydraulic continuously variable transmission, and a control means And when the detected value by the angle detection means becomes equal to or greater than the threshold value of the turning angle, the control means operates the speed change actuator so as to reach the set turning vehicle speed, When the detection value by the detection means is less than the threshold value of the turning angle, the shift actuator is controlled to reach the working speed, and the set turning vehicle speed set by the turning vehicle speed setting means is made to make a U-turn on a headland or the like. It is possible to set the direction changing vehicle speed, which is the vehicle speed when changing directions, and the avoidance turning vehicle speed, which is the vehicle speed when avoiding obstacles or traveling along the terrain .

  In Claim 2, the rotation speed setting means which sets the setting engine rotation speed when rotating the steering handle more than the threshold value of the rotation angle, and the rotation speed change actuator which adjusts the rotation speed of the engine, The rotation speed change actuator and the rotation speed setting means are connected to the control means, and the control means changes the rotation speed when the steering handle is rotated more than a threshold value of the rotation angle. The actuator is controlled so as to reach the set engine speed.

According to a third aspect of the present invention, the control means includes a rotation speed threshold value setting means for calculating a rotation speed of the steering handle from a value detected by the angle detection means and setting a threshold value of the rotation speed of the steering handle. Is connected to the turning speed threshold setting means, and when the turning speed of the steering handle is less than the threshold, the turning vehicle speed is controlled to be the working vehicle speed, and the turning speed of the steering handle is equal to or higher than the threshold. Then, control is performed so as to achieve the turning vehicle speed.

  According to a fourth aspect of the present invention, when the rotational speed of the steering handle is less than a threshold value, the control means controls the engine rotational speed so as to be the engine rotational speed at the time of work, and rotates the steering handle. When the moving speed is equal to or higher than a threshold value, the engine speed is controlled to become the set engine speed.

According to a fifth aspect of the present invention, the control means includes a rotation speed threshold value setting means for calculating a rotation speed of the steering handle from a value detected by the angle detection means and setting a threshold value of the rotation speed of the steering handle. Is connected to the turning speed threshold setting means, and the turning vehicle speed becomes the turning vehicle speed when the turning speed of the steering handle is not less than the threshold and the turning angle of the steering handle is not less than the threshold. If the turning speed of the steering handle is less than a threshold value and the turning angle of the steering handle is greater than or equal to the threshold value, the turning vehicle speed is controlled to be an avoiding turning vehicle speed.

  According to a sixth aspect of the invention, there is provided a rotation speed setting means for setting a set engine rotation speed when the steering handle is positioned above a threshold of the rotation angle, and the rotation speed setting means allows the set turning rotation speed to The control means controls the engine rotational speed to be the engine rotational speed during work when the rotational speed of the steering handle is less than a threshold, and the rotational speed of the steering handle When is equal to or greater than a threshold value, the engine speed is controlled to be the set turning speed.

  According to a seventh aspect of the present invention, the set rotation angle set by the angle threshold setting means can be changed from straight to turn and from turn to straight.

  The control means does not control the speed change actuator and the rotation speed changing actuator when the vehicle speed is equal to or higher than a specific vehicle speed.

  According to a ninth aspect of the invention, there is provided mode change means for setting whether to control the speed change actuator and the rotation speed change actuator.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, when the work vehicle is turning, the vehicle speed is different from the work vehicle speed, so that the work vehicle can be turned with high work efficiency without performing a special speed change operation. The reproducibility to the work vehicle speed at the end of turning can be maintained, and the work can be made uniform.

  In claim 2, by controlling the engine speed, useless rotation is suppressed and fuel efficiency is improved. In addition, work efficiency is ensured by controlling the vehicle speed so as not to decrease even when the engine speed is decreased.

  According to the third aspect of the present invention, in the avoidance turn where the rotation speed of the operation handle is slow, the vehicle speed control is not executed and the inadvertent speed change is prevented, and the vehicle speed control is executed in the direction change turning in the headland or the like. By doing so, efficient turning can be performed.

  According to the fourth aspect of the present invention, in avoidance turning where the rotation speed of the operation handle is slow, control of the engine speed is not executed, and an inadvertent change in the engine speed is prevented, and turning in a headland is changed. Then, efficient turning can be performed by controlling the engine speed.

  According to the fifth aspect, since the turning speed varies depending on the turning speed and the turning angle of the steering handle, it is possible to perform efficient turning such as when making a small turn or a large turn during work turning.

  According to the sixth aspect of the present invention, since the engine speed is different depending on the rotation speed and the rotation angle of the steering handle, an efficient turn can be performed, for example, when a small turn or a large turn is made during a work turn.

  According to the seventh aspect of the present invention, if an appropriate threshold value is set during straight turn to straight turn and straight turn to straight forward, the work finish is improved, the labor of reworking is saved, and the work efficiency is good.

  According to the eighth aspect of the present invention, the control is not performed when the straight-ahead vehicle speed is high, so that the vehicle is not decelerated suddenly at the start of turning, and the safety is ensured without sudden acceleration when traveling straight after turning.

  According to the ninth aspect, when the vehicle speed and / or the engine speed is increased / decreased by the operator's intention, the desired mode can be easily changed and the operation can be easily performed.

The figure which showed the control block circuit which concerns on 1st Example and 3rd Example of this invention. The figure which showed the control flowchart which concerns on 1st Example of this invention. The figure which showed the control block circuit based on 2nd Example of this invention. The figure which similarly showed the control flowchart. The figure which showed vehicle speed and engine speed control. The figure which showed the threshold value change of vehicle speed and engine speed control. The figure which showed the control flowchart which concerns on 3rd Example of this invention. The side view which showed the work vehicle which concerns on embodiment of this invention.

  Next, the overall configuration of the work vehicle 100 according to the embodiment of the present invention will be described with reference to FIG. The work vehicle 100 includes front wheels 1 and 1 supported on both front portions of the airframe and rear wheels 2 and 2 supported on both rear portions of the airframe. Further, an engine 21 serving as a prime mover is disposed inside the hood 6 at the front of the machine body, and a cabin 9 is disposed behind the hood 6. A steering handle 7 is provided in the front part of the cabin 9, a display panel 5 is arranged in front of the steering handle 7, and a seat 8 is arranged behind the steering handle 7. In addition, a main transmission lever 3, a sub transmission lever 4, and the like project from the side of the seat 8, and a forward / reverse switching lever is disposed on the side of the steering column of the steering handle 7. A brake pedal, a main clutch pedal, a differential lock pedal, and the like are disposed on the step below the front of the seat 8.

  As shown in FIGS. 1 and 8, a transmission housing is disposed at the rear of the engine 21, and a transmission case 11 containing a hydraulic continuously variable transmission 23 is disposed at the rear of the transmission housing. After shifting the power from the vehicle, it is transmitted and driven to the rear wheels 2 and 2, and the driving force can be transmitted to the front wheels 1 and 1 simultaneously through the four-wheel drive switching mechanism. Further, the driving force of the engine 21 is transmitted to the PTO shaft 12 protruding from the rear end of the transmission case 11, and is mounted from the PTO shaft 12 to the rear end of the machine body via a universal joint or the like (not shown) via a work implement mounting device. The work machine is configured to be driven.

  Furthermore, the turning control device 50 according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 8. In the following description, “work travel” means travel in a straight direction. The turning control device 50 mainly includes an angle detection means 51, a vehicle speed detection means 52, a rotation speed detection means 53, an angle threshold setting means 61, a turning vehicle speed setting means 62, a rotation speed setting means 63, a mode change means 71, and a control means 81. Prepare. The turning control device 50 controls the vehicle speed and the engine speed during turning while mainly based on the value obtained by detecting the rotation angle of the steering handle 7.

  The angle detection means 51 is a means for detecting the rotation angle of the steering handle 7 and detects the rotation angle of the steering handle 7 with reference to straight traveling using a potentiometer, a rotary encoder, or the like.

  The vehicle speed detection means 52 is a means for detecting the traveling vehicle speed of the work vehicle 100 and calculates the vehicle speed by detecting the rotational speed of the axle of the rear wheel 2 using a rotational speed sensor or the like.

  The rotational speed detection means 53 is a means for detecting the engine rotational speed, and detects the rotational speed of a flywheel (not shown) in the vicinity of the engine 21 using a magnetic pickup type sensor, a rotary encoder, or the like. It is.

  The angle threshold value setting means 61 arbitrarily sets a threshold value of the rotation angle of the steering handle 7 when starting the turning control of the vehicle speed and the engine speed and ending the turning control (hereinafter simply referred to as a turning angle threshold value). It is a means that can be set. The angle threshold setting means 61 is configured by a dial type switch or the like that can be adjusted by turning operation. However, the rotation angle of the steering handle 7 when starting the turning control and the rotation angle of the steering handle 7 when ending the turning control can be set separately, and a plurality of types of setting angles can be set. Make it possible.

  The turning vehicle speed setting means 62 is a means for arbitrarily setting the vehicle speed during turning. The turning vehicle speed setting means 62 is constituted by a dial type switch or the like that can be adjusted by turning operation.

  The rotation speed setting means 63 is a means for arbitrarily setting the engine speed during turning. The rotation speed setting means 63 is configured by a dial type switch or the like that can be adjusted by rotating operation.

  The mode changing means 71 is a means for setting whether or not to perform turning control, that is, control for setting the vehicle speed at the time of turning and / or whether to set the engine speed to be set at the time of turning, such as a switch or a dial. Consists of. When the control is performed by the mode changing unit 71 (control “ON”), the control mode of the display panel 5 provided in the cabin 9 is lit and displayed, and the mode changing unit 71 does not perform the control (control). In the case of “OFF”), the display on the display panel 5 is turned off.

  The hydraulic continuously variable transmission 23 includes a variable displacement hydraulic pump and a fixed or variable displacement hydraulic motor. The angle of the swash plate of the hydraulic pump or the hydraulic motor is displaced by the shift actuator 24 to change the output rotation. It is a device that changes speed. The speed change actuator 24 is constituted by a motor, a solenoid or the like and is connected to the control means 81 so that it can continuously change to the turning vehicle speed set by the turning vehicle speed setting means 62.

  The rotational speed changing actuator 22 is a means for controlling the engine rotational speed, and can control the rotational speed of the engine 21 by changing the fuel injection amount of the fuel injection device. In addition, the rotation speed changing actuator 22 is operated so that the detection value from the rotation speed detection means 53 is fed back to the set rotation speed.

  The control means 81 is connected to the angle detection means 51, the vehicle speed detection means 52, the rotation speed detection means 53, the angle threshold value setting means 61, the turning vehicle speed setting means 62, the rotation speed setting means 63, and the mode change means 71, respectively. The speed change actuator 24, the rotation speed changing actuator 22, and the display panel 5 are respectively connected. The control means 81 performs vehicle speed control, engine speed control, and display panel control. The control means 81 is connected to a storage device such as a CPU (Central Processing Unit), ROM, RAM, and HDD via a bus.

  The vehicle speed control, engine speed control, and display panel control in the turning control device 50 according to the first embodiment of the present invention will be described in the case where the work vehicle 100 is performing normal tillage work (rotary work). 1 and 2, the operation state is determined by the mode changing means 71 to determine whether or not the turning control mode, that is, the turning control device 50 is “ON” (S1).

  If the turning control mode is not entered in step S1, that is, if the mode change means 71 is “OFF”, the display panel 5 displays that effect (lights off) (S9). When the turning control is not performed, the operator operates at a speed corresponding to the operation of the main transmission lever 3 (sub transmission lever 4), the accelerator lever, and the like.

  In step S1, if the turning control mode, that is, if the mode changing means 71 is “ON”, the display panel 5 displays that effect (lights up) and makes the operator recognize that it is in the turning control mode (S2).

  Then, the turning angle threshold A set by the angle threshold setting means 61 for setting the turning angle of the steering handle 7 for starting and ending the turning control, and the turning vehicle speed setting means for setting the vehicle speed during turning control. The control means 81 acquires the set turning vehicle speed V set by 62 and the set engine speed X set by the speed setting means 63 for setting the engine speed at the time of turning control, and stores it in the storage device ( S3).

  Next, the vehicle speed detection means 52 detects the straight vehicle speed, that is, the working vehicle speed Vr, and the rotation speed detection means 53 detects the engine rotation speed during straight travel, that is, the work engine speed Xr. Then, the control means 81 acquires the work vehicle speed Vr and the work engine speed Xr and stores them in the storage device (S4).

  Next, the angle detection means 51 detects the rotation angle AtAt of the steering handle 7 based on the straight traveling direction. It is determined whether or not the rotation angle At is greater than or equal to the rotation angle threshold A previously acquired in step S3 (S5). In other words, the above-described determination is a determination as to whether or not the vehicle is turning. If the vehicle does not start turning, the tilling operation is continued at the work vehicle speed Vr and the work engine speed Xr.

  If it is determined in step S5 that the vehicle is turning, the actual vehicle speed and engine speed are changed to the set turning vehicle speed V and the set engine speed X acquired in step S3 (S6). That is, the control means 81 controls the hydraulic continuously variable transmission 23 through the speed change actuator 24 so as to achieve the set turning vehicle speed V, and the engine via the speed change actuator 22 so as to become the set engine speed X. 21 is controlled.

  Next, it is determined whether or not the actual rotation angle At of the steering handle 7 is less than the rotation angle threshold A previously acquired in step S3 (S7). In other words, the above-described determination is a determination as to whether or not the cornering has ended. If the turning is not finished, the set turning vehicle speed V and the set engine speed X controlled in step S6 are continued.

  If it is determined in step S7 that the turn is over, the actual vehicle speed and engine speed are changed to the work vehicle speed Vr and work engine speed Xr acquired in step S4 (S8). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so that the work vehicle speed Vr is reached, and the engine 21 via the speed change actuator 22 so as to become the work engine speed Xr. To control.

  In this way, the work vehicle 100 turns at the set turning vehicle speed V and the set engine speed X that are set in advance at the time of turning, with the turning angle threshold A of the steering handle 7 being set as a threshold, and at the time of straight running (at the time of working). Automatically controls to perform work travel at the work vehicle speed Vr and the work engine speed Xr before turning.

  Next, an example of increase / decrease in vehicle speed and engine speed during a turn depending on the type of work will be described with reference to FIG. As described above, the operator sets the set turning vehicle speed V (km / h) and the set engine speed X (rpm). When working at low speed or extremely low speed, such as hollowing out or trencher work, the speed of the vehicle is set to increase while turning and the engine speed decreases as shown by the solid line in FIG. Work efficiency can be improved. In other words, the working vehicle speed Vr is increased during turning to the set turning vehicle speed V, and the working engine speed Xr is decreased to the set engine speed X. In addition, when working at high speed, such as browsing or mower, the stable turning by setting the vehicle speed to be reduced during turning and the engine speed to be lowered as shown by the dashed line in FIG. Can do. In other words, the work vehicle speed Vr is decelerated during turning and becomes the set turning vehicle speed V, and the work engine speed Xr decreases and becomes the set engine speed X.

  Further, both the vehicle speed and the engine speed at the time of turning described above are controlled. However, the present invention is not limited to this, and it is possible to control either the vehicle speed or the engine speed. Yes, you can also set the mode.

  Next, a second embodiment based on the first embodiment of the present invention will be described with reference to FIG. 3, FIG. 4, and FIG. In addition, the same reference numerals are assigned to those common to the first embodiment, and description thereof is omitted.

  The work vehicle 100 travels in a substantially straight line direction (goes straight) and performs work. Normally, the work vehicle 100 turns by turning the steering handle 7 before the work vehicle 100 reaches an obstacle such as a water channel or a headland. In general rotary work or the like, the turning speed of the steering handle 7 is higher than that of avoiding an obstacle or operating along a bend of a saddle. The rotation speed tends to increase. A turning control device 250 capable of controlling different turning speeds and turning engine speeds depending on the turning speed of the steering handle 7 will be described below. For the sake of explanation, the turning operation of the steering handle 7 when avoiding an obstacle or traveling along the terrain is referred to as “avoidance turning”, and when making a U-turn or turning in a headland etc. The turning operation of the steering handle 7 is referred to as “direction changing turning”.

  The turning control device 250 of the second embodiment is configured such that the control means 81 calculates the turning speed of the steering handle 7 based on the detection value of the angle detection means 51 connected to the control means 81. Further, the rotation speed threshold value setting means 64 is connected to the control means 81.

  The rotation speed threshold value setting means 64 is a means for setting a rotation speed threshold value T of the steering handle 7, which is a threshold value for distinguishing the turning control mode from “avoidance turning” and “direction turning turning”. The rotation speed threshold value setting means 64 includes a dial switch that can be adjusted by a rotation operation.

  Below, the flow of control of the turning control device 250 according to the difference in the rotation speed of the steering handle 7 will be described.

  3 and 4, the operation state is determined by the mode changing means 71 to determine whether or not the turning control mode, that is, the turning control device 250 is “ON” (S1).

  If the turning control mode is not entered in step S1, that is, if the mode change means 71 is “OFF”, the display panel 5 does not display that fact (it remains unlit) (S9). At this time, the operator operates the main speed change lever 3 (sub speed change lever 4), the accelerator lever, etc., and turns at the set turning vehicle speed and engine speed.

  In step S1, if the turning control mode, that is, if the mode changing means 71 is "ON", the display panel 5 displays (lights up) to that effect and makes the operator recognize that it is in the turning control mode (S2). .

  Then, the rotation angle threshold A set by the angle threshold setting means 61, the first set turning vehicle speed V1 at the time of “turning turning” set by the turning vehicle speed setting means 62, and the first at the time of “avoidance turning”. A second set vehicle speed V2, a first set engine speed X1 for "turning turning" set by the speed setting means 63, a second set engine speed X2 for "avoidance turning", and a rotation speed threshold The control means 81 acquires the rotation speed threshold T set by the setting means 64 and stores it in the storage device (S23).

  Next, the vehicle speed detecting means 52 detects the straight vehicle speed, that is, the working vehicle speed Vr, and the rotation speed detecting means 53 detects the engine speed, that is, the work engine speed Xr. Then, the control means 81 acquires the work vehicle speed Vr and the work engine speed Xr (S4).

  Next, the angle detection means 51 detects the rotation angle At of the steering handle 7 based on the straight traveling direction. It is determined whether or not the rotation angle At is greater than or equal to the rotation angle threshold A previously acquired in step S23 (S5). In other words, the above-described determination is a determination as to whether or not the vehicle is turning. If the vehicle does not start turning, the tilling operation is continued at the work vehicle speed Vr and the work engine speed Xr.

  Next, based on the rotation angle At detected by the angle detection means 51, the actual handle rotation speed Tt of the steering handle 7 is calculated by the control means 81. It is determined whether or not the handle rotation speed Tt is equal to or higher than the rotation speed threshold T acquired in advance in step S23 (S25). In other words, the above-described determination is, in other words, a determination as to “turning turning” when the actual handle rotation speed Tt is equal to or higher than the rotation speed threshold T, and “avoidance turning” when it is less than the rotation speed threshold T. It is.

  If it is determined in step S5 that the turning control is started, in step S25, if the actual handle rotation speed Tt is equal to or higher than the rotation speed threshold T, it is determined that the direction is turning. The first set turning vehicle speed V1 and the first set engine speed X1 acquired in step S23 are changed (S26-1). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so as to become the first set turning vehicle speed V1, and the speed change actuator 22 so as to become the first set engine speed X1. The engine 21 is controlled via

  Next, it is determined whether or not the actual rotation angle At of the steering handle 7 is less than the rotation angle threshold A previously acquired in step S23 (S27-1). In other words, the above-described determination is a determination as to whether or not the turn-turning has ended. If the turning travel is not finished here, the first set turning vehicle speed V1 and the first set engine speed X1 changed in step S26-1 are continued.

  If it is determined in step S27-1 that the turn of turning has been completed, the actual vehicle speed and engine speed are changed to the work vehicle speed Vr and work engine speed Xr acquired in S4 (S8). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so that the work vehicle speed Vr is reached, and the engine 21 via the speed change actuator 22 so as to become the work engine speed Xr. To control.

  On the other hand, if it is determined in step S25 that the actual steering wheel rotation speed Tt is less than the rotation speed threshold value T and the avoidance turn is started, the actual vehicle speed and engine speed are acquired in step S23. The second set vehicle speed V2 and the second set engine speed X2 are changed (S26-2). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so as to become the second set vehicle speed V2, and controls the speed change actuator 22 so as to become the second set engine speed X2. The engine 21 is controlled via

  Next, it is determined whether or not the actual rotation angle At of the steering handle 7 is less than the rotation angle threshold A acquired in advance in step S23 (S27-2). In other words, the above-described determination is a determination as to whether or not the avoidance turn has ended. If the turning travel is not finished, the second set vehicle speed V2 and the second set engine speed X2 changed in step S26-2 are continued.

  If it is determined in step S27-2 that the avoidance turn has ended, the actual vehicle speed and engine speed are changed to the work vehicle speed Vr and work engine speed Xr acquired in S4 (S8). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so that the work vehicle speed Vr is reached, and the engine 21 via the speed change actuator 22 so as to become the work engine speed Xr. To control. In avoidance turning, the vehicle speed is approximately the same as or slower than the work vehicle speed Vr, and the engine is rotated carefully, and the engine speed is approximately the same as the work engine speed Xr, or a rotation is applied due to a load. It is preferable to increase the number slightly. Further, the first set turning vehicle speed V1 and the first set engine speed X1 in the “direction changing turn” are the same as those in the first embodiment. Further, in headland turning (direction turning turning), there are small turning (small turning radius) and large turning (large turning radius). In the case of turning, the turning speed of the steering handle 7 becomes slow. Since the turning speed of the large turn is faster than the turning speed of the avoiding turn, a set turning speed for determining the small turn and the large turn in the headland turn is set, and the first set turning vehicle speed V1 and the first setting are set. It is also possible to set the engine speed X1 in two more cases.

  In this way, the work vehicle 100 adds the turning angle threshold A of the steering handle 7 as a threshold for starting or ending turning control, and sets the turning speed threshold T as a threshold for controlling turning or avoiding turning. When turning, the vehicle travels with the first set turning vehicle speed V1 and the first set engine speed X1, and when avoiding turning, the second set vehicle speed V2 and the second set engine speed X2 are set. Turn around at. Further, during straight travel (during work), control is automatically performed so that work travels at the work vehicle speed Vr and work engine speed Xr before turning.

  It is also possible to configure so that the control is not actually performed during the avoidance turning. In other words, since the avoidance turn is a large turn while the work is performed, the same speed and engine speed as the work are set, and the second set vehicle speed V2 and the second set engine speed X2 described above are set in step S4. The control means 81 controls so that the values of the work vehicle speed Vr and the work engine speed Xr are obtained.

  Further, although both the vehicle speed and the engine speed at the time of turning are controlled, the present invention is not limited thereto, and it is possible to control either the vehicle speed or the engine speed.

  Next, a third embodiment based on the first embodiment of the present invention will be described with reference to FIG. 1, FIG. 7, and FIG. In addition, the same reference numerals are assigned to those common to the first embodiment, and description thereof is omitted.

  Generally, the vehicle speed of the work vehicle 100 is often different between the turning angle of the steering handle 7 when the working vehicle speed is finished and the turning angle of the steering handle 7 when starting the working vehicle speed. The angle threshold value setting means 61 can set the threshold value (rotation angle threshold value A) of the angle detection means 51 for each time from straight travel to turn and from turn to straight travel. That is, since the aircraft turns after reaching the headland and turning the steering handle 7 greatly, the turning angle threshold A of the steering handle 7 when finishing the work vehicle speed Vr is set large, and turning at the headland. When the operation is finished and the operation is started, the body is directed in the straight direction (substantially parallel to the adjacent strip), so that the turning angle threshold A of the steering handle 7 when the set turning vehicle speed V is finished is determined. Is preferably small (substantially straight). Therefore, the angle threshold value setting means 61 is set with a first rotation angle threshold value A1 corresponding to straight to turn and a second rotation angle threshold A2 corresponding to turn and straight.

  For example, in the work vehicle 100 for rotary work, when the handle is turned from the work running to the turning running, the steering handle 7 is temporarily turned to the right and turned to the first turning angle threshold A1 or more. In the case of returning the steering handle 7 from the turning traveling to the working traveling, when the steering handle 7 is rotated to the left to reach the second rotation angle threshold A2, the work vehicle speed Vr and the work engine speed Xr are obtained. (See FIG. 6).

  Vehicle speed control, engine speed control, and meter lighting control in the turning control device 350 of the third embodiment of the present invention will be described with reference to FIGS. It is assumed that the work vehicle 100 is performing normal tillage work (rotary work). Here, the operating state is determined by the mode changing means 71 to determine whether or not the turning control mode, that is, the turning control device 50 is “ON” (S1).

  If the turning control mode is not entered in step S1, that is, if the mode changing means 71 is “OFF”, the display panel 5 remains off (S9), and the operator changes the main speed change lever 3 (sub speed change lever). 4) Turn with the turning vehicle speed and engine speed set by operating the accelerator lever or the like.

  If the turning control mode, that is, the mode changing means 71 is “ON” in step S1, the display panel 5 is turned on to notify the operator that the turning control mode is set (S2).

  The first rotation angle threshold A1 and the second rotation angle threshold A2 set by the angle threshold setting means 61, the set turning vehicle speed V set by the turning vehicle speed setting means 62, and the rotation speed setting means. The control means 81 acquires the set engine speed X set by 63 and stores it in the storage device (S33).

  Next, the vehicle speed detection means 52 detects the straight-ahead vehicle speed, that is, the work vehicle speed Vr, and the rotation speed detection means 53 detects the straight-ahead engine speed, that is, the work engine speed Xr. Then, the control means 81 acquires the work vehicle speed Vr and the work engine speed Xr (S4).

  Next, the angle detection means 51 detects the rotation angle At of the steering handle 7 based on the straight traveling direction. It is determined whether or not the rotation angle At is greater than or equal to the first rotation angle threshold A1 acquired in advance in step S3 (S35). In other words, the above-described determination is a determination as to whether or not the vehicle is turning. If the vehicle does not start turning, the tilling operation is continued at the work vehicle speed Vr and the work engine speed Xr.

  If it is determined in step S5 that the vehicle is turning, the actual vehicle speed and engine speed are changed to the set turning vehicle speed V and the set engine speed X acquired in step S3 (S6). That is, the control means 81 controls the hydraulic continuously variable transmission 23 through the speed change actuator 24 so as to achieve the set turning vehicle speed V, and the engine via the speed change actuator 22 so as to become the set engine speed X. 21 is controlled.

  Next, it is determined whether or not the actual rotation angle At of the steering handle 7 is less than the second rotation angle threshold A2 acquired in advance in step S3 (S37). In other words, the above-described determination is a determination as to whether or not the cornering has ended. If the turning is not finished, the set turning vehicle speed V and the set engine speed X controlled in step S6 are continued.

  If it is determined in step S7 that the turn is over, the actual vehicle speed and engine speed are changed to the work vehicle speed Vr and work engine speed Xr acquired in step S4 (S8). That is, the control means 81 controls the hydraulic continuously variable transmission 23 via the speed change actuator 24 so that the work vehicle speed Vr is reached, and the engine 21 via the speed change actuator 22 so as to become the work engine speed Xr. To control.

  In this way, the work vehicle 100 controls the vehicle speed and the engine speed from straight to turn and from turn to straight, depending on the threshold value of the steering handle 7 (first turning angle threshold value A1, second turning angle threshold value A2). This can be done at different rotation angles.

  Another embodiment based on the above-described turning control devices 50, 250, and 350 will be described below with reference to FIGS. When the working vehicle speed Vr or the traveling speed is higher than a specific vehicle speed (set vehicle speed), the above-described vehicle speed control and engine speed control are not performed (the control means 81 is the speed change actuator 24 and the speed change actuator). 22 is not performed). With this configuration, the machine and work machine are not burdened, the operator can make a desired turn, and a stable turn is possible.

7 Steering handle 21 Engine 22 Speed change actuator 23 Hydraulic continuously variable transmission 24 Speed change actuator 51 Angle detection means 61 Angle threshold setting means 62 Turning vehicle speed setting means 63 Speed setting means 64 Rotation speed setting means 81 Control means 100 Work vehicle T Rotation speed threshold V Setting turning vehicle speed V1 First setting turning vehicle speed V2 Second setting turning speed X Setting engine speed X1 First setting engine speed X2 Second setting engine speed

Claims (9)

Engine,
A work vehicle comprising: a hydraulic continuously variable transmission that shifts and transmits rotational power generated by the engine to drive wheels; and a steering handle that performs a turning operation,
An angle detection means for detecting a rotation angle of the steering handle based on a straight traveling direction;
An angle threshold value setting means for setting a threshold value of the turning angle of the steering handle for starting and / or ending the control of the working speed and the turning speed;
A turning vehicle speed setting means for setting a set turning vehicle speed when the steering handle is rotated to be equal to or greater than a threshold value of the rotation angle;
A transmission actuator of the hydraulic continuously variable transmission;
Control means,
When the detection value by the angle detection means is equal to or greater than the threshold value of the rotation angle, the control means operates the speed change actuator so that the set turning vehicle speed is reached, and the detection value by the angle detection means is the rotation angle. If less than the threshold value, the shift actuator is controlled so as to be the working speed,
The set turning vehicle speed set by the turning vehicle speed setting means is a turning vehicle speed when the vehicle turns when making a U-turn on a headland or changing direction, avoids an obstacle, or runs along a terrain. A work vehicle characterized in that it can be set to an avoidance turning vehicle speed that is a vehicle speed at the time of driving . A rotation speed setting means for setting a set engine rotation speed when the steering handle is rotated to be equal to or greater than a threshold value of the rotation angle;
A rotational speed changing actuator for adjusting the rotational speed of the engine,
Connecting the rotation speed changing actuator and the rotation speed setting means to the control means;
The said control means controls a rotation speed change actuator so that it may become a setting engine rotation speed, if the said steering handle is rotated more than the threshold value of the said rotation angle. Work vehicle. Calculate the turning speed of the steering handle from the detection value by the angle detection means,
A rotation speed threshold setting means for setting a rotation speed threshold of the steering handle;
The control means is connected to the rotation speed threshold value setting means,
If the turning speed of the steering handle is less than the threshold, the turning vehicle speed is controlled to be the working vehicle speed,
The work vehicle according to claim 1 or 2, wherein when the turning speed of the steering handle becomes equal to or greater than a threshold value, the turning vehicle speed is controlled. The control means includes
When the rotational speed of the steering handle is less than a threshold value, the engine speed is controlled to be the engine speed during work,
The engine speed is controlled to be the set engine speed when the turning speed of the steering handle is equal to or higher than a threshold value. Work vehicle. Calculate the turning speed of the steering handle from the detection value by the angle detection means,
A rotation speed threshold setting means for setting a rotation speed threshold of the steering handle ;
The control means is connected to the rotation speed threshold value setting means,
When the turning speed of the steering handle is equal to or greater than a threshold value and the turning angle of the steering handle is equal to or greater than a threshold value, the turning vehicle speed is controlled to become the turning vehicle speed,
2. The turning vehicle speed is controlled to be an avoiding turning vehicle speed when the turning speed of the steering handle is less than a threshold value and the turning angle of the steering handle is a threshold value or more. The work vehicle according to claim 2. A rotation speed setting means for setting a set engine rotation speed when the steering handle is positioned above the rotation angle threshold;
The rotational speed setting means sets the set turning rotational speed,
The control means includes
When the rotational speed of the steering handle is less than a threshold value, the engine speed is controlled to be the engine speed during work,
The engine speed is controlled to be the set turning speed when the turning speed of the steering handle is equal to or higher than a threshold value. The work vehicle according to the item. The work vehicle according to any one of claims 1 to 4, wherein the set rotation angle set by the angle threshold setting means can be changed from straight to turn and from turn to straight. The work vehicle according to any one of claims 2 to 7 , wherein the control means does not control the speed change actuator and the rotation speed changing actuator when a vehicle speed is equal to or higher than a specific vehicle speed. The work vehicle according to any one of claims 2 to 8 , further comprising mode change means for setting whether to control the speed change actuator and the rotation speed change actuator.

Images