JP7327272B2 - work vehicle - Google Patents

Description

The present invention relates to a work vehicle such as a tractor.

Conventionally, a work vehicle such as a tractor is equipped with a speed-up switch or a deceleration switch for accelerating or decelerating during constant-speed travel, in addition to auto-cruise travel operation means for keeping travel speed constant. is known (Patent Document 1).

This conventional work vehicle rotates the trunnion shaft rotation mechanism so as to maintain the rotation angle of the trunnion shaft in the hydrostatic transmission in response to the amount of depression of the accelerator pedal when the operation means for auto-cruise travel is operated. Auto-cruise function that controls and keeps the running speed constant, and when the speed-up switch or deceleration switch is pressed for a short time within a predetermined time during the auto-cruise function, the trunnion shaft rotation mechanism is controlled. and a temporary acceleration/deceleration function for temporarily accelerating or decelerating the traveling speed of the vehicle for the predetermined time.

This conventional work vehicle also includes a memory switch that operates as follows. When the memory switch is pressed for a long time longer than a predetermined time, the current depression amount of the accelerator pedal is stored, and when the memory switch is pressed for a short time within the predetermined time, the stored depression amount is stored. Running is executed according to the Furthermore, this memory switch is lit up when it is pressed for a short time.

JP 2016-8665 A

In the above-mentioned conventional work vehicle, if you want to temporarily change the speed even when the vehicle is traveling at a constant speed by the auto-cruise function, if you press the speed increasing switch or the decelerating switch for a predetermined time, , the running speed at that time can be temporarily increased or decreased.

On the other hand, in a conventional work vehicle, when the speed during constant-speed running by the auto-cruise function is temporarily changed, the running speed at the time when the last auto-cruise function was started is temporarily stored. For the driver, it may be unclear at what time the speed when the vehicle was traveling at a constant speed was the stored speed, and what the speed was when the vehicle was accelerated or decelerated. Sometimes it was impossible to reproduce the speed because it was unknown.

In addition, in the conventional work vehicle, when the memory switch is pressed for a long time, the amount of depression of the accelerator pedal at that time is simply memorized. It is necessary to press the memory switch for a short time after memorizing it, and the amount of depression sometimes becomes unknown.

An object of the present invention is to make it easier for the driver to grasp the vehicle speed that he/she wants to store in memory while driving, and to realize continuation of driving at that vehicle speed and reproduction of driving at that vehicle speed with a simple operation. To provide a work vehicle.

The above problems of the present invention are solved by the following means.

That is, the invention according to claim 1 is
an engine (3);
an accelerator operation tool (15, 16) for adjusting the engine speed according to the operation amount;
an engine speed sensor (72) for detecting the speed of the engine (3);
It has a trunnion shaft (47) that rotates so as to adjust the inclination angle of the swash plate (45), and is a hydrostatic type non-rotating engine that outputs rotational power input from the engine (3) after steplessly changing the speed. a stepped transmission (41);
an auxiliary transmission (51) for outputting rotational power output from the continuously variable transmission (41) after shifting the speed in a plurality of stages;
a traveling vehicle body (2) that travels by receiving rotational power output from the auxiliary transmission (51);
a shaft rotation mechanism (60) for rotating the trunnion shaft (47);
A shift operation tool (23, 18) for adjusting the rotation angle of the trunnion shaft (47) by operating the shaft rotation mechanism (60) according to the amount of depression to change the vehicle speed of the traveling vehicle body (2). )and,
an angle sensor (97) for detecting the rotation angle of the trunnion shaft (47);
a vehicle speed memory button (28) which is a button capable of exhibiting a function of storing the engine speed corresponding to the vehicle speed and the rotation angle of the trunnion shaft (47), and which is turned on only while being pressed; ,
When the vehicle speed memory button (28) is pressed for a predetermined period of time or more while driving with the accelerator operation tools (15, 16) and the gear shift operation tools (23, 18) operated, the vehicle speed at that time is changed. The corresponding engine speed and the rotation angle of the trunnion shaft (47) are stored and held in a memory means (101), and the stored engine speed and the rotation angle of the trunnion shaft (47) are maintained. A first function of controlling the engine (3) and the shaft rotation mechanism (60) to run, and during running by operating the accelerator operation tool (15, 16) and the gear shift operation tool (23, 18). When the vehicle speed memory button (28) is pressed for less than a predetermined time, the engine speed and the rotation angle of the trunnion shaft (47) stored in the storage means (101) are maintained. a control device (100) having a second function for controlling said pivoting mechanism (60) to travel;
A work vehicle characterized by comprising

According to the second aspect of the invention, the control device (100) notifies by generating a sound when the engine speed and the rotation angle of the trunnion shaft (47) are stored in the first function. A work vehicle according to claim 1, characterized in that:

According to the third aspect of the present invention, the control device (100) cancels the traveling maintained at the engine speed and the rotation angle of the trunnion shaft (47) stored in the first function and the second function. 3. The work vehicle according to claim 1 or 2, wherein when the vehicle speed information stored in the storage means (101) remains, the fact that the vehicle speed information remains is indicated by lighting of an indicator. be.

According to a fourth aspect of the invention, the control device (100) stores the engine speed and the rotation angle of the trunnion shaft (47) in the storage means (101) in the first function, and The gear stage of the subtransmission (51) selected when the short press operation is performed in the second function is controlled to be stored in combination with the gear stage of the subtransmission (51) currently selected. , when the combination of the engine speed and the rotation angle of the trunnion shaft (47) stored in the storage means (101) and the shift stage of the subtransmission (51) do not match, a sound is generated. is notified by at least one of lighting of the indicator, and the shaft rotation mechanism (60) is controlled so as not to run while maintaining the rotation speed of the engine and the rotation angle of the trunnion shaft (47). A work vehicle according to any one of claims 1 to 3.

According to the fifth aspect of the invention, when the vehicle speed memory button (28) is pressed for a predetermined time or more while the vehicle is stopped, the control device (100) changes the engine speed stored in the storage means (101). 5. The work vehicle according to any one of claims 1 to 4, wherein information on the number and the rotation angle of the trunnion shaft (47) is deleted.

In the first aspect of the invention, when the vehicle speed memory button (28) is pressed for a predetermined period of time or more while the accelerator operation tool (15, 16) and the shift operation tool (23, 18) are operated, the vehicle speed memory button (28) is pressed for a long time. , the engine speed and the rotation angle of the trunnion shaft (47) at that time are stored and held in the storage means (101). Running is performed while maintaining the dynamic angle. When the vehicle speed memory button (28) is pressed for a short period of time less than a predetermined time while the accelerator operation tools (15, 16) and the gear shift operation tools (23, 18) are operated, the speed memory button (28) is stored in the storage means (101). The vehicle is driven while maintaining the engine speed and the rotation angle of the trunnion shaft (47).

As a result, according to the present invention, the driver performs the act of long-pressing the vehicle speed memory button (28) while driving, so that the driver can easily grasp the vehicle speed that he/she wants to store when driving. In addition, continuation of running at that vehicle speed or reproduction of running at that vehicle speed can be achieved by a simple operation of long-pressing or short-pressing the vehicle speed memory button (28).

According to the second aspect of the present invention, when the engine speed and the rotational angle of the trunnion shaft (47) are stored, a sound is generated to inform the user of the stored speed. It is possible to audibly recognize that the vehicle has been moved, making it easier to grasp the vehicle speed.

According to the third aspect of the present invention, when the running maintained at the engine speed and the rotation angle of the trunnion shaft (47) is canceled, the vehicle speed information stored in the storage means (101) remains. When the vehicle speed remains in the memory, the driver is notified visually that the vehicle speed he/she wants to store remains in the memory. easier.

According to the fourth aspect of the present invention, the storage means (101) stores the engine speed and the rotation angle of the trunnion shaft (47) in combination with the gear stage of the auxiliary transmission (51) selected at that time. Therefore, the vehicle speed that the driver desires to be stored can be stored for each gear position, thereby improving convenience. In addition, when the combination of the engine speed and the rotation angle of the trunnion shaft (47) stored in the storage means (101) and the gear stage of the auxiliary transmission (51) do not match, a sound is generated. is notified by at least one of lighting of the indicator, and the running is not performed while maintaining the engine speed and the rotation angle of the trunnion shaft (47). As a result, it is possible to detect that the gear stage of the sub-transmission was selected by the driver, and to prevent unexpected driving due to an unsuitable combination of vehicle speed and gear stage, thereby ensuring safety. .

According to the fifth aspect of the invention, when the vehicle speed memory button (28) is pressed for a predetermined time or longer while the vehicle is stopped, the engine speed stored in the storage means (101) and the trunnion shaft ( 47) is erased, so that if the stored vehicle speed is not suitable for some reason, the driver can change the unnecessary engine speed and the rotation of the trunnion shaft (47). It is possible to erase the information on the dynamic angle, and to prevent unnecessary use of unnecessary vehicle speed and wasteful running while maintaining the vehicle speed.

1 is a left side view of a tractor according to an embodiment of the present invention; FIG. Figure 2 is a plan view of the tractor of Figure 1; It is a power transmission diagram of a power transmission device. 1 is a schematic diagram showing the configuration and operating state of a hydrostatic continuously variable transmission; FIG. FIG. 4 is a schematic plan view showing the configuration of part of the adjustment panel; FIG. 2 is a block diagram showing a configuration of part of a control system of the tractor; FIG. FIG. 4 is a conceptual diagram showing an example of a control operation related to memory vehicle speed cruise, (A) is a conceptual diagram showing an execution example of the first function and the second function, and (B) shows an execution example including an additional configuration of the first function; It is a conceptual diagram.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a tractor 1 as an example of a work vehicle according to an embodiment of the present invention.

The tractor 1 includes a traveling vehicle body 2 in which devices such as an engine 3, a power transmission device 4, a pair of left and right front wheels 5 and a rear wheel 6, and a cockpit 7 are mounted or provided on a support frame or the like (not shown). Among them, the engine 3 is covered with a bonnet cover 11 that can be opened and closed. The power transmission device 4 includes a hydrostatic continuously variable transmission (HST: Hydraulic Static Transmission) 41, an auxiliary transmission 51, and the like, which are arranged in a transmission case 40. As shown in FIG.

In addition, the tractor 1 is a four-wheel drive (4WD) in which the rotational power of the engine 3 is transmitted to the left and right front wheels 5 and the left and right rear wheels 6 via the power transmission device 4 and the like, and the left and right rear wheels 6 are driven. The drive system can be switched between a two-wheel drive (2WD) that is transmitted and driven, and the vehicle travels in either drive system. The traveling speed (vehicle speed) of the traveling vehicle body 2 is detected by a vehicle speed sensor 92 ( FIG. 6 ), and the detection information is transmitted to the control device 100 .

Furthermore, the tractor 1 can perform desired work by mounting a work machine (not shown) such as a rotary tiller on the rear portion of the traveling vehicle body 2 via an attachment portion such as a lower link 29 . A PTO shaft 59 for outputting rotational power of the engine 3 to a working machine mounted on the traveling vehicle body 2 is provided at the rear portion of the traveling vehicle body 2 .

The operator's seat 7 has a seat portion 7a on which a driver sits and a step floor portion 7b on which the driver's feet rest when riding or driving.

A steering wheel (handle) 12 is provided in front of the operator's seat 7 to steer the front wheels 5 by turning left and right about a shaft (not shown) supported by a handle post 20 provided on a support frame of the traveling vehicle body 2. ing. A display panel 13 is provided in front of the steering wheel 12 to display information (driving speed, operation state, etc.) regarding steering to the driver.

A forward/reverse switching lever 14 is provided at the upper end of the handle post 20 and at the left end below the steering wheel 12 to switch between forward travel and reverse travel. The forward/reverse switching lever 14 has three switching positions, a forward position, a neutral position, and a reverse position. sent to.

An accelerator lever 15 for changing the number of revolutions of the engine 3 is provided at the other end of the handle post 20 and below the steering wheel 12 . The accelerator lever 15 is an example of an accelerator operation tool, and is used during work travel. Further, the accelerator lever 15 is held at that position even if the hand is released from the operated position. is sent to the control device 100 .

An accelerator pedal 16, left and right brake pedals 17L and 17R, an HST pedal 18, a clutch pedal 19, and the like are provided on the step floor portion 7b of the operator's seat 7 on the right side of the handle post 20. As shown in FIG. The left and right brake pedals 17L and 17R can be switched between a connected state in which the left and right brake pedals 17L and 17R are simultaneously operated by a connecting member and a non-connected state in which the left and right brake pedals can be operated separately, and the brake pedals detect whether they are in a connected state or a non-connected state. A connection sensor 81 (FIG. 6) is provided. If the operation of the accelerator pedal is detected by the detection value of the accelerator pedal position sensor 95 (FIG. 6) while the brake pedal connection sensor 81 is detecting the non-connection state, it is notified by a lamp and/or a buzzer to make it unsafe. Suppress running.

The accelerator pedal 16 is an example of an accelerator operation tool, and is a depression-type pedal that is operated to increase the engine speed and thus the vehicle speed of the traveling vehicle body 2 according to the amount of depression of the accelerator pedal 16 . This accelerator pedal 16 is basically used when traveling on the road. Further, the depression amount of the accelerator pedal 16 is detected by an accelerator pedal position sensor 95 ( FIG. 6 ) and the detection information is transmitted to the control device 100 .

The HST pedal 18 is an example of a shift operation tool, and the direction and amount of depression of the pedal 18 determine the direction and speed (number of revolutions) of the rotational power output from the continuously variable transmission 41 comprising the HST, and thus the traveling vehicle body. 2 is a seesaw-type step-on pedal that is operated when changing the running direction (forward or backward) and adjusting the vehicle speed. The HST pedal 18 is mainly used during work travel.

The HST pedal 18 has a stop operation position in which the entire pedal is maintained in a substantially horizontal state to bring it to a stopped state, and a forward movement position in which the entire pedal is depressed to tilt forward from the stop operation position. It has a forward operation area in which the vehicle speed can be increased or decreased, and a reverse operation area in which the vehicle speed can be increased or decreased during backward travel by depressing the entire pedal so as to tilt it backward from the stop operation position. Further, the direction and amount of depression of the HST pedal 18 are detected by the HST pedal position sensor 96 ( FIG. 6 ), and the detection information is transmitted to the control device 100 .

An auxiliary transmission lever 21, a PTO clutch lever 22, a main transmission lever 23, and the like are provided on the left side of the operator's seat 7 in the forward direction.

The sub-transmission lever 21 is a lever that is operated when selecting a gear stage (vehicle speed range), for example, low speed, medium speed, or high speed, for the rotation speed of the rotational power that transmits the sub-transmission device 51 . Of these gears, the low and medium speeds are suitable vehicle speed ranges for driving in fields when working in fields, and the high speed is suitable for driving on roads when moving between fields. area. The PTO clutch lever 22 is a lever that is operated when connecting and disconnecting drive transmission to the PTO shaft 59 . The main gearshift lever 23 is another example of a gearshift operation tool, and is a lever that operates the trunnion shaft 47 of the continuously variable transmission 41 to shift gears.

The selected operating position of the sub-transmission lever 21 is detected by the sub-transmission position sensor 95 ( FIG. 6 ), and the detection information is transmitted to the control device 100 . The selected operating position of the shift lever 23 is detected by the main shift position sensor 99 ( FIG. 6 ), and the detection information is transmitted to the control device 100 .

As shown in FIG. 2, a position lever 24 for raising and lowering the working machine, an adjustment panel 25, and the like are provided on the right side of the operator's seat 7 in the forward direction.

The position lever 24 is an operation lever that adjusts the height of the working machine when it is raised or lowered. The adjustment panel 25 is a part where dials, switches, etc. for setting necessary adjustments for part of the operation of the tractor 1 are arranged.

In the power transmission device 4, as shown in FIG. 3, first, the rotational power of the output shaft of the engine 3 is transmitted to the input shaft 32 of the transmission case 40 via the main clutch 31 and is transmitted to the speed increasing gears 33a and 33b. After being accelerated, it is configured to be transmitted to the input shaft 42 of the continuously variable transmission 41 . The main clutch 31 operates depending on whether or not the clutch pedal 18 is depressed.

The continuously variable transmission 41, to which the HST is applied, is a device in which a hydraulic pump 43 and a hydraulic motor 44 are combined and integrated.

The hydraulic pump 43 is a variable displacement hydraulic pump, and is operated by the rotational power of the engine 3 input through the input shaft 42. The hydraulic oil is sent to the hydraulic motor 44 by changing the inclination angle of the swash plate 45 in the pump. Adjust the discharge state (direction and flow rate (including zero)). The hydraulic motor 44 is, for example, a fixed capacity hydraulic motor, and rotates the motor output shaft 44a at a predetermined rotation direction and rotation speed (number of rotations) according to the state of hydraulic oil discharged from the hydraulic pump 43 .

In the power transmission device 4, as shown in FIG. 3, the rotational power of the motor output shaft 44a of the hydraulic motor 44 in the continuously variable transmission 41 is output through the auxiliary transmission 51 and then through the driving output shaft 34. Later, it is transmitted to the left and right rear wheels 6 via the rear wheel differential gear device 35 .

Further, in the power transmission device 4, when the drive switching device 36 including the connecting gear is switched to the four-wheel drive side, the rotational power output from the auxiliary transmission device 51 through the drive output shaft 34 is transferred through the drive switching device 36. After being transmitted to the front wheel relay shaft 37 , it is also transmitted to the left and right front wheels 5 via the front wheel speed increasing device 38 and the front wheel differential gear device 39 . The front wheels 5 receive rotational power at a speed higher than that of the rear wheels 6 only when the front wheel speed increasing device 38 is operated to increase the speed. transmitted.

Further, in the power transmission device 4, as shown in FIG. 3, the hydraulic pump 43 in the continuously variable transmission 41 is provided with a pump output shaft 43a that rotates in the same manner as the input shaft . As a result, in the power transmission device 4 , the rotational power of the pump output shaft 43 a is transmitted to the PTO relay shaft 57 via the PTO reversible clutch 56 and then transmitted to the PTO shaft 59 via the PTO transmission 58 .

In the continuously variable transmission 41, the swash plate 45 of the hydraulic pump 43 is switched to any one of forward output position, neutral position, and reverse output position.

When the swash plate 45 is switched to the forward output position, the continuously variable transmission 41 outputs from the motor output shaft 44a power for rotating the hydraulic motor 44 forward at a rotational speed corresponding to the tilt angle. When the plate 45 is switched to the reverse output position, the motor output shaft 44a outputs power to rotate the hydraulic motor 44 in the reverse direction at a rotation speed corresponding to the tilt angle. On the other hand, in the continuously variable transmission 41, when the swash plate 45 is switched to the neutral position, the hydraulic motor 44 does not rotate the motor output shaft 44a and outputs no power.

4, the continuously variable transmission 41 has a trunnion shaft 47 that rotates so as to adjust the inclination angle of the swash plate 45 of the hydraulic pump 43. As shown in FIG. The trunnion shaft 47 is rotated via the trunnion arm 48 which is moved by the operation of the shaft rotation mechanism 60 .

The shaft rotation mechanism 60 has a hydraulic cylinder mechanism 61 that serves as a drive source, and a link mechanism 65 that transmits the power of the hydraulic cylinder mechanism 61 to the trunnion arm 48 .

The hydraulic cylinder mechanism 61 is composed of a double-acting hydraulic cylinder 62 and a control valve 63 that operates the hydraulic cylinder 62 .

The link mechanism 65 includes a first swing arm 67 having one end connected to the tip of the piston rod 62a of the hydraulic cylinder 62 in the hydraulic cylinder mechanism 61 and rotatably supported by the first fixed shaft 66a, and a trunnion. A second rocking arm 68, one end of which is connected to the rear end of the arm 48 and rotatably supported by a second fixed shaft 66b, the other end of the first rocking arm 67, and a second rocking arm. and a connecting arm 69 that rotatably connects with the other end of the arm 68 .

The control valve 63 supplies hydraulic oil sent from a cylinder hydraulic pump (not shown) to one end and the other end of the double-acting cylinder portion 62b at a required timing, thereby extending or shortening the piston rod 62a. As the control valve 63, an electromagnetic hydraulic proportional valve having a pair of solenoids 63a and 63b for controlling the supply operation of hydraulic oil is applied. It is designed to operate for shortening. Reference numeral 64 in FIG. 4 indicates an oil feed pipe connecting between the control valve 63 and one end and the other end of the cylinder portion 62b.

When the piston rod 61a of the hydraulic cylinder mechanism 61 is extended in the direction indicated by the arrow D1 from the position corresponding to the neutral position shown in FIG. The force of the extending piston rod 61a is transmitted to the trunnion arm 48 via the link mechanism 62, and the trunnion arm 48 at this time operates to rotate the trunnion shaft 47 in the direction indicated by arrow E1. In this case, the swash plate 45 of the hydraulic pump 43 is moved to incline toward the forward output position.

In addition, when the piston rod 61a of the hydraulic cylinder mechanism 61 is shortened in the direction indicated by the arrow D2 from the position corresponding to the neutral position by the supply operation of the hydraulic oil of the control valve 63, the shaft rotation mechanism 60 moves the shortened piston rod 61a. The force of the rod 61a is transmitted to the trunnion arm 48 via the link mechanism 62, and the trunnion arm 48 at this time operates to rotate the trunnion shaft 47 in the direction indicated by arrow E2. In this case, the swash plate 45 of the hydraulic pump 43 is moved to incline toward the reverse output position.

Further, the continuously variable transmission 41 is provided with a neutral holding mechanism 49 for holding a trunnion shaft 47 for rotating the swash plate 45 and a trunnion arm 48 at a neutral position, as shown in FIG.

The neutral holding mechanism 49 includes a cam plate 49a configured to rotate integrally with a trunnion shaft 47 as a support shaft and return to a neutral position, and a recessed peripheral cam portion of the cam plate 49a. It has a roller 49b that receives a positive force and presses against it. One end of the trunnion shaft 47 with respect to the neutral holding mechanism 49 is rotatably connected to a part of the cam plate 49a.

In the continuously variable transmission 41, when the shaft rotation mechanism 60 does not operate, the trunnion arm 48 is held at the neutral position by the action of the neutral holding mechanism 49 (see FIG. 4), and the swash plate 45 is also held at the neutral position. It is designed to be moved (returned). The rotation angle of the trunnion shaft 47 is detected by a trunnion shaft angle sensor 97 ( FIG. 6 ) that confirms the movement of a part of the trunnion arm 48 , and the detected information is transmitted to the control device 100 .

In the continuously variable transmission 41, when the operation amount of the main gear shift lever 23 is detected by the main gear shift position sensor 99 or the depression direction and amount of the HST pedal 18 is detected by the HST pedal position sensor 96, each sensor The controller 100 controls the drive current values supplied to the solenoids 63a and 63b of the control valve 63 in the shaft rotation mechanism 60 according to the detected values of 99 and 96, respectively. As a result, in the continuously variable transmission 41, the trunnion shaft 47 is rotated in a desired direction via the trunnion arm 48 by a desired angle corresponding to the depression amount.

As a result, in the continuously variable transmission 41, the inclination angle of the swash plate 45 of the hydraulic pump 43 is arbitrarily changed in conjunction with the rotation of the trunnion shaft 47, and the hydraulic oil discharged from the hydraulic pump 43 to the hydraulic motor 44 is increased. Since the direction and the flow rate are adjusted, the hydraulic motor 44 rotates in a desired direction through the motor output shaft 44a, and outputs rotational power steplessly changed to a desired rotational speed (number of rotations).

As shown in FIG. 5, the adjustment panel 25 is provided with a maximum speed setting dial 26, a cruising button 27, a vehicle speed memory button 28, a speed increasing switch 29A, a decelerating switch 29B, and the like.

The maximum speed setting dial 26 is a dial-type operating tool that is operated when setting for limiting the maximum speed of the traveling vehicle body 2 . The maximum speed at this time can be arbitrarily set by the driver, and the settable maximum speed is, for example, in the range of 15 to 30 km/h. The setting information of the maximum speed setting dial 26 is transmitted to the control device 100 (Fig. 6).

When the maximum speed setting dial 26 is set, the rotation angle of the trunnion shaft 47 is adjusted (restricted) so that even if the main gearshift lever 23 is operated to the maximum or the HST pedal 18 is fully depressed, the tractor 1 will not reach the setting. Only the vehicle speed up to the specified maximum speed can be obtained.

The cruise travel switch 27 is an on/off switch for operating whether or not cruise travel is to be executed. Operation information of the cruise running switch 27 is transmitted to the control device 100 (FIG. 6).

In the tractor 1, when the cruise travel switch 27 is turned on while traveling at a certain speed, the vehicle speed at the time of the operation is stored in the memory 101 of the control device 100 as the cruise speed, and the travel speed is set to the accelerator pedal 16. The control device 100 starts auto-cruise control that maintains the cruise speed even if the HST pedal 18 is not depressed.

The vehicle speed memory button 28 is a push button capable of exhibiting the function of storing the engine speed corresponding to the vehicle speed and the rotation angle of the trunnion shaft 47 . This vehicle speed memory button 28 is a button that is operated only while it is pressed, and returns to its original position when it is released after being pressed by hand (self-recovery type button).

As will be described later, the vehicle speed memory button 28 has a function of being activated by a long press operation for a predetermined time or longer or a short press operation for less than a predetermined time while the vehicle is running or stopped. The predetermined time is arbitrarily set, and for example, a time of about 1 second is set.

The acceleration switch 29A and the deceleration switch 29B are used to increase the cruise speed and memory speed during the execution of auto-cruise control and during the execution of memory vehicle speed cruise (constant speed running at memory vehicle speed) control described later by operating the vehicle speed memory button 28. It is a push-button switch that is operated to adjust speed or slowdown. Each operation information of the speed-up switch 28A and the speed-down switch 28B is transmitted to the control device 100. FIG.

In the tractor 1, the controller 100 controls the memory vehicle speed cruise as follows.

The control device 100 includes an arithmetic processing unit, a memory 101 as storage means, an input/output device, and the like. control is performed. The memory 101 includes storage elements such as ROM and RAM, as well as storage devices such as hard disks.

For example, when the tractor 1 operates the accelerator lever 15 and the HST pedal 18 in a field and is traveling at an arbitrary vehicle speed, the driver presses the vehicle speed memory button 28 when the vehicle speed is desired to be stored. A long press operation is performed for a predetermined time or longer.

In this case, in the tractor 1, the control device 100 stores and holds the engine speed and the rotation angle of the trunnion shaft 47 corresponding to the vehicle speed at that time in the memory 101, and stores the stored engine speed and the rotation angle of the trunnion shaft 47. An operation is performed to control the shaft rotation mechanism 60 so that the vehicle travels while maintaining the rotation angle of the trunnion shaft 47 . A series of control operations at this time are executed as a "first function".

At this time, in the control device 100, as shown in FIG. 6, the trunnion shaft control section 103 controls the operation of the control valve 63 in the shaft rotation mechanism 60. As shown in FIG.

The trunnion shaft control unit 103 controls the driving current value supplied to the solenoids 63a and 63b of the control valve 63 in accordance with the detection value of the HST pedal position sensor 96 in a predetermined relationship. The rotation angle of the trunnion shaft 47 stored in the memory 101 is stored, for example, as a drive current value supplied to the solenoids 63a and 63b when the vehicle speed memory button 28 is pressed for a long time.

When performing auto-cruise control, which will be described later, the trunnion shaft control unit 103 supplies driving current to the solenoids 63a and 63b of the control valve 63 according to the detection value of the main transmission position sensor 99 when the control is started. The values are also controlled in a predetermined relationship.

Further, the rotation speed of the engine 3 is detected by an engine rotation speed sensor 72, and the rotation speed when the vehicle speed memory button 28 is pressed for a long time is stored.

As a result, in the tractor 1, as conceptually shown in the left half of FIG. is stored and retained in the memory 101, and constant speed running (memory vehicle speed cruise) is continued while maintaining the stored engine speed and rotational angle of the trunnion shaft 47. FIG. That is, the first function is executed.

Therefore, according to this tractor 1, the driver performs the act of long-pressing the vehicle speed memory button 28 during running, so that the driver can easily grasp the vehicle speed to be stored during running. In addition, continuation of constant speed running at the memory vehicle speed can be easily realized by a single operation of long-pressing the vehicle speed memory button 28 .

Further, when the tractor 1 operates the accelerator lever 15 and the HST pedal 18 and is traveling at an arbitrary vehicle speed, if the driver wishes to travel at the memorized memory vehicle speed instead of the arbitrary vehicle speed, , the driver presses the vehicle speed memory button 28 for a short time.

In this case, in the tractor 1 , the control device 100 controls the shaft rotation mechanism 60 so that the tractor 1 travels at the engine speed and the rotation angle of the trunnion shaft 47 stored in the memory 101 . The control operation at this time is executed as the "second function".

At this time, in the control device 100, the operation of the control valve 63 in the shaft rotation mechanism 60 is controlled by the trunnion shaft control section 103, as shown in FIG. there is At this time, the trunnion shaft control unit 103 predetermines the drive current value to be supplied to the solenoids 63a and 63b of the control valve 63 based on the rotation angle of the trunnion shaft 47 corresponding to the memory vehicle speed stored in the memory 101. control in relation to each other.

Further, the detected value of the engine speed sensor 72 is fed back to control the fuel injection timing and injection amount of the engine 3 so as to achieve the stored engine speed.

As a result, in the tractor 1, as conceptually shown in the right half of FIG. 7(A), when the vehicle speed memory button 28 is pressed for a short time, the memory vehicle speed stored and held in the memory 101 is maintained. Driving (memory vehicle speed cruise) is reproduced. That is, the second function is executed.

Therefore, according to this tractor 1, it is possible to easily reproduce traveling at the stored memory vehicle speed by a single operation of short-pressing the vehicle speed memory button 28 during traveling.

In the first function, the control device 100 also performs an operation of generating a sound to notify when the engine speed and the rotation angle (vehicle speed) of the trunnion shaft 47 are stored in the memory 101 .

At this time, as shown in FIG. 6, the control device 100 causes the panel driving control unit 104 to operate the sound generating unit 13b such as a buzzer attached to the display panel 13 or the like to generate a desired sound. is generated (for example, a buzzer sounds).

As a result, when the driver long-presses the vehicle speed memory button 28 in the first function, the driver will audibly recognize that the vehicle speed desired to be stored in the memory 101 during running is stored in the memory 101, and the vehicle speed is stored. It becomes easier to grasp the vehicle speed when you want to.

In this case, instead of or in addition to the notification by the generation of the sound, the vehicle speed memory button 28 may be illuminated when stored in the memory 101 to notify.

Further, the control device 100 changes the vehicle speed stored in the storage means 101 to the vehicle speed stored in the storage means 101 when the running (memory vehicle speed cruise) maintained at the engine speed and the rotation angle of the trunnion shaft 47 is canceled in the first function and the second function. When the information (the engine speed and the rotation angle of the trunnion shaft 47) remains, an operation is performed to notify that the information remains by lighting the indicator.

In this case, the control device 100 operates the display screen unit 13a attached to the display panel 13 or the like by the panel drive control unit 104 to turn on the display, as shown in FIG. indicator display), lighting a mark, etc., and lighting a notification lamp.

The memory vehicle speed cruise is canceled by pressing the vehicle speed memory button 28 for a short time, depressing the brake pedal 17, and depressing the HST pedal 18 during execution of the memory vehicle speed cruise. , the operation of the accelerator lever 15, or the like. Whether or not the brake pedal 17 is depressed is detected by a brake pedal position sensor 98 ( FIG. 6 ), and the detection information is transmitted to the control device 100 .

As a result, when the memory vehicle speed cruise is canceled in the first function or the second function, the driver is informed by lighting of the display device, so that the driver can visually recognize that the memory vehicle speed remains in memory. , and it becomes easier to grasp that the memory vehicle speed is stored in the memory 101 .

Further, when the vehicle speed memory button 28 is pressed for a predetermined time or longer while the tractor 1 is stopped, the control device 100 performs an operation to erase the memory vehicle speed information stored in the memory 101 . It's like

As a result, in the tractor 1, the vehicle speed information stored in the memory 101 by the driver can be erased. It is possible to prevent the constant speed running at the unsuitable unnecessary memory vehicle speed from being reproduced and misused.

In this case, the predetermined time for judging the long-press operation is the same as the predetermined time for judging the long-press operation when storing the vehicle speed, but it may be set to a different time.

Further, when the brake pedal 17 is depressed during memory vehicle speed cruising, the memory vehicle speed information stored in the memory 101 may be erased. With this configuration, it is possible to prevent erroneous rapid acceleration at the memory vehicle speed when the brake pedal 17 is released after the depression operation is completed.

On the other hand, the control device 100 is configured to retain the memory vehicle speed information stored in the memory 101 even when the engine 3 is stopped by turning off a key switch memory (not shown).

As a result, in the tractor 1, even if the key switch is turned off during a break or the like, the memory vehicle speed is not erased from the memory 101, so that when the key switch is turned on after that and the work is resumed, the previous memory vehicle speed remains. Therefore, the memory vehicle speed cruise based on the memory vehicle speed can be easily reproduced, and workability is improved.

Further, when the acceleration switch 29A or the deceleration switch 29B is turned on during the memory vehicle speed cruise, the control device 100 accelerates or decelerates the memory vehicle speed by the amount of the turn-on operation. The memory vehicle speed information stored in the memory 101 is retained even when control is performed to maintain constant speed running at the changed vehicle speed and the constant speed running at the changed vehicle speed is cancelled. ing.

Thus, in the tractor 1, as conceptually shown in the left half of FIG. 7(B), the vehicle speed is adjusted by increasing or decreasing the vehicle speed according to the working conditions and situations while the vehicle is traveling at the memory vehicle speed and working. It becomes possible to run. In addition, in this tractor 1, if it is desired to reproduce the constant speed running at the memory vehicle speed before the change after canceling the constant speed running at the changed vehicle speed, the constant speed running at the memory vehicle speed before the change is performed. It can be easily reproduced without performing an operation to store the vehicle speed again.

Further, in the control device 100, when the driver presses the vehicle speed memory button 28 when the vehicle speed is increased or decreased by turning on the acceleration switch 29A or the deceleration switch 29B and the vehicle speed is kept at the changed speed. is pressed for a long time, the vehicle speed after the change is rewritten in the memory 101 and stored.

As a result, in this tractor 1, as conceptually shown in the right half of FIG. 7(B), the turning-on operation of the speed-up switch 29A or the speed-down switch 29B is performed as necessary during memory vehicle speed cruising. Even when the vehicle speed is changed by , the changed vehicle speed can be newly stored as the memory vehicle speed, and the constant speed running kept at the changed memory vehicle speed can be easily resumed, which is convenient. Incidentally, if the vehicle speed memory button 28 is not pressed long while the vehicle speed is kept constant after being changed by turning on the acceleration switch 29A or the deceleration switch 29B, the vehicle speed after the change is stored in the memory 101. is not stored in

Further, in this tractor 1, as shown in FIG. 5, in addition to the vehicle speed memory button 28, a cruise running button 27 is provided.

For this reason, the control device 100 allows the driver to press the cruise travel button 27 when the driver operates the accelerator lever 15 and the HST pedal 18 to travel at an arbitrary vehicle speed on a road, for example, when moving between fields. When operated, the shaft rotation mechanism 60 is controlled so as to run at a constant speed while maintaining the engine speed and the rotation angle of the trunnion shaft 47 at that time.

As a result, the tractor 1 can easily perform constant-speed traveling (auto-cruise) while maintaining the cruise vehicle speed at that time without depressing the HST pedal 18 . As a result, the tractor 1 can be run at a fixed speed by pressing the vehicle speed memory button 28 or by pressing the cruise run button 27. Convenience is improved.

Incidentally, in this tractor 1, when the vehicle speed memory button 28 is pressed for a short time while the memory 101 does not store (does not exist) information on the memory vehicle speed, the controller 100 changes the vehicle speed at that time. It may be configured to perform control for executing fixed running.

In this case, since the vehicle speed memory button 28 has the same usage and function as the cruise run button 27, it is possible to adopt a configuration in which only the vehicle speed memory button 28 is provided without providing the cruise run button 27. .

When the driver presses the vehicle speed memory button 28 for a long time during auto-cruising at the cruise vehicle speed by pressing the cruise travel button 27, the control device 100 causes the memory 101 to store the cruise vehicle speed. It may also be configured to perform an operation to hold it.

In this case, it is possible to memorize and hold the cruise vehicle speed during auto-cruise, and furthermore, it is possible to reproduce running at the cruise vehicle speed by short-pressing the vehicle speed memory button 28 (second function described above). Convenience is improved.

Further, in the tractor 1, the control device 100 stores the engine speed, the rotational angle of the trunnion shaft 47, and the auxiliary transmission selected by the operation of the auxiliary transmission lever 21 in the memory 101 in the first function. 51 gear stages are combined (associated) and stored. In this case, when the vehicle speed memory button 28 is pressed for a short time thereafter, the memory vehicle speed cruise is reproduced by the combination of the stored shift stage of the auxiliary transmission 51 and the memory vehicle speed.

At this time, the control device 100 determines that the gear stage of the auxiliary transmission 51 selected when the vehicle speed memory button 28 is pressed for a short time in the second function is the engine speed stored in the memory 101. When the combination of the rotational angle of the trunnion shaft 47 and the shift speed of the subtransmission device 51 does not match, at least one of the generation of a sound and the illumination of the indicator is notified, and the engine speed and the rotation speed of the trunnion shaft 47 are notified. It also performs an operation to control the shaft rotation mechanism 60 so that the vehicle does not travel while maintaining the rotation angle.

As a result, in this tractor 1, since the vehicle speed can be stored for each gear stage of the auxiliary transmission 51, it is possible to store the vehicle speed not only at the gear stage suitable for work traveling but also at the gear stage for movement between fields or traveling on the road. memory and fixed running at that vehicle speed becomes possible, improving convenience. In addition, in this tractor 1, it is known by the notification that the gear stage of the auxiliary transmission 51 selected by the driver is inappropriate. This prevents such incidents from occurring and ensures safety.

In addition, the control device 100 stores the information on the memory vehicle speed stored in the memory 101, the information on the combination of the memory vehicle speed and the shift stage, and the information related to the memory vehicle speed cruise, such as the rotation speed of the engine 3, by panel driving. The control unit 104 performs the operation of displaying on the display screen unit 13a of the display panel 13. FIG.

The display at this time can be configured to be automatically performed in conjunction with the operation of storing the vehicle speed in the memory, or can be configured to be performed by the driver's switching operation of the display screen. Screen switching is performed by operating a display switching button screen displayed on the display screen portion 13 a of the display panel 13 or by operating a display switching button provided on the side of the display panel 13 .

As a result, the driver can easily visually confirm the information related to the memory vehicle speed cruise. In addition, the driver can use the information related to the memory vehicle speed cruise, correct the information, delete the information, etc., which improves usability.

In addition, the control device 100 stores the memory vehicle speed (engine speed and the rotation angle of the trunnion shaft 47) and the shift speed of the subtransmission 51 are not matched, information on the mismatched combination is displayed on the display screen portion 13a of the display panel 13. It is

As a result, the driver can easily know what gear stage of the auxiliary transmission 51 is inappropriate, and can easily and accurately change the inappropriate gear stage to an appropriate gear stage. can also be done.

In this case, the control device 100 is configured to perform an operation of displaying on the display panel 13 that the memory vehicle speed cruise can be reproduced and an operation of lighting the vehicle speed memory button 28 when the combinations match. You may

Furthermore, when there is a memory vehicle speed stored in the memory 101, the control device 100 selects a gear stage of the subtransmission device 5 that does not match the stored memory vehicle speed by operating the sub-transmission lever 21. is performed, an operation for erasing the memory vehicle speed information stored in the memory 101 is performed.

As a result, it is possible to avoid execution of an inappropriate memory vehicle speed cruise due to a combination of the memory vehicle speed and the shift stage of the auxiliary transmission 51 that does not match, thereby preventing the occurrence of an erroneous operation. By the way, if an operation is performed to select a gear that does not match the memory vehicle speed, driving in combination with a gear that does not match the rotation angle (opening) of the trunnion shaft corresponding to the memory vehicle speed will result in actual failure. is different from the memory vehicle speed, and the desired memory vehicle speed cruise cannot be reproduced accurately.

<Modification>
In the above-described embodiment, as an operation example of the control device 100, it is assumed that the first function and the second function are executed when the accelerator lever 15 and the HST pedal 18 are operated to drive the vehicle. The control device 100 of the present invention can similarly perform the first function and the second function when the accelerator pedal 16 and the main shift lever 23 are operated to drive.

Further, in the tractor 1, the control device 100 is configured to perform an operation of displaying on the display screen portion 13a of the display panel 13 that the tractor 1 is traveling at the memory vehicle speed cruise to inform the user that the vehicle is traveling at the memory vehicle speed cruise. You may The display that the memory vehicle speed cruise is in progress may be performed, for example, by displaying or lighting a display screen or mark indicating that the memory vehicle speed cruise is in progress.

With this configuration, the driver can easily and reliably recognize that the vehicle is automatically traveling at the memory vehicle speed cruise.

Further, in the tractor 1, the control device 100 informs the display screen portion 13a of the display panel 13 that the vehicle will shift to the memory vehicle speed cruise when the tractor 1 moves from traveling at an arbitrary vehicle speed to the memory vehicle speed cruise. It may be configured to operate. The notification of the shift to the memory vehicle speed cruise may be made by, for example, flashing a display screen or a mark indicating the shift to the memory vehicle speed cruise.

In this configuration, the vehicle speed does not change due to the driver's operation of the main gear shift lever 23 or the HST pedal 18, but the shift to the memory vehicle speed cruise. Temporary fluctuations can be easily and reliably recognized, and this also makes it possible to call the driver's attention.

Further, in the tractor 1, when the auto-cruise travel switch 27 is pushed during travel at the memory vehicle speed cruise, the control relating to the memory vehicle speed cruise (control for fixed travel at the memory vehicle speed) is canceled. You may

Further, in the tractor 1, when the operation of the accelerator pedal is detected by the detection value of the accelerator pedal position sensor 95 (FIG. 6) while the brake pedal connection sensor 81 is detecting the non-connection state, the lamp or the buzzer or the like is detected. Although the notification is given by both, the inclination of the vehicle body detected by the inclination sensor, the operating position of the sub-transmission lever, the operating position of the PTO lever, and the like may be added as conditions for notification.

The present invention is not limited to vehicles for agricultural work such as tractors, but can be applied to vehicles for various other work.

1 … Tractor (working vehicle)
2 ... traveling vehicle body 3 ... engine 15 ... accelerator lever (accelerator operation tool)
16 ... Accelerator pedal (accelerator operating tool)
18... HST pedal (shift operation tool)
23... Main shift lever (shift operation tool)
28... Vehicle speed memory switch 41... Continuously variable transmission (hydrostatic continuously variable transmission)
42 Subtransmission device 47 Trunnion shaft 60 Shaft rotation mechanism 97 Trunnion shaft angle sensor 100 Control device 101 Memory (storage means)

Claims (5)

an engine (3);
an accelerator operation tool (15, 16) for adjusting the engine speed according to the operation amount;
an engine speed sensor (72) for detecting the speed of the engine (3);
It has a trunnion shaft (47) that rotates so as to adjust the inclination angle of the swash plate (45), and is a hydrostatic type non-rotating engine that outputs rotational power input from the engine (3) after steplessly changing the speed. a stepped transmission (41);
an auxiliary transmission (51) for outputting rotational power output from the continuously variable transmission (41) after shifting the speed in a plurality of stages;
a traveling vehicle body (2) that travels by receiving rotational power output from the auxiliary transmission (51);
a shaft rotation mechanism (60) for rotating the trunnion shaft (47);
A shift operation tool (23, 18) for adjusting the rotation angle of the trunnion shaft (47) by operating the shaft rotation mechanism (60) according to the amount of depression to change the vehicle speed of the traveling vehicle body (2). )and,
an angle sensor (97) for detecting the rotation angle of the trunnion shaft (47);
a vehicle speed memory button (28) which is a button capable of exhibiting a function of storing the engine speed corresponding to the vehicle speed and the rotation angle of the trunnion shaft (47), and which is turned on only while being pressed; ,
When the vehicle speed memory button (28) is pressed for a predetermined period of time or more while driving with the accelerator operation tools (15, 16) and the gear shift operation tools (23, 18) operated, the vehicle speed at that time is changed. The corresponding engine speed and the rotation angle of the trunnion shaft (47) are stored and held in a memory means (101), and the stored engine speed and the rotation angle of the trunnion shaft (47) are maintained. A first function of controlling the engine (3) and the shaft rotation mechanism (60) to run, and during running by operating the accelerator operation tool (15, 16) and the gear shift operation tool (23, 18). When the vehicle speed memory button (28) is pressed for less than a predetermined time, the engine speed and the rotation angle of the trunnion shaft (47) stored in the storage means (101) are maintained. a control device (100) having a second function for controlling said pivoting mechanism (60) to travel;
A work vehicle comprising: 2. The control device (100) according to claim 1, characterized in that when the engine speed and the rotation angle of the trunnion shaft (47) are stored in the first function, the control device (100) notifies by generating a sound. work vehicle. When the control device (100) stops running at the engine speed and the rotation angle of the trunnion shaft (47) stored in the first function and the second function, the control device (100) stores 3. The work vehicle according to claim 1, wherein when the stored vehicle speed information remains, the remaining information is indicated by lighting of an indicator. In the first function, the control device (100) stores the engine speed and the rotation angle of the trunnion shaft (47) in the memory means (101) and the auxiliary transmission (51) selected at that time. The gear stage of the auxiliary transmission (51) selected when the short-pressing operation is performed in the second function is stored in the storage means (101). At least one of the generation of sound and lighting of an indicator occurs when the combination of the engine speed and the rotation angle of the trunnion shaft (47) and the gear stage of the sub transmission (51) does not match. 4. Any one of claims 1 to 3, characterized in that the shaft rotation mechanism (60) is controlled so as not to run while maintaining the engine speed and the rotation angle of the trunnion shaft (47). Work vehicle described in paragraph. When the vehicle speed memory button (28) is pressed for a predetermined period of time or longer while stopped, the control device (100) controls the engine speed stored in the storage means (101) and the speed of the trunnion shaft (47). 5. The work vehicle according to any one of claims 1 to 4, wherein information on the rotation angle is erased.