JP5858029B2 - Tractor - Google Patents

Description

  The present invention relates to a tractor that is an agricultural machine, and more particularly, to auto cruise control.

  Auto cruising of the tractor controls the running speed at a constant level without the operator having to operate the accelerator pedal or brake, and is mainly used during road cleaning and moving on the road. May also be used. However, if auto-cruise is used for work in a narrow field, auto-cruise is frequently turned on and off, and the operation of returning to the original traveling speed when auto-cruise is turned on is troublesome.

  For this reason, for example, as a conventional technique, Japanese Patent Laid-Open No. 1-168530 has an idea of canceling auto-cruise control at the start of inversion and returning to auto-cruise control at the end of inversion. Inversion means, for example, that the traveling direction is reversed forward and backward, and that the rotary is raised and lowered.

JP-A-1-168530

The automatic cruise control may be canceled not only when the tractor is reversed, but also when changing the tillage speed due to the hardness of the field or when adjusting the traveling speed when traveling on the road.
An object of the present invention is to reduce the handling burden on the operator by restoring the immediately preceding auto-cruise traveling speed when the on-off of the auto-cruise control is simply turned on in the tractor.

The problems of the present invention are solved by the following technical means.
The invention according to claim 1 is provided with a cruise travel switch 14c, an acceleration switch 26, and a deceleration switch 27. When the cruise travel switch 14c is turned on, the cruise speed at that time is stored and maintained as an auto cruise speed. start, the auto-cruise control is stopped by the stepping write only depression and a brake pedal 16, 17 of a predetermined angle or more of the turning operation or the accelerator pedal 15 of the steering wheel 7 is turned on at the same time the deceleration switch 27 and the speed increasing switch 26 Thus, the tractor is characterized in that the auto cruise control is activated to return to the auto cruise speed.

The invention according to claim 2 is the tractor according to claim 1, wherein the notifying means 28 is operated when the auto-cruise control is activated to return to the auto-cruise speed.
According to the third aspect of the present invention, when the speed increasing switch 26 and the speed reducing switch 27 are released while the auto cruise control is activated and returned to the auto cruise speed, the travel speed at that time is stored as a new auto cruise speed. The tractor according to claim 1, wherein the tractor is maintained.

  According to the fourth aspect of the present invention, when the accelerator pedal 15 is depressed while the automatic cruise control is activated and the vehicle returns to the automatic cruise speed, the vehicle speed increases beyond the automatic cruise speed. 2. The tractor according to claim 1, wherein when the switch 27 is turned off simultaneously, the increased traveling speed at that time is stored and maintained as a new auto-cruise speed.

  According to the first aspect of the present invention, unless the speed increasing switch 26 and the speed reducing switch 27 are turned on at the same time by the driver of the tractor consciously, the speed does not increase to the auto cruise speed. Safer than auto cruise control.

  According to the second aspect of the present invention, when returning to the auto-cruise speed, the operator is informed that the speed is automatically increased by the notification means 28 such as a buzzer or a panel display.

  According to the third aspect of the present invention, the original auto-cruise speed can be changed slowly by releasing the speed increasing switch 26 and the speed reducing switch 27 while returning to the auto-cruise speed, and the operation for changing the auto-cruise speed is simple. It is.

  In the invention according to claim 4, when the acceleration switch 26 and the deceleration switch 27 are turned on at the same time and the accelerator pedal 15 is depressed while returning to the auto-cruise speed, the travel speed increased to the original auto-cruise speed or higher is automatically set. It can be changed to the cruise speed, and the setting operation to the fast auto cruise speed is easy.

It is a side view of the tractor of the Example of this invention. It is a top view of a tractor. It is a power transmission mechanism diagram of the transmission of the tractor. 1 is a hydraulic circuit diagram of a hydrostatic continuously variable transmission. It is a control block diagram of a tractor. It is a top view of the lever guide part of a tractor. It is a side view of an HST pedal.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
In this specification, the left and right directions in the forward direction of the tractor are referred to as left and right, respectively, the forward direction is referred to as forward, and the reverse direction is referred to as rear.

  The tractor shown in FIGS. 1 and 2 includes front wheels 2 and 2 and rear wheels 3 and 3 at the front and rear portions of a traveling vehicle body 1, and the rotational power of an engine 5 mounted on the front portion of the vehicle body 1 is transmitted by a transmission in a transmission case. The vehicle is configured to be appropriately decelerated and transmitted to the front wheels 2 and 2 and the rear wheels 3 and 3.

A steering handle 7 is supported on the handle post 6 in the center of the vehicle body 1, and a seat 9 is provided behind the steering handle 7.
As shown in FIG. 1, the fuel tank 8 is stored in the bonnet 22, and the rear side of the fuel tank 8 main body is stored in the handle post 6.

  A forward / reverse lever 10 that switches the traveling direction of the vehicle body 1 to the front / rear direction is provided below the steering handle 7. When the forward / reverse lever 10 is moved forward, the vehicle body 1 moves forward, and when it is moved backward, it moves backward. A throttle lever 11 for changing the engine speed is provided on the opposite side of the forward / reverse lever 10 with the handle post 6 in between. An accelerator pedal 15 and left and right brake pedals 16 and 17 are provided at the right corner of the step floor 13. Is arranged. An emergency stop switch 60 is provided on the front side of the forward / reverse lever 10.

  The accelerator pedal 15 is basically used when traveling on the road, the engine speed increases according to the amount of depression, and the amount of depression of the accelerator pedal 15 is detected by an accelerator pedal potentiometer 76 (FIG. 5). The rotation angle of the trunnion shaft 30 (shown only in the control block diagram of FIG. 5) of the hydrostatic continuously variable transmission (HST) 34 can be changed according to the detected value of the accelerator pedal potentiometer 76. By changing the inclination angle of the swash plate 34d (FIG. 4) according to the rotation angle of the trunnion shaft 30, the output of the HST can be changed steplessly.

  The throttle lever 11 is used to change the engine speed and is used during work travel. The throttle lever 11 is configured so that the position is maintained even if the hand is released at the operated position.

  Further, a sub-shifting lever 21 that can select any of low speed, medium speed, high speed, and neutral position is arranged on the left side of the cockpit 9 and is mounted behind the front wheel 2 and the rear wheel 3 behind the mid work. Mid PTO speed change lever 23a for turning on and off the PTO shaft of a machine (moor, etc.), and Rear PTO speed change lever for turning on and off the PTO shaft of a work machine (mower, rotary, snowplow, etc.) mounted on the rear of the machine body 23b is provided. Further, the link 31 for connecting a work machine (not shown) is provided behind the vehicle body 1.

  The rotational power of the engine 5 is transmitted from the HST input shaft 33 to the HST 34. Further, the hydraulic pump 34a shown in FIG. 4 is operated by the power introduced from the HST input shaft 33, and pressure oil corresponding to the inclination angle of the swash plate 34d provided in the hydraulic pump 34a is supplied from the hydraulic closed circuit 34c to the hydraulic motor. The driving output shaft 35 is driven by the hydraulic motor 34b to transmit power to the meshing transmission 38.

As shown in FIG. 3, in the auxiliary transmission clutch 39 of the meshing transmission 38, the rotation of the transmission shaft 43 is driven through the differential device 46 and the rear wheel 3 is driven at the traveling speed of the auxiliary transmission high speed stage.
The power output from the HST 34 is transmitted from the travel output shaft 35 to the rotary shaft 36. The gear position by the transmission 38 is set as follows. That is, at the sub-shifting high speed (third speed), the power shifted from the gear 38 a by the gear 38 b is transmitted to the transmission shaft 43. In addition, the sub-shift medium speed (second speed) is transmitted from the gear 38c to the gear 38d, and the sub-shift low speed (first speed) is transmitted from the gear 38e to the gear 38f. It is transmitted to the transmission shaft 43. These three sub-shifts are switched by operating the sub-shift lever 21 and sliding the shifter 39 left and right. The rotation of the transmission shaft 43 is driven through the differential device 46 so that the rear wheel 3 is driven at the traveling speed of the sub-shift middle speed.

  On the other hand, power input from the HST input shaft 33 to the variable displacement hydraulic pump 34a (FIG. 4) is provided to the PTO shaft 52 from the pump output shaft 51 (shown only in FIG. 3) via the PTO hydraulic clutch 54 and the like. Is transmitted to the drive system for the PTO. Power is transmitted to the rear PTO shaft 55 and the mid PTO shaft 56 to the PTO shaft 52.

  Also, the gear 58 on the lower side of the sub-shift of the transmission shaft 43 is transmitted to the gear 57 of the front wheel output shaft 48 via the gear 47 of the PTO shaft 52 and the gear 59 integral with the gear 47, and the front wheel 2 is driven. The

  The hydrostatic continuously variable transmission (HST) 34 has its rotational speed determined by the rotational angle of the trunnion shaft 30 (FIGS. 4 and 5), that is, the rotational angle of the swash plate 34d, and detailed description thereof is omitted. However, when the depression amount of the accelerator pedal 15 is detected by the accelerator pedal potentiometer 76, the operation amount of the trunnion shaft 30 is automatically set by the controller 100 according to the detected value of the accelerator pedal potentiometer 76, and The hydraulic output rotation speed of the hydraulic continuously variable transmission (HST) 34 is automatically set to an appropriate value by the controller 100.

  It should be noted that the control device 100 can be operated in a hydrostatic manner by, for example, operating a changeover switch (not shown) provided at the rotation base of the forward / reverse switching lever 10 by switching the forward / reverse switching lever 10 to the forward side or the reverse side. The rotational direction of the trunnion shaft 30 of the step transmission (HST) 34 is set to the forward side or the reverse side. The turning direction of the trunnion shaft 30 is determined by the switching valve 63 (FIG. 4).

Then, the rotation angle of the trunnion shaft 30 changes according to the depression amount of the accelerator pedal 15. The rotation angle of the trunnion shaft 30 is determined by the amount of current to the proportional valve 65.
Further, in an emergency such as a valve stick where the valve is clogged with impurities, the HST trunnion shaft 30 can be forcibly returned to neutral when the brake pedals 16 and 17 in the control section are fully depressed. Stepping on the brakes 16 and 17 means that the trunnion shaft 30 returns to neutral because the foot is released from the accelerator pedal 15. At this time, whether the trunnion shaft 30 returns naturally or forcibly returns at a high speed differs depending on the model.

  In the hydraulic circuit 34c of the electronic servo HST 34 shown in FIG. 4, when a valve or the like is clogged with impurities (valve stick), the emergency stop lever 62 (shown only in FIG. 5) in the control unit is pulled, and the trunnion shaft of the HST 34 is pulled. Return 30 to neutral.

  Conventionally, a configuration in which the HST trunnion shaft 30 is returned to neutral in an emergency is known, but at the time of valve stick, the spool position is fixed and the traveling speed is fixed. Therefore, in an emergency, the emergency stop lever 62 is manually pulled to stop the tractor.

The tractor can be stopped in an emergency by the above-described two types of manual operation members (emergency stop lever 62 and brake pedals 16 and 17).
Further, when the emergency stop switch 60 (shown only in FIG. 5) is pressed, the engine is stopped, and this is used when an accident such as a collision is avoided.

  In addition, it is good to provide a seating sensor in the seat 9 so that it cannot run unless the operator is sitting. It is also preferable to provide a safety mechanism that slows the running speed when the seat belt provided on the seat 9 is pulled due to sudden start or the like.

  As shown in the overall plan view of the tractor shown in FIG. 2, a throttle lever 11 and a forward / reverse lever 10 are arranged on the left and right on the handle post 6 around the handle 7. An accelerator pedal 15 is disposed on the step floor 13 on the right side of the throttle lever 11. The accelerator pedal 15 can adjust the rotation angle of the trunnion shaft 30 of the HST 34 and the engine speed.

  Further, the lever guide 12a on the right side of the cockpit 9 has a maximum speed setting dial 14a, a vehicle speed slowness response dial 14b, and a cruise travel switch 14c arranged in a line in order from the front side to the rear side, and the dials 14a, 14b and the switch 14c On the outside, a position lever 18 for raising and lowering the work machine is arranged. The dials 14a and 14b and the switch 14c need only be arranged in a line in the front-rear direction, and the arrangement order of the dials 14a and 14b and the switch 14c is not particular. Further, since the position lever 18 for raising and lowering the work implement is disposed outside the dials and switches 14a, 14b, and 14c, the maneuverability is better than when these dials and switches 14a, 14b, and 14c are not provided. Become.

  The maximum speed setting dial 14a is a dial type, and regulates the maximum speed of the vehicle body by adjusting the rotation angle of the trunnion shaft 30. Therefore, even if the accelerator pedal 15 is depressed to the maximum, only the speed regulated by the maximum speed setting dial 14a can be obtained.

  The vehicle speed slowness response dial 14b also changes and sets the rotation speed of the trunnion shaft 30. When the accelerator pedal 15 is stepped on, the target speed, that is, the rotation angle of the target trunnion shaft 30 is determined by the accelerator pedal potentiometer 76. The trunnion shaft is reached by the position of the rotation angle of the target trunnion shaft 30. The time which 30 reaches | attains is changed.

  For example, if the vehicle speed slowness response dial 14b is made insensitive (slow), even if the accelerator pedal 15 is stepped on quickly, the time to reach the target rotation angle of the trunnion shaft 30 will be slow, so it will accelerate slowly. It is the composition which goes. The change of the arrival time to the target position is performed by changing the duty ratio of the current to the proportional valve 65 (FIG. 4).

  The cruise travel switch 14c is an on / off type switch. When the cruise travel switch 14c is turned on while traveling at a specific speed, the speed at that time is automatically set even when the accelerator pedal 15 is released. The control is maintained as the cruise speed, and the auto-cruise control is canceled when the cruise speed is turned off.

  On the outside of the lever guide 12a, a speed increasing switch 26 and a speed reducing switch 27 are provided in a push button type. Further, after canceling the auto-cruise, the acceleration switch 26 and the deceleration switch 27 are continuously pressed to return to the auto-cruise speed. While returning to the auto-cruise speed, the informing means 28 that sounds the buzzer intermittently informs the operator that the speed is being increased automatically. The notification means 28 may be means for blinking an auto cruise lamp provided on the operation panel 77. The auto cruise lamp lights up during auto cruise control.

  If the speed increasing switch 26 and the deceleration switch 27 are simultaneously turned on and the speed increasing switch 26 and the speed reducing switch 27 are released while returning to the auto cruise speed, the travel speed at that time is stored as a new auto cruise speed. Keep driving at auto cruise speed.

  Further, when the acceleration switch 26 and the deceleration switch 27 are turned on at the same time and the accelerator pedal 15 is depressed while returning to the auto cruise speed, the speed increases beyond the auto cruise speed, and when the speed is increased, the speed increase switch 26 and the deceleration switch are increased. When 27 is simultaneously turned off, the increased traveling speed at that time is set as a new auto-cruise speed.

  As shown in the enlarged plan view of FIG. 6, the maximum speed setting dial 14a changes the rotation angle of the trunnion shaft 30 and the output of the HST 34 corresponding to the maximum speed, and the operator determines a predetermined maximum speed. For example, it can be changed to a dial type in a range of about 15 to 30 km / h. The vehicle speed slowness response dial 14b changes the time for the trunnion shaft 30 to reach the position of the target rotation angle of the trunnion shaft 30 according to the depression of the accelerator pedal 15. The time until the vehicle speed slowness response dial 14b reaches a predetermined vehicle speed can be changed to a dial type from about 3 seconds to about 6 seconds, for example.

  Further, the cruise travel switch 14c keeps the rotation angle of the trunnion shaft 30 constant so as to match the vehicle speed when the cruise travel switch 14c is turned on, so that the output of the HST 34 is kept constant and the vehicle speed is kept constant. The Even if the foot is released from the accelerator pedal 15 after the cruise travel switch 14c is turned on, the speed at that time is maintained.

  In this way, the rotation angle of the trunnion shaft 30 of the HST 34 can be set to any one of three preset types simply by turning on any of the maximum speed setting dial 14a, the vehicle speed slowness response dial 14b, and the cruise travel switch 14c. Therefore, the maneuverability is improved as compared with the case where the dials 14a and 14b and the switch 14c are not provided. In addition, since the dials 14a, 14b and the switch 14c are arranged in a line in the front-rear direction at positions adjacent to the cockpit 9, there is no hesitation in selecting the dials 14a, 14b and the switch 14c. I can put it in quickly.

  Further, a position lever 18 for raising and lowering the work implement is disposed outside the dials 14a and 14b and the switch 14c, so that the position lever 18 for raising and lowering the work implement is provided with these dials and switches 14a, 14b and 14c. The maneuverability is improved as compared with the case where it is not provided in the immediate vicinity.

  These three dials and switches 14a, 14b, and 14c are collectively referred to as a servo switch. However, the order in which they are arranged in a line in the front-rear direction on the right lever guide 12a adjacent to the cockpit 9 is the highest from the front side to the rear side. The high-speed setting dial 14a, the cruise travel switch 14c, and the vehicle speed slowness response dial 14b may be arranged in this order.

  On the left side of the cockpit 9, an auxiliary transmission lever 21, a mid PTO lever 23a, a rear PTO lever 23b, and a 4WD lever 24 are arranged. The sub-transmission lever 21 is disposed outside the 4WD lever 24, and the mid PTO lever 23a is disposed outside the rear PTO lever 23b.

  FIG. 7 shows the HST pedal 20 that moves forward and backward by rotating the trunnion shaft 30 of the HST 34. The HST pedal 20 is pivotally supported on the step floor 13 by the support shaft 19 at the front and rear intermediate portions. When the front pedal 20a is depressed, the forward speed is increased, and when the rear pedal 20b is depressed, the reverse speed is increased. Since it is difficult to release the foot, the response of the rear pedal 20b is made higher than that of the front pedal 20a.

  Further, the neutral range of the rear pedal 20b is made wider than that of the front pedal 20a so that the rear pedal 20b may be accidentally depressed when the foot is released from the front pedal 20a.

  Since the driver always puts his / her foot on the HST pedal 20, there is a slight up / down swing. Therefore, when this swing disappears, the engine may be stopped or the running may be stopped by setting the HST 34 to neutral.

  When the HST pedal 20 is set to neutral, the HST pedal 20 stops at a constant stop deceleration rate on a flat ground, and it is preferable to monitor the stop deceleration rate and operate the automatic brake so that the stop distance on the slope does not become long.

  In addition, when the HST pedal 20 is depressed, the vehicle accelerates at a constant acceleration rate on flat ground, but this acceleration rate is monitored to activate the downhill automatic brake, and the engine rotation is increased on the uphill road in the same way as on flat ground. It is better to speed up.

  It is preferable that an obstacle detection device is provided toward the front and rear of the tractor so that the vehicle is stopped slowly or urgently when an obstacle is detected during forward or reverse travel.

7 Steering handle 14c Cruise travel switch 15 Accelerator pedals 16, 17 Brake pedal 26 Speed increase switch 27 Deceleration switch 28 Notification means

Claims (4)

A cruise travel switch (14c), an acceleration switch (26), and a deceleration switch (27) are provided. When the cruise travel switch (14c) is turned on, auto cruise control for storing and maintaining the current travel speed as the auto cruise speed is performed. start, depression and a brake pedal of a predetermined angle or more of the turning operation or the accelerator pedal of the steering wheel (7) (15) (16), stops the auto cruise control stepping write only (17), the speed increase switch (26 ) And the deceleration switch (27) are simultaneously turned on to start the auto cruise control and return to the auto cruise speed.   The tractor according to claim 1, wherein the notifying means (28) is activated when the auto-cruise control is activated to return to the auto-cruise speed.   When the speed increase switch (26) and the speed reduction switch (27) are released while the auto cruise control is activated and returned to the auto cruise speed, the current travel speed is stored and maintained as a new auto cruise speed. The tractor according to claim 1.   When the accelerator pedal (15) is depressed while the auto-cruise control is activated to return to the auto-cruise speed, the speed increases beyond the auto-cruise speed, and when the speed is increased, the speed increasing switch (26) and the speed reducing switch (27) are turned on. 2. The tractor according to claim 1, wherein when simultaneously turned off, the increased traveling speed at that time is stored and maintained as a new auto-cruise speed.

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