JP6417811B2 - Tractor - Google Patents

Description

  The present invention relates to a tractor that is a work vehicle that includes a continuously variable transmission and travels on a farm field.

  As shown in Patent Document 1, a tractor for field leveling provided with a hydrostatic continuously variable transmission mechanism can be operated at a constant vehicle speed by a speed change control unit. By turning acceleration control that controls speed increase only when the vehicle is turning, it is possible to quickly turn back at the end of the field and efficiently shift to the next constant vehicle speed operation without requiring a troublesome shifting operation before and after turning. it can.

Japanese Patent No. 5472397

  However, there is a case where it is desired to decelerate in conjunction with the turning of the aircraft for safe driving. On the other hand, it is also necessary to increase the speed of interlocking turning for shortening the work time, and both cannot be satisfied. was there.

  An object of the present invention is to provide a hydrostatic continuously variable transmission mechanism and travel at a predetermined speed, and in addition to turning acceleration control for speeding up only during turning, turning to reduce speed only during turning An object of the present invention is to provide a tractor that makes it possible to select a time deceleration control.

The invention according to claim 1 is a traveling device (4, 5) that supports the vehicle body so as to be able to turn, and a hydrostatic continuously variable transmission that continuously transmits the traveling power of the traveling device (4, 5). (8) and a tractor including the hydrostatic continuously variable transmission (8) and a shift control unit (60) that performs shift control according to conditions, and capable of traveling to ground.
The speed change control unit (60) is a speed increasing mode switch (shifting speed increasing control for shifting to a speed increasing side from a predetermined travel command speed according to the turning travel by the travel device (4, 5)). 61a) and a deceleration mode switch (61b) for shifting to a deceleration control during turning for performing a shift control from the predetermined traveling instruction speed to the deceleration side,
The left and right independent brakes of the travel device (4, 5), the brake pedals (21L, 21R), and the lock plate (23) that integrates the left and right brake pedals (21L, 21R) at the connection position. And when the lock plate (23) is in the connecting position, the shift control unit (60) regulates shift control by the acceleration mode switch (61a) .

According to a second aspect of the present invention, in the first aspect of the invention, when the airframe is provided with a tilt sensor (62), the speed change control unit (60) causes the speed increase when the airframe is tilted more than a predetermined value. The shift control by the mode switch (61a) is restricted.

The invention according to claim 3 is the invention according to claim 2 , wherein the airframe is provided with a tilt sensor (62), and when the amount of change in the tilt of the airframe is greater than or equal to a predetermined value, the shift control unit (60) The speed increasing control during turning by the speed increasing mode switch (61a) is restricted.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 ,
When the vehicle body is provided with a vehicle speed sensor (63), and the lock plate (23) is in the coupling position and the vehicle speed is equal to or higher than a predetermined value, the speed change mode switch (61a) It is characterized by restricting the acceleration control at the time of turning.

The invention according to claim 5 is the invention according to any one of claims 1 to 4 , further comprising a forward / reverse sensor (27s) for detecting reverse travel of the aircraft by the forward / reverse switching means (27), and the shift control. The speed increasing control during turning by the speed increasing mode switch (61a) is restricted by the part (60) for reverse travel.

  According to the first aspect of the invention, the shift control unit (60) shifts the hydrostatic continuously variable transmission (8) to a predetermined speed according to the conditions, and travels from the hydrostatic continuously variable transmission (8). The aircraft is driven at a predetermined speed by receiving the motive power from the traveling devices (4, 5). In this case, the speed change control unit (61a) is selected according to the mode selected by the acceleration mode switch (61a) or the deceleration mode switch (61b). 60) shifts the hydrostatic continuously variable transmission (8) to the speed increasing side or the speed reducing side according to the turning of the airframe, so that the vehicle speed during turning can be arbitrarily increased or decreased by a switch operation. Therefore, it is possible to make a turn according to the operator's intention.

In addition, when the left and right independent brakes are integrated by the lock plate (23) at the coupling position, even if the acceleration mode is selected by the acceleration mode switch (61a) due to the restriction of the acceleration control during turning, Since the vehicle travels without increasing the speed, the speed increasing mode switch (61a) is released when moving the vehicle by connecting the left and right brake pedals (21L, 21R), especially when adjusting the body position indoors, such as in a warehouse. A safe turning movement of the airframe is possible without requiring any operation.

According to the invention of claim 2 , in addition to the effect of the invention of claim 1 , the speed change control unit (60) is configured to increase when turning by the speed increasing mode switch (61a) when the airframe is tilted more than a predetermined value. Since the speed control is restricted, it is possible to prevent instability of travel due to the speed increase during cornering and tipping of the airframe without requiring the release operation of the speed increasing mode switch (61a) on the slope.

According to the invention of claim 3 , in addition to the effect of the invention of claim 2 , the shift control unit (60) is configured to turn by the speed increasing mode switch (61a) when a change in the inclination of the airframe is more than a predetermined value. Since the speed increase control is restricted, it is possible to prevent instability of the travel due to the speed increase during turning without requiring the release operation of the speed increase mode switch (61a) in a headland or the like with severe unevenness. it can.

The invention according to claim 4, in addition to the effect of the invention according to any one of claims 1 to 3, wherein the transmission control unit (60), said locking plate (23) is the vehicle speed is above a predetermined at the connecting position In this case, since the acceleration control during turning by the acceleration mode switch (61a) is restricted, it is not necessary to release the acceleration mode switch (61a) when traveling at high speed on the road or the like. The vehicle can be safely turned and traveled. In particular, it is possible to secure a backup of forgetting to turn off the acceleration mode switch (61a).

The invention according to claim 5, in addition to the effect of the invention according to any one of claims 1 to 4, the turning-state acceleration control by the speed increasing mode switch (61a) is restricted in the case of reverse running Therefore, the vehicle can safely turn backward without requiring the release operation of the acceleration mode switch (61a).

Top view of tractor Side view of tractor Enlarged view of the main parts of the brake pedal Transmission system development of the transmission Driving speed control configuration diagram Plan view of an example of field running

Embodiments specifically configured based on the above technical idea will be described below with reference to the drawings.
1 and 2 are a plan view and a side view of a tractor shown as an example of a work vehicle to which the present invention is applied. This tractor 1 supports a vehicle body by front and rear traveling wheels 4 and 5 so as to be able to work on a farm field, and receives a power of an engine 7 arranged at the front of the vehicle body to transmit a continuously variable transmission to the traveling wheels 4 and 5. It is provided with an internally installed transmission gear, and is configured to be able to drive a working machine such as a rear rotary tillage rotary.

  Further, as an operation tool for traveling operation and work machine operation, a clutch pedal 20, a brake pedal 21, an accelerator pedal 22, a forward / reverse lever 27, and a main transmission lever 30 around the work seat 12 are provided around the steering handle 13. The auxiliary transmission lever 31 and the work implement elevating lever 33 are arranged.

  As for the brake pedal 21, as shown in FIG. 3 which is an enlarged view of the main part of the brake pedal, the left and right independent brake pedals 21L and 21R can be operated on the left and right independent brakes, and the two pedals are connected at the connection position. The lock plate 23 is configured so as to be able to be integrally operated by connecting both of them when traveling outside the field, and a left and right brake connection release pedal on / off detection switch 23s which is a connection position sensor of the lock plate 23 is attached.

(Transmission system)
As shown in FIG. 4, the transmission transmission system receives engine power from the engine 7 through the clutch 42 to the input shaft 46 of the hydrostatic continuously variable transmission 8, abbreviated as HST. 50 and the same speed shaft 51 for output. The input shaft 46 drives the hydraulic pump 47 and outputs work machine power to the same speed shaft 51. The hydraulic pump 47 rotates the hydraulic motor 49 steplessly in the range of forward and reverse rotation by the trunnion arm 48. Driving power is output to the transmission shaft 50.

  The transmission shaft 50 transmits the traveling power to the rear wheel 5 via the three-speed switching sub-transmission unit 9 and continuously transfers the traveling power to the front wheel 4 via the two-speed switching front wheel acceleration unit 10. The same speed shaft 51 transmits work power to the PTO shaft 11 from the PTO forward / reverse switching section 53 through the relay shaft 54 and the three-stage switching transmission section 55.

(Shift control)
FIG. 5 is a control control configuration diagram of the traveling vehicle speed. The control configuration of the traveling vehicle speed is configured such that the traveling vehicle speed can be controlled by rotating the trunnion arm 48 with the controller 60. As input signals for vehicle speed control, a forward / reverse position detection switch 27s, which is a forward / reverse sensor for the linear lever 27 for forward / reverse selection, a lever position sensor 30s for the main transmission lever 30 for adjusting the vehicle speed, an inclination sensor 62, a vehicle speed sensor 63, a brake Signals such as the connection release pedal on / off detection switch 23s, the brake pedal sensor 21s, and the clutch pedal detection switch 20s are input to the controller 60, and an acceleration mode switch 61a and a deceleration mode switch 61b for adjusting the turning vehicle speed are provided. Input to the controller 60.

  The controller 60 can adjust the vehicle speed at a speed corresponding to the lever position of the main speed change lever 30, and the speed-up mode switch 61a and the speed-down mode switch 61b are configured to be capable of an alternative operation including a mode-off that is excluded from application. In addition to the speed increase control at the time of turning, the vehicle speed defined by the main speed change lever 30 is increased only when turning, and the deceleration at the time of turning is reduced only during turning. Configure to allow control selection.

  Specifically, as shown in FIG. 6 which is a plan view of a field traveling example, in the reciprocating operation traveling A in which the main transmission lever 30 is adjusted to a predetermined operation position and the optimum operation vehicle speed is maintained, the acceleration mode When the vehicle enters a turn from a straight run at the field end, the vehicle speed is controlled to the speed increasing side without requiring the operation of the main shift lever 30, and a turn can be made quickly. Since it will shift to the original work speed when it starts traveling, it is possible to efficiently advance the repeated traveling for each field edge.

  In addition, by selecting the deceleration mode in the rotation work traveling B at the periphery of the field, if the vehicle enters the reverse turning traveling at the field end, the vehicle speed is controlled to the low speed side without requiring the operation of the main shift lever 30, and the vehicle speed is carefully controlled. Therefore, when the next straight-line travel is started, the original work speed is transferred, so that reliable turn-back travel for each field corner becomes possible.

Next, turning vehicle speed adjustment based on the handling of the lock plate 23 will be described.
When the lock plate 23 is switched to the connected position and the left and right brake pedals 21L and 21R are connected by a signal from the brake connection release pedal on / off detection switch 23s, the turning vehicle speed is adjusted by the acceleration mode switch 61a and the deceleration mode switch 61b. Control to be regulated is provided in the controller 60.

  With the above control configuration, the speed increasing mode switch 61a and the deceleration mode switch 61b are effective only when the lock plate 23 is returned from the connection position. Therefore, the lock plate 23 is switched to the connection position and travels outside the field. In this case, the normal turning vehicle speed corresponding to the operation of the main shift lever 30 can be secured without requiring the release operation of the acceleration mode switch 61a, and the cover is provided even when the operator forgets to turn off the acceleration mode switch 61a. can do.

  Further, with regard to the acceleration at the time of turning by the acceleration mode switch 61a, when the lock plate 23 is switched to the coupling position, a control for switching to the deceleration at the time of turning is provided, so that the acceleration mode is set when the body is accommodated in a barn or the like. While avoiding the release of the switch 61a, it is possible to avoid a dangerous situation in which the speed is increased by performing a turning operation, and fine adjustment of the airframe movement is facilitated.

  Next, in the case where the vehicle body exceeds a predetermined inclination due to traveling on an inclined ground, a control for restricting the acceleration adjustment during turning by the acceleration mode switch 61a by the detection of the inclination sensor 62 is provided, so that the increase during turning on the inclined ground is provided. It is possible to reduce the risk of unstable running due to speed and falling of the aircraft.

  Further, in the case where the aircraft exceeds a predetermined inclination due to traveling on the slope, a control for switching the acceleration at the time of turning by the acceleration mode switch 61a to the deceleration at the time of turning by the detection of the inclination sensor 62 is provided. In this case, the running can be further stabilized.

  Further, when the change in inclination exceeds a predetermined level due to traveling of uneven parts such as a headland in the field, the acceleration adjustment during turning by the acceleration mode switch 61a is regulated by detecting the inclination change by the inclination sensor 62. By providing the control, it is possible to improve riding comfort and improve safety by stable running.

  Next, when the vehicle travels over a predetermined vehicle speed with the lock plate 23 as the coupling position, the speed increase adjustment during turning by the speed increase mode switch 61a is performed by the detection signal of the brake connection release pedal on / off detection switch 23s and the vehicle speed sensor 63. By configuring the controller 60 so as to regulate, it is possible to suppress the danger caused by the acceleration adjustment during turning during high-speed traveling, and to cover forgetting to turn off the operator.

  Next, with respect to the deceleration mode switch 61b, the deceleration adjustment during turning is limited only during backward turning, and the deceleration adjustment during forward turning is restricted, so that the deceleration adjustment during turning is performed for backward turning when turning over a headland or the like. It can be applied to ensure safety, and workability can be ensured by forward traveling without deceleration adjustment during turning.

  Further, as another example of the deceleration control during turning by the deceleration mode switch 61b, a small deceleration rate at a low vehicle speed is generally achieved by using a large deceleration rate during reverse turning and a small deceleration rate during forward traveling. Since a large deceleration at the time of turning is almost unnecessary, it is possible to improve safety and workability by adjusting the speed greatly only for the backward turning at the headland or the like.

  Regarding the reverse turning deceleration control by the deceleration mode switch 61b, the operability can be improved by releasing the reverse deceleration mode by depressing the clutch pedal 20, and by depressing the brake pedals 21L and 21R. The operability can be similarly improved by canceling the reverse deceleration mode.

(point)
The outline of the shift control technology for the tractor having the above-described configuration is as follows.
The tractor shift control unit 60 controls the hydrostatic continuously variable transmission 8 to a predetermined speed according to the conditions, and receives traveling power from the hydrostatic continuously variable transmission 8 on the traveling devices 4 and 5. In this case, the speed change control unit 60 moves to the speed increasing side or the speed reducing side according to the turning of the airframe depending on the mode selected by the speed increasing mode switch 61a or the speed reducing mode switch 61b. Since shift control of the hydrostatic continuously variable transmission 8 is performed, the increase or decrease of the traveling vehicle speed at the time of turning can be arbitrarily selected by a switch operation, so that the turning traveling according to the intention of the operator is possible.

  When the left and right independent brakes are integrated by the lock plate 23 at the coupling position, the left and right brakes are driven without turning even if the acceleration mode is selected due to the restriction of the acceleration control during turning. In the case of traveling by connecting the pedals 21L and 21R, in particular, when adjusting the position of the airframe indoors such as in a warehouse, the airframe can be safely turned without requiring the release operation of the acceleration mode switch 61a.

  When the airframe is tilted more than a predetermined value, the acceleration control during turning by the selection of the acceleration mode is restricted. Therefore, the acceleration during turning is not required without requiring the release operation of the acceleration mode switch 61a on the slope. It is possible to prevent instability of traveling and toppling of the aircraft.

  When the change in the inclination of the airframe is more than a predetermined value, the speed increase control during turning in the speed increasing mode is restricted. It is possible to prevent instability of travel due to speed increase during travel.

  When the lock plate 23 is in the connecting position and the vehicle speed is greater than or equal to a predetermined value, the speed increase control during turning by the selection of the speed increase mode is restricted. It is possible to safely turn and travel the aircraft without requiring the release operation of 61a, and in particular, it is possible to ensure backup of forgetting to turn off the acceleration mode switch 61a.

  In the case of reverse travel, since the speed increase control during turning in the speed increasing mode is restricted, the vehicle can safely turn backward without requiring the release operation of the speed increasing mode switch 61a.

1 Tractor 4 Front wheel (travel device)
5 Rear wheels (travel device)
8 Hydrostatic continuously variable transmission 21L Brake pedal 21R Brake pedal 23 Lock plate 23s Connection position sensor (Connection release pedal on / off detection switch)
27 Forward / reverse switching means (linear lever)
27s Forward / backward sensor (linear lever position detection switch)
60 Transmission Control Unit 61a Acceleration Mode Switch 61b Deceleration Mode Switch 62 Inclination Sensor 63 Vehicle Speed Sensor

Claims (5)

A traveling device (4, 5) that supports the vehicle body in a turnable manner, a hydrostatic continuously variable transmission (8) that continuously transmits the traveling power of the traveling device (4, 5), and the hydrostatic pressure In a tractor that is capable of traveling to the ground with a shift control unit (60) that performs shift control of the variable continuously variable transmission (8) according to conditions,
The speed change control unit (60) is a speed increasing mode switch (shifting speed increasing control for shifting to a speed increasing side from a predetermined travel command speed according to the turning travel by the travel device (4, 5)). 61a) and a deceleration mode switch (61b) for shifting to a deceleration control during turning for performing a shift control from the predetermined traveling instruction speed to the deceleration side,
The left and right independent brakes of the travel device (4, 5), the brake pedals (21L, 21R), and the lock plate (23) that integrates the left and right brake pedals (21L, 21R) at the connection position. provided, when the locking plate (23) of the connecting position, by the shift control unit (60), characterized and to belt Rakuta to regulate the shift control by the speed increasing mode switch (61a). A tilt sensor (62) is provided in the airframe, and when the airframe is tilted more than a predetermined level, the speed change control by the speed increasing mode switch (61a) is restricted by the speed change control unit (60). The tractor according to claim 1 . An inclination sensor (62) is provided in the airframe, and when the amount of change in the inclination of the airframe is greater than or equal to a predetermined value, the shift control unit (60) regulates the acceleration control during turning by the acceleration mode switch (61a). The tractor according to claim 2 , wherein: When the vehicle body is provided with a vehicle speed sensor (63), and the lock plate (23) is in the coupling position and the vehicle speed is equal to or higher than a predetermined value, the speed change mode switch (61a) tractor as claimed in any one of claims 3, characterized in that to regulate the turning-state acceleration control by. A forward / reverse sensor (27s) for detecting backward travel of the aircraft by the forward / reverse switching means (27) is provided, and the speed increase control during turning by the speed increase mode switch (61a) is reverse traveled by the shift control unit (60). tractor according to any of claims 1 to 4, characterized in that to regulate the.

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