JP5857985B2 - vehicle - Google Patents

Description

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

  Work vehicles, such as agricultural vehicles such as tractors, brake on wheels driven by power transmitted from the engine in response to external operations and transmission of power transmitted from the engine on and off It has a clutch to do.

  A work vehicle is known in which a controller turns off a clutch in response to a depression operation of a brake pedal by an operator (see, for example, Patent Document 1).

  Such a work vehicle can stop the vehicle without causing an engine stop even if the operator does not depress the clutch pedal.

JP2012-116301

  However, the present inventor has realized that sufficiently smooth start / stop control is not always realized even in the above-described conventional work vehicle.

  For example, when the clutch is turned off almost simultaneously with the depression of the brake pedal by the worker, the vehicle travels easily, and the worker may feel as if the vehicle jumps out even though the brake is depressed. there were.

  An object of the present invention is to provide a vehicle capable of realizing smoother start / stop control in consideration of the conventional problems described above.

The first aspect of the present invention is a brake that performs braking of a wheel driven by power transmitted from an engine in response to an operation from the outside;
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
The pressure increase pattern of the hydraulic pressure is a pattern in which the degree of pressure increase with respect to time decreases as the vehicle traveling speed decreases.
This is a vehicle.
As a result, the clutch can be connected by automatic control that changes the pressure increase pattern of the hydraulic pressure corresponding to the vehicle traveling speed, so that the vehicle can be started smoothly without causing a clutch shock or an engine stop.
The second aspect of the present invention is a brake for braking a wheel driven by power transmitted from an engine in response to an operation from the outside;
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
The hydraulic pressure increase pattern is a pattern in which the degree of pressure increase with respect to time decreases as the amount of vehicle inclination in the vehicle front-rear direction increases.
This is a vehicle.
As a result, the clutch can be connected by automatic control that changes the pressure increase pattern of the hydraulic pressure in accordance with the amount of vehicle inclination. Therefore, the vehicle can be started smoothly without causing a clutch shock or an engine stop.
According to a third aspect of the present invention, the clutch according to the first or second aspect of the present invention is characterized in that the clutch is a forward / reverse clutch that performs intermittent power according to selection of forward or reverse by a forward / reverse switching lever. It is.
As a result, the power can be switched according to the forward or reverse selection by the forward / reverse switching lever, so that the vehicle can be stopped or started smoothly.
According to a fourth aspect of the present invention, there is provided the vehicle according to the third aspect of the present invention, wherein the power interruption is performed even in response to an operation by a clutch pedal.
As a result, the power can be interrupted even in response to an operation by the clutch pedal, so that the vehicle can be smoothly stopped or started. In addition, since the forward / reverse clutch is shared and interrupted corresponding to the operation by the clutch pedal, it is not necessary to provide a dedicated main clutch.
First calling relevant to the present invention Ming, a brake to perform braking of the wheels driven by power coming transmitted from the engine, in response to an external operation,
A clutch for turning on / off transmission of the power transmitted from the engine;
A controller that turns off the clutch after an elapsed time after the wheel braking operation to the brake from the outside is detected to be a predetermined value or more;
A vehicle comprising:

  As a result, since the engine brake can be used by automatic control to turn off the clutch after a specified time has elapsed, the vehicle can be stopped smoothly without causing an engine stop even if the operator does not depress the clutch pedal. It becomes possible.

Second calling relevant to the present invention Ming, a brake to perform braking of the wheels driven by power coming transmitted from the engine, in response to an external operation,
A clutch for turning on / off transmission of the power transmitted from the engine;
A controller for turning off the clutch after the rotational speed of the engine becomes a predetermined value or less;
A vehicle comprising:

  As a result, since the engine brake can be used by automatic control to turn off the clutch after the engine speed becomes equal to or less than the specified speed, the engine stop is not caused even if the operator does not depress the clutch pedal. The vehicle can be stopped smoothly.

Third origination in the context of the present invention Ming, a brake to perform braking of the wheels driven by power coming transmitted from the engine, in response to an external operation,
A clutch for turning on / off transmission of the power transmitted from the engine;
And a controller that turns off the clutch after the vehicle traveling speed becomes a predetermined value or less.

  As a result, the engine brake can be used by automatic control to turn off the clutch after the vehicle traveling speed becomes less than the specified speed. Therefore, even if the operator does not depress the clutch pedal, the engine can be stopped smoothly without causing an engine stop. The vehicle can be stopped.

Fourth calling relevant to the present invention Ming, a brake to perform braking of the wheels driven by power coming transmitted from the engine, in response to an external operation,
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
As the hydraulic pressure increase pattern, a pattern corresponding to the vehicle traveling speed is selected.
This is a vehicle.

  As a result, the clutch can be connected by automatic control that changes the pressure increase pattern of the hydraulic pressure corresponding to the vehicle traveling speed, so that the vehicle can be started smoothly without causing a clutch shock or an engine stop.

Fifth calling relevant to the present invention Ming, a brake to perform braking of the wheels driven by power coming transmitted from the engine, in response to an external operation,
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
As the hydraulic pressure increase pattern, a pattern corresponding to the amount of vehicle inclination is selected.
This is a vehicle.

  As a result, the clutch can be connected by automatic control that changes the pressure increase pattern of the hydraulic pressure in accordance with the amount of vehicle inclination. Therefore, the vehicle can be started smoothly without causing a clutch shock or an engine stop.

Sixth inventions related to the present invention, the clutch is characterized by a forward or reverse selection by the forward-reverse switching lever is a positive reverse clutch to perform intermittent power corresponding, relevant to the present invention from the first is the fifth one of the inventions of the vehicle.

  As a result, the power can be switched according to the forward or reverse selection by the forward / reverse switching lever, so that the vehicle can be stopped or started smoothly.

A seventh inventions related to the present invention, intermittence of the power is characterized in that also performed in response to an operation by a clutch pedal, a sixth inventions of the vehicle related to the present invention.

  As a result, the power can be interrupted even in response to an operation by the clutch pedal, so that the vehicle can be smoothly stopped or started. In addition, since the forward / reverse clutch is shared and interrupted corresponding to the operation by the clutch pedal, it is not necessary to provide a dedicated main clutch.

  According to the present invention, it is possible to provide a vehicle capable of realizing smoother start / stop control.

Schematic side view of the work vehicle according to the first embodiment of the present invention. Schematic block diagram of a control mechanism for a work vehicle according to Embodiment 1 of the present invention. Flowchart for explaining the operation of the work vehicle control mechanism according to the first embodiment of the present invention (No. 1). Flowchart for explaining the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention (No. 2) Flowchart for explaining the operation of the control mechanism for the work vehicle according to the first embodiment of the present invention (No. 3). Flowchart for explaining the operation of the work vehicle control mechanism according to the first embodiment of the present invention (No. 4). FIG. 6 is a graph for explaining the operation of the control mechanism for the work vehicle according to the first embodiment in the invention related to the present invention (part 1); FIG. 6 is a graph for explaining the operation of the work vehicle control mechanism according to the first embodiment of the present invention (part 1); FIG. 3 is a graph for explaining the operation of the control mechanism for the work vehicle according to the first embodiment of the present invention (No. 2). FIG. 2 is a graph for explaining the operation of the control mechanism for the work vehicle according to the first embodiment in the invention related to the present invention (part 2); FIG. 3 is a graph for explaining the operation of the control mechanism for the work vehicle according to the first embodiment in the invention related to the present invention (part 3); Transmission diagram of power transmission mechanism of work vehicle according to embodiment 1 of the present invention Schematic development of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. Schematic front view of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. Schematic perspective view of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. Explanatory drawing of the voltage waveform and pressure waveform with the control output of the working vehicle of Embodiment 2 in the invention relevant to this invention Transmission diagram of power transmission mechanism of work vehicle of embodiment 2 in invention related to the present invention Schematic plan view of the power transmission mechanism of the work vehicle according to the second embodiment in the invention related to the present invention. Schematic partial plan view of the work vehicle according to the second embodiment in the invention related to the present invention.

  Hereinafter, embodiments of the present invention and inventions related to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
First, the configuration and operation of the work vehicle according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic side view of the work vehicle according to the first embodiment of the present invention.

  The work vehicle according to the first embodiment is an agricultural vehicle such as a tractor, and includes a brake 520, a clutch 510, a controller 500, and the like.

  The brake 520 is means for braking the wheel driven by the power transmitted from the engine 5 by an operation from the outside.

  The clutch 510 is a mechanism that turns on / off transmission of power transmitted from the engine 5.

  The controller 500 is a mechanism such as a computer that turns on and off the clutch 510.

  Next, the configuration of the control mechanism for the work vehicle according to the first embodiment will be specifically described with reference to FIG.

  FIG. 2 is a schematic block diagram of the work vehicle control mechanism according to the first embodiment of the present invention.

  The controller 500 reads various input signals from the clutch pedal sensor 501, the vehicle speed sensor 502, the brake switch 503, the linear shift switch 504, the engine rotation sensor 505, the shift position sensor 506, the front / rear slope sensor 507, and the like. It is means for controlling the clutch 510 and the brake 520 by performing various processes.

  The clutch 510 is a means having a clutch proportional solenoid 511, a forward solenoid 512, and a reverse solenoid 513 controlled by the state of the clutch pedal sensor 501 corresponding to an operator's stepping operation and by automatic control by a control mechanism described later. is there.

  The brake 520 is a means having a brake proportional solenoid 521, a brake right solenoid 522, and a brake left solenoid 523, which are controlled by the state of the brake switch 503 corresponding to an operator's stepping operation.

  The clutch pedal sensor 501 is a means for controlling the clutch proportional solenoid 511 that can turn off both the forward travel solenoid 512 and the reverse travel solenoid 513.

  When the depression operation of the clutch pedal 531 (see FIG. 12) is performed and the forward solenoid 512 or the reverse solenoid 513 selected by the forward / reverse switching lever 532 (see FIG. 12) is turned off, the power is not transmitted.

  Of course, when the depression of the clutch pedal 531 is not performed, the forward solenoid 512 or the reverse solenoid 513 selected by the forward / reverse switching lever 532 is turned on, and the power is transmitted again.

  The vehicle speed sensor 502 is a means for measuring the vehicle speed.

  The brake switch 503 is a means having a right switch and a left switch. When both the right switch and the left switch are turned on, the brake proportional solenoid 521 is turned on. When the right switch is turned on, the brake right solenoid 522 is turned on. When the left switch is turned on, the brake left solenoid 523 is turned on.

  That is, the brake switch 503 is means for reading the state of the brake pedal 533 (see FIG. 12).

  The linear shift switch 504 is means for selecting ON / OFF of the forward solenoid 512 and the reverse solenoid 513.

  That is, the linear shift switch 504 is a means for reading the state as to whether the forward or backward movement is selected by the forward / reverse switching lever 532.

  The engine speed sensor 505 is a means for measuring the engine speed.

  The shift position sensor 506 is a means for measuring whether the vehicle speed corresponds to a vehicle speed zone in which the vehicle speed is divided into predetermined ranges, such as a speed of 10 km to 20 km or a speed of 20 km to 30 km.

  Of course, the lever positions of the sub-transmission lever for shifting the sub-transmission unit 154 (see FIG. 12) and the main transmission lever for shifting the main transmission unit 150 (see FIG. 12) may be detected.

  The front / rear slope sensor 507 is means for measuring the amount of inclination in the vehicle front-rear direction.

  Of course, for the control of the clutch 510 and the brake 520 by the controller 500, the result of the reading process from other means such as a brake connection switch and a brake pedal sensor may be used.

  Next, the operation of the control mechanism for the work vehicle according to the first embodiment will be specifically described.

  The operation of the control mechanism will be described below by giving various examples of automatic control for the clutch 510.

  (1) An embodiment will be described in which the clutch 510 is automatically turned off after a specified time has elapsed when a wheel is braked by the brake 520.

  In this embodiment, the automatic control for turning off the clutch 510 after the lapse of the specified time allows the engine brake to be applied until the specified time elapses. Even if the clutch pedal 531 is not depressed, the vehicle can be smoothly stopped without causing an engine stop.

  Note that when the clutch 510 is turned off almost simultaneously with the depression of the brake pedal 533 by the worker, the engine brake cannot be used, so that the vehicle travel is likely to continue due to inertia, and the worker feels as if the vehicle jumps out. was there.

  Here, such automatic control will be described with reference mainly to FIG. 3 which is a flowchart (part 1) for explaining the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention. .

  The calling of the subroutine is started, and reading processing is performed on the clutch pedal sensor 501, the vehicle speed sensor 502, the brake switch 503, the linear shift switch 504, and the like (step S11), and it is determined whether or not the wheel is braked by the brake 520. (Step S12).

  When it is determined that the braking operation has been performed, it is determined whether or not the clutch 510 is on (step S13). When it is determined that the braking operation has not been performed, the process returns to the subroutine call.

  As a result of determining whether or not the clutch 510 is on (step S13), when it is determined that the clutch 510 is on, it is determined whether or not a specified time has elapsed after the braking operation (step S14). When it is determined that 510 is not on, the process returns to the subroutine call.

  Note that whether or not the specified time has elapsed after the braking operation may be determined using a clock or a timer.

  As a result of determining whether or not the specified time has elapsed after the braking operation (step S14), when it is determined that the specified time has elapsed, the clutch 510 is turned off (step S15), and then the subroutine is returned to calling the specified time. When it is determined that the predetermined time has not elapsed, it is determined again whether the specified time has elapsed (step S14).

  Note that if the specified time is too small, the operation of step S14 loses its substantial meaning, but if it is too large, the operations of the previous steps S11 to S13 may become ineffective as time elapses. Since the subsequent operation of step S15 is not executed and the traveling speed approaches the traveling speed in the stopped state before that, and the engine stops, it is desirable to set it to an appropriate size, for example, 1 second. .

  Of course, when the worker depresses the clutch pedal 531 after the operation of step S13 is executed, the operation of step S15 loses its substantial meaning, but the operator's instruction is respected. Therefore, this has no harmful effect.

  (2) An embodiment will be described in which the clutch 510 is turned off after the engine speed becomes equal to or lower than the specified speed when the wheel is braked by the brake 520.

  In this embodiment, the engine brake is used without causing engine stop even if the operator does not depress the clutch pedal 531 by automatic control to turn off the clutch 510 after the engine speed becomes equal to or less than the specified speed. This makes it possible to smoothly stop the vehicle.

  Note that when the engine speed is high, there is little risk that an engine stop will be caused even if the clutch 510 remains on.

  Here, such automatic control will be described with reference mainly to FIG. 4 which is a flowchart (part 2) for explaining the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention. .

  The subroutine call is started, and reading processing is performed on the clutch pedal sensor 501, the vehicle speed sensor 502, the brake switch 503, the linear shift switch 504, the engine rotation sensor 505, and the like (step S21). It is determined whether or not (step S22).

  When it is determined that the braking operation has been performed, it is determined whether or not the clutch 510 is on (step S23). When it is determined that the braking operation has not been performed, the process returns to the subroutine call.

  As a result of determining whether or not the clutch 510 is on (step S23), when it is determined that the clutch 510 is on, it is determined whether or not the engine speed has become equal to or less than a specified speed (step S24). When it is determined that 510 is not on, the process returns to the subroutine call.

  As a result of determining whether or not the engine speed is equal to or lower than the specified speed (step S24), when it is determined that the engine speed is equal to or lower than the specified speed, the clutch 510 is turned off (step S25), and then the subroutine is called. When it is determined that the engine speed is not lower than the specified speed, it is determined again whether the engine speed is lower than the specified speed (step S24).

  Note that if the specified rotational speed is too large, the operation of step S24 loses substantial meaning, that is, the brake pedal 533 is stepped on with a foot away from the accelerator pedal, and the clutch 510 is immediately turned off. Then, there is less room for the engine brake to work, but if it is too small, the clutch 510 is not easily turned off, and the subsequent operation of step S25 is not executed, so that the traveling speed becomes the traveling speed in the stopped state before that. Since the possibility of an engine stop occurring increases, the speed is preferably set to an appropriate size such as a rotational speed slightly higher than the idling rotational speed.

  Of course, when the worker depresses the clutch pedal 531 after the operation of step S23 is executed, the operation of step S25 loses its substantial meaning, but the operator's instruction is respected. Therefore, this has no harmful effect.

  (3) An embodiment will be described in which the clutch 510 is turned off after the vehicle speed becomes equal to or lower than the specified speed when the wheel is braked by the brake 520.

  The automatic control that turns off the clutch 510 after the vehicle speed falls below the specified speed enables the engine brake to be used without causing the engine to stop even if the operator does not depress the clutch pedal 531, thereby smoothly stopping the vehicle. It becomes possible.

  Note that when the vehicle speed is high, there is little risk that the engine will be stopped even if the clutch 510 remains on.

  Here, the automatic control as described above will be described with reference mainly to FIG. 5 which is a flowchart (part 3) illustrating the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention. .

  The subroutine call is started, and reading processing is performed on the clutch pedal sensor 501, the vehicle speed sensor 502, the brake switch 503, the linear shift switch 504, the engine rotation sensor 505, and the like (step S31). It is determined whether or not (step S32).

  When it is determined that the braking operation has been performed, it is determined whether or not the clutch 510 is on (step S33). When it is determined that the braking operation has not been performed, the process returns to the subroutine call.

  As a result of determining whether or not the clutch 510 is on (step S33), when it is determined that the clutch 510 is on, it is determined whether or not the vehicle speed is equal to or lower than the specified speed (step S34). When it is determined that it is not on, the process returns to the subroutine call.

  As a result of determining whether or not the vehicle speed has become equal to or less than the specified speed (step S34), when it is determined that the vehicle speed has become equal to or less than the specified speed, the clutch 510 is turned off (step S35). When it is determined that the vehicle speed is not lower than the specified speed, it is determined again whether the vehicle speed is lower than the specified speed (step S34).

  As for the specified speed, if it is too large, the operation of step S34 loses substantial meaning, that is, there is less room for engine braking, but if it is too small, the clutch 510 is not easily turned off. Therefore, since the operation of the subsequent step S35 is not executed, the traveling speed becomes close to the traveling speed in the stopped state before that, and there is a high possibility that the engine stop occurs. It is desirable.

  Of course, when the worker depresses the clutch pedal 531 after the operation of step S33 is executed, the operation of step S35 loses substantial meaning, but the operator's instruction is respected. Therefore, this has no harmful effect.

  (4) When the braking operation of the wheel by the brake 520 is performed and then the clutch 510 is turned off by the automatic control as described above, and then the braking operation is released (for example, when the brake switch 503 is turned off). An embodiment in which the clutch 510 is turned on while adjusting the clutch hydraulic pressure based on a predetermined pressure increase pattern will be described.

  Automatic control to turn on the clutch 510 while adjusting the clutch hydraulic pressure based on a predetermined pressure increase pattern allows the clutch 510 to be gradually connected rather than causing a clutch shock or engine stop, thereby smoothly starting the vehicle. Is possible. The present embodiment is further characterized in that a plurality of types of boosting patterns are prepared.

  A specific boosting pattern used when boosting the clutch proportional solenoid 511 by slowly increasing the energization after turning on the output of the forward solenoid 512 or the reverse solenoid 513 will be described in detail later.

  Here, such automatic control will be described with reference mainly to FIG. 6 which is a flowchart (part 4) for explaining the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention. .

  The subroutine call is started, and reading processing is performed on the clutch pedal sensor 501, the vehicle speed sensor 502, the brake switch 503, the linear shift switch 504, the engine rotation sensor 505, the shift position sensor 506, the front / rear slope sensor 507, and the like (step S41). Then, it is determined whether or not the clutch 510 is turned off by automatic control (step S42).

  The state in step S42 is a state where the brake pedal 533 is depressed and the clutch 510 is off.

  When it is determined that the clutch 510 is turned off by automatic control, it is determined whether or not the braking operation of the wheel by the brake 520 is released (step S43), and when it is determined that the clutch 510 is not turned off by automatic control. Return to the subroutine call.

  Of course, when the operator depresses the clutch pedal 531, even if it is determined that the clutch 510 is not turned off by automatic control in the operation of step S42, the clutch 510 is turned off. Even if the use of the boost pattern is stopped, there is no harmful effect.

  As a result of determining whether or not the braking operation of the wheel by the brake 520 is released (step S43), when it is determined that the braking operation is released, the output of the forward solenoid 512 or the reverse solenoid 513 is turned on (step S44). The clutch 510 is turned on while adjusting the clutch hydraulic pressure based on a predetermined pressure increase pattern (step S45), and then the process returns to the subroutine call. When it is determined that the brake operation is not released, the process returns to the subroutine call. .

  Next, a specific boosting pattern used when boosting and outputting the clutch proportional solenoid 511 will be described in detail.

  (4a) As shown in FIG. 7, which is a graph (part 1) for explaining the operation of the control mechanism of the work vehicle according to the first embodiment in the invention related to the present invention, it corresponds to the engine speed. To change the boost curve.

The same applies hereinafter, but the horizontal axis of the graph represents the time (sec) that has elapsed since the wheel braking operation to the brake 520 is no longer detected, and the vertical axis of the graph is transmitted from the engine using hydraulic pressure. This represents the pressure (kgf / cm ² ) of the clutch 510 that turns on / off the transmission of the incoming power.

  The automatic control that changes the boosting curve according to the engine speed allows the clutch 510 to be gradually connected without causing a clutch shock or an engine stop, and allows the vehicle to start smoothly.

  When the engine speed is low, there is a high possibility that the engine will be stopped. Therefore, during the beginning, the clutch 510 is connected without increasing the pressure of the clutch 510, and the clutch 510 is finally full. It is desirable to connect.

  (4b) As shown in FIG. 8 which is a graph (part 1) for explaining the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention, the boost curve is changed in accordance with the vehicle speed. .

  The automatic control that changes the pressure-up curve according to the vehicle speed allows the clutch 510 to be gradually connected without causing a clutch shock or engine stop, and allows the vehicle to start smoothly.

  Note that when the vehicle speed is low, there is a high possibility that the engine stop will be triggered. Therefore, during the beginning, the clutch 510 is connected over time without increasing the pressure of the clutch 510 so that the clutch 510 is finally connected. It is desirable to fully connect.

  That is, the pressure of the clutch 510 that can generate the same torque varies depending on the vehicle speed. For example, the pressure increases corresponding to several preset vehicle speed bands (for example, 10 km to 20 km band, 20 km to 30 km band, etc.). By using the pattern, it is possible to eliminate the inconvenience that a large time lag occurs with respect to the time required until the same torque is generated or an engine stop occurs.

  (4c) As shown in FIG. 9, which is a graph (part 2) illustrating the operation of the control mechanism of the work vehicle according to the first embodiment of the present invention, corresponding to the amount of inclination in the vehicle longitudinal direction. Change the boost curve.

  The automatic control that changes the boost curve according to the amount of inclination in the longitudinal direction of the vehicle allows the clutch 510 to be gradually connected without causing a clutch shock or engine stop, and allows the vehicle to start smoothly.

  When the amount of leaning in the longitudinal direction of the vehicle is large, there is a high possibility that an engine stop will be caused. Therefore, during the beginning, the clutch 510 is connected without increasing the pressure of the clutch 510 and finally the clutch is engaged. It is desirable to fully connect 510.

  That is, when the amount of leaning in the longitudinal direction of the vehicle is large, the vehicle speed tends to decrease because of the uphill, and the engine stop is likely to be triggered as described above. By using a pressure increase curve that suppresses the change and has a small amount of pressure change per time, it is possible to eliminate the inconvenience of the engine stop.

  (4d) In the above (4a) to (4c), FIG. 10 is a graph (part 2) illustrating the operation of the control mechanism of the work vehicle according to the first embodiment in the invention related to the present invention. As described above, the pressure of the clutch 510 may be controlled to increase in accordance with the depression amount of the brake pedal 533 measured by a potentiometer provided on the brake pedal 533.

  Here, since the vertical axis of the graph represents the pressure of the clutch 510 as described above, the amount of depression of the brake is not written on the vertical axis, and qualitative behavior is also entered for easy understanding. Only.

  For example, when the brake pedal 533 is fully depressed, the clutch 510 is completely turned off, and the pressure of the clutch 510 is gradually increased in response to the release of the brake pedal 533, so that the vehicle can be started smoothly. Become.

  (4e) Further, in the above (4d), FIG. 11 is a graph (part 3) illustrating the operation of the control mechanism of the work vehicle according to the first embodiment in the invention related to the present invention. As described above, the brake pressure of the left and right brakes B (see FIG. 12) for braking the rear wheel 3 (see FIG. 12) is controlled in consideration of the depression amount of the brake pedal 533 measured by the potentiometer provided on the brake pedal 533. May be.

  Here, since the vertical axis of the graph represents the pressure of the clutch 510 as described above, there is no scale on the vertical axis for the brake depression amount and the brake pressure, and a qualitative behavior is entered together to facilitate understanding. It has only been done.

  For example, by gradually releasing the brake pressure of the brake B while gradually connecting the clutch 510 in response to the release of the brake pedal 533, the vehicle does not move downward along the slope even on a slope. It is possible to start the vehicle smoothly.

  From what has been described above, for example, a hydraulic reverse clutch that can be electrically turned on / off, a potentiometer that detects the amount of depression of the clutch pedal, various switches, and a forward / reverse travel direction can be operated by levers. A reverse lever that can be selected correspondingly, and a switch that detects the depression of the brake pedal in a tractor that can control the boosting of the reverse clutch in accordance with the state of various sensors and switches and the selection state of forward and backward travel Equipped with an engine brake that automatically controls the reverse clutch to turn off properly after a predetermined time has elapsed without the clutch pedal being depressed when the brake pedal is detected. While simultaneously triggering an engine stop Ku can be achieved smooth starting stop control.

  Next, the configuration and operation of the power transmission mechanism of the work vehicle according to the present embodiment, which is controlled by the control mechanism, will be described in detail with reference mainly to FIGS.

  FIG. 12 is a transmission diagram of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. FIG. 13 is a schematic development view of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. FIG. 14 is a schematic front view of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. FIG. 15 is a schematic front view of the power transmission mechanism of the work vehicle according to the first embodiment of the present invention. It is a perspective view.

  In the following, regarding the power transmission mechanism of the transmission in the transmission case 8 in which the front case and the rear case are integrally assembled, from the engine 5, (1) the front wheel 2 and the rear wheel 3, and (2) the rotary work machine ( A transmission mechanism for transmission to the PTO output shaft 111 connected to the (not shown) will be described.

  First, the main transmission unit 150 will be described.

  The rotation of the engine output shaft 20 of the engine 5 is transmitted to the input shaft 21.

  That is, power interruption by the clutch pedal 531 is performed by the forward / reverse clutch 48, and the forward / reverse clutch 48 serves as a main clutch.

  The first input gear 22 fixed to the input shaft 21 meshes with the first low speed gear 26 of the first high / low clutch 24 and the second low speed gear 27 of the second high / low clutch 25, and fixed to the input shaft 21. The second input gear 23 meshes with the first high speed gear 30 of the first high / low clutch 24 and the second high speed gear 31 of the second high / low clutch 25.

  When the first high / low clutch 24 is connected to the first low speed gear 26 side, the rotation is transmitted from the first low speed gear 26 to the first clutch shaft 28, and the first high / low clutch 24 is connected to the first high speed gear 30 side. , The rotation is transmitted from the first high speed gear 30 to the first clutch shaft 28.

  When the second high / low clutch 25 is connected to the second low speed gear 27 side, the rotation is transmitted from the second low speed gear 27 to the second clutch shaft 29, and the second high / low clutch 25 is connected to the second high speed gear 31 side. , The rotation is transmitted from the second high speed gear 31 to the second clutch shaft 29.

  The first high / low clutch 24 and the second high / low clutch 25, which are the same hydraulic multi-plate clutch, respectively reduce the rotation of the input shaft 21 in two stages of high and low at the same reduction ratio. 28 and the second clutch shaft 29 are transmitted.

  The first high / low clutch 24 and the second high / low clutch 25 are immersed in the lubricating oil, and the first clutch shaft 28 and the second clutch shaft 29 are located slightly above the liquid level OL of the lubricating oil.

  An oil supply hole 8b drilled from the left and right opening sides of the case is provided in the built-up portion 181a formed on the front partition wall 181 that supports the first clutch shaft 28 and the second clutch shaft 29 to the transmission case 8. Thus, the fuel is supplied to the shafts of the first high / low clutch 24 and the second high / low clutch 25 from the oil supply hole 8b.

  The oil supply holes 8b are provided in a concentrated manner as oil passages in the vertical direction and the horizontal direction, avoiding the bearing portion, instead of the piping in the case.

  If an oil filter (not shown) is attached near the oil supply hole 8b, piping can be simplified.

  The first high / low clutch 24 and the second high / low clutch 25 are arranged on the left and right in the lower part of the downward inclined portion 8 c of the mission case 8.

  The first gear 113 fixed to the first clutch shaft 28 meshes with the second gear 35 fixed to the low-speed transmission shaft 34, the rotation is decelerated and transmitted, and the third gear 149 fixed to the second clutch shaft 29 is transmitted at high speed. The fourth gear 33 fixed to the transmission shaft 32 is engaged with the fourth gear 33, and the rotation is increased and transmitted.

  In the transmission so far, the low-speed transmission shaft 34 is shifted in two steps at a low speed, and the high-speed transmission shaft 32 is shifted in two steps at a high speed, so that a total of four speeds are changed.

  The rotation of the low speed transmission shaft 34 and the high speed transmission shaft 32 is transmitted to the first sync change 42 and the second sync change 36, respectively.

  The first sync small gear 43 of the first sync change 42 and the second sync small gear 37 of the second sync change 36 mesh with the fifth gear 40 of the first transmission shaft 39, and the first sync large gear of the first sync change 42. 44 and the second synchro large gear 38 of the second synchro change 36 mesh with the sixth gear 41 of the first transmission shaft 39, and the rotation is transmitted.

  The first sync small gear 43 of the first sync change 42 and the second sync small gear 37 of the second sync change 36 are exactly the same gear, and the first sync large gear 44 of the first sync change 42, The second synchro large gear 38 of the second sync change 36 is exactly the same gear.

  The low speed transmission shaft 34 rotates at a low speed, and the high speed transmission shaft 32 rotates at a high speed.

  Accordingly, when the first sync change 42 is switched, a further two-stage shift at a low speed is performed, and when the second sync change 36 is switched, a further two-stage shift at a high speed is performed.

  That is, the rotation of the first input shaft 21 is shifted by the first transmission shaft 39 to the low speed four stages and the high speed four stages.

  The first sync change 42 and the second sync change 36 are accommodated in the mission case 8 by sub-assembling the shifter stay and the shifter.

  The case opening of the speed change operation portion is provided on the left and right side surfaces of the case, and is provided above the lubricating oil level OL of the transmission case 8.

  Thus, the main transmission unit 150 reads the shift position of the main transmission lever (not shown) operated by the operator, and is a high / low hydraulic multi-plate clutch that is automatically operated by a traveling system ECU (Engine Control Unit). The high / low clutch 24 and the second high / low clutch 25, the first sync change 36 and the second sync change 42 are controlled, and the gears are shifted to the low speed four stages and the high speed four stages.

  In the mission case 8, the first high / low clutch 24 and the second high / low clutch 25 are arranged on the left and right.

  Below that, a low-speed transmission shaft 34 to which the first sync change 42 is attached and a high-speed transmission shaft 32 to which the second sync change 36 is attached are arranged on the left and right.

  Thus, a compact configuration in which the left and right width of the mission case 8 is narrow and the height is low is realized.

  Further, the first transmission shaft 39 is connected to the second transmission shaft 45 by shaft connection.

  A seventh gear 46 and an eighth gear 47 are fixed to the second transmission shaft 45.

  The seventh gear 46 is meshed with a forward clutch gear 49 of a hydraulic multi-plate forward / reverse clutch 48 (this corresponds to the clutch 510 described above, and the same applies hereinafter).

  The eighth gear 47 is meshed with the reverse gear 51 of the reverse shaft 52, and the reverse gear 51 is meshed with the reverse clutch gear 50 of the forward / reverse clutch 48.

  Therefore, when the forward / reverse clutch 48 is connected to the forward clutch gear 49 by boosting the forward clutch 48a, the rotation of the seventh gear 46 is transmitted to the auxiliary transmission shaft 53 connected to the forward / reverse clutch 48 in the forward rotation state. When the forward / reverse clutch 48 is connected to the reverse clutch gear 50 by boosting the reverse clutch 48b, the rotation of the eighth gear 47 is transmitted to the auxiliary transmission shaft 53 in the reverse state.

  The reduction ratio is different between forward rotation and reverse rotation, and the reverse rotation is slower. The selection of forward transmission (forward) and reverse transmission (reverse) is performed by operating the forward / reverse switching lever 532 provided on the left side of the handle column on which the handle is erected.

  Next, the auxiliary transmission unit 154 will be described.

  The ninth gear 54 and the tenth gear 55 fixed to the auxiliary transmission shaft 53 mesh with the third sync large gear 56 and the third sync small gear 59 of the third sync change 58, respectively.

  Accordingly, when the third sync change 58 is connected to the third sync large gear 56, the fifth transmission shaft 60 is driven at a high speed by increasing the speed transmitted from the ninth gear 54 to the third sync large gear 56. When the third sync change 58 is connected to the third sync small gear 59 side, the fifth transmission shaft 60 is decelerated by the rotation transmitted from the tenth gear 55 to the third sync small gear 59 and driven at medium speed. .

  The eleventh gear 57 fixed to the third synchro small gear 59 side of the third synchro change 58 meshes with the fourth synchro small gear 69 of the fourth synchro change 71.

  The fifteenth gear 70 fixed to the fourth synchro small gear 69 side meshes with the seventeenth gear 75 of the second cylindrical shaft 114, and the rotation starts from the eighteenth gear 76 fixed to the second cylindrical shaft 114. It is transmitted to the four synchro large gears 72.

  A sixteenth gear 74 is fixed to the first cylinder shaft 73 on which the fourth sync change 71 is mounted.

  Therefore, when the third sync change 58 is made neutral, the rotation of the tenth gear 55 is transmitted to the third sync small gear 59, and the rotation is transmitted from the eleventh gear 57 fixed to the third sync small gear 59 side. It is transmitted to the fourth synchro small gear 69.

  In this state, when the fourth sync change 71 is connected to the fourth sync small gear 69 side, the rotation of the fourth sync small gear 69 becomes the rotation of the sixteenth gear 74 and the speed is lowered. When connected to the fourth synchro large gear 72 side, the rotation of the fourth synchro small gear 69 is transmitted from the fifteenth gear 70 to the seventeenth gear 75, the eighteenth gear 76 and the fourth synchro large gear 72, The sixteenth gear 74 becomes extremely low speed.

  When the third sync change 58 is connected to the third sync large gear 56 side or the third sync small gear 59 side, the fourth sync change 71 is made neutral.

  Thus, with respect to the rotation of the sub-transmission shaft 53 that has been subjected to the 150-speed change in the main transmission unit, the sub-transmission unit 154 performs four-speed shifts to the low-speed 16 and high-speed 16 stages. A shift is made.

  The sixteenth gear 74 meshes with the twelfth gear 61 fixed to the fifth transmission shaft 60 to drive the fifth transmission shaft 60.

  The first bevel gear 62 fixed to the shaft end of the fifth transmission shaft 60 meshes with the second bevel gear 63 of the rear bevel case 64, and from the bevel output shaft 65 of the rear bevel case 64 to the thirteenth gear 66 and the tenth gear. The rear wheel output shaft 68 is rotated via the four gears 67 to drive the rear wheel 3.

  The twenty-first gear 117 is fixed to the fifth transmission shaft 60, and the twenty-second gear 118 and the twenty-second gear fixed to the second cylindrical shaft 119 supported by the auxiliary transmission shaft 53 are rotated. The sixteenth gear 77 of the first front wheel drive shaft 78 is transmitted to the nineteenth gear 77 through the gear 148, and the sixteenth gear 74 and the sixteenth rotation of the sixteenth gear 74 are transmitted to the first front wheel drive shaft 78. .

  This rotation is transmitted from the first front wheel drive shaft 78 to the second front wheel drive shaft 84 via the front wheel acceleration clutch 79 and is taken over by the third front wheel drive shaft 85, the fourth front wheel drive shaft 86 and the front wheel drive bevel shaft 87. It is transmitted by.

  The first front bevel gear 88 fixed to the shaft end of the front wheel drive bevel shaft 87 meshes with the second front bevel gear 115 of the front bevel case 89, and the front bevel output shaft 90 of the front bevel case 89, the first front bevel gear set. 91, the front wheel output shaft 93 is rotated via the front longitudinal axis 116 and the second front bevel gear set 92 to drive the front wheel 2.

  The first speed increasing clutch gear 82 and the second speed increasing clutch gear 80 of the front wheel speed increasing clutch 79 are engaged with the first speed increasing gear 83 and the second speed increasing gear 81, respectively. Change the speed increase rate.

  Thus, the sub-transmission unit 154 reads the shift position of the sub-transmission lever (not shown), and automatically controls the third sync change 58 and the fourth sync change 71 by the traveling system ECU to perform a shift.

  The first cylinder shaft 73 to which the fourth sync change 71 is attached is disposed below the fifth transmission shaft 60 to which the third sync change 58 is attached.

  Thus, a configuration in which the mission case 8 is short is realized.

  Next, the transmission path of the PTO output shaft 111 will be described.

  The main clutch gear 96 of the PTO main clutch 97 is engaged with the second input gear 23, and power is interrupted by the PTO main clutch 97.

  The PTO main clutch 97 is located below the first high / low clutch 24 and the second high / low clutch 25, and is cooled and lubricated with lubricating oil accumulated in the transmission case 8.

  A PTO transmission 157 is provided on the first PTO shaft 95 to which the PTO main clutch 97 is attached.

  The first PTO gear 98, the second PTO gear 99, the fifth synchro small gear 100 and the fifth synchro large gear 101 of the fifth sync change 151 are mounted.

  The twenty-second gear 102, the twenty-third gear 152, the twenty-first gear 103, and the twenty-fourth gear 153 are fixed to the second PTO shaft 104, and the PTO reverse rotation gear 105 is attached to the counter shaft 106. It is supported.

  When the first PTO gear 98 is slid and meshed with the twentieth gear 102, the second speed is obtained on the third PTO shaft 107.

  When the first PTO gear 98 is slid and meshed with the second PTO gear 99, the rotation of the first PTO shaft 95 is transmitted to the third PTO shaft 107 via the second PTO gear 99 and the twenty-third gear 152. , 4th speed is obtained.

  When the fifth sync change 151 is connected to the fifth sync small gear 100, the rotation is transmitted from the fifth sync small gear 100 to the 21st gear 103, and the first speed is obtained.

  When the fifth sync change 151 is connected to the fifth sync large gear 101, the rotation is transmitted from the fifth sync large gear 101 to the twenty-fourth gear 153 to obtain the third speed.

  When the PTO reverse rotation gear 105 is engaged with the first PTO gear 98 and the twentieth gear 102, the rotation of the first PTO shaft 95 is transferred from the first PTO gear 98 to the twentieth gear 102 via the PTO reverse rotation gear 105. It is transmitted to the third PTO shaft 107 and reverse rotation is obtained.

  The first PTO gear 98, the second PTO gear 99, and the fifth sync change 151 include the first high / low clutch 24 and the second high / low clutch 25, the first sync change 42, and the second sync change 36. Located between these underneath.

  The rotation of the third PTO shaft 107 is transmitted to the fifth PTO shaft 108 via the fourth PTO shaft 156, drives the first PTO output gear 109 and the second PTO output gear 110, and is further decelerated to generate the PTO output shaft. 111 is driven.

  The input shaft 21 and the fourth front wheel drive shaft 86 are located in the center of the left and right sides of the transmission case 8, the first high / low clutch 24 and the second high / low clutch 25 are disposed in symmetrical positions, and the high speed transmission shaft 32 and The low-speed transmission shaft 34 is disposed at the left / right symmetrical position, and the fourth PTO shaft 156 and the auxiliary transmission shaft 53 are disposed at the left / right symmetrical position.

  The fourth PTO shaft 156, the auxiliary transmission shaft 53, and the fourth front wheel drive shaft 86 are disposed below the inside of the transmission case 8, and form a vertex of a substantially isosceles triangle in a front view.

(Embodiment 2)
In the present embodiment, the configuration and operation of a work vehicle as described below will be described.

  A more specific configuration and operation of the work vehicle according to the second embodiment will be described in detail later.

  (A) In a utility tractor or the like having several stages of a main transmission mechanism and a sub-transmission mechanism, a reverse clutch shared with the main clutch (hereinafter the same, but a forward / reverse switching mechanism 15 described later corresponds to this) and Hi -Lo clutches (hereinafter the same, but a Hi-Lo transmission mechanism 16 described later corresponds to this) are laid out in series, and each clutch can be controlled by an electromagnetic valve.

  (A1) The Hi-Lo clutch outputs to the Lo side when the Hi-Lo changeover switch (hereinafter the same, but the Hi-Lo changeover switch 244 described later corresponds to this) is off, and the Hi-Lo When the changeover switch is on, output to the Hi side is performed.

  When the reverse clutch lever is neutral or the reverse clutch pedal is depressed, the Hi-Lo changeover switch is forcibly turned off and the Hi-Lo clutch outputs to the Lo side.

  Note that the engine brake-like brake action by the transmission mechanism is more effectively exhibited when the output to the Lo side is performed than when the output to the Hi side is performed.

  As a result, although the engine brake cannot be used because the reverse clutch is off, the impact of the roundabout that tends to occur when the engine brake cannot be used and the vehicle moves due to inertia is reduced. There is no increase in the sub-shift operation load, and a smooth shift operation is possible.

  (A2a) Pressure sensors that change the contact state when the reverse clutch hydraulic pressure reaches a predetermined threshold and are turned off are provided on each of the forward and reverse sides of the reverse clutch to instruct a change in the hydraulic pressure of the reverse clutch. Whether or not the output from the controller is executed is determined by the on / off logic state of the pressure sensors, and the occurrence of an abnormality that the instruction is not executed is detected.

  This makes it possible to detect the occurrence of an abnormality at a low cost by using an inexpensive pressure sensor, thereby ensuring safety.

  (A2b) In the above (A2a), when the output from the controller instructing to increase the hydraulic pressure is not executed and the pressure sensor is on and the pressureless state continues for, for example, 3 seconds or more, the output from the controller is temporarily turned off. , Buzzer warning is performed at the same time.

  Then, it becomes possible to reduce the risk that the reverse clutch will be used and worn for a long time despite the occurrence of an abnormality, and it is possible to quickly notify the operator of the occurrence of the abnormality.

  (A2c) In (A2b) above, the buzzer warning after the detection of the abnormality is continued until the engine stops, but the output from the controller is turned off only once, for example.

  Then, even when the reverse clutch used for work for a long time is burned and an abnormality has occurred, it is possible to reduce the risk of being unable to escape from the field.

  Note that if the output from the controller is turned off many times after the power is turned on, the vehicle may not be able to travel.

  (B1) In a tractor or the like having an engine coolant temperature sensor for engine cooling water, a hydraulic clutch (hereinafter the same, but later-described hydraulic multi-plate clutches C1 and C2 correspond to this) is a clutch pedal detected by a potentiometer. The pressure is controlled according to the operation amount.

  The target pressure of the hydraulic clutch is corrected corresponding to the detected temperature of the engine water temperature sensor.

  Then, it is possible to correct the target pressure of the hydraulic clutch according to the mission oil temperature while avoiding cost increase by diverting the engine water temperature sensor, reducing the shock to the hydraulic clutch due to gear shifting and starting, etc., and ensuring safety. Is possible.

  In the common rail engine, the engine water temperature sensor is indispensable and an existing component.

  Further, although the engine water temperature is not necessarily proportional to the mission oil temperature related to the hydraulic clutch, the mission oil temperature is low if the engine water temperature is low.

  (B2) In a tractor or the like having an engine coolant temperature sensor for engine cooling water, the Hi-Lo clutch is controlled in response to a switch operation.

  And the connection algorithm of a Hi-Lo clutch is changed corresponding to the detected temperature of an engine water temperature sensor.

  For example, as shown in FIG. 16, when the detected temperature is low, the output at the time of Hi-Lo clutch switching is not wrapped and double engagement is prevented, and when the detected temperature is high, the output at the time of Hi-Lo clutch switching. To reduce the power interruption and reduce the shock to the Hi-Lo clutch due to shifting and starting.

  FIG. 16 is an explanatory diagram of a voltage waveform and a pressure waveform associated with the control output of the work vehicle according to the second embodiment in the invention related to the present invention.

  By diverting the engine water temperature sensor, it is possible to change the connection algorithm of the Hi-Lo clutch according to the mission oil temperature while avoiding the cost increase, and it is possible to reduce the shock to the Hi-Lo clutch and to ensure safety. become.

  The above (B1) and (B2) can also be mounted on the work vehicle of the first embodiment described above.

  Next, a more specific configuration and operation of the power transmission mechanism of the work vehicle in the second embodiment will be described in detail with reference mainly to FIGS.

  FIG. 17 is a transmission diagram of the power transmission mechanism of the work vehicle according to the second embodiment in the invention related to the present invention, and FIG. 18 is a power diagram of the work vehicle according to the second embodiment in the invention related to the present invention. FIG. 19 is a schematic plan view of a work vehicle according to a second embodiment of the invention related to the present invention.

  The transmission includes a transmission case and a transmission mechanism that is disposed in the transmission case and transmits rotational power from the engine 4 to the rear wheel 3 and the like.

  The transmission mechanism transmits rotational power from the engine 4 to the front wheels 2, the rear wheels 3, and a work machine (not shown) mounted on the body, and drives them with rotational power from the engine 4.

  More specifically, the transmission mechanism includes an input shaft 14, a forward / reverse switching mechanism 15, a Hi-Lo transmission mechanism 16 as a high / low transmission mechanism, a main transmission mechanism 17, an auxiliary transmission mechanism 18, a 2WD / 4WD switching mechanism 19 and a PTO. (Power Take-Off) drive mechanism 220 and the like.

  The transmission mechanism transmits the rotational power generated by the engine 4 to the rear wheel 3 through the input shaft 14, the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16, the main transmission mechanism 17, and the auxiliary transmission mechanism 18 in order. be able to.

  Further, the transmission mechanism transmits the rotational power generated by the engine 4 to the input shaft 14, the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16, the main transmission mechanism 17, the auxiliary transmission mechanism 18, and the 2WD / 4WD switching mechanism 19. It can be transmitted to the front wheel 2 via the order.

  Further, the transmission mechanism can transmit the rotational power generated by the engine 4 to the work implement via the input shaft 14 and the PTO drive mechanism 220 in order.

  The input shaft 14 is coupled to the output shaft of the engine 4, and rotational power from the engine 4 is transmitted, that is, input.

  The forward / reverse switching mechanism 15 is capable of switching the rotational power transmitted from the engine 4 to forward rotation or reverse rotation.

  The forward / reverse switching mechanism 15 includes a forward gear stage 15a, a reverse gear stage 15b, a reverse gear 15c, a hydraulic multi-plate clutch C1 that is a forward clutch, and a hydraulic multi-plate clutch C2 that is a reverse clutch.

  The hydraulic multi-plate clutches C1 and C2 can switch the power transmission path in the forward / reverse switching mechanism 15 by switching the mesh release state.

  The forward / reverse switching mechanism 15 transmits the rotational power transmitted to the input shaft 14 corresponding to the disengagement state of the hydraulic multi-plate clutches C1 and C2 to the counter shaft 221 by changing the transmission path.

  When the hydraulic multi-plate clutch C1 is in the engaged state and the hydraulic multi-plate clutch C2 is in the released state, the forward / reverse switching mechanism 15 transmits the rotational power transmitted to the input shaft 14 to the forward gear stage 15a and the hydraulic multi-plate clutch. It is transmitted to the counter shaft 221 by forward rotation through C1.

  When the hydraulic multi-plate clutch C1 is in the released state and the hydraulic multi-plate clutch C2 is in the engaged state, the forward / reverse switching mechanism 15 converts the rotational power transmitted to the input shaft 14 to the reverse gear 15b, the reverse gear 15c, The torque is transmitted to the counter shaft 221 by reverse rotation through the hydraulic multi-plate clutch C2.

  Thereby, the forward / reverse switching mechanism 15 can switch the forward / backward movement of the tractor.

  The forward / reverse switching mechanism 15 also functions as a main clutch. When both the hydraulic multi-plate clutches C1 and C2 are released, a neutral state is established, and power transmission to the front wheel 2 side and the rear wheel 3 side is interrupted. be able to.

  The forward / reverse switching mechanism 15 can switch between forward, reverse, and neutral by hydraulic control, for example, when an operator operates the forward / reverse switching lever 243.

  Further, by depressing the clutch pedal, both the hydraulic multi-plate clutches C1 and C2 can be released.

  The Hi-Lo speed change mechanism 16 can change the rotational power transmitted from the engine 4 at a high speed stage or a low speed stage.

  The Hi-Lo transmission mechanism 16 includes a Hi (high speed) side gear stage 16a, a Lo (low speed) side gear stage 16b, a hydraulic multi-plate clutch C3 that is a Hi (high speed) side clutch, and a hydraulic pressure that is a Lo (low speed) side clutch. A multi-plate clutch C4 is provided.

  The hydraulic multi-plate clutches C3 and C4 can switch the power transmission path in the Hi-Lo transmission mechanism 16 by switching the mesh release state.

  The Hi-Lo speed change mechanism 16 transmits the rotational power transmitted to the counter shaft 221 to the speed change shaft 222 by changing the transmission path in response to the meshing release state of the hydraulic multi-plate clutches C3 and C4.

  The Hi-Lo transmission mechanism 16 transmits the rotational power transmitted to the counter shaft 221 to the hydraulic multi-plate clutch C3 and the Hi-side gear when the hydraulic multi-plate clutch C3 is engaged and the hydraulic multi-plate clutch C4 is released. The speed is changed via the stage 16a and transmitted to the transmission shaft 222.

  The Hi-Lo transmission mechanism 16 transmits the rotational power transmitted to the counter shaft 221 to the hydraulic multi-plate clutch C4 and the Lo-side gear when the hydraulic multi-plate clutch C3 is in the released state and the hydraulic multi-plate clutch C4 is in the meshed state. The speed is changed via the stage 16 b and transmitted to the speed change shaft 222.

  Thereby, the Hi-Lo transmission mechanism 16 can shift the rotational power from the engine 4 at the transmission ratio of the Hi side gear stage 16a or the transmission ratio of the Lo (low speed) side gear stage 16b and transmit it to the subsequent stage. .

  The Hi-Lo speed change mechanism 16 is configured such that, for example, the Hi-Lo changeover switch 244, which is a high / low speed change operation switch, is turned on and off by an operator, and the hydraulic control controls the Hi (high speed) side, the Lo (low speed) side, Can be switched, and the speed can be changed at any one of two stages of high speed and low speed.

  Further, the Hi-Lo speed change mechanism 16 can change speed during traveling of the tractor by the above-described configuration.

  When the reverse clutch lever is neutral or the reverse clutch pedal is depressed, the Hi-Lo changeover switch 244 is forcibly turned off and the Hi-Lo clutch outputs to the Lo side.

  The main transmission mechanism 17 can change the rotational power transmitted from the engine 4 at any one of a plurality of shift stages.

  The main speed change mechanism 17 is a synchromesh type speed change mechanism, and here, the rotational power transmitted from the engine 4 via the forward / reverse switching mechanism 15 and the Hi-Lo speed change mechanism 16 can be changed.

  The main speed change mechanism 17 includes a first speed gear stage 17a, a second speed gear stage 17b, a third speed gear stage 17c, a fourth speed gear stage 17d, a fifth speed gear stage 17e, and a sixth speed. A gear stage 17f is included.

  The main transmission mechanism 17 converts the rotational power transmitted to the transmission shaft 222 into the first speed gear corresponding to the coupling state of the first speed gear stage 17a, ... and the sixth speed gear stage 17f with the transmission shaft 222. .., And sixth speed gear stage 17f, the speed is changed and transmitted to transmission shaft 223.

  As a result, the main transmission mechanism 17 can change the rotational power from the engine 4 at any gear ratio of the first speed gear stage 17a,..., And the sixth speed gear stage 17f and transmit it to the subsequent stage. it can.

  The main transmission mechanism 17 can select and switch any of a plurality of shift stages by operating the main shift operation lever 245 by an operator, for example, and the first speed gear stage 17a,. The speed can be changed at any one of the six speeds of the sixth speed gear stage 17f.

  Further, the main transmission mechanism 17 can change gears during traveling of the tractor with the above-described configuration.

  The auxiliary transmission mechanism 18 can change the rotational power transmitted from the engine 4 through the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16 and the main transmission mechanism 17 in this order.

  The sub-transmission mechanism 18 includes a first sub-transmission 224 and a second sub-transmission 225. The sub-transmission mechanism 18 transmits the rotational power transmitted to the transmission shaft 223 to the first sub-transmission 224, the second sub-transmission 225, and the like. Through the transmission shaft 226 and transmitted to the transmission shaft 226.

  The first sub-transmission 224 can transmit the rotational power transmitted from the engine 4 and shifted by the main transmission mechanism 17 or the like at the high speed stage or the low speed stage and transmit it to the rear wheel 3 side which is a driving wheel.

  The second sub-transmission 225 shifts the rotational power transmitted from the engine 4 and shifted by the main transmission mechanism 17 or the like at an extremely low speed lower than that of the first sub-transmission 224, and is a rear wheel that is a drive wheel. It can be transmitted to the 3 side.

  The first auxiliary transmission 224 of the auxiliary transmission mechanism 18 includes a first gear 224a, a second gear 224b, a third gear 224c, a fourth gear 224d, a shifter 224e, and the like.

  The first gear 224a is coupled to the transmission shaft 223 so as to be integrally rotatable, and the rotational power from the transmission shaft 223 is transmitted, that is, input.

  The second gear 224b meshes with the first gear 224a.

  The third gear 224c is coupled to the second gear 224b so as to be integrally rotatable.

  The fourth gear 224d meshes with the third gear 224c.

  The shifter 224e switches the coupling state between the first gear 224a and the fourth gear 224d and the transmission shaft 226.

  The shifter 224e has a Hi (high speed) side position where the first gear 224a and the transmission shaft 226 are coupled so as to be integrally rotatable, and a Lo (low speed) side position where the fourth gear 224d and the transmission shaft 226 are coupled so as to be integrally rotatable. In addition, both the first gear 224a and the fourth gear 224d are movable to a neutral position (neutral position) where they are released without being coupled to the transmission shaft 226.

  The first auxiliary transmission 224 transmits the rotational power transmitted to the transmission shaft 223 to the transmission shaft 226 by switching the transmission path corresponding to the position of the shifter 224e.

  When the shifter 224e is at the Hi side position, the first auxiliary transmission 224 transmits the rotational power transmitted to the transmission shaft 223 via the first gear 224a, the second gear 224b, the third gear 224c, and the fourth gear 224d. Without being transmitted to the transmission shaft 226. That is, the rotational power is transmitted through the transmission shaft 223, the first gear 224a, and the transmission shaft 226 in order.

  When the shifter 224e is in the Lo side position, the first sub-transmission 224 transmits the rotational power transmitted to the transmission shaft 223 to the first gear 224a, the second gear 224b, the third gear 224c, the fourth gear 224d, and the shifter. The speed is sequentially reduced via 224e and transmitted to the transmission shaft 226.

  As a result, the first sub-transmission 224 transmits the rotational power from the engine 4 to the Hi (high speed) side gear ratio without passing through the second gear 224b, the third gear 224c, and the fourth gear 224d, or the second gear 224b. Then, the gear can be shifted at the Lo (low speed) side gear ratio via the third gear 224c and the fourth gear 224d and transmitted to the subsequent stage.

  In addition, when the shifter 224e is in the neutral position, the first auxiliary transmission 224 is in a state where both the first gear 224a and the fourth gear 224d are idle with respect to the transmission shaft 226, that is, in a neutral state.

  For example, the first sub-transmission 224 is operated by the operator operating the first sub-transmission operation lever 249 to switch the position of the shifter 224e, so that the Hi (high speed) side, the Lo (low speed) side, You can switch to neutral.

  The second auxiliary transmission 225 of the auxiliary transmission mechanism 18 includes a first gear 225a, a second gear 225b, a third gear 225c, a fourth gear 225d, a shifter 225e, and the like.

  The first gear 225a is coupled to the fourth gear 224d so as to be integrally rotatable.

  The second gear 225b meshes with the first gear 225a.

  The third gear 225c is coupled to the second gear 225b so as to be integrally rotatable.

  The fourth gear 225d meshes with the third gear 225c.

  The shifter 225e switches the coupling state of the fourth gear 225d and the transmission shaft 226.

  The shifter 225e includes a pole Lo (very low speed) side position where the fourth gear 225d and the transmission shaft 226 are coupled so as to be integrally rotatable, and a neutral position (neutral) where the fourth gear 225d and the transmission shaft 226 are released without being coupled. Position).

  The second auxiliary transmission 225 transmits the rotational power transmitted to the transmission shaft 223 to the transmission shaft 226 by switching the transmission path corresponding to the position of the shifter 225e.

  When the first sub-transmission 224 is in the neutral state and the shifter 225e is at the pole Lo side position, the second sub-transmission 225 uses the rotational power transmitted to the transmission shaft 223 as the first sub-transmission 224. The gear 224a, the second gear 224b, the third gear 224c and the fourth gear 224d, and the first gear 225a, the second gear 225b, the third gear 225c and the fourth gear 225d of the second auxiliary transmission 225, and the shifter 225e Are sequentially decelerated through this and transmitted to the transmission shaft 226.

  As a result, the second auxiliary transmission 225 transmits the rotational power from the engine 4 to the second gear 224b, the third gear 224c, the fourth gear 224d, the first gear 225a, the second gear 225b, the third gear 225c, and the second gear 225c. The speed can be changed at a speed ratio on the pole Lo (very low speed) side via the four gears 225d and transmitted to the subsequent stage.

  Further, when the shifter 225e is in the neutral position, the second auxiliary transmission 225 is in a state in which the fourth gear 225d is idled with respect to the transmission shaft 226, that is, in a neutral state.

  The second auxiliary transmission 225 is in a neutral state when the first auxiliary transmission 224 is on the Hi (high speed) side or the Lo (low speed) side.

  In the second auxiliary transmission 225, for example, when the second auxiliary transmission operation lever 250 is operated by an operator, the position of the shifter 25e is switched to switch between the pole Lo (very low speed) side and the neutral. be able to.

  Therefore, the subtransmission mechanism 18 combines the rotational power transmitted to the transmission shaft 223 with the first subtransmission 224 and the second subtransmission 225, so that the subtransmission mechanism 18 out of three stages of high speed, low speed, and extremely low speed can be obtained. Either can be shifted and transmitted to the transmission shaft 226.

  That is, the subtransmission mechanism 18 can shift at the Hi (high speed) stage when the first subtransmission 224 is in the Hi (high speed) side and the second subtransmission 225 is in the neutral state. When the sub-transmission 224 is in the Lo (low speed) side and the second sub-transmission 225 is in the neutral state, it is possible to shift at the Lo (low speed) stage, the first sub-transmission 224 is in the neutral state, When the sub-transmission 225 is on the pole Lo (very low speed) side, it is possible to shift at a pole Lo (very low speed) stage.

  The auxiliary transmission mechanism 18 is switched between high speed, low speed, and extremely low speed in a state where the tractor is stopped.

  The transmission mechanism of the transmission transmits the rotational power transmitted to the transmission shaft 226 to the rear wheel 3 via the rear wheel differential 227, the axle 228 as a drive shaft, the planetary gear mechanism 229, and the like.

  As a result, the rear wheel 3 of the tractor is rotationally driven as a drive wheel by the rotational power from the engine 4.

  To summarize the above description, the rotation of the input shaft 14 is first switched to forward rotation or reverse rotation by the forward / reverse switching mechanism 15, and is shifted by either the high-speed or low-speed two stages by the Hi-Lo transmission mechanism 16. The main transmission mechanism 17 is shifted in one of the six speeds of the first speed gear stage 17a,..., And the sixth speed gear stage 17f, and the auxiliary transmission mechanism 18 has three speeds of high speed, low speed, and extremely low speed. The speed is changed by one of them and transmitted to the axle 228.

  That is, the rotation of the input shaft 14 is shifted in any one of 36 (= 2 × 6 × 3) stages by the transmission mechanism of the transmission and is transmitted to the axle 228.

  The 2WD / 4WD switching mechanism 19 switches whether or not the rotational power transmitted to the transmission shaft 226 is transmitted to the front wheel 2 side.

  The 2WD / 4WD switching mechanism 19 includes a transmission shaft 19a, a first gear 19b, a second gear 19c, a transmission shaft 19d, a shifter 19e, and the like.

  Rotational power from the transmission shaft 226 is transmitted, that is, input to the transmission shaft 19a via the gear 230, the gear 231, the transmission shaft 232, the coupling 233, and the like.

  The first gear 19b is assembled so that the transmission shaft 19a is inserted and the transmission shaft 19a can rotate relative to the first gear 19b.

  The second gear 19c meshes with the first gear 19b.

  The transmission shaft 19d is coupled to the second gear 19c so as to be integrally rotatable.

  The shifter 19e switches the coupling state between the transmission shaft 19a and the first gear 19b.

  The shifter 19e moves to a 4WD position where the transmission shaft 19a and the first gear 19b are coupled so as to be integrally rotatable, and a 2WD position (neutral position) where the transmission shaft 19a and the first gear 19b are uncoupled and released. Is possible.

  When the shifter 19e is in the 4WD position, the 2WD / 4WD switching mechanism 19 transmits the rotational power transmitted to the transmission shaft 19a to the transmission shaft 19d via the first gear 19b and the second gear 19c.

  Thereby, the 2WD / 4WD switching mechanism 19 can transmit the rotational power from the engine 4 to the front wheel 2 side.

  The transmission mechanism of the transmission transmits the rotational power transmitted to the transmission shaft 19d to the front wheels 2 via the front wheel differential 234, the axle 235 as a drive shaft, the vertical shaft 236, the planetary gear mechanism 237, and the like.

  As a result, the tractor can be driven by four-wheel drive, with the front wheels 2 and the rear wheels 3 being rotationally driven as drive wheels by the rotational power from the engine 4.

  When the shifter 19e is in the 2WD position, the 2WD / 4WD switching mechanism 19 blocks the transmission of the rotational power transmitted to the transmission shaft 19a to the transmission shaft 19d side.

  As a result, the tractor can travel by two-wheel drive.

  The 2WD / 4WD switching mechanism 19 can switch between the two-wheel drive and the four-wheel drive by switching the position of the shifter 19e, for example, by operating the 2WD / 4WD switch lever 246 by an operator.

  The PTO drive mechanism 220 drives the work implement with the power from the engine 4 by shifting the rotational power transmitted from the engine 4 and outputting it to the work implement from the PTO shaft 240 of the rear body 1R.

  The PTO drive mechanism 220 includes a PTO clutch mechanism 238, a PTO transmission mechanism 239, a PTO shaft 240, and the like.

  The PTO clutch mechanism 238 switches between transmission and interruption of the power to the PTO shaft 240 side.

  The PTO clutch mechanism 238 includes a gear 238a, a hydraulic multi-plate clutch C5, a transmission shaft 238b, and the like.

  The gear 238a meshes with a gear 241 that is coupled to the input shaft 14 so as to be integrally rotatable.

  The hydraulic multi-plate clutch C5 switches the power transmission state between the gear 238a and the transmission shaft 238b by switching the mesh release state.

  The PTO clutch mechanism 238 enters a PTO drive state in which power is transmitted to the PTO shaft 240 side when the hydraulic multi-plate clutch C5 is engaged, and the rotational power transmitted from the input shaft 14 to the gear 238a via the gear 241 is transmitted. Then, it is transmitted to the transmission shaft 238b via the hydraulic multi-plate clutch C5.

  When the hydraulic multi-plate clutch C5 is released, the PTO clutch mechanism 238 enters a PTO non-driven state (neutral state) in which transmission of power to the PTO shaft 240 side is interrupted, and the rotational power transmitted to the gear 238a. Transmission to the transmission shaft 238b side is interrupted.

  The PTO clutch mechanism 238 can switch between a PTO drive state and a PTO non-drive state by hydraulic control, for example, when a PTO changeover switch 247 is turned on and off by an operator.

  The tractor is provided with a gear pump 270 through a gear 270a meshing with the gear 238a, a gear 270b meshing with the gear 270a, and the like.

  The gear pump 270 applies hydraulic pressure to a hydraulic system such as a transmission mechanism.

  The PTO speed change mechanism 239 performs speed change when power is transmitted to the PTO shaft 240 side.

  The PTO transmission mechanism 239 includes a Hi (high speed) side gear stage 239a, a Lo (low speed) side gear stage 239b, a transmission shaft 239c, a shifter 239d, and the like.

  The PTO speed change mechanism 239 shifts the rotational power transmitted to the transmission shaft 238b through the Hi side gear stage 239a or the Lo side gear stage 239b in accordance with the position of the shifter 239d, and transmits it to the transmission shaft 239c. .

  The shifter 239d switches a coupling state between the Hi-side gear stage 239a or the Lo-side gear stage 239b and the transmission shaft 239c.

  The shifter 239d includes a Hi (high speed) side position where the Hi side gear stage 239a and the transmission shaft 239c are coupled, a Lo (low speed) side position where the Lo side gear stage 239b and the transmission shaft 239c are coupled, and a Hi side gear stage. Both 239a and the Lo-side gear stage 239b are movable to a neutral position (neutral position) where the transmission shaft 239c is not coupled and released.

  When the shifter 239d is at the Hi side position, the PTO transmission mechanism 239 transmits the rotational power transmitted to the transmission shaft 238b to the transmission shaft 239c via the Hi side gear stage 239a.

  When the shifter 239d is in the Lo side position, the PTO transmission mechanism 239 transmits the rotational power transmitted to the transmission shaft 238b to the transmission shaft 239c via the Lo side gear stage 239b.

  Thereby, the PTO transmission mechanism 239 can shift the rotational power from the engine 4 at the transmission ratio of the Hi-side gear stage 239a or the transmission ratio of the Lo-side gear stage 239b and transmit it to the subsequent stage.

  Further, when the shifter 239d is in the neutral position, the PTO transmission mechanism 239 is in a state (neutral state) in which both the Hi-side gear stage 239a and the Lo-side gear stage 239b idle with respect to the transmission shaft 239c.

  For example, the PTO speed change mechanism 239 is operated by an operator operating a PTO speed change operation lever 248 described later, so that the position of the shifter 239d is switched, and the Hi (high speed) side, Lo (low speed) side, neutral, Can be switched, and the speed can be changed in one of two stages of high speed and low speed.

  The PTO shaft 240 is coupled to a work machine and transmits rotational power from the engine 4 to the work machine.

  The PTO shaft 240 is rotationally driven by the rotational power transmitted to the transmission shaft 239c being transmitted through the gear 241 that is the first gear, the gear 242 that is the second gear, and the like.

  To summarize the above description, the rotation of the input shaft 14 is transmitted to the PTO transmission mechanism 239 via the PTO clutch mechanism 238, and the PTO transmission mechanism 239 is shifted in one of two stages of high speed and low speed, It is transmitted to the PTO shaft 240 and rotationally drives the PTO shaft 240.

  As a result, the tractor can change the rotational power transmitted from the engine 4 and output it from the PTO shaft 240 to the work implement, thereby driving the work implement.

  In the tractor, various operation levers are arranged in the cabin or in the rear part 1R of the aircraft.

  For example, a forward / reverse selector lever 243, a Hi-Lo selector switch 244, a main transmission operation lever 245, a 2WD / 4WD selector lever 246, and a PTO selector switch 247 are provided.

  Further, a PTO speed change operation lever 248 is provided at the rear part 1R of the fuselage.

  The forward / reverse switching lever 243 is used to perform the forward / reverse switching operation of the forward / reverse switching mechanism 15, and when the operator operates the forward / backward switching lever 243, the forward / reverse switching mechanism 15 is moved forward, backward, and neutral. It can be switched to either.

  The Hi-Lo change-over switch 244 is for performing a Hi-Lo change-over operation (high / low-speed change operation) of the Hi-Lo change-over mechanism 16, and when an operator operates the Hi-Lo change-over switch 244, the Hi-Lo change-over switch 244 is performed. The mechanism 16 can be switched to high speed or low speed.

  The main transmission operation lever 245 performs the main transmission operation of the main transmission mechanism 17, and the operator operates the main transmission operation lever 245 so that the main transmission mechanism 17 is moved to the first speed gear stage 17a,. It can be switched to any one of the six stages of the sixth speed gear stage 17f, or to neutral.

  The 2WD / 4WD switching lever 246 is used to perform the 2WD / 4WD switching operation of the 2WD / 4WD switching mechanism 19, and when the operator operates the 2WD / 4WD switching lever 246, the 2WD / 4WD switching mechanism 19 is driven by two wheels. Or it can switch to four-wheel drive.

  The PTO changeover switch 247 is used to perform the clutch changeover operation of the PTO clutch mechanism 238. When the operator operates the PTO changeover switch 247, the PTO clutch mechanism 238 can be changed over to the PTO drive state or the PTO non-drive state. it can.

  The PTO speed change operation lever 248 is used to perform the PTO speed change operation of the PTO speed change mechanism 239. When the operator operates the PTO speed change operation lever 248, the PTO speed change mechanism 239 is set to any one of high speed, low speed, and neutral. Can be switched to.

  The first sub-transmission operation lever 249 that performs the first sub-transmission operation of the first sub-transmission 224 of the sub-transmission mechanism 18 and the second sub-transmission operation of the second sub-transmission 225 of the sub-transmission mechanism 18 are performed. The second sub-shift operation lever 250 is provided separately, so that versatility is improved.

  For example, the first sub-transmission operation lever 249 and the second sub-transmission operation lever 250 are both provided in the cabin, and the second sub-transmission 225 is added later to the first sub-transmission 224 in the sub-transmission mechanism 18. For example, a second sub-shift operation lever 250 is provided separately from the first sub-transmission operation lever 249 so that a gear stage such as an extremely low speed stage can be added and the gear stage by the addition of the second sub-transmission 225 is operated.

  The vehicle in the present invention can realize smoother start / stop control, and is useful for the purpose of being used for a work vehicle such as an agricultural vehicle such as a tractor.

5 Engine 500 Controller 510 Clutch 520 Brake

Claims (4)

A brake that performs braking of the wheel driven by the power transmitted from the engine in response to an external operation;
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
The hydraulic pressure of the boosted pattern, as the vehicle running speed is low, Ru pattern der boosted degree is reduced with respect to time,
A vehicle characterized by that. A brake that performs braking of the wheel driven by the power transmitted from the engine in response to an external operation;
A clutch that uses hydraulic pressure to turn on the transmission of the power transmitted from the engine by increasing pressure and turning it OFF by decreasing pressure;
A controller for turning on the clutch based on the pressure increase pattern of the hydraulic pressure, which defines a change in hydraulic pressure over time after a wheel braking operation to the brake from the outside is no longer detected,
The hydraulic pressure of the boosted pattern, as the vehicle inclination amount in the vehicle longitudinal direction is large, Ru pattern der boosted degree is reduced with respect to time,
A vehicle characterized by that. 3. The vehicle according to claim 1, wherein the clutch is a forward / reverse clutch that performs power interruption corresponding to selection of forward or reverse by a forward / reverse switching lever. 4. The vehicle according to claim 3 , wherein the power interruption is performed even in response to an operation by a clutch pedal.

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