[0001]The present invention relates to a working vehicle.
[BACKGROUND ART]
[0002] A technique disclosed in Patent Document 1 is known, which is a technique for
driving a PTO shaft that is configured to be driven by an engine power in a working vehicle.
A tractor disclosed in Patent Document 1 includes a PTO selecting switch to turn on/off driving of the PTO shaft, a detection switch to detect a state of a parking brake, and a controller to stop an engine, that is, to control the driving of the PTO shaft according to states of the PTO selecting switch and the detection switch. When the controller detects that the PTO selecting switch is turned on and the detection switch detects activation of the parking brake, the controller maintains the driving of the PTO shaft without stopping the engine. [RELATED ART DOCUMENTS] [PATENT DOCUMENTS]
[0003]
[Patent document 1] Japanese Unexamined Patent Publication No. 2012-30616 [DISCLOSURE OF THE INVENTION]
[PROBLEMS TO BE SOLVED BY THE INVENTION]
[0004] In Patent Document 1, the PTO shaft is driven under a condition that the detection
switch detects parking of the tractor, so that an operator can perform a work with the tractor being parked. If the PTO shaft can be driven with the tractor being parked, it is convenient for the operator and others. In recent years, a driving device for the PTO shaft that includes further developed functions has been desired.
[0005] In view of the above-described problems, the present invention intends to provide
a working vehicle that allows an operator to perform a work outside a vehicle body by driving a PTO shaft while the vehicle body is parked. [MEANS OF SOLVING THE PROBLEMS]
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[0006] Technical means of the invention to solve this technical problems are
characterized by the following points.
A working vehicle includes a prime mover, a driver’s seat selectively set in either a first posture where a driver can sit on the driver’s seat or a second posture where the driver cannot sit on the driver’s seat, a speed-changing device configured to receive power from the prime mover and to perform a speed-changing of the power, a PTO shaft configured to receive the speed-changed power output from the speed-changing device, a posture switch configured to detect whether the driver’s seat is set in the first posture or the second posture, a parking switch configured to detect parking of a vehicle body, and a first actuation device configured so that, during driving of the prime mover, the first actuation device maintains the driving of the prime mover when both the parking and the driver’s seat set in the second posture are detected, and the first actuation device stops the driving of the prime mover when neither the parking nor the driver’s seat set in the second posture is detected.
[0007] The working vehicle further includes a speed-changing switch configured to be
turned on to allow the speed-changing performed by the speed-changing device, and to be turned off to disable the speed-changing device from performing the speed-changing. The first actuation device is configured to maintain the driving of the prime mover when the speed-changing device is turned off, and to stop the driving of the prime mover when the speed-changing device is turned on.
The working vehicle further includes an on-off switch operable to be turned on to allow driving of the PTO shaft, and to be turned off to disable the PTO shaft from driving, a key switch operable to issue an instruction for starting of the prime mover, a second actuation device configured to output an allowance signal when the PTO shaft is disabled from driving and the speed-changing switch is turned off, and a third actuation device operably connected to the second actuation device, and configured to perform the starting of the prime mover when the instruction for the starting of the prime mover is issued and the allowance signal is input to the third actuation device.
[0008] The first actuation device is configured to maintain the driving of the prime mover
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when the allowance signal is input to the first actuation device during the driving of the prime mover.
The first actuation device is configured as a relay including a first input terminal, a second input terminal and a first output terminal. The second actuation device is configured as a relay including a third input terminal, a fourth input terminal and a second output terminal. The third actuation device is configured as a relay including a fifth input terminal, a sixth input terminal and a third output terminal. A first line connecting the first actuation device and the second actuation device to each other is connected to the first input terminal. An electric source line is connected to the second input terminal. An output terminal of the on-off switch is connected to the third input terminal. An output terminal of the speed-changing switch is connected to the fourth input terminal. An output terminal of the key switch is connected to the fifth input terminal. A second line connected to the second output terminal is connected to the sixth input terminal. A stopping device for stopping the prime mover is connected to the first output terminal. A starter for performing the starting of the prime mover is connected to the third output terminal.
[0009] The working vehicle further includes a seat switch configured to detect sitting of a
driver on the driver’s seat, and a notification device configured to notify information in correspondence to a predetermined condition. The notification device notifies the information when the speed-changing switch is turned off and the sitting of the driver is not detected.
[EFFECTS OF THE INVENTION]
[0010] According to the present invention, an operator is capable of performing a work
outside a vehicle body by driving a PTO shaft while the vehicle body is parked. [BRIEF DESCRIPTION OF THE DRAWINGS]
[0011]
FIG. 1 is a schematic view of a whole of a transmission device. FIG. 2 is a whole view of a control circuit of a PTO shaft. FIG. 3 is a side view of an operator seat.
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FIG. 4 is a whole view of a control circuit according to a modified example of FIG. 2.
FIG. 5 is a whole view of a working vehicle. [BEST MODE FOR CARRYING OUT THE INVENTION]
[0012] Referring to drawings, an embodiment of the present invention will be described
below.
FIG. 5 shows an overall view of a working vehicle 1 according to this embodiment. The working vehicle 1 is not limited to a tractor, but may be an agricultural machine such as a combine harvester or a rice transplanter.
First, an overall configuration of the tractor 1 will be explained.
As shown in FIG. 5, the tractor 1 includes a traveling vehicle body (hereinafter referred to as a vehicle body) 3 having wheels, a prime mover 4, and a speed-changing device 5. The prime mover 4 is a diesel engine, a gasoline engine, an electric motor, or the like. In this embodiment, the prime mover 4 is the diesel engine (hereinafter referred to as an engine).
[0013] The vehicle body 3 includes a driver's seat 6 and a cabin 7 surrounding the
driver’s seat 6 at a rear portion of the vehicle body 3, a connecting portion 8 constituted of a three-point linkage mechanism or the like. A working device 2 can be attached to and detached from the connecting portion 8. The working device 2, such as a cultivator, fertilizer applicator, chemical sprayer, or the like, can be connected to the connecting portion 8 to be towed by the vehicle body 3.
[0014] As shown in FIG. 1, the speed-changing device 5 includes a main shaft
(propulsion shaft) 5a, a main speed-changing unit 5b, a sub speed-changing unit 5c, a shuttle unit 5d, and a PTO power transmission unit 5e. The propulsion shaft 5a is rotatably supported by a housing case of the speed-changing device 5, and a power from a crankshaft of the prime mover 4 is transmitted to the propulsion shaft 5a. The main speed-changing unit 5b includes a plurality of gears and a shifter for changing connection between the gears. The main speed-changing unit 5b appropriately changes the connection (engagement) between the
5

plurality of gears with the shifter to change the rotation input from the propulsion shaft 5a, thereby outputting the changed rotation (changing a speed).
[0015] Similar to the main speed-changing unit 5b, the sub speed-changing unit 5c has a
plurality of gears and a shifter for selecting which gears to be drivingly connected. The sub speed-changing unit 5c appropriately changes the connection (engagement) between the plurality of gears with the shifter to change the rotation input from the main speed-changing unit 5b, thereby outputting the changed rotation (changing a speed).
The shuttle unit 5d includes a shuttle shaft 12 and a forward /backward-traveling
switching unit 13. A power output from the sub speed-changing unit 5c is transmitted to the
shuttle shaft 12 through the gears and the like. The forward /backward-traveling switching
unit 13 is constituted of, for example, a hydraulic clutch and the like, and engages or
disengages the hydraulic clutch to switch a rotational direction of the shuttle shaft 12, i.e., a
traveling direction of the tractor 1 between the forward traveling and the backward traveling.
[0016] The PTO power transmission unit 5e includes a PTO propulsion shaft 14 and a
PTO clutch 15. The PTO propulsion shaft 14 is rotatably supported and capable of
transmitting a power from the propulsion shaft 5a. The PTO propulsion shaft 14 is
connected to the PTO shaft 16 via a gear and the like. The PTO clutch 15 is a clutch to
selectively perform a first operation in which a power of the propulsion shaft 5a is transmitted
to the PTO propulsion shaft 14 or a second operation in which the power of the propulsion
shaft 5a is not transmitted to the PTO propulsion shaft 14. Specifically, the PTO clutch 15 is
constituted of a hydraulic clutch and includes a housing 15a that can rotate integrally with the
PTO propulsion shaft 14, a clutch member 15b that can rotate integrally with the propulsion
shaft 5a, and a piston 15c that can be moved in the housing 15a by hydraulic fluid.
[0017] Accordingly, when the piston 15c is moved and the clutch member 15b is joined
to the housing 15a, the PTO clutch 15 shifts to perform the first operation, a power from the prime mover 4 is transmitted to the PTO propulsion shaft 14 via the propulsion shaft 5a and the PTO clutch 15, and then a power of the PTO propulsion shaft 14 is transmitted to the PTO shaft 16. That is, the PTO shaft 16 is driven by the power of the prime mover 4 via the
6

speed-changing device 5. On the other hand, when the piston 15c is moved to separate the
clutch member 15b from the housing 15a, the PTO clutch 15 shifts to perform the second
operation, the power of the propulsion shaft 5a is not transmitted to the PTO propulsion shaft
14, and thus it is isolated from the power of the propulsion shaft 5a. The transmission or
disconnection of the power by the PTO clutch 15 is performed by an actuation valve 17
(switching valve) connected to the piston 15c via a fluid passage. A pump 18 for supplying
hydraulic fluid (oil) is connected to the actuation valve 17.
[0018] FIG. 2 shows the control circuit for driving the PTO shaft.
The control circuit 20 for the PTO shaft includes an on-off switch 21, a speed-changing switch 22, a parking switch 23, a posture switch 24, a key switch 25, and a seat switch 26.
The on-off switch 21 can be shifted between an on state and an off state so as to selectively allow or disable the driving of the PTO shaft 16. For example, when the on-off switch 21 is in the on state (a contact is closed), the PTO shaft 16 is "disabled" from driving, and when the on-off switch 21 is in the off state (the contact is opened), the PTO shaft 16 is "allowed" to drive. The on-off switch 21 is disposed in the vicinity of the driver's seat 6 and can be operated by an operator (driver). When the on-off switch 21 is shifted to the off state, the actuation valve 17 is shifted to a predetermined position, the PTO clutch 15 performs the first operation, and the PTO shaft 16 is driven (rotated). On the other hand, when the on-off switch 21 is shifted to the on state, the actuation valve 17 is shifted to another predetermined position, the PTO clutch 15 performs the second operation, and the PTO shaft 16 stops being driven (rotated).
[0019] The speed-changing switch 22 can be shifted between an on state and an off state
so as to selectively allow or disable the speed-changing of the speed-changing device 5. When the speed-changing switch 22 is in the on state (a contact is closed), the speed-changing device 5 is disabled from performing the speed-changing, and when the speed-changing switch 22 is in the off state (the contact is opened), the speed-changing device 5 is allowed to perform the speed-changing. The speed-changing switch 22 is disposed in the vicinity of the
7

driver's seat 6 and can be operated by an operator (driver). When the speed-changing switch 22 is shifted to the off state, the speed-changing is performed according to an operation of a speed-changing operation member (e.g., a speed-changing operation switch, a speed-changing operation lever) for performing the speed-changing by operating either the main
speed-changing unit 5b or the sub speed-changing unit 5c. When the speed-changing switch 22 is shifted to the on state, the speed-changing is not performed even if the speed-changing operation member is operated.
[0020] The parking switch 23 is a switch to detect parking of the traveling vehicle body
(vehicle body) 3. Specifically, the parking switch 23 is switchable to be on or off. When a parking (parking-brake) lever swingably supported by the vehicle body 3 is shifted to a position to brake the vehicle body 3 (a braking position), the parking switch 23 is switched to its on state (a contact is closed) in accordance with the swinging of the parking lever, and detects the parking. In addition, when the parking lever 3 is shifted to a position to release the braking of the vehicle body 3 (a releasing position), the parking switch 23 is switched to its off state (the contact is opened) in accordance with the swinging of the parking lever, and does not detect the parking.
[0021] The posture switch 24 is a switch to detect a state of the driver’s seat 6 as shown
in FIG. 3, the posture switch 24 is a switch configured to detect whether the driver's seat 6 is in a first posture H1 to allow a driver to sit thereon or in a second posture H2 to disable the driver from sitting thereon. Specifically, a seat portion 6a and backrest 6b of the driver's seat 6 are pivotable on a lateral axis 6c supported by the vehicle body 3 (driver's seat stand 3a). When the seat portion 6a is substantially parallel with an upper surface of the driver's seat stand 3a and the driver is allowed to be seated on the seat portion (in the first posture H1), the posture switch 24 is shifted to its off state, and when the seat portion 6a is substantially perpendicular to the upper surface of the driver’s seat stand 3a and the driver is disabled from being seated on the seat portion (in the second posture H2), the posture switch 24 is shifted to its on state.
[0022] The key switch 25 is shiftable to an on state to instruct starting (driving) of the
8

prime mover 4 or to an off state. For example, when the key switch 25 is shifted to the on state (a contact is closed), the key switch 25 is in the state of instructing the driving of the prime mover 4, and when the key switch 25 is shifted to the off state (the contact is opened), the key switch 25 is in the state of not-instructing the driving of the prime mover 4. The key switch 25 is disposed in the vicinity of the driver's seat 6 and can be operated by an operator (driver).
[0023] The seat switch 26 is a switch to detect the operator seated on the driver's seat 6.
For example, the seat switch 26 is shiftable to an on state or an off state. The seat switch 26 is disposed in a portion (seat portion, backrest) of the driver's seat 6, below the seat, or the like. When the operator is seated on the seat, the seat switch 26 is shifted to the on state (a contact is closed) to detect the seating. In addition, when the operator gets off the seat, the seat switch 26 is shifted to the off state (the contact is opened) to detect that the operator is not seated on the seat.
[0024] The control circuit 20 for the PTO shaft includes a first actuation device 31, a
second actuation device 32, a third actuation device 33, a fourth actuation device 34, and a notification device 35. The first actuation device 31, the second actuation device 32, the third actuation device 33, and the fourth actuation device 34 are, for example, contact relays, non-contact relays, sequencers, or the like.
After the driving of the prime mover is started, the first actuation device 31 maintains the driving of the prime mover 4 while the parking is detected and the second posture H2 is detected, and the first actuation device 31 stops the driving of the prime mover 4 when neither the parking nor the second posture H2 is detected. The first actuation device 31 is the contact relay including a coil portion 31a, a switch portion 31b, a first input terminal 31c, a second input terminal 31d, and a first output terminal 31e. The first actuation device (relay) 31 may be a "single-stable type" relay in which the switch portion 31b is shifted to an on state when the coil portion 31a is magnetized, may be a "latching type" relay in which the switch portion 31b is shifted to the on state with the magnetization of the coil portion 31a being held (latched), or may be any other relay.
9

[0025] In the first actuation device 31, when an allowance signal, which is a
predetermined voltage, electrically energizes the coil portion 31a from the first input terminal 31c and then the switch portion 31b is shifted to the on state (when the contact is closed), the stopping device 40 connected to the first output terminal 31e is continuously actuated to maintain the driving of the prime mover 4. On the other hand, when the first actuation device 31 does not electrically energize the coil portion 31a and the switch portion 31b is shifted to the off state (when the contact is opened), an electric power supply to the stopping device 40 is stopped, and the prime mover 4 stops. That is, the first actuation device 31 maintains the driving of the prime mover 4 when the allowance signal is input to the first actuation device 31 after the prime mover 4 has started to be driven. The stopping device 40 includes an engine-stopping solenoid, which maintains the driving of the prime mover 4 when it is magnetized (when it is supplied with electric power), and which stops the prime mover 4 when it is demagnetized (when it is not supplied with the electric power).
[0026] The second actuation device 32 outputs the allowance signal when the driving of
the PTO shaft 16 is disabled (ON) and the speed-changing switch 22 is shifted to the off state (ON). The second actuation device 32 is a contact relay including a coil portion 32a, a switch portion 32b, a third input terminal 32c, a fourth input terminal 32d, and a second output terminal 32e. The second actuation device (relay) 32 may be a single-stable type relay, a latching type relay, or any other relay.
[0027] When the coil portion 32a is electrically energized by electricity from the third
input terminal 32c and the switch portion 32b is shifted to the on state, the second actuation device 32 connects the fourth input terminal 32d to the second output terminal 32e, and outputs, from the second output terminal 32e, the allowance signal indicated by a predetermined voltage. On the other hand, when the coil portion 32a is not electrically energized and the switch portion 32b is shifted to the off state, the second actuation device 32 connects the fourth input terminal 32d to the output terminal 32f, and outputs a notification signal.
[0028] The third actuation device 33 is connected to the second actuation device 32 and
10

starts the prime mover 4 when the allowance signal is input to the third actuation device 33 under an instruction to start the prime mover 4. The third actuation device 33 is a contact relay including a coil portion 33a, a switch portion 33b, a fifth input terminal 33c, a sixth input terminal 33d, and a third output terminal 33e. The third actuation device (relay) 33 may be a single-stable type relay, a latching type relay, or any other relay.
[0029] When the coil portion 33a is electrically energized by electricity from the sixth
input terminal 33d of the third actuation device 33, the switch portion 33b is shifted to the on state (a contact is closed) and a starter 41 is activated to start the prime mover 4. On the other hand, when the coil portion 33a of the third actuation device 33 is not electrically energized, the switch portion 33b is shifted to the off state (the contact is opened), the starter 41 is not activated, and thus the prime mover 4 is not started.
[0030] The fourth actuation device 34 is connected to the seat switch 26 and outputs a
notification signal when the seat switch 26 is in the on state. The fourth actuation device 34
is a contact relay including a coil portion 34a, a switch portion 34b, a seventh input terminal
34c, an eighth input terminal 34d, and a fourth output terminal 34e. The fourth actuation
device (relay) 34 may be a single-stable type relay, a latching type relay, or any other relay.
[0031] When the coil portion 34a is electrically energized by electricity from the eighth
input terminal 34d of the fourth actuation device 34, the switch portion 34b is shifted to the on state (a contact is closed), and thus no notification signal is output. On the other hand, when the coil portion 34a of the fourth actuation device 34 is not electrically energized, the switch portion 34b is shifted to the off state (the contact is opened), and then the notification signal is output from the fourth output terminal 34e.
The notification device 35 is a device configured to execute a notification according to a predetermined condition, and is, for example, a speaker that generates sound. The notification device 35 outputs a notification when the notification signal output from the fourth actuation device 34 is input to the notification device 35. That is, the notification device 35 executes a notification when the input switch 21 is in the off state, the speed-changing switch 22 is in the on state, and the seat switch 26 is in the on state (the
11

seating is detected). It is desirable that the notification device 35 includes a timer. That is, the notification device 35 generates a sound for at least several seconds after the electrically energizing of the coil portion 34a is stopped.
[0032] Next, connections between the switches (on-off switch 21, speed-changing switch
22, parking switch 23, posture switch 24, key switch 25, seat switch 26), the actuation devices (first actuation device 31, second actuation device 32, third actuation device 33, fourth actuation device 34), and the notification device 35 will be described.
The first input terminal 31c of the first actuation device 31 is connected to the second output terminal 32e of the second actuation device 32 via the first line L1. The second input terminal 31d of the first actuation device 31 is connected to a power supply system. The first output terminal 31e of the first actuation device 31 is connected to the stopping device 40.
[0033] The input terminal 21a of the on-off switch 21 and the input terminal 22a of the
speed-changing switch 22 are connected to the power supply system. The output terminal 21b of the on-off switch 21 is connected to the third input terminal 32c of the second actuation device 32, and the output terminal 22b of the speed-changing switch 22 is connected to the fourth input terminal 32d of the second actuation device 32.
The second output terminal 32e of the second actuation device 32 is connected to the third actuation device 33 via a second line L2 connecting the second output terminal 32e to the sixth input terminal 33d of the third actuation device 33. The first line L1 includes a portion between the second output terminal 32e of the second actuation device 32 and a branching portion 39a, and the portion serves as a line (common line) shared with the second line L2. The power supply system is connected to the input terminal 25a of the key switch 25, and the fifth input terminal 33c of the third actuation device 33 is connected to the output terminal 25b.
[0034] A line L11 branches, via a branch 39b, from a line L10 which connects the output
terminal 22b of the speed-changing switch 22 to the fourth input terminal 32d of the second actuation device 32. The parking switch 23 and the posture switch 24 are connected in
12

series to the line L11, and the line L11 is connected to the first line L1. That is, an input terminal 23a of the parking switch 23 is connected to an intermediate portion of the line L11. An output terminal 23b of the parking switch 23 is connected to the input terminal 24a of the posture switch 24 via the line L11. The output terminal 24b of the posture switch 24 is connected to the first line L1 via the line L11.
[0035] Accordingly, even in a state where the speed-changing device 5 is disabled from
performing the speed-changing (the speed-changing switch 22 is in the on state), the switch portion 31b of the first actuation device 31 can be shifted to the on state when the parking switch 23 is in the on state and the posture switch 24 is in the on state, thereby maintaining the driving of the prime mover 4.
The output terminal 32f of the second actuation device 32 is connected to the seventh input terminal 34c of the fourth actuation device 34 via a line L13. The input terminal 26a of the seat switch 26 is connected to the power supply system. The output terminal 26b of the seat switch 26 is connected to the eighth input terminal 34d of the fourth actuation device 34 via a line L14. In addition, the output terminal 26b of the seat switch 26 is connected to the first line L1 via a line L15. Accordingly, also when the speed-changing device 5 is disabled from performing the speed-changing (the speed-changing switch 22 is in the on state) and the seat switch 26 is shifted to the on state, the driving of the prime mover 4 can be maintained.
[0036] It is preferable to provide diodes 43a, 43b, and 43c, each of which supplies
electric current (signal) in one direction, on the line (first line) L1, line 11, and line 15, respectively.
As shown in FIG. 4, a PTO selecting switch 28 may be provided on the line L11. The PTO selecting switch 28 is a switch to selectively supply the power of the PTO shaft 16 to either a front portion of the vehicle body 3 or a rear portion of the vehicle body 3. The PTO selecting switch 28 is in the on state (a contact is closed) when the PTO shaft 16 is set to supply power to the front, and is in the off state (the contact is opened) when the PTO shaft 16 is set to supply power to the rear. The input terminal 28a of the PTO selecting switch 28 is
13

connected to the output terminal 23b of the parking switch 23, and the input terminal 28b is connected to the input terminal 24a of the posture switch 24.
[0037] According to the above description, in a case where the PTO selecting switch 28 is
in the on state in addition to a case where the vehicle switch 23 is in the on state and the posture switch 24 is in the on state, the driving of the prime mover 4 can be maintained.
In the above-described embodiment, the PTO power transmission unit 5e is a clutch shiftable between an engaged state in which a power of the propulsion shaft 5a is transmitted to the PTO propulsion shaft 14 and a disengaged state in which the power of the propulsion shaft 5a is not transmitted to the PTO propulsion shaft 14; however, the PTO power transmission unit 5e may include a speed-changing mechanism configured to change a rotation speed of the PTO shaft 16 (PTO rotation speed) in multiple steps in the engaged state. For example, the PTO power transmission unit 5e switches the PTO rotation speed between the first speed, which is a low speed, and the second speed, which is a high speed. In this case, the on-off switch 21 can be shifted to three levels: a first speed, a second speed, and a neutral position (neutral). In the circuits in FIGS. 2 and 4, the on-off switch 21 is in the on state (a contact is closed) when in the neutral position, and is in the off state (the contact is opened) when in the first speed and the second speed.
[0038] The working vehicle 1 includes the prime mover 4, the driver’s seat 6 selectively
set in either the first posture H1 where a driver can sit on the driver’s seat 6 or the second posture H2 where the driver cannot sit on the driver’s seat 6, the speed-changing device 5 configured to receive power from the prime mover 4 and to perform a speed-changing of the power, the PTO shaft 16 configured to receive the speed-changed power output from the speed-changing device 5, the posture switch 24 configured to detect whether the driver’s seat 6 is set in the first posture H1 or the second posture H2, the parking switch 23 configured to detect parking of the vehicle body, and the first actuation device 31 configured so that, during driving of the prime mover 4, the first actuation device 31 maintains the driving of the prime mover 4 when both the parking and the driver’s seat 6 set in the second posture H2 are detected, and the first actuation device 31 stops the driving of the prime mover 4 when neither
14

the parking nor the driver’s seat 6 set in the second posture H2 is detected. According to this configuration, since the driving of the prime mover 4 is continued when the driver is in the second posture H2 in which the driver cannot be seated on the driver’s seat and the parking is detected, a work can be performed while the driver is outside the vehicle body 3 and the PTO shaft 16 is being driven. That is, an operator can perform the work outside the vehicle body by driving the PTO shaft while the vehicle body is parked.
[0039] The working vehicle 1 further includes the speed-changing switch 22 configured
to be turned on to allow the speed-changing performed by the speed-changing device 5, and to be turned off to disable the speed-changing device 5 from performing the speed-changing. The first actuation device 31 is configured to maintain the driving of the prime mover 4 when the speed-changing device 5 is turned off, and to stop the driving of the prime mover 4 when the speed-changing device 5 is turned on. According to this configuration, the driving of the prime mover 4 is stopped when the speed-changing of the speed-changing device 5 enters an on-state, while an outside work can be performed by driving the PTO shaft when the speed-changing of the speed-changing device 5 enters an off-state, that is, when the vehicle body 3 is securely parked.
[0040] The working vehicle 1 further includes the on-off switch 21 operable to be turned
on to allow driving of the PTO shaft 16, and to be turned off to disable the PTO shaft 16 from driving, the key switch operable to issue an instruction for starting of the prime mover 4, the second actuation device 32 configured to output an allowance signal when the PTO shaft 16 is disabled from driving and the speed-changing switch 22 is turned off, and the third actuation device 33 operably connected to the second actuation device 32, and configured to perform the starting of the prime mover 4 when the instruction for the starting of the prime mover 4 is issued and the allowance signal is input to the third actuation device 33. According to this configuration, the prime mover 4 can be started when the PTO shaft 16 is not driven and the traveling is not performed.
[0041] The first actuation device 31 is configured to maintain the driving of the prime
mover 4 when the allowance signal is input to the first actuation device 31 during the driving
15

of the prime mover 4. According to this configuration, when the PTO shaft is driven during the driving of the prime mover 4, the PTO shaft can be continuously driven.
The first actuation device 31 is configured as a relay including the first input terminal 31c, the second input terminal 31d and the first output terminal 31e. The second actuation device 32 is configured as a relay including the third input terminal 32c, the fourth input terminal 32d and the second output terminal 32e. The third actuation device 33 is configured as a relay including the fifth input terminal 33c, the sixth input terminal 33d and the third output terminal 33e. The first line L1 connecting the first actuation device 31 and the second actuation device 32 to each other is connected to the first input terminal 31c. The electric source line is connected to the second input terminal 31d. The output terminal 21b of the on-off switch 21 is connected to the third input terminal 32c. The output terminal 22b of the speed-changing switch 22 is connected to the fourth input terminal 32d. The output terminal 25b of the key switch 25 is connected to the fifth input terminal 33c. The second line L2 connected to the second output terminal 32e is connected to the sixth input terminal 33d. The stopping device 40 for stopping the prime mover 4 is connected to the first output terminal 31e. The starter 41 for performing the starting of the prime mover 4 is connected to the third output terminal 33e. According to this configuration, the starting, stopping, and continuous driving of the prime mover 4 can be performed stably and reliably by a sequential operation with the relay.
[0042] The working vehicle 1 further includes the seat switch 26 configured to detect
sitting of a driver on the driver’s seat 6, and the notification device 35 configured to notify information in correspondence to a predetermined condition. The notification device 35 notifies the information when the speed-changing switch 22 is turned off and the sitting of the driver is not detected. According to this configuration, it is easy to inform that the traveling is not being performed and a driver is not seated on the driver’s seat.
In the above description, the embodiment of the present invention has been explained. However, all the features of the embodiment disclosed in this application should be considered just as examples, and the embodiment does not restrict the present invention
16

accordingly. A scope of the present invention is shown not in the above-described
embodiment but in claims, and is intended to include all modifications within and equivalent
to a scope of the claims.
[0043] All combinations of the configurations described in the first to fourth
embodiments can be adopted to the present invention.
[DESCRIPTION OF THE REFERENCE NUMERAL]
[0044]

1 Working vehicle
2 Working device
3 Vehicle body
4 Prime mover
5 Speed-changing device
6 Driver’s seat
16 PTO shaft
21 On-off switch
21a Input terminal
21b Output terminal
22 Speed-changing switch
22a Input terminal
22b Output terminal
23 Parking switch
23a Input terminal
23b Output terminal
24 Posture switch
24a Input terminal
24b Output terminal
25 Key switch
25a Input terminal
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25b Output terminal
26 Seat switch
26a Input terminal
26b Output terminal
28a Input terminal
28b Output terminal
31 First actuation device
31c First input terminal
31d Second input terminal
31e First output terminal
32 Second actuation device
32c Third input terminal
32d Fourth input terminal
32e Second output terminal
32f Output terminal
33 Third actuation device
33c Fifth input terminal
33d Sixth input terminal
33e Third output terminal
35 Notification device
40 Stopping device
41 Starter

WE CLAIM

1.A working vehicle, comprising:
a prime mover;
a driver’s seat selectively set in either a first posture where a driver can sit on the driver’s seat or a second posture where the driver cannot sit on the driver’s seat;
a speed-changing device configured to receive power from the prime mover and to perform a speed-changing of the power;
a PTO shaft configured to receive the speed-changed power output from the speed-changing device;
a posture switch configured to detect whether the driver’s seat is set in the first posture or the second posture;
a parking switch configured to detect parking of a vehicle body; and
a first actuation device configured so that, during driving of the prime mover,
the first actuation device maintains the driving of the prime mover when
both the parking and the driver’s seat set in the second posture are detected, and
the first actuation device stops the driving of the prime mover when neither
the parking nor the driver’s seat set in the second posture is detected.
2. The working vehicle according to claim 1, further comprising:
a speed-changing switch configured to be turned on to allow the speed-changing performed by the speed-changing device, and to be turned off to disable the speed-changing device from performing the speed-changing, wherein the first actuation device is configured
to maintain the driving of the prime mover when the speed-changing device is turned off, and
to stop the driving of the prime mover when the speed-changing device is turned on.
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3. The working vehicle according to claim 2, further comprising:
an on-off switch operable to be turned on to allow driving of the PTO shaft, and to be turned off to disable the PTO shaft from driving;
a key switch operable to issue an instruction for starting of the prime mover; and
a second actuation device configured to output an allowance signal when the PTO shaft is disabled from driving and the speed-changing switch is turned off; and
a third actuation device operably connected to the second actuation device, and configured to perform the starting of the prime mover when the instruction for the starting of the prime mover is issued and the allowance signal is input to the third actuation device.
4. The working vehicle according to claim 3, wherein
the first actuation device is configured to maintain the driving of the prime mover when the allowance signal is input to the first actuation device during the driving of the prime mover.
5. The working vehicle according to claim 4, wherein:
the first actuation device is configured as a relay including a first input terminal, a second input terminal and a first output terminal;
the second actuation device is configured as a relay including a third input terminal, a fourth input terminal and a second output terminal;
the third actuation device is configured as a relay including a fifth input terminal, a sixth input terminal and a third output terminal;
a first line connecting the first actuation device and the second actuation device to each other is connected to the first input terminal;
an electric source line is connected to the second input terminal;
an output terminal of the on-off switch is connected to the third input terminal;
an output terminal of the speed-changing switch is connected to the fourth input terminal;
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an output terminal of the key switch is connected to the fifth input terminal;
a second line connected to the second output terminal is connected to the sixth input terminal;
a stopping device for stopping the prime mover is connected to the first output terminal; and
a starter for performing the starting of the prime mover is connected to the third output terminal.
6. The working vehicle according to any one of claims 2 to 5, further comprising: a seat switch configured to detect sitting of a driver on the driver’s seat; and a notification device configured to notify information in correspondence to a
predetermined condition, wherein
the notification device notifies the information when the speed-changing switch is
turned off and the sitting of the driver is not detected.