Work vehicles

Abstract

To provide a configuration in a work capable of performing a fixing work that facilitates an operation necessary for performing a fixing work and other works.SOLUTION: A tractor includes an engine, a vehicle body, a rear PTO shaft, a center PTO shaft, a permission switch, and a control unit. The engine generates power. The vehicle body includes a drivers seat. The rear PTO shaft supplies the power generated by the engine to a rear work machine fitted to a rear part of the vehicle body. The center PTO shaft supplies the power generated by the engine to a center work machine fitted to a center part of the vehicle body. The permission switch can be operated by an operator. The control unit sets an operation of the permission switch as one of the permission conditions of rotation of the rear PTO shaft at the time of getting off the vehicle and sets an operation of the permission switch as one of the permission conditions of rotation of the center PTO shaft at the time of backing.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates primarily to work vehicles that include a rear PTO shaft and a center PTO shaft. [Background technology]

[0002] Patent Document 1 discloses a tractor for performing stationary work. Stationary work involves driving a work implement attached to the tractor while the tractor is parked. The tractor in Patent Document 1 is also equipped with a seat sensor that detects whether an operator is seated in or leaving the driver's seat. The tractor has a function that stops the engine if it detects that the operator has left the driver's seat while the engine is running. This function can interfere with stationary work. Therefore, in Patent Document 1, if the driver's seat is moved to an unused position, the engine stop function upon detection of the operator leaving the seat is disabled. This allows stationary work to be performed with the operator away from the driver's seat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-68705 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the driver's seat must be moved to a non-use position to perform stationary work, which is time-consuming for the operator. On the other hand, if some kind of operating tool is provided to allow stationary work, the number of operating tools provided on the work vehicle increases, which poses problems in terms of space and operability.

[0005] The present invention has been made in view of the above circumstances, and its main object is to provide a construction for a work vehicle capable of performing stationary work, in which the operations required for performing stationary work and other work are simple.

[0006] The problem to be solved by the present invention is as described above. Next, the means for solving this problem and the effects thereof will be explained.

[0007] According to an aspect of the present invention, there is provided a work vehicle having the following configuration. That is, the work vehicle includes a drive unit, a vehicle body, a rear PTO shaft, a central PTO shaft, an enabling operation device, and a control unit. The drive unit generates power. The vehicle body includes a driver's seat. The rear PTO shaft supplies the power generated by the drive unit to a rear work implement attached to the rear of the vehicle body. The central PTO shaft supplies the power generated by the drive unit to a central work implement attached to the center of the vehicle body. The enabling operation device is operable by an operator. The control unit sets operation of the enabling operation device as one of the conditions for enabling rotation of the rear PTO shaft after dismounting, and also sets operation of the enabling operation device as one of the conditions for enabling rotation of the central PTO shaft when reversing.

[0008] This allows one permission operating device to have two functions. These two functions are similar in concept in that they both allow the PTO shaft to rotate, and are never used simultaneously. Therefore, by giving one permission operating device these two functions, it is possible to make the operation easier to understand and reduce the number of operating devices required.

[0009] The work vehicle is preferably configured as follows. That is, the work vehicle is equipped with a seat sensor that detects whether an operator is seated in the driver's seat. The control unit is capable of executing an automatic stop function that stops the drive unit when it is no longer possible to detect that the operator is seated. The automatic stop function is disabled when a condition allowing rotation of the rear PTO shaft after dismounting is satisfied.

[0010] This allows the rear work implement to be driven after dismounting, even in a work vehicle that has an automatic stop function.

[0011] The work vehicle is preferably configured as follows: That is, the control unit is capable of detecting whether the vehicle is in a parked state. The control unit sets the detection of the parked state after dismounting when the seat sensor does not detect the operator seated as one of the conditions for permitting rotation of the rear PTO shaft after dismounting.

[0012] This makes it possible to detect that the operator has dismounted and that the work vehicle is in a parked state.

[0013] The work vehicle preferably has the following configuration. That is, the work vehicle is equipped with a forward / reverse switching device and a parking brake operating device. The forward / reverse switching device can be operated to switch between forward, neutral, and reverse. The parking brake operating device switches the parking brake between enabled and disabled. The control unit detects that the vehicle is in a parked state when it detects at least one of the following: the forward / reverse switching device is switched to neutral, and the parking brake operating device has enabled the parking brake.

[0014] This makes it possible to detect whether the vehicle is in a parking state or not simply by detecting the operation state of the operating tool.

[0015] In the work vehicle, it is preferable that the permission operating tool is disposed in a position where it can be operated by an operator seated in the driver's seat.

[0016] This allows the operator to operate the permission operating tool while the seat sensor detects that the operator is seated.

[0017] The work vehicle is preferably configured as follows: The work vehicle is provided with a PTO drive / stop operating device that switches between driving and stopping the rear PTO shaft or the central PTO shaft. The permission operating device and the PTO drive / stop operating device are arranged side by side.

[0018] This allows two operating tools that are conceptually similar and have similar operation timing to be arranged side by side, thereby improving operability.

[0019] In the work vehicle, the permission operating device is preferably disposed closer to the center in the vehicle width direction than the PTO drive stop operating device.

[0020] This allows the permission operating device to be operated while seated, while the PTO drive stop operating device can be operated by an operator who has dismounted from the vehicle, thereby improving operability.

[0021] In the work vehicle, it is preferable that the permission operating tool emits light when rotation of the rear PTO shaft after dismounting or rotation of the central PTO shaft during reverse travel is valid.

[0022] This allows the operator to know that rotation of the rear PTO shaft after dismounting or rotation of the center PTO shaft when reversing is valid.

[0023] The work vehicle is preferably configured as follows: The work vehicle is equipped with a PTO drive stop operating device that switches between driving and stopping the rear PTO shaft or the central PTO shaft. If an operation is performed on the PTO drive stop operating device to stop the rotation of the rear PTO shaft or the central PTO shaft while the rear PTO shaft is rotating after dismounting or while the central PTO shaft is rotating during reverse travel, the illumination of the permission operating device stops.

[0024] This allows the operator to know that rotation of the rear PTO shaft after dismounting or rotation of the center PTO shaft when reversing has been disabled.

[0025] The work vehicle preferably has the following configuration: the work vehicle includes an auxiliary housing and a base housing; the permission operating device is attached to the auxiliary housing; and the auxiliary housing is attached to the base housing.

[0026] This allows for the manufacture of work vehicles that do not employ permitted operating tools, simply by omitting the attachment of the auxiliary housing.

[0027] The work vehicle preferably has the following configuration: a slit is formed in the base housing; a connector is inserted into the slit; and the auxiliary housing is attached to the base housing by the connector.

[0028] As a result, even if the attachment of the auxiliary housing is omitted, the appearance of the base housing is not significantly impaired because only the slit is formed in the base housing. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a side view of a tractor according to an embodiment of the present invention. [Figure 2] Plan view of the tractor. [Figure 3] FIG. 4 is a block diagram of a configuration for controlling a rear PTO clutch and a center PTO clutch. [Figure 4] FIG. [Figure 5] 10 is a flowchart showing processing relating to stationary work using a rear work implement. [Figure 6] 6 is a flowchart showing a process related to a reverse operation using a central work implement. DETAILED DESCRIPTION OF THE INVENTION

[0030] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a tractor (work vehicle) 1 according to an embodiment of the present invention. Fig. 2 is a plan view of the tractor 1. In the following description, terms such as "left" and "right" refer to the left and right as seen by an operator riding on the tractor 1.

[0031] The tractor 1 of this embodiment is a work vehicle used for agricultural work, civil engineering work, etc. The tractor 1 has a vehicle body 2 configured including a frame extending in the front-to-rear direction. The vehicle body 2 is supported by front wheels 3 and rear wheels 4 as running wheels. The front wheels 3 and rear wheels 4 are each provided in pairs on the left and right.

[0032] A hood 5 is provided at the front of the tractor 1. An engine 6 is provided inside the hood 5 as a drive unit. The engine 6 generates power. The engine 6 is a diesel engine, but may also be a gasoline engine. Alternatively, an electric motor may be provided instead of the engine 6.

[0033] A driver's seat 7 for an operator is provided behind the hood 5. Various operating tools are provided around the driver's seat 7 to allow the operator to perform various operations. The operating tools include, for example, a steering handle 11 and a switch box 12 shown in FIG. 1. The steering handle 11 is an operating tool for steering the tractor 1. The switch box 12 is configured to have a plurality of switches. Details of the switch box 12 will be described later.

[0034] A transmission case 13 is provided at the rear of the vehicle body 2. The power output by the engine 6 is input to the transmission case 13. An HST (hydrostatic continuously variable transmission), not shown, is arranged inside the transmission case 13, and the power of the engine 6 is changed in speed by this HST and transmitted to the rear wheels 4. This allows the tractor 1 to travel using the power output by the engine 6. Note that an HMT or a mechanical transmission may be provided instead of the HST.

[0035] A rear PTO shaft 14 and a central PTO shaft 15 are connected to the transmission case 13. A power transmission mechanism 18 composed of a hydraulic motor, a hydraulic pump, a hydraulic valve, etc. is disposed inside the transmission case 13, and power from the engine 6 is transmitted to the rear PTO shaft 14 or the central PTO shaft 15 by this power transmission mechanism.

[0036] A rear implement 21 is attached to the rear PTO shaft 14. The rear implement 21 is attached to the rear of the vehicle body 2 via the rear PTO shaft 14 and other attachment mechanisms. The rear implement 21 performs work using power input from the rear PTO shaft 14. A central implement 22 is attached to the central PTO shaft 15. The central implement 22 is attached to the center of the vehicle body 2 via the central PTO shaft 15 and other attachment mechanisms. The central implement 22 performs work using power input from the central PTO shaft 15. Examples of the rear implement 21 or the central implement 22 include various implements such as cultivators, plows, fertilizer applicators, brush cutters, seed sowers, log splitters, and pumps. In addition to the rear PTO shaft 14 and the central PTO shaft 15, the tractor 1 may also have a front PTO shaft for driving a front implement attached to the front of the vehicle body 2.

[0037] Next, stationary work and reverse work will be described. Stationary work refers to work performed by driving the rear implement 21 attached to the tractor 1 while the tractor 1 is parked. The rear implement 21 used in stationary work is, for example, a log splitter or a pump. Typically, the operator dismounts from the tractor 1 to operate the rear implement 21 or supply work objects to the rear implement 21. As will be described in detail later, the tractor 1 has an automatic stop function when leaving the seat. The automatic stop function when leaving the seat is a function that stops the engine 6 when it detects that the operator has left the driver's seat 7. If the automatic stop function when leaving the seat is enabled, the engine 6 and the rear implement 21 will stop when the operator leaves the driver's seat 7, preventing stationary work. Therefore, in this embodiment, when the conditions for permitting stationary work, which will be described later, are met, the automatic stop function when leaving the seat is disabled, allowing stationary work to be performed.

[0038] Reversing work refers to work performed by driving the central implement 22 attached to the tractor 1 while the tractor 1 is moving backward. An example of the central implement 22 used when performing reversing work is a brush cutter. The tractor 1 has an automatic stop function when reversing. The automatic stop function when reversing is a function that stops the central implement 22 when an operation to move the tractor 1 in reverse is detected while the central implement 22 is being driven. If the automatic stop function when reversing is enabled, the central implement 22 stops when reverse begins, making it impossible to perform reversing work. Therefore, in this embodiment, when the conditions for allowing reversing work, which will be described later, are met, the automatic stop function when reversing is disabled, making it possible to perform reversing work.

[0039] Next, the devices used in the processes related to these automatic stop functions and disabling them will be described. The control unit 30 shown in Fig. 3 is a device that executes the above-mentioned processes. The control unit 30 is disposed, for example, inside the hood 5. The control unit 30 is a computer that includes an arithmetic unit such as a CPU and a storage device such as an HDD, SSD, or flash memory. The arithmetic unit executes a program stored in the storage device, allowing the control unit 30 to perform the above-mentioned processes.

[0040] As shown in FIG. 3, the tractor 1 is provided with a seat sensor 31. The seat sensor 31 is disposed inside or below the seat portion of the driver's seat 7. The seat sensor 31 is turned on when a load is applied, and automatically turned off when the load is released. With this configuration, the seat sensor 31 is in the on state while the operator is seated in the driver's seat 7. The seat sensor 31 outputs a signal indicating the on state or the off state to the control unit 30.

[0041] The tractor 1 is equipped with the above-mentioned operating tools, namely, a PTO shaft switching operating tool 32, a forward / reverse switching operating tool 33, a parking brake operating tool 34, an enable switch (enable operating tool) 35, and a PTO switch (PTO drive stop operating tool) 36. These operating tools are arranged in positions where they can be operated by an operator seated in the driver's seat 7, specifically, on the steering column, above the fenders of the left and right rear wheels 4, below the driver's seat 7, or on the floor. These operating tools are, for example, levers, switches, buttons, pedals, or the like. Furthermore, position-switching operating tools such as levers or slide switches are provided with position sensors that detect the position of the operating tools and output the results to the control unit 30.

[0042] The PTO shaft switching device 32 is a device for switching the PTO shaft to be driven. Operating the PTO shaft switching device 32 allows switching between a state in which the rear PTO shaft 14 is driven and a state in which the central PTO shaft 15 is driven. Specifically, a power transmission mechanism 18 is provided inside the transmission case 13. The power transmission mechanism 18 includes, for example, a solenoid valve for switching hydraulic paths, and can change the PTO shaft to which power is transmitted based on the control of the control unit 30. Note that instead of a solenoid valve, a mechanical structure using gears or the like may be used to change the PTO shaft to which power is transmitted. The PTO shaft switching device 32 can be switched between a position pointing at the rear PTO shaft 14 and a position pointing at the central PTO shaft 15. When the PTO shaft switching device 32 is in a position pointing at the rear PTO shaft 14, the power generated by the engine 6 is transmitted to the rear PTO shaft 14. On the other hand, when the PTO shaft switching device 32 is in a position pointing at the central PTO shaft 15, the power generated by the engine 6 is transmitted to the central PTO shaft 15.

[0043] The forward / reverse switching device 33 is a device for switching the traveling direction of the tractor 1. By operating the forward / reverse switching device 33, the rotation direction of the axle or whether or not power is transmitted to the axle changes. This allows the tractor 1 to switch between a state in which it moves forward, a state in which it moves backward, and a state in which no power is supplied to the wheels of the tractor 1 (neutral).

[0044] The parking brake operating device 34 is an operating device for switching between enabling and disabling the parking brake. Operating the parking brake operating device 34 applies brakes to the rear wheels 4. The parking brake is used after the tractor 1 is parked.

[0045] The permission switch 35 is located on one side (right side) of the driver's seat 7 in the vehicle width direction. The permission switch 35 is a push-button switch, and the operator operates the permission switch 35 by pressing the permission switch 35. Operating the permission switch 35 is one of the permission conditions for the above-mentioned stationary work and reversing work. The permission switch 35 is an operating tool that the operator uses to notify the tractor 1 that he or she intends to perform stationary work or reversing work. By providing the permission switch 35, the automatic stop function can be disabled when the operator intends to perform stationary work or reversing work, and the automatic stop function can be enabled when the operator does not intend to perform stationary work or reversing work. The permission switch 35 is also an illuminating switch that illuminates when the automatic stop function is disabled (in other words, when stationary work or reversing work is permitted).

[0046] In this way, the permission switch 35 functions both as an operating tool that indicates to the tractor 1 that stationary work is intended, and as an operating tool that indicates to the tractor 1 that reverse work is intended. Here, when performing stationary work, only the rear work unit 21 is driven, and stationary work is not performed using the central work unit 22. Therefore, if the permission switch 35 is operated when the PTO shaft to be driven is the rear PTO shaft 14, it is considered that the operator intends stationary work. On the other hand, the automatic stop function for reverse travel only targets the central work unit 22, and it is not necessary to operate the automatic stop function for the rear work unit 21. Therefore, if the permission switch 35 is operated when the PTO shaft to be driven is the central PTO shaft 15, it is considered that the operator intends reverse work. In consideration of the above, the control unit 30 performs different processing when the permission switch 35 is operated depending on whether the PTO shaft to be driven is the rear PTO shaft 14 or the central PTO shaft 15.

[0047] The PTO switch 36 is an operating device for switching the drive of the PTO shaft on and off. When the PTO switch 36 is operated with the PTO shaft switching operating device 32 in a position pointing to the rear PTO shaft 14, the state of the power transmission mechanism 18 changes, switching the drive of the rear PTO shaft 14 on and off. When the PTO switch 36 is operated with the PTO shaft switching operating device 32 in a position pointing to the central PTO shaft 15, the state of the power transmission mechanism 18 changes, switching the drive of the central PTO shaft 15 on and off.

[0048] As shown in FIG. 2, the permission switch 35 and the PTO switch 36 are mounted side by side on the switch box 12. As shown in FIG. 4, the switch box 12 includes an auxiliary housing 40 and a base housing 50. The base housing 50 is mounted on the vehicle body 2 (for example, a rear wheel fender). The base housing 50 is provided with switches, a small item compartment, etc. A slit 51 for mounting the auxiliary housing 40 is formed on the surface of the base housing 50. A mounting fixture 52 is provided inside the base housing 50. A through hole is formed in the mounting fixture 52. The mounting fixture 52 is used to mount the auxiliary housing 40 to the base housing 50.

[0049] The auxiliary housing 40 is provided with an enable switch 35 and a PTO switch 36. As shown in FIG. 2, the enable switch 35 is disposed closer to the center in the vehicle width direction than the PTO switch 36. The auxiliary housing 40 is provided with a connecting device 41. A through hole is formed in the connecting device 41. By inserting the connecting device 41 into the slit 51, the position of the through hole of the connecting device 41 can be aligned with the position of the through hole of the mounting device 52. Thereafter, the connecting device 41 can be fixed to the mounting device 52 using a fastener such as a bolt. Thereafter, the auxiliary housing 40 can be attached and fixed to the base housing 50 at another location using a fastener such as a bolt.

[0050] It should be noted that when manufacturing a tractor 1 configured so that the permission switch 35 and PTO switch 36 are not required, the auxiliary housing 40 itself becomes unnecessary. If the base housing 50 has an opening on one side and the opening is covered by the auxiliary housing 40, and the auxiliary housing 40 is omitted, a cover member for covering the opening is required. In this regard, in this embodiment, the base housing 50 does not have an opening, but instead has a formed slit 51. Because the slit 51 is linear, the opening area is small, so the cover member can be omitted or made smaller.

[0051] Next, the steps from start to finish of the stationary work will be explained in order with reference to Fig. 5. Fig. 5 is a flow chart showing the processing relating to the stationary work using the rear work implement 21.

[0052] First, the flow of processing performed by the operator will be explained. The operator drives the tractor 1 to the location where the stationary work will be performed and parks it. At this point, the operator is seated in the driver's seat 7, and the engine 6 is running. After parking the tractor 1, the operator puts the forward / reverse switching operation device 33 into neutral and operates the parking brake operation device 34 to activate the parking brake. Also, if the PTO shaft to be driven is the center PTO shaft 15, the operator operates the PTO shaft switching operation device 32 to switch the PTO shaft to be driven to the rear PTO shaft 14. Next, the operator turns on the permission switch 35 and PTO switch 36, and then starts stationary work using the rear implement 21.

[0053] After completing the stationary work, the operator turns off the PTO switch 36. In this embodiment, the PTO switch 36 is located further outboard in the vehicle width direction than the permission switch 35, making it easy to operate from outside the tractor 1. The operator may also operate the PTO switch 36 after sitting in the driver's seat 7 of the tractor 1.

[0054] Next, the processing performed by the control unit 30 will be described. First, the control unit 30 determines whether or not all of the following conditions 1 to 3 are met (S101). Condition 1 is that the forward / reverse state is neutral, condition 2 is that the parking brake is active, and condition 3 is that the driven object is the rear PTO shaft 14. The control unit 30 determines whether or not condition 1 is met based on the operation state of the forward / reverse switching operation device 33. The control unit 30 determines whether or not condition 2 is met based on the operation state of the parking brake operation device 34. The control unit 30 determines whether or not condition 3 is met based on the operation state of the PTO shaft switching operation device 32. Note that these determination methods are merely examples, and for example, either condition 1 or condition 2 may be omitted.

[0055] After determining that conditions 1 to 3 are satisfied, the control unit 30 determines whether the PTO switch 36 is turned on (S102). If the control unit 30 determines that the PTO switch 36 is turned on, it drives the rear PTO shaft 14 to rotate (S103).

[0056] Next, the control unit 30 determines whether the permission switch 35 is turned on (S104). If the control unit 30 determines that the permission switch 35 is turned on, it turns on the permission switch 35 (S105) and disables the automatic stop control when the operator leaves the seat (S106). By disabling the automatic stop control when the operator leaves the driver's seat 7, the engine 6 will not stop even if the operator leaves the driver's seat 7 and the seat sensor 31 turns off. As a result, the operator can perform stationary work. Furthermore, by confirming that the PTO switch 36 is turned on, the operator can easily understand that the automatic stop control has been disabled and that stationary work can now be performed. If the conditions determined in steps S101, S102, and S104 (the permission conditions for permitting stationary work) are not met, the permission switch 35 will not turn on and the automatic stop control will not be disabled.

[0057] Next, the control unit 30 determines whether the PTO switch has been turned off (S107). If the control unit 30 determines that the PTO switch has been turned off, it stops the rotation of the rear PTO shaft 14 and turns off the permission switch (S108). The control unit 30 also determines whether the state of the forward / reverse or parking brake has changed (S109). For example, if the forward / reverse switching operating device 33 is set to forward or reverse by the operator's operation, or if the parking brake is disabled, there is a risk that the tractor 1 will travel with the rear implement 21 driven during stationary work, so the control unit 30 stops the engine 6 (S110).

[0058] Next, the reverse operation will be described in order from start to finish with reference to Fig. 6. Fig. 6 is a flowchart showing the processing related to the reverse operation using the central work implement 22.

[0059] First, the flow of processing performed by the operator will be explained. The operator moves the tractor 1 to a location where reversing work will begin and temporarily stops the tractor 1. Next, if the PTO shaft to be driven is the rear PTO shaft 14, the operator operates the PTO shaft switching operating device 32 to switch the PTO shaft to be driven to the central PTO shaft 15. Next, the operator turns on the permission switch 35 and the PTO switch 36, and then starts reversing work using the central implement 22 while reversing the tractor 1. After completing reversing work, the operator moves the tractor 1 forward or stops it, or turns off the PTO switch 36 or the key switch.

[0060] Next, the processing performed by the control unit 30 will be described. First, the control unit 30 determines whether or not the following conditions a and b are both met (S201). Condition a is that the driven object is the central PTO shaft 15. Condition b is that the PTO switch 36 is on. The control unit 30 determines whether or not condition A is met based on the operating state of the PTO shaft switching operating device 32. The control unit 30 determines whether or not condition B is met based on the operating state of the PTO switch 36.

[0061] If the control unit 30 determines that the conditions a and b are satisfied, it drives the central PTO shaft 15 to rotate (S202). Next, the control unit 30 determines whether the permission switch 35 is turned on (S203). If the control unit 30 determines that the permission switch 35 is turned on, it disables the automatic stop control during reverse travel (S204). As a result, even if the tractor 1 is reversed with the central PTO shaft 15 driven, the central PTO shaft 15 will not stop, making it possible to perform reverse travel work.

[0062] The control unit 30 also determines whether the forward / reverse switching device 33 has been changed to the reverse position (S205), and if it determines that the forward / reverse switching device 33 has been changed to the reverse position, it turns on the permission switch (S206). As described above, the automatic stop control during reverse travel is disabled, so the rotation of the central PTO shaft 15 does not stop even if the forward / reverse switching device 33 is changed to the reverse position. Furthermore, by confirming that the permission switch 35 has been turned on, the operator can easily understand that the automatic stop control has been disabled and that reverse travel is possible. If the conditions determined in steps S201, S203, and S205 (the permission conditions for permitting reverse travel) are not met, the permission switch 35 does not turn on, and the automatic stop control is not disabled. Thereafter, the tractor 1 moves in reverse, thereby performing reverse travel.

[0063] Next, the control unit 30 determines whether at least one of the following conditions A to C is met (S207). Condition A is that the forward / reverse state is forward or neutral, condition B is that the PTO switch 36 is off, and condition C is that the key switch is off. The control unit 30 determines whether or not condition A is met based on the operating state of the forward / reverse switching operation device 33. The control unit 30 determines whether or not condition B is met based on the operating state of the PTO switch 36. The control unit 30 determines whether or not condition C is met based on the operating state of the key switch. If the control unit 30 determines that at least one of the above conditions A to C is met, it stops the rotation of the central PTO shaft 15 and turns off the permission switch 35 (S208).

[0064] As described above, the tractor 1 of this embodiment has the following feature 1. That is, the tractor 1 includes an engine 6, a vehicle body 2, a rear PTO shaft 14, a central PTO shaft 15, a permission switch 35, and a control unit 30. The engine 6 generates power. The vehicle body 2 includes a driver's seat 7. The rear PTO shaft 14 supplies the power generated by the engine 6 to a rear implement 21 attached to the rear of the vehicle body 2. The central PTO shaft 15 supplies the power generated by the engine 6 to a central implement 22 attached to the center of the vehicle body 2. The permission switch 35 can be operated by an operator. The control unit 30 sets operation of the permission switch 35 as one of the conditions for allowing rotation of the rear PTO shaft 14 after dismounting from the vehicle, and also sets operation of the permission switch 35 as one of the conditions for allowing rotation of the central PTO shaft 15 during reverse travel.

[0065] This allows one permission switch 35 to have two functions. These two functions are similar in concept in that they both allow rotation of the PTO shaft, and are never used simultaneously. Therefore, by giving one permission switch 35 these two functions, it is possible to simplify operation and reduce the number of operating tools required.

[0066] The tractor 1 of this embodiment further has the following feature 2. Specifically, the tractor 1 is equipped with a seat sensor 31 that detects whether an operator is seated in the driver's seat 7. The control unit 30 can execute an automatic stop function that stops the engine 6 when it is no longer possible to detect that the operator is seated. The automatic stop function is disabled when the conditions for allowing rotation of the rear PTO shaft 14 after dismounting are met.

[0067] This allows the rear implement 21 to be driven after dismounting even in a tractor 1 that has an automatic stop function.

[0068] The tractor 1 of this embodiment further has the following feature 3. That is, the control unit 30 can detect whether or not the tractor is in a parked state. The control unit 30 sets the detection of the parked state after dismounting the tractor when the seat sensor 31 does not detect the operator sitting on the seat as one of the conditions for permitting rotation of the rear PTO shaft 14 after dismounting the tractor.

[0069] This makes it possible to detect that the operator has dismounted and that the tractor 1 is in a parked state.

[0070] The tractor 1 of this embodiment further has the following feature 4. That is, the tractor 1 is equipped with a forward / reverse switching device 33 and a parking brake operating device 34. The forward / reverse switching device 33 can be operated to switch between forward, neutral, and reverse. The parking brake operating device 34 switches the parking brake between enabled and disabled. The control unit 30 detects that the tractor is in a parked state when it detects at least one of the following: the forward / reverse switching device 33 is switched to neutral, and the parking brake operating device 34 has enabled the parking brake.

[0071] This makes it possible to detect whether the vehicle is in a parking state or not simply by detecting the operation state of the operating tool.

[0072] The tractor 1 of this embodiment further has the following feature 5. That is, in the tractor 1, the permission switch 35 is disposed at a position where it can be operated by an operator seated in the driver's seat 7.

[0073] This allows the operator to operate the permission switch 35 while the seat sensor 31 detects that the operator is seated. Therefore, while the operator is seated, the automatic stop control can be disabled.

[0074] The tractor 1 of this embodiment further has the following feature 6. That is, the tractor 1 is provided with a PTO switch 36 that switches between driving and stopping the rear PTO shaft 14 or the center PTO shaft 15. The permission switch 35 and the PTO switch 36 are arranged side by side.

[0075] This allows two operating tools that are conceptually similar and have similar operation timing to be arranged side by side, thereby improving operability.

[0076] The tractor 1 of this embodiment further has the following feature 7. That is, in the tractor 1, the permission switch 35 is disposed closer to the center in the vehicle width direction than the PTO switch 36.

[0077] This allows the permission switch 35 to be operated while seated, while the PTO switch 36 can be operated by an operator who has dismounted from the vehicle, thereby improving operability.

[0078] The tractor 1 of this embodiment further has the following feature 8. That is, in the tractor 1, the permission switch 35 lights up when rotation of the rear PTO shaft 14 after dismounting or rotation of the central PTO shaft 15 during reverse travel is enabled.

[0079] This allows the operator to know that rotation of the rear PTO shaft 14 after dismounting or rotation of the central PTO shaft 15 during reverse travel is valid.

[0080] The tractor 1 of this embodiment further has the following feature 9. Specifically, the tractor 1 is equipped with a PTO switch 36 that switches between driving and stopping the rear PTO shaft 14 or the central PTO shaft 15. If an operation is performed on the PTO switch 36 to stop the rotation of the rear PTO shaft 14 or the central PTO shaft 15 while the rear PTO shaft 14 is rotating after the vehicle has dismounted, or while the central PTO shaft 15 is rotating during reverse travel, the illumination of the enable switch 35 stops.

[0081] This notifies the operator that the rotation of the rear PTO shaft 14 after dismounting or the rotation of the central PTO shaft 15 during reverse travel has been disabled.

[0082] The tractor 1 of this embodiment further has the following feature 10. That is, the tractor 1 includes an auxiliary housing 40 and a base housing 50. The auxiliary housing 40 is attached with an authorization switch 35. The auxiliary housing 40 is attached to the base housing 50.

[0083] This allows for the manufacture of tractors 1 that do not employ the permission switch 35 by simply omitting the attachment of the auxiliary housing 40.

[0084] The tractor 1 of this embodiment further has the following feature 11. That is, in the tractor 1, a slit 51 is formed in the base housing 50. A connector 41 is inserted into the slit 51. The connector 41 attaches the auxiliary housing 40 to the base housing 50.

[0085] As a result, even if the attachment of the auxiliary housing 40 is omitted, the appearance of the base housing 50 is not significantly impaired because only the slits 51 are formed in the base housing 50.

[0086] The above-described features 1 to 11 can be combined as appropriate as long as no contradiction occurs. For example, feature 3 can be combined with at least one of features 1 and 2. feature 4 can be combined with at least one of features 1 to 3. feature 5 can be combined with at least one of features 1 to 4. feature 6 can be combined with at least one of features 1 to 5. feature 7 can be combined with at least one of features 1 to 6. feature 8 can be combined with at least one of features 1 to 7. feature 9 can be combined with at least one of features 1 to 8. feature 10 can be combined with at least one of features 1 to 9. feature 11 can be combined with at least one of features 1 to 10.

[0087] The preferred embodiment of the present invention has been described above, but the above configuration can be modified, for example, as follows.

[0088] In the above embodiment, the permission switch 35 and the PTO switch 36 are push-button operation devices, but they may be operation devices with other configurations. Examples of operation devices with other configurations include levers or pedals. Alternatively, they may be touch panel operation devices that are operated by touching a display.

[0089] The flowcharts shown in the above embodiments are merely examples, and some processes may be omitted, some processes may be changed, or new processes may be added. For example, in the flowchart of Fig. 5, the order of the process of determining whether the PTO switch 36 is on and then driving the PTO shaft 14 to rotate may be reversed with the process of determining whether the permission switch 35 is on and turning on the PTO switch 36. Also, in the flowchart of Fig. 6, the permission switch 35 may be turned on at the same time as disabling the automatic stop control.

[0090] The above embodiment describes an example in which the present invention is applied to a tractor, but the present invention can also be applied to work vehicles other than tractors, for example, agricultural work vehicles such as rice transplanters, and construction or civil engineering work vehicles such as hydraulic excavators. [Explanation of symbols]

[0091] 1 Tractor (work vehicle) 2. Body 6 Engine (drive unit) 7 Driver's seat 14 Rear PTO axis 15 Central PTO axis 21 Rear work equipment 22 Central work machine 30 Control Unit 31 Seat Sensor 33 Forward / reverse switching device 34 Parking brake operation device 36 PTO switch (PTO drive stop operation device) 40 Auxiliary Housing 50 Base Housing 51 Slit 35 Permission switch (permission operating device)

Claims

1. a drive unit that generates power; a vehicle body including a driver's seat; a rear PTO shaft that supplies power generated by the drive unit to a rear implement attached to the rear of the vehicle body; a central PTO shaft that supplies power generated by the drive unit to a central working machine attached to a central portion of the vehicle body; an operator-operable permission control that can be switched on and off; a control unit that sets the enabling operation device being turned on as one of the conditions for enabling rotation of the rear PTO shaft after dismounting, and that sets the enabling operation device being turned on as one of the conditions for enabling rotation of the center PTO shaft during reverse travel; A work vehicle comprising:

2. The work vehicle according to claim 1, a seat sensor for detecting whether an operator is seated in the driver's seat; the control unit is capable of executing an automatic stop function that stops the drive unit when it becomes impossible to detect that the operator is seated; A work vehicle characterized in that the automatic stop function is disabled when a condition for allowing rotation of the rear PTO shaft after dismounting is met.

3. The work vehicle according to claim 2, The control unit is capable of detecting whether the vehicle is in a parking state, The control unit sets the detection of a parked state after disembarking from the vehicle when the seat sensor has not detected the operator seated as one of the conditions for permitting rotation of the rear PTO shaft after disembarking from the vehicle.

4. The work vehicle according to claim 3, a forward / reverse switching device that can be operated to switch between forward, neutral, and reverse; a parking brake operating tool for switching between enabling and disabling the parking brake; Equipped with The control unit detects that the work vehicle is in a parked state when it detects at least one of the following: the forward / reverse switching device is switched to neutral, and the parking brake operating device has activated the parking brake.

5. The work vehicle according to claim 2, A work vehicle characterized in that the permission operating tool is disposed in a position where it can be operated by an operator seated in the driver's seat.

6. The work vehicle according to claim 1, a PTO drive stop operating device for switching between driving and stopping the rear PTO shaft or the central PTO shaft; A work vehicle characterized in that the permission operating tool and the PTO drive stop operating tool are arranged side by side.

7. The work vehicle according to claim 6, A work vehicle characterized in that the permission operating tool is arranged closer to the center in the vehicle width direction than the PTO drive stop operating tool.

8. The work vehicle according to claim 1, The work vehicle is characterized in that the permission operating tool emits light when rotation of the rear PTO shaft after dismounting or rotation of the center PTO shaft when reversing is valid.

9. The work vehicle according to claim 8, a PTO drive stop operating device for switching between driving and stopping the rear PTO shaft or the central PTO shaft; A work vehicle characterized in that, when an operation is performed using the PTO drive stop operating device to stop the rotation of the rear PTO shaft or the central PTO shaft while the rear PTO shaft is rotating after the vehicle has dismounted, or while the central PTO shaft is rotating when the vehicle is moving in reverse, the light emission of the permission operating device stops.

10. A drive unit that generates power; a vehicle body including a driver's seat; a rear PTO shaft that supplies power generated by the drive unit to a rear implement attached to the rear of the vehicle body; a central PTO shaft that supplies power generated by the drive unit to a central working machine attached to a central portion of the vehicle body; a permission operating tool operable by an operator; a control unit that sets the operation of the permission operating device as one of the permission conditions for rotation of the rear PTO shaft after dismounting, and that sets the operation of the permission operating device as one of the permission conditions for rotation of the center PTO shaft during reverse travel; an auxiliary housing to which the permission operating device is attached; a base housing to which the auxiliary housing is attached; A work vehicle comprising:

11. The work vehicle according to claim 10, A slit is formed in the base housing, A connector is inserted into the slit, A work vehicle, wherein the auxiliary housing is attached to the base housing by the connector.

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