Work vehicle, system including work vehicle, and method for controlling work vehicle

Abstract

A vibration suppressing device (40) suppresses lateral movement of a driver's seat (5S). A locking mechanism (30) switches between locking and unlocking the operation of the vibration suppressing device (40). A sensor (41) detects vibration information relating to lateral vibration of the driver's seat (5S). A controller (50) switches the locking mechanism (30) between locking and unlocking the vibration suppressing device (40) on the basis of a comparison between the vibration information detected by the sensor (41) and preset vibration base isolation operation information.

Description

Work vehicle, system including work vehicle, and work vehicle control method

[0001] The present disclosure relates to a work vehicle, a system including a work vehicle, and a method for controlling a work vehicle.

[0002] In work vehicles such as hydraulic excavators and wheel loaders, the driver's seat was fixed to the floor of the cab, so-called rigid seats were used. However, to improve ride comfort and reduce operator fatigue, work vehicles with mechanical suspension or air suspension between the driver's seat and the floor have appeared.

[0003] Furthermore, a lateral vibration suppression device capable of actively suppressing lateral vibration of a driver's seat in a vehicle is disclosed in Japanese Patent Laid-Open Publication No. 2021-123122 (Patent Document 1). Patent Document 1 describes controlling the operation of a fluid pressure actuator by operating a two-way selector valve disposed between a fluid pressure supply source and a fluid pressure actuator based on information related to lateral vibration acting on the seat.

[0004] Japanese Patent Application Laid-Open No. 2021-123122

[0005] In the technique of the above publication, the operation of the fluid pressure actuator is constantly controlled, which causes discomfort to the operator.

[0006] An object of the present disclosure is to provide a work vehicle, a system including a work vehicle, and a method for controlling a work vehicle that can reduce discomfort felt by an operator during operation of the work vehicle.

[0007] Each of the work vehicles and systems including the work vehicles of the present disclosure includes a driver's seat, a vibration suppression device, a locking mechanism, a sensor, and a controller. The vibration suppression device suppresses lateral movement of the driver's seat. The locking mechanism switches between locking and unlocking operation of the vibration suppression device. The sensor detects vibration information related to lateral vibration of the driver's seat. The controller switches between locking and unlocking the vibration suppression device using the locking mechanism based on a comparison between the vibration information detected by the sensor and preset seismic isolation operation information.

[0008] The control method for a work vehicle disclosed herein is a control method for a work vehicle equipped with a driver's seat, a vibration suppression device that suppresses lateral movement of the driver's seat, and a locking mechanism that switches between locking and unlocking the operation of the vibration suppression device, and has the following steps.

[0009] Vibration information relating to lateral vibrations of the driver's seat is detected. The acquired vibration information is compared with preset seismic isolation operation information, and the operation of the vibration suppression device by the locking mechanism is switched between locking and unlocking.

[0010] According to the present disclosure, it is possible to realize a work vehicle, a system including a work vehicle, and a method for controlling a work vehicle that can reduce discomfort felt by an operator when the work vehicle is in operation.

[0011] FIG. 1 is a side view showing the configuration of a wheel loader as an example of a work vehicle in an embodiment of the present disclosure; FIG. 2 is a diagram showing the configuration of a system including a work vehicle in an embodiment of the present disclosure; FIG. 3 is a plan view showing the configuration of an example of a locking mechanism employed in a system including a work vehicle in an embodiment of the present disclosure; FIG. 4 is a side view showing the configuration of an example of a locking mechanism employed in a system including a work vehicle in an embodiment of the present disclosure; FIG. 5 is a plan view showing the configuration of another example of a locking mechanism employed in a system including a work vehicle in an embodiment of the present disclosure; FIG. 6 is a side view showing the configuration of another example of a locking mechanism employed in a system including a work vehicle in an embodiment of the present disclosure; FIG. 7 is a diagram showing functional blocks of a controller employed in a system including a work vehicle in an embodiment of the present disclosure; and FIG. 8 is a flow chart showing a method for controlling a work vehicle in an embodiment of the present disclosure.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the specification and drawings, identical or corresponding components are designated by the same reference numerals, and redundant explanations will not be repeated. In addition, in the drawings, configurations may be omitted or simplified for the sake of convenience.

[0013] In the following description, the terms "up," "down," "front," "rear," "left," and "right" refer to directions relative to an operator seated in the driver's seat 5S in the driver's cab 5 shown in Fig. 1. In Fig. 1, the front-to-rear direction is indicated by Z, with Zf indicating the front direction and Zb indicating the rear direction. In Fig. 2, the up-down direction is indicated by Y, and in Figs. 3 to 6, the left-to-right direction is indicated by X. In the following description, a plan view refers to a perspective from above the work vehicle looking down, and is synonymous with a top view.

[0014] <Configuration of Work Vehicle> The configuration of a wheel loader will be described as an example of a work vehicle in this embodiment using Figure 1. Note that the work vehicle in this embodiment is not limited to a wheel loader. The work vehicle in this embodiment may be any work vehicle that has a work implement and a driver's seat, and may also be a hydraulic excavator, bulldozer, motor grader, etc.

[0015] Figure 1 is a side view showing the configuration of a wheel loader according to one embodiment of the present disclosure. As shown in Figure 1, the wheel loader 1 according to this embodiment has a running body 2 and a work implement 3. The work implement 3 is disposed on the running body 2. The running body 2 has a body frame 10, a pair of front wheels 4, a driver's compartment (cab) 5, an engine compartment 6, a pair of rear wheels 7, and a steering cylinder 9. The wheel loader 1 uses the work implement 3 to perform work such as loading earth and sand.

[0016] The body frame 10 is of a so-called articulated (rotating) type and includes a front frame 11, a rear frame 12, and a connecting shaft 13. The front frame 11 is disposed in a forward direction Zf of the rear frame 12. The connecting shaft 13 is provided in the center of the body frame 10 in the left-right direction (vehicle width direction), and connects the front frame 11 and the rear frame 12 to each other so that they can rotate. A pair of front wheels 4 are attached to the left and right of the front frame 11. Furthermore, a pair of rear wheels 7 are attached to the left and right of the rear frame 12.

[0017] The work implement 3 is driven by hydraulic oil from a work implement pump (not shown). The work implement 3 has a boom 14, a bucket 15, a lift cylinder 16, a bucket cylinder 17, and a bell crank 18. The boom 14 is attached to the front frame 11. The bucket 15 is attached to the tip of the boom 14.

[0018] The lift cylinder 16 and the bucket cylinder 17 are hydraulic cylinders. One end of the lift cylinder 16 is attached to the front frame 11, and the other end of the lift cylinder 16 is attached to the boom 14. The boom 14 rotates up and down as the lift cylinder 16 extends and retracts. One end of the bucket cylinder 17 is attached to the front frame 11, and the other end of the bucket cylinder 17 is attached to the bucket 15 via a bell crank 18. The bucket 15 rotates up and down as the bucket cylinder 17 extends and retracts.

[0019] The operator's cab 5 is mounted on the rear frame 12. Inside the operator's cab 5, there are arranged an operator's seat 5S for an operator to sit in, a handle for steering, levers for operating the work implement 3, various switches, display devices, etc. The engine room 6 is arranged on the rear frame 12 in the rear direction Zb of the operator's cab 5 and houses an engine.

[0020] <Configuration of a System Including a Work Vehicle> Next, the configuration of a system including a work vehicle in this embodiment will be described with reference to FIGS. 2 to 7. FIG.

[0021] Fig. 2 is a diagram showing the configuration of a system including a work vehicle according to an embodiment of the present disclosure. Figs. 3 and 4 are a plan view and a side view showing the configuration of an example of a locking mechanism employed in a system including a work vehicle according to an embodiment of the present disclosure. Figs. 5 and 6 are a plan view and a side view showing the configuration of another example of a locking mechanism employed in a system including a work vehicle according to an embodiment of the present disclosure. Fig. 7 is a diagram showing functional blocks of a controller employed in a system including a work vehicle according to an embodiment of the present disclosure.

[0022] As shown in FIG. 2 , the system including the work vehicle has a locking mechanism 30 , a vibration suppression device 40 , a sensor 41 , a fluid regulation device 42 , and a controller 50 .

[0023] The cab 5 (FIG. 1) has a floor 5F. A driver's seat 5S is disposed on the floor 5F of the cab 5. A vibration suppression device 40 is disposed between the floor 5F and the driver's seat 5S.

[0024] The vibration suppression device 40 includes a damper member 20 and elastic members SP1 and SP2. The damper member 20 absorbs lateral vibrations of the driver's seat 5S. The lateral direction refers to any direction within a plane including the mutually perpendicular longitudinal direction Z and lateral direction X (FIGS. 3 to 6). In other words, the lateral direction may be the longitudinal direction Z, the lateral direction X, or a direction other than the longitudinal direction Z and the lateral direction X, as long as it is within a plane including the longitudinal direction Z and the lateral direction X. Note that while FIG. 2 illustrates a case in which the vibration suppression device 40 is disposed in the longitudinal direction Z, the vibration suppression device 40 may also be disposed in the lateral direction X, or in both the longitudinal direction Z and the lateral direction X, or in a direction other than the longitudinal direction Z or the lateral direction X.

[0025] One end of the damper member 20 is connected to a fixed member BL1 fixed to the floor 5F. The other end of the damper member 20 is connected to a fixed member BL3 fixed to the driver's seat 5S. The damper member 20 has a first fluid chamber 20a and a second fluid chamber 20b separated by the piston portion of the piston rod. When the damper member 20 is inactive, the damper member 20 functions as a normal damper. On the other hand, when the damper member 20 is active, the damper member 20 can expand and contract by supplying and discharging fluid to and from the fluid chambers 20a and 20b in response to lateral vibrations of the driver's seat 5S.

[0026] The elastic members SP1 and SP2, together with the damper member 20, absorb lateral vibrations of the driver's seat 5S. Each of the elastic members SP1 and SP2 is formed, for example, by a spring. One end of the elastic member SP1 is connected to a fixed member BL1 fixed to the floor 5F. The other end of the elastic member SP1 is connected to a fixed member BL3 fixed to the driver's seat 5S. One end of the elastic member SP2 is connected to a fixed member BL2 fixed to the floor 5F. The other end of the elastic member SP2 is connected to a fixed member BL3 fixed to the driver's seat 5S.

[0027] One end of each of the damper member 20 and the elastic members SP1 and SP2 may be fixed directly to the floor 5F, and the other end of each of the damper member 20 and the elastic members SP1 and SP2 may be fixed directly to the driver's seat 5S.

[0028] The sensor 41 detects vibration information related to lateral vibrations of the driver's seat 5S relative to the floor 5F (any direction within a plane including the front-rear direction Z and the left-right direction X). The sensor 41 is, for example, an inertial measurement unit (IMU). The vibration information detected by the sensor 41 is, for example, at least one of the frequency and acceleration of lateral vibrations of the driver's seat 5S. The vibration information detected by the sensor 41 may also be one or more output signals selected from the group consisting of a work implement operation lever, a travel lever, and a work mode selector switch.

[0029] The vibration information detected by the sensor 41 may also be information regarding the acceleration of the floor 5F, the angular velocity of the floor 5F, the amount of operation of the accelerator pedal, the ON / OFF of the brake pedal, the amount of operation of the work equipment operation lever, changing the speed gear to a lower speed gear, the ON / OFF of the work equipment lock switch, the ON / OFF of the semi-automatic excavation function, and the operation of the steering lock lever.

[0030] The acceleration of the floor 5F is detected, for example, by an acceleration sensor. From the acceleration of the floor 5F, a waveform pattern or a peak value of the waveform of the acceleration of the floor 5F in a specific work mode is obtained. The angular velocity of the floor 5F is detected, for example, by an angular velocity sensor. From the angular velocity of the floor 5F, a waveform pattern or a peak value of the waveform of the angular velocity of the floor 5F in a specific work mode is obtained.

[0031] The accelerator pedal operation amount is detected by, for example, a potentiometer. From the accelerator pedal operation amount, the accelerator pedal opening pattern during a specific work mode is obtained. The brake pedal ON / OFF is detected by, for example, a pressure switch. From the brake pedal ON / OFF, the brake pedal ON / OFF pattern during a specific work mode is obtained.

[0032] The amount of operation of the work implement control lever is detected, for example, by a potentiometer. From the amount of operation of the work implement control lever, a pattern of operation and work implement lever angle in a specific work mode is obtained. A shift to a lower gear is detected, for example, by a switch. From the shift to a lower gear, the controller 50 obtains the change in gear in a specific work mode.

[0033] The ON / OFF state of the work equipment lock switch is detected, for example, by a switch. From the ON / OFF state of the work equipment lock switch, the controller 50 acquires whether the work equipment lock switch is OFF, the number of times it has been pressed, and so on. The ON / OFF state of the semi-automatic excavation function is detected, for example, by a switch. From the ON / OFF state of the semi-automatic excavation function, the controller 50 acquires whether the semi-automatic excavation function is ON, the number of times it has been pressed, and so on. The operation of the steering lock lever is detected, for example, by a pressure switch. From the operation of the steering lock lever, the controller 50 acquires whether the steering lock lever is free.

[0034] Semi-automatic excavation refers to excavation under semi-automatic control. Specifically, semi-automatic excavation refers to excavation under automatic control that automatically links the bucket 15 and the boom 14 while allowing the operator to manually operate the boom lever and bucket lever.

[0035] The locking mechanism 30 switches between locking and unlocking the operation of the vibration suppression device 40. When the operation of the vibration suppression device 40 is locked, the locking mechanism 30 restricts lateral movement of the driver's seat 5S relative to the floor 5F. When the operation of the vibration suppression device 40 is locked, the locking mechanism 30 restricts, for example, relative lateral movement between a plate PL1 fixed to the floor 5F and a plate PL2 fixed to the driver's seat 5S.

[0036] The locking mechanism 30 releases the restriction on lateral movement of the driver's seat 5S relative to the floor 5F when the operation of the vibration suppression device 40 is unlocked. When the operation of the vibration suppression device 40 is locked, the locking mechanism 30 releases the restriction on relative lateral movement between, for example, a plate PL1 fixed to the floor 5F and a plate PL2 fixed to the driver's seat 5S.

[0037] The plate PL1 may be indirectly connected to the floor 5F via a fixing member BL2, or may be directly connected to the floor 5F. The plate PL2 may be indirectly connected to the driver's seat 5S via a fixing member BL3, or may be directly connected to the driver's seat 5S.

[0038] As shown in FIG. 3 , the plates PL1 and PL2 are arranged so as to have overlapping regions in plan view when the wheel loader 1 is stopped. The plate PL1 has, for example, a notch NT on its side. The plate PL2 has, for example, a through hole TH. The through hole TH has, for example, an elongated hole shape in plan view. The elongated through hole TH has, for example, a longer dimension in the left-right direction X and a shorter dimension in the front-rear direction Z. The through hole TH may have a shorter dimension in the left-right direction X and a longer dimension in the front-rear direction Z. It is sufficient that the through hole TH extends long in any direction in a plane including the left-right direction X and the front-rear direction Z. The through hole TH may extend linearly or curvedly in plan view.

[0039] The notch NT and the through hole TH have overlapping portions in a plan view. A pin PN1 is inserted into the through hole TH. The pin PN1 is slidable within the through hole TH in the direction in which the through hole TH extends (for example, the left-right direction X). By sliding within the through hole TH, the pin PN1 is movable between an inserted state in which it is inserted into the notch NT and an ejected state in which it is ejected from the notch NT.

[0040] As shown in Figure 4, the locking mechanism 30 includes, for example, a pin PN1, a switching lever LE, an air cylinder AS, a control valve CB, and an air supply source SS. The pin PN is connected to the switching lever LE. The switching lever LE is connected to the air cylinder AS. The air cylinder AS can extend and retract in the lateral direction. The air cylinder AS is connected to the air supply source SS via the control valve CB. The air supply source SS is, for example, a compressor.

[0041] The control valve CB controls the supply of air from the air supply source SS to the air cylinder AS. The control valve CB also controls the exhaust of air from the air cylinder AS. The operation of the control valve CB is controlled by a command current from the controller 50.

[0042] The air cylinder AS expands and contracts laterally as air is supplied to and exhausted from the air cylinder AS. The expansion and contraction of the air cylinder AS causes the pin PN to slide laterally (e.g., in the left-right direction X) within the through-hole TH via the switching lever LE. The sliding of the pin PN1 causes the pin PN1 to move between an inserted state where it is inserted into the notch NT and an extracted state where it is extracted from the notch NT.

[0043] 3, when the pin PN1 (broken line) is inserted into the notch NT of the plate PL1, the relative movement of the plates PL1 and PL2 in the fore-and-aft direction Z is restricted. This restricts the movement of the driver's seat 5S relative to the floor 5F shown in FIG. 2 in the fore-and-aft direction Z, and the operation of the vibration suppression device 40 is locked.

[0044] 3, when the pin PN1 (solid line) is released from the notch NT of the plate PL1, the relative movement of the plates PL1 and PL2 in the fore-and-aft direction Z is not restricted. As a result, the movement of the driver's seat 5S relative to the floor 5F shown in FIG. 2 in the fore-and-aft direction Z is not restricted, and the operation lock of the vibration suppression device 40 is released.

[0045] 5 and 6, the operation of the vibration suppression device 40 may be switched between locked and unlocked by moving the pin PN2 in the up-down direction Y. In this case, as shown in FIG. 5, the pin PN2 of the locking mechanism 30 may be inserted into the through hole TH1 of the plate PL1 and the through hole TH2 of the plate PL2. The through holes NT1 and TH2 have portions that overlap each other in a plan view when the wheel loader 1 is stopped. The pin PN2 may remain inserted in the through hole TH2 as long as it is at least insertable and removable from the through hole TH1, or may be insertable and removable from the through hole TH2.

[0046] 6, the locking mechanism 30 includes, for example, a pin PN2, an air cylinder AS, a control valve CB, and an air supply source SS. The pin PN2 is connected to the air cylinder AS. The air cylinder AS can extend and retract in the vertical direction. The air cylinder AS is connected to the air supply source SS via the control valve CB.

[0047] By supplying and discharging air to and from the air cylinder AS, the air cylinder AS expands and contracts in the vertical direction Y. As the air cylinder AS expands and contracts in the vertical direction Y, the pin PN2 moves in the vertical direction Y. As the pin PN2 moves in the vertical direction Y, the pin PN2 is inserted into and removed from at least the through-hole TH1.

[0048] When the pin PN2 is inserted into the through-hole TH1 of the plate PL1, the relative movement between the plates PL1 and PL2 in the lateral direction (e.g., the left-right direction X and the front-rear direction Z) is restricted. This restricts the lateral movement of the driver's seat 5S relative to the floor 5F shown in FIG. 2, and locks the operation of the vibration suppression device 40.

[0049] On the other hand, as shown in Fig. 6, when the pin PN2 is in the released state after being released from the through-hole TH1 of the plate PL1, the relative lateral movement of the plates PL1 and PL2 is not restricted, and the lateral movement of the driver's seat 5S relative to the floor 5F shown in Fig. 2 is also not restricted, and the operation lock of the vibration suppression device 40 is released.

[0050] 2, when the damper member 20 is active, a fluid regulating device 42 is connected to the damper member 20. The fluid regulating device 42 regulates the supply and discharge of fluid to the damper member 20. The fluid regulating device 42 is, for example, a two-way switching valve, which is configured with a solenoid valve with fast operating response. In response to a command signal from the controller 50, the fluid regulating device 42 switches between a path that supplies fluid from the fluid pump to one fluid chamber of the damper member 20 and a path that discharges fluid from the other fluid chamber of the damper member 20 to a fluid tank.

[0051] The controller 50 acquires vibration information relating to lateral vibrations acting on the driver's seat 5S from the sensor 41, and controls the fluid adjusting device 42 to suppress the lateral vibrations, thereby controlling the operation of the damper member 20. By actively moving the driver's seat 5S in this way in response to the lateral vibrations acting on the driver's seat 5S, the lateral vibrations of the driver's seat 5S can be actively suppressed.

[0052] The fluid regulating device 42 may be, for example, a variable throttle valve. The fluid regulating device 42 changes the speed at which fluid moves from one of the first fluid chamber 20 a and the second fluid chamber 20 b of the damper member 20 to the other fluid chamber based on a control signal from the controller 50. This adjusts the damping force of the damper member 20.

[0053] The damper member 20 may also be of a type that has a magnetorheological fluid and a coil, and changes its damping force by applying a magnetic field generated by passing current through the coil to the magnetorheological fluid. If the damper member 20 is of this type, the controller 50 controls a current adjustment device that adjusts the amount of current passed through the coil. By adjusting the damping force of the damper member 20 in accordance with the strength of lateral vibration of the driver's seat 5S relative to the floor 5F, the discomfort felt by the operator can be further reduced.

[0054] The controller 50 includes a processor, a main memory, and a storage. The processor is, for example, a CPU (Central Processing Unit). The main memory includes, for example, a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). The controller 50 reads a program stored in the storage, loads it into the main memory, and executes predetermined processing in accordance with the program.

[0055] The controller 50 is electrically connected to each of the sensor 41, the fluid adjusting device 42, and the locking mechanism 30. The controller 50 acquires vibration information related to lateral vibration of the driver's seat 5S detected by the sensor 41. The controller 50 controls the locking mechanism 30 based on the vibration information detected by the sensor 41. The controller 50 switches between locking and unlocking the operation of the vibration suppression device 40 by the locking mechanism 30 based on a comparison between the vibration information detected by the sensor 41 and preset seismic isolation operation information.

[0056] The controller 50 may be mounted on the wheel loader 1, or may be located remotely outside the wheel loader 1. When the controller 50 is located remotely outside the wheel loader 1, the controller 50 may be wirelessly connected to the sensor 41, the fluid adjusting device 42, the locking mechanism 30, etc. The controller 50 may be stored in a server located remotely from the wheel loader 1.

[0057] 7 , the controller 50 has a sensor information acquisition unit 51, a lock switching determination unit 52, a lock control unit 53, and a memory 54. The sensor information acquisition unit 51 acquires vibration information detected by the sensor 41. The lock switching determination unit 52 determines whether or not to lock the vibration suppression device 40 by the lock mechanism 30 based on a comparison between the vibration information acquired by the sensor information acquisition unit 51 and preset seismic isolation operation information. When making this determination, the lock switching determination unit 52 refers to the seismic isolation operation information stored in the memory 54.

[0058] The vibration information is, for example, at least one of the frequency and acceleration of lateral vibrations of the driver's seat 5S. If the vibration information is the frequency of lateral vibrations of the driver's seat 5S, the seismic isolation operation information is a reference value for the number of lateral vibrations of the driver's seat 5S. If the vibration information is the acceleration of lateral vibrations of the driver's seat 5S, the seismic isolation operation information is a reference value for the acceleration of lateral vibrations of the driver's seat 5S.

[0059] Furthermore, the vibration information may be, for example, one or more output signals selected from the group consisting of a work machine operation lever, a travel lever, and a work mode selector switch. The seismic isolation operation information may be the amount of operation of each lever in a specific work mode, ON / OFF information of a switch, etc. The seismic isolation operation information may be stored in the memory 54 of the controller 50 from the time the wheel loader 1 is first sold, or may be input after the wheel loader 1 is sold. The seismic isolation operation information may be input to the memory 54 using an input device (such as a touch panel) installed outside the controller 50.

[0060] The lock control unit 53 controls the lock mechanism 30 based on the determination result of the lock switching determination unit 52. The lock control unit 53 controls the lock mechanism 30, for example, by outputting a command current to the lock mechanism 30. The lock control unit 53 controls the lock mechanism 30 so that the lock mechanism 30 switches between locking and unlocking the vibration suppression device 40.

[0061] As described above, if the controller 50 determines from the vibration information that the frequency and acceleration of vibration in the lateral direction of the driver's seat 5S are high, if it determines that the wheel loader 1 is in a specific work mode, or if it determines that there has been an intentional input from the operator, it controls to unlock the vibration suppression device 40 and activate the vibration suppression device 40. In addition, in cases other than those mentioned above, the controller 50 controls to lock the vibration suppression device 40 so that the vibration suppression device 40 does not activate.

[0062] <Work Vehicle Control Method> Next, a work vehicle control method will be described.

[0063] 8 is a flow diagram showing a control method for a work vehicle according to an embodiment of the present disclosure. As shown in FIGS. 7 and 8, the sensor 41 detects vibration information relating to lateral vibrations of the driver's seat 5S. The sensor 41 outputs a signal relating to the detected vibration information to the controller 50. The sensor information acquisition unit 51 of the controller 50 acquires vibration information relating to lateral vibrations of the driver's seat 5S from the sensor 41 (step S1: FIG. 8).

[0064] The sensor information acquisition unit 51 outputs a signal related to the acquired vibration information to the lock switching determination unit 52. The lock switching determination unit 52 determines whether or not to lock the vibration suppression device 40 using the lock mechanism 30 based on a comparison between the acquired vibration information and preset seismic isolation operation information (step S2: FIG. 8). When making this determination, the lock switching determination unit 52 refers to the seismic isolation operation information stored in the memory 54.

[0065] The lock switching determination unit 52 outputs a signal indicating the determination result to the lock control unit 53. The lock control unit 53 controls the lock mechanism 30, for example, by outputting a command current to the lock mechanism 30. Based on the obtained determination result, the lock control unit 53 controls the lock mechanism 30 so that the lock mechanism 30 switches between locking and unlocking the vibration suppression device 40. When the lock control unit 53 obtains a determination result that the vibration suppression device 40 should not be locked, it controls the lock mechanism 30 to unlock the vibration suppression device 40 (step S3: FIG. 8 ).

[0066] Specifically, the lock control section 53 of the controller 50 controls the control valve CB so that the pin PN1 escapes from the notch NT of the plate PL1 in Figures 3 and 4, or so that the pin PN2 escapes from the through-hole TH1 of the plate PL1 in Figures 5 and 6. This unlocks the vibration suppression device 40, and the restriction on the lateral movement of the driver's seat 5S relative to the floor 5F is released.

[0067] Furthermore, when the lock control unit 53 acquires a determination result that the vibration suppression device 40 should be locked, it controls the lock mechanism 30 to lock the vibration suppression device 40 (step S4: FIG. 8).

[0068] Specifically, the lock control section 53 of the controller 50 controls the control valve CB so that the pin PN1 is inserted into the notch NT of the plate PL1 in Figures 3 and 4, or so that the pin PN2 is inserted into the through-holes TH1 and TH2 in Figures 5 and 6. This locks the vibration suppression device 40, restricting lateral movement of the driver's seat 5S relative to the floor 5F.

[0069] <Effects> Next, the effects of this embodiment will be described.

[0070] 2 , in this embodiment, the locking mechanism 30 switches between locking and unlocking the vibration suppression device 40 based on a comparison between vibration information detected by the sensor 41 and preset seismic isolation operation information. This allows the operation of the vibration suppression device 40 to be locked at an appropriate timing, thereby reducing discomfort to the operator when the work vehicle 1 is operating.

[0071] Furthermore, lateral vibration of the driver's seat 5S relative to the floor 5F can be suppressed by unlocking the vibration suppression device 40. This reduces the physical strain on the operator caused by vibrations while working on the work vehicle, and can also lead to a reduction in the operator's physical fatigue after working for long periods of time.

[0072] In this embodiment, the vibration information is at least one of the frequency and acceleration of lateral vibrations of the driver's seat 5S. This allows the locking mechanism 30 to be controlled based on the frequency and acceleration of the lateral vibrations. For example, if the frequency of lateral vibrations is high (e.g., the frequency of lateral vibrations is low) or if the acceleration of lateral vibrations is high (e.g., the lateral vibrations are large), the vibration suppression device 40 can be unlocked to quickly attenuate the lateral vibrations.

[0073] In this embodiment, the vibration information is one or more output signals selected from the group consisting of a work machine control lever, a travel lever, and a work mode selector switch. This allows the locking mechanism 30 to be controlled based on the operation information of each lever and switch. For example, if the operation information of each lever and switch determines that a specific work mode is in which lateral vibrations are large, the lateral vibrations can be quickly attenuated by unlocking the vibration suppression device 40.

[0074] 2, the vibration suppression device 40 has damper members 20 connected to both the driver's seat 5S and the floor 5F. The damper members 20 can attenuate lateral vibration of the driver's seat 5S relative to the floor 5F.

[0075] 2, this embodiment is also provided with a fluid adjustment device 42 that adjusts the supply and discharge of fluid to and from the damper member 20. The supply and discharge of fluid to and from the damper member 20 is adjusted based on vibration information detected by the sensor 41. This makes it possible to actively move the driver's seat 5S in response to lateral vibrations acting on the driver's seat 5S, thereby actively suppressing lateral vibrations of the driver's seat 5S. This further reduces discomfort to the operator.

[0076] 2, the vibration suppression device 40 in this embodiment has elastic members SP1 and SP2 connected to the driver's seat 5S and the floor 5F, respectively, which can absorb lateral vibrations of the driver's seat 5S that cannot be fully absorbed by the damper member 20, thereby enabling rapid damping of the vibrations.

[0077] <Additional Notes> The above-described embodiment includes the following technical ideas.

[0078] (Supplementary Note 1) A work vehicle comprising: a driver's seat; a vibration suppression device that suppresses lateral movement of the driver's seat; a locking mechanism that switches between locking and unlocking the operation of the vibration suppression device; a sensor that detects vibration information related to lateral vibration of the driver's seat; and a controller that switches between locking and unlocking the vibration suppression device using the locking mechanism based on a comparison between the vibration information detected by the sensor and preset seismic isolation operation information.

[0079] (Supplementary Note 2) The work vehicle according to Supplementary Note 1, wherein the vibration information is at least one of a frequency and an acceleration of lateral vibration of the driver's seat.

[0080] (Supplementary Note 3) The work vehicle according to Supplementary Note 1, wherein the vibration information is one or more output signals selected from the group consisting of a work implement operation lever, a travel lever, and a work mode changeover switch.

[0081] (Supplementary Note 4) The work vehicle according to any one of Supplementary Note 1 to Supplementary Note 3, further comprising a floor supporting the driver's seat, wherein the vibration suppression device has a damper member connected to each of the driver's seat and the floor.

[0082] (Supplementary Note 5) The work vehicle according to Supplementary Note 4, further comprising a fluid adjusting device that adjusts the supply and discharge of fluid to and from the damper member.

[0083] (Supplementary Note 6) The work vehicle according to Supplementary Note 4 or Supplementary Note 5, wherein the vibration suppression device has elastic members connected to each of the driver's seat and the floor.

[0084] (Supplementary Note 7) The work vehicle according to any one of Supplementary Note 1 to Supplementary Note 6, wherein the seismic isolation operation information is stored in the controller.

[0085] (Appendix 8) A system including a work vehicle, comprising: a driver's seat; a vibration suppression device that suppresses lateral movement of the driver's seat; a locking mechanism that switches between locking and unlocking the operation of the vibration suppression device; a sensor that detects vibration information related to lateral vibration of the driver's seat; and a controller that switches between locking and unlocking the vibration suppression device using the locking mechanism based on a comparison between the vibration information detected by the sensor and preset seismic isolation operation information.

[0086] (Appendix 9) A control method for a work vehicle equipped with a driver's seat, a vibration suppression device that suppresses lateral movement of the driver's seat, and a locking mechanism that switches between locking and unlocking operation of the vibration suppression device, the control method for a work vehicle comprising the steps of: acquiring vibration information related to lateral vibration of the driver's seat; and switching between locking and unlocking operation of the vibration suppression device by the locking mechanism based on a comparison between the acquired vibration information and preset seismic isolation operation information.

[0087] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0088] REFERENCE SIGNS LIST 1 Wheel loader, 2 Traveling body, 3 Work machine, 4 Front wheel, 5 Driver's cab, 5F Floor, 5S Driver's seat, 6 Engine room, 7 Rear wheel, 9 Steering cylinder, 10 Body frame, 11 Front frame, 12 Rear frame, 13 Connecting shaft portion, 14 Boom, 15 Bucket, 16 Lift cylinder, 17 Bucket cylinder, 18 Bell crank, 20 Damper member, 30 Lock mechanism, 40 Vibration suppression device, 41 Sensor, 42 Fluid adjustment device, 50 Controller, 51 Sensor information acquisition unit, 52 Lock switching determination unit, 53 Lock control unit, 54 Memory, AS Air cylinder, BL1, BL2, BL3 Fixing member, CB Control valve, LE Switching lever, NT1, TH, TH1, TH2 Through hole, PL1, PL2 Plate, PN1, PN2 Pin, SP1, SP2 elastic member, SS air supply source.

Claims

1. A work vehicle comprising: a driver's seat; a vibration suppression device that suppresses lateral movement of the driver's seat; a locking mechanism that switches between locking and unlocking the operation of the vibration suppression device; a sensor that detects vibration information related to lateral vibration of the driver's seat; and a controller that switches between locking and unlocking the vibration suppression device using the locking mechanism based on a comparison between the vibration information detected by the sensor and preset seismic isolation operation information.

2. A work vehicle according to claim 1, wherein the vibration information is at least one of a frequency and an acceleration of lateral vibration of the driver's seat.

3. The work vehicle according to claim 1, wherein the vibration information is one or more output signals selected from the group consisting of a work equipment operation lever, a travel lever, and a work mode changeover switch.

4. A work vehicle according to claim 1, further comprising a floor supporting said driver's seat, said vibration suppression device having a damper member connected to each of said driver's seat and said floor.

5. A work vehicle according to claim 4, further comprising a fluid regulating device for regulating the supply and discharge of fluid to and from said damper member.

6. A work vehicle according to claim 4, wherein the vibration suppression device has elastic members connected to each of the driver's seat and the floor.

7. A work vehicle according to claim 1, wherein the seismic isolation operation information is stored in the controller.

8. A system including a work vehicle equipped with a driver's seat, a vibration suppression device that suppresses lateral movement of the driver's seat, a locking mechanism that switches between locking and unlocking the operation of the vibration suppression device, a sensor that detects vibration information related to lateral vibration of the driver's seat, and a controller that switches between locking and unlocking the vibration suppression device using the locking mechanism based on a comparison between the vibration information detected by the sensor and preset seismic isolation operation information.

9. A control method for a work vehicle equipped with a driver's seat, a vibration suppression device that suppresses lateral movement of the driver's seat, and a locking mechanism that switches between locking and unlocking operation of the vibration suppression device, comprising the steps of: acquiring vibration information relating to lateral vibration of the driver's seat; and switching between locking and unlocking operation of the vibration suppression device by the locking mechanism based on a comparison between the acquired vibration information and preset seismic isolation operation information.

Images