Work vehicle

Abstract

To satisfactorily perform confirmation work without feeling troublesomeness by an alarm even when an operator releases a maneuvering attitude and performs the confirmation work of a work place by visual observation.SOLUTION: The work vehicle includes a monitoring device, an alarm device, a posture detection unit that detects whether or not an operator is in a maneuvering posture for maneuvering the work vehicle, a hydraulic actuator for operating the work vehicle, an operation unit for driving the hydraulic actuator, a cut-off lever for switching an operation of the operation unit between a valid state and an invalid state, a cut-off switch that detects a rotation position of the cut-off lever, and a control unit. The control unit causes the alarm device to output the alarm based on the monitoring result of the monitoring device when it is detected that the operator is in the maneuvering posture, and stops the alarm device from outputting the alarm based on the monitoring result of the monitoring device when it is detected that the maneuvering posture of the operator is released and the operation unit is in the disabled state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] Various work vehicles, such as hydraulic excavators, have been proposed. For example, in the work vehicle disclosed in Patent Document 1, a state in which work can be performed by the work machine is detected based on the switching position of a cutoff lever, and the method of notification when an obstacle is detected is changed depending on whether the work machine is in a workable state or an unworkable state. Specifically, in the workable state, a continuous alarm sound is emitted when an obstacle is detected, and in the unworkable state, an intermittent alarm sound is emitted when an obstacle is detected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-63568 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a configuration that uniformly outputs an alarm when an obstacle is detected can sometimes interfere with the operator's actions. For example, if the operator leaves the seat of a work vehicle with the engine running and tries to release the driver from the driving position to visually check the work area, outputting an alarm based on the detection of an obstacle can be bothersome to the operator, and prevent them from satisfactorily performing their visual check.

[0005] The present invention has been made to solve the above problems, and its object is to provide a work vehicle that allows the operator to release the driving posture and perform visual inspection of the work area without being bothered by an alarm, and to carry out the inspection work satisfactorily. [Means for solving the problem]

[0006] a control unit that controls the alarm device based on the detection results of the attitude detection unit and the cutoff switch; and a work vehicle according to one aspect of the present invention, which is a work vehicle for performing work and includes: a monitoring device that monitors the periphery of the work vehicle; an alarm device that outputs an alarm based on the monitoring results of the monitoring device; a posture detection unit that detects whether an operator is seated in the driver's seat of the work vehicle and in a driving position to drive the work vehicle; a hydraulic actuator for operating the work vehicle; an operating unit that drives the hydraulic actuator; a cutoff lever that switches the operation of the operating unit between an enabled state that drives the hydraulic actuator and an disabled state that disables drive of the hydraulic actuator; a cutoff switch that detects the rotational position of the cutoff lever; and a control unit that controls the alarm device based on the detection results of the attitude detection unit and the cutoff switch; [Effects of the Invention]

[0007] With the above configuration, even when the operator releases the operating posture and visually checks the work area, the operator does not feel bothered by the alarm, and as a result, the operator can perform the visual check work satisfactorily (comfortably). [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view showing a schematic configuration of a hydraulic excavator, which is an example of a work vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory diagram showing the configuration of a main part of the hydraulic excavator. [Figure 3] 4 is a flowchart showing an example of an operation flow in the hydraulic excavator. [Figure 4] 10 is a flowchart showing another example of the flow of operations in the hydraulic excavator. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes an embodiment of the present invention with reference to the drawings.

[0010] [1. Work vehicles] 1 is a side view showing a schematic configuration of a hydraulic excavator 1, which is an example of a work vehicle according to this embodiment. The hydraulic excavator 1 is a work vehicle that performs work, and includes a lower traveling structure 2, a work implement 3, and an upper rotating structure 4.

[0011] Here, directions in FIG. 1 are defined as follows. First, the direction in which the lower traveling body 2 moves straight is the fore-and-aft direction, with one side of this being the "front" and the other side being the "rear." In FIG. 1, as an example, the side of the traveling motor 22 relative to the blade 23 is shown as the "front." Also, the lateral direction perpendicular to the fore-and-aft direction is the left-and-right direction. In this case, the left side as seen from the operator (operator) sitting in the cockpit 41a is defined as the "left," and the right side is defined as the "right." Furthermore, the direction of gravity perpendicular to the fore-and-aft direction and the left-and-right direction is defined as the up-and-down direction, with the upstream side of the direction of gravity being defined as the "up" and the downstream side being defined as the "down."

[0012] The lower traveling structure 2 is equipped with a pair of left and right crawlers 21 and a pair of left and right traveling motors 22. Each traveling motor 22 is a hydraulic motor. The left and right traveling motors 22 drive the left and right crawlers 21, respectively, to move the hydraulic excavator 1 forward and backward. The lower traveling structure 2 is provided with a blade 23 for performing ground leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 up and down.

[0013] The work implement 3 includes a boom 31, an arm 32, and a bucket 33. By independently driving the boom 31, the arm 32, and the bucket 33, it is possible to perform work of excavating earth and sand, etc. In other words, the hydraulic excavator 1 includes the work implement 3 that performs work.

[0014] The boom 31 is rotated by a boom cylinder 31a. A base end of the boom cylinder 31a is supported on the front part of the upper rotating body 4 and is movable so as to be telescopic. The arm 32 is rotated by an arm cylinder 32a. A base end of the arm cylinder 32a is supported on the tip part of the boom 31 and is movable so as to be telescopic. The bucket 33 is rotated by a bucket cylinder 33a. A base end of the bucket cylinder 33a is supported on the tip part of the arm 32 and is movable so as to be telescopic. The boom cylinder 31a, arm cylinder 32a, and bucket cylinder 33a are constituted by a hydraulic cylinder CY (see FIG. 2).

[0015] The upper rotating body 4 is configured to be rotatable relative to the lower traveling body 2 via a slewing bearing (not shown). A control unit 41, a slewing platform 42, a slewing motor 43, an engine room 44, etc. are arranged on the upper rotating body 4. The upper rotating body 4 rotates via the slewing bearing by driving the slewing motor 43, which is a hydraulic motor. In addition to an engine 40 that provides power to each part, multiple hydraulic pumps P0 (see Figure 2) are arranged at the rear of the upper rotating body 4.

[0016] Each hydraulic pump P0 supplies working oil (pressurized oil) to a hydraulic motor (e.g., the left and right travel motors 22, the swing motor 43) and a hydraulic cylinder CY (e.g., the blade cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the supply of working oil from any hydraulic pump P0 are collectively called hydraulic actuators AC (see FIG. 2).

[0017] A control seat 41a is arranged in the control section 41 where the operator sits. That is, the hydraulic excavator 1 is provided with the control section 41 where the control seat 41a is arranged and the operator sits. Operation sections 41b are arranged around the control seat 41a (particularly in front, on the left and right).

[0018] The operating unit 41b is composed of an operating lever, switch, button, etc. for driving the hydraulic actuator AC. The operator sits in the operator's seat 41a and operates the operating unit 41b to drive the hydraulic actuator AC. This enables the travel of the lower traveling structure 2, ground leveling work by the blade 23, excavation work by the work implement 3, rotation of the upper rotating structure 4, etc. In other words, the hydraulic excavator 1 is equipped with the hydraulic actuator AC for operating the work vehicle (hydraulic excavator 1) and the operating unit 41b for driving the hydraulic actuator AC.

[0019] Further, a cutoff lever 41c that can rotate up and down is provided near the operator's seat 41a. When the operator presses down the cutoff lever 41c, a cutoff switch 90 (see FIG. 2), which will be described later, is turned ON, and a state (enabled state) is achieved in which a predetermined hydraulic actuator AC can be driven by operating the operation unit 41b. On the other hand, when the operator pulls up the cutoff lever 41c, the cutoff switch 90 is turned OFF, and a state (disabled state) is achieved in which the hydraulic actuator AC cannot be driven even if the operator operates the operation unit 41b. When the operator wishes to get off the operation unit 41, the operator pulls up the cutoff lever 41c to disable the driving of the hydraulic actuator AC, and then leaves the operator's seat 41a. In this way, the hydraulic excavator 1 is provided with the cutoff lever 41c for switching the operation of the operation unit 41b between an enabled state in which the hydraulic actuator AC is driven and an disabled state in which the driving of the hydraulic actuator AC is disabled.

[0020] [2. Main components of a hydraulic excavator] 2 schematically shows the configuration of the main parts of the hydraulic excavator 1. The hydraulic excavator 1 further includes a monitoring device 50, an alarm device 60, an attitude detection unit 70, a control unit 80, a cutoff switch 90, and a stop notification unit 100.

[0021] (2-1. Monitoring device) The monitoring device 50 has an obstacle sensor that monitors the surroundings by detecting the presence or absence of obstacles around the hydraulic excavator 1. Obstacles include people, objects, animals, and other monitored objects. In this embodiment, the obstacle sensor is composed of a right camera, a left camera, and a rear camera that capture images of the right, left, and rear of the hydraulic excavator 1, respectively. In this way, the hydraulic excavator 1 is equipped with a monitoring device 50 that monitors the surroundings of the hydraulic excavator 1.

[0022] In the monitoring device 50, the number, installation locations, and installation method of the obstacle sensors are not particularly limited as long as they can detect obstacles within a required range. In addition to the cameras described above, known distance measuring devices capable of acquiring distance information about obstacles can be used as obstacle sensors. For example, ultrasonic radar using ultrasonic waves, millimeter-wave radar using millimeter-wave radio waves, LIDAR that determines distance by measuring scattered light in response to laser irradiation, and stereo cameras that combine the functions of multiple cameras and measure the distance to an object from a captured image can be used as obstacle sensors. Furthermore, a configuration in which image processing is performed on the captured image to detect an intrusion into the monitoring area may also be used.

[0023] (2-2.Alarm device) The warning device 60 has a display unit 61, a rotating light 62, and an alarm unit 63. The display unit 61 is configured, for example, with a liquid crystal display device, and displays information indicating that an obstacle has been detected when the monitoring device 50 detects an obstacle. The display unit 61 is installed in a position in the cockpit 41a where it can be seen by the operator (see FIG. 1).

[0024] The rotating light 62 is composed of a lamp that rotates when the monitoring device 50 detects an obstacle. The alarm unit 63 is composed of a buzzer that outputs a sound when the monitoring device 50 detects an obstacle. The alarm unit 63 may also be composed of a sound output unit that outputs a sound (electronic sound) when the monitoring device 50 detects an obstacle. The rotation of the lamp of the rotating light 62 and the issuance of an alarm by the alarm unit 63 outputting a buzzer sound or sound can make the operator aware that the monitoring device 50 has detected an obstacle.

[0025] It should be noted that if the monitoring device 50 does not detect an obstacle, the alarm device 60 does not output an alarm. In other words, no alarm is displayed on the display unit 61, the rotating light 62 does not rotate, and the alarm unit 63 does not output a buzzer sound or voice. From this, it can be said that the hydraulic excavator 1 is equipped with an alarm device 60 that outputs an alarm based on the monitoring results of the monitoring device 50.

[0026] (2-3. Posture detection unit) The posture detection unit 70 has a seating detection switch 71 and a belt fastening detection switch 72. The seating detection switch 71 is a sensor that detects whether the operator is seated in the seat 41a1 of the pilot's seat 41a (see FIG. 1) or when the operator is released from the seat. In other words, the posture detection unit 70 includes the seating detection switch 71 that detects whether the operator is seated in the seat 41a1 of the pilot's seat 41a.

[0027] The seating detection switch 71 outputs a detection signal that is turned OFF when the operator is seated in the seat 41a1 of the cockpit 41a, and is turned ON when the operator is not seated in the seat 41a1 (when the operator is released from the seat). This allows the control unit 80 to determine the seating state of the operator (seated / not seated) based on the detection signal from the seating detection switch 71.

[0028] The belt fastening detection switch 72 is a sensor that detects whether the tongue plate of a seat belt provided in the cockpit 41a is inserted into the buckle, thereby detecting whether the operator has fastened the seat belt. In other words, the attitude detection unit 70 includes the belt fastening detection switch 72 provided in the cockpit 41a that detects whether the seat belt is fastened. Note that the attitude detection unit 70 may be configured to have only one of the seating detection switch 71 and the belt fastening detection switch 72.

[0029] The belt fastening detection switch 72 outputs a detection signal that is turned OFF when the operator fastens the seat belt and turned ON when the operator releases the seat belt. This allows the control unit 80 to determine the seat belt fastening state (fastened / unfastened) by the operator based on the detection signal from the belt fastening detection switch 72.

[0030] When operating the operating unit 41b, the operator normally performs the operation while seated in the seat 41a1 of the operator's seat 41a. Furthermore, when operating the operating unit 41b, the operator performs the operation after fastening a seat belt while seated in the seat 41a1. Therefore, by detecting whether the operator is seated in the seat 41a1 or whether the operator is fastening a seat belt, it is possible to detect whether the operator is in a position to operate the hydraulic excavator 1 (hereinafter also referred to as the "operating position"). From this, it can be said that the hydraulic excavator 1 is equipped with a position detection unit 70 that detects whether the operator is seated in the operator's seat 41a of the hydraulic excavator 1 and in an operating position to operate the hydraulic excavator 1.

[0031] (2-4. Control Unit) The control unit 80 controls the operation of each part of the hydraulic excavator 1. In this embodiment, in particular, the control unit 80 controls the output of an alarm in the alarm device 60 based on the detection result of the operating attitude of the operator by the attitude detection unit 70. In other words, the hydraulic excavator 1 is provided with a control unit 80 that controls the alarm device 60 based on the detection result of the attitude detection unit 70. Such a control unit 80 is configured as an electronic control unit called an ECU (Electronic Control Unit).

[0032] The control unit 80 may include a storage unit. The storage unit stores programs and various types of information for operating the control unit 80. Such a storage unit may be a RAM (Random Access Memory), a ROM (Read Only Memory), a non-volatile memory, or the like.

[0033] When the attitude detection unit 70 detects that the operator is in the operating attitude, the control unit 80 causes the warning device 60 to output an alarm based on the monitoring results of the monitoring device 50, and when the attitude detection unit 70 detects that the operator has released the operating attitude, the control unit 80 stops the warning device 60 from outputting an alarm based on the monitoring results of the monitoring device 50. Details of the operation controlled by the control unit 80 will be described later.

[0034] (2-5. Cut-off switch) The cutoff switch 90 is a sensor that detects the rotational position of the above-mentioned cutoff lever 41c. That is, the hydraulic excavator 1 is provided with the cutoff switch 90 that detects the rotational position of the cutoff lever 41c. The cutoff switch 90 is turned ON when the cutoff lever 41c is pushed down (rotated downward), and is turned OFF when the cutoff lever 41c is pulled up (rotated upward).

[0035] The control unit 80 determines whether the operation of the operating unit 41b is in an enabled state or an disabled state based on the rotational position of the cutoff lever 41c detected by the cutoff switch 90. When the cutoff lever 41c is pressed down, the operating unit 41b is in an enabled state as described above, and the hydraulic actuator AC can be driven. In this case, it is considered that the operator is seated in the cockpit 41a. On the other hand, when the cutoff lever 41c is pulled up, the operating unit 41b is in an disabled state, and the hydraulic actuator AC cannot be driven. In this case, it is considered that the operator has exited or is about to exit the cockpit 41a.

[0036] Therefore, the control unit 80 can determine whether the operator is in the control unit 41 (or whether the operator has dismounted from the control unit 41) by determining whether the operation of the operating unit 41b is in an enabled or disabled state based on the rotational position of the cutoff lever 41c.

[0037] (2-6. Stop notification section) The stop notification unit 100, under the control of the control unit 80, notifies the alarm device 60 when it has stopped outputting an alarm based on the monitoring results of the monitoring device 50. In other words, the hydraulic excavator 1 is provided with a stop notification unit 100 that notifies the alarm device 60 that it has stopped outputting an alarm based on the monitoring results of the monitoring device 50.

[0038] The stop notification unit 100 is provided in the control unit 41. For example, the stop notification unit 100 is provided in a position in the control unit 41 that can be seen by an operator seated in the cockpit 41a (for example, diagonally forward to the right as seen from the seated operator). Such a stop notification unit 100 has a display unit 101 and a lamp 102.

[0039] The display unit 101 is configured with a liquid crystal display device that displays various information. The display unit 101 notifies the stop of execution by displaying information indicating the stop of alarm output. In this embodiment, the display unit 61 of the alarm device 60 also serves as the display unit 101 of the stop notification unit 100, but they may be configured as separate units. The lamp 102 is configured with, for example, a light-emitting diode (LED). The lamp 102 notifies the stop of alarm output by, for example, lighting up or flashing.

[0040] [3. Hydraulic circuit] Next, the hydraulic circuit of the hydraulic excavator 1 will be described with reference to Figures 1 and 2. The hydraulic excavator 1 is equipped with a plurality of hydraulic actuators AC, a hydraulic pump P0 that pumps hydraulic oil to the plurality of hydraulic actuators AC, and a pilot pump PP. For convenience, Figure 2 shows a hydraulic circuit corresponding to one hydraulic actuator AC, but similar hydraulic circuits are configured for the other hydraulic actuators AC.

[0041] The multiple hydraulic actuators AC include left and right travel motors 22 which are travel hydraulic actuators that drive the lower travel structure 2, a blade cylinder 23a which is a hydraulic actuator that rotates the blade 23 up and down, a swing motor 43 which is a swing hydraulic actuator that drives the upper swing structure 3, and a boom cylinder 31a, arm cylinder 32a, and bucket cylinder 33a which are work hydraulic actuators that drive the work implement 3. The blade cylinder 23a, boom cylinder 31a, arm cylinder 32a, and bucket cylinder 33a are collectively referred to as hydraulic cylinder CY.

[0042] The hydraulic excavator 1 may be configured with a so-called boom swing function that swings the work implement 3 (boom 31) left and right relative to the upper rotating body 4. When the hydraulic excavator 1 has a boom swing function, the hydraulic cylinder CY also includes a swing cylinder, which is a hydraulic actuator that swings the boom 31. Generally, a boom swing function is equipped on a mini excavator (small hydraulic excavator) used for construction in narrow spaces.

[0043] The multiple hydraulic pumps P0 include a variable displacement pump and a fixed displacement pump, and are driven by the engine 40. The variable displacement pumps pump oil under pressure to the left and right travel motors 22, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a. The fixed displacement pump pumps oil under pressure to the blade cylinder 23a, the swing motor 43, and the swing cylinder (not shown).

[0044] The actuators AC are each provided with a corresponding directional control valve CV. The directional control valve CV is a pilot-operated directional control valve that can switch the direction and flow rate of pressure oil pumped from the hydraulic pump P0 (a variable displacement pump or a fixed displacement pump), and is also called a control valve. The directional control valves CV in this embodiment include directional control valves corresponding to the left and right traveling motors 22, a directional control valve corresponding to the boom cylinder 31a, a directional control valve corresponding to the arm cylinder 32a, a directional control valve corresponding to the bucket cylinder 33a, a directional control valve corresponding to the blade cylinder 23a, a directional control valve corresponding to the swing motor 43, and a directional control valve corresponding to the swing cylinder.

[0045] The pilot pump PP discharges pilot oil, which serves as an input command for the directional control valves CV. The pilot pump PP, driven by the engine 40, discharges pressure oil to generate pilot pressure in a pilot oil passage. In the hydraulic excavator 1, pilot oil passages are provided that extend from the pilot pump PP to each of the directional control valves CV.

[0046] The operation unit 41b has a remote control valve RV for switching the direction and pressure of the pressurized oil supplied to the directional control valve CV. The remote control valve RV is supplied with pressurized oil discharged from the pilot pump PP. The remote control valve RV generates pilot pressure according to the operation direction and operation amount of the operation unit 41b. The operation unit 41b includes, for example, a travel lever for traveling the hydraulic excavator 1 and a control lever for operating the work equipment 3, etc.

[0047] A solenoid valve SV is provided in the oil passage between the pilot pump PP and each remote control valve RV. The solenoid valve SV adjusts the pilot pressure generated by the pilot pump PP in response to a control command from the control unit 80. By adjusting the pilot pressure, it is possible, for example, to simultaneously stop the drive of multiple hydraulic actuators AC and to uniformly control the drive speeds of the multiple hydraulic actuators AC.

[0048] [4. Operation] Next, the operation of the hydraulic excavator 1 configured as described above will be described. Figure 3 is a flowchart showing an example of the flow of operation of the hydraulic excavator 1 under the control of the control unit 80. When the operator gets into the control unit 41 of the hydraulic excavator 1, sits in the seat 41a1 of the operator's seat 41a, operates the operation unit 41b (for example, turns the ignition key) and starts the engine 40, the seating detection switch 71 detects that the operator is seated. Furthermore, when the operator fastens his / her seat belt while seated, the belt fastening detection switch 72 detects that the operator has fastened his / her seat belt. In other words, the posture detection unit 70 detects that the operator is in a posture to operate the hydraulic excavator 1 (S1).

[0049] Subsequently, when the operator presses down the cutoff lever 41c, the cutoff switch 90 is turned ON. In other words, the cutoff switch 90 detects that the operating unit 41b is in an enabled state where it can be operated (S2). Because the operating unit 41b is in an enabled state, the operator can operate the operating unit 41b to drive a predetermined hydraulic actuator AC, and cause the hydraulic excavator 1 to perform operations such as traveling, swinging, and excavation work.

[0050] If the monitoring device 50 detects the presence of an obstacle around the hydraulic excavator 1 during work by the hydraulic excavator 1 (Yes in S3), and the attitude detection unit 70 has not detected that the operator has released the operating attitude (No in S4), the control unit 80 controls the alarm device 60 to output an alarm that the monitoring device 50 has detected an obstacle (S5). For example, the alarm is output by displaying text information such as "An obstacle has been detected. Please be careful" on the display unit 61 of the alarm device 60. At this time, the alarm may be output by rotating the rotating light 62 while it is lit. The alarm may also be output by outputting a buzzer sound from the alarm unit 63 or by outputting a voice message indicating that an obstacle has been detected. The three types of alarms output by the display unit 61, rotating light 62, and alarm unit 63 may be output simultaneously, or any one or two of them may be output in combination.

[0051] The alarm output in S5 is continued as long as the monitoring device 50 detects an obstacle (Yes in S6). If the monitoring device 50 no longer detects the obstacle (No in S6), for example, because the obstacle has left the monitoring area of ​​the monitoring device 50, the control unit 80 controls the alarm device 60 to stop the alarm output (S7).

[0052] Thereafter, when the work by the hydraulic excavator 1 is completed (S8), the series of processes is terminated. Whether the work is completed can be determined by the control unit 80 based on a detection signal output from a sensor (not shown) when, for example, an operation to stop the engine 40 is performed using the operation unit 41b (an operation to turn the ignition key to the OFF position). If the control unit 80 determines in S8 that the work is not completed, the processes from S1 onwards are repeated.

[0053] On the other hand, if the monitoring device 50 detects an obstacle in S3 and the attitude detection unit 70 detects that the operator has released the operating attitude (Yes in S4), the control unit 80 controls the alarm device 60 to stop outputting an alarm indicating that the monitoring device 50 has detected an obstacle (S9). For example, if the operator unfastens his / her seat belt and stands up to visually check the work area, the belt fastening detection switch 72 detects that the seat belt is not fastened, and the seating detection switch 71 detects that the operator has released the seat. In this case, the attitude detection unit 70 detects that the operator has released the operating attitude, and the control unit 80 stops outputting an alarm from the alarm device 60.

[0054] Thereafter, the control unit 80 controls the stop notification unit 100 to display information indicating that the alarm device 60 has stopped outputting an alarm on the display unit 101 (S10). For example, the display unit 101 may display text information such as "Alarm output based on obstacle detection has been stopped." At this time, or instead of displaying this on the display unit 101, the lamp 102 may be turned on to notify that alarm output based on obstacle detection has stopped. Thereafter, the process proceeds to S8, where the same processing as described above is performed.

[0055] [5. Effects] As described above, when the attitude detection unit 70 detects that the operator is in the operating attitude (No in S4), the control unit 80 causes the alarm device 60 to output an alarm based on the monitoring results of the monitoring device 50 (S5). As a result, for example, if a person other than the operator approaches the hydraulic excavator 1 during operation, the control unit 80 can warn the person (intruder) to be aware of the danger, or can prompt the operator to stop operating the hydraulic excavator 1, i.e., to stop work using the hydraulic excavator 1.

[0056] On the other hand, when the attitude detection unit 70 detects that the operator has released the control attitude (Yes in S4), the control unit 80 stops the execution of outputting an alarm from the alarm device 60 based on the monitoring results of the monitoring device 50 (S9). In this case, even if the monitoring device 50 detects an abnormality in the surroundings (e.g., the presence of an obstacle) when the operator releases the control attitude and performs visual confirmation work, no alarm is output from the alarm device 60, so the operator does not feel annoyed by the alarm at all. As a result, the operator can perform visual confirmation work with satisfaction (comfort).

[0057] When the operator releases the operating posture and visually checks the work area, he or she temporarily suspends operation of the operating unit 41b. Therefore, even if an obstacle is present in the monitoring area of ​​the monitoring device 50, the hydraulic excavator 1 will not make an operation that would cause it to come into contact with the obstacle. Furthermore, for example, when the operator gets off the operator's seat 41a, even if no alarm is output from the alarm device 60, the operator can visually recognize the obstacle and can take appropriate action against the obstacle. For example, if the operator visually confirms an intruder, he or she can warn the intruder to leave the area.

[0058] In particular, in this embodiment, when the monitoring device 50 detects an obstacle around the hydraulic excavator 1 (Yes in S3) and the attitude detection unit 70 detects that the operator is in the operating attitude (No in S4), the control unit 80 causes the alarm device 60 to output an alarm (S5). On the other hand, when the monitoring device 50 detects an obstacle around the hydraulic excavator 1 (Yes in S3) and the attitude detection unit 70 detects that the operator has released the operating attitude (Yes in S4), the control unit 80 causes the alarm device 60 to stop outputting an alarm (S9).

[0059] By such control by the control unit 80, if an obstacle is detected during work by the hydraulic excavator 1, the safety of the work can be ensured by outputting an alarm from the alarm device 60. On the other hand, if the operator releases the operating posture and visually checks the work area, no alarm is output even if an obstacle is detected, so the operator can concentrate on visually checking the work without feeling bothered by the alarm.

[0060] Furthermore, when the warning device 60 stops outputting a warning based on the monitoring result of the monitoring device 50, the stop notification unit 100 notifies the operator that the output of a warning has been stopped (S10). In this case, the operator can recognize from the notification by the stop notification unit 100 that the output of a warning by the warning device 60 has been stopped due to his / her own action of releasing the control attitude.

[0061] Furthermore, the stop notification unit 100 is provided in the control unit 41 in which the operator's seat 41a is located (see FIG. 1). As a result, when the operator gets off the control unit 41 to check the work location and then gets back on the control unit 41, the operator can recognize from the notification by the stop notification unit 100 provided in the control unit 41 that the execution of alarm output has been stopped due to his or her own actions. Therefore, in the subsequent operation (operation of the hydraulic excavator 1), the operator can be alerted and can perform safe work.

[0062] In particular, since the stop notification unit 100 includes the display unit 101, the operator can easily recognize, based on the information displayed on the display unit 101, that the execution of alarm output has been stopped.

[0063] The posture detection unit 70 also includes a seating detection switch 71. By detecting whether the operator is seated in the seat 41a1 with the seating detection switch 71, it is possible to reliably detect whether the operator is in a posture to operate the hydraulic excavator 1 in the operator's seat 41a.

[0064] Moreover, the posture detection unit 70 includes a belt fastening detection switch 72. By detecting that the operator has fastened the seat belt using the belt fastening detection switch 72, it is possible to reliably detect whether or not the operator is in an operating posture in the operator's seat 41a of the hydraulic excavator 1.

[0065] [6. Other operations] Fig. 4 is a flowchart showing another example of the flow of the operation of the hydraulic excavator 1 under the control of the control unit 80. The processing from S1 to S8 is the same as in Fig. 3. Below, the parts that differ from Fig. 3 will be explained.

[0066] In S3, the monitoring device 50 detects an obstacle, the attitude detection unit 70 detects that the operator has released the control attitude (Yes in S4), and further, when the cutoff switch 90 detects that the operation of the operating unit 41b has become invalid due to the operator's rotation (pulling up) of the cutoff lever 41c (S4-1), the control unit 80 controls the alarm device 60 to stop outputting an alarm indicating that the monitoring device 50 has detected an obstacle (S9).

[0067] Thereafter, the control unit 80 controls the stop notification unit 100 to cause the display unit 101 to display information indicating that the alarm device 60 has stopped outputting an alarm (S10). Next, the control unit 80 stops the hydraulic actuator AC (S11). For example, the control unit 80 can cut off the pilot pressure sent from the remote control valve RV to the directional control valve CV by controlling to cut off the current flowing through the solenoid valve SV. This makes it possible to lock (stop) the hydraulic actuator AC. After that, the process proceeds to S8.

[0068] As described above, when the cut-off lever 41c disables the operation of the operating unit 41b, the control unit 80 stops the alarm device 60 from outputting an alarm based on the monitoring results of the monitoring device 50 (S4-1, S9).

[0069] When the operator gets off the cockpit 41a, the operator usually operates the cutoff lever 41c to disable the operation of the operation unit 41b before getting off. When the operation of the operation unit 41b is disabled by the cutoff lever 41c, the execution of alarm output by the alarm device 60 based on the monitoring results of the monitoring device 50 is stopped. Therefore, even if the operator gets off the cockpit 41a, an alarm is not output, so the operator can perform visual inspection work without feeling bothered by an alarm. In other words, the operator can get off the cockpit 41a and perform visual inspection work with satisfaction.

[0070] In particular, when the monitoring device 50 detects an obstacle around the hydraulic excavator 1 (Yes in S3) and the attitude detection unit 70 detects that the operator is in an operating attitude (No in S4), the control unit 80 causes the alarm device 60 to output an alarm (S5). On the other hand, when the monitoring device 50 detects an obstacle around the hydraulic excavator 1 (Yes in S3), and the attitude detection unit 70 detects that the operator has released the operating attitude, and the operation of the operating unit 41b is disabled by the cut-off lever 41c (Yes in S4-1), the control unit 80 causes the alarm device 60 to stop outputting an alarm (S9).

[0071] By such control by the control unit 80, if an obstacle is detected during work by the hydraulic excavator 1, the safety of the work can be ensured by an alarm output by the alarm device 60. On the other hand, if the operator releases the operating posture and disables the operation of the operating unit 41b by the cut-off lever 41c, no alarm is output even if an obstacle is detected, allowing the operator to get out of the operator's seat 41a and concentrate on visual confirmation work.

[0072] Furthermore, the control unit 80 stops the hydraulic actuator AC when the operation of the operating unit 41b is disabled by the cut-off lever 41c (S11). By stopping the hydraulic actuator AC when the operation of the operating unit 41b is disabled, the operation of the hydraulic excavator 1 (for example, traveling, swinging, excavation work, etc.) is stopped. This allows the operator to get off the operator's seat 41a and perform work (for example, visual inspection work) safely.

[0073] [7. Other] In this embodiment, the seating detection switch 71 and the belt fastening detection switch 72 are used as the posture detection unit 70, but an infrared sensor may also be used. By detecting the presence (seatedness) of the operator on the seat 41a1 using the infrared sensor, it is possible to detect whether the operator is in a driving posture. Alternatively, a sensor that detects capacitance may be used as the posture detection unit 70. For example, a sensor that detects capacitance may be attached to the grip portion of an operating lever that constitutes the operating unit 41b, and the sensor may detect whether the operator has touched the grip portion of the operating lever, thereby detecting whether the operator is in a driving posture.

[0074] The notification of the cessation of alarm output by the stop notification unit 100 may be made by rotating a rotating light or by outputting a sound. Furthermore, the execution of alarm output by the notification device 60 may be stopped regardless of the detection of the operating attitude by the attitude detection unit 70 or the rotation position of the cut-off lever 41c (the enabled / disabled state of the operation unit 41b), and in that case, the notification that the execution has been stopped may be made by the stop notification unit 100. In that case, the operator will recognize from the stop notification unit 100 that the alarm output has been stopped, and can pay attention to the surrounding environment when working with the hydraulic excavator 1.

[0075] In this embodiment, the hydraulic excavator 1, which is a construction machine, has been described as an example of the work vehicle, but the work vehicle is not limited to a hydraulic excavator and may be other construction machinery such as a wheel loader, or agricultural machinery such as a combine harvester. In other words, the control that stops the output of an alarm based on the monitoring results of the monitoring device 50 when the posture detection unit 70 detects that the operator has released his or her steering posture can also be applied to construction equipment and agricultural machinery other than the hydraulic excavator 1.

[0076] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0077] The present invention can be used in work vehicles such as construction machines and agricultural machines. [Explanation of symbols]

[0078] 1 Hydraulic excavator (work vehicle) 41 Control Unit 41a cockpit 41a1 sheet 41b Operation section 41c cut-off lever 50 Monitoring equipment 60 Alarm device 70 Attitude detection unit 71 Seat detection switch 72 Belt detection switch 80 Control Unit 90 Cut-off switch 100 Stop notification unit AC Hydraulic Actuator

Claims

1. A work vehicle for performing work, a monitoring device that monitors the surroundings of the work vehicle; an alarm device that outputs an alarm based on the monitoring result of the monitoring device; a posture detection unit that detects whether an operator is seated in a driver's seat of the work vehicle and in a driving posture for driving the work vehicle; a hydraulic actuator for operating the work vehicle; an operating unit for driving the hydraulic actuator; a cutoff lever for switching the operation of the operating unit between an enabled state in which the hydraulic actuator is driven and an disabled state in which the drive of the hydraulic actuator is disabled; a cutoff switch that detects the rotation position of the cutoff lever; a control unit that controls the alarm device based on detection results of the attitude detection unit and the cutoff switch, The control unit, when the attitude detection unit detects that the operator is in the operating attitude, causes the alarm device to output the alarm based on the monitoring results of the monitoring device, and, when the attitude detection unit detects that the operator has released the operating attitude and the operation unit is in an invalid state, stops the alarm device from outputting the alarm based on the monitoring results of the monitoring device.

2. 2. The work vehicle according to claim 1, wherein the control unit causes the alarm device to output the alarm if the attitude detection unit detects that the operator is in the operating attitude when the monitoring device detects an obstacle around the work vehicle, and causes the alarm device to stop outputting the alarm if the attitude detection unit detects that the operator has released the operating attitude when the monitoring device detects an obstacle around the work vehicle and the cut-off switch detects that the operating unit is in an invalid state.

3. The work vehicle according to claim 2 , wherein the control unit stops the hydraulic actuator when the cutoff switch detects that the operation of the operating unit is in the invalid state.

4. 4. The work vehicle according to claim 1, further comprising a stop notification unit that notifies the user that the execution of outputting the alarm based on the monitoring result of the monitoring device has been stopped when the alarm device has stopped executing the output of the alarm based on the monitoring result of the monitoring device.

5. The aircraft further includes a control section in which the operator sits and in which the operator's seat is located, The work vehicle according to claim 4 , wherein the stop notification unit is provided in the operation unit.

6. The work vehicle according to claim 1 , wherein the attitude detection unit includes a seating detection switch that detects whether the operator is seated in the driver's seat.

7. The work vehicle according to claim 1 , wherein the attitude detection unit includes a seatbelt detection switch provided in the driver's seat that detects whether a seatbelt is fastened.

8. 8. A work vehicle according to claim 1, wherein when the attitude detection unit detects that the operator has released the driving attitude, the control unit stops the output of all alarms in the work vehicle by the alarm devices provided in the work vehicle based on the monitoring results of the monitoring device.

Images