Work machine

Abstract

The present invention reduces power consumption during work, and is capable of appropriately illuminating a work area.　The present invention is provided with: a machine body (2); a boom (14), the base end side of which is connected to the machine body in a manner such that swinging vertically is possible; an arm (15) that is connected to the distal end side of the boom so as to be capable of swinging in the arm crowd direction and the arm dump direction; a work tool (16) that is attached to the distal end side of the arm; a work lamp (20) that is provided to the boom and illuminates a work area around the boom; and an illumination control unit (44) that controls the illumination operation of the work lamp. The work lamp has a first light source unit (25) and a second light source unit (26) which have different optical axis directions from one another. The optical axis direction (N1) of the first light source unit is oriented more toward the distal end side of the boom than is the second light source unit. Meanwhile, the optical axis direction (N2) of the second light source unit is oriented more toward the base end side of the boom than is the first light source unit. The illumination control unit controls the degree of illumination of the first light source unit so as to be lower when the arm is in a crowd range (P2), which is set to the arm crowd direction side of the possible swing range, than when the arm is in a dump range (P3), which is set to the arm dump direction side of the crowd range.

Description

Work equipment

[0001] The present invention relates to a work machine such as a backhoe.

[0002] The work machine disclosed in Patent Document 1 is provided with a work light on the boom for illuminating the surroundings of the work device.

[0003] Japanese Patent Publication No. 2019-142447

[0004] However, when a single work light mounted on the boom is used to illuminate a wide area around the operating device, as in the case of the conventional work machine described above, depending on the angle of the boom, the light may be illuminating areas that do not need to be illuminated, resulting in unnecessary power consumption.Furthermore, when the boom is raised high, it may unnecessarily illuminate areas outside the work area, such as nearby houses and cars.

[0005] The present invention has been made to solve such problems, and has an object to provide a work machine that can reduce power consumption during work and can properly illuminate the work area.

[0006] The present invention employs the following technical means to achieve the above object.

[0007] a work machine according to one aspect of the present invention, the work machine comprising: a body; a boom whose base end is connected to the body so as to be able to swing up and down; an arm connected to the tip end of the boom so as to be able to swing in an arm crowding direction which is a direction toward the boom and an arm dumping direction which is a direction away from the boom; a work implement attached to the tip end of the arm; a work light provided on the boom for illuminating a work area around the boom; and a lighting control unit which controls the lighting operation of the work light, the work light having a first light source unit and a second light source unit whose optical axis directions are different from each other, the optical axis direction of the first light source unit facing closer to the tip end of the boom than the second light source unit, and the optical axis direction of the second light source unit facing closer to the base end of the boom than the first light source unit; and the lighting control unit performs first control to lower the illuminance of the first light source unit when the arm is in a cloud range which is set on the arm crowding direction side of the swingable range, compared to when the arm is in a dumping range which is set on the arm dumping direction side of the cloud range.

[0008] The lighting control unit may perform a second control in which, when the arm is in the dump range, the illuminance of the second light source unit is controlled to be lower than when the arm is in the cloud range.

[0009] The lighting control unit may perform a third control when the arm is in an intermediate range set between the cloud range and the dump range, in which the illuminance of the first light source unit is controlled to be higher than the illuminance of the first light source unit when the arm is in the cloud range, and the illuminance of the second light source unit is controlled to be higher than the illuminance of the second light source unit when the arm is in the dump range.

[0010] In the third control, when the arm is in the intermediate range, the lighting control unit may control the illuminance of the first light source unit to be continuously lower as the arm swings from the dump range side to the cloud range side, and may control the illuminance of the first light source unit to be continuously higher as the arm swings from the cloud range side to the dump range side.

[0011] In the third control, when the arm is in the intermediate range, the lighting control unit may control the illuminance of the second light source unit to be continuously higher as the arm swings from the dump range side to the cloud range side, and may control the illuminance of the second light source unit to be continuously lower as the arm swings from the cloud range side to the dump range side.

[0012] The lighting control unit may be configured to perform a fourth control in which, when the boom is swung above a predetermined set position, the illuminance of the first light source unit is controlled to be lower than the illuminance of the first light source unit when the boom is below the set position, regardless of the operating state of the arm.

[0013] a work machine according to one aspect of the present invention, the work machine comprising: a machine body; a boom whose base end is connected to the machine body so as to be able to swing up and down; an arm connected to the tip end of the boom so as to be able to swing in an arm crowding direction which is a direction approaching the boom and an arm dumping direction which is a direction away from the boom; a work implement attached to the tip end of the arm; a work light provided on the boom for illuminating a work area around the boom; and a lighting control unit which controls the lighting operation of the work light, the work light having a first light source unit and a second light source unit whose optical axis directions are different from each other, the optical axis direction of the first light source unit facing closer to the tip end of the boom than the second light source unit, and the optical axis direction of the second light source unit facing closer to the base end of the boom than the first light source unit, the lighting control unit performing a fourth control in which, when the boom is swung above a predetermined set position, the illuminance of the first light source unit is controlled to be lower than the illuminance of the first light source unit when the boom is below the set position, regardless of the operating state of the arm.

[0014] The work machine may include a first switching operation unit for operating to enable or disable the fourth control of the lighting control unit.

[0015] The lighting control unit may be configured to control the illuminance of the second light source unit to be higher when the boom is swung above a predetermined set position than the illuminance of the second light source unit when the boom is below the set position, regardless of the operating state of the arm.

[0016] The work machine may include a second switching operation unit for operating to enable or disable the first to third controls of the lighting control unit.

[0017] The second light source unit may be configured to illuminate the area around the work implement when the arm is in a cloud range set on the arm cloud direction side of the swingable range, and the first light source unit may be configured to illuminate the area around the work implement when the arm is in a dump range set on the arm dump direction side of the cloud range.

[0018] The work machine may include a boom cylinder connected between the machine body and the boom for swinging the boom, the boom being provided with a cylinder bracket that rotatably supports one end of the boom cylinder, and the work light being provided in a gap inside the cylinder bracket.

[0019] The work light may have a third light source unit whose optical axis direction faces the tip side of the boom more than the second light source unit and faces the base side of the boom more than the first light source unit, and the lighting control unit may perform a fifth control that controls the illuminance of the third light source unit to be higher than at least one of the illuminance of the third light source unit when the arm is in the cloud range and the illuminance of the third light source unit when the arm is in the dump range when the arm is in the dump range, when the arm is in an intermediate range set between a cloud range set on the arm cloud direction side of the swingable range and a dump range set on the arm dump direction side of the cloud range.

[0020] According to the above-described work machine, by controlling the illuminance of the first light source unit and the second light source unit in accordance with the swing position of the arm, it is possible to reduce power consumption during work and to properly illuminate the work area.

[0021] 1 is a front perspective view of a working machine. FIG. 2 is a left side view of the working machine. FIG. 3 is a front perspective view of the working device. FIG. 4 is a left side view of the working device showing the operating state of the boom. FIG. 5 is a left side view of the cylinder bracket periphery. FIG. 6 is a left side view of the working device showing the operating state of the arm. FIG. 7 is a diagram showing the hydraulic system of the working device. FIG. 8 is a diagram showing an example of the relationship between the operating state of the working device and the output of the work light. FIG. 9 is a schematic view of the working device showing the swing range of the arm. FIG. 10 is a schematic view of the working device showing the swing range of the boom. FIG. 11 is a flowchart showing an example of lighting control of the work light. FIG. 12 is a diagram showing a second example of the relationship between the operating state of the working device and the output of the work light. FIG. 13 is a diagram showing a third example of the relationship between the operating state of the working device and the output of the work light. FIG. 14 is a diagram showing a fourth example of the relationship between the operating state of the working device and the output of the work light. FIG. 15 is a schematic view of the working device showing another form of the work light. FIG. 16 is a diagram showing a fifth example of the relationship between the operating state of the working device and the output of the work light. FIG. 17 is a diagram showing a sixth example of the relationship between the operating state of the working device and the output of the work light.

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0023] As shown in Figures 1 and 2, the work machine 1 of this embodiment is a backhoe including a machine body (swivel base) 2, a traveling device 3, and a work device 4. A canopy 5 is mounted on the machine body 2. A driver's seat 6 for an operator (driver) is provided inside the canopy 5. The canopy 5 is a protection mechanism that protects the driver's seat 6. Note that the work machine 1 is not limited to a backhoe, and may be another type of work machine. Furthermore, the machine body 2 may be equipped with a cabin that surrounds the driver's seat 6 instead of the canopy 5 as a protection mechanism that protects the driver's seat 6.

[0024] In this embodiment, the direction in which the operator seated in the driver's seat 6 faces (the direction indicated by arrow X1 in FIGS. 1 and 2) is referred to as the front of the machine body 2, and the opposite direction (the direction indicated by arrow X2 in FIGS. 1 and 2) is referred to as the rear of the machine body 2. The left side of the operator (the direction indicated by arrow Y1 in FIG. 1) is referred to as the left side of the machine body 2, and the opposite direction (the direction indicated by arrow Y2 in FIG. 1) is referred to as the right side of the machine body 2. Furthermore, the upper side of the operator (the direction indicated by arrow Z1 in FIGS. 1 and 2) is referred to as the top of the machine body 2, and the opposite direction (the direction indicated by arrow Z2 in FIGS. 1 and 2) is referred to as the bottom of the machine body 2.

[0025] 2, the machine body 2 is supported on the upper part of the traveling device 3 via a swivel bearing 2J. That is, the machine body 2 is supported rotatably about a swivel axis L1 (an axis extending in the vertical direction) relative to the traveling device 3. The swivel axis L1 is the rotation center of the swivel bearing 2J.

[0026] The machine body 2 is equipped with a prime mover U1, a hydraulic pump U2, a control device U3, and the like. The prime mover U1 is a diesel engine. The prime mover U1 may be a gasoline engine, an electric motor, or a hybrid prime mover having an engine and an electric motor. The hydraulic pump U2 is connected to the prime mover U1. The hydraulic pump U2 is driven by the power of the prime mover U1 and supplies hydraulic oil (pressurized oil) to hydraulic motors equipped in the work machine 1 and hydraulic actuators such as hydraulic cylinders C1 to C5, which will be described later. The control device U3 controls the operation of the prime mover U1, hydraulic pump U2, and the like.

[0027] A driver's seat 6, a travel lever 7, and control devices 8L and 8R are mounted on the machine body 2 forward of the prime mover U1. The travel lever 7 is a device for operating the travel device 3. The control devices 8L and 8R are devices for operating the work device 4 (operating the swing of the boom 14, arm 15, and bucket 16, which will be described later), rotating the machine body 2, and the like.

[0028] 1, the control devices 8L, 8R are provided on the left and right sides of the driver's seat 6. A control console 9 that supports the right control device 8R is provided on the right side of the driver's seat 6. In addition to the control device 8R, the control console 9 is provided with a plurality of operation switches for operating various functions installed in the work machine 1.

[0029] A lighting operation unit 9a for manually switching on and off the work light 20 described below, a first switching operation unit 9b for manually switching on and off a fourth control of the work light 20, and a second switching operation unit 9c for manually switching on and off the first to third controls of the work light 20 are provided on the control console 9. The first to fourth controls of the work light 20 will be described later.

[0030] A headlight 10 is mounted on the machine body 2 forward of the driver's seat 6. The headlight 10 is a lamp that illuminates the area ahead of the machine body 2, and as shown in Figures 1 and 2, in the work machine 1 of this embodiment, the headlight 10 is provided on the front lower part of the driver's seat 6 (in front of the operator's feet).

[0031] A support bracket 11 and a swing bracket 12 are provided at the front of the machine body 2. The support bracket 11 is provided to protrude forward from the front of the machine body 2. The swing bracket 12 is a member that supports the working device 4, and is provided at the tip of the support bracket 11 so as to be able to swing in the left-right direction. More specifically, the swing bracket 12 is supported so as to be able to rotate around a swing shaft 11J that is provided at the tip of the support bracket 11 and extends in the up-down direction. The swing bracket 12 can be swung in the left-right direction by the extension and contraction of a swing cylinder (hydraulic cylinder) C1 that connects the machine body 2 and the swing bracket 12.

[0032] <Traveling Device> The traveling device 3 is a crawler-type traveling device that supports the machine body 2 so that it can travel, and includes a traveling frame 3A and a traveling mechanism 3B. The traveling frame (track frame) 3A is a structure to which the traveling mechanism 3B is attached and that supports the machine body 2 from below. The traveling mechanism 3B is, for example, a crawler. A dozer device 13 is attached to the front of the traveling device 3. The dozer device 13 can raise and lower a blade (blade) 13A by extending and retracting a dozer cylinder (hydraulic cylinder) C2. The traveling device 3 is not limited to a crawler type, and may be a wheel type.

[0033] 1 to 3, the work device 4 has a boom 14, an arm 15, and a bucket (work tool) 16. The work device 4 is also provided with a work light 20. Note that the work machine 1 can be equipped with another work tool (hydraulic attachment) that can be driven by hydraulic oil, instead of or in addition to the bucket 16. Examples of such other work tools include a hydraulic breaker, hydraulic crusher, angle broom, earth auger, pallet fork, sweeper, mower, and snow blower.

[0034] The boom 14 is pivotally supported to be swingable about a boom support shaft 12J that extends in the left-right direction from the upper end of the swing bracket 12. That is, the boom 14 is pivotally connected to the upper end of the swing bracket 12 to be swingable upward (in the direction of arrow R4 in FIG. 4 ) and downward (in the direction of arrow R1 in FIG. 4 ). Note that the operation of raising the boom 14 is the operation of raising the boom 14 above the support bracket 11. On the other hand, the operation of lowering the boom 14 is the operation of tilting the boom 14 forward of the support bracket 11.

[0035] The boom 14 is a long member having a generally rectangular columnar shape, and is bent in a generally V-shape in a side view with an upward convex shape when swung downward and lowered in front of the support bracket 11. A first cylinder bracket 21, which serves as a coupling part for a boom cylinder (hydraulic cylinder) C3, is provided in a generally central portion (bent portion) between the front and rear of a boom lower surface portion 14A, which is the underside of the boom 14 when in the lowered state. A second cylinder bracket 22, which serves as a coupling part for an arm cylinder (hydraulic cylinder) C4, is provided in a generally central portion (bent portion) between the front and rear of a boom upper surface portion 14B, which is the upper surface of the boom 14 when in the lowered state.

[0036] A boom cylinder C3 is connected between the first cylinder bracket 21 and the swing bracket 12. The boom cylinder C3 is provided with a cylinder cover G3 that protects the cylinder rod of the boom cylinder C3. The boom 14 is swung downward by retracting the boom cylinder C3, and is swung upward by extending the boom cylinder C3. In this embodiment, the boom 14 is configured to stop swinging at a position (see FIG. 2 ) where it does not interfere with the canopy 5 or the aircraft body 2 when swung upward.

[0037] 3 and 5, the first cylinder bracket 21 has a pair of support side plates 21L, 21R arranged at a predetermined interval in the left-right direction. The work light 20 is provided in a gap H defined between the support side plates 21L, 21R. The configuration of the work light 20 will be described later.

[0038] 1 to 3 , the arm 15 is pivotally supported to be swingable about an arm support shaft 14J that extends in the left-right direction at the tip of the boom 14. That is, the arm 15 is pivotally connected to the tip of the boom 14 to be swingable in the arm dump direction (the direction of arrow R3 in FIG. 6 ) and the arm crowding direction (the direction of arrow R2 in FIG. 6 ). Note that movement of the arm 15 in the arm crowding direction is an operation (crowd operation) that moves the bucket 16 closer to the machine body 2. On the other hand, movement of the arm 15 in the arm dumping direction is an operation (dump operation) that moves the bucket 16 away from the machine body 2.

[0039] The arm 15 is a long member having a generally rectangular columnar shape. A third cylinder bracket 23, which serves as a connecting portion for the boom cylinder C3 and the implement cylinder C5, is provided at the upper end (base end) of the arm front surface portion 15B, which is on the front side of the arm 15 when the arm 15 is swung in the arm crowding direction and the boom 14 is swung upward (see FIG. 2 ).

[0040] An arm cylinder C4 is connected between the third cylinder bracket 23 and the second cylinder bracket 22 of the boom 14. A cylinder cover G4 that protects the cylinder rod of the arm cylinder C4 is provided on the arm cylinder C4. The arm 15 is swung in the arm dump direction (dumping operation) by retracting the arm cylinder C4, and is swung in the arm crowding direction (crowding operation) by extending the boom cylinder C3. In this embodiment, the arm 15 is configured so that when swung in the arm crowding direction, the swinging is stopped at a position (see FIG. 2 ) where the bucket 16 does not interfere with the boom cylinder C3 or the cylinder cover G3.

[0041] The bucket 16 is pivotally supported to be swingable about a work implement support shaft 15J that extends in the left-right direction at the tip of the arm 15. That is, the bucket 16 is pivotally connected to the tip of the arm 15 to be swingable in the work implement dump direction and the work implement crowding direction. Note that movement of the bucket 16 in the work implement crowding direction is an operation (crowding operation) of swinging the tip end toward the machine body 2, which is an operation, for example, when scooping up earth and sand with the bucket 16. On the other hand, movement of the bucket 16 in the work implement dumping direction is an operation (dumping operation) of swinging the tip end away from the machine body 2, which is an operation, for example, when dropping (discharging) scooped up earth and sand from the bucket 16.

[0042] A link mechanism 24 is provided at the base end of the bucket 16, connecting the bucket 16 to the tip end of the arm 15 and serving as a coupling for the implement cylinder C5. The implement cylinder C5 is connected between the link mechanism 24 and the third cylinder bracket 23 of the arm 15. A cylinder cover G5 is provided on the implement cylinder C5 to protect the cylinder rod of the implement cylinder C5. The bucket 16 is swung in the implement dump direction by retracting the implement cylinder C5, and is swung in the implement crowding direction by extending the implement cylinder C5. In this embodiment, the bucket 16 is configured to stop swinging at a position where it does not interfere with the arm 15 when swung in the implement crowding direction.

[0043] <Work Light> As shown in FIGS. 1 and 2 , the work machine 1 has a work light 20. The work light 20 is provided on the boom 14 and illuminates the work area around the boom 14. As shown in FIGS. 3 and 5 , the work light 20 is provided in a gap H inside the first cylinder bracket 21 of the boom 14. The work light 20 of this embodiment has two light source units (a first light source unit 25 and a second light source unit 26) whose optical axes are different from each other. The work light 20 includes a first work light (first light source unit) 25 that illuminates the direction of the tip of the boom 14 (toward the arm 15) when the boom 14 is swung downward to a predetermined set position S4(F) (see FIG. 4 ), and a second work light (second light source unit) 26 that illuminates the direction below the boom 14 when the boom 14 is in the set position S4(F). The configuration of the work light 20 (first work light 25, second work light 26) is not particularly limited, but in this embodiment, an LED is used.

[0044] The first work light 25 is attached to the first cylinder bracket 21 with its light-emitting surface (optical axis direction) facing diagonally downward (in the direction of arrow N1 in FIGS. 3 and 5 ) from the front in the extension direction of the tip-side extension 14T of the boom 14. The second work light 26 is attached to the first cylinder bracket 21 at a position rearward of the first work light 25 (toward the boom base end) with its light-emitting surface (optical axis direction) facing closer to the boom base end than the first work light 25 (in the direction of arrow N2 in FIGS. 3 and 5 ). That is, the optical axis direction N1 of the first work light 25 faces closer to the tip of the boom 14 than the second work light 26, and the optical axis direction N2 of the second work light 26 faces closer to the base end of the boom 14 than the first work light 25. Therefore, the work light 20 illuminates positions farther from the machine body 2 with the first work light 25 and illuminates positions closer to the machine body 2 with the second work light 26. In this embodiment, the first work light 25 illuminates the area around the bucket 16 when the arm 15 is in a dump range P3 (described later). The second work light 26 illuminates the area around the bucket 16 when the arm 15 is in a cloud range P2 (described later) (see FIG. 6).

[0045] The first work light 25 and the second work light 26 are both fixed to a first cylinder bracket 21 provided on the boom underside 14A. That is, the first work light 25 and the second work light 26 are provided side by side in the front and rear direction in the central part (bent part) of the boom underside 14A, and when turned on, can illuminate the work area in front of (the arm 15 side of) and below the boom 14. Furthermore, when the boom 14 is slid up and down, the illumination range of the first work light 25 and the second work light 26 also changes forward and backward accordingly.

[0046] As shown in Figures 4 and 6, the lighting directions of the first work light 25 and the second work light 26 are set so that their lighting ranges partially overlap in the front-to-rear direction. Therefore, when both the first work light 25 and the second work light 26 are turned on, continuous lighting is provided in the front-to-rear direction from the lighting range of the first work light 25 to the lighting range of the second work light 26. The maximum output and illumination angle (beam angle) of the first work light 25 and the second work light 26 may be set to be the same or different. In this embodiment, the output of the first work light 25 and the second work light 26 can be continuously changed between 0% and 100% by the control device U3.

[0047] <Hydraulic System> As described above, the work machine 1 is equipped with a hydraulic system that drives the work implement 4 by the extension and contraction of hydraulic cylinders (hydraulic actuators) C3 to C5. In more detail, as shown in Figure 7, the hydraulic system of the work machine 1 has a boom control valve 31, an arm control valve 32, an implement control valve 33, a control device U3, control devices 8L, 8R, a boom angle sensor 34, an arm angle sensor 35, and an implement angle sensor 36. The control devices 8L, 8R, the boom control valve 31, the arm control valve 32, the implement control valve 33, the boom angle sensor 34, the arm angle sensor 35, and the implement angle sensor 36 are each connected to the control device U3 via a communication cable.

[0048] The boom control valve 31, the arm control valve 32, and the implement control valve 33 are connected to the boom cylinder C3, the arm cylinder C4, and the implement cylinder C5 via oil passages, respectively. The boom control valve 31, the arm control valve 32, and the implement control valve 33 are connected to the hydraulic pump U2 via oil passages, respectively.

[0049] The boom control valve 31, the arm control valve 32, and the implement control valve 33 are, for example, electromagnetic three-position switching valves. More specifically, the boom control valve 31 is a direct-acting spool-type switching valve that can be switched between a first valve position V1, a second valve position V2, and a third valve position V3 by energizing or deenergizing a first solenoid 31A and a second solenoid 31B. When the boom control valve 31 is switched to the first valve position V1, hydraulic oil is supplied to and discharged from the boom cylinder C3, thereby extending the boom cylinder C3. On the other hand, when the boom control valve 31 is switched to the second valve position V2, hydraulic oil is supplied to and discharged from the boom cylinder C3, thereby retracting the boom cylinder C3. This causes the boom 14 to swing.

[0050] The arm control valve 32 is a direct-acting spool-type switching valve that can be switched to a first valve position V1, a second valve position V2, or a third valve position V3 by energizing or deenergizing a first solenoid 32A and a second solenoid 32B. When the arm control valve 32 is switched to the first valve position V1, hydraulic oil is supplied to and discharged from the arm cylinder C4, thereby extending the arm cylinder C4. On the other hand, when the arm control valve 32 is switched to the second valve position V2, hydraulic oil is supplied to and discharged from the arm cylinder C4, thereby contracting the arm cylinder C4. This causes the arm 15 to swing.

[0051] The implement control valve 33 is a direct-acting spool-type switching valve that can be switched between a first valve position V1, a second valve position V2, and a third valve position V3 by energizing or de-energizing a first solenoid 33A and a second solenoid 33B. When the implement control valve 33 is switched to the first valve position V1, hydraulic oil is supplied to and discharged from the implement cylinder C5, thereby extending the implement cylinder C5. On the other hand, when the implement control valve 33 is switched to the second valve position V2, hydraulic oil is supplied to and discharged from the implement cylinder C5, thereby retracting the implement cylinder C5. This causes the bucket 16 to swing.

[0052] The control device U3 has a boom control unit 41, an arm control unit 42, and an implement control unit 43. The boom control unit 41 controls the switching operation of the boom control valve 31, and the arm control unit 42 controls the switching operations of the arm control valve 32 and the implement control valve 33. In other words, the control device U3 controls the operations of the boom 14, the arm 15, and the bucket 16.

[0053] The control device U3 may be realized by hardware formed on an integrated circuit (IC chip) or the like, or by software using a computer. In the latter case, the computer includes a recording medium on which a program, which is software that realizes the functions of the control device U3, and various data related to the work machine 1 are recorded in a computer-readable manner, an arithmetic circuit such as a CPU (Central Processing Unit) that executes the instructions of the program, and a RAM (Random Access Memory) that expands the program and various data. The arithmetic circuit reads and executes the program from the recording medium, thereby realizing the functions of the control device U3.

[0054] Each of the control devices 8L, 8R has an operating lever 8A and a position sensor 8B. The operating lever 8A is configured to be manually pivotable in the forward / backward and left / right directions from a neutral position. The position sensor 8B detects the amount of pivoting (operation amount) of the operating lever 8A in the forward / backward and left / right directions from the neutral position.

[0055] For example, when the control lever 8A of the right control device 8R is swung back and forth, the boom control unit 41 (control device U3) energizes or de-energizes the first solenoid 31A and the second solenoid 31B in accordance with the swing direction and swing amount of the control lever 8A detected by the position sensor 8B, thereby switching the boom control valve 31. In other words, the boom control unit 41 controls the swing of the boom 14.

[0056] On the other hand, when the operating lever 8A of the left control device 8L is swung back and forth, the arm control unit 42 (control device U3) energizes or de-energizes the first solenoid 32A and the second solenoid 32B in accordance with the swing direction and swing amount of the operating lever 8A detected by the position sensor 8B, thereby switching the arm control valve 32. In other words, the arm control unit 42 controls the swing of the arm 15.

[0057] Furthermore, when the operating lever 8A of the right-side control device 8R is swung left or right, the implement control unit 43 (control device U3) energizes or de-energizes the first solenoid 33A and the second solenoid 33B in accordance with the swing direction and swing amount of the operating lever 8A detected by the position sensor 8B, thereby switching the implement control valve 33. In other words, the implement control unit 43 controls the swing of the bucket 16.

[0058] The boom angle sensor 34 detects the swing angle (swing position) of the boom 14. The arm angle sensor 35 detects the swing angle (swing position) of the arm 15. The implement angle sensor 36 detects the swing angle (swing position) of the bucket 16. In this embodiment, potentiometers are used as the boom angle sensor 34, arm angle sensor 35, and implement angle sensor 36, but this is not limiting and other types of angle sensors may be used. Furthermore, the swing angles (swing positions) of the boom 14, arm 15, and bucket 16 may be calculated based on the detection results by detecting the strokes (extended positions) of the boom cylinder C3, arm cylinder C4, and implement cylinder C5.

[0059] <Lighting Control Unit> The control device U3 has a lighting control unit 44. The work lights 20 (first work lights 25 and second work lights 26), lighting operation unit 9a, first switching operation unit 9b, and second switching operation unit 9c are each connected to the control device U3 via communication cables. The output of the work lights 20 is controlled by the lighting control unit 44. That is, the control device U3 controls the lighting operation of the first work lights 25 and the second work lights 26. Specifically, when the arm 15 is swung in the arm crowding direction and is in a cloud range P2 set on the arm crowding direction side of the predetermined swingable range, the lighting control unit 44 performs a first control to lower the illuminance of the first work light (first light source unit) 25 compared to when the arm 15 is in a dump range P3 set on the arm dumping direction side of the cloud range P2. On the other hand, when the arm 15 is swung in the arm dump direction and is in the dump range P3, the lighting control unit 44 performs a second control to lower the illuminance of the second work light (second light source unit) 26 compared to when the arm 15 is in the cloud range P2.

[0060] In addition, when the arm 15 is in an intermediate range P5 set between the cloud range P2 and the dump range P3, the lighting control unit 44 performs a third control in which the illuminance of the first work light (first light source unit) 25 is controlled to be higher than the illuminance of the first work light 25 when the arm 15 is in the cloud range P2, and the illuminance of the second work light (second light source unit) 26 is controlled to be higher than the illuminance of the second work light 26 when the arm 15 is in the dump range P3.

[0061] Furthermore, when the boom 14 is swung upward above the predetermined set position S4 and is in a predetermined raising range P4, the lighting control unit 44 performs a fourth control in which the illuminance of the first work light (first light source unit) 25 is controlled to be lower than the illuminance of the first work light 25 when the boom 14 is in a lowering range P1 below the above-mentioned set position S4, regardless of the operating state (position) of the arm 15.

[0062] In addition, the lighting control unit 44 controls switching between enabling and disabling the fourth control in accordance with the operation of the first switching operation unit 9b, and controls switching between enabling and disabling the first to third controls in accordance with the operation of the second switching operation unit 9c.

[0063] 8 , in this embodiment, when the swing position (arm angle) D2 of the arm 15 is in the cloud range P2, the output E1 of the first work light 25 is set to the minimum output (0%) (first control). Meanwhile, the output E2 of the second work light 26 is set to the maximum output (100%). That is, when the arm 15 is in the predetermined cloud range P2, the lighting control unit 44 limits the illuminance of the first work light 25 to low illuminance.

[0064] In this embodiment, when the swing position (arm angle) D2 of the arm 15 is in the dumping range P3, the output E2 of the second work light 26 is set to the minimum output (0%) (second control). On the other hand, the output E1 of the first work light 25 is set to the maximum output (100%). In other words, when the arm 15 is in the predetermined dumping range P3, the lighting control unit 44 limits the illuminance of the second work light 26 to low illuminance.

[0065] Furthermore, in this embodiment, when the swing position (arm angle) D2 of the arm 15 is in an intermediate range P5 set between the cloud range P2 and the dump range P3, the output E1 of the first work light 25 and the output E2 of the second work light 26 are both set to maximum output (100%) (third control). That is, the lighting control unit 44 maintains the illuminance of both the first work light 25 and the second work light 26 at high illuminance while the arm 15 is in the intermediate range P5 between the predetermined cloud range P2 and the dump range P3.

[0066] 11, when the boom 14 is swung upward from the set position S4 and is in the raising range P4, the output E1 of the first work light 25 is set to the minimum output (0%) (fourth control) regardless of the operating state (position) of the arm 15. On the other hand, the output E2 of the second work light 26 is set according to the operating state of the arm 15 by the first to third controls. That is, when the boom 14 is in the predetermined raising range P4, the lighting control unit 44 limits the illuminance of the first work light 25 to low illuminance.

[0067] The output E1 of the first work light 25 when the arm 15 is in the cloud range P2, the output E2 of the second work light 26 when the arm 15 is in the dump range P3, and the output E1 of the first work light 25 when the boom 14 is in the raising range P4 are not limited to the minimum output (0%) that indicates a completely off state. For example, the outputs E1 and E2 may be set to an output that is essentially an off state (e.g., 1%), or may be set to a low output (e.g., 20%) that does not cause discomfort to nearby residents and the like even if the light is shone on nearby houses or cars.

[0068] 9 , in this embodiment, the crowding range P2 of the arm 15 in the first to third controls is set between an extreme crowding position (A) where the bucket 16 is stopped from swinging so as not to interfere with the boom cylinder C3 or the cylinder cover G3, and a first reference position (B) where the bucket 16 is swung a predetermined angle (e.g., 30 degrees) from the extreme crowding position (A) in the arm dumping direction. On the other hand, the dumping range P3 of the arm 15 in the first to third controls is set between a limiting position (D) where the arm 15 is swung a predetermined angle (e.g., 90 degrees from the extreme crowding position (A)) in the arm dumping direction by retracting the arm cylinder C4 to a predetermined limiting position, and a second reference position (C) where the arm 15 is swung a predetermined angle (e.g., 30 degrees) from the limiting position (D) in the arm crowding direction.

[0069] 10 , in this embodiment, the raising range P4 of the boom 14 in the fourth control is set between a highest position (E) where the boom 14 is stopped from swinging so as not to interfere with the canopy 5 or the machine body 2, and a set position S4 (F) where the boom 14 is swung downward by a predetermined angle (e.g., 55 degrees) from the highest position (E). In this embodiment, the set position S4 is set to a position where the tip extension 14T of the boom 14 extends substantially horizontally forward of the machine body 2. On the other hand, the lowering range P1 of the boom 14 is set between the set position S4 (F) and a limit position (G) where the boom 14 is swung downward by a predetermined angle (e.g., 90 degrees from the highest position (E)) by retracting the boom cylinder C3 to a predetermined limit position.

[0070] An example of lighting control of the work light 20 by the lighting control unit 44 (control device U3) will be described with reference to the flowchart of Fig. 11. First, when the lighting operation unit 9a turns on the work light 20 (Yes in step ST1), the swing position (boom angle) D1 of the boom 14 is calculated based on the detection signal of the boom angle sensor 34, and the swing position (arm angle) D2 of the arm 15 is calculated based on the detection signal of the arm angle sensor 35 (ST2).

[0071] If the boom angle D1 is equal to or greater than the reference lifting angle DP4 indicating that the boom is in the predetermined lifting range P4 (Yes in step ST3), the output E1 of the first work light 25 is set to a predetermined low illuminance (here, minimum output) (ST4). If the arm angle D2 is equal to or greater than the reference dump angle DP3 indicating that the boom is in the predetermined dumping range P3 (Yes in step ST5), the output E2 of the second work light 26 is set to a predetermined low illuminance (here, minimum output) (ST6). If the arm angle D2 is less than the reference dumping angle DP3 (No in step ST5), the output E2 of the second work light 26 is set to a predetermined high illuminance (here, maximum output) (ST7). That is, when the work light 20 is turned on, if the boom 14 is in the lifting range P4, the first work light 25 is limited to low illuminance. Furthermore, if the arm 15 is in the dumping range P3, the second work light 26 is limited to low illuminance, and if the arm 15 is not in the dumping range P3, the second work light 26 is turned on at high illuminance.

[0072] Thereafter, if the lighting operation unit 9a performs an operation to turn off the work light 20 (Yes in step ST8), both the first work light 25 and the second work light 26 are turned off (ST9), and the process returns to step ST1. On the other hand, before the work light 20 is turned off (No in step ST8), for example, if the operation lever 8A is operated back and forth by the right control device 8R to swing the boom 14 downward, that is, if the boom angle D1 becomes less than the reference raising angle DP4 (No in step ST3), the illuminance limit for the first work light 25 is released, and the illuminance of each of the first work light 25 and the second work light 26 is set according to the swing position D2 of the arm 15.

[0073] Specifically, when the boom 14 is swung downward as described above (No in step ST3), if the arm angle D2 is equal to or less than the reference cloud angle DP2 indicating that the vehicle is within the predetermined cloud range P2 (Yes in step ST10), the output E1 of the first work light 25 is set to a predetermined low illuminance (here, minimum output) (ST4). If the arm angle D2 is greater than the reference cloud angle DP2 (No in step ST10), the output E1 of the first work light 25 is set to a predetermined high illuminance (here, maximum output) (ST11). Furthermore, as in steps ST5 to ST7, if the arm angle D2 is equal to or greater than the reference dump angle DP3 (Yes in step ST5), the output E2 of the second work light 26 is set to a low illuminance (ST6). If the arm angle D2 is less than the reference dump angle DP3 (No in step ST5), the output E2 is set to a high illuminance (ST7).

[0074] Thereafter, for example, when the operating lever 8A is operated back and forth by the left-side control device 8L and the arm 15 is swung in the arm crowding direction or arm dumping direction, the illuminance of each of the first work light 25 and the second work light 26 is changed according to the swing position D2 of the arm 15, as per steps ST5 to ST7 and steps ST10, ST4, and ST11.

[0075] Furthermore, if the first switching operation unit 9b performs an OFF operation (disable operation) of the fourth control before the work light 20 is turned on in step ST1, step ST3 is skipped and steps ST10 and thereafter are executed regardless of the swing position D1 of the boom 14. That is, when the fourth control is turned OFF, the lighting control unit 44 turns off the illuminance limiting function of the first work light 25 based on the swing position D1 of the boom 14, and sets the illuminance of each of the first work light 25 and the second work light 26 based on the swing position D2 of the arm 15.

[0076] Furthermore, if the second switching operation unit 9c performs an OFF operation (disable operation) for the first to third controls before the work light 20 is turned on in step ST1, step ST5 is skipped and step ST7 is executed regardless of the swing position D1 of the arm 15. Alternatively, step ST10 is skipped and step ST11 is executed. In other words, when the first to third controls are turned OFF, the lighting control unit 44 turns off the illuminance limiting function for the first work light 25 and the second work light 26 based on the swing position D2 of the arm 15, and sets the illuminance of the first work light 25 based on the swing position D1 of the boom 14.

[0077] Therefore, if the fourth control is turned off and the first to third controls are both turned off before the work light 20 is turned on in step ST1, both the first work light 25 and the second work light 26 will be maintained at high illumination at all times, regardless of the swing position D1 of the boom 14 or the swing position D2 of the arm 15.

[0078] In this embodiment, in step ST1, it is determined whether or not the operator has operated the lighting operation unit 9a to turn on the work light 20, but this is not limiting. For example, the work light 20 may be configured to be automatically turned on in response to the detection result of a light receiving sensor that detects ambient light, and in step ST1, it may be determined whether or not the detection result of the light receiving sensor satisfies a predetermined lighting condition.

[0079] <Other Embodiments> In the above embodiment, when the arm 15 is in the intermediate range P5 between the cloud range P2 and the dump range P3, the output E1 of the first work light 25 and the output E2 of the second work light 26 are both configured to be maintained at high illuminance regardless of changes in the arm angle D2. However, when the arm 15 is in the intermediate range P5, the illuminance of the first work light 25 and the second work light 26 may be continuously changed in accordance with changes in the arm angle D2 (second example).

[0080] 12 , when the swing position (arm angle) D2 of the arm 15 changes from the cloud range P2 side to the dump range P3 side (arm dump direction) in the intermediate range P5, the lighting control unit 44 accordingly changes the output E1 of the first work light (first light source unit) 25 to continuously increase (1% to 99%) and changes the output E2 of the second work light (second light source unit) 26 to continuously decrease (99% to 1%). On the other hand, when the swing position (arm angle) D2 of the arm 15 changes from the dump range P3 side to the cloud range P2 side (arm cloud direction) in the intermediate range P5, the lighting control unit 44 accordingly changes the output E1 of the first work light (first light source unit) 25 to continuously decrease (99% to 1%) and changes the output E2 of the second work light (second light source unit) 26 to continuously increase (1% to 99%).

[0081] Furthermore, in the above embodiment, when the arm 15 is in the cloud range P2, the output E1 of the first work light 25 is set to low illuminance and the output E2 of the second work light 26 is set to high illuminance; when the arm 15 is in the dump range P3, the output E1 of the first work light 25 is set to high illuminance and the output E2 of the second work light 26 is set to low illuminance; and when the arm 15 is in the intermediate range P5 between the cloud range P2 and the dump range P3, the output E1 of the first work light 25 and the output E2 of the second work light 26 are both set to high illuminance.

[0082] However, as shown in FIG. 13, the lighting control unit 44 may be configured to use a predetermined intermediate position S5 between a predetermined cloud range P2 and a dump range P3 as a reference and, when the swing position (arm angle) D2 of the arm 15 swings toward the cloud range P2 from the intermediate position S5, set the output E1 of the first work light 25 to a predetermined low illuminance (e.g., minimum output) and set the output E2 of the second work light 26 to a predetermined high illuminance (e.g., maximum output); and, when the swing position (arm angle) D2 of the arm 15 swings toward the dump range P3 from the intermediate position S5, set the output E1 of the first work light 25 to a predetermined high illuminance (e.g., minimum output) and set the output E2 of the second work light 26 to a predetermined low illuminance (e.g., minimum output) (third example).

[0083] Furthermore, in the above embodiment, when the boom 14 is swung above the set position S4 and is in a predetermined raising range P4, the output E2 of the second work light 26 is configured to be set according to the operating state of the arm 15; however, when the boom 14 is in the above-mentioned raising range P4, the output E2 of the second work light (second light source unit) 26 may also be controlled to be higher than the output E2 of the second work light 26 when the boom 14 is in a lowering range P1 below the set position S4 (fourth example).

[0084] 14 , when the boom 14 is swung downward from the set position S4 and is in a predetermined lowering range P1, the lighting control unit 44 sets the output E1 of the first work light (first light source unit) 25 to a predetermined high illuminance (e.g., maximum output) and sets the output E2 of the second work light (second light source unit) 26 to a predetermined low illuminance (e.g., minimum output), regardless of the operating state (position) of the arm 15. On the other hand, when the boom 14 is swung upward from the set position S4 and is in a predetermined raising range P4, the lighting control unit 44 sets the output E1 of the first work light 25 to a predetermined low illuminance (e.g., minimum output) and sets the output E2 of the second work light (second light source unit) 26 to a predetermined high illuminance (e.g., maximum output), regardless of the operating state (position) of the arm 15. In other words, the lighting control unit 44 sets the output E2 of the second work light 26 to a higher value than the output E2 of the second work light 26 when the boom 14 is in the lowering range P1.

[0085] In addition, in the above fourth example embodiment, when the boom 14 is swung downward from the set position S4 and is in a predetermined lowering range P1, the output E1 of the first work light 25 may be configured to be set according to the operating state (position) of the arm 15, as in the other embodiments above.

[0086] In the above embodiment, the work light 20 is provided in the gap H inside the first cylinder bracket 21 provided on the boom underside 14A, but as long as the work light 20 can appropriately illuminate the work area in front of and below the boom 14, the work light 20 may be provided on the outer surface of the first cylinder bracket 21 or on the side of the boom 14. Alternatively, the work light 20 may be provided at a position on the boom underside 14A different from the first cylinder bracket 21 (for example, on the underside of the tip-side extension 14T of the boom 14).

[0087] In the above embodiment, the first work light 25 and the second work light 26 are configured as separate bodies, but the first work light 25 and the second work light 26 may be integrated into a single casing. Furthermore, instead of the first work light 25 and the second work light 26, the work light 20 may have two light source units (a first light source unit and a second light source unit) corresponding to the first work light 25 and the second work light 26, and each of these light source units may be configured to have its illuminance controlled individually. Furthermore, one light source unit may be divided into two units, each of which may have its illuminance controlled individually.

[0088] Furthermore, in the above embodiment, the work light 20 is configured to illuminate the work area around the boom 14 by two light source units (first light source unit 25, second light source unit 26) with different optical axis directions, but the work light 20 may also have three or four or more light source units with different optical axis directions, and may be configured to illuminate the work area around the boom 14 by these multiple light source units.

[0089] 15 , the work light 20 has three light source units (first light source unit 25, second light source unit 26, and third light source unit 27) with different optical axis directions. The work light 20 includes a first work light (first light source unit) 25 that illuminates the same direction as in the above embodiment, a second work light (second light source unit) 26 that illuminates the same direction as in the above embodiment, and a third work light (third light source unit) 27 that illuminates the direction intermediate between the first work light 25 and the second work light 26.

[0090] The third work light 27 is attached to the first cylinder bracket 21 at a position between the first work light 25 and the second work light 26, with its light-emitting surface (optical axis direction) facing closer to the boom base end than the first work light 25 and closer to the boom tip end than the second work light 26 (in the direction of arrow N3 in FIG. 11 ). That is, the optical axis direction N3 of the third work light 27 faces closer to the tip end of the boom 14 than the second work light 26 and closer to the boom base end than the first work light 25. Therefore, the work lights 20 illuminate positions farther from the machine body 2 with the first work light 25, positions closer to the machine body 2 with the second work light 26, and positions intermediate therebetween with the third work light 27. In this embodiment, the first work light 25 illuminates the area around the bucket 16 when the arm 15 is in the dump range P3. The second work light 26 illuminates the area around the bucket 16 when the arm 15 is in the cloud range P2. The third work light 27 illuminates the area around the bucket 16 when the arm 15 is in the intermediate range P5.

[0091] In addition, when the arm 15 is in an intermediate range P5 between the cloud range P2 and the dump range P3, the lighting control unit 44 performs a fifth control in which the illuminance of the third work light 27 is controlled to be higher than at least one of the illuminance of the third work light 27 when the arm 15 is in the cloud range P2 or the illuminance of the third work light 27 when the arm 15 is in the dump range P3.

[0092] 16 , when the swing position (arm angle) D2 of the arm 15 is in the cloud range P2, the output E1 of the first work light 25 and the output E3 of the third work light 27 are both set to the minimum output (0%). Meanwhile, the output E2 of the second work light 26 is set to the maximum output (100%). Furthermore, when the swing position (arm angle) D2 of the arm 15 is in the dump range P3, the output E2 of the second work light 26 and the output E3 of the third work light 27 are both set to the minimum output (0%). Meanwhile, the output E1 of the first work light 25 is set to the maximum output (100%).

[0093] Furthermore, when the swing position (arm angle) D2 of the arm 15 is in the intermediate range P5, the output E1 of the first work light 25 and the output E2 of the second work light 26 are both set to intermediate output (50%), while the output E3 of the third work light 27 is set to maximum output (100%).

[0094] That is, while the arm 15 is in the intermediate range P5 between the cloud range P2 and the dump range P3, the lighting control unit 44 maintains the illuminance of the third work light 27 at a high illuminance and limits the illuminance of the first work light 25 and the second work light 26 to a medium illuminance (fifth example).

[0095] In this embodiment, when the arm 15 is in the intermediate range P5, either or both of the output E1 of the first work light 25 and the output E2 of the second work light 26 may be set to maximum output (high illuminance) or minimum output (low illuminance). Furthermore, when the arm 15 is in the dump range P3 or the cloud range P2, the output E3 of the third work light 27 may be set to maximum output (high illuminance).

[0096] Furthermore, when the arm 15 is in the cloud range P2 or the dump range P3, the output E3 of the third work light 27 may be continuously changed within a predetermined range (e.g., 0% to 99%) in accordance with changes in the swing position D2 of the arm 15.

[0097] 17 , when the swing position (arm angle) D2 of the arm 15 changes from the cloud range P2 side to the dump range P3 side (arm dump direction) while the arm 15 is in the intermediate range P5, the output E1 of the first work light (first light source unit) 25 is changed to continuously increase (1% to 99%), and the output E2 of the second work light (second light source unit) 26 is changed to continuously decrease (99% to 1%) accordingly. On the other hand, when the swing position (arm angle) D2 of the arm 15 changes from the dump range P3 side to the cloud range P2 side (arm cloud direction), the output E1 of the first work light (first light source unit) 25 is changed to continuously decrease (99% to 1%), and the output E2 of the second work light (second light source unit) 26 is changed to continuously increase (1% to 99%) accordingly.

[0098] Furthermore, when the swing position (arm angle) D2 of the arm 15 changes in the arm dump direction while the arm 15 is in the cloud range P2, the output E3 of the third work light 27 is changed accordingly to become continuously higher (0% to 99%). On the other hand, when the swing position (arm angle) D2 of the arm 15 changes in the arm cloud direction, the output E3 of the third work light 27 is changed accordingly to become continuously lower (99% to 0%).

[0099] Furthermore, when the swing position (arm angle) D2 of the arm 15 changes in the arm dumping direction while the arm 15 is in the dumping range P3, the output E3 of the third work light 27 is changed accordingly to continuously decrease (99% to 0%). On the other hand, when the swing position (arm angle) D2 of the arm 15 changes in the arm crowding direction, the output E3 of the third work light 27 is changed accordingly to continuously increase (0% to 99%).

[0100] That is, while the arm 15 is in the intermediate range P5 between the cloud range P2 and the dump range P3, the lighting control unit 44 maintains the illuminance of the third work light 27 at a higher illuminance than when the arm 15 is in the cloud range P2 or the dump range P3, and as the arm 15 moves out of the intermediate range P5 and swings toward the arm cloud direction or the arm dump direction, the lighting control unit 44 continuously changes the illuminance of the third work light 27 from high to low (sixth example).

[0101] The present invention provides a work machine 1 described in the following items: (Item 1) The work machine 1 includes a machine body 2, a boom 14 whose base end is connected to the machine body 2 so as to be able to swing up and down, an arm 15 connected to the tip of the boom 14 so as to be able to swing in an arm crowding direction approaching the boom 14 and an arm dumping direction moving away from the boom 14, a work implement 16 attached to the tip of the arm 15, a work light 20 provided on the boom 14 to illuminate a work area around the boom 14, and a lighting control unit 44 that controls the lighting operation of the work light 20, and the work light 20 includes a first light source unit 25 and a second light source unit 26 whose optical axis directions are different from each other. 6, an optical axis direction N1 of the first light source unit 25 faces closer to the tip of the boom 14 than the second light source unit 26, and an optical axis direction N2 of the second light source unit 26 faces closer to the base end of the boom 14 than the first light source unit 25, and the lighting control unit 44 performs a first control to control the illuminance of the first light source unit 25 to be lower when the arm 15 is in a cloud range P2 that is set on the arm cloud direction side of the swingable range, compared to when the arm 15 is in a dump range P3 that is set on the arm dump direction side of the cloud range P2.

[0102] According to the work machine 1 according to this item 1, power consumption during work can be reduced by controlling the illuminance of the first light source unit 25 in accordance with the swing position of the arm 15. Furthermore, by controlling the illuminance of the first light source unit 25 as described above, it is possible to prevent the first light source unit 25 from unnecessarily illuminating areas outside the work area when the boom 14 is raised high, thereby allowing the work area to be appropriately illuminated.

[0103] (Item 2) The work machine 1 according to Item 1, wherein the lighting control unit 44 performs second control to control the illuminance of the second light source unit 26 to be lower when the arm 15 is in the dump range P3 compared to when the arm 15 is in the cloud range P2.

[0104] According to the work machine 1 relating to this item 2, by controlling the illuminance of the first light source unit 25 and the second light source unit 26 according to the swing position of the arm 15, it is possible to appropriately illuminate the work area and further reduce power consumption during work.

[0105] (Item 3) The work machine 1 described in Item 1 or 2, wherein the lighting control unit 44 performs third control when the arm 15 is in an intermediate range P5 set between the cloud range P2 and the dump range P3, to control the illuminance of the first light source unit 25 to be higher than the illuminance of the first light source unit 25 when the arm 15 is in the cloud range P2, and to control the illuminance of the second light source unit 26 to be higher than the illuminance of the second light source unit 26 when the arm 15 is in the dump range P3.

[0106] According to the work machine 1 relating to this item 3, when the arm 15 is in the intermediate range P5, the first light source unit 25 and the second light source unit 26 can appropriately illuminate the area around the arm 15.

[0107] (Item 4) In the third control, when the arm 15 is in the intermediate range P5, the lighting control unit 44 controls the illuminance of the first light source unit 25 to be continuously lower as the arm 15 swings from the dump range P3 side to the cloud range P2 side, and controls the illuminance of the first light source unit 25 to be continuously higher as the arm 15 swings from the cloud range P2 side to the dump range P3 side. This is the work machine 1 described in Item 3.

[0108] According to the work machine 1 according to item 4, the brightness of the work area can be smoothly changed in accordance with the swinging of the arm 15 between the cloud range P2 and the dump range P3, allowing the operator to better concentrate on the work, thereby improving workability.

[0109] (Item 5) In the third control, when the arm 15 is in the intermediate range P5, the lighting control unit 44 controls the illuminance of the second light source unit 26 to be continuously higher as the arm 15 swings from the dump range P3 side to the cloud range P2 side, and controls the illuminance of the second light source unit 26 to be continuously lower as the arm 15 swings from the cloud range P2 side to the dump range P3 side. This is the work machine 1 described in item 3 or 4.

[0110] According to the work machine 1 relating to this item 5, the illumination of the second light source unit 26 can be gradually increased or decreased in accordance with the arm 15 swinging between the cloud range P2 and the dump range P3, thereby more appropriately illuminating the work area during work.

[0111] (Item 6) The work machine 1 described in any one of Items 3 to 5, wherein the lighting control unit 44 performs a fourth control when the boom 14 is swung above a predetermined setting position S4, to control the illuminance of the first light source unit 25 to be lower than the illuminance of the first light source unit 25 when the boom 14 is below the setting position S4, regardless of the operating state of the arm 15.

[0112] (Item 7) A machine comprising: a body 2; a boom 14 whose base end is connected to the body 2 so as to be able to swing up and down; an arm 15 connected to the tip side of the boom 14 so as to be able to swing in an arm crowding direction which is a direction approaching the boom 14 and an arm dumping direction which is a direction moving away from the boom 14; a work implement 16 attached to the tip side of the arm 15; a work light 20 provided on the boom 14 and illuminating a work area around the boom 14; and a lighting control unit 44 which controls the lighting operation of the work light 20, wherein the work light 20 has a first light source unit 25 and a second light source unit 26 whose optical axis directions are different from each other. The work machine 1 has two light source units 26, an optical axis direction N1 of the first light source unit 25 faces closer to the tip of the boom 14 than the second light source unit 26, and an optical axis direction N2 of the second light source unit 26 faces closer to the base end of the boom 14 than the first light source unit 25, and the lighting control unit 44 performs fourth control to control the illuminance of the first light source unit 25 to be lower than the illuminance of the first light source unit 25 when the boom 14 is below the set position S4, regardless of the operating state of the arm 15, when the boom 14 is swung above a predetermined set position S4.

[0113] According to the work machine 1 relating to items 6 and 7, when the boom 14 is raised high, it is possible to reliably prevent the first light source unit 25 from unnecessarily illuminating areas outside the work area, thereby more appropriately illuminating the work area and contributing to reducing power consumption.

[0114] (Item 8) The work machine 1 according to item 6 or 7, further comprising a first switching operation unit 9b for operating whether the fourth control of the lighting control unit 44 is enabled or disabled.

[0115] According to the work machine 1 according to this item 8, the fourth control can be switched between enabled and disabled as desired, so that the lighting control of the work light 20 can be selected according to the type of work, such as switching the fourth control to disabled when the work mainly involves loading earth and sand at high places or excavating at high places, thereby improving convenience.

[0116] (Item 9) The work machine 1 described in any one of Items 6 to 8, wherein the lighting control unit 44 controls the illuminance of the second light source unit 26 to be higher when the boom 14 is swung above a predetermined setting position S4, compared to the illuminance of the second light source unit 26 when the boom 14 is below the setting position S4, regardless of the operating state of the arm 15.

[0117] According to the work machine 1 relating to item 9, when the boom 14 is lowered, the work area can be properly illuminated by the first light source unit 25, and when the boom 14 is raised, the work area can be properly illuminated by the second light source unit 26, so that the work area around the boom 14 can always be properly illuminated using only the work lights 20 (first work light 25, second work light 26) provided on the boom 14.

[0118] (Item 10) The work machine 1 according to any one of Items 3 to 6, further comprising a second switching operation unit 9c for operating the first to third controls of the lighting control unit 44 to enable and disable them.

[0119] According to the work machine 1 of this item 10, the first to third controls can be switched between enabled and disabled as desired, so that the lighting control of the work light 20 can be selected according to the type of work, such as switching the first to third controls to disabled when performing excavation work while widely illuminating low areas, thereby further improving convenience.

[0120] (Item 11) The work implement 1 according to any one of Items 1 to 10, wherein the second light source unit 26 illuminates the area around the work implement 16 when the arm 15 is in a cloud range P2 that is set on the arm cloud direction side of the swingable range, and the first light source unit 25 illuminates the area around the work implement 16 when the arm 15 is in a dump range P3 that is set on the arm dump direction side of the cloud range P2.

[0121] According to the work machine 1 relating to this item 11, even when the above-mentioned first control and second control are performed, the area around the work implement 16 can be concentratedly illuminated by the first light source unit 25 and the second light source unit 26, so workability is not impaired.

[0122] (Item 12) The work implement 1 according to any one of Items 1 to 11, further comprising a boom cylinder C3 connected between the machine body 2 and the boom 14 and swinging the boom 14, the boom 14 being provided with a cylinder bracket 21 that rotatably supports one end of the boom cylinder C3, and the work light 20 being provided in a gap H inside the cylinder bracket 21.

[0123] According to the work machine 1 according to item 12, the light emitted from the work light 20 is less likely to leak unnecessarily outside the work area, so the work area can be more appropriately illuminated. Also, because the work light 20 is not exposed to the outside of the work device 4, it is possible to prevent external objects such as tree branches from coming into contact with the work light 20 during work, which could result in deviation in the illumination direction or damage, and this also improves the design of the work machine 1 as a whole.

[0124] (Item 13) The work implement 1 described in any one of Items 1 to 12, wherein the work light 20 has a third light source unit 27 whose optical axis direction faces more toward the tip side of the boom 14 than the second light source unit 26 and more toward the base end side of the boom 14 than the first light source unit 25, and the lighting control unit 44 performs fifth control to control the illuminance of the third light source unit 27 to be higher than at least one of the illuminance of the third light source unit 27 when the arm 15 is in the cloud range P2 and the illuminance of the third light source unit 27 when the arm 15 is in the dump range P3, when the arm 15 is in an intermediate range P5 that is set between a cloud range P2 that is set on the arm crowding direction side of the swingable range and a dump range P3 that is set on the arm dump direction side of the cloud range P2.

[0125] According to the work machine 1 according to this item 13, when the arm 15 is in the intermediate range P5, the third light source unit 27 can appropriately illuminate the area around the arm 15.

[0126] Although the present invention has been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. 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.

[0127] Furthermore, in the above-described embodiment, an example was described in which the present invention is applied to a work machine such as a backhoe, but the application of the present invention is not limited to this, and the present invention may be applied to other construction machines such as wheel loaders, compact track loaders, and skid steer loaders, as well as agricultural machines such as tractors, combine harvesters, rice transplanters, and lawn mowers.

[0128] REFERENCE SIGNS LIST 1 Work implement 2 Machine body 3 Traveling device 4 Work implement 6 Driver's seat 9a First switching operation unit 9b Second switching operation unit 14 Boom 15 Arm 16 Bucket (work implement) 20 Work light 21 Cylinder bracket 25 First work light (first light source unit) 26 Second work light (second light source unit) 44 Lighting control unit C3 Boom cylinder P1 Lowering range P2 Cloud range P3 Dumping range P4 Raising range P5 Intermediate range U3 Control device

Claims

1. The aircraft and a boom whose base end is connected to the machine body so as to be able to swing up and down; an arm connected to a tip end side of the boom so as to be swingable in an arm crowding direction that is a direction toward the boom and an arm dumping direction that is a direction away from the boom; a work tool attached to the tip side of the arm; a work light provided on the boom for illuminating a work area around the boom; a lighting control unit that controls the lighting operation of the work light, The work light has a first light source unit and a second light source unit whose optical axis directions are different from each other, an optical axis direction of the first light source unit faces a tip end side of the boom more than the second light source unit, and an optical axis direction of the second light source unit faces a base end side of the boom more than the first light source unit, The lighting control unit performs a first control to control the illuminance of the first light source unit to be lower when the arm is in a cloud range that is set on the arm cloud direction side of the swingable range, compared to when the arm is in a dump range that is set on the arm dump direction side of the cloud range, a second control to control the illuminance of the second light source unit to be lower when the arm is in the dump range, compared to when the arm is in the cloud range, and a fourth control to control the illuminance of the first light source unit to be lower when the boom is swung above a predetermined set position, regardless of the operating state of the arm, when the boom is swung above a predetermined set position.

2. 2. The work machine according to claim 1, wherein the lighting control unit performs third control to control the illuminance of the first light source unit to be higher than the illuminance of the first light source unit when the arm is in the cloud range, and to control the illuminance of the second light source unit to be higher than the illuminance of the second light source unit when the arm is in the dump range, when the arm is in an intermediate range set between the cloud range and the dump range.

3. 3. The work machine according to claim 2, wherein, in the third control, when the arm is in the intermediate range, the lighting control unit controls the illuminance of the first light source unit to be continuously lower as the arm swings from the dump range side to the cloud range side, and controls the illuminance of the first light source unit to be continuously higher as the arm swings from the cloud range side to the dump range side.

4. 3. The work machine according to claim 2, wherein, in the third control, when the arm is in the intermediate range, the lighting control unit controls the illuminance of the second light source unit to be continuously higher as the arm swings from the dump range side to the cloud range side, and controls the illuminance of the second light source unit to be continuously lower as the arm swings from the cloud range side to the dump range side.

5. The work machine according to claim 1 , further comprising a first switching operation unit for operating to enable or disable the fourth control of the lighting control unit.

6. 2. The work machine according to claim 1, wherein the lighting control unit controls the illuminance of the second light source unit to be higher when the boom is swung above a predetermined set position than the illuminance of the second light source unit when the boom is below the set position, regardless of the operating state of the arm.

7. 3. The work machine according to claim 2, further comprising a second switching operation unit for operating to enable or disable the first to third controls of the lighting control unit.

8. the second light source unit illuminates the surroundings of the work tool when the arm is in a crowding range that is set on the arm crowding direction side of the swingable range, The work machine according to claim 1 , wherein the first light source unit is configured to illuminate the area around the work implement when the arm is in a dump range that is set on the arm dump direction side of the cloud range.

9. a boom cylinder connected between the machine body and the boom for swinging the boom; The boom is provided with a cylinder bracket that rotatably supports one end of the boom cylinder, 2. The work machine according to claim 1, wherein the work light is provided in a gap inside the cylinder bracket.

10. the work light has a third light source unit whose optical axis direction faces the tip side of the boom more than the second light source unit and faces the base end side of the boom more than the first light source unit, 2. The work machine according to claim 1, wherein the lighting control unit performs fifth control to control the illuminance of the third light source unit to be higher than at least one of the illuminance of the third light source unit when the arm is in the cloud range and the illuminance of the third light source unit when the arm is in the dump range, when the arm is in an intermediate range set between a cloud range set on the arm cloud direction side of the swingable range and a dump range set on the arm dump direction side of the cloud range.