Work equipment

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

Technical Field

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

Background Art

[0002] The working machine disclosed in Patent Document 1 has a work lamp for illuminating the periphery of the working device provided on the boom.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when trying to widely illuminate the periphery of the working device with one work lamp provided on the boom as in the above conventional working machine, depending on the angle of the boom, it will illuminate even the range where illumination is not necessary, thus consuming wasted power. Also, when the boom is raised high, it may unnecessarily illuminate areas outside the working area such as neighboring houses and automobiles.

[0005] The present invention has been made to solve such problems, and aims to reduce power consumption during work and provide a working machine capable of appropriately illuminating the working area.

Means for Solving the Problems

[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 comprises 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 the arm cloud direction, which is a direction toward the boom, and in the arm dump direction, which is a direction toward the boom, a work tool attached to the tip end of the arm, a work light provided on the boom for illuminating the work area around the boom, and a lighting control unit for controlling the lighting operation of the work light, wherein the work light has 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 is directed toward the tip end of the boom than the second light source unit, and the optical axis direction of the second light source unit is directed toward the base end of the boom than the first light source unit. The lighting control unit performs a first control to control the illuminance of the first light source to be lower than when the arm is in the dump range, which is set on the arm-cloud side of the swingable range, compared to when the arm is in the dump range, which is set on the arm-dump side of the cloud range; a second control to control the illuminance of the second light source to be lower than when the arm is in the cloud range, compared to when the arm is in the dump range; and a fourth control to control the illuminance of the first light source to be lower than when the boom is below the set position, regardless of the operating state of the arm, when the boom is swinging above a predetermined set position. At the same time, if the arm is within the dump range, the second control is performed. .

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

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

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

[0014] The above-mentioned work machine may include a first switching operation unit for enabling and disabling the fourth control of the lighting control unit.

[0015] A work machine according to one aspect of the present invention comprises 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 the arm cloud direction, which is a direction toward the boom, and in the arm dump direction, which is a direction toward the boom, a work tool attached to the tip end of the arm, a work light provided on the boom for illuminating the work area around the boom, and a lighting control unit for controlling the lighting operation of the work light, wherein the work light has 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 is directed toward the tip end of the boom than the second light source unit, and the optical axis direction of the second light source unit is directed toward the base end of the boom than the first light source unit. The aforementioned lighting control unit, When the arm is in the cloud range, which is set on the arm cloud side of the swingable range, a first control is performed to control the illuminance of the first light source to a lower level compared to when the arm is in the dump range, which is set on the arm dump side of the cloud range. When the arm is in the dump range, a second control is performed to control the illuminance of the second light source to a lower level compared to when the arm is in the cloud range. If the boom is swinging above a predetermined set position, regardless of the operating state of the arm, The illuminance of the first light source is controlled to be lower than the illuminance of the first light source when the boom is below the set position, The illuminance of the second light source is controlled to be higher than the illuminance of the second light source when the boom is below the set position. ru.

[0016] The above-mentioned work machine may include a second switching operation unit for enabling and disabling 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 tool when the arm is in a cloud range set on the arm cloud side of the swingable range, and the first light source unit may be configured to illuminate the area around the work tool when the arm is in a dump range set on the arm dump side of the cloud range.

[0018] The work machine includes a boom cylinder connected between the machine body and the boom for swinging the boom. The boom is provided with a cylinder bracket for rotatably supporting one end of the boom cylinder. The work lamp may be provided in a gap inside the cylinder bracket.

[0019] The work lamp has a third light source portion whose optical axis direction faces the tip side of the boom rather than the second light source portion and faces the base end side of the boom rather than the first light source portion. When the arm is in an intermediate range set between a cloud range set on the cloud direction side within the swingable range of the arm and a dump range set on the dump direction side rather than the cloud range, the illumination control unit controls the illuminance of the third light source portion to be higher than at least one of the illuminance of the third light source portion when the arm is in the cloud range and the illuminance of the third light source portion when the arm is in the dump range. Fifth control may be performed as described above.

Advantages of the Invention

[0020] According to the above work machine, by controlling the illuminance of the first light source portion and the second light source portion according to the swing position of the arm, the power consumption during work can be reduced, and the work area can be appropriately illuminated.

Brief Description of the Drawings

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

Embodiments for Carrying Out the Invention

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

[0023] As shown in FIGS. 1 and 2, the working machine 1 of the present embodiment is a backhoe including a machine body (swing platform) 2, a traveling device 3, and a working device 4. A canopy 5 is mounted on the machine body 2. Inside the canopy 5, a driver's seat 6 on which an operator (driver) sits is provided. The canopy 5 is a protection mechanism for protecting the driver's seat 6. Note that the working machine 1 is not limited to a backhoe, and may be other types of working machines. Further, as a protection mechanism for protecting the driver's seat 6, instead of the canopy 5, a cab surrounding the driver's seat 6 may be mounted on the machine body 2.

[0024] [[ID=4...]] In this embodiment, the direction the operator seated in the driver's seat 6 is facing (indicated by arrow X1 in Figures 1 and 2) is the front of the aircraft 2, and the opposite direction (indicated by arrow X2 in Figures 1 and 2) is the rear of the aircraft 2. Also, the left side of the operator (indicated by arrow Y1 in Figure 1) is referred to as the left side of the aircraft 2, and the opposite direction (indicated by arrow Y2 in Figure 1) is referred to as the right side of the aircraft 2. Furthermore, the area above the operator (indicated by arrow Z1 in Figures 1 and 2) is referred to as the top of the aircraft 2, and the opposite direction (indicated by arrow Z2 in Figures 1 and 2) is referred to as the bottom of the aircraft 2.

[0025] <Aircraft> As shown in Figure 2, the machine body 2 is supported on the upper part of the running gear 3 via a slewing bearing 2J. That is, the machine body 2 is supported so as to be rotatable around the slewing axis (axis extending in the vertical direction) L1 relative to the running gear 3. The slewing axis L1 is the rotation center of the slewing bearing 2J.

[0026] The machine body 2 houses the prime mover U1, hydraulic pump U2, control device U3, etc. The prime mover U1 is a diesel engine. The prime mover U1 may also be a gasoline engine, an electric motor, or a hybrid prime mover having both 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 fluid (pressurized oil) to hydraulic actuators such as the hydraulic motor and hydraulic cylinders C1 to C5 equipped on the work machine 1, which will be described later. The control device U3 controls the operation of the prime mover U1, hydraulic pump U2, etc.

[0027] In the machine body 2, the driver's seat 6, travel lever 7, and control devices 8L and 8R are mounted in front 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 (such as the swinging operation of the boom 14, arm 15, and bucket 16, which will be described later) and the rotation operation of the machine body 2.

[0028] As shown in Figure 1, the control devices 8L and 8R are located on the left and right sides of the driver's seat 6. A control stand 9 is provided on the right side of the driver's seat 6 to support the right control device 8R. In addition to the control device 8R, the control stand 9 is equipped with multiple control switches for operating various functions mounted on the work machine 1.

[0029] The following are located on the control panel 9: a lighting control unit 9a for manually switching the work light 20 on and off (described later), a first switching control unit 9b for manually enabling and disabling the fourth control of the work light 20, and a second switching control unit 9c for manually enabling and disabling the first to third controls of the work light 20. The first to fourth controls of the work light 20 will be described later.

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

[0031] The front of the machine body 2 is provided with a support bracket 11 and a swing bracket 12. The support bracket 11 is provided projecting forward from the front of the machine body 2. The swing bracket 12 is a member that supports the work device 4 and is provided at the tip of the support bracket 11 so as to be able to swing from side to side. More specifically, the swing bracket 12 is supported so as to be able to rotate around a swing axis 11J that extends vertically from the tip of the support bracket 11. The swing bracket 12 can be swung from side to side by the extension and retraction of a swing cylinder (hydraulic cylinder) C1 that connects the machine body 2 and the swing bracket 12.

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

[0033] <Working equipment> As shown in Figures 1 to 3, the work device 4 has a boom 14, an arm 15, and a bucket (working tool) 16. The work device 4 is also equipped with a work light 20. The work machine 1 can be fitted with other working tools (hydraulic attachments) that can be driven by hydraulic fluid in place of or in addition to the bucket 16. Examples of other working tools include hydraulic breakers, hydraulic crushers, angle brooms, earth augers, pallet forks, sweepers, mowers, snow blowers, etc.

[0034] The boom 14 is pivotally supported so as to be able to swing around a boom support shaft 12J that extends horizontally 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 so as to be able to swing upward (in the direction of arrow R4 in Figure 4) and downward (in the direction of arrow R1 in Figure 4). Raising the boom 14 is the action of raising the boom 14 above the support bracket 11. On the other hand, lowering the boom 14 is the action of tilting the boom 14 forward of the support bracket 11.

[0035] The boom 14 is a long, roughly rectangular columnar member, and when it is swung downward and lowered in front of the support bracket 11, it is bent upward in a roughly V-shape when viewed from the side. A first cylinder bracket 21, which serves as the connection point for the boom cylinder (hydraulic cylinder) C3, is provided at approximately the center (bent portion) between the front and rear of the boom lower surface portion 14A, which is the lower surface side of the boom 14 when it is in the lowered state. A second cylinder bracket 22, which serves as the connection point for the arm cylinder (hydraulic cylinder) C4, is provided at approximately the center (bent portion) between the front and rear of the boom upper surface portion 14B, which is the upper surface side of the boom 14 when it is 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 to protect the cylinder rod of the boom cylinder C3. The boom 14 swings downward by retracting the boom cylinder C3 and swings upward by extending the boom cylinder C3. In this embodiment, the boom 14 is configured to stop swinging at a position (see Figure 2) where it does not interfere with the canopy 5 or the machine body 2 when swinging upward.

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

[0038] As shown in Figures 1 to 3, the arm 15 is pivotally supported around an arm support shaft 14J that extends laterally from the tip of the boom 14, allowing it to swing. That is, the arm 15 is pivotally connected to the tip of the boom 14 so that it can swing in the arm dump direction (direction R3 in Figure 6) and the arm cloud direction (direction R2 in Figure 6). The movement of the arm 15 in the arm cloud direction is the movement of bringing the bucket 16 closer to the machine body 2 (clouding operation). On the other hand, the movement of the arm 15 in the arm dump direction is the movement of moving the bucket 16 away from the machine body 2 (dumping operation).

[0039] The arm 15 is a long, roughly rectangular columnar member. When the arm 15 is swung in the direction of the arm cloud and the boom 14 is swung upward (see Figure 2), the upper end (base end) of the arm front portion 15B, which is the front side of the arm 15, is provided with a third cylinder bracket 23, which serves as the connecting part for the boom cylinder C3 and the work tool cylinder C5.

[0040] An arm cylinder C4 is connected between the third cylinder bracket 23 and the second cylinder bracket 22 of the boom 14. The arm cylinder C4 is provided with a cylinder cover G4 to protect the cylinder rod of the arm cylinder C4. The arm 15 swings in the arm dump direction (dumping operation) by retracting the arm cylinder C4 and swings in the arm cloud direction (clouding operation) by extending the boom cylinder C3. In this embodiment, the arm 15 is configured to stop swinging when it swings in the arm cloud direction at a position (see Figure 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 on the tip of the arm 15 so as to be able to swing around a work tool support shaft 15J that extends in the left-right direction. In other words, the bucket 16 is pivotally connected to the tip of the arm 15 so as to be able to swing in the work tool dump direction and the work tool cloud direction. The movement of the bucket 16 in the work tool cloud direction is an action that swings the tip of the bucket 16 toward the machine body 2 (cloud action), for example, the action when scooping up soil or sand with the bucket 16. On the other hand, the movement of the bucket 16 in the work tool dump direction is an action that swings the tip of the bucket 16 toward the machine body 2 (dump action), for example, the action when dropping (discharging) the scooped soil or 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 of the arm 15 and also serving as the connection point for the work tool cylinder C5. The work tool cylinder C5 is connected between the link mechanism 24 and the third cylinder bracket 23 of the arm 15. The work tool cylinder C5 is provided with a cylinder cover G5 to protect the cylinder rod of the work tool cylinder C5. The bucket 16 is swung in the work tool dump direction by contracting the work tool cylinder C5 and swung in the work tool cloud direction by extending the work tool 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 work tool cloud direction.

[0043] <Work light> As shown in Figures 1 and 2, the work machine 1 has a work light 20. The work light 20 is installed on the boom 14 and illuminates the work area around the boom 14. As shown in Figures 3 and 5, the work light 20 is installed in the gap H inside the first cylinder bracket 21 on the boom 14. The work light 20 of this embodiment has two light sources (first light source 25, second light source 26) with different optical axis directions. The work light 20 includes a first work light (first light source) 25 that illuminates the tip direction (arm 15 side) of the boom 14 when the boom 14 is swung downward to a predetermined set position S4(F) (see Figure 4), and a second work light (second light source) 26 that illuminates the downward direction of the boom 14 when the boom 14 is in the above set position S4(F). The configuration of the work lights 20 (first work light 25, second work light 26) is not particularly limited, but in this embodiment, LEDs are used.

[0044] The first work light 25 is mounted on the first cylinder bracket 21 with its light-emitting surface (in the direction of the optical axis) facing diagonally downward (in the direction of arrow N1 in Figures 3 and 5) from the forward direction of the extension of the tip extension 14T of the boom 14. The second work light 26 is mounted on the first cylinder bracket 21 at a position behind the first work light 25 (towards the base end of the boom) with its light-emitting surface (in the direction of the optical axis) facing towards the base end of the boom (in the direction of arrow N2 in Figures 3 and 5) from the first work light 25. That is, the optical axis direction N1 of the first work light 25 is directed towards the tip of the boom 14 than the second work light 26, and the optical axis direction N2 of the second work light 26 is directed towards the base end of the boom 14 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, and 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 the dump range P3 described later. The second work light 26 illuminates the area around the bucket 16 when the arm 15 is in the cloud range P2 described later (see Figure 6).

[0045] Both the first work light 25 and the second work light 26 are fixed to the first cylinder bracket 21, which is provided on the underside 14A of the boom. That is, the first work light 25 and the second work light 26 are provided side by side, front to back, in the central part (bent section) of the underside 14A of the boom, and when illuminated, they can illuminate the work area in front of (towards the arm 15) 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 is changed accordingly, front to back.

[0046] As shown in Figures 4 and 6, the illumination directions of the first work light 25 and the second work light 26 are set so that a portion of their illumination ranges overlaps in the front-to-back direction. Therefore, when both the first work light 25 and the second work light 26 are turned on, the area is continuously illuminated in the front-to-back direction from the illumination range of the first work light 25 to the illumination range of the second work light 26. The maximum output and irradiation angle (beam angle) of the first work light 25 and the second work light 26 may be set to the same value or to different values. In this embodiment, the output of the first work light 25 and the second work light 26 is configured to be continuously varied 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 device 4 by the extension and retraction of hydraulic cylinders (hydraulic actuators) C3 to C5. More specifically, as shown in Figure 7, the hydraulic system of the work machine 1 includes a boom control valve 31, an arm control valve 32, a work tool control valve 33, a control device U3, steering devices 8L and 8R, a boom angle sensor 34, an arm angle sensor 35, and a work tool angle sensor 36. The steering devices 8L and 8R, the boom control valve 31, the arm control valve 32, the work tool control valve 33, the boom angle sensor 34, the arm angle sensor 35, and the work tool angle sensor 36 are each connected to the control device U3 via a communication cable.

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

[0049] The boom control valve 31, arm control valve 32, and work tool 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 demagnetizing the first solenoid 31A and the second solenoid 31B. When the boom control valve 31 is switched to the first valve position V1, the boom cylinder C3 is extended by supplying and discharging hydraulic fluid to and from the boom cylinder C3. On the other hand, when the boom control valve 31 is switched to the second valve position V2, the boom cylinder C3 is retracted by supplying and discharging hydraulic fluid to and from the boom cylinder C3. As a result, the boom 14 swings.

[0050] The arm control valve 32 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 demagnetizing the first solenoid 32A and the second solenoid 32B. When the arm control valve 32 is switched to the first valve position V1, the arm cylinder C4 is extended by the supply and discharge of hydraulic fluid to and from the arm cylinder C4. On the other hand, when the arm control valve 32 is switched to the second valve position V2, the arm cylinder C4 is retracted by the supply and discharge of hydraulic fluid to and from the arm cylinder C4. As a result, the arm 15 swings.

[0051] The work tool 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 demagnetizing the first solenoid 33A and the second solenoid 33B. When the work tool control valve 33 is switched to the first valve position V1, the work tool cylinder C5 is extended by the supply and discharge of hydraulic fluid to and from the work tool cylinder C5. On the other hand, when the work tool control valve 33 is switched to the second valve position V2, the work tool cylinder C5 is retracted by the supply and discharge of hydraulic fluid to and from the work tool cylinder C5. As a result, the bucket 16 swings.

[0052] The control device U3 includes a boom control unit 41, an arm control unit 42, and a work tool 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 operation of the arm control valve 32 and the work tool control valve 33. In other words, the control device U3 controls the operation of the boom 14, the arm 15, and the bucket 16.

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

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

[0055] For example, when the operating lever 8A of the right-side control device 8R swings back and forth, the boom control unit 41 (control device U3) energizes or demagnetizes the first solenoid 31A and the second solenoid 31B according to the direction and amount of swing of the operating lever 8A detected by the position sensor 8B, and switches 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-side control device 8L swings back and forth, the arm control unit 42 (control device U3) energizes or demagnetizes the first solenoid 32A and the second solenoid 32B according to the direction and amount of swing of the operating lever 8A detected by the position sensor 8B, and switches 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 from side to side, the work tool control unit 43 (control device U3) energizes or demagnetizes the first solenoid 33A and the second solenoid 33B according to the direction and amount of swing of the operating lever 8A detected by the position sensor 8B, and switches the work tool control valve 33. In other words, the work tool control unit 43 controls the swinging 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 tool 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, the arm angle sensor 35, and the tool angle sensor 36, but 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 of the stroke (extended position) of the boom cylinder C3, arm cylinder C4, and tool cylinder C5.

[0059] <Lighting Control Unit> The control device U3 has a lighting control unit 44. The work lights 20 (first work light 25 and second work light 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 work lights 20 are output controlled by the lighting control unit 44. That is, the control device U3 controls the lighting operation of the first work light 25 and the second work light 26. Specifically, the lighting control unit 44 performs a first control in which, when the arm 15 is swung in the arm cloud direction and is in the cloud range P2 set on the arm cloud direction side of a predetermined swingable range, the illuminance of the first work light (first light source unit) 25 is controlled to be lower than when the arm 15 is in the dump range P3 set on the arm dump 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 control the illuminance of the second work light (second light source unit) 26 to a lower level compared to when the arm 15 is in the cloud range P2.

[0060] Furthermore, when the arm 15 is in the intermediate range P5 set between the cloud range P2 and the dump range P3, the lighting control unit 44 controls the illuminance of the first work light (first light source) 25 to be higher than the illuminance of the first work light 25 when the arm 15 is in the cloud range P2, and controls the illuminance of the second work light (second light source) 26 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 from a predetermined set position S4 and is in a predetermined lifting range P4, the lighting control unit 44 performs a fourth control, which controls the illuminance of the first work light (first light source) 25 to be lower than the illuminance of the first work light 25 when the boom 14 is in a lowering range P1 below the set position S4, regardless of the operating state (position) of the arm 15.

[0062] Furthermore, the lighting control unit 44 performs control to enable and disable the fourth control in response to the operation of the first switching operation unit 9b, and control to enable and disable the first to third controls in response to the operation of the second switching operation unit 9c.

[0063] As shown in Figure 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). On the other hand, the output E2 of the second work light 26 is set to the maximum output (100%). That is, when the arm 15 is in a predetermined cloud range P2, the lighting control unit 44 limits the illuminance of the first work light 25 to a low illuminance.

[0064] Furthermore, in this embodiment, when the swing position (arm angle) D2 of the arm 15 is within the dump 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%). That is, when the arm 15 is within a predetermined dump range P3, the lighting control unit 44 limits the illuminance of the second work light 26 to a low level.

[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] Furthermore, in this embodiment, as shown in the flowchart of Figure 11 described later, when the boom 14 is swung above the set position S4 and is in the lifting range P4, the output E1 of the first work light 25 is set to the minimum output (0%) regardless of the operating state (position) of the arm 15 (fourth control). 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 described above. That is, when the boom 14 is in the predetermined lifting range P4, the lighting control unit 44 limits the illuminance of the first work light 25 to a low illuminance.

[0067] Furthermore, 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 lifting range P4 are not limited to the minimum output (0%) which represents a completely off state. For example, the outputs E1 and E2 may be set to an output that can be considered substantially off (e.g., 1%), or to a low output (e.g., 20%) that does not cause discomfort to nearby residents or others even if illuminated to nearby houses or cars.

[0068] As shown in Figure 9, in this embodiment, the cloud range P2 of the arm 15 in the first to third control is set between the most cloudy position (A), where the swing is stopped so that the bucket 16 does not interfere with the boom cylinder C3 or cylinder cover G3, and a first reference position (B), which is swung by a predetermined angle (e.g., 30 degrees) toward the arm dump direction from the most cloudy position (A). On the other hand, the dump range P3 of the arm 15 in the first to third control is set between a limited position (D), which is swung by a predetermined angle (e.g., 90 degrees from the most cloudy position (A)) toward the arm dump direction by contracting the arm cylinder C4 to a predetermined limited position, and a second reference position (C), which is swung by a predetermined angle (e.g., 30 degrees) toward the arm cloud direction from the limited position (D).

[0069] Furthermore, as shown in Figure 10, in this embodiment, the raising range P4 of the boom 14 in the fourth control is set between the highest position (E) where the boom 14 stops swinging so as not to interfere with the canopy 5 or the machine body 2, and a set position S4(F) obtained by swinging downward by a predetermined angle (for example, 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 in front 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 limited position (G) obtained by swinging downward by a predetermined angle (for example, 90 degrees from the highest position (E)) by contracting the boom cylinder C3 to a predetermined limited position.

[0070] An example of lighting control of the work light 20 by the lighting control unit 44 (control device U3) will be explained according to the flowchart in Figure 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] Here, if the boom angle D1 is greater than or equal to the reference lifting angle DP4, which indicates that the boom angle D1 is within 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 (in this case, minimum output) (ST4). Also, if the arm angle D2 is greater than or equal to the reference dumping angle DP3, which indicates that the arm angle D2 is within 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 (in this case, 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 (in this case, maximum output) (ST7). In other words, when the work light 20 is turned on, if the boom 14 is within the lifting range P4, the first work light 25 is limited to low illuminance. As for the second work light 26, if the arm 15 is within the dumping range P3, it is limited to low illuminance, and if the arm 15 is not within the dumping range P3, it is turned on at high illuminance.

[0072] Subsequently, if the work light 20 is turned off by the lighting control unit 9a (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, if, before the work light 20 is turned off (No in step ST8), for example, the operating lever 8A is operated forward or backward by the right-side control device 8R, causing the boom 14 to swing downward, that is, if the boom angle D1 becomes less than the reference lifting angle DP4 (No in step ST3), the illuminance limit of the first work light 25 is released, and the illuminance of the first work light 25 and the second work light 26 are set according to the swinging position D2 of the arm 15.

[0073] More specifically, as described above, when the boom 14 swings downward (No in step ST3), if the arm angle D2 is less than or equal to the reference cloud angle DP2 indicating that it is in a 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). Also, as described in steps ST5 to ST7 above, the output E2 of the second work light 26 is set to a low illuminance (ST6) if the arm angle D2 is greater than or equal to the reference dump angle DP3 (Yes in step ST5), and to a high illuminance (ST7) if the arm angle D2 is less than the reference dump angle DP3 (No in step ST5).

[0074] Subsequently, for example, if the operating lever 8A is moved forward or backward by the control device 8L on the left side, causing the arm 15 to swing in the direction of arm cloud or arm dump, the illuminance of the first work light 25 and the second work light 26 are changed according to the swing position D2 of the arm 15, as described in steps ST5 to ST7 and steps ST10, ST4, and ST11 above.

[0075] Furthermore, if the first switching operation unit 9b turns off (disables) the fourth control before the work light 20 is turned on in step ST1, the ST3 step is skipped and the steps from ST10 onwards are executed, regardless of the swing position D1 of the boom 14. That is, if 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 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 first to third controls are turned off (disabled) by the second switching operation unit 9c before the work light 20 is turned on in step ST1, the 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, if the first to third controls are turned off, the lighting control unit 44 turns off the illuminance limiting function of 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 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 kept at high brightness 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, step ST1 determines whether or not the operator has performed an operation to turn on the work light 20 using the lighting control unit 9a, but this is not the only option. For example, the work light 20 may be automatically turned on according to the detection result of a light receiving sensor that detects ambient light, and step ST1 may determine whether or not the detection result of the light receiving sensor satisfies predetermined lighting conditions.

[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 maintain a high illuminance regardless of the change 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 the change in the arm angle D2 (second example).

[0080] More specifically, as shown in Figure 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 changes the output E1 of the first work light (first light source unit) 25 to continuously increase (1% to 99%) and 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 changes the output E1 of the first work light (first light source unit) 25 to continuously decrease (99% to 1%) and 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, both the output E1 of the first work light 25 and the output E2 of the second work light 26 are set to high illuminance.

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

[0083] Furthermore, in the above embodiment, when the boom 14 is swung upward from the set position S4 and is in a predetermined lifting 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 lifting range P4, the output E2 of the second work light (second light source unit) 26 may 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] More specifically, as shown in Figure 14, when the boom 14 is swung below the set position S4 and within 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 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 above the set position S4 and within 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 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 output E2 of the second work light 26 is made higher than the output E2 of the second work light 26 when the boom 14 is within the lowering range P1.

[0085] In the fourth embodiment described above, when the boom 14 is swung below 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, similar to the other embodiments described 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 lower surface portion 14A of the boom. However, the work light 20 may be provided on the outer surface portion of the first cylinder bracket 21 or on the side portion of the boom 14, as long as it can adequately illuminate the work area in front of or below the boom 14. Alternatively, it may be provided at a different position on the lower surface portion 14A of the boom from the first cylinder bracket 21 (for example, on the lower surface of the tip extension portion 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 components, but the first work light 25 and the second work light 26 may be integrated into a single casing and configured as a single unit. Alternatively, the work light 20 may have two light source units (first light source unit and second light source unit) corresponding to the first work light 25 and the second work light 26, with each of these light source units configured to allow individual illuminance control. Alternatively, one light source unit may be divided into two and configured to allow individual illuminance control.

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

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

[0090] The third work light 27 is mounted on 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 (in the direction of the optical axis) facing towards the base end of the boom than the first work light 25 and towards the tip of the boom than the second work light 26 (direction N3 in the view of the arrow in Figure 11). That is, the optical axis direction N3 of the third work light 27 is directed towards the tip of the boom 14 than the second work light 26 and towards the base end of the boom 14 than the first work light 25. Therefore, the work lights 20 illuminate positions far from the machine body 2 with the first work light 25, positions close to the machine body 2 with the second work light 26, and intermediate positions 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] Furthermore, the lighting control unit 44 performs a fifth control when the arm 15 is in an intermediate range P5 between the cloud range P2 and the dump range P3, which controls the illuminance of the third work light 27 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 when the arm 15 is in the dump range P3.

[0092] More specifically, as shown in Figure 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 minimum output (0%). On the other hand, the output E2 of the second work light 26 is set to 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 minimum output (0%). On the other hand, the output E1 of the first work light 25 is set to maximum output (100%).

[0093] Furthermore, when the swing position (arm angle) D2 of 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%). On the other hand, the output E3 of the third work light 27 is set to maximum output (100%).

[0094] In other words, 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 level, while limiting the illuminance of the first work light 25 and the second work light 26 to a medium level (5th 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 the maximum output (high brightness) or the minimum output (low brightness). Also, 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 the maximum output (high brightness).

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

[0097] More specifically, as shown in Figure 17, when the arm 15 is in the intermediate range P5, if 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), 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%). On the other hand, if 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%).

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

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

[0100] Specifically, the lighting control unit 44 maintains the illuminance of the third work light 27 at a higher level than when the arm 15 is in the cloud range P2 or dump range P3 while the arm 15 is in the intermediate range P5 between the cloud range P2 and the dump range P3, and continuously changes the illuminance of the third work light 27 from high to low as the arm 15 moves out of the intermediate range P5 and swings in the arm cloud direction or arm dump direction (Example 6).

[0101] The present invention provides a work machine 1 as described in the following items. (Item 1) The machine comprises 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 the arm cloud direction, which is the direction toward the boom 14, and in the arm dump direction, which is the direction toward the boom 14, a work tool 16 attached to the tip of the arm 15, a work light 20 provided on the boom 14 for illuminating the work area around the boom 14, and a lighting control unit 44 for controlling 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 2 with different optical axis directions. The work machine 1 has a first light source unit 25, wherein the optical axis direction N1 of the first light source unit 25 is directed toward the tip side of the boom 14 than the second light source unit 26, and the optical axis direction N2 of the second light source unit 26 is directed toward the base end side 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 a lower level when the arm 15 is in a cloud range P2 set toward the arm cloud direction side of the swingable range, compared to when the arm 15 is in a dump range P3 set toward the arm dump direction side of the cloud range P2.

[0102] According to the work machine 1 related to item 1, power consumption during operation can be reduced by controlling the illuminance of the first light source unit 25 according to the swinging position of the arm 15. Furthermore, by controlling the illuminance of the first light source unit 25 as described above, it is possible to suppress unnecessary illumination of areas outside the work area by the first light source unit 25 when the boom 14 is raised high, thereby enabling appropriate illumination of the work area.

[0103] (Item 2) The work machine 1 according to item 1, wherein the lighting control unit 44 performs a second control, which controls 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 related to item 2, by controlling the illuminance of the first light source unit 25 and the second light source unit 26 according to the swinging position of the arm 15, the work area can be appropriately illuminated, and power consumption during operation can be further reduced.

[0105] (Item 3) The work machine 1 according to item 1 or 2, wherein the lighting control unit 44 controls 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 controls 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, when the arm 15 is in an intermediate range P5 set between the cloud range P2 and the dump range P3, and performs a third control.

[0106] According to the work machine 1 related to 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) The work machine 1 according to item 3, wherein, in the third control, when the arm 15 is in the intermediate range P5, the illuminance of the first light source 25 is continuously controlled to decrease as it swings from the dump range P3 side to the cloud range P2 side, and the illuminance of the first light source 25 is continuously controlled to increase as it swings from the cloud range P2 side to the dump range P3 side.

[0108] According to the work machine 1 related 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 concentrate more on the work. Therefore, work efficiency is improved.

[0109] (Item 5) The work machine 1 according to item 3 or 4, wherein, in the third control, when the arm 15 is in the intermediate range P5, the illuminance of the second light source unit 26 is continuously increased as it swings from the dump range P3 side to the cloud range P2 side, and the illuminance of the second light source unit 26 is continuously decreased as it swings from the cloud range P2 side to the dump range P3 side.

[0110] According to the work machine 1 related to item 5, the illumination of the second light source unit 26 can be gradually raised or lowered in accordance with the swinging of the arm 15 between the cloud range P2 and the dump range P3, thereby allowing the work area to be illuminated more appropriately during operation.

[0111] (Item 6) The working machine 1 according to any one of items 3 to 5, wherein the lighting control unit 44 performs a fourth control, which, when the boom 14 is swinging above a predetermined set position S4, controls 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.

[0112] (Item 7) The machine comprises 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 the arm cloud direction, which is the direction toward the boom 14, and in the arm dump direction, which is the direction toward the boom 14, a work tool 16 attached to the tip of the arm 15, a work light 20 provided on the boom 14 for illuminating the work area around the boom 14, and a lighting control unit 44 for controlling 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 25 whose optical axis directions are different from each other. The work machine 1 has two light source units 26, the optical axis direction N1 of the first light source unit 25 is directed toward the tip side of the boom 14 than the second light source unit 26, and the optical axis direction N2 of the second light source unit 26 is directed toward the base end side of the boom 14 than the first light source unit 25, and the lighting control unit 44 performs a fourth control in which, when the boom 14 is swinging above a predetermined set position S4, the illuminance of the first light source unit 25 is controlled 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.

[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 25 from unnecessarily illuminating areas outside the work area, thereby enabling more appropriate illumination of the work area and contributing to a reduction in 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 the enabling and disabling of the fourth control of the lighting control unit 44.

[0115] According to the work machine 1 related to item 8, the fourth control can be enabled and disabled at will. For example, when mainly performing tasks such as loading soil and sand at high places or excavating at high places, the fourth control can be disabled, allowing the lighting control of the work light 20 to be selected according to the work type. Thus, convenience is improved.

[0116] (Item 9) The working machine 1 according to 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 than the illuminance of the second light source unit 26 when the boom 14 is swinging above a predetermined set position S4, regardless of the operating state of the arm 15.

[0117] According to the work machine 1 related to item 9, when the boom 14 is lowered, the work area can be appropriately illuminated by the first light source 25, and when the boom 14 is raised, the work area can be appropriately illuminated by the second light source 26. Therefore, the work area around the boom 14 can always be appropriately illuminated using only the work lights 20 (first work light 25, second work light 26) installed 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 enable and disable of the first to third controls of the lighting control unit 44.

[0119] According to the work machine 1 related to item 10, the first to third controls can be switched on and off as needed. For example, when performing excavation work while widely illuminating low areas, the first to third controls can be switched off, allowing the lighting control of the work light 20 to be selected according to the work type. Thus, convenience is further improved.

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

[0121] According to the work machine 1 related to item 11, even when the first and second controls described above are performed, the area around the work tool 16 can be concentratedly illuminated by the first light source unit 25 and the second light source unit 26, so work efficiency is not impaired.

[0122] (Item 12) A work machine 1 according to any one of items 1 to 11, wherein a boom cylinder C3 is connected between the machine body 2 and the boom 14 and swings the boom 14, the boom 14 is provided with a cylinder bracket 21 that rotatably supports one end of the boom cylinder C3, and the work light 20 is provided in the inner gap H of the cylinder bracket 21.

[0123] According to the work machine 1 in item 12, the light emitted from the work light 20 is less likely to leak unnecessarily outside the work area, thus allowing for more appropriate illumination of the work area. Furthermore, since the work light 20 is not exposed to the outside of the work device 4, it is possible to suppress lighting defects such as misalignment of the illumination direction or damage caused by external objects such as tree branches coming into contact with the work light 20 during work, and the overall design of the work machine 1 is also improved.

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

[0125] According to the work machine 1 related to 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] Having described the present invention above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended to be included.

[0127] Furthermore, although the embodiments described above illustrate the application of the present invention to work machines such as backhoes, the scope of application of the present invention is not limited to these. For example, it may be applied to other construction machinery such as wheel loaders, compact track loaders, and skid steer loaders, or to agricultural machinery such as tractors, combine harvesters, rice transplanters, and lawnmowers. [Explanation of symbols]

[0128] 1. Work machine 2 units 3. Traveling device 4. Working equipment 6. Driver's seat 9a First switching operation unit 9b Second switching operation unit 14 Boom 15 Arms 16 Buckets (work tools) 20 Work lights 21 Cylinder bracket 25 1st work light (1st light source) 26 2nd work light (2nd light source) 44 Lighting Control Unit C3 Boom Cylinder P1 Downward Range P2 Cloud Scope P3 Dump Range P4 Increase Range P5 Intermediate Range U3 Control Unit

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 is connected to the tip of the boom so as to be able to swing in the arm cloud direction, which is the direction toward the boom, and in the arm dump direction, which is the direction toward away from the boom, A work tool attached to the tip of the aforementioned arm, A work light is provided on the boom and illuminates the work area around the boom, The system includes a lighting control unit that controls the operation of the work light, The work light has a first light source and a second light source whose optical axis directions are different from each other. The optical axis direction of the first light source is directed towards the tip of the boom more than that of the second light source, and the optical axis direction of the second light source is directed towards the base end of the boom more than that of the first light source. The lighting control unit performs a first control to control the illuminance of the first light source to a lower level than when the arm is in the dump range, which is set on the arm dump side of the swingable range, when the arm is in the cloud range, which is set on the arm cloud side of the swingable range; a second control to control the illuminance of the second light source to a lower level than when the arm is in the cloud range, when the arm is in the dump range; a fourth control to control the illuminance of the first light source to a lower level than when the boom is below the set position, regardless of the operating state of the arm, when the boom is swinging above a predetermined set position, and also performs the second control if the arm is in the dump range.

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

3. In the third control, when the arm is in the intermediate range, the lighting control unit continuously controls the illuminance of the first light source to decrease as it swings from the dump range side to the cloud range side, and as it swings from the cloud range side to the dump range side The work machine according to claim 2, which continuously controls the illuminance of the light source to a high level.

4. The work machine according to claim 2, wherein, in the third control, when the arm is in the intermediate range, the lighting control unit continuously controls the illuminance of the second light source to increase as it swings from the dump range side to the cloud range side, and continuously controls the illuminance of the second light source to decrease as it 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 the enabling and disabling of the fourth control of the lighting control unit.

6. 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 is connected to the tip of the boom so as to be able to swing in the arm cloud direction, which is the direction toward the boom, and in the arm dump direction, which is the direction toward away from the boom, A work tool attached to the tip of the aforementioned arm, A work light is provided on the boom and illuminates the work area around the boom, The system includes a lighting control unit that controls the operation of the work light, The work light has a first light source and a second light source whose optical axis directions are different from each other. The optical axis direction of the first light source is directed towards the tip of the boom more than that of the second light source, and the optical axis direction of the second light source is directed towards the base end of the boom more than that of the first light source. The lighting control unit performs a first control to control the illuminance of the first light source to be lower than when the arm is in a dump range set on the arm dump direction side of the swingable range when the arm is in a cloud range set on the arm cloud direction side of the swingable range, and a second control to control the illuminance of the second light source to be lower than when the arm is in the cloud range when the arm is in the dump range, and when the boom is swinging above a predetermined set position, regardless of the operating state of the arm, the illuminance of the first light source is controlled to be lower than when the boom is below the set position, and the illuminance of the second light source is controlled to be higher than when the boom is below the set position.

7. The work machine according to claim 2, further comprising a second switching operation unit for enabling and disabling the first to third controls of the lighting control unit.

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

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

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

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