Work machinery

Abstract

To provide a work machine allowing an objective place of a lower structure to be adequately lighted up regardless of a rotation angle of an upper structure.SOLUTION: A work machine is provided with: a self-travelable lower traveling body (2); an upper structure supporting a cab; rotating wheels (10) having inner wheels fixed on an upper surface of the lower traveling body (2) and outer wheels fixed on a lower surface of the upper structure and rotatably supporting the upper structure with respect to the lower traveling body (2); and strings-like lighting devices (20) extending in a circumferential direction along an outer peripheral surface of the outer wheels to emit light outward in a radial direction of the rotating wheels (10).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work machine including a lower traveling body and an upper rotating body. [Background technology]

[0002] Generally, a hydraulic excavator, which is a typical example of a work machine, is composed of a self-propelled lower traveling body, an upper rotating body that supports a cab, a slewing ring that supports the upper rotating body so that it can swivel relative to the lower traveling body, and a front device that is mounted on the front side of the upper rotating body so that it can be raised and lowered. In such a hydraulic excavator, the operator accesses the cab using steps mounted on the four corners of the lower traveling body, but there is a problem in that the steps are difficult to see at night or in dark places.

[0003] To solve this problem, Patent Document 1 discloses a hydraulic excavator in which an ascent light that illuminates the operator's ascent path is installed on the upper rotating body. Hydraulic excavators in which lighting is installed on the upper rotating body are also disclosed in Patent Documents 2 and 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-240103 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-180503 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-67478 Summary of the Invention [Problem to be solved by the invention]

[0005] If lighting is installed on the upper rotating body as in Patent Documents 1 to 3, the steps may not be properly illuminated depending on the rotation angle of the upper rotating body. On the other hand, a method of installing lighting on the lower running body to illuminate the steps regardless of the rotation angle of the upper rotating body is also conceivable. In this case, an electrical joint or the like must be installed at the center of the rotating ring to supply power from a power source installed on the upper rotating body to the lighting installed on the lower running body, which leaves issues of increased costs and reduced reliability.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a work machine that can appropriately illuminate a desired location on a lower traveling body regardless of the rotation angle of the upper rotating body. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a work machine including a self-propelled lower traveling body, an upper rotating body supporting a cab, and a slewing ring consisting of an inner ring fixed to the upper surface of the lower traveling body and an outer ring fixed to the lower surface of the upper rotating body, and supporting the upper rotating body so that the upper rotating body can swivel relative to the lower traveling body, the work machine including a string-like light extending in a circumferential direction along the outer peripheral surface of the outer ring and irradiating light radially outward from the slewing ring. The outer ring has a circumferential groove extending in the circumferential direction along the outer peripheral surface, and the string-like illumination is disposed on the inner wall of the circumferential groove. It is characterized by the following. [Effects of the Invention]

[0008] According to the present invention, a work machine can be obtained that can appropriately illuminate a desired location on the undercarriage regardless of the rotation angle of the upper rotating body. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a hydraulic excavator. [Figure 2] FIG. 2 is a perspective view of a frame constituting a lower traveling body. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a perspective view of the main parts of the hydraulic excavator with the front working implement omitted. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] 1 is a cross-sectional view taken at the center of the hydraulic excavator in the front-rear direction, including the up-down and left-right directions. [Figure 8] FIG. 1 is a hardware configuration diagram of a hydraulic excavator. [Figure 9] FIG. 6 is a perspective view of a main part of a hydraulic excavator that is a modified example of FIG. 5. [Figure 10] FIG. 5 is a cross-sectional view of a main part of a slewing ring which is a modified example of FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a hydraulic excavator 1 (work machine) according to the present invention will be described with reference to the drawings. Specific examples of the work machine are not limited to the hydraulic excavator 1, but may include a crane, a forest work vehicle, or the like, as long as it is equipped with a lower traveling body 2 and an upper rotating body 3. Furthermore, unless otherwise specified, the terms front, back, left, and right in this specification are based on the viewpoint of an operator who is riding on and operating the hydraulic excavator 1.

[0011] Fig. 1 is a side view of a hydraulic excavator 1. As shown in Fig. 1, the hydraulic excavator 1 includes a lower traveling structure 2 and an upper rotating structure 3 supported by the lower traveling structure 2.

[0012] The lower traveling body 2 is equipped with a pair of left and right crawler devices 4, which are endless tracks. The pair of left and right crawler devices 4 are rotated independently by driving a traveling motor 4a (see FIG. 2). As a result, the hydraulic excavator 1 travels. However, the lower traveling body 2 may be of a wheeled type instead of the crawler devices 4.

[0013] FIG. 2 is a perspective view of the frame that constitutes the lower traveling body 2. As shown in FIG. 2, the lower traveling body 2 is composed of a center frame 2C and a pair of left and right side frames 2L, 2R. The center frame 2C is located in the center of the lower traveling body 2. The center frame 2C rotatably supports the upper rotating body 3 via a slewing ring 10. The side frames 2L, 2R are disposed at the left and right ends of the center frame 2C. The side frames 2L, 2R extend in the front-rear direction. Each of the side frames 2L, 2R rotatably supports a crawler device 4.

[0014] As shown in FIG. 1, steps 2a and 2b are provided on the outer surface of the side frame 2L. The steps 2a and 2b protrude outward (to the left) from the outer surface of the side frame 2L at positions spaced apart in the front-to-rear direction. The steps 2a and 2b are used as footholds for an operator getting in and out of the cab 8. That is, the operator steps on the steps 2a and 2b to get in and out of the cab 8. The same applies to the side frame 2R.

[0015] The crawler devices 4 are supported by a pair of left and right side frames 2L, 2R, respectively. The left and right crawler devices 4 rotate independently, allowing the hydraulic excavator 1 to move forward, backward, and turn. Since the left and right crawler devices 4 have the same configuration, the crawler device 4 supported by the left side frame 2L will be described in detail below. As shown in Figures 1 and 2, the crawler device 4 mainly includes a travel motor 4a, drive wheels 4b, driven wheels 4c, crawler belts 4d, and a plurality of guide rollers 4e.

[0016] The traveling motor 4a is supported at the rear end of the side frame 2L. The traveling motor 4a generates driving force when hydraulic oil stored in a hydraulic oil tank (not shown) is supplied from a hydraulic pump (not shown).

[0017] The drive wheels 4b are rotatably supported at the rear ends of the side frames 2L. The drive wheels 4b rotate by the driving force of the travel motor 4a. The driven wheels 4c are rotatably supported at the front ends of the side frames 2L. That is, the drive wheels 4b and the driven wheels 4c are rotatably supported by the side frames 2L at positions spaced apart in the front-to-rear direction.

[0018] The crawler belt 4d is configured in the shape of an endless loop. The crawler belt 4d is stretched over the drive wheels 4b and the driven wheels 4c. The lower side of the crawler belt 4d (the portion between the lower ends of the drive wheels 4b and the driven wheels 4c) comes into contact with the ground. The rotation of the drive wheels 4b is transmitted to the crawler belt 4d, causing it to rotate between the drive wheels 4b and the driven wheels 4c. The rotation of the crawler belt 4d is also transmitted to the driven wheels 4c, causing them to rotate.

[0019] The guide rollers 4e are arranged between the drive wheels 4b and the driven wheels 4c. The guide rollers 4e are rotatably supported by the side frames 2L at positions spaced apart in the front-rear direction. The guide rollers 4e abut against the inner circumferential surface of the crawler belt 4d. The guide rollers 4e rotate in conjunction with the rotation of the crawler belt 4d.

[0020] The upper rotating body 3 is rotatably supported on the lower traveling body 2 by a slewing ring 10. The upper rotating body 3 rotates relative to the lower traveling body 2 by the driving force of a swing motor 3a (see FIG. 8). The upper rotating body 3 mainly comprises a swing frame 5 serving as a base, a front work implement 6 (working device) attached to the front center of the swing frame 5 so as to be rotatable in the vertical direction, a counterweight 7 arranged at the rear of the swing frame 5, a cab 8 (operator's seat) arranged on the front left side of the swing frame 5, and an engine building 9.

[0021] The slewing frame 5 constitutes the lower part of the upper slewing body 3. A slewing ring 10 is disposed on the underside of the slewing frame 5. The slewing frame 5 supports, on its upper surface, a front working implement 6, a counterweight 7, a cab 8, and an engine building 9. Furthermore, when the hydraulic excavator 1 is viewed from above in the vertical direction, the slewing frame 5 extends to an extent that covers the entire slewing ring 10.

[0022] The front working implement 6 is supported by the revolving frame 5 at the front end and in the center in the left-right direction. The front working implement 6 includes a boom 6a supported on the upper revolving body 3 so that it can be raised and lowered, an arm 6b rotatably supported at the end of the boom 6a, a bucket 6c rotatably supported at the end of the arm 6b, a hydraulic cylinder 6d that drives the boom 6a, a hydraulic cylinder 6e that drives the arm 6b, and a hydraulic cylinder 6f that drives the bucket 6c. A counterweight 7 is supported at the rear end of the revolving frame 5. The counterweight 7 is a heavy object that is arc-shaped when viewed from above and is used to balance the weight of the front working implement 6.

[0023] The cab 8 is supported by the revolving frame 5 at the front end of the revolving frame 5 on one side in the left-right direction (the left side in the example of FIG. 1). In other words, the cab 8 is adjacent to the front working implement 6 in the left-right direction of the hydraulic excavator 1. An internal space is formed in the cab 8 for an operator to ride in and operate the hydraulic excavator 1. A seat for the operator to sit in and operating devices to be operated by the operator seated in the seat are arranged in the internal space of the cab 8.

[0024] The operating device accepts operations by the operator to operate the hydraulic excavator 1. When the operator operates the operating device, the lower traveling body 2 travels, the upper rotating body 3 rotates, and the front working implement 6 operates. The operating device includes at least a key switch 33 and a gate lock lever 34, which will be described later with reference to FIG. 8. Although not shown, the operating device may further include a swing lever, a front operating lever, a steering wheel, an accelerator pedal, a brake pedal, switches, etc.

[0025] The cab 8 is also provided with an opening / closing door 8a on its left side (the side opposite the front work implement 6). The cab 8 is also provided with a front window 8b at the front, a left window 8c on the left side, a right window 8d on the right side, and a rear window (not shown) at the back. That is, the operator opens the opening / closing door 8a to get in and out of the cab 8, and can see the outside from inside the cab 8 through the windows 8b to 8d.

[0026] The engine building 9 is supported on the revolving frame 5 behind the front work implement 6 and the cab 8 and in front of the counterweight 7. The engine building 9 has an internal space that houses a heat exchanger, a cooling fan, a generator, a battery, etc. in addition to the engine 9a and hydraulic circuit 9b shown in FIG. 8. The engine 9a generates driving force for operating the hydraulic excavator 1. The hydraulic circuit 9b uses the driving force of the engine 9a to supply hydraulic oil to the traveling motor 4a, the swing motor 3a, and the hydraulic cylinders 6d, 6e, and 6f.

[0027] The hydraulic excavator 1 also includes headwork lights 6g and 8e. The headwork lights 6g and 8e use power supplied from a battery to illuminate the forward field of view of the operator sitting in the cab 8. In this embodiment, the headwork light 6g is installed on the side of the boom 6a, and the headwork light 8e is installed at the upper front end of the cab 8. However, the installation locations and number of the headwork lights 6g and 8e are not limited to those shown in the example of FIG. 1.

[0028] 3 is a cross-sectional view of the slewing ring 10. The slewing ring 10 supports the upper slewing body 3 so that it can slew relative to the lower running body 2. The slewing ring 10 is disposed between the upper surface of the lower running body 2 and the lower surface of the upper slewing body. As shown in FIG. 3, the slewing ring 10 is composed of an inner ring 11, an outer ring 12, and a plurality of balls 13.

[0029] The inner ring 11 and the outer ring 12 have a ring-shaped outer shape. The inner ring 11 is disposed inside the outer ring 12 and is fixed to the upper surface of the lower running body 2. The outer ring 12 is disposed outside the inner ring 11 and is fixed to the lower surface of the upper rotating body 3 (more specifically, the rotating frame 5). A plurality of balls 13 are arranged in the circumferential direction between the outer peripheral surface of the inner ring 11 and the inner peripheral surface of the outer ring 12. The rotation of the outer ring 12 relative to the inner ring 11 causes the plurality of balls 13 to roll (rotate and revolve).

[0030] Additionally, the inner ring 11 has internal teeth 14 formed around the entire circumference of its inner peripheral surface. A drive gear (not shown) attached to the output shaft of the swing motor 3a is meshed with the internal teeth 14. As the swing motor 3a rotates, the drive gear meshed with the internal teeth 14 revolves along the inner ring 11. This causes the upper swing body 3 to swing relative to the lower running body 2.

[0031] FIG. 4 is a cross-sectional view of a main part of the slewing ring 10. As shown in FIG. 4, a circumferential groove 15 is formed along the outer peripheral surface 12a of the outer ring 12. The circumferential groove 15 is a portion of the outer peripheral surface 12a of the outer ring 12 that is recessed radially inward of the slewing ring 10. The circumferential groove 15 is a ring-shaped portion formed around the entire circumference of the outer peripheral surface 12a of the outer ring 12. The circumferential groove 15 is composed of a back wall 16 and a pair of side walls 17a, 17b. A string-like light 20 is attached inside the circumferential groove 15.

[0032] The rear wall 16 is a ring-shaped wall surface that extends concentrically with the outer peripheral surface 12a of the outer ring 12, radially inward of the slewing ring 10 from the outer peripheral surface 12a of the outer ring 12. The pair of side walls 17a, 17b are wall surfaces that extend in the circumferential direction of the outer ring 12. The pair of side walls 17a, 17b also connect the outer peripheral surface 12a of the outer ring 12 and the rear wall 16.

[0033] The string-like light 20 is arranged inside the circumferential groove 15. The string-like light 20 is ring-shaped and arranged along the entire circumference of the outer ring 12 along the circumferential groove 15. The number of string-like lights 20 arranged in the circumferential groove 15 is not limited to one, and multiple string-like lights 20 may be arranged in the vertical direction. The string-like light 20 mainly comprises a substrate 21, multiple LED elements 22, molded resin 23, and lead wires 24.

[0034] The substrate 21 is a strip-shaped member that circles the outer ring 12 along the rear wall 16 of the circumferential groove 15. The substrate 21 is fixed to the rear wall 16 by, for example, an adhesive 25. The LED elements 22 are arranged on the surface of the substrate 21 at predetermined intervals in the circumferential direction. The LED elements 22 are electrically connected in series. The molded resin 23 covers the entire LED elements 22. The molded resin 23 is made of a translucent material (e.g., transparent resin or translucent resin) to transmit light output from the LED elements 22. The lead wires 24 connect the LED elements 22 to a battery mounted on the upper rotating body 3.

[0035] That is, the string lighting 20 emits light using power supplied from a battery to the LED elements 22 through the lead wire 24. Furthermore, because the upper rotating body 3 and the outer wheel 12 rotate integrally, the lead wire 24 is not pulled or loosened as the upper rotating body 3 rotates. That is, in this embodiment, there is no need for a mechanism to pay out or reel in the lead wire 24 as the upper rotating body 3 rotates.

[0036] The string light 20 outputs light radially outward from the slewing ring 10 around the entire circumference of the slewing ring 10. More specifically, the optical axis L (center line) of the light output from the string light 20 is parallel to the radial direction of the slewing ring 10 (i.e., the rotation plane of the upper rotating body 3). That is, as shown in FIG. 7 , the light output from the string light 20 passes between the upper surface of the lower traveling body 2 and the lower surface of the upper rotating body 3 and is output to the outside of the hydraulic excavator 1. Furthermore, the light output from the string light 20 is diffused light. More specifically, the light output from the string light 20 is diffused at a predetermined diffusion angle θ (e.g., θ = 120°) around the optical axis L.

[0037] The distance between the outer peripheral surface 12a of the outer ring 12 and the rear wall 16 in the radial direction of the swivel ring 10 (hereinafter referred to as the "depth D of the circumferential groove 15") is set to be greater than the thickness of the string-like lighting 20 (for example, D = 5 mm). In other words, the depth D of the circumferential groove 15 is set to a depth at which the tip of the molded resin 23 is positioned inside the outer peripheral surface 12a of the outer ring 12. Furthermore, the distance between the pair of side walls 17a, 17b in the thickness direction of the swivel ring 10 (hereinafter referred to as the "width W of the circumferential groove 15") is set to a width that does not block the diffused light. In other words, the width W of the circumferential groove 15 is set appropriately depending on the combination of the diffusion angle θ of the diffused light and the depth D of the circumferential groove 15.

[0038] Fig. 5 is a perspective view of essential parts of the hydraulic excavator 1 with the front working implement 6 omitted. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5. As shown in Figs. 5 and 6, the revolving frame 5 extends forward of the front end of the revolving ring 10 (in other words, the string light 20). Therefore, light that diffuses from the string light 20 in front of and above the hydraulic excavator 1 is blocked by the revolving frame 5 and does not enter the interior of the cab 8 through the right window 8d.

[0039] Fig. 7 is a cross-sectional view including the up-down and left-right directions at the center in the fore-and-aft direction of the hydraulic excavator 1. As shown in Fig. 7, a gap is formed in the up-down direction between the upper side of the crawler 4d (the portion between the upper ends of the drive wheel 4b and the driven wheel 4c) and the upper surfaces of the side frames 2L, 2R. Therefore, light that is diffused downward and to the left and right of the hydraulic excavator 1 from the string light 20 passes through the gap between the upper side of the crawler 4d and the upper surfaces of the side frames 2L, 2R, and illuminates the steps 2a, 2b.

[0040] Fig. 8 is a hardware configuration diagram of the hydraulic excavator 1. As shown in Fig. 8, the hydraulic excavator 1 includes a controller 30. The controller 30 controls the overall operation of the hydraulic excavator 1. The controller 30 includes, for example, a CPU (Central Processing Unit) 31 and a memory 32. The controller 30 realizes the processing described below by having the CPU 31 read and execute program code stored in the memory 32.

[0041] However, the specific configuration of the controller 30 is not limited to this, and may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0042] Furthermore, the controller 30 may include an engine controller that controls the operation of the engine 9a, and a control controller that controls other components (e.g., the hydraulic circuit 9b, the string lights 20, etc.) of the hydraulic excavator 1. However, in this embodiment, the engine controller and the control controller are not distinguished from each other and are referred to as the "controller 30."

[0043] The controller 30 is connected to a key switch 33, a gate lock lever 34, pressure sensors 35 and 36, the engine 9a, the hydraulic circuit 9b, and the string light 20. The controller 30 controls the operation of the engine 9a, the hydraulic circuit 9b, and the string light 20 based on various signals output from the key switch 33, the gate lock lever 34, and the pressure sensors 35 and 36.

[0044] The key switch 33 is a switch that starts the engine 9a. The state (START, ON, OFF) of the key switch 33 can be switched, for example, by turning a key inserted in a key cylinder. The key switch 33 then outputs a state signal indicating the current state to the controller 30. When the key switch 33 is switched from OFF to START, the controller 30 starts the engine 9a. When the key switch 33 is switched from START to ON, the controller 30 continues to drive the engine 9a and supplies power to each part of the hydraulic excavator 1. When the key switch 33 is switched from ON to OFF, the controller 30 stops the engine 9a.

[0045] The gate lock lever 34 is configured so that it can be switched by an operator between an allowable position that allows operation of the hydraulic actuators (travel motor 4a, swing motor 3a, hydraulic cylinders 6d, 6e, 6f) and a restrictive position that restricts operation of the hydraulic actuators. The gate lock lever 34 outputs a position signal that indicates its current position to the controller 30. When the gate lock lever 34 is in the restrictive position, the controller 30 restricts the supply of hydraulic oil from the hydraulic circuit 9b to the hydraulic actuators. On the other hand, when the gate lock lever 34 is in the allowable position, the controller 30 allows the supply of hydraulic oil from the hydraulic circuit 9b to the hydraulic actuators. The restriction and permission of the supply of hydraulic oil can be switched between by opening and closing a solenoid valve included in the hydraulic circuit 9b, for example.

[0046] In other words, even if the operating device is operated when the gate lock lever 34 is in the restricting position, the lower traveling body 2 will not travel, the upper rotating body 3 will not rotate, and the front working implement 6 will not be raised or lowered. On the other hand, if the operating device is operated when the gate lock lever 34 is in the permissible position, the lower traveling body 2 will travel, the upper rotating body 3 will rotate, and the front working implement 6 will be raised or lowered.

[0047] The pressure sensor 35 detects the pressure of the hydraulic oil supplied to the travel motor 4a and outputs a pressure signal indicating the detected pressure to the controller 30. The pressure sensor 36 detects the pressure of the hydraulic oil supplied to the swing motor 3a and outputs a pressure signal indicating the detected pressure to the controller 30. The pressure sensors 35 and 36 are provided in the hydraulic oil flow path from the hydraulic pump to the travel motor 4a or swing motor 3a.

[0048] The key switch 33, the gate lock lever 34, and the pressure sensors 35 and 36 are examples of status sensors that detect the status of the hydraulic excavator 1. That is, the status signal output from the key switch 33 indicates whether the engine 9a has started or not. Furthermore, the position signal output from the gate lock lever 34 indicates whether the hydraulic actuator is operable or not. Furthermore, the pressure signals output from the pressure sensors 35 and 36 indicate whether the traveling motor 4a or the swing motor 3a is actually operating or not. However, specific examples of the status sensors are not limited to the above examples.

[0049] The controller 30 then changes the color of the light output from the string lighting 20 in accordance with the state of the hydraulic excavator 1 detected by the state sensor. The controller 30 changes the color of the light output from the string lighting 20, for example, by outputting a control signal to a control circuit mounted on the string lighting 20. The configuration for changing the color of the output light is already well known, so a detailed description will be omitted.

[0050] For example, when the key switch 33 is ON and the gate lock lever 34 is in the restricted position, the controller 30 causes the string lighting 20 to output light of a first color (e.g., green). When the key switch 33 is ON, the gate lock lever 34 is in the permitted position, and the pressure detected by both the pressure sensors 35 and 36 is less than the threshold, the controller 30 causes the string lighting 20 to output light of a second color (e.g., red) different from the first color. When the key switch 33 is ON, the gate lock lever 34 is in the permitted position, and the pressure detected by at least one of the pressure sensors 35 and 36 is equal to or greater than the threshold, the controller 30 causes the string lighting 20 to output light of a third color (e.g., blue) different from the first and second colors.

[0051] Furthermore, the controller 30 may supply power from the battery to the string lights 20 even while the engine 9a is stopped. As one example, the controller 30 may supply power to the string lights 20 while the opening and closing door 8a is open. As another example, the controller 30 may start or stop the supply of power to the string lights 20 in accordance with the operation of a remote control switch carried by the operator of the hydraulic excavator 1. As yet another example, the controller 30 may continue to supply power to the string lights 20 until a predetermined time (e.g., 30 seconds) has elapsed since the key switch 33 was switched OFF.

[0052] According to the above embodiment, the string lighting 20 installed between the lower traveling body 2 and the upper rotating body 3 can illuminate the entire periphery of the hydraulic excavator 1 (particularly the steps 2a and 2b). This ensures visibility for the operator getting in and out of the cab 8 even at night or in dark places (for example, forest roads, inside the hold of a transport ship, etc.).

[0053] Furthermore, when traveling at night on narrow forest roads or in places surrounded by obstacles, the operator needs to visually check the area around the crawler belt 4d while traveling the hydraulic excavator 1. In this case as well, the string lighting 20 illuminates the entire circumference of the hydraulic excavator 1, thereby preventing the crawler belt 4d from going beyond the width of the road or coming into contact with obstacles.

[0054] Components located on the optical path from the string lighting 20 to the steps 2a, 2b may be processed to improve light reflection. More specifically, the reflectivity of the upper surfaces of the side frames 2L, 2R may be increased. Methods for increasing reflectivity include polishing the upper surfaces of the side frames 2L, 2R, attaching a sticker to them, or painting them, for example.

[0055] Furthermore, in the above embodiment, an example has been described in which the string lighting 20 is provided around the entire circumference of the slewing ring 10, but the installation range of the string lighting 20 is not limited to this. For example, it is sufficient that the string lighting 20 illuminates at least a 90° range centered on the left side of the hydraulic excavator 1 and a 90° range centered on the right side of the hydraulic excavator 1 when the rotation angle of the upper rotating body 3 is 0° (the front working implement 6 faces the forward direction of the lower traveling body 2).

[0056] Furthermore, according to the above embodiment, the light diffusing upward from the string light 20 is blocked by the revolving frame 5 and does not enter the cab 8, thereby reducing the adverse effect on the visibility of the operator in the cab 8. Note that the configuration of FIG. 9 may be adopted to more effectively prevent the light output from the string light 20 from entering the cab 8. FIG. 9 is a perspective view of a main part of the hydraulic excavator 1 which is a modified example of FIG. 5.

[0057] As shown in FIG. 9, the upper revolving body 3 (more specifically, the revolving frame 5) may further include a shading plate 5a (shading portion) that blocks the optical path from the string light 20 to the cab 8 (more specifically, the right window 8d). The shading plate 5a is a plate-like member that protrudes from the revolving frame 5 at a position intervening in the optical path from the string light 20 to the cab 8. Note that the "optical path from the string light 20 to the cab 8" is not limited to a linear (in other words, the shortest) optical path between the string light 20 and the cab 8, but also includes an optical path in which light output from the string light 20 is reflected by other components (for example, the center frame 2C, etc.) and reaches the cab 8.

[0058] Furthermore, according to the above embodiment, by changing the color of light output from the string lighting 20 in accordance with the state of the hydraulic excavator 1, it is possible to allow surrounding workers to understand the state of the hydraulic excavator 1. Furthermore, since the light from the string lighting is output from the shadow of the upper rotating body 3, which is less susceptible to the influence of sunlight, it is possible to appropriately understand the state of the hydraulic excavator 1 not only at night but also in the daytime. Note that the controller 30 may change the light output mode (for example, the blinking interval, illuminance, etc.) instead of the color of light output from the string lighting 20.

[0059] Furthermore, according to the above embodiment, the string lights 20 are housed in the circumferential groove 15 formed in the outer peripheral surface 12a of the outer ring 12, thereby preventing foreign matter (e.g., earth and sand, branches and leaves, etc.) generated during operation of the hydraulic excavator 1 from coming into contact with the string lights 20. This reduces the possibility of damage to the string lights 20. Note that the configuration of FIG. 10 may be adopted to appropriately protect the string lights 20. FIG. 10 is a cross-sectional view of a main part of a slewing ring 10 that is a modified example of FIG. 4.

[0060] The circumferential groove 15 shown in FIG. 10(A) includes a first circumferential groove 15a and a second circumferential groove 15b. The first circumferential groove 15a is recessed radially inward from the outer peripheral surface 12a of the outer ring 12. The second circumferential groove 15b is recessed radially inward from the back wall of the first circumferential groove 15a at the center of the first circumferential groove 15a in the thickness direction of the slewing ring 10. That is, the circumferential groove 15 shown in FIG. 10(A) is recessed in two stages from the outer peripheral surface 12a of the outer ring 12. The width W1 of the first circumferential groove 15a is set larger than the width W2 of the second circumferential groove 15b. The depth D1 of the first circumferential groove 15a is set larger than the thickness of a protective plate 18 (protective member) (described later) (for example, D1 = 1 mm). Furthermore, the depth D2 of the second circumferential groove 15b is set to be equal to or greater than the thickness of the string-like illuminator 20 (for example, D2=5 mm).

[0061] The string light 20 shown in FIG. 10(A) is disposed on the back wall 16 of the second circumferential groove 15b. A protective plate 18 is disposed in the first circumferential groove 15a. The protective plate 18 is cylindrical and disposed around the entire circumference of the outer ring 12. The protective plate 18 covers the string light 20 from the radial outside of the slewing ring 10. The protective plate 18 is formed of a translucent material (e.g., transparent resin) that transmits the light output from the string light 20. That is, the protective plate 18 transmits the light output from the string light 20 and also serves to prevent foreign matter (e.g., soil, sand, branches, leaves, etc.) generated during operation of the hydraulic excavator 1 from coming into contact with the string light 20.

[0062] The circumferential groove 15 shown in Fig. 10(B) is composed of the outer peripheral surface 12a of the outer ring 12 and a pair of ring members 19a, 19b. That is, in Fig. 10(B), the outer peripheral surface 12a of the outer ring 12 forms the back wall 16 of the circumferential groove 15. The pair of ring members 19a, 19b are each fitted onto the outer ring 12 at positions spaced apart in the thickness direction of the slewing ring 10. Furthermore, the pair of ring members 19a, 19b protrude outward in the radial direction of the slewing ring 10 from the outer peripheral surface 12a of the outer ring 12. That is, in Fig. 10(B), the inner surfaces of the pair of ring members 19a, 19b facing each other form the side walls 17a, 17b of the circumferential groove 15.

[0063] The pair of ring members 19a, 19b have notches cut out along the entire circumference at the corners between the outer and inner surfaces. The notched portions of the pair of ring members 19a, 19b form a first circumferential groove 15a. The portion radially inward of the slewing ring 10 from the first circumferential groove 15a forms a second circumferential groove 15b. Furthermore, a protective plate 18 is disposed in the first circumferential groove 15a, and a string-like light 20 is disposed on the back wall 16 of the second circumferential groove 15b.

[0064] The configuration of Fig. 10(B) can also achieve the same effects as those of Fig. 4 and Fig. 10(A). That is, the circumferential groove 15 is not limited to being formed by recessing the outer peripheral surface 12a of the outer ring 12, but may be formed by a pair of ring members 19a, 19b fitted onto the outer ring 12 and the outer peripheral surface 12a of the outer ring 12. Furthermore, in Fig. 10(B), the first circumferential groove 15a and the protective plate 18 may be omitted.

[0065] The above-described embodiments are merely illustrative examples of the present invention, and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art can implement the present invention in various other forms without departing from the spirit of the present invention. [Explanation of symbols]

[0066] 1. Hydraulic excavator 2 Undercarriage 2C center frame 2L, 2R side frame Steps 2a and 2b 3 Upper rotating body 3a Swivel motor 4 Crawler device 4a Travel motor 4b Drive wheels 4c driven wheel 4d Tracks 4e Guide roller 5 Swivel frame 5a Light-shielding plate (light-shielding part) 6 Front work equipment 6a Boom 6b Arm 6c Bucket 6d, 6e, 6f hydraulic cylinders 6g,8e front work light 7 Counterweight 8 Cab 8a Opening and closing door 8b Front window 8c Left window 8d Right window 9 Engine Building 9a engine 9b Hydraulic circuit 10 Swivel ring 11 Inner Circle 12 outer ring 12a Outer surface 13 balls 14 Inner teeth 15 Circumferential groove 15a First circumferential groove 15b Second circumferential groove 16 Back wall 17a,17b side wall 18 Protective plate (protective member) 19a, 19b Ring members 20 String Lighting 21 PCB 22 LED elements 23 Molding resin 24 lead wire 25 Adhesive 30 Controllers 31 CPU 32 memory 33 key switches 34 Gate lock lever 35,36 Pressure sensor

Claims

1. a self-propelled lower traveling body; an upper rotating body supporting the cab; a slewing ring consisting of an inner ring fixed to an upper surface of the lower traveling body and an outer ring fixed to a lower surface of the upper rotating body, the slewing ring supporting the upper rotating body so that the upper rotating body can slew relative to the lower traveling body, a string-shaped light extending in a circumferential direction along an outer peripheral surface of the outer ring and emitting light radially outward from the swivel ring; the outer ring has a circumferential groove extending in a circumferential direction along an outer peripheral surface, A work machine characterized in that the string-like light is arranged on the back wall of the circumferential groove.

2. 2. The work machine according to claim 1, the circumferential groove includes a first circumferential groove and a second circumferential groove recessed inward in the radial direction of the slewing ring from a back wall of the first circumferential groove, the string-like illumination is disposed on the inner wall of the second circumferential groove, A work machine characterized in that a translucent protective member is arranged in the first circumferential groove so as to cover the string-shaped lighting from the radial outside of the slewing ring.

3. A self-propelled lower traveling body; an upper rotating body supporting the cab; a slewing ring consisting of an inner ring fixed to an upper surface of the lower traveling body and an outer ring fixed to a lower surface of the upper rotating body, the slewing ring supporting the upper rotating body so that the upper rotating body can slew relative to the lower traveling body, a string-shaped light extending in a circumferential direction along an outer peripheral surface of the outer ring and emitting light radially outward from the swivel ring; The work machine is characterized in that the upper rotating body is provided with a light blocking portion that blocks a light path from the string lighting to the cab.

Images