Excavator

Abstract

To suppress the load due to vibration on a hood that covers a prime mover.SOLUTION: An excavator according to one aspect of the present invention has a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a counterweight provided at a rear of the upper rotating body, a prime mover provided on the upper rotating body, a hood that covers the prime mover, and a rear frame supporting the hood. The rear frame is placed in front of the counterweight.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] An excavator has an upper rotating body equipped with a cabin for an operator, an engine, a counterweight, etc. Furthermore, in order to isolate the power room including the engine from the external environment, an excavator generally has a structure in which the power room is covered with an exterior cover.

[0003] However, there are cases where maintenance is required for the engine and other components in the power compartment. In such cases, since it is inefficient to remove the exterior cover, a technology has been proposed in which a hood with an opening and closing structure is provided to perform maintenance on the power compartment including the engine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 093175 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Cited Document 1, a hood covering an engine (an example of a prime mover) opens and closes in the front-to-rear direction around a hinge provided on the long side of the counterweight. In this way, one end of the hood is attached to the counterweight, and the other end is attached to a predetermined frame in front of the counterweight. However, in an excavator, the counterweight and the predetermined frame belong to different vibration systems. Therefore, if the hood is installed so that one end is attached to the counterweight and the other end is attached to the predetermined frame, vibrations from the counterweight may apply excessive loads to the hood, the hood hinge, the predetermined frame, etc.

[0006] One aspect of the present invention provides a technique for reducing the load on components that constitute a shovel. [Means for solving the problem]

[0007] A shovel according to one aspect of the present invention includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a counterweight provided at the rear of the upper rotating body, a prime mover provided on the upper rotating body, a hood covering the prime mover, and a rear frame supporting the hood, the rear frame being disposed in front of the counterweight, and the rear frame further includes a rotating frame provided on the upper rotating body below the rear frame. Plate member protruding from An engaging portion that engages with the plate member A support portion is formed on the upper end of the support member. [Effects of the Invention]

[0008] One aspect of the present invention is to suppress vibration loads on a hood that covers a prime mover. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a shovel according to an embodiment. [Figure 2] FIG. 2 is a top view schematically showing an upper rotating body of the excavator of FIG. [Figure 3] FIG. 3 is a perspective view showing the upper rotating body according to the embodiment, as seen from the upper left rear side. [Figure 4] FIG. 4 is a perspective view showing the frame structure of the upper rotating body according to the embodiment, as seen from the upper left rear side. [Figure 5] FIG. 5 is a perspective view of an upper rotating body according to the embodiment, as seen from below. [Figure 6] FIG. 6 is a perspective view showing the lower part of the rear frame according to the embodiment. [Figure 7] FIG. 7 is a perspective view showing a frame structure in the vicinity of the hood according to the embodiment. [Figure 8] FIG. 8 is a perspective view showing the inner structure of the hood according to the embodiment. [Figure 9] FIG. 9 is a perspective view showing the structure of the vicinity of the curved portion of the hood according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, non-limiting exemplary embodiments of the present invention will be described with reference to the drawings. Note that the same or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and descriptions thereof may be omitted. Furthermore, unless otherwise specified, the drawings are not intended to show the relative size ratios between members or components. Therefore, specific dimensions can be determined arbitrarily by those skilled in the art in light of the following non-limiting embodiments.

[0011] Furthermore, the embodiments described below are illustrative rather than limiting of the present invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0012] 1 is a side view of a shovel according to this embodiment. As shown in FIG. 1, the shovel 100 includes a lower traveling body 1, an upper rotating body 2, a cabin 3, a boom 4, an arm 5, and a bucket 6.

[0013] The upper rotating body 2 is rotatably mounted on the undercarriage 1 via a rotating mechanism (not shown). The cabin 3 is provided on the left front portion of the upper rotating body 2. A driver's seat is provided inside the cabin 3. The boom 4 is rotatably provided at the center of the front portion of the upper rotating body 2. The arm 5 is rotatably provided at the tip of the boom 4. The bucket 6 is an example of an end attachment and is rotatably provided at the tip of the arm 5. The bucket 6 is rotatably connected to the tip of the arm 5. An upper cover 2b is attached to the upper part of the housing 2a. In this embodiment, the upper cover 2b is divided into three parts in the vehicle width direction (Y-axis direction), and only the central part is configured to be rotatable (openable and closable) as a hood, but the entire cover may be configured to be rotatable (openable and closable). Therefore, hereinafter, the term "hood" refers to the rotatable (openable and closable) part, regardless of whether it is a part or the whole.

[0014] FIG. 2 is a top view schematically showing the upper rotating body 2 of the excavator 100. As shown in FIG. 2, a prime mover arrangement space 7 is formed within the housing 2a of the upper rotating body 2, and a diesel engine 8 and a generator 8a are installed within the prime mover arrangement space 7 as prime movers. A cooling fan 12 is installed on the Y1 side of the diesel engine 8, and a heat exchanger unit 13 including a radiator and the like is installed on the Y1 side of the cooling fan 12. In this embodiment, an example is shown in which the diesel engine 8 is used as the prime mover of the excavator 100, but this is not limited to this. For example, other internal combustion engines such as a gasoline engine or a hydrogen engine may be used as the prime mover instead of the diesel engine 8. Furthermore, an electric motor may be used as the prime mover of the excavator. In this case, the hydraulic pump 14 may be driven by an electric motor driven by power from a power storage device. A fuel cell, a lithium-ion battery, or the like may be used as the power storage device. Furthermore, the prime mover of the excavator is not limited to one, and a combination of two or more prime movers, such as an internal combustion engine and an electric motor, may be used.

[0015] A hydraulic pump 14 is installed on the Y2 side of the diesel engine 8. The rotational force of the diesel engine 8 is transmitted to the generator 8a and the cooling fan 12 via a belt 8b, and is also transmitted to the hydraulic pump 14 via a transmission.

[0016] An oil pan (not shown) for storing engine oil is provided below the diesel engine 8. An oil level gauge 8d for measuring the amount of engine oil is attached near the generator 8a of the diesel engine 8.

[0017] Furthermore, the diesel engine 8 draws in outside air through an air filter 9a and an intake pipe 9b installed outside the prime mover arrangement space 7. Furthermore, an exhaust pipe 9c is connected to the diesel engine 8, and an exhaust gas treatment device 10 that purifies nitrogen oxides (hereinafter referred to as NOx) in the engine exhaust gas is installed downstream of the exhaust pipe 9c.

[0018] In this embodiment, the exhaust gas treatment device 10 is a urea selective reduction type NOx treatment device that uses urea water as a reducing agent. The exhaust gas treatment device 10 reduces NOx in the exhaust gas by injecting urea water upstream of a reduction catalyst (not shown) provided in the exhaust pipe 9c, and this reduction reaction is promoted by the reduction catalyst to render the NOx harmless.

[0019] The urea water tank 20 is a container for storing urea water, and is disposed on the upper rotating body 2 on the opposite side (Y2 side) of the cabin 3 across the boom 4. A fuel tank 19 is disposed rearward (X2 side) of the urea water tank 20, and a hydraulic oil tank 18 is disposed rearward (X2 side) of the fuel tank 19. The hydraulic oil tank 18, the fuel tank 19, and the urea water tank 20 are installed outside the prime mover arrangement space 7. The urea water tank 20 is connected to the exhaust gas treatment device 10 via a urea water hose 69, a urea water supply pump 70, etc.

[0020] Fig. 3 is a perspective view showing the upper rotating body 2 as seen from the upper left rear side. Note that the cabin 3 mounted on the cabin mounting section 2d and the boom 4 connected to the boom connecting section 2e are not shown in Fig. 3. As shown in Fig. 3, the counterweight 2c is provided at the rear of the upper rotating body 2 (on the X2 side).

[0021] The above-mentioned prime mover arrangement space 7 is covered with a top cover 2b shown in Fig. 3. The top cover 2b includes a first plate portion 21 on the rear side, a second plate portion 22 on the front side, and a third plate portion 23 on the top surface. The first plate portion 21 has frame plates 211, 212, and 213. The frame plates 211, 212, and 213 are arranged in series in the vehicle width direction (Y1-Y2 direction).

[0022] 3 has an opening above (on the Z1 side of) the engine arrangement space 7, and a third plate portion 23 is provided to close this opening. The third plate portion 23 is divided into three parts in the vehicle width direction (Y1-Y2 direction), and has a radiator cover 231, a hood 232, and an exhaust gas treatment device cover 233.

[0023] The radiator cover 231 is provided above the heat exchanger unit 13, which includes a radiator and the like. The radiator cover 231 is formed in a plate shape. For example, when performing maintenance on the heat exchanger unit 13, an operator can attach and detach the radiator cover 231 by attaching and detaching bolts (not shown).

[0024] The exhaust gas treatment device cover 233 is provided above the exhaust gas treatment device 10. The exhaust gas treatment device cover 233 is formed in a plate shape. A tail pipe 11 is provided at the rear of the exhaust gas treatment device cover 233. For example, when performing maintenance on the exhaust gas treatment device 10, an operator can attach and detach the exhaust gas treatment device cover 233 by attaching and detaching bolts (not shown). In addition, the exhaust gas treatment device cover 233 is provided at a position higher than the hood 232 when the hood 232 is closed.

[0025] The hood 232 is provided above the diesel engine 8 so as to cover the diesel engine 8. The hood 232 is attached to the frame plate 212 by hinges 31a and 31b so as to be rotatable (openable and closable). In FIG. 3, the direction of rotation when opening the hood 232 is indicated by a white arrow. For example, when an operator measures the amount of engine oil using the oil level gauge 8d, the hood 232 can be opened or closed around the hinges 31a and 31b.

[0026] 4 is a perspective view showing the frame structure of the upper rotating body 2 as seen from the upper rear left side. In the example shown in FIG.

[0027] The rotating frame 30 includes a central right vertical member 30a and a central left vertical member 30b. The rotating frame 30 is a frame for installing the boom 4 and loading an object onto the upper rotating body 2. In order to load an object onto the upper rotating body 2, the rotating frame 30 extends in the Y1 direction from the central left vertical member 30b and also extends in the Y2 direction from the central right vertical member 30a. The rotating frame 30 also has a bottom plate 30c between the central right vertical member 30a and the central left vertical member 30b.

[0028] The central right vertical member 30a is a member that extends in the X-axis direction. The central right vertical member 30a is a member that becomes longer (higher) in the Z1 direction as it moves in the X1 direction. The upper surface (the surface facing the Z1 direction) of the central right vertical member 30a is provided with holes 30g and 30h for fixing (for example, with bolts) the counterweight 2c.

[0029] Similarly, the central left vertical member 30b is also a member that extends in the X-axis direction. The central left vertical member 30b is also a member that becomes longer (higher) in the Z1 direction as it moves in the X1 direction. Holes 30e and 30f for fixing (for example, with bolts) the counterweight 2c to the upper surface (the surface facing the Z1 direction) of the central left vertical member 30b are also provided.

[0030] In the upper revolving body 2, an air cleaner chamber 80 is formed on the revolving frame 30 on the left side (Y1 side) of the central left vertical member 30b. The air cleaner chamber 80 and the section in which the heat exchanger unit 13 and the like are mounted are spaces formed by house frames 81, 82, 83, etc., a top plate 84, and plate members 85, 86, and the air cleaner chamber 80 houses an air filter 9a and the like. The house frame is a frame that constitutes a building placed on the revolving frame 30.

[0031] Furthermore, in the upper revolving body 2, a compartment in which the exhaust gas treatment device 10 and the like are mounted is provided on the right side (Y2 side) of the central right vertical member 30a. The exhaust gas treatment device 10 and the like are housed in a space formed on the right side (Y2 side) of the central right vertical member 30a by house frames 71, 72, 73, 74, 75, 76, 77 and plate members 61, 62, 63. Furthermore, house frames 77, 78, 79 for supporting the exhaust gas treatment device cover 233 are formed above this space.

[0032] Next, a description will be given of the vicinity of the center of the revolving frame 30 that houses the diesel engine 8. As described above, the bottom plate 30c is provided near the center of the revolving frame 30.

[0033] A rear frame 41 extending upward (in the Z1 direction) is provided on the rear side (X2 side) of the bottom plate 30c. The rear frame 41 is a member disposed in front of the counterweight 2c and is provided to support the hood 232.

[0034] In the excavator 100 according to this embodiment, the hood 232 is connected to the rear frame 41. Next, the configuration of the rear frame 41 and the periphery of the rear frame 41 will be described.

[0035] In the illustrated example, the rear frame 41 is a plate member with holes punched. The material of the rear frame 41 may be any material that is strong enough to support the hood 232, and steel, for example, may be used. The rear frame 41 is further provided with a rib 32 extending in the vehicle width direction (Y1-Y2 direction) and a reinforcing plate 35. The rib 32 is provided on the rear side (X2 side) of the rear frame 41 and supports a force acting on the rear frame 41 in the vehicle width direction (Y1-Y2 direction). The reinforcing plate 35 is provided on the front side (X1 side) of the rear frame 41 and supports a force acting on the rear frame 41 in the vehicle width direction (Y1-Y2 direction).

[0036] The lower part of the rear frame 41 is fixed by bolts to a plate member 30d formed between the central right vertical member 30a and the central left vertical member 30b. In the example shown in Fig. 4, the rear frame 41 is fixed to the plate member 30d near the central right vertical member 30a with four bolts 44. Similarly, the rear frame 41 is fixed to the plate member 30d near the central left vertical member 30b with four bolts.

[0037] The plate member 30d of the revolving frame 30 is disposed vertically between the central right vertical member 30a and the central left vertical member 30b. The plate member 30d may be welded or bolted to each of the central right vertical member 30a and the central left vertical member 30b. The height of the plate member 30d (length in the Z1-Z2 direction) is approximately the same as the height of the central right vertical member 30a and the central left vertical member 30b near the plate member 30d.

[0038] Support members 41a and 41b are provided on the rear frame 41. The support members 41a and 41b are members extending in the X2 direction from a surface of the rear frame 41 facing the counterweight 2c. The rear frame 41 also has the support members 41a and 41b, and supports the frame plate 212 via the support members 41a and 41b.

[0039] Furthermore, support members 41c and 41d are provided on the lower part of the rear frame 41. The support members 41c and 41d are formed so as to abut against the plate member 30d of the revolving frame 30 provided on the upper revolving body 2. In this embodiment, the support members 41c and 41d are part of the rear frame 41, are made of the same material as the rear frame 41, and are integrated with the rear frame 41. The detailed configuration of the support members 41c and 41d will be described later.

[0040] In addition, a center frame 42 (an example of a first frame) is provided on the bottom plate 30c at a position rearward (X2 side) of the pivot shaft located near the center of the pivot frame 30 and forward (X1 side) of the rear frame 41.

[0041] In the illustrated example, the center frame 42 is a frame member extending upward (in the Z1 direction). The center frame 42 may be made of any material that is strong enough to support the force transmitted by the front and rear frames 43a and 43b (described later), and may be made of steel, for example.

[0042] The center frame 42 is fixed to the central right vertical member 30a and the central left vertical member 30b via support members 51. The central right vertical member 30a and the central left vertical member 30b are members that become longer (higher) in the Z1 direction as they move in the X1 direction. Therefore, the center frame 42 can be fixed to the central right vertical member 30a and the central left vertical member 30b at a location that is higher than the location near the rear frame 41.

[0043] Furthermore, the center frame 42 is provided with two ribs 33 and 34 extending in the vehicle width direction (Y1-Y2 direction). The ribs 33 and 34 are provided at different positions in the vertical direction (Z1-Z2 direction). For example, the rib 33 is provided near the bottom plate 30c, and the rib 34 is provided above the rib 33 in the Z1 direction. The ribs 33 and 34 support a force acting on the center frame 42 in the vehicle width direction (Y1-Y2 direction).

[0044] Front and rear frames are provided between the center frame 42 and the rear frame 41. In this embodiment, an example in which two front and rear frames 43a, 43b are provided will be described, but three or more frames, or one frame may be provided.

[0045] The front and rear frames 43a, 43b are pipe members extending in the X-axis direction and connect the top cover 46, center frame 42, and rear frame 41. While this embodiment describes an example in which the front and rear frames 43a, 43b are formed from pipe members, the present invention is not limited to pipe members and they may be formed from solid round bars. Furthermore, the front and rear frames 43a, 43b may be formed from any material that can ensure strength, and steel, for example, may be used. With this configuration, a force acting on the rear frame 41 in the front-rear direction (X1-X2 direction) is supported by the center frame 42, which is connected via the front and rear frames 43a, 43b and top cover 46.

[0046] A top cover 46 is provided at the upper end (the end in the Z1 direction) of the center frame 42. The top cover 46 is connected to the ends of the front and rear frames 43a, 43b and also functions as a foothold for workers. For example, a worker can perform various tasks by opening and closing the hood 232 while standing on the top cover 46.

[0047] In the excavator 100 according to this embodiment, the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, the top cover 46, and the bottom plate 30c form a box (rectangular parallelepiped) frame structure. As a result, a force acting on any one or more of the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, and the bottom plate 30c is supported by other components forming the frame structure.

[0048] Furthermore, since the vibration system is made up of the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, the top cover 46, and the bottom plate 30c, the frame structure can suppress vibrations from being applied to the hood 232 from other components such as the counterweight 2c.

[0049] By connecting the hood 232 to the rear frame 41, the hood 232 is incorporated into a vibration system made up of the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, the top cover 46, and the bottom plate 30c. This makes the hood 232 less susceptible to the vibration of the counterweight 2c. In addition, because the force acting on the hood 232 is supported by the combination of the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, the top cover 46, and the bottom plate 30c, it is possible to prevent the load from concentrating on only one of the front and rear frames 43a, 43b, the center frame 42, the rear frame 41, the top cover 46, and the bottom plate 30c.

[0050] 5 is a perspective view of the upper rotating body 2 seen from below. For example, when a worker crawls under the upper rotating body 2 to perform maintenance on the upper rotating body 2, the worker can see the underside of the upper rotating body 2 as shown in FIG.

[0051] 5, an opening ZZ accessible to an operator is formed on the underside of the upper revolving body 2 of the excavator 100, between the bottom plate 30c and the counterweight 2c included in the revolving frame 30. The bolts 44, 45 (an example of an engaging portion) that fasten (engage) the rear frame 41 to the revolving frame 30 (to the plate member 30d that is a part of the revolving frame 30) are provided near the opening ZZ. Therefore, an operator can attach and detach the bolts 44, 45 that fasten the rear frame 41 through the opening ZZ.

[0052] For example, a situation may arise in which it is necessary to replace the rear frame 41. In such a situation, if the rear frame 41 cannot be replaced without removing the counterweight 2c, the burden on the worker increases. In contrast, in this embodiment, the above-described configuration allows the rear frame 41 to be attached and detached without removing the counterweight 2c, thereby reducing the burden on the worker.

[0053] FIG. 6 is a perspective view showing the lower part of the rear frame 41 according to this embodiment. As shown in FIG. 6, the support members 41c and 41d are members that protrude in the X2 direction from the rear surface of the rear frame 41 (the surface facing the counterweight 2c). The lower ends (sides in the Z2 direction) of the support members (an example of a support portion) 41c and 41d are formed in a convex shape. The convex tips of the support members 41c and 41d are formed to contact the upper end (sides in the Z1 direction) of the plate member 30d. As a result, when the rear frame 41 is attached to the top of the excavator 100, the tips of the support members 41c and 41d come into contact with the upper end of the plate member 30d, thereby positioning the rear frame 41 with respect to the plate member 30d.

[0054] That is, the rear frame 41 is supported by bolts 44 and 45 fastened to the plate member 30d, and is also supported from the upper end of the plate member 30d via support members 41c and 41d provided on the rear frame 41.

[0055] The rear frame 41 is fixed to the plate member 30d of the revolving frame 30 with bolts, but if the rear frame 41 and other components are fixed only with bolts, the weight (vertical shear load) of the rear frame 41 and other components is concentrated on the bolts, increasing the load on the bolts. Therefore, in this embodiment, support members 41c and 41d are provided on the rear frame 41. As a result, the weight of the rear frame 41 (vertical shear load) is applied to the bolts and the upper end of the plate member 30d that contacts the support members 41c and 41d. This configuration reduces the load on the bolts.

[0056] That is, in the excavator 100 according to this embodiment, the load acting on the plate member 30d that supports the rear frame 41 can be reduced, and the stability of the rear frame 41 can be improved.

[0057] Fig. 7 is a perspective view showing the frame structure near the hood 232 according to this embodiment. As shown in Fig. 7, the front and rear frames 43a, 43b are fixed to the rear frame 41 by bolting.

[0058] A handle 92 is provided on the hood 232. An operator can grip the handle 92 and then open or close the hood 232 in the vertical direction (Z1-Z2 direction) around the hinges 31a and 31b as the center of rotation.

[0059] A damper mechanism 91 is provided between the hood 232 and the rear frame 41. Therefore, when the hood 232 is opened or closed about the hinges 31a, 31b, the damper mechanism 91 functions, and the damper mechanism 91 can suppress abrupt opening and closing of the hood 232. Therefore, the damper mechanism 91 can improve safety when an operator opens or closes the hood 232.

[0060] Moreover, the shovel 100 according to this embodiment is provided with a support member 93 between the frame plate 212 and the rear frame 41. The shovel 100 according to this embodiment can improve the strength of the frame plate 212 by using the support member 93.

[0061] Furthermore, a plurality of ribs (for example, ribs 95, 96) are provided on the inside of the hood 232. The strength of the hood 232 can be improved by the plurality of ribs (for example, ribs 95, 96).

[0062] Next, a description will be given of the structure of the hood 232. Figure 8 is a perspective view showing the structure inside the hood 232.

[0063] 8, hood 232 is formed to include top surface portion 301, curved portion 302, and side surface portion 303. Hood 232 is formed to include curved portion 302 by bending a single plate material or the like.

[0064] Furthermore, the hood 232 is provided on its inside with ribs 95, 96, 97a, 97b extending in the front-rear direction (X1-X2 direction) and ribs 98, 99 extending in the vehicle width direction (Y1-Y2 direction).

[0065] The rib 98 is formed, for example, from an L-shaped steel, and the rib 99 is formed, for example, from a hat-shaped steel. A hat-shaped steel is a steel material having a hat-shaped cross section.

[0066] The ribs 97a and 97b are formed of hat-shaped steel. However, the ribs 97a and 97b may be made of a material other than hat-shaped steel as long as they have the strength to support the hood 232.

[0067] The rib 97a is provided with an attachment portion 91a for attaching the damper mechanism 91. The rib 97b is provided with an attachment mechanism 94 for attaching a tension rod (not shown) for keeping the hood 232 open.

[0068] The ribs 95 and 96 are formed so as to fit along the top surface portion 301, the curved portion 302, and the side surface portion 303. Next, the specific shapes of the ribs 95 and 96 will be described.

[0069] Fig. 9 is a perspective view showing the structure of the vicinity of curved portion 302 of hood 232. As shown in Fig. 9, rib 95 is formed by combining three ribs 95a, 95b, and 95c and then spot welding them to the inner surface of hood 232. Similarly, rib 96 is formed by combining three ribs 96a, 96b, and 96c and then spot welding them to the inner surface of hood 232. Ribs 95a, 95b, and 95c, and ribs 96a, 96b, and 96c are formed from hat steel.

[0070] A hat-shaped steel beam can be stacked on another hat-shaped steel beam of a different size. Therefore, rib 95b is formed with a size large enough to be able to be stacked on ribs 95a and 95c. Similarly, rib 96b is formed with a size large enough to be able to be stacked on ribs 96a and 96c.

[0071] In this embodiment, the worker attaches rib 95b, which is bent to follow curved portion 302, so that it overlaps with rib 95a provided on top surface portion 301 and rib 95c provided on side surface portion 303, and then spot welds hood 232, rib 95b, and rib 95a together, and also spot welds hood 232, rib 95b, and rib 95c together.

[0072] The shovel 100 according to this embodiment is compared with an shovel having a structure in which bent ribs are connected between the top surface and side surfaces of the upper cover. In an shovel having a structure in which bent ribs are connected, for example, L-shaped steel beams are used for the ribs, whereas the shovel 100 according to this embodiment uses hat steel beams for the ribs 95 and 96. In a structure in which bent ribs are connected, I-butt welding or fillet welding is used to connect the ribs of the L-shaped steel beams. In this embodiment, however, the hat steel beams 95 and 96 are attached so that they overlap, enabling spot welding. When the hat steel beams 95 and 96 are attached so that they overlap and spot welding is performed, as in this embodiment, it is possible to suppress loads on folds and welds when the hood (e.g., hood 232) is deformed and to fully utilize the rigidity of the ribs, compared to when the L-shaped steel ribs are connected by I-butt welding or fillet welding.

[0073] The radius of curvature of the curved portion 302 according to this embodiment is set to an appropriate value depending on the implementation. For example, the radius of curvature of the curved portion 302 may be set within a range of bending that can be realized by the hat steel forming the rib 95b.

[0074] Next, the process of attaching the rib 95 to the hood 232 will be described. First, a worker spot-welds the rib 95a to the top surface portion 301, and spot-welds the rib 95c, which has the same dimensions as the rib 95a, to the side surface portion 303. Then, the worker aligns the rib 95b, which has larger dimensions than the ribs 95a and 95c, along the curved portion 302 and positions it so that it partially overlaps the ribs 95a and 95c, and then spot-welds the rib 95b to the curved portion 302. Furthermore, the worker spot-welds the rib 95a, the rib 95b, and the top surface portion 301 together, and spot-welds the rib 95c, the rib 95b, and the side surface portion 303 together.

[0075] In this embodiment, spot welding is used as the welding method for the rib 95. Spot welding is a technique in which overlapping metal members (e.g., a rib and a top surface portion) are sandwiched between the tips of electrodes and heated and welded. In this embodiment, the worker spot welds between the rib 95b, the rib 95a, and the hood 232, and also spot welds between the rib 95b, the rib 95c, and the hood 232, thereby improving the strength of the welded portion. In addition, the worker spot welds between the rib 95b and the curved portion 302 of the hood 232, thereby improving the strength even in the bent region of the hood 232. Note that the attachment process for the rib 96 is similar to the attachment process for the rib 95, and therefore a description thereof will be omitted.

[0076] The hood 232 and ribs 95, 96 of this embodiment have the above-described configuration, and therefore can be spot-welded along the ribs 95, 96 even at the curved portion (e.g., the curved portion 302) between the top surface portion 301 and the side surface portion 303. As a result, by spot-welding the hood 232 and ribs 95, 96 of this embodiment along the curved portion 302, a welding that is more resistant to loads can be achieved compared to when the hood 232 and ribs 95, 96 are connected by I-butt welding or fillet welding. This improves the strength of the entire hood 232. In other words, a hood 232 that is resistant to damage can be formed.

[0077] 9, rib 95a has a length L1 in the longitudinal direction, and rib 95c has a length L3 in the longitudinal direction. Rib 95b has a length L2 in the longitudinal direction so as to partially overlap rib 95a and rib 95c. The partially overlapping portions are spot-welded. In this embodiment, spot-welding the overlapping portions of ribs 95, 96 can improve the strength of ribs 95, 96.

[0078] The ribs 95a, 95b, and 95c in this embodiment are made by overlapping hat-shaped steel as described above and then spot welding, thereby realizing a structure that is less likely to be subjected to load at the area connecting the top surface portion 301 and the side surface portion 303.

[0079] Note that this embodiment shows an example of the process of attaching the ribs 95a, 95b, and 95c, and is not limited to the above-described process. For example, the ribs 95a and 95c may be attached after the rib 95b is attached. To achieve this attachment process, the dimensions of the rib 95b may be smaller than the dimensions of the ribs 95a and 95c.

[0080] Furthermore, although both ribs 95 and 96 are formed by combining three members, they are not limited to a configuration in which three members are combined, and may be realized by combining two members, or may be formed as a single member without overlapping.

[0081] The excavator 100 according to this embodiment is provided with a rear frame 41 for mounting the hood 232. In this embodiment, the hood 232 is mounted on the rear frame 41.

[0082] A comparison is made between a case in which the hood 232 is attached to the rear frame 41 of the excavator 100 according to this embodiment and a case in which one end of the hood provided above the engine is attached to the counterweight constituting the first vibration system and the other end is attached to the house frame constituting the second vibration system. When one end of the hood is attached to the counterweight constituting the first vibration system and the other end is attached to the house frame constituting the second vibration system, vibrations are transmitted to the hood from both the counterweight and the house frame.

[0083] In contrast, in the shovel 100 according to this embodiment, the hood 232 is attached to the rear frame 41, and therefore, compared to a case in which one end of the hood is attached to the counterweight that constitutes the first vibration system and the other end is attached to the house frame that constitutes the second vibration system, it is possible to suppress transmission of vibrations from the counterweight 2c to the hood 232. Therefore, compared to a case in which one end of the hood is attached to the counterweight that constitutes the first vibration system and the other end is attached to the house frame that constitutes the second vibration system, the shovel 100 according to this embodiment can suppress the occurrence of loads on the hood 232 body due to two vibrations of different natures.

[0084] Furthermore, the rear frame 41 according to this embodiment is fixed to the plate member 30d with bolts. An operator can visually check the bolts 44, 45 by looking into the interior of the prime mover arrangement space 7 through an opening ZZ on the underside of the upper rotating body 2, and can attach and detach the bolts 44, 45 to and from the plate member 30d. Therefore, in the excavator 100 according to this embodiment, an operator can replace the rear frame 41 without removing the counterweight 2c. This reduces the workload on the operator in this embodiment.

[0085] Furthermore, the ribs 95, 96 are arranged so as to follow the curved portion 302 of the hood 232, and are spot-welded to the hood 232. Therefore, in this embodiment, the rigidity of the ribs 95, 96 can be exerted, and the strength of the hood 232 can be improved.

[0086] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0087] 100 Shovel 1 Undercarriage 2 Upper rotating body 3 Cabins 4. Boom 5 Arm 6 buckets 8. Diesel engine 2a Housing 2b Top cover 232 Food 2c Counterweight 30 Swivel Frame 30a Center right vertical member 30b Center left vertical member 30c bottom plate 30d Plate material 41 Rear frame 41a, 41b Support members 41c, 41d Support member 42 Center Frame 43a, 43b Front and rear frames 44, 45 volts 95, 96 Ribs

Claims

1. a lower running body; an upper rotating body rotatably mounted on the lower traveling body; A counterweight provided at the rear of the upper rotating body; a prime mover provided on the upper rotating body; a hood covering the motor; a rear frame supporting the hood, the rear frame is disposed in front of the counterweight, The rear frame further includes an engaging portion below the rear frame that engages with a plate member protruding from a revolving frame provided on the upper revolving body, and a support portion that abuts against the plate member from an upper end portion. Shovel.

2. a first frame provided in front of the rear frame; a front and rear frame connecting the rear frame and the first frame; The shovel according to claim 1 ,

3. An opening is formed in the upper rotating body so that the engagement portion can be accessed from below the rotating frame. The shovel according to claim 1.

4. the hood is formed by a top surface portion, a side surface portion, and a curved portion between the top surface portion and the side surface portion, The rib further includes a hat-shaped steel bent along the curved portion. The shovel according to any one of claims 1 to 3.

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