JP2024049996A - Construction machine - Google Patents

Abstract

To provide a construction machine in which a plurality of batteries for supplying electric power to an electric motor as a drive source for traveling can be more appropriately mounted on a lower traveling body.SOLUTION: A hydraulic excavator 1 comprises a lower traveling body 2 including a chassis 30 having a pair of side plates 36 spaced apart in the vehicle width direction, and a cylindrical body 35 as an attachment part for an upper revolving body 6 having a work device 10 on an upper surface plate 32 and a first opening 341 on a lower surface plate 34, and an electric motor M as a driving drive source mounted on the lower traveling body 2. The hydraulic excavator 1 includes a battery assembly 50 that includes a plurality of batteries B that supply power to the electric motor M, and a base cover 51 on which the plurality of batteries B are mounted. In the battery assembly 50, a plurality of batteries are stored in an internal space V of the chassis 30 defined between the pair of side plates 36 through the first opening 341, and the base cover 51 is attached to the chassis 30.SELECTED DRAWING: Figure 3

Description

The present invention relates to construction machinery, and more particularly to construction machinery equipped with multiple batteries that supply power to an electric motor as a driving source for traveling.

Conventionally, there are known techniques for mounting batteries on the bodies of construction machinery and the like. For example, Patent Document 1 describes a structure in which, in a hydraulic excavator equipped with a lower traveling body and an upper rotating body, multiple batteries that supply power to an electric motor that drives a hydraulic pump are mounted on the rear vehicle body of the upper rotating body. Also, Patent Document 2 describes a structure in which, in a wheel loader equipped with a body and a cab mounted on the body, a storage structure consisting of a bottom plate, vertical plates, and horizontal plates is provided below the skeleton column of the cab, and a battery is placed inside the storage structure.

Japanese Patent No. 5670274 JP 2008-195348 A

Incidentally, an electric motor may be mounted on the lower traveling body of a construction machine as a driving source for traveling. However, for example, as in the hydraulic excavator described in Patent Document 1, when multiple batteries that supply power to the electric motor are mounted on the upper rotating body, the length of the wiring from the batteries to the electric motor becomes long, leading to increased electrical loss and an increase in the number of parts. Meanwhile, for example, in the structure described in Patent Document 2, it is difficult to secure sufficient space for mounting multiple batteries and space for assembling the multiple batteries one by one to the construction machine. There is also a demand for multiple batteries to be easily assembled to the construction machine.

The present invention was made in consideration of these problems, and its purpose is to provide a construction machine that can more appropriately mount multiple batteries on the undercarriage to supply power to an electric motor as a driving source for traveling.

In order to achieve the above object, the construction machine of the present invention is a construction machine having a lower running body including a chassis having a pair of side panels spaced apart in the vehicle width direction, an upper rotating body mounting portion having a work device on its upper surface, and an opening on its lower surface, and an electric motor mounted on the lower running body as a driving source for running, and is provided with a battery assembly having a plurality of batteries that supply power to the electric motor and a base cover on which the plurality of batteries are mounted, the battery assembly being provided with the plurality of batteries stored through the opening in the internal space of the chassis defined between the pair of side panels, and the base cover being attached to the chassis.

With this configuration, multiple batteries are stored in the internal space of the chassis of the lower traveling body, so that it is possible to secure sufficient space for mounting a relatively large number of batteries. In addition, by using a battery assembly in which multiple batteries are mounted on the base cover in advance, it is not necessary to consider the space required for the work of assembling the multiple batteries one by one in the internal space of the chassis. Furthermore, since the multiple batteries are inserted into the internal space from the opening on the underside of the chassis, the multiple batteries can be easily positioned in the mounting position. And, by mounting multiple batteries on the lower traveling body, it is possible to suppress the increase in the length of the wiring from the multiple batteries to the electric motor, and to suppress the increase in electrical loss and the increase in the number of parts. Therefore, according to the construction machine of the present invention, multiple batteries that supply power to the electric motor as a driving source for traveling can be more appropriately mounted on the lower traveling body.

It is also preferable that the electric motor is attached to a casing that supports the axle relative to the chassis, and the multiple batteries are stored in a range of the internal space that includes a portion located on the axle. This configuration reduces the distance between the electric motor and the multiple batteries, further suppresses the increase in wiring length from the multiple batteries to the electric motor, and further suppresses the increase in electrical loss and the increase in the number of parts.

It is also preferable that the multiple batteries are stored in a range of the internal space that includes a portion located on the axle to which the rear wheels are attached. This configuration makes it easier to guide the wind from the construction machine as it travels forward toward the multiple batteries. As a result, the multiple batteries can be cooled effectively.

The base cover preferably has a base plate on which the batteries are mounted, and an inclined portion extending downward from the front end of the base plate toward the front side. With this configuration, when the construction machine travels forward, the wind generated by the travel can be guided to the batteries via the inclined portion, thereby allowing the batteries to be cooled effectively.

Furthermore, it is preferable that the chassis includes a beam extending between the pair of side panels, the base cover has a mounting cover that extends in the vertical direction forward of the multiple batteries and is attached to the beam, and an opening is formed in the lower end of the mounting cover. With this configuration, the base cover is firmly attached to the chassis by the mounting cover, and when the construction machine travels forward, traveling wind can be guided to the multiple batteries through the opening in the mounting cover, thereby allowing the multiple batteries to be cooled well.

It is also preferable that an exhaust port is formed in a portion of the chassis located above the multiple batteries. With this configuration, for example, while the multiple batteries are being charged, hydrogen discharged from the multiple batteries can be discharged through the exhaust port, and hydrogen can be prevented from accumulating in the internal space of the chassis. In addition, an increase in the ambient temperature in the internal space of the chassis can be prevented, and the multiple batteries can be appropriately protected.

In addition, a pair of L-shaped support brackets having sides extending downward from the chassis and a bottom extending from the sides to the inside in the vehicle width direction are attached to the underside of the chassis with a gap in the vehicle width direction, and the base cover is preferably inserted between the sides of the pair of support brackets and supported by the bottom. This configuration makes it easy to assemble the battery assembly to the chassis.

The construction machine of the present invention makes it possible to more appropriately mount multiple batteries on the undercarriage to supply power to the electric motor that serves as the driving source for traveling.

1 is a schematic configuration diagram showing a hydraulic excavator as a construction machine according to an embodiment. 2 is a perspective view of the lower traveling body as viewed from above and from the right side in the vehicle width direction. FIG. FIG. 2 is a perspective view of the lower traveling body as viewed from below and from the right side in the vehicle width direction. 2 is a perspective view of a portion of the chassis as viewed from below and from the right side in the vehicle width direction. FIG. 2 is a perspective view of the battery assembly as viewed from above and from the right side in the vehicle width direction. FIG. 2 is a perspective view of the battery assembly as viewed from above and from the left side in the vehicle width direction. FIG. 2 is a perspective view of a lower traveling body on which a battery assembly is mounted, as viewed from below and from the right side in the vehicle width direction. FIG. 11 is an explanatory diagram showing a part of a procedure for assembling the battery assembly to the lower traveling body. FIG. FIG. 11 is an explanatory diagram showing another mounting space for the battery assembly.

One embodiment of the present invention will be described below with reference to the drawings. In the following description, the vehicle front-rear direction, vehicle width direction (left-right direction), and up-down direction are defined based on the driver riding on the hydraulic excavator 1 as a construction machine.

(hydraulic excavator)
FIG. 1 is a schematic diagram showing a hydraulic excavator 1 as a construction machine according to an embodiment.
The hydraulic excavator 1 is a wheel-type hydraulic excavator that travels by driving wheels 3 having front wheels 3a and rear wheels 3b arranged on a lower running body 2, and is capable of performing work such as excavation work by operating a work device 10 on an upper rotating body 6 arranged on the lower running body 2.

In the hydraulic excavator 1, an upper rotating body 6 is provided on a lower traveling body 2 so as to be able to rotate via a rotating bearing 4. The upper rotating body 6 has an upper frame 5, and a driver's cab 7 is provided on the front left side of the upper frame 5, and an engine room 9 is provided behind the driver's cab 7. A working device 10 is disposed in the center of the front side of the upper frame 5 on the right side of the driver's cab 7. The engine room 9 accommodates a boom cylinder 20, an arm cylinder 22, a bucket cylinder 24, and a hydraulic pump (not shown) for supplying pressure oil to a hydraulic motor for rotation (not shown), which will be described later. The engine room 9 also accommodates an engine (not shown) for driving the hydraulic pump (not shown). The lower traveling body 2 has a chassis 30 (see FIG. 2) as a vehicle frame, and front wheels 3a and rear wheels 3b are attached to the chassis 30. The lower traveling body 2 is also equipped with an electric motor M for driving the traveling and a battery assembly 50 (see FIG. 3).

The working device 10 includes a boom 12, an arm 14, and a bucket 16. The boom 12 is rotatably connected to the upper frame 5. The arm 14 is rotatably connected to the boom 12. The bucket 16 is rotatably connected to the arm 14. The working device 10 can raise and lower the boom 12 by extending and retracting the boom cylinder 20, rotate the arm 14 by extending and retracting the arm cylinder 22, and rotate the bucket 16 attached to the tip of the arm 14 by extending and retracting the bucket cylinder 24. The boom cylinder 20, arm cylinder 22, and bucket cylinder 24 are hydraulically operated.

(Configuration of the lower running body)
Next, the configuration of the lower traveling body 2 will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a perspective view of the lower traveling body 2 as viewed from above and from the right side in the vehicle width direction. Fig. 3 is a perspective view of the lower traveling body 2 as viewed from below and from the right side in the vehicle width direction. Fig. 4 is a perspective view of a part of the chassis 30 as viewed from below and from the right side in the vehicle width direction.

(Chassis)
The chassis 30 is a vehicle body frame that constitutes the lower traveling body 2. As shown in Figures 2 to 4, the chassis 30 has an upper plate (upper surface) 32, a lower plate (lower surface) 34, and a pair of side plates 36. The chassis 30 has an internal space V defined between the upper plate 32, the lower plate 34, and the pair of side plates 36.

The upper plate 32 extends in the fore-and-aft direction of the vehicle. As shown in FIG. 2, a cylindrical body (mounting portion) 35 is disposed in the approximate center of the upper plate 32 in the fore-and-aft direction of the vehicle, and the upper rotating body 6 is mounted on the cylindrical body 35 so as to be rotatable around the above-mentioned swivel bearing 4. As shown in FIG. 4, an exhaust port 32a is formed in the upper plate 32 so as to be located above the battery assembly 50 described below. As shown in FIG. 2, an exhaust port cover 32b is provided around the exhaust port 32a of the upper plate 32, which covers the exhaust port 32a from above and opens toward the rear.

As shown in Figs. 3 and 4, the lower plate 34 is provided facing the upper plate 32 in the vertical direction and extends in the vehicle longitudinal direction. The lower plate 34 is formed with a first opening (opening) 341 and a second opening 342 that open downward and communicate with the internal space V. The first opening 341 is provided rearward in the vehicle longitudinal direction from the second opening 342 and opens larger than the second opening 342. The first opening 341 opens including a position above the axle casing (casing) 35R of the axle (not shown) to which the rear wheel 3b (described later) is attached. In addition, the lower plate 34 is formed with a pair of frame side fastening parts 343 in the vehicle width direction, which extend downward on the side of the first opening 341 and have bolt insertion holes 343a formed therein. Furthermore, a pair of support brackets 40 are fixed near the rear end of the lower plate 34, as shown in Fig. 4. The pair of support brackets 40 are provided on the sides of the first opening 341 with a gap between them in the vehicle width direction. The support bracket 40 is an L-shaped member having a side portion 41 extending downward from the lower panel 34 and a bottom portion 42 extending from the side portion 41 toward the first opening 341. The bottom portion 42 of the support bracket 40 has bolt insertion holes 40a formed therein with a gap between them in the vehicle front-rear direction.

The pair of side panels 36 are connected to both ends of the upper panel 32 and the lower panel 34 in the vehicle width direction and extend in the vehicle front-rear direction. A beam 38 is connected between the pair of side panels 36 as a reinforcing member extending in the vehicle width direction. The beam 38 has two bosses 381 spaced apart from each other in the vehicle width direction to which bolts 83 (described later, see FIG. 7) are fastened.

As shown in FIG. 3, an axle (not shown) extending in the vehicle width direction is rotatably attached to the chassis 30 configured as described above near the front end of the lower plate 34 via an axle casing (casing) 35F, and left and right front wheels 3a are attached to the tip of the axle. In addition, an axle (not shown) extending in the vehicle width direction is rotatably attached to the rear end of the lower plate 34 via an axle casing 35R, and left and right rear wheels 3b are attached to the tip of the axle. In this embodiment, an electric motor M for driving the excavator 1 is fixed to the axle casing 35R, and the rotational driving force from the electric motor M is transmitted to the axle via a power transmission mechanism (not shown), thereby causing the hydraulic excavator 1 to travel.

(Battery Assembly)
In this embodiment, a battery assembly 50 for supplying electric power to the electric motor M is mounted on the lower traveling body 2. The configuration of the battery assembly 50 will be described below with reference to Figs. 5 to 7. In the following description, the directions of the components are defined based on the state in which the battery assembly 50 is mounted on the lower traveling body 2. Fig. 5 is a perspective view of the battery assembly 50 as viewed from above and from the right side in the vehicle width direction, and Fig. 6 is a perspective view of the battery assembly 50 as viewed from above and from the left side in the vehicle width direction. Fig. 7 is a perspective view of the lower traveling body 2 on which the battery assembly 50 is mounted as viewed from below and from the right side in the vehicle width direction.

(multiple batteries)
As shown in Figs. 5 and 6, the battery assembly 50 includes a plurality of batteries B mounted on a base cover 51. Note that in Fig. 5, illustration of cables connected to the plurality of batteries B is omitted. In this embodiment, the plurality of batteries B includes six batteries B1, B2, B3, B4, B5, and B6. For example, lithium ion secondary batteries capable of plug-in charging and power supply are used for each of the batteries B1 to B6, and each battery module is formed by connecting a plurality of battery cells (not shown). As shown in Fig. 6, the batteries B1 to B6 are electrically connected in series by cables 71. Furthermore, the battery B6 is electrically connected to the electric motor M by a cable 72 extending through a cable hole 510 formed in the base cover 51. Note that in order to charge the plurality of batteries B, a generator driven by an engine (not shown) may be mounted on the hydraulic excavator 1.

Battery B1 is also electrically connected to the base cover 51 via cables 73, 74 and a ground connection changeover switch 75. This causes the reference potentials of the multiple batteries B1 to B6 to be grounded when the battery assembly 50 is mounted on the undercarriage 2. The ground connection changeover switch 75 is a switch that can electrically connect and disconnect battery B1 from the base cover 51. For example, when the hydraulic excavator 1 is not to be used for a relatively long period of time or when electrical system maintenance is being performed, an operator can operate the ground connection changeover switch 75 to release the above-mentioned connection.

(Base cover)
The base cover 51 has a rectangular substrate portion 52 and an inclined portion 53 extending from a front end 52a of the substrate portion 52 in the vehicle front-rear direction. As shown in Fig. 7, the substrate portion 52 is a portion that is placed on the bottom portions 42 of the two support brackets 40 attached to the chassis 30. The length of the substrate portion 52 in the vehicle width direction is longer than the first opening 341 and slightly shorter than the distance in the vehicle width direction between the side portions 41 of the two support brackets 40. The inclined portion 53 is formed to extend downward as it moves away from the front end 52a of the substrate portion 52, i.e., as it moves from the rear side to the front side in the vehicle front-rear direction.

(Battery mounting structure on base cover)
The mounting structure of multiple batteries B on base cover 51 will be described. Multiple batteries B1 to B6 are arranged in two rows of three on board portion 52 of base cover 51, with a gap between each row. Hereinafter, the multiple batteries B1 to B3 on the front end 52a side of board portion 52 will be collectively referred to as "front row batteries BF," and the multiple batteries B4 to B6 on the rear end 52b side of board portion 52 will be collectively referred to as "rear row batteries BR."

A U-shaped first bracket 61 is attached to the substrate 52, covering the front and side of the lower part of the front battery BF. A U-shaped second bracket 62 is attached to the substrate 52, covering the rear and side of the lower part of the rear battery BR. A third bracket 63 is attached to the substrate 52, sandwiching the side of the front battery BF and the side of the rear battery BR from both sides. The third bracket 63 includes a connecting portion 631 that extends between the front battery BF and the rear battery BR, and an abutting portion 632 that abuts against the side, and the abutting portion 632 is fixed to the substrate 52.

Furthermore, a fourth bracket 64 is disposed above the front row battery BF and above the rear row battery BR. The fourth bracket 64 has a plate-shaped portion 641 extending in the vehicle width direction, and abutment portions 642 extending downward from the plate-shaped portion 641 and sandwiching the side surface from both sides. The fourth bracket 64 has stays 65 attached to both ends of the plate-shaped portion 641 in the vehicle width direction, which extend in the vertical direction, are engaged with the base plate portion 52, and can press the plate-shaped portion 641 toward the base plate portion 52. As a result, the front row battery BF and the rear row battery BR are immovably mounted on the base cover 51 by the first bracket 61, second bracket 62, third bracket 63, and fourth bracket 64.

(Base cover mounting structure)
A structure for attaching the base cover 51 to the chassis 30 will be described. As described above, the base cover 51 is placed on the bottom 42 of the support bracket 40, the substrate portion 52 of which is attached to the chassis 30. As shown in Figs. 5 and 6, the substrate portion 52 is provided at both ends in the vehicle width direction with cover-side fastening portions 522 each having a boss portion to which a bolt 81 (see Fig. 7) is fastened. When the battery assembly 50 shown in Fig. 7 is attached to the chassis 30, the cover-side fastening portion 522 abuts against the frame-side fastening portion 343 of the chassis 30. The cover-side fastening portion 522 is fastened to the frame-side fastening portion 343 by the bolt 81 inserted from the outside in the vehicle width direction through the bolt insertion hole 343a (see Fig. 4).

As shown in Figs. 5 and 6, two cover-side bosses 523 are provided at both ends of the base plate 52 in the vehicle width direction, spaced apart in the vehicle front-rear direction, to which bolts 82 (see Fig. 7) can be fastened. The two cover-side bosses 523 are aligned coaxially with the bolt insertion holes 40a (see Fig. 4) of the support bracket 40 when the battery assembly 50 shown in Fig. 7 is attached to the chassis 30. Each cover-side boss 523 is fastened to the support bracket 40 by a bolt 82 inserted from below through the bolt insertion holes 40a.

As shown in Figs. 5 and 6, a plate-shaped mounting cover 54 is attached to the base plate 52 near the front end 52a, and extends upward. A notch extending in the vehicle width direction is provided at the lower end of the mounting cover 54 on the base cover 51 side, thereby forming an opening 55 between the mounting cover 54 and the base cover 51. The mounting cover 54 abuts against the beam 38 from the front side when the battery assembly 50 shown in Fig. 7 is attached to the chassis 30. The mounting cover 54 also has a bolt insertion hole 54a (see Figs. 5 and 6) that is aligned coaxially with the boss portion 381 (see Fig. 4) of the beam 38. The mounting cover 54 is fixed to the beam 38 by fastening a bolt 83 inserted from the front side of the mounting cover 54 through the bolt insertion hole 54a to the boss portion 381.

The mounting cover 54 also functions as a mounting portion for the ground connection changeover switch 75. The operation end of the ground connection changeover switch 75 is exposed on the front side of the mounting cover 54 in the vehicle longitudinal direction. This allows an operator to easily operate the ground changeover switch 75. The operation end of the ground connection changeover switch 75 may be exposed on the underside of the substrate portion 52.

(Battery assembly installation procedure)
8 is an explanatory diagram showing a part of the procedure for assembling the battery assembly 50 to the lower running body 2. The battery assembly 50 is assembled to the lower running body 2 by an operator. As shown by the solid arrow in step S10 in the figure, the operator inserts the multiple batteries B and the mounting cover 54 of the battery assembly 50 from below into the internal space V through the first opening 341 of the chassis 30. At this time, the base cover 51 is located forward of the support bracket 40 in the vehicle front-rear direction.

Then, as shown in step S20, the worker positions the base plate 52 of the base cover 51 above the support bracket 40. Furthermore, the worker slides the battery assembly 50 rearward in the vehicle longitudinal direction as shown by the solid arrow in step S20. As a result, as shown in FIG. 7, the base cover 51 is inserted between the bottom 42 of the support bracket 40 and the lower plate 34 and placed on the bottom 42, and the battery assembly 50 is positioned in the vertical direction. In addition, the mounting cover 54 abuts against the beam 38, and the battery assembly 50 is positioned in the vehicle longitudinal direction. After that, the worker fastens and fixes the base cover 51 to the chassis 30 with the bolts 81, 82, and 83 according to the mounting structure of the base cover 51 described above. As a result, the battery assembly 50 stores the multiple batteries B in a range including the portion V1 (see the dashed line in FIG. 3) located on the axle to which the rear wheel 3b is attached, of the internal space V of the chassis 30. To remove the battery assembly 50 from the lower traveling body 2, simply reverse the above steps.

As described above, the hydraulic excavator (construction machine) 1 of the embodiment is a hydraulic excavator equipped with a lower traveling body 2 including a chassis 30 having a pair of side panels 36 spaced apart in the vehicle width direction, a cylinder 35 as a mounting part for an upper rotating body 6 having a working device 10 on an upper panel (upper surface) 32, and a first opening (opening) 341 on a lower panel (lower surface) 34, and an electric motor M as a traveling drive source mounted on the lower traveling body 2, and is equipped with a battery assembly 50 having a plurality of batteries B that supply power to the electric motor M and a base cover 51 on which the plurality of batteries B are mounted, and the battery assembly 50 is equipped with the battery assembly 50, which has a plurality of batteries B stored in the internal space V of the chassis 30 defined between the pair of side panels 36 through the first opening 341, and the base cover 51 is attached to the chassis 30.

With this configuration, multiple batteries B are stored in the internal space V of the chassis 30 of the lower traveling body 2, so that a sufficient space can be secured for mounting a relatively large number of batteries B. In addition, by using the battery assembly 50 in which multiple batteries B are mounted on the base cover 51 in advance, there is no need to consider the space required for assembling the multiple batteries B one by one in the internal space V of the chassis 30. Furthermore, since the multiple batteries B are inserted into the internal space V from the first opening 341 of the lower plate 34 of the chassis 30, the multiple batteries B can be easily positioned at the mounting position. And, by mounting multiple batteries B on the lower traveling body 2, it is possible to suppress an increase in the length of the wiring from the multiple batteries B to the electric motor M, and to suppress an increase in electrical loss and an increase in the number of parts. Therefore, according to the construction machine of the present invention, multiple batteries B that supply power to the electric motor M as a driving source for traveling can be more appropriately mounted on the lower traveling body 2.

The electric motor M is attached to an axle casing (casing) 35R that supports the axle on the chassis 30, and the multiple batteries B are stored in a range of the internal space V that includes the portion located on the axle. This configuration reduces the distance between the electric motor M and the multiple batteries B, further suppresses the increase in wiring length from the multiple batteries B to the electric motor M, and further suppresses the increase in electrical loss and the increase in the number of parts.

The multiple batteries B are stored in an area of the internal space V that includes a portion V1 (see dashed line in FIG. 3) located on the axle to which the rear wheels 3b are attached. This configuration makes it easier to guide the wind generated by the hydraulic excavator 1 as it travels forward toward the multiple batteries B. As a result, the multiple batteries B can be efficiently cooled.

The base cover 51 also has a base plate portion 52 on which the multiple batteries B are mounted, and an inclined portion 53 that extends downward from the front end of the base plate portion 52 toward the front side. With this configuration, when the hydraulic excavator 1 travels forward, the traveling wind can be guided to the multiple batteries B via the inclined portion 53, and the multiple batteries B can be cooled effectively.

The chassis 30 also includes a beam 38 extending between the pair of side panels 36, and the base cover 51 has a mounting cover 54 that extends in the vertical direction forward of the multiple batteries B and is attached to the beam 38, and an opening 55 is formed at the lower end of the mounting cover 54. With this configuration, the mounting cover 54 firmly attaches the base cover 51 to the chassis 30, and when the hydraulic excavator 1 travels forward, traveling wind can be guided to the multiple batteries B through the opening 55 of the mounting cover 54, allowing the multiple batteries B to be cooled effectively.

In addition, an exhaust port 32a is formed in a portion of the chassis 30 located above the multiple batteries B. With this configuration, for example, while the multiple batteries B are being charged, hydrogen discharged from the multiple batteries B can be discharged through the exhaust port 32a, making it possible to prevent the hydrogen from accumulating in the internal space V of the chassis 30. In addition, an increase in the atmospheric temperature in the internal space V of the chassis 30 can be prevented, making it possible to adequately protect the multiple batteries B.

A pair of L-shaped support brackets 40 are attached to the underside of the chassis 30 with a gap in the vehicle width direction. The support brackets 40 have side portions 41 extending downward from the chassis 30 and bottom portions 42 extending inward in the vehicle width direction from the side portions 41. The base cover 51 is inserted between the side portions 41 of the pair of support brackets 40 and supported by the bottom portions 42. This configuration allows the battery assembly 50 to be easily assembled to the chassis 30.

(Modification)
Although the description of the embodiment is finished above, the aspects of the present invention are not limited to this embodiment. For example, in this embodiment, the aspects of the present invention are described using a wheeled hydraulic excavator 1 as an example of a construction machine, but the type of construction machine is not limited to this, and the present invention may be applied to a construction machine that can run by an electric motor, such as a wheel loader.

The electric motor M is not limited to being mounted on the axle casing 35R of the axle to which the rear wheel 3b is attached, but may be mounted on any part of the lower traveling body 2. For example, the electric motor M may be a wheel-in motor, etc.

The batteries B may also be stored in a location in the internal space V other than the area including the position on the axle to which the rear wheels 3b are attached. FIG. 9 is an explanatory diagram showing another mounting space for the battery assembly 50. The battery assembly 50 may be mounted on the undercarriage 2 so that the batteries B are stored in the area V2 of the internal space V enclosed by a dashed line in FIG. 9. That is, the battery assembly 50 may be stored in the area V2 of the internal space V including the part located on the axle to which the front wheels 3a are attached. In this case, the batteries B may be stored in the area V2 so as to avoid the beam extending between the side panels 36.

In addition, the base cover 51 does not have to have an inclined portion 53.

Also, if the battery assembly 50 can be attached to the chassis 30, the mounting cover 54 may be omitted from the battery assembly 50. Also, the openings 55 of the mounting cover 54 may be omitted if the multiple batteries B can be sufficiently cooled.

Furthermore, as long as it is possible to prevent hydrogen from accumulating in the internal space V and prevent the atmospheric temperature from increasing, the exhaust port 32a of the top plate 32 may be omitted or may be formed in any other position on the chassis 30.

In addition, as long as the battery assembly 50 can be attached to the chassis 30, the base cover 51 may be supported by other support means, not limited to the support bracket 40.

1 Hydraulic excavator 2 Undercarriage 3 Wheels 3a Front wheels 3b Rear wheels 10 Work device 30 Chassis 32 Top plate (top surface)
32a Exhaust port 32b Exhaust port cover 34 Lower plate (lower surface)
35 Cylinder (mounting part)
35F, 35R Axle casing (casing)
36 Side panel 38 Beam 40 Support bracket 41 Side portion 42 Bottom portion 50 Battery assembly 51 Base cover 52 Base plate portion 52a Front end 52b Rear end 53 Sloping portion 54 Mounting cover 55 Opening 341 First opening (opening)
B, B1, B2, B3, B4, B5, B6 Battery M Electric motor V Internal space

Claims (7)

A construction machine comprising: a lower traveling body including a chassis having a pair of side panels spaced apart in a vehicle width direction, the chassis having an upper surface on which an upper rotating body is attached and an opening on a lower surface, and an electric motor as a traveling drive source mounted on the lower traveling body,
a battery assembly including a plurality of batteries for supplying power to the electric motor and a base cover on which the plurality of batteries are mounted;
The battery assembly is a construction machine in which the multiple batteries are stored through the opening in an internal space of the chassis defined between the pair of side panels, and the base cover is attached to the chassis. The electric motor is attached to a casing that supports an axle relative to the chassis;
The construction machine according to claim 1 , wherein the plurality of batteries are stored in a range of the internal space that includes a portion located above the axle. The construction machine according to claim 1, wherein the plurality of batteries are stored in an area of the interior space that includes a portion located above the axle to which the rear wheels are attached. The construction machine according to claim 1, wherein the base cover has a base plate portion on which the batteries are mounted and an inclined portion extending downward from the front end of the base plate portion toward the front side. The chassis includes a beam extending between the pair of side panels,
the base cover has an attachment cover that extends in a vertical direction forward of the plurality of batteries and is attached to the beam;
The construction machine according to claim 1 , wherein an opening is formed in a lower end of the mounting cover. The construction machine according to claim 1, wherein an exhaust port is formed in a portion of the chassis located above the plurality of batteries. a pair of L-shaped support brackets are attached to the underside of the chassis at a distance in the vehicle width direction, the L-shaped support brackets having a side portion extending downward from the chassis and a bottom portion extending from the side portion toward the inside in the vehicle width direction;
The construction machine according to claim 1 , wherein the base cover is inserted between the side portions of the pair of support brackets and supported by the bottom portions.

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