JP7431916B1 - construction machinery - Google Patents

Abstract

An object of the present invention is to provide a construction machine in which a plurality of batteries for supplying electric power to an electric motor as a driving source for traveling can be more appropriately mounted on a lower traveling body. A hydraulic excavator 1 has a pair of side plates 36 spaced apart in the vehicle width direction, and a cylindrical body 35 serving as an attachment part of an upper revolving body 6 having a working device 10 on an upper plate 32. The lower traveling body 2 includes a chassis 30 having a first opening 341 in the 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 an electric motor M, and a base cover 51 on which the plurality of batteries B are mounted. The base cover 51 is stored in the internal space V of the chassis 30 defined between the side plates 36 through the first opening 341, and the base cover 51 is attached to the chassis 30. [Selection diagram] Figure 3

Description

The present invention relates to a construction machine, and particularly to a construction machine equipped with a plurality of batteries that supply electric power to an electric motor as a drive source for traveling.

2. Description of the Related Art Conventionally, techniques for mounting a battery on a body such as a construction machine are known. For example, in Patent Document 1, in a hydraulic excavator equipped with a lower traveling body and an upper rotating body, a plurality of batteries are installed in the rear body of the upper rotating body to supply electric power to an electric motor for driving a hydraulic pump. The mounting structure is described. Furthermore, in Patent Document 2, in a wheel loader equipped with a body and a cab mounted on the body, a storage structure consisting of a bottom plate, a vertical plate, and a horizontal plate is provided below the skeleton column of the cab, and the storage structure is A structure is described in which a battery is placed inside the structure.

Patent No. 5670274 Japanese Patent Application Publication No. 2008-195348

By the way, an electric motor as a drive source for traveling is sometimes mounted on the lower traveling body of a construction machine. However, if a plurality of batteries are installed on the upper revolving body to supply power to the electric motor, as in the hydraulic excavator described in Patent Document 1, for example, the length of the wiring from the battery to the electric motor becomes long, and the electric This results in an increase in physical loss and an increase in the number of parts. On the other hand, with the structure described in Patent Document 2, for example, it is difficult to secure a sufficient space for mounting a plurality of batteries and a space for assembling the plurality of batteries one by one into a construction machine. It is also required that multiple batteries be easily assembled into construction machinery.

The present invention has been made in view of these problems, and its purpose is to more appropriately mount a plurality of batteries that supply electric power to an electric motor as a drive source for driving into an undercarriage body. Our goal is to provide quality construction machinery.

In order to achieve the above object, the construction machine of the present invention has a pair of side plates spaced apart in the vehicle width direction, an attachment part of an upper revolving structure having a working device on the upper surface, and an opening on the lower surface. A construction machine comprising: an undercarriage body including a chassis having a chassis; and an electric motor as a driving drive source mounted on the undercarriage body, the construction machine comprising: a plurality of batteries that supply electric power to the electric motor; a base cover on which the plurality of batteries are mounted, the battery assembly comprising: a base cover on which the plurality of batteries are mounted; and the base cover is attached to the chassis.

With this configuration, a plurality of batteries are stored in the internal space of the chassis of the undercarriage, so that a sufficient space for mounting a relatively large number of batteries can be secured. Further, by using a battery assembly in which a plurality of batteries are mounted on the base cover in advance, there is no need to consider the space for assembling the plurality of batteries one by one in the internal space of the chassis. Furthermore, since the plurality of batteries are inserted into the internal space through the opening on the bottom surface of the chassis, the plurality of batteries can be easily positioned at the mounting position. By mounting a plurality of batteries on the lower traveling body, it is possible to suppress an increase in the length of wiring from the plurality of batteries to the electric motor, 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, it is possible to more appropriately mount a plurality of batteries that supply electric power to the electric motor as a drive source for traveling on the lower traveling body.

Preferably, the electric motor is attached to a casing that supports an axle with respect to the chassis, and the plurality of batteries are stored in an area of the internal space that includes a portion located on the axle. . With this configuration, the distance between the electric motor and the multiple batteries is brought closer, the increase in the length of wiring from the multiple batteries to the electric motor is further suppressed, and the increase in electrical loss and increase in the number of parts can be further suppressed. Can be done.

Further, it is preferable that the plurality of batteries are stored in a range of the internal space that includes a portion located on an axle to which a rear wheel is attached. With this configuration, when the construction machine travels forward, it becomes easier to guide the traveling wind to the plurality of batteries. As a result, multiple batteries can be cooled well.

Further, it is preferable that the base cover has a substrate portion on which the plurality of batteries are mounted, and an inclined portion extending downward from the front end of the substrate portion toward the front side. With this configuration, when the construction machine travels forward, the traveling wind can be guided to the plurality of batteries via the inclined portion, and the plurality of batteries can be cooled well.

The chassis includes a beam extending between the pair of side plates, and the base cover includes a mounting cover that extends in the vertical direction in front of the plurality of batteries and is attached to the beam, and Preferably, an opening is formed at the lower end of the cover. With this configuration, while the base cover is firmly attached to the chassis using the mounting cover, when the construction machine moves forward, it is possible to guide the running wind to the multiple batteries through the opening in the mounting cover, and the multiple batteries can be cooled well.

Further, it is preferable that an exhaust port is formed in a portion of the chassis located above the plurality of batteries. With this configuration, for example, during charging of a plurality of batteries, hydrogen discharged from the plurality of batteries can be discharged from the exhaust port, and hydrogen can be prevented from staying in the internal space of the chassis. Further, it is possible to suppress an increase in the ambient temperature in the internal space of the chassis and appropriately protect the plurality of batteries.

Further, on the lower surface of the chassis, a pair of L-shaped support brackets, each having a side portion extending downward from the chassis and a bottom portion extending inward in the vehicle width direction from the side portion, are spaced apart in the vehicle width direction. Preferably, the base cover is inserted between the side portions of the pair of support brackets and supported by the bottom portion. This configuration allows the battery assembly to be easily assembled to the chassis.

According to the construction machine of the present invention, it becomes possible to more appropriately mount a plurality of batteries that supply electric power to an electric motor serving as a drive source for traveling on the lower traveling body.

1 is a schematic configuration diagram showing a hydraulic excavator as a construction machine according to an embodiment. FIG. 3 is a perspective view of the lower traveling body viewed from above and from the right side in the vehicle width direction. FIG. 2 is a perspective view of the lower traveling body viewed from the lower side and the right side in the vehicle width direction. FIG. 3 is a perspective view of a portion of the chassis viewed from below and from the right side in the vehicle width direction. FIG. 3 is a perspective view of the battery assembly viewed from above and from the right side in the vehicle width direction. FIG. 3 is a perspective view of the battery assembly viewed from above and from the left side in the vehicle width direction. FIG. 3 is a perspective view of the lower traveling body on which the battery assembly is mounted, viewed from the lower side and the right side in the vehicle width direction. It is an explanatory view showing a part of procedure of assembling a battery assembly to a lower traveling body. FIG. 7 is an explanatory diagram showing another mounting space for the battery assembly.

Hereinafter, one embodiment of the present invention will be described based on the drawings. In the following description, the vehicle longitudinal direction, vehicle width direction (horizontal direction), and vertical direction are defined based on a driver riding on the hydraulic excavator 1 as a construction machine.

(hydraulic excavator)
FIG. 1 is a schematic configuration diagram showing a hydraulic excavator 1 as a construction machine according to an embodiment.
The hydraulic excavator 1 travels by driving wheels 3 having a front wheel 3a and a rear wheel 3b disposed on a lower traveling body 2, and a working device 10 of an upper revolving body 6 disposed on the lower traveling body 2. This is a wheel-type hydraulic excavator that can perform tasks such as excavation by operating the .

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

The work device 10 includes a boom 12, an arm 14, and a bucket 16. Boom 12 is rotatably connected to upper frame 5. Arm 14 is rotatably coupled to boom 12 . Bucket 16 is rotatably connected to arm 14 . The working device 10 is attached to the tip of the arm 14 by extending and contracting the boom cylinder 20 to raise and lower the boom 12, by extending and contracting the arm cylinder 22 to rotate the arm 14, and by extending and contracting the bucket cylinder 24. It is possible to rotate the bucket 16. Boom cylinder 20, arm cylinder 22, and bucket cylinder 24 are hydraulically operated.

(Configuration of lower running body)
Next, the configuration of the undercarriage 2 will be explained with reference to FIGS. 2 to 4. FIG. 2 is a perspective view of the lower traveling body 2 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 viewed from below and from the right side in the vehicle width direction. FIG. 4 is a perspective view of a portion of the chassis 30 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 FIGS. 2 to 4, the chassis 30 includes an upper surface plate (upper surface) 32, a lower surface plate (lower surface) 34, and a pair of side plates 36. The chassis 30 has an internal space V defined between a top plate 32, a bottom plate 34, and a pair of side plates 36.

The top plate 32 extends in the vehicle longitudinal direction. As shown in FIG. 2, a cylindrical body (attachment part) 35 is disposed approximately at the center of the top plate 32 in the longitudinal direction of the vehicle. A revolving body 6 is rotatably attached. Furthermore, as shown in FIG. 4, the top plate 32 has an exhaust port 32a formed so as to be located above a battery assembly 50, which will be described later. As shown in FIG. 2, an exhaust port cover 32b that covers the exhaust port 32a from above and opens toward the rear is provided around the exhaust port 32a of the top plate 32.

As shown in FIGS. 3 and 4, the lower plate 34 is provided vertically facing the upper plate 32 and extends in the longitudinal direction of the vehicle. The lower surface plate 34 has 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 at a rear portion in the longitudinal direction of the vehicle than the second opening 342, and has a larger opening than the second opening 342. The first opening 341 opens to include a position above an axle casing (casing) 35R of an axle (not shown) to which a rear wheel 3b (described later) is attached. Furthermore, a pair of frame-side fastening portions 343 are formed on the lower surface plate 34 in the vehicle width direction, extending downward on the side of the first opening 341 and having 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. The pair of support brackets 40 are provided on the sides of the first opening 341 with an interval 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 bottom plate 34 and a bottom portion 42 extending from the side portion 41 toward the first opening 341 side. Bolt insertion holes 40a are formed in the bottom portion 42 of the support bracket 40 at intervals in the vehicle longitudinal direction.

The pair of side plates 36 are connected to both ends of the upper plate 32 and the lower plate 34 in the vehicle width direction, and extend in the longitudinal direction of the vehicle. A beam 38 serving as a reinforcing member extending in the vehicle width direction is connected between the pair of side plates 36 . The beam 38 is provided with two boss portions 381 spaced apart from each other in the vehicle width direction, to which bolts 83 (see FIG. 7), which will be described later, are fastened.

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

(Battery assembly)
Further, 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 each component will be 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 viewed from above and the right side in the vehicle width direction, and FIG. 6 is a perspective view of the battery assembly 50 viewed from above and the left side in the vehicle width direction. be. Further, FIG. 7 is a perspective view of the lower traveling body 2 on which the battery assembly 50 is mounted, viewed from the lower side and 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. As shown in FIGS. Note that in FIG. 5, illustrations of cables connected to the plurality of batteries B are omitted. In this embodiment, the plurality of batteries B includes six batteries B1, B2, B3, B4, B5, and B6. Each of the batteries B1 to B6 is a battery module in which, for example, a lithium ion secondary battery capable of plug-in charging and power supply is used, and a plurality of battery cells (not shown) are connected. Each of the batteries B1 to B6 is electrically connected in series by a cable 71, as shown in FIG. Further, 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.

Further, the battery B1 is electrically connected to the base cover 51 via cables 73 and 74 and a ground connection changeover switch 75. Thereby, when the battery assembly 50 is mounted on the lower traveling body 2, the reference potential of the plurality of batteries B1 to B6 is set to the ground potential. The ground connection changeover switch 75 is a switch that can electrically connect and disconnect the battery B1 and the base cover 51. For example, when the hydraulic excavator 1 is not used for a relatively long period of time or when performing electrical system maintenance, an operator can operate the ground connection changeover switch 75 to release the connection.

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

(Battery mounting structure on base cover)
A mounting structure for mounting a plurality of batteries B on the base cover 51 will be described. On the substrate portion 52 of the base cover 51, a plurality of batteries B1 to B6 are arranged in two rows, three each with an interval. Hereinafter, the plurality of batteries B1 to B3 on the front end 52a side of the board section 52 will be collectively referred to as "front row batteries BF", and the plurality of batteries B4 to B6 on the rear end 52b side of the board section 52 will be collectively referred to as "back row batteries BF". It is called BR.

A U-shaped first bracket 61 that covers the front and side surfaces of the lower part of the battery BF in the front row is attached to the board portion 52. Furthermore, a U-shaped second bracket 62 is attached to the substrate portion 52 to cover the rear and side surfaces of the lower part of the battery BR in the rear row. Furthermore, a third bracket 63 is attached to the substrate portion 52 to sandwich the side surface of the battery BF in the front row and the side surface of the battery BR in the rear row from both sides. The third bracket 63 includes a connecting portion 631 extending between the front row battery BF and the rear row battery BR, and a contact portion 632 that contacts the side surface, and the contact portion 632 is fixed to the base plate portion 52. .

Furthermore, fourth brackets 64 are arranged above the front row batteries BF and above the rear row batteries BR, respectively. The fourth bracket 64 has a plate-like portion 641 extending in the vehicle width direction, and a contact portion 642 extending downward from the plate-like portion 641 and sandwiching the side surface from both sides. The fourth bracket 64 has stays 65 attached to both ends of the plate portion 641 in the vehicle width direction that extend in the vertical direction, are locked to the base plate portion 52, and are capable of pressing the plate portion 641 toward the base plate portion 52. It is being 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, the second bracket 62, the third bracket 63, and the 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 part 42 of the support bracket 40 to which the board part 52 is attached to the chassis 30. As shown in FIGS. 5 and 6, cover-side fastening parts 522 are provided at both ends of the base plate part 52 in the vehicle width direction, in which a boss part to which a bolt 81 (see FIG. 7) is fastened is formed. . The cover-side fastening portion 522 comes into contact with the frame-side fastening portion 343 of the chassis 30 when the battery assembly 50 is attached to the chassis 30 shown in FIG. 7 . The cover-side fastening portion 522 is fastened to the frame-side fastening portion 343 by a 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 are provided at both ends of the base plate 52 in the vehicle width direction, spaced apart from each other in the longitudinal direction of the vehicle, to which bolts 82 (see FIG. 7) can be fastened. A section 523 is provided. The two cover-side boss portions 523 are aligned coaxially with the bolt insertion hole 40a (see FIG. 4) of the support bracket 40 when the battery assembly 50 is attached to the chassis 30 shown in FIG. Each cover-side boss portion 523 is fastened to the support bracket 40 by a bolt 82 inserted from below through the bolt insertion hole 40a.

Further, as shown in FIGS. 5 and 6, a plate-shaped attachment cover 54 is attached to the base plate 52 near the front end 52a and extending upward. A notch extending in the vehicle width direction is provided at the lower end of the attachment cover 54 on the base cover 51 side, thereby forming an opening 55 between the attachment cover 54 and the base cover 51. The mounting cover 54 contacts the beam 38 from the front side when the battery assembly 50 is mounted to the chassis 30 shown in FIG. 7 . Further, the mounting cover 54 is formed with a bolt insertion hole 54a (see FIGS. 5 and 6) that is coaxial with the boss portion 381 of the beam 38 (see FIG. 4). The mounting cover 54 is fixed to the beam 38 by fastening bolts 83 inserted from the front side of the mounting cover 54 through the bolt insertion holes 54a to the boss portions 381.

In addition, in the attachment cover 54, the ground connection changeover switch 75 also functions as an attachment part. The operating end of the ground connection changeover switch 75 is exposed on the front side of the mounting cover 54 in the vehicle longitudinal direction. Thereby, the operator can easily operate the ground changeover switch 75. Note that the ground connection changeover switch 75 may have an operating end exposed on the lower surface of the substrate portion 52.

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

Then, the operator positions the substrate portion 52 of the base cover 51 above the support bracket 40, as shown in step S20. Further, the operator slides the battery assembly 50 toward the rear in the longitudinal direction of the vehicle, as shown by the solid arrow in step S20. Thereby, as shown in FIG. 7, the base cover 51 is inserted between the bottom part 42 of the support bracket 40 and the bottom plate 34 and placed on the bottom part 42, and the battery assembly 50 is positioned in the vertical direction. . Further, the mounting cover 54 comes into contact with the beam 38, and the battery assembly 50 is positioned in the longitudinal direction of the vehicle. Thereafter, the operator fastens and fixes the base cover 51 to the chassis 30 using the bolts 81, 82, and 83 according to the above-described attachment structure for the base cover 51. As a result, in the battery assembly 50, the plurality of batteries B are stored in an area of the internal space V of the chassis 30 that includes a portion V1 located on the axle to which the rear wheel 3b is attached (see the broken line in FIG. 3). That will happen. Note that when removing the battery assembly 50 from the lower traveling body 2, the above procedure may be performed in reverse.

As described above, the hydraulic excavator (construction machine) 1 of the embodiment has a pair of side plates 36 spaced apart from each other in the vehicle width direction, and includes the working device 10 on the top plate (upper surface) 32. The undercarriage body 2 includes a cylindrical body 35 as an attachment part for the upper revolving body 6 and a chassis 30 having a first opening (opening) 341 in the lower surface plate (lower surface) 34, and is mounted on the undercarriage body 2. A battery assembly 50 that is a hydraulic excavator equipped with an electric motor M as a drive source for running, and that includes a plurality of batteries B that supply electric 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 B are stored in the 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. It is attached.

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

Further, the electric motor M is attached to an axle casing (casing) 35R that supports the axle with respect to the chassis 30, and the plurality of batteries B are stored in an area of the internal space V that includes a portion located on the axle. Ru. With this configuration, the distance between the electric motor M and the plurality of batteries B is brought closer, the increase in the length of the wiring from the plurality of batteries B to the electric motor M is further suppressed, and an increase in electrical loss and an increase in the number of parts are prevented. This can be further suppressed.

Further, the plurality of batteries B are stored in an area of the internal space V that includes a portion V1 (see the broken line in FIG. 3) located on the axle to which the rear wheel 3b is attached. With this configuration, when the hydraulic excavator 1 travels forward, it becomes easier to guide the traveling wind to the plurality of batteries B. As a result, the plurality of batteries B can be cooled well.

Further, the base cover 51 includes a substrate portion 52 on which a plurality of batteries B are mounted, and an inclined portion 53 extending downward from the front end of the substrate portion 52 toward the front side. With this configuration, when the hydraulic excavator 1 travels forward, the traveling wind can be guided to the plurality of batteries B through the inclined portion 53, and the plurality of batteries B can be cooled well.

Further, the chassis 30 includes a beam 38 extending between the pair of side plates 36, and the base cover 51 has a mounting cover 54 that extends in the vertical direction in front of the plurality of batteries B and is attached to the beam 38, An opening 55 is formed at the lower end of the attachment cover 54 . With this configuration, the base cover 51 is firmly attached to the chassis 30 by the attachment cover 54, and when the hydraulic excavator 1 travels forward, the traveling wind is guided to the plurality of batteries B through the opening 55 of the attachment cover 54. Therefore, the plurality of batteries B can be cooled well.

Further, an exhaust port 32a is formed in a portion of the chassis 30 located above the plurality of batteries B. With this configuration, for example, during charging of the plurality of batteries B, hydrogen discharged from the plurality of batteries B can be discharged from the exhaust port 32a, and hydrogen can be prevented from staying in the internal space V of the chassis 30. Further, it is possible to suppress an increase in the atmospheric temperature in the internal space V of the chassis 30, and to appropriately protect the plurality of batteries B.

Further, on the lower surface of the chassis 30, an L-shaped support bracket 40 having a side portion 41 extending downward from the chassis 30 and a bottom portion 42 extending inward in the vehicle width direction from the side portion 41 is spaced apart in the vehicle width direction. The base cover 51 is inserted between the side parts 41 of the pair of support brackets 40 and supported by the bottom part 42. With this configuration, the battery assembly 50 can be easily assembled to the chassis 30.

(Modified example)
This concludes the description of the embodiment, but aspects of the present invention are not limited to this embodiment. For example, in the present embodiment, aspects of the present invention have been explained using a wheel-type hydraulic excavator 1 as an example of a construction machine, but the type of construction machine is not limited to this, and for example, a wheel loader that can be driven by an electric motor. It may also be applied to construction machinery.

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

Further, the plurality of batteries B may be stored in a location in the interior space V other than the range including the location on the axle to which the rear wheel 3b is 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, for example, a plurality of batteries B are stored in an area V2 surrounded by a broken line in FIG. 9 in the internal space V. That is, the battery assembly 50 may be stored in a range V2 of the interior space V that includes a portion located on the axle to which the front wheel 3a is attached. In this case, the plurality of batteries B etc. may be stored in such a manner as to avoid the beam extending between the side plates 36 in the range V2.

Further, the base cover 51 does not need to have the slope portion 53.

Further, if the battery assembly 50 can be attached to the chassis 30, the attachment cover 54 may be omitted from the battery assembly 50. Moreover, the opening 55 of the attachment cover 54 may be omitted as long as the plurality of batteries B can be sufficiently cooled.

Further, the exhaust port 32a of the top plate 32 may be omitted, as long as it is possible to suppress hydrogen from remaining in the internal space V and to suppress an increase in the ambient temperature. It may also be formed at other locations.

Further, as long as the battery assembly 50 can be attached to the chassis 30, the base cover 51 may be supported not only by the support bracket 40 but also by other support means.

1 Hydraulic excavator 2 Lower traveling body 3 Wheel 3a Front wheel 3b Rear wheel 10 Working device 30 Chassis 32 Top plate (upper surface)
32a Exhaust port 32b Exhaust port cover 34 Bottom plate (bottom surface)
35 Cylindrical body (attachment part)
35F, 35R Axle casing (casing)
36 Side plate 38 Beam 40 Support bracket 41 Side part 42 Bottom part 50 Battery assembly 51 Base cover 52 Board part 52a Front end 52b Rear end 53 Inclined part 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 lower traveling body including a chassis having a pair of side plates spaced apart from each other in the vehicle width direction and having a mounting portion for an upper rotating body having a working device on the upper surface and an opening on the lower surface; A construction machine equipped with an electric motor as a drive source for traveling mounted on the body,
A battery assembly including a plurality of batteries that supply power to the electric motor and a base cover on which the plurality of batteries are mounted,
The base cover of the battery assembly is configured to transport the plurality of batteries into an internal space of the chassis defined between the pair of side plates through the opening at a position spaced rearward from the front edge of the opening. A construction machine that is attached to the chassis in a stored state . the electric motor is attached to a casing that supports an axle with respect to the chassis;
The construction machine according to claim 1, wherein the plurality of batteries are stored in an area of the internal space that includes a portion located on the axle. The construction machine according to claim 1, wherein the plurality of batteries are stored in an area of the internal space that includes a portion located on an axle to which a rear wheel is attached. 2. The construction machine according to claim 1, wherein the base cover includes a substrate portion on which the plurality of batteries are mounted, and an inclined portion extending downward from the front end of the substrate portion toward the front side. a lower traveling body including a chassis having a pair of side plates spaced apart from each other in the vehicle width direction and having a mounting portion for an upper rotating body having a working device on the upper surface and an opening on the lower surface; A construction machine equipped with an electric motor as a drive source for traveling mounted on the body,
A battery assembly including 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 is configured such that the plurality of batteries are stored in an internal space of the chassis defined between the pair of side plates through the opening, and the base cover is attached to the chassis.
The chassis includes a beam extending in the vehicle width direction by connecting the pair of side plates,
The base cover has an attachment cover that extends in the vertical direction in front of the plurality of batteries and is attached to the beam,
In the construction machine, an opening is formed in a lower end portion 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, each having a side portion extending downward from the chassis and a bottom portion extending inward in the vehicle width direction from the side portion, are attached to the lower surface of the chassis at an interval in the vehicle width direction. ,
The construction machine according to claim 1, wherein the base cover is inserted between the side parts of the pair of support brackets and supported by the bottom part.

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