WO2023140371A1

WO2023140371A1 - Crane

Info

Publication number: WO2023140371A1
Application number: PCT/JP2023/001840
Authority: WO
Inventors: 貴史川野; 王彦寺田; 将太中松
Original assignee: 株式会社タダノ
Priority date: 2022-01-24
Filing date: 2023-01-23
Publication date: 2023-07-27
Also published as: JP2023107414A

Abstract

A crane having an upper slewing body for supporting a boom, said crane being equipped with: a lower traveling body having a frame which supports a front-rear pair of vehicle axles; a power supply unit which includes an internal battery housed inside the frame; and a traveling motor which is driven by the power supply unit.

Description

crane

The present invention relates to cranes.

Patent Document 1 discloses a mobile crane provided with a lower traveling body having a traveling function and an upper revolving body provided on the upper portion of the lower traveling body in a rotatable state. The undercarriage has an engine and runs based on the power of the engine.

JP 2012-96928 A

In recent years, from the perspective of environmental protection, etc., there is a demand for electric cranes as described above.

The object of the present invention is to provide a crane that can run on electric power.

One aspect of the crane according to the present invention is
A crane having an upper rotating body that supports a boom,
a lower traveling body having a frame supporting a pair of front and rear axles;
a power supply including an internal battery housed in a frame;
a running motor driven by the power supply.

According to the present invention, it is possible to provide a crane that can run on electric power.

FIG. 1 is a schematic diagram of a mobile crane according to an embodiment. FIG. 2 is a block diagram schematically showing the configuration of the heavy-electric system. FIG. 3 is a perspective view of the crane with part of the configuration omitted. FIG. 4 is a perspective view of the crane with part of the configuration omitted. FIG. 5 is a schematic plan view for explaining the arrangement of the batteries. 6 is a schematic side view of the battery viewed from the direction of arrow _A1 in FIG. 5. FIG. FIG. 7 is a schematic plan view for explaining the arrangement of the battery provided in the front of the frame.

An example of an embodiment according to the present invention will be described in detail below with reference to the drawings. A crane according to an embodiment described later is an example of a crane according to the present invention, and the present invention is not limited to the embodiment described later.

[Embodiment]
FIG. 1 is a schematic diagram of a mobile crane 1 (a rough terrain crane in the illustrated case) according to this embodiment. Examples of mobile cranes include all-terrain cranes, truck cranes, and load-type truck cranes (also called cargo cranes).

The mobile crane 1 has a lower traveling body 2 and an upper rotating body 5. The mobile crane 1 is an electric crane equipped with a heavy-electric system battery 30 (see FIG. 2). The mobile crane 1 travels on the power supplied from the heavy-current system battery 30 . That is, the mobile crane 1 does not have an engine.

Also, the mobile crane 1 performs operations other than traveling (for example, crane work and/or heating) based on the power supplied from the heavy-electric system battery 30 . A crane operation is, for example, a swing operation and/or a winch operation in a cargo transport operation. A specific configuration of the mobile crane 1 will be described below.

First, the configuration of the upper revolving body 5 will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic diagram of a mobile crane 1. FIG. FIG. 2 is a block diagram schematically showing the configuration of the heavy electrical system 3 mounted on the mobile crane 1. As shown in FIG.

The heavy-current system 3 is a system powered by a heavy-current battery 30, which will be described later, and is composed of the heavy-current battery 30 and elements electrically connected to the heavy-current battery 30. Although FIG. 2 shows the main elements that make up the heavy-current system 3, the heavy-current system 3 may include elements other than the main elements shown in FIG.

The upper revolving body 5 is provided on the upper part of the lower traveling body 2, and is capable of revolving with respect to the lower traveling body 2 around the turning center axis α. The upper rotating body 5 has a swivel base 51, a telescopic boom 52, and a cab.

The swivel base 51 is supported above the lower traveling body 2 via bearings (not shown). The swivel base 51 swivels based on power generated by a swivel actuator (not shown) provided on the upper swivel body 5 . In this embodiment, the turning actuator is a hydraulic motor. This motor operates based on supply and discharge of hydraulic oil. Hydraulic oil is supplied from the undercarriage 2 . Incidentally, the turning actuator may be an electric motor. In this case, the electric motor for turning is driven based on electric power supplied from a heavy-current system battery 30, which will be described later.

The telescopic boom 52 is supported by the swivel base 51 and has a plurality of telescopically combined booms. The telescopic boom 52 can change its hoisting angle (raises and lowers) based on the power generated by the hoisting cylinder 54 .

The hoisting cylinder 54 is a telescopic hydraulic cylinder and is provided on the upper revolving body 5 . The hoisting cylinder 54 operates based on supply and discharge of hydraulic oil. Hydraulic oil is supplied from the lower traveling body 2 .

Also, the telescopic boom 52 telescopes based on the power generated by the telescopic cylinder 55 . The telescopic cylinder 55 is a hydraulic cylinder and is provided inside the telescopic boom 52 . The telescopic cylinder 55 operates based on supply and discharge of hydraulic oil. Hydraulic oil is supplied from the lower traveling body 2 .

Also, the telescopic boom 52 supports a wire rope 56 . A wire rope 56 hangs down from the tip of the telescopic boom 52 and has a hook 57 at the tip. A portion of the wire rope 56 is wound around a winch 58 .

The winch 58 is driven (rotated) based on power generated by a winch actuator (not shown). In this embodiment, the winch actuator is provided on the swivel base 51 and is a hydraulic motor. This motor operates based on supply and discharge of hydraulic oil. Hydraulic oil is supplied from the undercarriage 2 .

When the winch 58 rotates, the wire rope 56 is wound up or let out depending on the direction of rotation of the winch 58 . The winch motor may be an electric motor. In this case, the electric motor for the winch is driven based on power supplied from a heavy-current system battery 30, which will be described later.

Next, the lower running body 2 will be described with reference to FIGS. 1 to 7. FIG. In describing the structure of the undercarriage 2, an orthogonal coordinate system (X, Y, Z) shown in each drawing is used. The X direction coincides with the front-rear direction of the lower traveling body 2 . The X direction + side coincides with the front side of the lower traveling body 2 . The X direction - side coincides with the rear side of the lower traveling body 2 . The Y direction coincides with the horizontal direction of the lower traveling body 2 . The Y-direction + side coincides with the left side when viewed forward from the lower traveling body 2 . The negative side in the Y direction corresponds to the right side when viewed forward from the lower traveling body 2 . The Z direction coincides with the vertical direction of the lower traveling body 2 . The Z-direction + side coincides with the upper side of the lower traveling body 2 . The − side in the Z direction coincides with the lower side of the lower traveling body 2 .

The lower traveling body 2 can travel by electric power. Specifically, the undercarriage 2 has a frame 20 , a body 21 , a front axle 22 , a rear axle 23 , front tires 24 , rear tires 25 and outriggers 26 .

The frame 20 is a box-shaped member with a rectangular cross section extending in the front-rear direction, and constitutes the skeleton of the lower traveling body 2 . The frame 20 has an upper plate portion 20a, a lower plate portion 20b, a right plate portion 20c, a left plate portion 20d, a front plate portion 20e, and a rear plate portion 20f.

In addition, the frame 20 has a battery housing space 201 formed by a through hole penetrating the frame 20 in the vertical direction. The battery accommodation space 201 corresponds to an example of the rear battery accommodation space, and is provided in the frame 20 at a position extending from the upper side to the rear end of the rear axle 23 . In other words, the battery housing space 201 may be regarded as provided in the rear portion of the frame 20 .

The cross-sectional shape of the portion of the frame 20 where the battery housing space 201 is formed is a closed cross-section composed of a plurality of continuous plate portions. Note that the cross section of the frame 20 means a cross section when the frame 20 is cut along the YZ plane.

In the case of this embodiment,

first batteries

301a and 301b, which will be described later, are housed in the battery housing space 201 through an upper opening of the battery housing space 201.

In addition, the rear end portion of the battery housing space 201 is closed by the rear side plate portion 20f. When the rear side plate portion 20 f is removed from the frame 20 , an opening that opens rearward is formed at the rear end portion of the battery housing space 201 .

This opening may be, for example, an insertion port for inserting the below-described

first batteries

301a and 301b into the battery housing space 201, and an outlet for taking out the below-described

first batteries

301a and 301b from the battery housing space 201. Note that the opening may not always be formed. In other words, the opening may be formed when the rear side plate portion 20f is removed from the frame 20. As shown in FIG.

The battery housing space 201 may be a space surrounded by the upper plate portion 20a, the lower plate portion 20b, the right plate portion 20c, and the left plate portion 20d of the frame 20 in the vertical and horizontal directions instead of the through hole. With such a configuration, the rigidity of the portion of the frame 20 where the battery housing space is provided can be increased. Also in this case, it is preferable to employ a configuration in which the rear end of the battery housing space is closed by the rear side plate in an openable state.

Also, the position of the battery housing space is not limited to the illustrated case. The battery housing space may be provided in the frame 20 at a position extending from above the front axle 22 to the front end thereof. In this case, when the front side plate portion 20e is removed from the frame 20, an opening opening forward is formed at the front end portion of the battery housing space. This opening serves as an insertion port for inserting the battery into the battery housing space and an ejection port for removing the battery from the battery housing space. Note that the opening may not always be formed. In other words, the opening may be formed when the front side plate portion 20 e is removed from the frame 20 .

The frame 20 has a pair of front outrigger support portions 202 at the front end. The frame 20 has a pair of rear outrigger support portions 203 at its rear end.

The body 21 (see FIG. 1) is a member that forms the outer shape of the undercarriage 2 and is supported by the frame 20 .

The front axle 22 is a shaft member that extends in the left-right direction, and is supported by a portion of the lower plate portion 20b of the frame 20 near the front end. Front tires 24 are rotatably supported at both ends of the front axle 22 in the left-right direction.

The rear axle 23 is a shaft member that extends in the left-right direction, and is supported by a portion of the frame 20 near the rear end of the lower plate portion 20b. Rear tires 25 are rotatably supported at both ends of the rear axle 23 in the left-right direction.

Incidentally, in the case of this embodiment, the mobile crane 1 is a so-called two-axle type mobile crane having a front axle 22 and a rear axle 23 . However, the mobile crane may be a so-called multi-axle type mobile crane having three or more axles.

The outriggers 26 have a pair of front outriggers 26a and a pair of rear outriggers 26b. The pair of front outriggers 26a are supported by a pair of front outrigger support portions 202 of the frame 20, respectively. The pair of rear outriggers 26b are supported by the pair of rear outrigger support portions 203 of the frame 20, respectively.

Also, the mobile crane 1 of this embodiment has a high-power system 3 . The heavy-electric system 3 is a system for executing the traveling of the lower traveling body 2 and the operation other than traveling in the crane 1 (for example, crane work and/or heating) based on electric power supplied from a heavy-electric battery 30, which will be described later. The configuration of the high-voltage system 3 will be described below.

Although illustration and detailed description are omitted, the mobile crane 1 of this embodiment also has a light current system. The light current system is a system for executing a predetermined process for the mobile crane 1 based on power supplied from a light current battery (not shown) having a voltage lower than that of the heavy current battery 30 . The light current system is also a system for transmitting control signals for causing the mobile crane 1 to perform predetermined processing.

As shown in FIG. 2, the heavy-current system 3 has a heavy-current battery 30, a lower junction box 31, a running inverter 33, a running motor 34, a slip ring 35, and an upper device 39 as main elements.

The heavy-current system battery 30 corresponds to an example of a power supply unit, and includes a plurality of vertically placed (two in this embodiment)

first batteries

301a and 301b and a plurality of horizontally placed (two in this embodiment)

second batteries

302a and 302b.

The

first batteries

301a and 301b correspond to examples of an internal battery and a rear internal battery, respectively, and are arranged in the battery housing space 201 of the frame 20 while being aligned in the front-rear direction. That is, the

first batteries

301a and 301b are housed in the frame 20 respectively.

In this way, in the case of the present embodiment, the dead space of the frame 20 can be effectively utilized, so that the heavy-current system battery 30 can be arranged compactly, and damage to the heavy-current system battery 30 due to impact or the like can be suppressed. Note that the

first batteries

301a and 301b may be arranged in the battery housing space 201 of the frame 20 in a vertically overlapping state.

Each of the

first batteries

301a and 301b has a substantially rectangular parallelepiped shape and is arranged such that its longitudinal direction extends along the front-rear direction (that is, the axial direction of the frame 20).

The

first batteries

301a and 301b are fixed to the frame 20 via fixing devices such as brackets (not shown). A fixing device for fixing the

first batteries

301a and 301b to the frame 20 is preferably a fixing device capable of elastically supporting the

first batteries

301a and 301b to the frame 20, such as a rubber mount.

Such a fixing device can absorb vibrations and shocks applied to the

first batteries

301a and 301b, as well as twisting of the frame 20 during crane work, and thus contributes to improving the durability of the

first batteries

301a and 301b.

The

first batteries

301a and 301b have housings with the same external shape. Thus, in the case of the present embodiment, the

first batteries

301a and 301b have the same external shape, so the

first batteries

301a and 301b can be arranged efficiently while reducing the production cost.

The first battery 301a is arranged on the front side of the first battery 301b. Each of the

first batteries

301a and 301b has a power supply terminal. The first battery 301a on the front side has a power supply terminal portion on the rear side surface. The power supply terminal portion of the first battery 301a on the front side is arranged facing backward. On the other hand, the first battery 301b on the rear side has a power supply terminal portion on the front side surface. The power terminal portion of the first battery 301b on the rear side is arranged facing forward.

Therefore, the power supply terminal portion of the first battery 301a on the front side and the power supply terminal portion of the first battery 301b on the rear side face each other in the front-rear direction. In this embodiment, the first battery 301a on the front side and the first battery 301b on the rear side are not connected in series. The first battery 301a on the front side and the first battery 301b on the rear side are provided in parallel. However, if it is desired to increase the voltage, the first battery 301a on the front side and the first battery 301b on the rear side may be connected in series.

The first battery 301a on the front side and the first battery 301b on the rear side are connected via cables to a first sub-junction box 310 in the lower junction box 31, which will be described later.

In the case of this embodiment, the power supply terminal portion of the first battery 301a and the power supply terminal portion of the first battery 301b are arranged together in an area between the rear side surface of the first battery 301a and the front side surface of the first battery 301b. Therefore, it becomes easier to connect and disconnect power supply cables to and from the first battery 301a and the first battery 301b collectively, thereby improving work efficiency of connection work and maintenance work.

Also, the first battery 301a on the front side has a service plug on the front side. Also, the first battery 301b on the rear side has a service plug on the rear side. The first battery 301a on the front side may have a service plug on the rear side surface. Also, the rear first battery 301b may have a service plug on the front side.

As shown in FIG. 6, the first battery 301b on the rear side is arranged slightly below the first battery 301a on the front side. Such an arrangement ensures a space for arranging other elements above the first battery 301b. Specifically, in the case of this embodiment, a second sub-junction box 311, which will be described later, is arranged in this space.

The

second batteries

302a and 302b correspond to an example of external batteries, respectively, and are arranged above the

first batteries

301a and 301b and the frame 20 while being aligned in the left-right direction. In other words, the

second batteries

302a and 302b are each arranged outside the frame. Each of the

second batteries

302a and 302b is fixed to the upper plate portion 20a of the frame 20 via a fixing device such as a bracket (not shown).

Each of the

second batteries

302a and 302b has a substantially rectangular parallelepiped shape and is arranged so that its longitudinal direction extends along the left-right direction. The second battery 302a is arranged on the left side of the second battery 302b.

Each of the

second batteries

302a and 302b has a terminal portion. The left second battery 302a has a power supply terminal portion at the left end of the rear side surface. On the other hand, the second battery 302b on the right side has a power supply terminal portion at the right end of the front side surface. The positions of the power supply terminals of the

second batteries

302a and 302b are not limited to those of the present embodiment.

In the case of this embodiment, the second battery 302a on the left side and the second battery 302b on the right side are not connected in series. The left second battery 302a and the right second battery 302b are provided in parallel. However, if it is desired to increase the voltage, the second battery 302a on the left side and the second battery 302b on the right side may be connected in series.

The second battery 302a on the left side and the second battery 302b on the right side are connected to a second sub-junction box 311 in the lower junction box 31 described later via cables.

In addition, since the

first batteries

301a, 301b and the

second batteries

302a, 302b are collectively arranged in a predetermined area near the rear end of the frame 20, the connection structure (cable routing structure) relating to the

first batteries

301a, 301b and the

second batteries

302a, 302b can be made compact, electric loss can be reduced, noise can be reduced, and maintainability can be improved.

It should be noted that the position of the second battery is not limited to the illustrated case. For example, a second battery may be located outside the frame 20 and between the front axle 22 and the rear axle 23 . From the viewpoint of space saving, it is preferable that the second batteries are arranged side by side in the front-back direction or the up-down direction. Also in such a configuration, the

second batteries

302a and 302b are fixed to the frame 20 outside the frame 20 via a fixing device such as a bracket.

Also, the total capacity of the

second batteries

302a and 302b may be the same as or different from the total capacity of the

first batteries

301a and 301b. When the

first batteries

301a and 301b arranged inside the frame 20 are regarded as main batteries and the

second batteries

302a and 302b arranged outside the frame 20 are regarded as sub-batteries, the total capacity of the

second batteries

302a and 302b may be smaller than the total capacity of the

first batteries

301a and 301b.

It should be noted that the second battery arranged outside the frame 20 may be omitted if all the heavy-current system batteries can be accommodated within the frame 20 . With such a configuration, the height of the rear portion of the frame 20 can be lowered, so that a wide field of view can be ensured when the upper swing body 5 is swung backward.

Also, in the case of this embodiment, no heavy-current battery is arranged at the front end of the frame 20 . However, as shown in FIG. 7 , some of the heavy-current system batteries may be provided in the front of the frame 20 . FIG. 7 is a schematic plan view showing the front end portion of the frame 20 viewed from above.

As shown in FIG. 7, the front battery 305, which is part of the heavy-current system battery, is housed in the front battery housing space 204 of the frame 20. As shown in FIG. The front battery housing space 204 is formed by a through-hole penetrating the frame 20 in the vertical direction. The front battery housing space 204 is provided in the frame 20 at a position extending from the upper side to the front end of the front axle 22 .

The front battery 305 has a front first battery 305a provided on the front side and a front second battery 305b provided on the rear side of the front first battery 305a. The front first battery 305a and the front second battery 305b correspond to examples of an internal battery and a front internal battery. By arranging the heavy battery not only at the rear of the frame 20 but also at the front, the weight balance in the front-rear direction of the mobile crane 1 can be flexibly adjusted.

In the case of this embodiment, the front first battery 305a and the front second battery 305b are accommodated in the front battery accommodation space 204 from the upper opening of the front battery accommodation space 204.

As shown in FIG. 7, the front first battery 305a and the front second battery 305b are connected to the main junction box via a third sub-junction box 312, which will be described later. In this embodiment, the front first battery 305a and the front second battery 305b are not connected in series. The front first battery 305a and the front second battery 305b are provided in parallel. However, if it is desired to increase the voltage, the front first battery 305a and the front second battery 305b may be connected in series.

Also, in the case of this embodiment, no external battery is provided in the front of the frame 20 . By adopting a configuration in which no external battery is provided at the front of the frame 20, the height of the front of the frame 20 can be reduced. As a result, it is possible to secure a sufficient field of view from the cab when the mobile crane 1 moves forward.

When using the front battery 305, the

second batteries

302a and 302b (that is, external batteries) provided at the rear of the frame 20 may be omitted. When the

second batteries

302a and 302b are omitted, the heavy-current system 3 may be configured to have only internal batteries without external batteries.

The lower junction box 31 is for distributing the power supplied from the heavy current system battery 30 . The lower junction box 31 has a first sub-junction box 310, a second sub-junction box 311, a third sub-junction box 312 and a main junction box (not shown).

The first sub-junction box 310 is arranged in front of the front first battery 301a in the battery housing space 201 of the frame 20 .

First batteries

301a and 301b are connected to the first sub-junction box 310 via cables.

Also, the first subjunction box 310 is connected to the main junction box (not shown) via a cable. The first subjunction box 310 sends power supplied from the

first batteries

301a, 301b to a main junction box (not shown).

The second sub-junction box 311 is arranged above the rear first battery 301b in the battery housing space 201 of the frame 20 .

Second batteries

302a and 302b are connected to the second sub-junction box 311 via cables.

Also, the second subjunction box 311 is connected to the main junction box (not shown) via a cable. The second sub-junction box 311 sends power supplied from the

second batteries

302a, 302b to the main junction box.

The third sub-junction box 312 is arranged above the front first battery 305 a and outside the frame 20 . However, the position of the third sub-junction box 312 is not limited to the illustrated case. The third sub-junction box 312 may be arranged inside the frame 20, for example.

Also, the third sub-junction box 312 is connected to the main junction box via a cable. The third subjunction box 312 sends power supplied from the front first battery 305a and the front second battery 305b to a main junction box (not shown).

Also, the main junction box is connected to the running inverter 33 via a cable. Furthermore, the main junction box is connected to slip ring 35 via a cable. Incidentally, the main junction box may be connected to other elements provided on the lower traveling body 2 .

The running inverter 33 adjusts the current received from the main junction box and sends it to the running motor 34, which will be described later. If it is desired to increase the torque during travel of the mobile crane 1 , a travel converter (not shown) may be provided between the main junction box and the travel inverter 33 . Such a running converter boosts the electric power supplied from the main junction box and sends it to the running inverter 33 .

The driving motor 34 is driven based on the power supplied from the high-voltage system battery 30 under the control of a control unit (not shown). The controller adjusts the torque of the traveling motor 34 .

The slip ring 35 is for sending the power of the heavy-current system battery 30 supplied from the main junction box from the lower traveling structure 2 to the upper device 39 (see FIG. 2) of the upper revolving structure 5.

The slip ring 35 is also for sending the current flowing through the light current system and the control signal from the lower traveling body 2 to the upper device 39 of the upper revolving body 5 .

The upper device 39 is a device that is provided on the upper revolving body 5 and that operates based on the power of the high-voltage system battery 30 . If the turning actuator is an electric motor, the turning electric motor is an example of the upper device. Further, when the winch actuator is an electric motor, the winch electric motor corresponds to an example of the upper device. In this case, the slip ring 35 is connected to the turning electric motor and the winch electric motor via an upper junction box (not shown). Such an upper junction box has a function of allocating the electric power of the heavy current system battery 30 supplied via the slip ring 35 to the turning electric motor and the winch electric motor.

When the power of the high-voltage system battery 30 is supplied, the electric motor for turning is driven based on the power. The electric motor for turning causes the upper turning body 5 to turn.

Also, when the electric motor for the winch is supplied with power from the high-voltage system battery 30, it is driven based on the power. An electric motor for the winch then rotates a winch (not shown). As a result, the wire rope 56 is hoisted or let out, and the hook 57 is raised or lowered.

<Actions and effects of the present embodiment>
According to this embodiment having the configuration as described above, the mobile crane 1 that can travel based on the electric power of the heavy-current system battery 30 can be realized. Further, the mobile crane 1 according to this embodiment can drive the upper device 39 provided on the upper swing body 5 based on the electric power of the heavy-current system battery 30 . Other actions and effects provided by the mobile crane 1 according to the present embodiment are as described above.

The disclosure contents of the specification, drawings, and abstract contained in the Japanese application of Japanese Patent Application No. 2022-8608 filed on January 24, 2022 are incorporated herein by reference.

The cranes according to the present invention are not limited to rough terrain cranes, and may be various mobile cranes such as all-terrain cranes, truck cranes, or loading-type truck cranes (also called cargo cranes).

1 mobile crane 2 undercarriage 20 frame 20a upper side plate 20b lower side plate 20c right side plate 20d left side plate 20e front side plate 20f rear side plate 201 battery storage space 202 front outrigger support 203 rear outrigger support 204 front battery storage space 21 body 22 front axle 23 rear axle 24 front tire 25 rear tire 26 outrigger 26a front outrigger 26b rear outrigger 3 heavy current system 30 heavy

current system battery

301a, 301b

first battery

302a, 302b second battery 305 front battery 305a front first battery 305b front second battery 31 lower junction box 310 first subjunction box 31 1 second sub-junction box 312 third sub-junction box 33 traveling inverter 34 traveling motor 35 slip ring 39 upper device 5 upper revolving body 51 swivel base 52 telescopic boom 53 cab 54 hoisting cylinder 55 telescopic cylinder 56 wire rope 57 hook 58 winch

Claims

A crane having an upper rotating body that supports a boom,
a lower traveling body having a frame supporting a pair of front and rear axles;
a power supply including an internal battery housed in the frame;
and a traveling motor driven by the power supply unit. A crane.
The crane according to claim 1, wherein the internal battery is arranged such that its longitudinal direction extends along the front-rear direction.
The crane according to claim 1, wherein the internal battery is composed of a plurality of batteries arranged side by side in the longitudinal direction or the vertical direction.
The crane according to claim 3, wherein the internal battery is composed of a plurality of batteries having the same external shape and arranged side by side in the front-rear direction, and has a power supply terminal portion on a surface facing the adjacent internal batteries.
The crane according to claim 1, wherein the internal battery includes a rear internal battery arranged in a rear battery housing space provided at the rear of the frame.
The crane according to claim 5, wherein the internal battery includes a front internal battery arranged in a front battery housing space provided in the front portion of the frame.
The crane according to claim 5, wherein the power supply unit includes an external battery arranged outside the frame and above the rear internal battery, or outside the frame and between the pair of front and rear axles.
The crane of claim 7, wherein said external battery is connected in parallel with said internal battery.
A crane according to claim 7, wherein said external battery comprises a plurality of batteries arranged in series or in parallel.
The crane of claim 7, wherein the capacity of the external battery is less than the capacity of the internal battery.
The crane according to claim 7, wherein the external battery is arranged such that its longitudinal direction extends along the lateral direction.
The crane according to claim 7, wherein the external battery is composed of a plurality of batteries arranged side by side in the left-right direction outside the frame and above the rear internal battery.
8. The crane according to claim 7, wherein said external battery comprises a plurality of batteries arranged side by side in the front-rear direction outside said frame and between said pair of front and rear axles.