Crane

Abstract

To provide a crane capable of traveling by electric power.SOLUTION: A crane includes: a traveling vehicle body having a traveling motor that is driven by a power supply unit; a hydraulic oil supply device that is driven by the power supply unit and supplies hydraulic oil to a driven portion; and a regenerative brake device that performs regenerative brake control for generating braking force by supplying regenerative electric power generated by the traveling motor to the power supply unit during deceleration of the traveling vehicle body, where the regenerative brake device distributes the regenerative electric power to the hydraulic oil supply device and changes electric power consumed by the hydraulic oil supply device according to chargeable electric power of the power supply unit in the regenerative brake control.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a crane.

Background Art

[0002] Patent Document 1 discloses a mobile crane including a lower traveling body having a traveling function and an upper slewing body rotatably provided on the upper part of the lower traveling body. The lower traveling body has an engine and travels based on the power of the engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, from the viewpoints of environmental protection and the like, electrification of the above - described crane has been demanded.

[0005] An object of the present invention is to provide a crane that can travel by electric power.

Means for Solving the Problems

[0006] One aspect of the crane according to the present invention is a traveling vehicle body having a traveling motor driven by a power supply unit, a hydraulic oil supply device driven by a power supply unit and supplying hydraulic oil to a driven part, a regenerative brake device that performs regenerative brake control to supply regenerative power generated by the traveling motor during deceleration of the traveling vehicle body to the power supply unit to generate a braking force, In the regenerative brake control, the regenerative brake device distributes the regenerative power to the hydraulic oil supply device according to the chargeable power of the power supply unit and changes the power consumed by the hydraulic oil supply device.

Effects of the Invention

[0007] According to the present invention, a crane that can travel by power can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0009] Hereinafter, an example of an embodiment of a crane according to the present invention will be described in detail with reference to the drawings. Note that the crane according to the following embodiment is an example of the crane according to the present invention, and the present invention is not limited by the following embodiment.

[0010] [Embodiment] With reference to FIGS. 1 to 5, the mobile crane 1 according to the present embodiment will be described. FIG. 1 is a schematic diagram of the mobile crane 1 (in the illustrated case, a rough terrain crane) according to the present embodiment. The mobile crane is, for example, an all terrain crane, a truck crane, or a loading truck crane (also referred to as a cargo crane). However, the crane according to the present invention may be various types of cranes.

[0011] The mobile crane 1 has a lower traveling body 2 and an upper slewing body 3. The mobile crane 1 is an electric crane equipped with a high-voltage battery 60 (see Fig. 2). The mobile crane 1 travels using only the electric power supplied from the high-voltage battery 60 as power. That is, the mobile crane 1 does not have an engine.

[0012] In addition, the mobile crane 1 performs operations other than traveling (for example, crane work, air conditioning, and / or heating) based on the electric power supplied from the high-voltage battery 60. The crane work is, for example, a slewing operation and / or a winch operation in a cargo transportation operation.

[0013] When decelerating in the traveling state, such a mobile crane 1 performs regenerative brake control to supply the regenerative electric power generated by the traveling motor 63 to the high-voltage battery 60 to generate braking force.

[0014] And, in the regenerative brake control, the mobile crane 1 distributes the regenerative electric power to the hydraulic oil supply device 8 when the remaining battery level of the high-voltage battery 60 is greater than a predetermined value. At this time, the mobile crane 1 changes the electric power consumed by the hydraulic oil supply device 8 according to the remaining battery level. Hereinafter, the specific configuration of the mobile crane 1 will be described. Then, the regenerative brake control implemented in the mobile crane 1 will be described.

[0015] First, referring to Fig. 1, the configuration of the upper slewing body 3 will be described. Fig. 1 is a schematic diagram of the mobile crane 1. The upper slewing body 3 is provided above the lower traveling body 2 and slews around the slewing center axis α with respect to the lower traveling body 2. The upper slewing body 3 has a slewing platform 31, a telescopic boom 32, and a cab 33.

[0016] The slewing platform 31 is supported above the lower traveling body 2 via a bearing (not shown). The slewing platform 31 slews based on the power generated by a slewing actuator (not shown) provided on the upper slewing body 3.

[0017] In the case of this embodiment, the slewing actuator is a hydraulic motor. This motor operates based on the supply and discharge of hydraulic oil. The hydraulic oil is supplied from the lower traveling body 2. Note that the slewing actuator may be an electric motor. In this case, the slewing electric motor is driven based on the power supplied from a high-voltage battery 60 described later.

[0018] The telescopic boom 32 is supported by the slewing platform 31 and has a plurality of booms that are telescopically combined. The telescopic boom 32 can change its elevation angle based on the power generated by the elevation cylinder 34.

[0019] The elevation cylinder 34 is a telescopic hydraulic cylinder and is provided on the upper slewing body 3. The elevation cylinder 34 operates based on the supply and discharge of hydraulic oil. Note that the hydraulic oil is supplied by a hydraulic oil supply device 8 (see FIG. 2) provided on the lower traveling body 2.

[0020] Also, the telescopic boom 32 expands and contracts based on the power generated by the telescopic cylinder 35. The telescopic cylinder 35 is a hydraulic cylinder and is provided inside the telescopic boom 32. The telescopic cylinder 35 operates based on the supply and discharge of hydraulic oil. Note that the hydraulic oil is supplied by a hydraulic oil supply device 8 (see FIG. 2) provided on the lower traveling body 2.

[0021] Also, the telescopic boom 32 supports a wire rope 36. The wire rope 36 hangs down from the tip of the telescopic boom 32, and a hook 37 is provided at the tip. A part of the wire rope 36 is wound around a winch 38.

[0022] The winch 38 is driven based on the power generated by a winch actuator (not shown). In the case of this embodiment, the winch actuator is provided on the slewing platform 31 and is a hydraulic motor. This motor operates based on the supply and discharge of hydraulic oil. The hydraulic oil is supplied by a hydraulic oil supply device 8 (see FIG. 2) provided on the lower traveling body 2.

[0023] When the winch 38 rotates, the wire rope 36 is wound up or let out according to the rotation direction of the winch 38. Note that the motor for the winch may be an electric motor. In this case, the electric motor for the winch is driven based on the power supplied from the high-voltage battery 60 described later.

[0024] Next, with reference to FIGS. 1 to 4, the lower traveling body 2 will be described. Note that when explaining the structure of the lower traveling body 2, the orthogonal coordinate system (X, Y, Z) shown in each figure is used. The X direction coincides with the front-rear direction of the lower traveling body 2. The + side in the X direction coincides with the front side of the lower traveling body 2. The - side in the X direction coincides with the rear side of the lower traveling body 2. The Y direction coincides with the left-right direction of the lower traveling body 2. The + side in the Y direction coincides with the left side when the lower traveling body 2 is viewed from the rear. The - side in the Y direction coincides with the right side when the lower traveling body 2 is viewed from the rear. The Z direction coincides with the up-down direction of the lower traveling body 2. The + side in the Z direction 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.

[0025] The lower traveling body 2 corresponds to an example of a traveling vehicle body and can travel by power. Specifically, as shown in FIGS. 1 and 3, the lower traveling body 2 includes a frame 20, a body 21, a front axle 22, a rear axle 23, front tires 24, rear tires 25, and outriggers 26.

[0026] The frame 20 extends in the front-rear direction and is, for example, a box-shaped member with a rectangular cross-sectional shape, constituting the skeleton of the lower traveling body 2.

[0027] Further, the frame 20 has a transmission member arrangement space 200 formed by a through-hole that penetrates the frame 20 in the up-down direction. The transmission member arrangement space 200 is provided in an intermediate portion of the frame 20 in the front-rear direction.

[0028] Further, the frame 20 has a battery accommodation space 201 formed by a through-hole that penetrates the frame 20 in the up-down direction. The battery accommodation space 201 is provided at a position on the frame 20 that extends from above the rear axle 23 to the rear end.

[0029] That is, the battery accommodation space 201 is provided at the rear part of the frame 20. The position of the battery accommodation space is not limited to the illustrated case. The battery accommodation space may be provided at a position in the frame 20 extending from above the front axle 22 to the front end. Also in this case, the battery accommodation space may be constituted by a through hole penetrating the frame 20 in the vertical direction.

[0030] The frame 20 has a pair of front outrigger support portions 202 at the front end portion. The frame 20 has a pair of rear outrigger support portions 203 at the rear end portion.

[0031] The body 21 (see FIG. 1) is a member constituting the outer shape of the lower traveling body 2 and is supported by the frame 20.

[0032] The front axle 22 is a shaft member extending in the left - right direction and is supported at a portion near the front end of the frame 20. Front tires 24 are rotatably supported at both ends of the front axle 22 in the left - right direction, respectively.

[0033] The rear axle 23 is a shaft member extending in the left - right direction and is supported at a portion near the rear end of the frame 20. Rear tires 25 are rotatably supported at both ends of the rear axle 23 in the left - right direction, respectively.

[0034] In addition, in the case of this embodiment, the mobile crane 1 is a so - called two - axle type mobile crane equipped with the front axle 22 and the rear axle 23. However, the mobile crane may be a so - called multi - axle type mobile crane equipped with three or more axles.

[0035] The outriggers 26 have a pair of front outriggers 26a and a pair of rear outriggers 26b. The pair of front outriggers 26a are respectively supported by the pair of front outrigger support portions 202 in the frame 20. Also, the pair of rear outriggers 26b are respectively supported by the pair of rear outrigger support portions 203 in the frame 20.

[0036] Further, the mobile crane 1 has a transmission member 4 provided between the lower traveling body 2 and the upper slewing body 3. Specifically, the transmission member 4 is disposed in the transmission member arrangement space 200 of the frame 20. Such a transmission member 4 is a member for transmitting electric power, fluid (hydraulic oil and / or compressed air), signals, etc. between the relatively rotating lower traveling body 2 and the upper slewing body 3.

[0037] Further, as shown in FIG. 2, the mobile crane 1 has a low-voltage system 5, a high-voltage system 6, and a hydraulic system 7. Hereinafter, the configurations of the low-voltage system 5, the high-voltage system 6, and the hydraulic system 7 will be described.

[0038] First, the low-voltage system 5 will be described. The low-voltage system 5 includes a lower controller 50, a transmission member 4, an upper controller 51, and a low-voltage battery 53.

[0039] The lower controller 50 sends, for example, video signals, sensor detection signals, and control signals to the upper controller 51 via the transmission member 4. The control signal is a signal for controlling the operation of a device provided on the upper slewing body 3 which is the control target. The lower controller 50 operates based on the electric power supplied from the low-voltage battery 53.

[0040] The upper controller 51 sends the signals received from the lower controller 50 to a control device that controls the operation of a device provided on the upper slewing body 3. The control device is, for example, a solenoid valve that controls the operation of the upper hydraulic device 73 or a controller that controls the operation of the upper electric device 64.

[0041] In addition to signals, the low-voltage system 5 may send, for example, information regarding the operation of a device provided on the upper slewing body 3 and / or a current below a predetermined voltage supplied to the device from the lower traveling body 2 to the upper slewing body 3.

[0042] Next, the high-voltage system 6 will be described. The high-voltage system 6 is a system for executing the running of the lower traveling body 2 and operations other than running (for example, crane work, air conditioning, and / or heating) based on the power supplied from the high-voltage battery 60.

[0043] As shown in FIG. 2, the high-voltage system 6 includes a high-voltage battery 60, a traveling motor 63, a transmission member 4, an upper electric device 64, and a control unit 65.

[0044] The high-voltage battery 60 corresponds to an example of a power supply unit and has a plurality of batteries 601a and 601b as shown in FIG. 3. The batteries 601a and 601b are arranged outside (specifically, above) the frame 20. Further, the high-voltage battery 60 has a plurality of batteries (not shown) arranged in the battery accommodation space 201 of the frame 20.

[0045] The traveling motor 63 includes a front traveling motor 631 and a rear traveling motor 632. The front traveling motor 631 and the rear traveling motor 632 are provided below the frame 20 and between the front axle 22 and the rear axle 23.

[0046] The front traveling motor 631 is connected to the front axle 22. The front traveling motor 631 drives the front axle 22 based on the power supplied from the high-voltage battery 60.

[0047] The rear traveling motor 632 is connected to the rear axle 23. The rear traveling motor 632 drives the rear axle 23 based on the power supplied from the high-voltage battery 60.

[0048] The traveling motors 63 (specifically, the front traveling motor 631 and the rear traveling motor 632) as described above are driven based on the electric power supplied from the high-voltage battery 60 under the control of the control unit 65. When the traveling motors 63 are driven, the lower traveling body 2 (mobile crane 1) can travel based on the power of the traveling motors 63. Incidentally, the electric power of the high-voltage battery 60 is sent to the upper slewing body 3 via the transmission member 4.

[0049] The transmission member 4 constitutes an electric circuit for the electric power supplied from the high-voltage battery 60 to the upper electric device 64 between the relatively rotating lower traveling body 2 and the upper slewing body 3. The upper electric device 64 is a device provided on the upper slewing body 3 and operating based on the electric power of the high-voltage battery 60. The upper electric device 64 is, for example, a compressor for heating provided on the upper slewing body 3.

[0050] Incidentally, when the slewing actuator is an electric motor, the slewing electric motor corresponds to an example of the upper electric device. Also, when the winch actuator is an electric motor, the winch electric motor corresponds to an example of the upper electric device. In this case, the transmission member 4, the slewing electric motor, and the winch electric motor are connected via an upper junction box (not shown). Such an upper junction box has a function of allocating the electric power of the high-voltage battery 60 supplied via the transmission member 4 to the slewing electric motor and the winch electric motor.

[0051] When the electric power of the high-voltage battery 60 is supplied to the slewing electric motor, the slewing electric motor is driven based on the electric power. Then, the slewing electric motor slews the upper slewing body 3. Also, when the electric power of the high-voltage battery 60 is supplied to the winch electric motor, the winch electric motor is driven based on the electric power. Then, the winch electric motor rotates a winch (not shown). As a result, the wire rope 36 is wound up or paid out, and the hook 37 rises or falls.

[0052] Next, the hydraulic system 7 will be described. The hydraulic system 7 is a system for supplying hydraulic oil to a lower hydraulic device 72 provided on the lower traveling body 2 and an upper hydraulic device 73 provided on the upper slewing body 3.

[0053] The lower hydraulic device 72 includes, for example, a hydraulic cylinder constituting a suspension and / or a hydraulic cylinder constituting an outrigger. Further, the lower hydraulic device 72 may include a hydraulic cylinder constituting a steering device.

[0054] Further, the upper hydraulic device 73 includes a slewing actuator (not shown), a hoisting cylinder 34, a telescopic cylinder 35, and a winch actuator (not shown). The upper hydraulic device 73 may include an actuator for moving the jib.

[0055] The hydraulic system 7 includes a tank 71, a hydraulic oil supply device 8, and a transmission member 4. The lower hydraulic device 72 and the upper hydraulic device 73 are also included in the hydraulic system 7. The elements constituting the hydraulic system 7 are connected by a circuit shown by a thick line in FIG. 2.

[0056] The tank 71 and the hydraulic oil supply device 8 are provided on the lower traveling body 2. Specifically, as shown in FIG. 3, the tank 71 and the hydraulic oil supply device 8 are arranged in a predetermined region between the front axle 22 and the rear axle 23 and on the side (left side in this embodiment) of the frame 20 in the left-right direction.

[0057] The tank 71 corresponds to an example of a hydraulic oil tank and is a tank for storing hydraulic oil, and is substantially rectangular parallelepiped in shape. As shown in FIG. 4, the tank 71 is arranged on the side (left side in this embodiment) of the transmission member 4.

[0058] The tank 71 and the hydraulic oil supply device 8 are arranged side by side in the front-rear direction in the above-mentioned predetermined region. The tank 71 is arranged in front of the hydraulic oil supply device 8. The tank 71 and the hydraulic oil supply device 8 are fixed to the side surface (the left side surface in this embodiment) of the frame 20.

[0059] The hydraulic oil supply device 8 is provided on the side (the rear side in this embodiment) of the tank 71. The hydraulic oil supply device 8 includes an electric motor 80, a speed reducer 81, and a pump 82.

[0060] The speed reducer 81 is provided on one side in the axial direction of the electric motor 80 (the front side in this embodiment). In this embodiment, the axial direction of the electric motor 80 is a direction parallel to the front-rear direction. Note that the axial direction of the electric motor 80 may be a direction inclined with respect to the front-rear direction in the horizontal plane.

[0061] The speed reducer 81 decelerates the rotation of the electric motor 80 and transmits it to the pump 82. The electric motor 80 and the pump 82 (the first pump 820 and the second pump 821) are provided on opposite sides in the front-rear direction with the speed reducer 81 as the center. Specifically, the pump 82 (the first pump 820 and the second pump 821) is provided on the front side of the speed reducer 81. The electric motor 80 is provided on the rear side of the speed reducer 81. The electric motor 80 is driven based on the electric power supplied from the high-voltage battery 60 via an inverter 83 (see FIG. 2).

[0062] The inverter 83 is provided between the tank 71 and the hydraulic oil supply device 8 in the front-rear direction.

[0063] The speed reducer 81 decelerates the rotation of the electric motor 80 at a predetermined reduction ratio and transmits it to the pump 82.

[0064] The pump 82 corresponds to an example of a pump section and operates based on the rotation transmitted from the electric motor 80. The pump 82 has a first pump 820 (see FIG. 4) and a second pump 821. The first pump 820 and the second pump 821 are arranged in parallel. That is, the central axis of the first pump 820 and the central axis of the second pump 821 are parallel.

[0065] The central axes of the first pump 820 and the second pump 821 are parallel in the front-rear direction. The central axes of the first pump 820 and the second pump 821 are parallel to the central axis of the electric motor 80. Note that the central axes of the first pump 820 and the second pump 821 may be in a direction inclined with respect to the front-rear direction in the horizontal plane. Also in this case, the central axes of the first pump 820 and the second pump 821 may be parallel to the central axis of the electric motor 80.

[0066] The first pump 820 and the second pump 821 are each connected to the tank 71 via a discharge hose 88a. The discharge hose 88a extends from the tank 71 toward the pump 82.

[0067] The hydraulic oil flowing out from the tank 71 flows through the discharge hose 88a and into each of the first pump 820 and the second pump 821.

[0068] The first pump 820 corresponds to an example of a main pump and is driven based on the rotation of the electric motor 80 to supply hydraulic oil to the first driven part.

[0069] The first pump 820 is a variable displacement pump whose discharge amount can be changed. In the case of this embodiment, the first pump 820 has, as operation modes, a first mode in which the discharge capacity is a first discharge capacity and a second mode in which the discharge capacity is a second discharge capacity. The discharge capacity of the first pump 820 in the first mode is smaller than the discharge capacity of the first pump 820 in the second mode.

[0070] The discharge capacity of the first pump 820 in the first mode is the minimum discharge capacity of the first pump 820. The discharge capacity of the first pump 820 in the second mode is the maximum discharge capacity of the first pump 820.

[0071] In the case of this embodiment, the first driven part is the upper first hydraulic device 730 (see FIG. 2) included in the upper hydraulic device 73.

[0072] The upper first hydraulic device 730 is a hydraulic device that is driven during crane operation, and includes a hoisting cylinder 34, a telescopic cylinder 35, and a winch actuator (not shown). Further, the upper first hydraulic device 730 may include an actuator for moving the boom. Also, the first driven part includes the hydraulic cylinders of the outriggers included in the lower hydraulic device 72.

[0073] When supplying hydraulic oil to the upper first hydraulic device 730, the first pump 820 sends the hydraulic oil to the transmission member 4. In the case of this embodiment, in the crane operation state, the first pump 820 is constantly driven to supply hydraulic oil to the upper first hydraulic device 730.

[0074] The transmission member 4 constitutes a flow path for a fluid (for example, hydraulic oil and / or compressed air) supplied from the lower traveling body 2 to the upper revolving body 3 between the relatively rotating lower traveling body 2 and the upper revolving body 3.

[0075] Specifically, the transmission member 4 constitutes a part of the flow path for transmitting the hydraulic oil supplied from the hydraulic oil supply device 8 (the first pump 820) to the upper hydraulic device 73 provided on the upper revolving body 3.

[0076] The hydraulic oil used in the upper first hydraulic device 730 returns to the tank 71 through the transmission member 4. The transmission member 4 also constitutes a part of the flow path for the hydraulic oil returning from the upper revolving body 3 to the lower traveling body 2.

[0077] The first pump 820 and the transmission member 4 are connected via a discharge hose 88b (see FIG. 4).

[0078] When a winch actuator (not shown), a tilting cylinder 34, and a telescoping cylinder 35 are provided in mutually independent hydraulic circuits, the first pump 820 may be composed of a plurality of independent pumps corresponding to each hydraulic circuit.

[0079] Also, the second pump 821 corresponds to an example of a sub-pump and is driven based on the rotation of the electric motor 80 to supply hydraulic oil to the second driven part. In the case of this embodiment, the second pump 821 is a pump smaller than the first pump 820. In other words, the discharge amount of the second pump 821 is smaller than the discharge amount of the first pump 820.

[0080] In the case of this embodiment, the second driven part is the upper second hydraulic device 731 (see FIG. 2) included in the upper hydraulic device 73. The upper second hydraulic device 731 includes a swivel actuator (not shown) and an orbit roll (registered trademark) that constitutes a steering device. The orbit roll is attached to the handle part of the crane and is a hydraulic device that supplies pressure oil to a hydraulic cylinder provided in the lower traveling body 2.

[0081] When supplying hydraulic oil to the upper second hydraulic device 731, the second pump 821 sends the hydraulic oil to the transmission member 4. The transmission member 4 constitutes a part of a flow path that transmits the hydraulic oil supplied from the hydraulic oil supply device 8 (second pump 821) to the upper second hydraulic device 731 provided in the upper slewing body 3.

[0082] The hydraulic oil used in the upper second hydraulic device 731 returns to the tank 71 through the transmission member 4. The transmission member 4 also constitutes a flow path for the hydraulic oil returning from the upper slewing body 3 to the lower traveling body 2.

[0083] The second pump 821 and the transmission member 4 are connected via a discharge hose 88c (see FIG. 4). In FIG. 4, the discharge hose 88b and the discharge hose 88c are shown as a single discharge hose for convenience, but the discharge hose 88b and the discharge hose 88c are independent discharge hoses.

[0084] In the case of this embodiment, both the first pump 820 and the second pump 821 operate. However, the first pump 820 and the second pump 821 may operate independently of each other. That is, in a situation where the first driven part requires hydraulic oil, the first pump 820 operates, and in a situation where the first driven part does not require hydraulic oil, the first pump 820 may stop. Also, in a situation where the second driven part requires hydraulic oil, the second pump 821 operates, and in a situation where the second driven part does not require hydraulic oil, the second pump 821 may stop.

[0085] Alternatively, in a situation where the first driven part does not require hydraulic oil, the output of the first pump 820 may be set to a value equal to or less than a predetermined value. Also, in a situation where the second driven part does not require hydraulic oil, the output of the second pump 821 may be set to a value equal to or less than a predetermined value. Such a configuration can suppress the power consumption, thus achieving energy saving.

[0086] Next, the regenerative brake control implemented in the mobile crane 1 will be described. When the mobile crane 1 decelerates while in a traveling state, regenerative brake control is performed in which the regenerative power generated by the traveling motor 63 is supplied to the high-voltage battery 60 to generate braking force.

[0087] Specifically, when the driver returns the accelerator pedal while the mobile crane 1 is in a traveling state, the rotation of the front tires 24 and the rear tires 25 is transmitted to the traveling motor 63, and regenerative power is generated in the traveling motor 63 (specifically, the front traveling motor 631 and the rear traveling motor 632).

[0088] Then, a braking force corresponding to the regenerative power generated by the traveling motor 63 (specifically, the front traveling motor 631 and the rear traveling motor 632) acts on the front tires 24 and the rear tires 25 to decelerate the mobile crane 1.

[0089] In the case of this embodiment, in the regenerative brake control, the regenerative power generated by the traveling motor 63 is basically supplied to the high-voltage battery 60. Such control in the regenerative brake control is referred to as normal regenerative brake control.

[0090] By the way, in the regenerative brake control, depending on the remaining battery level of the high-voltage battery 60, there may be a case where the high-voltage battery 60 cannot accept all of the regenerative power.

[0091] If the high-voltage battery 60 cannot accept the regenerative power and the regenerative power generated by the traveling motor 63 cannot be consumed, there may be a case where braking force cannot be obtained to decelerate the mobile crane 1.

[0092] Therefore, in the case of this embodiment, when the remaining battery level of the high-voltage battery 60 is greater than a predetermined value in the regenerative brake control, the mobile crane 1 distributes the regenerative power to the hydraulic oil supply device 8. Such control in the regenerative brake control is referred to as regenerative power compensation control.

[0093] Also, in the case of this embodiment, the mobile crane 1 changes the power consumed by the hydraulic oil supply device 8 according to the remaining battery level of the high-voltage battery 60 in the regenerative power compensation control.

[0094] Hereinafter, with reference to FIG. 5, the regenerative power compensation control implemented in the regenerative brake control will be described. FIG. 5 is a flowchart of the regenerative power compensation control. The regenerative brake control and the regenerative power compensation control are implemented by the control unit 65. Therefore, the main body of the control process implemented in the regenerative brake control and the regenerative power compensation control is the control unit 65.

[0095] The control unit 65, the high-voltage battery 60, and the hydraulic oil supply device 8 constitute a regenerative brake device. In the following description, the term "power" may be replaced with the term "current".

[0096] First, in step S101 of FIG. 5, the control unit 65 obtains the required regenerative power P F . The required regenerative power P F is the sum of the power corresponding to the braking force to be applied to the front tire 24 (in other words, the front axle 22) and the power corresponding to the braking force to be applied to the rear tire 25 (in other words, the rear axle 23). The required regenerative power P F is also the regenerative power generated by the traveling motor 63 in regenerative brake control.

[0097] The power corresponding to the braking force to be applied to the front tire 24 is the power that the front traveling motor 631 should generate based on the rotation transmitted from the front tire 24 to the front traveling motor 631 (hereinafter referred to as the front required regenerative power).

[0098] Also, the power corresponding to the braking force to be applied to the rear tire 25 is the power that the rear traveling motor 632 should generate based on the rotation transmitted from the rear tire 25 to the rear traveling motor 632 (hereinafter referred to as the rear required regenerative power).

[0099] Therefore, the required regenerative power P F is the sum of the front required regenerative power and the rear required regenerative power. The front required regenerative power and the rear required regenerative power are obtained based on the vehicle speed of the mobile crane 1 and the required braking force corresponding to the vehicle speed.

[0100] In the case of this embodiment, the control unit 65 stores a first table (not shown) associating the vehicle speed with the required braking force (hereinafter referred to as the front required braking force). Note that the vehicle speed in the first table corresponds to the rotation speed of the front traveling motor 631.

[0101] Also, the control unit 65 stores a second table (not shown) associating the vehicle speed with the required braking force (hereinafter referred to as the rear required braking force). Note that the vehicle speed in the second table corresponds to the rotation speed of the rear traveling motor 632.

[0102] The control unit 65 acquires the front required braking force corresponding to the vehicle speed of the mobile crane 1 in the traveling state from the first table. Then, the control unit 65 calculates the front required regenerative power based on the vehicle speed and the front required braking force acquired from the first table. Thus, the front required regenerative power varies according to the vehicle speed of the mobile crane 1 in the traveling state.

[0103] Further, the control unit 65 acquires the rear required braking force corresponding to the vehicle speed of the mobile crane 1 in the traveling state from the second table. Then, the control unit 65 calculates the rear required regenerative power based on the vehicle speed and the rear required braking force acquired from the second table. Thus, the rear required regenerative power varies according to the vehicle speed of the mobile crane 1 in the traveling state.

[0104] Next, in step S102 of FIG. 5, the control unit 65 calculates the electric power P ePTO (hereinafter referred to as the first consumed power P ePTO ).

[0105] The first consumed power P ePTO is obtained by the following formula (1). P F is the required regenerative power. P 60 is the chargeable power of the high-voltage battery 60. The chargeable power of the high-voltage battery 60 may be regarded as the power that the high-voltage battery 60 can accept at that time (that is, the time when the process of step S102 is performed).

[0106] P α is the power consumed in the devices that operate based on the power of the high-voltage battery 60 at that time. The chargeable power of the high-voltage battery 60 may be regarded as the power that the high-voltage battery 60 can accept, which is determined according to the remaining battery level of the high-voltage battery 60. Incidentally, the chargeable power of the high-voltage battery 60 can also be regarded as the power that the high-voltage battery 60 can accept, which is determined according to the temperature of the high-voltage battery 60.

[0107]

Number

[0108] Next, in step S103 of FIG. 5, the control unit 65 determines whether the first power consumption P ePTO calculated in step S102 is greater than zero.

[0109] When the first power consumption P ePTO is greater than zero, it means that the remaining amount of the high-voltage battery 60 is greater than a predetermined value, and all of the required regenerative power cannot be charged to the high-voltage battery 60. On the other hand, when the first power consumption P ePTO is zero or less, it means that the remaining amount of the high-voltage battery 60 is less than or equal to the predetermined value, and all of the required regenerative power can be charged to the high-voltage battery 60.

[0110] When the control unit 65 determines that the first power consumption P ePTO is greater than zero (i.e., "YES" in step S103), the control process proceeds to step S104. That is, in the case of this embodiment, when the remaining amount of the high-voltage battery 60 is greater than the predetermined value, the control process proceeds to step S104.

[0111] As described above, in the case of this embodiment, the regenerative power generated by the traveling motor 63 is distributed to the hydraulic oil supply device 8 according to the chargeable power of the high-voltage battery 60. Specifically, in the case of this embodiment, when the remaining amount of the high-voltage battery 60 is greater than the predetermined value, the regenerative power generated by the traveling motor 63 is distributed to the hydraulic oil supply device 8 by regenerative power compensation control.

[0112] On the other hand, when the control unit 65 determines that the first power consumption P ePTO is less than zero (i.e., "NO" in step S103), the regenerative power compensation control is terminated. That is, the control unit 65 supplies the regenerative power generated by the traveling motor 63 to the high-voltage battery 60 by normal regenerative braking control.

[0113] Next, in step S104 of FIG. 5, the control unit 65 determines whether the temperature of the hydraulic oil is equal to or lower than a predetermined threshold value. The predetermined threshold value is, for example, 85°C. Note that the predetermined threshold value may be appropriately set according to the type of hydraulic oil or the usage environment.

[0114] If the temperature of the hydraulic oil is equal to or lower than the predetermined threshold value ( "YES" in step S104), the control unit 65 proceeds with the control process to step S105.

[0115] If the temperature of the hydraulic oil is greater than the predetermined threshold value ( "NO" in step S104), the control unit 65 terminates the regenerative power compensation control. When the temperature of the hydraulic oil is greater than the predetermined threshold value, the control unit 65 terminates the regenerative brake control.

[0116] Therefore, the braking force based on the regenerative brake control is not generated. In this case, the driver operates the foot brake to apply a braking force to the mobile crane 1 and decelerate the mobile crane 1. Note that when the control unit 65 terminates the regenerative brake control, it may notify the driver to that effect.

[0117] Further, when the temperature of the hydraulic oil is greater than the predetermined threshold value ( "NO" in step S104), the control unit 65 may control the cooling device 86 described later to cool the hydraulic oil in the tank 71. During this period, the control unit 65 may repeat the operation of step S104.

[0118] As described above, in the case of this embodiment, the control unit 65 sets the temperature condition of the hydraulic oil as one of the conditions for starting the regenerative power compensation control. However, the condition for starting the regenerative power compensation control is not limited to the temperature condition of the hydraulic oil. The condition for starting the regenerative power compensation control may include various conditions according to the state of the mobile crane 1.

[0119] Next, in step S105 of FIG. 5, the control unit 65 performs a pump capacity change process. The pump capacity change process is a process of switching the discharge capacity of the first pump 820 from the first discharge capacity to the second discharge capacity.

[0120] As described above, the first pump 820 has, as operation modes, a first mode in which the discharge capacity is the first discharge capacity and a second mode in which the discharge capacity is the second discharge capacity. The discharge capacity of the first pump 820 in the first mode is smaller than the discharge capacity of the first pump 820 in the second mode.

[0121] In a state where normal regeneration brake control is being performed in the traveling state of the mobile crane 1, the first pump 820 is driven in the first mode. Therefore, the electric power consumed by the first pump 820 (in other words, the hydraulic oil supply device 8) is relatively small. Such a configuration contributes to energy saving.

[0122] On the other hand, when regeneration power compensation control is performed in the traveling state of the mobile crane 1, it is desirable that the electric power consumed by the hydraulic oil supply device 8 be large. Therefore, in step S105, the control unit 65 switches the mode of the first pump 820 from the first mode to the second mode, thereby increasing the discharge amount of the first pump 820. When the discharge amount of the first pump 820 increases, the electric power consumed by the hydraulic oil supply device 8 increases.

[0123] Next, in step S106 of FIG. 5, the control unit 65 performs a return circuit switching process. The return circuit switching process is a process of switching the return circuit through which the hydraulic oil discharged from the first pump 820 returns to the tank 71.

[0124] In the traveling state of the mobile crane 1, the hydraulic oil discharged from the first pump 820 is not supplied to the upper first hydraulic device 730 and returns to the tank 71 through the return circuit 85 (see FIG. 2). The first pump 820 is constantly driven in the traveling state of the mobile crane 1.

[0125] The return circuit 85 has a low-load return circuit 851 and a high-load return circuit 852. The return circuit 85 (the low-load return circuit 851 and the high-load return circuit 852) may be regarded as an element of the hydraulic oil supply device 8.

[0126] In the low-load return circuit 851, the load pressure in the circuit is relatively low. That is, when the hydraulic oil discharged from the first pump 820 is supplied to the low-load return circuit 851, the load torque acting on the first pump 820 (in other words, the electric motor 80) is small.

[0127] The state in which the hydraulic oil discharged from the first pump 820 returns to the tank 71 through the low-load return circuit 851 is referred to as the low-load return state (in other words, the unloaded state) of the first pump 820. In the low-load return state, since the load torque acting on the first pump 820 (in other words, the electric motor 80) is small, the power consumed in the hydraulic oil supply device 8 is small.

[0128] On the other hand, the high-load return circuit 852 has a pressure regulating valve 852a. The pressure regulating valve 852a is, for example, a relief valve. Such a high-load return circuit 852 has a load pressure in the circuit higher than the load pressure of the low-load return circuit 851.

[0129] That is, when the hydraulic oil discharged from the first pump 820 is supplied to the high-load return circuit 852, the load torque acting on the first pump 820 (in other words, the electric motor 80) is large.

[0130] The state in which the hydraulic oil discharged from the first pump 820 returns to the tank 71 through the high-load return circuit 852 is referred to as the high-load return state of the first pump 820. In the high-load return state, since the load torque acting on the first pump 820 (in other words, the electric motor 80) is large, the power consumed in the hydraulic oil supply device 8 is large.

[0131] In the case of this embodiment, when the normal regeneration brake control is being implemented in the traveling state of the mobile crane 1, the hydraulic oil discharged from the first pump 820 returns to the tank 71 through the low-load return circuit 851.

[0132] That is, in a state where normal regeneration brake control is being performed during the traveling state of the mobile crane 1, the first pump 820 is in a low-load return state. As described above, in the low-load return circuit 851, the load pressure in the circuit is relatively low. Therefore, the power consumed by the hydraulic oil supply device 8 is small. Such a configuration contributes to energy saving.

[0133] On the other hand, when regeneration power compensation control is being performed during the traveling state of the mobile crane 1, it is desirable that the power consumed by the hydraulic oil supply device 8 be large. Therefore, in step S106, the control unit 65 switches the return circuit through which the hydraulic oil discharged from the first pump 820 returns to the tank 71 from the low-load return circuit 851 to the high-load return circuit 852.

[0134] As described above, in the high-load return circuit 852, the load pressure in the circuit is higher than the load pressure in the low-load return circuit 851. For this reason, when the hydraulic oil discharged from the first pump 820 is supplied to the high-load return circuit 852, the load torque acting on the first pump 820 (in other words, the electric motor 80) is large. Therefore, the power consumed by the hydraulic oil supply device 8 is also large.

[0135] As described above, in the case of the present embodiment, the control unit 65 increases the power consumed by the hydraulic oil supply device 8 in two steps by performing the pump capacity change process in step S105 and the return circuit switching process in step S106.

[0136] The pump capacity change process and / or the return circuit switching process may be omitted according to the magnitude of the power that the hydraulic oil supply device 8 should consume.

[0137] Next, in step S107 of FIG. 5, the control unit 65 performs a rotation speed change process. The rotation speed change process is a process of changing the rotation speed of the first pump 820 (in other words, the electric motor 80).

[0138] In other words, the rotation speed change process is a process of changing the electric power consumed by the hydraulic oil supply device 8 by changing the rotation speed of the first pump 820 (in other words, the electric motor 80) according to the remaining battery level.

[0139] In the rotation speed change process, the control unit 65 increases the rotation speed of the first pump 820 (in other words, the electric motor 80) as the remaining battery level increases, thereby increasing the electric power that can be consumed by the hydraulic oil supply device 8.

[0140] Specifically, the control unit 65 sets the rotation speed of the first pump 820 to the rotation speed N ePTO corresponding to the first power consumption P ePTO (hereinafter referred to as the first rotation speed N ePTO ).

[0141] The first rotation speed N ePTO is obtained by the following formula (2). P ePTO is the first power consumption calculated in step S104. E 80 is the motor efficiency of the electric motor 80. The motor efficiency of the electric motor 80 is a value preset according to the electric motor 80. T 80 is the motor shaft torque of the electric motor 80. The motor shaft torque of the electric motor 80 is a value preset according to the load torque acting on the first pump 820 and the reduction ratio of the speed reducer 81 (see FIG. 2).

[0142]

Equation

[0143] Then, the control unit 65 drives the first pump 820 at the first rotation speed N ePTO .

[0144] As described above, the control unit 65 sets the first rotation speed N ePTO corresponding to the first power consumption P ePTO calculated in step S104 as the rotation speed of the first pump 820. That is, the first power consumption PePTO is a value corresponding to the remaining battery level of the high-voltage battery 60. As shown in the above formula (2), the first rotational speed N ePTO is based on the first power consumption P ePTO is set. In other words, the first rotational speed N ePTO is set based on the remaining battery level of the high-voltage battery 60.

[0145] As a result of the above rotational speed change process, the regenerative power corresponding to the first power consumption P ePTO among the regenerative power generated by the driving motor 63 is distributed to the hydraulic oil supply device 8. Then, in the hydraulic oil supply device 8, the power corresponding to the remaining battery level (that is, the first power consumption P ePTO ) is consumed. Incidentally, the regenerative power generated by the driving motor 63 is equal to the required regenerative power P F calculated by the control unit 65 in step S101.

[0146] Also, even when the remaining battery level of the high-voltage battery 60 is greater than a predetermined value, there may be a case where the high-voltage battery 60 can accept a certain amount of regenerative power. In this case, the power that the high-voltage battery 60 can accept among the regenerative power generated by the driving motor 63 is distributed to the high-voltage battery 60.

[0147] On the other hand, the power that the high-voltage battery 60 cannot accept among the regenerative power generated by the driving motor 63 is distributed to the hydraulic oil supply device 8 as described above. The power that the high-voltage battery 60 cannot accept is the power P ePTO calculated by the control unit 65 in step S102.

[0148] The smaller the remaining battery level of the high-voltage battery 60, the greater the regenerative power that the high-voltage battery 60 can accept. Therefore, the smaller the remaining battery level of the high-voltage battery 60, the smaller the regenerative power distributed to the hydraulic oil supply device 8.

[0149] On the other hand, the larger the remaining battery level of the high-voltage battery 60, the smaller the regenerative power that can be received by the high-voltage battery 60. Therefore, the larger the remaining battery level of the high-voltage battery 60, the larger the regenerative power distributed to the hydraulic oil supply device 8.

[0150] The regenerative power distributed to the hydraulic oil supply device 8 is consumed in the hydraulic oil supply device 8 as described above. Specifically, the regenerative power supplied to the hydraulic oil supply device 8 flows into the electric motor 80 through the inverter 83. Then, the electric motor 80 drives.

[0151] When the electric motor 80 drives, the first pump 820 is driven via the speed reducer 81, and hydraulic oil is discharged from the first pump 820. In the case of this embodiment, in the traveling state of the mobile crane 1, the hydraulic oil discharged from the first pump 820 is not supplied to the upper first hydraulic device 730 and returns to the tank 71 through the high-load return circuit 852.

[0152] At this time, the regenerative power supplied to the hydraulic oil supply device 8 is converted into the kinetic energy of the first pump 820. Then, the kinetic energy of the first pump 820 is converted into the kinetic energy of the hydraulic oil discharged from the first pump 820.

[0153] Furthermore, the kinetic energy of the hydraulic oil is converted into thermal energy in the high-load return circuit 852. That is, the regenerative power distributed to the hydraulic oil supply device 8 is mainly consumed by being converted into thermal energy in the high-load return circuit 852.

[0154] In the case of this embodiment, in the pump capacity change process of step S105, the mode of the first pump 820 is changed so that the load torque acting on the first pump 820 increases.

[0155] Also, in the return circuit switching process of step S106, the return circuit through which the hydraulic oil discharged from the first pump 820 returns to the tank 71 is set to the high-load return circuit 852 so that the load torque acting on the first pump 820 increases.

[0156] Furthermore, in the rotation speed change process of step S107, the rotation speed of the first pump 820 is the first power consumption P calculated in step S104 ePTO corresponding to the first rotation speed N ePTO is set to.

[0157] Therefore, the regenerative power supplied to the hydraulic oil supply device 8 can be consumed by the hydraulic oil supply device 8.

[0158] Incidentally, the hydraulic oil supply device 8 may have a cooling device 86 for cooling the hydraulic oil. The cooling device 86 cools the hydraulic oil in the tank 71 when the temperature of the hydraulic oil exceeds a predetermined temperature in the traveling state of the mobile crane 1. Incidentally, the position of the cooling device 86 is not particularly limited. The cooling device 86 may be disposed at a position where the hydraulic oil can be cooled.

[0159] (Function and Effect of this Embodiment) According to the mobile crane 1 of this embodiment having the above-described configuration, a crane that can travel by electric power can be provided.

[0160] In particular, according to the mobile crane 1 of this embodiment, appropriate regenerative brake control according to the remaining battery level of the high-voltage battery 60 can be implemented.

[0161] Specifically, in the regenerative brake control, when the remaining battery level of the high-voltage battery 60 is greater than a predetermined value, the control unit 65 distributes the regenerative power generated by the traveling motor 63 to the hydraulic oil supply device 8. Therefore, even when the remaining battery level of the high-voltage battery 60 is large, regenerative brake control can be implemented.

[0162] Further, the control unit 65 changes the power consumed by the hydraulic oil supply device according to the remaining battery level of the high-voltage battery 60. Therefore, among the regenerative power generated by the traveling motor 63, the regenerative power supplied to the hydraulic oil supply device 8 can be surely consumed by the hydraulic oil supply device 8. As a result, regardless of the remaining battery level of the high-voltage battery 60, regenerative brake control can be stably performed.

[0163] Further, the regenerative power supplied to the hydraulic oil supply device 8 among the regenerative power generated by the traveling motor 63 is converted into thermal energy of the hydraulic oil of the hydraulic oil supply device 8 and consumed. The mobile crane 1 includes many hydraulic devices used during crane operation. For this reason, the mobile crane 1 has a large amount of hydraulic oil. For this reason, the hydraulic oil can accept a lot of thermal energy. That is, the hydraulic oil supply device 8 can accept a lot of regenerative power in the regenerative power compensation control. In addition, the actions and effects exhibited by the mobile crane 1 according to the present embodiment are as described above.

[0164] (Appendix) The crane according to the present invention including the above-described embodiment performs regenerative power compensation control in regenerative brake control to distribute the regenerative power generated by the traveling motor 63 to the hydraulic oil supply device 8 according to the chargeable power of the power supply unit (specifically, the high-voltage battery 60), and to change the power consumed by the hydraulic oil supply device 8.

[0165] In the above-described embodiment, an example in which regenerative power compensation control is performed based on the remaining battery level of the high-voltage battery 60 has been described. In the case of such an embodiment, the chargeable power of the high-voltage battery 60 is the power that the high-voltage battery 60 can accept, which is determined according to the remaining battery level of the high-voltage battery 60.

[0166] However, the crane according to the present invention may perform regenerative power compensation control based on the temperature of the power supply unit (specifically, the high-voltage battery 60). Specifically, in the regenerative brake control, when the temperature of the high-voltage battery 60 satisfies a predetermined condition, the crane may distribute the regenerative power generated by the traveling motor 63 to the hydraulic oil supply device 8 and change the power consumed by the hydraulic oil supply device 8.

[0167] In this case, the chargeable power of the high-voltage battery 60 is the power that the high-voltage battery 60 can accept, which is determined according to the temperature of the high-voltage battery 60.

[0168] The case where the temperature of the high-voltage battery 60 satisfies a predetermined condition means, for example, that the temperature of the high-voltage battery 60 is equal to or lower than a first predetermined temperature. When the temperature of the high-voltage battery 60 is lower than the first predetermined temperature, the chargeable power of the high-voltage battery 60 decreases. In such a situation, when the regenerative power compensation control is performed, a part of the regenerative power generated by the traveling motor 63 can be consumed by the hydraulic oil supply device 8.

[0169] Also, the case where the temperature of the high-voltage battery 60 satisfies a predetermined condition means, for example, that the temperature of the high-voltage battery 60 is equal to or higher than a second predetermined temperature. When the temperature of the high-voltage battery 60 is equal to or higher than the second predetermined temperature, the chargeable power of the high-voltage battery 60 decreases. In such a situation, when the regenerative power compensation control is performed, a part of the regenerative power generated by the traveling motor 63 can be consumed by the hydraulic oil supply device 8.

Industrial Applicability

[0170] The crane according to the present invention is not limited to a rough terrain crane, and may be various mobile cranes such as, for example, an all terrain crane, a truck crane, or a loading type truck crane (also referred to as a cargo crane).

Explanation of Reference Numerals

[0171] 1 Mobile crane 2 Lower Traveling Body 20 Frame 200 Transmission Member Arrangement Space 201 Battery Accommodation Space 202 Front Outrigger Support Portion 203 Rear Outrigger Support Portion 21 Body 22 Front Axle 23 Rear Axle 24 Front Tire 25 Rear Tire 26 Outrigger 26a Front Outrigger 26b Rear Outrigger 3 Upper Slewing Body 31 Slewing Platform 32 Telescopic Boom 33 Cab 34 Lifting Cylinder 35 Telescoping Cylinder 36 Wire Rope 37 Hook 38 Winch 4 Transmission Member 5 Low-Voltage System 50 Lower Controller 51 Upper Controller 53 Low-Voltage Battery 6 High-Voltage System 60 High-Voltage Battery 601a, 601b First Battery 63 Traveling Motor 631 Front Traveling Motor 632 Rear Traveling Motor 64 Upper Electric Device 65 Control Unit 7 Hydraulic System 71 Tank 72 Lower Hydraulic Device 73 Upper Hydraulic Device 730 Upper First Hydraulic Device 731 Upper Second Hydraulic Device 8 Hydraulic Oil Supply Device 80 Electric Motor 81 Reducer 82. Pump 820 First pump 821 Second pump 83 Inverter 85 Return circuit 851 Low-load return circuit 852 High-load return circuit 852a Pressure regulating valve 86 Cooling device 88a, 88b, 88c Discharge hose

Claims

1. A traveling vehicle body having a traveling motor driven by a power supply unit, An operating oil supply device driven by the power supply unit and supplying operating oil to a driven part, A regenerative brake device that performs regenerative brake control to generate braking force by supplying regenerative power generated by the traveling motor when the traveling vehicle body decelerates to the power supply unit, In the regenerative brake control, the regenerative brake device distributes the regenerative power to the operating oil supply device and changes the power consumed by the operating oil supply device according to the chargeable power of the power supply unit. A crane.

2. The chargeable power is the power that can be received by the power supply unit, which is determined according to the remaining battery level of the power supply unit. In the regenerative brake control, when the remaining battery level of the power supply unit is greater than a predetermined value, the regenerative brake device distributes the regenerative power to the operating oil supply device and changes the power consumed by the operating oil supply device according to the remaining battery level. The crane according to claim 1.

3. The chargeable power is the power that can be received by the power supply unit, which is determined according to the temperature of the power supply unit. In the regenerative brake control, when the temperature of the power supply unit satisfies a predetermined condition, the regenerative brake device distributes the regenerative power to the operating oil supply device and changes the power consumed by the operating oil supply device. The crane according to claim 1.

4. The operating oil supply device A pump motor driven by the power supply unit, And a first pump unit driven by the pump motor. The regenerative brake device changes the power consumed by the operating oil supply device by changing the rotation speed of the pump motor according to the remaining battery level. The crane according to claim 1.

5. The more the remaining battery level is, the greater the regenerative brake device increases the rotation speed of the pump motor to increase the power that can be consumed by the operating oil supply device. The crane according to claim 4.

6. When distributing the regenerative power to the operating oil supply device, the regenerative brake device switches the discharge capacity of the first pump unit from the minimum to the maximum. The crane according to claim 4.

7. When distributing the regenerative power to the hydraulic oil supply device, the regenerative brake device switches the hydraulic circuit through which the hydraulic oil passes from a hydraulic circuit with a low load torque acting on the first pump unit to a hydraulic circuit with a high load torque. The crane according to claim 4. **Claim 8** The hydraulic oil supply device In the crane working state, constantly drive the first pump unit to supply the hydraulic oil to the driven part. In the traveling state, constantly drive the first pump unit, do not supply the hydraulic oil to the driven part, and return it to the hydraulic oil tank. The crane according to claim 4. **Claim 9** In the traveling state, when the temperature of the hydraulic oil exceeds a predetermined temperature, further comprising a cooling device for cooling the hydraulic oil. The crane according to claim 1.

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