Construction Machine

TECHNICAL FIELD

The present invention relates to a construction machine such as a hydraulic excavator that performs excavation and loading work, and particularly relates to a construction machine with a high degree of freedom in layout and/or a construction machine that emits less greenhouse gas.

BACKGROUND

Conventionally, automatic operation has been developed in construction machines such as backhoes, and automation of excavation work is disclosed in JP Patent Publication No. 2020-41354 A.

Furthermore, vehicles that emit less greenhouse gas have been developed, and application of a fuel cell to a backhoe is disclosed in JP Patent Publication No. 2010-173639 A.

SUMMARY

However, in JP Patent Publication No. 2020-41354 A, because a construction machine has a driver's seat, a layout of the construction machine is limited.

Furthermore, JP Patent Publication No. 2010-173639 A discloses the fuel cell in detail but does not disclose how to mount the fuel cell on a construction machine. Thus, a construction machine that emits less greenhouse gas has not been achieved.

Therefore, an object of certain embodiments of the present invention is to provide a construction machine with a high degree of freedom in layout.

Furthermore, an object of certain embodiments of the present invention is to provide a construction machine that emits less greenhouse gas.

A construction machine according to a first implementation of the invention includes a main body unit revolvable by revolving of a revolving part, a working device connected to one end side of the main body unit, a drive system that drives at least one of the main body unit and the working device, and a mass body that corrects an unbalanced load acting on the main body unit by driving the working device, in which at least a part of the drive system is held by the mass body (e.g., the mass body holds the drive system).

A construction machine according to a second implementation of the invention includes a main body unit revolvable by revolving of a revolving part, a working device connected to one end side of the main body unit, a liquid tank that is provided inside another end side of the main body unit and stores liquid fuel that does not emit greenhouse gas, and a take-off and landing portion that is provided in the main body unit and at which an unmanned flying object is capable of taking off and landing.

A construction machine according to a third implementation of the invention includes a main body unit revolvable by revolving of a first revolving part, a first working device connected to one end side of the main body unit, a second working device connected to an other end side of the main body unit, a housing unit revolvable by a second revolving part different from the first revolving part, and a liquid tank that is provided in the housing unit and stores liquid fuel that does not emit greenhouse gas.

According to the first implementation, because at least a part of the drive system is held by the mass body, it is possible to provide the construction machine with a high degree of freedom in layout.

According to the second and third implementations, because the liquid fuel that does not emit greenhouse gas is used, it is possible to achieve the construction machine that emits less greenhouse gas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic top view of a construction machine representing a first embodiment, and FIG. 1B is a schematic front view thereof.

FIG. 2 is a schematic view of the construction machine when a counter mass of the construction machine of FIG. 1B moves.

FIG. 3A is a view taken along a line A-A of FIG. 1B, and FIG. 3B is a view taken along a line A-A of FIG. 2.

FIG. 4 is a block diagram of a main part of the first embodiment.

FIG. 5 is a flowchart executed by a heavy machine control device of the first embodiment.

FIG. 6A is a schematic top view of a construction machine representing a second embodiment, and FIG. 6B is a schematic front view thereof.

FIG. 7 is a flowchart executed by a heavy machine control device of the second embodiment.

FIG. 8A is a view illustrating excavation operation when working devices are at initial positions, FIG. 8B is a view illustrating a state at the time of excavation, FIG. 8C is a view illustrating a state at the end of the excavation, and FIG. 8D is a view illustrating a state after revolving.

FIG. 9A is a view illustrating operation following the excavation operation of FIGS. 8A to 8D when working devices are in a state of loading. FIG. 9B is a view illustrating when the working devices are at the initial positions, FIG. 9C is a view illustrating a state after an upper main body device is revolved, and FIG. 9D is a view illustrating a state at the time of excavation.

FIG. 10A and FIG. 10B are schematic views of a construction machine representing a third embodiment.

DETAILED DESCRIPTION

Hereinafter, a construction machine of embodiments of the invention will be described in detail with reference to the accompanying drawings. Note that the invention is not limited by the embodiments described below. In the embodiments, the description will be continued by using a hydraulic excavator 1 as an example of the construction machine.

First Embodiment

FIG. 1A is a schematic top view illustrating the hydraulic excavator 1 representing the first embodiment. FIG. 1B is a schematic front view illustrating the hydraulic excavator 1 representing the first embodiment. FIG. 2 is a schematic view of the construction machine when a counter mass 43 of the hydraulic excavator 1 of FIG. 1B moves in a-X direction. Furthermore, FIG. 3A is a view taken along the line A-A of FIG. 1B, and FIG. 3B is a view taken along the line A-A of FIG. 2. FIG. 4 is a block diagram of a main part of the first embodiment.

Hereinafter, a configuration of the hydraulic excavator 1 will be described with reference to FIGS. 1A to 4. Furthermore, as is clear from FIGS. 1A and 1B, the hydraulic excavator 1 of the present embodiment is an automatic operation type without a driver's seat and includes an unmanned aerial vehicle (UAV), hereinafter referred to as a drone 100. The hydraulic excavator 1 may be traveled by automatic operation at a construction site and may be loaded on a trailer for transportation on a public road. Furthermore, operation of the hydraulic excavator 1 may be automatic operation or a remote operation at a remote place away from an excavation place.

The hydraulic excavator 1 of the present embodiment includes a drive system 10 (see FIG. 4), a traveling device 20, a revolving device 30, a main body device 40, and a working device 60. Furthermore, the hydraulic excavator 1 includes the drone 100 that can take off and land at a take-off and landing portion provided on an upper surface of the main body device 40. Although one drone 100 is illustrated in FIGS. 1A and 1B, there may be a plurality of drones 100. Furthermore, the drone 100 may be a type that flies by power, or a type that flies by a fuel cell using hydrogen.

The drive system 10 includes an engine 11, a fuel tank 12, a leakage sensor 13, and a generator 14. The engine 11 is an internal combustion engine, and a diesel engine is adopted in this embodiment. The engine 11 burns fuel supplied from the fuel tank 12 to drive the generator 14.

The fuel tank 12 stores ammonia (NH₃) in a liquid state, and a residual meter (not illustrated) is provided inside. The ammonia in the liquid state is vaporized by a vaporizer (not illustrated), and the vaporized ammonia is burned by the engine 11 together with air. Note that a plurality of fuel tanks 12 may be provided as an ammonia storage tank and a gas oil storage tank. In this case, it is sufficient that the engine 11 is a mixed combustion type engine that performs mixed combustion of ammonia and gas oil.

The leakage sensor 13 (also called a leakage detection sensor) is a liquid leakage sensor that detects leakage of ammonia in a liquid state stored in the fuel tank 12, or a gas sensor that detects leakage of vaporized ammonia from a vicinity of the engine 11. As the liquid leakage sensor, there can be a liquid leakage sensor using a contact type detection system in which electricity flows by conduction via a liquid by contact of the liquid between two electrodes, a liquid leakage sensor using a non-contact type detection system in which liquid leakage is detected by using reflection and transmission by using a fiber sensor, and the like, and sensors using various systems may be appropriately used. As the gas sensor, there can be a solid-state sensor using a semiconductor, an electrochemical sensor of a constant potential electrolysis type, an optical sensor using infrared rays, and the like, and any sensor can be used. As the leakage sensor 13, both the liquid leakage sensor and the gas sensor may be installed, or either one may be installed.

The generator 14 is connected to an output shaft of the engine 11 and generates power by a rotational driving force of the output shaft of the engine 11. The power generated by the generator 14 is supplied to various cylinders, various motors, and the like as illustrated in the block diagram of FIG. 4. Furthermore, although details will be described later, in the present embodiment, the engine 11, the fuel tank 12, and the generator 14 are loaded on the counter mass 43 to be described later. Furthermore, the engine 11, the fuel tank 12, and the generator 14 may be exposed to the outside of the main body device 40 according to movement of the counter mass 43, and thus are covered with a cover 19.

The traveling device 20 includes a pair of crawler belts 23 wound around idler wheels 21 and drive wheels 22, and a traveling motor 24 that drives the drive wheels 22. The pair of crawler belts 23 is driven by the drive wheels 22 to cause the hydraulic excavator 1 to travel. A traveling motor 24 is driven by power supplied from the generator 14, and in the present embodiment, an in-wheel motor provided to be coaxially connected to the drive wheels 22 or hubs of the drive wheels 22 is adopted.

The revolving device 30 is disposed to the traveling device 20 and the main body device 40. The revolving device 30 includes a bearing (not illustrated) and a revolving motor 31 to which power is supplied from the generator 14, and the revolving device 30 revolves the main body device 40 and the working device 60. The revolving of the main body device 40 and the working device 60 by the revolving device 30 may be performed using hydraulic pressure instead of the revolving motor 31.

The main body device 40 has the upper surface having a flat shape and includes a power supply unit such as a power transmission device 15 that supplies power to the drone 100 and a shield member 16 on the upper surface.

Furthermore, the power transmission device 15 on the upper surface of the main body device 40 serves as the take-off and landing portion of the drone 100.

The power transmission device 15 supplies power to a power reception device 103, to be described later, of the drone 100, and the power transmission device 15 adopts wireless power supply in the present embodiment. The wireless power supply supplies power to the power reception device 103 in a non-contact manner, and a magnetic field resonance system, an electromagnetic induction system, and the like are known. The power transmission device 15 of the present embodiment includes a power supply, a control circuit, and a power transmission coil.

Furthermore, the power transmission device 15 may be a spatial transmission type instead of the proximity junction type described above. During power supply of the spatial transmission type, power is supplied to an object (such as the power reception device 103 of the drone 100) several meters to several tens of meters away by using an electromagnetic wave such as a microwave.

A contact-type power supply system may be adopted instead of the wireless power supply. In this case, a metal contact may be provided on each of the power transmission device 15 and the power reception device 103, and the contacts may be mechanically connected to each other for power supply. For example, a contact having a recess shape may be provided on the take-off and landing portion, and a contact having a projection shape may be provided on a side of the drone 100. One contact having the recess shape and one contact having the projection shape may be provided, or a plurality of the contacts having the recess shape and a plurality of the contacts having the projection shape may be provided.

The shield member 16 (e.g., a blocking unit) blocks or shields electromagnetic noise so that electromagnetic noise generated from the power transmission device 15 and the like does not affect antennas 48a to be described later. As illustrated in FIG. 1A, the shield member 16 is provided to surround the power transmission device 15, and the shield member 16 surrounds the drone 100 when the drone 100 is landing on the take-off and landing portion. It is sufficient that the shield member 16 can shield electromagnetic noise that may be generated from a battery 105 and a second communication device 106 to be described later, instead of surrounding the entire drone 100. Thus, the shield member 16 surrounds the power transmission device 15 and at least a part of the drone 100. As the shield member 16, for example, permalloy, which is an alloy of nickel (Ni) and iron (Fe), can be used.

The working device 60 is connected to a side surface of the main body device 40 via a swing unit 41 and a swing cylinder 42. Inside the main body device 40, in addition to the engine 11, the fuel tank 12, the leakage sensor 13, and the generator 14 described above, an attitude detector 18, the counter mass 43, a pair of sliders 44, a pair of bases 45, a counter mass motor 46, a first global navigation satellite system (GNSS) 47 that is a global positioning system, a first communication device 48, a first memory 49, and a heavy machine control device 50 that controls the entire hydraulic excavator 1 are included. Furthermore, the main body device 40 has an opening (not illustrated) through which the cover 19 and the counter mass 43 move to the outside of the main body device 40. An opening/closing unit for opening/closing the opening may be provided. In a case where the opening/closing unit is provided, the cover 19 may be omitted.

Although not illustrated in FIGS. 1A and 1B, the attitude detector 18 is a sensor that is attached inside the main body device 40 and detects an attitude of the main body device 40. As the attitude detector 18, an inclinometer, a level, or the like can be used.

The counter mass 43 corrects an unbalanced load acting on the hydraulic excavator 1 when the working device 60 is driven and is provided in the main body device 40 to be on an opposite side of the working device 60. The counter mass 43 is provided on a lower side of the main body device 40 and is attached to the pair of sliders 44 separated in a Y direction. The pair of sliders 44 extends in an X direction and is supported by the pair of bases 45 to be movable in the X direction. A conventional counter mass is provided along a Z direction, which is a vertical direction, whereas the counter mass 43 of the present embodiment is provided along an X-Y plane orthogonal to the Z direction. With this configuration, the center of gravity of the hydraulic excavator 1 can be lowered.

The counter mass motor 46 moves the counter mass 43 by moving the pair of sliders 44 along the pair of bases 45. In a case where the working device 60 is positioned on a +X side, the counter mass 43 moves to the −X side, and in a case where the working device 60 is positioned on the −X side due to revolving of the revolving device 30, the counter mass 43 moves to the +X side. In a case where the working device 60 is positioned on a +Y side, the counter mass 43 moves to a −Y side.

A size of the hydraulic excavator 1 depends on a size of a bucket 58, and sizes and weights of the engine 11, the fuel tank 12, the generator 14, and the counter mass 43 constituting the hydraulic excavator 1 also depend on the size of the bucket 58. Thus, although depending on the size of the bucket 58, a weight of about 1.5 tons to 4 tons is required to correct the unbalanced load acting on the hydraulic excavator 1 when the working device 60 is driven. Here, the weight of the engine 11 is about 350 Kg to 600 Kg, the weight of the fuel tank 12 when full is about 120 Kg to 400 Kg, and the weight of the generator 14 is about 450 Kg to 750 Kg. These add up to about 920 Kg to 1750 Kg, so the weight required for the counter mass 43 is about 580 Kg to 2750 Kg. The weight of the counter mass 43 can be reduced by loading the engine 11, the fuel tank 12, and the generator 14 on the counter mass 43. The counter mass 43 does not need to load all of the engine 11, the fuel tank 12, and the generator 14, but it is sufficient to load at least one of the engine 11, the fuel tank 12, or the generator 14. Thus, the counter mass 43 and what is loaded on the counter mass 43 serve as a mass body for correcting the unbalanced load acting on the hydraulic excavator 1.

In a case where the counter mass 43 loads the fuel tank 12, the weight of the fuel tank 12 is reduced as fuel is used. In such a case, the weight of the counter mass 43 may be set on the assumption that the fuel tank 12 is empty, or the counter mass 43 may be moved by the counter mass motor 46 as the fuel is used. In a case where the counter mass 43 is moved by the counter mass motor 46, the weight of the counter mass 43 may be further reduced. In a case where the counter mass 43 is not moved, the pair of sliders 44, the pair of bases 45, and the counter mass motor 46 may be omitted. However, even in a case where the counter mass 43 is not moved, when the engine 11, the fuel tank 12, and the generator 14 are pulled out to the outside of the main body device 40 by using the pair of sliders 44, the pair of bases 45, and the counter mass motor 46, maintenance of the engine 11 and the generator 14 becomes easy, and fuel supply to the fuel tank 12 becomes easy. For the movement of the counter mass 43, an actuator using another driving system such as hydraulic pressure may be used instead of the counter mass motor 46.

The swing unit 41 is pivotally supported such that a portion connected to the main body device 40 and a portion connected to a boom 53 are rotatable around a Z axis. The swing cylinder 42 is a cylinder having one end connected to the main body device 40 and another end connected to the swing unit 41, and extending and contracting operation thereof is performed by power supplied from the generator 14.

By extension and contraction of the swing cylinder 42, the working device 60 is driven in a clockwise direction or a counterclockwise direction of FIG. 1A.

A boom cylinder 54 is a cylinder where extending and contracting operation of the boom cylinder 54 is performed by power supplied from the generator 14 to drive the boom 53.

Furthermore, an arm cylinder 56 is a cylinder where extending and contracting operation of the arm cylinder 56 is performed by power supplied from the generator 14 to drive an arm 55.

Furthermore, a bucket cylinder 59 is a cylinder where an extending and contracting operation of the bucket cylinder 59 is performed by power supplied from the generator 14 to drive the bucket 58.

In the present embodiment, the swing cylinder 42, the boom cylinder 54, the arm cylinder 56, and the bucket cylinder 59 are driven by the power from the generator 14, but these cylinders may be driven by using hydraulic pressure.

The first GNSS 47 measures a position of the hydraulic excavator 1 by using an artificial satellite.

The first communication device 48 includes the antennas 48a, a transmitter, a receiver, various circuits, and the like, and is a wireless communication unit that accesses the second communication device 106 to be described later or a wide area network such as the Internet. In the present embodiment, the first communication device 48 communicates a flight path of the drone 100 to the second communication device 106 based on a position of the hydraulic excavator 1 detected by the first GNSS 47. Although two antennas 48a are illustrated in FIGS. 1A and 1B, the number of the antennas 48a may be one or three or more.

The first memory 49 is a nonvolatile memory (for example, a flash memory), and the first memory 49 stores various types of data and programs for driving the hydraulic excavator 1 and various types of data and programs for automatically operating the hydraulic excavator 1. Furthermore, the first memory 49 stores data related to a flight path of the drone 100.

The heavy machine control device 50 is a control device that includes a central processing unit (CPU) and controls the entire hydraulic excavator 1. The heavy machine control device 50 controls, for example, excavation operation of the working device 60, revolving operation, movement of the counter mass 43, and flight operation of the drone 100.

The working device 60 is connected to the main body device 40 via the swing unit 41 and the swing cylinder 42. The working device 60 includes the boom 53, the boom cylinder 54, the arm 55, the arm cylinder 56, the bucket 58, and the bucket cylinder 59.

The boom 53 is a chevron-shaped part connected to the main body device 40 via the swing unit 41. The boom 53 is rotated by the boom cylinder 54.

The arm 55 is connected to a distal end of the boom 53. The arm 55 is rotated by the arm cylinder 56.

The bucket 58 is connected to a distal end of the arm 55. The bucket 58 is rotated by the bucket cylinder 59. Instead of the bucket 58, a breaker or the like can be attached to the distal end of the arm 55.

The drone 100 of the present embodiment includes flight devices 101, an image capturing device 102, the power reception device 103, a sensor group 104, the battery 105, the second communication device 106, a second memory 107, and a UAV control device 108.

The flight device 101 includes a motor (not illustrated) and a plurality of propellers. The flight device 101 floats the drone 100 in the air and generates thrust to move the drone 100 in the air. As described above, the number of drones 100 that land on the take-off and landing portion can be optionally set. Furthermore, the configuration of each drone 100 may be the same, or a part thereof may be changed. Moreover, sizes of the respective drones 100 may be the same or different.

The image capturing device 102 is a digital camera that includes a lens, an imaging element, an image processing engine, and the like, and captures a moving image and a still image. In the present embodiment, the image capturing device 102 performs surveying and captures an image of an excavated portion.

In an enlarged view surrounded by an alternate long and short dash line in FIG. 2. the lens of the image capturing device 102 is attached to a side surface (e.g., a front surface) of the drone 100, but the lens of the image capturing device 102 may be attached to a lower surface of the drone 100, or a plurality of lenses may be provided in the drone 100. Furthermore, a moving mechanism that moves the lens attached to the side surface toward the lower surface may be provided. Furthermore, a mechanism that rotates the image capturing device 102 around the Z axis may be provided to position the lens of the image capturing device 102 at an optional position around the Z axis. An omnidirectional camera (i.e., a 360-degree Camera) may be used as the image capturing device 102, or a three-dimensional (3D) scanner may be used instead of the image capturing device 102.

The power reception device 103 includes power reception coils, charging circuits, and the like provided in leg portions 109 of the drone 100. The power reception device 103 charges the battery 105 with power from the power transmission device 15.

The battery 105 is a secondary battery connected to the power reception device 103, and a lithium-ion secondary battery, a lithium polymer secondary battery, or the like can be used as the battery 105, but the battery 105 not limited thereto. The battery 105 can supply power to the flight devices 101, the image capturing device 102, the second communication device 106, the second memory 107, and the UAV control device 108.

The sensor group 104 is a GNSS, an infrared sensor for avoiding collision between the drone 100 and another device (for example, the working device 60), an atmospheric pressure sensor that measures an altitude, a magnetic sensor that detects an azimuth, a gyro sensor that detects an attitude of the drone 100, an acceleration sensor that detects acceleration acting on the drone 100, and the like.

The second communication device 106 includes a wireless communication unit. The second communication device 106 accesses a wide area network such as the Internet and communicates with the first communication device 48. In the present embodiment, the second communication device 106 transmits image data captured by the image capturing device 102 and a detection result detected by the sensor group 104 to the first communication device 48. The second communication device 106 also transmits a flight command from the first communication device 48 to the UAV control device 108.

The second memory 107 is a nonvolatile memory (for example, a flash memory) that stores various types of data and programs for flying the drone 100, and that stores image data captured by the image capturing device 102, a detection result detected by the sensor group 104, and the like.

The UAV control device 108 includes a CPU, an attitude control circuit, a flight control circuit, and the like, and controls the entire drone 100. Furthermore, the UAV control device 108 determines timing of charging at the take-off and landing portion from a remaining amount of the battery 105, and the UAV control device 108 controls an image capturing position, an angle of view, a frame rate, and the like of the image capturing device 102.

In the hydraulic excavator 1 of the present embodiment configured as described above, the drone 100 can survey an excavation area prior to excavation of the working device 60 and can capture an image from the sky and capture an image of the bucket near the bucket 58 during the excavation of the working device 60. In this way, the excavation can be performed even when a worker is not in the excavation area. Furthermore, when the drone 100 performs image capturing at the take-off and landing portion, image capturing can be performed from substantially the same position as a driver's seat of a conventional hydraulic excavator.

By using a plurality of the drones 100, when a first drone 100 is flying, a second drone 100 can be charged at the take-off and landing portion. In this way, the first drone 100 and the second drone 100 can be alternately flown. The number of drones 100 may be three or more.

Hereinafter, the description will be continued for the control of the excavation operation by the heavy machine control device 50 of the present embodiment configured as described above. FIG. 5 is a flowchart executed by the heavy machine control device 50 of the present embodiment. Herein, it is assumed that the flowchart of FIG. 5 is performed in a state where the drive system 10 is driven.

Flowchart

The heavy machine control device 50 determines whether an abnormality has occurred in the hydraulic excavator 1 or not (Step S1). Here, the heavy machine control device 50 determines whether ammonia leaks from output of the leakage sensor 13 or not. When ammonia does not leak, the heavy machine control device 50 proceeds to Step S2. When ammonia leaks, the heavy machine control device 50 proceeds to Step S6 and stops the hydraulic excavator 1. In a case where ammonia leaks and the hydraulic excavator 1 is stopped, the heavy machine control device 50 opens an opening unit (not illustrated) of the main body device 40 to prevent the ammonia from remaining in the main body device 40 in a state where ammonia concentration is high. The heavy machine control device 50 may move a part of the engine 11 and the fuel tank 12 to the outside of the main body device 40 by driving the counter mass motor 46 to move the counter mass 43. With this configuration, the ammonia concentration in the main body device 40 can be reduced, and maintainability of the engine 11 and the fuel tank 12 can be improved. Furthermore, an opening unit (not illustrated) may be provided in the cover 19, and in a case where ammonia leaks, the opening unit may be opened by a motor (not illustrated). The opening unit is desirably opened when a part of the counter mass 43 moves to the outside of the main body device 40.

Next, it is assumed that the heavy machine control device 50 proceeds to Step S2 assuming that there is no ammonia leakage.

The heavy machine control device 50 performs excavation using the working device 60 based on a program of automatic operation of the working device 60 stored in the first memory 49 based on a result of surveying performed by using the drone 100, for example (Step S2). The program of automatic operation of the working device 60 is executed based on specifications such as a position of the hydraulic excavator 1 measured by the first GNSS 47, a height of an excavation object at an excavation point, and an excavation range of the working device 60, and the like. Furthermore, the program also includes control of the traveling device 20, the revolving device 30, the swing cylinder 42, and the like. The excavation in Step S2 may be performed by remote operation by a worker at a remote place instead of the automatic operation.

The heavy machine control device 50 determines whether it is necessary to correct, by driving the counter mass 43, an unbalanced load acting on the hydraulic excavator 1 by driving the working device 60 in Step S2 or not (Step S3). The description will be continued assuming that the weight of the counter mass 43 is set such that it is not necessary to move the counter mass 43 by driving the working device 60 when the fuel tank 12 is full.

The heavy machine control device 50 makes the determination in Step S3 based on output of the residual meter (not illustrated) provided in the fuel tank 12. It is assumed that the heavy machine control device 50 proceeds to Step S4 assuming that a remaining amount of the fuel tank 12 is, for example, less than 50%. Furthermore, it is assumed that, in a case where the remaining amount of the fuel tank 12 is 50% or more, the heavy machine control device 50 proceeds to Step S5 to be described later. The heavy machine control device 50 may determine whether to move the counter mass 43 or not based on output of the attitude detector 18 instead of the output of the residual meter or in combination with the output of the residual meter.

The heavy machine control device 50 drives the counter mass motor 46 to move the counter mass 43 together with the engine 11, the fuel tank 12, and the generator 14 (Step S4). To prevent an accident when the counter mass 43 moves to the outside of the main body device 40, it is preferable to provide a notification device in the main body device 40. For example, it is desirable to provide a warning light to the main body device 40 to visually call attention, to provide a speaker to the main body device 40 to aurally call attention, or to perform both.

The heavy machine control device 50 determines whether the work by the working device 60 has ended or not (Step S5). The heavy machine control device 50 causes Steps S1 to S5 to be repeatedly executed until the scheduled excavation work ends, and the heavy machine control device 50 proceeds to Step S6 when the scheduled excavation work has ended.

When the work by the working device 60 ends, the heavy machine control device 50 performs control for stopping the hydraulic excavator 1 (Step S6). Specifically, the heavy machine control device 50 moves the working device 60 to an initial position, and in a case where the counter mass 43 is moved to the outside of the main body device 40, the heavy machine control device 50 moves the counter mass 43 to the inside of the main body device 40. The initial position refers to when the working device 60 is at a position where an unbalanced load is unlikely to be generated (that is, position where a portion extending in the X direction is small).

The heavy machine control device 50 stops driving of the hydraulic excavator 1 after moving the hydraulic excavator 1 by the traveling device 20 as necessary, and the heavy machine control device 50 ends the flowchart in FIG. 5.

In the present embodiment, because the counter mass 43 is provided along the X-Y plane orthogonal to the Z direction using a space without a driver's seat, and the engine 11, the fuel tank 12, and the generator 14 are loaded (held) on the counter mass 43, the weight of the counter mass 43 can be reduced, As a result, a hydraulic excavator 1 with a high degree of freedom in layout can be achieved. In FIGS. 1A to 3B, the fuel tank 12 is disposed on the other end side (−X side) of the main body device 40, but the engine 11 may be disposed on the other end side of the main body device 40, or the generator 14 may be disposed on the other end side of the main body device 40.

Furthermore, an ammonia concentration meter may be provided in the main body device 40. In a case where the ammonia concentration exceeds, for example, 20 ppm, visual or auditory notification may be performed by the notification device described above. Furthermore, a solar power generator may be provided on the upper surface, the side surface, or the like of the main body device 40, and power generated by the solar power generator may be used for driving the hydraulic excavator 1. As the solar power generator, for example, a perovskite solar cell may be used. The perovskite solar cell is a solar cell using a perovskite crystal, and the perovskite solar cell can be attached to a structure having a curved surface because it is flexible. Furthermore, because the perovskite solar cell is lightweight, an increase in the weight of the hydraulic excavator 1 can be suppressed.

Furthermore, in a case where ammonia or the like that does not emit greenhouse gas is used as the fuel of the engine 11, it is possible to achieve a construction machine that emits less greenhouse gas. Gas oil, gasoline, or the like may be used without using ammonia in a situation where emission of greenhouse gas is permitted.

In a case where the generator 14 is loaded on the counter mass 43, it is sufficient that a length of wiring of various cylinders and various motors to which power is supplied from the generator 14 is increased in consideration of a movement stroke of the counter mass 43. Alternatively, the power supply from the generator 14 to various cylinders, various motors, and the like may be a power supply of the spatial transmission type (wireless power supply).

Second Embodiment

Hereinafter, a second embodiment will be described with reference to FIGS. 6A to 9D, but the same configurations as those of the first embodiment are denoted by the same reference signs, and description thereof will be omitted or simplified. In FIGS. 6A and 6B, illustration of a shield member 16, a cover 19, an antenna 48a, a drone 100, and the like is omitted in order to avoid complication of the drawing.

FIG. 6A is a schematic top view of a hydraulic excavator 1 representing an example of the construction machine representing the second embodiment, and FIG. 6B is a schematic front view of a hydraulic excavator 1 representing an example of the construction machine representing the second embodiment. A portion surrounded by a dotted line is illustrated as a partial cross-sectional view.

In the hydraulic excavator 1 of the second embodiment, a revolving device 30 and a main body device 40 are divided into two, and there are two working devices 60. The two revolving devices 30 will be described as an upper revolving device 30a and a lower revolving device 30b. Furthermore, the revolving motor 31 of the first embodiment is divided into two, that is, an upper revolving motor 31a and a lower revolving motor 31b. Similarly, the two main body devices 40 will be described as an upper main body device 40a and a lower main body device 40b. Furthermore, because configurations of the two working devices 60 are the same as those of the first embodiment, one is defined as a working device 60a and the other is defined as a working device 60b, and each element constituting the working device 60a and working device 60b is also denoted by a reference sign added with a or b in the end.

The upper main body device 40a is revolvable by the upper revolving device 30a having a bearing. The upper main body device 40a also functions as a housing unit, as the upper main body device 40a houses an engine 11, a fuel tank 12, a generator 14, a counter mass 43, a part of the upper revolving motor 31a for revolving the upper main body device 40a, and the like. The counter mass 43 has a rectangular shape in the first embodiment, but has a circular shape in the present embodiment, and loads the engine 11 and the generator 14 on one end side thereof (−X side in FIGS. 6A and 6B). Note that the shape of the counter mass 43 can be optionally set.

Furthermore, in the present embodiment, because the two working devices 60 are provided, for example, an unbalanced load acting on the hydraulic excavator 1 by driving the working device 60b can be corrected by a load of the working device 60a. Particularly, when the working device 60a is moved to −X, the unbalanced load acting on the hydraulic excavator 1 by the driving of the working device 60a can be further corrected. Thus, because the unbalanced load is corrected by loads of the engine 11 and the generator 14 disposed on the one end side of the counter mass 43, a weight of the counter mass 43 can be reduced, or the counter mass 43 can be omitted. Only one of the engine 11 or the generator 14 may be loaded on the counter mass 43 to correct the unbalanced load.

Furthermore, in the present embodiment, the fuel tank 12 has a cylindrical shape, which contributes to stabilize a weight balance of the upper main body device 40a rather than to correct the unbalanced load. Thus, the fuel tank 12 is not loaded on the counter mass 43. Furthermore, because the fuel tank 12 is used to stabilize the weight balance of the upper main body device 40a, the correction of the unbalanced load is not affected by a decrease in fuel in the fuel tank 12. Although illustration is omitted in FIGS. 6A and 6B, an attitude detector 18 is preferably provided in the upper main body device 40a.

Furthermore, an opening unit is formed in a lower center of the upper main body device 40a, and an upper slip ring 35 constituting a part of a slip ring mechanism to be described later is engaged with the opening unit. The upper slip ring 35 has an opening, and wiring or the like that supplies power to the lower revolving motor 31b and a traveling motor 24 is routed through the opening. A part of the upper slip ring 35 revolves with the revolving of the upper main body device 40a.

The slip ring mechanism includes, in addition to the upper slip ring 35, a lower slip ring 36, and a fixing unit 37 connected to a non-revolving portion of the upper slip ring 35 and a non-revolving portion of the lower slip ring 36. The lower slip ring 36 is provided in the lower main body device 40b and supports the fixing unit 37 from the outside. The fixing unit 37 is provided to penetrate the lower revolving device 30b and has an opening for routing the wiring from the upper slip ring 35. Thus, even when the upper main body device 40a and the lower main body device 40b revolve, because the wiring is routed by the slip ring mechanism, the wiring is not entangled or disconnected. A pipe for liquid (hydraulic pressure or water), gas, or the like may be routed by using the slip ring mechanism, as necessary.

The lower main body device 40b is revolvable by the lower revolving device 30b having a bearing. To the lower main body device 40b, the working device 60a is connected on a side in the −X direction via a swing unit 41a and a swing cylinder 42a, and the working device 60b is connected on a side in a +X direction via a swing unit 41b and a swing cylinder 42b. The working device 60a and the working device 60b are preferably disposed symmetrically with respect to the lower main body device 40b. Furthermore, by connecting the working device 60a and the working device 60b to the lower main body device 40b, it is possible to suppress an increase in the center of gravity of the hydraulic excavator 1.

Furthermore, the lower main body device 40b houses a part of the lower revolving motor 31b and the lower slip ring 36. The lower main body device 40b has an opening for penetrating the fixing unit 37, which is formed near a central portion. As is also clear from FIG. 6B, a large space is formed inside the lower main body device 40b. Thus, a maintenance tool of the hydraulic excavator 1, various replacement parts, the drone 100, replacement parts of the drone 100, and the like may be housed inside the lower main body device 40b. Furthermore, in a case where various cylinders are hydraulically driven, a hydraulic unit may be disposed inside the lower main body device 40b.

The upper main body device 40a and the lower main body device 40b are not limited to a cylindrical shape and may have an optional shape.

In the present embodiment, in a case where the counter mass 43 is moved to the outside of the upper main body device 40a, it is sufficient that the fuel tank 12 is loaded on the counter mass 43 to drive the counter mass 43 by a counter mass motor 46. Furthermore, in a case where it is not necessary to move the counter mass 43 to the outside of the upper main body device 40a, a pair of sliders 44, a pair of bases 45, and the counter mass motor 46 may be omitted.

Description of Flowchart

FIG. 7 is a flowchart executed by a heavy machine control device 50 of the present embodiment. FIG. 8A is a view illustrating excavation operation when the working devices 60 are at initial positions, FIG. 8B is a view illustrating a state at the time of excavation, FIG. 8C is a view illustrating a state at the end of the excavation, and FIG. 8D is a view illustrating a state after revolving. Furthermore, FIG. 9A is a view illustrating operation following the excavation operation of FIGS. 8A to 8D when the working devices 60 are in a state of loading, FIG. 9B is a view illustrating when the working devices 60 are at the initial positions, FIG. 9C is a view illustrating a state after the upper main body device 40a is revolved, and FIG. 9D is a view illustrating a state at the time of excavation.

Hereinafter, the flowchart of FIG. 7 will be described with reference to FIGS. 8A to 9D. In FIGS. 8A to 9D, portions surrounded by dotted lines are illustrated as partial cross-sectional views as in FIGS. 6A and 6B. Furthermore, in FIGS. 8A to 9D, illustration of reference signs is partially omitted in order to avoid complication of the drawings. The initial positions refer to when the two working devices 60 are at positions where an unbalanced load is unlikely to be generated (that is, positions where portions extending in an X direction are small). In the flowchart of FIG. 7, a part thereof may be performed by, for example, a worker in a remote place away from a civil engineering site.

The heavy machine control device 50 determines whether excavation preparation by the hydraulic excavator 1 is completed or not (Step S11). When the hydraulic excavator 1 arrives at an excavation place and can perform excavation, and a dump truck 70 arrives at a loading place as illustrated in FIG. 8A, the heavy machine control device 50 proceeds to Step S12 assuming that the excavation preparation is completed, and otherwise repeats Step S11. In this explanation, it is assumed that the heavy machine control device 50 proceeds to Step S12 assuming that the excavation preparation is completed.

As illustrated in FIG. 8B, the heavy machine control device 50 performs excavation by using a bucket 58a constituting a part of the working device 60a (Step S12). When performing the excavation by the bucket 58a, the heavy machine control device 50 can confirm an excavation situation by flying the drone 100 in the vicinity of the bucket 58a and causing an image capturing device 102 to capture an image of the excavation operation by the bucket 58a. In the present embodiment, because the working device 60a and the working device 60b have the same configuration, weights thereof are also assumed to be the same. However, as illustrated in FIG. 8B, when the working device 60a extends in the −X direction and an excavation object is housed in the bucket 58a, an unbalanced load in the −X direction acts on the hydraulic excavator 1. Therefore, the engine 11 and the generator 14 housed in the upper main body device 40a and loaded on the counter mass 43 are positioned in the +X direction to correct the unbalanced load.

The heavy machine control device 50 determines whether the excavation by the bucket 58a has ended or not (Step S13). In the case of determining that a predetermined amount of the excavation object is housed in the bucket 58a by the image capturing by the image capturing device 102 of the drone 100, the heavy machine control device 50 determines that the excavation by the bucket 58a has ended. Alternatively, a worker in a remote place may determine whether the excavation by the bucket 58a has ended or not based on an image capturing result of the image capturing device 102 of the drone 100. Furthermore, a gravimeter may be provided in the bucket 58a, and the heavy machine control device 50 may determine whether a predetermined amount of the excavation object is housed in the bucket 58a or not based on a measurement result of the gravimeter. Next, it is assumed that the heavy machine control device 50 proceeds to Step S14 assuming that the excavation by the bucket 58a has ended. When determining that the excavation by the bucket 58a has ended, the heavy machine control device 50 moves the working device 60a to the initial position as illustrated in FIG. 8C. This is to reduce an unbalanced load acting on the lower main body device 40b and the like by revolving by the working device 60a in Step S14 and to perform the revolving safely.

The heavy machine control device 50 revolves the upper main body device 40a by 180 degrees by the upper revolving motor 31a, and the heavy machine control device 50 revolves the lower main body device 40b by 180 degrees by the lower revolving motor 31b (Step S14). The lower main body device 40b is revolved to load the excavation object housed in the bucket 58a into the dump truck 70 and to move a bucket 58b constituting a part of the working device 60b to an excavation position. The upper main body device 40a is revolved to correct the unbalanced load acting on the hydraulic excavator 1 due to the revolving of the lower main body device 40b. With this configuration, it is possible to prevent the hydraulic excavator 1 from floating or falling when the lower main body device 40b is revolved. To reduce the unbalanced load acting on the hydraulic excavator 1, it is preferable that the upper main body device 40a and the lower main body device 40b are revolved in the same direction. Specifically, in a case where the upper main body device 40a is revolved in the clockwise direction, it is sufficient that the heavy machine control device 50 also revolves the lower main body device 40b in the clockwise direction. FIG. 8D is a view illustrating a state where the revolving in Step S14 is performed, the bucket 58a is positioned on the side in the +X direction, and the bucket 58b and the fuel tank 12 are positioned on the side in the −X direction.

As illustrated in FIG. 9A, the heavy machine control device 50 drives and controls the working device 60a to load the excavation object housed in the bucket 58a into the dump truck 70 (Step S15). At this time, the heavy machine control device 50 can confirm the loading work by flying the drone 100 in the vicinity of the bucket 58a and causing the image capturing device 102 to capture an image of the loading operation by the bucket 58a. In Step S15, the heavy machine control device 50 may finely adjust the position of the working device 60a by the swing unit 41a and the swing cylinder 42a.

The heavy machine control device 50 determines whether the loading work by the bucket 58a has ended or not based on the image capturing by the image capturing device 102 or a measurement result of the gravimeter (Step S16). The determination in Step S16 may be made by a worker in a remote place. When the loading work has ended, the heavy machine control device 50 moves the working device 60a to the initial position as illustrated in FIG. 9B.

The heavy machine control device 50 revolves the upper main body device 40a by 180 degrees to prepare for excavation work by the working device 60b (Step S17). Because the engine 11 and the generator 14 are positioned on the side in the +X direction as illustrated in FIG. 9C by the revolving of the upper main body device 40a by 180 degrees, it is possible to correct the unbalanced load acting on the hydraulic excavator 1 by the excavation operation of the working device 60b. By performing the movement of the working device 60a to the initial position illustrated in FIG. 9B and the revolving of the upper main body device 40a almost at the same time, the excavation work by the working device 60b can be started quickly. Moreover, when the movement of the working device 60a to the initial position and the revolving of the upper main body device 40a are performed, the working device 60b may be moved from the initial position to the excavation position. With this configuration, the excavation work by the working device 60b can be started more quickly. In this way, in a case where the working device 60b is moved from the initial position to the excavation position, because the excavation object is not housed in the bucket 58b, a large unbalanced load does not act on the hydraulic excavator 1. The correction of the unbalanced load on the hydraulic excavator 1 by the revolving of the upper main body device 40a is also possible in a case where an unexpected load acts on the hydraulic excavator 1. In such a case, it is sufficient that the heavy machine control device 50 revolves the upper main body device 40a based on output of the attitude detector 18.

The heavy machine control device 50 determines whether a predetermined amount of excavation has ended or not (Step S18). The heavy machine control device 50 returns to Step S12 assuming that the predetermined amount of excavation has not yet ended. Then, the heavy machine control device 50 performs a series of the excavation operation by the working device 60b, and thereafter, alternately repeats excavation by the working device 60a and excavation by the working device 60b until the predetermined amount of excavation is reached. A program for executing the flowchart of FIG. 7 is stored in a first memory 49. Step S1 of the flowchart of FIG. 5 may be added to the flowchart of FIG. 7 to perform abnormality detection such as ammonia leakage.

As described above, according to the second embodiment, because the excavation by the working device 60a and the excavation by the working device 60b are alternately repeated, a work period of excavation work can be shortened. Although one drone 100 is illustrated in FIGS. 8A to 9D, the flowchart of FIG. 7 may be executed by a plurality of drones 100. Furthermore, the image capturing by the image capturing device 102 of the drone 100 may be performed not only during the flight but also during landing on a take-off and landing portion of the upper main body device 40a. An image captured by the image capturing device 102 from the take-off and landing portion of the upper main body device 40a can be used as an image visually recognized by a worker from a conventional driver's seat.

In a case where the drone 100 is flown in the vicinity of the bucket 58, a UAV control device 108 can avoid collision between the bucket 58 and the drone 100 by recognizing the bucket 58 by an infrared sensor of a sensor group 104.

Furthermore, the heavy machine control device 50 may perform image capturing by the image capturing device 102 of the drone 100 when a failure occurs in the hydraulic excavator 1 or to determine whether maintenance is necessary or not. Also in the present embodiment, it is possible to achieve a hydraulic excavator 1 that emits less greenhouse gas.

Third Embodiment

FIGS. 10A and 10B are schematic views of a hydraulic excavator 1 representing an example of the construction machine representing a third embodiment, in which a portion surrounded by a dotted line is illustrated as a partial cross-sectional view. In FIGS. 10A and 10B, illustration of a shield member 16, a cover 19, an antenna 48a, a drone 100, and the like is omitted in order to avoid complication of the drawing. Hereinafter, the third embodiment will be described with reference to FIGS. 10A and 10B, but the same configurations as those of the first and second embodiments are denoted by the same reference signs, and description thereof will be omitted or simplified.

The third embodiment is different from the second embodiment in that an engine 11 and a generator 14 are disposed closer to a periphery of an upper main body device 40a than a fuel tank 12. Furthermore, in the third embodiment, the engine 11, the fuel tank 12, and the generator 14 are loaded on a counter mass 43. Thus, the fuel tank 12 is used as a mass body to correct an unbalanced load acting on the hydraulic excavator 1, which is different from the second embodiment. Therefore, a weight of the counter mass 43 of the third embodiment can be made lighter than the weight of the counter mass 43 of the second embodiment.

Furthermore, like the first embodiment, the counter mass 43 may be moved to the outside of the upper main body device 40a by a counter mass motor 46. With this configuration, maintenance of the engine 11, the generator 14, and the like can be performed outside the upper main body device 40a.

In the second and third embodiments, the upper main body device 40a is the housing unit (e.g., the housing unit is provided at an upper part of the main body unit), and the two working devices 60 are connected to the lower main body device 40b via the swing units 41 and the swing cylinders 42. Alternatively, the lower main body device 40b may be the housing unit, and the two working devices 60 are connected to the upper main body device 40a via the swing units 41 and the swing cylinders 42.

According to the first to third embodiments, because the drone 100 assists the hydraulic excavator 1, automated construction work can be efficiently implemented. In the first to third embodiments, ammonia is supplied to the engine 11 to drive the hydraulic excavator 1, but alternatively, hydrogen and a fuel cell may be used to drive the hydraulic excavator 1. In this case, it is sufficient to store high-pressure hydrogen gas in the fuel tank 12 and supply the hydrogen gas to the fuel cell. Furthermore, it is sufficient to load the fuel tank storing the hydrogen gas, the fuel cell, or the like on the counter mass 43. Furthermore, the hydraulic excavator 1 may be driven by using methane.

The embodiments described above are merely examples for describing the present invention, and various changes can be made without departing from the gist of the present invention. For example, when an infrared camera is used as the image capturing device 102, a series of work such as excavation and loading (dumping) can be performed even at night, and a work period can be shortened. Instead of the bucket 58, a breaker, a fork, a ripper, or a lifter may be attached to the arm 55. Furthermore, the first to third embodiments may be appropriately combined.

The following is a list of reference signs used in this specification and in the drawings.

- 1 Hydraulic excavator
- 10 Drive system
- 11 Engine
- 12 Fuel tank
- 13 Leakage sensor
- 14 Generator
- 15 Power transmission device
- 16 Shield member
- 18 Attitude detector
- 19 Cover
- 20 Traveling device
- 21 Idler wheels
- 22 Drive wheels
- 23 Crawler belts
- 24 Traveling motor
- 30 Revolving device
- 30a Upper revolving device
- 30b Lower revolving device
- 31 Revolving motor
- 31a Upper revolving motor
- 31b Lower revolving motor
- 35 Upper slip ring
- 36 Lower slip ring
- 37 Fixing unit
- 40 Main body device
- 40a Upper main body device
- 40b Lower main body device
- 41 Swing unit
- 42 Swing cylinder
- 43 Counter mass
- 44 Sliders
- 45 Bases
- 46 Counter mass motor
- 47 First global navigation satellite system (GNSS)
- 48 First communication device
- 48a Antennas
- 49 First memory
- 50 Heavy machine control device
- 51 Power transmission device
- 53 Boom
- 54 Boom cylinder
- 55 Arm
- 56 Arm cylinder
- 58 Bucket
- 59 Bucket cylinder
- 60 Working device
- 60a Working device
- 60b Working device
- 70 Dump truck
- 100 Drone
- 101 Flight device
- 102 Image capturing device
- 103 Power reception device
- 104 Sensor group
- 105 Battery
- 106 Second communication device
- 107 Second memory
- 108 UAV control device
- 109 Leg portion

Construction Machine

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CPC

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