Control method for work machines, control program for work machines, control system for work machines, and work machines

Abstract

The present invention provides a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work machine that facilitate the operation intended by the operator. [Solution] The control method for the work machine includes executing deceleration control when the deceleration condition is met, and changing the rated rotational speed in response to the operation of the accelerator control unit 37. In deceleration control, the target rotational speed of the prime mover 40 for driving the hydraulic pump 41 that discharges hydraulic fluid is switched from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. In this control method, if there is an operation on the accelerator control unit 37 while deceleration control is being executed, the deceleration control is continued.

Description

Technical Field

[0001] The present invention relates to a control method for a working machine including a prime mover for driving a hydraulic pump that discharges hydraulic oil, a control program for a working machine, a control system for a working machine, and a working machine.

Background Art

[0002] As related art, a working machine (working vehicle) including a prime mover composed of an electric motor is known (see, for example, Patent Document 1). The working machine according to the related art includes an accelerator operation unit (operation unit) for setting the rated rotational speed (rotational speed) of the prime mover, and normally rotates the prime mover at the rated rotational speed.

[0003] [[ID=I5]] This working machine determines whether it is in a no-load state where the prime mover is not performing work or traveling, and when it is determined to be in a no-load state, it executes deceleration control to rotate the prime mover at a rotational speed lower than the rated rotational speed (sets the auto-idle function to be effective). Further, when there is an operation on the accelerator operation unit during the execution of the deceleration control, this working machine determines that it is not in a no-load state and cancels the deceleration control (sets the auto-idle function to be effective).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above related art, for example, even when the operator operates the accelerator operation unit in advance to set the rated rotational speed for the next work during the execution of the deceleration control, the deceleration control is immediately canceled, so there is a possibility that the operation intended by the operator may not be achieved. [[ID=I41]]

[0006] The object of the present invention is to provide a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work machine that facilitate the operation intended by the operator. [Means for solving the problem]

[0007] A control method for a work machine according to one aspect of the present invention includes performing deceleration control when deceleration conditions are met, and changing the rated rotational speed in response to operation of an accelerator control unit. In the deceleration control, the target rotational speed of the prime mover for driving a hydraulic pump that discharges hydraulic fluid is switched from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. In this control method, if there is an operation on the accelerator control unit while the deceleration control is being performed, the deceleration control is continued.

[0008] A control program for a work machine according to one aspect of the present invention is a program that causes one or more processors to execute a control method for the work machine.

[0009] A control system for a work machine according to one aspect of the present invention comprises a control processing unit and a setting processing unit. The control processing unit can perform deceleration control when the deceleration conditions are met. In the deceleration control, the target rotational speed of the prime mover for driving a hydraulic pump that discharges hydraulic fluid is switched from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. The setting processing unit changes the rated rotational speed in response to the operation of the accelerator control unit. If there is an operation on the accelerator control unit while the deceleration control is being performed, the control processing unit continues the deceleration control.

[0010] A work machine according to one aspect of the present invention comprises a control system for the work machine and a machine body. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work machine that facilitate the operation intended by the operator. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic perspective view showing the overall configuration of the work machine according to Embodiment 1. [Figure 2] Figure 2 is a schematic diagram showing the hydraulic circuit and other components of the work machine according to Embodiment 1. [Figure 3] Figure 3 is a timing chart showing an example of the operation of the control system for a work machine according to Embodiment 1. [Figure 4] Figure 4 is a timing chart showing an example of the operation of the control system for a work machine according to Embodiment 1. [Figure 5] Figure 5 is a flowchart showing an example of the operation of the control system for a work machine according to Embodiment 1. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be described below with reference to the attached drawings. The following embodiments are examples that embody the present invention and are not intended to limit the technical scope of the present invention.

[0014] (Embodiment 1) [1] Overall structure As shown in Figure 1, the work machine 3 according to this embodiment is equipped with a traveling section 31, a rotating section 32, and a working section 33 on a machine body 30. Furthermore, as shown in Figure 2, the work machine 3 is equipped with a control system 1 for work machines (hereinafter also simply referred to as "control system 1"). In addition, as shown in Figures 1 and 2, the machine body 30 is further equipped with a display device 2, an operating device 35, a main switch 36, an accelerator operating section 37, and the like.

[0015] In this disclosure, "working machinery" refers to various types of machinery used for work, and examples include work vehicles such as backhoes (including hydraulic excavators, mini excavators, etc.), wheel loaders, and carriers. Working machinery 3 includes a working unit 33 configured to perform one or more tasks. Working machinery 3 is not limited to "vehicles," but may also be, for example, a work vessel, a drone, or a multicopter. Furthermore, working machinery 3 is not limited to construction machinery, but may also be, for example, agricultural machinery such as a rice transplanter, tractor, or combine harvester. In this embodiment, unless otherwise specified, the description will be based on the example where working machinery 3 is a ride-on type backhoe capable of performing tasks such as excavation, leveling, trenching, or loading.

[0016] Furthermore, in this embodiment, for the sake of explanation, the vertical direction when the work machine 3 is in a usable state is defined as the up-down direction D1. In addition, the forward-backward direction D2 and left-right direction D3 are defined based on the direction viewed from the user (operator) riding in the work machine 3 (operator's unit 321) when the slewing unit 32 is in a non-slewing state. In other words, each direction used in this embodiment is defined based on the body 30 of the work machine 3, with the direction in which the body 30 moves when the work machine 3 moves forward being "forward," and the direction in which the body 30 moves when the work machine 3 moves backward being "rear." Similarly, the direction in which the front end of the body 30 moves when the work machine 3 turns right is "to the right," and the direction in which the front end of the body 30 moves when the work machine 3 turns left is "to the left." However, these directions are not intended to limit the direction of use (direction during use) of the work machine 3.

[0017] The working machine 3 includes a prime mover 40 (see FIG. 2) that serves as a power source. The prime mover 40 is, for example, a device that converts energy such as electricity, combustion, or heat of steam into mechanical force (power) and generates power for driving each part of the machine body 30. In this embodiment, as an example, the prime mover 40 is an electric motor. The prime mover 40 is driven by receiving power supply from a battery 38 (see FIG. 2). In this embodiment, the prime mover 40 is an alternating current motor and is driven by alternating current power (alternating current voltage) supplied from a drive circuit 39 (see FIG. 2) composed of an inverter circuit. The drive circuit 39 is electrically connected to the battery 38, converts the direct current voltage output from the battery 38 into an alternating current voltage, and supplies it to the prime mover 40 to drive the prime mover 40. That is, the working machine 3 includes the battery 38 and the drive circuit 39.

[0018] The output shaft of the prime mover 40 is connected to a hydraulic pump 41 (see FIG. 2) via a power transmission part or the like, and the hydraulic pump 41 is driven by the power from the prime mover 40. In the working machine 3, the prime mover 40 drives the hydraulic pump 41, and hydraulic oil is supplied from the hydraulic pump 41 to hydraulic actuators (including a hydraulic motor 43, a hydraulic cylinder 44, etc.) of each part of the machine body 30, so that the machine body 30 is driven. That is, the prime mover 40 drives the hydraulic pump 41 to discharge hydraulic oil from the hydraulic pump 41, supplies power (hydraulic oil) to each part of the machine body 30 of the working machine 3, and drives each part of the machine body 30.

[0019] Such a working machine 3 is controlled, for example, by a user (operator) boarding on the operation part 321 of the machine body 30 operating an operation lever or the like of the operation device 35. That is, the power generated by the prime mover 40 is distributed to each part of the machine body 30 according to the operation of the operator, so that the working machine 3 operates according to the operation of the operator.

[0020] In this embodiment, since it is assumed that the working machine 3 is a ride-on type backhoe as described above, the working unit 33 is driven in accordance with the operation of a user (operator) who has boarded the driving unit 321, and performs operations such as excavation work. The driving unit 321 on which the user boards is provided on the revolving unit 32.

[0021] Here, a display device 2, an operation device 35, etc. are mounted on the driving unit 321 of the machine body 30, and the user can operate the operation device 35 while viewing various information related to the working machine 3 displayed on the display device 2. As an example, by displaying information related to the operating state of the working machine 3 such as the coolant water temperature and the operating oil temperature on the display screen of the display device 2, the user can confirm, on the display device 2, information related to the operating state of the working machine 3 necessary for operating the operation device 35.

[0022] The traveling unit 31 has a traveling function and is configured to be able to travel (including turning) on the ground. The traveling unit 31 has, for example, a pair of left and right crawlers 311, a blade 312, etc. The traveling unit 31 further has a hydraulic motor 43 (hydraulic actuator) for traveling for driving the crawlers 311.

[0023] The revolving unit 32 is located above the traveling unit 31 and is configured to be able to revolve about a rotation axis along the vertical direction D1 with respect to the traveling unit 31. The revolving unit 32 has a hydraulic motor (hydraulic actuator) for revolving, etc. In addition to the driving unit 321, a prime mover 40, a hydraulic pump 41, etc. are mounted on the revolving unit 32. Further, a boom bracket 322 to which the working unit 33 is attached is provided at the front end of the revolving unit 32.

[0024] The work unit 33 is configured to perform one or more tasks. The work unit 33 is supported by the boom bracket 322 of the slewing unit 32 and performs tasks. The work unit 33 has a bucket 331. The bucket 331 is a type of attachment (working tool) that is attached to the body 30 of the work machine 3, and consists of any tool selected from a plurality of types of attachments according to the content of the work. For example, the bucket 331 is detachably attached to the body 30 and is replaced according to the content of the work. In addition to the bucket 331, there are various other tools for the work machine 3, such as breakers, augers, crushers, forks, fork claws, steel frame cutters, asphalt milling machines, brush cutters, rippers, mulchers, tilt rotators, and tampers.

[0025] The working section 33 further includes a boom 332, an arm 333, and a hydraulic actuator (including a hydraulic cylinder 44 and a hydraulic motor, etc.). The bucket 331 is attached to the tip of the arm 333.

[0026] The boom 332 is rotatably supported by the boom bracket 322 of the slewing section 32. Specifically, the boom 332 is rotatably supported by the boom bracket 322 around a rotation axis along the horizontal direction. The boom 332 has a shape that extends upward from its base end, which is supported by the boom bracket 322. The arm 333 is connected to the tip of the boom 332. The arm 333 is rotatably supported relative to the boom 332 around a rotation axis along the horizontal direction.

[0027] The work unit 33 operates by receiving power from the prime mover 40, which serves as the power source. Specifically, the prime mover 40 drives the hydraulic pump 41, and hydraulic fluid is supplied from the hydraulic pump 41 to the hydraulic actuators (hydraulic cylinders 44, etc.) of the work unit 33, thereby causing each part of the work unit 33 (bucket 331, boom 332, and arm 333) to operate.

[0028] In this embodiment, the work unit 33 has a multi-joint structure in which the boom 332 and the arm 333 are configured to rotate independently. That is, by each of the boom 332 and the arm 333 rotating around a rotation axis along the horizontal direction, the multi-joint work unit 33 including the boom 332 and the arm 333 can be extended or folded as a whole.

[0029] The traveling section 31 and the slewing section 32, like the working section 33, operate by receiving power from the prime mover 40, which serves as the power source. In other words, the slewing section 32 and the traveling section 31 operate when hydraulic fluid is supplied from the hydraulic pump 41 to the hydraulic motor 43 of the traveling section 31 and the hydraulic motor of the slewing section 32, etc.

[0030] The actuators provided in various parts of the machine body 30 (hydraulic actuators including a hydraulic motor 43 and a hydraulic cylinder 44 in this embodiment) operate in response to the operation of the control device 35. In other words, the work machine 3 according to this embodiment is equipped with actuators that operate in response to the operation of the control device 35. Therefore, the work machine 3 will perform various operations such as forward and backward movement by the travel unit 31, rotation by the slewing unit 32, and excavation work by the work unit 33 in response to the operation of the control device 35 by the user (operator).

[0031] Figure 2 schematically shows the hydraulic and electrical circuits (electrical connection relationships) of the work machine 3 according to this embodiment. In Figure 2, solid lines indicate high-pressure (hydraulic oil) oil passages, dotted lines indicate low-pressure (pilot oil) oil passages, and dashed arrows indicate the paths of electrical signals. Furthermore, the thick line (solid line) between the prime mover 40 and the hydraulic pump 41 indicates the physical connection between the prime mover 40 (output shaft) and the hydraulic pump 41.

[0032] As shown in Figure 2, the work machine 3 includes a hydraulic pump 41, a hydraulic motor 43 (not shown in Figure 2), a hydraulic cylinder 44, a prime mover 40, a battery 38, and a drive circuit 39, as well as a pilot pump 42, a remote control valve 45, a control valve 461, a cutoff switch 462, a cutoff lever 463, a temperature sensor 47, a directional control valve 48, a hydraulic oil tank 49, a main switch 36, and an accelerator operating unit 37, etc.

[0033] The hydraulic fluid from the hydraulic pump 41, driven by the prime mover 40, is supplied to the hydraulic motor 43 of the travel section 31, the hydraulic motor of the slewing section 32, and the hydraulic cylinder 44 of the work section 33, etc. This drives the hydraulic actuators such as the hydraulic motor 43 and the hydraulic cylinder 44.

[0034] The drive circuit 39 drives the prime mover 40 at any desired rotational speed. In other words, by controlling the rotational speed of the prime mover 40, the drive circuit 39 can control the rotational speed of the hydraulic pump 41 driven by the prime mover 40, and thereby change the discharge amount of hydraulic fluid from the hydraulic pump 41. Thus, in this embodiment, the flow rate of hydraulic fluid supplied from the hydraulic pump 41 is not fixed but can be changed (variable) by appropriate means. The drive circuit 39 may change the rotational speed of the prime mover 40 continuously and steplessly, or it may change it in steps (for example, in 2 steps, 5 steps, or 10 steps).

[0035] Hydraulic actuators such as the hydraulic motor 43 and hydraulic cylinder 44 are equipped with a pilot-operated directional control valve 48 that can switch the direction and flow rate of the hydraulic fluid from the hydraulic pump 41. The directional control valve 48 is driven by pilot oil supplied from the pilot pump 42, which serves as an input command.

[0036] Here, for example, a remote control valve 45 is provided in the supply path for pilot oil to the directional control valve 48 corresponding to the hydraulic cylinder 44 of the work unit 33. The remote control valve 45 outputs work operation commands for the work unit 33 in response to the operation of the operating device 35 (operating lever). The work operation commands instruct the work unit 33 to perform operations such as extending and retracting. In addition, the flow rate of pilot oil supplied from the pilot pump 42 to the remote control valve 45 can be adjusted by the control valve 461.

[0037] The control valve 461 is an electromagnetic control valve (solenoid valve) and is inserted between the remote control valve 45 and the pilot pump 42. The control valve 461 is connected to the power supply via a cutoff switch 462 and operates according to the current supplied from the power supply. Here, the control valve 461 is assumed to be an (electromagnetic) proportional control valve, but it is not limited to this and may be an on-off valve that can switch between opening and closing the flow path, for example.

[0038] The control valve 461 opens the pilot oil passage when energized, i.e., when current as a control signal is supplied, and closes the pilot oil passage when de-energized, i.e., when current as a control signal is cut off. As a result, when the current (control signal) supplied to the control valve 461 is cut off, the hydraulic actuator (hydraulic cylinder 44, etc.) corresponding to the remote control valve 45 becomes unable to drive, and the hydraulic actuator is forcibly stopped without operation of the operating device 35.

[0039] Similarly, a remote control valve is also provided in the supply passage for pilot oil to the directional control valve corresponding to the hydraulic motor 43 of the travel unit 31. This remote control valve outputs a travel operation command for the travel unit 31 in response to the operation of the operating device 35 (operating lever). The travel operation command instructs the travel unit 31 to travel (forward or backward, etc.). Furthermore, a remote control valve is also provided in the supply passage for pilot oil to the directional control valve corresponding to the hydraulic motor of the slewing unit 32. This remote control valve outputs a slewing operation command for the slewing unit 32 in response to the operation of the operating device 35 (operating lever). The slewing operation command instructs the slewing unit 32 to slewing (left turn or right turn, etc.). A control valve 461 is also inserted between these remote control valves and the pilot pump 42.

[0040] The cutoff switch 462 is linked to the cutoff lever 463. The cutoff lever 463 is located in the control unit 321 of the machine body 30 and accepts operation input from the user (operator). In this embodiment, as an example, the cutoff lever 463 can be operated along the vertical direction D1. When the cutoff lever 463 is in the "up position", which is the upper end of its movable range, the cutoff switch 462 is "off", and when the cutoff lever 463 is in the "down position", which is the lower end of its movable range, the cutoff switch 462 is "on". The cutoff switch 462 is connected to the control system 1, and the on / off state of the cutoff switch 462, that is, the operating state of the cutoff lever 463, is monitored by the control system 1.

[0041] Therefore, when the cutoff lever 463 is in the "down position," the control valve 461 becomes energized, and the hydraulic actuator (hydraulic cylinder 44, etc.) is driven by the operation of the operating device 35. Conversely, when the cutoff lever 463 is in the "up position," the control valve 461 becomes de-energized, and the hydraulic actuator is forcibly stopped without operation of the operating device 35. For this reason, in order to drive the hydraulic actuator (hydraulic cylinder 44, etc.), the user (operator) needs to operate the cutoff lever 463 to the "down position."

[0042] Furthermore, since the slewing section 32 and the traveling section 31 are operated by hydraulic fluid supplied from the hydraulic pump 41 to the hydraulic actuator (hydraulic motor 43, etc.), if the cutoff lever 463 is in the "up position", the slewing section 32 and the traveling section 31 will also become inoperable. In other words, if the cutoff lever 463 is in the "up position", the working section 33, the slewing section 32, and the traveling section 31 are all forcibly rendered inoperable.

[0043] In this embodiment, the state in which the cutoff lever 463 is in the "up position," that is, the state in which the work machine 3 cannot be operated, is defined as the "locked state." On the other hand, the state in which the cutoff lever 463 is in the "down position," that is, the state in which the work machine 3 can be operated, is defined as the "unlocked state."

[0044] In short, the cutoff switch 462 is in a "locked state" when it is off, where the operation of the work machine 3 is restricted (including prohibited), and in an "unlocked state" when it is on, where the operation of the work machine 3 is not restricted. When the cutoff lever 463 is in the "up position" and the cutoff switch 462 is in the locked state (off), the operation of the work machine 3 is forcibly restricted without operation of the operating device 35. The cutoff lever 463 is the lever that is operated when locking the operation of the work machine 3 in this way, and is synonymous with the gate lock lever.

[0045] The operating device 35 is located in the operating section 321 of the machine body 30 and is a user interface for receiving operation input from the user (operator). The operating device 35 includes, for example, an operating lever and controls the remote control valve 45 according to the amount of operation of the operating lever. This allows the operator to operate the operating device 35 to activate the remote control valve 45, instruct the direction and flow rate of hydraulic fluid from the hydraulic pump 41, and operate the work machine 3.

[0046] The temperature sensor 47 detects the temperature of the hydraulic fluid discharged from the hydraulic pump 41 (hydraulic fluid temperature). Specifically, in this embodiment, the temperature sensor 47 is located in the hydraulic fluid tank 49 that stores the hydraulic fluid, and detects the temperature of the hydraulic fluid stored in the hydraulic fluid tank 49. Since the hydraulic pump 41 draws up the hydraulic fluid stored in the hydraulic fluid tank 49 and discharges it, the temperature sensor 47 detects the temperature of the hydraulic fluid discharged from the hydraulic pump 41. The temperature sensor 47 is connected to the control system 1, and the temperature detection signal indicating the temperature (hydraulic fluid temperature) detected by the temperature sensor 47 is input to the control system 1.

[0047] Here, the temperature sensor 47 is an example of a detection unit for detecting the state quantity of the hydraulic fluid. In this disclosure, "state quantity" refers to a physical quantity that represents the state of an object (in this case, hydraulic fluid), and means a value that is determined according to the state. Examples include temperature, viscosity, pressure, volume, density, or type of oil. In this embodiment, the temperature sensor 47 detects the temperature of the hydraulic fluid discharged from the hydraulic pump 41 as the state quantity of the hydraulic fluid.

[0048] The main switch 36 is located in the control unit 321 of the machine body 30 and is operated by the user (operator) when starting the work machine 3. While the main switch 36 is off, the machine body 30 (including the travel unit 31, slewing unit 32, and work unit 33) is not in a state to operate in response to the operation of the control device 35. Only when the main switch 36 is turned on does the machine body 30 become capable of operating in response to the operation of the control device 35. Also, when the main switch 36 is turned on, power is supplied to the display device 2, etc. In this embodiment, as an example, the main switch 36 is linked to the key cylinder and is turned on when the prime mover 40 is started using the key.

[0049] The accelerator control unit 37 is located in the driver's unit 321 of the machine body 30 and is operated by the user (operator) when starting the work machine 3. The accelerator control unit 37 is a device operated to set the rated rotational speed of the prime mover 40, and is, for example, an accelerator dial, an accelerator lever, or an accelerator pedal. The accelerator control unit 37 is connected to the control system 1, and the operation signal generated by the operation of the accelerator control unit 37 is input to the control system 1. In this embodiment, as an example, the accelerator control unit 37 is a rotary dial-type control unit that sets the rated rotational speed of the prime mover 40 according to its rotational position.

[0050] The control system 1 primarily consists of a computer system having, for example, one or more processors such as a CPU (Central Processing Unit) and one or more memories such as ROM (Read Only Memory) and RAM (Random Access Memory), and performs various processes (information processing). In this embodiment, the control system 1 is an integrated controller that controls the entire work machine 3, and consists of, for example, an electronic control unit (ECU). However, the control system 1 may be provided separately from the integrated controller, or it may primarily consist of one processor or multiple processors. The control system 1 will be explained in detail in the section "[2] Configuration of the Control System".

[0051] The display device 2 is located in the control unit 321 of the machine body 30 and is a user interface for receiving operation input from the user (operator) and outputting various information to the user. The display device 2 accepts various operations from the user by outputting electrical signals corresponding to the user's operations, for example. This allows the user (operator) to view the display screen shown on the display device 2 and to operate the display device 2 as needed.

[0052] As shown in Figure 2, the display device 2 comprises a control unit 21, an operation unit 22, and a display unit 23. The display device 2 is configured to communicate with the control system 1 and can exchange data with the control system 1. In this embodiment, as an example, the display device 2 is a dedicated device used in the work machine 3.

[0053] The control unit 21 controls the display device 2 according to data from the control system 1. Specifically, the control unit 21 outputs electrical signals corresponding to user operations received by the operation unit 22, and displays the display screen generated by the control system 1 on the display unit 23.

[0054] The operation unit 22 is a user interface for receiving user (operator) input for the display screen shown on the display unit 23. The operation unit 22 accepts various operations from the user, for example, by outputting electrical signals corresponding to the user's operations.

[0055] The display unit 23 is a user interface for presenting information to the user (operator), such as a liquid crystal display or an organic EL display that displays various types of information. The display unit 23 presents various types of information to the user through display.

[0056] Furthermore, in addition to the above-described configuration, the machine body 30 is further equipped with a drive system and a communication terminal, etc. The drive system is a device for supplying power to the attachment of the work unit 33, and consists of a device (mechanism) such as a PTO (Power take-off) for extracting power from the prime mover 40 as power for driving the attachment, which consists of hydraulic equipment. In addition, the machine body 30 is equipped with various sensors (including a camera) for detecting objects to be detected in the monitoring area around the work machine 3, such as a camera that takes images of the area around the machine body 30.

[0057] [2] Control system configuration Next, the configuration of the control system 1 according to this embodiment will be described with reference to Figure 2. The control system 1 controls each part of the machine body 30 (including the traveling section 31, the turning section 32, and the working section 33, etc.). In this embodiment, the control system 1 is a component of the work machine 3 and together with the machine body 30 etc., constitutes the work machine 3. In other words, the work machine 3 according to this embodiment comprises at least the control system 1 and the machine body 30.

[0058] As shown in Figure 2, the control system 1 comprises an acquisition processing unit 11, a control processing unit 12, and a setting processing unit 13. In this embodiment, as an example, the control system 1 mainly consists of a computer system having one or more processors, so these multiple functional units (acquisition processing unit 11, etc.) are realized by one or more processors executing a control program for the work machine. These multiple functional units included in the control system 1 may be distributed and provided in multiple housings, or they may be provided in a single housing.

[0059] The control system 1 is configured to communicate with devices provided in various parts of the aircraft body 30. Specifically, the control system 1 is connected to at least the drive circuit 39, the prime mover 40, the main switch 36, the accelerator control unit 37, the temperature sensor 47, the display device 2, and the cutoff switch 462. This allows the control system 1 to control the drive circuit 39 and the display device 2, and to acquire the rotational speed of the prime mover 40, the operating status of the accelerator control unit 37, and the detection results (hydraulic oil temperature) of the temperature sensor 47. Here, the control system 1 may exchange various types of information (data) directly with each device, or indirectly via a relay or the like. The control system 1 and the devices provided in various parts of the aircraft body 30 can communicate using a communication method such as CAN (Controller Area Network), for example.

[0060] The acquisition processing unit 11 performs an acquisition process to acquire the rotational speed of the prime mover 40, the operating state of the accelerator control unit 37, and the detection result (hydraulic oil temperature) of the temperature sensor 47. In this embodiment, the acquisition processing unit 11 acquires the rotational speed of the prime mover 40, the operating state of the accelerator control unit 37, and the detection result (hydraulic oil temperature) of the temperature sensor 47 periodically or irregularly.

[0061] Furthermore, the data acquisition processing unit 11 can periodically or irregularly acquire information such as the on / off status of the main switch 36 and the cutoff switch 462 through the data acquisition process. Here, the data acquisition processing unit 11 can also acquire the outputs (sensor signals) of the fuel level sensor, coolant temperature sensor, and hydraulic oil temperature sensor. The data acquisition processing unit 11 may acquire various data directly from various sensors (including cameras) or indirectly via an electronic control unit. The data acquired by the data acquisition processing unit 11 is stored, for example, in memory.

[0062] The control processing unit 12 adjusts the rotational speed of the prime mover 40 by controlling the drive circuit 39. Here, the control processing unit 12 sets a target rotational speed for the prime mover 40 and controls the rotational speed of the prime mover 40 using the drive circuit 39 so that the actual rotational speed of the prime mover 40, which is acquired by the acquisition processing unit 11 from the prime mover 40, approaches the target rotational speed. Specifically, if the actual rotational speed of the prime mover 40 is lower than the target rotational speed, the control processing unit 12 controls the drive circuit 39 to increase the rotational speed of the prime mover 40 (make it faster). Conversely, if the actual rotational speed of the prime mover 40 is higher than the target rotational speed, the control processing unit 12 controls the drive circuit 39 to decrease the rotational speed of the prime mover 40 (make it slower).

[0063] The setting processing unit 13 performs a setting process to set the rated rotational speed of the prime mover 40. The setting processing unit 13 changes the rated rotational speed in response to the operation of the accelerator control unit 37. In other words, the rated rotational speed of the prime mover 40 is not constant and can be arbitrarily set by the operator operating the accelerator control unit 37. This makes it possible to set the rated rotational speed according to the operation of the work machine 3, for example, by setting the rated rotational speed higher when performing heavy load work and lower when performing light load work.

[0064] More specifically, the setting processing unit 13 changes the rated rotational speed of the prime mover 40 to a lower or higher rotational speed than the current set value, according to the operating state of the accelerator operating unit 37 acquired by the acquisition processing unit 11. In this embodiment, as an example, since the accelerator operating unit 37 is a rotary dial operating unit, the setting processing unit 13 sets the rated rotational speed of the prime mover 40 to a value (rotational speed) corresponding to the rotational position of the accelerator operating unit 37. Here, the setting processing unit 13 may change the rated rotational speed of the prime mover 40 continuously and steplessly, or it may change it in steps (for example, in 2 steps, 5 steps, or 10 steps).

[0065] Incidentally, the control processing unit 12 can perform decelerator control, stop control, decelerator release control, and stop release control as controls to automatically change the target rotational speed of the prime mover 40.

[0066] Deceleration control is a control mechanism that switches the target rotational speed of the prime mover 40 from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. In other words, the control processing unit 12 has an auto-deceleration function that automatically reduces the rotational speed of the prime mover 40. For example, if the work unit 33 or the like is not operating and the output of the prime mover 40 is not required for a certain period of time, the control processing unit 12 outputs a control signal to the drive circuit 39 to reduce the target rotational speed and executes deceleration control to reduce the rotational speed of the prime mover 40.

[0067] The deceleration release control is a control that releases the deceleration control, and specifically, it is a control that switches the target rotational speed of the prime mover 40 from a first specific rotational speed to a first return rotational speed that is higher than the first specific rotational speed.

[0068] In other words, when the auto-deceleration function is activated, the control processing unit 12 switches the rotational speed of the prime mover 40 to a low idle speed (first specific rotational speed) that is lower than the rated rotational speed. On the other hand, when the auto-deceleration function is deactivated, the control processing unit 12 switches the rotational speed of the prime mover 40 to a high idle speed (first return speed) that is higher than the first specific rotational speed. In other words, the control processing unit 12 can automatically lower the rotational speed of the prime mover 40 through deceleration control and automatically increase the rotational speed of the prime mover 40 through deceleration release control. In this way, by keeping the rotational speed of the prime mover 40 low as needed, it is possible to reduce the noise and vibration generated by the prime mover 40, suppress energy (electricity) consumption by the prime mover 40, and suppress the occurrence of a time lag due to the restart of the prime mover 40.

[0069] Stop control is a control that stops the prime mover 40 and sets the target rotational speed to zero (0). In other words, the control processing unit 12 has an auto-stop function that automatically reduces the rotational speed of the prime mover 40 to zero (i.e., stops it). For example, if the work unit 33, etc., is not operating and the output of the prime mover 40 is not required for a certain period of time, the control processing unit 12 outputs a control signal to the drive circuit 39 to stop operation and executes stop control that stops the prime mover 40 in a manner that allows it to be restarted.

[0070] The stop release control is a control that releases the stop control, and specifically involves starting the prime mover 40 that has been stopped by the stop control and setting the target rotational speed of the prime mover 40 to a second specific rotational speed.

[0071] In other words, when the auto-stop function is activated, the control processing unit 12 temporarily stops the prime mover 40 (i.e., in a manner that allows it to be restarted by the control processing unit 12), thereby reducing the rotational speed of the prime mover 40 to zero. On the other hand, when the auto-stop function is released, the control processing unit 12 restarts the prime mover 40 and increases its rotational speed to a second specific rotational speed. In other words, the control processing unit 12 can automatically stop the prime mover 40 through stop control and automatically start (restart) the prime mover 40 through stop release control. By temporarily stopping the prime mover 40 as needed in this way, it is possible to further reduce the noise and vibration generated by the prime mover 40, as well as further suppress the energy (electricity) consumption of the prime mover 40.

[0072] Furthermore, the auto-deceleration function and the auto-stop function can each be switched on or off. The auto-deceleration function and the auto-stop function can be switched on or off by the user (operator), for example, by operating the auto-deceleration switch and auto-stop switch located on the control unit 321. In other words, if the auto-deceleration switch is on, the auto-deceleration function is enabled; if the auto-deceleration switch is off, the auto-deceleration function is disabled. Similarly, if the auto-stop switch is on, the auto-stop function is enabled; if the auto-stop switch is off, the auto-stop function is disabled.

[0073] [3] Control method for working machinery The following describes an example of a control method (hereinafter simply referred to as "control method") for the work machine 3, which is mainly performed by the control system 1, with reference to Figures 3 to 5.

[0074] The control method according to this embodiment is executed by a control system 1, which mainly consists of a computer system; in other words, it is embodied in a control program for a work machine (hereinafter simply referred to as the "control program"). That is, the control program according to this embodiment is a computer program that causes one or more processors to execute each process related to the control method. Such a control program may be executed in cooperation with, for example, the control system 1 and the display device 2.

[0075] Here, the control system 1 executes the following various processes related to the control method when a specific preset start operation is performed to execute the control program. The start operation is, for example, the operation to start the prime mover 40 of the work machine 3, that is, the operation to turn on the main switch 36. On the other hand, the control system 1 terminates the following various processes related to the control method when a specific preset end operation is performed. The end operation is, for example, the operation to stop the prime mover 40 of the work machine 3, that is, the operation to turn off the main switch 36.

[0076] [3.1] Desel control and desel release control First, we will describe the control method according to this embodiment, that is, the operation of the control system 1 according to this embodiment, specifically the operations related to deceleration control and deceleration release control.

[0077] The control processing unit 12 of the control system 1, when the auto-decel function is enabled (i.e., the auto-decel switch is on) and predetermined deceleration conditions are met, executes deceleration control to switch the target rotational speed of the prime mover 40 from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. The deceleration conditions are the conditions for executing deceleration control, and the control processing unit 12 reduces the target rotational speed of the prime mover 40 when the deceleration conditions are met.

[0078] The rated rotational speed is then changed by the setting processing unit 13 in accordance with the operation of the accelerator control unit 37. In other words, the rotational speed of the prime mover 40 before deceleration control is performed (rated rotational speed) is not constant and can be set arbitrarily by the operator. This makes it possible to set the rated rotational speed according to the operation of the work machine 3, for example, by setting it higher when performing heavy load work and lower when performing light load work.

[0079] In this embodiment, the deceleration conditions include conditions related to the operation of the work machine 3. That is, conditions related to the operator's operation of the work machine 3 (also called "operation-related conditions") are included in the deceleration conditions. Therefore, the operator's operation of the work machine 3 is reflected in whether or not the deceleration conditions are met, that is, whether or not deceleration control is performed. Consequently, for example, in situations where the work unit 33, etc., is not operating and the output of the prime mover 40 is not required, it is possible to perform deceleration control to reduce the target rotational speed of the prime mover 40 by satisfying the deceleration conditions based on the operator's operation of the work machine 3 at that time. In other words, it is possible for the operator to decide whether or not to perform deceleration control.

[0080] Here, the conditions related to the operation of the work machine 3 included in the deceleration conditions (operation-related conditions) include the fact that the operating device 35 of the work machine 3 has not been operated for a specified time. Specifically, if the operating device 35 includes an operating lever, the state in which the operating device 35 is not operated is defined as the state in which the operating device 35 is not operated when the user (operator) is not operating the operating lever and the operating lever is in the neutral position. When the operating device 35 is not operated, the work machine 3 is in a standby state, and the various parts of the machine body 30 (traveling section 31, slewing section 32, and working section 33) do not operate. Therefore, in situations where the standby state of the work machine 3 continues for a specified time or longer, and the output of the prime mover 40 is not required, the deceleration conditions are met, and deceleration control can be performed. In other words, when a situation in which the output of the prime mover 40 is not required continues for a specified time or longer, there is little need to immediately operate the work machine 3, and in such cases, deceleration control can be performed to reduce the noise and vibration generated by the prime mover 40, as well as to suppress the energy (electricity) consumption of the prime mover 40.

[0081] In other words, the deceleration condition includes the state in which the load on the work machine 3 is in a light load state. Here, "light load state" means a state in which the magnitude of the load related to the travel operation (of the travel unit 31) and / or the work operation (of the work unit 33) of the work machine 3 is less than a predetermined value, and also includes a no-load state in which the load related to the travel operation and / or work operation of the work machine 3 is approximately 0 (zero). In other words, at least in the standby state of the work machine 3, the load on the work machine 3 is in a light load state.

[0082] In this embodiment, the control processing unit 12 has a light load determination function that determines whether the load on the work machine 3 is in a light load state. The deceleration condition includes the determination by the light load determination function of the control processing unit 12 that the load on the work machine 3 is in a light load state. By including being in a light load state as the deceleration condition, when there is little need to operate the work machine 3 immediately, deceleration control can reduce the noise and vibration generated by the prime mover 40, as well as suppress energy (electricity) consumption by the prime mover 40.

[0083] In this embodiment, the control processing unit 12 specifically determines whether the work machine 3 is in a light load state based on the running and / or operation status of the work machine 3. In other words, the light load determination function of the control processing unit 12 does not directly detect the magnitude of the load on the work machine 3, but rather determines whether it is in a light load state based on the running and / or operation status of the work machine 3. Specifically, the light load determination function determines whether the load on the work machine 3 is in a light load state based on the operation status of the operating device 35 related to the running operation (of the running unit 31) and / or the operation (of the work unit 33) of the work machine 3. If the operating device 35 is not being operated and the work machine 3 is in a standby state, it is determined that it is in a light load state. With this configuration, the detection configuration can be easily simplified compared to the case where the magnitude of the load on the work machine 3 is directly detected.

[0084] Furthermore, if certain conditions are met, and there is movement of the work machine 3 and / or operation of the work machine, it is determined that the machine is not in a light load state. In other words, if certain conditions are met, and there is movement of the work machine 3 (traveling unit 31) and / or operation of the work machine (working unit 33) of the work machine, the control processing unit 12 determines that the machine is not in a light load state. This prevents the machine from being determined to have met the deceleration condition and executing deceleration control when the work machine 3 is not in a standby state.

[0085] In this embodiment, the specific condition includes the cutoff lever 463 being in the unlocked state. In other words, if the cutoff lever 463 is in the "lowered position", the specific condition is met, and if the work machine 3 is moved and / or operated in this state, it is determined that it is not in a light load state. With this configuration, if the cutoff lever 463 is in the "upper position" (i.e., in the locked state), it is possible to determine that it is in a light load state even if the work machine 3 is moved and / or operated.

[0086] Furthermore, the deceleration condition also includes the state in which the accelerator control unit 37 has not been operated for a specified period of time or longer. In other words, with the auto-deceleration function enabled, if the operating device 35 for operating the running section 31 and work section 33 of the machine 30, as well as the accelerator control unit 37, have not been operated for a specified period of time (for example, about 3 seconds) or longer, the control processing unit 12 determines that the deceleration condition has been met and executes deceleration control. Conversely, even if the operating device 35 for operating the running section 31 and work section 33 of the machine 30 has not been operated for a specified period of time or longer, if the accelerator control unit 37 has been operated within the most recent specified period, the deceleration condition has not been met and deceleration control will not be performed.

[0087] In short, the deceleration condition includes the non-operation of the operating device 35 for operating the drive unit 31, the non-operation of the operating device 35 for operating the work unit 33, and the non-operation of the accelerator operating unit 37 for changing the rated rotational speed, all of which continue for a specified time (for example, about 3 seconds). Only when all three of these conditions continue for a specified time or longer does the deceleration condition get met, and the control processing unit 12 reduces the target rotational speed of the prime mover 40 from the rated rotational speed to a low idle rotational speed (first specific rotational speed) lower than the rated rotational speed. If even one of these three conditions does not continue for a specified time or longer, the deceleration condition is not met, and the control processing unit 12 does not perform deceleration control and sets the target rotational speed of the prime mover 40 to the rated rotational speed.

[0088] In particular, when the accelerator control unit 37 is operated, the control processing unit 12 applies the rated rotational speed after it has been changed by the operation of the accelerator control unit 37 as the target rotational speed of the prime mover 40. Therefore, when the accelerator control unit 37 is operated, deceleration control is not performed, and the target rotational speed of the prime mover 40 is changed in real time. When the accelerator control unit 37 is operated, the operator must intend to change the rotational speed of the prime mover 40, such as increasing or decreasing it, so by changing the rotational speed of the prime mover 40 immediately, operation in accordance with the operator's intentions becomes possible. In other words, by including the condition that the accelerator control unit 37 has not been operated for a specified period of time or longer as a deceleration condition, operation in accordance with the operator's intentions is realized.

[0089] Meanwhile, the control processing unit 12 of the control system 1 executes deceleration release control, which switches the target rotational speed of the prime mover 40 from a first specific rotational speed to a first return rotational speed higher than the first specific rotational speed, when predetermined deceleration release conditions are met during deceleration control. The deceleration release conditions are conditions for executing deceleration release control, and the control processing unit 12 increases the target rotational speed of the prime mover 40 when the deceleration release conditions are met.

[0090] In this embodiment, the deceleration release condition includes conditions related to the operation of the work machine 3. That is, conditions related to the operator's operation of the work machine 3 (operation-related conditions) are also included in the deceleration release condition. Therefore, the operator's operation of the work machine 3 is reflected in whether or not the deceleration release condition is met, that is, whether or not deceleration release control is performed. Consequently, when the target rotational speed of the prime mover 40 is suppressed to a low idle speed (first specific rotational speed) by deceleration control, for example, in a situation where the output of the prime mover 40 is needed to operate the work unit 33, etc., it is possible to perform deceleration release control to increase the target rotational speed of the prime mover 40 by meeting the deceleration release condition based on the operator's operation of the work machine 3 at that time. In other words, it is possible for the operator to decide whether or not to perform deceleration release control.

[0091] Here, the conditions related to the operation of the work machine 3 included in the deceleration release conditions (operation-related conditions) include the operation of the operating device 35 of the work machine 3. Specifically, if the operating device 35 includes an operating lever, the deceleration release conditions include the operation of the operating lever to a position other than the neutral position. Therefore, when the target rotational speed of the prime mover 40 is suppressed to a low idle speed (first specific rotational speed) by deceleration control, and a situation arises where the output of the prime mover 40 is required, the deceleration release conditions are met, and deceleration release control can be performed.

[0092] By the way, the deceleration release condition does not include the operation of the accelerator control unit 37. In other words, even if the accelerator control unit 37 is operated while deceleration control is being performed, the control processing unit 12 will continue deceleration control without performing deceleration release control. That is, if any of the operating devices 35 for operating the running unit 31 and the work unit 33 of the machine body 30 are operated during deceleration control, the control processing unit 12 will increase the target rotational speed of the prime mover 40 from the low idle rotational speed (first specific rotational speed) to a high idle rotational speed (first return rotational speed) which is higher than the first specific rotational speed. On the other hand, even if the accelerator control unit 37 is operated during deceleration control, the control processing unit 12 will maintain the target rotational speed of the prime mover 40 at the low idle rotational speed (first specific rotational speed).

[0093] In other words, even if the accelerator control unit 37 is operated while deceleration control is being performed due to a light load condition being determined, the control processing unit 12 determines that the light load condition remains and continues deceleration control. As a result, for example, if the operator operates the accelerator control unit 37 in advance to set the rated rotational speed for the next task while deceleration control is being performed, the deceleration control will continue to be performed because the light load condition is considered to be continuing.

[0094] Furthermore, the deceleration release condition also includes the deactivation of the auto-deceleration function. In other words, after deceleration control is performed with the auto-deceleration switch ON and the auto-deceleration function enabled, if the auto-deceleration switch is turned OFF and the auto-deceleration function is disabled, the deceleration release condition is met, and the control processing unit 12 switches the target rotational speed of the prime mover 40 from the first specific rotational speed to the first return rotational speed.

[0095] In this embodiment, the first return speed is the same as the rated speed. In other words, the target speed of the prime mover 40 is switched from the rated speed to a first specific speed by deceleration control, and then switched back from the first specific speed to the rated speed (first return speed) by deceleration release control. Therefore, when the prime mover 40 is driven at the rated speed, the speed of the prime mover 40 is reduced by deceleration control and restored by deceleration release control.

[0096] The rated rotational speed, which is the first return rotational speed, is changed by the setting processing unit 13 in response to the operation of the accelerator operation unit 37. Specifically, if there is an operation on the accelerator operation unit 37 while deceleration control is being performed, the setting processing unit 13 changes the rated rotational speed in response to the operation of the accelerator operation unit 37. However, while deceleration control is being performed, the target rotational speed of the prime mover 40 is limited to a first specific rotational speed, not the rated rotational speed. Therefore, even if the rated rotational speed of the prime mover 40 changes, the target rotational speed of the prime mover 40 remains constant (the first specific rotational speed). Subsequently, when the target rotational speed of the prime mover 40 returns to the rated rotational speed by deceleration release control, it returns to the changed (modified) rated rotational speed.

[0097] In short, in this embodiment, even if the accelerator control unit 37 is operated while deceleration control is being performed, the deceleration control continues, so the change in rated rotational speed is not immediately reflected in the rotational speed of the prime mover 40. Therefore, the rated rotational speed changed by an operation of the accelerator control unit 37 performed while deceleration control is being performed is reflected when deceleration release control is performed. This makes it possible to reflect the change in rated rotational speed performed by an operation of the accelerator control unit 37 in the rotational speed of the prime mover 40 while deceleration control is being performed, that is, when the target rotational speed of the prime mover 40 is maintained at the first specific rotational speed (<rated rotational speed).

[0098] In the following, we assume that multiple rotational speeds (four in this case) of V21, V22, V23, and V24 can be set as the rated rotational speed V2, as shown in Figure 3. The rotational speeds V21, V22, V23, and V24 increase in the order of "V21" (lowest), "V22", "V23", and "V24" (fastest). <V22<V23<V24)。

[0099] Incidentally, in both deceleration control and deceleration release control, the control processing unit 12 does not switch the rotational speed of the prime mover 40 all at once, but rather gradually changes the rotational speed of the prime mover 40 over a certain period of transition time to reach the target rotational speed.

[0100] Figure 3 shows the rotational speed of the prime mover 40 as it changes due to deceleration control and deceleration release control, with the horizontal axis representing time. The control processing unit 12 gradually changes the actual rotational speed of the prime mover 40 (actual rotational speed) by changing the target rotational speed of the prime mover 40 during deceleration control and deceleration release control, as shown in Figure 3. Figure 3 shows the change in rotational speed of the prime mover 40 when the rated rotational speed V2 is set to rotational speeds V21, V22, V23, and V24, respectively.

[0101] Specifically, as shown in the upper part of Figure 3, during deceleration control, the control processing unit 12 gradually reduces the rotational speed of the prime mover 40 from the rated rotational speed V2 to the first specific rotational speed V1. The rotational speed of the prime mover 40 decreases with a certain slope from time t1 as time progresses, and is maintained at the first specific rotational speed V1 when it reaches that point. Here, the slope of the graph in Figure 3 corresponds to the amount of change in the rotational speed of the prime mover 40 per unit time, and is also called the "rate of change in rotational speed".

[0102] In the example in Figure 3, the rate of change of rotational speed during deceleration control is the same (uniform) regardless of whether the rated rotational speed V2 before deceleration control is V21, V22, V23, or V24. Therefore, the transition time (t3-t1) required for the rotational speed to transition to the first specific rotational speed V1 by deceleration control when the rated rotational speed V2 is V22 is longer than the transition time (t2-t1) required when the rated rotational speed V2 is V21. Similarly, the transition time (t4-t1) when the rated rotational speed V2 is V23 is even longer, and the transition time (t5-t1) when the rated rotational speed V2 is V24 is even longer.

[0103] Furthermore, as shown in the lower part of Figure 3, when deceleration is released, the control processing unit 12 gradually increases the rotational speed of the prime mover 40 from a first specific rotational speed V1 to the rated rotational speed V2 (first return rotational speed). The rotational speed of the prime mover 40 decreases with a certain slope from time t1 as time progresses, and is maintained at the rated rotational speed V2 when it reaches that speed.

[0104] However, if the accelerator control unit 37 is operated during deceleration control, the setting processing unit 13 changes the rated rotational speed V2, and the control processing unit 12 gradually increases the rotational speed of the prime mover 40 to the changed rated rotational speed V2 when deceleration release control is performed. For example, if the rated rotational speed V2 before deceleration control is rotational speed V21, and the accelerator control unit 37 is operated during deceleration control and the rated rotational speed V2 is changed to rotational speed V22, the control processing unit 12 restores the rotational speed of the prime mover 40 to rotational speed V22, which is the changed rated rotational speed V2, when deceleration release control is performed.

[0105] As described above, the control method according to this embodiment includes, when the deceleration condition is met, executing deceleration control by switching the target rotational speed of the prime mover 40 for driving the hydraulic pump 41 that discharges hydraulic fluid from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed, and changing the rated rotational speed in response to the operation of the accelerator operation unit 37. Here, (the control processing unit 12) continues the deceleration control if there is an operation on the accelerator operation unit 37 while the deceleration control is being executed.

[0106] In short, in the control method according to this embodiment, the deceleration release condition does not include the operation of the accelerator control unit 37. Therefore, even if the accelerator control unit 37 is operated while deceleration control is being performed, the deceleration control continues (without deceleration release control being performed). As a result, for example, even if the operator operates the accelerator control unit 37 in advance to set the rated rotational speed for the next task while deceleration control is being performed, the deceleration control is not released and continues. Therefore, while deceleration control is being performed, the operator can change the rated rotational speed by operating the accelerator control unit 37 without releasing the deceleration control.

[0107] Therefore, it is possible to avoid situations where the operation does not meet the operator's intentions, such as when the accelerator control unit 37 is operated while deceleration control is in progress, immediately canceling the deceleration control. As a result, it is possible to provide a control method for the work machine 3, a control program for the work machine, a control system 1, and the work machine 3 that make it easier to achieve the operation of the work machine 3 as intended by the operator. Furthermore, it is possible to suppress the waste of battery 38 power due to the cancellation of deceleration control.

[0108] In other words, the work machine 3 according to this embodiment is a work machine 3 equipped with a prime mover 40 (electric motor), and comprises an accelerator operation unit 37 for setting the rotational speed of the prime mover 40, a light load state determination unit, an auto-decel function setting unit, and a motor rotational speed control unit. The light load state determination unit determines whether or not the prime mover 40 is in a light load state, meaning it is not performing any work or driving. If the light load state determination unit determines that the prime mover 40 is in a light load state, the auto-decel function setting unit enables the auto-decel function, which rotates the prime mover 40 at a rotational speed lower than the rotational speed set by the accelerator operation unit 37. When the motor rotational speed control unit and the auto-decel function are enabled, the prime mover 40 rotates at a rotational speed lower than the rotational speed set by the accelerator operation unit 37. If there is an operation on the accelerator operation unit 37 while the auto-decel function setting unit is enabled (i.e., deceleration control is being performed), the light load state determination unit determines that the prime mover is in a light load state.

[0109] In this embodiment, the no-load state determination unit, the auto-deceleration function setting unit, and the motor rotation speed control unit are all included in the control processing unit 12 as functions of the control processing unit 12. In this way, when an operation is made to the accelerator operation unit 37 while deceleration control is being performed, it is determined that a light load state is present, and deceleration control is continued.

[0110] [3.2] Stop control and stop release control Next, the control method according to this embodiment, that is, the operation of the control system 1 according to this embodiment, specifically the operation related to stop control and stop release control, will be described.

[0111] The control processing unit 12 of the control system 1, when the auto-stop function is enabled (i.e., the auto-stop switch is on) and predetermined stop conditions are met, stops the prime mover 40 and performs stop control, switching the target rotational speed of the prime mover 40 from the rated rotational speed to zero. The stop conditions are the conditions for performing stop control, and the control processing unit 12 sets the target rotational speed of the prime mover 40 to zero when the stop conditions are met.

[0112] In this embodiment, the stop condition includes conditions related to the operation of the work machine 3. That is, conditions related to the operator's operation of the work machine 3 (operation-related conditions) are included in the stop condition. Therefore, the operator's operation of the work machine 3 is reflected in whether or not the stop condition is met, that is, whether or not stop control is performed. Accordingly, for example, in a situation where the work unit 33 etc. is not operating and the output of the prime mover 40 is not required, it is possible to perform stop control to set the target rotational speed of the prime mover 40 to zero (stop the prime mover 40) by meeting the stop condition based on the operator's operation of the work machine 3 at that time. In other words, it is possible for the operator to decide whether or not to perform stop control.

[0113] Here, the conditions related to the operation of the work machine 3 included in the stop condition (operation-related conditions) include the fact that the operating device 35 of the work machine 3 has not been operated for a specified time. Specifically, if the operating device 35 includes an operating lever, the state in which the operating device 35 is not operated is defined as the state in which the operating device 35 is not operated when the user (operator) is not operating the operating lever and the operating lever is in the neutral position. When the operating device 35 is not operated, the work machine 3 is in a standby state, and the various parts of the machine body 30 (traveling section 31, slewing section 32, and working section 33) do not operate. Therefore, in situations where the standby state of the work machine 3 continues for a specified time or longer, and the output of the prime mover 40 is not required, the stop condition is met, and stop control can be performed. In other words, when a situation in which the output of the prime mover 40 is not required continues for a specified time or longer, there is little need to immediately operate the work machine 3, and in such cases, by performing stop control, it is possible to reduce the noise and vibration generated by the prime mover 40, as well as suppress the energy (electricity) consumption of the prime mover 40.

[0114] Furthermore, the stop condition also includes the state in which the accelerator control unit 37 has not been operated for a specified period of time or longer. In other words, if the operating device 35 for operating the running unit 31 and the work unit 33 of the machine body 30, as well as the accelerator control unit 37, remain unoperated for a specified period of time (for example, about 5 minutes), the control processing unit 12 sets the target rotational speed of the prime mover 40 to zero and stops the prime mover 40. Here, the specified period in the stop condition is longer than the specified period in the deceleration condition for deceleration control. For example, if the specified period in the deceleration condition is "3 seconds", the specified period in the stop condition is set to "5 minutes".

[0115] Furthermore, when the cutoff lever 463 is operated to the "up position" and the cutoff switch 462 is turned "off", the control processing unit 12 executes stop control, which switches the target rotational speed of the prime mover 40 from the rated rotational speed to zero, regardless of whether the auto-stop function is enabled or disabled. In short, when the cutoff lever 463 is operated and the work machine 3 becomes inoperable (locked), stop control is exceptionally executed even if the auto-stop function is disabled (i.e., the auto-stop switch is off).

[0116] Even if stop control is executed and the prime mover 40 stops, power is supplied to the control system 1, so the control system 1 continues to operate.

[0117] Here, if both the deceleration condition and the stop condition are met, the control processing unit 12 activates the auto-stop function with priority over the auto-deceleration function and performs stop control to temporarily stop the prime mover 40. Since stop control is executed when the cutoff lever 463 is in the "up position", the deceleration condition does not include any conditions related to the operation of the cutoff lever 463.

[0118] Meanwhile, when the control processing unit 12 of the control system 1 is executing stop control, if a predetermined stop release condition is met, it starts the prime mover 40 and executes stop release control to switch the target rotational speed of the prime mover 40 from zero to a second specific rotational speed. The stop release condition is a condition for executing stop release control, and when the stop release condition is met, the control processing unit 12 increases the target rotational speed of the prime mover 40.

[0119] In this embodiment, the stop release condition includes conditions related to the operation of the work machine 3. That is, conditions related to the operator's operation of the work machine 3 (operation-related conditions) are also included in the stop release condition. Therefore, the operator's operation of the work machine 3 is reflected in whether or not the stop release condition is met, that is, whether or not stop release control is performed. Consequently, in a state where the target rotational speed of the prime mover 40 is suppressed to zero by stop control, for example, in a situation where the output of the prime mover 40 is needed to operate the work unit 33, it is possible to perform stop release control to increase the target rotational speed of the prime mover 40 by meeting the stop release condition based on the operator's operation of the work machine 3 at that time. In other words, it is possible for the operator to decide whether or not to perform stop release control.

[0120] Here, the conditions related to the operation of the work machine 3 included in the stop release conditions (operation-related conditions) include the operation of the operating device 35 of the work machine 3. Specifically, if the operating device 35 includes an operating lever, the stop release conditions include the operating lever being operated to a position other than the neutral position. Therefore, when the prime mover 40 is stopped due to the stop control and the target rotational speed of the prime mover 40 is set to zero, if a situation arises where the output of the prime mover 40 is needed, the stop release conditions are met, and stop release control can be performed.

[0121] Furthermore, the stop release condition also includes the operation of the accelerator control unit 37. In other words, during stop control, if either the operating device 35 for operating the running unit 31 and the work unit 33 of the machine body 30, or the accelerator control unit 37 is operated, the control processing unit 12 increases the target rotational speed of the prime mover 40 from zero to a second specific rotational speed.

[0122] Furthermore, the stop release condition also includes the case where the cutoff lever 463 is in the "down position" and the auto-stop function is disabled. In other words, after stop control is performed with the auto-stop switch ON and the auto-stop function enabled, when the auto-stop switch is turned OFF and the auto-stop function is disabled, the stop release condition is met, and the control processing unit 12 switches the target rotational speed of the prime mover 40 from zero to a second specific rotational speed.

[0123] Furthermore, if stop control is performed by operating the cutoff lever 463 to the "up position," when the cutoff lever 463 is operated to the "down position" and the cutoff switch 462 is turned "on," the control processing unit 12 performs stop release control to switch the target rotational speed of the prime mover 40 from zero to a second specific rotational speed. In other words, the stop release condition includes the operation of locking the cutoff lever 463 and then unlocking it. In short, when the cutoff lever 463 is operated and the working machine 3 changes from a state where it cannot be operated (locked state) to a state where it can be operated (unlocked state), stop release control is performed. As a result, stop control can be released simply by operating the cutoff lever 463.

[0124] In this embodiment, the second specific rotational speed is the same as the first return rotational speed. Furthermore, as described above in this embodiment, the first return rotational speed is the same as the rated rotational speed. In other words, the target rotational speed of the prime mover 40 is switched from the rated rotational speed to zero by the stop control, and then switched from zero to the rated rotational speed (second specific rotational speed = first return rotational speed) by the stop release control. Therefore, when the prime mover 40 is operating at the rated rotational speed, the prime mover 40 will stop temporarily by the stop control and then resume operation by the stop release control.

[0125] Incidentally, similar to deceleration control and deceleration release control, in both stop control and stop release control, the control processing unit 12 does not switch the rotational speed of the prime mover 40 all at once, but rather gradually changes the rotational speed of the prime mover 40 over a certain period of transition time to reach the target rotational speed.

[0126] Figure 4 shows the rotational speed of the prime mover 40 as it changes due to stop control and stop release control, with the horizontal axis representing time. The control processing unit 12 gradually changes the actual rotational speed of the prime mover 40 (actual rotational speed) by changing the target rotational speed of the prime mover 40 during stop control and stop release control, as shown in Figure 4. Figure 4 shows the change in rotational speed of the prime mover 40 when the rated rotational speed V2 is set to rotational speeds V21, V22, V23, and V24, respectively.

[0127] Specifically, as shown in the upper part of Figure 4, during stop control, the control processing unit 12 gradually reduces the rotational speed of the prime mover 40 from the rated rotational speed V2 to zero (0). The rotational speed of the prime mover 40 decreases with a certain slope from time t1 as time progresses, and is maintained at zero when it reaches zero. Here, the slope of the graph in Figure 4 corresponds to the amount of change in the rotational speed of the prime mover 40 per unit time, and is also called the "rate of change in rotational speed".

[0128] In the example in Figure 4, the rate of change in rotational speed during stop control is the same (uniform) regardless of whether the rated rotational speed V2 before stop control is V21, V22, V23, or V24. Therefore, the transition time (t3-t1) required for the rotational speed to transition to zero due to stop control when the rated rotational speed V2 is V22 is longer than the transition time (t2-t1) required when the rated rotational speed V2 is V21. Similarly, the transition time (t4-t1) when the rated rotational speed V2 is V23 is even longer, and the transition time (t5-t1) when the rated rotational speed V2 is V24 is even longer.

[0129] Furthermore, as shown in the lower part of Figure 4, when performing stop release control, the control processing unit 12 gradually increases the rotational speed of the prime mover 40 from zero to the rated rotational speed V2 (second specific rotational speed). The rotational speed of the prime mover 40 decreases with a certain slope from time t1 as time progresses, and is maintained at the rated rotational speed V2 once it reaches that speed.

[0130] [3.3] Flowchart Figure 5 is a flowchart showing an example of the processing related to deceleration control and deceleration release control in the control method of the work machine 3 according to this embodiment.

[0131] First, the control processing unit 12 controls the prime mover 40 by setting its target rotational speed to the rated rotational speed (S1). At this time, the rotational speed of the prime mover 40 is controlled to the rated rotational speed set by the accelerator operation unit 37.

[0132] Next, the control processing unit 12 confirms that no operations related to the movement of the work machine 3 are being performed (S2), no operations related to the work of the work machine 3 are being performed (S3), and the accelerator operation unit 37 is not being operated (S4). If no operations are being performed (S2: Yes, S3: Yes, S4: Yes), and a specified time has elapsed (S5: Yes), the control processing unit 12 determines that the deceleration condition is met and executes deceleration control. In other words, the control processing unit 12 reduces the rotational speed of the prime mover 40 by lowering the target rotational speed of the prime mover 40 from the rated rotational speed to a first specific rotational speed (S7).

[0133] On the other hand, if "No" is determined in any of steps S2 to S5, the control processing unit 12 determines that the deceleration condition is not met and returns the process to step S1, thereby maintaining the target rotational speed of the prime mover 40 at the rated rotational speed. However, only if the accelerator operation unit 37 is operated (S4: No), the setting processing unit 13 performs a process to change the rated rotational speed (S6) and then returns the process to step S1.

[0134] Following step S7, the control processing unit 12 confirms that no operations related to the movement of the work machine 3 have been performed (S8), no operations related to the work of the work machine 3 have been performed (S9), and the accelerator control unit 37 has not been operated (S10). If none of these operations have been performed (S8: Yes, S9: Yes, S10: Yes), the control processing unit 12 determines that the deceleration release conditions have not been met and returns the process to step S7, thereby maintaining the target rotational speed of the prime mover 40 at the first specific rotational speed. In other words, the control processing unit 12 continues the deceleration control.

[0135] On the other hand, if the work machine 3 is driven or operated, and the result is determined to be "No" in any of steps S8 to S9, the control processing unit 12 determines that the deceleration release condition is met and executes deceleration release control. In other words, the control processing unit 12 increases the rotational speed of the prime mover 40 by raising the target rotational speed of the prime mover 40 from the first specific rotational speed to the rated rotational speed (S12).

[0136] However, if the accelerator control unit 37 is operated while deceleration control is being performed (S10: No), the setting processing unit 13 performs a process to change the rated rotational speed (S11), and then the process returns to step S7. In other words, even if the accelerator control unit 37 is operated, the deceleration release condition is not met, so deceleration release control (S12) is not performed, and deceleration control continues. In this case, the changed rated rotational speed is reflected for the first time in step S12, when deceleration release control is performed.

[0137] The work machine 3 repeatedly executes the processes in steps S1 to S12 described above. However, the flowchart shown in Figure 5 is merely an example, and processes may be added or omitted as appropriate, or the order of processes may be changed as appropriate.

[0138] [4] Modified form The following lists some modifications of Embodiment 1. The modifications described below can be combined and applied as appropriate.

[0139] The control system 1 in this disclosure includes a computer system. The computer system mainly consists of one or more processors and one or more memories as hardware. The functions of the control system 1 in this disclosure are realized by the execution of a program recorded in the memory of the computer system by the processor. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. Furthermore, some or all of the functional parts included in the control system 1 may be composed of electronic circuits.

[0140] Furthermore, it is not essential for control system 1 to have at least some of its functions integrated into a single housing; the components of control system 1 may be distributed across multiple housings. Conversely, functions that are distributed across multiple devices (e.g., control system 1 and display device 2) in Embodiment 1 may be integrated into a single housing. Moreover, at least some of the functions of control system 1 may be implemented by the cloud (cloud computing) or the like.

[0141] Furthermore, the prime mover 40, which serves as the power source for the work machine 3, is not limited to an AC motor; for example, it may be a DC motor, or even something other than an electric motor. In other words, the prime mover 40 may be a diesel engine, an internal combustion engine other than a diesel engine, or a hybrid power source including an electric motor and an internal combustion engine.

[0142] Furthermore, it is not mandatory for the first return speed to be the same as the second specific speed; the first return speed may be higher or lower than the second specific speed. Moreover, it is not mandatory for the first return speed (or second specific speed) to be the same as the rated speed; the first return speed (or second specific speed) may be higher or lower than the rated speed.

[0143] Furthermore, the operating lever of the operating device 35 may be an electric operating device that accepts various operations by the user (operator) by outputting an electrical signal (operating signal) to the control system 1 in response to the user's (operator's) operation. In this case, the control system 1 can control the hydraulic actuator by, for example, controlling a control valve (solenoid valve) provided in place of the remote control valve 45 in response to the operation of the operating device 35 (operating lever).

[0144] Furthermore, it is not mandatory for the control system 1 to have both an auto-deceleration function and an auto-stop function; it may have only one of these functions.

[0145] Furthermore, the display device 2 is not limited to a dedicated device, but may be a general-purpose terminal such as a laptop computer, tablet terminal, or smartphone. Moreover, the display unit 23 is not limited to a configuration that directly displays the display screen, such as a liquid crystal display or an organic EL display, but may also be configured to display the display screen by projection, such as a projector.

[0146] Furthermore, the input method for information to the operation unit 22 may be other than push-button switches, touch panels, and operation dials. For example, the operation unit 22 may use methods such as a keyboard, a pointing device such as a mouse, voice input, gesture input, or input of operation signals from another terminal.

[0147] Furthermore, the actuators in each part of the machine body 30 are not limited to hydraulic actuators, but may also be, for example, pneumatic actuators driven by compressed air or other air pressure, or electric actuators driven by power supply, or a combination thereof.

[0148] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0149] <Note 1> When the deceleration conditions are met, deceleration control is performed to switch the target rotational speed of the prime mover for driving the hydraulic pump that discharges the hydraulic fluid from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. The system has the capability to change the rated rotational speed in response to the operation of the accelerator control unit, If an operation is performed on the accelerator control unit while the deceleration control is being executed, the deceleration control will continue. A method for controlling industrial machinery.

[0150] <Note 2> The deceleration condition includes the state in which the accelerator operating unit remains unoperated for a specified period of time or longer. Control method for the work machine described in Appendix 1.

[0151] <Note 3> The deceleration conditions include the load on the work machine being in a light load state. A control method for the work machine described in Appendix 1 or 2.

[0152] <Note 4> The system further includes determining whether the machine is in a light-load state based on its movement and / or operation status. The control method for the work machine described in Appendix 3.

[0153] <Note 5> If certain conditions are met, and the work machine is running and / or operating, it is determined that the state is not light load. Control method for the work machine described in Appendix 4.

[0154] <Note 6> The aforementioned specific conditions include the cutoff lever being in an unlocked state. Control method for the work machine described in Appendix 5.

[0155] <Note 7> The system further includes performing stop control to stop the prime mover and set the target rotational speed to zero when the stop condition is met. A control method for the work machine described in any of the appendices 1 to 6.

[0156] <Note 8> The system further includes, when the engine is stopped by the aforementioned stop control and the stop release condition is met, starting the engine and executing stop release control to set the target rotational speed to a second specific rotational speed. Control method for the work machine described in Appendix 7.

[0157] <Note 9> The aforementioned stop release condition includes an operation to lock the cutoff lever and then unlock the cutoff lever. Control method for the work machine described in Appendix 8.

[0158] <Note 10> If an operation is performed on the accelerator control unit while the deceleration control is being executed, the rated rotational speed is changed in accordance with the operation on the accelerator control unit. A control method for the work machine described in any of the appendices 1 to 9.

[0159] <Note 11> The system further includes, when the deceleration release condition is met while the target rotational speed is set to the first specific rotational speed by the deceleration control, deceleration release control is performed to switch the target rotational speed from the first specific rotational speed to the rated rotational speed. The rated rotational speed, which has been changed by an operation on the accelerator control unit performed during the execution of the deceleration control, is reflected when the deceleration release control is performed. Control method for the work machine described in Appendix 10.

[0160] <Note 12> The control method for the work machine described in any of the appendices 1 to 11, A control program for a work machine to be executed by one or more processors. [Explanation of Symbols]

[0161] 1. Control system for industrial machinery 3. Working Machines 12 Control Processing Unit 13. Configuration Processing Unit 30 aircraft 37 Accelerator control unit 40 Engine 41 Hydraulic pump 463 Cut-off Lever V1 First specific rotation speed V2 Rated rotational speed (second specific rotational speed)

Claims

1. When the deceleration conditions are met, deceleration control is performed to switch the target rotational speed of the prime mover for driving the hydraulic pump that discharges the hydraulic fluid from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed. The system has the capability to change the rated rotational speed in response to the operation of the accelerator control unit, If an operation is performed on the accelerator control unit while the deceleration control is being executed, the deceleration control will continue. A method for controlling industrial machinery.

2. The deceleration condition includes the state in which the accelerator operating unit remains unoperated for a specified period of time or longer. A method for controlling a work machine according to claim 1.

3. The deceleration conditions include the load on the work machine being in a light load state. A method for controlling a work machine according to claim 1 or 2.

4. The system further includes determining whether the machine is in the light-load state based on its movement and / or operation status. A method for controlling a work machine according to claim 3.

5. If certain conditions are met, and the work machine is running and / or operating, it is determined that the state is not light load. A method for controlling a work machine according to claim 4.

6. The aforementioned specific conditions include the cutoff lever being in an unlocked state. A method for controlling a work machine according to claim 5.

7. The system further includes performing stop control to stop the prime mover and set the target rotational speed to zero when the stop condition is met. A method for controlling a work machine according to claim 1 or 2.

8. The system further includes, when the prime mover is stopped by the aforementioned stop control and the stop release condition is met, the system starts the prime mover and performs stop release control to set the target rotation speed to a second specific rotation speed. A method for controlling a work machine according to claim 7.

9. The aforementioned stop release condition includes an operation to lock the cutoff lever and then unlock the cutoff lever. A method for controlling a work machine according to claim 8.

10. If an operation is performed on the accelerator control unit while the deceleration control is being executed, the rated rotational speed is changed in accordance with the operation on the accelerator control unit. A method for controlling a work machine according to claim 1 or 2.

11. The deceleration release condition is met when the target rotation speed is set to the first specific rotation speed by the deceleration control, and the deceleration release condition is met, further comprising executing a deceleration release control to switch the target rotation speed from the first specific rotation speed to the rated rotation speed. The rated rotational speed, which has been changed by an operation on the accelerator control unit performed during the execution of the deceleration control, is reflected when the deceleration release control is performed. A method for controlling a work machine according to claim 10.

12. A control method for a work machine according to claim 1 or 2, A control program for a work machine to be executed by one or more processors.

13. A control processing unit capable of performing deceleration control, which switches the target rotational speed of the prime mover for driving the hydraulic pump that discharges the hydraulic fluid from the rated rotational speed to a first specific rotational speed lower than the rated rotational speed when the deceleration conditions are met, It includes a setting processing unit that changes the rated rotational speed in response to the operation of the accelerator control unit, The control processing unit continues the deceleration control if there is an operation on the accelerator operation unit while the deceleration control is being performed. Control system for industrial machinery.

14. A control system for a work machine according to claim 13, Equipped with an aircraft, Agricultural machinery.

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