Construction machinery, control devices, and control programs

Abstract

This disclosure provides a construction machine capable of reducing the burden on the hydraulic drive system in a heat utilization mode that increases the load factor of the power source driving the hydraulic pump. [Solution] The construction machine (excavator 100) comprises an attachment, hydraulic actuators (slewing motor 2A, right travel motor 2MR, left travel motor 2ML, boom cylinder 7, arm cylinder 8, bucket cylinder 9), control valves 171-176, hydraulic pump (main pump 14), power source 11, regulator 13, and control device 30. In a heat utilization mode that increases the load rate of the power source 11, the control device 30 sets the maximum load rate of the power source 11 according to the rotational speed of the power source 11.

Description

【Technical Field】 【0001】 The present disclosure relates to construction machinery, a control device, and a control program. 【Background Art】 【0002】 Conventionally, a work vehicle having an engine equipped with an exhaust gas purification device is known (see Patent Document 1 below). The work vehicle described in Patent Document 1 includes an exhaust temperature detection unit, a differential pressure detection unit, a hydraulic cylinder, a hydraulic control valve, a work machine pump, an electromagnetic switching valve, an oil cooler, and a control unit. 【0003】 The exhaust temperature detection unit detects the exhaust temperature of the engine. The differential pressure detection unit detects the differential pressure between the upstream and downstream of the exhaust gas purification device. The hydraulic cylinder operates a work machine mounted on the work vehicle. The hydraulic control valve controls the operation of the hydraulic cylinder. The work machine pump supplies hydraulic oil to the hydraulic control valve. The electromagnetic switching valve is provided between the hydraulic control valve and the work machine pump and is configured to be able to switch whether to supply hydraulic oil to the hydraulic control valve or to hydraulic load means. The oil cooler cools the hydraulic oil discharged from the hydraulic load means. 【0004】 The control unit controls various operations of the work vehicle. This control unit obtains the engine load rate of the engine while the exhaust temperature and the differential pressure satisfy predetermined conditions, and performs control based on the exhaust temperature, the differential pressure, and the engine load rate. Further, when an operation lever for operating the work machine is not operated, this control unit switches and drives the electromagnetic switching valve, and guides the hydraulic oil to the oil cooler via the hydraulic load means, thereby increasing the load applied to the engine. 【Prior Art Documents】 【Patent Documents】 【0005】 [Patent Document 1] Japanese Patent Publication No. 2015-086854 [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 Patent Document 1 states that the above-mentioned work vehicle can enable stable continuous regeneration of the DPF (Diesel Particulate Filter). However, when the load applied to the engine of the work vehicle described in Patent Document 1 is increased, the hydraulic fluid pressure may rise excessively as the engine speed increases, potentially placing an excessive burden on the hydraulic drive system. 【0007】 This disclosure provides a construction machine, a control device, and a control program capable of reducing the burden on the hydraulic drive system in a heat utilization mode that increases the load on the power source driving the hydraulic pump. [Means for solving the problem] 【0008】 One aspect of the present disclosure provides a construction machine comprising: an attachment; a hydraulic actuator for driving the attachment; a control valve for controlling the flow rate and direction of hydraulic fluid supplied to the hydraulic actuator; a hydraulic pump for supplying hydraulic fluid to the hydraulic actuator via the control valve; a power source for driving the hydraulic pump; a regulator for controlling the discharge amount of the hydraulic pump; and a control device for controlling the control valve, the power source, and the regulator, wherein the control device sets the maximum load rate of the power source according to the rotational speed of the power source in a heat utilization mode that increases the load rate of the power source. 【0009】 Another aspect of the present disclosure provides a control device for a construction machine comprising an attachment, a hydraulic actuator for driving the attachment, a control valve for controlling the flow rate and direction of hydraulic fluid supplied to the hydraulic actuator, a hydraulic pump for supplying hydraulic fluid to the hydraulic actuator via the control valve, a power source for driving the hydraulic pump, and a regulator for controlling the discharge amount of the hydraulic pump, wherein the control device sets the maximum load rate of the power source according to the rotational speed of the power source in a heat utilization mode that increases the load rate of the power source. 【0010】 A further aspect of the present disclosure provides a control program for a control device of a construction machine comprising an attachment, a hydraulic actuator for driving the attachment, a control valve for controlling the flow rate and direction of hydraulic fluid supplied to the hydraulic actuator, a hydraulic pump for supplying hydraulic fluid to the hydraulic actuator via the control valve, a power source for driving the hydraulic pump, a regulator for controlling the discharge amount of the hydraulic pump, and a control device for controlling the control valve, the power source, and the regulator, wherein in a heat utilization mode that increases the load rate of the power source, the control program causes the control device to set the maximum load rate of the power source according to the rotational speed of the power source. [Effects of the Invention] 【0011】 According to each of the above embodiments of this disclosure, it is possible to provide a construction machine, a control device, and a control program that can reduce the burden on the hydraulic drive system in a heat utilization mode that increases the load factor of the power source driving the hydraulic pump. [Brief explanation of the drawing] 【0012】 [Figure 1] This is a side view showing an embodiment of the construction machinery relating to this disclosure. [Figure 2] Figure 1 is a block diagram showing an example of the configuration of a construction machine. [Figure 3] Figure 1 is a diagram showing the configuration of the hydraulic system installed in the construction machinery. [Figure 4] Figure 1 is a functional block diagram of the control system installed in the construction machinery. [Figure 5] Figure 4 is a flowchart illustrating the operation of the control device. [Figure 6] Figure 1 is a graph showing the rotational speed and load factor of the power source of the construction machinery. [Figure 7] This is a schematic diagram showing an embodiment of the control device relating to this disclosure. [Modes for carrying out the invention] 【0013】 Embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are illustrative and do not limit the invention. Not all features and combinations thereof in the embodiments of this disclosure are necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and redundant descriptions may be omitted. 【0014】 First, an embodiment of the construction machine according to this disclosure will be described with reference to Figures 1 to 5. Figure 1 is a side view of an excavator 100 showing an embodiment of the construction machine according to this disclosure. Figure 2 is a block diagram showing an example of the configuration of the excavator 100 shown in Figure 1. In Figure 2, double lines indicate the transmission of mechanical power, and solid lines indicate high-pressure hydraulic paths. Dashed lines indicate the transmission paths of pilot pressure, and dotted lines indicate the transmission paths of electrical signals and control signals. 【0015】 As shown in Figure 1, an example of a construction machine, the shovel 100, comprises a lower traveling body 1, an upper rotating body 3, an attachment AT, and a control device 30. 【0016】 The lower traveling body 1 includes, for example, crawlers that are driven by a traveling motor 2M to move the excavator 100. Specifically, the lower traveling body 1 includes a left crawler driven by a left traveling motor 2ML shown in FIG. 2 and a right crawler driven by a right traveling motor 2MR shown in FIG. 2. The traveling motor 2M including the left traveling motor 2ML and the right traveling motor 2MR is a hydraulic actuator that operates by the hydraulic pressure of hydraulic oil. Note that the excavator 100 may be a wheeled hydraulic excavator in which the lower traveling body 1 has tires. 【0017】 The upper revolving body 3 is provided rotatably on the lower traveling body 1. Specifically, the upper revolving body 3 is rotatably attached onto the lower traveling body 1 via a revolving mechanism 2 shown in FIG. 1. The revolving mechanism 2 is driven by a revolving motor 2A to revolve the upper revolving body 3 on the lower traveling body 1. The revolving motor 2A is mounted on the upper revolving body 3 and is a hydraulic actuator that operates by the hydraulic pressure of hydraulic oil. Note that the revolving motor 2A may be an electric actuator. 【0018】 On the front left side of the upper revolving body 3, a cabin 10 as an operator cab of the excavator 100 is provided. Inside the cabin 10, in addition to a control device 30, an operating device 26, a display device D1, an input device D2, etc. shown in FIG. 2 are provided. Further, on the upper revolving body 3, in addition to the revolving motor 2A, a power source 11 such as an engine or an electric motor is mounted. Further, as shown in FIG. 1, an external sensor 70 is attached to the upper revolving body 3. 【0019】 The external sensor 70 is configured to recognize objects around the excavator 100. The external sensor 70 may be configured to calculate the distance to the recognized objects. The external sensor 70 includes, for example, an imaging device, LiDAR, millimeter-wave radar, ultrasonic sensor, infrared sensor, or any combination thereof. The external sensor 70 includes, for example, a front sensor 70F, a rear sensor 70B, a left sensor 70L, and a right sensor (not shown). 【0020】 The front sensor 70F is attached, for example, to the upper front part of the cab 10 and recognizes an object in front of the excavator 100. The rear sensor 70B is attached to the rear part of the upper swing body 3 and recognizes an object behind the excavator 100. The left sensor 70L is attached to the left side part of the upper swing body 3 and recognizes an object to the left of the excavator 100. The right sensor, whose illustration is omitted, is attached to the right side part of the upper swing body 3 and recognizes an object to the right of the excavator 100. These external sensors 70 are arranged such that a part of the object detection range of adjacent external sensors 70 overlaps, and are configured to recognize an object existing in 360 degrees around the excavator 100. 【0021】 In addition, the front, rear, left, and right directions in the excavator 100 are the directions as seen from the operator boarding the cab 10. FIG. 1 shows a three-dimensional orthogonal coordinate system in which the front direction, rear direction, left direction, right direction, upward direction, and downward direction of the excavator 100 are the positive X-axis direction, negative X-axis direction, positive Y-axis direction, negative Y-axis direction, positive Z-axis direction, and negative Z-axis direction, respectively. 【0022】 The attachment AT is provided adjacent to the right side of the cab 10 at the front central part of the upper swing body 3. The attachment AT includes a boom 4, an arm 5, and a bucket 6. The boom 4 is rotatably supported by the upper swing body 3 via a boom foot pin. The arm 5 is rotatably supported by the boom 4 via a boom top pin. The bucket 6 is rotatably supported by the arm 5 via a bucket pin. 【0023】 The boom 4 is driven by a boom cylinder 7 to rotate up and down. Specifically, the boom cylinder 7 is a hydraulic actuator that performs a boom raising operation of extending the piston rod to rotate the boom 4 upward and a boom lowering operation of contracting the piston rod to rotate the boom 4 downward. 【0024】 The arm 5 is driven by the arm cylinder 8 to open and close relative to the boom 4. Specifically, the arm cylinder 8 is a hydraulic actuator that performs an arm closing operation by extending the piston rod to close the arm 5 relative to the boom 4, and an arm opening operation by retracting the piston rod to open the arm 5 relative to the boom 4. 【0025】 The bucket 6 is driven by a bucket cylinder 9 connected via a linkage mechanism to open and close relative to the arm 5. Specifically, the bucket cylinder 9 is a hydraulic actuator that performs a bucket closing operation by extending the piston rod to close the bucket 6 relative to the arm 5, and a bucket opening operation by retracting the piston rod to open the bucket 6 relative to the arm 5. 【0026】 Bucket 6 is an end attachment for excavation that is attached to the tip of attachment AT. The end attachment is not limited to bucket 6, and may be other types of buckets, such as a large bucket, a slope bucket, or a dredging bucket. Bucket 6 may also be provided with a bucket tilt mechanism. 【0027】 The control device 30 is, for example, a controller installed in the cabin 10 that controls the operation of the shovel 100. The control device 30 includes, for example, an auxiliary storage device 30A such as ROM (Read-Only Memory), a memory device 30B such as RAM (Random Access Memory), a processing device 30C such as a CPU (Central Processing Unit), and an interface device 30D that communicates with other devices. The control device 30 is, for example, a controller that controls various parts of the shovel 100. The control device 30 may consist of one controller or may consist of multiple controllers. 【0028】 As shown in Figure 2, the excavator 100 is equipped with a hydraulic drive system that drives hydraulic actuators including a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a slewing motor 2A, a left travel motor 2ML, and a right travel motor 2MR. The hydraulic drive system of the excavator 100 includes, for example, a power source 11, a regulator 13, a main pump 14, a pilot pump 15, and a control valve unit 17. 【0029】 The power source 11 is the main power source in the hydraulic drive system and is mounted, for example, at the rear of the upper slewing body 3. Specifically, the power source 11 rotates at a preset target rotational speed under direct or indirect control by the control device 30 (described later) and drives the main pump 14 and the pilot pump 15. The power source 11 is, for example, an engine. Specifically, the power source 11 is, for example, a diesel engine that uses light oil as fuel. The power source 11 may also be a gasoline engine or a hydrogen engine, etc. Furthermore, the power source 11 may be a combination of a power source such as a battery or fuel cell and an electric motor. 【0030】 The regulator 13 controls the discharge volume of the main pump 14, which is a hydraulic pump. The regulator 13 controls the discharge volume of the hydraulic fluid by the main pump 14 by adjusting the angle of the swash plate of the main pump 14, i.e., the tilt angle, in response to a control command from the control device 30. 【0031】 The main pump 14 is mounted, for example, at the rear of the upper slewing body 3, similar to the power source 11. The main pump 14 is a hydraulic pump that supplies hydraulic fluid to the control valve unit 17 through the high-pressure hydraulic line 16. The main pump 14 is driven by the power source 11, as described above. The main pump 14 is, for example, a variable displacement hydraulic pump. As described above, under the control of the control device 30, the piston stroke length of the main pump 14 can be adjusted by adjusting the tilt angle of the swash plate by the regulator 13, thereby controlling the discharge volume or discharge pressure. 【0032】 The pilot pump 15 is an example of a pilot pressure generating device and is configured to supply hydraulic fluid to hydraulic control equipment via a pilot line. In this embodiment, the pilot pump 15 is a fixed-displacement hydraulic pump. The pilot pressure generating device may also be implemented by the main pump 14. That is, the main pump 14 may have the function of supplying hydraulic fluid to the control valve unit 17 via a hydraulic fluid line, as well as the function of supplying hydraulic fluid to various hydraulic control equipment via a pilot line. In this case, the pilot pump 15 may be omitted. 【0033】 The control valve unit 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In this embodiment, the control valve unit 17 includes control valves 171-176. The control valve unit 17 is configured to selectively supply the hydraulic fluid discharged by the main pump 14 to one or more hydraulic actuators through the control valves 171-176. 【0034】 Control valves 171-176 control the flow rate of hydraulic fluid from the main pump 14 to the hydraulic actuator, and the flow rate of hydraulic fluid from the hydraulic actuator to the hydraulic fluid tank. More specifically, control valve 171 corresponds to the left travel motor 2ML, control valve 172 to the right travel motor 2MR, and control valve 173 to the slewing motor 2A. Additionally, control valve 174 corresponds to the bucket cylinder 9, control valve 175 to the boom cylinder 7, and control valve 176 to the arm cylinder 8. 【0035】 The operating system of the shovel 100 according to this embodiment includes, for example, an operating device 26, a discharge pressure sensor 28, an operating sensor 29, and a control device 30. 【0036】 The operating device 26 is a device used by the operator to operate the actuator. The operating device 26 includes, for example, an operating lever and an operating pedal. The actuator includes at least one of a hydraulic actuator and an electric actuator. 【0037】 The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs a signal to the control device 30 corresponding to the detected discharge pressure of the main pump 14. 【0038】 The operation sensor 29 is configured to detect the operator's actions using the operation device 26. In this embodiment, the operation sensor 29 detects the operating direction and amount of operation of the operation device 26 corresponding to each actuator, and outputs the detected values ​​to the control device 30. 【0039】 The control device 30 controls the opening area of ​​the proportional valve 31 according to the output of the operation sensor 29. The control device 30 then supplies the hydraulic fluid discharged by the pilot pump 15 to the pilot ports of the corresponding control valves 171-176 in the control valve unit 17. The pressure of the hydraulic fluid supplied to each pilot port (pilot pressure) is, in principle, the pressure corresponding to the operating direction and amount of the operating device 26 corresponding to each hydraulic actuator. In this way, the operating device 26 is configured to supply the hydraulic fluid discharged by the pilot pump 15 to the pilot ports of the corresponding control valves 171-176 in the control valve unit 17. 【0040】 The control system of the shovel 100 according to this embodiment includes a control device 30, a display device D1, an input device D2, and a communication device T1. The control system of the shovel 100 also includes, as a configuration for semi-automatic operation, a proportional valve 31, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body tilt sensor S4, a slewing angle sensor S5, an imaging device S6, and a positioning device PS. The control system of the shovel 100 also includes, as a configuration for the heat utilization mode described later, a control device 30, an input device D2, a discharge pressure sensor 28, a tilt angle sensor S7, a rotation speed sensor S8, a regulator 13, and a power source 11. 【0041】 The control device 30 sets a target rotational speed based on the operator's actions, for example, and performs drive control to rotate the power source 11 at a constant rotational speed. The control device 30 also outputs control commands to the regulator 13 as needed to change the discharge amount of the main pump 14. The control device 30 controls the regulator 13 based on the detected pilot pressure values ​​corresponding to the operating states of various operating elements (i.e., various hydraulic actuators) in the operating device 26, which are input from the operation sensor 29, and adjusts the discharge amount of the main pump 14. The control device 30 also performs control related to a machine guidance function that guides the operator's manual operation of the shovel 100 through the operating device 26. The control device 30 also performs control related to a machine control function that automatically assists the operator's manual operation of the shovel 100 through the operating device 26. 【0042】 Furthermore, the control device 30 is configured to allow selection of a heat utilization mode that utilizes the heat generated by the operation of the power source 11, for example. Specifically, the operator selects the heat utilization mode of the control device 30 via the input device D2, for example. The control device 30 also automatically selects the heat utilization mode according to the outside temperature and other conditions, for example. The heat utilization mode is intended for purposes such as preventing freezing of the blow-by gas passage including the PCV (Positive Crankcase Ventilation) piping, preventing freezing of the urea solution, regenerating the DPF (Diesel Particulate Filter), warming up the hydraulic drive system, and heating the cabin 10's air conditioning when the power source 11 is an engine. The heat utilization mode is also intended for purposes such as warming up the hydraulic drive system and heating the cabin 10's air conditioning when the power source 11 is an electric motor. As will be described in detail later, in the heat utilization mode, the control device 30 generates heat according to the above purposes by increasing the load factor of the power source 11. 【0043】 The display device D1 is installed in a location easily visible to a seated operator inside the cabin 10 and displays various information images under the control of the control device 30. The display device D1 may be connected to the control device 30 via an in-vehicle communication network such as CAN (Controller Area Network), or it may be connected to the control device 30 via a one-to-one dedicated line. Furthermore, the display device D1 is not limited to a device pre-installed in the cabin 10, and may be a detachable monitor. In addition, the display device D1 may be a portable information terminal such as a tablet PC (Personal Computer) that can communicate with the communication device T1. 【0044】 The input device D2 is located within reach of a seated operator in the cabin 10 and receives various operation inputs from the operator, outputting signals corresponding to the operation inputs to the control device 30. The input device D2 includes a touch panel mounted on the display of the display device D1 which displays various information images, a knob switch provided at the tip of the lever device of the operation device 26, and button switches, levers, toggles, rotary dials, etc., installed around the display device D1. Signals corresponding to the operations performed on the input device D2 are received by the control device 30. 【0045】 The communication device T1 communicates with external devices through a predetermined network, including a mobile communication network with a base station as its endpoint, a satellite communication network, and the Internet network. The communication device T1 is, for example, a mobile communication module that supports mobile communication standards such as LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation), or a satellite communication module for connecting to a satellite communication network. 【0046】 The proportional valve 31 functions as a control valve for machine control. The proportional valve 31 is located in the pipeline connecting the pilot pump 15 and the pilot port of the control valve in the control valve unit 17, and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 31 operates in response to control commands output by the control device 30. Therefore, the control device 30 can supply the hydraulic fluid discharged by the pilot pump 15 to the pilot port of the control valve in the control valve unit 17 via the proportional valve 31, independently of the operator's operation of the operating device 26. 【0047】 With this configuration, the control device 30 can operate the hydraulic actuator corresponding to a specific operating device 26 even when no operation is being performed on that specific operating device 26. Furthermore, if the excavator 100 does not have machine control or remote control functions, the excavator 100 does not need to have a proportional valve 31. 【0048】 The boom angle sensor S1 detects the rotation angle of the boom 4. In this embodiment, the boom angle sensor S1 is an acceleration sensor attached to the boom 4 and can detect the boom angle, which is the rotation angle of the boom 4 relative to the upper slewing body 3. The boom angle is smallest when the boom 4 is lowered to its lowest position, and increases as the boom 4 is raised. The detection signal corresponding to the boom angle from the boom angle sensor S1 is input to the control device 30. 【0049】 The arm angle sensor S2 detects the rotation angle of the arm 5. In this embodiment, the arm angle sensor S2 is an acceleration sensor attached to the arm 5 and can detect the arm angle, which is the rotation angle of the arm 5 relative to the boom 4. The arm angle is smallest when the arm 5 is closed to its shortest extent, and increases as the arm 5 is opened. The detection signal corresponding to the arm angle from the arm angle sensor S2 is input to the control device 30. 【0050】 The bucket angle sensor S3 detects the rotation angle of the bucket 6. In this embodiment, the bucket angle sensor S3 is an acceleration sensor attached to the link mechanism that drives the bucket 6, and can detect the bucket angle, which is the rotation angle of the bucket 6 relative to the arm 5. The bucket angle is smallest when the bucket 6 is closed to its lowest position, for example, and increases as the bucket 6 is opened. The detection signal corresponding to the bucket angle from the bucket angle sensor S3 is input to the control device 30. 【0051】 The boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 may be a potentiometer using a variable resistor, a stroke sensor that detects the stroke amount of the corresponding hydraulic cylinder, or a rotary encoder that detects the rotation angle around the connecting pin. The boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 constitute an attitude sensor that detects the attitude of the excavation attachment. 【0052】 The machine body tilt sensor S4 is attached to the upper rotating body 3 and is configured to detect the tilt of the upper rotating body 3 with respect to a predetermined plane. In this embodiment, the machine body tilt sensor S4 is an acceleration sensor that detects the tilt angle of the upper rotating body 3 around the longitudinal axis and the tilt angle around the left-right axis with respect to the horizontal plane. The longitudinal axis and left-right axis of the upper rotating body 3 are, for example, orthogonal to each other and pass through the shovel center point, which is a point on the rotation axis of the shovel 100. 【0053】 The rotation angle sensor S5 is attached to the upper rotating body 3 and is configured to detect the rotational angular velocity of the upper rotating body 3. In this embodiment, the rotation angle sensor S5 is a gyro sensor. The rotation angle sensor S5 may also be a resolver or a rotary encoder, etc. The rotation angle sensor S5 may also detect the rotational speed. The rotational speed may be calculated from the rotational angular velocity. 【0054】 Furthermore, if the aircraft tilt sensor S4 includes a gyro sensor, a 6-axis sensor, an IMU (Inertial Measurement Unit), etc., capable of detecting angular velocity around three axes, the rotation state of the upper rotating body 3 (for example, rotational angular velocity) may be detected based on the detection signal from the aircraft tilt sensor S4. In this case, the rotational angle sensor S5 may be omitted. 【0055】 The imaging device S6 is an example of an external sensor 70 shown in Figure 1. The imaging device S6 recognizes objects around the shovel 100 by capturing images of objects present around the shovel 100. The imaging device S6 includes, for example, a front camera as a front sensor 70F, a rear camera as a rear sensor 70B, a left camera as a left sensor 70L, and a right camera as a right sensor (not shown). 【0056】 The positioning device PS is configured to acquire information regarding the position of the shovel 100. In this embodiment, the positioning device PS is configured to measure the position and orientation of the shovel 100. Specifically, the positioning device PS is a GNSS (Global Navigation Satellite System) receiver incorporating an electronic compass, and measures the latitude, longitude, and altitude of the current position of the shovel 100, as well as the orientation of the shovel 100. 【0057】 The shovel 100 operates actuators (e.g., hydraulic actuators) in response to the operation of the operator sitting in the cabin 10, driving the moving elements (hereinafter referred to as "driven elements") such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6. 【0058】 Furthermore, instead of being configured to be operable by the operator in the cabin 10, or in addition to being configured to be operable by the operator in the cabin 10, the shovel 100 may also be configured to be remotely operated from outside the shovel 100. When the shovel 100 is remotely operated, the inside of the cabin 10 may be unoccupied. 【0059】 Furthermore, the shovel 100 may automatically operate its actuators regardless of the operator's actions. As a result, the control device 30 of the shovel 100 has the function of automatically operating at least some of the multiple actuators that operate each of the driven elements such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6, that is, a so-called "automatic driving function" or "machine control function". 【0060】 The automatic driving function may include a function that automatically operates driven elements (actuators) other than the target driven element (actuator) in response to the operator's operation of the control device 26 or remote control, i.e., a so-called "semi-automatic driving function" or "operation-assist type machine control function". The automatic driving function may also include a function that automatically operates at least some of the multiple driven elements (hydraulic actuators) on the premise that there is no operation of the operator's control device 26 or remote control, i.e., a so-called "fully automatic driving function" or "fully automatic machine control function". In the case of the excavator 100, when the fully automatic driving function is enabled, the interior of the cabin 10 may be unoccupied. Furthermore, the semi-automatic driving function and fully automatic driving function may include a mode in which the operation content of the driven elements (actuators) that are the target of automatic driving is automatically determined according to predetermined rules. Furthermore, semi-autonomous driving functions and fully autonomous driving functions may include a mode in which the shovel 100 autonomously makes various decisions, and the operation of the driven elements (hydraulic actuators) that are subject to autonomous driving is determined autonomously in accordance with the results of those decisions (so-called "autonomous driving function"). 【0061】 Specifically, the control device 30 may automatically operate at least one of the boom 4 and bucket 6 so that the tip position of the bucket 6 coincides with a predetermined target construction surface when the arm 5 is being operated by the operator via the operating device 26. In addition, the control device 30 may also automatically operate the arm 5 regardless of the operating state of the operating device 26 that operates the arm 5. In other words, the control device 30 may trigger the attachment to perform predetermined actions based on the operator's operation of the operating device 26. Hereinafter, the function of the control device 30 that operates not only the arm 5 but also at least one of the boom 4 and bucket 6 in response to the operation of the operating device 26 corresponding to the arm 5 will be referred to as the "semi-automatic operation function". The semi-automatic operation function may be executed, for example, by operating a predetermined switch (hereinafter referred to as the "MC (Machine Control) switch") located at the tip of any of the lever devices included in the operating device 26. In this embodiment, a paddle switch may be used as the MC switch, in which the machine control function is executed while it is pressed. 【0062】 Furthermore, some of the functions of the control device 30 may be implemented by other controllers (control devices). In other words, the functions of the control device 30 may be implemented in a manner distributed among multiple controllers. For example, the machine guidance function and the machine control function may be implemented by dedicated controllers (control devices). 【0063】 The tilt angle sensor S7 is installed, for example, on the main pump 14, which is a hydraulic pump, and detects the tilt angle of the swash plate. The tilt angle sensor S7 outputs the detected tilt angle of the main pump 14 to the control device 30. The tilt angle sensor S7 is, for example, a position sensor built into the main pump 14 that detects the position of the tilt angle of the swash plate. 【0064】 The rotational speed sensor S8 detects the rotational speed of the power source 11 and outputs the detected rotational speed to the control device 30. Specifically, if the power source 11 is an engine, the rotational speed sensor S8 detects the engine's rotational speed by detecting components such as the flywheel, camshaft, and crank pulley. If the power source 11 is an electric motor, the rotational speed sensor S8 is a mechanical, optical, magnetic, or electromagnetic induction encoder that detects the rotational speed of the electric motor. 【0065】 As will be described in more detail later, in the heat utilization mode, the control device 30 calculates the discharge volume of the main pump 14 based on the tilt angle of the main pump 14 obtained from the tilt angle sensor S7 and the rotational speed of the power source 11 obtained from the rotational speed sensor S8. In addition, in the heat utilization mode, the control device 30 calculates the drive torque of the main pump 14 based on the calculated discharge volume of the main pump 14 and the discharge pressure of the main pump 14 obtained from the discharge pressure sensor 28. 【0066】 Next, with reference to Figure 3, an example of the configuration of the hydraulic system mounted on the excavator 100 according to this embodiment will be described. Figure 3 is a diagram showing an example of the configuration of the hydraulic system mounted on the excavator 100 according to this embodiment. In Figure 3, the mechanical power transmission system, hydraulic fluid line, pilot line, and electrical control system are shown by double lines, solid lines, dashed lines, and dotted lines, respectively. 【0067】 The hydraulic system of the shovel 100 mainly includes a power source 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve unit 17, an operating device 26, a discharge pressure sensor 28, an operating sensor 29, and a control device 30, etc. 【0068】 In Figure 3, the hydraulic system is configured to circulate hydraulic fluid from the main pump 14, driven by the power source 11, to the hydraulic fluid tank via the center bypass pipeline 40 or the parallel pipeline 42. 【0069】 The power source 11 is the power source for the shovel 100. In this embodiment, the power source 11 is, for example, a diesel engine that operates to maintain a predetermined rotational speed. Alternatively, the power source 11 may be an electric motor. The output shaft of the power source 11 is connected to the input shafts of the main pump 14 and the pilot pump 15, respectively. 【0070】 The main pump 14 is configured to supply hydraulic fluid to the control valve unit 17 via a hydraulic fluid line. In this embodiment, the main pump 14 is a swashplate type variable displacement hydraulic pump. 【0071】 The regulator 13 is configured to control the discharge amount of the main pump 14. In this embodiment, the regulator 13 controls the discharge amount of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 in response to a control command from the control device 30. 【0072】 As described above, the pilot pump 15 is configured to supply hydraulic fluid to the hydraulic control equipment via the pilot line. 【0073】 As described above, the control valve unit 17 includes control valves 171-176. Control valve 175 includes control valves 175L and 175R, and control valve 176 includes control valves 176L and 176R. As described above, the control valve unit 17 is configured to selectively supply the hydraulic fluid discharged by the main pump 14 to one or more hydraulic actuators through the control valves 171-176. As described above, the control valves 171-176 control the flow rate of hydraulic fluid flowing from the main pump 14 to the hydraulic actuators and the flow rate of hydraulic fluid flowing from the hydraulic actuators to the hydraulic fluid tank. As described above, the hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel motor 2ML, a right travel motor 2MR, and a slewing motor 2A. 【0074】 The operating device 26 is configured to allow an operator to operate the actuator. In this embodiment, the operating device 26 includes a hydraulic actuator operating device configured to allow an operator to operate a hydraulic actuator. Specifically, the hydraulic actuator operating device is configured to supply hydraulic fluid discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17 via a pilot line. The pressure of the hydraulic fluid supplied to each pilot port (pilot pressure) is a pressure corresponding to the operating direction and amount of the operating device 26 corresponding to each hydraulic actuator. 【0075】 As described above, the discharge pressure sensor 28 detects the discharge pressure of the main pump 14 and outputs the detected value to the control device 30. As described above, the operation sensor 29 detects the operation of the operation device 26 by the operator, detects the operating direction and amount of the operation device 26 corresponding to each actuator, and outputs the detected value to the control device 30. 【0076】 The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L circulates the hydraulic fluid to the hydraulic fluid tank via the left center bypass pipeline 40L or the left parallel pipeline 42L, while the right main pump 14R circulates the hydraulic fluid to the hydraulic fluid tank via the right center bypass pipeline 40R or the right parallel pipeline 42R. 【0077】 The left center bypass pipeline 40L is a hydraulic fluid line that passes through control valves 171, 173, 175L, and 176L located within the control valve unit 17. The right center bypass pipeline 40R is a hydraulic fluid line that passes through control valves 172, 174, 175R, and 176R located within the control valve unit 17. 【0078】 The control valve 171 is a spool valve that switches the flow of hydraulic fluid to supply the hydraulic fluid discharged by the left main pump 14L to the left travel motor 2ML, and to discharge the hydraulic fluid discharged by the left travel motor 2ML to the hydraulic fluid tank. 【0079】 The control valve 172 is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the right travel motor 2MR, and switches the flow of the hydraulic fluid to discharge the hydraulic fluid discharged by the right travel motor 2MR to the hydraulic fluid tank. 【0080】 The control valve 173 is a spool valve that supplies the hydraulic fluid discharged by the left main pump 14L to the swing motor 2A, and switches the flow of the hydraulic fluid discharged by the swing motor 2A to the hydraulic fluid tank. 【0081】 The control valve 174 is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the bucket cylinder 9 and switches the flow of the hydraulic fluid in order to discharge the hydraulic fluid in the bucket cylinder 9 to the hydraulic fluid tank. 【0082】 Control valve 175L is a spool valve that switches the flow of hydraulic fluid to supply the hydraulic fluid discharged by the left main pump 14L to the boom cylinder 7. Control valve 175R is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the boom cylinder 7 and also switches the flow of hydraulic fluid to discharge the hydraulic fluid inside the boom cylinder 7 to the hydraulic fluid tank. 【0083】 Control valve 176L is a spool valve that supplies the hydraulic fluid discharged by the left main pump 14L to the arm cylinder 8 and switches the flow of hydraulic fluid to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank. Control valve 176R is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the arm cylinder 8 and switches the flow of hydraulic fluid to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank. 【0084】 The left parallel pipeline 42L is a hydraulic fluid line running parallel to the left center bypass pipeline 40L. The left parallel pipeline 42L can supply hydraulic fluid to a control valve further downstream if the flow of hydraulic fluid through the left center bypass pipeline 40L is restricted or blocked by any of the control valves 171, 173, and 175L. The right parallel pipeline 42R is a hydraulic fluid line running parallel to the right center bypass pipeline 40R. The right parallel pipeline 42R can supply hydraulic fluid to a control valve further downstream if the flow of hydraulic fluid through the right center bypass pipeline 40R is restricted or blocked by any of the control valves 172, 174, and 175R. 【0085】 The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L controls the discharge volume of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with the discharge pressure of the left main pump 14L. Specifically, the left regulator 13L reduces the discharge volume by adjusting the swash plate tilt angle of the left main pump 14L in accordance with an increase in the discharge pressure of the left main pump 14L. The same applies to the right regulator 13R. This is to ensure that the absorption power (absorption horsepower) of the main pump 14, which is expressed as the product of the discharge pressure and the discharge volume, does not exceed the output power (output horsepower) of the power source 11. 【0086】 The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a travel lever 26D. The travel lever 26D includes a left travel lever 26DL and a right travel lever 26DR. 【0087】 The left operating lever 26L is used for slewing and operating the arm 5. When the left operating lever 26L is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 176. When it is operated in the left / right direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 173. 【0088】 Specifically, when the left operating lever 26L is operated in the arm closing direction, it introduces hydraulic fluid into the right pilot port of control valve 176L and into the left pilot port of control valve 176R. When the left operating lever 26L is operated in the arm opening direction, it introduces hydraulic fluid into the left pilot port of control valve 176L and into the right pilot port of control valve 176R. Furthermore, when the left operating lever 26L is operated in the left rotation direction, it introduces hydraulic fluid into the left pilot port of control valve 173, and when operated in the right rotation direction, it introduces hydraulic fluid into the right pilot port of control valve 173. 【0089】 In the example shown in Figure 3, the left operating lever 26L functions as an arm operating lever when operated in the forward / backward direction and as a swivel operating lever when operated in the left / right direction. The left operating lever 26L is equipped with a switch NS (NSL). In this embodiment, switch NS is a push-button switch located at the tip of the left operating lever 26L. The operator can operate the left operating lever 26L while pressing switch NS. 【0090】 The right operating lever 26R is used to operate the boom 4 and the bucket 6. When the right operating lever 26R is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 175. When it is operated in the left / right direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 174. 【0091】 Specifically, when the right operating lever 26R is operated in the boom lowering direction, it introduces hydraulic fluid into the left pilot port of the control valve 175R. When the right operating lever 26R is operated in the boom raising direction, it introduces hydraulic fluid into the right pilot port of the control valve 175L and into the left pilot port of the control valve 175R. Furthermore, when the right operating lever 26R is operated in the bucket closing direction, it introduces hydraulic fluid into the right pilot port of the control valve 174, and when it is operated in the bucket opening direction, it introduces hydraulic fluid into the left pilot port of the control valve 174. 【0092】 In the example shown in Figure 3, the right operating lever 26R functions as a boom operating lever when operated in the forward / backward direction and as a bucket operating lever when operated in the left / right direction. A switch NS (NSR) may also be provided on the right operating lever 26R, or the switch NS may be located at another position within the cabin 10. 【0093】 The travel lever 26D is used to operate the crawler. Specifically, the left travel lever 26DL is used to operate the left crawler. The left travel lever 26DL may be configured to be linked with the left travel pedal. When the left travel lever 26DL is operated in the forward or backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 171. The right travel lever 26DR is used to operate the right crawler. The right travel lever 26DR may be configured to be linked with the right travel pedal. When the right travel lever 26DR is operated in the forward or backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 172. 【0094】 The discharge pressure sensor 28 includes discharge pressure sensor 28L and discharge pressure sensor 28R. Discharge pressure sensor 28L detects the discharge pressure of the left main pump 14L and outputs the detected value to the control device 30. The same applies to discharge pressure sensor 28R. 【0095】 The operation sensors 29 include operation sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. Operation sensor 29LA detects the operation performed by the operator on the left operation lever 26L in the forward and backward directions and outputs the detected value to the control device 30. The operation details include, for example, the direction of lever operation and the amount of lever operation (lever operation angle). 【0096】 Similarly, the operation sensor 29LB detects the operator's left-right operation of the left operation lever 26L and outputs the detected value to the control device 30. The operation sensor 29RA detects the operator's forward-backward operation of the right operation lever 26R and outputs the detected value to the control device 30. The operation sensor 29RB detects the operator's left-right operation of the right operation lever 26R and outputs the detected value to the control device 30. The operation sensor 29DL detects the operator's forward-backward operation of the left travel lever 26DL and outputs the detected value to the control device 30. The operation sensor 29DR detects the operator's forward-backward operation of the right travel lever 26DR and outputs the detected value to the control device 30. 【0097】 In this embodiment, the operating device 26 is described as a hydraulic operating lever equipped with a hydraulic pilot circuit, but an electric operating lever equipped with an electric pilot circuit may be used instead of a hydraulic operating lever. In this case, the amount of lever operation of the electric operating lever is input to the control device 30 as an electrical signal. A solenoid valve is also placed between the pilot pump 15 and the pilot port of each control valve. The solenoid valve is configured to operate in response to an electrical signal from the control device 30. With this configuration, when manual operation is performed using the electric operating lever, the control device 30 can move each control valve by controlling the solenoid valve with an electrical signal corresponding to the amount of lever operation to increase or decrease the pilot pressure. Each control valve may be composed of an electromagnetic spool valve. In this case, the electromagnetic spool valve operates in response to an electrical signal from the control device 30 corresponding to the amount of lever operation of the electric operating lever. 【0098】 The control device 30 receives the output of the operation sensor 29 and, if necessary, outputs a control command to the regulator 13 to change the discharge amount of the main pump 14. The control device 30 also receives the output of the control pressure sensor 19 located upstream of the throttle 18 and, if necessary, outputs a control command to the regulator 13 to change the discharge amount of the main pump 14. The throttle 18 includes a left throttle 18L and a right throttle 18R, and the control pressure sensor 19 includes a left control pressure sensor 19L and a right control pressure sensor 19R. 【0099】 In the left center bypass pipeline 40L, a left throttle 18L is located between the control valve 176L, which is the furthest downstream, and the hydraulic fluid tank. Therefore, the flow of hydraulic fluid discharged by the left main pump 14L is restricted by the left throttle 18L. The left throttle 18L then generates a control pressure to control the left regulator 13L. The left control pressure sensor 19L is a sensor for detecting this control pressure and outputs the detected value to the control device 30. The control device 30 controls the discharge amount of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with this control pressure. The larger the control pressure, the smaller the discharge amount of the left main pump 14L, and the smaller the control pressure, the larger the discharge amount of the left main pump 14L. The discharge amount of the right main pump 14R is controlled in the same way. 【0100】 Specifically, as shown in Figure 3, when none of the hydraulic actuators in the shovel 100 are operated and the system is in standby mode, the hydraulic fluid discharged from the left main pump 14L passes through the left center bypass pipe 40L to the left constriction 18L. The flow of hydraulic fluid discharged from the left main pump 14L increases the control pressure generated upstream of the left constriction 18L. As a result, the control device 30 reduces the discharge volume of the left main pump 14L to the minimum allowable discharge volume, suppressing the pressure loss (pumping loss) as the discharged hydraulic fluid passes through the left center bypass pipe 40L. On the other hand, when any of the hydraulic actuators are operated, the hydraulic fluid discharged from the left main pump 14L flows into the hydraulic actuator being operated via the control valve corresponding to that actuator. The flow of hydraulic fluid discharged from the left main pump 14L reduces or eliminates the amount reaching the left constriction 18L, lowering the control pressure generated upstream of the left constriction 18L. As a result, the control device 30 increases the discharge volume of the left main pump 14L, circulating sufficient hydraulic fluid to the hydraulic actuator being operated, and ensuring reliable operation of the hydraulic actuator. The control device 30 also controls the discharge volume of the right main pump 14R in the same manner. 【0101】 With the configuration described above, the hydraulic system in Figure 3 can suppress unnecessary energy consumption in the main pump 14 when in standby mode. Unnecessary energy consumption includes pumping losses caused by the hydraulic fluid discharged by the main pump 14 in the center bypass pipeline 40. Furthermore, when operating a hydraulic actuator, the hydraulic system in Figure 3 can reliably supply the necessary and sufficient hydraulic fluid from the main pump 14 to the hydraulic actuator being operated. 【0102】 Furthermore, boom cylinder 7 is equipped with boom rod pressure sensor S7R and boom bottom pressure sensor S7B. Arm cylinder 8 is equipped with arm rod pressure sensor S8R and arm bottom pressure sensor S8B. Bucket cylinder 9 is equipped with bucket rod pressure sensor S9R and bucket bottom pressure sensor S9B. The boom rod pressure sensor S7R, boom bottom pressure sensor S7B, arm rod pressure sensor S8R, arm bottom pressure sensor S8B, bucket rod pressure sensor S9R, and bucket bottom pressure sensor S9B are collectively referred to as "cylinder pressure sensors". Additionally, the slewing motor 2A is equipped with left slewing pressure sensor S10L and right slewing pressure sensor S10R. 【0103】 The boom rod pressure sensor S7R detects the pressure in the rod-side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom rod pressure"), and the boom bottom pressure sensor S7B detects the pressure in the bottom-side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom bottom pressure"). The arm rod pressure sensor S8R detects the pressure in the rod-side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm rod pressure"), and the arm bottom pressure sensor S8B detects the pressure in the bottom-side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm bottom pressure"). The bucket rod pressure sensor S9R detects the pressure in the rod-side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket rod pressure"), and the bucket bottom pressure sensor S9B detects the pressure in the bottom-side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket bottom pressure"). The left slewing pressure sensor S10L detects the hydraulic fluid pressure at the left port of the slewing motor 2A. The right slewing pressure sensor S10R detects the hydraulic fluid pressure at the right port of the slewing motor 2A. The values ​​detected by each sensor are transmitted to the control device 30. 【0104】 Next, the heat utilization modes of the shovel 100 will be explained with reference to Figures 4 to 6. Figure 4 is a functional block diagram of the control device 30 provided in the shovel 100 shown in Figure 1. Figure 5 is a flowchart illustrating the operation of the control device 30 in Figure 4. Figure 6 is a graph showing the relationship between the rotational speed RF and the load factor LR of the power source 11 of the shovel 100. 【0105】 In this embodiment, the control device 30 of the shovel 100 can select a heat utilization mode that generates heat according to the purpose by increasing the rotational speed RF of the power source 11 more than usual, as described above. In the heat utilization mode in which the rotational speed RF of the power source 11 is increased, the control device 30 is characterized by setting the maximum load rate LRmax of the power source 11 according to the rotational speed RF of the power source 11, as shown in Figure 6. 【0106】 The control device 30 includes, for example, a mode determination unit 301, a load factor setting unit 302, a load factor control unit 303, a flow rate control unit 304, and a rotational speed control unit 305, as shown in Figure 4. Each of these parts of the control device 30 represents a function of the control device 30 that is realized, for example, by loading a control program stored in the auxiliary storage device 30A shown in Figure 2 into the memory device 30B by the processing unit 30C and executing it. 【0107】 In other words, each part of the control device 30 shown in Figure 4 represents each part of the control program of this embodiment, which is installed in the control device 30 (a computer) and causes the control device 30 to perform predetermined operations. The operation of each part of the control device 30 shown in Figure 4 will be explained below with reference to the flowchart in Figure 5. 【0108】 When the control device 30 starts the processing flow shown in Figure 5, it executes a process P01 to control a construction machine, such as an excavator 100, in normal mode. In this process P01, as described above, the control device 30 controls the opening area of ​​the proportional valve 31 according to the output of the operation sensor 29 based on the operation of the operation device 26 by the operator. The control device 30 also sets a target rotational speed of the power source 11 based on the operation of the operator, etc., as described above, and performs drive control to rotate the power source 11 at a constant rotational speed. The control device 30 also performs control related to the machine guidance function and machine control function described above, for example. 【0109】 Next, the control device 30 executes a process P02 to determine the start of the heat utilization mode. In this process P02, the mode determination unit 301 of the control device 30 determines, for example, whether the operator of the shovel 100 has selected the heat utilization mode via the input device D2. Alternatively, in this process P02, the control device 30 determines, for example, whether the detection results of sensors that detect the state of the shovel 100, such as temperature sensors that detect the temperature of various parts of the shovel 100, satisfy the conditions for starting the heat utilization mode. 【0110】 When the power source 11 is an engine, the heat utilization mode is intended to prevent freezing of the blow-by gas passage, prevent freezing of the urea solution, regenerate the DPF, warm up the hydraulic drive system, and operate the air conditioning system for heating, as described above. When the power source 11 is an electric motor, the heat utilization mode is intended to warm up the hydraulic drive system and operate the air conditioning system for heating, as described above. 【0111】 In this process P02, if the mode determination unit 301 determines that the heat utilization mode is not selected or that the conditions for starting the heat utilization mode are not met (NO), the control device 30 terminates the processing flow shown in Figure 5 and repeats it at a predetermined cycle. On the other hand, in this process P02, if the mode determination unit 301 determines that the heat utilization mode is selected or that the conditions for starting the heat utilization mode are met (YES), the control device 30 executes process P03 to set the maximum load factor LRmax of the power source 11. 【0112】 In this process P03, the load factor setting unit 302 of the control device 30 sets the maximum load factor LRmax of the power source 11 according to the rotational speed RF of the power source 11, as shown in Figure 6. The load factor LR of the power source 11 is, for example, the ratio (Tp / Tmax) of the drive torque Tp that the power source 11 outputs to drive the main pump 14 to the maximum torque Tmax that the power source 11 can output at each rotational speed RF. 【0113】 In this process P03, the load factor setting unit 302 sets the maximum load factor LRmax of the power source 11 so that, for example, the discharge pressure of the main pump 14, which is a hydraulic pump, does not exceed the upper limit pressure of the hydraulic drive system including the control valves 171-176 of the control valve unit 17. Specifically, the load factor setting unit 302 sets the maximum load factor LRmax of the power source 11 at each rotational speed by, for example, the following procedure. 【0114】 The load factor setting unit 302 first sets the upper limit of the discharge pressure of the main pump 14 at each rotational speed of the power source 11 to an upper pressure that does not place a burden on the hydraulic drive system. The discharge pressure of the main pump 14 depends on the discharge volume of the main pump 14 and the opening area of ​​the throttle 18. Therefore, if the opening area of ​​the throttle 18 is constant, the load factor setting unit 302 can calculate the upper limit of the discharge volume of the main pump 14 based on the upper limit of the discharge pressure of the main pump 14. 【0115】 The discharge rate of the main pump 14 depends on the rotational speed RF of the power source 11 and the tilt angle of the main pump 14. Therefore, the load factor setting unit 302 can calculate the upper limit of the tilt angle of the main pump 14 at each rotational speed of the power source 11 based on the upper limit of the discharge pressure of the main pump 14 that it has calculated. 【0116】 The drive torque Tp required to drive the main pump 14 by the power source 11 is determined by the tilt angle and discharge pressure of the main pump 14. Therefore, the load factor setting unit 302 can calculate the maximum value of the drive torque Tp for the main pump 14, for each rotational speed of the power source 11, based on the calculated upper limit of the tilt angle and upper limit of the discharge pressure of the main pump 14, so that the discharge pressure of the main pump 14 does not exceed the upper limit pressure of the hydraulic drive system. Furthermore, data showing the maximum torque Tmax for each rotational speed of the power source 11 is stored, for example, in the auxiliary storage device 30A of the control device 30. 【0117】 Therefore, the load factor setting unit 302 can derive the maximum load factor LRmax for each rotational speed RF of the power source 11 based on the maximum value of the drive torque Tp for each rotational speed of the power source 11 and the data of the maximum torque Tmax for each rotational speed of the power source 11. Based on the derived maximum load factor LRmax for each rotational speed RF of the power source 11, the load factor setting unit 302 sets the maximum load factor LRmax according to the rotational speed of the power source 11, generates a maximum load factor map as shown in Figure 6, and stores it in the auxiliary storage device 30A or memory device 30B. 【0118】 The maximum load factor map shows the relationship between the rotational speed RF of the power source 11 and the maximum load factor LRmax. In the example shown in Figure 6, when the rotational speed RF of the power source 11 is in the low rotational speed range from any rotational speed RF1 to rotational speed RF2, the maximum load factor LRmax of the power source 11 is the highest load factor LR6. Furthermore, when the rotational speed RF of the power source 11 is in the medium-low rotational speed range from rotational speed RF2 to rotational speed RF3, the maximum load factor LRmax of the power source 11 is a lower load factor LR5 than load factor LR6. 【0119】 Furthermore, in the medium-to-high rotational speed range from rotational speed RF3 to rotational speed RF4, the maximum load factor LRmax of the power source 11 is LR4, which is lower than the load factor LR5. Also, in the high rotational speed range from rotational speed RF4 to rotational speed RF5, the maximum load factor LRmax of the power source 11 is LR3, which is lower than the load factor LR4. 【0120】 As shown in the example in Figure 6, the maximum load factor LRmax of the power source 11 decreases in stages as the rotational speed RF of the power source 11 increases. The maximum load factor LRmax of the power source 11 may decrease continuously and linearly, or continuously and curvilinearly, as the rotational speed RF of the power source 11 increases. In the example in Figure 6, the maximum load factor LRmax of the power source 11, shown by the dashed line, decreases linearly so that the load factors become LR6 and LR2 when the rotational speed RF of the power source 11 is RF1 and RF5, respectively. 【0121】 Next, the control device 30 executes a process P04 to set the minimum load ratio LRmin of the power source 11, for example, as shown in Figure 5. In this process P04, the load ratio setting unit 302 of the control device 30 sets the minimum load ratio LRmin of the power source 11 according to the lower limit of the required heat amount generated by driving the power source 11. The load ratio setting unit 302 sets the minimum load ratio LRmin of the power source 11 at each rotational speed to load ratio LR1, for example, based on a required heat amount map stored in advance in the auxiliary storage device 30A, as shown by the dashed line in Figure 6. 【0122】 Here, if the power source 11 is an engine, the amount of heat required to be generated by driving the power source 11 is, for example, the amount of heat required for preventing the blow-by gas passage from freezing, preventing the urea solution from freezing, DPF regeneration, warming up the hydraulic drive system, or heating the air conditioner. Also, if the power source 11 is an electric motor, the amount of heat required to be generated by driving the power source 11 is, for example, the amount of heat required for warming up the hydraulic drive system or heating the air conditioner. 【0123】 The aforementioned heat requirement map is, for example, data showing the relationship between the lower limit of the heat requirement of the power source 11 and the load factor LR for each rotational speed of the power source 11. If the power source 11 is an engine, the lower limit of the heat requirement can be determined based on, for example, the air temperature in the engine compartment, the engine coolant temperature, the exhaust temperature before and after the oxidation catalyst in the DPF, the hydraulic fluid temperature, the target fuel injection amount, etc. 【0124】 Next, the control device 30 executes a process P05 to acquire sensor detection values, for example, as shown in Figure 5. In this process P05, the load factor control unit 303 of the control device 30 acquires the tilt angle of the main pump 14 detected by the tilt angle sensor S7, as shown in Figure 4. The load factor control unit 303 also acquires the rotation speed RF of the power source 11 detected by the rotation speed sensor S8. The load factor control unit 303 also acquires the discharge pressure of the main pump 14 detected by the discharge pressure sensor 28. 【0125】 Next, the control device 30 executes a process P06 to calculate the discharge amount of the hydraulic pump, for example, as shown in Figure 5. In this process P06, the load ratio control unit 303 of the control device 30 calculates the discharge amount of the main pump 14, which is a hydraulic pump, based on the tilt angle of the main pump 14 obtained from the tilt angle sensor S7 in the previous process P05 and the rotation speed RF of the power source 11 obtained from the rotation speed sensor S8. 【0126】 Next, the control device 30 executes a process P07 to calculate the drive torque Tp of the hydraulic pump, for example, as shown in Figure 5. In this process P07, the load ratio control unit 303 of the control device 30 calculates the drive torque Tp of the main pump 14 based on the discharge amount of the main pump 14 calculated in the previous process P06 and the discharge pressure of the main pump 14 obtained from the discharge pressure sensor 28 in the preceding process P05. 【0127】 Next, the control device 30 executes a process P08 to calculate the load factor LR of the power source 11, for example, as shown in Figure 5. In this process P08, the load factor control unit 303 of the control device 30 calculates the load factor LR of the power source 11 based on the drive torque Tp of the main pump 14, which is a hydraulic pump, calculated in the previous process P07, and the maximum torque Tmax of the power source 11 driving the main pump 14 at rotational speed RF. As mentioned above, the data for the maximum torque Tmax of the power source 11 at each rotational speed is stored in advance, for example, in the auxiliary storage device 30A. 【0128】 Next, the control device 30 performs a process P09 to control the load factor LR of the power source 11, for example, as shown in Figure 5. As mentioned above, the load factor LR of the power source 11 is determined by the drive torque Tp of the main pump 14 and the maximum torque Tmax at the rotational speed RF of the power source 11 that drives the main pump 14. The drive torque Tp of the main pump 14 is determined by the tilt angle of the main pump 14 and the discharge pressure of the main pump 14. The discharge pressure of the main pump 14 is determined by the discharge volume of the main pump 14 and the opening area of ​​the throttle 18, and the discharge volume of the main pump 14 is determined by the tilt angle of the main pump 14 and the rotational speed of the power source 11. 【0129】 Therefore, in this process P09, the load factor control unit 303 of the control device 30 sets the target tilt angle of the main pump 14 and the target rotational speed of the power source 11, for example, so that the load factor LR of the power source 11 does not exceed the maximum load factor LRmax. The flow rate control unit 304 controls the regulator 13 to control the tilt angle of the main pump 14 to the target tilt angle set by the load factor control unit 303. 【0130】 Furthermore, the rotational speed control unit 305 controls the power source 11 to control its rotational speed to a target rotational speed set by the load ratio control unit 303. Specifically, if the power source 11 is an engine, the rotational speed control unit 305 controls the rotational speed RF of the power source 11 to the target rotational speed by, for example, controlling the intake air volume or fuel injection volume. If the power source 11 is an electric motor, the rotational speed control unit 305 controls the rotational speed RF of the power source 11 to the target rotational speed by, for example, controlling the inverter. 【0131】 As a result, the power source 11 is driven at a load ratio LR that does not exceed the maximum load ratio LRmax at the set target rotational speed, generating the required amount of heat needed for the heat utilization mode. Consequently, the objectives of the heat utilization mode, which utilizes the heat generated by the operation of the power source 11, are achieved, such as preventing freezing of the blow-by gas passage, preventing freezing of urea water, DPF regeneration, warming up the hydraulic drive system, or heating operation of the air conditioner. 【0132】 Furthermore, in this process P09, the load factor control unit 303 of the control device 30 may control the load factor LR of the power source 11 so that, for example, the temperature of the part that utilizes the temperature of the power source 11 maintains a preset target temperature. Specifically, the load factor control unit 303 acquires the target temperature for the heat utilization mode using temperature sensors, such as the air temperature in the engine compartment, the engine coolant temperature, the exhaust temperature before and after the oxidation catalyst in the DPF, and the hydraulic oil temperature. Target temperatures are set in advance for these temperatures and stored in the auxiliary storage device 30A of the control device 30. 【0133】 In this case, the load factor control unit 303 sets the target tilt angle of the main pump 14 and the target rotational speed of the power source 11 so that the temperature acquired by the temperature sensor maintains the target temperature. Specifically, if the temperature acquired by the temperature sensor is lower than the target temperature, the load factor control unit 303 increases at least one of the target tilt angle of the main pump 14 and the target rotational speed of the power source 11 so that the load factor LR of the power source 11 increases. Conversely, if the temperature acquired by the temperature sensor is higher than the target temperature, the load factor control unit 303 decreases at least one of the target tilt angle of the main pump 14 and the target rotational speed of the power source 11 so that the load factor LR of the power source 11 decreases. 【0134】 As a result, the power source 11 is driven at a load factor LR that does not exceed the maximum load factor LRmax at the set target rotational speed, generating the required amount of heat needed for the heat utilization mode. Consequently, the objectives of the heat utilization mode, which utilizes the heat generated by the operation of the power source 11, are achieved, such as preventing freezing of the blow-by gas passage, preventing freezing of urea water, DPF regeneration, warming up the hydraulic drive system, or heating operation of the air conditioner. Furthermore, by setting a target temperature, the load factor LR of the power source 11 is prevented from rising more than necessary, improving energy efficiency. 【0135】 Furthermore, if the temperature acquired by the temperature sensor does not reach the target temperature even when the power source 11 is driven at the maximum load rate LRmax, the load rate control unit 303 of the control device 30 may notify the operator of the shovel 100 of this fact, for example, via the display device D1. In this case, the load rate control unit 303 may, for example, accept permission from the operator to drive the power source 11 at a load rate LR exceeding the maximum load rate LRmax, via the input device D2. When the aforementioned permission is input via the input device D2, the load rate control unit 303 sets, for example, a target tilt angle of the main pump 14 and a target rotational speed of the power source 11 to drive the power source 11 at a load rate LR exceeding the maximum load rate LRmax, with a time limit. 【0136】 As a result, the power source 11 is driven at a load ratio LR that temporarily exceeds the maximum load ratio LRmax at the set target rotational speed, generating the required amount of heat needed for the heat utilization mode. Consequently, the objectives of the heat utilization mode, which utilizes the heat generated by the operation of the power source 11, are achieved, such as preventing freezing of the blow-by gas passage, preventing freezing of the urea solution, DPF regeneration, warming up the hydraulic drive system, or heating operation of the air conditioner. 【0137】 Next, the control device 30 executes a process P10 to determine the termination of the heat utilization mode, for example, as shown in Figure 5. In this process P10, the load factor control unit 303 of the control device 30 determines whether or not the termination conditions for the heat utilization mode are met. If the load factor control unit 303 determines that the termination conditions for the heat utilization mode are not met (NO), the control device 30 repeatedly executes processes P05 to P10 described above. On the other hand, if the load factor control unit 303 determines in this process P10 that the termination conditions for the heat utilization mode are met (YES), the control device 30 terminates the processing flow shown in Figure 5 and repeats it at a predetermined cycle. 【0138】 The termination conditions for the heat utilization mode in this process P10 are not particularly limited. Specifically, the termination conditions for the heat utilization mode include, for example, a predetermined time elapsed after the temperature at a predetermined location detected by a temperature sensor reached the target temperature. Alternatively, the termination conditions for the heat utilization mode may include, for example, the power source 11 being driven for a predetermined time at a load rate LR equal to or greater than the minimum load rate LRmin. 【0139】 The operation of the excavator 100, control device 30, and control program of this embodiment will be explained below in comparison with the work vehicle described in Patent Document 1 mentioned above. 【0140】 In the work vehicle described in Patent Document 1 mentioned above, the control unit controls various operations of the work vehicle based on the engine exhaust temperature, the differential pressure between the upstream and downstream exhaust of the exhaust purification device, and the engine load rate. Furthermore, in this conventional work vehicle, when the operating lever for operating the work implement is not operated, the control unit switches and drives an electromagnetic switching valve, and guides hydraulic fluid to the oil cooler via a hydraulic load means, thereby increasing the load applied to the engine. 【0141】 With this configuration, the conventional work vehicle described in Patent Document 1 enables stable continuous regeneration of the DPF. However, in this conventional work vehicle, when the load applied to the engine is increased, the pressure of the hydraulic fluid may increase excessively as the engine speed increases, potentially placing an excessive burden on the hydraulic drive system. 【0142】 In contrast, the excavator 100, a construction machine of this embodiment, includes an attachment AT, a hydraulic actuator that drives the attachment AT, and control valves 171-176 that control the flow rate and direction of the hydraulic fluid supplied to the hydraulic actuator. The excavator 100 also includes a main pump 14, which is a hydraulic pump that supplies hydraulic fluid to the hydraulic actuator via the control valves 171-176, a power source 11 that drives the main pump 14, and a regulator 13 that controls the discharge amount of the main pump 14. Furthermore, the excavator 100 includes a control device 30 that controls the control valves 171-176, the power source 11, and the regulator 13. In a heat utilization mode that increases the load factor LR of the power source 11, the control device 30 sets the maximum load factor LRmax of the power source 11 according to the rotational speed RF of the power source 11. 【0143】 With this configuration, in the heat utilization mode in which the load factor LR of the power source 11 is increased, the load factor LR of the power source 11 can be controlled to be less than or equal to the maximum load factor LRmax corresponding to the rotational speed of the power source 11, thereby preventing the discharge pressure of the main pump 14 from rising excessively. Specifically, the load factor LR of the power source 11 required to drive the power source 11 and generate the required amount of heat in the heat utilization mode decreases as the rotational speed RF of the power source 11 increases. Therefore, if the maximum load factor LRmax of the power source 11 is set to a constant load factor LR7 regardless of the rotational speed RF of the power source 11, as shown by the dashed line in Figure 6, for example, the discharge pressure of the main pump 14 may rise as the rotational speed RF of the power source 11 increases, potentially placing an excessive burden on the hydraulic drive system. On the other hand, according to the excavator 100 of this embodiment, as shown by the solid line in Figure 6, the maximum load factor LRmax of the power source 11 can be reduced in accordance with the increase in the rotational speed RF of the power source 11, thereby suppressing an excessive rise in the discharge pressure of the main pump 14. As a result, excessive load on the hydraulic drive system, including the control valves 171-176 of the control valve unit 17, is prevented, improving the reliability and safety of the shovel 100. 【0144】 Furthermore, in the heat utilization mode, the control device 30 of the excavator 100, which is a construction machine in this embodiment, sets the maximum load ratio LRmax so that the discharge pressure of the main pump 14, which is a hydraulic pump, does not exceed the upper limit pressure of the hydraulic drive system including the control valves 171-176. 【0145】 With this configuration, in the heat utilization mode of construction machinery such as the excavator 100, the load factor LR of the power source 11 is kept below the maximum load factor LRmax, thereby maintaining the discharge pressure of the main pump 14 below the upper limit pressure of the hydraulic drive system. Therefore, in the heat utilization mode of construction machinery such as the excavator 100, the burden on the hydraulic drive system, including the control valves 171-176, can be further reduced. 【0146】 Furthermore, in the heat utilization mode, the control device 30 of the excavator 100, which is a construction machine in this embodiment, controls the load rate of the power source 11 so that the temperature of the part that utilizes the heat of the power source 11 is maintained at a preset target temperature. 【0147】 With this configuration, in the heat utilization mode of construction machinery such as the shovel 100, the load factor LR is maintained at a level that does not exceed the maximum load factor LRmax, and the power source 11 can be driven at the minimum load factor LR required for the parts that utilize the heat of the power source 11. Therefore, an excessive increase in the load factor LR of the power source 11 is suppressed, and the energy efficiency of the shovel 100 is improved. 【0148】 Furthermore, in the heat utilization mode, the control device 30 of the excavator 100, which is a construction machine in this embodiment, sets the minimum load rate LRmin of the power source 11 according to the lower limit of the required amount of heat generated by driving the power source 11. 【0149】 With this configuration, in the heat utilization mode of construction machinery such as the shovel 100, by maintaining the power source 11 at a load rate LR of LR or higher than the minimum load rate LRmin, the amount of heat generated by driving the power source 11 is maintained above the lower limit of the required heat amount. As a result, the objectives of the heat utilization mode that utilizes the heat generated by driving the power source 11 can be achieved more reliably, for example, to prevent freezing of blow-by gas passages, prevent freezing of urea water, DPF regeneration, warm-up operation of hydraulic drive systems, and heating operation of air conditioning. 【0150】 Furthermore, in the excavator 100, which is a construction machine of this embodiment, the control device 30 calculates the load ratio LR of the power source 11 based on the drive torque Tp of the main pump 14, which is a hydraulic pump, and the maximum torque Tmax at the rotational speed RF of the power source 11 that drives the main pump 14. 【0151】 With this configuration, the control device 30 can calculate the load factor LR using the drive torque Tp of the main pump 14 and the maximum torque Tmax at the rotational speed RF of the power source 11 at that time. Therefore, the control device 30 can control the drive torque Tp of the main pump 14 or the rotational speed RF of the power source 11 so that the load factor LR of the power source 11 does not exceed the maximum load factor LRmax. 【0152】 Furthermore, the excavator 100, which is a construction machine in this embodiment, is equipped with a tilt angle sensor S7 for detecting the tilt angle of the main pump 14, which is a hydraulic pump, a rotation speed sensor S8 for detecting the rotation speed RF of the power source 11, and a discharge pressure sensor 28 for detecting the discharge pressure of the main pump 14.The control device 30 calculates the discharge amount of the main pump 14 based on the tilt angle obtained from the tilt angle sensor S7 and the rotation speed RF obtained from the rotation speed sensor S8.The control device 30 also calculates the drive torque Tp of the main pump 14 based on the calculated discharge amount and the discharge pressure obtained from the discharge pressure sensor 28. 【0153】 With this configuration, the drive torque Tp of the main pump 14 can be calculated using the detection results of the tilt angle sensor S7, the rotation speed sensor S8, and the discharge pressure sensor 28. Based on this drive torque Tp and the maximum torque Tmax of the power source 11, the load ratio LR of the power source 11 can be calculated. Therefore, the control device 30 can control the tilt angle of the main pump 14 or the rotation speed RF of the power source 11 so that the load ratio LR of the power source 11 does not exceed the maximum load ratio LRmax. 【0154】 Furthermore, in the excavator 100, which is a construction machine of this embodiment, the control device 30 controls the tilt angle of the main pump 14 or the rotational speed RF of the power source 11 so that the load ratio LR of the power source 11 does not exceed the maximum load ratio LRmax. 【0155】 With this configuration, the control device 30 can prevent the load factor LR of the power source 11 from exceeding the maximum load factor LRmax by feedback control of at least one of the tilt angle of the main pump 14 and the rotational speed RF of the power source 11. 【0156】 Furthermore, the control device 30 of this embodiment controls construction machinery such as an excavator 100. The excavator 100, which is construction machinery, is equipped with an attachment AT, a hydraulic actuator that drives the attachment AT, and control valves 171-176 that control the flow rate and direction of the hydraulic fluid supplied to the hydraulic actuator. The excavator 100 is also equipped with a main pump 14 as a hydraulic pump that supplies hydraulic fluid to the hydraulic actuator via the control valves 171-176, a power source 11 that drives the main pump 14, and a regulator 13 that controls the discharge amount of the main pump 14. In the heat utilization mode in which the load factor LR of the power source 11 is increased, the control device 30 sets the maximum load factor LRmax of the power source 11 according to the rotational speed RF of the power source 11. 【0157】 With this configuration, the control device 30 of this embodiment can achieve the same effects as the excavator 100, which is the construction machine of this embodiment described above. Specifically, in the heat utilization mode of the excavator 100, which increases the load ratio LR of the power source 11, the control device 30 controls the load ratio LR of the power source 11 to be less than or equal to the maximum load ratio LRmax corresponding to the rotational speed of the power source 11, thereby preventing the discharge pressure of the main pump 14 from rising excessively. Therefore, the control device 30 of this embodiment can prevent the hydraulic drive system, including the control valves 171-176, from becoming excessively burdened in construction machines such as the excavator 100, thereby improving the reliability and safety of the construction machine. 【0158】 Furthermore, the control program of this embodiment is a control program for the control device 30 of a construction machine, an excavator 100. As described above, the excavator 100 includes an attachment AT, a hydraulic actuator that drives the attachment AT, and control valves 171-176 that control the flow rate and direction of the hydraulic fluid supplied to the hydraulic actuator. The excavator 100 also includes a main pump 14 as a hydraulic pump that supplies hydraulic fluid to the hydraulic actuator via the control valves 171-176, a power source 11 that drives the main pump 14, and a regulator 13 that controls the discharge amount of the main pump 14. In the heat utilization mode in which the load rate LR of the power source 11 is increased, the control program of this embodiment causes the control device 30 to set the maximum load rate LRmax of the power source 11 according to the rotational speed RF of the power source 11. 【0159】 With this configuration, the control program of this embodiment can achieve the same effects as the control device 30 of the embodiment described above. Specifically, the control program of this embodiment operates the control device 30 as described above, and in the heat utilization mode of the shovel 100, controls the load ratio LR of the power source 11 to be less than or equal to the maximum load ratio LRmax corresponding to the rotational speed of the power source 11, thereby preventing the discharge pressure of the main pump 14 from rising excessively. Therefore, the control program of this embodiment can prevent the hydraulic drive system, including the control valves 171-176, from becoming excessively burdened in construction machinery such as the shovel 100, thereby improving the reliability and safety of the construction machinery. 【0160】 Next, another embodiment of the control device according to the present disclosure will be described with reference to Figure 7. Figure 7 is a schematic configuration diagram showing an embodiment of the control device according to the present disclosure. The remote control device 30E, as the control device of this embodiment, constitutes part of the construction machine operation system SYS. 【0161】 The construction machinery operation system SYS of this embodiment includes, for example, a construction machine such as an excavator 100 and a remote control room RC. Since the excavator 100 shown in Figure 7 has the same configuration as the excavator 100 shown in Figure 1, the detailed configuration of the excavator 100 is omitted from the illustration. 【0162】 The shovel 100 and the remote control room RC are connected to each other so that data can be sent and received via the remote communication device 60E and the communication line NW. Alternatively, the shovel 100 and the remote control room RC may be connected to each other so that data can be sent and received directly without using the communication line NW. In the illustrated example, the shovel 100 transmits information about the work site and the detection results of each sensor to the remote control room RC. This allows the remote operator RO in the remote control room RC to understand the situation at the work site and the status of the shovel 100 based on the information from the shovel 100. 【0163】 The shovel 100 is equipped with a sensor capable of recognizing the position and shape of objects present at the work site in three dimensions. Specifically, as shown in Figure 1, the shovel 100 is equipped with an external sensor 70. The shovel 100 can transmit the measurement results of the external sensor 70, which measures the work site in three dimensions, to the remote control room RC. 【0164】 The external sensor 70 is a device for recognizing the space surrounding the shovel 100. The external sensor 70 is, for example, a LiDAR. The LiDAR measures the distance between each of more than 1 million points within the monitoring range and the LiDAR itself. The external sensor 70 can be any device capable of measuring the distance to an object. For example, the external sensor 70 may be a stereo camera, or a combination of an imaging device S6 and a ranging device such as a millimeter-wave radar. 【0165】 The operating system SYS may include one or more excavators 100. If the operating system SYS includes multiple excavators 100, a remote operator RO operating a specific excavator 100 can obtain information about the work sites obtained by that specific excavator 100, as well as information about the work sites obtained by one or more other excavators 100. 【0166】 The remote control room RC is equipped with a remote communication device 60E, a remote control device 30E, a remote control device 26E, an operation sensor 29E, and a remote output device 50E including a display device. The remote control room RC also has an operator's seat DS where the remote operator RO sits to remotely control the shovel 100. 【0167】 The remote communication device 60E is configured to communicate with the communication device T1 attached to the shovel 100. 【0168】 The remote control device 30E is a computing device that performs various calculations. In this embodiment, the remote control device 30E has the same configuration as the control device 30 shown in Figures 2 and 4. That is, similar to the control device 30 mounted on the shovel 100, the remote control device 30E sets the maximum load rate LRmax of the power source 11 according to the rotational speed RF of the power source 11 in the heat utilization mode which increases the load rate of the power source 11 of the shovel 100. 【0169】 The display device included in the remote output device 50E is a device capable of displaying various types of information. The display device displays images based on information transmitted from the shovel 100 so that the remote operator RO in the remote control room RC can visually inspect the area around the shovel 100. The display device of the remote output device 50E is a liquid crystal display that displays images captured by the imaging device S6 mounted on the shovel 100 or objects detected by the external sensor 70. The display device may also be a display or projector that enables naked-eye stereoscopic viewing, or it may be a VR goggle or the like. 【0170】 The remote control device 26E is equipped with an operation sensor 29E for detecting the operation of the remote control device 26E. The operation sensor 29E is, for example, a tilt sensor that detects the tilt angle of the operating lever, or an angle sensor that detects the oscillation angle of the operating lever around its pivot axis. The operation sensor 29E may also consist of other sensors such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operation sensor 29E outputs information regarding the operation of the remote control device 26E that it has detected to the remote control device 30E. The remote control device 30E generates an operation signal based on the received information and transmits the generated operation signal to the shovel 100. The operation sensor 29E may be configured to generate the operation signal. In this case, the operation sensor 29E may output the operation signal to the remote communication device 60E without going through the remote control device 30E. With this configuration, the remote operator RO can remotely operate the shovel 100 from the remote control room RC. 【0171】 As described above, the remote control device 30E of this embodiment controls construction machinery such as an excavator 100. The excavator 100, which is construction machinery, is equipped with an attachment AT, a hydraulic actuator that drives the attachment AT, and control valves 171-176 that control the flow rate and direction of the hydraulic fluid supplied to the hydraulic actuator. The excavator 100 is also equipped with a main pump 14 as a hydraulic pump that supplies hydraulic fluid to the hydraulic actuator via the control valves 171-176, a power source 11 that drives the main pump 14, and a regulator 13 that controls the discharge amount of the main pump 14. In the heat utilization mode, which increases the load factor LR of the power source 11, the remote control device 30E sets the maximum load factor LRmax of the power source 11 according to the rotational speed RF of the power source 11. 【0172】 With this configuration, the remote control device 30E of this embodiment can achieve the same effects as the control device 30 described above. Specifically, in the heat utilization mode of the shovel 100 in which the load ratio LR of the power source 11 is increased, the remote control device 30E can control the load ratio LR of the power source 11 to be less than or equal to the maximum load ratio LRmax corresponding to the rotational speed of the power source 11, thereby preventing the discharge pressure of the main pump 14 from rising excessively. Therefore, the remote control device 30E of this embodiment can prevent the hydraulic drive system, including the control valves 171-176, from becoming excessively burdened in construction machinery such as the shovel 100, thereby improving the reliability and safety of the construction machinery. 【0173】 Preferred embodiments of the present disclosure have been described above. However, the inventions of the present disclosure are not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the inventions of the present disclosure. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict each other technically. 【0174】 In the above-described embodiment, an example was explained in which the maximum load ratio of the power source was controlled by adjusting the driving torque of the main pump, which is a hydraulic pump, by keeping the aperture area of ​​the throttling constant and varying the discharge amount by adjusting the tilt angle of the main pump. However, the maximum load ratio may also be controlled by adjusting the driving torque of the main pump by making the aperture area of ​​the throttling variable. Furthermore, if the power source is an engine, the load ratio of the power source may be controlled by controlling the intake air volume and fuel injection volume. 【0175】 This disclosure is also applicable to construction machinery other than excavators, such as cranes, wheel loaders, bulldozers, forklifts, dump trucks, application machines, forestry machinery, or transport machines based on hydraulic excavators. [Explanation of Symbols] 【0176】 2A Swivel Motor (Hydraulic Actuator) 2ML Left-hand drive motor (hydraulic actuator) 2MR Right-hand drive motor (hydraulic actuator) 7. Boom Cylinder (Hydraulic Actuator) 8. Arm Cylinder (Hydraulic Actuator) 9. Bucket cylinder (hydraulic actuator) 11 Power source 13 Regulator 14. Main pump (hydraulic pump) 28 Discharge pressure sensor 30 Control device 30E Remote Control Device (Control Device) 100 Shovel (Construction Machinery) 171 Control valve (hydraulic drive system) 172 Control valve (hydraulic drive system) 173 Control valve (hydraulic drive system) 174 Control valve (hydraulic drive system) 175 Control valve (hydraulic drive system) 176 Control valve (hydraulic drive system) AT attachment LR load factor LRmax Maximum load factor LRmin Minimum load factor RF rotation speed S7 Tilt Angle Sensor S8 Rotation speed sensor Tp drive torque Tmax Maximum Torque

Claims

[Claim 1] Attachments and, A hydraulic actuator for driving the aforementioned attachment, A control valve that controls the flow rate and direction of the hydraulic fluid supplied to the hydraulic actuator, A hydraulic pump that supplies hydraulic fluid to the hydraulic actuator via the control valve, A power source for driving the aforementioned hydraulic pump, A regulator that controls the discharge amount of the hydraulic pump, The system comprises a control device that controls the control valve, the power source, and the regulator, In a heat utilization mode in which the load factor of the power source is increased, the control device sets the maximum load factor of the power source according to the rotational speed of the power source. Construction machinery. [Claim 2] The control device sets the maximum load ratio in the heat utilization mode such that the discharge pressure of the hydraulic pump does not exceed the upper limit pressure of the hydraulic drive system including the control valve. The construction machine according to claim 1. [Claim 3] The control device controls the load rate of the power source in the heat utilization mode so that the temperature of the part that utilizes the heat of the power source is maintained at a preset target temperature. The construction machine according to claim 2. [Claim 4] The control device sets the minimum load factor of the power source in the heat utilization mode according to the lower limit of the required amount of heat generated by driving the power source. The construction machine according to claim 1. [Claim 5] The control device calculates the load ratio of the power source based on the driving torque of the hydraulic pump and the maximum torque at the rotational speed of the power source driving the hydraulic pump. The construction machine according to claim 1. [Claim 6] The system includes a tilt angle sensor for detecting the tilt angle of the hydraulic pump, a rotation speed sensor for detecting the rotation speed of the power source, and a discharge pressure sensor for detecting the discharge pressure of the hydraulic pump. The control device is Based on the tilt angle obtained from the tilt angle sensor and the rotation speed obtained from the rotation speed sensor, the discharge amount of the hydraulic pump is calculated. The drive torque of the hydraulic pump is calculated based on the calculated discharge volume and the discharge pressure obtained from the discharge pressure sensor. The construction machine according to claim 5. [Claim 7] The control device controls the tilt angle or rotational speed so that the load ratio of the power source does not exceed the maximum load ratio. The construction machine according to claim 6. [Claim 8] A control device for controlling the control valve, the power source, and the regulator of a construction machine comprising: an attachment; a hydraulic actuator for driving the attachment; a control valve for controlling the flow rate and direction of hydraulic fluid supplied to the hydraulic actuator; a hydraulic pump for supplying hydraulic fluid to the hydraulic actuator via the control valve; a power source for driving the hydraulic pump; and a regulator for controlling the discharge amount of the hydraulic pump, wherein In a heat utilization mode in which the load factor of the power source is increased, the maximum load factor of the power source is set according to the rotational speed of the power source. Control device. [Claim 9] A control program for a control device of a construction machine comprising: an attachment; a hydraulic actuator for driving the attachment; a control valve for controlling the flow rate and direction of hydraulic fluid supplied to the hydraulic actuator; a hydraulic pump for supplying hydraulic fluid to the hydraulic actuator via the control valve; a power source for driving the hydraulic pump; a regulator for controlling the discharge amount of the hydraulic pump; and a control device for controlling the control valve, the power source, and the regulator. In a heat utilization mode in which the load factor of the power source is increased, the control device is instructed to set the maximum load factor of the power source according to the rotational speed of the power source. Control program.

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