Construction machinery

Abstract

To provide a construction machine that allows an operator to recognize drive limitations of a hydraulic actuator based on detection of surrounding objects, by a feeling in the body.SOLUTION: A construction machine comprises: first and second operating devices 6, 7, 8 operating first and second hydraulic actuators 22, 23, 5; a gate lock device 9 switching an operation of the operating devices between enabled and disabled; object detection devices 36, 37, 38 detecting objects within a predetermined area; and a control device 70 capable of limiting drive of each hydraulic actuator. When the gate lock device is switched to enable operation of the operating device and the operating device is in a neutral state, in a case where operation of one operating device is started in a situation where it is determined that there is an object within the predetermined area based on an output of the object detection device, the control device allows drive of the hydraulic actuator corresponding to the operation until a predetermined time Δt1 elapses from the start point of the operation, and prohibits the drive of the hydraulic actuator after the predetermined time elapses.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to construction machinery, and more particularly to construction machinery provided with an object detection device for detecting an object existing around the construction machinery.

Background Art

[0002] Construction machinery such as a hydraulic excavator includes a gate lock lever as a safety device for preventing the hydraulic actuator from being driven unintentionally. The gate lock lever can be switched between a lock position for invalidating the operation of the hydraulic actuator by the operation device and a lock release position for validating the operation of the hydraulic actuator by the operation device. The operator of the construction machinery enables the operation device by switching the gate lock lever from the lock position to the lock release position at the start of work.

[0003] The excavator described in Patent Document 1 includes an operation device for operating a hydraulic actuator, an object detection device for detecting an object within a predetermined area set around the excavator, a gate lock lever for switching between an enabled state and a disabled state of the operation device, and a controller for switching between an enabled state and a disabled state of the operation device separately from the gate lock lever. When the excavator is in a standby state, the controller invalidates the operation device when the operation device is switched to the enabled state by the gate lock lever and it is determined that an object exists within the predetermined area based on the output of the object detection device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The excavator described in Patent Document 1 is equipped with multiple hydraulic actuators, such as a hydraulic motor for travel as a drive source for the lower traveling body and a hydraulic motor for slewing the upper slewing body, and multiple operating devices for operating them, and the controller can be configured to individually switch between the enabled and disabled states of the multiple operating devices. It is also possible to display a screen on the display device that shows the positional relationship between an object detected by an object detection device and the excavator body.

[0006] In an excavator with such a configuration, if the controller determines that an object is present within a predetermined area based on the output of the object detection device and switches one of the multiple operating devices to a disabled state, it is preferable for the operator to be able to recognize which of the multiple hydraulic actuators is unable to drive. However, in the excavator described in Patent Document 1, it is difficult to identify the hydraulic actuator that is unable to drive based on the display screen shown on the display device. Therefore, in order to notify the operator of a disabled operating device or a hydraulic actuator that is unable to drive, it is conceivable to display icons or text information on the display device or output sound from the speaker. However, it is conceivable that the operator may overlook the icons or text information on the display device because they are intently watching the work object, or that the sound from the speaker may be drowned out by engine noise, etc. For this reason, it is considered effective for the operator to recognize which hydraulic actuator is prohibited from being driven by the operation of the operating device through the feel (tactile sensation) of the operating device.

[0007] The present invention is based on the above-mentioned matters, and its purpose is to provide a construction machine that allows the operator to recognize, through tactile sensation (the feel of operating the control device), that the operation of a hydraulic actuator is prohibited due to the detection of objects around the construction machine. [Means for solving the problem]

[0008] The present invention includes multiple means for solving the above problems, but to give one example, in a construction machine comprising a first hydraulic actuator, a second hydraulic actuator, a first operating device for operating the first hydraulic actuator, a second operating device for operating the second hydraulic actuator, a switching device capable of switching the operation of the first operating device and the second operating device to an enabled or disabled state, an object detection device for detecting an object present in a predetermined area, and a control device capable of individually restricting the driving of the first hydraulic actuator and the second hydraulic actuator, the control device is characterized in that, when the switching device is switched to enable the operation of the first operating device and the second operating device and the first operating device and the second operating device are in a neutral state, and the object detection device is determined to be present in the predetermined area based on the output of the object detection device, when operation of one of the first operating device and the second operating device is started, the control device allows the driving of one hydraulic actuator corresponding to the operation of the first operating device until a predetermined time has elapsed from the time the operation of the first operating device has been started, and after the predetermined time has elapsed, the driving of the one hydraulic actuator is prohibited. [Effects of the Invention]

[0009] According to the present invention, the operator can recognize the prohibition of driving the hydraulic actuator due to object detection around the construction machine through tactile sensation (the feel of operating the control device). Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0010] [Figure 1] This is an external view showing a hydraulic excavator as a first embodiment of the construction machinery of the present invention. [Figure 2] Figure 1 is a top view showing a construction machine according to the first embodiment, along with a monitoring area set around the construction machine. [Figure 3]This is a hydraulic circuit diagram showing the hydraulic system provided in a construction machine according to the first embodiment. [Figure 4] Figure 3 is a block diagram showing the hardware and functions of the control device according to the first embodiment. [Figure 5] This is an explanatory diagram regarding the determination of an object in the control device according to the first embodiment shown in Figure 4. [Figure 6] Figure 4 is a flowchart showing an example of the procedure for limiting the drive of the hydraulic actuator during a slewing operation by the control device according to the first embodiment. [Figure 7] Figure 4 shows a flowchart illustrating an example of the procedure for limiting the drive of a hydraulic actuator during travel operation using the control device according to the first embodiment. [Figure 8] This is a time chart showing the temporal changes in the operation of the control device, the operation of the controlled object, and the operation of the operating device in a construction machine according to the first embodiment. [Figure 9] Block diagram showing the hardware and functions of a control device in a construction machine according to a modified example of the first embodiment. [Figure 10] This flowchart shows an example of the procedure for limiting the drive of a hydraulic actuator during a slewing operation by a control device according to a modified example of the first embodiment shown in Figure 9. [Figure 11] This flowchart shows an example of a procedure for limiting the drive of a hydraulic actuator during travel operation by a control device according to a modified example of the first embodiment shown in Figure 9. [Figure 12] This is a time chart showing the temporal changes in the operation of the control device, the operation of the controlled object, and the operation of the operating device in a construction machine according to a modified example of the first embodiment. [Figure 13] This is a hydraulic circuit diagram showing the hydraulic system of a construction machine according to the second embodiment. [Figure 14] Figure 13 is a block diagram showing the hardware and functions of the control device according to the second embodiment. [Figure 15] This is a time chart showing the temporal changes in the operation of the control device and the operation of the controlled object in a construction machine according to the second embodiment. [Figure 16] A time chart showing the temporal changes in the operations of the control device and the controlled objects in a construction machine according to a modification of the second embodiment.

Best Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the construction machine of the present invention will be described with reference to the drawings. In this embodiment, a hydraulic excavator will be described as an example of the construction machine.

[0012] [First Embodiment] First, the configuration of a hydraulic excavator as a construction machine according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an external view showing a hydraulic excavator as the first embodiment of the construction machine of the present invention. FIG. 2 is a top view showing the construction machine according to the first embodiment shown in FIG. 1 together with a monitoring area set around the construction machine. Here, the description will be made using the direction seen from the operator seated in the driver's cab.

[0013] [[ID=2,0]]In FIG. 1, a hydraulic excavator as a construction machine includes a front working device 1 for performing operations such as excavation, and a machine body to which the front working device 1 is attached so as to be able to rise and fall. The machine body is composed of a self-propelled lower traveling body 2 and an upper revolving body 3 mounted on the lower traveling body 2 so as to be able to revolve.

[0014] The front work device 1 is a multi-jointed work device composed of multiple driven members rotatably connected. The multiple driven members consist of, for example, a boom 11, an arm 12, and a bucket 13 as a work tool (attachment). The base end of the boom 11 is attached to a boom foot (not shown) provided at the front of the upper slewing body 3 so as to be able to swing up and down. The base end of the arm 12 is attached to the tip of the boom 11 so as to be able to swing in the front and rear directions. The base end of the bucket 13 is attached to the tip of the arm 12 so as to be able to rotate up and down. The boom 11, arm 12, and bucket 13 are driven by hydraulic actuators, namely a boom cylinder 15, an arm cylinder 16, and a bucket cylinder 17, respectively. The boom cylinder 15 is connected to the boom foot and the side of the boom 11. The arm cylinder 16 is connected to the rear of the boom 11 and the base end of the arm 12. The bucket cylinder 17 is connected to the rear of the arm 12 and the rear of the bucket 13.

[0015] The lower traveling body 2 is equipped with, for example, crawler-type traveling devices 21 on the left and right sides (only the left side is shown). The left and right traveling devices 21 include hydraulic actuators, which are travel hydraulic motors 22 and 23 (see also Figure 3, described later), as the driving source for travel.

[0016] The upper slewing body 3 is configured to slewing relative to the lower traveling body 2 by, for example, a slewing hydraulic motor 5, which is a hydraulic actuator. The upper slewing body 3 includes a driver's cab 31 located on the front left side and a machine room 32 located behind the driver's cab 31. The driver's cab 31 is where the operator who operates the hydraulic excavator sits. The driver's cab 31 contains a driver's seat (not shown) where the operator sits and operating devices (see Figure 3 below) for operating each of the hydraulic actuators 5, 15, 16, 17, 22, and 23. A gate lock device 9 (see Figure 3 below) is located near the side of the driver's seat. The driver's cab 31 also contains a monitor device 34 and a speaker 35 (see Figure 3 below). Details of the operating devices 6, 7, and 8, the gate lock device 9, the monitor device 34, and the speaker 35 will be described later. The machine room 32 houses various pieces of equipment, including, for example, the hydraulic equipment that constitutes the hydraulic system 40 (see Figure 3 below).

[0017] The upper rotating body 3 is equipped with an object detection device that detects objects present within a predetermined area designated as a monitoring area around the hydraulic excavator. The object detection device consists of, for example, a rear camera 36 mounted on the upper rear end of the upper rotating body 3 to photograph the area behind the hydraulic excavator, a left-side camera 37 mounted on the upper left end of the upper rotating body 3 to photograph the area to the left of the hydraulic excavator, and a right-side camera 38 mounted on the upper right end of the upper rotating body 3 to photograph the area to the right of the hydraulic excavator. The rear camera 36, ​​left-side camera 37, and right-side camera 38, which function as the object detection device, output the captured images to the control device 70 (see Figure 3 below).

[0018] The predetermined area around the hydraulic excavator captured by cameras 36, 37, and 38, which act as object detection devices, is, for example, a rectangular area Rm enclosed by the dashed line shown in Figure 2. Area Rm is composed of, for example, a semicircular first area Rsw centered on the pivot center of the upper slewing body 3 and having a radius somewhat larger behind the distance from the pivot center to the rear end of the upper slewing body 3, and a second area Rtr enclosed by a pair of tangents extending in the front-rear direction of the lower traveling body 2 and touching at the position of the semicircular diameter in the first area Rsw, and a straight line extending in the width direction of the lower traveling body 2 and further rearward by a predetermined distance from the rear end of the upper slewing body 3. The first area Rsw is the area around the hydraulic excavator that the upper slewing body 3 is expected to pass through when the upper slewing body 3 rotates left and right relative to the lower traveling body 2. The second region Rtr is the area around the hydraulic excavator that is expected to be passed through when the lower traveling body 2 travels in the longitudinal direction while the upper rotating body 3 is rotating left and right relative to the lower traveling body 2. Note that the area in front of the operator's cab 31 of the upper rotating body 3 is excluded from the monitoring area of ​​the object detection device because the operator can visually see the object there.

[0019] Next, the configuration of the hydraulic system in the construction machine according to the first embodiment will be explained using Figure 3. Figure 3 is a hydraulic circuit diagram showing the hydraulic system provided in the construction machine according to the first embodiment.

[0020] In Figure 3, the hydraulic excavator is equipped with a hydraulic system 40 that drives the front working device 1, the lower traveling body 2, and the upper slewing body 3 (see Figure 1) by hydraulic pressure. Note that Figure 3 only shows the hydraulic circuits for the left and right travel hydraulic motors 22 and 23, which are the driving sources for the left and right traveling devices 21, and the hydraulic circuit for the slewing hydraulic motor 5 that rotates the upper slewing body 3. The hydraulic circuits for the boom cylinder 15, arm cylinder 16, bucket cylinder 17 that operate the front working device 1 are omitted.

[0021] The hydraulic system 40 includes a first hydraulic pump 41 and a second hydraulic pump 42, and a plurality of hydraulic actuators (left-side travel hydraulic motor 22, right-side travel hydraulic motor 23, and slewing hydraulic motor 5 in Figure 3) driven by pressurized oil discharged from the first hydraulic pump 41 and the second hydraulic pump 42. The first hydraulic pump 41 and the second hydraulic pump 42 are variable displacement pumps driven by, for example, a prime mover 43. The prime mover 43 is an engine or an electric motor. The pressurized oil discharged from the first hydraulic pump 41 and the second hydraulic pump 42 is supplied to the plurality of hydraulic actuators 22, 23, and 5 via a control valve unit 44.

[0022] The control valve unit 44 has multiple spools (only the left travel hydraulic motor 22, the right travel hydraulic motor 23, and the swing hydraulic motor 5 are shown in Figure 3) corresponding to each of the multiple hydraulic actuators. Each of the spools 45, 46, and 47 is hydraulically pilot operated and has a pair of pressure-receiving parts to which the operating pilot pressure acts.

[0023] Specifically, the left travel spool 45 functions as a control valve that controls the supply and discharge of pressurized oil to the left travel hydraulic motor 22, and is connected to the first hydraulic pump 41 and the hydraulic oil tank 49. In other words, the left travel spool 45 controls the direction and flow rate of pressurized oil supplied from the first hydraulic pump 41 to the left travel hydraulic motor 22. The left travel spool 45 has a pair of pressure-receiving parts 45a and 45b on which the operating pilot pressure acts, and is configured so that its position (stroke) changes according to the magnitude of the operating pilot pressure input to the pressure-receiving parts 45a and 45b.

[0024] The right-travel spool 46 functions as a control valve that controls the supply and discharge of pressurized oil to the right-side travel hydraulic motor 23, and is connected to the second hydraulic pump 42 and the hydraulic oil tank 49. In other words, the right-travel spool 46 controls the direction and flow rate of pressurized oil supplied from the second hydraulic pump 42 to the right-side travel hydraulic motor 23. The right-travel spool 46 has a pair of pressure-receiving parts 46a and 46b on which the operating pilot pressure acts, and is configured so that its position (stroke) changes according to the magnitude of the operating pilot pressure input to the pressure-receiving parts 46a and 46b.

[0025] The swivel spool 47 functions as a control valve that controls the supply and discharge of pressurized oil to the swivel hydraulic motor 5, and is connected to the first hydraulic pump 41 and the hydraulic oil tank 49. In other words, the swivel spool 47 controls the direction and flow rate of pressurized oil supplied from the first hydraulic pump 41 to the swivel hydraulic motor 5. The swivel spool 47 has a pair of pressure-receiving parts 47a and 47b on which the operating pilot pressure acts, and is configured so that its position (stroke) changes according to the magnitude of the operating pilot pressure input to the pressure-receiving parts 47a and 47b.

[0026] The hydraulic system 40 is configured to control the drive of corresponding hydraulic actuators (only the left-side travel hydraulic motor 22, right-side travel hydraulic motor 23, and slewing hydraulic motor 5 are shown in Figure 3) by operating each of the multiple operating devices (only the left-side travel operating device 6, right-side travel operating device 7, and slewing operating device 8 are shown in Figure 3) located in the driver's cab 31 (see Figure 1). Each operating device is, for example, a hydraulic pilot type and includes a pair of pilot valves that generate an operating pilot pressure (pilot secondary pressure) according to the direction and amount of operation. The hydraulic pressure from the pilot hydraulic source is supplied as the pilot primary pressure to the pair of pilot valves of each operating device. The pilot hydraulic source is, for example, a pilot pump 51 driven by the prime mover 43, and is, for example, a fixed-displacement type hydraulic pump.

[0027] Specifically, the left-travel operating device 6 operates the left-side travel hydraulic motor 22 and has one pilot valve 6a connected via a pilot line to one pressure-receiving section 45a of the left-travel spool 45, and the other pilot valve 6b connected via a pilot line to the other pressure-receiving section 45b of the left-travel spool 45. The primary sides of the pair of pilot valves 6a and 6b are connected to the pilot pump 51 via a pilot line 52. The left-travel operating device 6 generates an operating pilot pressure by reducing the discharge pressure (primary pilot pressure) of the pilot pump 51 according to the operating direction and amount, and outputs the generated operating pilot pressure to the pressure-receiving sections 45a and 45b of the left-travel spool 45.

[0028] The right-hand travel operating device 7 operates the right-hand travel hydraulic motor 23 and has one pilot valve 7a connected via a pilot line to one pressure-receiving section 46a of the right-hand travel spool 46, and the other pilot valve 7b connected via a pilot line to the other pressure-receiving section 46b of the right-hand travel spool 46. The primary sides of the pair of pilot valves 7a and 7b are connected to the pilot pump 51 via a pilot line 52. The right-hand travel operating device 7 generates an operating pilot pressure by reducing the discharge pressure of the pilot pump 51 according to the operating direction and amount of operation, and outputs the generated operating pilot pressure to the pressure-receiving sections 46a and 46b of the right-hand travel spool 46.

[0029] The slewing control device 8 operates the slewing hydraulic motor 5 and has one pilot valve 8a connected to one pressure-receiving section 47a of the slewing spool 47 via a pilot line, and the other pilot valve 8b connected to the other pressure-receiving section 47b of the slewing spool 47 via a pilot line. The primary sides of the pair of pilot valves 8a and 8b are connected to the pilot pump 51 via a pilot line 52. The slewing control device 8 generates an operating pilot pressure by reducing the discharge pressure of the pilot pump 51 according to the operating direction and amount of operation, and outputs the generated operating pilot pressure to the pressure-receiving sections 47a and 47b of the slewing spool 47.

[0030] The pilot valves 6a and 6b of the left travel control device 6, the pilot valves 7a and 7b of the right travel control device 7, and the pilot valves 8a and 8b of the slewing control device 8 are connected to the pilot pump 51 via a gate lock valve 53 on the pilot line 52. The gate lock valve 53 can be switched between either an effective position A, which enables all operations of the multiple control devices by allowing the supply of hydraulic pressure from the pilot pump 51 to all pilot valves of the multiple control devices, or an inactive position D, which disables all operations of the multiple control devices by shutting off the supply of hydraulic pressure from the pilot pump 51 to all pilot valves of the multiple control devices.

[0031] Specifically, the gate lock valve 53 has a first port connected to the pilot pump 51, a second port connected to the hydraulic oil tank 49, and a third port connected to all the pilot valves (in Figure 3, pilot valves 6a, 6b, 7a, 7b, and 8a, 8b) of the multiple operating devices (in Figure 3, pilot valves 6a, 6b, 7a, 7b, and 8a, 8b). The gate lock valve 53 switches between an effective position A, which connects the primary sides of all the pilot valves (in Figure 3, pilot valves 6a, 6b, 7a, 7b, and 8a, 8b) of the multiple operating devices to the pilot pump 51 (pilot hydraulic power source), and an ineffective position D, which connects the primary sides of all the pilot valves of the multiple operating devices to the hydraulic oil tank 49. The gate lock valve 53 is configured to switch between effective position A and ineffective position D depending on the operation of the gate lock device 9. The gate lock valve 53 is, for example, a solenoid valve electrically connected to the gate lock device 9, and is switched between an active position A and an inactive position D by a command signal (excitation current) from the gate lock device 9. The gate lock valve 53 is configured to be in the inactive position D when, for example, no excitation current is applied.

[0032] The gate lock device 9 switches all operations of multiple operating devices (left-travel operating device 6, right-travel operating device 7, and turning operating device 8 in Figure 3) to either an enabled or disabled state by controlling the position of the gate lock valve 53. The gate lock device 9 has a gate lock lever 9a that can be operated to a locked position L that opens the entrance to the driver's cab 31 or an unlocked position U that blocks the entrance to the driver's cab 31, and a gate lock switch 9b that switches the opening and closing of a signal circuit in conjunction with the operation of the gate lock lever 9a. For example, when the gate lock lever 9a is operated to the locked position L, the gate lock switch 9b is in an open state (off), and the gate lock device 9 outputs a disable instruction (off electrical signal) to the gate lock relay 9c and the control device 70, which disables all operations of the multiple operating devices. On the other hand, when the gate lock lever 9a is operated to the unlocked position U, the gate lock switch 9b is closed (on), and outputs an enable instruction (on electrical signal) to the gate lock relay 9c and the control device 70, which enables all operations of the multiple operating devices. The gate lock relay 9c outputs a command signal (excitation current) to control the drive of the gate lock valve 53 in accordance with the instruction signal (enable instruction or disabled instruction) from the gate lock switch 9b. When the instruction signal from the gate lock switch 9b is an enable instruction (on electrical signal), the gate lock relay 9c outputs a command signal (predetermined excitation current) to switch the gate lock valve 53 to the enabled position A. On the other hand, when the instruction signal from the gate lock switch 9b is a disabled instruction (off electrical signal), the gate lock relay 9c outputs a command signal (zero excitation current) to switch the gate lock valve 53 to the disabled position D. In other words, the gate lock device 9 switches the gate lock valve 53 to the disabled position D and outputs a disabled instruction to the control device 70 when the gate lock lever 9a is operated to the locked position L, while switching the gate lock valve 53 to the enabled position A and outputting an enabled instruction to the control device 70 when the gate lock lever 9a is operated to the unlocked position U.

[0033] In this embodiment, solenoid valves (only the first to sixth solenoid valves 54 to 59 are shown in Figure 3) are provided on the pilot lines connecting a pair of pilot valves of each operating device (in Figure 3, only the pilot valves 6a and 6b of the left travel operating device 6, the pilot valves 7a and 7b of the right travel operating device 7, and the pilot valves 8a and 8b of the swivel operating device 8 are shown) and a pair of pressure-receiving parts of each spool (in Figure 3, only the pressure-receiving parts 45a and 45b of the left travel spool 45, the pressure-receiving parts 46a and 46b of the right travel spool 46, and the pressure-receiving parts 47a and 47b of the swivel spool 47 are shown). Each solenoid valve is electrically connected to a control device 70, which will be described later, and limits (shuts off) the operating pilot pressure input from the pilot valves of each operating device to the pressure-receiving parts of each spool according to the commands of the control device 70. In other words, these solenoid valves make it possible to individually limit the driving of the hydraulic actuator by each operation of the multiple operating devices.

[0034] Specifically, the pair of pilot valves 6a and 6b of the left-travel operating device 6 are connected to the pair of pressure-receiving sections 45a and 45b of the left-travel spool 45 via the first solenoid valve 54 and the second solenoid valve 55 (left-travel solenoid valve), respectively. The first solenoid valve 54 and the second solenoid valve 55 each have, for example, a first port connected to the secondary side of one pilot valve 6a and the other pilot valve 6b of the left-travel operating device 6, a second port connected to the hydraulic oil tank 49, and a third port connected to one pressure-receiving section 45a and the other pressure-receiving section 45b of the left-travel spool 45. The first solenoid valve 54 and the second solenoid valve 55 are switchable between a first position in which one pressure-receiving part 45a and the other pressure-receiving part 45b of the left travel spool 45 are connected to the secondary sides of one pilot valve 6a and the other pilot valve 6b, and a second position in which one pressure-receiving part 45a and the other pressure-receiving part 45b of the left travel spool 45 are connected to the hydraulic oil tank 49. In other words, the left travel solenoid valves 54 and 55 are switchable between a first position in which the driving of the left travel hydraulic motor 22 is permitted by allowing the input of operating pilot pressure from the pilot valves 6a and 6b to the pressure-receiving parts 45a and 45b of the left travel spool 45, and a second position in which the driving of the left travel hydraulic motor 22 is prohibited by blocking the input of operating pilot pressure from the pilot valves 6a and 6b to the pressure-receiving parts 45a and 45b of the left travel spool 45. The left-travel solenoid valves 54 and 55 are proportional valves in which the opening degree of the passage connecting the pilot valves 6a and 6b to the pressure-receiving sections 45a and 45b of the left-travel spool 45 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) from the control device 70. This makes it possible to reduce and limit the operating pilot pressure output from the pilot valves 6a and 6b to the pressure-receiving sections 45a and 45b of the left-travel spool 45 according to the opening degree. The left-travel solenoid valves 54 and 55 are configured such that, for example, when no excitation current is applied, they are in a first position (the maximum opening degree of the passage described above), while as the excitation current (command signal) increases, the opening degree of the passage described above decreases until it reaches a second position.

[0035] The pair of pilot valves 7a and 7b of the right-travel operating device 7 are connected to the pair of pressure-receiving sections 46a and 46b of the right-travel spool 46 via the third solenoid valve 56 and the fourth solenoid valve 57 (right-travel solenoid valve), respectively. The third solenoid valve 56 and the fourth solenoid valve 57 each have, for example, a first port connected to the secondary side of one pilot valve 7a and the other pilot valve 7b of the right-travel operating device 7, a second port connected to the hydraulic oil tank 49, and a third port connected to one pressure-receiving section 46a and the other pressure-receiving section 46b of the right-travel spool 46. The third solenoid valve 56 and the fourth solenoid valve 57 are switchable between a first position in which one pressure-receiving part 46a and the other pressure-receiving part 46b of the right travel spool 46 are connected to the secondary sides of one pilot valve 7a and the other pilot valve 7b, and a second position in which one pressure-receiving part 46a and the other pressure-receiving part 46b of the right travel spool 46 are connected to the hydraulic oil tank 49. In other words, the right travel solenoid valves 56 and 57 are switchable between a first position in which the driving of the right travel hydraulic motor 23 is permitted by allowing the input of operating pilot pressure from the pilot valves 7a and 7b to the pressure-receiving parts 46a and 46b of the right travel spool 46, and a second position in which the driving of the right travel hydraulic motor 23 is prohibited by blocking the input of operating pilot pressure from the pilot valves 7a and 7b to the pressure-receiving parts 46a and 46b of the right travel spool 46. The right-travel solenoid valves 56 and 57 are proportional valves in which the opening degree of the passage connecting the pilot valves 7a and 7b and the pressure-receiving sections 46a and 46b of the right-travel spool 46 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) from the control device 70. This makes it possible to reduce and limit the operating pilot pressure output from the pilot valves 7a and 7b to the pressure-receiving sections 46a and 46b of the right-travel spool 46 according to the opening degree. The right-travel solenoid valves 56 and 57 are configured such that, for example, they are in a first position (maximum opening of the passage) when no excitation current is applied, while the opening degree of the passage decreases as the excitation current (command signal) increases, eventually reaching a second position.

[0036] The pair of pilot valves 8a and 8b of the swivel control device 8 are connected to the pair of pressure-receiving sections 47a and 47b of the swivel spool 47 via the fifth solenoid valve 58 and the sixth solenoid valve 59 (swivel solenoid valve), respectively. The fifth solenoid valve 58 and the sixth solenoid valve 59 each have, for example, a first port connected to the secondary side of one pilot valve 8a and the other pilot valve 8b of the swivel control device 8, a second port connected to the hydraulic oil tank 49, and a third port connected to one pressure-receiving section 47a and the other pressure-receiving section 47b of the swivel spool 47. The fifth solenoid valve 58 and the sixth solenoid valve 59 are switchable between a first position in which one pressure-receiving part 47a and the other pressure-receiving part 47b of the swivel spool 47 are connected to the secondary sides of one pilot valve 8a and the other pilot valve 8b, and a second position in which one pressure-receiving part 47a and the other pressure-receiving part 47b of the swivel spool 47 are connected to the hydraulic oil tank 49. In other words, the swivel solenoid valves 58 and 59 are switchable between a first position in which the drive of the swivel hydraulic motor 5 is permitted by allowing the input of operating pilot pressure from the pilot valves 8a and 8b to the pressure-receiving parts 47a and 47b of the swivel spool 47, and a second position in which the drive of the swivel hydraulic motor 5 is prohibited by blocking the input of operating pilot pressure from the pilot valves 8a and 8b to the pressure-receiving parts 47a and 47b of the swivel spool 47. The swivel solenoid valves 58 and 59 are proportional valves in which the opening degree of the passage connecting the pilot valves 8a and 8b and the pressure-receiving sections 47a and 47b of the swivel spool 47 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) from the control device 70. This makes it possible to reduce and limit the operating pilot pressure output from the pilot valves 8a and 8b to the pressure-receiving sections 47a and 47b of the swivel spool 47 according to the opening degree. The swivel solenoid valves 58 and 59 are configured such that, for example, they are in a first position (maximum opening of the passage) when no excitation current is applied, while the opening degree of the passage decreases as the excitation current (command signal) increases, eventually reaching a second position.

[0037] The left-travel control device 6 is equipped with a first pressure sensor 61 and a second pressure sensor 62 on the output side (secondary side) of the pilot valves 6a and 6b, respectively, to detect the operating pilot pressure generated by the pilot valves 6a and 6b. The first pressure sensor 61 and the second pressure sensor 62 are electrically connected to the control device 70 and output the detection signal of the operating pilot pressure of the pilot valves 6a and 6b to the control device 70. The first pressure sensor 61 and the second pressure sensor 62 function as operating amount detection devices to detect the amount of operation of the left-travel control device 6.

[0038] The output side (secondary side) of the pilot valves 7a and 7b of the right-hand travel control device 7 is provided with a third pressure sensor 63 and a fourth pressure sensor 64, which detect the operating pilot pressure generated by the pilot valves 7a and 7b. The third pressure sensor 63 and the fourth pressure sensor 64 are electrically connected to the control device 70 and output the detection signal of the operating pilot pressure of the pilot valves 7a and 7b to the control device 70. The third pressure sensor 63 and the fourth pressure sensor 64 function as operating amount detection devices that detect the amount of operation of the right-hand travel control device 7.

[0039] The output side (secondary side) of the pilot valves 8a and 8b of the swing control device 8 is provided with a fifth pressure sensor 65 and a sixth pressure sensor 66, which detect the operating pilot pressure generated by the pilot valves 8a and 8b. The fifth pressure sensor 65 and the sixth pressure sensor 66 are electrically connected to the control device 70 and output the detection signal of the operating pilot pressure of the pilot valves 8a and 8b to the control device 70. The fifth pressure sensor 65 and the sixth pressure sensor 66 function as operating amount detection devices that detect the amount of operation of the swing control device 8.

[0040] The control device 70 is electrically connected to a rear camera 36, ​​a left-side camera 37, and a right-side camera 38, which serve as object detection devices. The control device 70 is also electrically connected to a monitor device 34, which serves as a display device, and a speaker 35, which serves as a notification device, located in the driver's cab 31. The monitor device 34 displays a warning screen in response to commands from the control device 70. The speaker 35 emits a warning sound in response to commands from the control device 70.

[0041] The control device 70 receives the output signal from the gate lock switch 9b, the output signals from the object detection devices 36, 37, and 38, and the output signals from each pressure sensor 61 to 66. Based on these output signals, it performs predetermined calculation processing and outputs command signals to each solenoid valve 54 to 59, as well as to the monitoring device 34 and the speaker 35, according to the results of the calculation processing. Details of the configuration and functions of the control device 70 will be described later.

[0042] Next, the hardware configuration and functions of the control device, which constitutes a part of the construction machine according to the first embodiment, will be described using Figures 4 and 5. Figure 4 is a block diagram showing the hardware and functions of the control device according to the first embodiment shown in Figure 3. Figure 5 is an explanatory diagram relating to the determination of the object determination unit in the control device according to the first embodiment shown in Figure 4.

[0043] In Figure 4, the control device 70 according to this embodiment, in general terms, when all of the multiple operating devices 6, 7, and 8 (see Figure 3) are active due to the operation of the gate lock device 9 (see Figure 3), and when the operating devices 6, 7, and 8 are in a neutral state (standby state, not in operation), and it is determined that objects B1 and B2 have been detected in a predetermined area Rm around the hydraulic excavator shown in Figure 5 based on the output of cameras 36, 37, and 38, which are object detection devices, does not immediately disable the operation of the operating devices 6, 7, and 8, but rather allows the hydraulic actuator to be driven based on the operation of the operating devices 6, 7, and 8, and then controls the first solenoid valve 54 to the sixth solenoid valve 59 to prohibit the driving of the hydraulic actuator by the operation of the operating devices after a very short predetermined time has elapsed from the time the operation of the operating devices started. The control device 70 has a hardware configuration that includes, for example, a storage device 71 consisting of RAM or ROM, and a processing device 72 consisting of a CPU or MPU. The storage device 71 has programs and various information necessary for the control to prohibit the driving of the hydraulic actuator by the operation of the operating devices 6, 7, and 8 stored in advance. The processing unit 72 reads programs and various information from the storage device 71 as appropriate and executes processing according to the program, thereby realizing various functions including the following functions.

[0044] The control device 70 includes an operation determination unit 81, an object determination unit 82, an image processing unit 83, a control calculation unit 84, and an output processing unit 85, as functions executed by the processing unit 72.

[0045] The operation determination unit 81 determines whether all of the multiple operating devices 6, 7, and 8 are in an enabled or disabled state based on the operation of the gate lock device 9. Specifically, it determines whether the operation of the multiple operating devices 6, 7, and 8 is enabled or disabled based on the instruction signal from the gate lock switch 9b. If the instruction signal from the gate lock switch 9b is an ON signal (enabled instruction), it determines that the operation of the multiple operating devices 6, 7, and 8 is enabled. On the other hand, if the instruction signal from the gate lock switch 9b is an OFF signal (disabled instruction), it determines that the operation of the multiple operating devices 6, 7, and 8 is disabled.

[0046] Furthermore, the operation determination unit 81 determines whether each operating device 6, 7, and 8 is in a standby state (neutral state) or in an operating state based on the detected values ​​of each pressure sensor 61, 62, 63, 64, 65, and 66 (operating pilot pressure generated by the pilot valves 6a, 6b, 7a, 7b, 8a, and 8b of each operating device 6, 7, and 8). Specifically, it determines whether the left-travel operating device 6 is in a standby state or in an operating state (forward or reverse operation) by comparing the detected values ​​of the first pressure sensor 61 and the second pressure sensor 62 (operating pilot pressure generated by the pilot valves 6a and 6b of the left-travel operating device 6) with a predetermined pressure threshold. Also, it determines whether the right-travel operating device 7 is in a standby state or in an operating state (forward or reverse operation) by comparing the detected values ​​of the third pressure sensor 63 and the fourth pressure sensor 64 (operating pilot pressure generated by the pilot valves 7a and 7b of the right-travel operating device 7) with a predetermined pressure threshold. Furthermore, the system determines whether the slewing control device 8 is in standby mode or operating mode (right turn operation or left turn operation) by comparing the detected values ​​of the fifth pressure sensor 65 and the sixth pressure sensor 66 (operating pilot pressure generated by the pilot valves 8a and 8b of the slewing control device 8) with a predetermined threshold. The predetermined pressure threshold is stored in advance in a storage device 71, for example. Note that the standby mode of each control device 6, 7, and 8 refers to the neutral state, which is an unoperated state where the operating position is in the neutral position and not being operated.

[0047] The object determination unit 82 determines whether or not an object exists within a predetermined area Rm around the hydraulic excavator based on the outputs of the rear camera 36, ​​left-side camera 37, and right-side camera 38, which are object detection devices. Specifically, it performs image processing on the images output from cameras 36, 37, and 38, and determines the presence or absence of objects B1 and B2 in the first area Rsw and the second area Rtr of the monitoring area Rm shown in Figure 5 based on the results of the image processing. The objects to be detected include, for example, other construction machinery and vehicles, structures such as fences and walls, and people. The object determination unit 82 can also be configured to detect only some of these as objects.

[0048] The image processing unit 83 processes the video output from the rear camera 36, ​​left-side camera 37, and right-side camera 38, which act as object detection devices, by adding object information detected by the object determination unit 82. Furthermore, it outputs a display command to the monitor device 34 to display the video with the added object information on the display screen.

[0049] Based on the determination results of the operation determination unit 81 and the object determination unit 82, the control calculation unit 84 decides to execute control to display a warning screen that alerts the user to the presence of objects B1 and B2 around the hydraulic excavator, and also decides to execute control to sound a warning sound that alerts the user to the presence of objects B1 and B2 around the hydraulic excavator. Furthermore, when commanding the display control of the warning screen and the sounding control of the warning sound, the unit executes processing for controlling the driving of hydraulic actuators 22, 23, and 5 based on the operation of the operation devices 6, 7, and 8, and for controlling the prohibition of such driving. Details of the display control of the warning screen and the sounding control of the warning sound, and details of the control to prohibit the driving of hydraulic actuators 22, 23, and 5 based on the operation of the operation devices 6, 7, and 8 will be described later.

[0050] The output processing unit 85 outputs a warning display command to the monitor device 34 to display the first warning icon and the second warning icon on the display screen based on a warning screen display control command from the control calculation unit 84. It also outputs a warning sound command to the speaker 35 to sound the first warning sound and the second warning sound based on a warning sound sound control command from the control calculation unit 84. Furthermore, it outputs drive commands to the solenoid valves 54 to 59 in response to a drive prohibition control command for the hydraulic actuators 22, 23, and 5 from the control calculation unit 84.

[0051] Next, the control procedure for limiting the drive of a hydraulic actuator by the control device of the construction machine according to the first embodiment will be described. First, the control procedure of the control device when an object is present in the first area around the hydraulic excavator will be described using Figures 4 to 6. Figure 6 is a flowchart showing an example of the processing procedure for limiting the drive of a hydraulic actuator during a slewing operation by the control device according to the first embodiment shown in Figure 4.

[0052] In Figure 6, the control device 70 (operation determination unit 81) shown in Figure 4 determines whether all of the multiple operating devices 6, 7, and 8 are in an active state (step S10). If the gate lock lever 9a is operated to the locked position L and the instruction signal of the gate lock switch 9b is an invalid instruction (off signal), it is determined that the operating devices 6, 7, and 8 are in an invalid state (NO), and the process returns to step S10. On the other hand, if the gate lock lever 9a is operated to the unlocked position U and the instruction signal of the gate lock switch 9b is an on signal (active instruction), it is determined that all of the operating devices 6, 7, and 8 are in an active state (YES), and the process proceeds to step S20.

[0053] If the result in step S10 is YES, the control device 70 (operation determination unit 81) determines whether the operating devices 6, 7, and 8 are in standby mode (step S20). If any of the detected values ​​of each pressure sensor 61 to 66 are above a predetermined pressure threshold, it is determined that any of the operating devices 6, 7, and 8 are not in standby mode (NO), and the process returns to step S10, repeating steps S10 to S20. On the other hand, if the detected values ​​of each pressure sensor 61 to 66 are below the predetermined pressure threshold, it is determined that the operating devices 6, 7, and 8 are in standby mode (YES), and the process proceeds to step S30.

[0054] If the result in step S20 is YES, the control device 70 (object detection unit 82) determines whether or not there is an object in the first region Rsw within a predetermined region Rm around the hydraulic excavator (step S30). Based on the output of cameras 36, 37, and 38, which act as object detection devices, it determines whether or not an object exists in the first region Rsw around the hydraulic excavator. If it is determined that no object exists (NO), the process returns to step S10 and steps S10 to S30 are repeated. On the other hand, if it is determined that object B1 exists in the first region Rsw (right side) as shown in Figure 5 (YES), the process proceeds to step S40.

[0055] If the result in step S30 is YES, the control device 70 (control calculation unit 84 and output processing unit 85) outputs a warning display command to the monitoring device 34 to display a first warning icon and a warning sound command to the speaker 35 to sound a first warning sound, as the first stage of alerting the operator to the presence of object B1 around the hydraulic excavator (step S40). The purpose of this first stage of alerting the operator is to warn the operator not to operate the hydraulic actuator. For this reason, for example, the first warning icon is made up of a yellow icon and the first warning sound is made up of an intermittent buzzer sound.

[0056] Next, the control device 70 (operation determination unit 81) determines whether the slewing control device 8 is in an operating state (step S50). If the detection values ​​of both the fifth pressure sensor 65 and the sixth pressure sensor 66 are lower than a predetermined pressure threshold, it is determined that the slewing control device 8 is not in an operating state (NO), and the process returns to step S10, repeating steps S10 to S50. On the other hand, if the detection value of either the fifth pressure sensor 65 or the sixth pressure sensor 66 is equal to or greater than the predetermined pressure threshold, it is determined that the slewing control device 8 is in an operating state (YES), and the process proceeds to step S60. In this embodiment, the point in time when the slewing control device 8 is determined to have changed from a standby state to an operating state is defined as the start time of operation of the slewing control device 8.

[0057] If the result in step S50 is determined to be YES, the control device 70 (control calculation unit 84) counts the elapsed time from the start of operation of the slewing control device 8 (step S60). Furthermore, as the second stage of alerting the user to the presence of object B1 around the hydraulic excavator, the control device 70 (control calculation unit 84 and output processing unit 85) outputs a warning display command to the monitor device 34 to display a second warning icon, and outputs a warning sound command to the speaker 35 to sound a second warning sound (step S60). The purpose of this second stage of alerting the user is to notify them that the driving of the slewing hydraulic motor 5 by operating the slewing control device 8 is prohibited due to the presence of object B1 around the hydraulic excavator. For this reason, for example, the second warning icon is made up of a red icon, and the second warning sound is made up of a continuous buzzer sound.

[0058] Next, the control device 70 (control calculation unit 84) determines whether the elapsed time from the start of the rotation operation of the rotation operating device 8 is less than a first predetermined time Δt1 (step S70). If the elapsed time is less than the first predetermined time Δt1 (YES), the process proceeds to step S80, while if the elapsed time is equal to or greater than the first predetermined time Δt1 (NO), the process proceeds to step S90. The first predetermined time Δt1 is, for example, stored in advance in the storage device 71.

[0059] If the result in step S70 is YES, the control device 70 (operation determination unit 81) determines whether the slewing control device 8 is in an operating state (step S80). If it is determined that the slewing control device 8 is in an operating state (YES), the process returns to step S60 and steps S60 to S80 are repeated. On the other hand, if it is determined that the slewing control device 8 is not in an operating state (NO), the process proceeds to step S90.

[0060] If NO is determined in step S70 or step S80, the control device 70 (control calculation unit 84 and output processing unit 85) sets the operating pilot pressure limit value of the fifth solenoid valve 58 and the sixth solenoid valve 59 (swivel solenoid valves) (the limit value of the operating pilot pressure input to the pressure receiving units 47a and 47b of the swivel spool 47) to 0 MPa and outputs a limit command for the operating pilot pressure limit value set to 0 MPa to the swivel solenoid valves 58 and 59 (step S90). As a result, the swivel solenoid valves 58 and 59 shown in Figure 3 switch to the second position in which the pressure receiving units 47a and 47b of the swivel spool 47 are connected to the hydraulic oil tank 49, and the input of the operating pilot pressure generated by the pilot valves 8a and 8b of the swivel operating device 8 to the pressure receiving units 47a and 47b of the swivel spool 47 is cut off. As a result, after the slewing hydraulic motor 5 is driven based on the operation of the slewing control device 8, the drive of the slewing hydraulic motor 5 is prohibited and the slewing operation stops. That is, when the control device 70 terminates the slewing operation of the slewing control device 8 after a first predetermined time Δt1 has elapsed from the start of the slewing operation of the slewing control device 8, or before the first predetermined time Δt1 has elapsed, it controls the slewing solenoid valves 58 and 59 to prohibit the drive of the slewing hydraulic motor 5 based on the operation of the slewing control device 8. Furthermore, the control device 70 (control calculation unit 84 and output processing unit 85) continues to output a warning display command to the monitoring device 34 to display a second warning icon, and continues to output a warning sound command to the speaker 35 to sound a second warning sound (step S90).

[0061] Next, the control device 70 (operation determination unit 81) determines whether all of the operation devices 6, 7, and 8 are in an inactive state by the gate lock device 9 (step S100). If the gate lock lever 9a is maintained in the unlocked position U, it is determined that all of the operation devices 6, 7, and 8 are in an active state (NO), and the process returns to step S90, repeating steps S90 to S100. On the other hand, if the gate lock lever 9a is switched to the locked position L, it is determined that the operation devices 6, 7, and 8 are in an inactive state (YES), and the series of processes for prohibiting the driving of the slewing hydraulic motor 5 by the slewing operation when an object is detected is terminated.

[0062] Next, the control procedure of the control device when an object is present in the second area surrounding the hydraulic excavator will be explained using Figures 4, 5, and 7. Figure 7 is a flowchart showing an example of the processing procedure for limiting the drive of the hydraulic actuator during travel operation by the control device according to the first embodiment shown in Figure 4.

[0063] In Figure 7, the control device 70 (operation determination unit 81) shown in Figure 4 determines whether all of the multiple operating devices 6, 7, and 8 are in an active state (step S10). If it determines that all of the operating devices 6, 7, and 8 are in an active state (YES), it determines whether the operating devices 6, 7, and 8 are in a standby state (step S20). Steps S10 and S20 shown in Figure 7 are the same as the flowchart shown in Figure 6, so their explanation is omitted.

[0064] If it is determined in step S20 that the operating devices 6, 7, and 8 are in a standby state (YES), the control device 70 (object determination unit 82) determines whether or not there is an object in the first region Rsw or the second region Rtr around the hydraulic excavator (step S230). Based on the output of cameras 36, 37, and 38, which act as object detection devices, it is determined whether or not an object exists in the first region Rsw or the second region Rtr around the hydraulic excavator. If it is determined that object B2 exists in the first region Rsw or the second region Rtr (rear) as shown in Figure 5 (YES), the process proceeds to step S40. Step S40, shown in Figure 7, is the same as the flowchart shown in Figure 6, so its explanation is omitted.

[0065] Next, the control device 70 (operation determination unit 81) determines whether the left-travel control device 6 or the right-travel control device 7 (travel control device) is in an operating state (step S250). If all the detection values ​​of the first pressure sensor 61 to the fourth pressure sensor 64 are lower than a predetermined pressure threshold, it is determined that the travel control devices 6 and 7 are not in an operating state (NO), and the process returns to step S10, and steps S10, S20, S230, S40, and S250 are repeated. On the other hand, if the detection value of any of the first pressure sensor 61 to the fourth pressure sensor 64 is equal to or greater than a predetermined pressure threshold, it is determined that the travel control devices 6 and 7 are in an operating state (YES), and the process proceeds to step S260. In this embodiment, the point in time when the travel control devices 6 and 7 are determined to have changed from a standby state to an operating state is defined as the start time of operation for the travel control devices 6 and 7.

[0066] If the result in step S250 is determined to be YES, the control device 70 (control calculation unit 84) counts the elapsed time from the start of operation of the driving operation devices 6 and 7 (step S260). Furthermore, the control device 70 (control calculation unit 84 and output processing unit 85) outputs a warning display command to the monitor device 34 to display the second warning icon, and outputs a warning sound command to the speaker 35 to sound the second warning sound, similar to step S60 shown in Figure 6 (step S260).

[0067] Next, the control device 70 (control calculation unit 84) determines whether the elapsed time from the start of the driving operation of the driving operation devices 6 and 7 is less than a second predetermined time Δt2 (step S270). If the elapsed time is less than the second predetermined time Δt2 (YES), the process proceeds to step S280. On the other hand, if the elapsed time is equal to or greater than the second predetermined time Δt2 (NO), the process proceeds to step S290. The second predetermined time Δt2 is, for example, stored in advance in the storage device 71.

[0068] If the result in step S270 is YES, the control device 70 (operation determination unit 81) determines whether the driving control devices 6 and 7 are in an operating state (step S280). If it is determined that the driving control devices 6 and 7 are in an operating state (YES), the process returns to step S260 and steps S260 to S280 are repeated. On the other hand, if it is determined that the driving control devices 6 and 7 are not in an operating state (NO), the process proceeds to step S290.

[0069] If NO is determined in step S270 or step S280, the control device 70 (control calculation unit 84 and output processing unit 85) sets the operating pilot pressure limit values ​​of the first solenoid valve 54 to the fourth solenoid valve 57 (travel solenoid valves) (the limit values ​​of the operating pilot pressure input to the pressure receiving units 45a and 45b of the left travel spool 45 and the limit values ​​of the operating pilot pressure input to the pressure receiving units 46a and 46b of the right travel spool 46) to 0 MPa and outputs a limit command for the operating pilot pressure limit value set to 0 MPa to the travel solenoid valves 54 to 57 (step S290). As a result, the solenoid valves 54-57 for travel shown in Figure 3 are switched to a second position in which the pressure-receiving sections 45a and 45b of the left travel spool 45 and 46a and 46b of the right travel spool 46 are connected to the hydraulic fluid tank 49. This shuts off the input of the operating pilot pressure generated by the pilot valves 6a and 6b of the left travel operating device 6 to the pressure-receiving sections 45a and 45b of the left travel spool 45, and the input of the operating pilot pressure generated by the pilot valves 7a and 7b of the right travel operating device 7 to the pressure-receiving sections 46a and 46b of the right travel spool 46. Consequently, after the left travel hydraulic motor 22 or the right travel hydraulic motor 23 (travel hydraulic motor) is driven based on the operation of the travel operating devices 6 and 7, their driving is immediately prohibited. In other words, when the control device 70 has elapsed a second predetermined time Δt2 from the start of the driving operation of the driving control devices 6 and 7, or has ended the driving operation of the driving control devices 6 and 7 before the second predetermined time Δt2 has elapsed, it controls the driving solenoid valves 54 to 57 to prohibit the driving of the driving hydraulic motors 22 and 23 based on the operation of the driving control devices 6 and 7. Furthermore, the control device 70 (control calculation unit 84 and output processing unit 85) continues to output a warning display command to the monitoring device 34 to display the second warning icon, and continues to output a warning sound command to the speaker 35 to sound the second warning sound, similar to step S90 shown in Figure 6 (step S290).

[0070] Next, the control device 70 (operation determination unit 81) determines that the gate lock lever 9a has been switched to the locked position L and that the operating devices 6, 7, and 8 are in an inactive state (YES), and repeats steps S290 and S100 until it has completed a series of processes for prohibiting the driving of the travel hydraulic motors 22 and 23 due to the travel operation when an object is detected.

[0071] Next, the operation of the control device of the construction machine according to the first embodiment when controlling the drive limit of the hydraulic actuator will be explained using Figure 8. Figure 8 is a time chart showing the temporal changes in the operation of the control device, the operation of the controlled object, and the operation of the operating device in the construction machine according to the first embodiment. In Figure 8, the horizontal axis T represents time, and the vertical axis P represents pressure. The solid line represents the operating pilot pressure limit value of the solenoid valve, the dashed line represents the pilot pressure generated by the pilot valve of the operating device, and the dotted line represents the secondary pressure of the solenoid valve (operating pilot pressure input to the pressure receiving part of each spool).

[0072] In Figure 8, time Tb indicates the moment when it is determined that an object is present within a predetermined area Rm around the hydraulic excavator, time Tc indicates the moment when operation of any of the operating devices 6, 7, or 8 is initiated, and time Te indicates the moment when all of the operating devices 6, 7, and 8 are switched to a disabled state by the operation of the gate lock device 9.

[0073] During the period from time 0 to time Tb, all operating devices 6, 7, and 8 are active due to the gate lock device 9, and each operating device 6, 7, and 8 is in a standby state. In addition, it is determined that no objects exist within a predetermined area Rm around the hydraulic excavator. In this situation, the control device 70 sets the operating pilot pressure limit value of each solenoid valve 54 to 59 to the maximum value Pmax and outputs it to each solenoid valve 54 to 59. That is, each solenoid valve 54 to 59 does not limit the operating pilot pressure input from each operating device 6, 7, and 8 to each spool 45, 46, and 47. The maximum value Pmax is set to be equal to, for example, the maximum value of the operating pilot pressure output from each operating device 6, 7, and 8.

[0074] Even if it is determined that an object is present within a predetermined region Rm at time Tb, the operating pilot pressure limit values ​​of solenoid valves 54-59 are maintained at the maximum value Pmax. In other words, the solenoid valves 54-59 do not restrict the driving of spools 45, 46, and 47, and the system does not switch to a state that prohibits the driving of hydraulic actuators 22, 23, and 5.

[0075] When operation of any of the operating devices 6, 7, or 8 is initiated at time Tc, the pilot valves 6a, 6b, 7a, 7b, 8a, and 8b of the operating devices 6, 7, and 8 generate an operating pilot pressure corresponding to the operating amount. When the operating pilot pressure generated by the operating devices 6, 7, and 8 exceeds the pressure threshold Pth, the control device 70 determines that the operating devices 6, 7, and 8 are in an operating state and counts the elapsed time from the start of operation of the operating devices 6, 7, and 8 (the time at which it is determined that they have transitioned from a standby state to an operating state). Furthermore, until a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the start of operation of the operating device, the control device 70 maintains the operating pilot pressure limit values ​​of the solenoid valves 54 to 59 at their maximum value Pmax. This allows the hydraulic actuators 22, 23, and 5 corresponding to the operating amounts of the operating devices 6, 7, and 8 to be driven.

[0076] At time Td, when a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the start of operation of the operating devices 6, 7, and 8, the control device 70 limits the operating pilot pressure limit of the solenoid valves 54 to 59 to the minimum value of 0. As a result, the secondary pressure output from the solenoid valves 54 to 59 becomes 0, and the driving of the hydraulic actuators 22, 23, and 5 by operating the operating devices 6, 7, and 8 is prohibited. Consequently, the hydraulic actuators 22, 23, and 5 are driven and then immediately stopped, which the operator experiences as a tactile response.

[0077] During the period from time Td to time Te, the control device 70 maintains the minimum limit of 0 for the operating pilot pressure limit of solenoid valves 54-59. As a result, the secondary pressure output from solenoid valves 54-59 is maintained at 0, thus maintaining the prohibition of driving the hydraulic actuators 22, 23, and 5 by operating the operating devices 6, 7, and 8.

[0078] When the gate lock device 9 is operated at time Te, and all operating devices 6, 7, and 8 are switched to a disabled state, the control device 70 returns the operating pilot pressure limit value of the solenoid valves 54-59 to the maximum value Pmax, and terminates the control to disable the operation of the hydraulic actuators 22, 23, and 5.

[0079] Thus, when an object is detected within a predetermined area Rm around the hydraulic excavator, the operation of the control devices 6, 7, and 8 is not immediately disabled. Instead, after a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the time the operation of the control devices 6, 7, and 8 is initiated, the driving of the hydraulic actuators 22, 23, and 5 by the operation of the control devices 6, 7, and 8 is prohibited. Therefore, after the hydraulic actuators 22, 23, and 5 have been driven by the operation of the control devices 6, 7, and 8, the driving of the hydraulic actuators 22, 23, and 5 can be stopped. Consequently, the operator can recognize the prohibition of driving the hydraulic actuators 22, 23, and 5 due to object detection through the feel (tactile sensation) of the operation of the control devices 6, 7, and 8.

[0080] The first predetermined time Δt1 and the second predetermined time Δt2 are set to allow the operator to be notified by their senses (operational feel of the control devices 8, 6, and 7) that the driving of the hydraulic actuators 5, 22, and 23 is restricted, and to suppress the amount of movement of the lower traveling body 2 or upper slewing body 3 to the necessary minimum while the driving of the hydraulic actuators 5, 22, and 23 by the operation of the control devices 8, 6, and 7 is permitted. Specifically, if objects B1 and B2 are present around the hydraulic excavator, it is necessary to immediately stop the hydraulic actuators 5, 22, and 23 after they start due to slewing or traveling operations in order to prevent the lower traveling body 2 or upper slewing body 3 (machine body) from coming into contact with objects B1 and B2 due to the driving of the hydraulic actuators 5, 22, and 23. For this reason, it is preferable that the first predetermined time Δt1 and the second predetermined time Δt2 be set to a period of several hundred msec or less, which is approximately equal to the response time from the start of operation of the control devices 8, 6, and 7 until the hydraulic actuators 5, 22, and 23 start. The first predetermined time Δt1 is set according to the response time of the rotational movement of the upper rotating body 3 due to a rotation operation. On the other hand, the second predetermined time Δt2 is set according to the response time of the travel movement of the lower traveling body 2 due to a travel operation. In other words, it is possible to set the first predetermined time Δt1 and the second predetermined time Δt2 to different values. However, in order to simplify the control of the control device 70, it is also possible to set the first predetermined time Δt1 and the second predetermined time Δt2 to the same value.

[0081] As described above, the hydraulic excavator (construction machine) according to the first embodiment includes a travel hydraulic motor 22, 23 and a slewing hydraulic motor 5 (first hydraulic actuator and second hydraulic actuator), travel operating devices 6, 7 for operating the travel hydraulic motor 22, 23 and a slewing operating device 8 for operating the slewing hydraulic motor 5 (first operating device and second operating device), a gate lock device 9 (switching device) that can switch the operation of the travel operating devices 6, 7 and the slewing operating device 8 (first operating device and second operating device) to an enabled or disabled state, cameras 36, 37, 38 as object detection devices for detecting objects present in a predetermined area, and a control device 70 that can individually restrict the driving of the travel hydraulic motor 22, 23 and the slewing hydraulic motor 5 (first hydraulic actuator and second hydraulic actuator). The control device 70 is configured such that, when the gate lock device 9 (switching device) is switched to enable the operation of the travel operating devices 6, 7 and the slewing operating device 8 (first operating device and second operating device), and when the travel operating devices 6, 7 and the slewing operating device 8 (first operating device and second operating device) are in a neutral state, and the control device 70 determines that an object exists within a predetermined area based on the output of the cameras 36, 37, 38 (object detection devices), if operation of one of the operating devices among the travel operating devices 6, 7 and the slewing operating device 8 (first operating device and second operating device) is initiated, the control device 70 allows the driving of one hydraulic actuator corresponding to the operation of the operating device that has been initiated until a predetermined time (first predetermined time Δt1 or second predetermined time Δt2) has elapsed from the time the operation of the operating device that has been initiated, and after the predetermined time (first predetermined time Δt1 or second predetermined time Δt2) has elapsed, the driving of the hydraulic actuator is prohibited.

[0082] With this configuration, by setting the predetermined time (the first predetermined time Δt1 or the second predetermined time Δt2) to an extremely short period, when an object is detected around the hydraulic excavator and the operating devices 6, 7, and 8 are operated, the hydraulic actuators 22, 23, and 5 will briefly drive and then immediately stop. This allows the operator to recognize the prohibition of driving the hydraulic actuators 22, 23, and 5 due to object detection around the hydraulic excavator through their senses (the feel of operating the operating devices 6, 7, and 8). Furthermore, in this embodiment, the first predetermined time Δt1 or the second predetermined time Δt2 is set to be different depending on whether the driving control devices 6 and 7 are operated or the turning control device 8 is operated.

[0083] With this configuration, the driving times of the travel hydraulic motors 22, 23 and the slewing hydraulic motor 5 (first hydraulic actuator and second hydraulic actuator) can be set according to the response characteristics of the travel hydraulic motors 22, 23 to the operation of the travel control devices 6, 7 and the response characteristics of the slewing hydraulic motor 5 to the operation of the slewing control device 8. Therefore, the travel hydraulic motors 22, 23 and the slewing hydraulic motor 5 (first hydraulic actuator and second hydraulic actuator) can be driven while reliably preventing contact between the lower travel body 2 or the upper slewing body 3 (machine body) and objects B1, B2 by the driving of the hydraulic actuators 5, 22, 23.

[0084] Furthermore, in this embodiment, the travel control devices 6 and 7 and the turning control device 8 (the first control device and the second control device) are configured to generate pilot pressure from the hydraulic pressure of the pilot pump 51 (pilot hydraulic power source) according to the operating direction and amount of operation, respectively. Furthermore, the hydraulic excavator includes travel spools 45, 46 and slewing spool 47 (first and second control valves) which are driven by pilot pressure generated by travel operating devices 6, 7 and slewing operating device 8 (first and second operating devices) and control the supply and discharge of pressurized oil to the travel hydraulic motors 22, 23 and slewing hydraulic motor 5 (first and second hydraulic actuators), and travel solenoid valves 54, 55, 56, 57 and slewing solenoid valves 58, 59 (first and second pressure reducing valves) which can reduce the pilot pressure generated by the travel operating devices 6, 7 and slewing operating device 8 (first and second operating devices) and input it to the travel spools 45, 46 and slewing spool 47 (first and second control valves). Furthermore, the control device 70 controls one of the pressure reducing valves among the travel solenoid valves 54, 55, 56, 57 and the slewing solenoid valves 58, 59 (first pressure reducing valve and second pressure reducing valve) so that the pilot pressure output from one of the travel operating devices 6, 7 and the slewing operating device 8, which has been started, to one of the travel spools 45, 46 and the slewing spool 47 (first control valve and second control valve) is cut off, thereby preventing the driving of one of the hydraulic actuators.

[0085] According to this configuration, when the travel control devices 6 and 7 and the turning control device 8 (the first and second control devices) are hydraulic pilot type, the control device 70 can perform control to individually prohibit the driving of the travel hydraulic motors 22 and 23 and the turning hydraulic motor 5 (the first and second hydraulic actuators).

[0086] Furthermore, the hydraulic excavator (construction machine) according to this embodiment comprises a lower traveling body 2 (traveling body) that is capable of travel, and an upper slewing body 3 (slewing body) that is rotatably mounted on the lower traveling body 2 (traveling body). The lower traveling body 2 (traveling body) is configured to be traveled by travel hydraulic motors 22 and 23, and the upper slewing body 3 (slewing body) is configured to be rotated relative to the lower traveling body 2 (traveling body) by a slewing hydraulic motor 5. In addition, the first hydraulic actuator and the second hydraulic actuator, which are the targets of the control device 70's drive prohibition control, are the travel hydraulic motors 22 and 23 and the slewing hydraulic motor 5.

[0087] With this configuration, even if the operator is unaware of the presence of an object behind or to the left or right sides (a predetermined area Rm around the excavator) where it is difficult to see, it is possible to prevent the lower traveling body 2 (traveling body) or the upper rotating body 3 (rotating body) from coming into contact with the object during traveling or rotating operations.

[0088] [Modified version of the first embodiment] Next, a construction machine according to a modified example of the first embodiment will be described using Figures 9 to 12. In Figures 9 to 12, parts with the same reference numerals as those in Figures 1 to 8 are similar parts, so a detailed explanation of them will be omitted. Figure 9 is a block diagram showing the hardware and functions of the control device in a construction machine according to a modified example of the first embodiment.

[0089] The difference between the modified construction machine of the first embodiment shown in Figure 9 and the first embodiment is that the processing method of the control calculation unit 84A of the control device 70A is different. The control device 70 (control calculation unit 84) of the first embodiment, when all operations of the multiple operating devices 6, 7, 8 (see Figure 3) are active by the gate lock device 9 (see Figure 3) and the operating devices 6, 7, 8 are in a neutral state (standby state), determines that objects B1 and B2 have been detected in a predetermined area Rm around the hydraulic excavator shown in Figure 5 based on the output of cameras 36, 37, 38 as object detection devices, does not immediately execute control to restrict the driving of the hydraulic actuators 22, 23, 5, but controls the first solenoid valve 54 to the sixth solenoid valve 59 to prohibit the driving of the hydraulic actuators 22, 23, 5 by the operation of the operating device after predetermined times Δt1 and Δt2 have elapsed from the start of operation of the operating device. In contrast, the control device 70A (control calculation unit 84A) according to this modified example controls the first solenoid valve 54 to the sixth solenoid valve 59 to restrict the driving of hydraulic actuators 22, 23, and 5 from the moment object detection is determined, when all of the multiple operating devices 6, 7, and 8 (see Figure 3) are in an active state due to the operation of the gate lock device 9 (see Figure 3), and the operating devices 6, 7, and 8 are in a standby state, and the control device 70A determines that objects B1 and B2 have been detected in a predetermined area Rm around the hydraulic excavator shown in Figure 5 based on the output of the object detection devices 36, 37, and 38.

[0090] Next, the control procedure for limiting the drive of a hydraulic actuator by a control device of a construction machine according to a modified example of the first embodiment will be described. First, the control procedure of the control device when an object is present in the first region Rsw around the hydraulic excavator (the procedure for limiting the drive of the slewing hydraulic motor due to slewing operation) will be explained using Figure 10. Figure 10 is a flowchart showing an example of the procedure for limiting the drive of a hydraulic actuator during slewing operation by a control device according to a modified example of the first embodiment shown in Figure 9.

[0091] The difference between the control flow of the control device according to this modified example shown in Figure 10 and the control flow of the control device according to the first embodiment (see Figure 6) is that when the control device 70A shown in Figure 9 determines that all of the multiple operating devices 6, 7, and 8 are in an active state by the gate lock device 9 (YES in step S10), and that the operating devices 6, 7, and 8 are in a standby state (YES in step S20), and determines that an object B1 exists in the first region Rsw around the hydraulic excavator based on the output of the cameras 36, 37, and 38 as object detection devices (YES in step S30), it sets the operating pilot pressure limit values ​​of the fifth solenoid valve 58 and the sixth solenoid valve 59 (swing solenoid valve) to a predetermined low value, and outputs a limit command to the fifth solenoid valve 58 and the sixth solenoid valve 59 (swing solenoid valve) according to the set operating pilot pressure limit value (step S40A). As a result, the fifth solenoid valve 58 and the sixth solenoid valve 59 (swivel solenoid valves) shown in Figure 3 switch to a state where their opening degree is reduced while maintaining the connection state of the pressure-receiving sections 47a and 47b of the swivel spool 47 to the pilot valves 8a and 8b of the swivel operating device 8. In this case, the operating pilot pressure generated by the pilot valves 8a and 8b of the swivel operating device 8 is reduced in pressure by the fifth solenoid valve 58 and the sixth solenoid valve 59 (swivel solenoid valves) before being input to the pressure-receiving sections 47a and 47b of the swivel spool 47. In other words, the operating pilot pressure input to the pressure-receiving sections 47a and 47b of the swivel spool 47 is limited in relation to the operating pilot pressure corresponding to the operating amount of the swivel operating device 8. This means that the stroke of the swivel spool 47 is limited, and the drive of the swivel hydraulic motor is restricted.

[0092] In step S40A, in addition to control based on the operating pilot pressure limit values ​​of the fifth solenoid valve 58 and the sixth solenoid valve 59 (swivel solenoid valve), a warning display command to display the first warning icon is output to the monitor device 34, and a warning sound command to sound the first warning sound is output to the speaker 35, similar to the process of step S40 shown in Figure 6 in the first embodiment. Furthermore, the processes other than step S40A in the control flow of the control device according to this modified example shown in Figure 10 (steps S10 to S30, S50 to S100) are the same as the processes in the control flow shown in Figure 6 in the first embodiment.

[0093] Next, the control procedure of the control device when an object is present in the second region Rtr around the hydraulic excavator (the procedure for limiting the drive of the travel hydraulic motor due to travel operation) will be explained using Figure 11. Figure 11 is a flowchart showing an example of the procedure for limiting the drive of the hydraulic actuator during travel operation by a control device relating to a modified example of the first embodiment shown in Figure 9.

[0094] The difference between the control flow of the control device according to this modified example shown in Figure 11 and the control flow of the control device according to the first embodiment (see Figure 7) is that when the control device 70A shown in Figure 9 determines that all of the multiple operating devices 6, 7, and 8 are in an active state by the gate lock device 9 (YES in step S10), and also determines that the operating devices 6, 7, and 8 are in a standby state (neutral state) (YES in step S20), and determines that an object B2 exists in the second region Rtr around the hydraulic excavator based on the output of the cameras 36, 37, and 38 as object detection devices (YES in step S230), it sets the operating pilot pressure limit values ​​of the first solenoid valve 54 to the fourth solenoid valve 57 (traveling solenoid valve) to a predetermined low value, and outputs a limit command to the first solenoid valve 54 to the fourth solenoid valve 57 (traveling solenoid valve) according to the set operating pilot pressure limit value (step S240A). As a result, the first solenoid valve 54 and the second solenoid valve 55 (travel solenoid valves) shown in Figure 3 are switched to a state where their opening is restricted while maintaining the connection state between the pressure-receiving sections 45a and 45b of the left travel spool 45 and the pilot valves 6a and 6b of the left travel operating device 6. Similarly, the third solenoid valve 56 and the fourth solenoid valve 57 (travel solenoid valves) are switched to a state where their opening is restricted while maintaining the connection state between the pressure-receiving sections 46a and 46b of the right travel spool 46 and the pilot valves 7a and 7b of the right travel operating device 7. In this case, the operating pilot pressure generated by the pilot valves 6a and 6b of the left travel operating device 6 is reduced in pressure by the first solenoid valve 54 and the second solenoid valve 55 (left travel solenoid valves) before being input to the pressure-receiving sections 45a and 45b of the left travel spool 45. Similarly, the operating pilot pressure generated by the pilot valves 7a and 7b of the right-travel operating device 7 is reduced in pressure by the third solenoid valve 55 and the third solenoid valve 56 (right-travel solenoid valve) before being input to the pressure receiving sections 46a and 46b of the right-travel spool 46. In other words, the operating pilot pressure corresponding to the operating amount of the left-travel operating device 6 and the right-travel operating device 7 is limited, so that the operating pilot pressure input to the pressure receiving sections 45a and 45b of the left-travel spool 45 and the operating pilot pressure input to the pressure receiving sections 46a and 46b of the right-travel spool 46 are limited.This means that the strokes of the left travel spool 45 and the right travel spool 46 are restricted, and the driving of the left travel hydraulic motor 22 and the right travel hydraulic motor 23 is restricted.

[0095] In step S240A, in addition to control based on the operating pilot pressure limit values ​​of the first solenoid valve 54 to the fourth solenoid valve 57 (travel solenoid valve), a warning display command to display the first warning icon is output to the monitor device 34, and a warning sound command to sound the first warning sound is output to the speaker 35, similar to the process of step S40 shown in Figure 7 in the first embodiment. Furthermore, the processes other than step S240A in the control flow of the control device according to this modified example shown in Figure 11 (steps S10, S20, S230, S250 to S290, S100) are the same as the processes in the control flow shown in Figure 7 in the first embodiment.

[0096] Next, the time progression of the control process described above by the control device of the construction machine according to a modified example of the first embodiment will be explained using Figure 12. Figure 12 is a time chart showing the time changes in the operation of the control device, the operation of the controlled object, and the operation of the operating device in the construction machine according to a modified example of the first embodiment. In Figure 12, the solid line represents the operating pilot pressure limit value of each solenoid valve, the dashed line represents the pilot pressure generated by the pilot valve of each operating device, and the dotted line represents the secondary pressure of the solenoid valve (operating pilot pressure input to the pressure receiving part of each spool).

[0097] The period from time 0 to time Tb, that is, the period from when all operating devices 6, 7, and 8 are active by the gate lock device 9 and when each operating device 6, 7, and 8 is in a standby state, until it is determined that objects B1 and B2 are present in a predetermined area Rm around the hydraulic excavator, is the same as in the first embodiment.

[0098] If it is determined that objects B1 and B2 are present within a predetermined area Rm around the hydraulic excavator at time Tb (YES in steps S30 and S230), the operating pilot pressure limit values ​​of solenoid valves 54-59 are changed from the maximum value Pmax to a predetermined value Pres that is lower than the maximum value Pmax (steps S40A and S240A). In other words, the solenoid valves 54-59 are switched to a state where the driving of spools 45, 46, and 47 is restricted. The operating pilot pressure limit values ​​of solenoid valves 54-59 are maintained at the predetermined value Pres until the operation of operating devices 6, 7, and 8 is started at time Tc.

[0099] When the operation of operating devices 6, 7, and 8 is initiated at time Tc, the pilot valves of operating devices 6, 7, and 8 generate an operating pilot pressure corresponding to the operating amount. When the operating pilot pressure generated by operating devices 6, 7, and 8 exceeds the pressure threshold Pth, the control device 70A determines that operating devices 6, 7, and 8 are in an operating state (steps S50 and S250) and counts the elapsed time from the start of operation of operating devices 6, 7, and 8 (the time at which it is determined that they have transitioned from a standby state to an operating state) (steps S60 and S260). Furthermore, until a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the start of operation of operating devices 6, 7, and 8, the operating pilot pressure limit values ​​of solenoid valves 54 to 59 are maintained at a predetermined value Pres. This reduces the operating pilot pressure generated in accordance with the operating amount of operating devices 6, 7, and 8 to a predetermined value Pres by solenoid valves 54 to 59. In other words, it reduces the secondary pressure of solenoid valves 54 to 59 input to the pressure receiving section of spools 45, 46, and 47. This allows for maintaining the drive of the hydraulic actuators 5, 22, and 23 based on the operation of the operating devices 6, 7, and 8, while simultaneously imposing a limit on the drive of the hydraulic actuators 5, 22, and 23 corresponding to the amount of operation of the operating devices. By limiting the operating pilot pressure input to the pressure-receiving parts of the spools 45, 46, and 47, the amount of operation of the hydraulic actuators 5, 22, and 23 can be suppressed compared to the first embodiment where no limit is imposed.

[0100] At time Td, when a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the start of operation of the operating device, the control device 70A limits the operating pilot pressure limit values ​​of the solenoid valves 54-59 to the minimum value of 0, similar to the first embodiment. As a result, the secondary pressure of the solenoid valves 54-59 becomes 0, thus prohibiting (blocking) the driving of the hydraulic actuator based on the operation of the operating device.

[0101] Here, the predetermined value Pres of the operating pilot pressure limit for solenoid valves 54 to 59 is set to allow the operator to be notified by their senses (operational feel of the operating devices 8, 6, and 7) that the driving of the hydraulic actuators 5, 22, and 23 is restricted, and to suppress the amount of movement of the lower traveling body 2 or upper slewing body 3 to the necessary minimum while the driving of the hydraulic actuators 5, 22, and 23 by the operation of the operating devices 8, 6, and 7 is permitted. Specifically, if objects B1 and B2 are present around the hydraulic excavator, it is necessary to immediately stop the hydraulic actuators 5, 22, and 23 after they start due to slewing or traveling operations in order to prevent the lower traveling body 2 or upper slewing body 3 (machine body) from coming into contact with objects B1 and B2 due to the driving of the hydraulic actuators 5, 22, and 23. For this reason, it is preferable that the predetermined value Pres of the operating pilot pressure limit is set according to the characteristics of the amount of movement of the hydraulic actuators 5, 22, and 23 with respect to the stroke of each spool 45, 46, and 47. In other words, the predetermined value Pres for the operating pilot pressure limit is set to a different value for the first solenoid valve 54 to the fourth solenoid valve 57 (travel solenoid valves) (when limiting the drive of the travel hydraulic motors 22 and 23) and for the fifth solenoid valve 58 and the sixth solenoid valve 59 (swing solenoid valves) (when limiting the drive of the swing hydraulic motor 5). However, to simplify the control of the control device 70A, it is also possible to set the predetermined value Pres for the operating pilot pressure limit to the same value for both travel and swing operations.

[0102] According to the modified version of the first embodiment described above, similar to the first embodiment, by setting the predetermined time (first predetermined time Δt1 or second predetermined time Δt2) to an extremely short period, when an object is detected around the hydraulic excavator and the operating devices 6, 7, and 8 are operated, the hydraulic actuators 22, 23, and 5 will briefly drive and then immediately stop. This allows the operator to recognize the prohibition of driving the hydraulic actuators 22, 23, and 5 due to object detection around the hydraulic excavator through their senses (the feel of operating the operating devices 6, 7, and 8).

[0103] Furthermore, in this modified example, when the control device 70A drives the hydraulic actuators 22, 23, and 5 corresponding to the operation of the operating devices 6, 7, and 8 that have been initiated, it is configured to restrict the driving of the hydraulic actuators 22, 23, and 5.

[0104] With this configuration, the amount of movement of hydraulic actuators 5, 22, and 23 can be suppressed compared to when there is no restriction on the driving of hydraulic actuators 22, 23, and 5. Therefore, even when hydraulic actuators 5, 22, and 23 are driven, contact with objects B1 and B2 around the hydraulic excavator can be reliably prevented.

[0105] Furthermore, in this modified example, the control device 70A is configured to use different limit values ​​Press depending on whether it is limiting the drive of the travel hydraulic motors 22 and 23 or limiting the drive of the slewing hydraulic motor 5.

[0106] With this configuration, the driving of each hydraulic actuator 5, 22, and 23 can be restricted according to the operating characteristics of each hydraulic actuator 5, 22, and 23.

[0107] [Second Embodiment] Next, a construction machine according to the second embodiment of the present invention will be described using Figures 13 to 16. In Figures 13 to 16, parts with the same reference numerals as those in Figures 1 to 12 are similar parts, so their detailed explanation will be omitted. First, the schematic configuration of the hydraulic system in the construction machine according to the second embodiment will be described using Figure 13. Figure 13 is a hydraulic circuit diagram showing the hydraulic system provided in the construction machine according to the second embodiment.

[0108] The main differences between the construction machine according to the second embodiment shown in Figure 13 and the first embodiment (see Figure 3) are as follows: Firstly, each operating device 6B, 7B, and 8B is an electric operating device rather than a hydraulic pilot type, and is equipped with operating detection devices 61B, 63B, and 65B that detect the direction and amount of operation. This configuration eliminates the need for the pressure sensors 61 to 66 that function as operating detection devices for detecting the direction and amount of operation of the hydraulic pilot type operating devices 6, 7, and 8 in the first embodiment. Secondly, each solenoid valve 54B, 55B, 56B, 57B, 58B, and 59B has both a function similar to the pilot valve of the hydraulic pilot type operating devices 6, 7, and 8 in the first embodiment, and a drive limiting function (function of each solenoid valve 54 to 59 in the first embodiment) that limits the operation pilot pressure input to each spool to limit the drive of the hydraulic actuator. Thirdly, because each solenoid valve 54B to 59B has both the function of a pilot valve and the function of limiting the drive of a hydraulic actuator, the control method of the control device 70B for each solenoid valve 54B to 59B is different.

[0109] Specifically, each operating device 6B, 7B, and 8B is an electrically operated operating device equipped with operating detection devices 61B, 63B, and 65B that detect the operating direction and operating amount (e.g., operating angle), and outputs an electrical signal (e.g., a voltage signal) corresponding to the operating direction and operating amount detected by the operating detection devices 61B, 63B, and 65B to the control device 70B. The operating detection devices 61B, 63B, and 65B are, for example, potentiometers.

[0110] The first solenoid valve 54B and the second solenoid valve 55B, which serve as left-travel solenoid valves, have a first port connected to the pilot pump 51 via the pilot line 52, a second port connected to the hydraulic oil tank 49, and a third port connected to the pressure-receiving sections 45a and 45b of the left-travel spool 45. The left-travel solenoid valves 54B and 55B are switchable between a first position in which the pressure-receiving sections 45a and 45b of the left-travel spool 45 are connected to the pilot pump 51, and a second position in which the pressure-receiving sections 45a and 45b of the left-travel spool 45 are connected to the hydraulic oil tank 49. The first solenoid valve 54B and the second solenoid valve 55B are proportional valves in which the opening degree of the passage connecting the pilot pump 51 and the pressure-receiving sections 45a and 45b of the left-travel spool 45 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) of the control device 70B. The left-travel solenoid valves 54B and 55B reduce the discharge pressure (primary pilot pressure) of the pilot pump 51 to generate an operating pilot pressure corresponding to the operating pilot pressure command value of the control device 70B (a command value calculated based on the operating amount of the left-travel operating device 6B), and output the generated operating pilot pressure to the pressure receiving sections 45a and 45b of the left-travel spool 45. In other words, the left-travel solenoid valves 54B and 55B have the same function as the pilot valves 6a and 6b of the left-travel operating device 6 in the first embodiment. The left-travel solenoid valves 54B and 55B are configured such that, for example, when no excitation current is applied, they are in a first position (the position where the opening of the passage described above is at its maximum), while in response to an increase in the excitation current (command signal), the opening of the passage described above decreases and eventually reaches a second position (a position where the output of the operating pilot pressure is cut off).

[0111] The third solenoid valve 56B and the fourth solenoid valve 57B, which serve as solenoid valves for right-hand travel, have a first port connected to the pilot pump 51 via the pilot line 52, a second port connected to the hydraulic oil tank 49, and a third port connected to the pressure-receiving sections 46a and 46b of the right-hand travel spool 46. The right-hand travel solenoid valves 56B and 57B are switchable between a first position in which the pressure-receiving sections 46a and 46b of the right-hand travel spool 46 are connected to the pilot pump 51, and a second position in which the pressure-receiving sections 46a and 46b of the right-hand travel spool 46 are connected to the hydraulic oil tank 49. The third solenoid valve 56B and the fourth solenoid valve 57B are proportional valves in which the opening degree of the passage connecting the pilot pump 51 and the pressure-receiving sections 46a and 46b of the right-hand travel spool 46 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) from the control device 70B. The right-travel solenoid valves 56B and 57B reduce the discharge pressure (primary pilot pressure) of the pilot pump 51 to generate an operating pilot pressure corresponding to the operating pilot pressure command value of the control device 70B (a command value calculated based on the operating amount of the right-travel operating device 7B), and output the generated operating pilot pressure to the pressure receiving sections 46a and 46b of the right-travel spool 46. In other words, the right-travel solenoid valves 56B and 57B have the same function as the pilot valves 7a and 7b of the right-travel operating device 7 in the first embodiment. The right-travel solenoid valves 56B and 57B are configured such that, for example, when no excitation current is applied, they are in a first position (the position where the opening of the passage described above is at its maximum), while in response to an increase in the excitation current (command signal), the opening of the passage described above decreases and eventually reaches a second position (a position where the output of the operating pilot pressure is cut off).

[0112] The fifth solenoid valve 58B and the sixth solenoid valve 59B, which function as swivel solenoid valves, have a first port connected to the pilot pump 51 via the pilot line 52, a second port connected to the hydraulic oil tank 49, and a third port connected to the pressure-receiving sections 47a and 47b of the swivel spool 47. The swivel solenoid valves 58B and 59B are switchable between a first position in which the pressure-receiving sections 47a and 47b of the swivel spool 47 are connected to the pilot pump 51, and a second position in which the pressure-receiving sections 47a and 47b of the swivel spool 47 are connected to the hydraulic oil tank 49. The fifth solenoid valve 58B and the sixth solenoid valve 59B are proportional valves in which the opening degree of the passage connecting the pilot pump 51 and the pressure-receiving sections 47a and 47b of the swivel spool 47 changes from a fully open state to a fully closed state according to the magnitude of the command signal (excitation current) from the control device 70B. The swivel solenoid valves 58B and 59B reduce the discharge pressure (primary pilot pressure) of the pilot pump 51 to generate an operating pilot pressure corresponding to the operating pilot pressure command value of the control device 70B (a command value calculated based on the operating amount of the swivel operating device 8B), and output the generated operating pilot pressure to the pressure receiving sections 47a and 47b of the swivel spool 47. In other words, the swivel solenoid valves 58B and 59B have the same function as the pilot valves 8a and 8b of the swivel operating device 8 in the first embodiment. The swivel solenoid valves 58B and 59B are configured such that, for example, when no excitation current is applied, they are in a first position (the position where the opening of the passage described above is at its maximum), while in response to an increase in the excitation current (command signal), the opening of the passage described above decreases and eventually reaches a second position (a position where the output of the operating pilot pressure is cut off).

[0113] Each solenoid valve 54B to 59B is connected to the pilot pump 51 via a gate lock valve 53 on the pilot line 52. The configuration of the gate lock valve 53 and the gate lock device 9 that switches the position of the gate lock valve 53 is the same as in the first embodiment. The configuration of the main hydraulic circuit for driving the hydraulic actuators 22, 23, and 5 (the first and second hydraulic pumps 41 and 42 and the spools 45, 46, and 47 of the control valve unit 44) is also the same as in the first embodiment.

[0114] Next, the hardware configuration and functions of the control device, which constitutes a part of the construction machine according to the second embodiment, will be described using Figure 14. Figure 14 is a block diagram showing the hardware and functions of the control device according to the second embodiment shown in Figure 13.

[0115] The main differences between the control device 70B according to the second embodiment shown in Figure 14 and the control device 70 according to the first embodiment (see Figure 4) are as follows: Firstly, in addition to the operation determination unit 81B, object determination unit 82, image processing unit 83, control calculation unit 84B, and output processing unit 85, the control device 70B also has a function unit for converting the manipulated quantity 86. Secondly, the determination method of the operation determination unit 81B has been changed to correspond to the electric operation devices 6B, 7B, and 8B. Thirdly, the processing method of the control calculation unit 84B has been changed to correspond to the functional changes of each solenoid valve 54B to 59B. The functions of the object determination unit 82, image processing unit 83, and output processing unit, other than the operation determination unit 81B and control calculation unit 84B, are the same as in the first embodiment.

[0116] Specifically, the operation determination unit 81B of the control device 70B determines whether each operating device 6B, 7B, and 8B is in a neutral state (standby state) or in an operating state, based on the electrical signals (outputs of each operating device 6B, 7B, and 8B) corresponding to the operation amount detected by the operation detection devices 61B, 63B, and 65B of each operating device 6B, 7B, and 8B. Specifically, it compares the electrical signals (e.g., voltage signals) of the operation detection devices 61B, 63B, and 65B of each operating device 6B, 7B, and 8B with a predetermined threshold. The predetermined threshold is, for example, stored in advance in the storage device 71. In addition, the operation determination unit 81B also determines whether the operation of the multiple operating devices 6B, 7B, and 8B is in an active state (or in an inactive state) based on the instruction signal from the gate lock switch 9b, similar to the first embodiment.

[0117] The manipulated variable conversion unit 86 converts the electrical signals (outputs of each manipulated device 6B, 7B, 8B) corresponding to the manipulated variables detected by the operation detection devices 61B, 63B, 65B of each manipulated device 6B, 7B, 8B into an operating pilot pressure command value. The operating pilot pressure command value is a command value for generating the operating pilot pressure corresponding to the manipulated variables of each manipulated device 6B, 7B, 8B in the solenoid valves 54B to 59B. The conversion to the pilot pressure command value is performed, for example, using a table pre-stored in the memory device 71. The manipulated variable conversion unit 86 outputs the converted operating pilot pressure command value to the control calculation unit 84B.

[0118] The control calculation unit 84B, similar to the first embodiment, determines whether or not to execute control of displaying a warning screen to alert the user to the presence of objects B1 and B2 around the hydraulic excavator, and also determines whether or not to execute control of sounding a warning sound to alert the user to the presence of objects B1 and B2 around the hydraulic excavator, based on the determination result of the operation determination unit 81B and the determination result of the object determination unit 82. In normal circumstances where control of displaying the warning screen and sounding a warning sound is not commanded, the position (drive) of the solenoid valves 54B to 59B is controlled based on the operation pilot pressure command value input from the operation amount conversion unit 86. This controls the solenoid valves 54B to 59B to function as pilot valves that generate operation pilot pressure according to the operation amount of each operation device 6B, 7B, and 8B. On the other hand, when control of displaying the warning screen and sounding a warning sound is commanded, processing is performed for driving the hydraulic actuators 22, 23, and 5 based on the operation of the operation devices 6B, 7B, and 8B, and for controlling the prohibition of said driving. In this case, the operating pilot pressure limit value that restricts the driving of hydraulic actuators 22, 23, and 5 is compared with the operating pilot pressure command value input from the operating amount conversion unit 86, and the relatively lower value is selected and output as the limit command value for solenoid valves 54B to 59B. Details of the driving of hydraulic actuators 22, 23, and 5 and the control to prohibit said driving based on the operation of operating devices 6B, 7B, and 8B when commands are issued for display control of the warning screen and sounding control of the warning sound will be described later.

[0119] Next, the time progression of the drive limit control of the hydraulic actuator by the control device of the construction machine according to the second embodiment will be explained using Figure 15. Figure 15 is a time chart showing the time changes in the operation of the control device and the operation of the controlled object in the construction machine according to the second embodiment. In Figure 15, the solid line shows the operating pilot pressure limit value used to control each solenoid valve, as in the first embodiment. The dashed line shows the operating pilot pressure command value used to control each solenoid valve and corresponding to the operating amount of each operating device, unlike in the first embodiment. The dotted line shows the secondary pressure of the solenoid valve (operating pilot pressure input to the pressure receiving part of each spool), as in the first embodiment.

[0120] During the period from time 0 to time Tb, all operating devices 6B, 7B, and 8B are active due to the gate lock device 9, and each operating device 6B, 7B, and 8B is in a standby state. In addition, it is determined that no objects B1 and B2 exist within a predetermined area Rm around the hydraulic excavator. In this specific situation, the control device 70B sets the operating pilot pressure command value to 0 according to the operating amount of the standby operating devices 6B, 7B, and 8B. Also, since no objects B1 and B2 exist within the predetermined area Rm around the hydraulic excavator, the operating pilot pressure limit value, which enables the driving restriction of hydraulic actuators 22, 23, and 5, is set to the maximum value Pmax. The control device 70B compares the operating pilot pressure command value and the operating pilot pressure limit value and selects the relatively lower operating pilot pressure command value of 0 MPa. The selected operating pilot pressure command value of 0 MPa is output to the solenoid valves 54B to 59B. As a result, the secondary pressure of the solenoid valves 54B to 59B becomes 0.

[0121] Even if it is determined that objects B1 and B2 are present within a predetermined region Rm at time Tb, the operating pilot pressure limit value is maintained at the maximum value Pmax during the period from time Tb to time Tc. In other words, the solenoid valves 54B to 59B do not impose any driving restrictions on spools 45, 46, and 47. However, since the operating devices 6B, 7B, and 8B are in standby mode, a relatively low operating pilot pressure command value of 0 MPa is output to the solenoid valves 54B to 59B. As a result, the secondary pressure of the solenoid valves 54B to 59B becomes 0.

[0122] When operation of any of the operating devices 6B, 7B, or 8B is initiated at time Tc, the control device 70B counts the elapsed time from the start of operation of the operating devices 6B, 7B, or 8B (the time at which it is determined that the device changes from a standby state to an operating state). From the start of operation of the operating devices 6B, 7B, or 8B until time Td, which is the elapsed of a first predetermined time Δt1 or a second predetermined time Δt2, the control device 70B maintains the operating pilot pressure limit value at its maximum value Pmax, while setting the operating pilot pressure command value according to the operating amount of the operating devices 6B, 7B, or 8B. As a result, the operating pilot pressure command value corresponding to the relatively low operating amount of the operating devices 6B, 7B, or 8B is output to the solenoid valves 54B to 59B. Consequently, the solenoid valves 54B to 59B generate an operating pilot pressure (secondary pressure) corresponding to the operating amount of the operating devices 6B, 7B, or 8B. Therefore, the hydraulic actuators 22, 23, and 5 are driven according to the operation of the operating devices 6B, 7B, and 8B.

[0123] At time Td, when a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed since the start of operation of the operating devices 6B, 7B, and 8B, the control device 70B sets the operating pilot pressure limit value to the minimum value of 0, while setting the operating pilot pressure command value according to the amount of operation of the operating devices 6B, 7B, and 8B. As a result, an operating pilot pressure limit value of the minimum value of 0, which is relatively low, is output to the solenoid valves 54B to 59B. This causes the secondary pressure of the solenoid valves 54B to 59B to become 0, and thus the driving of the hydraulic actuators 22, 23, and 5 by the operation of the operating devices 6B, 7B, and 8B is prohibited.

[0124] During the period from time Td to time Te, the operating pilot pressure limit is maintained at its minimum value of 0. This keeps the secondary pressure of solenoid valves 54-59 at 0, thus maintaining the prohibition of driving hydraulic actuators 22, 23, and 5 by operating the operating devices 6B, 7B, and 8B.

[0125] When the gate lock device 9 is operated at time Te, and all operating devices 6B, 7B, and 8B are switched to a disabled state, the control device 70B returns the operating pilot pressure limit to its maximum value Pmax and terminates the control to disable the operation of hydraulic actuators 22, 23, and 5.

[0126] Thus, in this embodiment, when objects B1 and B2 are detected within a predetermined area Rm around the hydraulic excavator, the operation of the control devices 6B, 7B, and 8B is not immediately disabled. Instead, after a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed from the time the operation of the control devices 6B, 7B, and 8B is started, the driving of the hydraulic actuators 22, 23, and 5 by the operation of the control devices 6B, 7B, and 8B is prohibited. Therefore, after the hydraulic actuators 22, 23, and 5 have been driven by the operation of the control devices 6B, 7B, and 8B, the driving of the hydraulic actuators 22, 23, and 5 can be stopped. Consequently, the operator can recognize the prohibition of driving the hydraulic actuators 22, 23, and 5 due to object detection through the feel (tactile sensation) of the control devices.

[0127] The control procedure for limiting the drive of the hydraulic actuator during turning operations in the control device 70B according to the second embodiment is the same as the control flow shown in Figure 6, which is the control procedure for the control device 70 according to the first embodiment, so the explanation is omitted here. Similarly, the control procedure for limiting the drive of the hydraulic actuator during traveling operations in the control device 70B according to the second embodiment is the same as the control flow shown in Figure 7, which is the control procedure for the control device 70 according to the first embodiment, so the explanation is omitted here.

[0128] Next, the time progression of the control process by the control device of the construction machine according to a modified example of the second embodiment will be explained using Figure 16. Figure 16 is a time chart showing the time changes in the operation of the control device and the operation of the controlled object in the construction machine according to a modified example of the second embodiment. In Figure 16, as in the case of the second embodiment, the solid line represents the operating pilot pressure limit value used to control each solenoid valve, the dashed line represents the operating pilot pressure command value used to control each solenoid valve and corresponding to the operating amount of each operating device, and the dotted line represents the secondary pressure of the solenoid valve (operating pilot pressure input to the pressure receiving part of each spool).

[0129] The period from time 0 to time Tb, that is, the period from when all operating devices 6B, 7B, and 8B are active by the gate lock device 9 and when each operating device 6B, 7B, and 8B is in a standby state, until it is determined that objects B1 and B2 are present in a predetermined area Rm around the hydraulic excavator, is the same as in the second embodiment.

[0130] If it is determined at time Tb that objects B1 and B2 are present within a predetermined area Rm around the hydraulic excavator, the control device 70B changes the operating pilot pressure limit value from the maximum value Pmax to a predetermined value Pres that is lower than Pmax, and maintains the operating pilot pressure limit value at the predetermined value Pres during the period from time Tb to time Tc. However, since the operating devices 6B, 7B, and 8B are in a standby state during the period from time Tb to time Tc, an operating pilot pressure command value of 0 MPa, which is relatively lower than the operating pilot pressure limit value of the predetermined value Pres, is output to the solenoid valves 54B to 59B. As a result, the secondary pressure of the solenoid valves 54B to 59B becomes 0.

[0131] When operation of any of the operating devices 6B, 7B, or 8B is initiated at time Tc, the control device 70B counts the elapsed time from the start of operation of the operating devices 6B, 7B, or 8B (the time at which it is determined that the device changes from a standby state to an operating state). From the start of operation of the operating devices 6B, 7B, or 8B until time Td, which is the elapsed of a first predetermined time Δt1 or a second predetermined time Δt2, the control device 70B maintains the operating pilot pressure limit value at a predetermined value Pres, while setting the operating pilot pressure command value according to the operating amount of the operating devices 6B, 7B, or 8B. In Figure 16, an operating pilot pressure limit value of a predetermined value Pres, which is relatively low, is output for the solenoid valves 54B to 59B. As a result, the secondary pressure of the solenoid valves 54B to 59B is limited to a predetermined value Pres, which is lower than the operating pilot pressure corresponding to the operating amount of the operating devices 6B, 7B, or 8B. Therefore, the driving of the hydraulic actuators 22, 23, and 5 corresponding to the operation of the operating devices 6B, 7B, and 8B is restricted. Furthermore, if the operating amount of operating devices 6B, 7B, and 8B is small, such as during fine operation, an operating pilot pressure command value corresponding to the operating amount of operating devices 6B, 7B, and 8B is output to solenoid valves 54B to 59B.

[0132] At time Td, when a first predetermined time Δt1 or a second predetermined time Δt2 has elapsed since the start of operation of the operating devices 6B, 7B, and 8B, the control device 70B sets the operating pilot pressure limit value to the minimum value of 0, while setting the operating pilot pressure command value according to the amount of operation of the operating devices 6B, 7B, and 8B. As a result, an operating pilot pressure limit value of the minimum value of 0, which is relatively low, is output to the solenoid valves 54B to 59B. This causes the secondary pressure of the solenoid valves 54B to 59B to become 0, and thus the driving of the hydraulic actuators 22, 23, and 5 by the operation of the operating devices 6B, 7B, and 8B is prohibited.

[0133] During the period from time Td to time Te, the operating pilot pressure limit is maintained at its minimum value of 0. This keeps the secondary pressure of solenoid valves 54B to 59B at 0, thus maintaining the prohibition of driving hydraulic actuators 22, 23, and 5 by operating devices 6B, 7B, and 8B.

[0134] Thus, in this modified example, when objects B1 and B2 are detected within a predetermined area Rm around the hydraulic excavator, the operating pilot pressure limit value is changed to a lower predetermined value Pres, thereby limiting the operating pilot pressure input to the spools 45, 46, and 47 to the predetermined value Pres. As a result, the driving of the hydraulic actuators 22, 23, and 5 based on the operation of the operating devices 6B, 7B, and 8B is restricted, and the amount of operation within a predetermined time Δt1 or Δt2 in which the driving of the hydraulic actuators 22, 23, and 5 is permitted can be suppressed.

[0135] The control procedure for limiting the drive of the hydraulic actuator during turning operations in the control device 70B according to the modified version of the second embodiment is the same as the control flow shown in Figure 10, which is the control procedure for the control device 70A according to the modified version of the first embodiment, so the explanation is omitted here. Also, the control procedure for limiting the drive of the hydraulic actuator during traveling operations in the control device 70B according to the modified version of the second embodiment is the same as the control flow shown in Figure 11, which is the control procedure for the control device 70A according to the modified version of the first embodiment, so the explanation is omitted here.

[0136] According to the second embodiment and its modified version described above, similar to the first embodiment and its modified version, by setting the predetermined time (first predetermined time Δt1 or second predetermined time Δt2) to an extremely short period, when an object is detected around the hydraulic excavator and the operating devices 6B, 7B, and 8B are operated, the hydraulic actuators 22, 23, and 5 are driven for a moment and then immediately stopped. This allows the operator to recognize the prohibition of driving the hydraulic actuators 22, 23, and 5 due to object detection around the hydraulic excavator through their senses (the feel of operating the operating devices 6B, 7B, and 8B).

[0137] Furthermore, the hydraulic excavator (construction machine) according to the second embodiment and its modified form includes hydraulic pilot-operated travel spools 45 and 46 (control valves) that control the supply and discharge of pressurized oil to the travel hydraulic motors 22 and 23 (hydraulic actuators), hydraulic pilot-operated slewing spool 47 (control valve) that controls the supply and discharge of pressurized oil to the slewing hydraulic motor 5 (hydraulic actuator), travel solenoid valves 54B to 57B (pilot valves) that generate pilot pressure input to the travel spools 45 and 46 (control valves), and slewing solenoid valves 58B and 59B (pilot valves) that generate pilot pressure input to the slewing spool 47 (control valve). The travel operating devices 6B and 7B are configured to output operations on the travel hydraulic motors 22 and 23 (hydraulic actuators) as electrical signals to the control device 70B, and the slewing operating device 8B is configured to output operations on the slewing hydraulic motor 5 (hydraulic actuator) as electrical signals to the control device 70B. The control device 70B controls one of the pilot valves 54B to 59B corresponding to one of the hydraulic actuators 22, 23, 5 among the travel solenoid valves 54B to 57B (pilot valves) and the swivel solenoid valves 58B and 59B (pilot valves) to one of the control valves 45, 46, and 47 corresponding to one of the hydraulic actuators 22, 23, 5 among the travel spools 45 and 46 (control valves) and the swivel spool 47 (control valve), thereby preventing the driving of one of the hydraulic actuators 22, 23, 5.

[0138] According to this configuration, when the travel control devices 6B, 7B and the turning control device 8B (the first and second control devices) are electrically operated, the control device 70B can perform control to individually prohibit the driving of the travel hydraulic motors 22, 23 and the turning hydraulic motor 5 (the first and second hydraulic actuators).

[0139] [Other embodiments] It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications. The embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. It is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations.

[0140] For example, in the first and second embodiments and their modifications described above, a hydraulic excavator equipped with an object detection device was used as an example. However, the present invention can also be applied to various construction machines other than hydraulic excavators that are equipped with an object detection device.

[0141] Furthermore, in the embodiments and modifications thereof described above, an example was shown in which the object determination unit 82 of the control device 70 is configured to perform image processing on images input from cameras 36, 37, and 38, which act as object detection devices, and to determine the presence or absence of objects in the first region Rsw and the second region Rtr of the monitoring area based on the image information after image processing. However, it is also possible for the cameras 36, 37, and 38 themselves to perform image processing on the images they capture and to detect objects in the first region Rsw and the second region Rtr of the monitoring area based on the image information after image processing. In this case, the object determination unit 82 of the control device 70 should be configured to determine the presence or absence of objects in the first region Rsw and the second region Rtr (a predetermined region) of the monitoring area based on the object detection signals output from the cameras 36, 37, and 38.

[0142] Furthermore, in the embodiments and their modifications described above, an example was shown in which the object detection device is composed of a rear camera 36, ​​a left-side camera 37, and a right-side camera 38. However, the object detection device can also be composed of a laser radar sensor, an infrared sensor, an ultrasonic sensor, a millimeter-wave sensor, or the like instead of these cameras. [Explanation of symbols]

[0143] 2...Lower traveling body (traveling body), 3...Upper rotating body (rotating body), 5...Rotating hydraulic motor (hydraulic actuator), 6, 6B...Operating device for left travel (operating device), 7, 7B...Operating device for right travel (operating device), 8, 8B...Operating device for rotation (operating device), 9...Gate lock device (switching device), 22...Left traveling hydraulic motor (hydraulic actuator), 23...Right traveling hydraulic motor (hydraulic actuator), 36...Rear camera (object detection device), 37...Left side camera (object detection device), 38...Right side camera (object detection device), 45...Left traveling spool (control valve), 46...Right traveling spool (control valve), 47...Rotating spool (control valve), 51...Pilot pump (pilot hydraulic source), 54~59...Solenoid valve (pressure reducing valve), 54B~59B...Solenoid valve (pilot valve), 70, 70A, 70B... Control devices

Claims

1. The first hydraulic actuator and The second hydraulic actuator, A first operating device for operating the first hydraulic actuator, A second operating device for operating the second hydraulic actuator, A switching device capable of switching the operation of the first operating device and the second operating device to an enabled state or an disabled state, An object detection device that detects objects present within a predetermined area, In a construction machine comprising a control device capable of individually limiting the driving of the first hydraulic actuator and the second hydraulic actuator, When the control device is switched to enable operation of the first and second operating devices, and the first and second operating devices are in a neutral state, and the control device determines that an object exists within the predetermined area based on the output of the object detection device, the control device will be activated when operation of one of the first and second operating devices is initiated. Until a predetermined time has elapsed from the start of operation of the one operating device whose operation has been initiated, the driving of the hydraulic actuator corresponding to the operation of the one operating device whose operation has been initiated is permitted. After the predetermined time has elapsed, the operation of one of the hydraulic actuators is prohibited. A construction machine characterized by the following features.

2. In the construction machine described in claim 1, When the control device causes the one hydraulic actuator to be driven in response to the operation of the one operating device that has been started, it restricts the driving of the one hydraulic actuator. A construction machine characterized by the following features.

3. In the construction machine described in claim 2, The control device controls the operation of the first hydraulic actuator using different limit values ​​depending on whether it is restricting the operation of the second hydraulic actuator or not. A construction machine characterized by the following features.

4. In the construction machine described in claim 1, The predetermined time is set to differ depending on whether the first operating device is being operated or the second operating device is being operated. A construction machine characterized by the following features.

5. In the construction machine described in claim 1, The first operating device and the second operating device are each configured to generate pilot pressure from the hydraulic pressure of a pilot hydraulic source according to the operating direction and the amount of operation. A first control valve, driven by the pilot pressure generated by the first operating device, controls the supply and discharge of pressurized oil to the first hydraulic actuator, A second control valve, driven by the pilot pressure generated by the second operating device, controls the supply and discharge of pressurized oil to the second hydraulic actuator, A first pressure reducing valve capable of reducing the pilot pressure generated by the first operating device and inputting it to the first control valve, The system includes a second pressure reducing valve that can reduce the pilot pressure generated by the second operating device and input it to the second control valve, The control device prevents the operation of the one hydraulic actuator by controlling the first pressure reducing valve and the second pressure reducing valve corresponding to the one operating device, so as to shut off the pilot pressure output from the one operating device that has been started to the first control valve and the one of the second control valves corresponding to the one operating device. A construction machine characterized by the following features.

6. In the construction machine described in claim 1, A hydraulic pilot-operated first control valve controls the supply and discharge of pressurized oil to the first hydraulic actuator, A hydraulic pilot-operated second control valve controls the supply and discharge of pressurized oil to the second hydraulic actuator, A first pilot valve that generates the pilot pressure input to the first control valve, The system comprises a second pilot valve that generates a pilot pressure input to the second control valve, The first operating device is configured to output the operation of the first hydraulic actuator as an electrical signal to the control device. The second operating device is configured to output the operation of the second hydraulic actuator as an electrical signal to the control device. The control device is configured to control the first pilot valve based on an electrical signal from the first operating device, and to control the second pilot valve based on an electrical signal from the second operating device. The control device controls one of the pilot valves such that the pilot pressure output from the pilot valve corresponding to one of the hydraulic actuators (one of the first pilot valves and the second pilot valve) to the control valve corresponding to the one of the hydraulic actuators (one of the first control valves and the second control valve) is cut off, thereby preventing the operation of the one hydraulic actuator. A construction machine characterized by the following features.

7. In the construction machine described in claim 1, The aforementioned construction machine comprises a mobile body and a rotating body mounted on the mobile body so as to be rotatable, The aforementioned traveling body is configured to be driven by a hydraulic motor, The rotating body is configured to rotate relative to the traveling body by a rotating hydraulic motor, The first hydraulic actuator and the second hydraulic actuator are the travel hydraulic motor and the slewing hydraulic motor, respectively. A construction machine characterized by the following features.

Images