JP7385477B2 - working machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to working machines.

Equipped with a hydraulic pilot type control valve that controls the flow of pressure oil from the hydraulic pump to the hydraulic actuator, an electromagnetic proportional pressure reducing valve that generates pilot pressure to the control valve, and an electric lever device that commands the operation of the hydraulic actuator. 2. Description of the Related Art A working machine is known that controls an electromagnetic proportional pressure reducing valve in response to an operation signal of an electric lever device (see Patent Document 1).

The work machine described in Patent Document 1 includes an operation detecting means for detecting whether the spool of the control valve is in an operating state, and an abnormality detecting means for determining an abnormality based on the operation signal of the electric lever device and the detection result of the operation detecting means. The hydraulic actuator includes a determining means and an actuator stopping means that stops the hydraulic actuator when it is determined that there is an abnormality.

The operation detection means described in Patent Document 1 includes a pressure sensor that detects the pressure on the upstream side of a hydraulic signal line whose upstream side is connected to a pilot hydraulic pressure source, whose downstream side is connected to a tank, and which is shut off by movement of a spool of a control valve. have. The abnormality determining means determines that there is an abnormality, for example, when the spool of the control valve is operating when the electric lever device is in a non-operated state.

Therefore, if a malfunction occurs in which the proportional electromagnetic pressure reducing valve is stuck on the open side due to foreign matter entering the inside of the hydraulic pressure reducing valve and getting caught in the drive part, the abnormality determination means will Since the hydraulic actuator is stopped when it is determined that there is an abnormality, it is possible to prevent an operation that is not intended by the operator.

However, in a configuration in which the operating state of the control valve spool is detected by a pressure sensor that detects the pressure of the hydraulic oil in the oil pressure signal line, when the temperature of the hydraulic oil is low and the viscosity of the hydraulic oil is high, the oil pressure signal Misjudgment may occur due to the influence of residual pressure in the line. Therefore, in the work machine described in Patent Document 1, in order to prevent erroneous judgment when the temperature of the hydraulic oil is low, after the electric lever device is in the non-operating state, after a predetermined delay time has elapsed, Start determining abnormality.

Japanese Patent Application Publication No. 2006-308073

In the work machine described in Patent Document 1, it is possible to prevent erroneous judgments when the temperature of the hydraulic oil is low, but since a delay time is set to prevent erroneous judgments, the electromagnetic proportional pressure reducing valve (Solenoid valve) abnormality detection may be delayed.

An object of the present invention is to quickly detect an abnormality in a solenoid valve even when the temperature of hydraulic oil is low.

A work machine according to one aspect of the present invention includes a machine body, a work device having a hydraulic actuator attached to the machine body and driven by hydraulic oil discharged from a hydraulic pump, and a working machine that supplies hydraulic oil from the hydraulic pump to the hydraulic actuator. a control valve that controls the flow of the control valve, an electric operating device that outputs a signal according to the amount of operation of the operating member, and a solenoid valve that generates a command pilot pressure to the control valve using the hydraulic pressure of a pilot hydraulic pressure source as a source pressure. a control device that controls the solenoid valve based on a signal from the operating device; a posture sensor that detects the posture of the working device; and a notification device that makes a notification based on the signal from the control device. The working machine further includes a pressure sensor that detects the command pilot pressure, and the control device determines whether or not the operating device is operating the working device based on a signal from the operating device. a first operation determination for determining whether or not the working device is operating based on a signal from the posture sensor; and a first operation determination for determining whether or not the working device is operating based on the signal from the pressure sensor. a second operation determination for determining whether or not the solenoid valve based on a first abnormality determination for determining whether an abnormality has occurred in the operating device, a determination result for determining whether or not an operation is being performed on the working device by the operating device, and a determination result for the second operation determination. and a second abnormality determination to determine whether or not an abnormality has occurred in the solenoid valve, and at least one of the determination result of the first abnormality determination and the determination result of the second abnormality determination is If the determination result is that an abnormality has occurred in the electromagnetic valve, the notification device is made to notify that an abnormality has occurred in the electromagnetic valve.

According to the present invention, an abnormality in a solenoid valve can be quickly detected even when the temperature of the hydraulic oil is low.

A side view of a hydraulic excavator. A schematic diagram of the inside of the driver's cab viewed from the rear of the driver's seat toward the front. FIG. 1 is a diagram showing a hydraulic system and a control device mounted on a hydraulic excavator. FIG. 2 is a functional block diagram of a control device according to the present embodiment. FIG. 3 is a diagram showing the relationship between the operating angle of the operating lever and the target pilot pressure. A diagram showing the relationship between target pilot pressure and target current. The figure which shows the dimension data used for calculation of the stroke of a boom cylinder. The figure which shows the relationship between the temperature of hydraulic oil and a time threshold value. 5 is a flowchart showing the contents of notification processing executed by the control device according to the present embodiment. 7 is a flowchart showing the contents of the first abnormality determination process executed by the control device according to the present embodiment. 7 is a flowchart showing the contents of a second abnormality determination process executed by the control device according to the present embodiment. 7 is a flowchart showing the contents of a notification process executed by a control device according to modification 1 of the present embodiment. FIG. 7 is a functional block diagram of a control device according to modification example 2-1 of the present embodiment. 12 is a flowchart showing the contents of the first abnormality determination process executed by the control device according to modification example 2-1 of the present embodiment. 12 is a flowchart showing the contents of a notification process executed by a control device according to a fourth modification of the present embodiment.

A working machine according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example in which the work machine is a crawler type hydraulic excavator will be described.

FIG. 1 is a side view of the hydraulic excavator 1. For convenience of explanation, the longitudinal and vertical directions of the hydraulic excavator 1 are defined as shown in FIG. That is, in this embodiment, unless otherwise specified, the front of the driver's seat (to the left in the figure) is the front of the hydraulic excavator 1. The hydraulic excavator 1 includes a body (vehicle body) 4 and a working device 10 attached to the body 4. The body 4 includes a traveling body 2 and a revolving body 3 rotatably provided on the traveling body 2, and a working device 10 is attached to the front part of the revolving body 3. The traveling body 2 travels by driving a pair of left and right crawlers by a travel motor 2a.

The revolving body 3 includes a revolving frame 8 serving as a base member, a driver's cab 7 provided on the front left side of the revolving frame 8, a counterweight 9 provided at the rear of the revolving frame 8, and a driver's cab 7 in the revolving frame 8. It has an engine compartment 6 provided on the rear side. The engine room 6 houses an engine that is a power source, hydraulic equipment, and the like. A working device 10 is rotatably connected to the front center of the swing frame 8 .

The working device 10 is a multi-jointed working device that includes a plurality of rotatably connected front members and a plurality of hydraulic cylinders that drive the front members. In this embodiment, a boom 11, an arm 12, and a bucket 13 as three front members are connected in series. The base end of the boom 11 is rotatably connected to the front part of the swing frame (base member) 8 by a boom pin 11b. The base end of the arm 12 is rotatably connected to the distal end of the boom 11 by an arm pin 12b. The bucket 13 is rotatably connected to the tip of the arm 12 by a bucket pin 13b. The boom pin 11b, the arm pin 12b, and the bucket pin 13b are arranged parallel to each other, and each member (8, 11, 12, 13) is relatively rotatable within the same plane.

The boom 11 is driven by a hydraulic cylinder (hereinafter also referred to as a boom cylinder 11a) that is an actuator, and rotates with respect to the swing frame 8. The arm 12 is driven by a hydraulic cylinder (hereinafter also referred to as arm cylinder 12a) that is an actuator, and rotates with respect to the boom 11. The bucket 13 is driven by a hydraulic cylinder (hereinafter also referred to as bucket cylinder 13a) that is an actuator, and rotates with respect to the arm 12. The boom cylinder 11a has one end connected to the boom 11 and the other end connected to the swing frame 8. The arm cylinder 12a has one end connected to the arm 12 and the other end connected to the boom 11. The bucket cylinder 13a has one end connected to the bucket 13 via a link member and the other end connected to the arm 12.

A boom angle sensor 50a is attached to the boom 11 for measuring the angle of the boom 11 with respect to the rotating structure 3 (boom angle). An arm angle sensor 50b for measuring the angle of the arm 12 with respect to the boom 11 (arm angle) is attached to the arm 12. A bucket angle sensor 50c for measuring the angle of the bucket 13 with respect to the arm 12 (bucket angle) is attached to a link member connecting the bucket 13 and the arm 12. A rotating body angle sensor 50d is attached to the rotating body 3 to measure the inclination angle of the rotating body 3 (airframe 4) with respect to a reference plane (for example, a horizontal plane). Note that the angle sensors 50a, 50b, and 50c can be replaced with angle sensors that can each detect the angle of inclination (that is, the angle from the ground) with respect to a reference plane (horizontal plane).

FIG. 2 is a schematic diagram of the inside of the driver's cab 7 when viewed from the rear side of the driver's seat 75 toward the front. As shown in FIG. 2, inside the operator's cab 7, there is a driver's seat 75 where an operator sits, control levers (B1 to B4) for operating various parts of the hydraulic excavator 1, and control levers for controlling the operation of the hydraulic excavator 1. A control device 100 and a display device 18 that displays a predetermined display image on a display screen based on a signal from the control device 100 are provided. A right operating lever B1 is provided on the right side of the driver's seat 75 for operating the bucket 13 and the boom 11, and a right operating lever B1 is provided on the left side of the driver's seat 75 for operating the rotating structure 3 and the arm 12. A left operating lever B2 is provided. A pair of left and right travel levers (a left travel lever B4 and a right travel lever B3) are provided in front of the driver's seat 75. The left traveling lever B4 is an operating lever for operating the left crawler, and the right traveling lever B3 is an operating lever for operating the right crawler.

A gate lock lever (pilot shutoff lever) B5 is provided on the left side of the left operation lever B2. The gate lock lever B5 is a member that can be operated between a lock position (raised position) that allows entry and exit of the driver's cab 7 and an unlocked position (lower position) that prohibits entry and exit of the driver's cab 7.

The display device 18 is composed of, for example, a liquid crystal panel, etc., and is connected to the control device 100, and displays a display image representing operating information of the hydraulic excavator 1, etc. on the display screen based on a display control signal from the control device 100. let The display device 18 is attached to the right pillar 76 when viewed from the driver's seat 75 side. The control device 100 is provided behind the driver's seat 75 in the driver's cab 7 .

FIG. 3 is a diagram showing the hydraulic system 30 and control device 100 mounted on the hydraulic excavator 1. In addition, in the following, a travel motor (hydraulic motor), a swing motor (hydraulic motor), a boom cylinder (hydraulic cylinder) 11a, an arm cylinder (hydraulic cylinder) 12a, and a bucket cylinder (hydraulic cylinder) 13a mounted on the hydraulic excavator 1 will be described. They are also collectively referred to as hydraulic actuators. The hydraulic system 30 is provided with a plurality of hydraulic actuators, and in FIG. 3, a hydraulic cylinder 37 (for example, the boom cylinder 11a) for driving the front member of the working device 10 is shown as a representative. . Furthermore, an electric operating device 34 that operates the hydraulic actuator and a control valve 40 that is driven in accordance with the operation of the operating device 34 are provided for each of a plurality of hydraulic actuators, but in FIG. An operating device (for example, an operating device having an operating lever B1 (34a)) 34 and one control valve 40 are illustrated.

The hydraulic system 30 includes a main pump 31 , a pilot pump 32 , a hydraulic cylinder 37 driven by hydraulic oil as a working fluid discharged from the main pump 31 , and a hydraulic cylinder 37 that controls the flow of hydraulic oil from the main pump 31 to the hydraulic cylinder 37 . It includes a control valve 40 to be controlled, and electromagnetic proportional pressure reducing valves (hereinafter referred to as electromagnetic valves) 33a, 33b (33) that generate a command pilot pressure to pressure receiving parts 41a, 41b (41) of the control valve 40.

The main pump 31 and the pilot pump 32 are connected to the engine 80 and are driven by the engine 80 to discharge hydraulic oil (pressure oil). The main pump 31 is a variable displacement hydraulic pump, and the pilot pump 32 is a fixed displacement hydraulic pump. The engine 80 is a power source for the hydraulic excavator 1, and is configured by, for example, an internal combustion engine such as a diesel engine. The hydraulic cylinder 37 includes a bottomed cylindrical cylinder tube 37s with one end closed, a head cover that closes the opening at the other end of the cylinder tube 37s, and a piston rod 37r that passes through the head cover and is inserted into the cylinder tube 37s. A piston is provided at the tip of the piston rod 37r and partitions the inside of the cylinder tube 37s into a rod chamber and a bottom chamber.

The electromagnetic valves 33a, 33b generate command pilot pressures to be output to the pressure receivers 41a, 41b of the control valve 40 using the discharge pressure (hydraulic pressure) of the pilot pump 32, which is a pilot oil pressure source, as a source pressure. The solenoid valves 33a and 33b are controlled based on signals from the control device 100. The operating device 34 outputs a signal to the control device 100 according to the amount of operation of the operating lever (operating member) 34a. Control device 100 controls electromagnetic valves 33a and 33b based on signals from operating device 34.

When the command pilot pressure generated by the solenoid valve 33a acts on the pressure receiving part 41a of the control valve 40 located at the neutral position (N), the control valve 40 is driven in one direction, and the control valve 40 is moved to the neutral position (N). N) to the first position (P1). As a result, the pressure oil discharged from the main pump 31 is guided to the bottom chamber of the hydraulic cylinder 37 (boom cylinder 11a), and the hydraulic oil is discharged from the rod chamber to the tank 39, causing the hydraulic cylinder 37 (boom cylinder 11a) to extend. do. As a result, the front member (boom 11) rotates in the first direction (upward).

When the command pilot pressure generated by the solenoid valve 33b acts on the pressure receiving part 41b of the control valve 40 located at the neutral position (N), the control valve 40 is driven in the other direction, and the control valve 40 is moved to the neutral position (N). N) to the second position (P2). As a result, the pressure oil discharged from the main pump 31 is guided to the rod chamber of the hydraulic cylinder 37 (boom cylinder 11a), and the hydraulic oil is discharged from the bottom chamber to the tank 39, causing the hydraulic cylinder 37 (boom cylinder 11a) to contract. do. As a result, the front member (boom 11) rotates in the second direction (downward).

A pressure sensor is installed in the pilot line connecting the solenoid valves 33a, 33b (33) and the pressure receiving parts 41a, 41b (41) of the control valve 40 to detect the command pilot pressure, which is the pressure of the hydraulic oil acting on the pressure receiving part 41. 38a, 38b (38) are provided. The pressure sensors 38a and 38b are connected to a control device 100, which will be described later, and output a signal related to the detected command pilot pressure to the control device 100.

Hydraulic oil discharged from the main pump 31 is supplied to the hydraulic cylinder 37 through the control valve 40, and the working device 10 is driven. Although not shown, the hydraulic oil discharged from the main pump 31 is supplied to the swing hydraulic motor and the traveling hydraulic motor through a control valve, and the rotating body 3 and the traveling body 2 are each driven.

When the gate lock lever B5 (see FIG. 2) is operated to the lock position, the switching valve 36 provided in the pilot line between the pilot pump 32 and the electromagnetic valve 33 is switched to the cutoff position. As a result, the pilot source pressure to the solenoid valve 33 is cut off, and the operation by the operating lever 34a is disabled. When the gate lock lever B5 is operated to the unlock position, the switching valve 36 provided in the pilot line between the pilot pump 32 and the electromagnetic valve 33 is switched to the communication position. Therefore, when the gate lock lever B5 is in the unlocked position, a command pilot pressure corresponding to the amount of operation of the operating lever 34a is generated by the solenoid valve 33, and the hydraulic actuator corresponding to the operated operating lever 34a is operated. .

The hydraulic excavator 1 includes a control device 100 for controlling each device mounted on the hydraulic excavator 1, an input device 19 that inputs a predetermined signal to the control device 100 when operated by an operator, and a It includes a display device 18 that displays a predetermined image on a display screen based on the output signal.

The control device 100 includes a CPU (Central Processing Unit) 111 as an operating circuit, a ROM (Read Only Memory) 112 as a storage device, a RAM (Random Access Memory) 113 as a storage device, an input interface 114, an output interface 115, and others. It consists of a microcomputer with peripheral circuits. The control device 100 may be composed of one microcomputer or may be composed of multiple microcomputers. The ROM 112 of the control device 100 is a nonvolatile memory such as an EEPROM, and stores programs that can execute various calculations. That is, the ROM 112 of the control device 100 is a storage medium that can read a program that implements the functions of this embodiment. The RAM 113 is a volatile memory, and is a work memory that directly inputs and outputs data to and from the CPU 111. The RAM 112 temporarily stores necessary data while the CPU 111 is executing a program. Note that the control device 100 may further include a storage device such as a flash memory or a hard disk drive.

The CPU 111 is a processing device that loads a control program stored in the ROM 112 into the RAM 113 and executes arithmetic operations, and performs predetermined arithmetic processing on signals taken in from the input interface 114 and the ROM 112 and RAM 113 according to the control program. Signals from the input device 19, the pressure sensors 38a and 38b, the temperature sensor 20, the posture detection device 50, and the operation sensor 34b of the operation device 34 are input to the input interface 114. The input interface 114 converts the input signal so that the CPU 111 can perform calculations. The output interface 115 generates an output signal according to the calculation result of the CPU 111, and outputs the signal to the electromagnetic valves 33a, 33b of the hydraulic system 30 and the display device 18.

The temperature sensor 20 detects the temperature T of the hydraulic oil discharged from the pilot pump 32 and outputs a signal representing the detection result to the control device 100. The operation sensor 34b detects the operation angle θ (operation amount) of the operation lever 34a, and outputs a signal representing the detection result to the control device 100. The operating angle θ of the operating lever 34a detected by the operating sensor 34b is 0° when the operating lever 34a is at the neutral position, and its absolute value becomes larger as it is tilted from the neutral position.

The attitude detection device 50 includes a boom angle sensor 50a, an arm angle sensor 50b, a bucket angle sensor 50c, and a rotating body angle sensor 50d. These angle sensors 50a, 50b, 50c, and 50d acquire information regarding the posture of the working device 10, and output signals according to the information. That is, the angle sensors 50a, 50b, 50c, and 50d function as posture sensors that detect the posture of the working device 10.

For example, the angle sensors 50a, 50b, and 50c may be potentiometers that obtain a boom angle, an arm angle, and a bucket angle as information regarding the posture, and output a signal (voltage) according to the obtained angles. In addition, the rotating body angle sensor 50d acquires the angular velocity and acceleration of three orthogonal axes as information regarding the attitude, calculates the tilt angle of the rotating body 3 (airframe 4) based on this information, and controls the signal representing the tilt angle. An IMU (Inertial Measurement Unit) that outputs to the device 100 can be employed. Note that the calculation of the inclination angle of the rotating body 3 (aircraft body 4) may be performed by the control device 100 based on the output signal of the IMU. Further, the angle sensors 50a, 50b, 50c of the present embodiment are not limited to the case where potentiometers are used to detect the angles of the front members 11, 12, 13, and instead of the potentiometers, the angle sensors 50a, 50b, 50c of the front members 11, 12, 13 IMUs capable of detecting angles may be employed as the angle sensors 50a, 50b, and 50c.

FIG. 4 is a functional block diagram of the control device 100. As shown in FIG. 4, the control device 100 executes the program stored in the ROM 112 to control the target pilot pressure calculation section 101, the target current calculation section 102, the current supply section 103, the cylinder stroke calculation section 104, and the stroke It functions as a displacement amount calculation section 105, a first abnormality determination section 106, a second abnormality determination section 107, and a display control section 108.

The target pilot pressure calculation unit 101 calculates the target pilot pressure Pt based on the operation angle θ (operation amount) of the operation lever 34a detected by the operation sensor 34b. The target pilot pressure Pt is a target value of the command pilot pressure applied to the pressure receiving parts 41a and 41b of the control valve 40.

FIG. 5 is a diagram showing the relationship between the operating angle θ of the operating lever 34a and the target pilot pressure Pt. The characteristic N1 shown in FIG. 5 is stored in the ROM 112 of the control device 100 in a look-up table format. Characteristic N1 is a characteristic in which the target pilot pressure Pt increases as the absolute value of the operating angle θ increases. The target pilot pressure calculation unit 101 refers to the table of characteristics N1 shown in FIG. 5 and calculates the target pilot pressure Pt based on the operation angle θ detected by the operation sensor 34b. The target pilot pressure Pt is the minimum value Ptmin when the operating lever 34a is in the dead zone including the neutral position (operating angle θ = 0), and when the operating lever 34a is operated to the maximum operating position (operating angle θ = θmax). The maximum value is Ptmax.

The target current calculation section 102 shown in FIG. 4 calculates the target current It based on the target pilot pressure Pt calculated by the target pilot pressure calculation section 101. The target current It is a target value of the control current supplied to the solenoid of the electromagnetic valve 33.

FIG. 6 is a diagram showing the relationship between target pilot pressure Pt and target current It. The ROM 112 of the control device 100 stores the characteristic N2 shown in FIG. 6 in a look-up table format. Characteristic N2 is a characteristic in which the target current It increases as the target pilot pressure Pt increases. The target current calculation unit 102 refers to the table of characteristics N2 shown in FIG. 6 and calculates the target current It based on the target pilot pressure Pt calculated by the target pilot pressure calculation unit 101. The target current It becomes the minimum value Itmin when the target pilot pressure Pt is the minimum value Ptmin, and becomes the maximum value Itmax when the target pilot pressure Pt is the maximum value Ptmax.

The current supply unit 103 shown in FIG. 4 adjusts the magnitude of the control current supplied to the solenoid of the electromagnetic valve 33 based on the target current It calculated by the target current calculation unit 102. In this embodiment, the solenoid valve 33 is configured such that the degree of pressure reduction decreases as the control current input to the solenoid increases. That is, the solenoid valve 33 is a positive type electromagnetic proportional pressure reducing valve in which the generated command pilot pressure (secondary pressure) increases as the input control current increases.

The cylinder stroke calculation unit 104 calculates the stroke (length) of the hydraulic cylinder 37 based on the dimensional data of the hydraulic excavator 1 and the detection result by the posture detection device 50. Referring to FIG. 7, as an example of a method of calculating the stroke of the hydraulic cylinder 37, the stroke BmSt of the boom cylinder 11a (that is, from the center point P of the bottom side pin of the boom cylinder 11a to the center of the rod side pin of the boom cylinder 11a The calculation method for the length (to point Q) will be explained. FIG. 7 is a diagram showing dimensional data (AP, AQ, ∠BAQ, ∠PAX) used to calculate the stroke BmSt of the boom cylinder 11a. The cylinder stroke calculation unit 104 calculates the stroke BmSt in an excavator reference coordinate system (vehicle body coordinate system) in which the z-axis is the rotation center axis of the rotating body 3, and the x-axis is an axis orthogonal to each of the boom pin 11b and the rotation center axis. .

The stroke BmSt of the boom cylinder 11a is determined by the boom angle BmAng calculated based on the dimensional data (AP, AQ, ∠BAQ, ∠PAX) of the hydraulic excavator 1 and the detection result of the attitude detection device 50 according to the cosine theorem. , expressed by equation (1).

Here, AP is the length from the center point A of the boom pin 11b to the center point P of the bottom side pin of the boom cylinder 11a, and AQ is the length from the center point A of the boom pin 11b to the rod side pin of the boom cylinder 11a. is the length to the center point Q. ∠BAQ is the angle formed by the line segment (AQ), which is a straight line connecting center point A and center point Q, and the line segment (AB), which is a straight line connecting center point A and center point B of arm pin 12b. . ∠PAX is the angle formed by the line segment (AP), which is a straight line connecting center point A and center point P, and the x-axis. These dimension data (AP, AQ, ∠BAQ, ∠PAX) are stored in the ROM 112 in advance. BmAng is the angle between the line segment (AB) and the x-axis, and corresponds to the boom angle calculated based on the detection result by the attitude detection device 50.

The cylinder stroke calculation unit 104 shown in FIG. 4 similarly calculates the stroke of the arm cylinder 12a and the stroke of the bucket cylinder 13a. Hereinafter, the stroke BmSt of the boom cylinder 11a, the stroke of the arm cylinder 12a, and the stroke of the bucket cylinder 13a calculated by the cylinder stroke calculation unit 104 will be collectively referred to as a stroke St.

The stroke displacement calculation section 105 calculates the stroke displacement amount Δx based on the stroke St calculated by the cylinder stroke calculation section 104. The stroke displacement amount Δx is calculated by the stroke St (current value) calculated by the cylinder stroke calculation unit 104 and the stroke St′ (current value) calculated by the cylinder stroke calculation unit 104 before a predetermined control cycle (for example, one control cycle ago). It corresponds to the absolute value of the difference between (previous value) and (Δx=|St−St′|).

The first abnormality determination section 106 and the second abnormality determination section 107 determine whether or not an abnormality has occurred in the solenoid valve 33. Here, the abnormality of the solenoid valve 33 refers to contamination, which is a sticking phenomenon in which the valve body of the solenoid valve 33a stops moving due to foreign matter entering the inside of the solenoid valve 33a and getting caught in the driving part. , indicates that the solenoid valve 33 is unable to operate appropriately in response to the operation of the operating device 34.

The first abnormality determining unit 106 and the second abnormality determining unit 107 detect the operating device 10 in a state where the operating lever 34a of the operating device 34 is being operated, and which corresponds to the operation of the operating lever 34a of the operating device 34. If the state in which the hydraulic cylinder 37 is not operating continues for a predetermined period of time or more, it is determined that a closing-side sticking abnormality in which the electromagnetic valve 33 is stuck on the closing side has occurred. Note that the closed-side sticking abnormality refers to an abnormality in which the valve body of the solenoid valve 33 is stuck so that the state in which the pilot pump 32 and the pressure receiving part 41 are kept disconnected via the solenoid valve 33 is maintained. refers to

For example, if the boom cylinder 11a is not operated for a predetermined period of time or more even though the boom is raised by the operation lever B1, the first abnormality determination section 106 and the second abnormality determination section 107 It is determined that a closed side sticking abnormality has occurred, in which the door is stuck on the closed side.

The first abnormality determination unit 106 and the second abnormality determination unit 107 are in a state in which the hydraulic cylinder 37 of the working device 10 is operating, and the operating lever 34a of the operating device 34 for driving the hydraulic cylinder 37 is activated. If the state in which the solenoid valve 33 is not operated continues for a predetermined period of time or more, it is determined that an open side sticking abnormality in which the solenoid valve 33 is stuck on the open side has occurred. Note that the open side sticking abnormality refers to an abnormality in which the valve body of the solenoid valve 33 is stuck so that the pilot pump 32 and the pressure receiving part 41 are maintained in communication via the solenoid valve 33. refers to

For example, after the boom cylinder 11a is extended in response to a boom raising operation using the operating lever B1, the operating lever B1 is returned to the neutral position, and then the operating lever B1 is not operated for a predetermined period of time. As described above, when the boom cylinder 11a is operating, the first abnormality determining section 106 and the second abnormality determining section 107 determine that an open side sticking abnormality in which the solenoid valve 33a is stuck on the open side has occurred. .

The first abnormality determination unit 106 determines whether the electromagnetic valve 33 is abnormal based on the target pilot pressure Pt calculated by the target pilot pressure calculation unit 101 and the stroke displacement amount Δx calculated by the stroke displacement amount calculation unit 105. Determine whether it has occurred.

The second abnormality determination unit 107 determines whether an abnormality has occurred in the solenoid valve 33 based on the target pilot pressure Pt calculated by the target pilot pressure calculation unit 101 and the command pilot pressure Pp detected by the pressure sensor 38. Determine whether or not there is.

Hereinafter, the abnormality determination methods by the first abnormality determination section 106 and the second abnormality determination section 107 will be described in detail.

The first abnormality determination unit 106 determines that the operating lever 34a of the operating device 34 is being operated when the target pilot pressure Pt is equal to or higher than the threshold value Pt0, and when the target pilot pressure Pt is less than the threshold value Pt0, the operating device It is determined that the operating lever 34a of No. 34 is not operated. Note that the threshold value Pt0 is a threshold value for determining whether or not the operating lever 34a is operated, and is stored in advance in the ROM 112 of the control device 100. The threshold value Pt0 is a value larger than the above-mentioned minimum value Ptmin and smaller than the maximum value Ptmax (Ptmin<Pt0<Ptmax).

Further, the first abnormality determination unit 106 determines that the hydraulic cylinder 37 of the working device 10 is operating when the stroke displacement amount Δx is greater than or equal to the threshold value x0, and when the stroke displacement amount Δx is less than the threshold value x0, It is determined that the hydraulic cylinder 37 of the working device 10 is not operating. Note that the threshold value x0 is a threshold value for determining whether or not the hydraulic cylinder 37 is performing an expansion/contraction or contraction operation, and in this embodiment, a value that can be determined as the beginning of movement of the hydraulic cylinder 37 is set. There is. When the operating lever 34a of the operating device 34 is operated, a predetermined time is required until the cylinder speed reaches a cylinder speed corresponding to the operating amount (operating angle θ). Therefore, in the present embodiment, the stroke displacement amount during a predetermined control period before reaching the cylinder speed corresponding to the operation amount (operation angle θ) is set as the threshold value x0.

The first abnormality determination unit 106 determines that the target pilot pressure Pt is less than the threshold value Pt0 (the operating lever 34a is not operated) and the stroke displacement amount Δx is greater than or equal to the threshold value x0 (the hydraulic cylinder 37 is not operated). In this case, the first timer built in the control device 100 measures the time. The first abnormality determination unit 106 determines that when the time t1 measured by the first timer becomes the time threshold ta or more in a state where the target pilot pressure Pt is less than the threshold value Pt0 and the stroke displacement amount Δx is the threshold value x0 or more, It is determined that an open side sticking abnormality in which the solenoid valve 33 is stuck on the open side has occurred. The time threshold ta is a threshold for determining whether an open side sticking abnormality has occurred, and is stored in the ROM 112 of the control device 100 in advance. If the first abnormality determining unit 106 determines that the open side sticking abnormality has occurred, it sets the first open side sticking flag Fo1 to ON (Fo1=1).

Further, the first abnormality determination unit 106 determines that the target pilot pressure Pt is equal to or higher than the threshold value Pt0 (the operating lever 34a is in the operated state), and the stroke displacement amount Δx is less than the threshold value x0 (the hydraulic cylinder 37 is in the stopped state). ), the first timer built into the control device 100 measures the time. The first abnormality determination unit 106 determines that when the time t1 measured by the first timer becomes the time threshold tb or more in a state where the target pilot pressure Pt is the threshold value Pt0 or more and the stroke displacement amount Δx is less than the threshold value x0, It is determined that a closing side sticking abnormality in which the electromagnetic valve 33 is stuck on the closing side has occurred. The time threshold tb is a threshold for determining whether a closed side sticking abnormality has occurred, and is stored in the ROM 112 of the control device 100 in advance. In this embodiment, the time threshold ta and the time threshold tb are set to the same value, but may be set to different values. If the first abnormality determining unit 106 determines that the closing side sticking abnormality has occurred, it sets the first closing side sticking flag Fc1 to ON (Fc1=1).

When the target pilot pressure Pt is equal to or greater than the threshold value Pt0 and the stroke displacement amount Δx is equal to or greater than the threshold value x0, the first abnormality determination unit 106 resets the first timer and sets the measurement time t1 to 0 (zero). At the same time, the first closed side fixing flag Fc1 is set to OFF (Fc1=0). When the target pilot pressure Pt is less than the threshold value Pt0 and the stroke displacement amount Δx is less than the threshold value x0, the first abnormality determination unit 106 resets the first timer and sets the measurement time t1 to 0 (zero). At the same time, the first open side fixation flag Fo1 is set to OFF (Fo1=0).

Similar to the first abnormality determining unit 106, the second abnormality determining unit 107 determines that the operating lever 34a of the operating device 34 is operated when the target pilot pressure Pt is equal to or higher than the threshold value Pt0, and the target pilot pressure Pt is If it is less than the threshold value Pt0, it is determined that the operating lever 34a of the operating device 34 is not operated.

Furthermore, when the command pilot pressure Pp detected by the pressure sensor 38 is equal to or higher than the threshold value Pp0, the second abnormality determination unit 107 determines that the hydraulic cylinder 37 of the working device 10 is operating, and the command pilot pressure Pp is If it is less than the threshold Pp0, it is determined that the hydraulic cylinder 37 of the working device 10 is not operating. Note that the threshold value Pp0 is a threshold value for determining whether or not the hydraulic cylinder 37 is performing an expansion/contraction or contraction operation, and in this embodiment, a value that can be determined as the beginning of movement of the hydraulic cylinder 37 is set. There is.

The second abnormality determination unit 107 determines that the target pilot pressure Pt is less than the threshold value Pt0 (the operating lever 34a is in the non-operated state) and the command pilot pressure Pp is the threshold value Pp0 or more (the hydraulic cylinder 37 is in the operating state). In this case, the second timer built into the control device 100 measures the time. The second abnormality determination unit 107 determines that when the time t2 measured by the second timer becomes the time threshold tc or more in a state where the target pilot pressure Pt is less than the threshold Pt0 and the command pilot pressure Pp is the threshold Pp0 or more, It is determined that an open side sticking abnormality in which the solenoid valve 33 is stuck on the open side has occurred. When determining that the open side sticking abnormality has occurred, the second abnormality determining unit 107 sets the second open side sticking flag Fo2 to ON (Fo2=1).

Further, the second abnormality determination unit 107 determines that when the target pilot pressure Pt is equal to or higher than the threshold value Pt0 (the operating lever 34a is in the operating state) and the command pilot pressure Pp is less than the threshold value Pp0 (the hydraulic cylinder 37 is stopped). state), the second timer built into the control device 100 measures the time. The second abnormality determination unit 107 determines that when the time t2 measured by the second timer becomes the time threshold td or more in a state where the target pilot pressure Pt is the threshold value Pt0 or more and the command pilot pressure Pp is less than the threshold value Pp0, It is determined that a closing side sticking abnormality in which the electromagnetic valve 33 is stuck on the closing side has occurred. When the second abnormality determining unit 107 determines that the closing side sticking abnormality has occurred, it sets the second closing side sticking flag Fc2 to ON (Fc2=1).

Here, when the temperature T of the hydraulic oil is low and the viscosity of the hydraulic oil is high, the rate at which the command pilot pressure Pp increases when the operating lever 34a is operated from the neutral position to the maximum operating position is higher than the temperature T of the hydraulic oil. slower than usual. Further, when the temperature T of the hydraulic oil is low, the rate of decrease in the command pilot pressure when the operating lever 34a is returned from the maximum operating position to the neutral position is slower than when the temperature of the hydraulic oil is high.

Therefore, when the temperature T of the hydraulic oil is low, the time thresholds tc, td used for the determination by the second abnormality determination section 107 are set to the same level as the time thresholds ta, tb used for the determination by the first abnormality determination section 106. If the time threshold value is set to , there is a risk that an erroneous determination will occur. In this embodiment, the time threshold values tc and td are set based on the temperature T of the hydraulic oil in order to prevent erroneous determination when the temperature T of the hydraulic oil is low. The second abnormality determination unit 107 refers to the threshold value setting table shown in FIG. 8 and calculates the time threshold values tc and td based on the temperature T of the hydraulic oil detected by the temperature sensor 20. FIG. 8 is a diagram showing the relationship between the temperature T of the hydraulic oil and the time thresholds tc and td.

As shown in FIG. 8, in this embodiment, the time threshold values tc and td are the maximum value tmax (for example, about 1.0 [sec]) when the temperature T of the hydraulic oil is less than the first temperature T1, and the When the temperature T is higher than the first temperature T1 and lower than the second temperature T2, it becomes shorter as the temperature T of the hydraulic oil increases, and when the temperature T of the hydraulic oil is higher than the second temperature T2, the minimum value tmin (for example, 0.2 [ sec). In the figure, the time threshold value tc=td=tmin set when the temperature T of the hydraulic oil is sufficiently high (T≧T2) is the time threshold value ta, tb used for abnormality determination in the first abnormality determination section 106. Same value. In this embodiment, the same threshold setting table is used to calculate the time threshold tc and the time threshold td, but a different threshold setting table may be used to calculate the time threshold tc and td. .

The second abnormality determination unit 107 shown in FIG. 4 resets the second timer and sets the measurement time t2 to 0 ( zero), and the second closed side fixing flag Fc2 is set to OFF (Fc2=0). When the target pilot pressure Pt is less than the threshold value Pt0 and the command pilot pressure Pp is less than the threshold value Pp0, the second abnormality determination unit 107 resets the second timer and sets the measurement time t2 to 0 (zero). At the same time, the second open side fixation flag Fo2 is set to OFF (Fo2=0).

When the first abnormality determining section 106 or the second abnormality determining section 107 determines that an abnormality has occurred in the solenoid valve 33, the display control section 108 sends a predetermined display control signal to the display device 18 as a notification device. Execute notification processing to output. In the notification process, when a predetermined display control signal is output from the control device 100 to the display device 18, the display device 18 displays a display image indicating that an abnormality has occurred in the solenoid valve 33 on the display screen. As a result, a notification is issued to inform the operator that an abnormality has occurred in the solenoid valve 33.

As described above, the control device 100 according to the present embodiment determines whether or not the operating device 34 is operating the work device 10 based on the signal from the electric operating device 34, and It is determined whether or not the working device 10 is operating based on the signal from the operating device 34, and the result of the determination as to whether or not the operating device 10 is operated by the operating device 34 and whether or not the working device 10 is operating is determined. Based on the determination result, it is determined whether or not an abnormality has occurred in the solenoid valve 33.

The details of the processing executed by the control device 100 will be described below with reference to FIGS. 9 to 11. For convenience of explanation, an example will be described in which the hydraulic cylinder 37 to be operated by the operator is the boom cylinder 11a. FIG. 9 is a flowchart showing the details of the notification process executed by the control device 100. The process of the flowchart shown in FIG. 9 is started when an ignition switch (not shown) is turned on, and after initial settings (not shown) are performed, it is repeatedly executed at a predetermined control cycle. In the initial settings, flags Fo1, Fc1, Fo2, and Fc2 are set to off (Fo1=Fc1=Fo2=Fc2=0. Note that the processing in steps S10 and S15 and the processing in steps S20 and S25 are performed as parallel processing. executed.

As shown in FIG. 9, in step S10, the control device 100 determines whether either the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 is on (Fo1=1 or Fc1=1). Determine. In step S10, if it is determined that either the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 is on, the process proceeds to step S15, and the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 is turned on. If it is determined that none of the flags Fc1 is on (that is, off (Fo1=Fc1=0)), the process shown in the flowchart of FIG. 9 ends.

In step S15, the control device 100 executes the first notification process, and ends the process shown in the flowchart of FIG. In the first notification process S15, if the first open side sticking flag Fo1 is set to ON, the control device 100 sends a message indicating that the solenoid valve 33 is in an abnormal state stuck on the open side. It is displayed on the display screen of the display device 18. In the first notification process S15, the control device 100 sends a message indicating that the solenoid valve 33 is in an abnormal state stuck on the closed side when the first closed side stuck flag Fc1 is set to ON. It is displayed on the display screen of the display device 18.

In step S20, the control device 100 determines whether either the second open-side fixation flag Fo2 or the second close-side fixation flag Fc2 is on (Fo2=1 or Fc2=1). If it is determined in step S20 that either the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is on, the process proceeds to step S25, where the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is turned on. If it is determined that none of the flags Fc2 is on (that is, off (Fo2==Fc2=0)), the process shown in the flowchart of FIG. 9 ends.

In step S25, the control device 100 executes the second notification process, and ends the process shown in the flowchart of FIG. In the second notification process S25, if the second open side sticking flag Fo2 is set to ON, the control device 100 sends a message indicating that the solenoid valve 33 is in an abnormal state stuck on the open side. It is displayed on the display screen of the display device 18. In the second notification process S25, the control device 100 sends a message indicating that the solenoid valve 33 is in an abnormal state stuck on the closed side when the second closed side stuck flag Fc2 is set to ON. It is displayed on the display screen of the display device 18.

FIG. 10 is a flowchart showing the contents of the first abnormality determination process executed by the control device 100. FIG. 11 is a flowchart showing the contents of the second abnormality determination process executed by the control device 100. The processes in the flowcharts shown in FIGS. 10 and 11 are started when an ignition switch (not shown) is turned on, and after initial settings (not shown) are performed, they are repeatedly executed at a predetermined control cycle. In the initial setting, flags Fo1, Fc1, Fo2, and Fc2 are set to off (Fo1=Fc1=Fo2=Fc2=0, and the measurement time t1 by the first timer and the measurement time t2 by the second timer are reset (t1= 0, t2=0).

Note that the flow for determining whether or not the solenoid valve 33 that drives the boom cylinder 11a is abnormal, the flow for determining whether or not the solenoid valve 33 that drives the arm cylinder 12a is abnormal, and the flow for determining whether or not the solenoid valve 33 that drives the arm cylinder 12a is abnormal, and the flow for determining whether or not the solenoid valve 33 that drives the arm cylinder 12a is abnormal. The flow for determining whether or not the electromagnetic valve 33 to be driven is abnormal is the same flow. Therefore, below, the flow for determining whether or not the solenoid valve 33 that drives the boom cylinder 11a is abnormal will be described as a representative example.

As shown in FIG. 10, in step S102, the control device 100 acquires the angle of the front member (boom angle BmAng) from the attitude detection device 50, and proceeds to step S104.

In step S104, control device 100 determines whether engine 80 is in operation. In step S104, if it is determined that the engine 80 is in operation, the process proceeds to step S106, and if it is determined that the engine 80 is not in operation (that is, stopped), the process proceeds to step S148. When the engine 80 is stopped, the working device 10 does not operate in response to the operating device 34. Therefore, the operation determination process (S104) of the engine 80 is performed, and only when the engine 80 is operating, the setting process of the first open side sticking flag Fo1 and the first closing side sticking flag Fc1 is performed.

In step S106, the control device 100 calculates the stroke St of the hydraulic cylinder 37 (stroke BmSt of the boom cylinder 11a) based on the dimensional data of the hydraulic excavator 1 and the angle of the front member acquired in step S102, The process advances to step S108.

In step S108, the control device 100 calculates the stroke displacement amount Δx, and proceeds to step S110. The stroke displacement amount Δx is the stroke St calculated in step S106 in the present control cycle, the previous value St' corresponding to the stroke St calculated in step S106 before a predetermined control cycle (for example, one control cycle ago), is the absolute value of the difference.

In step S110, the control device 100 determines whether the operating lever 34a (operating lever B1) of the operating device 34 is operated. In step S110, if it is determined that the operating lever 34a is being operated, the process proceeds to step S132, and if it is determined that the operating lever 34a is not being operated, the process proceeds to step S112.

In step S112, the control device 100 determines whether the stroke displacement amount Δx calculated in step S108 is greater than or equal to the threshold value x0. In step S112, if it is determined that the stroke displacement amount Δx is greater than or equal to the threshold value x0, the process proceeds to step S121, and if it is determined that the stroke displacement amount Δx is less than the threshold value x0, the process proceeds to step S115.

In step S115, the control device 100 resets the first timer (t1=0), and proceeds to step S118.

In step S118, the control device 100 sets the first open side fixation flag Fo1 to OFF (Fo1=0), and proceeds to step S148.

In step S121, the control device 100 executes a time measurement process using the first timer, that is, a timer count-up process (t1=t1+Δt) that adds a time Δt corresponding to the control period to the measured time t1, and proceeds to step S123. .

In step S123, the control device 100 determines whether the time t1 measured by the first timer is greater than or equal to the time threshold ta. If it is determined in step S123 that the measured time t1 is less than the time threshold ta, the process advances to step S148. If it is determined in step S123 that the measured time t1 is equal to or greater than the time threshold ta, the process advances to step S126.

In step S126, the control device 100 sets the first open side fixing flag Fo1 to ON (Fo1=1), and proceeds to step S148.

In step S132, the control device 100 determines whether the stroke displacement amount Δx calculated in step S108 is less than the threshold value x0. In step S132, if it is determined that the stroke displacement amount Δx is less than the threshold value x0, the process proceeds to step S141, and if it is determined that the stroke displacement amount Δx is greater than or equal to the threshold value x0, the process proceeds to step S135.

In step S135, the control device 100 resets the first timer (t1=0), and proceeds to step S138.

In step S138, the control device 100 sets the first closed side fixation flag Fc1 to OFF (Fc1=0), and proceeds to step S148.

In step S141, the control device 100 executes a time measurement process using the first timer, that is, a timer count-up process (t1=t1+Δt) that adds a time Δt corresponding to the control period to the measured time t1, and proceeds to step S143. .

In step S143, the control device 100 determines whether the time t1 measured by the first timer is greater than or equal to the time threshold tb. If it is determined in step S143 that the measured time t1 is less than the time threshold tb, the process advances to step S148. If it is determined in step S143 that the measured time t1 is equal to or greater than the time threshold tb, the process advances to step S146.

In step S146, the control device 100 sets the first closed side fixation flag Fc1 to ON (Fc1=1), and proceeds to step S148.

In step S148, the control device 100 sets the stroke St calculated in step S106 as the previous value St' to be used in step S108 in a predetermined control period after the main control period (for example, the next control period after the main control period). It is stored in the RAM 113, and the processing shown in the flowchart of FIG. 10 in this control cycle is ended.

As shown in FIG. 11, in step S152, the control device 100 acquires the command pilot pressure Pp detected by the pressure sensor 38, and proceeds to step S154.

In step S154, control device 100 determines whether engine 80 is in operation, similar to step S104. In step S104, if it is determined that the engine 80 is in operation, the process advances to step S160, and if it is determined that the engine 80 is not in operation (that is, stopped), the flowchart of FIG. 11 in this control cycle shows Finish the process. As described above, when the engine 80 is stopped, the working device 10 does not operate in response to the operating device 34. Therefore, the operation determination process (S154) of the engine 80 is performed, and only when the engine 80 is operating, the setting process of the second open side sticking flag Fo2 and the second closing side sticking flag Fc2 is performed.

In step S160, the control device 100 determines whether the control lever 34a (control lever B1) of the control device 34 is operated, as in step S110. In step S160, if it is determined that the control lever 34a is being operated, the process proceeds to step S182, and if it is determined that the control lever 34a is not being operated, the process proceeds to step S162.

In step S162, the control device 100 determines whether the command pilot pressure Pp acquired in step S152 is equal to or greater than a threshold value Pp0. In step S162, if it is determined that the command pilot pressure Pp is greater than or equal to the threshold value Pp0, the process advances to step S171, and if it is determined that the command pilot pressure Pp is less than the threshold value Pp0, the process advances to step S165.

In step S165, the control device 100 resets the second timer (t2=0), and proceeds to step S168.

In step S168, the control device 100 sets the second open side fixation flag Fo2 to OFF (Fo2=0), and ends the process shown in the flowchart of FIG. 11 in this control cycle.

In step S171, the control device 100 executes a time measurement process using the second timer, that is, a timer count-up process (t2=t2+Δt) that adds a time Δt corresponding to the control period to the measured time t2, and proceeds to step S173. .

In step S173, the control device 100 determines whether the time t2 measured by the second timer is greater than or equal to the time threshold tc. If it is determined in step S173 that the measured time t2 is less than the time threshold tc, the process shown in the flowchart of FIG. 11 in this control cycle is ended. If it is determined in step S173 that the measured time t2 is equal to or greater than the time threshold tc, the process advances to step S176.

In step S176, the control device 100 sets the second open side fixing flag Fo2 to ON (Fo2=1), and ends the process shown in the flowchart of FIG. 11 in this control cycle.

In step S182, control device 100 determines whether command pilot pressure Pp acquired in step S152 is less than threshold value Pp0. In step S182, if it is determined that the command pilot pressure Pp is less than the threshold value Pp0, the process proceeds to step S191, and if it is determined that the command pilot pressure Pp is greater than or equal to the threshold value Pp0, the process proceeds to step S185.

In step S185, the control device 100 resets the second timer (t2=0), and proceeds to step S188.

In step S188, the control device 100 sets the second closed side fixation flag Fc2 to OFF (Fc2=0), and ends the process shown in the flowchart of FIG. 11 in this control cycle.

In step S191, the control device 100 executes a time measurement process using the second timer, that is, a timer count-up process (t2=t2+Δt) that adds a time Δt corresponding to the control period to the measured time t2, and proceeds to step S193. .

In step S193, the control device 100 determines whether the time t2 measured by the second timer is equal to or greater than the time threshold td. If it is determined in step S193 that the measured time t2 is less than the time threshold td, the process shown in the flowchart of FIG. 11 in this control cycle is ended. If it is determined in step S193 that the measured time t2 is equal to or greater than the time threshold td, the process advances to step S196.

In step S196, the control device 100 sets the second closed side fixing flag Fc2 to ON (Fc2=1), and ends the process shown in the flowchart of FIG. 11 in this control cycle.

An example of the operation of this embodiment will be described. The operator can start the engine 80 by sitting in the driver's seat 75 of the driver's cab 7 shown in FIG. 2 and operating the ignition switch (engine key switch) from the off position to the on position and then to the start position. can. The ignition switch is configured to momentarily operate the start position, and automatically returns to the on position when the operator stops operating the start position. When the gate lock lever B5 is in the unlocked position (lowered position), the corresponding hydraulic actuator is ready to operate in response to the operation of the operating levers (B1 to B4).

When the operating lever 34a (B1) is tilted from the neutral position to the maximum operating position on one side (boom raising operation side), the control device 100 operates based on the operating angle θ (θ=θmax) of the operating lever 34a (B1). A target pilot pressure Pt (Pt=Ptmax) is calculated, and a target current It (It=Itmax) is calculated based on the target pilot pressure Pt. The control device 100 adjusts the control current so that the control current to the solenoid of the electromagnetic valve 33a becomes the target current It (It=Itmax).

As a result, the command pilot pressure Pp (Pp=Ppmax) corresponding to the target pilot pressure Pt (Pt=Ptmax) is generated by the solenoid valve 33a, and the command pilot pressure Pp (Pp=Ppmax) is applied to the pressure receiving part 41a of the control valve 40. act. When the command pilot pressure Pp acts on the pressure receiving part 41a, the control valve 40 is switched to the position (P1), the pressure oil discharged from the main pump 31 is guided to the bottom chamber of the hydraulic cylinder 37 (boom cylinder 11a), and the hydraulic pressure is increased. Cylinder 37 is extended. As a result, the front member (boom 11) rotates in the first direction (upward).

Thereafter, when the operator returns the operating lever 34a (B1) to the neutral position, the control device 100 sets the target pilot pressure Pt (Pt=Ptmin) based on the operating angle θ (θ=0) of the operating lever 34a (B1). The target current It (It=Itmin) is calculated based on the target pilot pressure Pt (Pt=Ptmin). The control device 100 adjusts the control current so that the control current to the solenoid of the electromagnetic valve 33a becomes the target current It (It=Itmin (standby current)).

In this way, under normal conditions, when the operator operates the operating lever 34a to the maximum operating position, the front member moves at a speed corresponding to the amount of operation, and the first closing side sticking flag Fc1 and the second closing side sticking flag Fc2 are respectively set to off (Y→S132 in step S110 in FIG. 10→S135→S138, Y→S182 in step S160 in FIG. 11→N→S185→S188). Similarly, under normal conditions, when the operator returns the operation to the neutral position, the front member stops, and the first open-side fixation flag Fo1 and the second open-side fixation flag Fo2 are each set to OFF (step in FIG. 10). N in S110 → N in S112 → S115 → S118, N in step S160 in FIG. 11 → N in S162 → S165 → S168).

On the other hand, if a contamination phenomenon occurs, which is a sticking phenomenon in which the valve body of the solenoid valve 33a does not move due to foreign matter entering the inside of the solenoid valve 33a and getting caught in the driving part, it will not respond to the operator's operation. The front member (boom 11) will not operate properly.

A case will be described in which the solenoid valve 33a is stuck in the closed position that blocks the pilot pump 32 and the pressure receiving part 41a. When the operator operates the operating lever 34a from the neutral position to the maximum operating position, the target pilot pressure Pt becomes the maximum value Ptmax, and the target current It becomes the maximum value Itmax.

When the control device 100 adjusts the magnitude of the control current supplied to the solenoid valve 33a to the maximum value Itmax, in a normal state where no contamination occurs, the solenoid valve The maximum command pilot pressure Ppmax is output from 33a. However, if contamination occurs and an abnormal state occurs in which the solenoid valve 33a is stuck on the closed side, the state in which the pilot pump 32 and the pressure receiving part 41a are cut off by the solenoid valve 33a is maintained. Therefore, even if the operating lever 34a is operated to the maximum operating position, the stroke displacement amount Δx will be less than the threshold value Δx0 (for example, Δx=0), and if this state continues for a predetermined period of time, The first closed side fixing flag Fc1 is set to ON (Y in step S110 in FIG. 10 → Y in S132 → Y in S141 → Y in S143 → S146).

As a result, the control device 100 causes the display device 18 to notify that the solenoid valve 33 is in an abnormal state stuck on the closed side (Y→S15 in step S10 in FIG. 9).

A case will be described in which the solenoid valve 33a is stuck in the open position where the pilot pump 32 and the pressure receiving part 41a are communicated. When the operator returns the operating lever 34a from the maximum operating position to the neutral position, the target pilot pressure Pt becomes the minimum value Ptmin (tank pressure) and the target current It becomes the minimum value Itmin (standby current).

When the control device 100 adjusts the magnitude of the control current supplied to the solenoid valve 33a to be the minimum value Itmin (standby current), the pilot pump 32 is in a normal state where no contamination occurs. and the pressure receiving part 41a are shut off by the solenoid valve 33a, and the pressure receiving part 41a communicates with the tank 39. However, if contamination occurs and an abnormal state occurs in which the solenoid valve 33a is stuck on the open side, the state in which the pilot pump 32 and the pressure receiving part 41a are communicated with each other by the solenoid valve 33a is maintained. Therefore, even if the operating lever 34a is in a non-operating state where the operating lever 34a is in the neutral position, the stroke displacement amount Δx becomes equal to or greater than the threshold value Δx0, and this state continues for a predetermined period of time, so that the first open side fixation flag Fo1 is turned on. (N in step S110 in FIG. 10 → Y in S112 → S121 → Y in S123 → S126).

As a result, the control device 100 causes the display device 18 to notify that the solenoid valve 33 is in an abnormal state stuck on the open side (Y→S15 in step S10 in FIG. 9). Although not shown, when the first open side sticking flag Fo1 is set to ON, the control device 100 controls a solenoid switching valve (not shown) provided in the pilot line between the pilot pump 32 and the solenoid valve 33. It also has the function of switching from the communicating position to the blocking position, cutting the source pressure of the solenoid valve 33, stopping the engine 80, and forcibly stopping the operation of the working device 10.

As described above, in the abnormality determination method of the second abnormality determination unit 107, in order to prevent erroneous determination, when the temperature T of the hydraulic oil is low (for example, when the temperature T of the hydraulic oil is T=T1), , the time thresholds tc, td are set to longer values (for example, tc, td=tmax) than the time thresholds ta, tb (=tmin) used for abnormality determination by the first abnormality determination unit 106 (FIG. 8 reference). In other words, in the abnormality determination method of the first abnormality determination unit 106, relatively short time thresholds ta and tb can be used regardless of the temperature T of the hydraulic oil. Thereby, the first abnormality determining section 106 can detect the abnormality of the electromagnetic valve 33 earlier than the second abnormality determining section 107 detects the abnormality of the electromagnetic valve 33 . In other words, when detecting an abnormality in the electromagnetic valve 33 based on a signal from the attitude detection device 50, compared to detecting an abnormality in the electromagnetic valve 33 based on a signal from the pressure sensor 38, The time required to detect an abnormality can be shortened.

Note that in this embodiment, it is not only determined whether or not an abnormality has occurred in the solenoid valve 33 based on the signal from the attitude detection device 50, but also based on the signal from the pressure sensor 38. Determine whether an abnormality has occurred. Therefore, if the attitude detection device 50 fails, it can be determined based on the signal from the pressure sensor 38 whether or not an abnormality has occurred in the solenoid valve 33.

According to the embodiment described above, the following effects are achieved.

(1) The control device 100 determines whether or not the operating device 34 is operating the working device 10 based on a signal from the operating device 34, and includes angle sensors (posture sensors) 50a, 50b, and 50c. Based on the signal from the posture detection device 50, it is determined whether or not the working device 10 is operating, and the result of the determination as to whether or not the operating device 10 is being operated by the operating device 34 and the operating device 10 are determined. It is determined whether or not an abnormality has occurred in the electromagnetic valve 33 based on the determination result as to whether or not the solenoid valve 33 is abnormal.

The control device 100 controls the solenoid valve 33 when it is determined that the operating device 34 is operating the working device 10 and the hydraulic actuator of the working device 10 corresponding to the operation is not operating. It is determined that an open side sticking abnormality has occurred where the open side is stuck. In addition, when it is determined that the hydraulic actuator of the work device 10 is operating, and it is determined that the operating device 34 corresponding to the hydraulic actuator is not operated, the control device 100 closes the solenoid valve 33. It is determined that a closed side sticking abnormality has occurred. When it is determined that an abnormality has occurred in the solenoid valve 33 (that is, when an abnormality is detected), the control device 100 outputs a control signal to the display device (notification device) 18, and the display device 18 outputs a control signal to the solenoid valve 33. to notify that an abnormality has occurred.

In this manner, in this embodiment, since it is determined whether or not the working device 10 is operating based on the signal from the attitude detection device 50, the detection result of the pressure sensor 38, which is affected by the temperature of the hydraulic oil, is Compared to the case where it is determined whether or not the working device 10 is operating based on this, the time required until an abnormality of the electromagnetic valve 33 is detected can be shortened. That is, according to the present embodiment, even when the temperature of the hydraulic oil is low, an abnormality in the electromagnetic valve 33 can be promptly detected in the same way as when the temperature of the hydraulic oil is high. As a result, even when the temperature of the hydraulic oil is low, an abnormality in the solenoid valve 33 can be promptly notified to the operator.

(2) The control device 100 performs a first operation determination (steps S112 and S132 in FIG. 10) that determines whether the work device 10 is operating based on the signal from the posture detection device 50, and the pressure sensor 38. A second operation determination (steps S162 and S182 in FIG. 11) is performed to determine whether or not the working device 10 is operating based on the signal from. The control device 100 determines whether an abnormality has occurred in the solenoid valve 33 based on the determination result of whether or not the operation device 10 is operated by the operating device 34 and the determination result of the first operation determination. The electromagnetic valve 33 A second abnormality determination (see FIG. 11) is performed to determine whether or not an abnormality has occurred. If at least either the first abnormality determination result or the second abnormality determination result indicates that an abnormality has occurred in the solenoid valve 33, the control device 100 determines that the solenoid valve 33 is abnormal. The display device (notification device) 18 notifies that this has occurred (see FIG. 9). As a result, even if the attitude detection device 50 is out of order (for example, if a wire breakage, short circuit, etc. occurs), the control device 100 can determine the abnormality based on the signal from the pressure sensor 38 and control the solenoid valve. If it is determined that there is an abnormality in 33, the display device 18 can notify the operator of this fact.

The following modified examples are also within the scope of the present invention, and it is also possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, or to combine the configurations described in the following different modified examples. It is.

<Modification 1>
A control device 100 according to modification 1 of the present embodiment will be described with reference to FIG. 12. FIG. 12 is a diagram similar to FIG. 9, and is a flowchart showing the contents of the notification process executed by the control device 100 according to the first modification of the present embodiment. The process of the flowchart shown in FIG. 12 is started when an ignition switch (not shown) is turned on, and after initial settings (not shown) are performed, it is repeatedly executed at a predetermined control cycle.

As shown in FIG. 12, in step S30, the control device 100 determines whether or not there is an abnormality in the attitude detection device 50. For example, the control device 100 determines that there is no abnormality in the posture detection device 50 when the voltage value output from the posture detection device 50 is within a predetermined range (above the first voltage threshold and less than the second voltage threshold). That is, the control device 100 determines that the attitude detection device 50 is not out of order. Furthermore, if the voltage value output from the attitude detection device 50 is not within a predetermined range (above the first voltage threshold and less than the second voltage threshold), the control device 100 determines that there is an abnormality in the attitude detection device 50. That is, the control device 100 determines that the attitude detection device 50 is out of order. The first voltage threshold is a threshold for determining whether or not a disconnection has occurred in the attitude detection device 50, and is stored in advance in the ROM 112 of the control device 100. The second voltage threshold is a threshold for determining whether a short circuit has occurred in the attitude detection device 50, and is stored in advance in the ROM 112 of the control device 100.

In step S30, if it is determined that there is no abnormality in the attitude detection device 50, the process proceeds to step S40, and if it is determined that there is an abnormality in the attitude detection device 50, the process proceeds to step S45.

In step S40, the control device 100 determines whether either the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 set by the first abnormality determining unit 106 is set to ON. If it is determined in step S40 that either the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 is set to ON, the process proceeds to step S50, and the first open side sticking flag Fo1 or the first closing side sticking flag Fc1 is set to ON. If all of the closed side fixing flags Fc1 are set to OFF, the process shown in the flowchart of FIG. 12 is ended.

In step S45, the control device 100 determines whether either the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 set by the second abnormality determining unit 107 is set to ON. If it is determined in step S45 that either the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is set to ON, the process proceeds to step S50, and the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is set to ON. If all of the closed side fixation flags Fc2 are set to OFF, the process shown in the flowchart of FIG. 12 is ended.

In step S50, the control device 100 causes the display device 18 to notify that an abnormality has occurred in the solenoid valve 33 according to the flags Fo1, Fc1, Fo2, and Fc2 that are set to on.

As described above, in the present modification example 1, when there is no abnormality in the posture detection device 50, the control device 100 determines whether the work device 10 is operating based on the signal from the posture detection device 50. do. On the other hand, if there is an abnormality in the posture detection device 50, the control device 100 determines whether the work device 10 is operating based on the signal from the pressure sensor 38. According to this modification 1, the same effects as those of the above embodiment can be obtained.

<Modification 2>
In the embodiment described above, the control device 100 calculates the angle of the front member based on the signal from the attitude detection device 50, calculates the stroke displacement amount Δx of the hydraulic cylinder 37 based on the calculated angle of the front member, Although an example has been described in which it is determined whether or not the working device 10 is operating based on the calculated stroke displacement amount Δx, the present invention is not limited thereto.

<Modification 2-1>
For example, the control device 100B calculates the angle of the front member based on the signal from the attitude detection device 50, calculates the cylinder speed of the hydraulic cylinder 37 based on the calculated angle of the front member, and calculates the cylinder speed of the hydraulic cylinder 37 based on the calculated angle of the front member. It may be determined whether the working device 10 is operating based on the following.

FIG. 13 is a functional block diagram of a control device 100B according to modification example 2-1 of the present embodiment. As shown in FIG. 13, the control device 100B executes the program stored in the ROM 112 to control the target pilot pressure calculation section 101, target current calculation section 102, current supply section 103, cylinder stroke calculation section 104, cylinder It functions as a speed calculation section 205, a first abnormality determination section 206, a second abnormality determination section 107, and a display control section 108.

The cylinder speed calculation unit 205 calculates the cylinder speed of the hydraulic cylinder 37, which is the speed in the axial direction of the piston rod 37r with respect to the cylinder tube 37s, based on the dimensional data of the hydraulic excavator 1 and the detection result by the attitude detection device 50. do. As an example of a method for calculating the cylinder speed of the hydraulic cylinder 37, a method for calculating the cylinder speed BmSpd of the boom cylinder 11a will be described.

The cylinder speed BmSpd of the boom cylinder 11a is expressed by Equation (2) by differentiating both sides of Equation (1) above with respect to time.

Note that ω is expressed by equation (3).

Here, θ=∠BAQ+∠PAX+BmAng.

The cylinder speed calculation unit 205 similarly calculates the cylinder speed of the arm cylinder 12a and the cylinder speed of the bucket cylinder 13a. Hereinafter, the cylinder speed BmSpd of the boom cylinder 11a, the cylinder speed of the arm cylinder 12a, and the cylinder speed of the bucket cylinder 13a calculated by the cylinder speed calculation unit 205 will be collectively referred to as cylinder speed Sv.

The first abnormality determining unit 206 determines that the hydraulic cylinder 37 of the working device 10 is operating when the cylinder speed Sv is equal to or higher than the threshold value v0, and determines that the hydraulic cylinder 37 of the working device 10 is operating when the cylinder speed Sv is less than the threshold value v0. It is determined that the hydraulic cylinder 37 is not operating. Note that the threshold value v0 is a threshold value for determining whether the hydraulic cylinder 37 is performing an expansion/contraction or contraction operation, and in this embodiment, a value that can be determined as the beginning of movement of the hydraulic cylinder 37 is set. There is. When the operating lever 34a of the operating device 34 is operated, a predetermined time is required until the cylinder speed reaches a cylinder speed corresponding to the operating amount (operating angle θ). Therefore, in this modification, the cylinder speed before reaching the cylinder speed corresponding to the operation amount (operation angle θ) is set as the threshold value v0.

The first abnormality determination unit 206 determines that the target pilot pressure Pt is less than the threshold value Pt0 (the operating lever 34a is in the non-operated state) and the cylinder speed Sv is equal to or higher than the threshold value v0 (the hydraulic cylinder 37 is in the operating state). ), the first timer built into the control device 100 measures the time. When the time t1 measured by the first timer becomes the time threshold ta or more in a state where the target pilot pressure Pt is less than the threshold Pt0 and the cylinder speed Sv is the threshold v0 or more, the first abnormality determination unit 206 detects an electromagnetic It is determined that an open side sticking abnormality in which the valve 33 is stuck on the open side has occurred. If the first abnormality determining unit 206 determines that the open side sticking abnormality has occurred, it sets the first open side sticking flag Fo1 to ON (Fo1=1).

Further, the first abnormality determination unit 206 determines that the target pilot pressure Pt is equal to or higher than the threshold value Pt0 (the operating lever 34a is in the operating state), and the cylinder speed Sv is less than the threshold value v0 (the hydraulic cylinder 37 is in the stopped state). In this case, the first timer built in the control device 100 measures the time. When the time t1 measured by the first timer becomes the time threshold tb or more in a state where the target pilot pressure Pt is the threshold Pt0 or more and the cylinder speed Sv is less than the threshold v0, the first abnormality determination unit 206 detects an electromagnetic It is determined that a closed-side sticking abnormality in which the valve 33 is stuck on the closed side has occurred. If the first abnormality determining unit 206 determines that the closing side sticking abnormality has occurred, it sets the first closing side sticking flag Fc1 to ON (Fc1=1).

FIG. 14 is a flowchart showing the contents of the first abnormality determination process executed by the control device 100B according to modification example 2-1 of the present embodiment. In the flowchart of FIG. 14, the processes of steps S208, S212, and S232 are performed instead of the processes of steps S108, S112, and S132 of the flowchart of FIG. Note that in the flowchart of FIG. 14, the process of step S148 in the flowchart of FIG. 10 is not performed. Note that in FIG. 14, the same processes as those in FIG. 10 are given the same reference numerals (step numbers), and the parts that are different from the processes in FIG. 10 will be mainly described. The process shown in this flowchart is started when an ignition switch (not shown) is turned on, and after initial settings (not shown) are performed, it is repeatedly executed at a predetermined control cycle.

As shown in FIG. 14, in step S208, the control device 100B uses the dimensional data of the hydraulic excavator 1, the angle of the front member obtained in step S102, and the stroke St of the hydraulic cylinder 37 calculated in step S106 (for example, the boom The cylinder speed Sv (for example, boom cylinder speed BmSpd) of the hydraulic cylinder 37 is calculated based on the stroke BmSt) of the cylinder 11a, and the process proceeds to step S110.

In step S212, the control device 100B determines whether the cylinder speed Sv calculated in step S208 is greater than or equal to the threshold value v0. In step S212, if it is determined that the cylinder speed Sv is greater than or equal to the threshold value v0, the process proceeds to step S121, and if it is determined that the cylinder speed Sv is less than the threshold value v0, the process proceeds to step S115.

In step S232, the control device 100B determines whether the cylinder speed Sv calculated in step S208 is less than the threshold value v0. In step S232, if it is determined that the cylinder speed Sv is less than the threshold value v0, the process proceeds to step S141, and if it is determined that the cylinder speed Sv is equal to or greater than the threshold value v0, the process proceeds to step S135.

In this way, even when determining whether or not the working device 10 is operating based on the cylinder speed Sv instead of the stroke displacement amount Δx described in the above embodiment, the same effects as in the above embodiment can be obtained. play.

<Modification 2-2>
The control device 100 calculates the amount of angular displacement of the front member based on the signal from the posture detection device 50, and determines whether or not the working device 10 is operating based on the calculated amount of angular displacement. good.

<Modification 2-3>
The control device 100 calculates the angular velocity (rotation speed) ω of the front member based on the signal from the attitude detection device 50, and determines whether the working device 10 is operating based on the calculated angular velocity ω of the front member. It may be determined whether

<Modification 3>
In the above embodiment, an example was described in which the angle sensors 50a, 50b, and 50c that detect the angle of the front member are employed as the attitude sensor that detects the attitude of the work device 10 with respect to the machine body 4, but the present invention is not limited to this. . A stroke sensor that detects the stroke of the hydraulic cylinder 37 that drives the front member may be employed as the attitude sensor. In this case, by calculating the stroke displacement amount based on the signal from the stroke sensor, it is possible to quickly detect an abnormality in the solenoid valve 33 as in the above embodiment.

<Modification 4>
The control device 100 has a low temperature operation mode suitable for operating the hydraulic excavator 1 in a cold region or in the winter, and a low temperature operation mode suitable for operating the hydraulic excavator 1 in a warm region or in the summer. It may also be possible to switch between an appropriate high-temperature operation mode and an appropriate high-temperature operation mode.

The operator's cab 7 is provided with a mode changeover switch that can set the operating mode to either a low-temperature operating mode or a high-temperature operating mode. Note that the input device 19 shown in FIG. 3 can have a function as a mode changeover switch. When the mode changeover switch is operated to the low temperature operation mode position, the control device 100 sets the operation mode to the low temperature operation mode. When the mode changeover switch is operated to the high temperature operation mode position, the control device 100 sets the operation mode to the high temperature operation mode.

When the low temperature operation mode is set, the control device 100 executes the same abnormality determination process as in the above embodiment, including the first abnormality determination process (see FIG. 10) and the second abnormality determination process (see FIG. 11). ), if it is determined that there is an abnormality in the solenoid valve 33, the display device 18 will notify that an abnormality in the solenoid valve 33 has been detected.

When the high temperature operation mode is set, the control device 100 determines that there is an abnormality in the solenoid valve 33 in both the first abnormality determination process (see FIG. 10) and the second abnormality determination process (see FIG. 11). When the abnormality of the electromagnetic valve 33 is detected, the display device 18 notifies the user that an abnormality in the electromagnetic valve 33 has been detected.

The control device 100 according to the fourth modification of the present embodiment executes the process shown in the flowchart of FIG. 9 when the low temperature operation mode is set as the operation mode, and executes the process shown in the flowchart of FIG. 9 when the high temperature operation mode is set as the operation mode. 15 is executed. FIG. 15 is a flowchart showing the contents of the notification process executed by the control device 100 according to the fourth modification of the present embodiment.

As shown in FIG. 15, in step S340, the control device 100 determines whether either the first open-side fixation flag Fo1 or the first close-side fixation flag Fc1 is set to on. If it is determined in step S340 that either the first open-side fixation flag Fo1 or the first close-side fixation flag Fc1 is set to ON, the process advances to step S345, and the first open-side fixation flag Fo1 and the first close-side fixation flag Fc1 are set to ON. When all of the closed side fixation flags Fc1 are set to OFF, the process shown in the flowchart of FIG. 15 is ended.

In step S345, the control device 100 determines whether either the second open-side fixation flag Fo2 or the second close-side fixation flag Fc2 is set to on. If it is determined in step S345 that either the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is set to ON, the process advances to step S350, and the second open side sticking flag Fo2 or the second closing side sticking flag Fc2 is set to ON. If both of the closed side fixing flags Fc2 are set to OFF, the process shown in the flowchart of FIG. 15 is ended.

In step S350, the control device 100 causes the display device 18 to notify that an abnormality has occurred in the solenoid valve 33 according to the flags Fo1, Fc1, Fo2, and Fc2 that are set to on.

According to such a modification, when the high temperature operation mode is set in a state where the temperature of the hydraulic oil is high, the reliability of detecting abnormality of the solenoid valve 33 can be improved. Note that the operating mode is not limited to being switched to either the low-temperature operating mode or the high-temperature operating mode by a mode changeover switch operated by the operator. The control device 100 sets the high temperature operation mode when the temperature T of the hydraulic oil detected by the temperature sensor 20 is equal to or higher than a predetermined value, and sets the low temperature operation mode when the temperature T of the hydraulic oil detected by the temperature sensor 20 is less than the predetermined value. You can also set it to mode.

<Modification 5>
In the above embodiment, an example has been described in which the time threshold values tc and td are set according to the temperature T of the hydraulic oil, but the present invention is not limited to this. For example, regardless of the temperature T of the hydraulic oil, a time tmax that can prevent erroneous determination when the temperature of the hydraulic oil is low may be set as the time thresholds tc and td.

<Modification 6>
In the above embodiment, an example has been described in which the electromagnetic valve 33 is a positive type electromagnetic valve in which the generated command pilot pressure increases as the input control current increases, but the present invention is not limited to this. Instead of the positive type solenoid valve, a negative type solenoid valve may be used in which the larger the input control current, the smaller the generated command pilot pressure. In this case, instead of the characteristic N2 shown in FIG. 6, a characteristic is adopted in which the target current It becomes smaller as the target pilot pressure Pt becomes larger.

<Modification 7>
In the embodiment described above, an example has been described in which the display device 18 is used as a notification device for notifying that an abnormality has occurred in the electromagnetic valve 33, but the present invention is not limited thereto. A sound output device such as a speaker that outputs sound to notify that an abnormality has occurred in the electromagnetic valve 33 may be employed as the notification device.

<Modification 8>
In the embodiment described above, an example has been described in which it is determined whether or not the operating lever 34a of the operating device 34 is operated based on the target pilot pressure Pt, but the present invention is not limited to this. The control device 100 determines that the operating lever 34a of the operating device 34 is being operated when the operating angle θ of the operating lever 34a is greater than or equal to a predetermined threshold θ0, and when the operating angle θ is less than the threshold θ0, It may be determined that the operating lever 34a of the operating device 34 is not operated. Further, the control device 100 may determine whether the operating lever 34a of the operating device 34 is being operated based on the target current It.

<Modification 9>
In the above embodiment, an example has been described in which the control device 100 makes an abnormality determination when the engine 80 is in operation, and does not make an abnormality determination when the engine 80 is stopped. but not limited to. The control device 100 determines an abnormality when the engine 80 is operating and the gate lock lever B5 is in the unlocked position, and determines that the engine 80 is stopped or the gate lock lever B5 is in the locked position. In this case, the abnormality determination may not be performed.

<Modification 10>
In the embodiment described above, an example has been described in which the working device 10 is composed of a plurality of front members (boom 11, arm 12, and bucket 13), but the present invention is not limited to this. The structure, number of joints, etc. of the working device 10 can be arbitrarily configured. For example, instead of the bucket 13, an attachment such as a grapple that opens and closes hydraulically to grip an object, a breaker that excavates rock by repeatedly hitting the object, etc. may be provided.

<Modification 11>
In the above embodiment, an example has been described in which the hydraulic actuator that drives the members constituting the working device 10 is the hydraulic cylinder 37, but the present invention is not limited to this. The present invention can also be applied to a working device that can perform a predetermined work by driving a member by a hydraulic motor serving as a hydraulic actuator.

<Modification 12>
In the above embodiment, the case where the working machine is the crawler type hydraulic excavator 1 has been described as an example, but the present invention is not limited to this. The present invention can be applied to various working machines including working devices operated by hydraulic actuators, such as wheeled hydraulic excavators, wheel loaders, crawler cranes, and dump trucks.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. do not have.

DESCRIPTION OF SYMBOLS 1...Hydraulic excavator (work machine), 4...Body, 10...Work device, 11...Boom (member), 11a...Boom cylinder (hydraulic cylinder, hydraulic actuator), 12...Arm (member), 12a...Arm cylinder ( Hydraulic cylinder, hydraulic actuator), 13... Bucket (member), 13a... Bucket cylinder (hydraulic cylinder, hydraulic actuator), 18... Display device (notification device), 31... Main pump (hydraulic pump), 32... Pilot pump (pilot Hydraulic source), 33... Solenoid valve, 34... Operating device, 34a... Operating lever (operating member), 37... Hydraulic cylinder (hydraulic actuator), 38... Pressure sensor, 40... Control valve, 50a, 50b, 50c... Angle sensor (Attitude sensor), 100, 100B...control device

Claims (5)

a machine body; a working device that is attached to the machine body and has a hydraulic actuator driven by hydraulic oil discharged from a hydraulic pump; a control valve that controls the flow of hydraulic oil from the hydraulic pump to the hydraulic actuator; an electric operating device that outputs a signal according to the amount of operation of a member; an electromagnetic valve that generates a command pilot pressure to the control valve using the hydraulic pressure of a pilot hydraulic source as a source pressure; and a solenoid valve that generates a command pilot pressure to the control valve based on the signal from the operating device. A working machine comprising: a control device that controls the solenoid valve; a posture sensor that detects the posture of the working device; and a notification device that issues a notification based on a signal from the control device.
further comprising a pressure sensor that detects the command pilot pressure,
The control device includes:
Based on a signal from the operating device, determining whether or not the operating device is operating the working device;
a first operation determination for determining whether or not the working device is operating based on a signal from the posture sensor; and a first operation determination for determining whether or not the working device is operating based on the signal from the pressure sensor. performing a second motion determination;
A first step of determining whether an abnormality has occurred in the solenoid valve based on a determination result of whether or not the operating device is operated on the working device and a determination result of the first operation determination . Based on the first abnormality determination, the determination result of whether or not the operating device is operating the working device, and the determination result of the second operation determination, whether or not an abnormality has occurred in the solenoid valve. perform a second abnormality determination to determine whether
If at least either the first abnormality determination result or the second abnormality determination result indicates that an abnormality has occurred in the solenoid valve, an abnormality has occurred in the solenoid valve. causing the notification device to notify that the
A working machine characterized by: The working machine according to claim 1,
The hydraulic actuator is a hydraulic cylinder,
The control device calculates a stroke displacement amount of the hydraulic cylinder based on a signal from the attitude sensor, and determines whether the working device is operating based on the stroke displacement amount.
A working machine characterized by: The working machine according to claim 1,
The hydraulic actuator is a hydraulic cylinder,
The control device calculates a cylinder speed of the hydraulic cylinder based on a signal from the attitude sensor, and determines whether the work device is operating based on the cylinder speed.
A working machine characterized by: The working machine according to claim 1,
The working device has a plurality of members rotatably connected,
The hydraulic actuator is a hydraulic cylinder,
The posture sensor is an angle sensor that detects the angle of the member,
The control device calculates a stroke displacement amount of the hydraulic cylinder based on the angle of the member, and determines whether the working device is operating based on the stroke displacement amount.
A working machine characterized by: The working machine according to claim 1,
The working device has a plurality of members rotatably connected,
The hydraulic actuator is a hydraulic cylinder,
The posture sensor is an angle sensor that detects the angle of the member,
The control device calculates a cylinder speed of the hydraulic cylinder based on the angle of the member, and determines whether the working device is operating based on the cylinder speed.
A working machine characterized by:

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