JP6978462B2 - Construction machinery - Google Patents

Description

The present invention relates to construction machinery such as hydraulic excavators.

In construction machinery such as hydraulic excavators, when the hydraulic oil decreases, when the hydraulic pump sucks the hydraulic oil from the tank, air is sucked in and cavitation occurs, which damages the hydraulic pump. In the conventional tank for storing hydraulic oil, an oil level gauge made of a transparent material such as glass is provided as a communication pipe on the side plate of the tank so that the liquid level in the tank can be seen. Before starting work on the hydraulic excavator, the operator inspects the oil level gauge installed in the tank to check whether the hydraulic oil is in a predetermined amount.

In the case of the method in which the operator visually confirms the amount of oil in the tank as described above, it takes time and effort for the operator to move to the tank every time the hydraulic oil is inspected. Therefore, there has been proposed a level detection device that can detect a decrease in the amount of liquid stored in a tank while the operator is in the driver's cab even during work (Patent Document 1).

Patent Document 1 describes a traveling body, a swivel body provided so as to be able to swivel on the traveling body, a tank for storing liquid provided in the swivel body, and an cab for an operator to operate a machine. In the construction machine equipped with the above, the liquid liquid stored in the hydraulic oil tank corresponds to the reference liquid level of the liquid stored in the tank on the side plate constituting the hydraulic oil tank and at equidistant positions in the circumferential direction of the tank. Four detection sensors that detect the surface level are provided, and a judgment means that judges the liquid level drop of the stored liquid based on the signals obtained from these detection sensors and outputs an alarm signal is connected to these detection sensors. Described is a level detector for the liquid in the tank of a construction machine, characterized by the fact that it has been done.

Japanese Unexamined Patent Publication No. 2002-339902

When driving a hydraulic motor such as a traveling hydraulic motor, the flow rate of hydraulic oil supplied from the hydraulic pump to the hydraulic motor and the flow rate of hydraulic oil returned from the hydraulic motor to the hydraulic oil tank match. Therefore, the liquid level of the hydraulic oil tank is stable during traveling when only the traveling hydraulic motor is driven.

On the other hand, when driving a single-rod hydraulic cylinder such as a boom cylinder or arm cylinder, hydraulic oil supplied from the hydraulic pump to the single-rod hydraulic cylinder due to the difference in pressure receiving area between the bottom-side oil chamber and the rod-side oil chamber. The flow rate of the hydraulic oil returned from the single rod type hydraulic cylinder to the hydraulic oil tank does not match. Therefore, when working to drive the boom cylinder, arm cylinder, etc., the liquid level of the hydraulic oil tank fluctuates greatly.

Here, the level detection device described in Patent Document 1 determines that the amount of hydraulic oil stored in the tank has decreased when the liquid level of the hydraulic oil stored in the tank is lower than the reference position. There is. Therefore, if the reference position is set high, there is a risk of erroneous detection of hydraulic oil leakage during work when the liquid level of the hydraulic oil tank fluctuates greatly, and if the reference position is set low, the hydraulic oil tank There is a risk that the detection of hydraulic oil leaks will be delayed during driving when the liquid level is stable.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent erroneous detection of hydraulic oil leakage during work in which the work device is operated, and at an early stage of hydraulic oil leakage during traveling when the work device is not operated. The purpose is to provide construction machinery that can be detected.

In order to achieve the above object, the present invention has a vehicle body, a working device attached to the vehicle body, a working operating device for operating the working device, and a traveling device for operating the traveling of the vehicle body. It is possible to switch between the operation device, the parking brake that makes the vehicle body inoperable, the lock position that invalidates the operation of the work operation device, and the unlock position that enables the operation of the work operation device. A gate lock lever, a hydraulic oil tank for storing hydraulic oil, a traveling hydraulic motor for driving the vehicle body, at least one single-rod hydraulic cylinder for driving the working device, and a hydraulic oil tank for storing the hydraulic oil. In a construction machine equipped with a hydraulic pump that sucks hydraulic oil and supplies it to the traveling hydraulic motor and the single-rod hydraulic cylinder, a controller having a calculation function, and a notification device that outputs the calculation result of the controller. The controller is provided with a first level detection sensor provided at a first predetermined height of the hydraulic oil tank and detects the presence or absence of hydraulic oil at the first predetermined height, and the controller has the gate lock lever. When the hydraulic oil is not detected by the first level detection sensor while the vehicle is in the locked position and the parking brake is released, warning information is output to the notification device.

According to the present invention configured as described above, the liquid level of the hydraulic oil tank is lower than the first predetermined height position when the gate lock lever is in the locked position and the parking brake is released. In that case, warning information is output to the notification device. This makes it possible to prevent erroneous detection of hydraulic oil leakage during work when the work device is operated, and to detect hydraulic oil leakage during travel when the work device is not operated.

According to the construction machine according to the present invention, it is possible to prevent erroneous detection of hydraulic oil leakage during work when the work device is operated, and to detect hydraulic oil leak at an early stage when the work device is not operated.

It is a side view of the wheel type hydraulic excavator which concerns on embodiment of this invention. It is a schematic block diagram of the hydraulic drive system mounted on the wheel type hydraulic excavator shown in FIG. It is a top view of the hydraulic oil tank. FIG. 3 is a cross-sectional view taken along the line AA of FIG. It is an enlarged view of the level detection sensor shown in FIG. It is a functional block diagram of the controller shown in FIG. It is a flowchart which shows the process of the controller shown in FIG.

Hereinafter, a wheel-type hydraulic excavator will be taken as an example of the construction machine according to the embodiment of the present invention, and will be described with reference to the drawings. In each figure, the same members are designated by the same reference numerals, and duplicated description will be omitted as appropriate.

In FIG. 1, the wheel-type hydraulic excavator 1 includes a self-propelled lower traveling body 2 and an upper turning body 6 mounted on the upper part of the lower traveling body 2 via a turning mechanism. The swivel mechanism is, for example, a swivel wheel 4, and the upper swivel body 6 is rotatably attached to the lower traveling body 2 via the swivel wheel 4. The lower traveling body 2 is driven by the traveling hydraulic motor 3, and the upper rotating body 6 is swiveled by the swirling hydraulic motor 5.

A cab 8 and a working device 9 are provided at the front portion of the upper swivel body 6. The cab 8 is provided with operating members 31 to 35 (shown in FIG. 2), a display device 60, a controller 70, and the like, which will be described later. The work device 9 is rotatably attached to the boom 10 rotatably attached to the upper swing body 6, the arm 12 rotatably attached to the tip of the boom 10, and the tip of the arm 12. It has a bucket 14, a boom cylinder 11 for driving the boom 10, an arm cylinder 13 for driving the arm 12, and a bucket cylinder 15 for driving the bucket 14.

An engine room 16 is arranged at the rear of the upper swing body 6. The engine 23, the hydraulic pump 21 (shown in FIG. 2), and the like are housed in the engine room 16. The hydraulic pump 21 is driven by the engine 23 and supplies hydraulic oil to the hydraulic actuators 3, 5, 11, 13, and 15. At the rear end of the upper swing body 6 (rear side of the engine room 16), a counterweight 18 for balancing the weight with the working device 9 is arranged. A hydraulic oil tank 19 in which hydraulic oil is stored and a fuel tank 20 in which fuel for the engine 23 is stored are arranged on the front side of the engine room 16 of the upper swing body 6.

FIG. 2 is a schematic configuration diagram of a hydraulic drive system mounted on the wheel type hydraulic excavator 1.

In FIG. 2, the variable capacity hydraulic pump 21 and the fixed capacity pilot pump 22 are driven by the engine 23. The hydraulic pump 21 is a drive source for driving hydraulic actuators such as a traveling hydraulic motor 3, a swing hydraulic motor 5, a boom cylinder 11, an arm cylinder 13, and a bucket cylinder 15. The pilot pump 22 is a drive source for driving control valves such as a traveling flow rate control valve 51, an arm flow rate control valve 52, a turning flow rate control valve 53, a boom flow rate control valve 54, and a bucket flow rate control valve 55. Is.

The hydraulic oil discharged from the hydraulic pump 21 is supplied to the hydraulic actuators 3, 5, 11, 13 and 15 via the flow rate control valves 51 to 55. The hydraulic oil discharged from the hydraulic actuators 3, 5, 11, 13 and 15 is returned to the hydraulic oil tank 19 via the flow control valves 51 to 55.

The pilot pump 22 is connected to the traveling reverse pilot pressure control valve 31a and the traveling forward pilot pressure control valve 31b. Further, the pilot pump 22 has, via the pilot cut valve 25, an arm pulling pilot pressure control valve 32a, an arm pushing pilot pressure control valve 32b, a turning left pilot pressure control valve 33a, a turning right pilot pressure control valve 33b, and the like. It is connected to a boom raising pilot pressure control valve 34a, a boom lowering pilot pressure control valve 34b, a bucket excavation pilot pressure control valve 35a, and a bucket soil discharge pilot pressure control valve 35b.

The pilot cut valve 25 is opened and closed by a gate lock lever 61 provided at the entrance / exit of the cab 8 (shown in FIG. 1). When the operator operates the gate lock lever 61 to the boarding / alighting permission position (lock position), the pilot cut valve 25 closes. As a result, the supply of pressure oil (pilot primary pressure) from the pilot pump 22 to the pilot pressure control valves 32a to 35a and 32b to 35b is stopped, and the pilot secondary pressure is generated according to the operation of the operating members 32 to 35. It becomes impossible. On the other hand, when the operator operates the gate lock lever 61 to the boarding / alighting blocking position (lock release position), the pilot cut valve 25 opens. As a result, pressure oil (pilot primary pressure) is supplied from the pilot pump 22 to the pilot pressure control valves 32a to 35a and 32b to 35b, and it becomes possible to generate a pilot secondary pressure according to the operation of the operating members 32 to 35. .. The traveling reverse pilot pressure control valve 31a and the traveling forward pilot pressure control valve 31b generate a pilot secondary pressure according to the operation of the traveling operation member 31 regardless of the position of the gate lock lever 61.

The traveling reverse pilot pressure control valve 31a and the traveling forward pilot pressure control valve 31b are opened and closed via the traveling operation member 31. The arm pulling pilot pressure control valve 32a and the arm pushing pilot pressure control valve 32b are opened and closed via the arm operating member 32. The turning left pilot pressure control valve 33a and the turning right pilot pressure control valve 33b are opened and closed via the turning operation member 33. The boom raising pilot pressure control valve 34a and the boom lowering pilot pressure control valve 34b are opened and closed via the boom operating member 34. The bucket excavation pilot pressure control valve 35a and the bucket soil discharge pilot pressure control valve 35b are opened and closed via the bucket operation member 35.

A shuttle block 36 is connected to the downstream side of the pilot pressure control valves 31a to 35a and 31b to 35b. The hydraulic oil discharged from the pilot pressure control valves 31a to 35a and 31b to 35b is once introduced into the shuttle block 36. On the downstream side of the shuttle block 36, a traveling reverse pilot pipe 41a, a traveling forward pilot pipe 41b, an arm pulling pilot pipe 42a, an arm pushing pilot pipe 42b, a turning left pilot pipe 43a, and a turning right pilot pipe 43b. A boom raising pilot pipe 44a, a boom lowering pilot pipe 44b, a bucket excavation pilot pipe 45a, and a bucket soil discharge pilot pipe 45b are connected.

A traveling flow rate control valve 51 is connected to the downstream side of the traveling reverse pilot pipe 41a and the traveling forward pilot pipe 41b. An arm flow rate control valve 52 is connected to the downstream side of the arm pulling pilot pipe 42a and the arm pushing pilot pipe 42b. A flow rate control valve 53 for turning is connected to the downstream side of the pilot pipe 43a for turning left and the pilot pipe 43b for turning right. A boom flow rate control valve 54 is connected to the downstream side of the boom raising pilot pipe 44a and the boom lowering pilot pipe 44b. A flow control valve 55 for a bucket is connected to the downstream side of the pilot pipe 45a for excavating the bucket and the pilot pipe 45b for excavating the bucket.

A regulator 26 attached to the hydraulic pump 21 is also connected to the downstream side of the shuttle block 36. The regulator 26 has a function of changing the tilt of the hydraulic pump 21 and adjusting the discharge flow rate according to the operation amount of the operating members 31 to 35. That is, the shuttle block 36 has a function of generating a signal pressure supplied to the regulator 26 based on the operation signal pressure (pilot secondary pressure) from the pilot pressure control valves 31a to 35a and 31b to 35b. Further, the flow rate control valves 51 to 55 can adjust the switching amount according to the operation amount of the operation members 31 to 35.

Next, the hydraulic oil tank 19 will be described with reference to FIGS. 3 and 4. FIG. 3 is a plan view of the hydraulic oil tank 19 as viewed from above. FIG. 4 is a cross-sectional view taken along the line AA of FIG.

In these figures, 19a is an upper plate constituting the hydraulic oil tank 19, 19b, 19c, 19d, 19e are side plates constituting the hydraulic oil tank 19, and 19f is a lower plate constituting the hydraulic oil tank 19. The upper plate, side plate and lower plate are fixed to each other by appropriate means such as welding and bolt fastening, and are manufactured so that hydraulic oil does not leak to the outside. The cross-sectional shape of the hydraulic oil tank 19 in the plan view is not limited to a square shape, and may be a rectangle or a circle.

Reference numerals 80 and 90 schematically show level detection sensors for detecting the presence or absence of hydraulic oil in the hydraulic oil tank 19, and are attached to the side plates 19b, respectively. The level detection sensors 80 and 90 are located substantially in the center on the plane of the hydraulic oil tank 19, that is, on the paper surface of FIG. 3, and are arranged at different heights.

In FIG. 4, X1 is the liquid level when the minimum required amount of hydraulic oil is stored in the hydraulic oil tank 19 and the working device 9 is in the running posture. X2 is the liquid level when the minimum required amount of hydraulic oil is stored in the hydraulic oil tank 19 and the boom cylinder 11, arm cylinder 13, and bucket cylinder 15 are extended to the maximum.

When driving a hydraulic motor such as a traveling hydraulic motor 3, the flow rate of the hydraulic oil supplied from the hydraulic pump 21 to the hydraulic motor and the flow rate of the hydraulic oil returned from the hydraulic motor to the hydraulic oil tank 19 match. Therefore, the liquid level of the hydraulic oil tank 19 is stable during traveling when only the traveling hydraulic motor 3 is driven.

On the other hand, when driving a single-rod hydraulic cylinder such as a boom cylinder 11 or an arm cylinder 13, the hydraulic pump 21 supplies the single-rod hydraulic cylinder to the single-rod hydraulic cylinder due to the difference in pressure receiving area between the bottom-side oil chamber and the rod-side oil chamber. The flow rate of the hydraulic oil does not match the flow rate of the hydraulic oil returned from the single rod type hydraulic cylinder to the hydraulic oil tank 19. Therefore, when the boom cylinder 11, the arm cylinder 13, and the like are driven, the liquid level of the hydraulic oil tank 19 fluctuates greatly.

The hydraulic oil tank 19 can store a sufficient amount of hydraulic oil to be sufficiently supplied to each actuator even if a combined operation such as excavation or turning is performed, and the maximum amount of hydraulic oil is supplied to the actuator when the actuator is driven. It is necessary to leave a predetermined minimum amount at which the hydraulic pump 21 does not suck in air and cause cavitation even in such a state.

In the present embodiment, the height position of the liquid level when the minimum amount of hydraulic oil is stored in the hydraulic oil tank 19 is referred to as a reference position.

Next, the level detection sensors 80 and 90 for detecting the presence or absence of hydraulic oil will be described with reference to FIG. FIG. 5 is an enlarged view of the level detection sensor 80 shown in FIG. Since the structure of the level detection sensor 90 is the same as that of the level detection sensor 80, the description thereof will be omitted.

In FIG. 5, 81 is a float that operates following the movement of hydraulic oil in the hydraulic oil tank 19, 82 is a rod for operating a switch fixed to the float, and 83 is a rod 82 that operates as the float a1 moves up and down. The guide 84 that guides while sliding is the tip end portion of the rod 82. Reference numeral 85 is a movable terminal having a spring function and being brought into contact with the fixed terminal 86 facing the tip portion 84 when pressed, 87 is a substrate of a member constituting the level detection sensor 80, and 88 is a lead wire.

In the level detection sensor 80 having the configuration shown in FIG. 5, the tip portion 84 of the rod 82 that moves together with the float 81 when the oil level of the hydraulic oil stored in the hydraulic oil tank 19 is at the reference position or above the reference position. Does not push down the movable terminal 85 and come into contact with the opposite fixed terminal 86. On the contrary, when the oil level of the hydraulic oil falls below the reference position, the float 81 is lowered accordingly, and the tip portion 84 of the rod 82 pushes down the movable terminal 85 to make contact with the fixed terminal 86 as shown by the dotted line in FIG. , The lead wires 88 and 88 are short-circuited. In this way, the level detection sensor 80 may be short-circuited, non-short-circuited, that is, operated ON / OFF to detect the presence or absence of hydraulic oil.

Further, the configuration of FIG. 5 schematically shows a configuration in which the movement of the float 81 is directly transmitted to the switch of the detection sensor, but in addition to this, the movement of the float is optically transmitted by a light emitting and light receiving element. It is also possible to use a non-contact proximity switch or the like for detection.

FIG. 6 is a functional block diagram of the controller 70.

In FIG. 6, the controller 70 has a mode determination unit 71 and an oil leak determination unit 72.

The mode determination unit 71 is based on the state of the parking brake switch 62 instructing the operation of the parking brake 27 (shown in FIG. 2) and the position of the gate lock lever 61 for operating the pilot cut valve 25 (shown in FIG. 2). Then, it is determined whether the operation mode of the wheel type hydraulic excavator 1 is the traveling mode or the working mode, and the determination result is output to the oil leak determination unit 72.

When the oil leak determination unit 72 determines the presence or absence of a hydraulic oil leak based on the operation mode input from the mode determination unit 71 and the signals from the level detection sensors 80 and 90, and determines that there is a hydraulic oil leak. The warning information is output to the display device 60.

FIG. 7 is a flowchart showing the processing of the controller 70. Hereinafter, each step will be described in order.

In step S1, it is determined whether or not the parking brake switch 62 is OFF. When the parking brake switch 62 is OFF, the process proceeds to step S2, and when the parking brake switch 62 is ON, the process proceeds to step S7.

In step S2, it is determined whether or not the gate lock lever 61 is in the locked position. If the gate lock lever 61 is in the locked position, the process proceeds to step S5, and if the gate lock lever 61 is not in the locked position (in the unlocked position), the process proceeds to step S3.

In step S3, it is determined whether or not the working device 9 is stopped. If the working device 9 is stopped, the process proceeds to step S4, and if the work device 9 is not stopped, the process proceeds to step S7. Whether or not the working device 9 is stopped is determined based on, for example, a signal of a pressure sensor (not shown) provided in the pilot pipes 42a, 42b, 44a, 44b, 45a, 45b (shown in FIG. 2). To.

In step S4, it is determined whether or not the accelerator is depressed (whether or not the traveling operation member 31 is operated). If the accelerator is stepped on, the process proceeds to step S5, and if the accelerator is not stepped on, the process proceeds to step S7. Whether or not the traveling operation member 31 is operated is determined based on, for example, a signal of a pressure sensor (not shown) provided in the pilot pipes 41a and 41b (shown in FIG. 2). Steps S1 to S4 correspond to the processing of the mode determination unit 71 (shown in FIG. 6).

In step S5, it is determined whether or not the first level detection sensor 80 has detected hydraulic oil. If the first level detection sensor 80 detects hydraulic oil, the flow is terminated, and if it is not detected, the process proceeds to step S6.

In step S6, the alarm information indicating that the hydraulic oil is leaking is output to the display device 60, and the flow is terminated.

In step S7, it is determined whether or not the second level detection sensor 90 has detected the hydraulic oil. If the second level detection sensor 90 detects hydraulic oil, the flow is terminated, and if it is not detected, the process proceeds to step S8.

In step S8, the alarm information indicating that the hydraulic oil is leaking is output to the display device 60, and the flow is terminated. Steps S5 to S8 correspond to the processing of the oil leak determination unit 72 (shown in FIG. 6). In the present embodiment, the alarm information is displayed on the display device 60 to notify the operator of the hydraulic oil leak, but the buzzer may be sounded or the lamp may be turned on. .. Further, in the present embodiment, the alarm information is only output to the display device 60, but the engine 23 may be stopped at the same time as or immediately after the alarm information is output.

In the present embodiment, the vehicle bodies 2 and 6, the working device 9 attached to the vehicle body 6, the working operation devices 32 to 35 for operating the working device 9, and the traveling for operating the traveling of the vehicle body 2 are performed. Operation device 31, parking brake 27 that makes it impossible for the vehicle body 2 to travel, a lock position that invalidates the operation of the work operation devices 32 to 35, and unlocking that enables the operation of the work operation devices 32 to 35. A gate lock lever 61 that can be switched between positions, a hydraulic oil tank 19 that stores hydraulic oil, a traveling hydraulic motor 3 that drives the running of the vehicle body 2, and at least one single-rod hydraulic that drives the working device 9. A hydraulic pump 21 that sucks the hydraulic oil stored in the cylinders 11, 13 and 15 and the hydraulic oil tank 19 and supplies them to the traveling hydraulic motor 3 and the single-rod type hydraulic cylinders 11, 13 and 15 and a controller having a calculation function. In the construction machine 1 provided with the 70 and the notification device 60 for outputting the calculation result of the controller 70, the hydraulic oil tank 19 is provided at the first predetermined height position X1 and is provided at the first predetermined height position X1. A first level detection sensor 80 for detecting the presence or absence of hydraulic oil in the hydraulic oil is provided, and the controller 70 is operated by the first level detection sensor 80 with the gate lock lever 61 in the locked position and the parking brake 27 released. When oil is not detected, warning information is output to the notification device 60.

Further, the first predetermined height position X1 is based on the liquid level of the hydraulic oil tank 19 when the minimum required amount of hydraulic oil is stored in the hydraulic oil tank 19 and the working device 9 is in the traveling posture. Is set.

According to the present embodiment configured as described above, the liquid level of the hydraulic oil stored in the hydraulic oil tank 19 is set in a state where the gate lock lever 61 is in the locked position and the parking brake 27 is released. When the height falls below the first predetermined height position X1, the warning information is output to the notification device 60. This makes it possible to prevent erroneous detection of hydraulic oil leakage during work when the work device 9 is operated, and to detect hydraulic oil leakage at an early stage when the work device 9 is not operated.

Further, the construction machine 1 according to the present embodiment is provided at a second predetermined height position X2 lower than the first predetermined height position X1 of the hydraulic oil tank 19, and has a second predetermined height. A second level detection sensor 90 for detecting the presence or absence of hydraulic oil at the position X2 is further provided, and the controller 70 does not detect the hydraulic oil by the second level detection sensor 90 while the gate lock lever 61 is in the unlocked position. If so, the warning information is output to the notification device 60.

Further, the second predetermined height position X2 stores the minimum required amount of hydraulic oil in the hydraulic oil tank 19, and the hydraulic oil tank 19 when the single rod type hydraulic cylinders 11, 13 and 15 are extended to the maximum. It is set based on the liquid level of.

According to the present embodiment configured as described above, it is possible to detect a hydraulic oil leak during the work in which the work device 9 is operated. This makes it possible to prevent the hydraulic pump 21 from being damaged by cavitation during work such as excavation.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, in the above-described embodiment, the wheel type hydraulic excavator is taken as an example, but the present invention can be applied to other construction machines such as a crawler type hydraulic excavator. Further, the above-described embodiments have been described in detail for facilitating the understanding of the present invention, and the present invention is not necessarily limited to those having all the described configurations.

1 ... Wheel type hydraulic excavator (construction machine), 2 ... Lower traveling body (body), 3 ... Running hydraulic motor, 4 ... Swivel wheel, 5 ... Swivel hydraulic motor, 6 ... Upper revolving body (body), 8 ... Cab, 9 ... Working equipment, 10 ... Boom, 11 ... Boom cylinder (single rod type hydraulic cylinder), 12 ... Arm, 13 ... Arm cylinder (single rod type hydraulic cylinder), 14 ... Bucket, 15 ... Bucket cylinder (single rod type hydraulic pressure) Cylinder), 16 ... engine room, 18 ... counter weight, 19 ... hydraulic oil tank, 20 ... fuel tank, 21 ... hydraulic pump, 22 ... pilot pump, 23 ... engine, 25 ... pilot cut valve, 26 ... regulator, 27 ... Parking brake, 31 ... Driving operation member (driving operation device), 32 ... Arm operation member (work operation device), 33 ... Turning operation member (travel operation device), 34 ... Boom operation member (work) Operation device), 35 ... Bucket operation member (work operation device), 31a ... Traveling reverse pilot pressure control valve, 31b ... Traveling forward pilot pressure control valve, 32a ... Arm pulling pilot pressure control valve, 32b ... Arm pushing pilot pressure control valve, 33a ... turning left pilot pressure control valve, 33b ... turning right pilot pressure control valve, 34a ... boom raising pilot pressure control valve, 34b ... boom lowering pilot pressure control valve, 35a ... bucket Pilot pressure control valve for excavation, 35b ... Pilot pressure control valve for bucket soil discharge, 36 ... Shuttle block, 41a ... Pilot piping for traveling backward, 41b ... Pilot piping for traveling forward, 42a ... Pilot piping for arm pulling, 42b ... Arm Pushing pilot piping, 43a ... Swivel left pilot piping, 43b ... Swivel right pilot piping, 44a ... Boom raising pilot piping, 44b ... Boom lowering pilot piping, 45a ... Bucket excavation pilot piping, 45b ... Bucket discharge Pilot piping, 51 ... Travel flow control valve, 52 ... Arm flow control valve, 53 ... Swirling flow control valve, 54 ... Boom flow control valve, 55 ... Bucket flow control valve, 60 ... Display device (notification device) ), 61 ... Gate lock lever, 62 ... Parking brake switch, 70 ... Controller, 71 ... Mode determination unit, 72 ... Oil leak determination unit, 80 ... Level detection sensor (first level detection sensor), 81 ... Float, 82 ... Rod, 83 ... Guide, 84 ... Tip, 85 ... Movable terminal, 86 ... Fixed terminal, 87 ... Board, 88 ... Lead wire, 90 ... Level detection sensor ( Second level detection sensor).

Claims (4)

With the car body
The work device attached to the vehicle body and
A work operation device for operating the work device, and
A traveling operation device for operating the traveling of the vehicle body,
The parking brake that makes it impossible to drive the car body,
A gate lock lever that can be switched between a lock position that invalidates the operation of the work operation device and an unlock position that enables the operation of the work operation device.
A hydraulic oil tank that stores hydraulic oil and
The traveling hydraulic motor that drives the traveling of the vehicle body and
At least one single-rod hydraulic cylinder that drives the work equipment,
A hydraulic pump that sucks hydraulic oil stored in the hydraulic oil tank and supplies it to the traveling hydraulic motor and the single-rod hydraulic cylinder.
A controller with an arithmetic function and
In a construction machine equipped with a notification device that outputs the calculation result of the controller.
A first level detection sensor provided at a first predetermined height position of the hydraulic oil tank and detecting the presence or absence of hydraulic oil at the first predetermined height position is provided.
The controller issues warning information to the notification device when the hydraulic oil is not detected by the first level detection sensor when the gate lock lever is in the lock position and the parking brake is released. A construction machine characterized by outputting. In the construction machine according to claim 1,
The first predetermined height position is set based on the liquid level of the hydraulic oil tank when the minimum required amount of hydraulic oil is stored in the hydraulic oil tank and the working device is in the traveling posture. Construction machinery characterized by being. In the construction machine according to claim 1,
A second level detection provided at a second predetermined height position lower than the first predetermined height position of the hydraulic oil tank and detecting the presence or absence of hydraulic oil at the second predetermined height position. With more sensors
The controller is constructed by outputting warning information to the notification device when the hydraulic oil is not detected by the second level detection sensor while the gate lock lever is in the unlocked position. machine. In the construction machine according to claim 3,
The second predetermined height position is based on the liquid level of the hydraulic oil tank when the minimum required amount of hydraulic oil is stored in the hydraulic oil tank and the single rod type hydraulic cylinder is extended to the maximum. Construction machinery characterized by being set up.

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