EP4733485A1

EP4733485A1 - Construction machine

Info

Publication number: EP4733485A1
Application number: EP23943803.9A
Authority: EP
Inventors: Minsung KIM; Sungsu Kim; Jiyun Kim
Original assignee: Volvo Construction Equipment AB
Current assignee: Volvo Construction Equipment AB
Priority date: 2023-06-26
Filing date: 2023-06-26
Publication date: 2026-04-29
Also published as: WO2025005310A1

Abstract

One aspect of the present disclosure provides a construction machinery including a hydraulic pump, a working device including a boom, an arm, and a bucket, a hydraulic actuator that is operated by a working fluid discharged from the hydraulic pump and includes a boom actuator, an arm actuator, and a bucket actuator that operate the boom, the arm, and the bucket, respectively, a manipulation lever that outputs an electrical manipulation signal in response to manipulation by a worker, a pressure sensor that detects a pressure generated by the hydraulic pump or the hydraulic actuator, and an electronic controller that controls an operation of the hydraulic actuator based on the manipulation signal output by the manipulation lever, wherein, when the pressure detected by the pressure sensor during an excavating operation of the working device is higher than or equal to a boom driving start pressure, the electronic controller controls an operation of the boom actuator to perform boom-up driving.

Description

[Technical Field]

The present disclosure relates generally to construction machinery. In particular aspects, the disclosure relates to construction machinery. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

[Background Art]

Generally, an excavator is a type of construction machinery that performs various tasks, such as a drilling task for digging into the ground, a loading task for transporting soil, an excavating task for creating a foundation, a crushing task for dismantling a building, a preparing task for preparing the ground, and a leveling task for leveling the ground, at a construction site.
As illustrated in FIG. 1, generally, in an excavating task, after a boom B1 is lowered and a bucket B3 is inserted into soil, the bucket B3 is closed by closing an arm B2, the soil is inserted into the bucket B3, and then, the boom B1 is lifted again, and the soil is dumped in a designated place.
In recent years, attempts have been made for a control technology for controlling a hydraulic actuator and a trajectory and semiautomatically assisting manipulation by a worker by having an angle sensor, a cylinder displacement sensor, etc., for measuring the posture of a working device in order to facilitate an excavating task. For example, with the corresponding semiautomatically-assisting control technology, even when a worker manipulates only an arm, operations of a boom and a bucket are automatically controlled by an electronic controller, and predetermined soil is inserted into the bucket, and the boom is lifted.
However, when the load applied to the bucket increases as when the bucket is inserted deep into the soil or the soil being excavated is hard and heavy, an operation of closing the arm or the bucket is not possible in some cases.
In such cases, the worker needs to manually perform an excavating operation by releasing a semiautomatic function, lifting the boom, and setting an excavation depth shallow, or needs to set the semiautomatic function again, and thus there are problems that the worker's fatigue caused by the work increases, and the work efficiency decreases.

[Disclosure]

[Technical Solution]

According to a first aspect of the disclosure, there is provided a construction machinery including a hydraulic pump, a working device including a boom, an arm, and a bucket, a hydraulic actuator that is operated by a working fluid discharged from the hydraulic pump and includes a boom actuator, an arm actuator, and a bucket actuator that operate the boom, the arm, and the bucket, respectively, a manipulation lever that outputs an electrical manipulation signal in response to manipulation by a worker, a pressure sensor that detects a pressure generated by the hydraulic pump or the hydraulic actuator, and an electronic controller that controls an operation of the hydraulic actuator based on the manipulation signal output by the manipulation lever, wherein, when the pressure detected by the pressure sensor during an excavating operation of the working device is higher than or equal to a boom driving start pressure, the electronic controller controls an operation of the boom actuator to perform boom-up driving. The first aspect of the disclosure may seek to provide a construction machinery in which boom-up driving is automatically performed when an overload occurs during an excavating operation. A technical benefit may include allowing a worker to pay less attention to the load applied to the arm or the bucket during the excavating operation, thus reducing the worker's fatigue caused by the work and improving the work efficiency, because the boom-up driving is automatically performed when it is determined by the electronic controller that there is an abnormality in the excavating operation.
Optionally in some examples, the electronic controller may control an operation of one or more of the boom actuator, the arm actuator, and the bucket actuator by assisting the manipulation signal output by the manipulation lever to allow the working device to semiautomatically perform the excavating operation when a semiautomatic excavation mode is set.
Optionally in some examples, the manipulation lever may include a first manipulation lever that performs an arm-in operation when manipulated in one direction and performs an arm-out operation when manipulated in another direction.
Optionally in some examples, a switch configured to turn the semiautomatic excavation mode on/off may be provided on the first manipulation lever. A technical benefit may include that the worker can control the excavating operation of the working device with one hand because the switch for the semiautomatic excavation mode is provided on the first manipulation lever.
Optionally in some examples, the electronic controller may automatically control operations of the boom actuator and the bucket actuator for the working device to perform the excavating operation when the first manipulation lever is manipulated in the one direction in the semiautomatic excavation mode.
Optionally in some examples, the electronic controller may cause the boom-up driving to be performed while the first manipulation lever returns to a neutral position when the first manipulation lever is released in a state in which the first manipulation lever is manipulated in the one direction in the semiautomatic excavation mode. A technical benefit may include that the worker can lift the boom and reduce the load applied to the arm or the bucket just by releasing the manipulation of the first manipulation lever without manipulating a second manipulation lever.
Optionally in some examples, the electronic controller may automatically control operations of the boom actuator, the arm actuator, and the bucket actuator for the working device to perform the excavating operation in the semiautomatic excavation mode.
Optionally in some examples, the electronic controller may store a first soil quality map showing a relationship between a soil quality of soil subjected to work and the boom driving start pressure, and the boom driving start pressure may be changeable according to the soil quality of the soil.
Optionally in some examples, in the first soil quality map, the boom driving start pressure may be set to increase with an increase in a density or a hardness of the soil.
Optionally in some examples, the electronic controller may maintain the boom-up driving for a boom driving maintaining time when the pressure detected by the pressure sensor during the excavating operation of the working device is higher than or equal to the boom driving start pressure.
Optionally in some examples, when the pressure detected by the pressure sensor decreases to lower than or equal to a boom driving release pressure due to the boom-up driving, the electronic controller may release the boom-up driving, and when the pressure detected by the pressure sensor remains higher than the boom driving release pressure even when the boom-driving is maintained for the boom driving maintaining time, the electronic controller may maintain the boom-up driving for the boom driving maintaining time once again.
Optionally in some examples, the electronic controller may store a second soil quality map showing a relationship between a soil quality of soil subjected to work and the boom driving maintaining time, and the boom driving maintaining time may be changeable according to the soil quality of the soil.
Optionally in some examples, in the second soil quality map, the boom driving maintaining time may be set to increase with an increase in a density or a hardness of the soil.
Optionally in some examples, the electronic controller may increase the boom driving start pressure when an amount of time taken for the excavating operation of the working device is more than or equal to a first set time or less than or equal to a second set time.
Optionally in some examples, the electronic controller may increase the boom driving start pressure with an increase in a number of times of the boom-up driving of the working device.
The above and subsequent embodiments disclosed herein, the appended claims, and/or examples may be appropriately combined as would be apparent to those skilled in the art.
Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein.

[Description of Drawings]

With reference to the accompanying drawings, a more detailed description of the embodiments of the present disclosure, cited herein by way of example, will follow.

FIG. 1 is a view schematically showing an excavating task of a construction machinery.
FIG. 2 is a perspective view illustrating a construction machinery according to one embodiment of the present invention.
FIG. 3 is a block diagram illustrating a basic configuration of the construction machinery.
FIG. 4 is a view schematically showing an overall configuration of the construction machinery.
FIG. 5 is a block diagram of an electronic controller.
FIG. 6 is a view schematically showing first and second soil quality maps.
FIGS. 7 to 9 are views showing examples of semiautomatic excavation control of the electronic controller.

[Modes of the Invention]

The embodiments described below provide the information necessary for those skilled in the art to carry out the present disclosure.
FIG. 2 is a perspective view illustrating a construction machinery according to one embodiment of the present invention.
Referring to FIG. 2, a construction machinery 100, such as an excavator, has an operator cabin 10, a lower traveling body 20, an upper slewing body 30 slewably installed on the lower traveling body 20, and a working device 40 and a hydraulic actuator 50 that are installed to be operable in an up-down direction on the upper slewing body 30.
The working device 40 is formed of multiple joints and has a boom 41 that has a rear end portion rotatably supported by the upper slewing body 30, an arm 42 that has a rear end portion rotatably supported by a distal end of the boom 41, and a bucket 43 that is rotatably installed on a distal end side of the arm 42. The hydraulic actuator 50 includes a boom actuator 51, an arm actuator 52, and a bucket actuator 53. Then, when a working fluid is supplied according to manipulation of a manipulation lever by a worker, the boom actuator 51, the arm actuator 52, and the bucket actuator 53 operate the boom 41, the arm 42, and the bucket 43, respectively.
FIG. 3 is a block diagram illustrating a basic configuration of the construction machinery, and FIG. 4 is a view schematically showing an overall configuration of the construction machinery.
Referring to FIGS. 3 and 4, the construction machinery 100 may include a hydraulic pump 110, a control valve part 120, an electronic proportional pressure reducing valve 130, a sensor part 140, a manipulation lever 150, a setting part 160, and an electronic controller 170.
The hydraulic pump 110 is driven by an engine E and discharges a high-pressure working fluid for operating the hydraulic actuator 50. The hydraulic pump 110 may include first and second hydraulic pumps 111 and 112.
The control valve part 120 is a member for opening or closing a flow path by a spool receiving a hydraulic pressure of the working fluid discharged by the hydraulic pump 110 and moving in an axial direction, and may include a first control valve 121, a second control valve 122, and a third control valve 123 that operate the boom actuator 51, the arm actuator 52, and the bucket actuator 53, respectively. The control valve part 120 is connected to the hydraulic pump 110 through a hydraulic line and induces the supply of the working fluid from the hydraulic pump 110 to the boom actuator 51, the arm actuator 52, and the bucket actuator 53.
A relief valve (not illustrated) for preventing damage to a hydraulic device may be provided on the hydraulic line connected to the hydraulic pump 110 or the control valve part 120. When the construction machinery 100 performs work such as excavation, a load pressure is generated due to an excavation load inside the hydraulic actuator 50. In order to prevent a pressure in a hydraulic circuit from exceeding an internal pressure of a hydraulic device due to an increase in the load pressure, the relief valve may open to release a hydraulic oil to a tank when a predetermined set pressure is reached.
The electronic proportional pressure reducing valve 130 is an electronically manipulated valve and generates a hydraulic pressure in response to an electrical signal applied by the electronic controller 170, and the generated hydraulic pressure is transferred to the control valve part 120. The hydraulic pressure from the electronic proportional pressure reducing valve 130 causes the spool in the control valve part 120 to axially move.
The sensor part 140 may include a pressure sensor 141 and a posture measurement sensor 142.
The pressure sensor 141 may detect a head-side pressure and/or a rod-side pressure of the hydraulic actuator 50 and may provide a detected pressure value to the electronic controller 170. However, the present disclosure is not limited thereto, and the pressure sensor 141 may be connected to the hydraulic line between the control valve part 120 and the hydraulic pump 110, may detect the pressure of the hydraulic pump 110, and may provide a detected pressure value to the electronic controller 170.
The posture measurement sensor 142 measures the positions and/or postures of the boom 41, the arm 42, and the bucket 43, the slope of a main body of the construction machinery 100, etc., using a plurality of inertial measurement units (IMUs), an angle sensor, etc. For example, the boom 41, the arm 42, and the bucket 43 may each have an IMU disposed thereon.
The manipulation lever 150 may be a hydraulic joystick or an electric joystick, and preferably, the manipulation lever 150 may be an electric joystick that generates an electrical signal proportional to a manipulated variable of the worker and provides the electrical signal to the electronic controller 170.
The manipulation lever 150 may manipulate up-down movement of the boom 41, pivoting of the arm 42 and the bucket 43, slewing of the upper slewing body 30, etc. The manipulation lever 150 may be configured to include a first manipulation lever 151a and a second manipulation lever 151b.
For example, the first manipulation lever 151a is used in manipulation of the arm 42 and slewing manipulation of the upper slewing body 30. When the first manipulation lever 151a is manipulated toward the front of the worker, an arm-out operation is performed, that is, the arm actuator 52 operates so that the arm 42 opens. When the first manipulation lever 151a is manipulated toward the rear of the worker, an arm-in operation is performed, that is, the arm actuator 52 operates so that the arm 42 closes. In addition, when the first manipulation lever 151a is manipulated toward the left of the worker, a leftward slewing operation is performed, that is, a slewing hydraulic motor (not illustrated) operates so that the upper slewing body 30 slews leftward. When the first manipulation lever 151a is manipulated toward the right of the worker, a rightward slewing operation is performed, that is, the slewing hydraulic motor operates so that the upper slewing body 30 slews rightward.
The second manipulation lever 151b is used in manipulation of the boom 41 and manipulation of the bucket 43. When the second manipulation lever 151b is manipulated toward the front of the worker, a boom-down operation is performed, that is, the boom actuator 51 operates so that the boom 41 moves downward. When the second manipulation lever 151b is manipulated toward the rear of the worker, a boom-up operation is performed, that is, the boom actuator 51 operates so that the boom 41 moves upward. In addition, when the second manipulation lever 151b is manipulated toward the left of the worker, a bucket-in operation is performed, that is, the bucket actuator 53 operates so that the bucket 43 closes. When the second manipulation lever 151b is manipulated toward the right of the worker, a bucket-out operation is performed, that is, the bucket actuator 53 operates so that the bucket 43 opens.
However, the present disclosure is not limited thereto, and of course, methods of manipulating the first manipulation lever 151a and the second manipulation lever 151b may be changed by a user. For example, the first manipulation lever 151a may be used in manipulation of the boom 41 and the bucket 43, and the second manipulation lever 151b may be used in manipulation of the arm 42 and the upper slewing body 30.
Switches of various functions may be provided on the manipulation lever 150, and in particular, a semiautomatic excavation mode switch 152 for turning a semiautomatic excavation mode ON/OFF may be provided on the first manipulation lever 151a. However, the present disclosure is not limited thereto, and the semiautomatic excavation mode switch 152 may be provided on the second manipulation lever 151b.
Through the setting part 160, the worker may change soil quality information of soil subjected to work and one or more of a boom driving start pressure and a boom driving maintaining time that serve as criteria when determining whether there is an abnormality in excavation. For example, the setting part 160 may be configured as a display or a switch.
Specifically, through the setting part 160, the worker may set a soil quality of soil on which work is being performed. Here, the soil quality may relate to the type, density, hardness, etc., of the soil of the work site. For example, through the setting part 160, the worker may set a pre-stored type of soil, such as sandy soil or cohesive soil, as the type of soil. Further, through the setting part 160, the worker may set a pre-stored density level or hardness level as the density level or hardness level of soil. The present disclosure is not limited thereto, and the worker may directly input information on the soil quality of the soil through the setting part 160.
Further, the worker may change a pre-stored boom driving start pressure level, a pre-stored boom driving maintaining time level, etc., through the setting part 160. The present disclosure is not limited thereto, and the worker may directly input information on the boom driving start pressure and the boom driving maintaining time through the setting part 160.
The electronic controller 170 generates an electrical signal and outputs the electrical signal to the electronic proportional pressure reducing valve 130 according to an operation of the manipulation lever 150. A plurality of electronic proportional pressure reducing valves 130 may each supply a pilot signal pressure, which is proportional to an intensity of current applied by the electronic controller 170, to one of a plurality of spools of the control valve part 120, thereby causing the spools of the control valve part 120 to move according to the intensity of the applied pilot signal pressure. That is, the electronic controller 170 controls an operation of the hydraulic actuator 50 based on a manipulation signal output by the manipulation lever 150.
FIG. 5 is a block diagram of an electronic controller.
Referring to FIG. 5, the electronic controller 170 may include a data receiver 171, a storage 172, an excavating operation assister 173, a boom driving determiner 174, and an output part 175.
The data receiver 171 may receive information output by various devices during an operation of the construction machinery. For example, the data receiver 171 may receive a head-side pressure and a rod-side pressure of the hydraulic actuator 50 that are detected by the pressure sensor 141. Further, the data receiver 171 may receive posture information detected by the posture measurement sensor 142. Further, the data receiver 171 may receive information on the soil quality, the boom driving start pressure, and the boom driving maintaining time that are set through the setting part 160. Further, the data receiver 171 may receive a manipulated variable of the manipulation lever 150 as a working device manipulation signal for the boom 41, the arm 42, and the bucket 43 from the manipulation lever 150. Further, the data receiver 171 may receive an ON/OFF signal of the semiautomatic excavation mode from the semiautomatic excavation mode switch 152 provided on the first manipulation lever 151a. In addition, the data receiver 171 may receive information on the working time, the number of times of boom-up driving, etc., from the pressure sensor 141 mounted on the manipulation lever 150 or the boom actuator 51.
The storage 172 may store information output by various devices during an operation of the construction machinery. Further, the storage 172 may store a pilot signal pressure for semiautomatically controlling the hydraulic actuator 50.
FIG. 6 is a view schematically showing first and second soil quality maps.
Referring to FIG. 6(a), the storage 172 stores a first soil quality map that shows the relationship between the soil quality and the boom driving start pressure.
For example, the first soil quality map may show the relationship between the soil density and the boom driving start pressure. Specifically, when soil of a work site is sandy soil, because the density is relatively low and excavation can be performed without high output horsepower, a discharge pressure basically required for the hydraulic pump 110 is low. On the other hand, when soil of a work site is cohesive soil, because the density is relatively high and high output horsepower is required for excavation, the discharge pressure basically required for the hydraulic pump 110 is high. That is, in the first soil quality map, the boom driving start pressure for high-density soil may be set to be higher than the boom driving start pressure for low-density soil.
Further, the first soil quality map may show the relationship between the soil hardness and the boom driving start pressure. Specifically, when soil subjected to work has a low hardness, because excavation can be performed without high output horsepower, a discharge pressure basically required for the hydraulic pump 110 is low. On the other hand, when soil subjected to work has a high hardness, because high output horsepower is required for excavation, the discharge pressure basically required for the hydraulic pump 110 is high. That is, in the first soil quality map, the boom driving start pressure for high-hardness soil may be set to be higher than the boom driving start pressure for low-hardness soil. In other words, in the the first soil quality map, the boom driving start pressure may be set to increase with an increase in the density or hardness of soil.
Referring to FIG. 6(b), the storage 172 stores a second soil quality map that shows the relationship between the soil quality and the boom driving maintaining time.
For example, the second soil quality map may show the relationship between the hardness or density of soil and the boom driving maintaining time. Specifically, when the hardness or density of soil on which work is being performed is low, even when boom-up driving is maintained for a short time, the pressure of the hydraulic actuator 50 may deviate from a relief pressure or deviate from a stall situation. On the other hand, when the hardness or density of soil subjected to work is high, boom-up driving needs to be maintained for a long time for the pressure of the hydraulic actuator 50 to deviate from the relief pressure or deviate from the stall situation. That is, in the second soil quality map, the boom driving maintaining time for soil with high hardness or density may be set to be shorter than the boom driving maintaining time for soil with low hardness or density. In other words, in the second soil quality map, the boom driving maintaining time may be set to increase with an increase in the density or hardness of soil.
The storage 172 stores a restriction map that shows the relationship between the working time and the boom driving start pressure. For example, because a long time being taken for an excavating operation of the working device 40 in a situation in which excavation work is being carried out normally means that a load acting on the bucket 43 is high, the restriction map may be set so that the boom driving start pressure increases when the working time is more than or equal to a first set time.
However, because the excavating operation may end rather quickly in a stall condition in which a load acting on the arm 42 or the bucket 43 is excessively high, the restriction map may be set so that the boom driving start pressure increases even when the working time is less than or equal to a second set time. Here, the second set time may be set to be less than the first set time.
The storage 172 stores a boom driving release pressure that serves as a criterion for releasing boom-up driving. The boom driving release pressure may be set to be lower than or equal to the boom driving start pressure.
Further, the storage 172 stores a restriction map showing the relationship between the number of times of boom-up driving and the boom driving start pressure. For example, because an increase in the number of times of boom-up driving of the working device 40 means that the load acting on the bucket 43 is high, the restriction may may be set so that the boom driving start pressure increases when the number of times of boom-up driving increases.
Meanwhile, referring to FIGS. 1 and 2, during an excavating operation, the worker performs a series of manipulations of inserting the bucket 43 into soil by the boom-down operation, closing the arm 42 and closing the bucket 43 by the arm-in operation and the bucket-in operation to insert the soil into the bucket 43, and then lifting the boom 41 back by the boom-up operation. However, the present disclosure is not limited thereto, and the excavating operation may also include an operation in which the upper slewing body 30 slews to dump the soil in a designated place.
That is, during excavation work, the worker manipulates the arm 42 using the first manipulation lever 151a with one hand and manipulates the boom 41 and the bucket 43 by manipulating the second manipulation lever 151b with the other hand. In this way, because the excavation work requires extreme concentration of the worker, the worker's fatigue increases.
Accordingly, when the data receiver 171 receives an ON signal of the semiautomatic excavation mode, the excavating operation assister 173 assists the manipulation signal output from the manipulation lever 150 so that the working device 40 can perform the excavating operation semiautomatically.
Here, the semiautomatic excavation mode refers to a mode in which control of an excavating operation is performed semiautomatically, and is a control technology for assisting manipulation of the manipulation lever 150 to allow the worker to perform the excavating operation with one hand.
FIGS. 7 to 9 are views showing examples of semiautomatic excavation control of the electronic controller.
Specifically, the excavating operation assister 173 may compute a pilot signal pressure for automatically controlling the hydraulic actuator 150 during excavation work. For example, referring to FIGS. 5 to 7, when the worker presses the semiautomatic excavation mode switch 152 provided on the first manipulation lever 151a, executes the semiautomatic excavation mode, and pulls the first manipulation lever 151a toward the rear so that the arm-in operation is performed, the excavating operation assister 173 computes a pilot signal pressure for the boom actuator 51 and the bucket actuator 53 to automatically perform the excavating operation and outputs the pilot signal pressure to the output part 175.
Accordingly, movements of the boom 41 and the bucket 43 may be automatically controlled, and the worker an perform excavation work by simultaneously moving the boom 41, the arm 42, and the bucket 43 just by manipulating the first manipulation lever 151a.
Meanwhile, generally, when a worker estimates a load applied to the bucket 43 from a feeling of manipulation during excavation and thinks that a load is acting on the bucket 43, the worker reduces the load applied to the bucket 43 through the boom-up operation.
Therefore, referring to FIGS. 5 and 8, when the first manipulation lever 151a is released in the state in which it is manipulated toward the rear, the excavating operation assister 173 computes a pilot signal pressure for boom-up driving to occur while the first manipulation lever 151a returns to a neutral position, and outputs the pilot signal pressure to the output part 175. In this case, the worker can reduce the load applied to the bucket 43 by lifting the boom 41 just by releasing manipulation of the first manipulation lever 151a.
Meanwhile, the semiautomatic excavation mode is not limited to automatically controlling the movements of the boom 41 and the bucket 43 as described above. For example, referring to FIG. 9, movements of all of the boom 41, the arm 42, and the bucket 43 may be automatically controlled when the semiautomatic excavation mode switch 152 provided on the first manipulation lever 151a is pressed and the semiautomatic excavation mode is executed.
The boom driving determiner 174 determines whether there is an abnormality in the excavating operation, based on the pressure information of the hydraulic actuator 50 received by the data receiver 171, the information on the soil quality, the boom driving start pressure, and the boom driving maintaining time set through the setting part 160, and the information stored in the storage 172.
The boom driving determiner 174 determines the boom driving start pressure based on the soil quality information of soil set through the setting part 160 and the first soil quality map stored in the storage 172. For example, when a soil hardness level is set to be high through the setting part 160, the boom driving start pressure may be set to be relatively high, and when the soil hardness level is set to be low through the setting part 160, the boom driving start pressure may be set to be relatively low.
The boom driving determiner 174 may determine the boom driving start pressure based on the time taken for an excavating operation. For example, the boom driving determiner 174 may automatically increase the boom driving start pressure when the time taken for the excavating operation is more than or equal to the first set time based on the restriction map stored in the storage 172. However, the present disclosure is not limited thereto, and the boom driving determiner 174 may automatically increase the boom driving start pressure even when the time taken for the excavating operation decreases to less than or equal to the second set time due to a stall situation.
Further, the boom driving determiner 174 may determine the boom driving start pressure based on the number of times of boom-up driving. For example, the boom driving determiner 174 may automatically increase the boom driving start pressure when the number of times of boom-up driving increases based on the restriction map stored in the storage 172.
Further, the boom driving start pressure may be a relief pressure. Further, the boom driving start pressure may be a value directly input through the setting part 160 by the worker.
The boom driving determiner 174 determines the boom driving maintaining time based on the soil quality information of soil set through the setting part 160 and the second soil quality map stored in the storage 172. For example, when a soil hardness level is set to be high through the setting part 160, the boom driving maintaining time may be set to be relatively long, and when the soil hardness level is set to be low through the setting part 160, the boom driving maintaining time may be set to be relatively short. However, the present disclosure is not limited thereto, and the boom driving maintaining time may be a value directly input through the setting part 160 by the worker.
The boom driving determiner 174 determines whether the pressure of the hydraulic actuator 50 exceeds or is higher than or equal to a set boom driving start pressure, determines that there is an abnormality in the excavating operation when the condition is satisfied, and outputs the corresponding result to the output part 175.
The boom driving determiner 174 determines the time during which boom-up driving is maintained, that is, the boom driving maintaining time, when the boom-up operation is being performed, and outputs the boom driving maintaining time to the output part 175.
Further, when the boom-up operation is automatically performed, the boom driving determiner 174 compares the pressure of the hydraulic actuator 50 received by the data receiver 171 and the boom driving release pressure pre-stored in the storage 172 and determines whether to release boom-up driving.
Specifically, the boom driving determiner 174 determines whether the pressure of the hydraulic actuator 50 measured by the pressure sensor 141 is reduced to lower than or equal to the boom driving release pressure, determines that there is no abnormality in the excavating operation when the condition is satisfied, and outputs the corresponding result to the output part 175 to release boom-up driving.
However, when the pressure of the hydraulic actuator 50 does not reduce to the boom driving release pressure until the boom driving maintaining time reaches an end, the boom driving determiner 174 determines that there is an abnormality in the excavating operation and outputs the corresponding result to the output part 175 to maintain boom-up driving for the boom driving maintaining time once again.
When the pressure of the hydraulic actuator 50 still does not reduce to the boom driving release pressure, the boom driving determiner 174 determines that there is an abnormality in the excavating operation and outputs the corresponding result to the output part 175 to release the semiautomatic mode and allow the worker to perform manual manipulation.
In this way, because the boom-up operation is automatically performed by the output part 175 when it is determined by the boom driving determiner 174 that there is an abnormality in the excavating operation, the worker may pay less attention to the load applied to the arm 42 or the bucket 43 during the excavating operation, and thus the worker's fatigue caused by the work can be reduced and the work efficiency can be improved.
The output part 175 may receive a manipulation signal proportional to the manipulated variable of the worker from the manipulation lever, may generate a control signal, for example, current, corresponding to the received manipulation signal, and may apply the current to the electronic proportional pressure reducing valve 130.
The output part 175 may generate current corresponding to a pilot signal pressure computed by the excavating operation assister 173 and may apply the current to the electronic proportional pressure reducing valve 130 of each of the control valves 121, 122, and 123. In this way, the working fluid can be supplied to the hydraulic actuator 50, and the excavating operation can be automatically performed.
When it is determined by the boom driving determiner 174 that there is an abnormality in the excavating operation, the output part 175 may generate predetermined current and may apply the current to the electronic proportional pressure reducing valve 130 of the first control valve 121. In this way, the working fluid can be supplied to the boom actuator 51, and the boom-up operation can be performed for the boom driving maintaining time.
The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.
Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Claims

A construction machinery comprising:
a hydraulic pump;

a working device including a boom, an arm, and a bucket;

a hydraulic actuator that is operated by a working fluid discharged from the hydraulic pump and includes a boom actuator, an arm actuator, and a bucket actuator that operate the boom, the arm, and the bucket, respectively;

a manipulation lever that outputs an electrical manipulation signal in response to manipulation by a worker;

a pressure sensor that detects a pressure generated by the hydraulic pump or the hydraulic actuator; and

an electronic controller that controls an operation of the hydraulic actuator based on the manipulation signal output by the manipulation lever,

wherein, when the pressure detected by the pressure sensor during an excavating operation of the working device is higher than or equal to a boom driving start pressure, the electronic controller controls an operation of the boom actuator to perform boom-up driving
The construction machinery of claim 1, wherein the electronic controller controls an operation of one or more of the boom actuator, the arm actuator, and the bucket actuator by assisting the manipulation signal output by the manipulation lever to allow the working device to semiautomatically perform the excavating operation when a semiautomatic excavation mode is set.
The construction machinery of claim 2, wherein the manipulation lever includes a first manipulation lever that performs an arm-in operation when manipulated in one direction and performs an arm-out operation when manipulated in another direction.
The construction machinery of claim 3, wherein a switch configured to turn the semiautomatic excavation mode on/off is provided on the first manipulation lever.
The construction machinery of claim 3, wherein the electronic controller automatically controls operations of the boom actuator and the bucket actuator for the working device to perform the excavating operation when the first manipulation lever is manipulated in the one direction in the semiautomatic excavation mode.
The construction machinery of claim 3, wherein the electronic controller causes the boom-up driving to be performed while the first manipulation lever returns to a neutral position when the first manipulation lever is released in a state in which the first manipulation lever is manipulated in the one direction in the semiautomatic excavation mode.
The construction machinery of claim 2, wherein the electronic controller automatically controls operations of the boom actuator, the arm actuator, and the bucket actuator for the working device to perform the excavating operation in the semiautomatic excavation mode.
The construction machinery of claim 1, wherein the electronic controller stores a first soil quality map showing a relationship between a soil quality of soil subjected to work and the boom driving start pressure, and
the boom driving start pressure is changeable according to the soil quality of the soil.
The construction machinery of claim 8, wherein, in the first soil quality map, the boom driving start pressure is set to increase with an increase in a density or a hardness of the soil.
The construction machinery of claim 1, wherein the electronic controller maintains the boom-up driving for a boom driving maintaining time when the pressure detected by the pressure sensor during the excavating operation of the working device is higher than or equal to the boom driving start pressure.
The construction machinery of claim 10, wherein:
when the pressure detected by the pressure sensor decreases to lower than or equal to a boom driving release pressure due to the boom-up driving, the electronic controller releases the boom-up driving, and

when the pressure detected by the pressure sensor remains higher than the boom driving release pressure even when the boom-driving is maintained for the boom driving maintaining time, the electronic controller maintains the boom-up driving for the boom driving maintaining time once again.
The construction machinery of claim 10, wherein the electronic controller stores a second soil quality map showing a relationship between a soil quality of soil subjected to work and the boom driving maintaining time, and
the boom driving maintaining time is changeable according to the soil quality of the soil.
The construction machinery of claim 12, wherein, in the second soil quality map, the boom driving maintaining time is set to increase with an increase in a density or a hardness of the soil.
The construction machinery of claim 1, wherein the electronic controller increases the boom driving start pressure when an amount of time taken for the excavating operation of the working device is more than or equal to a first set time or less than or equal to a second set time.
The construction machinery of claim 1, wherein the electronic controller increases the boom driving start pressure with an increase in a number of times of the boom-up driving of the working device.