WO2025005310A1 - Construction machine - Google Patents

Abstract

An aspect of the present disclosure provides a construction machine comprising: a working device including a hydraulic pump, a boom, an arm, and a bucket; a hydraulic actuator which is operated by a working fluid discharged from the hydraulic pump, and comprises a boom actuator, an arm actuator, and a bucket actuator for operating the boom, the arm, and the bucket, respectively; a manipulation lever for outputting an electrical manipulation signal in response to a worker's manipulation; a pressure sensor for detecting pressure generated by the hydraulic pump or the hydraulic actuator; and an electronic control unit for controlling the operation of the hydraulic actuator on the basis of the manipulation signal output from the manipulation lever, wherein when the pressure detected by the pressure sensor during the excavation operation of the working device is greater than or equal to boom driving start pressure, the electronic control unit controls the operation of the boom actuator to drive the boom up.

Description

Construction machinery

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

In general, an excavator is a type of construction machine that performs various tasks such as digging the ground at construction sites, loading work to transport soil, excavation work to create foundations, crushing work to dismantle buildings, leveling work to prepare the ground, and leveling work to level the ground.

As shown in Fig. 1, in general, in excavation work, the boom (B1) is lowered, the bucket (B3) is inserted into the soil, the arm (B2) is closed while closing the bucket (B3), the soil is inserted into the bucket (B3), and then the boom (B1) is raised again to dump the soil to a designated location.

Recently, in order to smoothly perform excavation work, control technologies have been attempted that control the hydraulic actuator and trajectory by installing angle sensors or cylinder displacement sensors to measure the posture of the work device, and that assist the operator's operation semi-automatically. For example, in the semi-automatic auxiliary control technology, even if the operator only operates the arm, the operation of the boom and bucket is automatically controlled by the electronic control unit, so that a certain amount of soil is inserted into the bucket cut and lifted.

However, when the load on the bucket increases, such as when the bucket is buried deep in the soil or the soil being excavated is hard and heavy, there are cases where the arm or bucket cannot be closed.

In this case, the worker must manually perform excavation operations, such as raising the boom and reducing the excavation depth after disabling the semi-automatic function, or re-enable the semi-automatic function, which increases the worker's work fatigue and reduces work efficiency.

According to a first aspect of the present disclosure, a construction machine is provided, comprising: a working device including a hydraulic pump, a boom, an arm, and a bucket; a hydraulic actuator including a boom actuator, an arm actuator, and a bucket actuator, which are operated by working fluid discharged from the hydraulic pump and operate the boom, the arm, and the bucket, respectively; an operating lever which outputs an electric operating signal corresponding to an operation of a worker; a pressure sensor which detects a pressure generated in the hydraulic pump or the hydraulic actuator; and an electronic control unit which controls the operation of the hydraulic actuator based on the operating signal output from the operating lever; wherein the electronic control unit controls the operation of the boom actuator to drive a boom-up when the pressure detected by the pressure sensor is higher than a boom drive start pressure during an excavation operation of the working device. The first aspect of the present disclosure can pursue a construction machine in which boom-up driving is automatically performed when overload occurs in an excavation operation. The technical advantage is that since the boom-up operation is automatically performed when the electronic control unit determines that there is an abnormality in the excavation operation, the operator is less concerned about the load applied to the arm or bucket during the excavation operation, and thus the operator's work fatigue can be reduced and work efficiency can be improved.

Optionally, in some examples, the electronic control unit may control the operation of one or more of the boom actuator, the arm actuator and the bucket actuator by assisting an operation signal output from the operation lever so that the work device can perform a semi-automatic excavation operation when the semi-automatic excavation mode is set.

Optionally, in some examples, the operating lever may include a first operating lever that, when operated in one direction, causes an arm-in operation and, when operated in the other direction, causes an arm-out operation.

Optionally, in some examples, the first operating lever may be provided with a switch configured to turn the semi-automatic excavation mode on and off. A technical advantage is that the semi-automatic excavation mode switch is provided on the first operating lever, allowing the operator to control the excavation operation of the work tool with one hand.

Optionally, in some examples, the electronic control unit can automatically control the operation of the boom actuator and the bucket actuator so that the work device performs an excavation operation when the first operating lever is operated in one direction in the semi-automatic excavation mode.

Optionally, in some examples, the electronic control unit can drive the boom-up while the first operating lever returns to the neutral position when the first operating lever is released from the unidirectionally operated state in the semi-automatic excavation mode. The technical advantage is that the boom can be raised by only releasing the operation of the first operating lever without the operator operating the second operating lever, thereby reducing the load applied to the arm or bucket.

Optionally, in some examples, the electronic control unit can automatically control the operation of the boom actuator, the arm actuator and the bucket actuator to cause the work device to perform an excavation operation in the semi-automatic excavation mode.

Optionally, in some examples, the electronic control unit stores a first soil map indicating a relationship between the soil quality of the soil being worked on and the boom driving initiation pressure, and the boom driving initiation pressure may be changed according to the soil quality of the soil.

Optionally, in some examples, in the first soil map, the boom drive initiation pressure may be set to increase as the density or hardness of the soil increases.

Optionally, in some examples, the electronic control unit may maintain the boom-up operation for a boom operation maintenance time if the pressure detected by the pressure sensor during the excavation operation of the work device is higher than the boom operation initiation pressure.

Optionally, in some examples, the electronic control unit releases the boom-up operation when the pressure detected by the pressure sensor decreases below the boom-up release pressure due to the boom-up operation, and if the boom-up operation is maintained for the boom-up maintenance time and the pressure detected by the pressure sensor is maintained to exceed the boom-up release pressure, the boom-up operation can be maintained again for the boom-up maintenance time.

Optionally, in some examples, the electronic control unit stores a second soil map indicating a relationship between the soil quality of the soil being worked on and the boom driving maintenance time, and the boom driving maintenance time can be changed according to the soil quality of the soil.

Optionally, in some examples, in the second soil map, the boom driving maintenance time may be set to increase as the density or hardness of the soil increases.

Optionally, in some examples, the electronic control unit may increase the boom drive initiation pressure if the time required for the excavation operation of the work device is longer than the first set time or shorter than the second set time.

Optionally, in some examples, the electronic control unit may increase the boom drive initiation pressure as the number of boom-up operations of the work device increases.

The above and hereinafter disclosed aspects, appended claims, and/or examples may be suitably combined with one another as would be apparent to one of ordinary skill in the art.

Additional features and advantages are set forth in the following description, claims, and drawings, and in part will be readily apparent to those skilled in the art from the foregoing or may be recognized by practicing the teachings herein.

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

Figure 1 is a drawing schematically showing the excavation work of construction machinery.

FIG. 2 is a perspective view illustrating a construction machine according to one embodiment of the present invention.

Figure 3 is a block diagram showing the basic configuration of construction equipment.

Figure 4 is a drawing schematically showing the overall configuration of the construction machine.

Figure 5 is a block diagram of the electronic control unit.

Figure 6 is a schematic diagram showing the first and second soil maps.

Figures 7 to 9 are drawings showing examples of semi-automatic excavation control of an electronic control unit.

The embodiments described below present information necessary to enable a person skilled in the art to practice the present disclosure.

FIG. 2 is a perspective view illustrating a construction machine according to one embodiment of the present invention.

Referring to FIG. 2, a construction machine (100) such as an excavator has a driver's cab (10), a lower body (20), an upper swivel body (30) that is swivellably installed on the lower body (20), and a work device (40) and a hydraulic actuator (50) that are movably installed on the upper body (30).

The work device (40) is formed with a multi-joint structure and has a boom (41) whose rear end is rotatably supported on an upper swivel body (30), an arm (42) whose rear end is rotatably supported on a front end of the boom (41), and a bucket (43) rotatably installed on a front end side of the arm (42). The hydraulic actuator (50) includes a boom actuator (51), an arm actuator (52), and a bucket actuator (53). When operating fluid is supplied according to the operator's operation of the operating lever, 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.

Figure 3 is a block diagram showing the basic configuration of construction equipment, and Figure 4 is a drawing schematically showing the overall configuration of construction equipment.

Referring to FIGS. 3 and 4, the construction machine (100) may include a hydraulic pump (110), a control valve unit (120), an electronic proportional pressure reducing valve (130), a sensor unit (140), an operating lever (150), a setting unit (160), and an electronic control unit (170).

The hydraulic pump (110) is driven by the engine (E) and discharges high-pressure operating fluid for operating the hydraulic actuator (50). The hydraulic pump (110) may include first and second hydraulic pumps (111, 112).

The control valve unit (120) is a member that opens and closes a flow path by a spool that moves in the axial direction under the hydraulic pressure of the operating fluid discharged from the hydraulic pump (110), and may include a first control valve (121), a second control valve (122), and a third control valve (123) that operate a boom actuator (51), an arm actuator (52), and a bucket actuator (53), respectively. The control valve unit (120) is connected to the hydraulic pump (110) through a hydraulic line, and induces the supply of operating fluid from the hydraulic pump (110) to the boom actuator (51), the arm actuator (52), and the bucket actuator (53).

A relief valve (not shown) may be provided on the hydraulic line connected to the hydraulic pump (110) or the control valve unit (120) to prevent damage to the hydraulic device. When the construction machine (100) performs work such as excavation, a load pressure according to the excavation load is generated inside the hydraulic actuator (50). The relief valve opens when the pressure in the hydraulic circuit reaches a predetermined set pressure so that the pressure does not exceed the internal pressure of the hydraulic device due to the increase in the load pressure, thereby releasing the pressurized oil into the tank.

The electronic proportional pressure reducing valve (130) is an electronically operated valve that generates hydraulic pressure in response to an electric signal applied by an electronic control unit (170), and the generated hydraulic pressure is transmitted to the control valve unit (120). The hydraulic pressure from the electronic proportional pressure reducing valve (130) causes the spool in the control valve unit (120) to move along the axis.

The sensor unit (140) may include a pressure sensor (141) and a posture measurement sensor (142).

The pressure sensor (141) detects the head side and/or load side pressure of the hydraulic actuator (50) and can provide the detected pressure value to the electronic control unit (170). However, it is not limited thereto, and the pressure sensor (141) can be connected to the hydraulic line between the control valve unit (120) and the hydraulic pump (110) to detect the pressure of the hydraulic pump (110) and provide the detected pressure value to the electronic control unit (170).

The attitude measurement sensor (142) measures the position and/or attitude of the boom (41), the arm (42), and the bucket (43), as well as the inclination of the main body of the construction machine (100), using a plurality of inertial measurement units (IMUs), angle sensors, etc. For example, an inertial measurement device may be placed on each of the boom (41), the arm (42), and the bucket (43).

The operating lever (150) may be a hydraulic joystick or an electric joystick, and preferably, the operating lever (150) may be an electric joystick that generates an electric signal in proportion to the amount of manipulation by the operator and provides it to the electronic control unit (170).

The operating lever (150) can operate the up and down movement of the boom (41), the rotation of the arm (42) and bucket (43), and the rotation of the upper swivel body (30). The operating lever (150) can be configured to include a first operating lever (151a) and a second operating lever (151b).

For example, the first operating lever (151a) is used to operate the arm (42) and the swing operation of the upper swivel body (30). When the first operating lever (151a) is operated toward the front of the worker, the arm actuator (52) is operated to perform an arm-out operation, that is, to open the arm (42). When the first operating lever (151a) is operated toward the rear of the worker, the arm actuator (52) is operated to perform an arm-in operation, that is, to close the arm (42). In addition, when the first operating lever (151a) is operated toward the left of the worker, the swing hydraulic motor (not shown) is operated to perform a left swing operation, that is, to swing the upper swivel body (30) to the left. When the first operating lever (151a) is operated to the right of the operator, the turning hydraulic motor is operated to perform a priority turning operation, that is, to turn the upper turning body (30) to the right.

The second operating lever (151b) is used to operate the boom (41) and the bucket (43). When the second operating lever (151b) is operated toward the front of the worker, the boom actuator (51) is operated to perform a boom-down operation, that is, to lower the boom (41). When the second operating lever (151b) is operated toward the rear of the worker, the boom actuator (51) is operated to perform a boom-up operation, that is, to raise the boom (41). In addition, when the second operating lever (151b) is operated toward the left of the worker, the bucket actuator (53) is operated to perform a bucket-in operation, that is, to close the bucket (43). When the second operating lever (151b) is operated to the right of the operator, the bucket actuator (53) is operated to perform a bucket-out operation, i.e., to open the bucket (43).

However, it is not limited thereto, and the operating methods of the first operating lever (151a) and the second operating lever (151b) can of course be changed by the user. For example, the first operating lever (151a) can be used to operate the boom (41) and the bucket (43), and the second operating lever (151b) can be used to operate the arm (42) and the upper swivel body (30).

Switches with various functions may be provided on the operating lever (150), and in particular, a semi-automatic excavation mode switch (152) that turns the semi-automatic excavation mode ON/OFF may be provided on the first operating lever (151a). However, this is not limited thereto, and the semi-automatic excavation mode switch (152) may also be provided on the second operating lever (151b).

Through the setting unit (160), the worker can change at least one of the soil quality information of the soil being worked on and the boom drive start pressure and boom drive maintenance time that serve as criteria when determining that there is an abnormality in excavation. The setting unit (160) can be composed of, for example, a display or a switch.

In detail, the worker can set the soil quality of the soil being worked on through the setting unit (160). At this time, the soil quality may be related to the type, density, hardness, etc. of the soil at the work site. For example, the worker can set the type of soil, such as sandy soil or clayey soil, that has been previously stored through the setting unit (160). In addition, the worker can set the density level or hardness level of the previously stored soil through the setting unit (160). It is not limited thereto, and the worker can directly input information on the soil quality of the soil through the setting unit (160).

In addition, the worker can change the boom drive start pressure and boom drive maintenance time levels that have been previously stored through the setting unit (160). This is not limited thereto, and the worker can directly input information about the boom drive start pressure and boom drive maintenance time through the setting unit (160).

The electronic control unit (170) generates an electric signal according to the operation of the operating lever (150) and outputs it to the electronic proportional pressure reducing valve (130). The electronic proportional pressure reducing valves (130) supply a pilot signal pressure proportional to the intensity of the current applied by the electronic control unit (170) to the spools of the control valve unit (120), thereby moving the spools of the control valve unit (120) according to the intensity of the applied pilot signal pressure. That is, the electronic control unit (170) controls the operation of the hydraulic actuator (50) based on the operating signal output from the operating lever (150).

Figure 5 is a block diagram of the electronic control unit.

Referring to FIG. 5, the electronic control unit (170) may include a data receiving unit (171), a storage unit (172), an excavation operation assistance unit (173), a boom drive determination unit (174), and an output unit (175).

The data receiving unit (171) can receive information output by various devices during the operation of the construction machine. For example, the data receiving unit (171) can receive the head-side and load-side pressure of the hydraulic actuator (50) detected by the pressure sensor (141). In addition, the data receiving unit (171) can receive the attitude information detected by the attitude measurement sensor (142). In addition, the data receiving unit (171) can receive information on the soil quality, boom drive start pressure, and boom drive maintenance time set by the setting unit (160). In addition, the data receiving unit (171) can receive the operation amount of the operation lever (150) as a work device operation signal for the boom (41), the arm (42), and the bucket (43) from the operation lever (150). In addition, the data receiving unit (171) can receive an ON/OFF signal of the semi-automatic excavation mode from the semi-automatic excavation mode switch (152) provided on the first operating lever (151a). In addition, the data receiving unit (171) can receive information on the working time, the number of boom-up operations, etc. from the pressure sensor (141) mounted on the operating lever (150) or the boom actuator (51).

The storage unit (172) can store information output by various devices during the operation of the construction machine. In addition, the storage unit (172) can store pilot signal pressure for semi-automatically controlling the hydraulic actuator (50).

Figure 6 is a schematic diagram showing the first and second soil maps.

Referring to Fig. 6(a), the storage unit (172) stores a first soil map indicating the relationship between the soil and the boom start pressure.

For example, the first soil map can represent the relationship between the density of the soil and the boom start pressure. Specifically, when the soil at the work site is sandy soil, the density is relatively low and excavation can be performed without requiring a large output horsepower, so the discharge pressure of the hydraulic pump (110) that is basically required is low. On the other hand, when the soil to be worked is viscous soil, the density is relatively high and a large output horsepower is required for excavation, so the discharge pressure of the hydraulic pump (110) that is basically required is high. That is, in the first soil map, the boom start pressure for soil with a high density can be set higher than the boom start pressure for soil with a low density.

In addition, the first soil map can represent the relationship between the hardness of the soil and the boom start pressure. Specifically, when the hardness of the soil to be worked is low, excavation can be performed without requiring a large output horsepower, so the discharge pressure of the hydraulic pump (110) that is basically required is low. On the other hand, when the hardness of the soil to be worked is high, excavation requires a large output horsepower, so the discharge pressure of the hydraulic pump (110) that is basically required is high. That is, in the first soil map, the boom start pressure for soil with high hardness can be set higher than the boom start pressure for soil with low hardness. In other words, in the first soil map, the boom start pressure can be set to increase as the density or hardness of the soil increases.

Referring to Fig. 6(b), the storage unit (172) stores a second soil map indicating the relationship between the soil and the boom driving maintenance time.

For example, the second soil map can represent the relationship between the hardness or density of the soil and the boom drive maintenance time. Specifically, when the hardness or density of the soil being worked on is low, the pressure of the hydraulic actuator (50) can be released from the relief pressure or the stall situation even if the boom-up operation is maintained for a short time. On the other hand, when the hardness or density of the ground to be worked on is high, the boom-up operation must be maintained for a long time so that the pressure of the hydraulic actuator (50) can be released from the relief pressure or the stall situation. That is, in the second soil map, the boom drive maintenance time for soil with high hardness and density can be set shorter than the boom drive maintenance time for soil with low hardness and density. In other words, in the second soil map, the boom drive maintenance time can be set to increase as the density or hardness of the soil increases.

The storage unit (172) stores a restriction map that indicates the relationship between the working time and the boom drive start pressure. For example, in a situation where the excavation work is normally in progress, since a longer time required for the excavation operation of the work device (40) means a greater load on the bucket (43), the restriction map can be set so that the boom drive start pressure increases when the working time is longer than the first set time.

However, since the excavation operation may end earlier in stall conditions where the load on the arm (42) or bucket (43) is excessively high, the restriction map may be set so that the boom drive start pressure increases even when the working time is less than the second set time. At this time, the second set time may be set to be smaller than the first set time.

The storage unit (172) stores the boom drive release pressure that serves as a release criterion for boom-up drive. The boom drive release pressure can be set to be equal to or less than the boom drive start pressure.

In addition, the storage unit (172) stores a restriction map indicating the relationship between the number of boom-up operations and the boom operation start pressure. For example, since an increase in the number of boom-up operations of the work device (40) means that the load applied to the bucket (43) is large, the restriction map can be set so that the boom operation start pressure increases as the number of boom-up operations increases.

Meanwhile, referring to FIGS. 1 and 2, during an excavation operation, a worker performs a series of operations including inserting a bucket (43) into soil by a boom-down operation, closing the arm (42) by an arm-in operation and a bucket-in operation, closing the bucket (43), inserting soil into the bucket (43), and then raising the boom (41) again by a boom-up operation. However, this is not limited thereto, and the excavation operation may also include an operation in which the upper body (30) turns to dump soil to a designated location.

That is, during excavation work, the worker operates the arm (42) with one hand using the first operating lever (151a), and operates the boom (41) and bucket (43) with the other hand using the second operating lever (151b). In this way, excavation work requires concentration from the worker, which increases worker fatigue.

Accordingly, when the data receiving unit (171) receives an ON signal for the semi-automatic excavation mode, the excavation operation assistance unit (173) assists the operation signal output from the operation lever (150) so that the work device (40) can perform the excavation operation semi-automatically.

Here, the semi-automatic excavation mode refers to a mode in which the excavation operation is controlled semi-automatically, and is a control technology that assists the operation of the operating lever (150) so that the worker can perform the excavation operation with one hand.

Figures 7 to 9 are drawings showing examples of semi-automatic excavation control of an electronic control unit.

In detail, the excavation operation assistance unit (173) can calculate a pilot signal pressure for automatically controlling the hydraulic actuator (50) during excavation work. For example, referring to FIG. 5 and FIG. 7, the excavation operation assistance unit (173) calculates a pilot signal pressure for automatically controlling the boom actuator (51) and the bucket actuator (53) to perform an excavation operation when the worker presses the semi-automatic excavation mode switch (152) provided on the first operating lever (151a) to execute the semi-automatic excavation mode and pulls the first operating lever (151a) forward to perform an arm-in operation, and outputs the calculated pilot signal pressure to the output unit (175).

Accordingly, the movement of the boom (41) and bucket (43) can be automatically controlled, and the worker can perform excavation work by simultaneously moving the boom (41), arm (42) and bucket (43) simply by operating the first operating lever (151a).

Meanwhile, the worker generally estimates the load applied to the bucket (43) from the operational feel during excavation, and if he thinks that the bucket (43) is under load, he reduces the load applied to the bucket (43) through a boom-up operation.

Accordingly, referring to FIG. 5 and FIG. 8, the excavation operation assistance unit (173) calculates a pilot signal pressure for boom-up operation while the first operation lever (151a) returns to the neutral position when the first operation lever (151a) is released from the forward-operated state, and outputs the calculated signal pressure to the output unit (175). In this case, the worker can reduce the load applied to the bucket (43) by raising the boom (41) simply by releasing the operation of the first operation lever (151a).

Meanwhile, the semi-automatic 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, when the operator presses the semi-automatic excavation mode switch (152) provided on the first operating lever (151a) to execute the semi-automatic excavation mode, the movements of the boom (41), the arm (42), and the bucket (43) can all be automatically controlled.

The boom drive judgment unit (174) determines whether there is an abnormality in the excavation operation based on the pressure information of the hydraulic actuator (50) received by the data receiving unit (171), the soil quality of the soil set by the setting unit (160), the boom drive start pressure, and the boom drive maintenance time, and the information stored in the storage unit (172).

The boom drive judgment unit (174) determines the boom drive start pressure based on the soil quality information set in the setting unit (160) and the first soil quality map stored in the storage unit (172). For example, if the level of soil hardness is set high in the setting unit (160), the boom drive start pressure can be set relatively high, and if the level of soil hardness is set low in the setting unit (160), the boom drive start pressure can be set relatively low.

The boom drive determination unit (174) can determine the boom drive start pressure based on the time required for the excavation operation. For example, the boom drive determination unit (174) can automatically increase the boom drive start pressure if the time required for the excavation operation is longer than the first set time based on the restriction map stored in the storage unit (172). However, the present invention is not limited thereto, and the boom drive determination unit (174) can automatically increase the boom drive start pressure even if the time required for the excavation operation is shorter than the second set time due to a stall situation.

In addition, the boom drive determination unit (174) can determine the boom drive start pressure based on the number of boom-up operations. For example, the boom drive determination unit (174) can automatically increase the boom drive start pressure when the number of boom-up operations increases based on the restriction map stored in the storage unit (172).

In addition, the boom drive start pressure can be a relief pressure. In addition, the boom drive start pressure can be a value directly input by the operator through the setting unit (160).

The boom drive determination unit (174) determines the boom drive maintenance time based on the soil quality information set in the setting unit (160) and the second soil quality map stored in the storage unit (172). For example, if the level of soil hardness is set high in the setting unit (160), the boom drive maintenance time can be set relatively long, and if the level of soil hardness is set low in the setting unit (160), the boom drive maintenance time can be set relatively short. However, it is not limited thereto, and the boom drive maintenance time can be a value directly input by the operator through the setting unit (160).

The boom drive judgment unit (174) determines whether the pressure of the hydraulic actuator (50) exceeds or exceeds the set boom drive start pressure, and if the condition is satisfied, determines that there is an abnormality in the excavation operation and outputs the result to the output unit (175).

The boom drive judgment unit (174) determines the time for which the boom-up drive is maintained, i.e., the boom drive maintenance time, when the boom-up operation is performed, and outputs this to the output unit (175).

In addition, when the boom-up operation is automatically performed, the boom drive judgment unit (174) compares the pressure of the hydraulic actuator (50) received by the data receiving unit (171) with the boom drive release pressure stored in the storage unit (172) to determine whether the boom-up operation is released.

In detail, the boom drive judgment unit (174) determines whether the pressure of the hydraulic actuator (50) measured by the pressure sensor (141) has decreased below the boom drive release pressure, and if the condition is satisfied, determines that there is no problem with the excavation operation, and outputs the result to the output unit (175) to release the boom-up drive.

However, if the pressure of the hydraulic actuator (50) does not decrease to the boom release pressure until the boom drive maintenance time is reached, the boom drive judgment unit (174) determines that there is an abnormality in the excavation operation, outputs the result to the output unit (175), and maintains the boom-up operation again for the boom drive maintenance time.

However, if the pressure of the hydraulic actuator (50) does not decrease to the boom release pressure, the boom drive judgment unit (174) determines that there is an abnormality in the excavation operation and outputs the corresponding result to the output unit (175), thereby releasing the semi-automatic mode and allowing the operator to operate manually.

In this way, if the boom drive judgment unit (174) determines that there is an abnormality in the excavation operation, the boom-up operation is automatically performed by the output unit (175), so the worker need not be concerned about the load applied to the arm (42) or bucket (43) during the excavation operation, and thus the worker's work fatigue can be reduced and work efficiency can be improved.

The output unit (175) receives an operation signal proportional to the operator's operation amount from the operation lever, and can generate a control signal corresponding to the received operation amount, for example, a current, and apply it to the electronic proportional pressure reducing valve (130).

The output unit (175) can generate a current corresponding to the pilot signal pressure calculated in the excavation operation assistance unit (173) and apply it to the electronic proportional pressure reducing valve (130) of each control valve (121, 122, 123). As a result, operating fluid is supplied to the hydraulic actuator (50), so that the excavation operation can be performed automatically.

If the boom drive judgment unit (174) determines that there is an abnormality in the excavation operation, the output unit (175) can generate a predetermined current and apply it to the electronic proportional pressure reducing valve (130) of the first control valve (121). As a result, operating fluid is supplied to the boom actuator (51), so that the boom-up operation can be performed during the boom drive maintenance time.

The terminology used herein is used only to describe particular embodiments and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will also be understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated functions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other functions, integers, steps, operations, elements, components, and/or groups thereof.

Although the terms first, second, etc. may be used herein to describe various components, it will be understood that these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a second component, and similarly, a second component could be referred to as a first component.

Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe one element's relationship to another, as illustrated in the drawings. It will be understood that these terms, and the terms discussed above, are intended to encompass different orientations of the device in addition to the orientations depicted in the drawings. When an element is referred to as being "connected to" or "coupled to" another element, it will be understood that it may be directly connected or coupled to the other element, or that intervening elements may be present. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, no intervening elements are 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 is also to be understood that terms used herein should be interpreted to have a meaning consistent with their meaning in the context of this specification and the related art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

Claims (15)

hydraulic pump; A working device including a boom, arm, and bucket; A hydraulic actuator including a boom actuator, an arm actuator and a bucket actuator, which are operated by operating fluid discharged from the hydraulic pump, and which operate a boom, an arm and a bucket, respectively; An operating lever that outputs an electrical operating signal corresponding to the operator's operation; A pressure sensor that detects the pressure generated in the hydraulic pump or the hydraulic actuator; and An electronic control unit that controls the operation of a hydraulic actuator based on an operation signal output from the above operation lever; The above electronic control unit, A construction machine that controls the operation of the boom actuator to drive the boom up when the pressure detected by the pressure sensor during the excavation operation of the above work device is higher than the boom drive start pressure. In paragraph 1, The above electronic control unit, A construction machine that controls the operation of at least one of the boom actuator, the arm actuator, and the bucket actuator by assisting the operation signal output from the operation lever so that the work device can perform a semi-automatic excavation operation when the semi-automatic excavation mode is set. In the second paragraph, The above operating lever is, A construction machine including a first operating lever that performs an arm-in motion when operated in one direction and an arm-out motion when operated in the other direction. In the third paragraph, A construction machine, wherein the first operating lever is provided with a switch configured to turn the semi-automatic excavation mode on/off. In the third paragraph, The above electronic control unit, A construction machine, which automatically controls the operation of the boom actuator and the bucket actuator so that the work device performs an excavation operation when the first operating lever is operated in one direction in the above semi-automatic excavation mode. In the third paragraph, The above electronic control unit, A construction machine, wherein, in the above semi-automatic excavation mode, when the first operating lever is released from a state in which it is operated in one direction, the boom-up is driven while the first operating lever returns to the neutral position. In the second paragraph, The above electronic control unit, A construction machine, which automatically controls the operation of the boom actuator, the arm actuator and the bucket actuator so that the work device performs an excavation operation in the above semi-automatic excavation mode. In paragraph 1, In the above electronic control unit, A first soil map is stored that shows the relationship between the soil quality of the soil being worked on and the boom start pressure. A construction machine in which the above boom driving pressure can be changed depending on the soil quality. In Article 8, In the above first soil map, A construction machine in which the above boom driving pressure is set to increase as the density or hardness of the soil increases. In paragraph 1, The above electronic control unit, A construction machine that maintains boom-up operation for a boom operation maintenance time when the pressure detected by the pressure sensor during the excavation operation of the above work device is higher than the boom operation start pressure. In Article 10, The above electronic control unit, When the pressure detected by the pressure sensor decreases below the boom drive release pressure by the boom-up drive, the boom-up drive is released. A construction machine in which, if the pressure detected by the pressure sensor exceeds the boom drive release pressure even though the boom-up drive is maintained for the boom drive maintenance time, the boom-up drive is maintained again for the boom drive maintenance time. In Article 10, In the above electronic control unit, a second soil map indicating the relationship between the soil quality of the soil being worked on and the boom driving maintenance time is stored. The above boom operation maintenance time can be changed depending on the soil quality of the construction equipment. In Article 12, In the above second soil map, A construction machine in which the above boom driving maintenance time is set to increase as the density or hardness of the soil increases. In paragraph 1, The above electronic control unit, A construction machine that increases the boom drive start pressure when the time required for the excavation operation of the above work device is longer than the first set time or shorter than the second set time. In paragraph 1, The above electronic control unit, A construction machine that increases the boom drive start pressure as the number of boom-up operations of the above work device increases.

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