EP4650531A1

EP4650531A1 - Construction machine

Info

Publication number: EP4650531A1
Application number: EP23916340.5A
Authority: EP
Inventors: Jieun Kim; Bokeun HA; Okjin SUK
Original assignee: Volvo Construction Equipment AB
Current assignee: Volvo Construction Equipment AB
Priority date: 2023-01-12
Filing date: 2023-01-12
Publication date: 2025-11-19
Also published as: WO2024150855A1

Abstract

One aspect of the present disclosure provides a construction machine including: a first hydraulic pump and a second hydraulic pump for discharging working fluid; a first hydraulic line connected to the first hydraulic pump; a second hydraulic line connected to the second hydraulic pump; a first spool connected to the first hydraulic line and configured to control a flow of the working fluid supplied to an actuator; a second spool connected to the second hydraulic line and configured to control a flow of the working fluid supplied to the actuator; a relief valve disposed on the first hydraulic line and the second hydraulic line; a first pressure sensor and a second pressure sensor respectively disposed on the first hydraulic line and the second hydraulic line to measure pressures of the first and second hydraulic pumps, respectively; an operation lever configured to output an operation signal corresponding to an operator's manipulation amount; an electronic control unit configured to provide operation information of the actuator based on the pressures measured by the first and second pressure sensors and the operation signal output from the operation lever, and an output unit configured to output information from the electronic control unit.

Description

[Technical Field]

The present disclosure generally relates to construction machinery. In a specific aspect, the present disclosure relates to construction machinery. The present disclosure can be applied to large vehicles such as trucks, buses, and construction equipment. While the present disclosure may be described with reference to specific vehicles, it is not limited to any particular type of vehicle.

[Background Art]

In general, an excavator is a type of construction machinery capable of performing various operations at construction sites and the like, including excavation work for digging earth, loading work for transporting soil, trenching work for foundation construction, crushing work for building demolition, leveling work for site preparation, and grading work for surface smoothing.
Control valves for such purposes of the excavator are equipped with a relief valve to prevent damage to the hydraulic device. When construction machinery performs operations such as excavation, a load pressure corresponding to the excavation load is generated inside the hydraulic actuator. The relief valve opens upon reaching a predetermined set pressure to prevent the pressure in the hydraulic circuit from exceeding the pressure resistance of the hydraulic device due to an increase in load pressure, thereby discharging hydraulic fluid to the tank.
However, when the excavator reaches a relief pressure, the output of the actuator has exceeded its limit, so even when the operator applies greater force to the lever operation, the condition does not improve, resulting in reduced work productivity.

[Detailed Description of Invention]

[Means for Solving Problem]

According to a first aspect of the present disclosure, there is provided a construction machine including: a first hydraulic pump and a second hydraulic pump for discharging working fluid; a first hydraulic line connected to the first hydraulic pump; a second hydraulic line connected to the second hydraulic pump; a first spool connected to the first hydraulic line and configured to control a flow of the working fluid supplied to an actuator; a second spool connected to the second hydraulic line and configured to control flow of the working fluid supplied to the actuator; a relief valve disposed on the first hydraulic line and the second hydraulic line; a first pressure sensor and a second pressure sensor respectively disposed on the first hydraulic line and the second hydraulic line to measure pressures of the first and second hydraulic pumps, respectively; an operation lever configured to output an operation signal corresponding to an operator's manipulation amount; an electronic control unit configured to provide operation information of the actuator based on the pressures measured by the first and second pressure sensors and the operation signal output from the operation lever; and an output unit configured to output information from the electronic control unit. The first aspect of the present disclosure may provide construction machinery that recommends actuator operation to the operator in specific situations. A technical advantage is that the operator can perform lever operations with less effort by following the provided recommended actions while achieving the same output, thereby potentially improving productivity.
In some examples, the electronic control unit may include a work pattern analysis unit configured to analyze data of operation signals from the operation lever and determine the current work pattern.
In some examples, the electronic control unit may include a guide unit configured to provide operation information of the actuator.
In some examples, the guide unit may output boom raise or boom lower feedback to the output unit under predetermined conditions.
In some examples, the predetermined conditions may include: the current work pattern being classified as an excavation operation by the work pattern analysis unit, the pressure of the first hydraulic pump or the second hydraulic pump exceeding a preset relief pressure, and an arm-in operation signal of the operation lever exceeding a preset value.
In some examples, the guide unit may output arm-out feedback to the output unit under predetermined conditions.
In some examples, the predetermined conditions may include: the current work pattern being classified as an excavation operation by the work pattern analysis unit; the pressure of the first hydraulic pump or the second hydraulic pump exceeding a preset relief pressure; and the boom up operation signal of the operation lever exceeding a preset value.
In some examples, the electronic control unit may include a computation unit configured to calculate a relief operation ratio, which represents the proportion of operation time performed under a relief condition relative to the total operation time.
In some examples, the relief operation ratio may be defined as relief operation time / total operation time * 100.
In some examples, the output unit may be configured to visualize and display the relief operation ratio. A technical advantage is that the operator can more intuitively recognize the current relief operation ratio via a graph displayed on the display.
In some examples, the output unit may display the relief operation ratio using different colors according to the numerical value.
In some examples, the output unit may be configured to visualize and display a preset target relief operation ratio together with the visualized relief operation ratio.
In some examples, the output unit may be a display provided in an operator cab.
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 described in the following description, claims, and drawings, and will be recognized in part as being readily apparent to those skilled in the art or through the practice of the disclosures set forth herein.

[Brief 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 perspective view illustrating a basic configuration of a general construction machine.
FIG. 2 is a block diagram illustrating a basic configuration of a construction machine.
FIG. 3 is a schematic diagram illustrating the overall configuration of the construction machine.
FIG. 4 is a block diagram of the electronic control unit.
FIGS. 5 and 6 are diagrams illustrating examples of operation recommendations provided by the guide unit.
FIG. 7 is a diagram illustrating an example of the output unit.

[Mode for Carrying Out Invention]

The embodiments described below provide the information necessary for those skilled in the art to carry out the present disclosure.
FIG. 1 is a perspective view illustrating a basic configuration of a general construction machine.
With reference to FIG. 1, a construction machine 100, such as an excavator, includes a cab 10, a lower traveling body 20, an upper rotating body 30 rotatably installed on the lower traveling body 20, a working device 40 installed on the upper rotating body 30 to be operable in the vertical direction, and an actuator 50.
Inside the cab 10, an output unit may be provided to allow the operator to recognize the operating information of the excavator during work.
The work device 40 is formed as a multi-joint structure and includes a boom 41 having a rear end pivotally supported by the upper revolving body 30, an arm 42 having a rear end pivotally supported at a front end of the boom 41, and a bucket 43 pivotally installed at a front end of the arm 42. The actuator 50 includes a boom cylinder 51 (work actuator), an arm cylinder 52 (work actuator), and a bucket cylinder 53 (work actuator). When working fluid is supplied in response to the manipulation of the operator of the operation lever, the boom cylinder 51, arm cylinder 52, and bucket cylinder 53, each being a working actuator, respectively operate the boom 41, arm 42, and bucket 43.
FIG. 2 is a block diagram illustrating a basic configuration of the construction machine, and FIG. 3 is a schematic diagram illustrating the overall configuration of the construction machine.
With reference to FIGS. 2 and 3, the construction machine 100 may include a hydraulic pump 110, a spool 120, a relief valve 130, a pressure sensor 140, an operation lever 150, an electronic control unit 160, and an output unit 170.
The hydraulic pump 110 is driven by an engine and discharges high-pressure working fluid to operate the actuator 50. The hydraulic pump 110 may include first and second hydraulic pumps 111, 112.
The spool 120 moves by working fluid being discharged from the hydraulic pump 110 to operate first and second actuators 50a, 50b. More specifically, the first actuator 50a is operated by receiving working fluid supplied from the first hydraulic pump 111, and the second actuator 50b may be operated by receiving hydraulic fluid supplied from the second hydraulic pump 112. The first and second actuators 50a, 50b may, for example, be the aforementioned boom cylinder 51, arm cylinder 52, and bucket cylinder 53, but are not limited thereto.
The spool 120 may include a first spool 121 and a second spool 122. More specifically, the first hydraulic pump 111 and the first spool 121 are connected by a first hydraulic line 121a, and the second hydraulic pump 112 and the second spool 122 may be connected by a second hydraulic line 122a. The first spool 121 is located on a flow path connecting the first hydraulic pump 111 and the first actuator 50a and controls the flow of working fluid supplied from the first hydraulic pump 111 to the first actuator 50a. The second spool 122 is located on a flow path connecting the second hydraulic pump 112 and the second actuator 50b and controls the flow of working fluid supplied from the second hydraulic pump 112 to the second actuator 50b.
When displacement of the spool 120 is large, in other words, when the ports of the spool 120 are widely opened, the flow rate of working fluid supplied to the actuator 50 increases; conversely, when the displacement of the spool 120 is small, in other words, when the ports of the spool 120 are slightly opened, the flow rate of working fluid supplied to the actuator 50 decreases.
The relief valve 130 may be disposed between the first hydraulic line 121a and the second hydraulic line 122a.
The relief valve 130 may include first and second relief valves (not shown) connected to the respective hydraulic lines 121a and 122a. Relief pressures may be set for the first and second relief valves. Accordingly, when an abnormal high pressure is generated in the first hydraulic line 121a, the first relief valve opens, thereby maintaining the relief pressure in the first hydraulic line 121a. Similarly, when an abnormal high pressure is generated in the second hydraulic line 122a, the second relief valve opens, thereby maintaining the relief pressure in the second hydraulic line 122a.
The pressure sensor 140 is connected to the first and second hydraulic lines 121a and 122a between the spool 120 and the hydraulic pump 110, senses the pressure of the hydraulic pump 110 to determine whether relief occurs, and may provide the sensed pressure value to the electronic control unit 160. That is, the first and second pressure sensors 141 and 142 may be respectively disposed on the outlets of the first and second hydraulic pumps 111 and 112 from which working fluid is discharged.
The operation lever 150 may be a hydraulic joystick or an electric joystick, preferably an electric joystick(electric joystick) that generates an electrical signal proportional to the manipulation of the operator amount and provides the signal to the electronic control unit 160.
FIG. 4 is a block diagram of the electronic control unit.
Referring to FIG. 4, the electronic control unit 160 determines the operator's current work pattern based on the pressure values of the hydraulic pump 110 provided from the pressure sensor 140 and the electrical signals of the operation lever 150, outputs appropriate control information for the current work pattern to the output unit 170, and may include a work pattern analysis unit 161, a calculation unit 162, a guide unit 163, and a storage unit 164.
The work pattern analysis unit 161 analyzes the input control signals of the operation lever 150 to analyze the work pattern of the currently ongoing operation. More specifically, the work pattern analysis unit 161 uses machine learning techniques based on collected or pre-stored big data stored in the storage unit 164 to analyze the correlation between specific operations and the manipulation amount of the operation lever 150, and selects one work pattern from among various work patterns based on the analyzed correlation.
For example, the work pattern analysis unit 161 analyzes the input control signals of the operation lever 150 and classifies the current work pattern as one of excavation work, lifting work for transporting earth and sand, demolition work for dismantling buildings, or leveling work for ground preparation.
The work pattern analysis unit 161 may store data regarding the correlation between the input control signals of the operation lever 150 and the classified work pattern in the storage unit 164.
The work pattern analysis unit 161 may output the classified work pattern to the output unit 170.
The calculation unit 162 calculates the ratio of the total cumulative work performed without relief being activated based on the pressure value provided from the hydraulic pump 110. The calculation unit 162 starts calculating the total work time when the pressure sensor 140 of the hydraulic pump 110 detects a pressure exceeding 0, and further calculates the time during which the pressure exceeds a predetermined set value to compute the relief operation ratio. More specifically, the calculation unit 162 calculates the total work time starting from the moment when the pressure of one or more of the first hydraulic pump 111 or the second hydraulic pump 112 is non-0. In addition, the calculation unit 162 calculates the time during which the pressure of one or more of the first hydraulic pump 111 or the second hydraulic pump 112 exceeds a predetermined relief pressure (for example, 320 bar) as the relief operation time. At this time, the relief operation ratio (%) may be calculated as (relief operation time ÷ total work time)x100. In addition, the current work ratio (%) representing the proportion of work performed without relief during the total cumulative work may be calculated as [(total work time - relief operation time) / total work time] * 100.
The guide unit 163 outputs information related to recommended operations for the work classified by the work pattern analysis unit 161 to the output unit 170.
FIGS. 5 and 6 illustrate an example of operation recommendation by the guide unit 163. An example where the work pattern analysis unit 161 classifies the operator's work pattern as an excavation operation will be described below with reference to FIGS. 5 and 6.
As illustrated in FIG. 5, when the bucket 43 of the construction machine 100 becomes caught on rocks in the work area, when the operator continues to manipulate the operation lever 150 to move the arm inward, the relief valve 130 connected to the arm 42 opens, and the corresponding hydraulic line maintains the relief pressure. Accordingly, even when the operator applies greater force to the ar-in operation, since the output of the arm 42 has exceeded its limit, the work does not proceed, resulting in reduced work productivity.
At this time, when the work pattern analysis unit 161 classifies the operator's work pattern as an excavation operation, and the pressure of the first hydraulic pump 111 or the second hydraulic pump 112 exceeds the relief pressure, and the arm-in control signal of the operation lever 150 exceeds a preset value, the guide unit 163 outputs feedback to the output unit 170 instructing to move the boom 41. When the operator raises or lowers the boom in response to the feedback, the bucket 43 may be released from the rock root, thereby allowing the operator to exert less force on the lever while achieving the same output, which can improve productivity.
Additionally, as shown in FIG. 6, when the operator continuously operates the operation lever 150 to raise the boom for excavating the front portion of the work area, the relief valve 130 connected to the boom 41 opens, and the corresponding hydraulic line maintains the relief pressure. Accordingly, even when the operator further manipulates the operation lever 150, the output of the boom 41 has exceeded its limit, and thus the work does not proceed, resulting in reduced work productivity.
At this time, when the pressure of the first hydraulic pump 111 or the second hydraulic pump 112 exceeds the relief pressure, and the boom-up operation signal of the operation lever 150 exceeds a predetermined set value, the guide unit 163 outputs feedback to the output unit 170 to move the arm 42. According to the feedback, the operator can extend the arm 42 to proceed with the excavation work; therefore, the operator can exert less force on the operation lever while achieving the same output, which can result in improved productivity.
Further, the guide unit 163 outputs feedback to the output unit 170 recommending a high-power mode when the relief operation ratio exceeds a preset value.
The storage unit 164 may store big data on the correlation between the operation signals of the operation lever 150 and the corresponding work patterns, as well as algorithms for machine learning. The storage unit 164 may store data relating to preset values for the operation signals of the operation lever 150. The storage unit 164 may store data on the correlation between the input operation signals of the operation lever 150 and the work patterns classified by the work pattern analysis unit 161.
The output unit 170 feeds back the output value outputted from the electronic control unit 160 to the operator. The output unit 170 is provided in the operator cabin and may be a display that provides visual feedback; however, it is not limited thereto and may be a speaker that provides auditory feedback.
FIG. 7 is a diagram illustrating an example of the output unit. As illustrated in FIG. 7, the output unit 170 may visualize and output the relief operation ratio calculated by the arithmetic unit 162. For example, the relief operation ratio graph 171 is visualized as a ring-shaped graph and may be displayed on one side of the output unit 170. Specifically, the output unit 170 may display only the area corresponding to the relief operation ratio in the graph 171. For example, as shown, when the relief operation ratio is approximately 25%, only the area corresponding to 25% of the entire graph 171, designated as 171a, may be filled and displayed to the user. Additionally, information 171b regarding a preset target relief operation ratio may be displayed inside the graph 171. That is, the graph 171 visualizing the relief operation ratio may also display the target relief operation ratio information 171b. In this case, the user can easily compare the relief operation ratio and the target relief operation ratio through the graph 171. However, the present disclosure is not limited thereto, and the area 171a of the graph 171 corresponds to the current operation ratio, while information 171b regarding the target operation ratio may be displayed inside the graph 171.
Preferably, the output unit 170 may display the graph 171 in different colors depending on the relief operation ratio or the current operation ratio. For example, when the current operation ratio is 90% or more, that is, the relief operation ratio is less than 10%, the graph 171 may be displayed in green. When the current operation ratio is less than 90%, that is, the relief operation ratio is 10% or more, the graph 171 may be displayed in yellow. Additionally, when the current operation ratio is less than 50%, that is, the relief operation ratio is 50% or more, the graph 171 may be displayed in red. In this way, when the relief operation ratio or the current operation ratio is visualized by a graph, the operator can more intuitively understand the current relief operation ratio or the current operation ratio. The color, shape, and numerical values of the graph may be variously modified and implemented.
The terminology used herein is employed solely to describe specific embodiments and is not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. As used herein, the term "and/or" encompasses any and all possible combinations of one or more of the associated listed items. As used herein, the terms "comprises," "comprising," "includes," and/or "including" specify the presence of the stated functions, integers, steps, operations, elements, and/or components, but are understood not to exclude the presence or addition of one or more other functions, integers, steps, operations, elements, components, and/or groups thereof.
Although terms such as first and second may be used herein to describe various components, it is to be understood that these components are not limited by these terms. These terms are used solely to distinguish one element from another. For example, without departing from the scope of the present disclosure, the first component may be referred to as the second component, and similarly, the second component may be referred to as the first component.
Relative terms such as "below," "above," "upper side," "lower side," "horizontal," and "vertical" may be used herein to describe the relationship between one element and another as illustrated in the drawings. It should be understood that these terms, along with the terms discussed above, are intended to include different directions of the apparatus in addition to the directions illustrated in the drawings. When an element is described as being "connected" or "coupled" to another element, it is to be understood that the element may be directly connected or coupled to the other element, or may be connected or coupled via one or more intervening elements. In contrast, when an element is described as "directly connected" or "directly coupled" to another element, no intervening element exists therebetween.
Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure pertains. Additionally, the terms used herein are to be interpreted as having meanings consistent with their meanings in the context of this specification and the related art, and unless explicitly defined herein, are not to be construed in an idealized or overly formal manner.

Claims

A construction machine comprising:
a first hydraulic pump and a second hydraulic pump for discharging working fluid;

a first hydraulic line connected to the first hydraulic pump;

a second hydraulic line connected to the second hydraulic pump;

a first spool connected to the first hydraulic line and configured to control the flow of working fluid supplied to an actuator;

a second spool connected to the second hydraulic line and configured to control the flow of working fluid supplied to an actuator;

a relief valve disposed on the first and second hydraulic lines;

a first pressure sensor and a second pressure sensor respectively disposed on the first and second hydraulic lines, each configured to measure the pressure of the first and second hydraulic pumps, respectively;

an operation lever configured to output an operation signal corresponding to the amount of manipulation by an operator;

an electronic control unit configured to provide actuator operation information based on the pressures of the first and second hydraulic pumps measured by the first and second pressure sensors, and the operation signal output from the operation lever; and an output unit configured to output the information output from the electronic control unit.
The construction machine of claim 1, wherein
the electronic control unit includes

a work pattern analysis unit configured to analyze data of the operation signal from the operation lever and determine a current work pattern.
The construction machine of claim 2, wherein
the electronic control unit includes

a guide unit configured to provide operation information of the actuator.
The construction machine of claim 3, wherein
the guide unit is configured to output boom up or boom down feedback to the output unit under predetermined conditions.
The construction machine of claim 4, wherein
the predetermined condition is

a case in which the work pattern analysis unit classifies a current work pattern as an excavation operation, the pressure of the first hydraulic pump or the second hydraulic pump exceeds a preset relief pressure, and an arm-in operation signal from the operation lever exceeds a preset value.
The construction machine of claim 3, wherein
the guide unit is configured to output arm-out feedback to the output unit under predetermined conditions.
The construction machine of claim 6, wherein
the predetermined condition is

a case in which the work pattern analysis unit classifies the current work pattern as an excavation operation, the pressure of the first hydraulic pump or the second hydraulic pump exceeds a preset relief pressure, and a boom-up operation signal from the operation lever exceeds a preset value.
The construction machine of claim 1, wherein
the electronic control unit includes

a calculation unit configured to compute a relief operation ratio representing a proportion of work performed under a relief condition during the total operation time.
The construction machine of claim 8, wherein
the relief operation ratio is defined as relief operation time / total operation time*100.
The construction machine of claim 9, wherein
the output unit visualizes and displays the relief operation ratio.
The construction machine of claim 10, wherein
the output unit displays the relief operation ratio in different colors according to the numerical value thereof.
The construction machine of claim 10, wherein
the output unit visualizes and displays a preset target relief operation ratio along with the visualized relief operation ratio.
The construction machine of claim 1, wherein
the output unit is a display provided in a driver cab.