EP4692462A1

EP4692462A1 - Work machine

Info

Publication number: EP4692462A1
Application number: EP24839460.3A
Authority: EP
Inventors: Hidenori Tanaka
Original assignee: Kobelco Construction Machinery Co Ltd
Current assignee: Kobelco Construction Machinery Co Ltd
Priority date: 2023-07-10
Filing date: 2024-06-21
Publication date: 2026-02-11
Also published as: WO2025013564A1; JP2025010677A; CN121152914A

Abstract

Provided is a working machine (1) that achieves prevention of excessive excavation by a leading end attachment to a position deeper than a target work surface. The working machine (1) includes an operation control part and an operation restriction part. The operation restriction part executes an operation control of controlling an operation of an attachment (30) so that a work surface (73) comes closer to a target work surface (71) set in advance when a manipulation part receives a control instruction manipulation given thereto. The operation restriction part restricts, under no execution of the operation control, the operation of the attachment (30) to prevent a bucket (33) from approaching the target work surface (71) beyond an entry prohibited surface (72) set at a position spaced from the target work surface (71) in an opposite direction to a direction in which the work surface (73) comes closer the target work surface (71).

Description

Technical Field

The present invention relates to a working machine that is configured to semi-automatically or automatically control an operation of an attachment.

Background Art

Patent Literature 1 discloses control of an attachment to prevent a tooth tip of a bucket from crossing a target profile. Specifically, disclosed are: setting of an offset profile separated by a predetermined distance from a target excavation profile being a target profile for finishing of an object to be excavated; excavation based on the offset profile as the target profile; and execution of compaction based on the target excavation profile as a target profile.
Meanwhile, a working machine has been under consideration for semi-automatically or automatically controlling an operation of an attachment so that a work surface comes closer to a target work surface. Unfortunately, at a start of the operation of the attachment, pressure confinement in a hydraulic cylinder, structural rattling, swaying of a vehicle body, or other incident may induce a certain action different from a target action of the attachment, e.g., a slight fall of a leading end attachment like a bucket. When such an action different from the target action occurs in a state where the bucket approaches the target work surface, the bucket may reach the target work surface and the bucket may result in excessively excavating to a position deeper than the target work surface.

Citation List

Patent Literature

Patent Literature 1: International Unexamined Patent Publication No. 2016/129708

Summary of Invention

An object of the present invention is to provide a working machine that includes a leading end attachment configured to perform a work and prevents the leading end attachment from advancing beyond a target work surface.
A working machine including a machine main body, an attachment, an operation control part, a manipulation part, and an operation restriction part is provided. The attachment includes a leading end attachment configured to perform a work, and is attached to the machine main body. The manipulation part permits a manipulation for moving the attachment to be given thereto. The operation control part executes an operation control of controlling an operation of the attachment so that a work surface to be subjected to the work by the leading end attachment comes closer to a target work surface set in advance when the manipulation given to the manipulation part includes a predetermined control instruction manipulation. The operation restriction part imposes an operation restriction of restricting, under no execution of the operation control by the operation control part, the operation of the attachment to prevent the leading end attachment from approaching the target work surface beyond an entry prohibited surface. The entry prohibited surface is set at a position spaced from the target work surface in an opposite direction to a direction in which the work surface comes closer to the target work surface.

Brief Description of Drawings

Fig. 1 is a side view of a working machine according to an embodiment of the present invention.
Fig. 2 is a block diagram showing constituent elements of the working machine.
Fig. 3 is a side view of the working machine to show semi-automatic control of an operation of an attachment in the working machine.
Fig. 4 is a side view of the working machine to show no execution of the semi-automatic control in the working machine.
Fig. 5 is a graph showing a relation between a separation distance L from a bucket of the attachment to an entry prohibited surface and a maximum value of a y-directional speed of the bucket.
Fig. 6 is a graph showing a relation between the separation distance L and a maximum value of a positive x-directional speed of the bucket.
Fig. 7 is a graph showing a relation between the separation distance L and a maximum value of a negative x-directional speed of the bucket.
Fig. 8 is a plan view illustrating the working machine and the entry prohibited surface.

Description of Embodiments

Hereinafter, a preferable embodiment of the present invention will be described with reference to the accompanying drawings.
Fig. 1 is a side view of a working machine 1 according to the embodiment of the present invention. The working machine 1 exemplified in Fig. 1 is a hydraulic excavator, and includes: a machine main body 24 including a lower traveling body 21 and an upper slewing body 22; an attachment 30; and a plurality of cylinders 40.
The lower traveling body 21 can travel, and includes, for example, a pair of left and right crawlers. The upper slewing body 22 is mounted on the lower traveling body 21 in a slewable manner via a slewing device 25. The upper slewing body 22 includes a cab (operating compartment) 23 constituting a front portion of the upper slewing body 22.
The working machine 1 further includes a manipulation part. The manipulation part includes a plurality of manipulation levers 29 located in the cab 23. Each of the manipulation levers 29 permits an operator to give a manipulation for moving the attachment 30 to the manipulation lever 29.
The attachment 30 is attached to the upper slewing body 22 rotatably in an up-down direction. The attachment 30 includes a boom 31, an arm 32, and a bucket 33. The boom 31 is attached to the upper slewing body 22 rotatably, or in a tiltable manner, in the up-down direction. The arm 32 is attached to the boom 31 rotatably in the up-down direction. The bucket 33 represents a leading end attachment constituting a leading end of the attachment 30, and is attached to the arm 32 rotatably in a front-rear direction of the upper slewing body 22. The bucket 33 performs works to soil and sand, e.g., excavation, leveling, and scooping.
Examples of kinds of the bucket include a standard bucket, a wide bucket having a width greater than a width of the standard bucket, a narrow bucket having a width smaller than the width of the standard bucket, and a slope bucket having a flat bottom surface. The leading end attachment is not limited to the bucket 33.
Each of the cylinders 40 is disposed to allow the attachment 30 to rotate under hydraulic pressure. Each cylinder 40 is an extendable and contractible hydraulic cylinder. Alternatively, each cylinder 40 may be an electric cylinder.
The cylinders 40 include a boom cylinder 41, an arm cylinder 42, and a bucket cylinder 43.
The boom cylinder 41 is disposed so as to rotate the boom 31 with respect to the upper slewing body 22. The boom cylinder 41 has a proximal end and a distal end opposite to the proximal end. The proximal end is rotatably connected to the upper slewing body 22. The distal end is rotatably connected to the boom 31.
The arm cylinder 42 rotates the arm 32 with respect to the boom 31. The arm cylinder 42 has a proximal end and a distal end opposite to the proximal end. The proximal end is rotatably connected to the boom 31. The distal end is rotatably connected to the arm 32.
The bucket cylinder 43 rotates the bucket 33 with respect to the arm 32. The bucket cylinder 43 has a proximal end and a distal end opposite to the proximal end. The proximal end is rotatably connected to the arm 32. The distal end is rotatably connected to a link member 34, and the link member 34 is rotatably connected to the bucket 33.
The working machine 1 further includes a slewing angle sensor 52 and a plurality of tilt angle sensors 60.
The slewing angle sensor 52 detects a slewing angle of the upper slewing body 22 to the lower traveling body 21. Specifically, the slewing angle sensor 52 detects a present angle being a present slewing angle of the upper slewing body 22 to the lower traveling body 21. The slewing angle sensor 52 includes, for example, an encoder, a resolver, or a gyro sensor. In the embodiment, the upper slewing body 22 has a slewing angle of 0° when a forward direction of the upper slewing body 22 and a forward direction of the lower traveling body 21 agree with each other.
Each of the tilt angle sensors 60 constitutes a posture detector that detects a posture of the attachment 30. The tilt angle sensors 60 include a boom tilt angle sensor 61, an arm tilt angle sensor 62, a bucket tilt angle sensor 63, and an unillustrated upper slewing body tilt angle sensor.
Each of the boom tilt angle sensor 61 and the upper slewing body tilt angle sensor is, for example, a tilt (acceleration) sensor. The boom tilt angle sensor 61 is attached to the boom 31 to detect a tilt angle of the boom 31 to a horizontal line. The upper slewing body tilt angle sensor is located at the upper slewing body 22 to detect a tilt angle of the upper slewing body 22 to the horizontal line. An angle of the boom 31 to the upper slewing body 22 is calculated on the basis of the tilt angle of the boom 31 to the horizontal line detected by the boom tilt angle sensor 61 and the tilt angle of the upper slewing body 22 to the horizontal line detected by the upper slewing body tilt angle sensor. Alternatively, the boom tilt angle sensor 61 may be a rotation angle sensor that detects a rotation angle of a boom foot pin at the proximal end of the boom 31, or may be a stroke sensor that detects a stroke of the boom cylinder 41 in an extension-contraction direction.
The arm tilt angle sensor 62 is, for example, a tilt (acceleration) sensor. The arm tilt angle sensor 62 is attached to the boom 32 to detect a tilt angle of the arm 32 to the horizontal line. An angle of the arm 32 to the upper slewing body 22 is calculated on the basis of the tilt angle of the arm 32 to the horizontal line detected by the arm tilt angle sensor 62 and the tilt angle of the upper slewing body 22 to the horizontal line detected by the upper slewing body tilt angle sensor. Alternatively, the arm tilt angle sensor 62 may be a rotation angle sensor that detects a rotation angle of an arm connection pin at the proximal end of the arm 32, or may be a stroke sensor that detects a stroke of the arm cylinder 42 in an extension-contraction direction.
The bucket tilt angle sensor 63 is, for example, a tilt (acceleration) sensor. The bucket tilt angle sensor 63 is attached to the link member 34 to detect a tilt angle of the bucket 33 to the horizontal line. An angle of the bucket 33 to the upper slewing body 22 is calculated on the basis of the tilt angle of the bucket 33 to the horizontal line detected by the bucket tilt angle sensor 63 and the tilt angle of the upper slewing body 22 to the horizontal line detected by the upper slewing body tilt angle sensor. Alternatively, the bucket tilt angle sensor 63 may be a rotation angle sensor that detects a rotation angle of a bucket connection pin at the proximal end of the bucket 33, or may be a stroke sensor that detects a stroke of the bucket cylinder 43 in an extension-contraction direction.
As shown in Fig. 2, the working machine 1 further includes a controller 11 and a storage device 13.
The storage device 13 stores a target work surface 71 illustrated in Fig. 3. The storage device 13 is configured to further store an entry prohibited surface 72 set on the basis of the target work surface 71 serving as a reference as illustrated in Fig. 3.
The controller 11 receives an input of information detected by the slewing angle sensor 52, that is, information about a slewing angle or posture of the upper slewing body 22 to the lower traveling body 21. The controller 11 receives an input of information detected by the boom tilt angle sensor 61, that is, information about a posture of the boom 31. The controller 11 receives an input of information detected by the arm tilt angle sensor 62, that is, information about a posture of the arm 32. The controller 11 receives an input of information detected by the bucket tilt angle sensor 63, that is, information about a posture of the bucket 33.
The controller 11 has a manual manipulation mode and a machine control (MC) mode as modes to control an operation of the attachment 30, and switches between the two modes. Specifically, an unillustrated mode changeover switch receives a manipulation to switch the mode of the controller 11 given thereto. In this manner, the controller 11 receives an input of an instruction to designate the mode of the controller 11. The mode changeover switch may be provided to any one of the manipulation levers 29, may be provided to a display device that displays information to be given to the operator, or may be provided to a switch console or other device.
The controller 11 operates, in the manual manipulation mode, each of the boom 31, the arm 32, and the bucket 33 in response to an associated manipulation given to corresponding one of the manipulation levers 29 by the operator. In other words, in the manual manipulation mode, the operator can move each of the boom 31, the arm 32, and the bucket 33 through a manual manipulation to corresponding one of the manipulation levers 29.
The controller 11 executes an operation control of semi-automatically controlling an operation of the attachment 30 in the MC mode. Specifically, the controller 11 includes an operation control part that executes the operation control. The controller 11 is configured to execute the operation control, specifically, a semi-automatic control of the operation of the attachment 30 in the embodiment, when the manipulation given to the manipulation lever 29 by the operator is a predetermined control instruction manipulation. In the embodiment, the control instruction manipulation is a manipulation given to an arm manipulation lever being the manipulation lever 29 to move the arm 32 among the manipulation levers 29 in the MC mode, that is, a manipulation or an arm pulling manipulation in an arm pulling direction of pulling the arm 32, i.e., in a direction in which the arm 32 approaches the upper slewing body 22.
The semi-automatic control means a control of automatically controlling, on the basis of only a manipulation for moving one or more movable parts among the movable parts of the attachment 30, an operation of another movable part except the one or more movable parts. Specifically, the controller 11 in the embodiment automatically controls, in the MC mode, an operation of the boom 31 and an operation of the bucket 33 to allow the bucket 33 to perform a target operation in association with movement of the arm 32 corresponding to a control instruction manipulation amount indicating an amount of the control instruction manipulation or the arm pulling manipulation given to the arm manipulation lever. More specifically, the controller 11 executes a semi-automatic control of an operation of the attachment 30, i.e., an automatic control of the operation of the boom 31 and the operation of the bucket 33, so that a work surface , i.e., the work surface 73 illustrated in Fig. 3 to be subjected to a work by the operation of the bucket 33 accompanied by the arm pulling manipulation comes closer to a target work surface set in advance, i.e., the target work surface 71 in the example illustrated in Fig. 3. For instance, the semi-automatic control can adopt detected values respectively acquired by the slewing angle sensor 52 and the tilt angle sensors 60.
Fig. 3 illustrates an example of a work under the semi-automatic control of the operation of the attachment 30. In the example illustrated in Fig. 3, the work surface 73 includes a slope, and the target work surface 71 is set below the work surface 73. In the MC mode, the controller 11 executes the semi-automatic control of the operation of the attachment 30 so that the work surface 73 to be subjected to the work by the bucket 33 comes closer to the target work surface 71. In this manner, slope forming is performed in the example illustrated in Fig. 3.
In the MC mode, the semi-automatic control of the operation of the attachment 30 in the MC mode is a so-called machine control. The machine control indicates an assistive function to be utilized to finish the work.
The target work surface 71 is a surface that specifies a target shape of the ground to be excavated and defines a three-dimensional design landform. The target work surface 71 may be a curved surface without limitation to a flat surface. The target work surface 71 may be specified with external data, such as Construction Information Modeling/Management (CIM), or may be set on the basis of a position of the upper slewing body 22 as a reference.
A manual manipulation for moving the bucket 33 to a control start position and temporarily suspending an operation of the attachment 30 at the control start position in the manual manipulation mode is performed, before the semi-automatic control, i.e., the operation control, of the operation of the attachment 30 in the MC mode. The control start position represents a position where the semi-automatic control is to be started, for example, in the vicinity of the work surface 73. The mode of the controller 11 is switched from the manual manipulation mode to the MC mode while the bucket 33 is suspended at the control start position. Thereafter, the attachment 30 may unintentionally act, that is, differently act from a target action, for example, the bucket 33 slightly falls, due to pressure confinement in at least a part of the cylinders 40, structural rattling in the working machine 1 (e.g., rattling between the bucket 33 and the link member 34), swaying of the machine main body 24, or other factor, at the start of the operation of the attachment 30 under the semi-automatic control. When such an unintentional action occurs in a state where the bucket 33 approaches the target work surface 71, the bucket 33 may result in excessively excavating to a position deeper than the target work surface 71 beyond the target work surface 71.
The unintentional action of the attachment 30 indicates, for example, actual displacement of the bucket 33 from a target position of the bucket 33, or an actual speed deviation of the bucket 33 from a target speed of the bucket 33. The fall of the bucket 33 means lowering of the arm 32 at a speed equal to or higher than the target speed corresponding to a manipulation amount of the arm manipulation lever. The unintentional action different from the target action further includes upward displacement of the actual position of the bucket 33 from the target position in addition to the slight fall of the bucket 33.
The unintentional action may occur in another case or mode without limitation to the MC mode. At a start of the temporarily suspended operation of the attachment 30, the attachment 30 may unintentionally act regardless of the manual manipulation mode or the MC mode.
The controller 11 in the embodiment is configured to set, in consideration of the unintentional action, the entry prohibited surface 72 at a position spaced from the target work surface 71 in an opposite direction to a direction in which the work surface 73 comes closer to the target work surface 71, that is, in an opposite direction to a direction in which the work by the bucket 33 proceeds. Specifically, the controller 11 includes an entry prohibited surface setting part. The entry prohibited surface 72 may be a curved surface without limitation to a flat surface in the same manner as the target work surface 71. In the embodiment, a surface interval being an interval between the target work surface 71 and the entry prohibited surface 72 is uniform. Alternatively, the surface interval may not be necessarily uniform. For instance, a corner between a horizontally flat section and a slope section of the target work surface 71 may be given a surface interval larger than a surface interval of another portion in terms of a possible delay in a change in the posture of the attachment 30.
Fig. 4 shows an example of a work in a state of no execution of the semi-automatic control of the operation of the attachment 30. The controller 11 includes an operation restriction part. The operation restriction part imposes an operation restriction of restricting, under no execution of the semi-automatic control of the operation of the attachment 30 in the manual manipulation mode, the operation of the attachment 30 to prevent the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72.
The operator performs a manual manipulation for moving the bucket 33 to the control start position and temporarily suspending the operation of the attachment 30 in the manual manipulation mode before the semi-automatic control of the operation of the attachment 30 in the MC mode. The control start position is, for example, in the vicinity of the entry prohibited surface 72. The operation restriction, that is, a restriction on the operation of the attachment 30 to prevent the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72, keeps the bucket 33 away from the target work surface 71. This configuration prevents the bucket 33 from reaching the target work surface 71 due to the unintentional action of the attachment 30, e.g., a slight fall of the bucket 33, when the controller 11 is switched from the manual manipulation mode to the MC mode and the semi-automatic control of the operation of the attachment 30 is started. In other words, the configuration prevents the bucket 33 from excessively excavating the ground to a position deeper than the target work surface 71.
The controller 11 executes a feedback control of the operation of the working machine 1 in the MC mode. The feedback control includes: consecutively detecting a speed of a distal end of the bucket 33; and adjusting extension and contraction of one or more specific cylinders 40 (the boom cylinder 41 and the bucket cylinder 43 in the embodiment) among the cylinders 40 so that the detected speed comes closer to the target speed. The feedback control corrects a lowering speed of the attachment 30 even if, for example, the bucket 33 falls at the start of the semi-automatic control of the operation of the attachment 30 in the state of the temporal suspension of the operation of the attachment 30. This enables the bucket 33 to stop before reaching the target work surface 71.
Besides, even when the bucket 33 unintentionally moves toward the entry prohibited surface 72 due to an incorrect manipulation before the semi-automatic control of the operation of the attachment 30, the operation restriction, that is, a restriction on the operation of the attachment 30 to prevent the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72, succeeds in preventing the bucket 33 from reaching the target work surface 71.
The operator is permitted to give a manipulation to the associated manipulation levers 29 so as to operate at least one of the boom 31 or the bucket 33 despite execution of the semi-automatic control of the operation of the attachment 30 in the MC mode. Further, the manual manipulation by the operator is prioritized over the semi-automatic control of the operation of the attachment 30 if necessary, for example, to avoid a sudden obstacle. In contrast, the restriction on the operation of the attachment 30 with respect to the entry prohibited surface 72 is removed during the semi-automatic control of the operation of the attachment 30 in the MC mode.
In the MC mode, the operation control part of the controller 11 may execute an automatic control of the operation of the attachment 30. The automatic control is a control in which the controller 11 automatically moves all the boom 31, the arm 32, and the bucket 33 of the attachment 30 without any manipulation by the operator. For instance, the switching of the controller 11 to the MC mode after the movement of the bucket 33 to the control start position in the manual manipulation mode may allow the operation control part of the controller 11 to automatically control the operation of the attachment 30 so that the work surface 73 to be subjected to the work by the bucket 33 comes closer to the target work surface 71 set in advance. The automatic control requires no manipulation by the operator.
For example, in the manual manipulation mode shown in Fig. 4, the operation restriction part of the controller 11 restricts the operation of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72. Specifically, the operation restriction part of the controller 11 restricts an operation speed of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72. The restriction on the operation of the attachment 30 is not limited to the restriction on the operation speed of the attachment 30.
Regarding the movement of the bucket 33, an x-axis and a y-axis shown in Fig. 4 are set. The x-axis extends in a direction parallel to the entry prohibited surface 72. The y-axis extends in a direction perpendicular to the x-axis. A positive direction of the x-axis is a direction from an upper position to a lower position along the entry prohibited surface 72. A positive direction of the y-axis is a direction from the entry prohibited surface 72 toward a position opposite to the target work surface 71. Fig. 4 illustrates a separation distance L between the bucket 33 and the entry prohibited surface 72 in the y-direction.
The controller 11 restricts a y-directional speed being a speed of the bucket 33 in the y-direction on the basis of a relation shown in Fig. 5. Fig. 5 shows a relation between the separation distance L and a maximum value of the y-directional speed. The operator is permitted to operate the attachment 30 in such a manner as to move the bucket 33 at a speed of the maximum value or smaller in the y-direction. As shown in Fig. 5, the operation restriction part of the controller 11 decreases the maximum value of the y-directional speed as the separation distance L is shorter, and sets the maximum value of the y-directional speed to zero when the separation distance L reaches zero. In this manner, the operation restriction part of the controller 11 prevents the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72 in the y-direction.
Abrupt deceleration or abrupt stop of the attachment 30 around the entry prohibited surface 72 may cause swaying of the machine main body 24 or pressure confinement in each of the cylinders 40. A start of the semi-automatic control of the operation of the attachment 30 accompanied by such pressure confinement may cause the unintentional action of the attachment 30, i.e., an action different from the target action, for example, a slight fall of the bucket 33. To prevent the attachment 30 from unintentionally acting, the operation restriction part restricts the operation of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72, thereby enabling the attachment 30 to gradually stop. This configuration avoids occurrence of the pressure confinement in the cylinder 40 attributed to abrupt deceleration or abrupt stop of the attachment 30, and leads to achievement in preventing the attachment 30 from unintentionally acting at the start of the semi-automatic control of the operation of the attachment 30 to be executed thereafter.
On the other hand, as illustrated in Fig. 5, the operation restriction part of the controller 11 increases the maximum value of the y-directional speed as the separation distance L is longer. In other words, the operation restriction part of the controller 11 permits the bucket 33 to move in a direction away from the entry prohibited surface 72 along the y-direction. This enables the bucket 33 to move in the direction away from the entry prohibited surface 72 e.g., in a direction toward the control start position, despite imposition of the restriction on the operation of the attachment 30.
The operation restriction part of the controller 11 restricts an x-directional speed being a speed of the bucket 33 in the x-direction on the basis of a relation shown in Fig. 6 and a relation shown in Fig. 7. Fig. 6 shows the relation between the separation distance L and a maximum value of a positive directional speed of the bucket 33 on the x-axis, i.e., a positive x-directional speed. Fig. 7 shows the relation between the separation distance L and a minimum value of a negative directional speed of the bucket 33 on the x-axis, i.e., a negative x-directional speed. The operator is permitted to operate the attachment 30 in such a manner as to move the bucket 33 at a speed of the maximum value or smaller when the x-directional speed is positive, and at a speed of the minimum value or larger (i.e., at a speed at which an absolute value of the x-directional speed is equal to or smaller than an absolute value of the minimum value) when the x-directional speed is negative. As shown in Fig. 6 and Fig. 7, the operation restriction part decreases the maximum value of the positive x-directional speed and the absolute value of the minimum value of the negative x-directional speed as the separation distance L is shorter. The restriction imposed on the operation of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72 enables gradual stop of the attachment 30 and prevents pressure confinement in the cylinder 40 attributed to abrupt deceleration or abrupt stop of the attachment 30. Here, it is optional to decrease the maximum value or the absolute value of the minimum value of the x-directional speed as the separation distance L is shorter.
When the separation distance L is zero, the maximum value of the positive x-directional speed and the absolute value of the minimum value of the negative x-directional speed are not zero and larger than zero. Specifically, the operation restriction part of the controller 11 permits the bucket 33 to move along the entry prohibited surface 72 at a restricted speed despite the imposition of the restriction on the operation of the attachment 30. This enables, for example, the bucket 33 to move toward the control start position along the entry prohibited surface 72.
The operation restriction part of the controller 11 determines, on the basis of the relation similar to the relation shown in each of Fig. 6 and Fig. 7, a maximum value of a slewing speed of the upper slewing body 22 associated with the separation distance L. Specifically, a right slewing direction of the upper slewing body 22 is defined as a positive direction and a left slewing direction of the upper slewing body 22 is defined as a negative direction. In this case, the relation between the maximum value of the slewing speed in the positive direction and the separation distance L is equivalent to the relation shown in Fig. 6, and a relation between a minimum value of the slewing speed in the negative direction and the separation distance L is equivalent to the relation shown in Fig. 7. Therefore, the operation restriction part of the controller 11 decreases the maximum value of the slewing speed in the positive direction and the absolute value of the minimum value of the slewing speed in the negative direction as the separation distance L is shorter. In this manner, a stricter restriction on the slewing operation of the upper slewing body 22, i.e., the slewing operation of the attachment 30, for a shorter distance to the entry prohibited surface 72 enables the slewing of the attachment 30 to gradually stop. This achieves prevention of pressure confinement in the cylinder 40 attributed to abrupt deceleration or abrupt stop of the slewing of the attachment 30. Here, it is optional to decrease the maximum value or the absolute value of the minimum value of the slewing speed as the separation distance L is shorter.
The operation restriction part of the controller 11 keeps the maximum value or the absolute value of the minimum value of the slewing speed at a value larger than zero even when the separation distance L reaches zero. Specifically, the operation restriction part of the controller 11 permits the upper slewing body 22 to slew despite imposition of the restriction on the operation of the attachment 30. This enables, for example, the bucket 33 to move in a slewing direction toward the control start position. On the other hand, it is possible to prevent the bucket 33 from reaching the target work surface 71 due to the slewing of the upper slewing body 22.
Fig. 8 is a plan view illustrating the working machine 1 and the entry prohibited surface 72 set in front of the working machine. The operation restriction part of the controller 11 removes the restriction on the operation of the attachment 30 when the bucket 33 is out of an entry prohibited space under the restriction on the operation of the attachment 30 in the manual manipulation mode. The entry prohibited space is a space that faces the entry prohibited surface 72 in a facing direction. The facing direction may be a vertical direction, or may be a normal direction to the entry prohibited surface 72, i.e., the y-direction.
The bucket 33 may be out of the entry prohibited space due to, for example, slewing of the upper slewing body 22, traveling of the lower traveling body 21, approaching of the bucket 33 to the upper slewing body 22, or receding of the bucket 33 from the upper slewing body 22. The bucket 33 may perform a task of grounding preparation of the ground or movement of a mound, or other task at such a position outside the entry prohibited space. Removing the restriction on the operation of the attachment 30 outside the entry prohibited space allows the task to be preferably performed.
The operation restriction part of the controller 11 restricts the operation of the attachment 30 again when the bucket 33 enters the entry prohibited space after the removal of the operation restriction being a restriction on the operation of the attachment 30 in the manual manipulation mode. Such re-imposition of the operation restriction leads to achievement in preventing the bucket 33 facing the entry prohibited surface 72 in the facing direction from reaching the target work surface 71. The operation restriction part of the controller 11 is preferably configured to notify the operator of the entry of the bucket 33 into the entry prohibited space in association with the re-imposition of the restriction on the operation of the attachment 30. The notification can be made through, for example, displaying on a display provided in the cab 23, output of a sound from a speaker, or vibration of a specific manipulation lever among the manipulation levers 29.
The working machine 1 further includes a restriction switch part. The restriction switch part switches between a condition of validating the restriction on the operation of the attachment 30 by the operation restriction part and a condition of invalidating the restriction.
In the embodiment, the restriction switch part is included in the controller 11, and switches between the validation and the invalidation of the restriction on the operation in response to a restriction switch instruction input through a restriction changeover switch 27 shown in Fig. 2. The restriction changeover switch 27 is provided in the cab 23 so that the restriction changeover switch 27 can receive a restriction switch manipulation for an input of the restriction switch instruction by the operator. The restriction switch part of the controller 11 validates or invalidates the restriction on the operation of the attachment 30 imposed by the operation restriction part in response to the restriction switch manipulation (e.g., an on-off manipulation) given to the restriction changeover switch 27. The validation or invalidation of the restriction on the operation of the attachment 30 is preferably notified to the operator. The notification may be made, for example, through displaying on the display provided in the cab 23. The notification allows the operator to grasp whether the restriction on the operation of the attachment 30 is valid or invalid. Alternatively, the notification may be made through output of a sound from the speaker provided in the cab 23, vibration of a suitable manipulation lever among the manipulation lever 29, or through another way.
Such invalidation of the operation restriction enables, for example, preferable performance of a different task that is different from a task of making the attachment 30 operate (a task under the semi-automatic control) so that the work surface 73 comes closer to the target work surface 71. The different task includes, for example, a task of refilling the work surface 73 by adding soil to the work surface 73.
The controller 11 further includes an inter-surface distance setting part. The inter-surface distance setting part sets an inter-surface distance being a distance between the target work surface 71 and the entry prohibited surface 72 in response to a distance designation manipulation given by the operator. The working machine 1 further includes an input device 28 shown in Fig. 2. The input device 28 is, for example, a touch screen and is provided in the cab 23 to allow the operator to give the distance designation manipulation to the input device 28. The operator can input, into the controller 11, the inter-surface distance, i.e., a distance between the target work surface 71 and the entry prohibited surface 72 to be set by the inter-surface distance setting part, by giving the distance designation manipulation to the input device 28. The inter-surface distance setting part of the controller 11 sets the inter-surface distance in response to the distance designation manipulation given to the input device 28 by the operator.
For instance, the setting of the inter-surface distance, i.e., the distance between the target work surface 71 and the entry prohibited surface 72, means arrangement of the entry prohibited surface 72 to a position above the target work surface 71 by a distance (mm) indicated by the distance designation manipulation given to the input device 28. Alternatively, the setting may include such arrangement of the entry prohibited surface 72 that the entry prohibited surface 72 involves a position of a tip of the bucket 33 at present or a position of the tip of the bucket 33 at a time when the restriction on the operation of the attachment 30 is switched to validation. In a case where the input device 28 is a touch screen, the inter-surface distance is settable by arranging the entry prohibited surface 72 at a position corresponding to the position input into the input device 28 along a line traced on the touch screen by the operator with a finger of the operator.
In the working machine 1, the bucket 33 is replaceable depending on a purpose. The replacement may cause displacement of the bucket 33 at the start of the semi-automatic control of the operation of the attachment 30 depending on a mass or shape of the bucket 33. The inter-surface distance designation part allows the operator to designate the inter-surface distance, i.e., the distance between the target work surface 71 and the entry prohibited surface 72 for example, depending on a kind of the bucket 33 to be used. The designation leads to achievement in preventing the bucket 33 from reaching the target work surface 71 due to the unintentional action of the attachment 30 at the start of the semi-automatic control of the operation of the attachment 30.
The inter-surface distance setting part of the controller 11 may be configured to automatically set the inter-surface distance depending on the kind of the bucket 33 to be attached to the arm 32. Information about the kind of the bucket 33 to be attached to the arm 32 may be given to the controller 11 through a manipulation given to the input device 28 by the operator, or may be automatically acquired by the controller 11.
The controller 11 includes an area setting part that sets an area of the entry prohibited surface 72. The operator can input, into the controller 11, the area of the entry prohibited surface 72 set by the area setting part through a manipulation given to the input device 28. The controller 11 receives an input of, for example, a coordinate of the entry prohibited surface 72. The area setting part of the controller 11 sets the area of the entry prohibited surface 72 in response to the manipulation given to the input device 28 by the operator. The setting of the area of the entry prohibited surface 72 may include teaching. The teaching includes arranging the bucket 33 at two or more positions on the work surface 73 through a manual manipulation by the operator, and registering a tip position of the bucket 33 in the arrangement to the storage device 13 by the area setting part. The area of the entry prohibited surface 72 is defined by the registered positions. Alternatively, the area setting part may be configured to automatically set the area of the entry prohibited surface 72 on the basis of a slewing angle of the upper slewing body 22 or an area reachable by the attachment 30.
For instance, although the entry prohibited surface 72 set in two-dimensional cross-section as illustrated in Fig. 3 has an unlimited length in a direction perpendicular to the cross-section, the setting of the area of the entry prohibited surface 72 prevents the entry prohibited surface 72 from being excessively large.
The area of the entry prohibited surface 72 prior to the input via the input device 28 may be set to a default area. The default area is set in front of the upper slewing body 22 on the basis of, for example, the slewing angle of the upper slewing body 22 and/or the area reachable by the attachment 30. In this case, the area setting part may be configured to enlarge or reduce the default area in response to an input via the input device 28 by the operator.
As described heretofore, in the working machine 1 according to the embodiment, the operation control part of the controller 11 controls the operation of the attachment 30, for example, automatically or semi-automatically so that the work surface 73 to be subjected to a work by the bucket 33 comes closer to the target work surface 71 set in advance, for example, as illustrated in Fig. 3, when the manipulation part including the manipulation levers 29 receives the control instruction manipulation given thereto. In contrast, as illustrated in Fig. 4, the operation restriction part of the controller 11 imposes an operation restriction of restricting, under no execution of the control of the operation of the attachment 30 by the operation control part, the operation of the attachment 30 to prevent the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72. Even in a case where the bucket 33 is moved to, for example, the control start position in the vicinity of the entry prohibited surface 72 before the control of the operation of the attachment 30, the operation restriction allows the bucket 33 to be kept away from the target work surface 71. The operation restriction accordingly leads to achievement in preventing the bucket 33 from reaching the target work surface 71 due to an unintentional action different from a target action of the attachment 30, e.g., a slight fall of the bucket 33, at the start of the control of the operation of the attachment 30. This prevents excessive excavation by the bucket 33 to a position deeper than the target work surface 71. Besides, even in a case where the bucket 33 moves toward the entry prohibited surface 72 due to, for example, an incorrect manipulation before the control of the operation of the attachment 30, the operation restriction leads to achievement in preventing the bucket 33 from reaching the target work surface 71.
For instance, as shown in Fig. 5 to Fig. 7, the operation restriction part restricts the operation of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72. For instance, the operation restriction part restricts the operation speed of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72. Abrupt deceleration or abrupt stop of the attachment 30 around the entry prohibited surface 72 may cause swaying of the machine main body 24 or pressure confinement in the cylinder 40, resulting in occurrence of the unintentional action of the attachment 30, e.g., a slight fall of the bucket 33, at the start of the control of the operation of the attachment 30. In this regard, a restriction imposed on the operation of the attachment 30 by a greater degree as the bucket 33 approaches the entry prohibited surface 72, e.g., a restriction imposed on the operation speed of the attachment 30 by a greater degree, achieves prevention of the unintentional action of the attachment 30.
As shown in Fig. 6 and Fig. 7, the operation restriction part permits the bucket 33 to move along the entry prohibited surface 72 despite imposition of the operation restriction. This enables, for example, the bucket 33 to move toward the control start position along the entry prohibited surface 72.
For instance, as illustrated in Fig. 8, when the bucket 33 is out of the entry prohibited space facing the entry prohibited surface 72 under the restriction on the operation of the attachment 30, the operation restriction part removes the operation restriction. This enables preferable performance of a task of grounding preparation of the ground or movement of a mound outside the entry prohibited space.
For instance, as illustrated in Fig. 8, the operation restriction part restricts the operation of the attachment 30 again when the bucket 33 enters the entry prohibited space under the removal of the operation restriction. The restriction prevents the bucket 33 facing the entry prohibited surface 72 from reaching the target work surface 71.
The controller 11 includes the restriction switch part. The restriction switch part switches between the condition of validating the operation restriction and the condition of invalidating the operation restriction in response to, for example, a restriction switch instruction input through a restriction switch manipulation given to the manipulation restriction changeover switch 27. The invalidation of the operation restriction enables preferable performance of a different task that is different from a task performed under a control to operate the attachment 30 so that the work surface 73 comes closer to the target work surface 71, the different task being preferably performed in the vicinity of the work surface 73, e.g., a task of re-filling the work surface 73 by adding the soil to the work surface 73.
The controller 11 includes the inter-surface distance setting part. The inter-surface distance setting part sets an inter-surface distance being a distance between the target work surface 71 and the entry prohibited surface 72 in response to a manipulation given by the operator. In a case where the bucket 33 is replaced depending on a purpose in the working machine 1, variation in the position of the bucket 33 at the start of the control of the operation of the attachment 30 depends on a mass or shape of the bucket 33. In this regard, the operator sets a distance between the target work surface 71 and the entry prohibited surface 72 depending on, for example, a kind of the bucket 33 to be used. This setting prevents the bucket 33 from reaching the target work surface 71 regardless of the unintentional action of the attachment 30 at the start of the control of the operation of the attachment 30.
The controller 11 includes an area setting part that sets an area of the entry prohibited surface 72. The entry prohibited surface 72 has an unlimited length in the direction perpendicular to the cross-section under setting only in the two dimensional cross-section. The setting of the area of the entry prohibited surface 72 by the area setting part prevents the entry prohibited surface 72 from being excessively large.
The embodiment of the present invention is described heretofore, but is merely described as an example without particularly limiting the present invention. It is the matter of design choice for changes in the details of the configuration. Furthermore, the operations and effects described in the embodiment of the present invention are merely listed as optimal operations and effects attained by the present invention, and thus should not be limited thereto.
For instance, when the manipulation lever 29 receives a manipulation corresponding to the control instruction manipulation in the MC mode in a state of low responsiveness of the working machine 1 attributed to a low temperature of hydraulic fluid or other factor, the bucket 33 may approach the target work surface 71 beyond the entry prohibited surface 72. Hence, when the low responsiveness of the working machine 1 is detected, the operation restriction part of the controller 11 may be configured to restrict, or impose the operation restriction on, the operation of the attachment 30 to prevent the bucket 33 from approaching the target work surface 71 beyond the entry prohibited surface 72 even during execution of the control by the operation control part. This configuration prevents the attachment 30 from unintentionally acting or differently acting from the target action due to the low responsiveness, resulting in achieving more stable working accuracy.
Conclusively, a working machine including a machine main body, an attachment, an operation control part, a manipulation part, and an operation restriction part is provided. The attachment includes a leading end attachment configured to perform a work, and is attached to the machine main body. The manipulation part permits a manipulation for moving the attachment to be given thereto. The operation control part executes an operation control of controlling an operation of the attachment so that a work surface to be subjected to the work by the leading end attachment comes closer to a target work surface set in advance when the manipulation given to the manipulation part includes a predetermined control instruction manipulation. The operation restriction part imposes an operation restriction of restricting, under no execution of the operation control by the operation control part, the operation of the attachment to prevent the leading end attachment from approaching the target work surface beyond an entry prohibited surface. The entry prohibited surface is set at a position spaced from the target work surface in an opposite direction to a direction in which the work surface comes closer to the target work surface.
In the working machine, the operation control part executes an operation control of controlling the operation of the attachment so that the work surface to be subjected to the work by the leading end attachment comes closer to the target work surface set in advance when a manipulation given to the manipulation part is the control instruction manipulation. In contrast, the operation restriction part imposes the operation restriction, that is, restricts, under no execution of the operation control, the operation of the attachment to prevent the leading end attachment from approaching the target work surface beyond the entry prohibited surface. Even in a case where the leading end attachment is moved to, for example, a control start position in the vicinity of the entry prohibited surface before the control of the operation of the attachment, the operation restriction allows the leading end attachment to be kept away from the target work surface. This configuration prevents the leading end attachment from reaching the target work surface due to an unintentional action different from a target action, e.g., a slight fall of the leading end attachment. This prevents excessive excavation by the leading end attachment to a position deeper than the target work surface. Besides, even in a case where the leading end attachment moves toward the entry prohibited surface due to, for example, an incorrect manipulation before the control of the operation of the attachment, the operation restriction leads to achievement in preventing the leading end attachment from reaching the target work surface.
The operation restriction part is preferably configured to restrict the operation of the attachment by a larger degree as the leading end attachment approaches the entry prohibited surface, for example, configured to restrict an operation speed of the attachment by a larger degree as the leading end attachment approaches the entry prohibited surface.
The operation restriction part is preferably configured to permit the leading end attachment to move along the entry prohibited surface despite imposition of the operation restriction.
The operation restriction part is preferably configured to remove the operation restriction when the leading end attachment is out of an entry prohibited space that faces the entry prohibited surface under the operation restriction.
The operation restriction part is preferably configured to impose the operation restriction again when the leading end attachment enters the entry prohibited space that faces the entry prohibited surface under the removal of the operation restriction.
The working machine preferably further includes a restriction switch part that is configured to switch between a condition of validating the operation restriction and a condition of invalidating the operation restriction.
The working machine further preferably includes an inter-surface distance setting part that sets an inter-surface distance being a distance between the target work surface and the entry prohibited surface in response to the manipulation given by the operator.
The working machine preferably further includes an area setting part that sets an area of the entry prohibited surface.

Claims

A working machine, comprising:
a machine main body;

an attachment that includes a leading end attachment configured to perform a work, and is attached to the machine main body;

a manipulation part that permits a manipulation for moving the attachment to be given thereto;

an operation control part that executes an operation control of controlling an operation of the attachment so that a work surface to be subjected to the work by the leading end attachment comes closer to a target work surface set in advance when the manipulation given to the manipulation part includes a predetermined control instruction manipulation; and

an operation restriction part that imposes an operation restriction of restricting, under no execution of the operation control by the operation control part, the operation of the attachment to prevent the leading end attachment from approaching the target work surface beyond an entry prohibited surface set at a position spaced from the target work surface in an opposite direction to a direction in which the work surface comes closer to the target work surface.
The working machine according to claim 1, wherein the operation restriction part restricts the operation of the attachment by a greater degree as the leading end attachment approaches the entry prohibited surface.
The working machine according to claim 2, wherein the operation restriction part restricts an operation speed of the attachment by a greater degree as the leading end attachment approaches the entry prohibited surface.
The working machine according to claim 1, wherein the operation restriction part is configured to permit the leading end attachment to move along the entry prohibited surface despite the imposition of the operation restriction.
The working machine according to any one of claims 1 to 4, wherein the operation restriction part is configured to remove the operation restriction when the leading end attachment is out of an entry prohibited space that faces the entry prohibited surface under the operation restriction.
The working machine according to claim 5, wherein the operation restriction part is configured to impose the operation restriction again when the leading end attachment enters the entry prohibited space that faces the entry prohibited surface under the removal of the operation restriction.
The working machine according to any one of claims 1 to 4, further comprising a restriction switch part that is configured to switch between a condition of validating the operation restriction and a condition of invalidating the operation restriction.
The working machine according to any one of claims 1 to 4, further comprising an inter-surface distance setting part that sets an inter-surface distance being a distance between the target work surface and the entry prohibited surface in response to the manipulation given by the operator.
The working machine according to any one of claims 1 to 4, further comprising an area setting part that sets an area of the entry prohibited surface.