EP4603642A1

EP4603642A1 - Work support device and work machine

Info

Publication number: EP4603642A1
Application number: EP25155260.0A
Authority: EP
Inventors: Takashi Yokono; Sei Shimahara; Ikuto YAGI
Original assignee: Caterpillar SARL
Current assignee: Caterpillar SARL
Priority date: 2024-02-16
Filing date: 2025-01-31
Publication date: 2025-08-20
Anticipated expiration: 2045-01-31
Also published as: JP2025125887A; EP4603642B1

Abstract

PROBLEMS: To provide a work support device capable of automatically aligning a blade edge of a bucket along a work surface even changeable an angle of the bucket by a tilt mechanism and a swivel mechanism, and to provide a work machine equipped with the same. SOLUTIONS: A work support device for automatically controlling a position of a bucket (9) includes a controller (50) for controlling at least one of a tilt angle of the bucket (9) by a tilt mechanism (25) and a rotation angle of the bucket (9) by a bucket cylinder (21) so as to reduce an angle residual between an angle of a blade edge of the bucket (9) calculated based on detection of a sensor unit (52) and an angle of a work surface input in advance.

Description

Technical Field

The present invention relates to a work support device for automatically controlling a position of a bucket and a work machine comprising the same.

Background

Conventionally, in a hydraulic excavator with a tilt mechanism capable of supporting a bucket at the tip of a work device within a predetermined angle range from left to right relative to a stick (arm), it is known to automatically control and move the tilt angle so that the blade edge of the bucket is always parallel to the normal surface when drilling or molding the normal surface (inclined surface) by the bucket (see, for example, Patent Document 1).

Prior Art Documents

Patent Document

Patent Document 1: Japanese Patent No. 6591531

Summary of the Invention

Problems to be Solved by the Invention

In the case of a hydraulic excavator equipped with a tilt rotator capable of causing the bucket to swivel 360° relative to the tilt mechanism, if the swivel angle (rotate angle) is tried to be, for example, 90° or 270°, that is, it works as a state that the bucket is facing sideways with respect to the front and rear direction of the vehicle, the tilt angle control as described above alone may not enable the bucket blade edge to approach the working surface.
In view of this, it is an object of the present invention to provide a work support device capable of automatically making a blade edge of a bucket following a work surface, even if the angle of the bucket can be changed by a tilt mechanism and a swivel mechanism, and a work machine comprising the same.

Means for Solving the Problem

The invention according to claim 1 is a work support device for automatically controlling a position of a bucket and applied to a work machine, the work machine including a machine body, a work device having a bucket, and an actuator for rotating the bucket, and a sensor unit for detecting a posture, a tilt mechanism for swingably supporting the bucket in a direction intersecting a rotation direction and a swivel mechanism for rotatably supporting the bucket with respect to the tilt mechanism being mountable on the work device, wherein the work support device comprises a control unit configured to control at least one of a tilt angle of the bucket by the tilt mechanism and a rotation angle of the bucket by the actuator so as to reduce an angle residual between an angle of a blade edge of the bucket calculated based on detection of the sensor unit and an angle of a work surface input in advance.
The invention of claim 2, wherein the control unit in the work support device of claim 1 repeats selective control of the tilt angle of the bucket by the tilt mechanism and the rotation angle of the bucket by the actuator until the angle residual between the angle of the blade edge of the bucket and the angle of the work surface input in advance becomes substantially zero.
The invention according to claim 3, wherein the control unit in the work support device according to claim 1 determines whether or not the rotation angle of the bucket by the actuator is controllable when a target relative tilt angle calculated based on the angle residual is not within a tiltable angle range of the bucket by the tilt mechanism.
The invention according to claim 4, wherein the control unit in the work support device according to claim 3 tilts the bucket by the tilt mechanism to an end of the tiltable angle range, when the target relative bucket angle calculated based on the angle residual is not within a rotatable angle range of the bucket by the actuator.
The invention according to claim 5 is a working machine comprising a machine body; a bucket; a work device that includes a bucket and an actuator that rotates the bucket, and a tilt mechanism that supports the bucket so as to be swingable in a direction intersecting a rotation direction, and a swivel mechanism that supports the bucket so as to be rotatable with respect to the tilt mechanism being mountable on the work device; a sensor unit for detecting a posture; and the work support device according to any one of claims 1 to 4.

Effect of the Invention

According to the invention described in claim 1, even a work machine that can change the angle of the bucket by the tilt mechanism and the swivel mechanism, it is possible to automatically move the bucket by at least one of the tilt mechanism and the actuator to make the blade edge of the bucket follow the working surface.
According to the invention described in claim 2, a selective combination of tilt action by a tilt mechanism and rotary action by an actuator with different action directions from each other can cause the blade edge of the bucket to be aligned with the work surface with high precision.
According to the invention described in claim 3, by prioritizing the tilt movement of the bucket by the tilt mechanism over the rotational movement of the bucket by the actuator, the blade edge of the bucket can be more efficiently aligned with the work surface.
According to the invention described in claim 4, in a case where the angle residual is large and it is difficult to align the blade edge of the bucket along the work surface even if either of the tilt mechanism and the actuator is used, the angle of the blade edge of the bucket is brought as close as possible to the angle of the work surface by the tilt function of the tilt mechanism, so that the angle of the blade edge of the bucket can be gradually brought closer to the angle of the work surface by repeating the automatic control flow.
According to the invention described in claim 5, it is possible to provide a work machine capable of easily performing work by aligning the blade edge of a bucket, which generally requires skill, along the work surface, and having good workability.

Brief Description of the Drawings

FIG. 1 is a side view schematically shows an embodiment of a work machine including a work support device according to the present invention.
FIG. 2 is a front view showing of the same work machine.
FIG. 3 illustrates a tilt mechanism and a swivel mechanism of the above work machine, with (a) being a side view thereof and (b) being a front view schematically illustrated;
FIG. 4 is a hydraulic circuit diagram of the above work machine.
FIG. 5 is a block diagram illustrating the above work support device.
FIG. 6 is a model diagram of a machine body roll angle calculated by the automatic control function of the above work support device.
FIG. 7 is a model diagram of a machine body pitch angle, a relative boom angle, a relative stick angle, and a relative bucket angle calculated by the automatic control function of the above work support device.
FIG. 8 is a flowchart illustrating the automatic control function of the above work support device.

Detailed Description of the Invention

Hereinafter, the present invention will be described in detail based on an embodiment shown in FIGS. 1 to 8.
In FIGS. 1 and 2, 1 is a work machine. In the present embodiment, a hydraulic excavator, is taken as an example of a work machine 1. The working machine 1 is provided with a machine body 4 on which an upper swivel body 3 is rotatably provided with respect to a lower traveling body 2, and the swivel body 3 is mounted with a work device 5 and a cab 6 surrounding an operator's driving cab inside.
The work device 5 includes a boom 7, a stick (arm) 8, and a bucket 9 as an end attachment. A proximal end of the boom 7 is rotatably attached to the swivel body 3, and a proximal end of the stick 8 is rotatably attached to a tip portion of the boom 7. In addition, in the present embodiment, a tilt rotator 10 can be attached to the work device 5, and the bucket 9 is rotatably attached to a tip portion of the stick 8 via the tilt rotator 10. The boom 7 may be formed of a plurality of boom members, such as a so-called two-piece boom employed in a high-posture disassembling machine.
In the present embodiment, a bucket for shaping and leveling a normal surface, also referred to as a grading bucket (normal bucket) or the like, is used as the bucket 9. The bucket 9 has a curved or bent bottom plate 12, side plates 13 connected to both sides of the bottom plate 12, and a connecting part 14 for connecting with the tilt rotator 10. A tip portion of the bottom plate 12 is a blade portion 15 extending in a width direction of the bucket 9.
The traveling body 2, the swivel body 3, and the work device 5 are each driven by an actuator. The actuator, for example, a fluid pressure actuator, in this embodiment a hydraulic actuator, a hydraulic cylinder, a hydraulic motor, etc. is used.
The traveling body 2 is driven by left and right traveling motors 17, which are hydraulic motors as actuators, to drive the work machine 1 to travel.
The swivel body 3 is driven by a swivel motor 18, which is a hydraulic motor as an actuator, to swivel with respect to the traveling body 2.
The boom 7 is driven by a boom cylinder 19, which is a hydraulic cylinder as an actuator, to rotate relative to the swivel body 3. The proximal end or cylinder portion of the boom cylinder 19 is rotatably axial supported to a side of the cab 6 at the swivel body 3, and the tip portion or rod is rotatably axial supported to the boom 7.
The stick 8 is driven by a stick cylinder (arm cylinder) 20, which is a hydraulic cylinder as an actuator, to rotate relative to the boom 7. The proximal end or cylinder portion of the stick cylinder 20 is rotatably axial supported at a top of the boom 7, and the tip portion or rod is rotatably axial supported at the proximal end of the stick 8.
The bucket 9 is driven by a bucket cylinder 21, which is a hydraulic cylinder as an actuator, to rotate with the tilt rotator 10 relative to the stick 8. The proximal end or cylinder portion of the bucket cylinder 21 is rotatably axial supported to a front portion of the stick 8, and a tip portion or rod is rotatably axial supported to the idler link 22 that is rotatably connected to the tip portion of the stick 8.
The tilt rotator 10 has a tilt mechanism 25 and a swivel mechanism 26, and allows an angle of the tip portion of the blade portion 15 of the bucket 9, that is, an angle of a blade edge, and an orientation of the bucket 9 to be changed, thereby enabling multi-directional and diverse work by the bucket 9 with respect to the work surface P without requiring a movement of the work machine 1 or a large working space.
The tilt mechanism 25 swingably supports the bucket 9 and the swivel mechanism 26 on the stick 8. The tilt mechanism 25 comprises a first portion 31 on a root side that is attached to the stick 8, a second portion 32 on a tip side that is attached to the bucket 9, and a tilt cylinder 33, which is a hydraulic cylinder as an actuator that swings the second portion 32, or a bucket 9 side, relative to the first portion 31. As shown in FIGS. 3 (a) and 3 (b), the first portion 31 is formed in parallel with a mounting hole 35 rotatably axial supported directly on the tip of the stick 8 or indirectly via an adapter or coupler on the tip of the stick 8, and an axial support hole 36 rotatably axial supported on the idler link 22, either directly or indirectly via an adapter or coupler. The second portion 32 is rotatably axial supported on the first portion 31 via a tilt axis 38 along a direction intersecting or orthogonal to a penetration direction of the mounting hole 35 and the axial support hole 36 of the first portion 31. Thus, the second portion 32 and the bucket 9 attached to the second portion 32 are capable of swinging at a predetermined angle range in a direction intersecting or orthogonal to a longitudinal direction, that is, the width direction of the bucket 9, relative to the first portion 31 and the stick 8 to which the first portion 31 is attached. One or two tilt cylinders 33 are arranged. In the tilt cylinder 33, a proximal end portion, that is, a cylinder portion, is rotatably axial supported on the first portion 31, and a distal end portion, that is, a rod is rotatably axial supported on the second portion 32. In the present embodiment, the tilt mechanism 25 allows the bucket 9 to swing at a predetermined angle in the width direction, for example, in a range of 40 °, as indicated by arrow D1.
The swivel mechanism 26 supports the bucket 9 to enable the tilt mechanism 25 to be swingable. The swivel mechanism 26 comprises the second portion 32 of the tilt mechanism 25, a swivel axis 40, and a swivel motor 41, which is a hydraulic motor as an actuator to swivel the bucket 9 side relative to the second portion 32. The swivel axis 40 rotatably supports the bucket 9 on the second portion 32 along a direction intersecting or orthogonal to the tilt axis 38. Thus, the bucket 9 is able to swivel relative to the second portion 32 while remaining parallel or substantially parallel to the tilt axis 38. For example, in the present embodiment, by the swivel mechanism 26, the bucket 9 may swivel 360 ° with respect to the second portion 32 as indicated by an arrow D2.
The hydraulic oil, which is the working fluid supplied to each actuator, is controlled in a flow rate and direction by the control valve 43 shown in FIG. 4. In the control valve 43, a control valve, which is a spool corresponding to each actuator, is arranged, and hydraulic oil is drained to each actuator via each control valve.
A main pump 45 is connected to the control valve 43, and the main pump 45 is driven by an engine 46. In the present embodiment, the main pump 45 is a variable-capacity pump, wherein a variable-capacity means, such as a swash plate, is controlled via a regulator 47 or a control valve, so that the discharge flow rate is variable and adjustable.
Also, the operation of each control valve of the control valve 43, the main pump 45, the engine 46, etc. is controlled by a controller 50 as a control unit. The controller 50 generates a control signal based on a command signal input from an operator via an operation device 51, such as an operating lever or an operating pedal disposed in the cab 6 (FIG. 1), and outputs the control signal to each control valve of the control valve 43, the main pump 45, the engine 46, etc. In other words, in the present embodiment, each control valve is an electromagnetic proportional valve directly operated by an electrical signal, but it is not limited thereto, and may be a control valve operated by pilot pressure.
In the present embodiment, the controller 50 is equipped with a function to automatically control the position of the bucket 9 as a work support device.
Next, the automatic control function of the controller 50 will be specifically described. In FIG. 5, in order to clarify the description, basically only the part related to the automatic control function of the controller 50 is shown, and the other parts are omitted.
For example, as shown in FIGS. 1 and 2, in the case of the work machine 1 comprising the tilt rotator 10, i.e., the tilt mechanism 25 and the swivel mechanism 26 of the bucket 9, depending on the angle of the bucket 9, the tilt function within a movable range of the tilt mechanism 25 alone may make it difficult to align the tip of the blade portion 15 of the bucket 9, i.e., the blade edge, with the work surface P, such as a work target surface or a design surface. Therefore, the controller 50 has a function of automatically controlling by controlling at least one of the tilt angle of the bucket 9 by the tilt mechanism 25 and the rotation angle of the bucket 9 by the bucket cylinder 21 based on the posture of the work machine 1, so as to reduce an angle deviation of the blade edge (toe line) of the bucket 9 from a pre-inputted angle of the work surface P, and automatically enabling the blade edge of the bucket 9 to be parallel or substantially parallel to the work surface P. In the present embodiment, the controller 50 repeats the selective control of the tilt angle of the bucket 9 by the tilt mechanism 25 and the rotation angle of the bucket 9 by the bucket cylinder 21 until the angle residual between the angle of the blade edge of the bucket 9 and the angle of the work surface P is substantially zero. For the work surface P, it may be based on 3D data of the construction site saved in advance in a storage unit that can be referenced by the controller 50, or it may be based on data input by an operator such as an input means such as a touch panel monitor provided inside the cab 6.
As shown in FIG. 5, the controller 50 is connected with a sensor unit 52 for posture detection to obtain information for calculating the angle of the blade edge of the bucket 9 (FIG. 1). In the present embodiment, the sensor unit 52 detects the posture information of each part of the work machine 1 and inputs a signal indicating the detected posture information to the controller 50.
The sensor portion 52 is provided with a machine body tilt angle sensor 54.
The machine body tilt angle sensor 54 is a sensor that detects a roll angle q3r of the machine body 4 shown in FIG. 6 and a pitch angle q3p of the machine body 4 shown in FIG. 7. The roll angle q3r of the machine body 4 shown in FIG. 6 is a relative inclination angle of the machine body 4 in the left and right directions with respect to the horizontal direction, for example, an angle of the left and right direction of a virtual plane including the underside of the traveling body 2 with respect to the horizontal plane. The roll angle q3r of the present embodiment is, for example, plus in the counterclockwise direction in FIG. 6 and minus in the clockwise direction. Also, the pitch angle q3p of the machine body 4 shown in FIG. 7 is a relative inclination angle of the machine body 4 in the front-back direction with respect to the horizontal direction, for example, an angle of the front-back direction of a virtual plane including the underside of the traveling body 2 with respect to the horizontal plane. The pitch angle q3p of the present embodiment is, for example, plus in the counterclockwise direction in FIG. 7 and minus in the clockwise direction. The machine body tilt angle sensor 54 is an acceleration sensor, such as an inertial measurement unit (IMU), and may be located at any position if each angle can be detected, but in the illustrated example is located, for example, at the swivel body 3.
Also, the sensor unit 52 shown in FIG. 5 is provided with a boom angle sensor 56, a stick angle sensor 57, and a bucket angle sensor 58.
The boom angle sensor 56 shown in FIG. 7 is a sensor that detects a rotation angle of the boom 7 relative to the machine body 4, i.e., a relative boom angle q5. The relative boom angle q5 is defined as an angle (q5 = θ-q3p) obtained by subtracting the pitch angle q3p of the machine body 4 from an angle θ with respect to the horizontal direction of a virtual line L1 connecting an axial support position of the proximal end of the boom 7 to the machine body 4 (the center of the boom foot pin) and the axial support position of the stick 8 at the tip portion of the boom 7 (the center of the stick root pin), as viewed from the side of the machine body 4 or the side of the work device 5. The relative boom angle q5 of the present embodiment is, for example, plus in the counterclockwise direction in FIG. 7 and minus in the clockwise direction. The boom angle sensor 56 is, for example, an acceleration sensor, such as an inertial measurement unit, and may be positioned at any position if the relative boom angle q5 can be detected, but in the illustrated example is positioned, for example, between both ends of the boom 7. By way of example and not limitation, the boom angle sensor 56 may be a general rotational angle sensor, for example, or may detect the relative boom angle q5 by detecting an amount of expansion and contraction of the boom cylinder 19 (FIG. 1). In addition, if the boom 7 consists of a plurality of boom members, such as a two-piece boom, a boom angle sensor 56 may be arranged for each boom member, and the relative boom angle q5 may be detected from the respective detection results.
The stick angle sensor 57 is a sensor that detects a rotation angle of the stick 8 with respect to the boom 7, i.e., a relative stick angle q7. The relative stick angle q7 is defined as a relative angle of a virtual line L2 to the virtual line L1, from the side of the machine body 4 or the side of the work device 5, connecting the axial support position of the proximal end of the stick 8 to the boom 7 (the center of the stick root pin) and the axial support position of the tip portion of the stick 8 to the bucket 9 or tilt rotator 10 (FIG. 1) (the center of the stick tip pin or the center of the bucket pin). The relative stick angle q7 of the present embodiment is plus in the clockwise direction and minus in the counterclockwise direction, for example, in FIG. 7. The stick angle sensor 57 is, for example, an acceleration sensor, such as an inertial measurement unit, and may be disposed at any position if the relative stick angle q7 can be detected, but in the illustrated example is disposed, for example, between both ends of the stick 8. By way of example but not limitation, the stick angle sensor 57 may be a general rotational angle sensor, for example, or may detect the relative stick angle q7 by detecting an amount of expansion or contraction of the stick cylinder 20.
The bucket angle sensor 58 is a sensor that detects a rotation angle of the bucket 9 relative to the stick 8, i.e., a relative bucket angle q8. The relative bucket angle q8 is defined as a relative angle of the virtual line L2 to a virtual line L3 connecting the center of the bucket pin and the tip portion of the blade portion 15 of the bucket 9, as seeing from the side of the machine body 4 or the side of the work device 5. The relative bucket angle q8 of the present embodiment is plus in the clockwise direction and minus in the counterclockwise direction, for example, in FIG. 7. In the figure, although the tilt rotator 10 (FIG. 1) is omitted, when the tilt rotator 10 (FIG. 1) is provided, the virtual line L3 is a virtual line connecting the axial support position of the tilt mechanism 25 (FIG. 1) to the stick 8 (the center of the mounting hole 35 of the first portion 31) and the tip portion of the blade portion 15 of the bucket 9, based on the state that a relative tilt angle q9t and a swivel angle q9r described later are 0°, respectively. The bucket angle sensor 58 is, for example, an acceleration sensor, such as an inertial measurement unit, and may be positioned at any position if the relative bucket angle q8 can be detected, but in the illustrated example is positioned, for example, at the tip portion of the idler link 22. By way of example but not limitation, the bucket angle sensor 58 may be a general rotation angle sensor, for example, or may detect the relative bucket angle q8 by detecting an amount of expansion and contraction of the bucket cylinder 21. Thus, these arrangements allow the bucket angle sensor 58 to detect the relative bucket angle q8 independently of the angle of the relative tilt angle q9t and/or the swivel angle q9r.
Furthermore, the sensor portion 52 shown in FIG. 5 is provided with a tilt angle sensor 60 and a swivel angle sensor 61.
The tilt angle sensor 60 shown in FIGS. 3 (a) and 3 (b) is a sensor that detects the tilt angle or relative tilt angle q9t of the bucket 9 by the tilt mechanism 25. The relative tilt angle q9t is defined as an angle formed by a vertical line through a central position of the tilt axis 38, that is, the axis Zt perpendicular to the tilt axis direction, as seeing from the tilt axis direction, and a downward direction (not limited to the vertical downward) of the bucket 9, which is a downward direction of the tilt angle sensor 60. The axis Zt is a local coordinate system on the non-rotating root side (bucket pin side) of the tilt mechanism 25 and is a reference axis for the measurement of the relative tilt angle q9t perpendicular to the central axis direction Yt of the tilt axis 38 and the bucket pin attachment portion. The relative tilt angle q9t of the present embodiment is plus in the counterclockwise direction and minus in the clockwise direction, for example, as seen from the operator side or from the rear. The tilt angle sensor 60 is, for example, an acceleration sensor, such as an inertial measurement unit, and may be disposed at any position if the relative tilt angle q9t can be detected, but in the illustrated example is disposed, for example, on the second portion 32 side of the tilt mechanism 25, for example, within the second portion 32. By way of example but not limitation, the tilt angle sensor 60 may be a general rotational angle sensor, for example, or may detect the relative tilt angle q9t by detecting an amount of expansion or contraction of at least any of the tilt cylinders 33.
The swivel angle sensor 61 is a sensor that detects the swivel angle (rotate angle) q9r of the bucket 9. The swivel angle q9r is, as seeing from the stick 8 side in the swivel axis direction, is plus in the counterclockwise direction with a predetermined reference position, for example, the position where the back of the bucket 9 faces forward as the reference position, and is minus in the clockwise direction. The swivel angle sensor 61 is, for example, a swivel angle sensor (rotary encoder) and may be positioned at any position if the swivel angle q9r can be detected, but in the illustrated example is positioned, for example, on the second portion 32 side of the tilt mechanism 25, for example, within the second portion 32.
In addition, the sensor portion 52 shown in FIG. 5 is provided with a pressure sensor 63. The pressure sensor 63 detects the pressure corresponding to, for example, an operation of the operation device 51, i.e., an operation of the boom 7, the stick 8, the bucket 9, and swivel of the swivel body 3, etc., as shown in FIG. 1.
Then, the controller 50 shown in FIG. 5 comprises a machine guidance unit 65 that processes a signal input from the sensor unit 52 and calculates information for automatic control, and a machine control unit (machine control unit) 66 that generates and outputs a control signal based on the information calculated by the machine guidance unit 65.
The machine guidance unit 65 has a first residual calculation unit 68 and a second residual calculation unit 69. In addition, the machine guidance unit 65 may be equipped with a function to generate data for displaying various information used to support the work of the operator, on a display device such as a monitor provided inside the cab 6 (FIG. 1), in accordance with the calculation results of the first residual calculation unit 68 and/or the second residual calculation unit 69.
The first residual calculation unit 68 is a relative tilt angle residual calculation unit that calculates an angle deviation, or relative tilt angle residual, between the current angle of the blade edge of the bucket 9 and the angle of the work surface P in the tilt direction of the bucket 9 by the tilt mechanism 25, which is necessary to align the blade edge of the bucket 9 along the work surface P shown in FIG. 1.
In addition, the second residual calculation unit 69 shown in FIG. 5 is a relative bucket angle residual calculation unit that calculates an angular deviation, or residual, between the current angle of the blade edge of the bucket 9 and the angle of the work surface in the rotation direction of the bucket 9 by the bucket cylinder 21, which is necessary to align the blade edge of the bucket 9 along the work surface shown in FIG. 1.
Here, the following equation is generally established from the constraint conditions of the respective parts of the work machine 1 among the roll angle q3r of the machine body 4 detected by the sensor unit 52, the pitch angle q3p of the machine body 4, the relative boom angle q5, the relative stick angle q7, the relative bucket angle q8, the relative tilt angle q9t, the swivel angle q9r, and the angle q9w of the blade edge of the bucket 9. sin (q9w) = cos(q9r) * (cos(q9t) * sin(q3r) - in(q5 + q7 + q8 + q3p) * cos(q3r) * sin(q9t)) + cos(q5 + q7 + q8 + q3p) * cos(q3r) * sin(q9r)
Therefore, in the first residual calculation unit 68 shown in FIG. 5, by solving the above equation (A) for the relative tilt angle q9t, the current relative tilt angle q9t of the bucket 9 shown in FIG. 1, that is, the angle of the blade edge of the bucket 9 in the tilt direction of the bucket 9 by the tilt mechanism 25, is calculated, and similarly, assuming that the angle q9w of the blade edge of the bucket 9 is equal to a work surface angle q9wT and the relative tilt angle q9t is equal to a target relative tilt angle q9tT, by substituting these into the above equation (A) and solving the above equation (A) for the target relative tilt angle q9tT, the difference between the calculated relative tilt angle q9t and the target relative tilt angle q9tT is calculated as the relative tilt angle residual in the tilt direction of the bucket 9 by the tilt mechanism 25.
Similarly, in the second residual calculation unit 69 shown in FIG. 5, by solving the above formula (A) for the relative bucket angle q8, the current relative bucket angle q8 of the bucket 9 shown in FIG. 1, that is, the angle of the blade edge of the bucket 9 in the rotation direction of the bucket 9 by the bucket cylinder 21, is calculated, and similarly, assuming that the angle q9w of the blade edge of the bucket 9 is equal to a work surface angle q9wT and the relative bucket angle q8 is equal to a target relative bucket angle q8tT, by substituting these into the above formula (A) and solving the above formula (A) for the target relative bucket angle q8tT, the difference between the calculated relative bucket angle q8 and the target relative bucket angle q8tT is calculated as the relative bucket angle residual in the rotation direction of the bucket 9 by the bucket cylinder 21.
When calculating by the first residual calculation unit 68 and the second residual calculation unit 69 shown in FIG. 5, the specification values of the known work device 5 (FIG. 1) may be added in advance.
The calculation results by the first residual calculation unit 68 and the second residual calculation unit 69 are output to a first angle control unit 70 and a second angle control unit 71 included in the machine control unit 66.
The first angle control unit 70 generates a signal for controlling a control valve 73 for the tilt cylinder 33 (FIG. 2) of the tilt mechanism 25 in accordance with the relative tilt angle residual calculated by the first residual calculation unit 68.
The second angle control unit 71 generates a signal for controlling a control valve 74 for the bucket cylinder 21 (FIG. 2) in accordance with the relative bucket angle residual calculated by the second residual calculation unit 69.
Then, the signals output from the first angle control unit 70 and the second angle control unit 71 are input to a control value calculation unit 75. The control value calculation unit 75 calculates current values to be output to the control valve 73 and the control valve 74 in accordance with the signals generated by the first angle control unit 70 and the second angle control unit 71, and outputs the control signals to the control valves 73 and 74.
Further, in a case where the angular residual calculated by the first residual calculation unit 68 and/or the second residual calculation unit 69 is large, it is preferable to increase the flow rate of the main pump 45 to bring the angular residual close to 0 as soon as possible. Therefore, in the present embodiment, the machine control unit 66 generates and outputs a control signal of the regulator 47 for the main pump 45. For example, the control value calculation unit 75 calculates a current value to be output to the regulator 47 in accordance with the current values to be output to the control valve 73 and the control valve 74, and outputs the calculated current value to the regulator 47.
Then, the automatic control function of the controller 50 of the present embodiment basically operates only when the work machine 1 shown in FIGS. 1 and 2 is operated, for example, the swivel body 3 is rotated, or the boom 7 and/or the stick 8 of the work device 5 is operated, and does not operate while the work machine 1 is stopped.
In addition, when the bucket 9 is far away from the work surface P, for example, when the blade edge of the bucket 9 is at a position higher than a predetermined height set in advance from the work surface P, it is preferable that the controller 50 does not operate the automatic control function in consideration of the operability of the work device 5. The height here is, for example, a distance in a direction perpendicular to the work surface P. The preset height may be set by, for example, an operator through input means such as a touch panel monitor.
The above automatic control function may be arbitrarily switched by the operator as necessary. For example, in the present embodiment, an operation device 51 such as an operation lever disposed inside the cab 6 is provided with a switch 77, and the on/off of the automatic control function can be switched by the switch 77.
Next, the operation of the present embodiment will be described with reference to the flowchart illustrated in FIG. 8 too.
As illustrated in FIG. 1, when the blade edge of the bucket 9 is aligned with the work surface P, in the present embodiment, the switch 77 is turned on, so that the controller 50 automatically controls the position of the bucket 9 using the tilt mechanism 25 and/or the bucket cylinder 21, thereby supporting the work.
In step S1 of FIG. 8, the controller 50 determines whether or not the switch 77 is turned on. In step S1, when it is determined that the switch 77 is not ON (in the case of NO in step S1), the control is ended without performing the automatic control, and step S1 is repeated. Further, in a case where it is determined in step S1 that the switch 77 is ON (in a case of YES in step S1), in step S2, the controller 50 calculates the target relative tilt angle q9tT in the first residual calculation unit 68.
Subsequently, in step S3, the controller 50 determines whether or not the height of the blade edge of the bucket 9 is within a predetermined height with respect to the work surface P.
In step S3, when it is determined that the height of the blade edge of the bucket 9 is not within the predetermined height with respect to the work surface P (in the case of NO in step S3), the control is ended without performing the automatic control, and the process proceeds to step S1. Further, in a case where it is determined in step S3 that the height of the blade edge of the bucket 9 is within a predetermined height with respect to the work surface P (in a case of YES in step S3), in step S4, the controller 50 calculates the current relative tilt angle q9t in the first residual calculation unit 68 and determines whether or not the relative tilt angle q9t is equal to the target relative tilt angle q9tT, that is, whether or not the relative tilt angle residual is substantially zero.
In step S4, when it is determined that the relative tilt angle q9t is equal to the target relative tilt angle q9tT (in the case of YES in step S4), it is determined that the blade edge of the bucket 9 is in a state parallel to the work surface P, and the control is ended without performing the automatic control, and then the process proceeds to step S1.
Further, in a case where it is determined in step S4 that the relative tilt angle q9t is not equal to the target relative tilt angle q9tT (in a case of NO in step S4), in step S5, the controller 50 determines in the first residual calculation unit 68 whether the target relative tilt angle q9tT is within a tiltable angle range of the bucket 9 by the tilt mechanism 25.
In a case where it is determined in step S5 that the target relative tilt angle q9tT is within the tiltable angle range (in a case of YES in step S5), in step S6, the controller 50 determines whether or not at least one of the operation of the boom 7, the operation of the stick 8, and/or the operation of the swivel body 3 is performed based on the output of the pressure sensor 63 or the like.
In a case where it is determined in step S6 that the operation is not performed (in a case of NO in step S6), the work machine 1 is determined not to perform work, and the control is ended without performing the automatic control, and then the process proceeds to step S1. Further, in a case where it is determined in step S6 that the operation is being performed (in a case of YES in step S6), in step S7, the controller 50 causes the first angle control unit 70 to generate a signal for controlling the control valve 73 for the tilt cylinder 33 of the tilt mechanism 25 in accordance with the relative tilt angle residual calculated by the first residual calculation unit 68, calculates a current value to be output to the control valve 73 by the control value calculation unit 75 in accordance with the signal, generates and outputs the control signal, thereby automatically controlling the tilt angle by extending and contracting the tilt cylinder 33 until the current relative tilt angle q9t becomes the target relative tilt angle q9tT via the control valve 73 until the relative tilt angle q9t becomes the target relative tilt angle q9tT, that is, until the relative tilt angle residual becomes substantially 0, and automatically aligning the angle of the blade edge of the bucket 9 to be parallel or substantially parallel to the work surface P. At this time, the control value calculation unit 75 may simultaneously calculate a current value to be output to the regulator 47 in accordance with the control signal of the control valve 73, generate and output the control signal, thereby increasing the discharge flow rate of the hydraulic oil from the main pump 45 and increasing the expansion and contraction of the tilt cylinder 33. Thereafter, the process proceeds to step S1.
Further, when it is determined in step S5 that the target relative tilt angle q9tT is not within the tiltable angle range (in the case of NO in step S5), it is determined that the relative tilt angle residual cannot physically substantially be zero in the tilt angle control at the present time (the angle of the blade edge of the bucket 9 cannot be matched with the angle of the work surface P by the tilt mechanism 25), and the following shifts to the control of the rotation angle of the bucket 9, that is, the bucket angle.
In step S8, the controller 50 calculates the target relative bucket angle q8tT in the second residual calculation unit 69.
Subsequently, in step S9, the controller 50 calculates the current relative bucket angle q8 in the second residual calculation unit 69, and determines whether the relative bucket angle q8 is equal to the target relative bucket angle q8tT, that is, whether the relative bucket angle residual is 0.
When it is determined in step S9 that the relative bucket angle q8 is equal to the target relative bucket angle q8tT (in the case of YES in step S9), the blade edge of the bucket 9 is determined to be in a state parallel to the work surface P, and the control is ended without performing the automatic control, and the process proceeds to step S1.
Further, in a case where it is determined in step S9 that the relative bucket angle q8 is not equal to the target relative bucket angle q8tT (in a case of NO in step S9), in step S10, the controller 50 determines in the second residual calculation unit 69 whether the target relative bucket angle q8tT is within a rotatable angle range of the bucket 9 by the bucket cylinder 21.
In a case where it is determined in step S10 that the target relative bucket angle q8tT is within the rotation angle range (in a case of YES in step S10), in step S11, the controller 50 determines whether at least one of the operation of the boom 7, the operation of the stick 8, and/or the swivel operation of the swivel body 3 is performed based on the output of the pressure sensor 63 or the like.
In a case where it is determined in step S11 that the operation has not been performed (in a case of NO in step S11), the work machine 1 is determined not performing work, and the control is ended without performing the automatic control, and the process proceeds to step S1. Further, in a case where it is determined in step S11 that the operation is being performed (in a case of YES in step S11), in step S12, the controller 50 causes the second angle control unit 71 to generate a signal for controlling the control valve 74 for the bucket cylinder 21 in accordance with the relative tilt angle residual calculated by the second residual calculation unit 69, calculates a current value to be output to the control valve 74 by the control value calculation unit 75 in accordance with the signal, generates and outputs the control signal, thereby automatically controlling the rotation angle by extending and contracting the bucket cylinder 21 until the current relative bucket angle q8 becomes the target relative bucket angle q8tT until the relative bucket angle q8 becomes the target relative bucket angle q8tT, that is, until the relative bucket angle residual becomes substantially 0, via the control valve 74, and automatically aligning the angle of the blade edge of the bucket 9 to be parallel or substantially parallel to the work surface P. At this time, the control value calculation unit 75 may simultaneously calculate a current value to be output to the regulator 47 in accordance with the control signal of the control valve 74, generate and output the control signal, thereby increasing the discharge flow rate of the hydraulic oil from the main pump 45 and increasing the expansion and contraction of the bucket cylinder 21. Thereafter, the process proceeds to step S1.
Further, in a case where it is determined in step S10 that the target relative bucket angle q8tT is not within the rotatable angle range (in a case of NO in step S10), it is determined that the relative bucket angle residual cannot be physically made substantially zero (the angle of the blade edge of the bucket 9 cannot be matched with the angle of the work surface P by the bucket cylinder 21) at the present time in the bucket angle control, and in step S13, the controller 50 determines whether at least one of the operation of the boom 7, the operation of the stick 8, and/or the rotation operation of the swivel body 3 is performed based on the output of the pressure sensor 63 or the like.
In a case where it is determined in step S13 that the operation is not being performed (in a case of NO in step S13), it is determined that the work machine 1 is not performing work, and the control is ended without performing the automatic control, and the process proceeds to step S1. Further, in a case where it is determined in step S13 that the operation is being performed (in a case of YES in step S13), in step S14, the controller 50 changes the target relative tilt angle q9tT to a maximum (maximum in the plus direction) or minimum (maximum in the minus direction) relative tilt angle that can be tilted by the tilt mechanism 25, the first angle control unit 70 generates a signal for controlling the control valve 73 for the tilt cylinder 33 in accordance with the relative tilt angle residual calculated by the first residual calculation unit 68, and in accordance with the signal, the control value calculation unit 75 calculates a current value to be output to the control valve 73, and generates and outputs the control signal, whereby the controller 50 automatically controls the tilt angle by extending and contracting the tilt cylinder 33 until the current relative tilt angle q9t becomes the target relative tilt angle q9tT (= maximum or minimum relative tilt angle), via the control valve 73, and automatically tilts the bucket 9 until to reach an end of the tiltable angle range to make the angle of the blade edge close to the angle of the work surface P. That is, in the present embodiment, in a case where the angle of the blade edge of the bucket 9 cannot be made parallel or substantially parallel to the angle of the work surface P even by using either of the tilt mechanism 25 and the bucket cylinder 21, the angle of the blade edge of the bucket 9 is made as close as physically possible to the angle of the work surface P so that the angle of the blade edge of the bucket 9 is made parallel or substantially parallel to the angle of the work surface P by repeating the automatic control flow subsequently. At this time, the control value calculation unit 75 may simultaneously calculate a current value to be output to the regulator 47 in accordance with the control signal of the control valve 73, generate and output the control signal, thereby increasing the discharge flow rate of the hydraulic oil from the main pump 45 and increasing the expansion and contraction speed of the tilt cylinder 33. Thereafter, the process proceeds to step S1.
Note that, in the present embodiment, the calculation cycle in the controller 50 is, for example, 0.01 seconds. Therefore, when it is terminated without occurring the automatic control, the next automatic control flow is executed again after 0.01 seconds. Further, when the automatic control occurs, the next calculation cycle is started after a series of controls, that is, after the operation of the tilt cylinder 33 or the bucket cylinder 21 is completed (the cylinders 33 and 21 operate for 0.01 seconds or more until the control is completed).
As described above, in the work machine 1 including the tilt rotator 10, since the tilt axis 38 of the tilt mechanism 25 is independent of the swivel angle of the bucket 9 by the swivel mechanism 26 and maintains a direction crossing or orthogonal to the width direction of the arm 8, the tilt rotation of the bucket 9 by the tilt mechanism 25 basically obtains an inclination in the left-right direction and cannot obtain a rotation in the front-rear direction. Therefore, in the case where the blade edge of the bucket 9 extends in the front-rear direction, as in the case where the bucket 9 is rotated by the swivel mechanism 26 so as to be oriented directly laterally, for example, 90° or 270° (-90°), for example, when the blade edge of the bucket 9 is inclined in the front-rear direction with respect to the work surface P, it is difficult to align the blade edge of the bucket 9 along the work surface P only by the operation of the tilt mechanism 25.
Therefore, in the present embodiment, the controller 50 controls at least one of the tilt angle of the bucket 9 by the tilt mechanism 25 and the rotation angle of the bucket 9 by the bucket cylinder 21 so as to reduce the angle residual between the angle of the blade edge of the bucket 9 calculated based on the detection of the sensor unit 52 and the angle of the work surface P input in advance, thereby automatically moving the bucket 9 by at least one of the tilt mechanism 25 and the swivel mechanism 26 of the bucket 9, even if it is difficult to align the blade edge of the bucket 9 along the work surface P in the work machine 1 which may change the angle of the bucket 9 by the tilt mechanism 25 and the swivel mechanism 26 of the bucket 9, to make it possible to align the blade edge of the bucket 9 along the work surface P.
In the present embodiment, the controller 50 repeats selective control of the tilt angle of the bucket 9 by the tilt mechanism 25 and the rotation angle of the bucket 9 by the bucket cylinder 21 until the angle residual between the angle of the blade edge of the bucket 9 and the angle of the work surface P input in advance becomes substantially zero, so that the blade edge of the bucket 9 can be made to follow the work surface P with high precision by selective combination of the tilt operation by the tilt mechanism 25 and the rotation operation by the bucket cylinder 21 whose operation directions are different from each other.
In the illustrated example, when the target relative tilt angle calculated on the basis of the angle residual is not within the tiltable angle range of the bucket 9 by the tilt mechanism 25, the controller 50 determines whether or not the rotation angle of the bucket 9 by the bucket cylinder 21 can be controlled, whereby the tilt operation of the bucket 9 by the tilt mechanism 25 is controlled to be prioritized over the rotation operation of the bucket 9 by the bucket cylinder 21. Generally, when the operator causes the blade edge of the bucket 9 to follow the work surface, the tilt mechanism 25 is often first operated, so that the blade edge of the bucket 9 can be more efficiently aligned along the work surface P by prioritizing the tilt operation by the tilt mechanism 25.
In addition, when the target relative bucket angle calculated based on the angle residual is not within the rotatable angle range of the bucket 9 by the bucket cylinder 21, that is, when the angle residual is large and it is difficult to align the blade edge of the bucket 9 along the work surface P even when either of the tilt mechanism 25 and the bucket cylinder 21 is used, the controller 50 tilts the bucket 9 to the end of the tiltable angle range and makes the angle of the blade edge of the bucket 9 as close as possible to the angle of the work surface P by the tilt function of the tilt mechanism 25, thereby gradually bringing the angle of the blade edge of the bucket 9 to the angle of the work surface P by repeating the automatic control flow.
Further, when the tilt cylinder 33 or the bucket cylinder 21 of the tilt mechanism 25 is extended and contracted during the automatic control, the controller 50 increases the flow rate of the main pump 45, so that the angular residual can be quickly brought to 0 to make the blade edge of the bucket 9 along the construction surface P.
Then, by incorporating such a controller 50 or the work support device (work support program) into the working machine 1, it is possible to easily perform the work such as excavation and molding of the working surface (inclined surface) of the bucket 9 along the construction surface P, and it is possible to provide the work machine 1 which is convenient for the operator because of good workability.
Note that, in the above-described embodiment, the automatic control of the controller 50 prioritizes the tilt operation of the bucket 9 by the tilt mechanism 25, but the present invention is not limited thereto, and the rotation operation of the bucket 9 by the bucket cylinder 21 may be prioritized too.

Industrial Applicability

The present invention has industrial applicability for businesses engaged in manufacturing and sales of work machines such as hydraulic excavators and work support devices thereof.

Description of Reference Signs

1 work machine
4 machine body
5 work device
9 bucket
21 bucket cylinder as actuator
25 tilt mechanism
26 swivel mechanism
50 controller as control unit
52 sensor unit
P work surface

Claims

A work support device for automatically controlling a position of a bucket and applied to a work machine, the work machine including a machine body, a work device having a bucket, and an actuator for rotating the bucket, and a sensor unit for detecting a posture, a tilt mechanism for swingably supporting the bucket in a direction intersecting a rotation direction and a swivel mechanism for rotatably supporting the bucket with respect to the tilt mechanism being mountable on the work device,
wherein the work support device comprises a control unit configured to control at least one of a tilt angle of the bucket by the tilt mechanism and a rotation angle of the bucket by the actuator so as to reduce an angle residual between an angle of a blade edge of the bucket calculated based on detection of the sensor unit and an angle of a work surface input in advance.
The work support device according to claim 1, wherein the control unit repeats selective control of the tilt angle of the bucket by the tilt mechanism and the rotation angle of the bucket by the actuator until the angle residual between the angle of the blade edge of the bucket and the angle of the work surface input in advance becomes substantially zero.
The work support device according to claim 1, wherein the control unit determines whether or not the rotation angle of the bucket by the actuator is controllable when a target relative tilt angle calculated based on the angle residual is not within a tiltable angle range of the bucket by the tilt mechanism.
The work support device according to claim 3, wherein the control unit tilts the bucket by the tilt mechanism to an end of the tiltable angle range, when the target relative bucket angle calculated based on the angle residual is not within a rotatable angle range of the bucket by the actuator.
A work machine characterized by comprising:
a machine body,

a work device that includes a bucket and an actuator that rotates the bucket, and a tilt mechanism that supports the bucket so as to be swingable in a direction intersecting a rotation direction, and a swivel mechanism that supports the bucket so as to be rotatable with respect to the tilt mechanism being mountable on the work device;

a sensor unit for detecting a posture; and

the work support device according to any one of claims 1 to 4.