KR20220002641A - Working machine and method of controlling the working machine - Google Patents

Abstract

Suppresses the occurrence of slippage due to the turning of the revolving body. The working machine includes a traveling body, a revolving body mounted on the traveling body so as to be able to turn, and a controller for controlling the operation of the working machine. The controller determines the occurrence of slippage of the traveling body during the swinging operation of the swinging body during automatic operation of the working machine. If it is determined that slippage has occurred, the controller executes processing for reducing the rotational inertia force generated during the turning operation.

Description

Working machine and method of controlling the working machine

The present disclosure relates to a working machine and a method for controlling the working machine.

Regarding the excavator, Japanese Patent Laid-Open No. 2019-7173 (Patent Document 1) discloses that the excavation reaction force causes the excavation reaction force even though the operator does not operate the traveling body as an operation of the excavator not intended by the operator. This forward dragging operation is exemplified, and the rear dragging operation in which the shovel is dragged backward by a reaction force from the ground in the leveling operation is exemplified.

Japanese Laid-Open Patent Publication No. 2019-7173

In the above document, it is described that the operation of the excavator not intended by the operator is due to the operation of the attachment, that is, the boom, arm, and bucket, and that unintended operation can be suppressed by controlling the attachment. Specifically, it is described that the dragging operation of the excavator can be suppressed by correcting the operation of the boom cylinder, which is a hydraulic actuator for driving the boom.

In a shovel having a traveling body and a revolving body mounted on the traveling body so as to be able to turn, it is preferable from the viewpoint of work efficiency to suppress the occurrence of slippage of the traveling body when the revolving body turns with respect to the traveling body. However, there is no description from this point of view in the above document.

In the present disclosure, a working machine capable of suppressing the occurrence of slippage due to the turning of the revolving body, and a method for controlling the working machine are provided.

According to the present disclosure, there is provided a working machine including a traveling body, a swinging body mounted so as to be able to turn on the traveling body, and a controller for controlling the operation of the working machine. The controller determines the occurrence of slippage of the traveling body during the swinging operation of the swinging body during automatic operation of the working machine. If it is determined that slippage has occurred, the controller executes processing for reducing the rotational inertia force generated during the turning operation.

ADVANTAGE OF THE INVENTION According to this indication, generation|occurrence|production of slippage by the turning of a revolving body can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the hydraulic excavator based on embodiment.
It is a figure which shows the outline of the system structure of the hydraulic excavator based on embodiment.
It is a figure which shows the structure for controlling the turning of a revolving body.
Fig. 4 is a block diagram showing a partial electrical configuration of a hydraulic excavator based on the embodiment.
5 is a block diagram showing the functional configuration of the controller.
It is a schematic diagram which shows the turning operation|movement of the hydraulic excavator for the earth-draining to a dump truck.
It is a schematic diagram which shows the generation|occurrence|production situation of the sliding of the hydraulic excavator during turning deceleration.
It is a flowchart which shows the flow of processing in the case where slipping generate|occur|produced in the hydraulic excavator during turning deceleration.
[FIG. 9] It is a graph for demonstrating the 1st process of reducing the rotational inertia force which generate|occur|produces during turning deceleration.
It is a schematic diagram for demonstrating the 2nd process of reducing the rotational inertia force which generate|occur|produces during turning deceleration.
It is a schematic diagram for demonstrating the 3rd process of reducing the rotational inertia force which generate|occur|produces during turning deceleration.
12 is a schematic diagram of a system including a hydraulic excavator.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is described with reference to drawings. In the following description, the same code|symbol is attached|subjected to the same component. Their names and functions are also the same. Accordingly, detailed descriptions thereof will not be repeated.

1 is an external view of a hydraulic excavator 100 based on an embodiment. As shown in FIG. 1, as a working machine, in this example, the hydraulic excavator 100 is mainly taken as an example and demonstrated.

The hydraulic excavator 100 includes a main body 1 and a work machine 2 operated by hydraulic pressure. The main body 1 is provided with the revolving body 3 and the traveling body 5. As shown in FIG. The traveling body 5 includes a pair of crawler belts 5Cr and a traveling motor 5M. The traveling motor 5M is provided as a driving source of the traveling body 5 . The travel motor 5M is a hydraulic motor operated by hydraulic pressure.

During operation of the hydraulic excavator 100 , the traveling body 5 , more specifically, the crawler belt 5Cr, is in contact with the ground. The traveling body 5 can travel on the ground by rotation of the crawler belt 5Cr. In addition, the traveling body 5 may have a wheel (tire).

The revolving body 3 is arrange|positioned on the traveling body 5, and is supported by the traveling body 5 also. The revolving body 3 is mounted on the traveling body 5 so as to be able to pivot with respect to the traveling body 5 centering on the revolving shaft RX. The revolving body 3 has a cab 4 . An occupant (operator) of the hydraulic excavator 100 rides the cab 4 and controls the hydraulic excavator 100 . The cab 4 is provided with a driver's seat 4S on which the operator sits. The operator can operate the hydraulic excavator 100 in the cab 4 . In the cab 4 , the operator can operate the working machine 2 , and can operate the swing body 3 with respect to the traveling body 5 , and also a hydraulic excavator ( 100) driving operation is possible.

The revolving body 3 is equipped with the engine room 9 in which the engine is accommodated, and the counterweight provided in the rear part of the revolving body 3 . In the engine room 9 , an engine 31 , a hydraulic pump 33 , and the like, which will be described later, are arranged.

In the revolving body 3 , a handrail 19 is provided in front of the engine room 9 . An antenna 21 is provided on the handrail 19 . The antenna 21 is, for example, an antenna for GNSS (Global Navigation Satellite Systems). The antenna 21 has a first antenna 21B and a second antenna 21B provided on the revolving body 3 so as to be spaced apart from each other in the vehicle width direction.

The work machine 2 is mounted on the revolving body 3 , and is supported by the revolving body 3 . The work machine 2 has a boom 6 , an arm 7 , and a bucket 8 . The boom 6 is rotatably connected to the revolving body 3 . The arm 7 is rotatably connected to the boom 6 . The bucket 8 is rotatably connected to the arm 7 . The bucket 8 has a plurality of blades. The tip of the bucket 8 is referred to as a cutting edge 8a.

And the bucket 8 does not need to have a blade. The tip of the bucket 8 may be formed of a straight steel plate.

The base end of the boom 6 is connected to the revolving body 3 via a boom pin 13 . The proximal end of the arm 7 is connected to the distal end of the boom 6 via an arm pin 14 . The bucket 8 is connected to the distal end of the arm 7 via a bucket pin 15 .

In addition, in this embodiment, the positional relationship of each part of the hydraulic excavator 100 is demonstrated on the basis of the work machine 2 .

The boom 6 of the work machine 2 rotates with respect to the revolving body 3 around a boom pin 13 provided at the base end of the boom 6 . A specific portion of the boom 6 rotating with respect to the revolving body 3, for example, a locus on which the tip of the boom 6 moves is arc-shaped, and a plane including the arc is specified. When the hydraulic excavator 100 is viewed from a plane, the plane is expressed as a straight line. The extending direction of this straight line is the front-back direction of the main body 1 of the hydraulic excavator 100, or the front-back direction of the revolving body 3, and is also referred to only as a front-back direction below. The left-right direction (vehicle width direction) of the main body 1 of the hydraulic excavator 100 or the left-right direction of the revolving body 3 is a direction orthogonal to the front-rear direction in a planar view, and is hereinafter also referred to simply as a left-right direction. The up-down direction of the vehicle body or the up-down direction of the revolving body 3 is a direction orthogonal to a plane defined by the front-rear direction and the left-right direction, and is hereinafter also referred to simply as an up-down direction.

In the front-rear direction, the side on which the working machine 2 protrudes from the main body 1 of the hydraulic excavator 100 is the front direction, and the direction opposite to the front direction is the rear direction. When looking at the omnidirectional direction, the right and left sides of the left and right directions are the right and left directions, respectively. In the vertical direction, the side with the paper sheet is the lower side, and the empty side is the upper side.

The front-rear direction is the front-rear direction of the operator seated on the driver's seat 4S in the cab 4 . The direction facing the operator seated in the driver's seat 4S is a forward direction, and the rear direction of the operator seated in the driver's seat 4S is a rearward direction. The left-right direction is the left-right direction of the operator seated in the driver's seat 4S. When the operator seated in the driver's seat 4S is seated in front of the operator, the right and left sides are the right and left directions, respectively. The up-down direction is the up-down direction of the operator seated in the driver's seat 4S. The foot side of the operator seated in the driver's seat 4S is the lower side, and the upper side of the head is the upper side. .

The boom 6 is rotatable about the boom pin 13 . The arm 7 is rotatable about the female pin 14 . The bucket 8 is rotatable about a bucket pin 15 . Each of the arm 7 and the bucket 8 is a movable member movable toward the tip side of the boom 6 . The boom pin 13 , the female pin 14 , and the bucket pin 15 extend in the left-right direction.

The work machine 2 includes a boom cylinder 10 , an arm cylinder 11 , and a bucket cylinder 12 . The boom cylinder 10 drives the boom 6 . The arm cylinder 11 drives the arm 7 . Bucket cylinder 12 drives bucket 8 . Each of the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 is a hydraulic cylinder driven by hydraulic oil.

Bucket cylinder 12 is mounted on arm 7 . When the bucket cylinder 12 expands and contracts, the bucket 8 rotates with respect to the arm 7 . The work machine 2 is provided with a bucket link. The bucket link connects the bucket cylinder 12 and the bucket 8 .

The hydraulic excavator 100 is equipped with a controller 26 . The controller 26 controls the operation of the hydraulic excavator 100 . The details of the controller 26 will be described later.

Fig. 2 is a block diagram showing the system configuration of the hydraulic excavator 100 according to the embodiment. As shown in FIG. 2 , the hydraulic excavator 100 includes a controller (main controller) 26 , an engine 31 , a hydraulic pump 33 , a tank 35 , a main valve 40 and , and a turning motor 3M.

The system shown in FIG. 2 is comprised so that the hydraulic pump 33 is driven by the engine 31, and the hydraulic oil discharged from the hydraulic pump 33 is supplied to various hydraulic actuators through the main valve 40. By controlling the supply and discharge of hydraulic pressure to the hydraulic actuator, the operation of the working machine 2 , the turning of the revolving body 3 , and the traveling operation of the traveling body 5 are controlled. The hydraulic actuator includes a boom cylinder 10 , an arm cylinder 11 , a bucket cylinder 12 , a swing motor 3M, and a travel motor 5M shown in FIG. 1 . The turning motor 3M is provided as a drive source for turning the turning body 3 .

The engine 31 is, for example, a diesel engine. The engine controller 36 controls the operation of the engine 31 . By controlling the amount of fuel injected into the engine 31 by the engine controller 36 , the output of the engine 31 is controlled. The engine 31 has a drive shaft for connecting to the hydraulic pump 33 .

The hydraulic pump 33 supplies hydraulic oil used for driving the work machine 2 and turning the revolving body 3 . The hydraulic pump 33 is connected to a drive shaft of the engine 31 . When the rotational driving force of the engine 31 is transmitted to the hydraulic pump 33 , the hydraulic pump 33 is driven. The hydraulic pump 33 is a variable displacement hydraulic pump having a swash plate and changing the discharge capacity by changing the inclination angle of the swash plate.

The tank 35 is a tank that stores oil used by the hydraulic pump 33 . Oil stored in the tank 35 is sucked out from the tank 35 by driving the hydraulic pump 33 , and is supplied to the main valve 40 via the hydraulic oil flow passage 42 .

The main valve 40 is a spool type valve that changes the direction in which the hydraulic oil flows by moving a rod-shaped spool. The main valve 40 has each spool which adjusts the supply amount of each hydraulic oil of the boom cylinder 10, the arm cylinder 11, the bucket cylinder 12, and the swing motor 3M. When each spool moves in the axial direction, the supply amount of hydraulic oil to the hydraulic actuators, that is, the boom cylinder 10 , the arm cylinder 11 , the bucket cylinder 12 , and the swing motor 3M is adjusted. The hydraulic oil is oil supplied to the hydraulic actuator in order to operate the hydraulic actuator.

A part of the oil sent out from the hydraulic pump 33 branches off from the hydraulic oil flow path 42 and flows into the pilot flow path 50 . A part of the oil delivered from the hydraulic pump 33 is pressure-reduced by a self-pressure pressure reducing valve 52, and the pressure-reduced oil is used as the pilot oil. The pilot oil is oil supplied to the main valve 40 in order to operate the spool of the main valve 40 .

The pilot flow path 50 is provided with an EPC valve (electromagnetic proportional control valve) 54 . Each EPC valve 54 is provided for each spool which adjusts the supply amount of each hydraulic oil of the boom cylinder 10, the arm cylinder 11, the bucket cylinder 12, and the turning motor 3M. The EPC valve 54 adjusts the oil pressure (pilot oil pressure) of the pilot oil based on the control signal (EPC current) from the controller 26 . The EPC valve 54 is controlled based on a control signal from the controller 26 .

The EPC valve 54 adjusts the pilot oil pressure of the pilot oil supplied to each of a pair of pressure chambers of the main valve 40, and is supplied to the hydraulic actuator via the main valve 40 Adjust the supply amount of hydraulic oil. The flow direction and flow rate of hydraulic oil supplied to each hydraulic actuator are adjusted by the main valve 40, and supply of hydraulic oil to each hydraulic actuator is controlled, whereby the output of each hydraulic actuator is controlled. Thereby, the operation of the work machine 2 and the turning operation of the revolving body 3 are controlled.

3 : is a figure which shows the structure for controlling the turning of the revolving body 3 . The hydraulic oil flow path 42 through which the hydraulic oil used for turning of the revolving body 3 with respect to the traveling body 5 flows is a supply flow path 43 through which the hydraulic oil supplied to the revolving motor 3M flows, and the revolving motor 3M. ) has a discharge flow path 44 through which the hydraulic oil discharged from the flows flows. A hydraulic pump 33 and a meter in throttle 61 are provided in the supply flow passage 43 . A meter out throttle 62 is provided in the discharge flow path 44 . The meter out throttle 62 may change the opening area. By changing the opening area of the meter-out throttle 62 , the flow rate of the hydraulic oil flowing through the discharge flow path 44 can be controlled.

The main valve 40 shown in FIG. 3 has the turning spool 41 which adjusts the supply amount of the hydraulic oil to the turning motor 3M. A meter in throttle 61 and a meter out throttle 62 are included in the swing spool 41 .

A relief valve 66 is provided in a branch line branching from the discharge flow path 44 between the swing motor 3M and the meter-out throttle 62 . The input port of the relief valve 66 is connected to the discharge flow path 44, and the output port of the relief valve 66 is connected to the tank. When the pressure of the hydraulic oil flowing out from the turning motor 3M and flowing in the discharge passage 44 becomes equal to or higher than the relief pressure, the relief valve 66 is opened, and a part of the hydraulic oil in the discharge passage 44 is removed from the relief valve ( 66) and flows into the tank. Usually, the flow of the hydraulic oil in the flow path 42 for hydraulic oil is controlled so that the pressure of the hydraulic oil in the discharge flow path 44 may become smaller than a relief pressure.

The deceleration of the turning of the revolving body 3 , that is, the decrease amount of the turning speed per unit time is controlled using the meter-out throttle 62 . The EPC valve (FIG. 2) which received the control signal from the controller 26 adjusts the pilot oil pressure by adjusting the opening degree. The turning spool 41 moves in the axial direction according to the pilot hydraulic pressure. The meter-out throttle 62 changes the opening area according to the movement amount of the turning spool 41 .

By making the opening area of the meter-out throttle 62 small, the pressure of the hydraulic oil in the discharge flow path 44 on the meter-out side becomes high, and the braking force obtained becomes large. Thereby, the deceleration of the revolving body 3 becomes large, and the revolving body 3 decelerates rapidly in a short time. By enlarging the opening area of the meter-out throttle 62, the pressure of the hydraulic oil in the discharge flow path 44 on the meter-out side falls, and the braking force obtained becomes small. Thereby, the deceleration of the revolving body 3 becomes small, and the revolving body 3 decelerates slowly.

4 is a block diagram showing a partial electrical configuration of the hydraulic excavator 100 according to the embodiment. As shown in FIG. 4 , the controller 26 has a memory 261 . The memory 261 stores a program for controlling various operations of the hydraulic excavator 100 . The controller 26 executes various processes for controlling the operation of the hydraulic excavator 100 based on the program stored in the memory 261 . The memory 261 is a nonvolatile memory and is provided as an area for storing necessary data.

The antenna 21 outputs a signal according to the received radio wave (GNSS radio wave) to the global coordinate calculating unit 23 . The global coordinate calculating unit 23 detects the installation position of the antenna 21 in the global coordinate system. The global coordinate system is a three-dimensional coordinate system based on a reference position set in the work area. The reference position may be the position of the tip of a reference marker set in the work area.

An IMU (Inertial Measurement Unit) 24 is installed in the revolving body 3 . In this example, the IMU 24 is disposed under the cap 4 . In the revolving body 3 , a high rigidity frame is disposed under the cap 4 . The IMU 24 is disposed on the frame. In addition, the IMU 24 may be arrange|positioned at the side (right or left side) of the turning axis RX of the revolving body 3 . The IMU 24 measures the acceleration of the revolving body 3 in the front-rear direction, the left-right direction, and the up-down direction, and the angular velocity of the revolving body 3 around the front-back direction, the left-right direction, and the up-down direction.

The man machine interface unit 28 includes an input unit 281 and a display unit (monitor) 282 . The input unit 281 is operated by an operator. The input unit 281 has operation buttons arranged around the display unit 282 . The input unit 281 may have a touch panel. The command signal generated by the operation of the input unit 281 is output to the controller 26 . The display unit 282 displays basic information such as the remaining fuel amount and coolant temperature, and operation information of the hydraulic excavator 100 .

The controller 26 sends a control signal to the EPC valve 54 . The EPC valve 54 is controlled based on a control signal from the controller 26 . The EPC valve 54 adjusts the opening degree based on the control signal input from the controller 26 to adjust the pressure of the pilot oil supplied to each spool of the main valve 40 . By moving each spool in the axial direction according to the pilot oil pressure, the supply amount of hydraulic oil to the hydraulic actuators, that is, the boom cylinder 10 , the arm cylinder 11 , the bucket cylinder 12 , and the swing motor 3M is adjusted.

When the EPC valve 54 corresponding to the swing spool 41 adjusts the opening degree based on the control signal input from the controller 26, the pilot oil pressure supplied to the swing spool 41 is adjusted, and the swing spool 41 ) moves in the axial direction. According to the movement amount of the turning spool 41, the meter-out throttle 62 adjusts the opening area of the hydraulic oil flow path 42 (discharge flow path 44, FIG. 3), and the pressure of the hydraulic oil in the discharge flow path 44 is adjusted. to adjust

The controller 26 transmits a control signal to the relief valve 66 . The relief valve 66 is controlled based on a control signal from the controller 26 . The controller 26 outputs to the relief valve 66 a control signal instructing the set value of the relief pressure.

5 is a block diagram showing the functional configuration of the controller 26 . As shown in FIG. 5 , the controller 26 includes a swing body position acquisition unit 102 , a turning deceleration setting unit 104 , a target excavation amount setting unit 106 , and a working machine posture setting unit 108 at the time of turning. ) is provided.

The revolving object position acquisition unit 102 is based on the GNSS radio wave received by the antenna 21 , and the antenna 21 is based on the detection result of the installation position of the antenna 21 in the global coordinate system detected by the global coordinate calculation unit 23 . ) to acquire the coordinates for the reference position of the revolving body 3 on which it is mounted. Typically, the swing body position acquisition unit 102 acquires the coordinates of the swing axis RX. Moreover, the revolving body position acquisition part 102 acquires the turning angle of the revolving body 3 with respect to the ground from the measurement result of the angular velocity by the IMU24.

The turning deceleration setting unit 104 sets the deceleration of the turning of the turning body 3 , that is, the amount of decrease in the turning speed per unit time. The controller 26 generates a control signal corresponding to the turning deceleration set by the turning deceleration setting unit 104 , and outputs the control signal to the EPC valve 54 . The opening area of the meter-out throttle 62 is adjusted by adjusting the pilot oil pressure supplied to the turning spool 41 to move the turning spool 41 in the axial direction.

The target excavation amount setting unit 106 sets a target value of the excavation amount for excavating an excavation target such as earth and sand with the work machine 2 . The target value of this excavation amount is hereinafter referred to as a target excavation amount. The target excavation amount setting unit 106 sets a target excavation amount of the object to be excavated. The controller 26 generates a control signal corresponding to the target excavation amount set by the target excavation amount setting unit 106 , outputs the control signal to the EPC valve 54 , and sends the target excavation amount to the bucket 8 . The work machine 2 is controlled so that the excavated object of

The turning work machine posture setting unit 108 sets a relative position of the work machine 2 with respect to the turning body 3 when the turning body 3 is performing a turning operation. The controller 26 generates a control signal corresponding to the posture of the work machine 2 set by the work machine attitude setting unit 108 at the time of turning, and outputs the control signal to the EPC valve 54 , and outputs the control signal to the work machine at the time of turning. The work machine 2 is controlled so that (2) takes the set posture.

FIG. 6 : is a schematic diagram which shows the turning operation|movement of the hydraulic excavator 100 for the dumping of the dump truck 200. As shown in FIG. As shown by the curved arrow in FIG. 6(A), the revolving body 3 turns with respect to the traveling body 5 centering on the revolving axis RX (FIG. 1). As shown in FIG. 6(B) , the revolving body 3 stops revolving at a position where it faces the work machine 2 on a platform 202 of the dump truck 200 . At this position, the hydraulic excavator 100 dumps a load object such as earth and sand loaded in the bucket 8 onto the carrier 202 of the dump truck 200 . The load target such as earth and sand loaded on the bucket 8 is an example of the load carried by the work machine 2 in the embodiment.

7 : is a schematic diagram which shows the generation|occurrence|production situation of slippage of the hydraulic excavator 100 during turning deceleration. Fig. 7(A) shows the rotation of the revolving body 3 with the revolving shaft RX as the rotation center, similar to that of Fig. 6(A) . When the revolving speed of the revolving body 3 is reduced, a rotational inertia force due to the moment of inertia of the revolving revolving body 3 acts on the traveling body 5 . When this rotational inertia force is larger than the maximum static friction force of the crawler belt 5Cr with respect to the ground, sliding of the traveling body 5 with respect to the ground will generate|occur|produce. When the frictional resistance between the ground and the crawler belt 5Cr becomes small, such as when the ground with which the crawler belt 5Cr is contacting is wet with rain, slippage of the traveling body 5 becomes easy to generate|occur|produce.

A ground plane G indicated by a broken line in FIG. 7B indicates the ground surface on which the traveling body 5 is in contact with the rotation of the revolving body 3 . As indicated by the white arrow in Fig. 7B, when slippage of the traveling body 5 occurs, the crawler belt 5Cr moves in the turning direction of the revolving body 3, and the crawler belt 5Cr It deviates from the ground plane (G). When the sliding of the traveling body 5 with respect to the ground plane G occurs, the hydraulic excavator 100 as a whole moves with respect to the ground, and the relative position of the working machine 2 with respect to the dump truck 200 is shifted. .

If the displacement of the hydraulic excavator 100 due to the sliding of the working machine 2 from the carrier 202 of the dump truck 200 after the turning of the swing body 3 is large, the position of the dump truck 200 is displaced. There is a possibility that overload may occur due to the deviation. When the revolving body 3 is rotated in the reverse direction in order to prevent overload, the cycle time becomes long. In this way, due to the occurrence of slippage, the efficiency of the excavation loading operation is lowered.

The hydraulic excavator 100 of the embodiment slides such a traveling body 5 at the time of turning of the revolving body 3 during automatic operation in which loading is carried out automatically from the hydraulic excavator 100 to the dump truck 200. When a load generate|occur|produces, generation|occurrence|production of the slippage of the traveling body 5 when the revolving body 3 turns next is suppressed. 8 : is a flowchart which shows the flow of a process in the case where slipping generate|occur|produces in the hydraulic excavator 100 during turning deceleration.

As shown in FIG. 8, first, in step S1, excavation is performed. The controller 26 controls the operation of the work machine 2 and the revolving body 3 by transmitting a control signal to the EPC valve 54 . By moving the bucket 8 to an appropriate position for carrying out the excavation work and appropriately operating the work machine 2 at that position, an excavated object such as earth and sand is excavated by the bucket 8, and the The excavated object is loaded.

In step S2, the revolving body 3 is made to revolve. The controller 26 controls the operation of the work machine 2 and the revolving body 3 by transmitting a control signal to the EPC valve 54 . While maintaining the relative position of the work machine 2 with respect to the revolving body 3 with a load loaded in the bucket 8, or raising or lowering the work machine 2, the revolving body 3 with respect to the traveling body 5 ) is rotated by a predetermined angle. The angle at which the revolving body 3 turns is automatically set by the controller 26 based on the position at which the excavation work was performed and the position of the carrier 202 of the dump truck 200 .

In step S3, the position of the revolving body 3 after the revolving body 3 has stopped turning is acquired. The controller 26, specifically, the revolving object position acquisition unit 102 (FIG. 5) turns on the basis of the GNSS radio wave received by the antenna 21 and/or the measurement result of the angular velocity by the IMU 24 The position of the revolving body 3 after the sieve 3 stops turning is acquired.

In step S4, it is determined whether or not the traveling body 5 (crawler belt 5Cr) slides with respect to the ground. For example, an operation for driving the traveling body 5 is not performed, a signal for driving the traveling motor 5M (FIG. 1) to the EPC valve 54 is not transmitted, and thus the traveling motor 5M is not In the case where the position of the turning shaft RX is changed before and after turning in spite of being stopped, the controller 26 determines that the traveling body 5 is sliding with respect to the ground.

Alternatively, the turning angle of the revolving body 3 with respect to the traveling body 5 is detected by the turning angle sensor, the turning angle of the revolving body 3 with respect to the ground is detected by the IMU 24, and the detected turning angle is When the difference is equal to or greater than a predetermined threshold, the controller 26 determines that the traveling body 5 is sliding with respect to the ground. Alternatively, the turning target angle automatically set by the controller 26 based on the position at which the excavation work was performed and the position of the carrier 202 of the dump truck 200, and the turning angle of the turning body 3 with respect to the ground When the difference is equal to or greater than a predetermined threshold, the controller 26 determines that the traveling body 5 is sliding with respect to the ground.

The turning angle of the revolving body 3 with respect to the ground is detected by acquiring an image with a visual sensor mounted on the hydraulic excavator 100 and estimating the position and posture of the hydraulic excavator 100 by scan matching do. You may detect the turning angle of the turning object 3 with respect to the ground from the difference of the azimuth of GNSS before turning, and the azimuth of GNSS after turning.

When it is determined that the traveling body 5 is sliding with respect to the ground (YES in step S4), the flow advances to step S5 to determine whether or not the number of times determined as slippage occurrence is less than a threshold value. The controller 26 reads the threshold value of the number of times determined as slippage occurrence and the number of times determined as slippage occurrence before the judgment of the immediately preceding step S4, stored in the memory 261 . The controller 26 adds 1 to the number of times determined to be slipping before the determination in step S4 immediately before, compares the number after addition with a threshold value, and determines whether the number of times after addition is less than the threshold value .

When it is determined that the number of times after addition is less than the threshold value (YES in step S5), the flow advances to step S6, where the controller 26 next decreases the turning speed of the revolving body 3 with respect to the traveling body 5 A process for reducing the rotational inertia force generated during the operation is executed.

9 is a graph for explaining the first process for reducing the rotational inertia force generated during turning deceleration. 9, there is shown a graph showing the change of the turning speed with respect to time at the time of slippage occurrence and at the next time. The horizontal axis of the graph represents time, and the vertical axis of the graph represents the turning speed.

At the time of slippage occurrence, it is assumed that the turning speed ω is maintained from time 0 to time T1, deceleration is started at time T1, and it is decelerated to turning speed 0 at the time point of time T2. In this case, at the time of the next turn, if the turning speed ω is the same at the time 0, the time at which the deceleration starts to decelerate to the turning speed 0 at the same time T2 and turn the turning body 3 by the turning target angle , set to time T0 before time T1.

When it is determined that slippage has occurred, when the next swing speed is decreased, the timing of starting the swing deceleration is advanced, so that the amount of decrease in the swing speed per unit time is made smaller than when slippage occurs. By making the deceleration at the time of turning deceleration small, the rotational inertia force is reduced. By gently decelerating the revolving body 3, generation|occurrence|production of slip is suppressed. By making the rotational inertia force smaller than the maximum static friction force of the crawler belt 5Cr with respect to the ground, generation|occurrence|production of slipping can be prevented.

The reduction amount of the turning speed is controllable using the meter-out throttle 62 of the turning spool 41 in the main valve 40 shown in FIG. The pressure of the hydraulic oil in the discharge flow path 44 between the turning motor 3M and the meter out throttle 62 is controlled before the relief pressure of the relief valve 66 . When the pressure of the hydraulic oil in the discharge flow path 44 on the downstream side of the swing motor 3M is high, the resistance to rotation of the swing motor 3M increases, and it operates as a brake for stopping the rotation of the swing motor 3M.

By controlling the opening degree of the EPC valve 54 by the controller 26 , the pilot oil pressure supplied to the swing spool 41 is adjusted, and the opening area of the meter-out throttle 62 is changed. By controlling the meter out throttle 62 in the opening direction, the resistance to the flow of hydraulic oil passing through the meter out throttle 62 is lowered. In the discharge flow path 44 between the turning motor 3M and the meter-out throttle 62, the pressure of the hydraulic oil becomes low.

By lowering the pressure of the hydraulic oil in the discharge flow path 44 on the downstream side of the swing motor 3M, the brake force acting on the swing motor 3M becomes small, and the amount of decrease in the swing speed can be made small. Accordingly, by opening the meter-out throttle 62, it is possible to reduce the amount of decrease in the turning speed per unit time.

Alternatively, the amount of decrease in the turning speed can be controlled using the relief valve 66 shown in FIG. 3 . When the set value of the relief pressure of the relief valve 66 is set high, the deceleration of turning becomes large. When the set value of the relief pressure of the relief valve 66 is set low, the deceleration of turning becomes small. Then, when slippage of the traveling body 5 occurs, you may control so that the set value of the relief pressure when the turning speed of the revolving body 3 with respect to the traveling body 5 decreases next may be made low.

It is a schematic diagram for demonstrating the 2nd process of reducing the rotational inertia force which generate|occur|produces during turning deceleration. Fig. 10 shows a bucket 8 and a load carried by the bucket 8, typically an object to be excavated such as earth and sand loaded in the bucket 8 during an excavation operation.

It is assumed that the load of the loading amount P1 is loaded in the bucket 8 at the time of slippage occurrence, and the amount of the load conveyed by the work machine 2 was the loading amount P1. In this case, the target excavation amount setting unit 106 sets and changes the next target excavation quantity to an amount smaller than the current target excavation quantity. The amount of the load carried by the work machine 2 is set to a loading amount P2 smaller than the loading amount P1. By making the amount of the load carried by the work machine 2 small, the rotational inertia force when the turning speed decreases is reduced. Thereby, generation|occurrence|production of slippage is suppressed. By making the rotational inertia force smaller than the maximum static friction force of the crawler belt 5Cr with respect to the ground, generation|occurrence|production of slipping can be prevented.

11 : is a schematic diagram for demonstrating the 3rd process of reducing the rotational inertia force which generate|occur|produces during turning deceleration. 11, the schematic diagram of the hydraulic excavator 100 seen from the left is shown. The revolving body 3 is mounted on the traveling body 5 so as to be able to revolve around the revolving shaft RX. The work machine 2 is attached to the revolving body 3 so as to be movable relative to the revolving body 3 . The bucket 8 is loaded with dripping P.

Compared with the posture of the work machine 2 at the time of slippage occurrence, at the next turning, the work machine 2 approaches by the turning axis RX whose center is the turning of the revolving body 3 . A bucket for loading the load P from the turning shaft RX to the work machine 2, typically from the turning shaft RX, with the work machine 2 in the folded position when the revolving body 3 is turned. By making the distance to (8) small, the rotational inertia force when the turning speed decreases is reduced. Thereby, generation|occurrence|production of slippage is suppressed. By making the rotational inertia force smaller than the maximum static friction force of the crawler belt 5Cr with respect to the ground, generation|occurrence|production of slipping can be prevented.

In this way, when slippage of the traveling body 5 with respect to the ground (ground plane G, Fig. 7) occurs, the rotational inertia force generated when the turning speed of the revolving body 3 is reduced next is reduced By doing so, generation|occurrence|production of slippage by turning of the revolving body 3 can be suppressed. Then, the process ends ("end" in Fig. 8).

In the judgment of step S5 of Fig. 8, when it is judged that the number of times judged to be slippage is equal to or greater than the threshold value (NO in step S5), the process proceeds to step S7 and the automatic operation is stopped. The phenomenon in which slippage of the traveling body 5 occurs is repeated even at the time of the next turn after executing the process for reducing the rotational inertia force in step S6, and when the phenomenon reaches the threshold number of times, the controller 26 ) stops the automatic operation of the hydraulic excavator 100 . Automatic operation of the hydraulic excavator 100 is stopped in order to avoid problems that the target working efficiency is not obtained or the posture of the hydraulic excavator 100 becomes unstable due to the repeated occurrence of slippage. Then, the process ends ("end" in Fig. 8).

An integer of 1 or more is set as the threshold value of the number of times judged to be slipping. This threshold value may be previously stored in the memory 261 . The set value of the threshold value may be input to the controller 26 by the operator operating the input unit 281 of the man machine interface unit 28 ( FIG. 4 ).

In the determination of step S4, if it is determined that the traveling body 5 does not slide with respect to the ground (NO in step S4), the processing for reducing the rotational inertia force is not performed, and the processing for stopping the automatic operation is also performed. Without it, the process ends as it is (“End” in Fig. 8).

When the processing for reducing the rotational inertia force is executed in step S6 and when the processing for stopping the automatic operation is executed in step S7, the controller 26 may notify the operator that this processing has been executed. In addition, you may notify an operator that slippage generate|occur|produced at the time of turning of the revolving body 3, and may promote the movement to a slippery work place to an operator. This notification may be performed by displaying a notification indication on the display unit 282 (FIG. 4), may be performed using another device that visually notifies an operator, such as a lamp, or a buzzer or a voice to an operator such as a speaker You may use a device that notifies you with

In the description of step S7 above, an example has been described in which the number of times determined as slippage is used in determining whether or not to stop the automatic operation. Changing this example, if the threshold value of the amount of sliding is exceeded, the control may be controlled so as to stop the automatic operation. When the amount of sliding is large, there is a possibility that the vehicle body becomes unstable due to occurrence of one slip. By controlling the amount of slippage in determining whether or not to stop the automatic operation, it is possible to more reliably avoid a phenomenon in which the vehicle body becomes unstable.

In the description of the embodiments so far, the hydraulic excavator 100 includes the controller 26 and the controller 26 mounted on the hydraulic excavator 100 automatically controls the operation of the work machine 2 . explained about it. The controller for controlling the operation of the work machine 2 does not necessarily need to be mounted on the hydraulic excavator 100 .

12 is a schematic diagram of a system including a hydraulic excavator 100 . An external controller 260 installed separately from the controller 26 mounted on the hydraulic excavator 100 may constitute a system for controlling the operation of the work machine 2 .

The controller 260 may be disposed at the work site of the hydraulic excavator 100 , or may be disposed at a remote location away from the work site of the hydraulic excavator 100 .

In embodiment, when slippage generate|occur|produced, the control which suppressed generation|occurrence|production of slippage at the time of reduction of the next turning speed was demonstrated. The control for reducing the deceleration during turning deceleration described with reference to FIG. 9 and the control for bringing the work machine 2 close to the turning shaft with reference to FIG. 11 can be controlled without being limited to the next turning deceleration. For example, if slipping is detected during automatic turning, the work machine 2 is brought closer to the turning shaft RX immediately after slipping is detected, or the amount of decrease in the turning speed per unit time is reduced immediately after slipping is detected. , the rotational inertia force may be reduced.

In the embodiment, the slip countermeasure at the time of the turning deceleration of the revolving body 3 was demonstrated. The control to reduce the load carried by the bucket 8 described with reference to FIG. 10 and the control to bring the work machine 2 closer to the turning axis RX described with reference to FIG. 11 are performed when the turning body 3 is accelerated. It is equally effective as a countermeasure in the case where slippage of the traveling body 5 occurs in the Accordingly, when slippage of the traveling body 5 occurs when the swing speed of the swing body 3 fluctuates, the occurrence of slippage can be suppressed by executing a process for reducing the rotational inertia force.

In the embodiment, the slip countermeasure at the time of the fluctuation|variation in the turning speed of the revolving body 3 was demonstrated. The control to reduce the load carried by the bucket 8 described with reference to FIG. 10 and the control to bring the work machine 2 closer to the turning shaft RX described with reference to FIG. 11 are performed such that the turning body 3 has a constant turning speed. It is similarly effective as a countermeasure in case slippage of the traveling body 5 occurs when turning with Accordingly, when slippage of the traveling body 5 occurs during the swing operation of the swing body 3, the occurrence of slippage can be suppressed by executing a process for reducing the rotational inertia force.

In the embodiment, the hydraulic excavator 100 has been described as an example of the working machine. However, the working machine to which the idea of the present disclosure can be applied is a mechanical super-large rope shovel that is not driven by hydraulic pressure, and an electric excavator driven by an electric motor. etc. may be

The disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

1: main body, 2: implement, 3: slewing body, 3M: slewing motor, 5: traveling body, 5Cr: crawler belt, 5M: traveling motor, 6: boom, 7: arm, 8: bucket, 8a: blade tip, 9 : engine room, 10: boom cylinder, 11: female cylinder, 12: bucket cylinder, 21: antenna, 21A: first antenna, 21B: second antenna, 23: global coordinate calculator, 24: IMU, 26, 260: controller , 28: man machine interface part, 31: engine, 33: hydraulic pump, 35: tank, 36: engine controller, 40: main valve, 41: slewing spool, 42: flow path for hydraulic oil, 43: supply flow path, 44: discharge Flow path, 50: pilot flow path, 52: self-pressure reducing valve, 54: EPC valve, 61: meter in throttle, 62: meter out throttle, 66: relief valve, 100: hydraulic excavator, 102: swivel body position acquisition part, 104 : turning deceleration setting unit, 106: target excavation amount setting unit, 108: working machine posture setting unit during turning, 200: dump truck, 202: load carrier, 261: memory, 281: input unit, 282: display unit, G: ground plane, P: load, P1, P2: payload, RX: pivot.

Claims (6)

running body;
a revolving body rotatably mounted on the traveling body; and
a controller for controlling the operation of the working machine; and
The controller determines, during automatic operation of the working machine, the occurrence of slippage of the traveling body during the swinging operation of the swinging body, and when it is determined that slippage has occurred, the rotational inertia force generated during the swinging operation to carry out a process to reduce,
working machine. The method of claim 1,
and the controller executes a process for reducing the rotational inertia force by reducing an amount of change in the rotational speed per unit time when the swinging speed at which the swinging body swings with respect to the traveling body varies. 3. The method of claim 1 or 2,
Further comprising a work machine mounted on the revolving body,
and the controller executes a process for reducing the rotational inertia force by bringing the work machine closer to a center of rotation of the revolving body. 4. The method according to any one of claims 1 to 3,
Further comprising a work machine mounted on the revolving body,
The work machine has a bucket for excavating an excavation object,
The controller has a target excavation quantity setting unit for setting a target excavation quantity of the excavation object, and when it is determined that slippage of the traveling body has occurred, the next target excavation quantity is set to be higher than the current target excavation quantity. A working machine that executes a process for reducing the rotational inertia force in the next time by changing the setting in a small amount. 5. The method according to any one of claims 1 to 4,
and the controller stops the automatic operation of the working machine when it is determined that slippage of the traveling body has occurred after executing the process for reducing the rotational inertia force. The working machine includes a traveling body and a revolving body mounted rotatably on the traveling body,
determining, during automatic operation of the working machine, the occurrence of slippage of the traveling body during the swinging operation of the swinging body; and
executing a process for reducing a rotational inertia force generated during a turning operation if it is determined in the determining step that slippage has occurred;
A method of controlling a working machine, comprising:

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