Patent Application
20230122177
The present invention relates to a working machine such as a hydraulic excavator.
In recent years, there has been known a hydraulic excavator having a function of calculating a total weight of an excavated object loaded into a box bed, and notifying an operator whether the total weight reaches a maximum loading capacity of a dump truck or not in order to improve the efficiency in a loading work of loading the excavated object into the box bed of the dump truck.
For example, in Patent Literature 1, it is disclosed that an operation of discharging an excavated object from a bucket into a box bed is determined to be started when a relative angle between an arm for discharging the excavated object from the bucket and the bucket reaches or exceeds a threshold; a weight of the excavated object accommodated in the arm is measured at the time; and the measured weight is added.
A hydraulic excavator is capable of discharging an excavated object from a bucket into a box bed of a dump truck not only by swinging the bucket to an arm, but also by an arm pushing operation of forwardly swinging the arm to a boom while maintaining a relative angle between the boom and the bucket. However, in Patent Literature 1, the start in the discharge operation is determined based on the fact that relative angle between the arm and the bucket reaches or exceeds a threshold as described above. This causes a problem of failing to detect a discharge of an excavated object when the excavated object is discharged by the above-described arm pushing operation.
Patent Literature 1: Japanese Unexamined Patent Publication No. 2019-158774
The present invention has been made in order to solve the problem described above, and the object thereof is to provide a working machine that makes it possible to accurately detect a discharge of an object accommodated in a bucket from the bucket.
A working machine according to an aspect of the present invention is provided with a main body and a working device attached to the main body. The working device includes: a working arm having a distal end movable in vertical directions and front-rear directions; and a bucket rotatably attached to the distal end and defining a space for accommodating an object and an opening face letting the space open. The working machine includes: a load detection part for detecting a load value of the object accommodated in the bucket; a posture detector for detecting a posture of the working device; an angle detection part for detecting a bucket angle that is an angle of the opening face of the bucket with respect to a vertical direction orthogonal to a horizontal plane on the basis of detection data indicating the posture of the working device detected by the posture detector; an accommodation determination part for determining whether the object is accommodated in the bucket or not on the basis of the load value detected by the load detection part; and a discharge determination part for determining that the object accommodated in the bucket is discharged when the bucket angle detected by the angle detection part is on a discharge side beyond a predetermined discharge reference angle, and the load value detected by the load detection part is smaller than a load threshold, after the accommodation determination part determines that the object is accommodated in the bucket. In the working machine, the discharge reference angle is an angle of the bucket in a posture allowing the accommodated object to be discharged.
According to the present configuration, a discharge of an accommodated object from a bucket can be accurately detected.
Hereinafter, an embodiment of the present invention will be described with reference to the accompanied drawings. It should be noted that the below-described embodiment is a specific example of the present invention, and will not delimit the technical scope of the present invention.
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
As shown in
The lower travelling body 11 and the upper slewing body 12 constitute a main body of the hydraulic excavator 10. The lower travelling body 11 has an unillustrated travelling device for causing the hydraulic excavator 10 to travel, and thus is capable of travelling on the ground G. The upper slewing body 12 has a slewing frame 12A, an engine room 12B mounted thereon, and a cab 12C. The engine room 12B accommodates an engine, and the cab 12C is provided with a seat where an operator sits on, various kinds of operation levers and control pedals.
The working device 13 includes a boom 14, an arm 15, and a bucket 16, and performs a loading work of loading soil and sand on a dump truck. The soil and sand are an example of an object to be accommodated in the bucket 16. The boom 14 and the arm 15 are examples of the working arm having a distal end movable in vertical directions and front-rear directions. The bucket 16 is rotatably attached to the distal end, and defines a space for accommodating an object and an opening face 16a letting the space open. The vertical directions are, for example, directions orthogonal to the ground G. The front-rear directions are, for example, directions orthogonal to both a longitudinal direction 15a of the arm 15 and the directions orthogonal to the ground G.
The loading work includes an accommodation task (excavation task) of excavating soil and sand and accommodating in the bucket 16, a transfer task of transferring the accommodated soil and sand above the dump truck, and a discharge task (soil discharge task) of discharging the soil and sand onto the dump truck.
The boom 14 includes a proximal end supported by a front portion of a slewing frame 12A to be tiltable, i.e., rotatable about a horizontal axis as indicated by an arrow A1 in
The hydraulic actuators include a plurality of hydraulic cylinders and a slewing motor 20. The hydraulic cylinders include at least one boom cylinder 17 for moving the boom 14, an arm cylinder 18 for moving the arm 15, and a bucket cylinder 19 for moving the bucket 16. Although
The at least one boom cylinder 17 is provided between the upper slewing body 12 and the boom 14, and extends or retracts upon supply of hydraulic oil discharged from the hydraulic pump 21 to thereby swing the boom 14 in a rising direction +A1 or a lowering direction −A1.
The arm cylinder 18 is provided between the boom 14 and the arm 15, and extends or retracts upon supply of hydraulic oil to thereby swing the arm 15 in an arm pulling direction −A2 or an arm pushing direction +A2. The arm pulling direction is a direction in which the distal end of the arm 15 moves closer to the boom 14, whereas the arm pushing direction is a direction in which the distal end of the arm 15 moves away from the boom 14.
The bucket cylinder 19 is provided between the arm 15 and the bucket 16, and extends or retracts upon supply of hydraulic oil to thereby swing the bucket 16 in a dumping direction +A3 or a crowding direction −A3. The crowding direction is a direction in which an angle θ between the longitudinal direction 15a of the arm 15 and the opening face 16a of the bucket 16 shown in
As shown in
As the control valve 40, there are provided a boom control valve 41, an arm control valve 42, a bucket control valve 43, a slewing control valve 44, a pair of boom proportional solenoid valves 45, a pair of arm proportional solenoid valves 46, a pair of bucket proportional solenoid valves 47, and a pair of slewing proportional solenoid valves 48.
For example, when the operation lever 63A of the bucket operation device 63 is operated, the operation amount of the operation lever 63A is converted into an electric signal (operation signal), and is input to the controller 50. The controller 50 inputs an instruction signal (instruction current) corresponding to the operation signal to the bucket proportional solenoid valve 47 of the pair that corresponds to the operation direction of the operation lever 63A. The bucket proportional solenoid valve 47 reduces the pressure of pilot oil discharged from the pilot pump 22 in response to an instruction signal, and transmits the reduced pilot pressure to one of a pair of pilot ports of the bucket control valve 43. Accordingly, the bucket control valve 43 opens in a direction corresponding to the pilot port which receives the pilot pressure and in a stroke corresponding to a magnitude of the pilot pressure. This consequently allows the hydraulic oil discharged from the hydraulic pump 21 to flow to a head-side chamber or a rod-side chamber of the bucket cylinder 19 at a flow rate corresponding to the stroke. Description about operation of the respective operation levers of the boom operation device 61, the arm operation device 62, and the slewing operation device 64 is omitted because they are operated in the same manner as that described above.
Although a diagram of the hydraulic circuit in the case that each operation device is hydraulic is omitted, the hydraulic circuit of the hydraulic excavator 10 performs as described below. For example, when the operation lever 63A of the bucket operation device 63 is operated, the primary pilot pressure from the pilot pump is reduced in a remotely-controlled valve of the bucket operation device 63 according to the operation amount of the operation lever 63A, and the reduced pilot pressure is output from the remotely-controlled valve. The output pilot pressure is input to one of the pair of pilot ports of the bucket control valve. Accordingly, the bucket control valve opens in a direction corresponding to the pilot port which receives the pilot pressure and in a stroke corresponding to a magnitude of the pilot pressure. This consequently allows the hydraulic oil discharged from the hydraulic pump to flow to the head-side chamber or the rod-side chamber of the bucket cylinder 19 at a flow rate corresponding to the stroke.
As shown in
The posture sensor 30 includes a boom posture sensor 31 capable of detecting a posture of the boom 14, an arm posture sensor 32 capable of detecting a posture of the arm 15, and a bucket posture sensor 33 capable of detecting a posture of the bucket 16. For example, the boom posture sensor 31 includes an angle sensor for detecting a boom angle which is a swing angle of the boom 14 with respect to the upper slewing body 12. For example, the arm posture sensor 32 includes an angle sensor for detecting an arm angle which is a swing angle of the arm 15 with respect to the boom 14. For example, the bucket posture sensor 33 includes an angle sensor for detecting a bucket angle which is a swing angle of the arm 15 with respect to the bucket 16. The boom angle, the arm angle, and the bucket angle are respectively detected in a predetermined sampling cycle, and are input to the controller 50 as detection data. The posture sensor 30 may include, for example, an Inertial Measurement Unit: IMU.
The controller 50 includes, for example, a computer. The controller 50 includes an operation determination part 51, an angle detection part 52, a load detection part 53, an accommodation determination part 54, a discharge determination part 55, a temporary storage part 56, a cumulative load value calculation part 57, a display control part 58, and memory 59. The operation determination part 51 to the display control part 58 may be embodied through an execution of a predetermined program by a CPU of the controller 50, or may include a dedicated electric circuit. The memory 59 includes a rewritable non-volatile storage device, e.g., Flash Memory.
For example, the operation device 6 includes an electric operation device shown in
The operation to be determined by the operation determination part 51 includes, for example, an operation of scooping up an object accommodated in the bucket 16 as a result of an excavation by the hydraulic excavator 10, a boom raising operation, a boom lowering operation, an arm pushing operation, a boom pulling operation, a bucket raising operation, and a bucket lowering operation.
The operation device 60 may include a hydraulic operation device. In this case, the operation determination part 51 may determine the input operation on the basis of a pilot pressure corresponding to the operation amount. Further, the operation determination part 51 may determine the input operation on the basis of the detection data detected by the posture sensor 30.
The angle detection part 52 detects a bucket angle being an angle of the opening face of the bucket 16 with respect to a vertical direction orthogonal to a horizontal plane on the basis of detection data indicating the posture of the working device 13 detected by the posture sensor 30.
For example, when the ground G (see
On the other hand, when the ground G is not parallel to the horizontal plane SA, i.e., the hydraulic excavator 10 is located on a slope, the angle detection part 52 sets the horizontal plane SA on the basis of an inclination angle of the hydraulic excavator 10 detected by an inclination sensor 80, and sets a direction orthogonal to the horizontal plane SA as the vertical direction L1. Thereafter, the proximal end T2 and the distal end T1 may be calculated in the manner described above, and an angle formed between a line connecting the proximal end 12 with the distal end T1 and the vertical direction L1 may be calculated as the bucket angle α. Accordingly, the bucket angle α can be accurately calculated even when the hydraulic excavator 10 works on a slope by calculating the bucket angle α in consideration of an inclination angle detected by the inclination sensor 80.
The discharge reference angle η refers to an angle indicating that the bucket 16 is in a posture allowing the accommodated object to be discharged. When the bucket angle α is on the discharge side D1 beyond the discharge reference angle η, the bucket 16 can discharge the accommodated object by the force of gravity.
For example, when the bucket 16 is swung toward the discharge side D1, dry and fine soil and sand start being discharged before the opening face 16a turns to be parallel to the vertical direction. Accordingly, in the present embodiment, the discharge reference angle η is set to a predetermined angle on the non-discharge side D2 with respect to the vertical direction L1. The discharge reference angle η includes, for example, angles such as −10 degrees and −20 degrees.
In the present embodiment, the angle detection part 52 repeatedly calculates a bucket angle α of the accommodated object in a predetermined sampling cycle while the hydraulic excavator 10 is in operation.
The load detection part 53 detects a load value of an object accommodated in the bucket 16. For example, the load detection part 53 calculates the load value of the accommodated object in a manner described below.
In the present embodiment, the load detection part 53 calculates a load of an object accommodated in the bucket 16 by using the following Equation (1).
M=M1+M2+M3+W×L (1)
In Equation (1), the sign “M” denotes a moment of the boom cylinder 17 around a boom foot pin. The sign “M1” denotes a moment of the boom 14 around the boom foot pin. The sign “M2” denotes a moment of the arm 15 around the boom foot pin. The sign “M3” denotes a moment of the bucket 16 around the boom foot pin. The sign “W” denotes a load of an object accommodated in the bucket 16. The sign “L” denotes a horizontal distance from the boom foot pin to the proximal end T2 of the bucket 16.
The moment M is calculated on the basis of the head pressure and the rod pressure of the boom cylinder 17. The moment M1 is calculated by a product of a distance from a gravity center of the boom 14 to the boom foot pin and a weight of the boom 14. The moment M2 is calculated by a product of a distance from a gravity center of the arm 15 to the boom foot pin and a weight of the arm 15. The moment M3 is calculated by a product of a distance from a gravity center of the bucket 16 to the boom foot pin and a weight of the bucket 16.
A position of the gravity center of the boom 14, a position of the gravity center of the arm 15, and a position of the gravity center of the bucket 16 are respectively calculated on the basis of detection data detected by the posture sensor 30. The head pressure of the boom cylinder 17 is detected by the pressure sensor 35, and the rod pressure of the boom cylinder 17 is detected by the pressure sensor 36. The distance L is calculated on the basis of the detection data of the posture sensor 30.
In the present embodiment, the load detection part 53 repeatedly calculates a load value of the accommodated object in a predetermined sampling cycle while the hydraulic excavator 10 is in operation.
The load value of the accommodated object may be calculated not exclusively according to the way described above but also by using other ways. For example, the load detection part 53 may calculate a volume of the accommodated object on the basis of image data of an opening portion of the bucket 16 taken by a camera or a depth sensor, and calculate the load value on the basis of the calculation result.
The accommodation determination part 54 determines whether the object is accommodated in the bucket 16 or not on the basis of the load value detected by the load detection part 53. In the present embodiment, the accommodation determination part 54 determines that an object is accommodated in the bucket 16, when load values repeatedly calculated by the load detection part 53 fluctuate not larger than a predetermined value and then stabilizes, and a load value detected by the load detection part 53 at this time is equal to or greater than a load threshold. The load threshold is a predetermined value indicating that the bucket 16 is emptied. The load threshold is set to 100 kg, 200 kg, for example. The setting of the load threshold to such a great value as 100 kg and 200 kg involves consideration of a calculation tolerance for a load value calculated by Equation (1).
During the accommodation task, the load value considerably fluctuates because the bucket 16 comes into contact with the ground G, and the amount of the accommodated object changes. On the other hand, when the accommodation task ends, the load value stabilizes because the bucket 16 is away from the ground G, and the amount of the object accommodated in the bucket 16 is invariable. Accordingly, the accommodation determination part 54 determines that the object is accommodated in the bucket 16 when the load value is not smaller than the load threshold and stabilizes.
The discharge determination part 55 determines that the object accommodated in the bucket 16 is discharged, when the bucket angle α detected by the angle detection part 52 is on the discharge side D1 beyond the discharge reference angle η, and the load value detected by the load detection part 53 is smaller than the load threshold after the accommodation determination part 54 determines that the object is accommodated in the bucket 16.
Reference is made to
In the state S200, the bucket angle α is further on the discharge side D1 with respect to the vertical direction L1, and the opening face 16a faces the horizontal plane SA. Thus, a larger amount of accommodated object is discharged compared with the state S100. When all the accommodated object is discharged in this manner, the discharge task ends.
After the accommodation determination part 54 determines that the object is accommodated in the bucket 16, further, the discharge determination part 55 determines that the dropping task of discharging a part of the object accommodated in the bucket 16 is performed when the bucket angle α shifts to the non-discharge side D2 beyond the discharge reference angle η after shifting to the discharge side D1 beyond the discharge reference angle η, and the load value detected by the load detection part 53 is equal to or greater than the load threshold.
In the state S400, the bucket 16 is swung to the non-discharge side D2, so that the bucket angle α is on the non-discharge side D2 beyond the discharge reference angle η. Consequently, the bucket 16 is in a non-dischargeable posture, and the discharge task ends with a certain amount of object remaining in the bucket 16. If the amount of the object accommodated in the bucket 16 still exceeds the target amount after the execution of the operation of the state S300 and the operation of the state S400, the operations of the state S300 and the state S400 are repeated. The dropping task is performed in this way until the amount of the object accommodated in the bucket 16 decreases to the target amount. After the dropping task ends, the transfer task is performed to move the bucket 16 above the box bed of the dump truck, and then the discharge task is performed to discharge the accommodated object onto the box bed. In this way, the series of tasks are repeatedly performed to load the object onto the box bed.
Reference is made again to
The cumulative load value calculation part 57 calculates a cumulative load value of the object by adding the load value temporarily stored in the memory 59 when the discharge determination part 55 determines that the object accommodated in the bucket 16 is discharged. The cumulative load value is stored in the memory 59. Further, in a case that a target amount for the cumulative load value is preset, the cumulative load value calculation part 57 calculates a difference between the target amount and the calculated cumulative load value.
The display control part 58 causes a display device 70 to display a variety of information. For example, the display control part 58 causes the display device 70 to display a display screen G1 shown in
The memory 59 stores the load value of the object temporarily stored in the temporary storage part 56. The memory 59 stores the cumulative load value calculated by the cumulative load value calculation part 57 and the target value thereof.
The inclination sensor 80 detects an inclination angle of the hydraulic excavator 10 with respect to the horizontal plane SA. The inclination angle is an angle of the ground G (slope) on which the hydraulic excavator 10 is with respect to the horizontal plane SA, for example.
In a hydraulic excavator 10 supposed to mainly work over flat land, the inclination sensor 80 may be omitted. In this case, the angle detection part 52 may calculate a bucket angle α in the assumption that the ground G is the horizontal plane SA.
The display device 70 includes, for example, a display device such as a liquid crystal panel or an organic EL panel. The display device 70 is disposed at a position which enables an operator in the cab 12C of the hydraulic excavator 10 to see it.
The distal end load indication field 501 indicates a load value, detected by the load detection part 53, of an object currently accommodated by the bucket 16. Here, a load value of 0.0 t is indicated. The carry load indication field 502 indicates a cumulative load value calculated by the cumulative load value calculation part 57. Here, a cumulative load value of 0.0 t is indicated due to the fact that the loading onto the dump truck is not started. The target load indication field 503 indicates a target value of the cumulative load value of an object to be loaded onto the box bed of the dump truck. The target value is a value preliminarily input by the operator. The loading work number indication field 504 indicates the number of discharge tasks of discharging the object onto the box bed of the dump truck. Here, the discharge task is not performed. Thus, the fraction 0/4 is indicated. The denominator of the fraction 0/4 denotes the number of discharge tasks that is required to be performed so that the cumulative load value reaches the target value thereof. The number of tasks is calculated, for example, by dividing the target value of the cumulative load value by a load value of soil and sand corresponding to the capacity of the bucket 16.
The display device 70 may be a display device such as a personal computer and a mobile information terminal that are disposed at a place apart from the hydraulic excavator 10.
Next, a process in the hydraulic excavator 10 will be described.
In Step S1, the accommodation determination part 54 determines whether a load value detected by the load detection part 53 stabilizes, and a load value at this time is not smaller than a load threshold. When the load value is not smaller than the load threshold (YES in Step S1), the accommodation determination part 54 determines that an object is accommodated in the bucket 16, and the flow proceeds to Step S2. On the other hand, when the load value is smaller than the load threshold (NO in Step S1), the accommodation determination part 54 determines that an object is not accommodated in the bucket 16, and the process returns to Step S1.
In Step S2, the temporary storage part 56 temporarily stores, in the memory 59, the load value detected when determined to be stabilized in Step S1. In Step S3, the discharge determination part 55 determines whether the latest bucket angle α detected by the angle detection part 52 is larger than the discharge reference angle f or not. With reference to
When the bucket angle α is larger than the discharge reference angle η (YES in Step S3), the flow proceeds to Step S4. On the other hand, when the bucket angle α is equal to or smaller than the discharge reference angle η (NO in Step S3), the process returns to Step S3. Accordingly, the flow waits for Step S3 until the bucket angle α shifts to the discharge side D1 beyond the discharge reference angle q.
In Step S4, the discharge determination part 55 determines whether the latest load value detected by the load detection part 53 is smaller than the load threshold or not. When the load value is equal to or greater than the load threshold (NO in Step S4), the flow proceeds to Step S5. The state of NO in Step S4 indicates a state where the object is still left in the bucket 16 although the bucket 16 is in a dischargeable posture.
On the other hand, when the load value is smaller than the load threshold (YES in Step S4), the flow proceeds to Step S7. The state of YES in Step S4 indicates a state where almost all the object accommodated in the bucket 16 is discharged.
In Step S5, the discharge determination part 55 determines whether the bucket angle α is equal to or smaller than the discharge reference angle q or not. When the bucket angle α is larger than the discharge reference angle η (NO in Step S5), the flow returns to Step S3. The state of NO in Step S5 indicates that the bucket 16 is in the dischargeable posture with the object still left in the bucket 16, wherein the accommodated object decreases in the discharge task or the dropping task.
On the other hand, when the bucket angle α is equal to or smaller than the discharge reference angle η (YES in Step S5), the bucket 16 is put in a non-dischargeable posture with the object still left in the bucket 16. The dropping task is determined to be ended once, and the flow returns to Step S3.
In Step S6, the temporary storage part 56 updates the load value temporarily stored in the memory 59 with the latest load value detected in Step S4. This allows the load value temporarily stored in the memory 59 to be updated with the load value of the accommodated object at the end of the dropping task. When the update ends, the flow returns to Step S3.
In Step S7, the cumulative load value calculation part 57 calculates a cumulative load value by adding a load value temporarily stored in the memory 59. Accordingly, a cumulative load value of the accommodated object discharged by the bucket 16 from the start of the loading work to the present can be obtained. When the process of Step S7 ends, the flow returns to Step S1, and the flow starting from Step 1 is subsequently executed.
For example, when the working machine is in the state S300 in
Thereafter, when the bucket 16 is positioned above the box bed of the dump truck and the transfer task ends, the discharge task starts. When the discharge task starts, the bucket 16 is put in the dischargeable posture, and thus the determination of YES is made in Step S3. When the bucket 16 is emptied, the determination of YES is made in Step S4. Thereafter, the load value is added in Step S7.
As described above, in the present embodiment, attention is paid to a bucket angle α that is an angle of the opening face 16a of the bucket 16 with respect to the vertical direction L1. An accommodated object is determined to be discharged when the bucket angle α is on the discharge side D1 beyond the discharge reference angle η, and the load of the accommodated object is smaller than the load threshold. Therefore, according to the present configuration, a discharge of an accommodated object can be accurately detected even when, for example, the accommodated object is discharged by an arm pushing operation in which a bucket angle is maintained constant.
The embodiment may be modified as described below.
The flowchart in
In the flowchart in
A working machine according to an aspect of the present invention is provided with a main body and a working device attached to the main body. The working device includes: a working arm having a distal end movable in vertical directions and front-rear directions; and a bucket rotatably attached to the distal end and defining a space for accommodating an object and an opening face letting the space open. The working machine includes: a load detection part for detecting a load value of the object accommodated in the bucket; a posture detector for detecting a posture of the working device; an angle detection part for detecting a bucket angle that is an angle of the opening face of the bucket with respect to a vertical direction orthogonal to a horizontal plane on the basis of detection data indicating the posture of the working device detected by the posture detector; an accommodation determination part for determining whether the object is accommodated in the bucket or not on the basis of the load value detected by the load detection part; and a discharge determination part for determining that the object accommodated in the bucket is discharged when the bucket angle detected by the angle detection part is on a discharge side beyond a predetermined discharge reference angle, and the load value detected by the load detection part is smaller than a load threshold, after the accommodation determination part determines that the object is accommodated in the bucket. In the working machine, the discharge reference angle is an angle of the bucket in a posture allowing the accommodated object to be discharged.
In the present configuration, attention is paid to a bucket angle that is an angle of the opening face of the bucket with respect to the vertical direction. An accommodated object is determined to be discharged when the bucket angle is on the discharge side beyond the discharge reference angle, and the load of the accommodated object is smaller than the load threshold. Therefore, a discharge of an accommodated object can be detected even when, for example, the accommodated object is discharged by an arm pushing operation that is performed while maintaining an angle between the arm and the bucket constant. Thus, the discharge of the accommodated object can be accurately detected.
In the working machine, preferably, the discharge determination part may determine that a dropping task of discharging a part of the object accommodated in the bucket is performed when the bucket angle is on a non-discharge side beyond the discharge reference angle after the bucket angle is on the discharge side beyond the discharge reference angle, and the load value detected by the load detection part is equal to or greater than the load threshold, after the accommodation determination part determines that the object is accommodated in the bucket.
In a working machine, an operation of swinging the bucket to the discharge side and an operation of swinging the bucket to the non-discharge side are liable to be performed more than once in order to discharge a part of the object accommodated in the bucket. In this operation, the object is still left in the bucket even after the operation is completed. The present configuration makes it possible to determine that a dropping task of discharging a part of the accommodated object is performed as long as the bucket angle is on the non-discharge side beyond the discharge reference angle after the bucket angle is on the discharge side beyond the discharge reference angle, and the load value is equal to or greater than the load threshold. Therefore, according to the present configuration, the dropping task can be accurately detected.
In the working machine, preferably, the discharge reference angle may be a predetermined angle to the vertical direction and be on the non-discharge side.
The object to be accommodated includes the one smoothly separable from a bucket, such as dry fine soil, and the one hardly separable from the bucket, such as humid soil. An accommodated object smoothly separable from the bucket is discharged before the opening face of the bucket turns to be parallel to the vertical direction as the bucket is swung to the discharge side. In the present configuration, the discharge reference angle is a predetermined angle to the vertical direction and is on the non-discharge side. Therefore, according to the present configuration, a discharge of an accommodated object can be accurately detected even when a substance smoothly separable from the bucket is accommodated as the object.
The working machine may preferably further include a temporary storage part for temporarily storing the load value of the accommodated object in the memory when the accommodation determination part determines that the object is accommodated in the bucket, and a cumulative load value calculation part for calculating a cumulative load value of the accommodated object by adding a load value temporarily stored in the memory when the discharge determination part determines that the object accommodated in the bucket is discharged.
According to the present configuration, the load value is temporarily stored in the memory. Therefore, for example, when the amount of the accommodated object is changed during an operation, the temporarily stored load value can be updated with the changed load value of the accommodated object. This prevents the cumulative load value from being calculated by the addition of the unchanged load value. Thus, a cumulative load value can be accurately detected.
In the working machine, preferably, the discharge determination part may determine that the dropping task of discharging a part of the object accommodated in the bucket is performed when the bucket angle is on the non-discharge side beyond the discharge reference angle after the bucket angle is on the discharge side beyond the discharge reference angle, and the load value detected by the load detection part is equal to or greater than the load threshold, after the accommodation determination part determines that the object is accommodated in the bucket, and the temporary storage part may update the load value temporarily stored in the memory with the load value detected by the load detection part after the discharge determination part determines that the dropping task is performed.
According to the present configuration, when the dropping task is determined to be performed, the load value temporarily stored in the memory is updated with the load value detected when the dropping task is determined to be performed. Therefore, the cumulative load value can be calculated by taking into account the load value of the accommodated object partially dropped off by the dropping task.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-048693 | Mar 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/001656 | 1/19/2021 | WO |
