Shovel

Abstract

To provide a shovel capable of suppressing the scatter of sediment in a structure including a rotator part.SOLUTION: A shovel 100 includes an undercarriage 1, a super structure 2 turnably mounted on the undercarriage 1, and an attachment AT provided on the super structure 2 for holding a bucket 6. The attachment AT has a rotator mechanism 22 for rotating the bucket 6 in a rolling direction as a direction around an axis of a base end of the bucket 6 to adjust a rolling angle of an opening face 6Co of the bucket 6. The attachment AT allows an operation of the rotator mechanism 22 in a turning operation of the super structure 2 to incline the opening face 6Co of the bucket 6 to a turning plane formed by a turning direction, in the rolling direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a shovel. [Background technology]

[0002] When an excavator performs an operation from excavation to dumping soil, the upper rotating body and the attachment are rotated together with the bucket filled with soil to move the bucket to a dumping position on the bed of a dump truck, etc. During this swing operation, the soil contained in the bucket may spill out during the swing operation.

[0003] Patent Document 1 discloses an excavator that tilts the bucket angle based on the centrifugal force acting on the bucket during the above-mentioned swing operation, thereby tilting the opening surface of the bucket relative to the horizontal direction. This inclined bucket posture prevents soil from spilling out even when centrifugal force is applied during the swing operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6851701 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, some excavators are equipped with a rotator unit that not only changes the bucket angle of the bucket but also rotates the bucket in a roll direction.

[0006] The present disclosure provides a technology that can significantly reduce the spillage of soil and sand in a shovel equipped with a rotator unit. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, there is provided a shovel comprising a lower running body, an upper rotating body rotatably mounted on the lower running body, and an attachment mounted on the upper rotating body and holding a bucket, wherein the attachment has a rotator unit that rotates the bucket in a roll direction about an axis of a base end of the bucket to adjust the roll angle of an opening surface of the bucket, and the rotator unit is operated during the rotating operation of the upper rotating body to tilt the opening surface of the bucket in the roll direction with respect to a rotation plane formed by the rotation direction. Effect of the Invention

[0008] According to one aspect, in a shovel equipped with a rotator unit, spillage of soil and sand can be significantly suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing a schematic overall configuration of a shovel according to an embodiment. [Diagram 2] FIG. 1 is a diagram illustrating an example of a configuration of a shovel according to an embodiment. [Diagram 3] FIG. 4 is a schematic plan view for explaining forces acting on a bucket during a swing operation of a shovel. [Figure 4] 5A and 5B are explanatory diagrams showing the principle of calculating the attitude of the opening surface of the bucket, in which (A) shows the attitude of the bucket angle, and (B) shows the attitude of the bucket roll angle. [Diagram 5] FIG. 4 is a block diagram showing a signal flow when automatically adjusting the attitude of the bucket during turning. [Figure 6] Fig. 6(A) is a flowchart showing a method for adjusting the attitude of a bucket during a swing operation according to an embodiment, and Fig. 6(B) is a flowchart showing a method for adjusting the attitude of a bucket during a swing operation according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0011] Fig. 1 is a side view showing a schematic overall configuration of a shovel 100 according to an embodiment. As shown in Fig. 1, the shovel 100 includes a lower traveling body 1, an upper rotating body 2, and an attachment AT.

[0012] The lower traveling body 1 has a pair of left and right crawlers 1C. The crawlers 1C are driven by traveling actuators 1L, 1R (see FIG. 2) mounted on the lower traveling body 1. The upper rotating body 2 is mounted on the lower traveling body 1 so as to be rotatable via a turning mechanism 3. The turning mechanism 3 has a turning actuator 3A (see FIG. 2) and turns the upper rotating body 2 with the turning actuator 3A. The traveling actuators 1L, 1R and the turning actuator 3A may be any of hydraulic actuators, internal combustion engines, and electric actuators.

[0013] The upper rotating body 2 is provided with a cabin 10, which is an operation room where an operator rides and operates the shovel 100, at the front and left side (to the left of the boom 4). The upper rotating body 2 also has a counterweight at the rear, and various devices for operating the shovel 100 are provided therein.

[0014] The attachment AT according to the embodiment is an excavation attachment, and includes a boom 4 attached to the upper rotating body 2 so as to be able to move up and down, an arm 5 attached to the tip of the boom 4 so as to be able to rotate, and a bucket 6 attached to the tip of the arm 5 so as to be able to rotate. The bucket 6 is an end attachment having a recess 6C capable of containing soil and sand, and having multiple claws 6N on the edge opposite to the connection point of the arm 5. The bucket 6 may be a slope bucket.

[0015] The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9. The boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 constitute an attachment actuator.

[0016] Moreover, the shovel 100 according to the embodiment includes a tiltrotator 20 between the arm 5 and the bucket 6. The tiltrotator 20 enables the angle of the bucket 6 in the left-right direction (width direction, yaw direction: hereinafter referred to as tilt angle) to be changed with the center supported by the arm 5 as the base point, and also enables the angle of the bucket 6 around the axis of the base end (roll direction: hereinafter referred to as roll angle).

[0017] The tilt rotator 20 has, for example, a tilt mechanism 21 provided on the arm 5 side, and a rotator mechanism 22 provided between the tilt mechanism 21 and the bucket 6. The tilt mechanism 21 includes a base 211 fixed to the arm 5, a tilt shaft 212 connected to the base 211, a support plate 213 supported so as to be swingable relative to the tilt shaft 212, and a tilt actuator 214 that changes the tilt angle of the support plate 213. The tilt actuator 214 is composed of, for example, a pair of cylinders sandwiching the tilt shaft 212 therebetween.

[0018] The rotator mechanism 22 includes a rotator motor 221 fixed to the support plate 213 of the tilt mechanism 21, a rotating shaft 222 rotated by the rotator motor 221, and a connecting part 223 that connects the rotating shaft 222 and the bucket 6. The rotating shaft 222 protrudes a short distance from the center of the support plate 213 and is connected to the connecting part 223. The connecting part 223 fixes the center of the base end of the bucket 6, and adjusts the roll angle of the bucket 6 by rotating the bucket 6 around the central axis of the base end.

[0019] The shovel 100 rotates the entire tilt rotator 20 in the pitch direction in accordance with the extension and retraction operation of the arm cylinder 8, thereby changing the entire tilt rotator 20 and the bucket angle (pitch angle) of the bucket 6 together. The shovel 100 also changes the tilt angle of the bucket 6 by rotating the support plate 213 in the left-right direction relative to the base 211 in accordance with the operation of the tilt actuator 214. For example, the tilt angle of the opening surface 6Co of the bucket 6 is adjusted within a desired angle range (for example, a range of 45° to the right and 45° to the left). Furthermore, the shovel 100 rotates the connecting portion 223 and the bucket 6 around the axis in accordance with the operation of the rotator motor 221. As a result, the roll angle of the opening surface 6Co of the bucket 6 is adjusted within a range of 360°.

[0020] Next, a specific configuration of the shovel 100 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram that shows an example of the configuration of the shovel 100 according to the embodiment. In Fig. 2, a mechanical power system is indicated by double lines, hydraulic oil lines are indicated by solid lines, pilot lines are indicated by dashed lines, and an electrical control system is indicated by dotted lines.

[0021] The drive system of the excavator 100 includes an engine 11, a regulator 13, a main pump 14, and a control valve 17. The hydraulic drive system of the excavator 100 also includes hydraulic actuators that hydraulically drive the lower traveling structure 1, the upper rotating structure 2, the boom 4, the arm 5, and the bucket 6. These hydraulic actuators include traveling actuators 1L, 1R, a rotating actuator 3A, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a tilt actuator 214, a rotator motor 221, etc.

[0022] The engine 11 is a main power source in the hydraulic drive system, and is mounted, for example, on the rear of the upper rotating body 2. Specifically, the engine 11 rotates at a constant target rotation speed under the control of a controller 30 (described later), and drives the main pump 14 and the pilot pump 15. The engine 11 is, for example, a diesel engine that uses diesel as fuel.

[0023] The regulator 13 controls the discharge amount of the main pump 14. For example, the regulator 13 adjusts the angle (tilt angle) of the swash plate of the main pump 14 in response to a control command from the controller 30.

[0024] The main pump 14 is mounted on the rear of the upper rotating body 2, for example, in the same manner as the engine 11. The main pump 14 is driven by the engine 11 and supplies hydraulic oil to a control valve 17 through a high-pressure hydraulic line. The main pump 14 is, for example, a variable displacement hydraulic pump, and the tilt angle of the swash plate is adjusted by the regulator 13 to adjust the stroke length of the piston, thereby controlling the discharge amount (discharge pressure).

[0025] The control valve 17 is, for example, mounted in the center of the upper rotating body 2, and is a hydraulic control device that controls the hydraulic drive system in response to an operation of the operating device 26 by an operator. The control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line, and selectively supplies hydraulic oil supplied from the main pump 14 to the hydraulic actuators (travel actuators 1L, 1R, swing actuator 3A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, tilt actuator 214, and rotator motor 221) in response to the operating state of the operating device 26.

[0026] Specifically, the control valve 17 includes control valves 171-178 that control the flow rate and flow direction of the hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators. For example, the control valve 171 corresponds to the left traveling actuator 1L, the control valve 172 corresponds to the right traveling actuator 1R, and the control valve 173 corresponds to the swing actuator 3A. Furthermore, the control valve 174 corresponds to the bucket cylinder 9, the control valve 175 corresponds to the boom cylinder 7, and the control valve 176 corresponds to the arm cylinder 8. Furthermore, the control valve 177 corresponds to the tilt actuator 214, and the control valve 178 corresponds to the rotator motor 221.

[0027] The operation system of the shovel 100 includes the pilot pump 15 and an operation device 26. The operation system of the shovel 100 also includes a shuttle valve 32 as a component related to the machine control function by the controller 30.

[0028] The pilot pump 15 is mounted, for example, on the rear of the upper rotating body 2 and supplies pilot pressure to the operation device 26 via a pilot line. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11.

[0029] The operation device 26 is provided near the cockpit of the cabin 10, and is an operation input means for the operator to operate various operating elements (lower traveling body 1, upper rotating body 2, boom 4, arm 5, bucket 6, etc.). The operation device 26 operates the hydraulic actuators (traveling actuators 1L, 1R, rotating actuator 3A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, tilt actuator 214, rotator motor 221, etc.) based on the operation of the operator.

[0030] The operation device 26 is connected to the control valve 17 directly through a secondary pilot line or indirectly through a shuttle valve 32 provided in the secondary pilot line. Thus, a pilot pressure according to the operation states of the lower traveling structure 1, the upper rotating structure 2, the boom 4, the arm 5, the bucket 6, etc. in the operation device 26 is input to the control valve 17.

[0031] Therefore, the control valve 17 can drive each hydraulic actuator according to the operation state of the operation device 26. The operation device 26 includes, for example, lever devices for operating each of the boom 4 (boom cylinder 7), arm 5 (arm cylinder 8), bucket 6 (bucket cylinder 9), and upper rotating body 2 (swing actuator 3A). The operation device 26 also includes, for example, lever devices and pedal devices for operating each of the pair of left and right crawlers 1C (travel actuators 1L, 1R) of the lower traveling body 1. The operation device 26 also includes, for example, buttons, rotary dials, and the like for operating the tilt angle and roll angle of the tilt rotator 20 (tilt actuator 214, rotator motor 221).

[0032] The shuttle valve 32 has two inlet ports and one outlet port, and outputs hydraulic oil having a higher pilot pressure of the two pilot pressures input to the two inlet ports to the outlet port. One of the two inlet ports of the shuttle valve 32 is connected to the operating device 26, and the other is connected to the proportional valve 31. The outlet port of the shuttle valve 32 is connected to the pilot port of the corresponding control valve in the control valve 17 through a pilot line. Therefore, the shuttle valve 32 can apply the higher of the pilot pressure generated by the operating device 26 or the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0033] In other words, by outputting a pilot pressure from the proportional valve 31 that is higher than the secondary pilot pressure output from the operating device 26, the controller 30 can control the corresponding control valve and control the operation of various operating elements regardless of the operation of the operating device 26 by the operator.

[0034] The operating device 26 (left operating lever, right operating lever, left travel lever, and right travel lever) may be an electric type that outputs an electric signal, rather than a hydraulic pilot type that outputs a pilot pressure. In this case, the electric signal from the operating device 26 is input to the controller 30, and the controller 30 controls the control valves 171-178 in the control valve 17 according to the input electric signal, thereby realizing the operation of the various hydraulic actuators according to the operation content of the operating device 26.

[0035] For example, the control valves 171-178 in the control valve 17 may be electromagnetic solenoid spool valves that are driven by commands from the controller 30. Also, for example, solenoid valves that operate in response to electrical signals from the controller 30 may be disposed between the pilot pump 15 and the pilot ports of the control valves 171-178.

[0036] In this case, when manual operation is performed using the electric operating device 26, the controller 30 controls the solenoid valve and increases or decreases the pilot pressure using an electric signal corresponding to the amount of operation (e.g., the amount of lever operation), thereby operating each control valve 171-178 in accordance with the operation content of the operating device 26.

[0037] The control system of the excavator 100 in this embodiment includes a controller 30, a discharge pressure sensor 28, an operating pressure sensor 29, a proportional valve 31, a display device 40, an input device 42, an audio output device 43, a memory device 57, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body inclination sensor S4, a turning state sensor S5, an imaging device S6, a boom pressure sensor S7, an arm pressure sensor S8, a bucket pressure sensor S9, a tilt angle sensor 215, a roll angle sensor 224, a positioning device PS, and a communication device T1.

[0038] The controller 30 is provided, for example, in the cabin 10, and controls the driving of the excavator 100. The functions of the controller 30 may be realized by any hardware, software, or a combination thereof. For example, the controller 30 is a computer having one or more processors, a memory, an input / output interface, and a communication interface (not shown). The one or more processors are one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit made of a plurality of discrete semiconductors, and the like, and executes and processes a program stored in the memory. The memory includes a main storage device made of a semiconductor memory or the like, and an auxiliary storage device made of a disk, a semiconductor memory (flash memory), or the like.

[0039] For example, the controller 30 sets a target rotation speed based on a work mode or the like that is set in advance by the operation of an operator or the like, and performs drive control to rotate the engine 11 at a constant speed. Also, the controller 30 outputs a control command to the regulator 13 as necessary, and changes the discharge rate of the main pump 14. Also, for example, the controller 30 performs control related to a machine guidance function that guides (guides) the manual operation of the shovel 100 by the operator through the operation device 26. Alternatively, the controller 30 performs control related to a machine control function that automatically assists the manual operation of the shovel 100 by the operator through the operation device 26.

[0040] For this reason, the controller 30 has a machine guidance unit 50 as a functional unit related to the machine guidance function or the machine control function. The controller 30 also has a soil weight processing unit 60 that calculates the weight of soil. Note that some of the functions of the controller 30 may be realized by another controller. That is, the functions of the controller 30 may be realized in a distributed manner by a plurality of controllers. For example, the machine guidance function and the machine control function may be realized by a dedicated controller.

[0041] The discharge pressure sensor 28 detects the discharge pressure of the main pump 14 and transmits a detection signal to the controller 30. The operating pressure sensor 29 detects the pilot pressure on the secondary side of the operating device 26, in other words, the pilot pressure according to the operating state of the operating device 26 for each operating element (for example, the operating content such as the operating direction and the operating amount) and transmits the detection signal to the controller 30. Note that instead of the operating pressure sensor 29, other sensors (encoders, potentiometers, etc.) capable of detecting the operating state of the operating device 26 for each operating element may be provided.

[0042] The proportional valve 31 is provided in a pilot line connecting the pilot pump 15 and the shuttle valve 32, and is configured so that its flow path area (cross-sectional area through which hydraulic oil can flow) can be changed. The proportional valve 31 operates in response to a control command input from the controller 30. As a result, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via the proportional valve 31 and the shuttle valve 32, even when the operating device 26 is not being operated.

[0043] The display device 40 is provided at a location where it can be easily seen by an operator seated in the cabin 10, and displays various information under the control of the controller 30. The input device 42 is provided within reach of the operator seated in a seat in the cabin 10, and receives various operation inputs from the operator and outputs signals corresponding to the operation inputs to the controller 30. The input device 42 includes a touch panel mounted on the display of the display device 40 that displays various information images, a knob switch provided at the tip of a lever device, a button switch, a lever, a toggle, a rotary dial, and the like that are provided around the display device 40. The audio output device 43 is, for example, a speaker or a buzzer provided in the cabin 10, and outputs audio under the control of the controller 30.

[0044] The storage device 57 is, for example, a non-volatile storage medium such as a semiconductor memory, is provided in the cabin 10, and stores various information under the control of the controller 30. The storage device 57 may store data relating to a target construction surface acquired via the communication device T1 or the like, or set via the input device 42 or the like. The target construction surface may be set (saved) by the operator of the shovel 100, or may be set by a construction manager or the like.

[0045] The boom angle sensor S1 detects the elevation angle of the boom 4 relative to the upper rotating body 2 (hereinafter referred to as the "boom angle"), for example, the angle formed by a straight line connecting the fulcrums at both ends of the boom 4 relative to the rotation plane of the upper rotating body 2 in a side view, and transmits the information to the controller 30. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU (Inertial Measurement Unit), etc. The boom angle sensor S1 may also include a potentiometer using a variable resistor, a stroke sensor that detects the stroke amount of a hydraulic cylinder (boom cylinder 7) corresponding to the boom angle, etc. The same applies to the arm angle sensor S2 and bucket angle sensor S3 described below.

[0046] The arm angle sensor S2 detects the rotation angle of the arm 5 relative to the boom 4 (hereinafter referred to as the "arm angle"), for example, the angle between a line connecting the fulcrums at both ends of the boom 4 and a line connecting the fulcrums at both ends of the arm 5 in a side view, and transmits the information to the controller 30.

[0047] The bucket angle sensor S3 detects the rotation angle of the bucket 6 relative to the arm 5 (hereinafter referred to as the “bucket angle”), for example, the angle formed by a line connecting the fulcrums at both ends of the arm 5 and a line connecting the fulcrum and tip of the bucket 6 in a side view, and transmits this information to the controller 30.

[0048] The machine body tilt sensor S4 detects the tilt state of the machine body (upper rotating body 2, lower running body 1) with respect to the horizontal plane, and transmits the information to the controller 30. The machine body tilt sensor S4 is attached to, for example, the upper rotating body 2, and detects the tilt angle of the excavator 100 (upper rotating body 2) about two axes in the forward / backward and left / right directions. The machine body tilt sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU, etc.

[0049] The turning state sensor S5 detects the turning state of the upper turning body 2 and transmits the information to the controller 30. The turning state includes, for example, the turning speed and turning angle of the upper turning body 2. The turning state sensor S5 may include, for example, a gyro sensor, a resolver, a rotary encoder, etc.

[0050] The imaging device S6 is a spatial recognition device that captures images of the periphery of the shovel 100 and transmits the information to the controller 30. The imaging device S6 may include cameras on the front, rear, left and right sides of the shovel 100, or may include an attachment camera attached to an attachment. A monocular wide-angle camera, a stereo camera, a distance image camera, or the like may be applied to the imaging device S6. The spatial recognition device may calculate the distance to an object present around the shovel 100, and may apply an ultrasonic sensor, a millimeter wave radar, a LiDAR, an infrared sensor, or the like in addition to (or instead of) a camera. The controller 30 can output the captured image to the display device 40.

[0051] The boom pressure sensor S7 detects the boom pressure of the boom cylinder 7 and transmits the information to the controller 30. The arm pressure sensor S8 detects the arm pressure of the arm cylinder 8 and transmits the information to the controller 30. The bucket pressure sensor S9 detects the bucket pressure of the bucket cylinder 9 and transmits the information to the controller 30. The boom pressure sensor S7, the arm pressure sensor S8 and the bucket pressure sensor S9 may each have a pressure gauge that detects the rod side pressure and the bottom side pressure.

[0052] The tilt angle sensor 215 detects the tilt angle, which is the left-right inclination of the bucket 6 with respect to the arm 5, and transmits the information to the controller 30. The roll angle sensor 224 detects the roll angle of the bucket 6 with respect to the arm 5 (support plate 213 of the tilt rotator 20), and transmits the information to the controller 30.

[0053] The positioning device PS measures the position and orientation of the upper rotating body 2. The positioning device PS is, for example, a Global Navigation Satellite System (GNSS) compass, detects the position and orientation of the upper rotating body 2, and transmits information on the position and orientation of the upper rotating body 2 to the controller 30.

[0054] The communication device T1 communicates with external devices through a predetermined network including a mobile communication network with a base station as an end, a satellite communication network, an Internet network, etc. Examples of the external devices include other shovels 100, a management computer that manages a work site where the shovel 100 works, a worker's smartphone, a tablet-type terminal device, etc.

[0055] The machine guidance unit 50 executes control of the excavator 100 relating to, for example, a machine guidance function and a machine control function. For example, the machine guidance unit 50 acquires information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclination sensor S4, the turning state sensor S5, the imaging device S6, the positioning device PS, the communication device T1, the input device 42, etc. Then, based on the acquired information, the machine guidance unit 50 automatically controls the operation of the attachment so that the tip of the attachment coincides with the target trajectory, and notifies the operator via the display device 40, the audio output device 43, etc.

[0056] On the other hand, the soil weight processing unit 60 calculates the weight of the soil (soil weight) excavated by the bucket 6. For example, the soil weight processing unit 60 calculates the weight of the soil based on the thrust of the boom cylinder 7, the distance from the pin connecting the upper rotating body 2 and the boom 4 to the position of the center of gravity of the soil, and an equation for the moment around the pin connecting the upper rotating body 2 and the boom 4.

[0057] The soil weight processing unit 60 also calculates the position of the center of gravity of the soil (cargo) in the bucket 6 immediately after excavation (immediately before the start of the swing operation). The position of the soil's center of gravity is used to calculate the radius r (see FIG. 3) from the center of rotation of the upper swing body 2 to the center of gravity of the soil. The position of the soil's center of gravity can be calculated based on the attitude of the attachment AT (the length of the boom 4, the length of the arm 5, the length of the bucket 6, the boom angle, the arm angle, and the bucket angle). The length of the boom 4, the length of the arm 5, and the length of the bucket 6 are preset fixed values ​​and can be stored in the controller 30. Meanwhile, the boom angle can be obtained from detection information of the boom angle sensor S1, the arm angle from detection information of the arm angle sensor S2, and the bucket angle from detection information of the bucket angle sensor S3.

[0058] Here, when excavating and discharging soil, the shovel 100 rotates the upper rotating body 2 with soil in the bucket 6, and moves the bucket 6 to a soil discharging position. As described above, if the upper rotating body 2 rotates too quickly at this time, the soil may spill out along the way. The forces acting on the bucket 6 during this rotation will be described below with reference to Fig. 3. Fig. 3 is a schematic plan view for explaining the forces acting on the bucket 6 during the rotation of the shovel 100.

[0059] The falling of the soil from the bucket 6 is caused by a force F acting on the soil during the swing. This force F can be decomposed into a vector of a centrifugal force (centrifugal acceleration) acting on the soil in the bucket 6 combined with a vector of an acceleration in the tangential direction of the swing. If the swing speed of the shovel 100 is ω, the centrifugal force acting on the soil in the bucket 6 can be calculated using a radius r from the swing center of the shovel 100 to the center of gravity of the soil in the bucket 6, the swing speed ω, and the weight of the soil. However, the soil coming out of the opening surface 6Co of the bucket 6 is in a free state, so its weight may be set to any value (for example, 1). In addition, the vector of the acceleration in the tangential direction of the shovel 100 can be calculated using the radius r to the center of gravity of the soil in the bucket 6 and the swing acceleration differentiated from the swing speed ω. Note that the expression "swing acceleration" in the embodiment is a concept including an acceleration at which the swing speed increases at the beginning of the swing and a deceleration at which the swing speed decreases at the end of the swing.

[0060] For this reason, the controller 30 has an attitude calculation unit 70 that calculates the angle of the opening plane 6Co of the bucket 6 based on the rotation speed and the rotation acceleration, and an attitude control unit 80 that adjusts the attitude of the bucket 6 based on the calculated angle of the opening plane 6Co (see FIG. 2).

[0061] The attitude calculation unit 70 acquires information such as the rotation speed and rotation acceleration of the upper rotating body 2, the position of the center of gravity of the soil contained in the bucket 6, and the attitude of the bucket 6, and calculates a target angle of the opening surface 6Co of the bucket 6 that will not spill soil. The rotation speed and rotation acceleration of the upper rotating body 2 can be obtained using detection information from an acceleration sensor, a six-axis sensor, an IMU, or the like applied to the bucket angle sensor S3. When the attitude calculation unit 70 acquires the rotation acceleration from the bucket angle sensor S3, it may obtain the rotation speed by integrating the rotation acceleration.

[0062] Furthermore, the swing speed may be calculated based on the swing angular speed detected by the swing state sensor S5 instead of (or in combination with) the detection information of the bucket angle sensor S3, or on information on the orientation of the excavator 100 detected by the positioning device PS. In this case, the swing acceleration can be calculated by differentiating the acquired swing speed.

[0063] The position of the center of gravity of the soil can be calculated by the above-mentioned soil weight processing unit 60. Furthermore, the attitude of the bucket 6 can be recognized by the bucket angle sensor S3, the tilt angle sensor 215, the roll angle sensor 224, and the like.

[0064] 4A and 4B are explanatory diagrams showing the principle of calculating the attitude of the opening surface 6Co of the bucket 6, where (A) shows the attitude of the bucket angle of the bucket 6 and (B) shows the attitude of the roll angle of the bucket 6. As shown in FIG. 4A, the centrifugal force acting on the soil at the position of the center of gravity of the soil, which is a radius r away from the rotation axis 3s of the rotation mechanism 3, is rω 2 As shown in the figure.

[0065] In the embodiment, the "bucket angle θ" of the bucket 6 refers to the angle at which the opening surface 6Co of the bucket 6 is tilted in a direction facing the upper rotating body 2 with respect to the rotation plane TF (horizontal in FIG. 4) formed by the rotation of the bucket 6 in the swing direction. This bucket angle θ may be calculated mainly as an inclination that offsets the centrifugal force acting on the soil of the bucket 6, and the posture calculation unit 70 obtains a resultant vector of the centrifugal force and gravitational acceleration, and calculates the bucket angle θ so that this resultant vector is perpendicular to the opening surface 6Co of the bucket 6. Specifically, the gravity acting on the soil is g, the centrifugal force acting on the soil is rω, 2 In this case, the inclination angle (bucket angle θ) of the opening surface 6Co of the bucket 6 with respect to the turning plane TF can be approximated by the following formula (1).

[0066] θ ≒ tan -1 (rω 2 / g) ···(1)

[0067] 4(B), in the embodiment, the "roll angle φ" of the bucket 6 refers to an angle at which the opening surface 6Co of the bucket 6 is tilted in the same direction as the vector of the swing acceleration with respect to the swing plane TF (horizontal in FIG. 4) formed by the rotation of the bucket 6 in the swing direction. The roll angle φ of the bucket 6 may be calculated so as to cancel out the tangential acceleration acting on the soil of the bucket 6, and the attitude calculation unit 70 obtains a resultant vector of the swing acceleration and the gravitational acceleration, and calculates the roll angle φ so that this resultant vector is perpendicular to the opening surface 6Co of the bucket 6. Specifically, when the gravity acting on the soil is g and the tangential acceleration is r(dω / dt), the tilt angle (roll angle φ) of the opening surface 6Co of the bucket 6 with respect to the swing plane TF can be approximated by the following formula (2).

[0068] φ ≒ tan -1 (r(dω / dt) / g) (2)

[0069] The attitude control unit 80 controls the operation of the bucket cylinder 9 and the rotator motor 221 when the upper rotating body 2 rotates, based on the attitude (bucket angle θ, roll angle φ) of the opening surface 6Co of the bucket 6 calculated by the attitude calculation unit 70. The attitude control unit 80 automatically adjusts the angle of the opening surface 6Co in response to the rotation of the upper rotating body 2 by controlling the control valve 17 regardless of the operation state of the operation device 26 by the operator described above during the rotation operation.

[0070] For example, the absolute value of the rotation acceleration (acceleration, deceleration) of the rotation mechanism 3 at the beginning and end of the rotation operation is larger than the rotation acceleration during the intermediate period of the rotation operation. The controller 30 controls the roll angle φ with respect to the rotation plane TF to be larger as the absolute value of the rotation acceleration is larger. In other words, the opening surface 6Co is controlled to tilt upward and toward the rotation direction as the acceleration increases. This allows the roll angle φ of the opening surface 6Co of the bucket 6 to be appropriately tilted, and the spilling of soil and sand can be significantly suppressed according to the rotation acceleration. Note that, when the rotation operation is decelerated, the controller 30 tilts the opening surface 6Co of the bucket 6 in the opposite direction to the tilt when the rotation operation is accelerated. In other words, the opening surface 6Co is controlled to tilt upward and toward the opposite direction to the rotation direction as the deceleration increases (becomes more negative). This makes it possible to prevent the spilling of soil and sand even during deceleration.

[0071] Also, for example, the controller 30 adjusts the bucket angle θ based on the rotation speed of the upper rotating body 2 (bucket 6). In other words, the opening surface 6Co is controlled to tilt upward and inward (toward the upper rotating body 2) as the rotation speed increases. The rotation speed in the intermediate period of the rotation operation is greater than the rotation speed in the initial and final periods of the rotation operation. Therefore, the controller 30 controls the bucket angle θ in the intermediate period of the rotation operation to be greater than the bucket angle θ in the initial and final periods of the rotation operation. This allows the bucket angle θ of the opening surface 6Co of the bucket 6 to be appropriately tilted, and the spillage of soil and sand can be significantly suppressed according to the rotation speed.

[0072] The bucket angle θ and roll angle φ of the bucket 6 may be adjusted as appropriate depending on the external environment of the bucket 6 and the state of the soil and sand. For example, in consideration of the effect of wind on the turning operation as a disturbance, the roll angle φ of the opening surface 6Co may be slightly tilted even when the turning acceleration is zero during an intermediate period of the turning operation. Also, when the attachment AT is operated during the turning operation of the excavator 100, the bucket angle θ and roll angle φ can be readjusted to appropriate angles by re-entering the radius r in the above formulas (1) and (2).

[0073] Fig. 5 is a block diagram showing a signal flow when automatically adjusting the attitude of the bucket 6 during a swing. As shown in Fig. 5, when the upper swing body 2 swings, information required for adjusting the attitude of the bucket 6 (for example, information on the swing acceleration of the bucket 6 detected by the bucket angle sensor S3) is transmitted from an appropriate sensor to the controller 30. As described above, the information required for adjusting the attitude of the bucket 6 may be information detected by the swing state sensor S5, the positioning device PS, etc.

[0074] Based on the received information, the attitude calculation unit 70 of the controller 30 calculates the attitude of the opening plane 6Co of the bucket 6 using the above-mentioned equations (1) and (2). Then, the attitude calculation unit 70 outputs a control command for adjusting the calculated bucket angle θ of the bucket 6 and a control command for adjusting the roll angle φ of the bucket 6 to the attitude control unit 80.

[0075] The attitude control unit 80 operates the bucket cylinder 9 and the tiltrotator 20 when the upper rotating body 2 rotates by outputting a command to the control valve 17 based on the control command received from the attitude calculation unit 70. At this time, the attitude control unit 80 controls the proportional valve 31 (see FIG. 2 ) to output a pressure higher than the pilot pressure generated by the operation device 26 to the shuttle valve 32, thereby automatically controlling the bucket cylinder 9 and the tiltrotator 20.

[0076] The shovel 100 according to the embodiment is basically configured as described above, and its operation will be described below with reference to Fig. 6. Fig. 6(A) is a flowchart showing a method for adjusting the attitude of the bucket 6 during a swing operation according to the embodiment. Fig. 6(B) is a flowchart showing a method for adjusting the attitude of the bucket 6 during a swing operation according to a modified example.

[0077] The shovel 100 excavates soil with the bucket 6 based on the operation of the operator, and then rotates the upper rotating body 2 toward a soil discharge position (above the bed of a dump truck, etc.). At this time, the controller 30 of the shovel 100 adjusts the attitude of the opening surface 6Co of the bucket 6 to control the shovel 100 so as not to spill the soil.

[0078] After the controller 30 excavates soil and sand with the bucket 6 under the operation of the operator, the controller 30 receives an operation by the operator to rotate the upper rotating body 2 and first starts the rotation operation of the rotation mechanism 3 (step S101), as shown in Figure 6 (A).

[0079] At this time, the controller 30 acquires detection information from various sensors of the shovel 100 as information for adjusting the attitude of the opening surface 6Co of the bucket 6 (step S120). Specifically, the controller 30 acquires information on the turning acceleration and information on the current bucket angle θ from the bucket angle sensor S3, and acquires information on the current roll angle from the roll angle sensor 224. Furthermore, in order to calculate the position of the center of gravity of the soil, the controller 30 acquires the boom angle from the boom angle sensor S1, and receives information on the arm angle from the arm angle sensor S2. Alternatively, when the controller 30 uses information from the turning state sensor S5 or information from the positioning device PS to calculate the attitude of the bucket 6, the controller 30 acquires information from these sensors.

[0080] Next, the attitude calculation unit 70 of the controller 30 calculates the bucket angle θ and the roll angle φ, which are the attitude of the bucket 6 during turning, based on the information obtained from the sensor group (step S103). This bucket angle θ can be calculated using the above-mentioned formula (1). The roll angle φ can also be calculated using the above-mentioned formula (2).

[0081] Thereafter, the attitude control unit 80 of the controller 30 controls the operation of the bucket cylinder 9 and the tiltrotator 20 based on the bucket angle θ and roll angle φ calculated by the attitude calculation unit 70 to tilt the bucket 6 (step S104). As a result, the opening surface 6Co of the bucket 6 is inclined at an angle corresponding to the centrifugal force (swing speed) of the swing operation of the upper swing body 2, and at the same time, is inclined at an angle corresponding to the swing acceleration of the upper swing body 2. As a result, the excavator 100 can prevent the soil accommodated in the recessed portion 6C of the bucket 6 from spilling out.

[0082] Furthermore, while the turning mechanism 3 is turning, the controller 30 monitors the status of the turning operation by the operator and determines whether the turning operation has stopped (step S105). If the turning operation is continuing (step S105: NO), the controller 30 returns to step S102 and repeats the same process flow thereafter.

[0083] On the other hand, when the controller 30 determines that the swing operation has been stopped by the operator's operation (step S105: YES), the controller 30 ends the method for adjusting the attitude of the opening plane 6Co of the bucket 6 by the controller 30. At the end of the swing operation, the controller 30 performs an operation to align the bucket angle θ and roll angle φ of the bucket 6 with the swing plane TF based on the swing speed becoming zero. However, when the bucket 6 is in the soil unloading position, the bucket angle θ and roll angle φ may be left inclined in order to immediately perform soil unloading from the bucket 6, or the attitude may be guided in a direction that deepens the inclination of the bucket 6.

[0084] The shovel 100 of the present disclosure is not limited to the above embodiment, and may have various modifications. For example, the shovel 100 according to the embodiment applies a tilt rotator 20 capable of adjusting the tilt angle in the left-right direction of the bucket 6 and the roll angle in the roll direction. However, the shovel 100 may have only a rotator mechanism 22 (rotator unit) capable of adjusting only the roll angle of the bucket 6. In addition, the occurrence of spillage of soil is affected by the viscosity of soil, etc., so there are cases where soil is difficult to spill. Therefore, the shovel 100 may adjust the attitude of the bucket 6 to be small with respect to the swing acceleration or swing speed of the swing operation. In addition, for example, the shovel 100 may perform control in which only the roll angle φ of the bucket 6 is adjusted during the swing operation, and the bucket angle θ is not adjusted.

[0085] Furthermore, during the turning operation, the shovel 100 may execute a method for adjusting the attitude of the bucket 6 according to a modified example shown in Fig. 6(B) . Specifically, the controller 30 of the shovel 100 starts the turning operation of the turning mechanism 3 by receiving an operation for turning the upper turning body 2 by the operator (step S201).

[0086] During this swing operation, the controller 30 reads out the bucket angle θ and roll angle φ stored in the controller 30, and tilts the attitude of the opening surface 6Co of the bucket 6 based on the bucket angle θ and roll angle φ (step S202). The bucket angle θ and roll angle φ stored in the controller 30 may be angles at which soil and sand are less likely to spill out of the bucket 6, for example, obtained through experiments or simulations. Alternatively, the controller 30 may store map information of multiple bucket angles θ and roll angles φ corresponding to multiple swing speeds and multiple swing accelerations, and change the set values ​​of the bucket angle θ and roll angle φ based on the swing speed and swing acceleration acquired during the swing operation. Furthermore, the controller 30 may change the set values ​​of the multiple bucket angles θ and multiple roll angles φ based on the passage of time during the swing operation.

[0087] The controller 30 monitors the state of the rotation operation by the operator while executing the rotation operation of the rotation mechanism 3, and determines whether the rotation operation has stopped (step S203). If the rotation operation has stopped (step S203: YE), the controller 30 proceeds to step S204.

[0088] In step S204, the controller 30 returns the bucket angle θ and the roll angle φ so that the tilted opening surface 6Co of the bucket 6 coincides with the turning plane TF. This enables the excavator 100 to turn without spilling the soil in the bucket 6.

[0089] In this way, the method for adjusting the attitude of the bucket 6 according to the modified example also makes it possible to change the bucket angle θ and the roll angle φ of the bucket 6 during the turning operation, thereby significantly suppressing spillage of soil and sand. In particular, the modified example does not use the detection results of the sensors, thereby promoting the efficiency of processing and enabling the attitude of the bucket 6 to be quickly adjusted.

[0090] The technical ideas and effects of the present disclosure explained in the above embodiments will be described below.

[0091] A first aspect of the present disclosure comprises a lower running body 1, an upper rotating body 2 rotatably mounted on the lower running body 1, and an attachment AT mounted on the upper rotating body 2 and holding a bucket 6, the attachment AT having a rotator section (rotator mechanism 22) that rotates the bucket 6 in a roll direction about the axis of the base end of the bucket 6 to adjust the roll angle φ of the opening surface 6Co of the bucket 6, and operates the rotator section during the rotating operation of the upper rotating body 2, thereby tilting the opening surface 6Co of the bucket 6 in the roll direction with respect to the rotation plane formed by the rotation direction.

[0092] As described above, the shovel 100 equipped with the rotator unit (rotator mechanism 22) can significantly prevent the spilling of soil and sand by tilting the opening surface 6Co of the bucket 6 in the roll direction. That is, in a turning operation, a force caused by the turning acceleration is applied to the soil and sand (cargo), but the spilling of soil and sand can be prevented by tilting the bucket 6 to correspond to this force. This enables the shovel 100 to stably transport the soil and sand to the discharge position, etc., and makes it possible to accurately calculate, for example, the accumulated weight of the soil and sand to be discharged.

[0093] The excavator 100 also includes a controller 30 for controlling the operation of the rotator unit (rotator mechanism 22), and the controller 30 adjusts the roll angle based on the rotation acceleration applied in the rotation direction of the upper rotating body 2. This allows the excavator 100 to adjust the inclination of the opening surface 6Co of the bucket 6 based on the rotation acceleration, and further suppresses spillage of soil during the rotation operation.

[0094] Moreover, the controller 30 increases the roll angle relative to the rotation plane as the absolute value of the rotation acceleration increases. This allows the excavator 100 to significantly suppress spillage of soil and sand by adjusting the roll angle φ of the opening surface 6Co of the bucket 6 even if the rotation acceleration applied to the bucket 6 is large.

[0095] Also, a controller 30 is provided for controlling the operation of the rotator unit (rotator mechanism 22), and the controller 30 tilts the opening surface 6Co of the bucket 6 in the roll direction based on a preset roll angle during the rotation operation of the upper rotating body 2. Even in this case, the excavator 100 can appropriately tilt the bucket 6, thereby preventing the spillage of soil and sand.

[0096] In addition, the attachment AT sets the roll angle φ at the beginning and end of the swing operation to be larger than the roll angle φ in the middle of the swing operation. This allows the excavator 100 to tilt the roll angle φ of the bucket 6 in accordance with the swing acceleration that increases at the beginning and end of the swing operation, thereby more effectively suppressing spillage of soil and sand at the beginning and end of the swing operation.

[0097] Furthermore, during the rotation of the upper rotating body 2, the attachment AT operates the bucket cylinder 9 that adjusts the bucket angle of the bucket 6, and tilts the opening surface 6Co of the bucket 6 relative to the rotation plane in a direction facing the upper rotating body 2. This allows the excavator 100 to adjust the bucket angle during the rotation, making it possible to further suppress spillage of soil and sand.

[0098] Furthermore, the attachment AT sets the bucket angle θ in the middle of the swing operation to be larger than the bucket angle θ at the beginning of the swing operation and at the end of the swing operation. This allows the excavator 100 to tilt the bucket angle θ of the bucket 6 in accordance with the swing speed that increases in the middle of the swing operation, thereby more effectively reducing spillage of soil in the middle of the swing operation.

[0099] The excavator 100 also includes a controller 30 that controls the operation of the bucket cylinder 9, and the controller 30 adjusts the bucket angle θ based on the rotation speed of the upper rotating body 2. This allows the excavator 100 to set the bucket angle θ to correspond to the centrifugal force applied to the soil during the rotation operation, and can more reliably prevent the soil from spilling out.

[0100] The shovel 100 according to the embodiment disclosed herein is illustrative in all respects and not restrictive. The embodiment can be modified and improved in various forms without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent. [Explanation of symbols]

[0101] 1 Undercarriage 2 Upper rotating body 6 Bucket 6Co opening surface 9 Bucket Cylinder 20 Tiltrotator 22 Rotator mechanism 30 Controller 100 Shovel AT Attachment θ Bucket angle φ Roll angle

Claims

1. A lower running body; An upper rotating body rotatably provided on the lower traveling body; an attachment provided on the upper rotating body and holding a bucket; The attachment has a rotator unit that rotates the bucket in a roll direction about an axis of a base end of the bucket to adjust a roll angle of an opening surface of the bucket, The rotator unit is operated during the rotation operation of the upper rotating body, and the opening surface of the bucket is tilted in the roll direction with respect to a rotation plane formed by a rotation direction. Shovel.

2. A controller for controlling an operation of the rotator unit, The controller adjusts the roll angle based on a rotation acceleration applied to the upper rotating body in a rotation direction. The shovel according to claim 1.

3. The controller increases the roll angle with respect to the turning plane as the absolute value of the turning acceleration increases. The shovel according to claim 2.

4. A controller for controlling an operation of the rotator unit, The controller tilts the opening surface of the bucket in the roll direction based on a preset roll angle during the rotation operation of the upper rotating body. The shovel according to claim 1.

5. The attachment sets the roll angle to be larger at the beginning of the turning motion and at the end of the turning motion than at the intermediate period of the turning motion. A shovel according to any one of claims 1 to 4.

6. The attachment operates a bucket cylinder that adjusts the bucket angle of the bucket during the rotation operation of the upper rotating body, and tilts the opening surface of the bucket in a direction facing the upper rotating body with respect to the rotation plane. A shovel according to any one of claims 1 to 4.

7. The attachment sets a bucket angle in an intermediate period of the swing motion larger than a bucket angle in an initial period of the swing motion and a bucket angle in an end period of the swing motion. The shovel according to claim 6.

8. A controller for controlling the operation of the bucket cylinder, The controller adjusts the bucket angle based on the rotation speed of the upper rotating body. The shovel according to claim 6.

Images