Work equipment

Abstract

The present application provides a kind of working equipment. The characteristic operation part (71) of controller (70) is based on the detection signal input from posture detector (61,62,63) and calculates the horizontal distance (L') between boom base end and stick distal end;In the state that distal end attachment (16) is configured in pressure release position, based on the detection signal input from holding pressure detector (64,65) and horizontal distance (L'), the weight (M3) of distal end attachment is calculated;In the state that distal end attachment (16) is configured in the position different from pressure release position, i.e. position change position, based on the detection signal input from holding pressure detector (64,65), the detection signal input from posture detector (61,62,63) and the weight (M3) of distal end attachment (16), the center of gravity position of distal end attachment (16) is calculated.

Description

Technical Field

[0001] This invention relates to a working device such as a hydraulic excavator. Background Technology

[0002] Previously, working equipment such as hydraulic excavators was known. These hydraulic excavators have a working device including a boom, stick, and remote attachments, and are used for loading workpieces such as sand and waste onto a mobile destination such as a dump truck at the work site. It is known that such hydraulic excavators are equipped with a so-called payload function. This payload function measures the load of the sand, waste, etc., held in the remote attachments such as the bucket and lifting magnet. By utilizing this payload function during the loading operation of the hydraulic excavator onto the dump truck, the amount of the workpiece loaded onto the dump truck (amount of sand, amount of waste) can be calculated. In the calculation of the load using this payload function, data on the weight of the remote attachments and the center of gravity position are used.

[0003] Japanese Patent Publication No. 2007-178362 discloses a method for correcting auxiliary device data, which can easily perform corrections even when an auxiliary device with unknown center of gravity position and weight data is installed on the boom. In this correction method, the pressure of the bucket hydraulic cylinder is released, and the center of gravity of the magnet is positioned directly below the auxiliary device mounting pin. Because the error between the holding force torque calculated based on the boom hydraulic cylinder pressure and the torque of the boom (excluding the magnet) is equal to the torque based on the magnet's weight, the magnet's weight can be calculated. The magnet's center of gravity angle in the magnet's coordinate system is calculated, and the magnet's angle relative to the ground is set. Based on the holding force torque around the auxiliary device mounting pin calculated based on the bucket hydraulic cylinder pressure and the magnet's weight, the horizontal distance from the auxiliary device mounting pin to the magnet's center of gravity is calculated.

[0004] The working device disclosed in Japanese Patent Publication No. 2007-178362 requires pressure sensors for both the boom hydraulic cylinder and the bucket hydraulic cylinder in order to calculate the weight and center of gravity of the magnet. This complicates the device's structure and increases costs. Furthermore, if the pressure sensors are placed near remote attachments such as the bucket or lifting magnet, they are prone to damage. Summary of the Invention

[0005] The purpose of this invention is to provide a working device that can determine the weight and center of gravity of a remote auxiliary device with a simple configuration.

[0006] The provided operating equipment includes: a machine body; a boom having a base end portion, i.e., a boom base end portion, which is undulatingly supported by the machine body; a stick having a stick base end portion, rotatably supported by the distal end portion of the boom, and a distal end portion, i.e., a stick distal end portion, located on the opposite side; a distal attachment having a base end portion, i.e., a distal attachment base end portion, rotatably supported by the distal end portion of the stick; a boom hydraulic cylinder, which is a hydraulic cylinder that causes the boom to undulate relative to the machine body; a stick hydraulic cylinder, which is a hydraulic cylinder that causes the stick to rotate relative to the boom; a distal hydraulic cylinder, which is a hydraulic cylinder that causes the distal attachment to rotate relative to the stick; a posture detector for detecting the posture of the boom, the stick, and the distal attachment; and a holding pressure detector for detecting the... The controller includes: a holding pressure of the boom hydraulic cylinder; and a controller having a characteristic calculation unit, wherein the characteristic calculation unit: calculates the horizontal distance between the base end of the boom and the distal end of the stick based on a detection signal input from the posture detector; calculates the weight of the distal attachment based on the detection signal input from the holding pressure detector and the horizontal distance when the distal attachment is positioned at the pressure release position of the distal hydraulic cylinder; and calculates the center of gravity position of the distal attachment based on the detection signal input from the holding pressure detector, the detection signal input from the posture detector, and the weight of the distal attachment when the distal attachment is positioned at a position different from the pressure release position. Attached Figure Description

[0007] Figure 1 This is a side view of a hydraulic excavator, which is an example of a working device according to an embodiment of the present invention.

[0008] Figure 2 This is a block diagram illustrating the functional structure of the controller for the aforementioned hydraulic excavator.

[0009] Figure 3 This is a schematic diagram illustrating the method for determining the weight and center of gravity of the remote attachment of the aforementioned hydraulic excavator.

[0010] Figure 4 This is a schematic diagram illustrating the method for determining the weight and center of gravity of the remote attachment of the aforementioned hydraulic excavator.

[0011] Figure 5 This is a schematic diagram illustrating the method for determining the weight and center of gravity of the remote attachment of the aforementioned hydraulic excavator.

[0012] Figure 6 This is a schematic diagram illustrating an example of a display screen used to explain the steps of the above-described determination method to an operator.

[0013] Figure 7 This is a schematic diagram illustrating an example of a display screen used to explain the steps of the above-described determination method to an operator. Detailed Implementation

[0014] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

[0015] Figure 1 The embodiment of the present invention refers to a hydraulic excavator as an example of an operating device. Figure 2 This is a schematic diagram showing the configuration of the controller mounted on the aforementioned hydraulic excavator and the circuit controlled by the controller.

[0016] like Figure 1 as well as Figure 2 As shown, the hydraulic excavator 10 includes a lower traveling body 11, an upper slewing body 12 rotatably mounted on the lower traveling body 11, a working device 13 mounted on the upper slewing body 12, multiple operating devices, multiple hydraulic actuators, a hydraulic pump 21A for discharging working oil, a control valve unit 21B, an oil tank 21C, multiple sensors, a controller 70, and a display 80.

[0017] The lower traveling body 11 and the upper slewing body 12 constitute the body of the supporting working device 13. The lower traveling body 11 has a traveling device for moving the hydraulic excavator 10 and can travel on the ground G. The upper slewing body 12 includes a slewing frame 12A, a cab 12B mounted on the frame, and a counterweight. The cab 12B is equipped with an operator's seat, various control levers, operating pedals, etc.

[0018] The working device 13, which performs loading operations to load sand into a dump truck, includes a boom 14, a stick 15, and a bucket 16. The bucket 16 is an example of a remote attachment. Sand is an example of the object of the work, and the dump truck is an example of the destination. The loading operation includes digging to excavate sand and hold it in the bucket 16, moving the held sand onto the dump truck, and discharging the sand onto the dump truck.

[0019] The boom 14 has a base end, i.e., the boom base end, supported by the slewing frame 12A in a manner rotatable about a horizontal axis of rotation A1, and a distal end, i.e., the boom distal end, opposite to it. The stick 15 has a base end, i.e., the stick base end, mounted on the distal end of the boom in a manner rotatable about a horizontal axis of rotation A2, and a distal end, i.e., the stick distal end, opposite to it. The bucket 16 has a base end, i.e., the bucket base end, mounted on the distal end of the stick in a manner rotatable about a horizontal axis of rotation A3, via a bucket mounting pin 26, and a distal end, i.e., the bucket distal end. The bucket base end is an example of a distal accessory base end.

[0020] The system includes multiple operating devices, including a boom operating device 85, a stick operating device 86, and a bucket operating device 87. The boom operating device 85 includes an operating lever for the operator to specify the boom 14's lifting direction, and an operating command signal (i.e., an operation command signal) that inputs the operating direction and amount of the operating lever to the controller 70. The stick operating device 86 includes an operating lever for the operator to specify the stick 15's rotation direction, and an operating command signal (i.e., an operation command signal) that inputs the operating direction and amount of the operating lever to the controller 70. The bucket operating device 87 includes an operating lever for the operator to specify the bucket 16's rotation direction, and an operating command signal (i.e., an operation command signal) that inputs the operating direction and amount of the operating lever to the controller 70.

[0021] Multiple hydraulic actuators include a boom hydraulic cylinder 17 for raising and lowering the boom 14, a stick hydraulic cylinder 18 for rotating the stick 15, a bucket hydraulic cylinder 19 for rotating the bucket 16, and a swing motor 20 for rotating the upper slewing body 12 relative to the lower traveling body 11. The bucket hydraulic cylinder 19 is an example of a distal hydraulic cylinder.

[0022] The boom hydraulic cylinder 17 is located between the slewing frame 12A of the upper slewing body 12 and the boom 14. It extends or retracts by receiving working oil discharged from the hydraulic pump 21A, thereby causing the boom 14 to rotate relative to the slewing frame 12A in the standing or falling direction.

[0023] The boom hydraulic cylinder 18, located between the boom 14 and the boom 15, extends or retracts by receiving working oil discharged from the hydraulic pump 21A, thereby causing the boom 15 to rotate relative to the boom 14 in either the retracting or pushing direction. The retracting direction is the direction in which the distal end of the boom 15 approaches the boom 14, while the pushing direction is the direction in which the distal end of the boom 15 moves away from the boom 14.

[0024] The bucket hydraulic cylinder 19, located between the stick 15 and the bucket 16, extends or retracts by receiving working oil discharged from the hydraulic pump 21A, thereby causing the bucket 16 to rotate relative to the stick 15 in either the retracting or pushing direction. The retracting direction is the direction in which the distal end of the bucket 16 approaches the boom 14, and the pushing direction is the direction in which the distal end of the bucket 16 moves away from the boom 14.

[0025] Specifically, the base end of the bucket hydraulic cylinder 19 is rotatably connected to the vicinity of the base end of the stick 15. The distal end of the bucket hydraulic cylinder 19 is connected to the stick 15 via a first connecting rod member 22A and to the bucket 16 via a second connecting rod member 22B. The base end of the first connecting rod member 22A is rotatably mounted to the distal end of the bucket hydraulic cylinder 19 via a connecting rod mounting pin 23, and the distal end of the first connecting rod member 22A is rotatably mounted to the stick 15 via a connecting rod mounting pin 24. The base end of the second connecting rod member 22B is rotatably mounted to the distal end of the bucket hydraulic cylinder 19 via a connecting rod mounting pin 23, and the distal end of the second connecting rod member 22B is rotatably mounted to the bucket 16 via a connecting rod mounting pin 25. By having the first and second connecting rod components 22A and 22B extend and retract along with the bucket hydraulic cylinder 19, the driving force of the bucket hydraulic cylinder 19 is transmitted to the bucket 16, and the bucket 16 rotates around the bucket mounting pin 26 (around the rotating shaft A3).

[0026] The control valve unit 21B is located between the hydraulic pump 21A and multiple hydraulic actuators, regulating the flow rate and direction of the working oil supplied to each of the multiple hydraulic actuators. Specifically, the control valve unit 21B includes a boom control valve that regulates the flow rate and direction of the working oil supplied to the boom hydraulic cylinder 17, a stick control valve that regulates the flow rate and direction of the working oil supplied to the stick hydraulic cylinder 18, and a bucket control valve that regulates the flow rate and direction of the working oil supplied to the bucket hydraulic cylinder 19.

[0027] For example, if the aforementioned operation command signal is input from the bucket operating device 87, the controller 70 inputs a command signal corresponding to that operation command signal to the bucket proportional valve 21D. The pilot pressure, reduced by the pressure in the bucket proportional valve 21D according to the command signal, is input to one of a pair of pilot ports of the bucket control valve. Because the working oil of the hydraulic pump 21A is supplied at a flow rate corresponding to the command signal to the head chamber and the stick chamber of the bucket hydraulic cylinder 19 corresponding to the command signal, the bucket 16 rotates at a speed corresponding to the command signal in the direction corresponding to the command signal. The boom control valve and the stick control valve operate on the boom 14 and the stick 15 in the same way as the bucket 16.

[0028] Furthermore, when performing pressure release control to relieve pressure in the bucket hydraulic cylinder 19, the controller 70 outputs a command signal to the bucket proportional valve 21D (electromagnetic proportional pressure reducing valve) for adjusting the position of the spool valve of the bucket control valve. This disconnects the oil circuit between the bucket hydraulic cylinder 19 and the hydraulic pump 21A, allowing the working oil of the bucket hydraulic cylinder 19 to return to the oil tank 21C. Moreover, in the case where a pressure release valve is separately provided for releasing pressure, distinct from the bucket control valve, the controller 70 outputs a command signal to the aforementioned pressure release valve to disconnect the oil circuit between the bucket hydraulic cylinder 19 and the hydraulic pump 21A, allowing the working oil of the bucket hydraulic cylinder 19 to return to the oil tank 21C via the aforementioned pressure release valve. As a result, the pressure in the head chamber and the rod chamber of the bucket hydraulic cylinder 19 is released, and the bucket 16 is configured to hang downwards from the stick 15 using its own weight.

[0029] like Figure 2 As shown, the aforementioned sensors include a boom angle sensor 61, a stick angle sensor 62, a bucket angle sensor 63 (remote attachment angle sensor), a boom head pressure sensor 64 (boom H pressure sensor), and a boom rod pressure sensor 65 (boom R pressure sensor). The boom head pressure sensor 64 and the boom rod pressure sensor 65 are examples of holding pressure detectors. The holding pressure detector inputs a detection signal regarding the holding pressure of the boom hydraulic cylinder 17 to the controller 70.

[0030] The boom angle sensor 61 generates a detection signal regarding the angle of the boom 14, i.e., the boom angle, and inputs this detection signal to the controller 70. The boom angle sensor 61 is configured, for example, at the boom base end. Figure 1 As shown, the aforementioned boom angle can be represented by the angle θ1 formed by the straight line 14L passing through the base end and the distal end of the boom and the horizontal plane H. However, it can also be represented by the angle θ1 formed by the straight line 14L and other reference lines (reference planes). Specifically, the straight line 14L can, for example, be... Figure 1 A straight line passing through rotation axis A1 and rotation axis A2 in the side view.

[0031] The stick angle sensor 62 generates a detection signal regarding the angle of the stick 15, i.e., the stick angle, and inputs this detection signal to the controller 70. The stick angle sensor 62 is configured, for example, at the base end of the stick. The aforementioned stick angle can be represented by the angle θ2 formed by the straight line 15L passing through the base end and the distal end of the stick and the aforementioned straight line 14L. Specifically, the straight line 15L can also be, for example, in... Figure 1 A straight line passing through rotation axis A2 and rotation axis A3 in the side view.

[0032] The bucket angle sensor 63 generates a detection signal regarding the angle of the bucket 16, i.e., the bucket angle, and inputs this detection signal to the controller 70. The bucket angle sensor 63 is positioned, for example, near the connecting rod mounting pin 24, and can generate the detection signal regarding the bucket angle by detecting the rotation of the first connecting rod member 22A or the rotation of the connecting rod mounting pin 24. However, the bucket angle sensor 63 can also generate the detection signal regarding the bucket angle by, for example, detecting the rotation of the connecting rod mounting pin 23, the rotation of the connecting rod mounting pin 25, or the rotation of the bucket 16 about the rotation axis A3. The aforementioned bucket angle can be represented by the angle θ3 formed by the straight line 16L passing through the base end and the distal end of the bucket and the aforementioned straight line 15L. Specifically, the straight line 16L can also be, for example, in… Figure 1 A straight line passing through the rotation axis A3 and the far end of the bucket 16 in the side view.

[0033] The boom head pressure sensor 64 generates a detection signal regarding the pressure in the head chamber of the boom hydraulic cylinder 17, i.e., the head pressure, and inputs this detection signal to the controller 70. The boom rod pressure sensor 65 generates a detection signal regarding the pressure in the rod chamber of the boom hydraulic cylinder 17, i.e., the rod pressure, and inputs this detection signal to the controller 70.

[0034] The boom angle sensor 61, stick angle sensor 62, and bucket angle sensor 63 (remote attachment angle sensor) are examples of attitude detectors that detect the posture of the boom 14, stick 15, and bucket 16 (remote attachment). However, the attitude detector is not limited to the angle sensors 61, 62, and 63 described above. For example, the attitude detector may be composed of multiple sensors capable of detecting the strokes of the boom hydraulic cylinder 17, stick hydraulic cylinder 18, and bucket hydraulic cylinder 19, respectively. Furthermore, the attitude detector may be a device that includes a receiver capable of receiving satellite signals, for example, from a GNSS satellite positioning system. Moreover, the attitude detector may be a device that includes, for example, an inertial measurement unit (IMU).

[0035] The display 80 is positioned within the cab 12B in a location accessible to an operator seated in their seat. The display 80 can transmit electrical signals to the controller 70. Specifically, the display 80 can, for example, receive input image signals related to the displayed image from the controller 70 and display the image on its screen. Furthermore, the display 80 includes, for example, an input device that allows the operator to input a command signal corresponding to a portion of the image displayed on the screen of the display 80 to the controller 70.

[0036] The hydraulic excavator 10 includes a start input receiving unit for allowing the operator to specify the start of a calibration (an example of a determination process) to determine the weight and center of gravity position of the bucket 16. Upon receiving input from the operator, this start input receiving unit inputs a start command signal, indicating the commencement of the aforementioned remote calibration, to the controller 70. In this embodiment, the start input receiving unit includes a switch 81 mounted on the display 80. Specifically, for example, the start input receiving unit may include a switch image displayed on the screen of the display 80 as the switch 81, or it may be an input device containing a switch located elsewhere on the display 80.

[0037] The controller 70 includes components such as a CPU and a memory. The controller 70 is used to determine the weight and center of gravity of the bucket 16, and includes a characteristic calculation unit 71, a data storage unit 72, and a guide output unit 73.

[0038] The characteristic calculation unit 71 performs various calculations for performing the aforementioned remote calibration to determine the weight and center of gravity position of the bucket 16.

[0039] During the aforementioned remote calibration process, the data storage unit 72 temporarily stores various data, including data related to the weight and center of gravity position of the bucket 16 determined through the remote calibration. Furthermore, the data storage unit pre-stores data related to the boom 14, including its dimensions, weight, and center of gravity position; and data related to the stick 15, including its dimensions, weight, and center of gravity position. The data related to the boom 14's dimensions includes the distance from rotation axis A1 to rotation axis A2, and the data related to the stick 15's dimensions includes the distance from rotation axis A2 to rotation axis A3.

[0040] The guide output unit 73 outputs information indicating the steps of the remote calibration to the display 80 during the remote calibration process.

[0041] Determining the weight and center of gravity of the remote accessory device Secondly, refer to Figures 3 to 5 The method for determining the weight and center of gravity of an example of a remote auxiliary device, namely the bucket 16, is explained.

[0042] If the operator presses the switch 81 of the aforementioned start input receiving unit, the start input receiving unit will input a start command signal indicating the start of remote calibration to the controller 70.

[0043] If the controller 70 receives the aforementioned start command signal, it automatically begins the aforementioned remote calibration. If the controller 70 receives the aforementioned start command signal, it first executes the pressure release mode (pressure release control). The pressure release mode is a control mode that performs pressure release to release the pressure of the bucket hydraulic cylinder 19.

[0044] In pressure relief mode, if the operator operates the lever of the bucket operating device 87 to input an operation command signal to the controller 70, the controller 70 outputs a command signal allowing the working oil (working oil on the holding side) of the bucket hydraulic cylinder 19 to return to the oil tank 21C through the aforementioned bucket control valve or the aforementioned pressure relief valve. That is, the controller 70, based on the operation command signal output from the bucket operating device 87 through the operator's operation of the lever, outputs a command signal to the bucket proportional valve 21D or the aforementioned pressure relief valve. As a result, the pressure in the bucket hydraulic cylinder 19 is released, and the bucket 16 rotates under its own weight, configured to drop downwards from the distal end (top position of the stick) of the stick 15. That is, the bucket 16 falls freely about the rotation axis A3 and stops. At this time, the center of gravity of the bucket 16, as... Figure 3 As shown, it is located directly below the rotation axis A3, that is, on the vertical line passing through the rotation axis A3. Figure 3 The position of the bucket 16 shown is called the pressure release position.

[0045] The bucket 16 is configured in Figure 3 In the pressure release position shown, assume the horizontal distance between the boom base end (boom foot) and the stick distal end (stick top) is L'. That is, the horizontal distance L' is the horizontal distance between rotation shaft A1 and rotation shaft A3, and also the horizontal distance between the boom base end and the bucket base end. The characteristic calculation unit 71 of the controller 70 calculates the horizontal distance L' based on the detection signal input from the boom angle sensor 61 and the detection signal input from the stick angle sensor 62.

[0046] Secondly, the characteristic calculation unit 71, with the bucket 16 configured in the pressure release position, calculates the holding force of the boom hydraulic cylinder 17 based on the detection signals from the boom head pressure sensor 64 and the boom lever pressure sensor 65. Furthermore, based on the calculated holding force of the boom hydraulic cylinder 17 and the distance between the boom foot and the hydraulic cylinder axis of the boom hydraulic cylinder 17, the characteristic calculation unit 71 calculates the torque τ of the working device 13 around the boom foot (around the rotation axis A1).

[0047] Here, the total torque τ is the sum of the torque of the boom 14 about the boom base end (about the rotation axis A1), i.e., the boom torque τb, the torque of the stick 15 about the boom base end (about the rotation axis A1), i.e., the stick torque τa, and the torque of the bucket 16 about the boom base end (about the rotation axis A1), i.e., the bucket torque τbu (τ=τb+τa+τbu). Therefore, the bucket torque τbu is expressed by the following formula (1).

[0048] τbu=τ-τb-τa... (1) Moreover, since the bucket torque τbu acts as a torque about the boom base end (about the rotation axis A1), the bucket torque τbu can be expressed by formula (2) which utilizes the above-mentioned horizontal distance L' and the weight M3 of the bucket 16 (far end weight M3), and formula (2) can be rewritten as formula (3).

[0049] τbu=M3×L' …… (2) M3=τbu / L' …… (3) Because the weight and center of gravity of the boom 14 and the stick 15 are pre-stored in the data storage unit 72, the boom torque τb and the stick torque τa can be calculated based on the weight and center of gravity of the boom 14 and the stick 15, the detection signal input from the boom angle sensor 61 and the detection signal input from the stick angle sensor 62, respectively.

[0050] Furthermore, the boom angle θ1 of the boom 14 and the stick angle θ2 of the stick 15 are adjusted to a preset posture with high detection accuracy (specific boom angle θ1s, specific stick angle θ2s), and corresponding remote calibration is performed in this state. In this case, the data storage unit 72 stores the specific boom angle θ1s and the specific stick angle θ2s in advance. The specific boom angle θ1s and the specific stick angle θ2s are set, for example, as follows: With the bucket 16 (remote attachment) not installed on the stick 15, multiple postures are used to change the settings of the boom angle 14 and the stick angle 15. Multiple data such as the boom moment τb and the stick moment τa around the boom base end are obtained in advance through actual measurement. The posture with high detection accuracy can be selected from the multiple actual measurement data obtained, and the angle of the boom 14 and the angle of the stick 15 corresponding to the selected posture are stored in advance as the specific boom angle θ1s and the specific stick angle θ2s in the data storage unit 72 of the controller 70. Thus, by adjusting the boom angle θ1 and stick angle θ2 to obtain high-precision torques τb and τa (specific boom angle θ1s, specific stick angle θ2s) for remote calibration, the resultant torque (total torque τ, τ') when the bucket 16 is installed onto the stick 15 can be calculated with high precision.

[0051] The characteristic calculation unit 71 calculates the bucket torque τbu according to formula (1), total torque τ, boom torque τb and stick torque τa, and calculates the weight M3 of bucket 16 according to the calculated bucket torque τbu and formula (3).

[0052] Here, as Figure 3 As shown, assume that the straight line connecting the rotating shaft A3 of the bucket 16 and the far end of the bucket 16 is the reference line RL, and the angle between the reference line RL and the vertical line is the ground angle η. When the bucket 16 is configured in the pressure release position described above, since the center of gravity of the bucket 16 is located on the vertical line connecting the rotating shaft A3 of the bucket 16, the ground angle η of the bucket 16 and the angle between the straight line connecting the rotating shaft A3 and the center of gravity of the bucket 16 and the reference line RL are the same as the bucket center of gravity angle Bugdeg.

[0053] The aforementioned bucket center of gravity angle Bugdeg is calculated as shown below. The feature calculation unit 71 can calculate the aforementioned bucket center of gravity angle Bugdeg based on the detection signal input from the bucket angle sensor 63 when the bucket 16 is positioned so that the reference line RL is oriented vertically (reference position) and the detection signal input from the bucket angle sensor 63 when the bucket 16 is positioned in the aforementioned pressure release position.

[0054] Once the calculations for the weight M3 of the bucket 16 and the bucket center of gravity angle Bugdeg are completed, the controller 70 will terminate the pressure release mode (pressure release control).

[0055] Secondly, the bucket 16 is positioned at a different location than the aforementioned pressure release position, i.e., a displaced position. This displaced position is the position where the bucket 16 is repositioned from the aforementioned pressure release position towards either the bucket retraction direction or the bucket push direction. Figure 4 , from the bucket 16 Figure 3 The pressure release position shown is exemplified as the displacement position after rotating around the rotation axis A3 towards the direction of pushing the bucket. However, the displacement position of the bucket 16 can also be the position after rotating around the rotation axis A3 towards the direction of retracting the bucket.

[0056] If the bucket 16 moves from the pressure release position to the displacement position, because the center of gravity of the bucket 16 shifts, the torque of the working device 13 around the boom foot (around the rotation axis A1) changes from the total torque τ to the total torque τ'. During the process of the bucket 16 moving from the pressure release position to the displacement position, because the boom 14 and stick 15 do not shift, the boom torque τb and stick torque τa remain unchanged. However, if the bucket 16 moves from the pressure release position to the displacement position, the position of the center of gravity of the bucket 16 is as follows: Figure 4 The horizontal movement distance x is shown. Therefore, the difference between the total torque τ' and the total torque τ is due to the change in the torque of the bucket 16 around the boom foot (around the rotation axis A1) from bucket torque τbu to bucket torque τ'bu as the center of gravity of the bucket 16 changes. Therefore, the following formula (4) holds.

[0057] τ'bu=τ'-τb-τa... (4) The characteristic calculation unit 71, when the bucket 16 is configured in the displaced position, calculates the holding force of the boom hydraulic cylinder 17 based on the detection signals from the boom head pressure sensor 64 and the boom lever pressure sensor 65. Furthermore, based on the calculated holding force of the boom hydraulic cylinder 17 and the distance between the boom foot and the hydraulic cylinder axis of the boom hydraulic cylinder 17, the characteristic calculation unit 71 calculates the torque τ' of the working device 13 about the boom foot (about the rotation axis A1).

[0058] Since the bucket torque τ'bu acts as a torque around the boom base end (around the rotation axis A1), the bucket torque τ'bu can be expressed by formula (5) which utilizes the above-mentioned horizontal distance (L'+x) and the weight M3 of the bucket 16.

[0059] τ'bu = M3×(L'+x) ... (5) Formula (5) can be rewritten as the following formula (6).

[0060] x=τ'bu / M3 - L' …… (6) The characteristic calculation unit 71 calculates the horizontal movement distance x based on the calculated total torque τ' and formulas (4) and (6).

[0061] Here, it is assumed that by causing bucket 16 to... Figure 3 The pressure release position shown above has been shifted to Figure 4 The angle of change of the center of gravity position due to the above displacement position is ΔBudeg, as shown above. Figure 5 As shown, the length from the bucket mounting pin 26 (rotation shaft A3) to the center of gravity of the bucket 16 is L. In this case, the length L can be expressed by the following formula (7) using the horizontal movement distance x and the center of gravity change angle Δbudeg mentioned above.

[0062] L=x / sin(ΔBudeg)……(7) The characteristic calculation unit 71 calculates the aforementioned center of gravity change angle ΔBudeg based on the detection signal input from the bucket angle sensor 63. Furthermore, the characteristic calculation unit 71 calculates the length L based on the calculated center of gravity change angle ΔBudeg and formula (7).

[0063] Here, refer to Figure 5 The length L, the baseline RL, and the bucket center of gravity angle Bugdeg have a relationship expressed by the following formulas (8) and (9).

[0064] L3g=L・cos(Bugdeg)……(8) H3g=L・sin(Bugdeg)……(9) L3g is the component of length L in the direction parallel to the baseline RL, and H3g is the component of length L in the direction perpendicular to the baseline RL. The characteristic calculation unit 71 calculates the parallel component L3g and the perpendicular component H3g of length L based on the calculated length L and formulas (8) and (9). Thus, the center of gravity position of the bucket 16 can be determined by these components L3g and H3g.

[0065] As described above, the hydraulic excavator 10 of this embodiment can determine the weight and center of gravity of the bucket 16 even without using the detection results of a pressure sensor that detects the pressure of the bucket hydraulic cylinder. For example, in the technology disclosed in Japanese Patent Publication No. 2007-178362, when determining the center of gravity of the remote accessory, in order to detect the holding pressure of the bucket hydraulic cylinder, a pressure sensor and its associated wiring need to be installed in a location near the bucket that is prone to damage, which also leads to increased costs. However, the hydraulic excavator 10 of this embodiment does not require a pressure sensor for detecting the pressure of the bucket hydraulic cylinder. However, the present invention does not exclude the use of a pressure sensor for detecting the pressure of the bucket hydraulic cylinder. In applications other than determining the weight and center of gravity of the remote accessory, if necessary, a working device equipped with a pressure sensor for detecting the pressure of the bucket hydraulic cylinder may be included.

[0066] Guide function Secondly, refer to Figure 6 as well as Figure 7 The guidance function related to determining the weight and center of gravity of the remote accessory device is explained.

[0067] The hydraulic excavator 10 according to this embodiment displays the process for determining the weight and center of gravity of the aforementioned remote auxiliary device on the screen of the display 80. The operator can proceed with the process according to the instructions on the screen (cluster screen guidance function). Moreover, as described above, this guidance automatically begins when the operator presses the switch 81 of the start input reception unit, first executing the pressure release mode. Therefore, it is possible to simplify the execution of the aforementioned process and shorten the time, and to ensure an easy-to-operate configuration for the operator. Specifically, as shown below.

[0068] Figure 6The “(1) Pre-pressure release posture” shown in the left figure indicates the display screen of the display 80 before the above calibration begins. This display screen (1) provides guidance to the operator to adjust the boom angle θ1 of the boom 14 to the aforementioned specific boom angle θ1s (e.g., 40 degrees) and the stick angle θ2 of the stick 15 to the aforementioned specific stick angle θ2s (e.g., 147 degrees). This display screen (1) also provides guidance to the operator to adjust the specific boom angle θ1s to, for example, a range of boom angle θ1 = 38 to 42 degrees and the specific stick angle θ2s to, for example, a range of 145 to 149 degrees. The operator, according to this guidance, operates the boom operating device 85 and the stick operating device 86 to adjust the boom angle θ1 of the boom 14 to the aforementioned specific boom angle θ1s and the stick angle θ2 of the stick 15 to the aforementioned specific stick angle θ2s. Furthermore, after adjusting the boom angle θ1 and stick angle θ2, the display screen (1) provides guidance to the operator to press the switch 81. The guidance output unit 73 of the controller 70 outputs the image signal of the aforementioned display screen (1) to the display screen 80.

[0069] Figure 6 The central image shown as "(2) Pressure Relief Digging Operation" indicates the display screen of the monitor 80 after the aforementioned calibration has begun. This display screen (2) provides guidance to the operator that the control mode has been set to pressure relief mode. Furthermore, this display screen (2) also provides guidance to the operator that the lever of the bucket operating device 87 is operated in the bucket retraction direction (digging operation direction), that this operation continues until the bucket 16 is configured to hang downwards from the distal end of the stick and the wobbling of the bucket 16 stops, and that after the bucket 16 stops, the lever lock is opened (ON) (the lever lock is lifted upwards). The guidance output unit 73 outputs the image signal of the aforementioned display screen (2) to the monitor 80. Figure 6 The specific example shown in the central diagram illustrates how pressure is released from the bucket hydraulic cylinder 19 by operating the lever of the bucket operating device 87 in the bucket retraction direction. Furthermore, the aforementioned lever lock is located in an operator-operable position within the cab 12B. If the lever lock is open, the operation of the operating lever cannot be accepted. That is, with the lever lock open, even if the operator operates the operating levers of the boom operating device 85, stick operating device 86, bucket operating device 87, etc., the working device 13 of the hydraulic excavator 10 will not operate. If the lever lock is open, a second sampling is performed.

[0070] Figure 6The "(3) Sample Hold" screen shown in the right figure is a display screen that is automatically displayed when a signal indicating that the lever lock is open is input to the controller 70. This display screen (3) serves as a guide to inform the operator to remain in standby mode until the buzzer sounds. The guide output unit 73 outputs the image signal of the aforementioned display screen (3) to the display 80. During this standby time, the characteristic calculation unit 71 of the controller 70 performs the aforementioned calculations and obtains the weight M3 of the bucket 16 while the bucket 16 is configured in the aforementioned pressure release position. If the buzzer sounds after the standby time, the operator can realize that the lever lock can be turned off (downward lever lock operation). The operator turns off the lever lock.

[0071] Figure 7 The “(4) Displacement of remote auxiliary device” shown in the left figure is a display screen that is automatically displayed after the aforementioned standby time. This display screen (4) provides guidance to the operator to move the bucket 16 from the aforementioned pressure release position to the aforementioned displacement position. Figure 7 The specific example shown in the left figure involves the bucket 16 being pulled from... Figure 6 The position where the pressure release position is rotated towards the bucket retraction direction in the central image is shown as the displacement position. The display screen (4) also shows instructions to the operator to operate the lever of the bucket operating device 87 towards the bucket retraction direction until the buzzer sounds (until the notification device notifies the operator that the bucket 16 has moved from the pressure release position to the displacement position), to return the lever to the neutral position when the notification device notifies the operator, and then to unlock the lever (lift the lever lock upwards). By having the operator perform these operations, the bucket 16 is positioned in the displacement position. The guide output unit 73 outputs the image signal of the display screen (4) to the display 80.

[0072] Figure 7The "(5) Sample Hold" screen shown in the central diagram is a display screen that is automatically displayed when a signal indicating that the lever lock is open is input to the controller 70. This display screen (5) serves as a guide to inform the operator to remain in standby mode until the buzzer sounds. The guide output unit 73 outputs the image signal of the aforementioned display screen (5) to the display 80. During this standby time, the characteristic calculation unit 71 of the controller 70 performs the aforementioned calculations and obtains the center of gravity position of the bucket 16, i.e., the parallel component L3g and the vertical component H3g of the length L. If the aforementioned standby time has elapsed, the aforementioned remote calibration, i.e., the process for determining the weight and center of gravity position of the remote auxiliary device, ends. Since the buzzer sounds when the processing ends, the operator can be aware that the aforementioned remote calibration has been completed.

[0073] Figure 7 The display screen shown in the lower right figure is the screen that is automatically displayed after the aforementioned remote calibration is completed. This display screen is for the loading operation performed after the aforementioned remote calibration. The hydraulic excavator 10 according to this embodiment includes a load measuring device (load measuring device) for measuring the load of sand held by the bucket 16. Since various known technologies can be used for the load measuring device, a detailed description of it is omitted. The hydraulic excavator 10 performs excavation operations to dig sand and hold it in the bucket 16, movement operations to move the held sand onto a dump truck, and dumping operations to discharge the sand onto the dump truck. Figure 7 The lower right image displays the load of the sand held by the bucket 16 as the "remote load", the total load of the soil discharged into the dump truck (total weight of sand) as the "loading load", and the target load of loading sand into the dump truck as the "loading target" in real time.

[0074] As described above, in the hydraulic excavator 10 of this embodiment, the characteristic calculation unit 71 of the controller 70 calculates the horizontal distance L' between the base end of the boom and the distal end of the stick based on the detection signals input by the driven boom angle sensor 61 and the stick angle sensor 62; when the bucket 16 is positioned at the pressure release position when the pressure of the bucket hydraulic cylinder 19 is released, the weight M3 of the bucket 16 is calculated based on the detection signals input by the driven boom head pressure sensor 64 and the boom rod pressure sensor 65 and the horizontal distance L'; when the bucket 16 is positioned at a position different from the pressure release position, i.e., the displacement position, the center of gravity position of the bucket 16 is calculated based on the detection signals input by the driven boom head pressure sensor 64 and the boom rod pressure sensor 65, the detection signal input by the bucket angle sensor 63, and the weight M3 of the bucket 16.

[0075] That is, the characteristic calculation unit 71 can calculate the weight M3 of the bucket 16 based on the horizontal distance L' and the holding pressure of the boom hydraulic cylinder 17 when the bucket 16 is configured in the pressure release position, and calculate the center of gravity position of the bucket 16 based on the holding pressure of the boom hydraulic cylinder 17 when the bucket 16 is configured in the displacement position, position data related to the displacement of the bucket 16, and the calculated weight M3. Therefore, it is not necessary to use a pressure sensor to detect the pressure of the bucket hydraulic cylinder as described in the prior art, and the weight and center of gravity position of the remote auxiliary device can be determined with a simple configuration.

[0076] Furthermore, in this embodiment, the operator does not need to perform cumbersome operations. The operator only needs to input information into the start input reception unit to begin the aforementioned remote calibration (determination process). Moreover, the operator only needs to operate the hydraulic excavator 10 according to the guidance of this determination process displayed on the display 80, which allows the controller 70 to determine the weight and center of gravity position of the bucket 16. The guidance involves a simple operation, such as moving the bucket 16 from the aforementioned pressure release position to the aforementioned displacement position. Thus, by simplifying the operations required of the operator, operability can be improved and the time required for the determination process can be shortened.

[0077] Furthermore, in this embodiment, the aforementioned determination process is performed while the postures of the boom 14 and the stick 15 are adjusted to a pre-set posture with high detection accuracy (a specific boom angle θ1s and a specific stick angle θ2s). Thus, for example, multiple data such as the boom torque τb and the stick torque τa around the boom base end can be pre-acquired through actual measurements, and a posture with high detection accuracy can be selected and stored in the data storage unit 72 of the controller 70. This allows for high-precision determination of the weight and center of gravity position of the bucket 16 using the stored posture with high accuracy.

[0078] This invention is not limited to the embodiments described above. For example, this invention also includes embodiments as described below.

[0079] (A) Regarding operating equipment The working equipment involved in the above embodiments is a hydraulic excavator 10, but the working equipment can also be other than a hydraulic excavator.

[0080] (B) Regarding remote auxiliary devices The remote attachment device involved in the above embodiment is the bucket 16, but the remote attachment device can also be other remote attachment devices such as lifting magnets, forks, grabs, etc.

[0081] (C) Regarding the boom angle and stick angle In the above embodiment, the characteristic calculation unit 71 calculates the weight and center of gravity position of the remote auxiliary device when the angle θ1 of the boom 14 is adjusted to a specific boom angle θ1s and the angle θ2 of the stick 15 is adjusted to a specific stick angle θ2s, but it is not limited to this. The characteristic calculation unit may also calculate the weight and center of gravity position of the remote auxiliary device when the angle of the boom is adjusted to any angle other than the specific boom angle θ1s and the angle of the stick is adjusted to any angle other than the specific stick angle θ2s.

[0082] (D) Regarding pressure relief mode (pressure relief control) In the above embodiment, the controller 70, in pressure release mode (pressure release control), outputs a command signal to the bucket proportional valve 21D or the pressure release valve to release the pressure of the bucket hydraulic cylinder 19 according to the operator's operation of the control lever, but is not limited thereto. If the controller 70 receives the start command signal from the start input receiving unit, it can output a command signal to the bucket proportional valve 21D or the pressure release valve to release the pressure of the bucket hydraulic cylinder 19 even if the operator does not operate the control lever.

[0083] Furthermore, in the above embodiment, in the pressure release mode, a guidance display is provided for operating the lever of the bucket operating device 87 in the direction of retracting the bucket, but a guidance display can also be provided for operating in the direction of pushing the bucket.

[0084] As described above, according to the present invention, a working device is provided that can determine the weight and center of gravity position of a remote accessory with a simple configuration.

[0085] The provided operating equipment includes: a machine body; a boom having a base end portion, i.e., a boom base end portion, which is undulatingly supported by the machine body; a stick having a stick base end portion, rotatably supported by the distal end portion of the boom, and a distal end portion, i.e., a stick distal end portion, located on the opposite side; a distal attachment having a base end portion, i.e., a distal attachment base end portion, rotatably supported by the distal end portion of the stick; a boom hydraulic cylinder, which is a hydraulic cylinder that causes the boom to undulate relative to the machine body; a stick hydraulic cylinder, which is a hydraulic cylinder that causes the stick to rotate relative to the boom; a distal hydraulic cylinder, which is a hydraulic cylinder that causes the distal attachment to rotate relative to the stick; a posture detector for detecting the posture of the boom, the stick, and the distal attachment; and a holding pressure detector for detecting the... The controller includes: a holding pressure of the boom hydraulic cylinder; and a controller having a characteristic calculation unit, wherein the characteristic calculation unit: calculates the horizontal distance between the base end of the boom and the distal end of the stick based on a detection signal input from the posture detector; calculates the weight of the distal attachment based on the detection signal input from the holding pressure detector and the horizontal distance when the distal attachment is positioned at the pressure release position of the distal hydraulic cylinder; and calculates the center of gravity position of the distal attachment based on the detection signal input from the holding pressure detector, the detection signal input from the posture detector, and the weight of the distal attachment when the distal attachment is positioned at a position different from the pressure release position.

[0086] In this working device, the controller's characteristic calculation unit can calculate the weight of the remote attachment based on the horizontal distance and the holding pressure of the boom hydraulic cylinder when the remote attachment is configured in the pressure release position. It can also calculate the center of gravity position of the remote attachment based on the holding pressure of the boom hydraulic cylinder when the remote attachment is configured in the displacement position, position data related to the displacement of the remote attachment, and the calculated weight. Therefore, it eliminates the need for a pressure sensor to detect the pressure of the bucket hydraulic cylinder, as described in the prior art, and the weight and center of gravity position of the remote attachment can be determined with a simple configuration. The holding pressure detector can, for example, be constructed from at least one pressure sensor used to detect the holding pressure of the boom hydraulic cylinder.

[0087] Furthermore, preferably, the operating equipment further includes: a start input receiving unit for receiving input from the operator to specify the start of a determination process for determining the weight and center of gravity position of the remote accessory device, and outputting a command signal corresponding to the input to the controller. The controller, upon receiving the command signal, initiates the determination process. The controller also includes a guidance output unit that, upon initiation of the determination process, outputs an image signal to a display causing the display to show an image related to the guidance of the determination process. With this configuration, the operator does not need to perform cumbersome operations; the operator only needs to input into the start input receiving unit to start the determination process. Moreover, the operator only needs to manipulate the operating equipment according to the guidance of the determination process displayed on the display to enable the controller to determine the weight and center of gravity position of the remote accessory device. Thus, by simplifying the operations required of the operator, operability is improved and the time required for the determination process is shortened.

[0088] Furthermore, preferably, the controller, upon receiving the instruction signal, performs pressure release control during the determination process to release the pressure of the remote hydraulic cylinder. In this configuration, pressure release control is automatically performed (automatically set to pressure release mode) if the operator inputs information to the start input reception unit. Therefore, the operation required by the operator can be further simplified, and the time required for the determination process can be further shortened.

[0089] Furthermore, preferably, the controller also includes a data storage unit for storing a pre-set boom angle (specific boom angle) and a pre-set stick angle (specific stick angle). The characteristic calculation unit calculates the weight and center of gravity position of the remote auxiliary device when the boom angle and stick angle are adjusted to the specific boom angle and the stick angle, respectively. With this configuration, the determination process can be performed while the boom and stick postures are adjusted to a pre-set posture with high detection accuracy. Specifically, for example, multiple data points on the boom torque and stick torque around the boom base end can be pre-acquired through actual measurements under multiple postures with varying boom and stick angles. From these acquired data points, a posture with high detection accuracy is selected, and the boom and stick angles corresponding to the selected posture are pre-stored as the specific boom angle and the specific stick angle in the data storage unit. Therefore, the weight and center of gravity position of the remote auxiliary device can be determined with high accuracy using a posture with high detection accuracy.

Claims

1. A working device, characterized in that... include: Organism; The boom has a base end portion, i.e., the boom base end portion, which is supported by the body in an undulating manner. The stick has a stick base end rotatably supported by the distal end of the boom and a distal end, i.e., the stick distal end, located on the opposite side of the stick base end; The distal attachment has a base end that is rotatably supported by the distal end of the stick, i.e., the distal attachment base end; A boom hydraulic cylinder is a hydraulic cylinder that causes the boom to move up and down relative to the machine body. A boom hydraulic cylinder is a hydraulic cylinder that causes the boom to rotate relative to the boom. A remote hydraulic cylinder is a hydraulic cylinder that enables the remote auxiliary device to rotate relative to the boom. A posture detector is used to detect the posture of the boom, the stick, and the distal attachment. A holding pressure detector is used to detect the holding pressure of the boom hydraulic cylinder; and, The controller has a characteristic calculation unit, wherein, The boom, the stick, and the distal auxiliary device constitute the working device. The characteristic calculation unit: When the distal accessory is positioned at the pressure release position of the distal hydraulic cylinder, the horizontal distance between the base end of the boom and the distal end of the stick is calculated based on the detection signal input from the posture detector. With the distal accessory configured in the pressure release position, the torque of the working device around the boom base end is calculated, i.e., the total torque, based on the detection signal input from the holding pressure detector. Calculate the weight of the remote accessory based on the total torque and the horizontal distance; With the distal accessory configured in a position different from the pressure release position, i.e., a displaced position, the torque of the working device around the boom base end is calculated based on the detection signal input from the holding pressure detector. Based on the total torque at the pressure release position and the total torque at the displacement position, calculate the torque of the distal accessory at the displacement position around the boom base end; Based on the detection signal input from the posture detector, the angle of change of the center of gravity of the distal accessory as the distal accessory moves from the pressure release position to the displacement position is calculated. Based on the torque of the distal accessory around the boom base end at the displacement position, the weight of the distal accessory, and the horizontal distance, calculate the horizontal movement distance of the distal accessory as it moves from the pressure release position to the displacement position, and the distance of its center of gravity. The position of the center of gravity of the remote auxiliary device is calculated based on the angle of change of the center of gravity and the horizontal movement distance.

2. The operating equipment according to claim 1, characterized in that... Also includes: The input reception unit receives input from the operator to specify the start of the process for determining the weight and center of gravity position of the remote accessory device, i.e., the determination process, and outputs a command signal corresponding to the input to the controller. The controller, upon receiving the instruction signal, initiates the determination process. The controller also includes a guidance output unit, which outputs an image signal to the display to cause the display to show an image related to the guidance of the determination process if the determination process is started.

3. The operating equipment according to claim 2, characterized in that, If the controller is input with the instruction signal, it performs pressure release control in the determination process to release the pressure of the remote hydraulic cylinder.

4. The operating equipment according to any one of claims 1 to 3, characterized in that, The controller also includes a data storage unit for storing a preset boom angle (i.e., a specific boom angle) and a preset stick angle (i.e., a specific stick angle). The characteristic calculation unit calculates the weight and center of gravity position of the remote auxiliary device when the boom angle is adjusted to the specific boom angle and the stick angle is adjusted to the specific stick angle.

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