Work machine and transported goods weight measurement system

Abstract

To provide a work machine and an article weight measurement system for accurately measuring the weight of an article.SOLUTION: This work machine comprises: an attachment for conveying an article; a weight calculation unit that calculates the weight of the article on the basis of weight during real loading and weight during empty conveying; and a zero reset motion mode switch for starting a process for setting the weight during the empty conveying.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a work machine and a transported object weight measurement system. [Background technology]

[0002] For example, a shovel is known that calculates the weight of the amount of soil in a bucket from the weight of the bucket when it is empty and the weight of the bucket after excavation (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 6-89550 Summary of the Invention [Problem to be solved by the invention]

[0004] In a work machine that measures the weight of transported objects such as soil and sand, it is required that the operator be able to easily adjust the system that measures the weight of the transported object when the work machine starts working or when there is a large error between the measured weight of the transported object and the actual weight of the transported object.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a work machine and a transported object weight measurement system that can calculate the weight of a transported object with high accuracy. [Means for solving the problem]

[0006] In order to achieve the above object, one embodiment of the present invention provides a work machine including an attachment for transporting an object, and a weight calculation unit for calculating a weight of the object based on a weight when the object is actually loaded and a weight when the object is transported empty, the work machine including a zero reset operation mode switch for starting a process for setting the weight when the object is transported empty. The weight calculation unit calculates the weight of the transported object when the attachment reaches a trigger height, and the process also sets the trigger height. A work machine is provided. Effect of the Invention

[0007] According to the above-described embodiment, it is possible to provide a work machine and a transported object weight measurement system that accurately calculate the weight of a transported object. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a shovel as an excavator according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a block diagram illustrating the process of a weight calculation unit. [Diagram 3] 10 is a flowchart illustrating a correction method for a weight calculation unit of a shovel according to the present embodiment. [Figure 4A] FIG. 1 is a diagram showing an example of a work site. [Figure 4B] FIG. 1 is a diagram showing an example of a work site. [Diagram 5] 4 is a graph showing an example of a boom height and a boom raising speed during a boom raising operation. [Figure 6] 13 is an example of a display screen before a reset is started. [Figure 7] 13 is an example of a display screen during a reset process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0010] [Outline of the excavator] First, with reference to FIG. 1, an overview of a shovel 100 according to this embodiment will be described.

[0011] FIG. 1 is a side view of a shovel 100 serving as an excavator, which is an example of a work machine according to this embodiment.

[0012] The excavator 100 in this embodiment comprises a lower running body 1, an upper rotating body 3 mounted on the lower running body 1 so as to be freely rotatable via a rotating mechanism 2, a boom 4, an arm 5, and a bucket 6 that constitute an attachment (work machine), and a cabin 10.

[0013] The lower traveling body 1 has a pair of left and right crawlers that are hydraulically driven by traveling hydraulic motors (not shown), thereby causing the excavator 100 to travel. In other words, the pair of traveling hydraulic motors drive the lower traveling body 1 (crawlers) as a driven part.

[0014] The upper rotating body 3 is driven by a swing hydraulic motor (not shown) to swing relative to the lower traveling body 1. In other words, the swing hydraulic motor is a swing drive part that drives the upper rotating body 3 as a driven part, and can change the orientation of the upper rotating body 3.

[0015] The upper rotating body 3 may be electrically driven by an electric motor (hereinafter, "electric motor for rotation") instead of the hydraulic motor for rotation. In other words, the electric motor for rotation is a rotation drive part that drives the upper rotating body 3 as a driven part, similar to the hydraulic motor for rotation, and can change the orientation of the upper rotating body 3.

[0016] The boom 4 is pivotally attached to the front center of the upper rotating body 3 so as to be able to tilt up and down, an arm 5 is pivotally attached to the tip of the boom 4 so as to be able to rotate up and down, and a bucket 6 as an end attachment is pivotally attached to the tip of the arm 5 so as to be able to rotate up and down. The boom 4, arm 5, and bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, each of which serves as a hydraulic actuator.

[0017] Incidentally, the bucket 6 is an example of an end attachment, and other end attachments, such as a slope bucket, a dredging bucket, a breaker, a lifting magnet, or a grapple, may be attached to the tip of the arm 5 instead of the bucket 6 depending on the work content, etc.

[0018] The rod side end of the bucket cylinder 9 and the bucket 6 are connected by a bucket link 6a. Specifically, the upper end side of the bucket link 6a is rotatably connected to the rod side end of the bucket cylinder 9 and an arm link 6c via a bucket cylinder top pin 6b. The lower end side of the bucket link 6a is rotatably connected to a bracket on the rear surface of the bucket 6 via a bucket pin 6d. In addition, a hook for crane work may be attached to the bucket link 6a so as to be retractable and rotatable.

[0019] During excavation work, the hook is stored in a hook storage section that is mainly composed of the bucket link 6a so as not to interfere with the operation of the bucket 6. On the other hand, during crane work, the hook is configured so that its tip protrudes from the hook storage section.

[0020] The hook storage section may also be provided with a detection device (not shown) that detects the storage state of the hook. For example, the detection device may be a switch that is in a conductive state when a hook is present in the hook storage section and in a cut-off state when no hook is present in the hook storage section, and may be provided in the hook storage section where the hook is stored. The detection signal of the detection device may be input to the controller 30, which will be described later.

[0021] The cabin 10 is a cab in which an operator sits, and is mounted on the front left side of the upper rotating body 3.

[0022] The engine 11 is the main power source in the hydraulic drive system, and is mounted, for example, on the rear of the upper rotating body 3. Specifically, the engine 11 rotates at a constant speed at a preset target speed under direct or indirect control by a controller 30 (described later), and drives a main pump (not shown) and a pilot pump (not shown). The engine 11 is, for example, a diesel engine that uses diesel as fuel.

[0023] 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 mainly configured with a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a non-volatile auxiliary storage device, various input / output interfaces, etc. The controller 30 realizes various functions by, for example, executing various programs stored in the ROM or the non-volatile auxiliary storage device on the CPU.

[0024] For example, the controller 30 sets a target rotation speed based on a work mode or the like that is set in advance by a predetermined operation by an operator or the like, and performs drive control to rotate the engine 11 at a constant speed.

[0025] The controller 30 also has a weight calculation unit 70 (see FIG. 2 described later) that calculates the weight of the object carried by the attachment. When earth and sand are excavated with the bucket 6, the weight calculation unit 70 calculates the weight of the object, such as earth and sand, in the bucket 6. When a load is lifted by the hook, the weight calculation unit 70 calculates the weight of the load (load) lifted by the hook.

[0026] The display device 40 is provided in a location that is easily visible to an operator seated in the cabin 10, and displays various information images under the control of the controller 30. The display device 40 may be connected to the controller 30 via an in-vehicle communication network such as a Controller Area Network (CAN), or may be connected to the controller 30 via a one-to-one dedicated line.

[0027] The input device 42 is provided within reach of an operator seated in the cabin 10, accepts various operational inputs by the operator, and outputs signals corresponding to the operational 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 portion of a lever device (not shown), and button switches, levers, toggles, rotary dials, etc. that are provided around the display device 40. A signal corresponding to the content of an operation performed on the input device 42 is taken into the controller 30.

[0028] The input device 42 also has a mode changeover switch (not shown). The mode changeover switch is a switch for changing the work mode of the shovel 100. The work mode means the type of work performed by the shovel 100, and includes, for example, a crane mode, a normal mode, and the like. The mode changeover switch may be a software switch on a touch panel arranged on the screen of the display device 40, or may be a hardware switch installed in the periphery of the display device 40, or may be a switch installed in another position within the cabin 10.

[0029] The audio output device 43 is provided, for example, in the cabin 10, connected to the controller 30, and outputs audio under the control of the controller 30. The audio output device 43 is, for example, a speaker or a buzzer. The audio output device 43 outputs various information by audio in response to an audio output command from the controller 30.

[0030] The storage device 47 is provided, for example, in the cabin 10, and stores various pieces of information under the control of the controller 30. The storage device 47 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 47 may store information output by various devices during operation of the shovel 100, or may store information acquired via various devices before operation of the shovel 100 is started.

[0031] The boom angle sensor S1 is attached to the boom 4 and detects the elevation angle of the boom 4 relative to the upper rotating body 3 (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 3 in a side view. 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 cylinder 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 below. A detection signal corresponding to the boom angle by the boom angle sensor S1 is taken into the controller 30.

[0032] The arm angle sensor S2 is attached to the arm 5 and detects the rotation angle of the arm 5 relative to the boom 4 (hereinafter referred to as the “arm angle”), for example, the angle formed by a line connecting the fulcrums at both ends of the arm 5 with respect to a line connecting the fulcrums at both ends of the boom 4 in a side view. A detection signal corresponding to the arm angle by the arm angle sensor S2 is input to the controller 30.

[0033] The bucket angle sensor S3 is attached to the bucket 6 and detects the rotation angle of the bucket 6 with respect to the arm 5 (hereinafter referred to as the “bucket angle”), for example, the angle formed by a line connecting the fulcrum of the bucket 6 and the tip (blade tip) with respect to a line connecting the fulcrums of both ends of the arm 5 in a side view. A detection signal corresponding to the bucket angle by the bucket angle sensor S3 is input to the controller 30.

[0034] The machine body inclination sensor S4 detects the inclination state of the machine body (upper rotating body 3 or lower running body 1) with respect to a horizontal plane. The machine body inclination sensor S4 is attached to, for example, the upper rotating body 3, and detects the inclination angles around two axes in the forward / backward and left / right directions (hereinafter, "fore / aft inclination angle" and "left / right inclination angle") of the shovel 100 (i.e., upper rotating body 3). The machine body inclination sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU, etc. A detection signal corresponding to the inclination angle (fore / aft inclination angle and left / right inclination angle) by the machine body inclination sensor S4 is input to the controller 30.

[0035] The turning state sensor S5 outputs detection information related to the turning state of the upper rotating body 3. The turning state sensor S5 detects, for example, the turning angular velocity and turning angle of the upper rotating body 3. The turning state sensor S5 may include, for example, a gyro sensor, a resolver, a rotary encoder, etc. A detection signal corresponding to the turning angle and turning angular velocity of the upper rotating body 3 detected by the turning state sensor S5 is input to the controller 30.

[0036] The imaging device S6 as a spatial recognition device captures images of the periphery of the shovel 100. The imaging device S6 includes a camera S6F that captures an image in front of the shovel 100, a camera S6L that captures an image to the left of the shovel 100, a camera S6R that captures an image to the right of the shovel 100, and a camera S6B that captures an image behind the shovel 100.

[0037] Camera S6F is attached, for example, to the ceiling of the cabin 10, i.e., inside the cabin 10. Camera S6F may also be attached to the outside of the cabin 10, such as to the roof of the cabin 10 or the side of the boom 4. Camera S6L is attached to the left end of the upper surface of the upper rotating body 3, camera S6R is attached to the right end of the upper surface of the upper rotating body 3, and camera S6B is attached to the rear end of the upper surface of the upper rotating body 3.

[0038] The imaging device S6 (cameras S6F, S6B, S6L, and S6R) is, for example, a monocular wide-angle camera having a very wide angle of view. The imaging device S6 may also be a stereo camera or a distance imaging camera. Images captured by the imaging device S6 are input to the controller 30 via the display device 40.

[0039] The imaging device S6 as a spatial recognition device may function as an object detection device. In this case, the imaging device S6 may detect an object present around the shovel 100. The objects to be detected may include, for example, a person, an animal, a vehicle (including the tailgate of the loading platform of the dump truck DT), a construction machine, a building, a hole, and the like. The imaging device S6 may also calculate the distance from the imaging device S6 or the shovel 100 to the recognized object. The imaging device S6 as an object detection device may include, for example, a stereo camera, a distance image sensor, and the like. The spatial recognition device is, for example, a monocular camera having an imaging element such as a CCD or a CMOS, and outputs a captured image to the display device 40. The spatial recognition device may also be configured to calculate the distance from the spatial recognition device or the shovel 100 to the recognized object. In addition to the imaging device S6, other object detection devices such as an ultrasonic sensor, a millimeter wave radar, a LIDAR, an infrared sensor, and the like may also be provided as the spatial recognition device. When using a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like as a spatial recognition device, a number of signals (laser light, etc.) may be emitted to an object and the reflected signals may be received to detect the distance and direction of the object from the reflected signals.

[0040] The imaging device S6 may be directly connected to the controller 30 so as to be able to communicate with it.

[0041] A boom rod pressure sensor S7R and a boom bottom pressure sensor S7B are attached to the boom cylinder 7. An arm rod pressure sensor S8R and an arm bottom pressure sensor S8B are attached to the arm cylinder 8. A bucket rod pressure sensor S9R and a bucket bottom pressure sensor S9B are attached to the bucket cylinder 9. The boom rod pressure sensor S7R, the boom bottom pressure sensor S7B, the arm rod pressure sensor S8R, the arm bottom pressure sensor S8B, the bucket rod pressure sensor S9R and the bucket bottom pressure sensor S9B are collectively referred to as "cylinder pressure sensors."

[0042] The boom rod pressure sensor S7R detects the pressure in the rod side oil chamber of the boom cylinder 7 (hereinafter referred to as the "boom rod pressure"), and the boom bottom pressure sensor S7B detects the pressure in the bottom side oil chamber of the boom cylinder 7 (hereinafter referred to as the "boom bottom pressure"). The arm rod pressure sensor S8R detects the pressure in the rod side oil chamber of the arm cylinder 8 (hereinafter referred to as the "arm rod pressure"), and the arm bottom pressure sensor S8B detects the pressure in the bottom side oil chamber of the arm cylinder 8 (hereinafter referred to as the "arm bottom pressure"). The bucket rod pressure sensor S9R detects the pressure in the rod side oil chamber of the bucket cylinder 9 (hereinafter referred to as the "bucket rod pressure"), and the bucket bottom pressure sensor S9B detects the pressure in the bottom side oil chamber of the bucket cylinder 9 (hereinafter referred to as the "bucket bottom pressure").

[0043] The positioning device P1 measures the position and orientation of the upper rotating body 3. The positioning device P1 is, for example, a Global Navigation Satellite System (GNSS) compass, and detects the position and orientation of the upper rotating body 3, and a detection signal corresponding to the position and orientation of the upper rotating body 3 is input to the controller 30. Furthermore, among the functions of the positioning device P1, a function of detecting the orientation of the upper rotating body 3 may be substituted by a direction sensor attached to the upper rotating body 3.

[0044] The communication device T1 communicates with external devices through a predetermined network including a mobile communication network with a base station as a terminal, a satellite communication network, the Internet, etc. The communication device T1 is, for example, a mobile communication module compatible with mobile communication standards such as LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation), or a satellite communication module for connecting to a satellite communication network.

[0045] [Weight calculation section] The controller 30 has a weight calculation unit 70 that calculates the weight of an object such as soil or sand transported by the bucket 6. The weight calculation unit 70 calculates the weight of the object transported by the attachment based on input information and a predetermined calculation formula. In addition, a zero reset is performed to adjust the zero point of the weight calculated by the weight calculation unit 70 by performing a transport operation with no object in the bucket 6 (empty load transport operation).

[0046] [Weight calculation method] Next, a method for calculating the weight of a transported object (earth and sand, a suspended load, etc.) transported by the attachment in weight calculation unit 70 based on the thrust of boom cylinder 7 will be described with reference to FIG.

[0047] 2 is a block diagram illustrating the processing of the weight calculation unit 70. The weight calculation unit 70 has a torque calculation unit 71, an inertia force calculation unit 72, a centrifugal force calculation unit 73, a stationary torque calculation unit 74, a weight conversion unit 75, and a correction unit 76.

[0048] The torque calculation unit 71 calculates the torque (detected torque) around the foot pin of the boom 4. The calculation is performed based on the pressure of the hydraulic oil in the boom cylinder 7 (boom rod pressure sensor S7R, boom bottom pressure sensor S7B).

[0049] The inertia force calculation unit 72 calculates the torque (inertia term torque) caused by the inertial force around the foot pin of the boom 4. The inertia term torque is calculated based on the angular acceleration around the foot pin of the boom 4 and the moment of inertia of the boom 4. The angular acceleration around the foot pin and the moment of inertia of the boom 4 are calculated based on the output of the attitude sensor.

[0050] The centrifugal force calculation unit 73 calculates the torque (centrifugal torque) around the foot pin of the boom 4 due to Coriolis and centrifugal forces. The centrifugal torque is calculated based on the angular velocity of the boom 4 around the foot pin and the weight of the boom 4. The angular velocity of the boom 4 around the foot pin is calculated based on the output of the attitude sensor. The weight of the boom 4 is known.

[0051] A stationary torque calculation unit 74 calculates a stationary torque τ W Here, the equation for the torque around the foot pin of the boom 4 is shown in equation (1). Note that τ on the left side of equation (1) represents the detection torque, the first term on the right side represents the inertia term torque, the second term on the right side represents the centrifugal term torque, and the third term on the right side represents the static torque τ W Shows.

[0052]

number

[0053] As shown in equation (1), the static torque τ is obtained by subtracting the inertial torque and the centrifugal torque from the detected torque τ. W In this way, in this embodiment, it is possible to compensate for the effect caused by the rotational movement of the boom or the like about the pin.

[0054] The weight conversion unit 75 converts the static torque τ W Based on this, the weight of the transported goods W 1 Calculate the weight of the transported goods W 1 For example, the static torque τ WThe torque when no load is loaded on the attachment can be calculated by dividing the torque obtained by subtracting the torque when no load is loaded on the attachment by the horizontal distance from the foot pin of the boom 4 to the center of gravity of the load. Note that the torque when no load is loaded on the attachment may be calculated based on the respective center of gravity positions of the boom 4, arm 5, and bucket 6 calculated based on the detection values ​​of the boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3, and the respective weights of the boom 4, arm 5, and bucket 6. Also, the horizontal distance from the foot pin of the boom 4 to the center of gravity of the load may be calculated based on the detection values ​​of the boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3, for example, by estimating a predetermined position within the bucket 6 as the center of gravity position of the load accommodated in the bucket 6.

[0055] The correction unit 76 receives the weight W of the transported object calculated by the weight conversion unit 75. 1 The weight W of the transported object calculated by the weight conversion unit 75 is input to the correction unit 76. 1 and zero reset correction value W 0 Based on this, the zero-point corrected weight W of the transported item (= W 1 -W 0 ) is calculated. Here, the zero reset correction value W 0 The weight calculation unit 70 calculates the apparent weight of the transported object calculated by the weight conversion unit 75 when the transport operation is performed with no load in the bucket 6 (during empty transport). 1 Zero reset correction value W during empty transport 0 The zero-point corrected weight W of the transported item is calculated by subtracting 1 -W 0 ) can be calculated.

[0056] Then, when the attachment reaches the trigger height during boom raising operation, for example, when the height of a predetermined point of the bucket 6 reaches the trigger height Ht, the weight calculation unit 70 calculates and outputs the weight W of the transported object. Here, the trigger height Ht is a threshold value for the weight calculation unit 70 to calculate and output the weight W of the transported object. Note that the trigger height Ht may be a fixed height or may have a predetermined range.

[0057] <Correction method> Next, a correction method of the weight calculation unit 70 will be described with reference to Fig. 3. Fig. 3 is a flowchart illustrating a correction method of the weight calculation unit 70 of the shovel 100 according to this embodiment. Note that the correction method is performed when work at the site starts or when an operator is changed.

[0058] In step S101, the operator operates the zero reset operation mode switch 41u. Here, as shown in FIG. 6 described later, a main screen 41V is displayed on the image display section of the display device 40. The main screen 41V is provided with the zero reset operation mode switch 41u as a software button. When the operator operates the zero reset operation mode switch 41u, the controller 30 switches the image display section of the display device 40 to a correction time screen 41V2 shown in FIG. 7 described later. Then, the process of the controller 30 proceeds to step S102.

[0059] In step S102, the operator operates the excavator 100 to perform an empty load transport operation. Here, as shown in FIG. 7, which will be described later, a correction time screen 41V2 is displayed on the image display unit of the display device 40. The correction time screen 41V2 displays the current zero reset correction value W 0 The current trigger height Ht and the remaining number of empty transport operations are displayed. The controller 30 may display a message in the message display area 41m1 (see FIG. 7) to prompt the operator to perform an empty transport operation.

[0060] Before describing the empty-load transport operation, the work performed by the operator of the shovel 100 in the transport operation for transporting the transported object to the dump truck DT will be described with reference to Figs. 4A and 4B. Figs. 4A and 4B show an example of the state of a work site where the shovel 100 is loading earth and sand into the dump truck DT. Specifically, Fig. 4A is a top view of the work site. Fig. 4B is a view of the work site as viewed from the direction indicated by the arrow AR1 in Fig. 4A. In Fig. 4B, the shovel 100 (excluding the bucket 6) is omitted for clarity. In Fig. 4A, the shovel 100 drawn with a solid line represents the state of the shovel 100 when the excavation operation is completed, the shovel 100 drawn with a dashed line represents the state of the shovel 100 during the combined operation, and the shovel 100 drawn with a dashed line represents the state of the shovel 100 before the soil discharge operation is started. Similarly, in Fig. 4B, the bucket 6A drawn in solid lines represents the state of the bucket 6 when the excavation operation is completed, the bucket 6B drawn in dashed lines represents the state of the bucket 6 during the combined operation, and the bucket 6C drawn in dashed lines represents the state of the bucket 6 before the soil discharge operation is started. Also, the thick dashed lines in Fig. 4A and Fig. 4B represent the trajectory of a predetermined point on the back surface of the bucket 6.

[0061] The operator performs a combined operation using an operating device (not shown). In this embodiment, the operator performs a combined operation including a right turning operation. Specifically, the operator performs a combined operation including at least one of a boom raising operation and an arm closing operation and a right turning operation until the posture of the shovel 100 becomes the posture shown by the dashed line, that is, until a predetermined point on the back surface of the bucket 6 reaches point P2. The combined operation may also include an opening and closing operation of the bucket 6. This is to move the bucket 6 onto the bed of the dump truck DT at height Hd while preventing the bucket 6 from coming into contact with the bed.

[0062] Thereafter, the operator performs a combined operation including an arm opening operation and a right turning operation until the posture of the excavator 100 becomes as shown by the dashed line, that is, until a predetermined point on the back surface of the bucket 6 reaches point P3. The combined operation may include at least one of an operation of the boom 4 and an operation of opening and closing the bucket 6. This is to enable earth and sand to be discharged to the front side (driver's seat side) of the bed of the dump truck DT.

[0063] 3, in step S102, the operator performs an empty-load transport operation by operating the shovel 100. In an empty-load transport operation, the operator performs a combined operation including at least one of a boom-raising operation and an arm-closing operation and a right-turn operation, until a predetermined point on the back surface of the bucket 6 reaches point P2 from point P1, without performing an excavation operation and with no load being transported in the bucket 6, and further performs a combined operation including an arm-opening operation and a right-turn operation, until the predetermined point on the back surface of the bucket 6 reaches point P3.

[0064] The controller 30 stores the empty transport operation in the storage device 47. For example, the controller 30 stores the maximum height of the bucket 6 at a predetermined point during the empty transport operation in the storage device 47. The controller 30 also stores the weight W of the transported object calculated by the weight conversion unit 75 at the trigger height Ht. 1 Memorize.

[0065] In step S103, the controller 30 determines whether or not the empty transport operation has been performed a predetermined number of times. If the empty transport operation has not been performed the predetermined number of times (S103: No), the process of the controller 30 repeats step S102. The operator refers to the remaining number of empty transport operations displayed on the display device 40 and repeats the empty transport operation. If the empty transport operation has been performed the predetermined number of times (S103: Yes), the process of the controller 30 proceeds to step S104.

[0066] In step S104, the controller 30 sets the trigger height Ht based on the trajectory of the motion of the attachment during empty transport operations that have been performed multiple times.

[0067] 5 is a graph showing an example of the boom height (bucket height) and boom raising speed during boom raising operation. The horizontal axis shows time, the boom raising speed is shown by a solid line, and the boom height (or bucket height) is shown by a dashed line.

[0068] In the boom raising operation, the boom raising speed increases in the acceleration section (t 0 ~t 1 ), the boom raising speed is approximately constant (t 1 ~t 2 ), the deceleration section where the boom raising speed decreases (t 2 ~t 3 Since the acceleration section and the deceleration section are affected by inertial forces, it is preferable to detect the weight of the transported article in the constant speed section.

[0069] The controller 30 sets the tailgate height Hd of the dump truck DT based on the maximum height of the bucket 6 at a predetermined point in the empty transport operation performed multiple times. The controller 30 then subtracts a predetermined height (see black arrow) from the tailgate height Hd and sets the height as the trigger height Ht. The predetermined height to be subtracted is a preset value. This allows the trigger height Ht to be set in a constant speed section where the boom raising speed is approximately constant. In addition, when the tailgate of the dump truck DT can be detected by the spatial recognition device, the controller 30 may detect the tailgate height Hd of the dump truck DT and then set the trigger height Ht based on the tailgate height Hd. The controller 30 may then generate a target trajectory through which the bucket 6 should pass based on the detected tailgate height Hd. The generated target trajectory includes the maximum height of the bucket 6 at a predetermined point in the empty transport operation. Usually, near the tailgate of the dump truck DT, the operator reduces the speed of the bucket 6 so as not to contact the tailgate. Therefore, when the tilt is detectable, the controller 30 may set the trigger height Ht based on the tilt height Hd.

[0070] In step S105, the controller 30 calculates the zero reset correction value W based on the empty transport operation performed multiple times. 0 The controller 30 sets the weight W of the transported object calculated by the weight conversion unit 75 at the trigger height Ht calculated during the empty transport operation performed multiple times. 1 The average value of the zero reset correction value W 0 It is to be noted that the value is not limited to the average value, and may be the median value.

[0071] This results in a zero reset correction value W 0 and the trigger height Ht can be set. The zero reset correction value W 0 The trigger height Ht is displayed in the zero reset correction value display area 41v and the confirmed trigger height setting value display area 41w of the correction time screen 41V2. Also, the trigger height Ht is reflected in the processing of the weight calculation unit .

[0072] Thereafter, when performing a transport operation (actual loading) of loading the transported object onto the bed of the dump truck DT by performing an excavation operation, the weight calculation unit 70 calculates the weight W of the transported object when the height of a predetermined point of the bucket 6 reaches the trigger height Ht during the boom raising operation. 1 Then, the weight calculation unit 70 calculates the zero reset correction value W 0 is used as the correction value, and the zero-point corrected weight of the transported item W (= W 1 -W 0 The weight calculation unit 70 calculates the weight W1 of the transported object at a predetermined control period, and calculates the weight W1 of the transported object when the height of the predetermined point of the bucket 6 becomes the trigger height Ht as a zero reset correction value W 0 It may be adopted as.

[0073] Furthermore, this configuration may be applied to automatic control. In this case, when the zero reset operation mode switch is operated, the controller 30 detects the tailgate of the loading platform of the dump truck DT using the spatial recognition device, and generates a target trajectory along which the bucket 6 should pass based on the detected tailgate height Hd. Then, the controller 30 sets the trigger height Ht in the generated target trajectory. Thereafter, the controller 30 repeats the empty transport operation a predetermined number of times by automatic control, and calculates the zero reset correction value W 0 Set.

[0074] Next, a configuration example of the main screen 41V displayed on the display device 40 will be described with reference to Fig. 6. The main screen 41V in Fig. 6 is displayed on the image display section of the display device 40, for example, in a state before the zero reset operation mode switch 41u is operated.

[0075] The main screen 41V includes a date and time display area 41a, a driving mode display area 41b, an attachment display area 41c, a fuel efficiency display area 41d, an engine control status display area 41e, an engine operating time display area 41f, a coolant temperature display area 41g, a remaining fuel amount display area 41h, an RPM mode display area 41i, a remaining urea water amount display area 41j, a hydraulic oil temperature display area 41k, a camera image display area 41m, a current weight display area 41p, a cumulative weight display area 41q, a reset button 41r, a remaining weight display area 41s, a target weight display area 41t and a zero reset operation mode switch 41u.

[0076] The travel mode display area 41b, the attachment display area 41c, the engine control state display area 41e, and the rotation speed mode display area 41i are areas that display setting state information, which is information about the setting state of the shovel 100. The fuel consumption display area 41d, the engine operation time display area 41f, the coolant temperature display area 41g, the remaining fuel amount display area 41h, the remaining urea water amount display area 41j, the hydraulic oil temperature display area 41k, the current weight display area 41p, and the accumulated weight display area 41q are areas that display operating state information, which is information about the operating state of the shovel 100.

[0077] Specifically, the date and time display area 41a is an area for displaying the current date and time. The travel mode display area 41b is an area for displaying the current travel mode. The attachment display area 41c is an area for displaying an image representing the currently mounted end attachment. Fig. 6 shows a state in which an image representing the bucket 6 is displayed.

[0078] The fuel efficiency display area 41d is an area that displays fuel efficiency information calculated by the controller 30. The fuel efficiency display area 41d includes an average fuel efficiency display area 41d1 that displays a lifetime average fuel efficiency or an interval average fuel efficiency, and an instantaneous fuel efficiency display area 41d2 that displays an instantaneous fuel efficiency.

[0079] The engine control status display area 41e is an area that displays the control status of the engine 11. The engine operating time display area 41f is an area that displays the accumulated operating time of the engine 11. The coolant temperature display area 41g is an area that displays the current temperature state of the engine coolant. The remaining fuel amount display area 41h is an area that displays the remaining amount of fuel stored in the fuel tank. The rotation speed mode display area 41i is an area that displays the current rotation speed mode set by the engine rotation speed adjustment dial (not shown). The urea water remaining amount display area 41j is an area that displays the remaining amount of urea water stored in the urea water tank. The hydraulic oil temperature display area 41k is an area that displays the temperature state of the hydraulic oil in the hydraulic oil tank.

[0080] The camera image display area 41m is an area for displaying an image captured by the spatial recognition device. In the example of Fig. 6, the camera image display area 41m displays a rear camera image captured by the camera S6B. The rear camera image is a rear image that shows the space behind the excavator 100, and includes the image 3a of the counterweight.

[0081] The current weight display area 41p is an area that displays the weight (current weight) of the object currently being lifted by the bucket 6. Fig. 6 shows that the current weight is 550 kg.

[0082] The controller 30 calculates the current weight based on, for example, the attitude of the work attachment, the boom bottom pressure, and preregistered specifications of the work attachment (weight, center of gravity position, etc.) Specifically, the controller 30 calculates the current weight based on the outputs of information acquisition devices such as the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the boom bottom pressure sensor S7B.

[0083] The accumulated weight display area 41q is an area for displaying the integrated value of the weight of objects lifted by the bucket 6 during a predetermined period (hereinafter referred to as the "accumulated weight"). Fig. 6 shows that the accumulated weight is 9500 kg.

[0084] The predetermined period is, for example, a period that starts when the reset button 41r is pressed. For example, when the operator loads transported goods such as earth and sand into the bed of a dump truck DT, the operator presses the reset button 41r to reset the accumulated weight every time the dump truck DT to be loaded is changed. This is to make it easy to grasp the total weight of the transported goods loaded into each dump truck DT.

[0085] With this configuration, the shovel 100 can prevent the load of transported goods from exceeding the maximum load weight of the dump truck DT and being loaded onto the bed of the dump truck DT. When the load of transported goods exceeding the maximum load weight is detected by weight measurement at the bed span, the driver of the dump truck DT must return to the loading yard and perform the task of unloading some of the transported goods loaded onto the bed. The shovel 100 can prevent the occurrence of such load weight adjustment tasks.

[0086] The predetermined period may be, for example, the period from the start of a day's work to the end of a day's work, in order to allow the operator or manager to easily recognize the total weight of the transported goods transported in a day's work.

[0087] The reset button 41r is a software button for resetting the accumulated weight, and may be a hardware button arranged on the input device 42, the left operation lever (not shown), or the right operation lever (not shown), etc.

[0088] The controller 30 may be configured to automatically recognize the replacement of the dump truck DT and automatically reset the accumulated weight. In this case, the controller 30 may recognize the replacement of the dump truck DT by using an image captured by the spatial recognition device, or may recognize the replacement of the dump truck DT by using the communication device T1.

[0089] The controller 30 may be configured to recognize that the transported object lifted by the bucket 6 has been loaded onto the bed of the dump truck DT based on the image captured by the spatial recognition device, and then calculate the current weight. This is to prevent the transported object that has been moved to a location other than the bed of the dump truck DT from being calculated as the transported object loaded onto the dump truck DT.

[0090] The controller 30 may determine whether or not the transported object lifted by the bucket 6 has been loaded onto the bed of the dump truck DT based on the posture of the work attachment. Specifically, the controller 30 may determine that the transported object has been loaded onto the bed of the dump truck DT, for example, when the height of the bucket 6 exceeds a predetermined value (for example, the height of the bed of the dump truck DT) and the bucket 6 has been opened.

[0091] The controller 30 may be configured to output an alarm when it determines that the current weight exceeds a predetermined value. The predetermined value may be, for example, a value based on the rated lifting weight. The alarm may be a visual alarm, an audible alarm, or a tactile alarm. In this manner, the controller 30 can inform the operator that the current weight has exceeded or is likely to exceed the predetermined value.

[0092] The remaining weight display area 41s is an area for displaying the remaining weight. Fig. 6 shows that the accumulated weight is 9500 kg and the remaining weight is 500 kg. In other words, it shows that the maximum load capacity is 10000 kg. However, the display device 40 may display the maximum load capacity without displaying the remaining weight, or may display the maximum load capacity separately from the remaining weight.

[0093] Target weight display area 41t is an area for displaying a target weight of an object to be attracted by bucket 6. The target weight is set to a value that does not exceed the remaining weight.

[0094] In the example shown in Fig. 6, since the remaining weight is 500 kg, the target weight is set to 500 kg. Meanwhile, the current weight is 550 kg. Therefore, the controller 30 performs control to reduce the current of the bucket 6 until the current weight becomes 500 kg (target weight). This makes it possible to prevent the dump truck DT from being overloaded.

[0095] As described above, according to the shovel 100 according to this embodiment, the weight (current weight) of the object lifted by the bucket 6 can be set as the target weight.

[0096] Also, a message is displayed in the message display area 41m1. For example, when the current weight exceeds the target weight, a message to that effect is displayed. This makes it possible to prevent the loading operation from being performed before the weight adjustment is completed. Also, a message may be displayed when the accumulated weight exceeds the maximum load capacity. This makes it possible to prompt the operator to perform the loading / unloading operation, and to prevent overloading of the dump truck DT.

[0097] The zero reset operation mode switch 41u starts the flow shown in FIG. 3 and sets the zero reset correction value W 0 and a software button for setting the trigger height Ht.

[0098] When the operator operates the zero reset operation mode switch 41u, the correction process is started, and the display screen displayed on the image display section of the display device 40 is switched to a correction-time screen 41V2 shown in FIG.

[0099] The correction time screen 41V2 includes a date and time display area 41a, a driving mode display area 41b, an attachment display area 41c, a fuel efficiency display area 41d, an engine control status display area 41e, an engine operating time display area 41f, a coolant temperature display area 41g, a remaining fuel amount display area 41h, a rotation speed mode display area 41i, a remaining urea water amount display area 41j, a hydraulic oil temperature display area 41k, a camera image display area 41m, a zero reset correction value display area 41v, a confirmed trigger height setting value display area 41w and a remaining number of times display area 41x.

[0100] The zero reset correction value display area 41v displays the current zero reset correction value W 0 Also, the zero reset correction value W 0 When the zero reset correction value W is set (S104), 0 is displayed.

[0101] The confirmed trigger height setting value display area 41w displays the current confirmed trigger height Ht. When the trigger height Ht is set by the process shown in FIG. 3 (S105), the set trigger height Ht is displayed.

[0102] The remaining number of empty transport operations is displayed in the remaining number display area 41x. The remaining number of empty transport operations is decreased each time an empty transport operation is performed by the process shown in Fig. 3. Note that the controller 30 may determine that one empty transport operation has been performed, for example, when the boom 4 or the bucket 6 is raised to a predetermined height or higher and then lowered to a predetermined height or lower.

[0103] As described above, according to the shovel 100 according to this embodiment, the operator performs the empty transport operation multiple times in the actual work environment, thereby obtaining the zero reset correction value W 0and the trigger height Ht can be set.

[0104] Here, the weight W of the transported object calculated by the weight calculation unit 70 may fluctuate depending on the operator's skill, the trajectory during the transport operation, the layout of the excavator 100 and dump truck DT at the site, the ambient temperature, etc.

[0105] In contrast, according to the shovel 100 according to the present embodiment, the zero reset correction value W 0 and the trigger height Ht can be set. This allows the zero reset correction value W to be adjusted according to the operator's skill, the trajectory during the transport operation, the layout of the excavator 100 and the dump truck DT at the site, the environmental temperature, etc. 0 and the trigger height Ht can be set, the detection accuracy of the weight W of the transported object calculated by the weight calculation unit 70 can be improved.

[0106] In addition, the zero reset correction value W 0 When setting the trigger height Ht, the operator operates the zero reset operation mode switch 41u and executes the empty transport operation multiple times according to the remaining number of times displayed in the remaining number of times display area 41x, and the zero reset correction value W 0 In addition, the trigger height Ht can be easily set.

[0107] Moreover, according to the excavator 100 according to this embodiment, the sidewall height Hd can be set based on the empty load transport operation. This eliminates the need for the operator to measure the sidewall height Hd of the dump truck DT and input the measured value to the controller 30.

[0108] Moreover, according to the shovel 100 of this embodiment, the trigger height Ht can be automatically set by subtracting a predetermined value from the set tailgate height Hd. This makes it possible to set the trigger height Ht to a constant speed section where the influence of inertial force during acceleration and deceleration of the boom 4 is small, and improves the detection accuracy of the weight W of the transported object calculated by the weight calculation unit 70.

[0109] In addition, according to the shovel 100 of this embodiment, the empty transport operation is performed multiple times depending on the actual work environment, so that the zero reset correction value W 0 In the actual loading operation, the weight calculation unit 70 sets the weight W of the transported object calculated by the weight conversion unit 75. 1 Zero reset correction value W 0 By correcting the weight W of the transported object with the above formula, the weight W of the transported object can be calculated with high accuracy.

[0110] Furthermore, according to the excavator 100 of this embodiment, the accuracy of calculation of the weight W of the transported object by the weight calculation unit 70 is improved, so that the cumulative weight of the transported object loaded onto the dump truck DT can also be calculated with high accuracy. This makes it possible to prevent the transported object from being loaded onto the bed of the dump truck DT in excess of the maximum load weight of the dump truck DT. Furthermore, since the load weight of the dump truck DT can be brought close to the maximum load weight, the transport efficiency of the transported object by the dump truck DT can be improved.

[0111] The above describes the embodiments of the shovel 100, but the present invention is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the gist of the present invention described in the claims.

[0112] The weight calculation unit 70 that detects the weight of the transported object has been described as being provided in the controller 30 of the shovel 100, but is not limited to this. It may be a transported object weight measurement system that is communicatively connected to the controller 30. The transported object weight measurement system may be provided in the shovel 100, or may be provided outside the shovel 100 and configured to be able to communicate with the shovel 100. [Explanation of symbols]

[0113] 100 Shovel 1 Undercarriage 2 Swivel mechanism 3. Upper rotating body 4 Boom (attachment) 5 Arm (attachment) 6 Bucket (attachment) 7 Boom cylinder 8 Arm Cylinder 9 Bucket Cylinder 30 Controller 40 Display device 70 Weight calculation section 71 Torque calculation section 72 Inertia force calculation section 73 Centrifugal force calculation unit 74 Stationary torque calculation section 75 Weight conversion section 76 Correction section 40 Display device 41u Zero reset operation mode switch 41v Zero reset correction value display area 41w Confirmed trigger height setting value display area 41x remaining number display area

Claims

1. An attachment for transporting an object to be transported; A work machine including a weight calculation unit that calculates a weight of the transported object based on a weight when actually loaded and a weight when empty transported, a zero reset operation mode switch for starting a process for setting the weight during empty transportation; the weight calculation unit calculates a weight of the transported object when the attachment reaches a trigger height, The process also sets the trigger height.

2. The process comprises: setting the trigger height based on a trajectory of the motion of the attachment during the empty transport; 2. The work machine of claim 1.

3. The process comprises: Calculating the weight during empty transportation based on the weight calculated by the weight calculation unit during empty transportation. A work machine according to claim 1 or 2.

4. The zero reset operation mode switch is displayed on a display screen. A work machine according to any one of claims 1 to 3.

5. A transported object weight measurement system including a weight calculation unit that calculates a weight of a transported object based on a weight when actually loaded and a weight when empty transported, a zero reset operation mode switch for starting a process for setting the weight during empty transportation; the weight calculation unit calculates a weight of the transported object when the attachment reaches a trigger height, The process also sets the trigger height.

6. The process comprises: setting the trigger height based on a trajectory of the motion of the attachment during the empty transport; 6. The transported object weight measuring system according to claim 5.

Images