JP2020164325A - Work machine - Google Patents

Abstract

To provide a work machine that adjusts the weight of an object lifted by a lifting magnet.SOLUTION: There is provided a work machine comprising a lower traveling body, an upper rotating body mounted on the lower traveling body via a rotating mechanism, an attachment attached to the upper rotating body, a lifting magnet attached to the attachment, and a control device. The control device includes: a weight calculation unit that calculates a current weight, which is a weight of an object attracted by the lifting magnet; and a power control unit that controls the power supplied to the lifting magnet. The power control unit compensates for the power supplied to the lifting magnet based on the current weight and a target weight.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a work machine provided with a lifting magnet.

As a work machine for transporting or moving an object such as a steel material, a work machine provided with a lifting magnet is known (see Patent Document 1).

International Publication No. 2016/076271

By the way, a work machine equipped with a lifting magnet performs a work of loading an object such as iron scrap into a dump truck, for example. When the loading operation is completed, the dump truck moves to the truck scale, and the loaded weight is measured by the truck scale. If there is an excess or deficiency in the load weight, the dump truck may return to the position of the work machine and adjust the load weight by the work machine.

Further, when loading an object on a dump truck, the operator of the work machine visually adjusts the weight of the object attracted by the lifting magnet. Therefore, depending on the experience of the operator, there is a possibility that the adjustment may be repeated a plurality of times.

Therefore, an object of the present invention is to provide a working machine for adjusting the weight of an object lifted by a lifting magnet.

The work machine of one aspect of the embodiment includes a lower traveling body, an upper rotating body mounted on the lower traveling body via a swivel mechanism, an attachment attached to the upper swivel body, and a lifting magnet attached to the attachment. The control device includes a weight calculation unit that calculates the current weight, which is the weight of an object attracted by the lifting magnet, and a power control unit that controls the electric power supplied to the lifting magnet. The power control unit compensates for the power supplied to the lifting magnet based on the current weight and the target weight.

According to the present invention, it is possible to provide a working machine for adjusting the weight of an object lifted by a lifting magnet.

It is a side view of the work machine which concerns on this embodiment. It is a block diagram which shows the structural example of the drive system mounted on the work machine shown in FIG. It is a block diagram explaining the current compensation of a lifting magnet. It is a figure which shows the configuration example of a main screen.

FIG. 1 is a side view of the work machine 100 according to the present embodiment. The lower traveling body 1 of the work machine 100 is mounted with the upper rotating body 3 via the turning mechanism 2. A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4, and a lifting magnet 6 as an end attachment is attached to the tip of the arm 5. The boom 4 and the arm 5 form a work attachment which is an example of the attachment. The boom 4 is driven by the boom cylinder 7, the arm 5 is driven by the arm cylinder 8, and the lifting magnet 6 is driven by the lifting magnet cylinder 9.

A boom angle sensor S1 is attached to the boom 4, an arm angle sensor S2 is attached to the arm 5, and a lifting magnet angle sensor S3 is attached to the lifting magnet 6. A controller 30, a display device 40, a space recognition device 80, an airframe tilt sensor S4, and a swivel angular velocity sensor S5 are attached to the upper swivel body 3.

The boom angle sensor S1 is configured to detect a boom angle which is a rotation angle of the boom 4 with respect to the upper swing body 3. The boom angle sensor S1 is, for example, a rotation angle sensor that detects the rotation angle of the boom 4 around the boom foot pin, a cylinder stroke sensor that detects the stroke amount (boom stroke amount) of the boom cylinder 7, or an inclination angle of the boom 4. It may be an inclination (acceleration) sensor or the like that detects the above, or it may be a combination of an acceleration sensor and a gyro sensor. The same applies to the arm angle sensor S2 that detects the arm angle that is the rotation angle of the arm 5 with respect to the boom 4, and the lifting magnet angle sensor S3 that detects the lifting magnet angle that is the rotation angle of the lifting magnet 6 with respect to the arm 5. is there.

The airframe tilt sensor S4 is configured to detect the tilt (airframe tilt angle) of the upper swivel body 3 with respect to the horizontal plane. In the present embodiment, the body tilt sensor S4 is an acceleration sensor that detects the tilt angles around the front-rear axis and the left-right axis of the upper swing body 3. The front-rear axis and the left-right axis of the upper swivel body 3 pass, for example, a machine center point which is one point on the swivel axis of the work machine 100 at right angles to each other.

The turning angular velocity sensor S5 detects the turning angular velocity of the upper swing body 3. In this embodiment, it is a gyro sensor. It may be a resolver, a rotary encoder, or the like.

The space recognition device 80 is configured to image the surroundings of the work machine 100. The space recognition device 80 is, for example, a monocular camera, a stereo camera, a distance image camera, an infrared camera, LIDAR, or the like. In the example of FIG. 1, the space recognition device 80 includes a front camera 80F attached to the front end of the upper surface of the upper swing body 3, a back camera 80B attached to the rear end of the upper surface of the upper swing body 3, and a left end of the upper surface of the upper swing body 3. Includes a left camera 80L attached to and a right camera 80R (invisible in FIG. 1) attached to the upper right end of the upper swing body 3.

The space recognition device 80 is, for example, a monocular camera having an image sensor such as a CCD or CMOS, and outputs the captured image to the display device 40. Further, the space recognition device 80 may be configured to calculate the distance from the space recognition device 80 or the work machine 100 to the recognized object. When not only the captured image is used but also a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like is used as the space recognition device 80, a large number of signals (laser light, etc.) are transmitted to an object and reflected. By receiving the signal, the distance and direction of the object may be detected from the reflected signal.

The space recognition device 80 is configured to detect an object existing around the work machine 100. Objects are, for example, dump trucks, terrain shapes (slopes, holes, etc.), electric wires, utility poles, people, animals, vehicles, construction machinery, buildings, walls, helmets, safety vests, work clothes, or predetermined marks on helmets. And so on. In this way, the space recognition device 80 may be configured to be able to identify at least one of the type, position, shape, and the like of the object. For example, the space recognition device 80 may be configured to distinguish between a person and a non-human object.

A boom rod pressure sensor S6a, a boom bottom pressure sensor S6b, and a boom cylinder stroke sensor S7 may be attached to the boom cylinder 7. An arm rod pressure sensor S6c, an arm bottom pressure sensor S6d, and an arm cylinder stroke sensor S8 may be attached to the arm cylinder 8. A lifting magnet rod pressure sensor S6e, a lifting magnet bottom pressure sensor S6f, and a lifting magnet cylinder stroke sensor S9 may be attached to the lifting magnet cylinder 9.

The boom rod pressure sensor S6a detects the pressure in the rod side oil chamber of the boom cylinder 7 (hereinafter referred to as “boom rod pressure”), and the boom bottom pressure sensor S6b detects the pressure in the bottom side oil chamber of the boom cylinder 7 (hereinafter referred to as “boom rod pressure”). , "Boom bottom pressure") is detected. The arm rod pressure sensor S6c detects the pressure in the rod side oil chamber of the arm cylinder 8 (hereinafter referred to as “arm rod pressure”), and the arm bottom pressure sensor S6d detects the pressure in the bottom side oil chamber of the arm cylinder 8 (hereinafter referred to as “arm rod pressure”). , "Arm bottom pressure") is detected. The lifting magnet rod pressure sensor S6e detects the pressure in the rod side oil chamber of the lifting magnet cylinder 9 (hereinafter referred to as "lifting magnet rod pressure"), and the lifting magnet bottom pressure sensor S6f is the bottom side oil of the lifting magnet cylinder 9. The chamber pressure (hereinafter referred to as "lifting magnet bottom pressure") is detected.

The upper swing body 3 is provided with a cabin 10 as an cab and is equipped with a power source such as an engine 11.

FIG. 2 is a diagram showing a configuration example of a drive system mounted on the work machine 100. In FIG. 2, the mechanical power transmission system is indicated by a double-dashed line, the hydraulic oil line is indicated by a thick solid line, the pilot line is indicated by a broken line, the electric control system is indicated by a dashed-dotted line, and the electric drive system is indicated by a thick dotted line.

The drive system of the work machine 100 is mainly composed of an engine 11, a main pump 14, a hydraulic pump 14G, a pilot pump 15, a control valve 17, an operating device 26, a controller 30, and an engine control device 74.

The engine 11 is a power source for the work machine 100, and is, for example, a diesel engine that operates so as to maintain a predetermined rotation speed. The output shaft of the engine 11 is connected to each of the input shafts of the alternator 11a, the main pump 14, the hydraulic pump 14G, and the pilot pump 15.

The main pump 14 supplies hydraulic oil to the control valve 17 via the hydraulic oil line 16. In the present embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

The regulator 14a controls the discharge amount of the main pump 14. In the present embodiment, the regulator 14a controls the discharge amount of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 in response to a control signal or the like from the controller 30.

The pilot pump 15 supplies hydraulic oil to various hydraulic control devices including the operating device 26 via the pilot line 25. In the present embodiment, the pilot pump 15 is a fixed displacement hydraulic pump.

The control valve 17 is a hydraulic control device that controls a hydraulic system in the work machine 100. The control valve 17 is, for example, for one or more of the boom cylinder 7, the arm cylinder 8, the lifting magnet cylinder 9, the left-side traveling hydraulic motor 1L, the right-side traveling hydraulic motor 1R, and the turning hydraulic motor 2A. The hydraulic oil discharged by the main pump 14 is selectively supplied. In the following description, the boom cylinder 7, the arm cylinder 8, the lifting magnet cylinder 9, the left side traveling hydraulic motor 1L, the right side traveling hydraulic motor 1R, and the turning hydraulic motor 2A are collectively referred to as "hydraulic actuators".

The operating device 26 is a device used by the operator to operate the hydraulic actuator. In this embodiment, the operating device 26 supplies hydraulic oil from the pilot pump 15 to the pilot port of the corresponding flow control valve in the control valve 17 to generate pilot pressure. Specifically, the operating device 26 includes a left operating lever for turning operation and arm operation, a right operating lever for boom operation and lifting magnet operation, a traveling pedal, and a traveling lever (none of which are shown). Etc. are included. The pilot pressure changes according to the operation content (for example, the operation direction and the operation amount) of the operation device 26.

The operating pressure sensor 29 detects the pilot pressure generated by the operating device 26. In the present embodiment, the operating pressure sensor 29 detects the pilot pressure generated by the operating device 26 and outputs the detected value to the controller 30. The controller 30 grasps each operation content of the operation device 26 based on the output of the operation pressure sensor 29.

The controller 30 is a control device that executes various operations. In the present embodiment, the controller 30 is a microcomputer provided with a CPU, a volatile storage device, a non-volatile storage device, and the like. For example, the controller 30 reads programs corresponding to various functions from the non-volatile storage device, loads them into the volatile storage device, and causes the CPU to execute the processes corresponding to each of the programs.

The hydraulic pump 14G supplies hydraulic oil to the hydraulic motor 60 via the hydraulic oil line 16a. In the present embodiment, the hydraulic pump 14G is a fixed-capacity hydraulic pump, and supplies hydraulic oil to the hydraulic motor 60 through a switching valve 61.

The switching valve 61 is configured to switch the flow of hydraulic oil discharged by the hydraulic pump 14G. In the present embodiment, the switching valve 61 is a solenoid valve whose valve position is switched according to a control command from the controller 30. The switching valve 61 has a first valve position for communicating between the hydraulic pump 14G and the hydraulic motor 60, and a second valve position for shutting off between the hydraulic pump 14G and the hydraulic motor 60.

When the mode changeover switch 62 is operated and the operation mode of the work machine 100 is switched to the lifting magnet mode, the controller 30 outputs a control signal to the changeover valve 61 to switch the changeover valve 61 to the first valve position. Further, when the mode changeover switch 62 is operated and the operation mode of the work machine 100 is switched to other than the lifting magnet mode, the controller 30 outputs a control signal to the changeover valve 61 to position the changeover valve 61 at the second valve position. Switch to. FIG. 2 shows a state in which the switching valve 61 is in the second valve position.

The mode changeover switch 62 is a switch for switching the operation mode of the work machine 100. In this embodiment, it is a rocker switch installed in the cabin 10. The operator operates the mode changeover switch 62 to switch between the excavator mode and the lifting magnet mode. The excavator mode is an operation mode when the work machine 100 is operated as an excavator (excavator), and is selected when, for example, a bucket is attached to the tip of the arm 5 instead of the lifting magnet 6. The lifting magnet mode is a mode for operating the work machine 100 as a work machine with a lifting magnet, and is selected when the lifting magnet 6 is attached to the tip of the arm 5. The controller 30 may automatically switch the operation mode of the work machine 100 based on the outputs of various sensors.

When the lifting magnet mode is selected, the switching valve 61 is set to the first valve position, and the hydraulic oil discharged by the hydraulic pump 14G flows into the hydraulic motor 60. On the other hand, when an operation mode other than the lifting magnet mode is selected, the switching valve 61 is set to the second valve position, and the hydraulic oil discharged by the hydraulic pump 14G flows out to the hydraulic oil tank without flowing into the hydraulic motor 60. ..

The rotating shaft of the hydraulic motor 60 is mechanically connected to the rotating shaft of the generator 63. The generator 63 generates electric power for exciting the lifting magnet 6. In the present embodiment, the generator 63 is an AC generator that operates in response to a control command from the power control device 64.

The electric power control device 64 controls the supply / cutoff of electric power for exciting the lifting magnet 6. In the present embodiment, the power control device 64 controls the start / stop of AC power generation by the generator 63 in response to the power generation start command / power generation stop command from the controller 30. Further, the power control device 64 converts the AC power generated by the generator 63 into DC power and supplies it to the lifting magnet 6. Further, the power control device 64 can control the magnitude of the voltage applied to the lifting magnet 6 and the magnitude of the current flowing through the lifting magnet 6.

The controller 30 outputs a suction command to the power control device 64 when the lifting magnet switch 65 is turned on and turned on. The power control device 64 that receives the adsorption command converts the AC power generated by the generator 63 into DC power and supplies it to the lifting magnet 6 to excite the lifting magnet 6. The excited lifting magnet 6 is in an adsorbed state capable of adsorbing an object (magnetic material).

Further, the controller 30 outputs a release command to the power control device 64 when the lifting magnet switch 65 is turned off and turned off. The power control device 64 that has received the release command stops the power generation by the generator 63 and puts the lifting magnet 6 in the suction state into the non-suction state (release state). The released state of the lifting magnet 6 means a state in which the power supply to the lifting magnet 6 is stopped and the electromagnetic force generated by the lifting magnet 6 disappears.

The lifting magnet switch 65 is a switch for switching between adsorption and release of the lifting magnet 6. In the present embodiment, the lifting magnet switch 65 includes a weak excitation button 65A and a strong excitation button 65B as push button switches provided on the top of the left operation lever 26L, and a push button switch provided on the top of the right operation lever 26R. Includes release button 65C.

The weak excitation button 65A is an example of an input device for applying a predetermined voltage to the lifting magnet 6 to bring the lifting magnet 6 into an suction state (weak suction state). The predetermined voltage is, for example, a voltage set through the magnetic force adjusting dial 66.

The strong excitation button 65B is an example of an input device for applying a maximum allowable voltage to the lifting magnet 6 to bring the lifting magnet 6 into an suction state (strong suction state).

The release button 65C is an example of an input device for releasing the lifting magnet 6.

The magnetic force adjusting dial 66 is a dial for adjusting the magnetic force (adhesive force) of the lifting magnet 6. In the present embodiment, the magnetic force adjusting dial 66 is installed in the cabin 10 and is configured so that the magnetic force (adhesive force) of the lifting magnet 6 when the weak excitation button 65A is pressed can be switched in four stages. Specifically, the magnetic force adjusting dial 66 is configured so that the magnetic force (adhesive force) of the lifting magnet 6 can be switched in four stages from the first level to the fourth level. FIG. 2 shows a state in which the third level is selected by the magnetic force adjusting dial 66.

The lifting magnet 6 is controlled to generate a level of magnetic force (adhesive force) set by the magnetic force adjusting dial 66. The magnetic force adjustment dial 66 outputs data indicating the level of magnetic force (adhesive force) to the controller 30.

With this configuration, the operator operates the left operating lever 26L with his left hand and the right operating lever 26R with his right hand to operate the work attachment, while adsorbing and releasing the object (magnetic material) by the lifting magnet 6 with his fingers. Can be executed. Typically, the operator pushes the weak excitation button 65A with the lifting magnet 6 in contact with an object (for example, iron scrap) to attract the iron scrap to the lifting magnet 6. After that, the operator gently raises the boom 4, lifts the lifting magnet 6 that has attracted iron scraps, and then presses the strong excitation button 65B to increase the magnetic force (adhesive force) of the lifting magnet 6. This is to prevent the iron scraps from falling from the lifting magnet 6 during the transportation of the iron scraps by the attachment operation (operation including at least one of the boom operation, the arm operation and the bucket operation) or the turning operation.

Further, the operator can sort the objects by adjusting the magnetic force (adhesive force) of the lifting magnet 6 with the magnetic force adjusting dial 66. The operator, for example, uses a relatively weak level of magnetic force (adsorption force) to selectively lift and move a relatively light object from a pile of scrap to separate a relatively light object from a relatively heavy object. be able to. This is because the operator can prevent a relatively heavy object from being lifted by using a relatively weak level of magnetic force (adsorption force).

The work machine 100 may be configured to automatically switch the operation mode to the speed limit mode when the weak excitation button 65A or the strong excitation button 65B is pressed. The speed limiting mode is, for example, an operation mode in which the turning speed and the driving speed of the attachment are limited in the lifting magnet mode.

Further, in the work machine 100, when a predetermined operation is performed after the weak excitation button 65A is pressed, or when a predetermined state is reached, the strong excitation button 65B presses the state of the lifting magnet 6. It may be automatically shifted to the strong adsorption state which is the state when it is done. The predetermined operation is, for example, a turning operation. The predetermined state is, for example, a state in which the attachment is in a predetermined posture, specifically, a state in which the boom angle is a predetermined angle. In this case, the work machine 100 is strong when, for example, the turning operation is performed after the lifting magnet 6 in the weakly attracted state is lifted in response to the boom raising operation by pressing the weak excitation button 65A. Even if the excitation button 65B is not pressed, the state of the lifting magnet 6 can be automatically changed to the strong suction state.

The display device 40 is a device that displays various types of information. In the present embodiment, the display device 40 is fixed to a pillar (not shown) on the right front side of the cabin 10 provided with a driver's seat. Further, as shown in FIG. 2, the display device 40 can display information about the work machine 100 on the image display unit 41 and provide the information to the operator. The display device 40 also includes a switch panel 42 as an input device. The operator can input various commands to the controller 30 by using the switch panel 42.

The switch panel 42 is a panel including various switches. In this embodiment, the switch panel 42 includes a light switch 42a, a wiper switch 42b, and a window washer switch 42c as hardware buttons. The light switch 42a is a switch for switching on / off of a light attached to the outside of the cabin 10. The wiper switch 42b is a switch for switching the operation / stop of the wiper. The window washer switch 42c is a switch for injecting the window washer liquid.

The display device 40 operates by receiving electric power from the storage battery 70. The storage battery 70 is charged with the electric power generated by the alternator 11a. The electric power of the storage battery 70 is also supplied to the electrical components 72 and the like other than the controller 30 and the display device 40. The starter 11b of the engine 11 is driven by the electric power from the storage battery 70 to start the engine 11.

The engine control device 74 controls the engine 11. In the present embodiment, the engine control device 74 collects various data indicating the state of the engine 11 and transmits the collected data to the controller 30. Although the engine control device 74 and the controller 30 are configured as separate bodies, they may be configured integrally. For example, the engine control device 74 may be integrated with the controller 30.

The engine speed adjustment dial 75 is a dial for adjusting the engine speed. In the present embodiment, the engine speed adjusting dial 75 is installed in the cabin 10 and is configured so that the engine speed can be switched in four stages. Specifically, the engine speed adjustment dial 75 is configured so that the engine speed can be switched in four stages of SP mode, H mode, A mode, and idling mode. FIG. 2 shows a state in which the H mode is selected by the engine speed adjustment dial 75.

The SP mode is a rotation speed mode selected when it is desired to prioritize the amount of work, and the highest engine speed is used. The H mode is a rotation speed mode selected when it is desired to achieve both work load and fuel consumption, and uses the second highest engine speed. The A mode is a rotation speed mode selected when it is desired to operate the work machine with low noise while giving priority to fuel consumption, and uses the third highest engine speed. The idling mode is a rotation speed mode selected when the engine is to be operated in the idling state, and uses the lowest engine speed (idling speed).

The engine 11 is controlled so that the engine speed corresponding to the speed mode set by the engine speed adjustment dial 75 is maintained. The engine speed adjustment dial 75 outputs data indicating the setting state of the engine speed to the controller 30.

Further, the controller 30 includes a target weight setting unit 31, a weight calculation unit 32, an suction force control unit 33, a maximum load capacity setting unit 34, a cumulative weight calculation unit 35, and a remaining weight calculation unit 36. are doing.

The target weight setting unit 31 acquires the target weight of the object attracted by the lifting magnet 6. The target weight may be input by the operator, may be set based on the residual weight of the residual weight calculation unit 36 described later, or may be set in advance.

The weight calculation unit 32 calculates the weight (current weight) of the object attracted to the lifting magnet 6. The current weight is calculated, for example, by balancing the torque around the base of the boom 4. Specifically, the thrust of the boom cylinder 7 is increased by the object attracted to the lifting magnet 6, and the torque around the root of the boom 4 calculated from the thrust of the boom cylinder 7 is also increased. The amount of increase in torque and the torque calculated from the weight of the object and the center of gravity of the object match. In this way, the weight calculation unit 32 can calculate the weight of the object based on the thrust of the boom cylinder 7 (measured values of the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B) and the center of gravity of the object. The center of gravity of the object is obtained experimentally in advance and stored in the controller 30, for example. The method for calculating the weight of an object is not limited to this, and various methods can be applied.

The suction force control unit 33 controls the current command value of the current supplied to the lifting magnet 6 to control the suction force of the lifting magnet 6.

The maximum load capacity setting unit 34 sets the maximum load capacity of the dump truck for loading an object. The maximum load capacity may be input by the operator, for example, and the vehicle type (size, etc.) of the dump truck is determined based on the dump truck image captured by the space recognition device 80, and the determined vehicle type (for example). The maximum load capacity may be set based on the size, etc.).

The cumulative weight calculation unit 35 calculates the cumulative weight of the object loaded on the loading platform of the dump truck.

The remaining weight calculation unit 36 calculates the remaining weight, which is the difference between the maximum load capacity and the cumulative weight.

Hereinafter, an example of the operation of the work machine 100 according to the present embodiment will be described.

First, the target weight setting unit 31 of the controller 30 sets the target weight of the object attracted by the lifting magnet 6. Further, the maximum load capacity setting unit 34 sets the maximum load capacity of the dump truck for loading the object.

Next, the operator operates the operating device 26 to move the lifting magnet 6 onto the object to be attracted.

Next, the operator operates the weak excitation button 65A to generate a magnetic force (adhesive force) on the lifting magnet 6. As a result, the object is attracted to the lifting magnet 6. At this time, the suction force control unit 33 of the controller 30 commands the first current command value as the current command value. The first current command value is set to a sufficient current value so that the object attracted to the lifting magnet 6 has a target weight or more. The power control device 64 controls the current supplied to the lifting magnet 6 based on the current command value.

Next, the operator operates the operating device 26 to raise the lifting magnet 6 to a predetermined height. As a result, the object attracted to the lifting magnet 6 is lifted together with the lifting magnet 6. In addition, the controller 30 serves as a trigger for starting compensation control described later. Whether or not the lifting magnet 6 has risen to a predetermined height may be determined by the position of the lifting magnet 6, and the posture of the attachment, the position of each connecting pin of the attachment, and the lifting of the lifting magnet 6 are started. The determination may be made based on the elapsed time from the start, the operating state of the suction switch, and the like.

Next, the weight calculation unit 32 of the controller 30 calculates the weight (current weight) of the object (suspended) attracted to the lifting magnet 6.

Next, when the current weight is heavier than the target weight, the suction force control unit 33 of the controller 30 performs compensation control of the current supplied to the lifting magnet 6. For example, the suction force control unit 33 adjusts so as to reduce the current command value. As a result, the magnetic force (adhesive force) of the lifting magnet 6 decreases, and a part of the object attracted to the lifting magnet 6 falls. That is, the weight of the object attracted to the lifting magnet 6 is reduced.

Hereinafter, in the compensation control, the controller 30 repeats the calculation of the weight (current weight) of the object attracted to the lifting magnet 6 and the adjustment (decrease) of the current command value, and repeats until the current weight reaches the target weight. The current command value when the current weight reaches the target weight is used as the second current command value.

Next, the suction force control unit 33 of the controller 30 sets the current command value as the third current command value. The third current command value is a current command value larger than the second current command value. As a result, the object having the target weight is prevented from falling off from the lifting magnet 6.

Next, the controller 30 notifies the operator when the current weight reaches the target weight. The notification method may be, for example, a method of displaying on the display device 40 or a voice method.

Next, the notified operator operates the strong excitation button 65B to put the lifting magnet 6 in the suction state (strong suction state). Next, the operator operates the operating device 26 to move the upper swing body 3, the work attachments (boom 4, arm 5), and move the lifting magnet 6 onto the loading platform of the dump truck. Next, the operator operates the release button 65C, and the release button 65C releases the lifting magnet 6. As a result, an object of the target weight is loaded on the loading platform of the dump truck.

The cumulative weight calculation unit 35 adds the current target weight to the cumulative weight up to the previous time to update the cumulative weight. The remaining weight calculation unit 36 calculates the remaining weight based on the updated cumulative weight.

By repeating these operations, an object having a desired cumulative weight can be loaded on the loading platform of the dump truck.

The controller 30 prohibits the upper swing body 3 from turning after the lifting magnet 6 is raised to a predetermined height until the current weight reaches the target weight (while repeating the calculation of the current weight and the current adjustment). Alternatively, it may be limited within a predetermined angle range. As a result, it is possible to prevent falling objects from being scattered around when the current living amount is adjusted to the target weight.

The case of loading onto a dump truck has been described as an example, but the present invention is not limited to this, and an object having a desired target weight can be similarly loaded / unloaded from the dump truck at the time of loading / unloading.

Next, an example of a block diagram of the work machine 100 is shown with reference to FIG. FIG. 3 is a block diagram illustrating current compensation for the lifting magnet 6. As shown in FIG. 3, it has a suction start determination unit 101, a compensator 102, and a weight detection unit 103.

The suction start determination unit 101 has a function of switching the target weight to be input to the compensator 102. For example, when the weak excitation button 65A is operated, the suction start determination unit 101 switches to input Wref + ΔW as the target weight to the compensator 102. Further, the suction start determination unit 101 switches to input Wref as a target weight to the compensator 102, for example, when the lifting magnet 6 is raised to a predetermined height. In this way, the target weight is increased from the time the weak excitation button 65A is operated until the lifting magnet 6 rises to a predetermined height.

After raising the lifting magnet 6 to a predetermined height, the compensator 102 compensates for the current supplied to the lifting magnet 6 based on the difference between the target weight Wref and the current weight detected by the weight detecting unit 103. Here, the current may be compensated not only after the object is hung on the lifting magnet 6, but also the current corresponding to the target flow rate Wref calculated before the object is hung.

The weight detection unit 103 detects the weight of the object attracted by the lifting magnet 6.

In this way, by compensating for the current supplied to the lifting magnet 6 based on the target weight Wref and the current weight, the weight of the object adsorbed on the lifting magnet 6 can be set as the target weight.

Next, a configuration example of the main screen 41V displayed on the display device 40 will be described with reference to FIG. The main screen 41V of FIG. 4 is displayed on the image display unit 41, for example, when the operation mode is the lifting magnet mode.

The main screen 41V has a date / time display area 41a, a running mode display area 41b, an attachment display area 41c, a fuel consumption display area 41d, an engine control status display area 41e, an engine operating time display area 41f, a cooling water temperature display area 41g, and a fuel remaining amount display. Area 41h, rotation speed mode display area 41i, urea water remaining amount display area 41j, hydraulic oil temperature display area 41k, camera image display area 41m, current weight display area 41p, cumulative weight display area 41q, reset button 41r, remaining weight display The area 41s and the target weight display area 41t are included.

The traveling 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 for displaying the setting state information which is the information regarding the setting state of the work machine 100. Fuel consumption display area 41d, engine operating time display area 41f, cooling water temperature display area 41g, fuel remaining amount display area 41h, urea water remaining amount display area 41j, hydraulic oil temperature display area 41k, current weight display area 41p and cumulative weight display area 41q is an area for displaying operating state information, which is information related to the operating state of the work machine 100.

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. 4 shows a state in which an image representing the lifting magnet 6 is displayed.

The fuel consumption display area 41d is an area for displaying fuel consumption information calculated by the controller 30. The fuel consumption display area 41d includes an average fuel consumption display area 41d1 for displaying the lifetime average fuel consumption or the section average fuel consumption, and an instantaneous fuel consumption display area 41d2 for displaying the instantaneous fuel consumption.

The engine control state display area 41e is an area for displaying the control state of the engine 11. The engine operating time display area 41f is an area for displaying the cumulative operating time of the engine 11. The cooling water temperature display area 41g is an area for displaying the current temperature state of the engine cooling water. The fuel remaining amount display area 41h is an area for displaying the remaining amount state of the fuel stored in the fuel tank. The rotation speed mode display area 41i is an area for displaying the current rotation speed mode set by the engine rotation speed adjustment dial 75. The urea water remaining amount display area 41j is an area for displaying the remaining amount state of the urea water stored in the urea water tank. The hydraulic oil temperature display area 41k is an area for displaying the temperature state of the hydraulic oil in the hydraulic oil tank.

The camera image display area 41m is an area for displaying an image captured by the space recognition device 80. In the example of FIG. 4, the camera image display area 41 m displays the back camera image captured by the back camera 80B. The back camera image is a rear image that reflects the space behind the work machine 100, and includes a counterweight image 3a.

The current weight display area 41p is an area for displaying the weight (current weight) of the object actually being lifted by the lifting magnet 6. FIG. 4 shows that the current weight is 550 kg.

The controller 30 calculates the current weight based on, for example, the posture of the work attachment, the boom bottom pressure, and the specifications (weight, center of gravity position, etc.) of the work attachment registered in advance. 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 lifting magnet angle sensor S3, and the boom bottom pressure sensor S6b.

The cumulative weight display area 41q is an area for displaying an integrated value (hereinafter, referred to as “cumulative weight”) of the weight of an object lifted by the lifting magnet 6 in a predetermined period. FIG. 4 shows that the cumulative weight is 9500 kg.

The predetermined period is, for example, a period that starts when the reset button 41r is pressed. For example, when loading iron scraps on the loading platform of a dump truck, the operator presses the reset button 41r every time the dump truck to be loaded is replaced to reset the cumulative weight. This is so that the total weight of the iron scraps loaded on each dump truck can be easily grasped.

With this configuration, the work machine 100 can prevent iron scraps from being loaded on the loading platform of the dump truck in excess of the maximum load weight of the dump truck. When the weight measurement on the truck detects that iron scraps have been loaded in excess of the maximum load weight, the dump truck driver returns to the loading yard and removes some of the iron scraps loaded on the loading platform. It is necessary to carry out the work of lowering. The work machine 100 can prevent the occurrence of such load weight adjustment work.

The predetermined period may be, for example, a period from the time when the work of the day starts to the time when the work of the day ends. This is so that the operator or the manager can easily recognize the total weight of the iron scraps carried by the work in one day.

The reset button 41r is a software button for resetting the cumulative weight. The reset button 41r may be a hardware button arranged on the switch panel 42, the left operating lever 26L, the right operating lever 26R, or the like.

The controller 30 may be configured to automatically recognize the replacement of dump trucks and automatically reset the cumulative weight. In this case, the controller 30 may recognize the replacement of the dump trucks by using the image captured by the space recognition device 80, or may recognize the replacement of the dump trucks by using the communication device.

Further, the controller 30 is configured to integrate the current weight after recognizing that the iron scraps lifted by the lifting magnet 6 are loaded on the loading platform of the dump truck based on the image captured by the space recognition device 80. You may be. This is to prevent iron scraps that have been moved to a place other than the dump truck's loading platform from being accumulated as iron scraps loaded on the dump truck.

The controller 30 may determine whether or not the iron scraps lifted by the lifting magnet 6 are loaded on the loading platform of the dump truck based on the posture of the work attachment. Specifically, in the controller 30, for example, when the height of the lifting magnet 6 exceeds a predetermined value (for example, the height of the loading platform of the dump truck) and the release button 65C is pressed, the iron scraps of the dump truck It may be determined that the truck has been loaded on the loading platform.

The controller 30 may be configured to output an alarm when it is determined that the current weight exceeds a predetermined value. The predetermined value is, for example, a value based on the rated lifting weight. The alarm may be a visual alarm, an auditory alarm or a tactile alarm. With this configuration, the controller 30 can inform the operator that the current weight exceeds or is likely to exceed a predetermined value.

When a relatively small scrap such as iron scrap is to be lifted, the volume of the scrap attracted to the lifting magnet 6 is limited, so that the work machine 100 does not excessively increase the current weight. However, when a relatively large object such as an iron plate or an iron ingot is to be lifted, the work machine 100 lifts an excessively heavy object such that the stability SV of the work machine 100 falls below a predetermined value (for example, 1.0). It may end up. The stability SV of the work machine 100 is represented by SV = (W2 × L2) / (W1 × L1). W1 is the weight of the work attachment (including the weight of the lifted object), and L1 is the horizontal distance from the tipping fulcrum to the center of gravity of the work attachment. Further, W2 is the weight of the machine body of the work machine 100 (excluding the weight of the work attachment), and L2 is the horizontal distance from the fall fulcrum to the center of gravity of the machine body.

When an excessively heavy object is lifted, the controller 30 can sound a buzzer and display an image indicating that the current weight exceeds a predetermined value on the display device 40. Therefore, it is possible to prevent an excessively heavy object from being continuously lifted without being noticed by the operator. As a result, the safety of work by the work machine 100 can be enhanced.

The remaining weight display area 41s is an area for displaying the remaining weight. FIG. 4 shows that the cumulative weight is 9500 kg and the remaining weight is 500 kg. That is, it shows that the maximum load capacity is 10,000 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.

The target weight display area 41t is an area for displaying the target weight of the object attracted by the lifting magnet 6. The target weight is set at a value that does not exceed the remaining weight.

In the example shown in FIG. 4, since the remaining weight is 500 kg, the target weight is set to 500 kg. On the other hand, the current weight is 550 kg. Therefore, the controller 30 controls to reduce the current of the lifting magnet 6 until the current weight reaches 500 kg (target weight). This makes it possible to prevent the dump truck from being overloaded.

As described above, according to the work machine 100 according to the present embodiment, the weight (current weight) of the object lifted by the lifting magnet 6 can be set as the target weight.

It should be noted that a table in which the target weight and the target current command are associated with each other is provided, and the target current command of the current supplied to the lifting magnet 6 is generated based on the target weight to generate the target current command of the object lifted by the lifting magnet 6. A configuration is conceivable in which the weight approaches the target weight. However, when the object attracted by the lifting magnet 6 is, for example, an object having irregularities such as iron scraps and steel frames, it is actually attracted to the lifting magnet 6 even if a current value corresponding to the target weight is applied. It is assumed that the weight of the object deviates from the target weight. On the other hand, according to the work machine 100 according to the present embodiment, the weight of the object attracted to the lifting magnet can be set as the target weight.

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. As a result, it is possible to prevent the loading operation from being performed before the weight adjustment is completed. A message may also be displayed when the cumulative weight exceeds the maximum load capacity. As a result, the operator can be encouraged to carry out the loading and unloading work, and the dump truck can be prevented from being overloaded.

The preferred embodiment of the present invention has been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications, substitutions, etc. can be applied to the above-described embodiments without departing from the scope of the present invention. Also, the features described separately can be combined as long as there is no technical conflict.

The suction force control unit 33 has been described as controlling the current supplied to the lifting magnet 6, but the present invention is not limited to this. For example, it may be configured to control the voltage. That is, the suction force control unit 33 may control the suction force of the lifting magnet 6 by controlling the electric power supplied to the lifting magnet 6.

100 Work machine 1 Lower traveling body 2 Swivel mechanism 3 Upper swivel body 4 Boom (attachment)
5 arm (attachment)
6 Lifting magnet 7 Boom cylinder 8 Arm cylinder 9 Lifting magnet cylinder 30 Controller 31 Target weight setting unit 32 Weight calculation unit 33 Adhesive force control unit (power control unit)
34 Maximum load setting unit 35 Cumulative weight calculation unit 36 Residual weight calculation unit 100 Work machine 101 Adsorption start determination unit (power control unit)
102 Compensator (power control unit)
103 Weight detector

Claims (5)

With the lower running body,
An upper swivel body mounted on the lower traveling body via a swivel mechanism and
The attachment attached to the upper swing body and
The lifting magnet attached to the attachment and
Equipped with a control device,
The control device
A weight calculation unit that calculates the current weight, which is the weight of an object attracted by the lifting magnet,
It has a power control unit that controls the power supplied to the lifting magnet.
The power control unit
Compensates for the power supplied to the lifting magnet based on the current weight and the target weight.
Work machine. The power control unit
After the object is suspended from the lifting magnet, the electric power to be supplied is compensated so that the attractive force of the lifting magnet is reduced based on the current weight and the target weight.
The work machine according to claim 1. The power control unit
When the object is attracted by the lifting magnet, electric power is supplied so that the weight of the attracted object becomes larger than the target weight.
The work machine according to claim 1 or 2. A notification unit for notifying that the weight of the object reaches the target weight is provided.
The work machine according to any one of claims 1 to 3. The power control unit
After the lifting magnet has risen to a predetermined height, the electric power supplied to the lifting magnet is compensated based on the current weight and the target weight.
The work machine according to any one of claims 1 to 4.

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