JP7227829B2 - working machine - Google Patents

Description

The present disclosure relates to work machines with lifting magnets.

A working machine equipped with a lifting magnet is known as a working machine for transporting or moving an object such as steel (see Patent Document 1).

WO2016/076271

By the way, a work machine equipped with a lifting magnet performs a work of loading objects such as iron scraps onto a dump truck. After the loading operation is completed, the dump truck moves to the truck scale, and the weight of the load 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 with the work machine.

Further, when loading an object onto a dump truck, the operator of the work machine visually adjusts the weight of the object to be attracted by the lifting magnet. For this reason, there is a risk that the adjustment will be repeated multiple times depending on the experience of the operator.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a working machine that adjusts the weight of an object lifted by a lifting magnet.

A work machine according to one aspect of an embodiment includes a lower traveling body, an upper revolving body mounted on the lower traveling body via a revolving mechanism, an attachment attached to the upper revolving body, and a lifting magnet attached to the attachment. and a control device, wherein the control device includes a target weight setting unit that acquires a target weight of an object to be attracted by the lifting magnet, and a current weight that is the weight of the object that is attracted by the lifting magnet. and a power control unit configured to control power supplied to the lifting magnet, wherein the power control unit adjusts the current weight to the target weight after the object is suspended by the lifting magnet. The power supplied to the lifting magnet is compensated so that the attraction force of the lifting magnet decreases until .

ADVANTAGE OF THE INVENTION According to this invention, the working machine which adjusts the weight of the object lifted by the lifting magnet can be provided.

1 is a side view of a working machine according to this embodiment; FIG. 2 is a block diagram showing a configuration example of a drive system mounted on the work machine shown in FIG. 1; FIG. FIG. 4 is a block diagram illustrating current compensation of a lifting magnet; It is a figure which shows the structural example of a main screen.

FIG. 1 is a side view of a work machine 100 according to this embodiment. An upper revolving body 3 is mounted on a lower traveling body 1 of the work machine 100 via a revolving mechanism 2 . A boom 4 is attached to the upper revolving body 3 . An arm 5 is attached to the tip of the boom 4, and a lifting magnet 6 is attached to the tip of the arm 5 as an end attachment. The boom 4 and arm 5 constitute a working attachment, which is an example of an attachment. The boom 4 is driven by a boom cylinder 7 , the arm 5 is driven by an arm cylinder 8 , and the lifting magnet 6 is driven by a 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, a body tilt sensor S4, and a turning angular velocity sensor S5 are attached to the upper swing body 3. As shown in FIG.

The boom angle sensor S<b>1 is configured to detect a boom angle, which is the 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 of the boom cylinder 7 (boom stroke amount), or the tilt angle of the boom 4. It may be a tilt (acceleration) sensor or the like that detects the , or 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, which is the rotation angle of the arm 5 with respect to the boom 4, and the lifting magnet angle sensor S3, which detects the lifting magnet angle that is the rotation angle of the lifting magnet 6 with respect to the arm 5. be.

The fuselage tilt sensor S4 is configured to detect the tilt of the upper revolving structure 3 with respect to the horizontal plane (body tilt angle). In this embodiment, the machine body tilt sensor S4 is an acceleration sensor that detects the tilt angles of the upper revolving structure 3 about the longitudinal axis and the lateral axis. For example, the front-rear axis and the left-right axis of the upper revolving body 3 are orthogonal to each other and pass through a machine center point, which is one point on the revolving axis of the work machine 100 .

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

Space recognition device 80 is configured to image the surroundings of work machine 100 . The space recognition device 80 is, for example, a monocular camera, stereo camera, range image camera, 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 rotating body 3, a back camera 80B attached to the rear end of the upper surface of the upper rotating body 3, and a left end of the upper surface of the upper rotating body 3. and a right camera 80R (not visible in FIG. 1) attached to the right end of the upper surface of the upper rotating body 3 .

The space recognition device 80 is, for example, a monocular camera having an imaging device such as a CCD or CMOS, and outputs captured images to the display device 40 . Further, space recognition device 80 may be configured to calculate the distance from space recognition device 80 or work machine 100 to a recognized object. In addition to using a captured image, when using a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like as the space recognition device 80, a large number of signals (laser light, etc.) are transmitted to an object, and its reflection is detected. Receiving the signal may detect the distance and direction of the object from the reflected signal.

Space recognition device 80 is configured to detect objects existing around work machine 100 . Objects are, for example, dump trucks, terrain features (slopes, holes, etc.), electric wires, utility poles, people, animals, vehicles, construction machinery, buildings, walls, helmets, safety vests, work clothes, or predetermined markings on helmets. etc. 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 an object. For example, the space recognition device 80 may be configured to be able to distinguish between humans and non-human objects.

The boom cylinder 7 may be provided with a boom rod pressure sensor S6a, a boom bottom pressure sensor S6b, and a boom cylinder stroke sensor S7. The arm cylinder 8 may be provided with an arm rod pressure sensor S6c, an arm bottom pressure sensor S6d, and an arm cylinder stroke sensor S8. The lifting magnet cylinder 9 may be provided with a lifting magnet rod pressure sensor S6e, a lifting magnet bottom pressure sensor S6f, and a lifting magnet cylinder stroke sensor S9.

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”). 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. A 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"). 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 operator's 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 work machine 100. As shown in FIG. In FIG. 2, the mechanical power transmission system is indicated by a double line, the hydraulic oil line by a thick solid line, the pilot line by a dashed line, the electric control system by a dashed line, and the electric drive system by a thick dotted line.

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

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

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

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

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

Control valve 17 is a hydraulic control device that controls a hydraulic system in work machine 100 . For example, the control valve 17 controls one or more of the boom cylinder 7, the arm cylinder 8, the lifting magnet cylinder 9, the left traveling hydraulic motor 1L, the right traveling hydraulic motor 1R, and the turning hydraulic motor 2A. 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 traveling hydraulic motor 1L, the right 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 an operator to operate the hydraulic actuator. In this embodiment, the operating device 26 supplies hydraulic fluid 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 swing operation and arm operation, a right operating lever for boom operation and lifting magnet operation, a travel pedal, and a travel lever (none of which are shown). etc. The pilot pressure changes according to the details of the operation of the operating device 26 (including, for example, the direction of operation and the amount of operation).

The operating pressure sensor 29 detects pilot pressure generated by the operating device 26 . In this 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 the contents of each operation 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 calculations. In this embodiment, the controller 30 is a microcomputer including a CPU, a volatile memory device, a nonvolatile memory device, and the like. The controller 30, for example, reads programs corresponding to various functions from the nonvolatile storage device and loads them into the volatile storage device, and causes the CPU to execute processes corresponding to each of the programs.

The hydraulic pump 14G supplies hydraulic fluid to the hydraulic motor 60 via the hydraulic fluid line 16a. In this embodiment, the hydraulic pump 14</b>G is a fixed displacement hydraulic pump, and supplies working oil to the hydraulic motor 60 through the switching valve 61 .

The switching valve 61 is configured to switch the flow of hydraulic oil discharged by the hydraulic pump 14G. In this embodiment, the switching valve 61 is an electromagnetic valve whose valve position is switched according to a control command from the controller 30 . The switching valve 61 has a first valve position that allows communication between the hydraulic pump 14G and the hydraulic motor 60 and a second valve position that blocks communication between the hydraulic pump 14G and the hydraulic motor 60 .

When mode switching switch 62 is operated to switch the operation mode of working machine 100 to the lifting magnet mode, controller 30 outputs a control signal to switching valve 61 to switch switching valve 61 to the first valve position. Further, when the operation mode of work machine 100 is switched to other than the lifting magnet mode by operating mode switch 62, controller 30 outputs a control signal to switching valve 61 to move switching valve 61 to the second valve position. switch to FIG. 2 shows the switching valve 61 in the second valve position.

Mode changeover switch 62 is a switch for switching the operation mode of 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 alternatively switch between the excavator mode and the lifting magnet mode. The shovel mode is an operation mode when working machine 100 is operated as an excavator (shovel), and is selected when a bucket is attached to the tip of arm 5 instead of lifting magnet 6, for example. The lifting magnet mode is a mode when working machine 100 is operated as a working machine with a lifting magnet, and is selected when lifting magnet 6 is attached to the tip of arm 5 . Note that 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 to allow hydraulic fluid discharged from the hydraulic pump 14G to flow 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 from the hydraulic pump 14G is allowed to flow out to the hydraulic oil tank without flowing into the hydraulic motor 60. .

A rotating shaft of the hydraulic motor 60 is mechanically connected to a rotating shaft of the generator 63 . A generator 63 generates electric power for exciting the lifting magnet 6 . In this embodiment, the generator 63 is an alternating current generator that operates according to control instructions from the power control device 64 .

A power control device 64 controls the supply/cutoff of power for exciting the lifting magnet 6 . In this embodiment, the power control device 64 controls the start/stop of AC power generation by the generator 63 according to the power generation start command/power generation stop command from the controller 30 . Also, the power control device 64 converts the AC power generated by the generator 63 into DC power and supplies the DC power to the lifting magnet 6 . Also, 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 an attraction command to the power control device 64 when the lifting magnet switch 65 is turned on and turned on. Upon receiving the attraction command, the power control device 64 converts the AC power generated by the generator 63 into DC power, supplies the DC power to the lifting magnet 6 , and excites the lifting magnet 6 . The energized lifting magnet 6 enters an attraction state capable of attracting an object (magnetic body).

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. Upon receiving the release command, the power control device 64 stops the power generation by the generator 63 and puts the lifting magnet 6 in the attracted state into the non-attracted state (released state). The release 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 attraction and release of the lifting magnet 6 . In this embodiment, the lifting magnet switch 65 includes a weak excitation button 65A and a strong excitation button 65B as pushbutton switches provided on the top of the left operating lever 26L, and a pushbutton switch provided on the top of the right operating lever 26R. and 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 place the lifting magnet 6 in an attracted state (weakly attracted state). The predetermined voltage is, for example, the voltage set through the magnetic force adjustment dial 66 .

The strong excitation button 65B is an example of an input device for applying the maximum allowable voltage to the lifting magnet 6 to place the lifting magnet 6 in an attracted state (strongly attracted state).

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

The magnetic force adjustment dial 66 is a dial for adjusting the magnetic force (adsorption force) of the lifting magnet 6 . In this embodiment, the magnetic force adjustment dial 66 is installed in the cabin 10 and is configured to switch the magnetic force (adsorption force) of the lifting magnet 6 in four steps when the weak excitation button 65A is pressed. Specifically, the magnetic force adjustment dial 66 is configured to switch the magnetic force (adsorption force) of the lifting magnet 6 in four stages from the first level to the fourth level. FIG. 2 shows a state in which the third level is selected with the magnetic force adjustment dial 66. FIG.

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

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

Further, the operator can sort the objects by adjusting the magnetic force (adsorption force) of the lifting magnet 6 with the magnetic force adjustment dial 66 . The operator sorts the relatively light objects from the relatively heavy objects by selectively lifting and moving the relatively light objects from the pile of scrap using, for example, a relatively weak level of magnetic force (adsorption force). 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).

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

In addition, when a predetermined operation is performed after the weak excitation button 65A is pressed, or when a predetermined state is reached, the working machine 100 changes the state of the lifting magnet 6 by pressing the strong excitation button 65B. It may be automatically shifted to the strong adsorption state, which is the state when it is held. 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 has reached a predetermined angle. In this case, for example, when the lifting magnet 6, which is in the weakly attracted state by pressing the weak excitation button 65A, is lifted in response to the boom raising operation, the work machine 100 is strongly rotated. Even if the excitation button 65B is not pushed, the state of the lifting magnet 6 can be automatically changed to the strong attraction state.

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

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 42 a 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 operation/stop of the wiper. The window washer switch 42c is a switch for injecting the window washer fluid.

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

The engine control device 74 controls the engine 11 . In this 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, engine controller 74 may be integrated into controller 30 .

The engine speed adjustment dial 75 is a dial for adjusting the engine speed. In this embodiment, the engine speed control dial 75 is installed in the cabin 10 and is configured to switch the engine speed in four steps. Specifically, the engine speed adjustment dial 75 is configured to switch the engine speed in four stages of SP mode, H mode, A mode and idling mode. FIG. 2 shows a state in which the engine speed control dial 75 is used to select the H mode.

The SP mode is a rotation speed mode that is selected when it is desired to give priority to the amount of work, and utilizes the highest engine speed. The H mode is a rotational speed mode that is selected when it is desired to achieve both work load and fuel efficiency, and utilizes the second highest engine rotational speed. The A mode is a rotational speed mode selected when it is desired to operate the work machine with low noise while giving priority to fuel efficiency, and utilizes the third highest engine rotational speed. The idling mode is a rotation speed mode that is selected when it is desired to operate the engine in an idling state, and utilizes the lowest engine rotation speed (idling rotation 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 set state of the engine speed to the controller 30 .

The controller 30 also includes a target weight setting unit 31, a weight calculation unit 32, an adsorption force control unit 33, a maximum load setting unit 34, a cumulative weight calculation unit 35, and a residual weight calculation unit 36. are doing.

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

The weight calculator 32 calculates the weight (current weight) of the object attracted by the lifting magnet 6 . The current weight is calculated, for example, by the torque balance around the base of the boom 4 . Specifically, the object attracted to the lifting magnet 6 increases the thrust of the boom cylinder 7, and the torque around the base of the boom 4 calculated from the thrust of the boom cylinder 7 also increases. The torque increment and the torque calculated from the weight of the object and the center of gravity of the object match. Thus, the weight calculator 32 can calculate the weight of the object based on the thrust of the boom cylinder 7 (the measured values of the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B) and the center of gravity of the object. Note that the center of gravity of the object is obtained in advance experimentally and stored in the controller 30, for example. Note that the method for calculating the weight of the object is not limited to this, and various methods can be applied.

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

The maximum loading capacity setting unit 34 sets the maximum loading capacity of the dump truck for loading objects. Note that the maximum load capacity may be input by an operator, for example. size, etc.).

The cumulative weight calculator 35 calculates the cumulative weight of the objects loaded on the loading platform of the dump truck.

The remaining weight calculator 36 calculates the remaining weight, which is the difference between the maximum load capacity and the accumulated weight.

An example of the operation of the work machine 100 according to this embodiment will be described below.

First, the target weight setting section 31 of the controller 30 sets the target weight of the object to be attracted by the lifting magnet 6 . Also, the maximum loading amount setting unit 34 sets the maximum loading amount of the dump truck that loads the object.

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

Next, the operator operates the weak excitation button 65A to cause the lifting magnet 6 to generate magnetic force (adsorption force). Thereby, the object is attracted to the lifting magnet 6 . At this time, the attraction force control section 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 such that the weight of the object attracted by the lifting magnet 6 is equal to or greater than the target weight. 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 . It also serves as a trigger for the controller 30 to start compensation control, which will be 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, such as the attitude of the attachment, the positions of the connecting pins of the attachment, and when the lifting magnet 6 starts to rise. The determination may be made based on the elapsed time since, the operating state of the suction switch, or the like.

Next, the weight calculator 32 of the controller 30 calculates the weight (current weight) of the object attracted (suspended) by the lifting magnet 6 .

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

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

Next, the attraction force control section 33 of the controller 30 sets the current command value to the third current command value. The third current command value is a current command value greater than the second current command value. This prevents the object having the target weight from dropping off from the lifting magnet 6 .

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

Next, the notified operator operates the strong excitation button 65B to bring the lifting magnet 6 into the attraction state (strong attraction state). Next, the operator operates the operating device 26 to move the upper revolving structure 3 and the work attachments (boom 4 and arm 5) to move the lifting magnet 6 above the loading platform of the dump truck. Next, the operator operates the release button 65C, and the release button 65C puts the lifting magnet 6 in the release state. As a result, the object with the target weight is loaded onto the loading platform of the dump truck.

The cumulative weight calculator 35 updates the cumulative weight by adding the current target weight to the previous cumulative weight. The remaining weight calculator 36 calculates the remaining weight based on the updated cumulative weight.

By repeating these operations, it is possible to load an object with a desired cumulative weight onto the loading platform of the dump truck.

After the lifting magnet 6 is lifted to a predetermined height, the controller 30 prohibits the upper swing body 3 from swinging until the current weight reaches the target weight (while the calculation of the current weight and the current adjustment are repeated). Alternatively, it may be restricted within a predetermined angle range. As a result, it is possible to suppress scattering of falling objects around when the current living weight is adjusted to the target weight.

Although the case of loading onto a dump truck has been described as an example, the present invention is not limited to this, and an object of a desired target weight can be unloaded from the dump truck in the same manner during loading and unloading.

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

The adsorption 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 adsorption start determination unit 101 switches to input Wref+ΔW as the target weight to the compensator 102 . For example, when the lifting magnet 6 is raised to a predetermined height, the adsorption start determination unit 101 switches to input Wref as the target weight to the compensator 102 . In this way, the target weight is increased during the period from when the weak excitation button 65A is operated until the lifting magnet 6 rises to a predetermined height.

After lifting the lifting magnet 6 to a predetermined height, the compensator 102 compensates 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 detector 103. Here, the current compensation may be performed not only after the object is suspended by the lifting magnet 6, but also the current corresponding to the target flow rate Wref calculated before the object is suspended.

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

Thus, by compensating the current supplied to the lifting magnet 6 based on the target weight Wref and the current weight, the weight of the object attracted to the lifting magnet 6 can be made 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 section 41, for example, when the operation mode is the lifting magnet mode.

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 consumption display area 41d, an engine control state display area 41e, an engine operating time display area 41f, a cooling water temperature display area 41g, and a remaining fuel amount display. Area 41h, rpm mode display area 41i, residual urea water display area 41j, hydraulic oil temperature display area 41k, camera image display area 41m, current weight display area 41p, accumulated weight display area 41q, reset button 41r, remaining weight display It includes an area 41s and a target weight display area 41t.

The running 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 setting state information, which is information regarding the setting state of work machine 100. FIG. 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, operating 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 relating to the operating state of work machine 100 .

Specifically, the date and time display area 41a is an area for displaying the current date and time. The running mode display area 41b is an area for displaying the current running mode. The attachment display area 41c is an area for displaying an image representing the currently attached end attachment. FIG. 4 shows a state in which an image representing the lifting magnet 6 is displayed.

The fuel consumption display area 41 d 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 that displays the lifetime average fuel consumption or the section average fuel consumption, and an instantaneous fuel consumption display area 41d2 that displays the instantaneous fuel consumption.

The engine control state display area 41e is an area where the control state of the engine 11 is displayed. The engine operating time display area 41f is an area for displaying the cumulative operating time of the engine 11. FIG. 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 of 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 speed adjustment dial 75. FIG. 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 in which an image captured by the space recognition device 80 is displayed. In the example of FIG. 4, the camera image display area 41m displays the back camera image captured by the back camera 80B. The back camera image is a rearward image of the space behind the work machine 100 and includes the image 3a of the counterweight.

The current weight display area 41p is an area for displaying the weight (current weight) of the object that the lifting magnet 6 is currently lifting. 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 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 accumulated weight display area 41q is an area for displaying the integrated value of the weight of the object lifted by the lifting magnet 6 during a predetermined period (hereinafter referred to as "accumulated weight"). Figure 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, in the case of loading iron scrap onto the loading platform of a dump truck, the operator presses the reset button 41r to reset the accumulated weight each time the dump truck to be loaded is replaced. This is so that the total weight of scrap iron loaded on each dump truck can be easily grasped.

With this configuration, work machine 100 can prevent iron scrap from being loaded onto the loading platform of the dump truck in excess of the maximum loading weight of the dump truck. When it is detected that the scrap iron is loaded in excess of the maximum loading weight, the driver of the dump truck returns to the loading yard and removes part of the scrap iron loaded on the platform. I need to do some unloading work. 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 for the day is started to the time when the work for the day is finished. This is so that the operator or manager can easily recognize the total weight of scrap iron transported in one day's work.

The reset button 41r is a software button for resetting the accumulated 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 dump truck changes and automatically reset the accumulated weight. In this case, the controller 30 may recognize the replacement of the dump truck using the image captured by the space recognition device 80, or may recognize the replacement of the dump truck using the communication device.

Further, the controller 30 is configured to recognize that the iron scrap lifted by the lifting magnet 6 has been loaded onto the dump truck bed based on the image captured by the space recognition device 80, and then accumulate the current weight. may be This is to prevent scrap iron moved to a place other than the loading platform of the dump truck from being accumulated as scrap iron loaded onto the dump truck.

The controller 30 may determine whether or not the iron scrap lifted by the lifting magnet 6 has been loaded onto the dump truck bed based on the attitude of the work attachment. Specifically, 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 scrap is removed from the dump truck. It may be determined that the vehicle has been loaded onto the platform.

The controller 30 may be configured to output an alarm when determining that the current weight exceeds a predetermined value. The predetermined value is, for example, a value based on the rated lifting weight. The alert may be a visual alert, an audible alert or a tactile alert. With this configuration, the controller 30 can notify the operator that the current weight exceeds the predetermined value or that there is a possibility of doing so.

When relatively small scraps such as iron scraps are to be lifted, the volume of the scraps that can be attracted to the lifting magnet 6 is limited, so the working machine 100 does not excessively increase its current weight. However, when a relatively large object such as an iron plate or an iron block is to be lifted, work machine 100 lifts an excessively heavy object such that the stability SV of work machine 100 falls below a predetermined value (for example, 1.0). may be lost. Stability SV of 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. W2 is the weight of the body of work machine 100 (excluding the weight of the work attachment), and L2 is the horizontal distance from the tipping fulcrum to the center of gravity of the body.

If an excessively heavy object is lifted, the controller 30 can sound a buzzer and cause the display device 40 to display an image indicating that the current weight exceeds a predetermined value. Therefore, it is possible to prevent the state in which an excessively heavy object is lifted from being continued without the operator noticing. As a result, the safety of work performed by work machine 100 can be enhanced.

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

The target weight display area 41t is an area for displaying the target weight of the object to be attracted by the lifting magnet 6. FIG. 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. In contrast, the current weight is 550 kg. Therefore, the controller 30 performs control to decrease the current of the lifting magnet 6 until the current weight reaches 500 kg (target weight). As a result, overloading of the dump truck can be prevented.

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.

By having a table that associates the target weight with the target current command, and generating the target current command for the current supplied to the lifting magnet 6 based on the target weight, the object lifted by the lifting magnet 6 can be measured. A configuration in which the weight is brought closer to the target weight is conceivable. However, if the object to be attracted by the lifting magnet 6 is, for example, an object with variations in density such as iron scraps or a steel frame, the object will not actually be 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 obtained will deviate from the target weight. In contrast, according to work machine 100 according to the present embodiment, the weight of the object that is 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 urged to perform loading and unloading work, and overloading of the dump truck can be prevented.

The preferred embodiments of the present invention have been described in detail above. However, the invention is not limited to the embodiments described above. Various modifications, replacements, etc., may be applied to the above-described embodiments without departing from the scope of the present invention. Also, features described separately can be combined unless technical contradiction arises.

Although the attraction force control section 33 has been described as controlling the current supplied to the lifting magnet 6, it is not limited to this. For example, it may be configured to control the voltage. That is, the attraction force control section 33 may control the attraction force of the lifting magnet 6 by controlling the electric power supplied to the lifting magnet 6 .

100 working machine 1 lower traveling body 2 turning mechanism 3 upper turning 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 Attraction force control unit (power control unit)
34 Maximum load capacity setting unit 35 Accumulated weight calculation unit 36 Remaining weight calculation unit 100 Working machine 101 Suction start determination unit (power control unit)
102 compensator (power control unit)
103 weight detector

Claims (5)

a lower running body;
an upper revolving body mounted on the lower traveling body via a revolving mechanism;
an attachment attached to the upper revolving body;
a lifting magnet attached to the attachment;
a controller;
The control device is
a target weight setting unit that acquires a target weight of an object to be attracted by the lifting magnet;
a weight calculation unit that calculates a current weight, which is the weight of the object attracted by the lifting magnet;
a power control unit that controls power supplied to the lifting magnet;
The power control unit
After the object is suspended by the lifting magnet, the power supplied to the lifting magnet is compensated so that the attraction force of the lifting magnet decreases until the current weight reaches the target weight.
working machine. The power control unit
after the object is suspended by the lifting magnet, compensating the power supplied to the lifting magnet based on the difference between the current weight and the target weight;
A work machine according to claim 1. The power control unit
When the object is attracted by the lifting magnet, power is supplied so that the weight of the object attracted is greater than the target weight.
A work machine according to claim 1 or claim 2. a notification unit that notifies when the weight of the object reaches the target weight;
The working machine according to any one of claims 1 to 3. The power control unit
Compensating the power supplied to the lifting magnet based on the current weight and the target weight after the lifting magnet rises to a predetermined height;
The working machine according to any one of claims 1 to 4.

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