Lifting magnet device

Abstract

To provide a lifting magnet device capable of easily and accurately determining a size of a gap between an attracting surface and an attracted surface.SOLUTION: A lifting magnet device comprises: an electromagnet capable of being attracted to a suspended object; a fluid passage connecting between an attracting surface of the electromagnet and an attracted surface of the suspended object; and an air pressure sensor that measures the pressure of air flowing in the fluid passage.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a lifting magnet device.

Background Art

[0002] A lifting magnet device is a device that suspends an electromagnet hung by a wire rope on a suspended object such as steel material, and adsorbs the suspended object to lift and transport it. Patent Document 1 describes a technique for monitoring whether an electromagnet is adsorbing and holding a suspended object by sensing using magnetic flux.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] If there is a large gap between the electromagnet and the suspended object, the adsorption of the suspended object becomes unstable. Therefore, it is preferable that the size of the gap can be accurately detected. However, the above-mentioned gap is caused by various factors such as foreign matters on the adsorbed surface of the suspended object, unevenness or bending of the adsorbed surface, and deflection due to the dead weight of the suspended object. Therefore, it is not easy to accurately detect the size of the gap. Furthermore, the above-mentioned gap rarely occurs uniformly over the entire adsorbed surface, and large and small portions often coexist. Therefore, even if there is a gap in a portion hidden from the outside, it is not easy to accurately grasp the size of the gap visually.

[0005] An object of the present invention is to provide a lifting magnet device that can easily and accurately determine the size of the gap between the adsorption surface and the adsorbed surface.

Means for Solving the Problems

[0006] The lifting magnet device according to the present invention is an electromagnet capable of adsorbing a suspended object, a fluid passage connecting between the adsorption surface of the electromagnet and the adsorbed surface of the suspended object, an air pressure sensor for measuring the pressure of air flowing through the fluid passage, and includes.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a lifting magnet device capable of easily and accurately determining the size of the gap between the adsorption surface and the adsorbed surface.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing a lifting magnet device according to an embodiment of the present invention.

[0010] The lifting magnet device 1 of the present embodiment includes a plurality of electromagnets 10 that can adsorb a suspended object 80, an air device 20 that can suck in and blow out air through a fluid passage H, an air pressure sensor 21 that measures the pressure of the air flowing through the fluid passage H, a crane 30 that can lift and transport the plurality of electromagnets 10, an operation unit 50 that performs operation control of the electromagnets 10 and the crane 30, a control unit 60 that performs operation support control, and a temperature sensor 18 that detects the temperature of the electromagnets 10. The suspended object 80 is a magnetic material such as a steel plate that can be adsorbed by a magnet. Although not particularly limited, the plurality of electromagnets 10 are suspended from a beam 19, and the crane 30 can lift and transport the plurality of electromagnets 10 via the beam 19.

[0011] The electromagnet 10 is configured to be able to generate and release magnetic force, and can adsorb the suspended object 80 by the magnetic force and lift the suspended object 80. Although details will be described later, the electromagnet 10 has a fluid passage H through which air can be sucked in and blown out between the adsorption surface 15 (see FIG. 2) and the adsorbed surface of the suspended object 80.

[0012] The air device 20 is a device that can suck in and blow out air through the fluid passage H. Specifically, the air device 20 has an air compressor and an air pump, blows out air by the air compressor, and sucks in air by the air pump. Note that the configuration is not limited to the above. For example, the air device 20 may have an air compressor while the air pump is omitted, and a configuration may be adopted in which air is sucked in from the fluid passage H using the compressed air of the air compressor. Any configuration may be applied to the air device 20 as long as it can blow out and suck in air.

[0013] The air pressure sensor 21 measures, for example, the pressure of the air flowing through the fluid passage H. The air pressure sensor 21 may measure the pressure of the air in the fluid passage H of the electromagnet 10, may measure the pressure of the air in the fluid passage H of the air hose connected to the electromagnet 10, or may be configured to measure the pressure in the air tank provided in the middle of the air hose.

[0014] The crane 30 is, for example, an overhead crane. Note that the crane 30 is not limited to an overhead crane, and in addition to mobile cranes such as crawler cranes, wheel cranes, truck cranes, rough terrain cranes, and all terrain cranes, all kinds of cranes such as tower cranes, jib cranes, retractable cranes, stacker cranes, gantry cranes, and unloaders are applicable.

[0015] The operation unit 50 is provided with an operation operation unit 51 that enables the operator to operate the electromagnet 10 and the crane 30, an air operation unit 52 that enables the operator to operate the air device 20, and a warning output unit 53 that can output warnings such as abnormalities to the operator. The warning output unit 53 can output warnings by means of sound, light, display, or a combination of these means. In addition, the warning output unit 53 may be able to output an output indicating the absence of a warning (output of continued OK).

[0016] The operation signal of the operation operation unit 51 is sent to the drive circuit of the electromagnet 10 and the control mechanism of the crane 30. By operating the drive circuit and the control mechanism based on the operation signal, the driving of the electromagnet 10 and the crane 30 is realized. The operation of the electromagnet 10 includes operations for generating and releasing a large magnetic force. In addition, the operation of the electromagnet 10 may include operations for changing the magnitude of the magnetic force in multiple stages, such as generating a medium magnetic force and generating a small magnetic force. The driving of the crane 30 includes the lifting and lowering of the electromagnet 10 via the beam 19 and the horizontal movement. The operation signal of the air operation unit 52 is sent to the air device 20, and air is sucked in or blown out according to the operation.

[0017] The control unit 60 is a computer that operates according to a sequencer or a control program. The control unit 60 mainly provides work support regarding the gap between the adsorption surface 15 (see FIG. 2) of the electromagnet 10 and the surface to be adsorbed of the suspended object 80. More specifically, the control unit 60 determines the size of the above-mentioned gap and performs warning processing based on the determination result. In addition, the control unit 60 may perform warning processing regarding the heat generation of the electromagnet 10. The control unit 60 receives outputs from the temperature sensor 18 and the air pressure sensor 21. The control unit 60 can output a signal for operating the warning output unit 53. Furthermore, the control unit 60 receives a signal that can recognize the driving state of the electromagnet 10 and the operating state of the crane 30. The signals indicating the above-mentioned driving state and operating state may be sent from the operation unit 50 to the control unit 60, or may be sent from the drive circuit of the electromagnet 10 and the control mechanism of the crane 30 to the control unit 60.

[0018] <Detailed Structure of Electromagnet> FIG. 2 is a diagram for explaining the structure of the electromagnet 10. FIG. 3 is a diagram showing an operation example of the electromagnet, where (A) shows an operation example immediately before adsorption, (B) shows an operation example during adsorption, and (C) shows an operation example when suspending a suspended object. In FIGS. 2 and 3, the electromagnet 10 is shown by a longitudinal sectional view passing through the center. The electromagnet 10 has an adsorption surface 15 facing the surface to be adsorbed of the suspended object 80. Openings Ua and Ub of the fluid passage H connected to the air device 20 are provided on the adsorption surface 15. The opening Ua corresponds to an example of the first opening according to the present invention, and the opening Ub corresponds to an example of the second opening according to the present invention.

[0019] More specifically, the electromagnet 10 includes a coil 11, an inner pole 12 around which the coil 11 is wound, and an outer pole 13 surrounding the outside of the coil 11 (on the opposite side of the inner pole 12 with the coil 11 interposed therebetween). The inner pole 12 and the outer pole 13 are made of a magnetic material. The end face 12a of the inner pole 12 and the end face 13a of the outer pole 13 form an adsorption surface 15 facing the suspended object 80. One or more openings Ua are provided in the end face 12a of the inner pole 12. A plurality of openings Ub are provided in the end face 13a of the outer pole 13. The plurality of openings Ub are respectively provided at a plurality of positions dispersed in the circumferential direction. The circumferential direction means the direction along the winding direction of the coil 11.

[0020] The fluid passage H is provided so as to penetrate the inside of the inner pole 12 and the outer pole 13 so as to connect to the plurality of openings Ua and Ub. The fluid passages H may be combined into one fluid passage H, for example, by being connected at the upper part of the electromagnet 10. A connector for connecting to a hose that is part of the fluid passage H may be provided at the upper part of the electromagnet 10.

[0021] With the above configuration of the electromagnet 10, as shown in Fig. 3(A), immediately before the electromagnet 10 contacts the suspended object 80, even if there is a foreign object e1 such as dust on the adsorbed surface of the suspended object 80, by blowing air from the openings Ua and Ub, the foreign object e1 can be swept away. Thereby, it is possible to reduce the possibility of sandwiching the foreign object e1 between the adsorption surface 15 of the electromagnet 10 and the adsorbed surface of the suspended object 80, which can contribute to a strong adsorption force between the electromagnet 10 and the suspended object 80.

[0022] Furthermore, as shown in Fig. 3(B), when the electromagnet 10 is placed on the suspended object 80 or in a state of being adsorbed to the suspended object 80, if compressed air is supplied to the fluid passage H, air is blown out from the openings Ua and Ub. At this time, the air is sent out to the outside through the gap between the adsorption surface 15 of the electromagnet 10 and the adsorbed surface of the suspended object 80, and when passing through the gap, it is resisted according to the size of the gap (the distance in the direction perpendicular to the adsorption surface 15 and the width in the direction along the adsorption surface 15). That is, if the gap is large, the resistance is small, and if the gap is small, the resistance is large. Therefore, when measuring the pressure of the compressed air sent to the fluid passage H, measurement values different according to the size of the above gap can be obtained. That is, the size of the gap generated between the adsorption surface 15 of the electromagnet 10 and the adsorbed surface of the suspended object 80 can be accurately determined by the said measurement value.

[0023] The above gap may occur in various ways. For example, due to unevenness or bending on the adsorbed surface, a large gap and a small gap may be mixed partially between the adsorption surface 15 and the adsorbed surface, and there may be a gap in a portion that is difficult to see from the side. Furthermore, there may be a gap at a location far from the openings Ua and Ub. However, even in such a case, the compressed air moves along the entire gap, and while receiving resistance according to the overall size of the gap, it flows out to the outside of the adsorbed surface. Therefore, no matter in what manner the gap occurs, the size of the gap can be accurately determined from the pressure of the compressed air.

[0024] Also, as shown in Fig. 3(C), when the electromagnet 10 is in a state of being adsorbed to the suspended object 80 and air is sucked in from the openings Ua and Ub through the fluid passage H, although it does not become a large force, it can assist the force for adsorbing the suspended object 80 by the suction of the air.

[0025] Furthermore, when air is sucked through the fluid passage H with the electromagnet 10 adsorbed to the suspended object 80, the air flows from the outside of the adsorption surface 15 through the gap to the openings Ua and Ub. When the air flows, the air receives resistance according to the size of the gap. Therefore, even in this case, the size of the gap can be accurately determined from the pressure of the air decompressed to suck the air. When the suspended object 80 is in a lifted state, as shown in Fig. 3(C), the suspended object 80 may bend under its own weight and the size of the gap may change. Even in such a case, the change in the size of the gap can be accurately determined from the pressure value of the decompressed air.

[0026] <Suspended object transfer process> Subsequently, the operation process and control process when adsorbing and transporting the suspended object 80 to the electromagnet 10 will be described. Fig. 4 is a flowchart showing the flow of the transfer process of the suspended object 80 by the operator. Fig. 5 is a flowchart showing an example of the control process executed by the control unit 60.

[0027] When transporting the suspended object 80, the operator first lowers the electromagnet 10 toward the suspended object 80 by operating the crane 30 (step J1). After lowering, the operator generates a large magnetic force from the electromagnet 10 to adsorb the suspended object 80 to the electromagnet 10 (step J3). The above timing for generating the magnetic force from the electromagnet 10 is an example. For example, a magnetic force or a weak magnetic force may be generated from the electromagnet 10 before the electromagnet 10 contacts the suspended object 80.

[0028] When lowering the electromagnet 10 to the suspended object 80, the operator starts sending compressed air from the air device 20 by operating the air operation unit 52 (step J2). As a result, as shown in Fig. 3(A), air is blown out from the openings Ua and Ub of the fluid passage H, and foreign matter e1 on the adsorbed surface of the suspended object 80 can be swept away.

[0029] Note that the above-described delivery of compressed air may not be configured to start based on the operation of the air operation unit 52, but may be configured to be automatically started by the control device of the air device 20 based on, for example, the lowering of the electromagnet 10. Alternatively, it may be configured to be automatically started by the control device of the air device 20 based on information indicating the start of the suction process for the suspended object 80.

[0030] Even during the period when the electromagnet 10 descends to the suspended object 80 and the weight of the electromagnet 10 is applied to the suspended object 80, or during the period when the electromagnet 10 attracts the suspended object 80 by magnetic force and has not yet lifted the suspended object 80, the delivery of compressed air from the air device 20 is continued.

[0031] When the control process starts, the control unit 60 repeatedly performs a process of determining whether the electromagnet 10 has attracted the suspended object 80 by magnetic force (or whether it has descended to the suspended object 80) (step S1). When the determination result is YES, the control unit 60 captures the measured value of the air pressure sensor 21 (that is, the pressure value P1 of the compressed air) (step S2). Then, the control unit 60 determines whether the pressure value P1 of the compressed air is less than the pressure threshold value Pth1 (step S3). The pressure threshold value Pth1 is set to a value that differentiates whether the gap between the suction surface 15 and the surface to be suctioned is of a size that may impede stable suction.

[0032] If the result of the determination in step S3 is NO, the control unit 60 outputs a "continuation OK" from the warning output unit 53 (step S4), but if it is YES, the warning output unit 53 outputs a warning indicating that stable suction cannot be obtained (step S5).

[0033] The operator checks the warning output in step S4 or S5 (step J4). If there is a warning, the operator checks whether there is an abnormality on the suction surface 15 and the surface to be suctioned, and if there is an abnormality, removes it (step J5). For example, in step J5, if there is a foreign object on the suction surface 15 or the surface to be suctioned, the operator removes the foreign object. Also, if there are irregularities or bends on the surface to be suctioned, the suction location is changed to a location without irregularities or bends. After that, the operator repeats the operation from step J1.

[0034] On the other hand, if the output of the warning output unit 53 continues to be OK, the driver operates the air operation unit 52 to start sucking air by reducing the pressure of the air with the air device 20 (step J6). By this operation, air is sucked from the adsorption surface 15 of the electromagnet 10, and the suction of the suspended object 80 by the electromagnet 10 can be assisted. Further, based on the pressure value P2 of the decompressed air measured by the air pressure sensor 21, it becomes possible to determine the change in the size of the gap of the adsorption surface 15.

[0035] Furthermore, the driver operates the operation control unit 51 to lift the suspended object 80 with the crane 30 and start conveyance (step J7).

[0036] After the output in step S4, the control unit 60 repeatedly performs a process of determining whether an operation to lift the suspended object 80 has been started (step S6). If it has been started, the measured value of the air pressure sensor 21 (that is, the pressure value P2 of the decompressed air) is taken in (step S7). Then, the control unit 60 determines whether the pressure value P2 of the decompressed air exceeds the pressure threshold value Pth2 (step S8). The pressure threshold value Pth2 is set to a value that divides whether the gap between the adsorption surface 15 and the surface to be adsorbed is of a size that may inhibit stable adsorption. As shown in FIG. 5(C), when the suspended object 80 is lifted, the suspended object 80 is bent due to its own weight, and there is a possibility that the above-described gap becomes large and a phenomenon that inhibits stable adsorption occurs. This phenomenon can be determined by the process in step S8.

[0037] On the other hand, if the determination result in step S8 is YES, the control unit 60 performs a warning output from the warning output unit 53 to notify the possibility of inhibiting stable adsorption (step S9).

[0038] The driver determines whether there is a warning output during the operation of transporting the suspended object 80 (step J8). If there is a warning, operations corresponding to the warning (step J9) are performed, such as gently moving the crane 30, increasing the driving current of the electromagnet 10 to increase the adsorption force, or moving the suspended object 80 to a grounded place and then lowering the electromagnet 10.

[0039] On the one hand, if there is no warning output, the driver determines whether the transportation of the suspended object 80 to the destination has been completed (step J10), and continues the confirmation in step J8 and the transportation operation until it is completed. On the other hand, if the transportation is completed, the driver stops the drive of the electromagnet 10 and the output of the air device 20, and releases the suspended object 80 from the electromagnet 10 (step J11). Then, the driver starts to move the electromagnet 10 toward the position corresponding to the next suspended object 80 (step J12).

[0040] If the determination result in step S8 is NO, the control unit 60 determines whether the transportation is completed and the electromagnet 10 has released the suspended object 80 (whether the drive of the electromagnet 10 has stopped) (step S10). If the determination result in step S10 is NO, the process returns to step S7, and the processes in steps S7, S8, and S10 are repeated. On the other hand, if it is determined as YES in step S10, the control unit 60 determines whether the output value T1 of the temperature sensor 18 exceeds the temperature threshold value Tth (step S11). The temperature threshold value Tth is set to the lower limit value of the temperature that recommends cooling of the coil 11. If the determination result in step S11 is NO, the control unit 60 returns the process to step S1 so that the next transportation process can be performed. On the other hand, if the determination result in step S11 is YES, the control unit 60 outputs a warning indicating the need for cooling from the warning output unit 53 (step S12), and returns the process to step S1 so that the next transportation process can be performed.

[0041] During the movement of the electromagnet 10 in step J12, the driver determines whether there is a warning for the need for cooling (step J13). If so, the driver operates the air operation unit 52 to output compressed air from the air device 20 (step J14). By the output of the compressed air, during the movement of the electromagnet 10, the coil of the electromagnet 10 can be cooled by the flow of the compressed air through the fluid passage H. Then, it is determined whether the movement of the electromagnet 10 to the position corresponding to the next suspended object 80 is completed (step J15), and the confirmation in step J13 and the movement operation in step J12 are continued until it is completed. On the other hand, if the movement is completed, the driver repeats the process from step J1.

[0042] Note that all or part of the processes of steps J1 to J14 described as the driver's processes may be executed by a control device such as a sequencer or a computer.

[0043] As described above, the lifting magnet device 1 of the present embodiment includes a fluid passage H connecting between the adsorption surface 15 of the electromagnet 10 and the adsorbed surface of the suspended object 80. Further, the lifting magnet device 1 includes an air pressure sensor 21 that measures the pressure of the air flowing through the fluid passage H. Therefore, based on the output of the air pressure sensor 21, the size of the gap between the adsorption surface 15 and the adsorbed surface can be accurately determined. Further, the lifting magnet device 1 performs work support regarding the above gap based on the output of the air pressure sensor 21. Therefore, it is possible to realize a highly reliable conveyance process of the suspended object 80 according to the size of the gap.

[0044] Furthermore, according to the lifting magnet device 1 of the present embodiment, the fluid passage H opens to the adsorption surface 15 of the electromagnet 10. Therefore, it is possible to easily realize blowing or suction of air so as to pass through the gap between the adsorption surface 15 and the adsorbed surface of the suspended object 80. And the size of the gap can be accurately determined by the air pressure. Note that the arrangement of the fluid passage H and its openings Ua and Ub is not limited to the configuration of the above embodiment. For example, a configuration in which the fluid passage H opens to the side surface of the space holding the coil 11 may be adopted, or an air hose may be provided so that an opening of the air hose serving as the fluid passage H is arranged between the adsorption surface 15 and the adsorbed surface. Various configurations are possible.

[0045] Furthermore, according to the lifting magnet device 1 of the present embodiment, the opening Ua of the fluid passage H is provided on the end surface 12a of the inner pole 12 of the electromagnet 10. According to this configuration, by blowing out air from the opening Ua, a large amount of air can be sent from the center to the outside on the adsorption surface 15, and it is possible to efficiently sweep foreign matters such as dust on the adsorption surface 15 or the adsorbed surface.

[0046] Furthermore, according to the lifting magnet device 1 of the present embodiment, a plurality of openings Ub of the fluid passage H are provided on the end face 13a of the outer pole 13 of the electromagnet 10. According to this configuration, even when the gap becomes large only in a part of the peripheral portion of the adsorption surface 15, it is possible to determine the size of the entire gap reflecting the state of the gap by the air pressure.

[0047] Furthermore, according to the lifting magnet device 1 of the present embodiment, the air device 20 can suck and blow air through the fluid passage H. Therefore, it is possible to switch between the action of sweeping out foreign matter when blowing air from the fluid passage H and the action of adding an attractive force when sucking air from the fluid passage H.

[0048] Furthermore, according to the lifting magnet device 1 of the present embodiment, when the electromagnet 10 approaches the suspended object 80, air is blown out through the fluid passage H. With this configuration, it is possible to sweep out foreign matter such as dust from the adsorption surface 15 and the adsorbed surface before the adsorption surface 15 of the electromagnet 10 comes into contact with or adsorbs to the adsorbed surface of the suspended object 80.

[0049] Furthermore, according to the lifting magnet device 1 of the present embodiment, when the suspended object 80 is lifted by the electromagnet 10, air is sucked in through the fluid passage H. With this configuration, the suction force of the electromagnet 10 can be assisted by the suction of air.

[0050] The lifting magnet device 1 of the present embodiment may include means for sweeping out foreign matter from the adsorption surface 15, the adsorbed surface of the suspended object 80, or both when the electromagnet 10 approaches the suspended object 80. Furthermore, the above-mentioned sweeping means may be provided on the electromagnet 10. The sweeping means may be realized by means of pushing out and pulling in a broom-shaped member from below the electromagnet 10 and means for moving it such as rotation, or by means of pushing out and pulling in a wiping member from below the electromagnet 10 and means for moving it such as reciprocating movement.

[0051] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. For example, in the above embodiments, it has been described that air is blown out from the fluid passage H when the electromagnet 10 approaches the suspended object 80. However, in an environment where there are no foreign matters or the like to be swept away by the blowing of air, or when it is possible to suck up foreign matters from the fluid passage H and move them to a dust pack or the like, air may be sucked into the fluid passage H when the electromagnet 10 approaches the suspended object 80, or a configuration in which air is not flowed may be adopted.

[0052] Also, in the above embodiments, it has been described that air is sucked into the fluid passage H when the suspended object 80 is being lifted. However, when the suspended object 80 is heavy, the influence of the blowing or sucking of air on the adsorption force between the electromagnet 10 and the suspended object 80 can be ignored. Therefore, in such a case, air may be blown out from the fluid passage H even when the suspended object 80 is being lifted. Even in this case, by measuring the pressure of the air, the change in the gap between the adsorption surface 15 and the adsorbed surface can be accurately determined from the measured pressure.

[0053] Furthermore, air may be blown out from the fluid passage H both when the electromagnet 10 is adsorbing and when the suspended object 80 is being lifted. According to this configuration, the configuration for sucking air from the air device 20 can be omitted. That is, in this case, the air device 20 only needs to have a configuration for blowing out compressed air. Conversely, air may be sucked into the fluid passage H both when the electromagnet 10 is adsorbing and when the suspended object 80 is being lifted. According to this configuration, the configuration for blowing out air from the air device 20 can be omitted. That is, in this case, the air device 20 only needs to have a configuration for decompressing air. In addition, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

Explanation of Reference Numerals

[0054] 1 Lifting Magnet Device 10 Electromagnet 11 Coil 12 Inner Pole 13 Outer Pole End faces of 12a and 13a Suction surface 15 Temperature sensor 18 Beam 19 Air device 20 Air pressure sensor 21 Crane 30 Operation unit 50 Operation control unit 51 Air operation unit 52 Warning output unit 53 Control unit 60 Lifted object 80 Fluid passage H Openings Ua and Ub

Claims

1. An electromagnet capable of adsorbing a suspended object, A fluid passage connecting between the adsorption surface of the electromagnet and the adsorbed surface of the suspended object, An air pressure sensor for measuring the pressure of air flowing through the fluid passage, Comprising, A lifting magnet device.

2. Performing work support regarding the gap between the adsorption surface and the adsorbed surface based on the output of the air pressure sensor, The lifting magnet device according to Claim 1.

3. The fluid passage is open to the adsorption surface, The lifting magnet device according to Claim 1.

4. The fluid passage has one or more first openings, The adsorption surface includes an end face of an inner pole around which a coil is wound, The first opening is provided on the end face of the inner pole, The lifting magnet device according to Claim 3.

5. The fluid passage has a plurality of second openings, The adsorption surface further includes an end face of an outer pole surrounding the outside of the coil, The plurality of second openings are provided on the end face of the outer pole, The lifting magnet device according to Claim 4.

6. Through the fluid passage, suction and blowing of air can be switched, The lifting magnet device according to Claim 1.

7. When approaching the suspended object with the electromagnet, blowing air through the fluid passage, The lifting magnet device according to Claim 1.

8. When suspending the suspended object with the electromagnet, sucking air through the fluid passage, The lifting magnet device according to Claim 7.

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