JP4256192B2 - Electromagnetic pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic pump that transfers liquid metal by electromagnetic force.
[0002]
[Prior art]
As a conventional electromagnetic pump, for example, one having a structure described in Patent Document 1 below is known. That is, an annular electromagnetic coil that generates a magnetic field, an iron core that forms a magnetic circuit, and a clamp mechanism that tightly contacts the iron core with the duct are provided. An iron core is made up of a plurality of magnetic steel plates stacked to form a block, and a plurality of blocks are arranged in the circumferential direction. Further, a stainless steel casing is provided so as to cover these pump internal structures, and the shape of this casing is usually cylindrical. A cylindrical outer duct installed through the casing and a cylindrical inner duct inserted into the outer duct are provided. A flow path through which liquid metal flows is formed between the outer duct and the inner duct.
[0003]
A structure in which an electromagnetic coil, an iron core, etc. (these structures are referred to as a stator) are installed outside the inner duct and inside the inner duct across the flow path is called a double stator electromagnetic pump. A structure in which only the iron core is installed inside the inner stator is called a single stator electromagnetic pump. A bottom plate connected to the casing is provided at the end of these stators. Moreover, the cable which supplies an alternating current to the electromagnetic coil provided in the casing is provided. The liquid metal is sucked from the fluid inlet that is one opening of the duct, is pressurized by the electromagnetic force in the flow path, and is pumped outside from the fluid outlet that is the other opening of the duct.
[0004]
The electromagnetic pump is a pump that transfers the liquid metal by utilizing the conductivity of the liquid metal. In a generally known three-phase induction type electromagnetic pump, the shaft of the electromagnetic pump in which the three-phase winding is the fluid flow direction. Distribution is arranged in the order of each phase in the direction. Then, a three-phase alternating current is passed through the three-phase winding to generate a traveling magnetic field in the direction of current flow, and an induced current is passed through the liquid metal, which is a conductive fluid, according to the so-called Fleming's right-hand rule. An electromagnetic force is generated by the interaction between the induced current and the traveling magnetic field, and this electromagnetic force becomes a driving force for transferring the liquid metal and acts as a pump. This electromagnetic force is the same as the force that generates torque in the induction motor, the thrust in the linear motor, and the like.
[0005]
Conventional electromagnetic pumps use electromagnetic coils with excellent heat resistance, and because the heat generated in the pump is transferred to liquid metal by closely contacting the iron core and duct, there is no need for a device to cool the pump. Yes, it is possible to install an electromagnetic pump submerged in a liquid metal (this type of pump is called an immersion electromagnetic pump). At this time, a leaf spring or a disc spring is used as a clamping mechanism for bringing the iron core and the duct into close contact with each other. Further, the cable port of the conventional immersion type electromagnetic pump is provided in the upper part of the casing, and the cable of the electromagnetic coil is wired between the iron core block and the iron core block, and finally bundled at the upper part of the iron core. At this time, a number of electromagnetic coil cables are evenly arranged between several blocks of iron cores.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 62-178153 [0007]
[Problems to be solved by the invention]
The conventional immersion type electromagnetic pump has a problem that the pumping height is high and the outer dimensions are large and the pressure loss is large because the cable outlet is the upper part of the pump. In addition, the iron core is pressed against the outer periphery of the outer duct in order to transfer heat generated in the pump to the liquid metal, but there is a problem that the size of the pressing clamp mechanism is large and the degree of contact is uneven in the circumferential direction. .
[0008]
Accordingly, an object of the present invention is to provide an electromagnetic pump in which the iron core is brought into close contact with the outer periphery of the outer duct with a uniform clamping force in the circumferential direction by a small clamping mechanism, and the overall outer dimension is small and the pressure loss is small.
[0009]
[Means for solving the problems]
According to the first aspect of the present invention, a plurality of outer iron cores and a plurality of electromagnetic coils provided on the outer periphery of a cylindrical outer duct and an outer peripheral side of the outer iron core and the electromagnetic coils connected to the outer duct via a bottom plate are provided. A casing that covers, an inner stator provided with a gap in the center hole of the outer duct, and a partially-notched ring that binds the back surface of the plurality of outer iron cores and presses the outer iron core against the outer circumferential surface of the outer duct It is characterized by comprising .
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, a flow skirt that is detachably attached to the bottom plate and supports the inner stator is provided.
[0011]
A third aspect of the present invention, in claim 1 or 2, before Symbol inner stator is characterized by having a core of round bar or strip-shaped or wedge-shaped cross section.
[0013]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the casing has a rectangular shape, and a side surface of the casing is provided with a port for taking out a wiring for supplying an alternating current to the electromagnetic coil.
[0014]
The invention of claim 5, in any one of claims 1 to 4, before Symbol plurality of electromagnetic coils are wired connected together between the two outer core at the same position on the circumference of the electromagnetic coil It is characterized by that.
[0015]
According to a sixth aspect of the invention, in any one of claims 1 to 4, the front Symbol bottom plate and having a groove to be fitted on the end face of the outer core.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows the structure of the electromagnetic pump according to the first embodiment. That is, this electromagnetic pump includes an electromagnetic coil 2 that is provided in a structure that fits into the outer duct 5 and generates a magnetic field, an outer iron core 3 that forms a magnetic circuit, and a stainless steel casing 22 that covers these pump internal structures. . The outer stator 11 is constituted by the outer duct 5, the electromagnetic coil 2, the outer iron core 3, and the casing 22, and the inner stator 12 is provided coaxially inside the outer stator 11. An inner iron core is provided in the inner stator 12. Between the inner peripheral surface of the outer duct 5 and the outer peripheral surface of the inner stator 12, a liquid metal channel is formed.
[0018]
The outer iron core 3 has a strip shape. In addition, the electromagnetic pump uses a three-phase AC power source, and the electromagnetic coil 2 is connected by in-machine wiring (cable) in order to pass a three-phase AC current. Therefore, a cable port 26 for taking out this cable to the outside is provided. This is an immersion type electromagnetic pump.
[0019]
In the electromagnetic pump according to the present embodiment, disk rings 27 a are provided by welding on the upper and lower portions of the outer iron core 3, and both the upper and lower disk rings 27 a are also welded to the bottom plate 29.
[0020]
The action of the combination of the disk ring 27a and the welded joint is as follows. That is, since the immersion type electromagnetic pump has Joule heat generation of the electromagnetic coil 2, it is necessary to press the outer iron core 3 against the outer duct 5 in order to transfer these heat generation to the liquid metal. At this time, the temperature of the outer iron core 3 becomes higher than the liquid metal temperature due to Joule heat generation of the electromagnetic coil 2. For this reason, there is a temperature difference between the outer duct 5 and the outer iron core 3 that have substantially the same temperature as the liquid metal, resulting in a difference in thermal expansion. Moreover, it is necessary to fix the iron core so that it does not displace in the circumferential direction when it expands. In the present embodiment, the combination of the disc ring 27a and the welded joint absorbs the difference in thermal expansion between the outer duct 5 and the outer iron core 3 due to these temperature differences, and the outer iron core 3 is radially outside by the disc ring 27a. There exists an effect | action which adheres to the duct 5. FIG.
[0021]
The conventional electromagnetic pump uses a leaf spring or a disc spring as a clamp mechanism that presses the outer iron core 3 against the outer duct 5, and these structures are very large. Since the combination of the disk ring 27a and the welded joint in the present embodiment takes almost no installation place, it is miniaturized as a clamp mechanism that closely contacts and presses the outer iron core 3 against the outer duct 5. This achieves a uniform radial clamping force and miniaturization of the electromagnetic pump.
[0022]
Furthermore, the electromagnetic pump of the first embodiment has a structure in which a flat plate 12a through which the inner stator 12 passes is provided, and the flat plate 12a and the flow skirt 13 are fixed to the bottom plate 29 of the casing 22 with bolts 13a. The shape of the flat plate 12a includes a rectangle and a disc shape. Although it is necessary to fix the inner stator 12 to a building or the like in which the casing 22 or the electromagnetic pump is installed, the inner stator 12 can be fixed to the casing 22 by the flat plate 12a and the bolt 13a. Further, the fixing with the bolts 13a also has an effect of facilitating the attachment / detachment of the inner stator 12.
[0023]
In the electromagnetic pump according to the present embodiment, the casing 22 has a rectangular shape, and the outer iron core 3 is installed on the square of the rectangular casing. With such a structure, the internal space of the casing 22 can be used effectively, and the electromagnetic pump can be reduced in size.
[0024]
Next, an electromagnetic pump according to a second embodiment of the present invention will be described with reference to FIG. The electromagnetic pump according to the second embodiment has substantially the same internal structure as the electromagnetic pump according to the first embodiment, and includes a C-shaped partially-notched ring 27b around the outer iron core 3. It has become. One or more partially notched rings 27b are installed in the axial direction of the outer iron core 3, and the partially notched rings 27b and the outer iron core 3 are joined to each other by welding or by cutting a groove in the outer iron core 3. . Inconel or the like having high strength is used as the partially cut-out ring 27b.
[0025]
The partially cut-out ring 27b has a spring force depending on its shape, and absorbs a difference in thermal expansion between the outer duct 5 and the outer iron core 3 due to a temperature difference. The material of the partially-notched ring 27b is hardened so that the outer iron core 3 is in close contact with the outer duct 5 in the radial direction. The conventional electromagnetic pump uses a leaf spring or a disc spring as a clamp mechanism that presses the outer iron core 3 against the outer duct 5, and these structures are very large. On the other hand, in the case of the partially cut-out ring 27b in the present embodiment, the installation place is hardly taken, so that it is miniaturized as a clamp mechanism for closely contacting and pressing the outer iron core 3 to the outer duct 5. This has an effect of uniform clamping force in the radial direction and miniaturization of the electromagnetic pump.
[0026]
A use example of the electromagnetic pump of the first or second embodiment as described above will be described with reference to FIG. 3 in the case of using solder for joining a printed circuit board as a liquid metal. FIG. 3 shows a state in which the immersion type electromagnetic pump 1 is installed in the solder bath 16. In the solder tank 16 that accommodates the molten solder 17, a nozzle 15 through which the molten solder 17 flows, an electromagnetic pump 1, and a pipe 18 to the nozzle 15 are installed.
[0027]
The molten solder 17 is pressurized and transferred by the electromagnetic pump 1 and jetted from the nozzle 15. The printed circuit board 19 passes over the jet solder 14 and the lead wires of the printed circuit board 19 are joined. As described above, the electromagnetic pump 1 of the first or second embodiment is used by being immersed in the molten solder 17.
[0028]
The electromagnetic pump 1 has the internal structure shown in FIG. 1 or FIG. 2, and has a structure in which a port 26 for taking out a cable for energizing the electromagnetic coil 2 is a side surface of the casing 22. The port 26 is installed through the solder bath 16 and is fixed to the solder bath with bolts. The installation position of the port 26 is below the liquid surface of the molten solder 17, and the port 26 also has a sealing structure for the molten solder 17.
[0029]
Since the port 26 is installed on the side surface of the casing 22, the in-machine wiring of the electromagnetic coil normally performed on the upper part of the iron core can be performed on the side surface of the iron core, and the height of the electromagnetic pump can be reduced. This is effective in reducing the size of the electromagnetic pump. Furthermore, piping pressure loss can also be reduced by reducing the height of the electromagnetic pump.
[0030]
Further, the molten solder 17 is oxidized in an air atmosphere to produce solder oxide. However, since this solder oxide is not conductive, when it is transferred together with the molten solder 17, the lead wire of the printed circuit board 19 is joined. The part which cannot be done will arise. In the first or second embodiment, since the port 26 that has conventionally been at the top of the electromagnetic pump is installed on the side surface of the casing 22, the electromagnetic pump can be installed completely below the liquid level of the molten solder 17. There is an effect that the solder oxide on the surface is not easily transferred.
[0031]
Next, a third embodiment of the present invention will be described with reference to FIG. In the electromagnetic pump of this embodiment, the inner iron core provided in the inner stator 12 is a combination of a round bar 23, a strip 24 and a wedge 25, or a combination of a strip 24 and a round bar 23. The inner iron core is installed in the inner stator 12 with as little gap as possible. This is because the portion without the iron core has a large magnetic resistance and a leakage magnetic flux is generated, so that the electromagnetic force is small. The immersion type electromagnetic pump generates an electromagnetic force by the interaction between the induced current and the traveling magnetic field, and this electromagnetic force becomes a force for transferring the liquid metal and acts as a pump. For this reason, if a magnetic circuit is not comprised, it will not become the force which transfers a liquid metal. This embodiment has an effect of increasing the electromagnetic force, that is, the force for transferring the liquid metal without changing the dimensions of the electromagnetic pump, by arranging the inner iron core on the inner stator inner surface without any gap. This is effective in reducing the size of the electromagnetic pump.
[0032]
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a connection diagram between coils. This figure is an annular coil developed at 360 ° C.
In the electromagnetic pump of the present embodiment, the electromagnetic coil 2 has a structure capable of conducting a three-phase alternating current, and the electromagnetic coils 2 of each phase are connected to each other by an in-machine wiring 28 using a cable. It is provided between the iron cores 3 together. If it demonstrates using the core number shown in FIG. 5, conventionally, for example, between iron core No1 and iron core No2, between iron core No2 and iron core No3, between iron core No3 and iron core No4, and between iron core No4 and iron core No1 The cable is installed and wired. In the present embodiment, the cables are concentrated between the iron core No3 and the iron core No4, and no cables are arranged between the other iron cores. This eliminates the need for cable wiring space between other iron cores that are not cable-wired, and has the effect of reducing the size of the electromagnetic pump. Furthermore, the wiring of the cables together between the iron cores in one direction has the effect of increasing the work efficiency during production.
[0033]
Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a plan view of the bottom plate 29. The electromagnetic pump according to the present embodiment includes a bottom plate 29 in which a groove 30 is formed. The groove 30 of the bottom plate 29 is provided in a cross shape in accordance with the dimension of the outer iron core 3. The depth of the groove 30 is about several mm. The circumferential position of the outer iron core 3 is fixed by the groove 30 so that it does not shift in the circumferential direction not only during operation of the electromagnetic pump but also during manufacture and movement. Thereby, the clearance gap which generate | occur | produces by the position of the circumferential direction of the outer side iron core 3 shifting | deviating does not arise, but since there exists a space between the iron cores 3, it can prevent that magnetic resistance becomes large and electromagnetic force falls.
[0034]
Although the first to fifth embodiments have been described above, embodiments having a plurality of configurations of these embodiments are also possible, and in this case, combined effects are produced.
[0035]
【The invention's effect】
According to the present invention, it is possible to provide an electromagnetic pump in which the iron core is brought into close contact with the outer periphery of the outer duct with a uniform clamping force in the circumferential direction by a small clamping mechanism, and the overall outer dimension is small and the pressure loss is small.
[Brief description of the drawings]
1A and 1B show an electromagnetic pump according to a first embodiment of the present invention, in which FIG. 1A is an overall cross-sectional view, and FIG. 1B is a cross-sectional view taken along line bb in FIG.
FIGS. 2A and 2B show an electromagnetic pump according to a second embodiment of the present invention, in which FIG. 2A is an overall cross-sectional view, and FIG. 2B is a cross-sectional view taken along line bb in FIG.
FIG. 3 is a diagram showing an example of use of the electromagnetic pump according to the first and second embodiments of the present invention.
FIGS. 4A and 4B are cross-sectional views of different examples, showing the main part of an electromagnetic pump according to a third embodiment of the present invention. FIGS.
FIG. 5 is a development view showing a main part of an electromagnetic pump according to a fourth embodiment of the present invention.
FIG. 6 is a plan view showing a main part of an electromagnetic pump according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electromagnetic pump, 2 ... Electromagnetic coil, 3 ... Outer iron core, 5 ... Outer duct, 11 ... Outer stator, 12 ... Inner stator, 12a ... Planar plate, 13 ... Flow skirt, 13a ... Flow skirt fixing bolt, 14 ... Jet Solder, 15 ... nozzle, 16 ... solder bath, 17 ... molten solder, 18 ... piping, 19 ... printed circuit board, 20 ... inner iron core fixing bolt, 21 ... magnetic circuit, 22 ... casing, 23 ... inner iron core, 24 ... Strip inner iron core, 25 ... wedge inner iron core, 26 ... cable port, 27a ... disc ring, 27b ... partially cut ring, 28 ... in-machine wiring, 29 ... bottom plate, 30 ... groove, F ... liquid metal flow.

Claims (6)

A plurality of outer iron cores and a plurality of electromagnetic coils provided on the outer periphery of a cylindrical outer duct; a casing which is connected to the outer duct via a bottom plate and covers the outer peripheral side of the outer iron core and the electromagnetic coils; and the outer duct an inner stator disposed in the central hole to exist a gap, in that the outer core rear tight binding of the previous SL plurality of outer cores and a part cutaway ring is pressed against the outer circumferential surface of the outer duct Features an electromagnetic pump. Electromagnetic pump according to claim 1, further comprising a flow skirt for supporting the inner stator freely mounted removably before Symbol bottom plate. Before Symbol inner stator, an electromagnetic pump according to claim 1 or 2, characterized in that it comprises a core of a round bar or a strip-shaped or wedge-shaped cross section. 4. The electromagnetic pump according to claim 1, wherein the casing has a rectangular shape, and a port for taking out a wiring for supplying an alternating current to the electromagnetic coil is provided on a side surface of the casing. Before SL plurality of electromagnetic coils, electromagnetic according to any one of claims 1 to 4, characterized in that collectively are wired connected between the two outer core at the same position on the circumference of the electromagnetic coil pump. Before Symbol bottom plate electromagnetic pump according to any one of claims 1 to 4, characterized in that it has a groove to be fitted on the end face of the outer core.

Images