JP6518524B2 - Electromagnetic pump for molten metal water heater - Google Patents

Description

  The present invention relates to an electromagnetic pump for a molten metal water heater, which is used, for example, to supply molten metal to a casting apparatus.

  As background art of this technical field, there exists Unexamined-Japanese-Patent No. 2012-232338 (patent document 1). In this publication, a molten metal electromagnetic pump is connected to the lower side of the injection sleeve of a die casting machine, and the molten metal pumped up from the hot water supply source (molten metal tank) of the molten metal from the lower side of the injection sleeve Molten metal water heaters to be filled in are described (see abstract).

  Further, in the molten metal electromagnetic pump of Patent Document 1, the pump side duct and the injection sleeve side duct (hot water supply side duct) are closely connected via a flange joint, and the flange of the protective pipe accommodating the core is on the pump side. It is pinched between the flange joint of the duct and the injection sleeve side duct. Thus, the core accommodated in the protective pipe is held so as to be located at the center of the pump side duct (see paragraph 0030).

JP, 2012-232338, A

  In the molten metal electromagnetic pump of Patent Document 1, the support portion (flange) of the protective pipe is the upper end portion of the protective pipe and is disposed outside the molten metal in the molten metal tank. In this case, since the surface of the molten metal in the tact of the molten metal electromagnetic pump oxidizes in the same manner as the surface of the molten metal in the molten metal tank, if the oxide in this duct is absorbed together with the molten metal, the oxide forms a support for the protective tube. It becomes easy to get stuck.

  An object of the present invention is to provide an electromagnetic pump for a molten metal water heater which is less likely to cause clogging of a duct with oxide.

In order to achieve the above object, the electromagnetic pump for molten metal water heater of the present invention is
A duct disposed at a central portion, a plurality of coils disposed along the axial direction of the duct at an outer peripheral portion of the duct, a protective tube disposed inside the duct and having a core housed inside the duct; An electromagnetic pump for a molten metal water heater which is immersed in the molten metal and sucks the molten metal;
A pressing member for pressing the upper portion of the duct downward in the axial direction;
The protective tube has a protruding portion radially projecting on the outer peripheral surface of the lower end portion,
The duct has a stepped portion formed by an enlarged diameter portion on the inner peripheral surface of the lower end portion,
The projecting portion of the protective tube constitutes a support for supporting the protective tube inside the duct ,
When the duct is pressed by the pressing member, the stepped portion presses the protruding portion of the protective tube downward.
The protective tube is fixed inside the duct by pressing the protruding portion toward the bottom surface of the housing of the electromagnetic pump.
With the support portion is disposed at a lower end portion of the protective tube Ru is configured to be immersed in the molten metal.

  According to the present invention, it is possible to provide an electromagnetic pump for a molten metal water heater which is less likely to cause clogging of a duct with oxide.

It is a front view concerning one example of a low pressure casting device to which the present invention is applied, and is a figure showing a part in section. It is a side view concerning one example of a low pressure casting device to which the present invention is applied, and is a figure showing a part in section. It is a cross-sectional view of the electromagnetic pump used for the low pressure casting apparatus of FIG. FIG. 4 is an exploded perspective view showing parts of a duct of the electromagnetic pump of FIG. 3 in an exploded manner on a common axis. It is an expanded sectional view which expands and shows the suction inlet vicinity of the duct in the electromagnetic pump of FIG. It is VI-VI arrow sectional drawing of the duct of an electromagnetic pump shown in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A plurality of inventions are included in the present embodiment. In this embodiment, an example in which a plurality of inventions are applied to a low pressure casting apparatus will be described. The low pressure casting apparatus is an apparatus for filling molten metal into a mold (mold) at a relatively low pressure (about 0.5 atm) to perform molding. The present invention is also applicable to devices other than low pressure casting devices. For example, it is applicable also to hot-water supply to the sleeve of the die-cast apparatus which press-fits a molten metal in the mold by the pressure of 500-1000 atm, and is shape | molded.

  The configuration of an embodiment of a low pressure casting apparatus to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view according to an embodiment of a low pressure casting apparatus to which the present invention is applied, and is a view showing a part in cross section. FIG. 2 is a side view according to an embodiment of the low pressure casting apparatus to which the present invention is applied, and is a view showing a part in cross section.

  The low pressure casting apparatus 100 includes a casting unit 200 and a molten metal hot water supply unit 300.

  The casting unit 200 includes a mold 201 having a lower mold 201a and an upper mold 201b, and an actuator 202 which is expanded and contracted in the vertical direction.

  The lower mold 201 a of the mold 201 is placed on the upper surface of the bed plate 203 and fixed to the bed plate 203. The upper mold 201 b is connected to the tip of the actuator 202 by a connecting member 204. A cavity 201c is formed in the lower mold 201a and the upper mold 201b by depressions formed in both. In addition, the mold 201 is provided with a push pin unit 205. The push pin unit 205 is provided with one or more push pins 205a. The push pin unit 205 is slidably attached to the upper mold 201b in the vertical direction. When the lower mold 201a and the upper mold 201b are combined to form the cavity 201c, the lower end of the support portion 205b of the push pin unit 205 abuts on the lower mold 201a, and the tip of the push pin 205a is in the cavity 201c. It is supported by the push pin unit 205 at a position where it does not protrude.

  The actuator 202 is mounted on the top surface of the bed plate 206, and the lower end is fixed to the bed plate 206. The actuator 202 is a linear actuator, and by expanding and contracting, the position of the upper end moves in the vertical direction (height direction). The upper end of the actuator 202 is connected to the connecting member 204.

  The connection member 204 includes an upper connection plate 204a, a connection post 204b, and a lower connection plate 204c. The connection post 204b extends downward from the upper connection plate 204a. The lower connecting plate 204c is attached to the lower end of the connecting post 204b. The upper mold 201b of the mold 201 is fixed to the lower connection plate 204c. When the actuator 202 is driven to move its tip upward, the upper mold 201b is lifted by the connecting member 204, separates from the lower mold 201a, and moves upward.

  The base plate 206 on which the actuator 202 is mounted is supported on the upper side of the base plate 203 by a plurality of columns 207. The columns 207 extend from the floor surface F to the mounting portion of the base plate 206. A stopper 207 a is provided at an intermediate portion of the support column 207. The base plate 203 is disposed above the stoppers 207 a provided on the support columns 207, and is connected to the support columns 207 in a slidable manner along the longitudinal direction (extension direction) of the support columns 207. That is, the base plate 203 is formed of a slide plate which can slide in the vertical direction. The stopper 207 a regulates the slidable lower range of the base plate 203. The portion of the support column 207 above the stopper 207 a constitutes a slide guide of the base plate 203.

  On the lower surface side of the base plate 206, an abutting member 208 with which the push pin unit 205 abuts is provided. The push pin unit 205 is a unit for removing the casting from the upper mold 201b. When the upper mold 201 b is lifted by the actuator 202, the upper end of the push pin unit 205 abuts on the lower surface of the contact member 208. When the upper die 201b is further lifted by the actuator 202 from this state, the lower end portion of the push pin 205a of the push pin unit 205 protrudes from the upper die 201b, and the cast product is pushed out of the upper die 201b.

  The molten metal hot water supply unit 300 includes a molten metal tank body 310 for holding the molten metal, an electromagnetic pump 320 for sucking the molten metal from the molten metal tank body 310, and an electric furnace 340 for melting an aluminum alloy ingot. The low pressure casting apparatus 100 of this embodiment is directed to an apparatus using an aluminum alloy as a molten metal. For this reason, in the molten metal tank main body 310, the electromagnetic pump 320 and the electric furnace 340, heat resistance to a high temperature exceeding 600 ° C. is required in the portion in contact with the melted aluminum alloy and in the vicinity thereof.

  The molten metal tank main body 310 has a storage tank (molten metal tank) 311 of the molten metal 301. The electromagnetic pump 320 and the electric furnace 340 are disposed inside the storage tank 311.

  The electromagnetic pump 320 has a duct 321 serving as a flow path for the molten metal 301 and a coil 322 wound around the outer periphery of the duct 321. The electromagnetic pump 320 is an immersion type electromagnetic pump in which at least the lower end portion is immersed in the molten metal 301, and the lower end portion (suction port) 321 a of the duct 321 faces the bottom surface 311 a of the storage tank 311. The duct 321 is made of Si3N4. The electromagnetic pump 320 sucks up the molten metal using the electromagnetic force generated by energizing the coil 322 with a three-phase alternating current.

  The electromagnetic pump 320 is suspended from the base plate 203 by the suspending unit 110. By connecting the lower mold 201a and the upper mold 210b to extend the actuator 202, the base plate 203 is lifted. The lift of the base plate 203 separates the electromagnetic pump 320 from the molten metal tank body 310 and lifts it.

  A level gauge 323 for detecting the liquid level of the molten metal 301 is disposed on the outer periphery of the upper end portion of the duct 321. The level meter 323 is composed of an inductive level meter having an excitation coil (induction coil) and a detection coil. The level of the liquid level detected by the level meter 323 is maintained in a predetermined range, and a fixed amount of molten metal 301 is supplied to the cavity 201c at the time of casting. In the induction type level meter, there are various types of configurations of the excitation coil and the detection coil. In the present embodiment, the inductive level meter may be in any form.

  A bell mouth 324 is provided at the upper end of the duct 321. The bell mouth 324 is formed to be reduced in diameter from the lower end side to the upper end side. A heater 325 is provided on the outer peripheral portion of the bell mouth 324 to prevent solidification of the molten metal 301.

  The bell mouth formed in the bell mouth 324 is provided to communicate the hot water supply passage of the molten metal formed by the duct 321 with the communication hole 201 d formed in the lower mold 201 a. The communication hole 201d penetrates the lower mold 201a, and is formed to communicate the cavity 201c with the outside of the lower mold 201a. The duct 321, the bell mouth 324 and the communication hole 201d constitute a hot water supply passage of molten metal to the cavity 201c.

  The electric furnace 340 includes a melting furnace 341, a plurality of electric furnace heaters 342, and an opening / closing member (lid) 343. A metal material storage chamber 341 a is formed in the melting pot 341. A through hole 341b is formed at the bottom of the metal material storage chamber 341a. In the present embodiment, an aluminum alloy ingot is used as the metal material to be melted. Therefore, the ingot 302 of aluminum alloy is accommodated in the metal material accommodation chamber 341a.

  The description now returns to the molten metal tank 310.

  The upper surface of the storage tank 311 is covered with a lid (ceiling member) 315. A storage tank heater 316 for heating the inside of the storage tank 311 is provided on the lower surface side (the inner surface side facing the storage tank 311) of the lid 315.

  As shown in FIG. 2, a connector 317 a and a ceramic terminal 317 b are disposed on the surface side of the lid 315 of the storage tank 311. The reservoir heater 316 receives the supply of power through the connector 317a and the ceramic terminal 317b.

  A blower 318 is disposed on the surface side of the lid 315, and an operation box 109 is provided at a position not affected by the high heat generated by the molten metal tank 310. The operation box 109 incorporates a controller for controlling the low pressure casting apparatus 100. The controller controls the actuator 202, the electromagnetic pump 320, and the like.

  Next, the casting process by the low pressure casting apparatus 100 of the present embodiment will be described.

  From the state where the molten metal 301 is not contained in the storage tank 311, the ingot 302 of aluminum alloy is supplied to the electric furnace 340, and the electric furnace heater 342 is energized to heat the ingot 302. The melted ingot flows down to the storage tank 311 from the through hole 341 b formed in the lower part of the melting pot 341. At this time, the storage tank 311 is heated by the storage tank heater 316 to a temperature higher than the melting point of the aluminum alloy.

  The molten metal 301 melted by the electric furnace heater 342 is collected in the storage tank 311. The molten metal 301 is stored until the liquid level reaches a predetermined level.

  When the molten metal 301 is stored in the storage tank 311 to a predetermined liquid level, casting is started. In the casting process, the liquid level of the molten metal 301 detected by the level meter 323 is maintained within a predetermined range, and a fixed amount of molten metal 301 is supplied to the cavity 201c during casting. At this time, the mold 201 is in the assembled state in which the upper mold 201b is superimposed on the lower mold 201a.

  Maintenance of the liquid level of the molten metal 301 and hot water supply into the cavity 201 c are performed by driving the electromagnetic pump 320. In order to start the casting process, hot water supply to the mold 201 by the electromagnetic pump 320 is necessary. In order to operate the electromagnetic pump 320 reliably, it is desirable that the height of the liquid level of the molten metal 301 be higher than the two coils 322 disposed on the lower side of the outer periphery of the duct 321. The molten metal hot-water supply unit 300 is provided with a level meter (not shown) that detects the liquid level of the storage tank 311.

  When the cast is formed, the actuator 202 is driven to raise the upper mold 201b. When the upper mold 201b is raised, the upper mold 201b separates from the lower mold 201a, and the cavity 201c of the mold 201 is opened. When the upper die 201b is further raised, the upper end of the push pin unit 205 abuts on the lower surface of the contact member 208, and the push pin unit 205 is pushed down with respect to the upper die 201b. As a result, the lower end portion of the push pin 205a protrudes from the upper mold 201b. The cast product is pushed out of the upper mold 201b by the protrusion of the push pin 205a. The cast product extruded from the upper mold 201b is received by a receiving member (not shown). When one casting process is completed, the upper mold 201b is again placed on the lower mold 201a, the mold 201 is assembled, and molding is repeated.

  Next, the configuration of the electromagnetic pump 320 will be described.

  FIG. 3 is a cross-sectional view of an electromagnetic pump 320 used in the low pressure casting apparatus 100 of FIG. The electromagnetic pump for the molten metal water heater of the present embodiment is an immersion type electromagnetic pump which is immersed in the molten metal and sucks the molten metal.

  A duct 321 is disposed at the center of a housing 320 a of the electromagnetic pump 320. A plurality of coils 322 are disposed on the outer peripheral portion of the duct 321. In this embodiment, a three-phase alternating current is supplied to the coil. Therefore, multiples of three coils 322 are disposed along the axial direction of the duct 321. A heater 329 is provided between the duct 321 and the coil 322. The heater 329 is wound around the duct 321 so as to be in contact with the outer peripheral surface of the duct 321. Inside the duct 321, a protective pipe 327 accommodating the core 328 is disposed.

  A flange 321 b is provided at the top of the duct 321. By pressing the flange 321b downward with the pressing member 319, the lower end portion of the duct 321 is pressed against the inner surface 320b of the housing 320a via the packing 331, and the duct 321 is fixed to the housing 320a.

  The pressing member 319 includes a pressing plate 319a in contact with the flange 321b, a support member 319b fixed to the flange portion 326 provided on the top of the housing 320a, one end supported by the support member 319b, and the other end A coil spring 319c is supported by 319a. The coil spring 319 c biases the pressing plate 319 a downward, and the pressing plate 319 a exerts a downward force on the duct 321.

  FIG. 4 is an exploded view of the components of the duct 321 of the electromagnetic pump 320 of FIG. 3 taken along a common axis.

  The first screw member 333 is screwed into the lower end portion of the core 328. The core 328 is inserted into the inside of the protective pipe 327 from the lower end side of the protective pipe 327, and the second screw member 332 is screwed to the lower end of the protective pipe 327. A packing 330 is interposed between the protection pipe 327 and the second screw member 332 to prevent the molten metal 301 from infiltrating the inside of the protection pipe 327. The second screw member 332 presses the first screw member 333 from the lower end side, and sandwiches the first screw member 333 with the protective tube 327. As a result, since the first screw member 333 with the core 328 is tightly fixed to the protective tube 327 without rattling, not only the small electromagnetic vibration of the core 328 does not induce large vibration, but also the thermal expansion of the core 328 The direction is always constant, and the design of the thermal expansion and absorption margin is simplified.

  The protective tube 327 accommodating the core 328 is inserted into the duct 321 from the lower end side of the duct 321. At this time, the projecting portion 327a formed on the lower end outer peripheral portion of the protective pipe 327 abuts on the stepped portion 321a formed on the lower end inner peripheral surface of the duct 321, so that the protective pipe 327 is axially Positioned in the direction. Further, since the projecting portion 327c is inserted while being inscribed in the lower end inner circumferential surface of the duct 321, lateral blurring of the protective tube 327 can also be prevented. The projecting portion 327 a of the protective tube 327 is formed to project radially from the outer peripheral surface of the protective tube 327. Thus, the stepped portion 321a of the duct 321 is constituted by an enlarged diameter portion formed on the inner peripheral surface of the lower end portion in order to secure strength.

  FIG. 5 is an enlarged sectional view showing the vicinity of a suction port of a duct in the electromagnetic pump of FIG. 3.

  The duct 321 is accommodated inside the housing 320a from the upper end side of the housing 320a. At this time, a packing 331 is interposed between the lower end portion of the duct 321 and the housing 320 a to prevent the molten metal 301 from entering the inside of the electromagnetic pump 320.

  When the duct 321 is pressed downward by the pressing member 319, the stepped portion 321a of the duct 321 presses the protruding portion 327a of the protective tube 327 downward. Thereby, the lower end portion of the protective tube 327 is pressed against the inner surface 320 b of the housing 320 a via the packing 331, and the protective tube 327 is fixed inside the duct 321. That is, the duct 321 and the protective pipe 327 are pushed against the housing 320a by pressing the duct 321 and the protective pipe 327 toward the housing 320a of the electromagnetic pump 320 in a state where the projecting part 327a is in contact with the stepped part 321a. Supported by The lower end portion of the protective tube 327 may not be in contact with the packing 331, and may be in direct contact with the inner surface 320b.

  The inner surface 320b of the housing 320a in which the lower end portion of the protective pipe 327 and the lower end portion of the duct 321 are pressed through the packing 331 is the suction port 321a formed in the lower end surface (bottom surface) of the housing 320a of the electromagnetic pump 320 It is an inner surface (casing surface) of an outer peripheral part.

  6 is a cross-sectional view of the duct 321 of the electromagnetic pump 320 shown in FIG.

  In the present embodiment, three protruding portions 327 a are formed on the outer peripheral surface of the protective tube 327. The three projecting portions 327a are provided at intervals in the circumferential direction. In the present embodiment, the three projecting portions 327a are arranged at equal intervals in the circumferential direction. In this case, the angular interval at which the protrusions 327a are disposed is 120 °.

  The protective pipe 327 needs to be disposed at the center of the duct 321 without tilting. When the protective tube 327 is inclined inside the duct 321, the position of the core 328 housed inside the protective tube 327 is offset from the center of the coil 322. Then, the electromagnetic force acting on the molten metal 301 becomes nonuniform, which leads to the performance degradation of the electromagnetic pump 320.

  Further, due to the inclination of the protective pipe 327, the width of the flow path of the molten metal formed between the outer peripheral surface of the protective pipe 327 and the inner peripheral surface of the duct 321 becomes uneven in the circumferential direction. In particular, the upper end portion of the protective tube 327 forms a contact portion on the inner peripheral surface of the duct 321 or forms a narrow flow passage portion with the inner peripheral surface of the duct 321. In this case, the contact portion or the narrow flow passage portion is located outside the molten metal 301 stored in the storage tank 311.

  In the electromagnetic pump of Patent Document 1, the support portion (flange) of the protective pipe is provided at the upper end of the protective pipe, and is disposed outside the molten metal in the molten metal tank. In this case, if the electromagnetic pump sucks up the oxide in the molten metal tank together with the molten metal, the oxide is likely to be clogged at the supporting portion of the protective tube.

  Therefore, when the contact portion or the narrow width flow path portion is formed at the upper end portion of the protection pipe 327 due to the inclination of the protection pipe 327, the oxide is formed in the contact portion or the narrow width flow path portion as in Patent Document 1. It becomes easy to get stuck.

  In the present embodiment, the provision of three projecting portions 327a can prevent the protective pipe 327 from being inclined in the duct 321. Moreover, compared with the case where four or more protruding portions 327a are provided, the flow passage resistance of the flow passage of the molten metal 301 formed in the duct 321 can be reduced. That is, in the present embodiment, by providing the three protruding portions 327a, the inclination of the protective tube 327 can be prevented, and the flow resistance of the molten metal 301 can be minimized.

  In the present embodiment, the projecting portion 327a and the projecting portion 327c constitute a support portion of the protective tube 327. The projecting portion (supporting portion) 327 a and the projecting portion 327 c are configured at the lower end portion of the protective pipe 327, and are immersed in the molten metal 301 stored in the storage tank 311. Therefore, when the electromagnetic pump 320 is driven to suck up the molten metal 301, the oxide does not easily get stuck in the projecting portion (supporting portion) 327 a of the protective tube 327. Thereby, the frequency | count of maintenance of the electromagnetic pump 320 can be reduced, and the operation rate of the low pressure casting apparatus 100 can be raised.

  In order for the electromagnetic pump 320 to pump up the molten metal 301, the liquid level of the molten metal 301 is preferably higher than the second lower one of the multiples of the coils 322 of three. Therefore, it is preferable that the projecting portion (support portion) 327 a and the projecting portion 327 c be disposed below the upper surface of the second lowermost coil 322. The electromagnetic pump 320 can suck up the molten metal 301 if the liquid level of the molten metal 301 is located 1.5 coils above the lower end of the coil 322 disposed on the lowermost side. Therefore, the projecting portion (supporting portion) 327a and the projecting portion 327c are disposed below the lower end of the coil 322 disposed at the lowermost position below the height position of 1.5 coils. preferable.

  In the electromagnetic pump 320 of the present embodiment, the coil 322 is disposed only inside the storage tank 311, but in addition to the coil 322, a second coil group may be disposed outside the storage tank 311.

  DESCRIPTION OF SYMBOLS 100 ... Low pressure casting apparatus, 200 ... Casting part, 202 ... Actuator, 205 ... Push pin unit, 300 ... Molten metal hot-water supply part, 201 ... Mold | mold ... 310 ... Molten metal tank main body, 311 ... Reservoir, 311a ... Reservoir 311 Bottom surface 315 Lid (ceiling member) 316 Storage tank heater 319 Pressing member 319a Pressing plate 319b Supporting member 319c Coil spring 320 Electromagnetic pump 320a Housing 320b Housing Inner surface of body 320a, 321: duct, 321a: stepped portion of duct 321, 321b: flange, 322: coil, 327: protective tube, 327a, 327c: projecting portion of protective tube 327, 328: core, 329: heater , 330: packing, 331: packing, 332: second screw member, 333: first screw member, 340: electric furnace.

Claims (6)

A duct disposed at a central portion, a plurality of coils disposed along the axial direction of the duct at an outer peripheral portion of the duct, a protective tube disposed inside the duct and having a core housed inside An electromagnetic pump for a molten metal water heater which is immersed in the molten metal and sucks the molten metal;
A pressing member for pressing the upper portion of the duct downward in the axial direction;
The protective tube has a protruding portion radially projecting on the outer peripheral surface of the lower end portion,
The duct has a stepped portion formed by an enlarged diameter portion on the inner peripheral surface of the lower end portion,
The projecting portion of the protective tube constitutes a support for supporting the protective tube inside the duct ,
When the duct is pressed by the pressing member, the stepped portion presses the protruding portion of the protective tube downward.
The protective tube is fixed inside the duct by pressing the protruding portion toward the bottom surface of the housing of the electromagnetic pump.
The electromagnetic pump for a molten metal water heater according to claim 1, wherein the support portion is disposed at a lower end portion of the protective pipe and is immersed in the molten metal. An electromagnetic pump for a molten metal water heater according to claim 1 .
The housing has a suction port formed on the lower end surface,
Lower end, an electromagnetic pump for molten metal hot-water supply apparatus characterized by being pressed toward the bottom surface of the housing of the outer peripheral portion of the suction port of the lower end portion and the protective tube of the duct. An electromagnetic pump for a molten metal water heater according to claim 2 .
An electromagnetic pump for a molten metal water heater according to claim 1, wherein three protrusions are disposed at intervals in the circumferential direction of the protective tube. An electromagnetic pump for a molten metal water heater according to claim 3 .
An electromagnetic pump for a molten metal water heater, wherein a packing is interposed between at least a lower end portion of the duct and the housing. An electromagnetic pump for a molten metal water heater according to claim 1.
The coils are provided in multiples of three and supplied with three-phase alternating current,
The electromagnetic pump for a molten metal water heater according to claim 1, wherein the support portion is disposed lower than an upper surface of a second lowermost coil of the plurality of the plurality of third coils. An electromagnetic pump for a molten metal water heater according to claim 1.
Includes a first threaded member screwed to the lower end portion of the core, and a second threaded member screwed to the lower end of the protective tube, a,
The first screw member is fixed in close contact with the protective tube by holding the first screw member between the second screw member and the protective tube, for a molten metal water heater Electromagnetic pump.

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