JP2011094190A - Method for manufacturing steel having non-magnetic reforming phase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a steel having a non-magnetic reforming phase in which stability of quality is attained. <P>SOLUTION: In the method for manufacturing the steel having the non-magnetic reforming phase, reforming metal 30 is put into an inner space 20 in which a plurality of steel materials 1 are piled up and the reforming metal 30 is melted together with a part of surrounding steel materials 1 by energization and pressurization with a pair of electrodes 5 to form the non-magnetic reforming-phase, the reforming metal 30 is a round member having a thickness, a size in the pressurizing direction of the electrode 5 is larger than the space 20 and a size in a lateral direction orthogonal to the pressurizing direction is smaller than the space 20, and a projecting and recessed surface 31 is continuously formed in the circumferential direction on the circumferential surface in the lateral direction. The method includes a positioning step in which projecting parts 21 for positioning of the reforming metal 30 are formed in the space 20, before the energization and pressurization with the pair of electrodes 5, rotation is given to the steel materials 1 piled up by putting the reforming metal 30 into the space 20, and the reforming metal 30 shifted in the space 20 with centrifugal force is abutted on the projections 21 in the space 20 for positioning. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a manufacturing method for forming a steel material partially including a non-magnetic modified phase by sandwiching a non-magnetic material in a steel material and melting it by heating with heating, and in particular, a steel material that forms a stable non-magnetic modified phase. It relates to a manufacturing method.

  Since iron cores used for electric motors and generators generally require high magnetic permeability, a magnet is attached to the rotor. In order to prevent the performance from being deteriorated by the leakage magnetic flux of the magnet, the rotor is partially processed to be non-magnetic. FIG. 7 is a view showing a modified portion where the rotor is made non-magnetic. A non-magnetic modified phase peribridge portion 92 and a center bridge portion 93 are formed on the magnet 91 provided on the rotor 90, and the performance is prevented from being deteriorated due to leakage magnetic flux by increasing the magnetic resistance.

  As a method for producing a steel material having such a nonmagnetic modified phase, for example, Patent Document 1 discloses a technique for forming an austenite region by locally heating a corresponding portion of an iron core and then cooling it. Yes. That is, laser irradiation is performed as a means of local heating, and a metastable austenitic stainless steel is made into a ferromagnetic martensite structure by cold rolling, so that part of it becomes a nonmagnetic austenitic structure . In addition, as disclosed in Patent Document 2, there is a method in which a target magnetic member is locally melted and a modifying element is added from the outside to be solid-dissolved to be non-magnetic.

Japanese Patent No. 3507395 JP 2001-93717 A

  However, in such a conventional manufacturing method, when martensitic austenitic stainless steel is used, the permeability is inferior to that of a general electromagnetic steel sheet due to crystal distortion or the like, and the maximum magnetic flux density is insufficient. In addition, the method of adding the modifying element in the melted state has problems that a long processing time is required and that the nonmagnetic modified phase cannot be formed as desired because the control in the depth direction is difficult. In addition, in the case of the rotor 90, since a plurality of electromagnetic steel plates are stacked, the amount of addition of the modifying element is increased in volume, and the flatness after processing is poor, so that airtight stacking cannot be performed. Arise. Therefore, a new method for solving these problems is desired for the production of a steel material having a nonmagnetic modified phase, and the present applicant has proposed a new production method according to Japanese Patent Application No. 2008-192468.

  The present invention relates to such a novel production method, and an object thereof is to provide a method for producing a steel material having a nonmagnetic modified phase with stable quality.

  A method of manufacturing a steel material having a nonmagnetic modified phase according to the present invention includes forming a space inside by superposing a plurality of steel materials, putting a reformed metal in the space, and then modifying the superposed steel material By energizing and pressurizing with a pair of electrodes sandwiched in the overlapping direction at the position where the metal exists, the modified metal is melted together with a part of the surrounding steel material to form a nonmagnetic modified phase, The modified metal is a circular member having a thickness, and the dimension in the pressing direction by the electrode is larger than the space, and the lateral dimension perpendicular to the pressing direction is smaller than the space. Concavities and convexities are formed continuously in the circumferential direction on the circumferential surface, and a protrusion for positioning the modified metal is formed in the space, before energization and pressurization by the electrode. And put the modified metal into the space It combined giving a rotation to steel, the modified metal is moved in the space by the centrifugal force, characterized by having a step of positioning by applying the projection in the space.

Further, in the method of manufacturing a steel material including the nonmagnetic modified phase according to the present invention, the modified metal is formed with a triangular uneven portion, and a protruding portion protruding from the bottom surface in the pressing direction is formed in the space. Are formed at a plurality of locations, and the positioning is preferably performed such that the protrusions are fitted into the recesses of the modified metal that moves in the space by centrifugal force.
Further, in the method of manufacturing a steel material including the nonmagnetic modified phase according to the present invention, the protrusion formed in the space has 3 on the circumference of a circle centered on the center point of the bottom surface in the pressing direction. It is preferable that the modified metal which is formed so as to be fitted into the modified metal at a point and moves in the space by centrifugal force is supported at three points for positioning.

  According to the present invention, by adjusting the size of the space formed by the steel material overlapped with the reformed metal, the quality of the reformed metal is improved by causing the reformed metal to generate heat and melt from both the upper and lower surfaces during energization and pressurization. A nonmagnetic modified phase can be obtained, and further, a steel material having a more stable and high quality nonmagnetic modified phase can be produced by arranging the modified metal at an appropriate position in the space by the positioning step. Can do.

It is the figure which showed the modified metal put into the electromagnetic steel plate of a rotor, and its recessed hole. It is sectional drawing shown about the manufacturing method of steel materials provided with a nonmagnetic modification phase. It is sectional drawing which showed the subject about the manufacturing method of steel materials provided with a nonmagnetic modification phase. It is the top view which showed the positioning performed about the modified metal put in the space of an electromagnetic steel plate. It is sectional drawing which showed 1st Embodiment about the manufacturing method of steel materials provided with a nonmagnetic modification phase. It is sectional drawing which showed 2nd Embodiment about the manufacturing method of steel materials provided with a nonmagnetic modification phase. It is the figure which showed the modification location which made the rotor non-magnetic.

Next, an embodiment of a method for producing a steel material having a nonmagnetic modified phase according to the present invention will be described below with reference to the drawings.
In the present embodiment, a case where a nonmagnetic modified phase is formed on the rotor constituting the motor will be described. As described above, a magnet is attached to the rotor in order to obtain a high magnetic permeability, and a nonmagnetic modified phase is formed in order to prevent performance degradation due to leakage flux of the magnet.

  As shown in FIG. 1, the rotor is formed by laminating a large number of doughnut-shaped ultrathin electromagnetic steel plates (for example, Fe—Si) 1. In the present embodiment, a plurality of circular concave holes 2 are formed at predetermined locations on the electromagnetic steel sheet 1, and one modified metal (for example, NiCr) 3 that is a small circular piece having a thickness in each of them. The nonmagnetic modified phase is formed at a plurality of locations. Here, FIG. 2 is a cross-sectional view showing a manufacturing method for one portion of the nonmagnetic modified phase.

  First, as shown in FIG. 2 (a), two electromagnetic steel sheets 1 each having a concave hole 2 are stacked one on top of the other, and at that time, a modification is made in a space 20 formed by overlapping both the upper and lower concave holes 2. Metal 3 is placed. Next, as shown in FIG. 2 (b), the two electromagnetic steel plates 1 sandwiching the modified metal 3 so that the upper surface and the lower surface are in contact with the bottom surface of the recessed hole 2 are positioned where the modified metal 3 is located. Then, the electrode 5 is sandwiched from above and below, and energization and pressurization are performed.

  Here, the thickness of the modified metal 3 is larger than the height of the space 20 where the concave holes 2 of the electromagnetic steel sheet 1 are stacked, and the upper surface and the lower surface of the modified metal 3 are always formed so as to contact the bottom surface of the concave hole 2. Yes. Therefore, the energization current flows through both the upper and lower surfaces of the modified metal 3 in contact with the electromagnetic steel sheet 1, and heat is generated from the upper end portion 3 a and the lower end portion 3 b to melt the whole. As the reformed metal 3 melts, the upper and lower electromagnetic steel plates 1 that are pressed are pressed up and down to fill the sealed space 20 with the reformed metal 3 and melt together with the surrounding electromagnetic steel plates 1. And it solidifies again after completion | finish of electricity supply, and as shown in FIG.2 (c), the nonmagnetic modification | reformation phase 11 is formed.

  Although the thickness of the modified metal 3 is formed to be larger than the height of the space 20, if the thickness of the modified metal 3 and the height of the space 20 are set equal, the modified metal 3 is modified due to an error. When the thickness of the porous metal 3 is reduced, a gap is formed in the pressing direction of the electrode 5, and the modified metal 3 is not melted by sufficient heating, and the quality of the nonmagnetic modified phase 11 is improved. This is because there is a risk of lowering.

  The formation of the nonmagnetic modified phase 11 is performed in the same manner at a plurality of concave holes 2 provided in the electromagnetic steel sheet 1 shown in FIG. 1, and thereby the rotor member 10 having a plurality of nonmagnetic modified phases 11. Is obtained. The rotor constituting the motor is formed by stacking a plurality of such rotor members 10 with the position of the nonmagnetic modified phase 11 aligned. The nonmagnetic modified phase 11 corresponds to the peribridge portion 92 and the center bridge portion 93 shown in FIG. Therefore, the rotor member 10 on which the nonmagnetic modified phase 11 is formed has an installation hole for loading the magnet 91 at a predetermined location, and the outer periphery thereof is scraped off.

  By the way, the diameter of the circular modified metal 3 is made smaller than that of the recessed hole 2 by the increase in the thickness dimension. This is to make the volume of the modified metal 3 substantially equal to the space 20 of the recessed hole 2 so that the molten modified metal 3 can be appropriately filled into the sealed space 20. However, since the diameter of the recessed hole 2 is larger than that of the modified metal 3, even if the central positions are aligned, the displacement may occur. In particular, since the electromagnetic steel sheets 1 are stacked, visual confirmation cannot be performed. If the reforming is performed while the positional deviation of the reforming metal 3 is generated, the quality of the nonmagnetic reforming phase 11 is deteriorated.

  Here, FIG. 3 is a diagram showing an example of the case where the nonmagnetic modified phase is not stably obtained. If the reformed metal 3 in the space 20 is biased to one side, for example, as shown in FIG. 3A, the reformed metal 3 and the electrical steel sheet 1 are in contact with each other on the biased side (the right side in the drawing), but the opposite. A large gap is formed on the side (left side of the drawing). When the two electromagnetic steel sheets 1 sandwiching the reforming metal 3 in such a state are sandwiched by the electrodes 5 from above and below as shown in FIG. The modified metal 3 melts around the contact portion with the electromagnetic steel sheet 1.

  Accordingly, the modified metal 3 is heated from the right side surface of the drawing that is in contact with the electromagnetic steel sheet 1 and is sufficiently melted, but the melting is not sufficient on the left side of the drawing where current is difficult to pass, so as shown in FIG. An asymmetric nonmagnetic modified phase 111 is formed. In this case, since the modification on the right side of the drawing is not sufficient, the leakage magnetic flux is increased when the rotor is configured, and the strength of the nonmagnetic modified phase 111 may be reduced due to the distorted shape. Therefore, in order to obtain the rotor member 10 with good quality, the modified metal 3 is accurately positioned so that the nonmagnetic modified phase 11 as shown in FIG. 2C can be stably obtained. Measures are needed.

  Therefore, in the present embodiment, a manufacturing method is proposed in which the modified metal 3 is necessarily positioned at the center of the space 20 and a stable nonmagnetic modified phase 11 can be obtained. Specifically, it has a configuration for positioning the modified metal 3 at the center of the space 20 and a positioning step using it. FIG. 4 is a plan view showing the positioning performed for the modified metal in the space 20. The modified metal 30 of the present embodiment has an uneven portion 31 in which triangular unevenness is continuously formed on the peripheral side surface. On the other hand, a projection 21 is formed on the bottom surface of the concave hole 2 so as to position the modified metal 30 so that the center O1 of the modified metal 30 overlaps the center O2 of the concave hole 2. The protrusions 21 are arranged at three locations on the circumference of a circle centered on O2, and support the modified metal 30 at three points so as to be surely positioned. In addition, such uneven | corrugated | grooved part 31 and the processus | protrusion 21 are formed in connection with processing the modified metal 30 and the electromagnetic steel plate 1 by a press or cutting.

  The positioning of the modified metal 30 is performed as a pre-process for processing the nonmagnetic modified phase 11 shown in FIG. There, the modified metal 30 is put into each concave hole 2 of the lower electromagnetic steel sheet 1, and the upper electromagnetic steel sheet 1 is overlapped so that the concave holes 2 are aligned. Then, by applying rotation to the stacked electrical steel sheets 1, the modified metal 30 in the space 20 is moved in the outer diameter direction by centrifugal force. At that time, the modified metal 30 moves as indicated by an arrow in FIG. 4B, and the concave portion of the concavo-convex portion 31 is fitted into the projection 21, so that the center of the modified metal 30 is centered on the center O 2 of the concave hole 2. Positioning is performed so that O1 overlaps. Then, after such a positioning step, a processing step of the nonmagnetic modified phase 11 is executed.

  FIG. 5 is a cross-sectional view of the first embodiment showing one place when a nonmagnetic modified phase is formed by the positioned modified metal 30. As shown in FIG. 5A, the positioned modified metal 30 is disposed so that both upper and lower surfaces thereof are in contact with the electromagnetic steel sheet 1 and that there is an equal gap in the horizontal direction of the drawing in the radial direction. Therefore, as shown in FIG. 5B, the upper and lower electromagnetic steel sheets 1 are sandwiched by the electrode 5 at the position where the modified metal 30 is positioned, and energization and pressurization are performed. At this time, the energization current flows through the upper and lower surfaces of the modified metal 30 that is in contact with the electromagnetic steel sheet 1 and does not create a flow on the side surface. Then, by solidifying again after the end of energization, a stable nonmagnetic modified phase 11 is formed as shown in FIG.

  In the present embodiment, when the modified metal 30 is positioned, the electromagnetic steel sheet 1 is rotated at a rotational speed of about 200 rpm in a state in which almost no load is applied in the up-down direction. The electromagnetic steel sheet 1 has a thickness of 0.3 mm, and the diameter of the recessed hole 2 formed therein is 3.05 mm and the depth is 0.15 mm. On the other hand, the modified metal 30 has an outermost diameter of the concavo-convex portion 31 of 2.5 mm, a thickness of 0.43 mm, 0.13 mm higher than the height of the space 20, and a gap of 0.53 mm in the radial direction. The dimensions are set so that The energization and pressurization performed between the pair of upper and lower electrodes 5 is, for example, a pressing force of about 2 KN and a current value of about 7.2 KA for 0.15 seconds.

  According to the manufacturing method of the present embodiment, by adjusting the dimensions of the modified metal 30 and the space 20, the nonmagnetic modified phase 11 having a high quality is obtained in that the modified metal 30 generates heat from both the upper and lower surfaces and melts. can get. In addition, by arranging the modified metal 30 at an appropriate position in the positioning step, it is possible to manufacture the rotor member 10 having the nonmagnetic modified phase 11 with higher quality and stability. The positioning of the modified metal 30 is also a simple method of simply rotating the electromagnetic steel sheet 1 after being inserted into the recessed hole 2, and the effect of improving the quality can be achieved while increasing the work efficiency. And the structure for performing a positioning process is also a simple thing which forms the uneven | corrugated | grooved part 31 in the modified metal 30, and forms the protrusion 21 in the recessed hole 2. FIG.

  Next, FIG. 6 is a cross-sectional view of a second embodiment showing a method for producing a nonmagnetic modified phase. In the present embodiment, a manufacturing method in the case where a rotor member is formed by stacking three electromagnetic steel sheets is shown in the first embodiment in which the rotor member 10 is formed by stacking two electromagnetic steel sheets 1. . In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.

  In the present embodiment, two electromagnetic steel plates 41 having a flat surface and one electromagnetic steel plate 42 having through holes 42a are prepared. As shown in FIG. The reformed metal 3 is placed in the space 40 of the through hole 42a formed by overlapping the electromagnetic steel plates 41. At this time, the height dimension in the pressing direction of the modified metal 30 is larger than the thickness of the electromagnetic steel sheet 42, and conversely, the horizontal dimension orthogonal to the pressing direction is smaller than the through hole 42a. Also in this embodiment, the positioning step shown in FIG. 4 is executed, and by rotating the stacked electromagnetic steel sheets 41, 42, 41, the modified metal 30 in the space 40 is given a centrifugal force and moved in the outer diameter direction. Then, positioning is performed by contacting the projection 21 formed on the lower electromagnetic steel sheet 41.

  Thereafter, as shown in FIG. 6B, the upper and lower electromagnetic steel plates 41, 42, 41 are sandwiched by the electrode 5 at the location where the modified metal 30 is located, and energization and pressurization are performed. At this time, the energization current flows through the upper and lower surfaces of the modified metal 30 in contact with the electromagnetic steel sheet 41 and does not create a flow on the side surface, so that the whole is uniformly melted by the resistance heat generation at the contact portion. Then, by solidifying again after the end of energization, as shown in FIG. 6C, a rotor member 60 having a stable nonmagnetic modified phase 61 is formed.

  Therefore, also in the manufacturing method of the present embodiment, by adjusting the dimensions of the modified metal 30 and the space 40, the nonmagnetic modified phase 61 having a high quality in that the modified metal 30 generates heat from both the upper and lower surfaces and melts. can get. In addition, by arranging the modified metal 30 at an appropriate position in the positioning step, it is possible to manufacture the rotor member 60 having the nonmagnetic modified phase 61 with higher quality and stability.

As mentioned above, although embodiment was described about the manufacturing method of the steel materials provided with the nonmagnetic modification phase concerning the present invention, the present invention is not limited to this, and various changes are possible in the range which does not deviate from the meaning. is there.
For example, in the above-described embodiment, three protrusions 21 are provided in the recessed hole 2, but the protrusions 21 may be two. Further, the protrusion formed in the recessed hole 2 may be formed so as to protrude from the circular wall surface depending on the space, in addition to the protrusion formed on the bottom surface like the protrusion 21 of the embodiment.
Moreover, although the said embodiment demonstrated the case where the nonmagnetic modified phase 11 was formed in the rotor member which piled up the two electromagnetic steel plates 1, it is applicable also when performing about another member.

Moreover, in the said 2nd Embodiment, although the electromagnetic steel plate 41 was made into the plane, a concave hole is formed also in the electromagnetic steel plate 41 similarly to 1st Embodiment, By the concave hole and the through-hole 42a of the electromagnetic steel plate 42, it is. You may make it put a modified metal in the formed space.
Furthermore, in the said 2nd Embodiment, although the space 40 was comprised with the one electromagnetic steel plate 42 in which the through-hole 42a was formed, you may make it pile up two or more electromagnetic steel plates 42 between the upper and lower electromagnetic steel plates 41. FIG. Good.

DESCRIPTION OF SYMBOLS 1 Electromagnetic steel plate 2 Concave hole 3 Modified metal 5 Electrode 10 Rotor member 11 Nonmagnetic modified phase 20 Space 21 Protrusion 30 Modified metal 31 Uneven portion

Claims (3)

A space is formed by superposing a plurality of steel materials, a reformed metal is placed in the space, and electricity is supplied by a pair of electrodes sandwiched in the superposition direction at the position where the reformed metal exists. By pressurizing, the modified metal is melted together with a part of the surrounding steel material to form a nonmagnetic modified phase,
The modified metal is a circular member having a thickness, the dimension in the pressurizing direction by the electrode is larger than the space, and the lateral dimension orthogonal to the pressurizing direction is smaller than the space. Concave and convex portions are formed continuously in the circumferential direction on the lateral circumferential surface,
A protrusion for positioning the modified metal is formed in the space,
Prior to energization and pressurization by the electrodes, the steel that has been superposed with the reformed metal placed in the space is rotated, and the reformed metal moved in the space by the centrifugal force is projected into the projection in the space. A method for producing a steel material comprising a non-magnetically modified phase, characterized by having a step of positioning by being applied to the surface. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to claim 1,
In the modified metal, a triangular uneven portion is formed, and in the space, protrusions protruding on the bottom surface in the pressurizing direction are formed at a plurality of locations,
A method for producing a steel material having a nonmagnetic modified phase, wherein positioning is performed such that a protrusion fits into a recessed portion of the modified metal that moves in the space by centrifugal force. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to claim 1 or claim 2,
The protrusions formed in the space are formed so as to fit into the modified metal at three points on the circumference of a circle centered on the center point of the bottom surface in the pressing direction,
A method for producing a steel material comprising a nonmagnetic modified phase, wherein the modified metal that moves in the space by centrifugal force is supported at three points for positioning.

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