JP2011097745A - Method for manufacturing steel material with non-magnetically modified phase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a steel material of improved quality with non-magnetically modified phase. <P>SOLUTION: The method for manufacturing the steel material with non-magnetically modified phase includes: forming a space 20 inside by stacking a plurality of steel materials 1; putting a modified metal 3 into the space 20; energizing and pressurizing the stacked steel materials 1 using a pair of electrodes 5 interposed in a stacking direction at a location of the modified metal 3, and melting the modified metal 3 together with a part of the surrounding steel materials 1 to form the non-magnetically modified phase. In this method, the steel material includes the modified metal 3 which is larger in a direction of being pressurized by the electrodes 5 than the space 20. <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 rotor from being deteriorated in performance due to the magnetic flux leakage of the magnet, a process for making the rotor partially non-magnetic has been conventionally performed. FIG. 6 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 having a dimension in the pressurizing direction by an electrode larger than that of the space is placed.

Further, in the method of manufacturing a steel material including the nonmagnetic modified phase according to the present invention, the space is formed by superimposing two steel materials each having a concave hole on each facing surface. It is preferable that the metal is pressed with a dimension in the pressing direction larger than that of the space.
Moreover, the manufacturing method of the steel material provided with the nonmagnetic modified phase according to the present invention is for the space to close the through hole from above and below both the one steel material in which the through hole is formed or the steel material in which two or more are stacked. It is preferably formed by sandwiching between steel materials, and is performed by inserting a material having a dimension in the pressurizing direction of the reformed metal larger than the space.
Moreover, the manufacturing method of the steel material provided with the nonmagnetic modified phase according to the present invention is such that the dimension of the modified metal is smaller than the space in the direction perpendicular to the pressing direction by the electrode. preferable.
Moreover, it is preferable that the manufacturing method of the steel material provided with the nonmagnetic modified phase according to the present invention is such that the volume of the modified metal is substantially equal to the volume of the space.

  According to the present invention, the dimension in the pressing direction by the electrodes is larger in the reformed metal than in the space in the stacked steel material. Comes into contact with steel. For this reason, when energization and pressurization is performed with the electrodes, it is possible to obtain a stable non-magnetic modified phase in which the entire surface is reformed and melted by resistance heat generation and reformed.

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 which showed 1st Embodiment 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 sectional drawing which showed the modified metal and the space by a recessed hole in embodiment. 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, while 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 such a magnetic steel sheet 1, and one circular modified metal (for example, NiCr) 3 is placed therein, and a plurality of non-magnetic holes are nonmagnetic. A reforming phase is formed. Here, FIG. 2 is a cross-sectional view showing the manufacturing method of the first embodiment at one place 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. As shown in FIG. 2 (b), the two electromagnetic steel sheets 1 sandwiching the modified metal 3 are sandwiched by a pair of electrodes 5 from above and below at the location where the modified metal 3 is located, which is similar to spot welding. Perform energization and pressurization in the same way. For example, the applied pressure at this time is about 2 KN, and the current value is about 8 KA.

  The energization and pressurization by the electrode 5 is performed for about 0.15 seconds, and the reformed metal 3 is melted together with the surrounding electrical steel sheet 1 by the resistance heat generated there. Thus, the inside of the electromagnetic steel sheet 1 is melted together with the reforming metal 3, while the surface portion is not melted because it is in contact with the electrode 5 and heat is taken away. 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. The nonmagnetic modified phase 11 is formed in the same manner at the plurality of concave holes 2 formed in the electromagnetic steel sheet 1 shown in FIG.

  The rotor constituting the motor is formed by further stacking a plurality of such two-layered rotor members 10 having the nonmagnetic modified phase 11 so that the positions of the nonmagnetic modified phase 11 are 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 in 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, if the quality of the reforming of the nonmagnetic reforming phase 11 formed for each rotor member 10 is deteriorated, the leakage magnetic flux cannot be prevented appropriately, and the performance of the motor is deteriorated. Therefore, regarding the manufacture of the nonmagnetic modified phase 11, it is required to effectively suppress the leakage flux of the magnet 91. In addition, the non-magnetic modified phase 11 is required to have a strength that does not cause breakage from the position where the above-described magnet installation hole is formed by centrifugal force acting on the magnet 91. . For that purpose, as shown in FIG. 2C, a measure for ensuring that the modified nonmagnetic modified phase 11 is obtained in a stable state is necessary.

  Here, FIG. 3 shows an example of the case where the nonmagnetic modified phase is not stably obtained. A possible cause of the nonmagnetic modified phase becoming unstable is a dimensional error between the modified metal 103 and the recessed hole 102. That is, the volume of the modified metal 103 is preferably formed to be the same as the volume of the space 120 formed by the concave hole 102 of the electromagnetic steel sheet 101, but since both have tolerances, as shown in FIG. In addition, when the thickness dimension of the modified metal 103 is small and the concave hole 102 is deep, a gap 110 is formed in the pressing direction of the electrode 5.

  When the two electromagnetic steel plates 101 sandwiching the modified metal 103 in this state are sandwiched by the electrodes 5 from above and below as shown in FIG. An electric current flows through the contact portion between the lateral side surface of the modified metal 103 and the electrical steel sheet 101, and the modified metal 103 is melted together with the surrounding electrical steel sheet 101 by resistance heat generated there. Therefore, the non-metallic reformed phase 111 as shown in FIG. 3C is formed, which is melted and reformed from the side surface portion of the reformed metal 103 and the center portion where current does not pass is not sufficiently reformed. End up. In this case, since the modification of the central portion is not sufficient, the leakage magnetic flux is increased when the rotor is configured, and the shape of the nonmagnetic modified phase 111 is distorted, which may cause damage with low strength.

  Therefore, in the present embodiment, a manufacturing method is proposed in which a stable nonmagnetic modified phase 11 can be obtained by the method shown in FIG. Specifically, as shown in FIG. 4, by adjusting the dimensions of the modified metal 3 and the recessed hole 2 of the electromagnetic steel sheet 1, a stable nonmagnetic modified phase 11 is to be formed. The thickness t of the modified metal 3 of the present embodiment is set to be larger than the height H of the space 20 where the concave holes 2 of the electromagnetic steel sheet 1 are overlapped.

  For example, the thickness of the two laminated steel sheets 1 is 0.3 mm, and the space 20 formed by the recessed holes 2 formed therein has a diameter D of 3.05 mm and a height H of 0.15 mm. On the other hand, the circular modified metal 3 has a diameter d of 3.0 mm and a thickness t of 0.2 mm. Therefore, the dimension is determined so that the thickness t of the modified metal 3 is 0.05 mm larger than the height H of the space 20 where the concave holes 2 of the electromagnetic steel sheet 1 are overlapped.

  Therefore, as shown in FIG. 2A, when the modified metal 3 is put in the space 20 of the recessed hole 2 and the electromagnetic steel sheets 1 are overlapped with each other, the upper surface and the lower surface of the modified metal 3 are always the recessed holes 2. Hit the bottom. Then, as shown in FIG. 2 (b), the two electromagnetic steel sheets 1 sandwiching the modified metal 3 are sandwiched by the electrodes 5 from above and below at the location where the modified metal 3 is positioned, and energization pressurization is performed. . At this time, since the energizing current flows through the upper and lower surfaces of the modified metal 3 in contact with the electromagnetic steel sheet 1, the modified metal 3 generates heat from the upper end portion 3a and the lower end portion 3b and melts as a 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.

  Therefore, according to the manufacturing method of the present embodiment, the upper surface and the lower surface of the modified metal 3 are surely formed by making the thickness dimension t of the modified metal 3 larger than the height of the space 20 that can be formed in the stacked electromagnetic steel sheets 1. And a non-magnetically modified phase 11 which is entirely modified is obtained by melting by resistance heating. Thus, the rotor member 10 in which the quality of the nonmagnetic modified phase 11 is stable can be obtained.

  By the way, the modified metal 3 of the present embodiment has a diameter d smaller than the diameter D of the circular concave hole 2 as the thickness dimension is increased. This is because the volume of the modified metal 3 is 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. On the other hand, when the difference between the volume of the modified metal 3 and the volume of the space 20 is large, the molten modified metal 3 flows out of the space 20, increases the thickness of the nonmagnetic modified phase 11 portion, or On the contrary, the plate thickness is reduced, which causes a decrease in the performance of the rotor.

  Therefore, in the present embodiment, as described above, the thickness dimension of the modified metal 3 is increased, so that the lateral dimension is decreased to match the size of the space 20. As a result, the molten modified metal 3 can be filled so as to fit properly in the space 20, and a more stable nonmagnetic modified phase 11 can be formed. However, it is desirable that the sizes of the modified metal 3 and the space 20 are equal, but if the difference becomes large, the above-described disadvantages are likely to occur, and some errors are not unacceptable.

  Next, FIG. 5 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 of the modified metal 3 in the pressing direction is larger than the thickness of the electromagnetic steel plate 42, and the horizontal dimension orthogonal to the pressing direction is smaller than the through hole 42a.

Therefore, when three electromagnetic steel plates 41, 42, 41 are sandwiched between the electrodes 5 as shown in FIG. 5 (b), the upper and lower surfaces of the modified metal 3 are always in contact with the electromagnetic steel plate 41. Pressure is applied. The energizing current flows through the upper and lower surfaces of the reformed metal 3 that is in contact with the electromagnetic steel plate 41, and the reformed metal 3 generates heat from the upper end portion 3a and the lower end portion 3b and is melted as a whole. Then, the reformed metal 3 is filled in the space 40 sealed by pressing up and down, melted together with the surrounding electromagnetic steel sheet 1, and solidified again after the energization is completed, as shown in FIG. A rotor member 60 having a magnetically modified phase 61 is formed.

  Therefore, even in the manufacturing method of the present embodiment, the upper and lower surfaces of the modified metal 3 are surely formed by making the thickness dimension of the modified metal 3 larger than the height of the space 40 formed by overlapping the electromagnetic steel plates 41 and 42. As a result, the whole is reformed by the resistance heat generated in contact with the electromagnetic steel sheet 41, and the rotor member 60 in which the quality of the nonmagnetic modified phase 61 is stable can be obtained.

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, the radial dimension of the modified metal 3 is reduced so that the sizes of the modified metal 3 and the space 20 are substantially the same. It is also conceivable to adjust the volume by making the same as that of the recessed hole 2 and making a through hole at the center.
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 Magnetic steel plate 2 Concave hole 3 Modified metal 5 Electrode 10 Rotor member 11 Nonmagnetic modified phase 20 Space

Claims (5)

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,
A method for producing a steel material having a non-magnetic modified phase, wherein the modified metal having a dimension in the pressurizing direction by the electrode larger than that of the space is placed. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to claim 1,
The space is formed by stacking two steel materials each having a concave hole on the opposite surface,
A method for producing a steel material having a non-magnetically modified phase, characterized in that the metal in the direction of pressure applied by the electrode is larger than the space. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to claim 1,
The space is formed by sandwiching one steel material in which a through hole is formed or a steel material in which two or more are stacked, with a steel material for closing the through hole from both upper and lower surfaces,
A method for producing a steel material having a non-magnetically modified phase, characterized in that the metal in the direction of pressure applied by the electrode is larger than the space. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to any one of claims 1 to 3,
The method for producing a steel material having a nonmagnetic modified phase, wherein the modified metal has a dimension in a direction orthogonal to a pressing direction by the electrode smaller than the space. In the manufacturing method of the steel material provided with the nonmagnetic modified phase according to any one of claims 1 to 4,
A method for producing a steel material comprising a nonmagnetic modified phase, wherein the volume of the modified metal and the volume of the space are substantially equal.

Images