JP5876210B2 - Motor core with low iron loss degradation under compressive stress - Google Patents
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/64—Electric machine technologies in electromobility
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- Iron Core Of Rotating Electric Machines (AREA)
Description
本発明は、家庭用エアコンのコンプレッサーモータや、ハイブリッド電気自動車（ＥＶ；Ｅｌｅｃｔｒｉｃ Ｖｅｈｉｃｌｅ）の駆動モータや発電機（以降、単に「モータ」という。）などに用いられるモータコアに関し、具体的には、圧縮応力の存在下においても鉄損劣化が小さい（鉄損増加が小さい）モータコアに関するものである。 The present invention relates to a motor core used in a compressor motor of a home air conditioner, a drive motor or a generator (hereinafter simply referred to as “motor”) of a hybrid electric vehicle (EV), and more specifically, compression. The present invention relates to a motor core that is small in iron loss degradation (small increase in iron loss) even in the presence of stress.
家庭用エアコンのコンプレッサーモータは、一般に最高周波数が２００〜４００Ｈｚ程度での可変速運転が行われており、さらに、ＰＷＭ（Ｐｕｌｓｅ Ｗｉｄｔｈ Ｍｏｄｕｌａｔｉｏｎ）方式のインバータ制御等では、数ｋＨｚのキャリア周波数が重畳されて使用されている。また、最近、急速に普及しているハイブリッド電気自動車の駆動モータも、高出力化や小型化を図る観点から、数ｋＨｚ程度の周波数で駆動されている。 Compressor motors for home air conditioners are generally operated at variable speeds with a maximum frequency of about 200 to 400 Hz. Furthermore, in PWM (Pulse Width Modulation) type inverter control, a carrier frequency of several kHz is superimposed. Have been used. Recently, a drive motor of a hybrid electric vehicle that is rapidly spreading is also driven at a frequency of about several kHz from the viewpoint of high output and miniaturization.
上記のようなモータのステータ（固定子）やロータ（回転子）等のモアに用いられる素材（コア材）には、エネルギー効率を向上する観点から、鉄損が低いことが求められる。そこで、上記モータコア材には、使用される高周波域における鉄損を低減するため、一般に、ＳｉとＡｌを合計で３〜４ｍａｓｓ％程度添加した高グレードの無方向性電磁鋼板が使用されている。 A material (core material) used for a mower such as a stator (stator) or a rotor (rotor) of the motor as described above is required to have low iron loss from the viewpoint of improving energy efficiency. Therefore, in order to reduce the iron loss in the high frequency range to be used, a high grade non-oriented electrical steel sheet to which about 3 to 4 mass% in total of Si and Al are added is used for the motor core material.
ところで、エアコンのコンプレッサーモータやハイブリッド電気自動車のモータでは、ステータをハウジング（モータケース）に固定する方法として、焼き嵌め法や圧入法が採用されており、これに起因して、ステータの円周方向には最大１００ＭＰａ程度の圧縮応力が発生する。また、ハイブリッド電気自動車の駆動モータには、一般に樹脂モールドが施されるため、やはりモータコアには圧縮応力が加わることとなる。このような圧縮応力の存在下では、コアを構成する電磁鋼板の磁気特性が大きく劣化する（鉄損が増加する）ことが知られている。そのため、圧縮応力による鉄損劣化が小さい電磁鋼板の開発が望まれている。 By the way, in a compressor motor of an air conditioner or a motor of a hybrid electric vehicle, a shrink fitting method or a press-fitting method is adopted as a method for fixing the stator to the housing (motor case). A maximum of about 100 MPa compressive stress is generated. Moreover, since the resin motor is generally applied to the drive motor of the hybrid electric vehicle, a compression stress is also applied to the motor core. In the presence of such compressive stress, it is known that the magnetic properties of the electrical steel sheet constituting the core are greatly deteriorated (iron loss increases). Therefore, it is desired to develop an electrical steel sheet that is small in iron loss deterioration due to compressive stress.
圧縮応力存在下での鉄損特性を改善した材料としては、例えば、特許文献１には、Ｓｉ：２．６〜４ｍａｓｓ％を含有し、比抵抗が５０〜７５×１０−８Ωｍ、平均結晶粒径が６０μｍ超１６５μｍ以下とした無方向性電磁鋼板が開示されている。 As a material having improved iron loss characteristics in the presence of compressive stress, for example, Patent Document 1 contains Si: 2.6 to 4 mass%, specific resistance is 50 to 75 × 10 −8 Ωm, average crystal A non-oriented electrical steel sheet having a particle size of more than 60 μm and 165 μm or less is disclosed.
しかしながら、特許文献１の無方向性電磁鋼板は、現在市販されている高グレード電磁鋼板と同等レベルの固有抵抗、結晶粒径でしかない。そのため、この材料を用いてモータコアを製造したとしても、圧縮応力による鉄損劣化の程度は従来材と大きく異なるものではないため、鉄損の応力依存性をより小さくできる技術の開発が求められている。 However, the non-oriented electrical steel sheet of Patent Document 1 has only a specific resistance and crystal grain size equivalent to those of a high-grade electrical steel sheet currently on the market. For this reason, even if a motor core is manufactured using this material, the degree of iron loss deterioration due to compressive stress is not significantly different from that of conventional materials, so the development of technology that can reduce the stress dependence of iron loss is required. Yes.
そこで、本発明の目的は、圧縮応力の存在下においても高周波での鉄損特性の劣化が小さいモータコアを提供することにある。 Accordingly, an object of the present invention is to provide a motor core in which deterioration of iron loss characteristics at a high frequency is small even in the presence of compressive stress.
発明者らは、上記課題の解決に向けて鋭意検討した。その結果、ステータを構成する電磁鋼板（以降、「ステータコア材」とも称する。）のバックヨーク部に、周方向に沿って並行する複数のスリットを設けることで、圧縮応力による鉄損特性の劣化を抑制できることを見出し、本発明を完成させた。 The inventors diligently studied to solve the above problems. As a result, by providing a plurality of slits parallel to the circumferential direction in the back yoke portion of the electromagnetic steel sheet (hereinafter also referred to as “stator core material”) constituting the stator, the iron loss characteristics are deteriorated due to the compressive stress. The inventors have found that it can be suppressed, and completed the present invention.
すなわち、本発明は、打抜加工した電磁鋼板を積層したステータが、モータケースに固定され、該ステータの周方向に１０ＭＰａ以上の圧縮応力が付与されてなるモータコアにおいて、上記ステータを構成する電磁鋼板のティース接続部を除くバックヨーク部に、上記電磁鋼板を貫通し、周方向に沿って並行する複数のスリットを設けてなり、かつ、上記並行する複数のスリットは、間隔が１０ｍｍ以下、スリット空隙部の幅が０．５ｍｍ以下であり、上記電磁鋼板表面をオージェ電子分光法で測定したときのＳ濃度が電磁鋼板表面のいずれの部分においても１０ａｔ％以下であることを特徴とするモータコアである。 That is, the present invention relates to an electromagnetic steel sheet constituting the stator in a motor core in which a stator in which punched electromagnetic steel sheets are laminated is fixed to a motor case and a compressive stress of 10 MPa or more is applied in the circumferential direction of the stator. The back yoke part excluding the teeth connecting part is provided with a plurality of slits penetrating the electromagnetic steel sheet and parallel in the circumferential direction, and the parallel slits have a gap of 10 mm or less and a slit gap. The motor core is characterized in that the width of the portion is 0.5 mm or less and the S concentration when the surface of the electromagnetic steel sheet is measured by Auger electron spectroscopy is 10 at% or less in any part of the surface of the electromagnetic steel sheet. .
また、本発明のモータコアにおける上記電磁鋼板は、Ｓｉ：７ｍａｓｓ％以下、Ａｌ：３ｍａｓｓ％以下、Ｍｎ：０．０５〜３ｍａｓｓ％、Ｓ：０．００５ｍａｓｓ％以下、Ｎ：０．００５ｍａｓｓ％以下、Ｏ：０．０１０ｍａｓｓ％以下、残部がＦｅおよび不可避不純物からなることを特徴とする。 Further, the electromagnetic steel sheet in the motor core of the present invention has Si: 7 mass% or less, Al: 3 mass% or less, Mn: 0.05 to 3 mass%, S: 0.005 mass% or less, N: 0.005 mass% or less, O : 0.010 mass% or less, the balance being Fe and inevitable impurities.
本発明によれば、圧縮応力の存在下においても高周波での鉄損増加が小さいモータコアを提供することができる。したがって、本発明の上記モータコアは、焼き嵌めや圧入あるいは樹脂モールド等によって圧縮応力が付与された状態で使用されるエアコンのコンプレッサ用モータやハイブリッド電気自動車の駆動モータ、燃料電池自動車（ＦＣＥＶ）の駆動モータ、高速発電機の高周波回転機等に好適に用いることができる。 According to the present invention, it is possible to provide a motor core with a small increase in iron loss at high frequencies even in the presence of compressive stress. Therefore, the motor core of the present invention is a compressor motor for an air conditioner, a drive motor for a hybrid electric vehicle, and a drive for a fuel cell vehicle (FCEV) that are used in a state where compressive stress is applied by shrink fitting, press fitting, resin molding or the like. It can be suitably used for motors, high-frequency rotating machines for high-speed generators, and the like.
先ず、本発明の基本的な技術思想について説明する。
家電用エアコンのコンプレッサ用モータやハイブリッド電気自動車（ＥＶ）用の駆動モータでは、コアをモータケースに固定する手段として、焼き嵌めや圧入が行われている。この焼き嵌めや圧入によってモータコアの周方向に付与される圧縮応力は、通常、２０〜１００ＭＰａ程度であると言われている。この圧縮応力は、モータコアを構成する電磁鋼板の鉄損特性を劣化させ、ひいては、モータ効率の低下を招くことが知られている。
First, the basic technical idea of the present invention will be described.
In compressor motors for home appliance air conditioners and drive motors for hybrid electric vehicles (EV), shrink fitting and press fitting are performed as means for fixing the core to the motor case. It is said that the compressive stress applied in the circumferential direction of the motor core by shrink fitting or press fitting is usually about 20 to 100 MPa. It is known that this compressive stress degrades the iron loss characteristics of the electrical steel sheet constituting the motor core, which in turn causes a reduction in motor efficiency.
また、エアコンのコンプレッサ用モータやハイブリッド車のＥＶモータは、基本周波数が高周波であることに加えて、インバータ制御のため、数ｋＨｚの高調波も重畳されて駆動されているのが一般的である。そこで、発明者らは、モータのステータを構成する電磁鋼板の圧縮応力下における高周波鉄損特性について調査したところ、圧縮応力の存在下では、ヒステリシス損だけでなく、渦電流損も増加していることが明らかとなった。したがって、高周波鉄損特性を改善するには、渦電流損の増加を抑制することが重要な課題となる。 In addition, the compressor motor for an air conditioner and the EV motor for a hybrid vehicle are generally driven with a high frequency of several kHz in addition to the fundamental frequency being high for inverter control. . Therefore, the inventors investigated the high-frequency iron loss characteristics under the compressive stress of the electrical steel sheet constituting the stator of the motor, and in the presence of the compressive stress, not only the hysteresis loss but also the eddy current loss increased. It became clear. Therefore, in order to improve the high frequency iron loss characteristic, it is an important issue to suppress an increase in eddy current loss.
そこで、圧縮応力の存在下で渦電流損が増加する原因について調査したところ、材料に圧緒応力が付与されると、鋼板内の磁化ベクトルは、その圧縮応力を緩和するために鋼板板面方向を向くように変化する。そして、これを磁化しようとすると、上記磁化ベクトルを磁化方向に向かせるための渦電流が鋼板板面内に流れることになり、その結果、無応力の状態に比べて渦電流が増加し、渦電流損が増加することが明らかとなった。 Therefore, when the cause of the increase in eddy current loss in the presence of compressive stress was investigated, when a compressive stress was applied to the material, the magnetization vector in the steel sheet was It changes so that it faces. When this is attempted to be magnetized, an eddy current for directing the magnetization vector in the magnetization direction flows in the steel plate surface. As a result, the eddy current increases as compared with the unstressed state, It became clear that the current loss increased.
そこで、発明者らは、圧縮応力が加えられても、渦電流損が増大しないモータコア（ステータ）について検討を重ねた。その結果、ステータを構成する積層された電磁鋼板（ステータコア材）のバックヨーク部の周方向に沿って、すなわち、圧縮応力と平行な方向に、並行する複数のスリットを設けてやれば、鋼板板面内に流れる渦電流の経路を小さくすることができ、渦電流による鉄損の増加を効果的に抑制できるのではないかと考えた。 Thus, the inventors have repeatedly studied a motor core (stator) in which eddy current loss does not increase even when compressive stress is applied. As a result, if a plurality of parallel slits are provided along the circumferential direction of the back yoke portion of the laminated electromagnetic steel plates (stator core material) constituting the stator, that is, in the direction parallel to the compressive stress, the steel plate We thought that the path of the eddy current flowing in the plane could be reduced and the increase in iron loss due to eddy current could be effectively suppressed.
上記考えを検証するため、以下の実験を行った。
Ｓｉ：３ｍａｓｓ％−Ａｌ：１ｍａｓｓ％−Ｍｎ：０．３ｍａｓｓ％−Ｓ：０．００３ｍａｓｓ％−Ｎ：０．００１０ｍａｓｓ％−Ｏ：０．００１２ｍａｓｓ％の成分組成からなる板厚：０．３５ｍｍの冷延無方向性電磁鋼板を用いて、外径：１５０ｍｍφ、バックヨーク幅：２０ｍｍで、１２スロットのステータコア材を打抜加工により作製した。なお、上記ステータコア材のバックヨーク部（ティース接続部を除く）には、図１に示したように、ステータの周方向に沿って、空隙幅：０．３ｍｍのスリットを間隔：５ｍｍで３本（円周方向に１２箇所）打抜加工により付与した。
In order to verify the above idea, the following experiment was conducted.
Si: 3 mass% -Al: 1 mass% -Mn: 0.3 mass% -S: 0.003 mass% -N: 0.0010 mass% -O: 0.0012 mass% Plate thickness: 0.35 mm cold Using a non-oriented electrical steel sheet, a 12-slot stator core material having an outer diameter of 150 mmφ and a back yoke width of 20 mm was produced by punching. As shown in FIG. 1, the stator core material has three back yoke portions (excluding the teeth connection portion) having a gap width of 0.3 mm and a gap of 5 mm along the circumferential direction of the stator. (12 places in the circumferential direction) It was given by punching.
次いで、上記ステータコア材を積み厚３０ｍｍに積層してステータコアを作製し、モータケースを模した非磁性のステンレス製リングに焼き嵌め代を０〜７０μｍの範囲で変化させて焼き嵌めし、固定した。この際、バックヨーク中央部の周方向の圧縮応力を、歪みゲージを用いて測定したところ、０〜８０ＭＰａの圧縮応力が発生していた。 Next, the stator core material was laminated to a stack thickness of 30 mm to produce a stator core, which was shrink-fitted and fixed to a non-magnetic stainless steel ring imitating a motor case by changing the shrinkage allowance in the range of 0 to 70 μm. At this time, when the compressive stress in the circumferential direction of the central portion of the back yoke was measured using a strain gauge, a compressive stress of 0 to 80 MPa was generated.
次いで、上記ステンレス製リングに固定したステータコアに、図２のように、ステンレス製リングも含めてバックヨーク部の周囲に励磁コイルおよびピックアップコイルを巻き線し、モータコア円周方向の高周波鉄損（Ｗ１０／３ｋ）を測定した。図３は、上記測定の結果を、焼き嵌めによって発生したステータ周方向の圧縮応力と高周波鉄損との関係として示したものである。これから、ステータコア材のバックヨーク部にスリットを付与することにより、焼き嵌めで発生する圧縮応力による鉄損の増大を抑制できることがわかる。 Next, an excitation coil and a pickup coil are wound around the back yoke portion including the stainless steel ring on the stator core fixed to the stainless steel ring, as shown in FIG. 10 / 3k ). FIG. 3 shows the result of the above measurement as a relationship between the compressive stress in the circumferential direction of the stator generated by shrink fitting and the high-frequency iron loss. From this, it can be seen that by providing a slit in the back yoke portion of the stator core material, an increase in iron loss due to compressive stress generated by shrink fitting can be suppressed.
なお、上記ステータコア材のバックヨーク部に付与する複数の並行するスリットは、スリットの長手方向と圧縮応力の方向とを一致させるのが好ましい。その理由は、この場合に最も渦電流の抑制効果が大きいからである。したがって、焼き嵌め等で圧縮応力がステータの周方向に発生するモータでは、スリットの長さ方向をステータの周方向に合わせることが好ましい。 In addition, it is preferable that the plurality of parallel slits applied to the back yoke portion of the stator core material match the longitudinal direction of the slits with the direction of compressive stress. The reason is that the eddy current suppression effect is the largest in this case. Therefore, in a motor in which compressive stress is generated in the circumferential direction of the stator due to shrink fitting or the like, the length direction of the slit is preferably matched with the circumferential direction of the stator.
また、上記複数の並行するスリットは、空隙部の幅が０．５ｍｍ以下で、スリットの間隔が１０ｍｍ以下であることが好ましい。スリットの空隙部の幅が、０．５ｍｍを超えると磁束密度が低下し、また、スリットの間隔が１０ｍｍを超えると、鉄損特性の劣化を抑制する効果が小さくなるためである。スリットの間隔は、より好ましくは５ｍｍ以下である。なお、並行するスリットの本数は、特に規定しないが、バックヨーク幅と上記スリット間隔とから、適宜決定すればよい。 The plurality of parallel slits preferably have a gap width of 0.5 mm or less and a slit interval of 10 mm or less. This is because when the width of the gap portion of the slit exceeds 0.5 mm, the magnetic flux density decreases, and when the interval between the slits exceeds 10 mm, the effect of suppressing the deterioration of the iron loss characteristic is reduced. The interval between the slits is more preferably 5 mm or less. The number of parallel slits is not particularly defined, but may be determined as appropriate based on the back yoke width and the slit interval.
次に、本発明のモータコアに用いる電磁鋼板の表面性状について説明する。
発明者らは、種々の製造履歴の電磁鋼板を用いて、図１と同様、バックヨーク部に２ｍｍ間隔で空隙幅が０．２ｍｍのスリットを７本付与したステータコア材を打抜加工し、これを積層してステータコアを作製し、上記実験と同様にして圧縮応力と鉄損との関係を調査したところ、スリットを付与しているにも拘わらず、鉄損特性が改善されないものが存在した。そこで、このステータコアについて詳細に観察したところ、スリットの打抜加工の際に発生した「だれ」近傍の絶縁被膜が一部剥離しているのが確認された。これから、鉄損改善効果が得られなかった理由は、だれ近傍の被膜剥離部で短絡が生じ、これによって渦電流が増大したためであることがわかった。
Next, the surface properties of the electromagnetic steel sheet used for the motor core of the present invention will be described.
The inventors punched a stator core material having seven slits having a gap width of 0.2 mm at intervals of 2 mm in the back yoke portion using electromagnetic steel sheets having various manufacturing histories, as in FIG. A stator core was manufactured by laminating the same, and the relationship between the compressive stress and the iron loss was examined in the same manner as in the above experiment. Therefore, when the stator core was observed in detail, it was confirmed that a part of the insulating coating in the vicinity of the “sag” generated during the punching of the slit was peeled off. From this, it was found that the reason why the iron loss improvement effect was not obtained was that a short-circuit occurred at the film peeling portion in the vicinity of anyone, thereby increasing the eddy current.
そこで、絶縁被膜が剥離した原因を調べるため、剥離が発生した電磁鋼板と発生しなかった電磁鋼板の両鋼板について、絶縁被膜をアルカリ液（４５ｍａｓｓ％ＮａＯＨ）で除去した後、その鋼板表面を、オージェ電子分光法を用いて詳細に調査した。その結果、被膜剥離が発生した電磁鋼板の表面にはＳの濃縮が認められ、特に表面のＳ濃度が１０ａｔ％以上の鋼板で被膜剥離が顕著に起きていることがわかった。そこで、本発明に用いる電磁鋼板は、鋼板表面のＳ濃度を１０ａｔ％以下に制限することとした。なお、上記Ｓ濃度は、オージェ電子分光法で測定した鋼板表面のＳピーク強度と、Ｓ濃度を変えて作製した標準サンプルのＳピーク強度とを比較することにより決定した。 Therefore, in order to investigate the cause of the peeling of the insulating coating, after removing the insulating coating with an alkaline solution (45 mass% NaOH) for both of the electrical steel plate where the peeling occurred and the electromagnetic steel plate where the peeling did not occur, A detailed investigation was made using Auger electron spectroscopy. As a result, it was found that the concentration of S was observed on the surface of the electromagnetic steel sheet on which the film peeling occurred, and that the film peeling occurred particularly in the steel sheet having a surface S concentration of 10 at% or more. Therefore, in the electrical steel sheet used in the present invention, the S concentration on the steel sheet surface is limited to 10 at% or less. The S concentration was determined by comparing the S peak intensity of the steel sheet surface measured by Auger electron spectroscopy with the S peak intensity of a standard sample prepared by changing the S concentration.
なお、鋼板表面のＳの濃縮が、絶縁被膜の剥離を引き起こす原因については、現在のところ明確になっていないが、鋼板表面に偏析したＳによって被膜の密着性が低下するためではないかと考えている。 The reason why the concentration of S on the surface of the steel sheet causes peeling of the insulating film is not clear at present, but it is thought that the adhesion of the film is reduced by S segregated on the surface of the steel sheet. Yes.
通常のステータコア材では、スリットの打抜加工は行われることはないため、鋼板表面にＳが多少濃縮していても絶縁被膜の剥離は生じない。しかし、本発明のステータコア材のようにスリット加工が行われる場合には、ブリッジ部（スリット加工したバックヨーク部）の被膜は、打ち抜き時に両サイドのパンチに引き込まれる方向の大きな引張応力を受けるため、被膜剥離を起こしたものと考えられる。 In a normal stator core material, since the slit is not punched, even if S is somewhat concentrated on the surface of the steel sheet, the insulating coating does not peel off. However, when slit processing is performed as in the stator core material of the present invention, the coating on the bridge portion (slit back yoke portion) receives a large tensile stress in the direction of being drawn into the punches on both sides at the time of punching. It is considered that the film was peeled off.
また、Ｓが鋼板表面に濃化する原因は、Ｓは表面偏析元素であるため、熱延板焼鈍時および仕上焼鈍時によって鋼板表面に偏析してくるためと考えられる。
一方、鋼板表面のＳ濃度を１０ａｔ％以下とする方法については、特に制限はなく、例えば、素材（鋼スラブ）のＳ含有量の上限を規制する方法、熱延板焼鈍後、２０ｍａｓｓ％程度の塩酸溶液中で２０ｓｅｃ以上の酸洗を行って鋼板表面のＳ偏析層を除去する方法、仕上焼鈍後、鋼板表面を酸洗する方法などを挙げることができる。ただし、熱延板焼鈍後の酸洗のみでは、仕上焼鈍時におけるＳの偏析を防止できないため、仕上焼鈍後に酸洗する方法が最も好ましい。
In addition, it is considered that the reason why S is concentrated on the steel sheet surface is that S is a surface segregation element and segregates on the steel sheet surface during hot-rolled sheet annealing and finish annealing.
On the other hand, the method for setting the S concentration on the surface of the steel sheet to 10 at% or less is not particularly limited. Examples include a method of removing the S segregation layer on the surface of the steel sheet by performing pickling for 20 seconds or more in a hydrochloric acid solution, and a method of pickling the surface of the steel sheet after finish annealing. However, since pickling after hot-rolled sheet annealing alone cannot prevent segregation of S during finish annealing, pickling after finish annealing is most preferable.
また、本発明のモータコアに用いる電磁鋼板表面に被成する絶縁被膜は、電磁鋼板との密着性に優れるものであれば特に制限はなく、例えば、通常公知の半有機の被膜であれば好適に用いることができる。また、被膜の厚さ（焼付後）は、層間抵抗を確保しかつ占積率を高める観点から、０．３〜１．０μｍの範囲であることが好ましい。 The insulating coating formed on the surface of the electromagnetic steel sheet used for the motor core of the present invention is not particularly limited as long as it has excellent adhesion to the electromagnetic steel sheet. For example, a generally known semi-organic film is suitable. Can be used. The thickness of the coating (after baking) is preferably in the range of 0.3 to 1.0 μm from the viewpoint of securing interlayer resistance and increasing the space factor.
次に、本発明のモータコアの素材となる電磁鋼板の成分組成について説明する。
Ｓｉ：７ｍａｓｓ％以下
Ｓｉは、鋼の固有抵抗を高めるのに有効な元素であるが、７ｍａｓｓ％を超えて添加すると、飽和磁束密度の低下に伴い、モータコアの磁束密度も低下するようになる。また、最終板厚に圧延する際、たとえ温間圧延しても板破断を起こすおそれがあるため、上限は７ｍａｓｓ％とするのが好ましい。なお、下限は特に制限しないが、固有抵抗を高める観点からは、０．１ｍａｓｓ％以上であることが好ましい。より好ましくは１〜４ｍａｓｓ％の範囲である。
Next, the component composition of the electrical steel sheet used as the material for the motor core of the present invention will be described.
Si: 7 mass% or less Si is an element effective for increasing the specific resistance of steel. However, when added in excess of 7 mass%, the magnetic flux density of the motor core also decreases as the saturation magnetic flux density decreases. Further, when rolling to the final plate thickness, there is a possibility that the plate breaks even if it is warm-rolled, so the upper limit is preferably 7 mass%. In addition, although a minimum in particular is not restrict | limited, From a viewpoint of raising specific resistance, it is preferable that it is 0.1 mass% or more. More preferably, it is the range of 1-4 mass%.
Ａｌ：３ｍａｓｓ％以下
Ａｌは固有抵抗を上げるために有効な元素であるが、３ｍａｓｓ％を超えると飽和磁束密度の低下が低下するのに伴い、モータコアの磁束密度も低下するため、上限は３ｍａｓｓ％とするのが好ましい。より好ましくは２ｍａｓｓ％以下である。
Al: 3 mass% or less Al is an element effective for increasing the specific resistance. However, when the mass exceeds 3 mass%, the decrease in saturation magnetic flux density decreases, and the magnetic flux density of the motor core also decreases, so the upper limit is 3 mass%. Is preferable. More preferably, it is 2 mass% or less.
Ｍｎ：０．０５〜３ｍａｓｓ％
Ｍｎは、Ｓ等による赤熱脆性を防止するために必要な元素であり、０．０５ｍａｓｓ％以上添加するのが好ましい。一方、３ｍａｓｓ％を超えて添加すると、飽和磁束密度が低下するため、上限は３ｍａｓｓ％とするのが好ましい。より好ましくは、０．１〜２ｍａｓｓ％の範囲である。
Mn: 0.05-3 mass%
Mn is an element necessary for preventing red heat brittleness due to S or the like, and it is preferable to add 0.05 mass% or more. On the other hand, if the addition exceeds 3 mass%, the saturation magnetic flux density decreases, so the upper limit is preferably 3 mass%. More preferably, it is the range of 0.1-2 mass%.
Ｓ：０．００５ｍａｓｓ％以下
Ｓは、不可避的に混入してくる不純物であり、含有量が多くなると、熱延板焼鈍や仕上焼鈍時に鋼板表面にＳが濃縮し、被膜剥離を引き起こす原因となる。また、Ｓが多くなると、硫化物系介在物が多量に形成されて、鉄損が増加する原因となる。よって、本発明では、上限を０．００５ｍａｓｓ％とするのが好ましい。より好ましくは０．００２ｍａｓｓ％以下である。
S: 0.005 mass% or less S is an impurity that is inevitably mixed in. When the content increases, S is concentrated on the surface of the steel sheet during hot-rolled sheet annealing or finish annealing, and causes film peeling. . Moreover, when S increases, a large amount of sulfide inclusions are formed, which causes an increase in iron loss. Therefore, in the present invention, the upper limit is preferably set to 0.005 mass%. More preferably, it is 0.002 mass% or less.
Ｎ：０．００５ｍａｓｓ％以下
Ｎは、Ｓと同様、不可避的に混入してくる不純物であり、含有量が多いと窒化物が多量に形成されて、鉄損が増加する原因となるため、上限は０．００５ｍａｓｓ％とするのが好ましい。
N: 0.005 mass% or less N is an impurity that is inevitably mixed in as in S, and if the content is large, a large amount of nitride is formed, causing iron loss to increase. Is preferably 0.005 mass%.
Ｏ：０．０１０ｍａｓｓ％以下
Ｏは、ＳやＮと同様、不可避的に混入してくる不純物であり、含有量が多いと酸化物系介在物が多量に形成されて、鉄損が増加する原因となるため、上限は０．０１０ｍａｓｓ％とするのが好ましい。
O: 0.010 mass% or less O, like S and N, is an impurity that is inevitably mixed in. If the content is large, a large amount of oxide inclusions are formed, and the iron loss increases. Therefore, the upper limit is preferably 0.010 mass%.
本発明のモータコアに用いる電磁鋼板は、上記成分以外の残部はＦｅおよび不可避不純物である。ただし、本発明の効果を害さない範囲内であれば、上記以外の他成分の含有を拒むものではない。 In the electrical steel sheet used for the motor core of the present invention, the balance other than the above components is Fe and inevitable impurities. However, as long as the effect of the present invention is not impaired, the inclusion of other components other than the above is not rejected.
なお、本発明のモータコアが適用できるモータは、モータコアに圧縮応力が付与されるものであれば、いずれの形式のものでもよく、例えば、図１に示した集中巻形式の永久磁石モータ、分布巻き形式の永久磁石モータ、分割コアタイプの永久磁石モータ、誘導モータ、リラクタンスモータ等に適用することができる。 The motor to which the motor core of the present invention can be applied may be of any type as long as compressive stress is applied to the motor core. For example, the concentrated winding type permanent magnet motor shown in FIG. It can be applied to types of permanent magnet motors, split core type permanent magnet motors, induction motors, reluctance motors, and the like.
転炉−脱ガス処理で鋼を所定の成分組成に調整する通常公知の精錬プロセスで、表１に示す成分組成の鋼を溶製し、連続鋳造して鋼スラブとした。次いで、この鋼スラブを１１４０℃×１ｈｒの再加熱後、仕上圧延終了温度を８００℃とする熱間圧延で板厚２．０ｍｍの熱延板とし、６１０℃で巻き取った後、この熱延板を１０００℃×３０ｓｅｃで熱延板焼鈍し、酸洗し、冷間圧延して、板厚０．３５ｍｍの冷延板とした。その後、９５０℃×１０ｓｅｃの仕上焼鈍を施し、２０ｍａｓｓ％の濃度の塩酸溶液で酸洗時間を変えて軽酸洗した後、無機有機の被膜を、０．３〜０．５μｍの厚さに塗布し、各種の無方向性電磁鋼板を製造した。 The steel having the composition shown in Table 1 was melted and continuously cast into a steel slab by a generally known refining process in which the steel was adjusted to a predetermined composition by converter-degassing treatment. Next, this steel slab was reheated at 1140 ° C. × 1 hr, and hot rolled to a finish rolling temperature of 800 ° C. to obtain a hot rolled sheet having a thickness of 2.0 mm, and wound at 610 ° C. The plate was annealed by hot rolling at 1000 ° C. for 30 seconds, pickled, and cold rolled to obtain a cold rolled plate having a thickness of 0.35 mm. Then, finish annealing at 950 ° C. × 10 sec, light pickling with a hydrochloric acid solution having a concentration of 20% by changing the pickling time, and then applying an inorganic organic coating to a thickness of 0.3 to 0.5 μm Various non-oriented electrical steel sheets were manufactured.
上記電磁鋼板について、以下の評価を行った。
＜表面のＳ濃度分析＞
上記電磁鋼板の表面に被成した絶縁被膜をアルカリ液（４５ｍａｓｓ％ＮａＯＨ）を用いて除去した後、前述した実験と同様にして、オージェ電子分光法を用いて鋼板表面のＳ濃度を分析した。
＜磁束密度Ｂ５０の測定＞
上記電磁鋼板から、幅３０ｍｍ、長さ２８０ｍｍのエプスタイン試験片を圧延方向および圧延直角方向より採取し、ＪＩＳ Ｃ２５５０に準拠して５０００Ａ／ｍで磁化したときの磁束密度Ｂ５０を測定した。
＜モータコアの鉄損測定＞
上記無方向性電磁鋼板を、図１と同じ形状で、表１に示した各種スリットを有する、外径：１５０ｍｍφ、バックヨーク幅：２０ｍｍで１２スロットのステータコア材に打抜加工し、これを積み厚：３０ｍｍに積層し、ステータコアを作製した。次いで、上記ステータコアを、内径が約１５０ｍｍφの非磁性ステンレスリングに、焼き嵌め代を０〜７０μｍの範囲で変えて固定し、ステータの周方向に圧縮応力を発生させた。なお、上記圧縮応力は、ステータのバックヨーク中央部に貼り付けた歪みゲージを用いて測定した。次いで、図２に示したように、ステンレス製リングも含めてバックヨーク部の周囲に励磁コイルおよびピックアップコイルを巻き線し、周波数３ｋＨｚ、最大磁束密度１Ｔにおけるモータコア円周方向の鉄損Ｗ１０／３ｋを測定した。
The following evaluation was performed on the electromagnetic steel sheet.
<S concentration analysis of surface>
After removing the insulating coating formed on the surface of the magnetic steel sheet using an alkaline solution (45 mass% NaOH), the S concentration on the steel sheet surface was analyzed using Auger electron spectroscopy in the same manner as in the experiment described above.
<Measurement of magnetic flux density B 50 >
From the magnetic steel sheet, an Epstein test piece having a width of 30 mm and a length of 280 mm was taken from the rolling direction and the direction perpendicular to the rolling direction, and the magnetic flux density B 50 when magnetized at 5000 A / m in accordance with JIS C2550 was measured.
<Motor core iron loss measurement>
The non-oriented electrical steel sheet is punched into a 12-slot stator core material having the same shape as in FIG. 1 and having various slits shown in Table 1, with an outer diameter of 150 mmφ and a back yoke width of 20 mm. Thickness: Laminated to 30 mm to produce a stator core. Next, the stator core was fixed to a non-magnetic stainless steel ring having an inner diameter of about 150 mmφ with a shrinkage fitting range of 0 to 70 μm changed to generate a compressive stress in the circumferential direction of the stator. The compressive stress was measured using a strain gauge attached to the center of the back yoke of the stator. Next, as shown in FIG. 2, an excitation coil and a pickup coil including the stainless steel ring are wound around the back yoke portion, and the iron loss W 10 / in the motor core circumferential direction at a frequency of 3 kHz and a maximum magnetic flux density of 1T is obtained. 3k was measured.
表１に、上記測定の結果を併記して示した。この結果から、本発明に適合する成分組成を有する無方向性電磁鋼板を用いて、本発明に適合するスリットを付与して作製したステータコアは、圧縮応力下における鉄損特性の劣化を抑制できることが確認された。 Table 1 also shows the results of the above measurements. From this result, the stator core produced by applying the slit suitable for the present invention using the non-oriented electrical steel sheet having the component composition suitable for the present invention can suppress the deterioration of the iron loss property under the compressive stress. confirmed.
本発明のモータコア技術は、ハイブリッド電気自動車の駆動モータや発電機、エアコンのコンプレッサ用モータ、工作機械の主軸モータ等、焼き嵌めして固定される高速モータに適用することができる。 The motor core technology of the present invention can be applied to high-speed motors that are fixed by shrinkage fitting, such as drive motors and generators for hybrid electric vehicles, compressor motors for air conditioners, and spindle motors for machine tools.
１：ステータコア
２：スリット
３：ロータ
４：永久磁石
５：ステンレス製リング（非磁性）
６：巻き線
1: Stator core 2: Slit 3: Rotor 4: Permanent magnet 5: Stainless steel ring (non-magnetic)
6: Winding
Claims (2)
Priority Applications (1)
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| JP5782929B2 (en) * | 2011-09-01 | 2015-09-24 | Ｊｆｅスチール株式会社 | Motor stator core |
| JP6436381B2 (en) | 2014-08-27 | 2018-12-12 | 日本電産株式会社 | Motor armature and motor |
| CN104333152B (en) * | 2014-11-14 | 2017-12-22 | 广东美芝制冷设备有限公司 | Stator punching, motor and compressor |
| KR102521943B1 (en) * | 2021-05-24 | 2023-04-14 | 엘지전자 주식회사 | Hermetic compressor |
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| JPS5974212A (en) * | 1982-10-20 | 1984-04-26 | Kawasaki Steel Corp | Ladle refining method of molten steel to be used for producing non-directional electrical sheet having less iron loss |
| JP2956406B2 (en) * | 1993-01-25 | 1999-10-04 | 日本鋼管株式会社 | High silicon magnetic steel sheet with excellent workability |
| JP4170193B2 (en) * | 2003-10-22 | 2008-10-22 | 新日鐵住金ステンレス株式会社 | Stainless steel plate with less heat generation and method for producing the same |
| JP4276613B2 (en) * | 2004-11-11 | 2009-06-10 | 新日本製鐵株式会社 | Non-oriented electrical steel sheet and ladle refining method for molten steel for non-oriented electrical steel sheet |
| JP2008193778A (en) * | 2007-02-02 | 2008-08-21 | Mitsubishi Electric Corp | Stator and enclosed compressor and rotating machine |
| JP2009261162A (en) * | 2008-04-18 | 2009-11-05 | Toyota Motor Corp | Split stator core |
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