JP6575192B2

JP6575192B2 - Electromagnetic chuck and composite grinding machine equipped with electromagnetic chuck

Info

Publication number: JP6575192B2
Application number: JP2015140371A
Authority: JP
Inventors: 昌史頼経
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2015-07-14
Filing date: 2015-07-14
Publication date: 2019-09-18
Anticipated expiration: 2035-07-14
Also published as: JP2017019073A; DE102016112726A1; CN106346359A; CN106346359B

Description

本発明は、電磁チャック、及びその電磁チャックを備えた複合研削盤に関する。 The present invention relates to an electromagnetic chuck and a composite grinding machine including the electromagnetic chuck.

従来、工作物に対して切削、及び研削等の加工を行なう場合、工作物を、爪などによって締め付ける一般的な機械的チャックによって固定するのではなく、工作物の形状、及び加工したい部位に応じて、電磁気による吸着力（磁気吸引力）を利用して、面板上に固定する技術が有る（特許文献１−２参照）。 Conventionally, when processing such as cutting and grinding is performed on a workpiece, the workpiece is not fixed by a general mechanical chuck that is tightened with a nail or the like, but according to the shape of the workpiece and the part to be processed. Thus, there is a technique of fixing on a face plate using an electromagnetic attraction (magnetic attraction) (see Patent Document 1-2).

特開昭５３−１１１５８４号公報JP-A-53-111584 特開昭５４−９０６７４号公報JP 54-90674 A

しかしながら、特許文献１−２に開示される技術では、工作物、及び工作物が固定される電磁チャックの面板の材質は、通常、ともに金属である。このため、接触する工作物の下面と面板の上面との間の摩擦係数は小さくなりやすい。従って、たとえば、工作物の研削中に、工作物を固定する吸着力（磁気吸引力）を超える大きな力が工作物に付与された場合、工作物が面板上で、初期位置からずれる虞が有る。これに対し、コイルに流す電流量を増加させる、又はコイルの巻数を増加させる等、によって工作物に対する吸着力を向上させ、工作物に対する保持力を向上させる対策が考えられる。しかし、コイルに流す電流量を増加させる場合には、発熱量が増加するという課題がある。また、コイルの巻数を増加させる場合には、電磁チャックの体格が大きくなってしまうという課題がある。 However, in the technique disclosed in Patent Literature 1-2, both the workpiece and the material of the face plate of the electromagnetic chuck to which the workpiece is fixed are usually metals. For this reason, the coefficient of friction between the lower surface of the workpiece to contact and the upper surface of the face plate tends to be small. Therefore, for example, when a large force exceeding the attraction force (magnetic attraction force) for fixing the workpiece is applied to the workpiece during grinding of the workpiece, the workpiece may be shifted from the initial position on the face plate. . On the other hand, it is conceivable to increase the amount of current flowing through the coil or increase the number of turns of the coil to improve the attracting force on the workpiece and improve the holding force on the workpiece. However, when increasing the amount of current flowing through the coil, there is a problem that the amount of heat generation increases. Further, when increasing the number of turns of the coil, there is a problem that the size of the electromagnetic chuck becomes large.

本発明は、このような事情に鑑みてなされたものであり、加工時において、十分な保持力によって工作物の固定が可能な小型の電磁チャック、及び電磁チャックを備えた複合研削盤を提供することを目的とする。 The present invention has been made in view of such circumstances, and provides a compact electromagnetic chuck capable of fixing a workpiece with a sufficient holding force during machining, and a composite grinding machine including the electromagnetic chuck. For the purpose.

上記課題を解決するため、請求項１の電磁チャックは、面板上面に所定方向に配列された複数の磁極部、及び隣り合う前記磁極部の間に形成された溝部を備え、前記磁極部の磁気力によって、前記磁極部の上面に工作物を吸着し固定する電磁チャック本体と、前記溝部に、深さ方向に移動可能に配置され、前記工作物が前記磁極部の上面に固定された場合、前記工作物の下面に対し、前記磁極部による前記工作物に対する吸着力よりも小さな力で前記工作物を吸着方向と反対方向である押圧方向に押圧する押圧部材と、前記押圧部材が前記工作物の前記下面を前記吸着力よりも前記小さな力で押圧するよう、前記押圧部材を前記押圧方向に付勢する付勢部材と、前記押圧部材を支持し、前記押圧部材を前記溝部の前記深さ方向に案内するとともに前記面板における前記溝部が延びる方向への前記押圧部材の移動を規制するガイド部材と、を備え、前記ガイド部材は、前記溝部に配置され、前記溝部が延びる方向に弾性変形可能な板ばねであるとともに、前記溝部が延びる方向における前記押圧部材の内側端部及び外側端部の少なくとも一方を前記電磁チャック本体に固定する。 In order to solve the above problem, an electromagnetic chuck according to claim 1 includes a plurality of magnetic pole portions arranged in a predetermined direction on the upper surface of the face plate and a groove portion formed between the adjacent magnetic pole portions, When the electromagnetic chuck main body that attracts and fixes the work piece on the upper surface of the magnetic pole part by force and the groove part is movably disposed in the depth direction, and the work piece is fixed on the upper surface of the magnetic pole part, A pressing member that presses the workpiece in a pressing direction that is opposite to the attracting direction with a force smaller than the attracting force of the magnetic pole portion against the workpiece against the lower surface of the workpiece, and the pressing member is the workpiece An urging member for urging the pressing member in the pressing direction so as to press the lower surface of the pressing member with a force smaller than the suction force; and supporting the pressing member; and pressing the pressing member with the depth of the groove portion. When guiding in the direction E Bei and a guide member for restricting the movement of the pressing member of the direction in which the groove extends in the plane plate, the guide member, the disposed in the groove, an elastically deformable plate spring in a direction in which the groove extends In addition, at least one of the inner end and the outer end of the pressing member in the direction in which the groove extends extends to the electromagnetic chuck body.

このように、面板上面に形成された溝部に、工作物の下面を押圧方向に押圧する押圧部材が配置される。押圧部材による工作物の下面への押圧は、付勢部材の押圧部材への付勢により行なわれる。このとき、押圧部材は、ガイド部材によって、溝部の深さ方向に案内されるとともに、面板における溝部が延びる方向への移動が規制される。このため、付勢部材によって押圧部材が押圧方向に付勢されても、押圧部材の側面が、溝部の側面に強く押し付けられる虞は低い。これにより、付勢部材による押圧部材の押圧方向への付勢力が、押圧部材の側面と溝部の側面との接触によって消費され低下する虞は低い。このため、押圧部材による工作物の下面への押圧によって、押圧部材の上面と工作物の下面との間の摩擦力は向上し、工作物への加工時においても工作物は面板上に良好に保持される。 Thus, the pressing member that presses the lower surface of the workpiece in the pressing direction is disposed in the groove formed on the upper surface of the face plate. The pressing to the lower surface of the workpiece by the pressing member is performed by urging the urging member to the pressing member. At this time, the pressing member is guided in the depth direction of the groove by the guide member, and movement in the direction in which the groove in the face plate extends is restricted. For this reason, even if the pressing member is urged in the pressing direction by the urging member, the possibility that the side surface of the pressing member is strongly pressed against the side surface of the groove portion is low. Thereby, the urging force of the urging member in the pressing direction of the pressing member is less likely to be consumed and reduced due to the contact between the side surface of the pressing member and the side surface of the groove. For this reason, the pressing force on the lower surface of the workpiece by the pressing member improves the frictional force between the upper surface of the pressing member and the lower surface of the workpiece, and the workpiece is satisfactorily placed on the face plate even when machining the workpiece. Retained.

また、上記課題を解決するため、請求項５の複合研削盤は、旋回軸線回りに旋回可能な旋回テーブルと、前記旋回テーブルにおける前記旋回軸線を中心とする円周上にそれぞれ設けられ、前記旋回軸線と平行な主軸線回りに回転可能な工作主軸を有する複数の主軸台と、複数の前記工作主軸に設けられ、それぞれ前記工作物の保持が可能な複数の保持装置と、前記旋回テーブルに対して相対移動可能にそれぞれ設けられ、前記旋回テーブルの旋回により前記工作物が順次搬送されることで、対応するそれぞれの研削旋回位置に前記工作物が位置決めされる場合に、対応する前記工作物を研削する複数の砥石と、を備え、前記保持装置は、上述の電磁チャックである。
また、上記課題を解決するため、請求項６の複合研削盤は、旋回軸線回りに旋回可能な旋回テーブルと、前記旋回テーブルにおける前記旋回軸線を中心とする円周上にそれぞれ設けられ、前記旋回軸線と平行な主軸線回りに回転可能な工作主軸を有する複数の主軸台と、複数の前記工作主軸に設けられ、それぞれ工作物の保持が可能な複数の保持装置と、前記旋回テーブルに対して相対移動可能にそれぞれ設けられ、前記旋回テーブルの旋回により前記工作物が順次搬送されることで、対応するそれぞれの研削旋回位置に前記工作物が位置決めされる場合に、対応する前記工作物を研削する複数の砥石と、を備え、前記保持装置は、面板上面に所定方向に配列された複数の磁極部、及び隣り合う前記磁極部の間に形成された溝部を備え、前記磁極部の磁気力によって、前記磁極部の上面に前記工作物を吸着し固定する電磁チャック本体と、前記溝部に、深さ方向に移動可能に配置され、前記工作物が前記磁極部の上面に固定された場合、前記工作物の下面に対し、前記磁極部による前記工作物に対する吸着力よりも小さな力で前記工作物を吸着方向と反対方向である押圧方向に押圧する押圧部材と、前記押圧部材が前記工作物の前記下面を前記吸着力よりも前記小さな力で押圧するよう、前記押圧部材を前記押圧方向に付勢する付勢部材と、前記押圧部材を支持し、前記押圧部材を前記溝部の前記深さ方向に案内するとともに前記面板における前記溝部が延びる方向への前記押圧部材の移動を規制するガイド部材と、を備える電磁チャックである。 In order to solve the above-mentioned problem, the composite grinding machine according to claim 5 is provided on a turning table capable of turning around a turning axis, and on a circumference around the turning axis in the turning table, and the turning A plurality of spindle stock having a work spindle that can rotate around a spindle parallel to the axis, a plurality of holding devices that are provided on the plurality of work spindles and can hold the workpiece, respectively, and the swivel table The workpieces are sequentially conveyed by turning of the turning table, and the workpieces are positioned at the corresponding grinding turning positions. A plurality of grindstones to be ground, and the holding device is the electromagnetic chuck described above.
In order to solve the above-mentioned problem, the composite grinding machine according to claim 6 is provided on a turning table capable of turning around a turning axis, and on a circumference centered on the turning axis of the turning table. A plurality of spindle stock having a work spindle that can rotate around a spindle parallel to the axis, a plurality of holding devices that are provided on the plurality of work spindles and each can hold a workpiece, and the swivel table Each of the workpieces is provided so as to be relatively movable, and when the workpiece is sequentially transferred by turning of the turning table, the corresponding workpiece is ground when the workpiece is positioned at the corresponding grinding turning position. A plurality of grindstones, and the holding device includes a plurality of magnetic pole portions arranged in a predetermined direction on the upper surface of the face plate, and a groove portion formed between the adjacent magnetic pole portions, An electromagnetic chuck main body that attracts and fixes the workpiece to the upper surface of the magnetic pole portion by the magnetic force of the pole portion, and the groove portion are arranged to be movable in the depth direction, and the workpiece is placed on the upper surface of the magnetic pole portion. A pressing member that, when fixed, presses the workpiece against the lower surface of the workpiece in a pressing direction that is opposite to the attracting direction with a force smaller than the attracting force of the magnetic pole on the workpiece; An urging member that urges the pressing member in the pressing direction so that the member presses the lower surface of the workpiece with the force smaller than the suction force, and the pressing member is supported, and the pressing member is And a guide member that guides the groove in the depth direction and restricts movement of the pressing member in a direction in which the groove in the face plate extends.

このように、工作物の研削が連続的に多数行なわれる複合研削盤の保持装置に上記電磁チャックを適用することによって、工作物は、加工中に面板上でズレることなく安定して研削できる。これにより、工作物の加工精度が向上する。 As described above, by applying the electromagnetic chuck to the holding device of the composite grinding machine in which a large number of workpieces are continuously ground, the workpiece can be stably ground without being displaced on the face plate during processing. Thereby, the machining accuracy of the workpiece is improved.

本実施形態に係る複合研削盤の全体構成を示す概略図である。It is the schematic which shows the whole structure of the composite grinding machine which concerns on this embodiment. 図１の複合研削盤が備える旋回テーブルの平面図である。It is a top view of the turning table with which the composite grinding machine of FIG. 1 is provided. 図２の旋回テーブルのＥ−Ｅ矢視断面図である。It is EE arrow sectional drawing of the turning table of FIG. 第一実施形態に係る電磁チャックの斜視図である。It is a perspective view of the electromagnetic chuck which concerns on 1st embodiment. 第一実施形態に係る電磁チャックの平面図である。It is a top view of the electromagnetic chuck which concerns on 1st embodiment. 工作物が固定された状態における図５の電磁チャックのＦ−Ｆ矢視断面図である。FIG. 6 is a cross-sectional view of the electromagnetic chuck of FIG. 5 taken along the line FF in a state where the workpiece is fixed. 工作物が固定された状態における図５の電磁チャックのＨ−Ｈ矢視断面図である。FIG. 6 is a cross-sectional view of the electromagnetic chuck of FIG. 5 taken along the line HH in a state where the workpiece is fixed. 複合研削盤の状態を説明する第一の図である。It is a 1st figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第二の図である。It is a 2nd figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第三の図である。It is a 3rd figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第四の図である。It is a 4th figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第五の図である。It is a 5th figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第六の図である。It is a 6th figure explaining the state of a compound grinder. 複合研削盤の状態を説明する第七の図である。It is a 7th figure explaining the state of a compound grinder. 工作物が固定されていない状態における図５の電磁チャックのＦ−Ｆ矢視断面図である。FIG. 6 is a cross-sectional view of the electromagnetic chuck of FIG. 5 taken along the line FF in a state where the workpiece is not fixed. 工作物が固定されていない状態における図５の電磁チャックのＨ−Ｈ矢視断面図である。FIG. 6 is a cross-sectional view taken along the line HH of the electromagnetic chuck in FIG. 5 in a state where the workpiece is not fixed. 図１０に相当する第二実施形態の断面図である。It is sectional drawing of 2nd embodiment corresponded to FIG.

＜第一実施形態＞
（１．複合研削盤の構成）
以下、本発明の第一実施形態に係る電磁チャックに相当する各保持装置６１，６２，６３，６４を、工作物Ｗであるベアリングの外輪Ｗａ及び内輪Ｗｂに対する複数種の研削を１台で行なう複合研削盤１に適用した場合について説明する。なお、図１においては、水平面で直交する方向をＸ軸線方向及びＹ軸線方向とし、Ｘ軸線方向及びＹ軸線方向に直交する方向をＺ軸線方向とする。図１に示すように、複合研削盤１は、ベッド２を備え、ベッド２上には、旋回テーブル５と、コラム３ａ，３ｂ，３ｃと、図略の駆動機構でＺ軸線方向と平行なＺｄ軸線回りに旋回可能な旋回アーム３ｄと、を備える。 <First embodiment>
(1. Configuration of composite grinding machine)
Hereinafter, each holding device 61, 62, 63, 64 corresponding to the electromagnetic chuck according to the first embodiment of the present invention performs a plurality of types of grinding on the outer ring Wa and the inner ring Wb of the bearing, which is the workpiece W, by one unit. The case where it applies to the composite grinding machine 1 is demonstrated. In FIG. 1, the direction orthogonal to the horizontal plane is defined as the X axis direction and the Y axis direction, and the direction orthogonal to the X axis direction and the Y axis direction is defined as the Z axis direction. As shown in FIG. 1, the composite grinding machine 1 includes a bed 2. On the bed 2, a swivel table 5, columns 3 a, 3 b, 3 c, and a Zd parallel to the Z-axis direction by an unillustrated drive mechanism. A swivel arm 3d that can swivel about an axis.

旋回テーブル５は、図３に示す駆動機構５１によって、Ｚ軸線方向と平行なＣ軸線（旋回軸線）回りに旋回可能に構成される。図１及び図２に示すように、旋回テーブル５には、４つの保持装置６１〜６４（電磁チャック、後に詳述する）が、Ｃ軸線を中心とする同一円周上に等角度間隔（９０度間隔）で設けられる。図３に示すように、各保持装置６１〜６４には、主軸台８１〜８４がそれぞれ取り付けられる（ただし、図３では、代表として保持装置６１及び主軸台８１のみ示す）。ここでは、各保持装置６１〜６４は、同一装置であり、主軸台８１〜８４も同一主軸台となっている。主軸台８１は、主軸本体８１１と、工作主軸８１２とを備える。工作主軸８１２は、主軸本体８１１に内蔵される図略の駆動機構でＣ軸線方向と平行なＧ軸線（主軸線）回りに回転可能に、主軸本体８１１の上端から突出するように設けられる。工作主軸８１２の上端には、保持装置（図３では保持装置６１を示す）が固定される。 The turning table 5 is configured to be turnable about a C axis (swivel axis) parallel to the Z axis direction by a drive mechanism 51 shown in FIG. As shown in FIGS. 1 and 2, the rotating table 5 includes four holding devices 61 to 64 (electromagnetic chucks, which will be described in detail later) at equal angular intervals (90 on the same circumference around the C axis. Degree intervals). As shown in FIG. 3, spindle stocks 81 to 84 are attached to the holding devices 61 to 64 (however, only the holding device 61 and the spindle stock 81 are shown as representatives in FIG. 3). Here, the holding devices 61 to 64 are the same device, and the headstocks 81 to 84 are also the same headstock. The headstock 81 includes a main spindle body 811 and a work spindle 812. The work spindle 812 is provided so as to protrude from the upper end of the spindle body 811 so as to be rotatable about a G axis (main axis) parallel to the C axis direction by a drive mechanism (not shown) built in the spindle body 811. A holding device (the holding device 61 is shown in FIG. 3) is fixed to the upper end of the work spindle 812.

各保持装置６１〜６４が配置される旋回テーブル５には、貫通穴５２がそれぞれ穿設される。そして、主軸台８１の主軸本体８１１が、各貫通穴５２に対応する旋回テーブル５の裏面に固定され、主軸台８１の工作主軸８１２が、各貫通穴５２に貫装される。各保持装置６１〜６４は、磁気力で外輪Ｗａ又は内輪Ｗｂ（工作物Ｗ）を吸引して面板の上面に保持し、工作主軸８１２とともにＧ軸線回りに回転する。 Through-holes 52 are formed in the turntable 5 on which the holding devices 61 to 64 are arranged. The spindle body 811 of the headstock 81 is fixed to the back surface of the turntable 5 corresponding to each through hole 52, and the work spindle 812 of the headstock 81 is inserted into each through hole 52. Each holding device 61 to 64 attracts the outer ring Wa or the inner ring Wb (workpiece W) by magnetic force and holds it on the upper surface of the face plate, and rotates around the G axis along with the work spindle 812.

外輪Ｗａ又は内輪Ｗｂは、図２の紙面上において左側に位置する保持装置（図２の状態では保持装置６１であるが、旋回テーブル５の旋回により入れ替わる。以下、同様である。）に搬入され、図２の紙面上において下側に位置する保持装置（図２の状態では保持装置６４であるが、旋回テーブル５の旋回により入れ替わる。以下、同様である。）から搬出される。外輪Ｗａ又は内輪Ｗｂの搬入及び搬出は、図略のロボットにより行われる。ロボットは、外輪Ｗａ又は内輪Ｗｂの中心軸線を保持装置６１の回転中心と一致させた状態で、外輪Ｗａ又は内輪Ｗｂを搬入可能に構成される。なお、外輪Ｗａ又は内輪Ｗｂの搬入及び搬出は、作業者により行なうようにしてもよく、その場合の上記中心位置合わせは、治具等を用いて行なう。 The outer ring Wa or the inner ring Wb is carried into a holding device (the holding device 61 in the state of FIG. 2 is replaced by turning of the turning table 5. The same applies hereinafter) located on the left side on the paper surface of FIG. 2 is carried out from the holding device (the holding device 64 in the state of FIG. 2 is replaced by turning of the turning table 5. The same applies hereinafter) located on the lower side on the paper surface of FIG. The outer ring Wa or the inner ring Wb is carried in and out by a robot (not shown). The robot is configured to be able to carry the outer ring Wa or the inner ring Wb in a state where the center axis of the outer ring Wa or the inner ring Wb is aligned with the rotation center of the holding device 61. The outer ring Wa or the inner ring Wb may be carried in and out by an operator, and the center alignment in that case is performed using a jig or the like.

詳細は後述するが、旋回テーブル５は、図２の時計回りに所定角度で旋回して外輪Ｗａ又は内輪Ｗｂを搬送する。そして、図２において、左側に位置する保持装置６１では、搬入される工作物Ｗが外輪Ｗａの場合には外周面研削が行われる。また、搬入される工作物Ｗが内輪Ｗｂの場合には内周面研削が行われる。上側に位置する保持装置６２では、外輪Ｗａの内周面に設けられる軌道溝ＷａＧに対する研削である外輪軌道溝面研削が行われる。 Although details will be described later, the turning table 5 turns at a predetermined angle clockwise in FIG. 2 to convey the outer ring Wa or the inner ring Wb. In FIG. 2, the holding device 61 located on the left side performs outer peripheral surface grinding when the workpiece W to be loaded is the outer ring Wa. Further, when the work W to be loaded is an inner ring Wb, inner peripheral surface grinding is performed. In the holding device 62 located on the upper side, outer ring raceway groove surface grinding, which is grinding with respect to the raceway groove WaG provided on the inner peripheral surface of the outer ring Wa, is performed.

また、右側に位置する保持装置６３では、内輪Ｗｂの外周面に設けられる軌道溝ＷｂＧに対する研削である内輪軌道溝面研削が行われる。そして、下側に位置する保持装置６４では、外輪Ｗａの内周面に設けられる軌道溝ＷａＧに対して行なわれる外輪軌道溝面超仕上げ研削、又は内輪Ｗｂの外周面に設けられる軌道溝ＷｂＧに対して行なわれる内輪軌道溝面超仕上げ研削が行われて搬出される。なお、以下の説明では、旋回テーブル５において上記左側の位置は、周面研削位置Ｐｐ、上記上側の位置は、外輪研削位置Ｐｏ、上記右側の位置は、内輪研削位置Ｐｉ、上記下側の位置は、超仕上げ研削位置Ｐｂという。 Further, in the holding device 63 located on the right side, inner ring raceway groove surface grinding that is grinding with respect to the raceway groove WbG provided on the outer peripheral surface of the inner ring Wb is performed. In the holding device 64 located on the lower side, the outer ring raceway groove surface superfinishing performed on the raceway groove WaG provided on the inner peripheral surface of the outer ring Wa, or the raceway groove WbG provided on the outer peripheral surface of the inner ring Wb. On the other hand, the inner ring raceway groove surface super-finish grinding is carried out and carried out. In the following description, in the turning table 5, the left position is the peripheral grinding position Pp, the upper position is the outer ring grinding position Po, the right position is the inner ring grinding position Pi, and the lower position. Is referred to as a superfinishing grinding position Pb.

コラム３ａ，３ｂ，３ｃは、駆動機構（図１にコラム３ａの駆動機構３Ａのみ示す）によって、Ｘ軸線方向と平行なＸａ軸線方向、Ｘｂ軸線方向、Ｘｃ軸線方向にそれぞれ往復移動（進退）可能に構成される。図１に示すように、各コラム３ａ，３ｂ，３ｃの側面には、駆動機構４１ａ，４１ｂ，４１ｃによって、Ｚ軸線方向と平行なＺａ軸線方向、Ｚｂ軸線方向、Ｚｃ軸線方向にそれぞれ昇降（進退）可能な砥石台４ａ，４ｂ，４ｃをそれぞれ備える。各砥石台４ａ，４ｂ，４ｃは、駆動機構９１ａ，９１ｂ，９１ｃによって、Ｚａ軸線（砥石軸線）回り、Ｚｂ軸線（砥石軸線）回り、Ｚｃ軸線（砥石軸線）回りにそれぞれ回転駆動可能なロータリー型の砥石車９ａ，９ｂ，９ｃをそれぞれ備える。各砥石車９ａ，９ｂ，９ｃは、下方に延びる保持軸９２ａ，９２ｂ，９２ｃの下端にそれぞれ保持される。 The columns 3a, 3b, 3c can be reciprocated (advanced / retracted) in the Xa axis direction, the Xb axis direction, and the Xc axis direction parallel to the X axis direction by a driving mechanism (only the driving mechanism 3A of the column 3a is shown in FIG. 1). Configured. As shown in FIG. 1, the side surfaces of the columns 3a, 3b, 3c are moved up and down (advanced / retracted) by drive mechanisms 41a, 41b, 41c in the Za axis direction, Zb axis direction, and Zc axis direction parallel to the Z axis direction, respectively. ) Possible grindstone stands 4a, 4b, 4c are provided. Each of the grinding wheel bases 4a, 4b, 4c is a rotary type that can be driven to rotate around the Za axis (grinding wheel axis), the Zb axis (grinding wheel axis), and the Zc axis (grinding wheel axis) by drive mechanisms 91a, 91b, 91c, respectively. Grinding wheels 9a, 9b, 9c. Each grinding wheel 9a, 9b, 9c is held at the lower end of a holding shaft 92a, 92b, 92c extending downward.

各砥石車９ａ，９ｂ，９ｃが、周面研削位置Ｐｐ、外輪研削位置Ｐｏ、内輪研削位置Ｐｉに対しそれぞれ進退可能となるように、各コラム３ａ，３ｂ，３ｃは、ベッド２上に配置される。砥石車９ａは、外輪Ｗａの外周面研削、又は内輪Ｗｂの内周面研削を行なうため、例えばＣＢＮ（ＣｕｂｉｃＢｏｒｏｎＮｉｔｒｉｄｅ）砥石が用いられる。また、砥石車９ｂ，９ｃは、外輪Ｗａの外輪軌道溝面研削（内周面）、内輪Ｗｂの内輪軌道溝面研削（外周面）を行なうため、例えばアルミナ砥石が用いられる。 The columns 3a, 3b, 3c are arranged on the bed 2 so that the grinding wheels 9a, 9b, 9c can advance and retreat with respect to the circumferential grinding position Pp, the outer ring grinding position Po, and the inner ring grinding position Pi, respectively. The For the grinding wheel 9a, for example, a CBN (Cubic Boron Nitride) grinding wheel is used for grinding the outer peripheral surface of the outer ring Wa or the inner peripheral surface of the inner ring Wb. The grinding wheels 9b and 9c use, for example, an alumina grindstone for grinding the outer ring raceway groove surface (inner peripheral surface) of the outer ring Wa and inner ring raceway surface grinding (outer peripheral surface) of the inner ring Wb.

旋回アーム３ｄは、図略の駆動機構でＺ軸線方向と平行なＺｅ軸線方向に昇降可能且つＺｅ軸線（砥石軸線）回りに回転可能な単石型の砥石９ｄを備える。砥石９ｄは、旋回アーム３ｄの先端から下方に延びる保持軸９２ｄの下端部の外周面に砥石９ｄの研削部がＺｅ軸線に直角な方向を向くように保持される。砥石９ｄは、外輪Ｗａの内周面の外輪軌道面超仕上げ研削又は内輪Ｗｂの外周面の内輪軌道面超仕上げ研削を行うため、例えばＣＢＮ砥石が用いられる。なお、単石型の砥石９ｄに代えて、ロータリー型の砥石車でもよい。 The swivel arm 3d includes a monolithic grindstone 9d that can be moved up and down in the Ze axis direction parallel to the Z axis direction by a drive mechanism (not shown) and that can rotate about the Ze axis (grinding stone axis line). The grindstone 9d is held on the outer peripheral surface of the lower end portion of the holding shaft 92d extending downward from the tip of the turning arm 3d so that the grinding portion of the grindstone 9d faces a direction perpendicular to the Ze axis. For the grindstone 9d, for example, a CBN grindstone is used in order to perform the outer ring raceway surface super-finish grinding on the inner circumferential surface of the outer ring Wa or the inner ring raceway surface super-finish grinding on the outer circumferential surface of the inner ring Wb. Note that a rotary grinding wheel may be used instead of the single stone grinding wheel 9d.

（２．電磁チャック）
次に、本発明に係る電磁チャックである各保持装置６１〜６４について、図４〜図７に基づき説明する。図４〜図７に示すように、保持装置６１〜６４は、それぞれ電磁チャック本体１７０、押圧部材１８０、複数のバネ１８３（付勢部材に相当する）、及び二個のガイド部材１９０，１９１を備える。なお、保持装置６１〜６４は、電磁コイル等も備えるが、公知であるので、その構成、及び作動についての詳細な説明は省略する。また、図４には、一部の押圧部材１８０、及びガイド部材１９０，１９１のみ図示してある。 (2. Electromagnetic chuck)
Next, each holding device 61 to 64 that is an electromagnetic chuck according to the present invention will be described with reference to FIGS. As shown in FIGS. 4 to 7, the holding devices 61 to 64 each include an electromagnetic chuck main body 170, a pressing member 180, a plurality of springs 183 (corresponding to a biasing member), and two guide members 190 and 191. Prepare. Although the holding devices 61 to 64 include electromagnetic coils and the like, since they are well-known, detailed description of the configuration and operation thereof will be omitted. FIG. 4 shows only a part of the pressing members 180 and the guide members 190 and 191.

電磁チャック本体１７０は、例えば鉄系の磁性材料によって、底部である円形の面板１７１を上側にして有底筒状に形成される。図４，図５に示すように、面板１７１の上面は、磁極部１７２と、溝部１７３とを備える。磁極部１７２は、面板１７１上で、面板１７１の周方向（所定方向に相当）に複数配列される。本実施形態では、扇状に形成された８個（複数に相当）の磁極部１７２が、面板１７１のＧ軸線（主軸線）回りで周方向に等間隔に配列される。８個の磁極部１７２の上面高さは全て同一である。なお、以降、磁極部１７２の上面を保持面１７２ａと称す。８個の磁極部１７２は、磁化されると、周方向にＳ極、Ｎ極が順に形成される（図５参照）。また、溝部１７３は、面板１７１の周方向に配列された隣り合う磁極部１７２の間の凹部によって、面板１７１の径方向に延びるよう形成される。 The electromagnetic chuck main body 170 is formed in a bottomed cylindrical shape, for example, with an iron-based magnetic material with a circular face plate 171 as a bottom portion facing upward. As shown in FIGS. 4 and 5, the upper surface of the face plate 171 includes a magnetic pole part 172 and a groove part 173. A plurality of magnetic pole portions 172 are arranged on the face plate 171 in the circumferential direction of the face plate 171 (corresponding to a predetermined direction). In the present embodiment, eight (corresponding to plural) magnetic pole portions 172 formed in a fan shape are arranged at equal intervals around the G axis (main axis) of the face plate 171 in the circumferential direction. The top surface heights of the eight magnetic pole portions 172 are all the same. Hereinafter, the upper surface of the magnetic pole portion 172 is referred to as a holding surface 172a. When the eight magnetic pole portions 172 are magnetized, an S pole and an N pole are sequentially formed in the circumferential direction (see FIG. 5). Further, the groove portion 173 is formed so as to extend in the radial direction of the face plate 171 by a recess between adjacent magnetic pole portions 172 arranged in the circumferential direction of the face plate 171.

図５に示すように、溝部１７３の幅は、面板１７１の中心（Ｇ軸線）から外周に向かって拡幅するよう形成される。なお、この態様に限らず、溝部１７３の幅は、面板１７１の中心（Ｇ軸線）から外周に向かって平行であってもよい。また、溝部１７３の幅は、面板１７１の中心（Ｇ軸線）から外周に向かって縮幅するよう形成されてもよい。また、磁極部１７２及び溝部１７３の数は、８個未満でもよいし、８個を超えて設けてもよい。 As shown in FIG. 5, the width of the groove 173 is formed so as to increase from the center (G axis) of the face plate 171 toward the outer periphery. The width of the groove 173 may be parallel from the center (G axis) of the face plate 171 toward the outer periphery. The width of the groove 173 may be formed so as to be reduced from the center (G axis) of the face plate 171 toward the outer periphery. Further, the number of the magnetic pole portions 172 and the groove portions 173 may be less than 8 or more than 8.

図６に示すように、溝部１７３は、側面１７３ａ，１７３ａ、及び底面１７３ｂを備える。前述したように、溝部１７３は、磁極部１７２の側面に沿って、面板１７１の中心（Ｇ軸線）から外周に向かって拡幅し、且つ面板１７１上において放射状に形成される。また、図７に示すように、溝部１７３は、面板１７１の中心から径方向外方に向かう全長に亘って、磁極部１７２の上面から底面１７３ｂまでの距離（深さ）が一定に形成される。溝部１７３に囲まれた部分は空間であるので、非磁性領域である。 As shown in FIG. 6, the groove 173 includes side surfaces 173a and 173a and a bottom surface 173b. As described above, the groove portion 173 is widened from the center (G axis) of the face plate 171 toward the outer periphery along the side surface of the magnetic pole portion 172, and is formed radially on the face plate 171. Further, as shown in FIG. 7, the groove 173 has a constant distance (depth) from the top surface to the bottom surface 173b of the magnetic pole portion 172 over the entire length from the center of the face plate 171 to the radially outward direction. . Since the portion surrounded by the groove 173 is a space, it is a nonmagnetic region.

図７に示すように、電磁チャック本体１７０が備える溝部１７３の底面１７３ｂには、六面体形状を呈する内側固定部１７４、及び外側固定部１７５が底面１７３ｂに固定されている。このとき、固定の方法は問わないが、本実施形態では、内側固定部１７４、及び外側固定部１７５の下面にそれぞれ凸部を突設し、各凸部を底面１７３ｂに設けた各嵌合孔に圧入している。内側固定部１７４は、面板１７１の径方向内側で中心近傍の底面１７３ｂ上に固定される。外側固定部１７５は、面板１７１の径方向外側の底面１７３ｂ上に固定される。内側固定部１７４、及び外側固定部１７５の上面からは、めねじ１７４ａ，１７５ａが内部に向って形成される。 As shown in FIG. 7, on the bottom surface 173b of the groove 173 provided in the electromagnetic chuck main body 170, an inner fixing portion 174 and an outer fixing portion 175 having a hexahedral shape are fixed to the bottom surface 173b. At this time, the fixing method is not limited, but in the present embodiment, each of the fitting holes is provided with protrusions on the lower surfaces of the inner fixing portion 174 and the outer fixing portion 175, and each protrusion is provided on the bottom surface 173b. It is press-fitted into. The inner fixing portion 174 is fixed on the bottom surface 173 b near the center on the radially inner side of the face plate 171. The outer fixing portion 175 is fixed on the bottom surface 173 b on the outer side in the radial direction of the face plate 171. From the upper surfaces of the inner fixing portion 174 and the outer fixing portion 175, female screws 174a and 175a are formed inward.

押圧部材１８０は、非磁性体で形成される。また、押圧部材１８０は、面板１７１の径方向（溝部１７３が延びる方向に相当）に延在して形成され、溝部１７３内において、内側固定部１７４と外側固定部１７５との間に配置される。なお、以降の説明において、特別な説明なく径方向といった場合、面板１７１における径方向のことをいうものとする。押圧部材１８０は、隣り合う各磁極部１７２の間にそれぞれ形成される各溝部１７３の形状に合わせて形成されて各溝部１７３に嵌合される。 The pressing member 180 is made of a nonmagnetic material. The pressing member 180 is formed to extend in the radial direction of the face plate 171 (corresponding to the direction in which the groove portion 173 extends), and is disposed between the inner fixing portion 174 and the outer fixing portion 175 in the groove portion 173. . In the following description, the term “radial direction” refers to the radial direction of the face plate 171 without any special explanation. The pressing member 180 is formed in accordance with the shape of each groove portion 173 formed between each adjacent magnetic pole portion 172 and is fitted into each groove portion 173.

図６，図７に示すように、押圧部材１８０は、最表面部材１８１と、支持体１８２と、を備える。支持体１８２は、支持体本体１８２ａと、各ガイド部材１９０，１９１とそれぞれ連結されるための内側端部１８２ｂ、及び外側端部１８２ｃと、を備える（図７参照）。内側端部１８２ｂ、及び外側端部１８２ｃは、支持体本体１８２ａの径方向両側からそれぞれ径方向外方又は径方向内方に突出して形成される。支持体本体１８２ａの上面と、内側端部１８２ｂ，及び外側端部１８２ｃの各上面とは相互に平行である。内側端部１８２ｂ、及び外側端部１８２ｃの上面から下面にかけては、ともに、めねじが貫通して形成される。 As shown in FIGS. 6 and 7, the pressing member 180 includes an outermost surface member 181 and a support body 182. The support 182 includes a support body 182a, an inner end 182b and an outer end 182c to be connected to the guide members 190 and 191, respectively (see FIG. 7). The inner end portion 182b and the outer end portion 182c are formed so as to project radially outward or radially inward from both radial sides of the support body 182a, respectively. The upper surface of the support body 182a and the upper surfaces of the inner end portion 182b and the outer end portion 182c are parallel to each other. Both the inner end portion 182b and the outer end portion 182c are formed so as to penetrate from the upper surface to the lower surface.

内側端部１８２ｂ及び外側端部１８２ｃの上面は、最表面部材１８１の上面よりも溝部１７３の底面１７３ｂ側の低い位置に設けられる。なお、図６に示すように、面板１７１の周方向において、溝部１７３の両側面１７３ａ、１７３ａと、各側面１７３ａ、１７３ａに対向する押圧部材１８０の各側面１８０ｄ，１８０ｅとの間には、所定の隙間ｔを備えている。所定の隙間ｔは、押圧部材１８０が溝部１７３の深さ方向（図６における上下方向）に移動する際、側面１８０ｄ，１８０ｅが、溝部１７３の側面１７３ａ，１７３ａと接触せずに移動可能となるよう設けられる。 The upper surfaces of the inner end portion 182b and the outer end portion 182c are provided at lower positions on the bottom surface 173b side of the groove portion 173 than the upper surface of the outermost surface member 181. As shown in FIG. 6, in the circumferential direction of the face plate 171, there is a predetermined gap between the side surfaces 173a and 173a of the groove 173 and the side surfaces 180d and 180e of the pressing member 180 facing the side surfaces 173a and 173a. The gap t is provided. When the pressing member 180 moves in the depth direction of the groove portion 173 (vertical direction in FIG. 6), the predetermined gap t becomes movable without the side surfaces 180d and 180e coming into contact with the side surfaces 173a and 173a of the groove portion 173. It is provided as follows.

押圧部材１８０は、工作物Ｗが、磁気力によって磁極部１７２の保持面１７２ａに吸着されて固定された場合、工作物Ｗの下面に対して、磁極部１７２の磁化による工作物Ｗに対する吸着力Ｆｍａｇ（磁気吸引力）よりも小さな押圧力Ｆｇで工作物Ｗを吸着方向と反対方向（押圧方向）に押圧する（Ｆｍａｇ＞Ｆｇ）。そのため、図６，図７に示すように、押圧部材１８０の下面と、溝部１７３の底面１７３ｂとの間にＮ個（本実施形態では５個）のバネ１８３（付勢部材）を備える。押圧部材１８０は、圧縮された各バネ１８３の各反力の総和によって工作物Ｗを吸着方向と反対方向（押圧方向）に押圧する。つまり、押圧力Ｆｇは、一個のバネ１８３の押圧力ｆｇ×Ｎ個に等しい（Ｆｇ＝ｆｇ×Ｎ）。本実施形態においては、図５，図７に示すように、バネ１８３は、面板１７１の中心から径方向外方に向って、例えば、５個配置されている。 When the workpiece W is attracted and fixed to the holding surface 172a of the magnetic pole portion 172 by magnetic force, the pressing member 180 attracts the workpiece W with respect to the lower surface of the workpiece W due to magnetization of the magnetic pole portion 172. The workpiece W is pressed in the direction opposite to the attracting direction (pressing direction) with a pressing force Fg smaller than Fmag (magnetic attractive force) (Fmag> Fg). Therefore, as shown in FIGS. 6 and 7, N (five in this embodiment) springs 183 (biasing members) are provided between the lower surface of the pressing member 180 and the bottom surface 173 b of the groove portion 173. The pressing member 180 presses the workpiece W in the direction opposite to the suction direction (pressing direction) by the sum of the reaction forces of the compressed springs 183. That is, the pressing force Fg is equal to the pressing force fg × N of one spring 183 (Fg = fg × N). In the present embodiment, as shown in FIGS. 5 and 7, for example, five springs 183 are arranged from the center of the face plate 171 toward the radially outer side.

最表面部材１８１は、支持体本体１８２ａの上面に設けられる。最表面部材１８１は、非磁性体で形成され、上面が工作物Ｗの下面に当接する。最表面部材１８１は、例えば、エポキシ樹脂に所定の粒径の砥粒を混ぜ込んで形成される。詳細には、最表面部材１８１は、最表面部材１８１の上面と工作物Ｗの下面との間の摩擦係数μ２が、磁極部１７２の保持面１７２ａと工作物Ｗの下面との間の摩擦係数μ１より大きな高摩擦材によって形成される（μ１＜μ２）。ただし、この態様には限らず、μ１≧μ２でもよい。これによっても、最表面部材１８１が工作物Ｗの下面と当接しない場合と比較すれば、当接面積が増えた分だけ、工作物Ｗの下面と保持装置６１，６２，６３，６４の上面との間の摩擦力は向上するので、本発明に係る効果についても、相応に得ることができる。 The outermost surface member 181 is provided on the upper surface of the support body 182a. The outermost surface member 181 is formed of a nonmagnetic material, and the upper surface is in contact with the lower surface of the workpiece W. For example, the outermost surface member 181 is formed by mixing abrasive grains having a predetermined particle diameter with epoxy resin. Specifically, the outermost surface member 181 has a friction coefficient μ2 between the upper surface of the outermost surface member 181 and the lower surface of the workpiece W, and the friction coefficient between the holding surface 172a of the magnetic pole portion 172 and the lower surface of the workpiece W. It is formed of a high friction material larger than μ1 (μ1 <μ2). However, it is not limited to this aspect, and μ1 ≧ μ2 may be satisfied. Also by this, compared with the case where the outermost surface member 181 does not contact the lower surface of the workpiece W, the lower surface of the workpiece W and the upper surfaces of the holding devices 61, 62, 63, 64 are increased by the increased contact area. Therefore, the effects according to the present invention can be obtained accordingly.

支持体１８２は、例えば、ＳＵＳ３０４、ＳＵＳ３１６等の非磁性体で形成される。支持体１８２は、最表面部材１８１と、バネ１８３との間に介在される。支持体１８２は、最表面部材１８１より、硬度が高い高硬度材料により形成される。このように配置されることで、最表面部材１８１とバネ１８３との直接の当接を回避し、バネ１８３による最表面部材１８１の摩耗を効果的に防止できる。ただし、この態様には限らず、支持体１８２の硬度が、最表面部材１８１の硬度以下でもよい。 The support 182 is formed of a nonmagnetic material such as SUS304 or SUS316, for example. The support body 182 is interposed between the outermost surface member 181 and the spring 183. The support body 182 is formed of a high hardness material having higher hardness than the outermost surface member 181. By arranging in this way, direct contact between the outermost surface member 181 and the spring 183 can be avoided, and wear of the outermost surface member 181 by the spring 183 can be effectively prevented. However, the present invention is not limited to this, and the hardness of the support 182 may be equal to or less than the hardness of the outermost surface member 181.

また、支持体１８２の材質は、ＳＵＳ３０４、ＳＵＳ３１６等の金属に限らず樹脂によって形成してもよい。このとき、支持体１８２の硬度は、最表面部材１８１の硬度より高いほうが好ましい。しかし、上述したとおり、支持体１８２の硬度が、最表面部材１８１の硬度以下でもよい。なお、押圧部材１８０が溝部１７３内で深さ方向にスムーズに移動可能であれば、押圧部材１８０の側面１８０ｄ，１８０ｅのうち一方の側面と対向する溝部１７３の側面１７３ａとの間は若干、接触していてもよい。 The material of the support 182 is not limited to a metal such as SUS304 or SUS316, and may be formed of a resin. At this time, the hardness of the support 182 is preferably higher than the hardness of the outermost surface member 181. However, as described above, the hardness of the support 182 may be equal to or less than the hardness of the outermost surface member 181. If the pressing member 180 can move smoothly in the depth direction within the groove 173, there is a slight contact between the side surface 173a of the groove 173 that faces one of the side surfaces 180d and 180e of the pressing member 180. You may do it.

バネ１８３（付勢部材）は、例えば、ＳＵＳ３０４、ＳＵＳ３１６等の非磁性体で形成される。本実施形態では、バネ１８３は、ウェーブワッシャを含む複数（Ｎ個）の板バネである。前述したように、バネ１８３は、支持体１８２と底面１７３ｂとの間に、必要な個数（Ｎ個）だけ配置される。そして、工作物Ｗが、磁気力によって磁極部１７２の保持面１７２ａに吸着され固定された際に、最表面部材１８１が、工作物Ｗの下面に当接し、その下面に向かって所望の押圧力Ｆｇ（＝ｆｇ×Ｎ）で付勢する。なお、本実施形態では、一例として、バネ１８３は、支持体１８２と底面１７３ｂとの間に、それぞれ５個ずつ配置される。 The spring 183 (biasing member) is formed of a nonmagnetic material such as SUS304 or SUS316, for example. In the present embodiment, the spring 183 is a plurality (N) of leaf springs including wave washers. As described above, the necessary number (N) of the springs 183 is disposed between the support 182 and the bottom surface 173b. When the workpiece W is attracted and fixed to the holding surface 172a of the magnetic pole portion 172 by magnetic force, the outermost surface member 181 contacts the lower surface of the workpiece W, and a desired pressing force is applied toward the lower surface. Energize with Fg (= fg × N). In the present embodiment, as an example, five springs 183 are arranged between the support 182 and the bottom surface 173b.

ガイド部材１９０，１９１は、例えば、ＳＫ材（ＪＩＳＧ４８０２）によって形成され、同じ形状を有する。図５、図７、図１０に示すように、ガイド部材１９０，１９１は、厚みの薄い直方体形状で形成された薄板状部材である。そして、ガイド部材１９０，１９１は、長手方向が、面板１７１の径方向（溝部１７３が延びる方向）に延在するよう配置される。ガイド部材１９０，１９１は、延在する長手方向に所定の大きさの引張り力を付与されると、弾性変形域内において弾性変形が可能な板ばねである。なお、本発明では、ガイド部材１９０，１９１は、延在方向において、弾性変形域内で使用される。ガイド部材１９０，１９１の長手方向両端部には、それぞれ後述するボルトＢ１〜Ｂ４の軸部を挿通するための貫通孔が設けられる。 The guide members 190 and 191 are made of, for example, SK material (JIS G 4802) and have the same shape. As shown in FIGS. 5, 7, and 10, the guide members 190 and 191 are thin plate-like members formed in a thin rectangular parallelepiped shape. The guide members 190 and 191 are arranged such that the longitudinal direction extends in the radial direction of the face plate 171 (the direction in which the groove 173 extends). The guide members 190 and 191 are leaf springs that can be elastically deformed in an elastic deformation region when a predetermined tensile force is applied in the extending longitudinal direction. In the present invention, the guide members 190 and 191 are used in the elastic deformation region in the extending direction. At both ends in the longitudinal direction of the guide members 190 and 191, through holes for inserting shaft portions of bolts B <b> 1 to B <b> 4 described later are provided.

ガイド部材１９０は、押圧部材１８０に設けられた内側端部１８２ｂと溝部１７３に設けられた内側固定部１７４と、をボルトＢ１，Ｂ２により連結されて押圧部材１８０を支持する。また、ガイド部材１９１は、押圧部材１８０に設けられた外側端部１８２ｃと溝部１７３に設けられた外側固定部１７５と、をボルトＢ３，Ｂ４により連結して押圧部材１８０を支持する。このとき、図１０に示すように、工作物Ｗが、磁極部１７２の保持面１７２ａに、磁気力によって吸着されていない場合には、押圧部材１８０は、自由長状態のバネ１８３の上端部に載置される状態となる。このような状態で、ガイド部材１９０，１９１は、ガイド部材１９０，１９１の平面部が、溝部１７３の底面１７３ｂと平行になるよう内側端部１８２ｂ，内側固定部１７４，外側端部１８２ｃ、及び外側固定部１７５に、ボルトＢ１〜Ｂ４によって固定される。 The guide member 190 supports the pressing member 180 by connecting the inner end portion 182b provided in the pressing member 180 and the inner fixing portion 174 provided in the groove portion 173 by bolts B1 and B2. Further, the guide member 191 supports the pressing member 180 by connecting the outer end portion 182c provided on the pressing member 180 and the outer fixing portion 175 provided on the groove portion 173 by bolts B3 and B4. At this time, as shown in FIG. 10, when the workpiece W is not attracted to the holding surface 172 a of the magnetic pole portion 172 by magnetic force, the pressing member 180 is placed on the upper end portion of the free-length spring 183. It will be in the state to be mounted. In such a state, the guide members 190 and 191 have an inner end 182b, an inner fixing portion 174, an outer end 182c, and an outer end so that the flat portion of the guide members 190 and 191 is parallel to the bottom surface 173b of the groove 173. It is fixed to the fixing portion 175 with bolts B1 to B4.

このように、押圧部材１８０の内側端部１８２ｂ、及び外側端部１８２ｃと、電磁チャック本体１７０の固定された内側固定部１７４、及び外側固定部１７５とが、ガイド部材１９０，１９１を介して連結固定される。これにより、ガイド部材１９０，１９１は、押圧部材１８０を径方向（溝部１７３が延びる方向）両側から支持し、溝部１７３の深さ方向に案内するとともに、面板１７１における周方向（磁極部１７２の配列方向）、及び径方向への押圧部材１８０の移動を良好に規制する。 As described above, the inner end portion 182b and the outer end portion 182c of the pressing member 180 and the inner fixing portion 174 and the outer fixing portion 175 to which the electromagnetic chuck main body 170 is fixed are connected via the guide members 190 and 191. Fixed. Accordingly, the guide members 190 and 191 support the pressing member 180 from both sides in the radial direction (direction in which the groove portion 173 extends), guide the pressure member 180 in the depth direction of the groove portion 173, and the circumferential direction (arrangement of the magnetic pole portions 172) in the face plate 171. Direction) and the movement of the pressing member 180 in the radial direction are well regulated.

このように構成された電磁チャック（保持装置６１，６２，６３，６４）は、電磁チャック本体１７０内の磁極用鋼材（図略）に巻いたコイル（図略）に通電されることによって磁極部１７２が磁化される。これにより、押圧部材１８０の最表面部材１８１上に載置された工作物Ｗを、保持面１７２ａ上に磁気力で吸引し、工作物Ｗの下面と磁極部１７２の保持面１７２ａとを密着固定する（図６，図７参照）。このとき、押圧部材１８０（最表面部材１８１）は、工作物Ｗの下面に押し込まれ、溝部１７３内に収容される。 The electromagnetic chuck (holding devices 61, 62, 63, 64) configured as described above is energized by a coil (not shown) wound around a magnetic pole steel material (not shown) in the electromagnetic chuck body 170. 172 is magnetized. As a result, the workpiece W placed on the outermost surface member 181 of the pressing member 180 is attracted to the holding surface 172a by magnetic force, and the lower surface of the workpiece W and the holding surface 172a of the magnetic pole portion 172 are closely fixed. (See FIGS. 6 and 7). At this time, the pressing member 180 (outermost surface member 181) is pressed into the lower surface of the workpiece W and is accommodated in the groove 173.

図１に示すように、複合研削盤１は、制御装置３０を備えており、制御装置３０の機能的構成として、コラム３ａ，３ｂ，３ｃの送りの制御、砥石台４ａ，４ｂ，４ｃの昇降の制御、旋回テーブル５の旋回の制御、主軸台８１〜８４の回転と保持装置６１〜６４の吸引の制御、砥石車９ａ，９ｂ，９ｃの回転の制御、旋回アーム３ｄの旋回と砥石９ｄの回転及び昇降の制御、及びデータやプログラムの記録等を行なう。制御装置３０は、予め設定された制御データに基づき、各装置を制御することで、複数の研削工程を実施する。 As shown in FIG. 1, the composite grinding machine 1 includes a control device 30. As a functional configuration of the control device 30, the feed control of the columns 3 a, 3 b, 3 c and the raising / lowering of the grinding wheel platforms 4 a, 4 b, 4 c , Turning control of the turning table 5, rotation of the headstocks 81 to 84 and suction of the holding devices 61 to 64, control of rotation of the grinding wheels 9a, 9b, 9c, turning of the turning arm 3d and turning of the grinding wheel 9d Controls rotation and elevation, and records data and programs. The control device 30 implements a plurality of grinding steps by controlling each device based on preset control data.

（３．複合研削盤の作動）
次に、複数種類の工作物Ｗの研削としてベアリングの外輪Ｗａの外周面研削、外輪軌道面研削、外輪軌道面超仕上げ研削、及び内輪Ｗｂの内周面研削、内輪軌道面研削、及び内輪軌道面超仕上げ研削を行なう複合研削盤１の動作を図２及び図８Ａ〜図８Ｇを参照して説明する。ここで、複合研削盤１では、保持装置６１が周面研削位置Ｐｐに位置決めされている状態（図２、図８Ａに示す状態）を初期状態とし、この時の旋回テーブル５の旋回位置を基準位置の０度とする。 (3. Operation of composite grinding machine)
Next, the outer peripheral surface grinding of the outer ring Wa of the bearing, the outer ring raceway surface grinding, the outer ring raceway surface superfinishing grinding, and the inner peripheral surface grinding of the inner ring Wb, the inner ring raceway surface grinding, and the inner ring raceway are ground as a plurality of types of workpieces W. The operation of the composite grinding machine 1 that performs surface superfinish grinding will be described with reference to FIGS. 2 and 8A to 8G. Here, in the composite grinding machine 1, the state in which the holding device 61 is positioned at the circumferential grinding position Pp (the state shown in FIGS. 2 and 8A) is set as an initial state, and the turning position of the turning table 5 at this time is used as a reference. The position is 0 degree.

先ず、制御装置３０は、最初の外輪Ｗａａを磁気による吸着力（磁気吸引力）によって保持装置６１の磁極部１７２の保持面１７２ａに吸引固定する（図８Ａ参照）。そして、制御装置３０は、外周面研削プログラムに基づき外輪Ｗａａの外周面研削を制御する（図８Ａ参照）。 First, the control device 30 sucks and fixes the first outer ring Waa to the holding surface 172a of the magnetic pole portion 172 of the holding device 61 by magnetic attraction (magnetic attraction) (see FIG. 8A). Then, the control device 30 controls the outer peripheral surface grinding of the outer ring Waa based on the outer peripheral surface grinding program (see FIG. 8A).

このとき、外輪Ｗａａの外周面を研削するため、砥石車９ａを外輪Ｗａａの外周面に押し付ける。これにより、外輪Ｗａａは、砥石車９ａとの接点において、法線方向、及び接線方向に大きな研削抵抗を受ける。保持装置６１は、外輪Ｗａａが、砥石車９ａから、このような大きな研削抵抗を受けても、面板（保持面１７２ａ）上で移動しないよう固定する必要がある。本発明は、このような場合に、外輪Ｗａａが面板上で移動しないよう、保持装置６１に大きな固定力（吸着力）を発生させることを目的とする。また、外輪Ｗａの内周面、及び各軌道溝面に対する各研削、又は内輪Ｗｂの外周面、内周面、及び各軌道溝面に対する各研削においても、外輪Ｗａ又は内輪Ｗｂは、上記と同様に各砥石から大きな研削抵抗を受ける。そこで、このような研削抵抗を受けても、外輪Ｗａ又は内輪Ｗｂが、保持装置６１〜６４の面板上（保持面１７２ａ）で移動しないよう十分な固定力（吸着力）を保持装置６１〜６４に発生させることを目的とする。なお、本発明に係る磁気の吸着力による外輪Ｗａ又は内輪Ｗｂの保持装置６１〜６４への固定の詳細については、後に詳述する。 At this time, in order to grind the outer peripheral surface of the outer ring Waa, the grinding wheel 9a is pressed against the outer peripheral surface of the outer ring Waa. As a result, the outer ring Waa receives a large grinding resistance in the normal direction and the tangential direction at the contact point with the grinding wheel 9a. The holding device 61 needs to be fixed so that the outer ring Waa does not move on the face plate (holding surface 172a) even if it receives such a large grinding resistance from the grinding wheel 9a. An object of the present invention is to generate a large fixing force (adsorption force) in the holding device 61 so that the outer ring Waa does not move on the face plate in such a case. The outer ring Wa or the inner ring Wb is also the same as described above in each grinding on the inner circumferential surface of the outer ring Wa and each raceway groove surface, or in each grinding on the outer circumferential surface, inner circumference surface, and each raceway groove surface of the inner ring Wb. Each wheel receives a large grinding resistance. Therefore, the holding devices 61 to 64 have a sufficient fixing force (adsorption force) so that the outer ring Wa or the inner ring Wb does not move on the face plate (holding surface 172a) of the holding devices 61 to 64 even when receiving such grinding resistance. The purpose is to generate. The details of fixing the outer ring Wa or the inner ring Wb to the holding devices 61 to 64 by the magnetic attractive force according to the present invention will be described in detail later.

次に、制御装置３０は、外輪Ｗａａの外周面研削が完了したら、旋回テーブル５を９０度旋回させる（図８Ｂ参照）。これにより、保持装置６１は、外輪研削位置Ｐｏに位置決めされ、保持装置６４は、周面研削位置Ｐｐに位置決めされることになる。そして、制御装置３０は、最初の内輪Ｗｂａを保持装置６４に取り付ける（図８Ｃ図参照）。このときにも、保持装置６１における外輪Ｗａａと同様、内輪Ｗｂａは、保持装置６４の磁極部１７２の保持面１７２ａに磁気による吸着力（磁気吸引力）によって固定される。 Next, when the outer peripheral surface grinding of the outer ring Waa is completed, the control device 30 turns the turning table 5 by 90 degrees (see FIG. 8B). Thereby, the holding device 61 is positioned at the outer ring grinding position Po, and the holding device 64 is positioned at the circumferential surface grinding position Pp. Then, the control device 30 attaches the first inner ring Wba to the holding device 64 (see FIG. 8C). Also at this time, like the outer ring Waa in the holding device 61, the inner ring Wba is fixed to the holding surface 172a of the magnetic pole portion 172 of the holding device 64 by a magnetic attraction force (magnetic attraction force).

そして、制御装置３０は、内周面研削プログラムに基づき内輪Ｗｂａの内周面研削を制御するとともに、外輪軌道溝面研削プログラムに基づき外輪Ｗａａの外輪軌道溝面研削を制御する（図８Ｃ参照）。これらの制御は、平行して行われる。なお、以降においても、保持装置６２、６３に対して、外輪Ｗａ又は内輪Ｗｂは、保持装置６４の磁極部１７２の保持面１７２ａに磁気による吸着力によって固定される。 Then, the control device 30 controls the inner peripheral surface grinding of the inner ring Wba based on the inner peripheral surface grinding program and also controls the outer ring raceway groove surface grinding of the outer ring Waa based on the outer ring raceway groove surface grinding program (see FIG. 8C). . These controls are performed in parallel. In the following, the outer ring Wa or the inner ring Wb is fixed to the holding surface 172a of the magnetic pole portion 172 of the holding device 64 by the magnetic attraction force with respect to the holding devices 62 and 63.

次に、制御装置３０は、内輪Ｗｂａの内周面研削、及び外輪Ｗａａの外輪軌道溝面研削が完了したら、旋回テーブル５を１８０度旋回させる（図８Ｄ参照）。これにより、保持装置６１は、超仕上げ研削位置Ｐｂに位置決めされる。保持装置６４は、内輪研削位置Ｐｉに位置決めされ、保持装置６２は、周面研削位置Ｐｐに位置決めされる。また、保持装置６３は、外輪Ｗａ及び内輪Ｗｂが吸着されていない空の状態で外輪研削位置Ｐｏに位置決めされる。 Next, when the inner peripheral surface grinding of the inner ring Wba and the outer ring raceway groove surface grinding of the outer ring Waa are completed, the control device 30 turns the turning table 5 by 180 degrees (see FIG. 8D). Thereby, the holding device 61 is positioned at the superfinishing grinding position Pb. The holding device 64 is positioned at the inner ring grinding position Pi, and the holding device 62 is positioned at the circumferential surface grinding position Pp. The holding device 63 is positioned at the outer ring grinding position Po in an empty state in which the outer ring Wa and the inner ring Wb are not attracted.

次に、制御装置３０は、磁気力によって次の外輪Ｗａｂを保持装置６２に固定する（図８Ｅ参照）。そして、制御装置３０は、外周面研削プログラムに基づき外輪Ｗａｂの外周面研削を制御する。また、制御装置３０は、内輪軌道溝面研削プログラムに基づき内輪Ｗｂａの内輪軌道溝面研削を制御する。さらに、制御装置３０は、外輪超仕上げ研削プログラムに基づき外輪Ｗａａの外輪軌道溝面超仕上げ研削を制御する（図８Ｅ参照）。これらの制御は、平行して行われる。 Next, the control device 30 fixes the next outer ring Wab to the holding device 62 by magnetic force (see FIG. 8E). And the control apparatus 30 controls the outer peripheral surface grinding of the outer ring Wab based on an outer peripheral surface grinding program. Further, the control device 30 controls the inner ring raceway surface grinding of the inner ring Wba based on the inner ring raceway surface grinding program. Furthermore, the control device 30 controls the outer ring raceway surface superfinishing grinding of the outer ring Waa based on the outer ring superfinishing grinding program (see FIG. 8E). These controls are performed in parallel.

次に、制御装置３０は、外輪Ｗａａの外輪超仕上げ研削を完了後、砥石９ｄを待機位置へ退避させる。そして、制御装置３０は、保持装置６１の磁気吸着力を解除し、外輪Ｗａａを保持装置６１から取り出す（図８Ｅ参照）。 Next, the control device 30 retracts the grindstone 9d to the standby position after completing the outer ring super-finish grinding of the outer ring Waa. Then, the control device 30 releases the magnetic attraction force of the holding device 61 and takes out the outer ring Waa from the holding device 61 (see FIG. 8E).

次に、制御装置３０は、外輪Ｗａａの外周面研削、及び内輪Ｗｂａの内輪軌道溝面研削が完了したら、旋回テーブル５を９０度旋回させる（図８Ｆ参照）。これにより、保持装置６１は、周面研削位置Ｐｐに位置決めされ、保持装置６２は、外輪研削位置Ｐｏに位置決めされ、保持装置６４は、超仕上げ研削位置Ｐｂに位置決めされる。そして、保持装置６３は、外輪Ｗａ及び内輪Ｗｂが吸着されていない空の状態で内輪研削位置Ｐｉに位置決めされることになる。 Next, when the outer peripheral surface grinding of the outer ring Waa and the inner ring raceway surface grinding of the inner ring Wba are completed, the control device 30 turns the turning table 5 by 90 degrees (see FIG. 8F). As a result, the holding device 61 is positioned at the circumferential grinding position Pp, the holding device 62 is positioned at the outer ring grinding position Po, and the holding device 64 is positioned at the superfinishing grinding position Pb. The holding device 63 is positioned at the inner ring grinding position Pi in an empty state in which the outer ring Wa and the inner ring Wb are not attracted.

制御装置３０は、次の内輪Ｗｂｂを保持装置６１に磁気力によって固定する（図８Ｇ参照）。そして、制御装置３０は、内周面研削プログラムに基づき内輪Ｗｂｂの内周面研削を制御する。また、制御装置３０は、外輪軌道溝面研削プログラムに基づき外輪Ｗａｂの外輪軌道溝面研削（内周面）を制御する。さらに、制御装置３０は、内輪軌道溝面超仕上げ研削プログラムに基づき内輪Ｗｂａの内輪軌道溝面超仕上げ研削（外周面）を制御する（図８Ｇ参照）。これらの制御は、平行に行われる。 The control device 30 fixes the next inner ring Wbb to the holding device 61 by magnetic force (see FIG. 8G). Then, control device 30 controls inner peripheral surface grinding of inner ring Wbb based on the inner peripheral surface grinding program. Further, the control device 30 controls the outer ring raceway groove surface grinding (inner peripheral surface) of the outer ring Wab based on the outer ring raceway groove surface grinding program. Furthermore, the control device 30 controls the inner ring raceway groove surface superfinish grinding (outer peripheral surface) of the inner ring Wba based on the inner ring raceway groove surface superfinishing grinding program (see FIG. 8G). These controls are performed in parallel.

次に、制御装置３０は、内輪Ｗｂａの内輪超仕上げ加工の完了後、砥石９ｄを待機位置へ退避させる。そして、制御装置３０は、保持装置６４の磁気吸着力を解除し、内輪Ｗｂａを保持装置６４から取り出す（図８Ｇ参照）。 Next, after completing the inner ring superfinishing of the inner ring Wba, the control device 30 retracts the grindstone 9d to the standby position. And the control apparatus 30 cancels | releases the magnetic attraction force of the holding | maintenance apparatus 64, and takes out the inner ring | wheel Wba from the holding | maintenance apparatus 64 (refer FIG. 8G).

（４．電磁チャックの作用）
次に、保持装置６１〜６４（電磁チャック）の作用について詳細に説明する。説明には、代表として、外輪Ｗａａを磁気による吸着力（磁気吸引力）によって保持装置６１（電磁チャック）の磁極部１７２の保持面１７２ａに吸引固定する場合について説明する。 (4. Action of electromagnetic chuck)
Next, the operation of the holding devices 61 to 64 (electromagnetic chuck) will be described in detail. As a representative, a case will be described in which the outer ring Waa is attracted and fixed to the holding surface 172a of the magnetic pole portion 172 of the holding device 61 (electromagnetic chuck) by magnetic attraction (magnetic attraction).

まず、外輪Ｗａａが、磁極部１７２の保持面１７２ａに載置されていない状態について説明する。外輪Ｗａａが磁極部１７２の保持面１７２ａ上に載置されていない状態において、押圧部材１８０を構成する最表面部材１８１及び支持体１８２と，バネ１８３（付勢部材）と、ガイド部材１９０，１９１とは、溝部１７３内において図９，図１０に示す状態で配置される。本実施形態においては、バネ１８３は、一つの溝部１７３に、例えば５個ずつ配置される（図５，図１０参照）。これにより、最表面部材１８１は、溝部１７３の開口から上方へ若干、突出（図９，図１０の寸法Ｌ参照）する。これは、バネ１８３が、圧縮されておらず自由高さ（自由長）状態であることによる。このときの溝部１７３の開口から突出する寸法は、例えば数十μｍ〜数百μｍオーダーである。ただし、この態様には限らず、溝部１７３の開口から突出する寸法Ｌは、工作物Ｗが保持装置６１の保持面１７２ａに吸着されたときに、押圧部材１８０が、溝部１７３内に完全に収容可能であれば、いくつでもよく任意に設定すればよい。 First, a state where the outer ring Waa is not placed on the holding surface 172a of the magnetic pole portion 172 will be described. In a state where the outer ring Waa is not placed on the holding surface 172a of the magnetic pole portion 172, the outermost surface member 181 and the support 182 that constitute the pressing member 180, the spring 183 (biasing member), and the guide members 190 and 191 Is arranged in the state shown in FIGS. 9 and 10 in the groove 173. In the present embodiment, for example, five springs 183 are arranged in one groove 173 (see FIGS. 5 and 10). Thereby, the outermost surface member 181 slightly protrudes upward from the opening of the groove 173 (see the dimension L in FIGS. 9 and 10). This is because the spring 183 is not compressed and is in a free height (free length) state. At this time, the dimension protruding from the opening of the groove 173 is, for example, on the order of several tens μm to several hundreds μm. However, the dimension L protruding from the opening of the groove portion 173 is not limited to this mode. The dimension L protruding from the opening of the groove portion 173 is that the pressing member 180 is completely accommodated in the groove portion 173 when the workpiece W is attracted to the holding surface 172a of the holding device 61. Any number can be set arbitrarily if possible.

このとき、ガイド部材１９０，１９１の上面（平面）は、図１０に示すように、溝部１７３の底面１７３ｂとほぼ平行である。つまり、ガイド部材１９０，１９１は、曲げ応力も、延在方向への引張り応力も発生していない自由長状態である。 At this time, the upper surfaces (planes) of the guide members 190 and 191 are substantially parallel to the bottom surface 173b of the groove 173, as shown in FIG. That is, the guide members 190 and 191 are in a free length state in which neither bending stress nor tensile stress in the extending direction is generated.

次に、磁極用鋼材（図略）に巻いたコイル（図略）に通電することによって磁極部１７２を磁化する。これにより、各磁極部１７２の保持面１７２ａに外輪Ｗａａの底面が磁気力によって吸引され、外輪Ｗａａの下面が各保持面１７２ａ上に密着固定される（図６，図７参照）。 Next, the magnetic pole portion 172 is magnetized by energizing a coil (not shown) wound around the steel for a magnetic pole (not shown). As a result, the bottom surface of the outer ring Waa is attracted by the magnetic force to the holding surface 172a of each magnetic pole portion 172, and the lower surface of the outer ring Waa is tightly fixed on each holding surface 172a (see FIGS. 6 and 7).

このように、磁気力によって吸着され、外輪Ｗａａの下面が磁極部１７２の保持面１７２ａ上に固定された場合、外輪Ｗａａの下面が、吸着力が発生する前には溝部１７３の開口から上方へ突出していた最表面部材１８１の上面を下方に押圧して移動させる。そして、最表面部材１８１の上面と保持面１７２ａと、が同一面高さとなる。これに伴い、支持体１８２の下面に当接するバネ１８３（付勢部材）の上端部が、最表面部材１８１，支持体１８２を介して下方に押され、圧縮方向に所定の撓み量δ（＝Ｌ）だけ撓む。このとき、一個のバネ１８３のバネ定数をｋとすると、バネ１８３の１個あたりの押圧力ｆｇは、ｆｇ＝ｋδとなる。これにより、全部でＮ個配置されるバネ１８３は、撓みの反力としての押圧力Ｆｇ（＝ｆｇ×Ｎ）で、外輪Ｗａａを吸着方向と反対方向に押圧する。 As described above, when the outer ring Waa is attracted by the magnetic force and the lower surface of the outer ring Waa is fixed on the holding surface 172a of the magnetic pole portion 172, the lower surface of the outer ring Waa is moved upward from the opening of the groove 173 before the adsorption force is generated. The upper surface of the projecting outermost surface member 181 is pressed downward and moved. The upper surface of the outermost member 181 and the holding surface 172a have the same height. Along with this, the upper end portion of the spring 183 (biasing member) that contacts the lower surface of the support 182 is pushed downward via the outermost surface member 181 and the support 182, and a predetermined deflection amount δ (= L) Deflection only. At this time, if the spring constant of one spring 183 is k, the pressing force fg per spring 183 is fg = kδ. Thereby, the N springs 183 arranged in total press the outer ring Waa in the direction opposite to the suction direction with a pressing force Fg (= fg × N) as a reaction force of bending.

このとき、押圧部材１８０は、図７に示すように、径方向両側に固定されたガイド部材１９０，１９１の作用によって、径方向両側から均等な力を受けながら溝部１７３の底面１７３ｂの方向に移動する。これに伴い、ガイド部材１９０，１９１は、図７に示すように弾性域内において均等に曲げ変形されるとともに、弾性域内において、延在方向に均等に伸長し、引張り応力Ｐを発生させる。ガイド部材１９０，１９１のこのような均等な変形によって、押圧部材１８０は、溝部１７３の深さ方向にバランスよく案内されながら溝部１７３の底面１７３ｂの方向に向って安定して移動する。また、このような状態においては、押圧部材１８０は、ガイド部材１９０，１９１によって、径方向及び周方向の移動も規制される。言い換えると、押圧部材１８０は、両端からのガイド部材１９０，１９１の作用によって、深さ方向（押圧方向）を移動する間、底面１７３ｂと平行な平面上における位置が良好に規制される。 At this time, as shown in FIG. 7, the pressing member 180 moves in the direction of the bottom surface 173b of the groove 173 while receiving an equal force from both sides in the radial direction by the action of the guide members 190 and 191 fixed on both sides in the radial direction. To do. Accordingly, the guide members 190 and 191 are bent and deformed evenly in the elastic region as shown in FIG. 7, and are uniformly extended in the extending direction in the elastic region to generate a tensile stress P. By such uniform deformation of the guide members 190 and 191, the pressing member 180 stably moves in the direction of the bottom surface 173 b of the groove portion 173 while being guided in a balanced manner in the depth direction of the groove portion 173. Further, in such a state, the pressing member 180 is also restricted from moving in the radial direction and the circumferential direction by the guide members 190 and 191. In other words, the position of the pressing member 180 on the plane parallel to the bottom surface 173b is well regulated while moving in the depth direction (pressing direction) by the action of the guide members 190 and 191 from both ends.

このため、押圧部材１８０の側面１８０ｄ，１８０ｅが、底面１７３ｂと平行な平面上において大きく移動し、溝部１７３の側面１７３ａ，１７３ａと強く当接して、複数のバネ１８３による押圧部材１８０の上方への押圧力Ｆｇを減少させる虞はない。これにより、押圧部材１８０の最表面部材１８１が、外輪Ｗａａの下面を押圧力Ｆｇで押圧し、外輪Ｗａａの下面と最表面部材１８１との間の摩擦力を増加させて、外輪Ｗａａを良好に保持する。 For this reason, the side surfaces 180d and 180e of the pressing member 180 greatly move on a plane parallel to the bottom surface 173b, strongly contact with the side surfaces 173a and 173a of the groove portion 173, and the pressing members 180 by the plurality of springs 183 are moved upward. There is no risk of reducing the pressing force Fg. Thereby, the outermost surface member 181 of the pressing member 180 presses the lower surface of the outer ring Waa with the pressing force Fg, and the frictional force between the lower surface of the outer ring Waa and the outermost surface member 181 is increased, so that the outer ring Waa is improved. Hold.

なお、上述したガイド部材１９０，１９１の曲げ変形及び伸び変形の反力によって、押圧部材１８０が、ガイド部材１９０，１９１から押圧方向に付勢される場合もある。この場合には、バネ１８３による押圧力Ｆｇ（＝ｆｇ×Ｎ）に対し、ガイド部材１９０，１９１による押圧力も考慮に入れて演算すればよい。ただし、説明が複雑になるので、以降においては、上述したガイド部材１９０，１９１の変形により発生する反力に基づく押圧力は、考慮に入れずに説明する。 In addition, the pressing member 180 may be urged in the pressing direction from the guide members 190 and 191 due to the reaction force of the bending deformation and the extension deformation of the guide members 190 and 191 described above. In this case, the calculation may be performed in consideration of the pressing force by the guide members 190 and 191 with respect to the pressing force Fg (= fg × N) by the spring 183. However, since the description is complicated, hereinafter, the pressing force based on the reaction force generated by the deformation of the guide members 190 and 191 described above will be described without taking into consideration.

上記において、押圧力Ｆｇは、磁極部１７２の磁化による外輪Ｗａａ（工作物Ｗ）に対する吸着力Ｆｍａｇよりも小さな押圧力となるよう設定されている（Ｆｍａｇ＞Ｆｇ）。このため、押圧部材１８０（最表面部材１８１、支持体１８２、及びバネ１８３）は、磁気力による外輪Ｗａａの保持面１７２ａ上への固定によって、最表面部材１８１が外輪Ｗａａの下面と当接し、溝部１７３の内部に確実に押し込まれ収容される。 In the above, the pressing force Fg is set to be a pressing force smaller than the attractive force Fmag to the outer ring Waa (workpiece W) due to the magnetization of the magnetic pole portion 172 (Fmag> Fg). For this reason, the pressing member 180 (the outermost surface member 181, the support 182, and the spring 183) is brought into contact with the lower surface of the outer ring Waa by fixing the outer ring Waa onto the holding surface 172 a by magnetic force. The groove portion 173 is securely pushed into and accommodated inside the groove portion 173.

上記より、外輪Ｗａａ（工作物Ｗ）と保持装置６１との間の摩擦力Ｆは、（数１）式によって求められる。
（数１）
Ｆ＝μ１×（Ｆｍａｇ−Ｎ×ｆｇ）＋μ２×Ｎ×ｆｇ
Ｆ；外輪Ｗａａ（工作物Ｗ）と保持装置６１との間の摩擦力
μ１；各磁極部１７２の８個の保持面１７２ａ（上面）と外輪Ｗａａの下面との間の摩擦係数
Ｆｍａｇ；磁極部１７２の磁化による外輪Ｗａａに対する吸着力
μ２；８個の最表面部材１８１と外輪Ｗａａの下面との間の摩擦係数
Ｎ；バネ１８３の総個数
ｆｇ；バネ１８３の一個あたりの押圧力（バネ荷重）（ｆｇ＝ｋδ） From the above, the frictional force F between the outer ring Waa (workpiece W) and the holding device 61 is obtained by the equation (1).
(Equation 1)
F = μ1 × (Fmag−N × fg) + μ2 × N × fg
F: Friction force between the outer ring Waa (workpiece W) and the holding device 61 μ1; Friction coefficient between the eight holding surfaces 172a (upper surface) of each magnetic pole portion 172 and the lower surface of the outer ring Waa Fmag: Magnetic pole portion Adsorption force μ2 on the outer ring Waa due to magnetization of 172; friction coefficient between the eight outermost surface members 181 and the lower surface of the outer ring Waa N; total number of springs 183 fg; pressing force per one spring 183 (spring load) (Fg = kδ)

上記（数１）式からわかるように、吸着力Ｆｍａｇが変化した場合には、バネ１８３の総個数Ｎを変更する、若しくはバネ１８３の１個あたりの押圧力ｆｇ（バネ荷重）を構成するバネ定数ｋ、または撓み量δの少なくとも一方を変更することによって、対応すればよい。そして、摩擦力Ｆが所定の値以上となるよう、各数値を設定する。なお、摩擦力Ｆの所定の値は、事前に実験等によって設定すればよい。 As can be seen from the above equation (1), when the attractive force Fmag changes, the total number N of the springs 183 is changed, or the springs constituting the pressing force fg (spring load) per one spring 183 What is necessary is just to respond | correspond by changing at least one of the constant k or bending amount (delta). Each numerical value is set so that the frictional force F is equal to or greater than a predetermined value. In addition, what is necessary is just to set the predetermined value of the frictional force F by experiment etc. beforehand.

上記より、保持装置６１だけでなく、保持装置６１と同様の構成を有する保持装置６２〜６４においても、外輪Ｗａａ（工作物Ｗ）又は内輪Ｗｂａ（工作物Ｗ）が、保持装置６１〜６４の各磁極部１７２の各保持面１７２ａに十分な摩擦力Ｆによって強固に固定される。これにより、工作物Ｗは、初期に保持装置６１〜６４の上面に配置された位置からずれないので、精度よく各研削ができる。 From the above, not only the holding device 61 but also the holding devices 62 to 64 having the same configuration as the holding device 61, the outer ring Waa (workpiece W) or the inner ring Wba (workpiece W) is the same as the holding devices 61 to 64. It is firmly fixed to each holding surface 172a of each magnetic pole portion 172 by a sufficient frictional force F. Thereby, since the workpiece W does not shift | deviate from the position initially arrange | positioned on the upper surface of the holding | maintenance apparatuses 61-64, each grinding | polishing can be performed accurately.

（５．実施形態による効果）
上述の説明から明らかなように、上記第一実施形態の保持装置６１〜６４（電磁チャック）によれば、円形の面板１７１上面に、所定方向（周方向）に配列された複数の磁極部１７２、及び隣り合う磁極部１７２の間に形成された溝部１７３を備え、磁極部１７２の磁気力によって、磁極部１７２の上面に工作物Ｗ，Ｗａ，Ｗｂを吸着し固定する電磁チャック本体１７０と、溝部１７３に、深さ方向に移動可能に配置され、工作物Ｗが磁極部１７２の上面に固定された場合、工作物Ｗの下面に対し、磁極部１７２による工作物Ｗに対する吸着力よりも小さな力で工作物Ｗを吸着方向と反対方向である押圧方向に押圧する押圧部材１８０と、押圧部材１８０が工作物Ｗの下面を吸着力よりも小さな力で押圧するよう、押圧部材１８０を押圧方向に付勢する付勢部材１８３と、押圧部材１８０を支持し、押圧部材１８０を溝部１７３の深さ方向に案内するとともに面板１７１における径方向（溝部１７３が延びる方向）への押圧部材１８０の移動を規制するガイド部材１９０，１９１と、を備える。 (5. Effect by embodiment)
As is clear from the above description, according to the holding devices 61 to 64 (electromagnetic chucks) of the first embodiment, a plurality of magnetic pole portions 172 arranged in a predetermined direction (circumferential direction) on the upper surface of the circular face plate 171. And an electromagnetic chuck main body 170 that includes a groove portion 173 formed between adjacent magnetic pole portions 172, and attracts and fixes the workpieces W, Wa, Wb on the upper surface of the magnetic pole portion 172 by the magnetic force of the magnetic pole portion 172, and When the workpiece W is disposed in the groove portion 173 so as to be movable in the depth direction and the workpiece W is fixed to the upper surface of the magnetic pole portion 172, the lower surface of the workpiece W is smaller than the attracting force of the magnetic pole portion 172 to the workpiece W. The pressing member 180 that presses the workpiece W in the pressing direction opposite to the suction direction with force, and the pressing member 180 in the pressing direction so that the pressing member 180 presses the lower surface of the workpiece W with a force smaller than the suction force. The urging member 183 for urging and the pressing member 180 are supported, the pressing member 180 is guided in the depth direction of the groove portion 173, and the pressing member 180 is moved in the radial direction (direction in which the groove portion 173 extends) in the face plate 171. And guide members 190 and 191 to be regulated.

このように、面板１７１の上面に形成された溝部１７３に、工作物Ｗの下面を押圧方向に押圧する押圧部材１８０が配置される。押圧部材１８０による工作物Ｗの下面への押圧は、押圧部材１８０へのバネ１８３（付勢部材）の付勢により行なわれる。このとき、押圧部材１８０は、ガイド部材１９０，１９１によって支持され、溝部１７３の深さ方向に案内されるとともに、面板１７１における径方向への移動が規制される。このため、押圧部材１８０を溝部１７３に配置する際、押圧部材１８０の側面１８０ｄ，１８０ｅが、溝部１７３の側面１７３ａ，１７３ａに、強く接触しないよう配置すれば、バネ１８３（付勢部材）によって押圧部材１８０が押圧方向に付勢された場合にも、押圧部材１８０の側面１８０ｄ，１８０ｅが、溝部１７３の側面１７３ａ，１７３ａに強く押し付けられる虞は低い。 Thus, the pressing member 180 that presses the lower surface of the workpiece W in the pressing direction is disposed in the groove portion 173 formed on the upper surface of the face plate 171. The pressing member 180 presses the lower surface of the workpiece W by urging a spring 183 (urging member) to the pressing member 180. At this time, the pressing member 180 is supported by the guide members 190 and 191, guided in the depth direction of the groove portion 173, and movement of the face plate 171 in the radial direction is restricted. For this reason, when the pressing member 180 is disposed in the groove portion 173, if the side surfaces 180d and 180e of the pressing member 180 are disposed so as not to come into strong contact with the side surfaces 173a and 173a of the groove portion 173, the pressing member 180 is pressed by the spring 183 (biasing member). Even when the member 180 is urged in the pressing direction, the possibility that the side surfaces 180d and 180e of the pressing member 180 are strongly pressed against the side surfaces 173a and 173a of the groove 173 is low.

これにより、バネ１８３（付勢部材）による押圧部材１８０の押圧方向への押圧力Ｆｇ（＝ｆｇ×Ｎ）が、押圧部材１８０の側面１８０ｄ，１８０ｅと溝部１７３の側面１７３ａ，１７３ａとの接触によって消費され低下する虞は低い。従って、工作物Ｗの下面と、保持装置６１〜６４（電磁チャック）の面板１７１との間の摩擦力に加え、工作物Ｗの下面と押圧部材１８０との間の摩擦力が追加されるので、研削加工時においても工作物Ｗは面板１７１上に良好に保持される。 Thereby, the pressing force Fg (= fg × N) in the pressing direction of the pressing member 180 by the spring 183 (biasing member) is caused by the contact between the side surfaces 180d and 180e of the pressing member 180 and the side surfaces 173a and 173a of the groove portion 173. There is a low risk of consumption and decline. Therefore, in addition to the frictional force between the lower surface of the workpiece W and the face plate 171 of the holding devices 61 to 64 (electromagnetic chuck), the frictional force between the lower surface of the workpiece W and the pressing member 180 is added. Even during grinding, the workpiece W is satisfactorily held on the face plate 171.

また、上記実施形態によれば、ガイド部材１９０，１９１は、押圧部材１８０の、面板１７１における周方向（磁極部１７２が配列される方向）への移動を規制する。これにより、押圧部材１８０の上面と工作物Ｗの下面とが周方向に相対移動し、表面を相互に摩耗させる虞はない。 Further, according to the embodiment, the guide members 190 and 191 restrict the movement of the pressing member 180 in the circumferential direction (direction in which the magnetic pole portions 172 are arranged) on the face plate 171. Thereby, the upper surface of the pressing member 180 and the lower surface of the workpiece W are relatively moved in the circumferential direction, and there is no possibility that the surfaces are worn away from each other.

また、上記実施形態によれば、押圧部材１８０は、径方向（溝部１７３が延びる方向）に延在して形成され、ガイド部材１９０，１９１は、押圧部材１８０の径方向における内側の内側端部１８２ｂ及び外側の外側端部１８２ｃで押圧部材１８０を電磁チャック本体１７０に固定する。これにより、押圧部材１８０の下面と溝部１７３の底面１７３ｂとの間には、バネ１８３（付勢部材）を配置するスペースを大きく確保できる。従って、バネ１８３による押圧部材１８０を押圧する押圧力の調整幅を広く取ることができ汎用性が向上する。 Further, according to the embodiment, the pressing member 180 is formed to extend in the radial direction (the direction in which the groove portion 173 extends), and the guide members 190 and 191 are the inner end portions on the inner side in the radial direction of the pressing member 180. The pressing member 180 is fixed to the electromagnetic chuck main body 170 by the outer end 182c and the outer end 182c. Thereby, a large space for arranging the spring 183 (biasing member) can be secured between the lower surface of the pressing member 180 and the bottom surface 173b of the groove portion 173. Therefore, the adjustment range of the pressing force for pressing the pressing member 180 by the spring 183 can be widened, and versatility is improved.

また、上記実施形態によれば、ガイド部材１９０，１９１は、径方向（溝部１７３が延びる方向）に延在し、延在する方向に弾性変形可能な板ばねである。これにより、押圧部材１８０の径方向両端で、押圧部材１８０を支持できるので、保持面１７２ａの径方向中央では、ガイド部材１９０，１９１の存在によって磁気力に影響を及ぼされる虞は少ないので、良好に工作物Ｗを吸着できる。 Further, according to the embodiment, the guide members 190 and 191 are leaf springs that extend in the radial direction (the direction in which the groove 173 extends) and can be elastically deformed in the extending direction. Thereby, since the pressing member 180 can be supported at both ends in the radial direction of the pressing member 180, the presence of the guide members 190 and 191 is less likely to affect the magnetic force at the radial center of the holding surface 172a. The workpiece W can be adsorbed on the surface.

また、上記実施形態によれば、板ばねのガイド部材１９０，１９１は、押圧部材１８０と工作物Ｗとの接触面より溝部１７３の底面１７３ｂ側に上面が形成される。これにより、保持面１７２ａから上に突出する部材を排除しやすいので、工作物Ｗと保持面１７２ａから突出する部材とが干渉する虞がない。 Further, according to the above embodiment, the upper surfaces of the guide members 190 and 191 of the leaf spring are formed on the bottom surface 173b side of the groove portion 173 from the contact surface between the pressing member 180 and the workpiece W. Accordingly, since the member protruding upward from the holding surface 172a can be easily removed, there is no possibility that the workpiece W and the member protruding from the holding surface 172a interfere with each other.

また、上記実施形態によれば、複合研削盤１は、旋回軸線回りに旋回可能な旋回テーブル５と、旋回テーブル５における旋回軸線を中心とする円周上にそれぞれ設けられ、旋回軸線と平行な主軸線回りに回転可能な工作主軸８１２〜８４２（工作主軸８２２，８３２、８４２は図示しない）を有する複数の主軸台８１〜８４と、工作主軸８１２〜８４２に設けられ、それぞれ工作物Ｗの保持が可能な複数の保持装置６１〜６４と、旋回テーブル５に対して相対移動可能にそれぞれ設けられ、旋回テーブル５の旋回により工作物Ｗが順次搬送されることで、対応するそれぞれの研削旋回位置に工作物Ｗが位置決めされる場合に、対応する工作物Ｗを研削する複数の砥石と、を備え、保持装置６１〜６４は、上述の電磁チャックである。 Further, according to the above embodiment, the composite grinding machine 1 is provided on the turning table 5 that can turn around the turning axis, and on the circumference around the turning axis in the turning table 5, and is parallel to the turning axis. A plurality of spindle stocks 81 to 84 having work spindles 812 to 842 (work spindles 822, 832, and 842 are not shown) rotatable around the spindle and work spindles 812 to 842, respectively, for holding the workpiece W Can be moved relative to the swivel table 5, and the workpieces W are sequentially conveyed by the swivel of the swivel table 5. A plurality of grindstones for grinding the corresponding workpiece W when the workpiece W is positioned, and the holding devices 61 to 64 are the above-described electromagnetic chucks.

このように、ベアリングの内輪及び外輪の研削が連続的に多数行なわれる複合研削盤１の保持装置６１〜６４に本発明に係る電磁チャックを適用することによって、Ｘ−Ｙ軸平面で研削抵抗を受ける工作物Ｗは、加工中に面板１７１上でズレることなく安定して研削できる。これにより、内輪Ｗｂ及び外輪Ｗａは、加工精度が向上する。また、工作物Ｗとして、加工精度が必要な複数の部品（組合わせて製品となる部品）を同時加工する場合には、加工効率も向上する（工作物Ｗとして、ボールベアリング，プレーンベアリングなどのベアリング、その他の組合せ製品等を適用した場合）。 In this way, by applying the electromagnetic chuck according to the present invention to the holding devices 61 to 64 of the composite grinding machine 1 in which a large number of grindings of the inner ring and outer ring of the bearing are continuously performed, the grinding resistance is reduced on the XY axis plane. The workpiece W to be received can be stably ground without being displaced on the face plate 171 during processing. Thereby, the processing accuracy of the inner ring Wb and the outer ring Wa is improved. In addition, when a plurality of parts that require machining accuracy (parts that are combined to form a product) are simultaneously machined as the workpiece W, machining efficiency is also improved (such as ball bearings, plain bearings, etc. as the workpiece W). When bearings and other combination products are applied).

<第二実施形態＞
上記、第一実施形態では、ガイド部材１９０，１９１を板状部材とし、ガイド部材１９０，１９１を押圧部材１８０と、電磁チャック本体１７０との間に固定した。しかし、この態様には、限らない。第二実施形態として、図１１に示すようにガイド部材２９０，２９１が、ブッシュ２８３，２８３と、ピン２８４，２８４とによって構成されてもよい。なお、第二実施形態では、第一実施形態と異なる部分のみ符号を替えて説明し、変更のない部分については、説明を省略するとともに、第一実施形態での説明と同じ符号を用いて説明する場合もある。 <Second embodiment>
In the first embodiment, the guide members 190 and 191 are plate-like members, and the guide members 190 and 191 are fixed between the pressing member 180 and the electromagnetic chuck main body 170. However, this aspect is not limited. As a second embodiment, as shown in FIG. 11, the guide members 290 and 291 may be configured by bushes 283 and 283 and pins 284 and 284. In the second embodiment, only the parts different from the first embodiment are described by changing the reference numerals, and the parts that are not changed are not described and are described using the same reference numerals as those in the first embodiment. There is also a case.

図１１に示すように、第二実施形態では、押圧部材２８０が、径方向（溝部１７３が延びる方向）に延在している。押圧部材２８０の上面全面には、最表面部材１８１が設けられている。そして、押圧部材２８０は、下面に開口する開口孔２８１，２８２を径方向における両端に一個ずつ備える。開口孔２８１，２８２には、ドライ軸受であるブッシュ２８３，２８３が各開口孔２８１，２８２にそれぞれ圧入されている。また、ピン２８４，２８４が、溝部１７３の底面１７３ｂの圧入孔に圧入により立設される。そして、各ピン２８４，２８４と各ブッシュ２８３，２８３とが軸線方向に相対移動可能に係合し、ガイド部材２９０，２９１が、構成される。これにより、ガイド部材２９０，２９１が、押圧部材２８０を溝部１７３の深さ方向に案内するとともに面板１７１における径方向（溝部１７３が延びる方向）、及び周方向（磁極部１７２が配列される方向）への移動を規制する。これによっても、第一実施形態と同様の効果が期待できる。 As shown in FIG. 11, in the second embodiment, the pressing member 280 extends in the radial direction (the direction in which the groove portion 173 extends). An outermost surface member 181 is provided on the entire upper surface of the pressing member 280. And the pressing member 280 is provided with the opening holes 281 and 282 which open to a lower surface one each at the both ends in radial direction. Bushings 283 and 283, which are dry bearings, are press-fitted into the opening holes 281 and 282 in the opening holes 281 and 282, respectively. The pins 284 and 284 are erected by press-fitting into the press-fitting holes in the bottom surface 173b of the groove 173. And each pin 284,284 and each bush 283,283 engage so that a relative movement is possible in an axial direction, and the guide members 290 and 291 are comprised. As a result, the guide members 290 and 291 guide the pressing member 280 in the depth direction of the groove portion 173, the radial direction (direction in which the groove portion 173 extends) in the face plate 171, and the circumferential direction (direction in which the magnetic pole portion 172 is arranged). Restrict movement to Also by this, the same effect as the first embodiment can be expected.

（６．その他）
なお、上記第一，第二実施形態においては、本発明に係る保持装置６１〜６４（電磁チャック）を複合研削盤１に適用したが、この態様には限らない。保持装置６１〜６４はどのような加工機の保持装置として適用してもよい。また、加工機に限らず、部品を固定する固定具として、どのような装置に用いてもよい。これらによっても同様の効果が期待できる。 (6. Others)
In the first and second embodiments, the holding devices 61 to 64 (electromagnetic chucks) according to the present invention are applied to the composite grinding machine 1, but the present invention is not limited to this mode. The holding devices 61 to 64 may be applied as holding devices for any processing machine. Moreover, you may use for not only a processing machine but what kind of apparatus as a fixing tool which fixes components. The same effect can be expected by these.

また、上記第一，第二実施形態においては、最表面部材１８１は、例えば、エポキシ樹脂に所定の粒径の砥粒を混ぜ込んで形成されるものと説明した。しかし、この態様には限らない。最表面部材１８１は、どのような部材で形成されてもよい。たとえば、通常、自動車の変速機に使用されるクラッチ板を用いてもよい。また、さまざまな金属板の表面に凹凸を設けて摩擦係数を向上させたものでもよい。また、前述したように、摩擦係数μ２が、摩擦係数μ１より小さくてもよい。さらには、最表面部材１８１はなくてもよく、この場合、支持体１８２の上面を直接、工作物Ｗの下面に当接させればよい。 In the first and second embodiments, it has been described that the outermost surface member 181 is formed by mixing abrasive grains having a predetermined particle diameter with, for example, an epoxy resin. However, it is not limited to this aspect. The outermost surface member 181 may be formed of any member. For example, you may use the clutch board normally used for the transmission of a motor vehicle. Moreover, the thing which provided the unevenness | corrugation on the surface of various metal plates, and improved the friction coefficient may be used. Further, as described above, the friction coefficient μ2 may be smaller than the friction coefficient μ1. Furthermore, the outermost surface member 181 may not be provided. In this case, the upper surface of the support 182 may be directly brought into contact with the lower surface of the workpiece W.

また、上記第一，第二実施形態においては、電磁チャックの磁極部１７２の磁化は、磁極用鋼材（図略）に巻いたコイル（図略）に通電することで実現するものとした。しかし、この態様には限らない。電磁チャックの磁極部１７２の磁化は、電磁チャック本体１７０内の永久磁石（図略）を移動することによって実現させる方式のものでもよい。これによっても同様の効果が得られる。 In the first and second embodiments, the magnetization of the magnetic pole portion 172 of the electromagnetic chuck is realized by energizing a coil (not shown) wound around a magnetic pole steel (not shown). However, it is not limited to this aspect. Magnetization of the magnetic pole portion 172 of the electromagnetic chuck may be realized by moving a permanent magnet (not shown) in the electromagnetic chuck main body 170. This also provides the same effect.

また、上記第一，第二実施形態においては、押圧部材１８０を溝部１７３の深さ方向に案内するガイド部材１９０，１９１，２９０，２９１は、面板１７１の径方向（溝部１７３が延びる方向）において押圧部材１８０，２８０の両端に設けられた。しかし、この態様には限らない。ガイド部材１９０，１９１，２９０，２９１は、径方向における押圧部材１８０，２８０のいずれか一方の端部のみに設けてもよい。これによっても、押圧部材１８０の径方向への移動は十分規制できる。また、ガイド部材１９０，１９１（２９０，２９１）のうち、いずれか一方のガイド部材１９０，１９１（２９０，２９１）を一個だけ設ける場合、押圧部材１８０，２８０に周り止めを設けて周方向（磁極部１７２が配列される方向）への移動を規制してもよい。 In the first and second embodiments, the guide members 190, 191, 290, and 291 that guide the pressing member 180 in the depth direction of the groove 173 are in the radial direction of the face plate 171 (the direction in which the groove 173 extends). The pressing members 180 and 280 are provided at both ends. However, it is not limited to this aspect. The guide members 190, 191, 290, and 291 may be provided only at one end of the pressing members 180 and 280 in the radial direction. This also sufficiently restricts the movement of the pressing member 180 in the radial direction. Further, when only one guide member 190, 191 (290, 291) is provided among the guide members 190, 191 (290, 291), the pressing members 180, 280 are provided with a detent to provide a circumferential direction (magnetic pole). The movement in the direction in which the portions 172 are arranged may be restricted.

また、上記第二実施形態においては、ブッシュ２８３，２８３はドライ軸受であるとして説明した。しかし、この態様には、限らない。ピンに対してスラスト方向に相対移動するシャフト用の軸受であれば、何でもよい。たとえば、ニードルベアリングやボールベアリングでもよい。 In the second embodiment, the bushes 283 and 283 are described as dry bearings. However, this aspect is not limited. Any shaft bearing that moves relative to the pin in the thrust direction may be used. For example, a needle bearing or a ball bearing may be used.

１・・・複合研削盤、２・・・ベッド、５・・・旋回テーブル、９ａ，９ｂ，９ｃ・・・砥石車、９ｄ・・・砥石、３０・・・制御装置、６１〜６４・・・保持装置（電磁チャック）、８１〜８４・・・主軸台、１７０・・・電磁チャック本体、１７１・・・面板、１７２・・・磁極部、１７２ａ・・・保持面、１７３・・・溝部、１７３ａ・・・側面、１７３ｂ・・・底面、１７４・・・内側固定部、１７５・・・外側固定部、１８０，２８０・・・押圧部材、１８０ｄ，１８０ｅ・・・側面、１８２・・・支持体、１８２ａ・・・支持体本体、１８２ｂ・・・内側端部、１８２ｃ・・・外側端部、１８３・・・バネ（付勢部材）、１９０，１９１，２９０，２９１・・・ガイド部材、Ｆ・・・摩擦力、Ｆｇ，ｆｇ・・・押圧力、Ｆｍａｇ・・・吸着力、Ｗ・・・工作物、Ｗａ，Ｗａａ，Ｗａｂ・・・外輪（工作物）、ＷａＧ，ＷｂＧ・・・軌道溝、Ｗｂ，Ｗｂａ，Ｗｂｂ・・・内輪（工作物）。 DESCRIPTION OF SYMBOLS 1 ... Composite grinding machine, 2 ... Bed, 5 ... Turning table, 9a, 9b, 9c ... Grinding wheel, 9d ... Grinding wheel, 30 ... Control device, 61-64 · Holding device (electromagnetic chuck), 81 to 84 ··· spindle head, 170 ··· electromagnetic chuck body, 171 ··· face plate, 172 ··· magnetic pole portion, 172a · · · holding surface, 173 ··· groove portion 173a ... side surface, 173b ... bottom surface, 174 ... inner fixing portion, 175 ... outer fixing portion, 180,280 ... pressing member, 180d, 180e ... side surface, 182 ... Support body, 182a ... support body, 182b ... inner end, 182c ... outer end, 183 ... spring (biasing member), 190, 191, 290, 291 ... guide member F Friction force Fg, fg ... pressing force, Fmag ... adsorption force, W ... workpiece, Wa, Waa, Wab ... outer ring (workpiece), WaG, WbG ... raceway groove, Wb, Wba, Wbb ... Inner ring (workpiece).

Claims

面板上面に所定方向に配列された複数の磁極部、及び隣り合う前記磁極部の間に形成された溝部を備え、前記磁極部の磁気力によって、前記磁極部の上面に工作物を吸着し固定する電磁チャック本体と、
前記溝部に、深さ方向に移動可能に配置され、前記工作物が前記磁極部の上面に固定された場合、前記工作物の下面に対し、前記磁極部による前記工作物に対する吸着力よりも小さな力で前記工作物を吸着方向と反対方向である押圧方向に押圧する押圧部材と、
前記押圧部材が前記工作物の前記下面を前記吸着力よりも前記小さな力で押圧するよう、前記押圧部材を前記押圧方向に付勢する付勢部材と、
前記押圧部材を支持し、前記押圧部材を前記溝部の前記深さ方向に案内するとともに前記面板における前記溝部が延びる方向への前記押圧部材の移動を規制するガイド部材と、
を備え、
前記ガイド部材は、前記溝部に配置され、前記溝部が延びる方向に弾性変形可能な板ばねであるとともに、前記溝部が延びる方向における前記押圧部材の内側端部及び外側端部の少なくとも一方を前記電磁チャック本体に固定する、電磁チャック。 A plurality of magnetic pole portions arranged in a predetermined direction on the upper surface of the face plate and a groove portion formed between the adjacent magnetic pole portions, and a workpiece is attracted and fixed to the upper surface of the magnetic pole portion by the magnetic force of the magnetic pole portion. An electromagnetic chuck main body,
When the workpiece is fixed to the upper surface of the magnetic pole portion, the groove portion is arranged to be movable in the depth direction, and the lower surface of the workpiece is smaller than the attraction force of the magnetic pole portion to the workpiece. A pressing member that presses the workpiece with a force in a pressing direction opposite to the suction direction;
An urging member that urges the pressing member in the pressing direction so that the pressing member presses the lower surface of the workpiece with the force smaller than the suction force;
A guide member that supports the pressing member, guides the pressing member in the depth direction of the groove portion, and restricts movement of the pressing member in a direction in which the groove portion in the face plate extends;
Bei to give a,
The guide member is a leaf spring disposed in the groove and elastically deformable in a direction in which the groove extends, and at least one of the inner end and the outer end of the pressing member in the direction in which the groove extends extends. Electromagnetic chuck fixed to the chuck body .

前記ガイド部材は、前記押圧部材の、前記面板における前記複数の磁極部の配列方向への移動を規制する、請求項１に記載の電磁チャック。 The electromagnetic chuck according to claim 1, wherein the guide member regulates movement of the pressing member in the arrangement direction of the plurality of magnetic pole portions on the face plate.

前記押圧部材は、前記溝部が延びる方向に延在して形成され、
前記ガイド部材は、前記溝部が延びる方向に延在して形成される、請求項１又は２に記載の電磁チャック。 The pressing member is formed to extend in a direction in which the groove extends.
It said guide member, prior SL are formed to extend in a direction extending groove portion, an electromagnetic chuck according to claim 1 or 2.

前記板ばねは、前記押圧部材と前記工作物との接触面より前記溝部の底面側に上面が形成される、請求項１−３の何れか１項に記載の電磁チャック。 The leaf spring, the top to the bottom side of the groove than the contact surface between the pressing member and the workpiece is formed, electromagnetic chuck according to any one of claims 1-3.

旋回軸線回りに旋回可能な旋回テーブルと、
前記旋回テーブルにおける前記旋回軸線を中心とする円周上にそれぞれ設けられ、前記旋回軸線と平行な主軸線回りに回転可能な工作主軸を有する複数の主軸台と、
複数の前記工作主軸に設けられ、それぞれ前記工作物の保持が可能な複数の保持装置と、
前記旋回テーブルに対して相対移動可能にそれぞれ設けられ、前記旋回テーブルの旋回により前記工作物が順次搬送されることで、対応するそれぞれの研削旋回位置に前記工作物が位置決めされる場合に、対応する前記工作物を研削する複数の砥石と、
を備え、
前記保持装置は、請求項１−４の何れか一項に記載の電磁チャックである、複合研削盤。 A swivel table capable of swiveling around a swivel axis;
A plurality of headstocks each having a work spindle that is provided on a circumference around the swivel axis in the swivel table and is rotatable about a main axis parallel to the swivel axis;
A plurality of holding devices provided on a plurality of the work spindles, each capable of holding the workpiece;
Corresponding to the case where the workpiece is positioned at each of the corresponding grinding turning positions by sequentially moving the workpiece by turning the turning table. A plurality of grindstones for grinding the workpiece;
With
The composite grinding machine, wherein the holding device is the electromagnetic chuck according to any one of claims 1 to 4 .

旋回軸線回りに旋回可能な旋回テーブルと、A swivel table capable of swiveling around a swivel axis;
前記旋回テーブルにおける前記旋回軸線を中心とする円周上にそれぞれ設けられ、前記旋回軸線と平行な主軸線回りに回転可能な工作主軸を有する複数の主軸台と、A plurality of headstocks each having a work spindle that is provided on a circumference around the swivel axis in the swivel table and is rotatable about a main axis parallel to the swivel axis;
複数の前記工作主軸に設けられ、それぞれ工作物の保持が可能な複数の保持装置と、A plurality of holding devices provided on the plurality of work spindles, each capable of holding a workpiece;
前記旋回テーブルに対して相対移動可能にそれぞれ設けられ、前記旋回テーブルの旋回により前記工作物が順次搬送されることで、対応するそれぞれの研削旋回位置に前記工作物が位置決めされる場合に、対応する前記工作物を研削する複数の砥石と、Corresponding to the case where the workpiece is positioned at each of the corresponding grinding turning positions by sequentially moving the workpiece by turning the turning table. A plurality of grindstones for grinding the workpiece;
を備え、With
前記保持装置は、The holding device is
面板上面に所定方向に配列された複数の磁極部、及び隣り合う前記磁極部の間に形成された溝部を備え、前記磁極部の磁気力によって、前記磁極部の上面に前記工作物を吸着し固定する電磁チャック本体と、A plurality of magnetic pole portions arranged in a predetermined direction on the upper surface of the face plate, and a groove portion formed between the adjacent magnetic pole portions, and the workpiece is attracted to the upper surface of the magnetic pole portion by the magnetic force of the magnetic pole portion. An electromagnetic chuck body to be fixed;
前記溝部に、深さ方向に移動可能に配置され、前記工作物が前記磁極部の上面に固定された場合、前記工作物の下面に対し、前記磁極部による前記工作物に対する吸着力よりも小さな力で前記工作物を吸着方向と反対方向である押圧方向に押圧する押圧部材と、When the workpiece is fixed to the upper surface of the magnetic pole portion, the groove portion is arranged to be movable in the depth direction, and the lower surface of the workpiece is smaller than the attraction force of the magnetic pole portion to the workpiece. A pressing member that presses the workpiece with a force in a pressing direction opposite to the suction direction;
前記押圧部材が前記工作物の前記下面を前記吸着力よりも前記小さな力で押圧するよう、前記押圧部材を前記押圧方向に付勢する付勢部材と、An urging member that urges the pressing member in the pressing direction so that the pressing member presses the lower surface of the workpiece with the force smaller than the suction force;
前記押圧部材を支持し、前記押圧部材を前記溝部の前記深さ方向に案内するとともに前記面板における前記溝部が延びる方向への前記押圧部材の移動を規制するガイド部材と、A guide member that supports the pressing member, guides the pressing member in the depth direction of the groove portion, and restricts movement of the pressing member in a direction in which the groove portion in the face plate extends;
を備える電磁チャックである、複合研削盤。A composite grinding machine, which is an electromagnetic chuck comprising: