JP2005116554A

JP2005116554A - High-sensitivity electromagnet

Info

Publication number: JP2005116554A
Application number: JP2003344755A
Authority: JP
Inventors: Tsuneo Kamitsubara; 常男上津原
Original assignee: CHUNICHI DENKI KOGYO KK
Current assignee: CHUNICHI DENKI KOGYO KK
Priority date: 2003-10-02
Filing date: 2003-10-02
Publication date: 2005-04-28

Abstract

PROBLEM TO BE SOLVED: To provide a small high-sensitivity electromagnet which generates a proper attractive force when a movable iron core is attracted to a stationary iron core, and has an attractive force that becomes strong when it starts attracting. SOLUTION: An electromagnet is equipped with a stationary iron core 21 provided with a truncated cavity and a truncated cone iron core as a movable iron core 11 which is attracted to the truncated cavity. The top surface having the smallest diameter and the axial adjoining part of the truncated cone cavity are formed of a non-magnetic material, stoppers 14 which specify the position of the movable iron core 11 attracted to the stationary iron core 21 are provided, the ratio of operating gap permeance to sliding gap permeance is set at 0.7 to 4:1 at the position of the movable iron core 11 attracted to the stationary iron core 21, and an angle θ of inclination which the conical surface of the truncated cone movable iron core makes with a plane perpendicular to the axis of the truncated cone movable iron core is set at 75° to 85°. COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、高感度電磁石に関する。 The present invention relates to a high sensitivity electromagnet.

図１５に従来のプランジャー型電磁石の模式構造断面図を示した。上半分は可動鉄心１１ａが作動しない状態、下半分は可動鉄心１１ｂが固定鉄心２１に吸着された状態を示している。図１６（ａ）、図１６（ｂ）、図１６（ｃ）は可動鉄心１１の作動工程を示す説明図である。 FIG. 15 shows a schematic cross-sectional view of a conventional plunger type electromagnet. The upper half shows a state where the movable iron core 11a is not operated, and the lower half shows a state where the movable iron core 11b is adsorbed to the fixed iron core 21. FIGS. 16A, 16 B, and 16 C are explanatory diagrams illustrating an operation process of the movable iron core 11.

プランジャー型電磁石の発生する吸引力の近似値は、図１５、図１６に掲げる従来技術の電磁石の模式構造断面図を参照して、周知の下記の式で算定することができる。 The approximate value of the attractive force generated by the plunger type electromagnet can be calculated by the following well-known formula with reference to the schematic structural sectional views of the conventional electromagnets shown in FIGS.

Ｆ_x：ストローク方向の動作間隔がｘの位置における可動鉄心に作用する吸引力
Ｕ_x：ストローク方向の動作間隔がｘの位置における可動鉄心に作用する起磁力
Ｐ：電磁石磁路のパアミアンス値
ｘ：ストローク方向の可動鉄心と固定鉄心との動作間隔
ｈ：電磁石の全ストローク長
ｒ_m：鉄心の円錐台部空洞挿入部の平均半径
θ：円錐台鉄心の円錐面と軸直交面との傾斜角度
また、図６に掲げる電磁石磁路の等価電気回路図を参照すれば、下記の関係式が成立する。

F _x : Attraction force acting on the movable iron core at the position where the operation interval in the stroke direction is x U _x : Magnetomotive force acting on the movable iron core at the position where the operation interval in the stroke direction is x P: Pamance value of the electromagnetic path x: operation interval between the stroke direction of the movable and stationary iron cores h: the entire stroke length of the electromagnet r _m: mean radius of frustoconical portion cavity insertion portion of the iron core theta: the inclination angle of the conical surface and the axial plane perpendicular to the truncated cone core Referring to the equivalent electric circuit diagram of the electromagnet magnetic path shown in FIG. 6, the following relational expression is established.

Φ：電磁石の磁路を通過する磁束
Ｕ：電磁石のコイル通電による起磁力
Ｕ_s；摺動間隙に作用する起磁力
Ｕ_i；動作間隙を形成する鉄心磁路に作用する起磁力
Ｕ_x：ストローク方向の動作間隔がｘの位置における動作間隙に作用する起磁力
Ｐ_s：摺動間隙のパアミアンス値
Ｐ_i：動作間隙を含む鉄心磁路のパアミアンス値
Ｐ_x：ストローク方向の動作間隔がｘの位置における可動鉄心の動作間隙のパアミ
アンス値
ここで、ｋ＝（Ｐ_x／Ｐ_s）を電磁石磁路のパアミアンス比、η＝（１／１＋ｋ）を電磁石の起磁力係数と定義し、上記式で電磁石の鉄心磁路の磁気飽和が発生しないとして、
ｋ≒ｋ₁≒ｋ₂
即ち
Ｐ_i／Ｐ_s≒Ｐ_x／Ｐ_i
が成立すると仮定し

Φ: Magnetic flux passing through the magnetic path of the electromagnet U: Magnetomotive force due to the coil energization of the electromagnet U _s ; Magnetomotive force acting on the sliding gap U _i ; Magnetomotive force acting on the iron core magnetic path forming the operating gap U _x : Stroke Magnetomotive force acting on the operating gap at the position where the movement interval in the direction is x P _s : The value of the sliding gap P _i : The value of the iron core magnetic path including the movement gap P _x : The position of the movement interval in the stroke direction is x Of the gap in the movable core
Anse value where k = (P _x / P _s ) is defined as the permeance ratio of the electromagnet magnetic path and η = (1/1 + k) is defined as the magnetomotive force coefficient of the electromagnet. Will not occur,
k ≒ k ₁ ≒ k ₂
That is, P _i / P _s ≈P _x / P _i
Assuming that

式の成立を想定する。

Assume that the formula holds.

ここで電磁石磁路の磁束密度を１．２ｗｂ／ｍ²以下の範囲に設定する試作実験によって、上記想定式が近似的に成立することが確認できる。 Here, it can be confirmed that the above assumption formula is approximately established by a prototype experiment in which the magnetic flux density of the electromagnet magnetic path is set to a range of 1.2 wb / m ² or less.

また上記（２）式に従って、パアミアンス比ｋ値の変化に伴う起磁力係数ηとη²の変動状況を算定し、動作間隙の起磁力Ｕ_x／Ｕの値のグラフを作成すると図７に示すとおりである。 FIG. 7 shows the graph of the value of magnetomotive force U _x / U of the operating gap by calculating the fluctuation state of the magnetomotive force coefficients η and η ² according to the change of the permeance ratio k value according to the above equation (2). It is as follows.

図１５は従来の電磁石の断面図を示すもので、中心線より上側はコイル３１が励磁されていない状態（可動鉄心１１が始動時の状態（１１ａ））を示し、中心線より下側はコイル３１が励磁され、可動鉄心１１が固定鉄心に吸着されている状態（１１ｂ）を示すものである。なお、図１５において、固定鉄心２１及び可動鉄心１１の動作間隙は円錐台形の空所と突起が形成する空間２４となっている。固定鉄心２１、ヨーク２２、２３、可動鉄心１１は磁路を形成しており、ボビン３２に巻回されたコイル３１は、磁路に磁束を発生させる。 FIG. 15 shows a cross-sectional view of a conventional electromagnet, in which the coil 31 is not energized above the center line (the movable core 11 is in a starting state (11a)), and the coil below the center line is the coil. The state (11b) in which 31 is excited and the movable iron core 11 is attracted to the fixed iron core is shown. In FIG. 15, the operating gap between the fixed iron core 21 and the movable iron core 11 is a space 24 formed by a frustoconical space and a projection. The fixed iron core 21, the yokes 22 and 23, and the movable iron core 11 form a magnetic path, and the coil 31 wound around the bobbin 32 generates a magnetic flux in the magnetic path.

図１６（ａ）〜図１６（ｃ）は従来の電磁石の可動鉄心１１と固定鉄心２１の位置関係を示す断面図で、図１６（ａ）は可動鉄心１１の始動時の位置関係を示しており、図１６（ｂ）は可動鉄心１１の吸引動作の途中の位置、図１６（ｃ）は可動鉄心１１と固定鉄心２１が吸着した時の状態を示している。 16 (a) to 16 (c) are sectional views showing the positional relationship between the movable iron core 11 and the fixed iron core 21 of a conventional electromagnet, and FIG. 16 (a) shows the positional relationship when the movable iron core 11 is started. FIG. 16B shows a position during the suction operation of the movable iron core 11, and FIG. 16C shows a state when the movable iron core 11 and the fixed iron core 21 are adsorbed.

図１６（ａ）〜図１６（ｃ）に掲げた従来技術の電磁石の作用説明図を参照して、従来技術の問題点を説明すると次の通りである。 The problems of the prior art will be described with reference to the operation explanatory diagrams of the conventional electromagnets shown in FIGS. 16 (a) to 16 (c).

Ａ）従来の電磁石は、可動鉄心１１と固定鉄心２１との動作間隙δ_xの鉄心相互間の機械的摩擦を避け、可動鉄心１１の運動を円滑に行うために、両鉄心１１，２１の吸着時（ｘ＝０のとき）の円錐台と円錐台空所の円錐磁極面間に、図１６（ｃ）に図示する微小間隙ｃ、例えば０．１ｍｍ〜０．２ｍｍ程度の隙間が生ずるようにしている。 A) conventional electromagnet, avoiding mechanical friction between the iron core mutual operation gap [delta] _x of the movable iron core 11 and the fixed iron core 21, in order to perform the movement of the movable core 11 smoothly, adsorption of both cores 11 and 21 A small gap c shown in FIG. 16C, for example, a gap of about 0.1 mm to 0.2 mm, is formed between the truncated cone at the time (when x = 0) and the conical magnetic pole surface of the truncated cone space. ing.

Ｂ）また摺動間隙の間隙寸法はできるだけ小さくすることが望ましいが、電磁石コイルを固定する便宜上、可動鉄心１１の外周とボビン３１の内径との隙間及びボビン３１の内周側肉厚との合計寸法、すなわち摺動間隙離隔長ｄ（図１５参照）を微小化するには限度があり、通常０．２ｍｍ程度以上の間隙を配置する。この摺動間隙のパアミアンスは可動鉄心のストローク方向の位置に関係なく一定値となっている。 B) Although it is desirable to make the gap size of the sliding gap as small as possible, for the convenience of fixing the electromagnetic coil, the total of the gap between the outer periphery of the movable iron core 11 and the inner diameter of the bobbin 31 and the inner peripheral side wall thickness of the bobbin 31. There is a limit to miniaturizing the dimension, that is, the sliding gap separation length d (see FIG. 15), and a gap of about 0.2 mm or more is usually arranged. The sliding clearance has a constant value regardless of the position of the movable iron core in the stroke direction.

Ｃ）従って従来技術の電磁石では、摺動間隙のパアミアンス値Ｐ_sに対し，可動鉄心の吸引に従って増加する動作間隙のパアミアンス値Ｐ_xが過大となり、パアミアンス比ｋ＝Ｐ_x／Ｐ_sの値が増大し、前記（２）式の動作問隙の起磁力Ｕ_xが減少し、前記（１）式で算定する吸引力Ｆ_xが低下する。 C) Therefore, in the electromagnet of the prior art, the permeance value P _x of the operating gap that increases as the moving core is attracted becomes excessive with respect to the permeance value P _s of the sliding gap, and the value of the permeance ratio k = P _x / P _s As a result, the magnetomotive force U _x of the operation gap of the equation (2) decreases, and the attractive force F _x calculated by the equation (1) decreases.

Ｄ）また従来技術の電磁石は、動作間隙を形成する円錐台円錐面と軸直交面との傾斜角度θは４５゜〜７０゜程度である。 D) Further, in the conventional electromagnet, the inclination angle θ between the frustoconical conical surface forming the operating gap and the axis orthogonal surface is about 45 ° to 70 °.

図１６（ａ）〜図１６（ｃ）に図示するように、
δ_x＝（ｘｃｏｓθ＋ｃ）ｓｉｎθ ……（３）
で算定する動作間隙離隔寸法δ_xは、傾斜角度θの増大に従って、上記（３）式の（ｓｉｎθｃｏｓθ）項の数値を減少させ、動作間隙のパアミアンス値Ｐ_xを増加して前記（２）式の起磁力Ｕ_xを減少し、その結果前記（１）式の（１／ｓｉｎθｃｏｓθ）項の増大を相殺して、電磁石の吸引力Ｆ_xを低下させている。 As illustrated in FIGS. 16A to 16C,
δ _x = ( _x cos θ + c) sin θ (3)
The operating gap separation dimension δ _x calculated in step (3) decreases the numerical value of the (sin θ cos θ) term in the above equation (3) and increases the operating gap permeance value P _x in accordance with the increase in the inclination angle θ. of reducing the magnetomotive force U _x, the result of (1) to offset an increase in the expression (1 / Sinshitashioesushita) term, and reduces the suction force F _x of the electromagnet.

従来技術の電磁石では、傾斜角度θを７０度程度以下に設定し、動作間隙離隔寸法δ_xを増加させ、上記の吸引力相殺を解消する手段としている。可動鉄心のストローク方向の動作間隔ｘ値とδ_x値との関係を示すグラフを図９に掲げた。そのδ_x増大による吸引力改善の効果は、傾斜角度θが６０゜の近傍では図示の横軸ｘ値が１ｍｍ乃至２ｍｍ程度の範囲に限定され、上記の従来技術の問題点の解決手段としては評価し難い。 In prior art electromagnet, and the inclination angle θ below about 70 degrees, to increase the operating clearance separation distance [delta] _x, is a means to solve the above-mentioned attraction force cancellation. A graph showing the relationship between the motion interval x value in the stroke direction of the movable iron core and the δ _x value is shown in FIG. The effect of the suction force improvement due to the [delta] _x increases, the inclination angle θ is 60 ° vicinity to be limited in scope abscissa x values shown is about 1mm to 2 mm, as solving means of the above-mentioned problems of the prior art are It is difficult to evaluate.

微小な入力電力で高吸引力を発生する小型軽量な電磁石については、非常に多くの工夫がなされており、動作間隙のパアミアンスに着目した技術もある（例えば、特許文献１参照。）。 A lot of contrivances have been made for small and light electromagnets that generate a high attractive force with a very small input power, and there is also a technology that focuses on the permeance of the operating gap (see, for example, Patent Document 1).

この技術はすぐれた技術であるが、鉄心磁路の磁気飽和についての考慮がなされておらず、また、摺動間隙のパアミアンス値の設定についてもなんら考慮されていなかった。
特開２００１−１３５５２０号公報（第２−４頁、図１） Although this technique is an excellent technique, no consideration has been given to the magnetic saturation of the iron core magnetic path, and no consideration has been given to the setting of the permeance value of the sliding gap.
JP 2001-135520 A (page 2-4, FIG. 1)

本発明は電磁石の鉄心磁路の磁気飽和をも十分考慮に入れて検討した結果に基いて開発されたもので、可動鉄心の吸引に対応して、適切な吸引力を発生する小型高感度の電磁石を提供することを目的とするものである。 The present invention has been developed based on the results of studies that have taken into consideration the magnetic saturation of the iron core magnetic path of the electromagnet, and is a compact and highly sensitive device that generates an appropriate suction force in response to the suction of the movable core. The object is to provide an electromagnet.

また、本発明は、吸引開始時の吸引力を選択して所要の吸引特性を発揮する大きくした小型高感度の電磁石を提供する。 In addition, the present invention provides a large and small high-sensitivity electromagnet that selects a suction force at the start of suction and exhibits required suction characteristics.

本発明は、上記問題点を解決するためになされたもので、次の技術手段を講じたことを特徴とする高感度電磁石である。すなわち、本発明は、固定鉄心又は可動鉄心の一方に形成した円錐台空洞とこれに対向する同軸の他方の円錐台鉄心を設けた電磁石において、円錐台空洞の最小径頂面及びその軸方向隣接部を非磁性体とし、可動鉄心と上記固定鉄心との吸着位置を規定するストッパを設け、かつ、鉄心磁路の磁気飽和を発生しない所定起磁力における固定鉄心と可動鉄心の吸着位置における動作間隙パアミアンス値と摺動間隙パアミアンス値との比を一定範囲内に定めたことを特徴とする高感度電磁石である。 The present invention has been made to solve the above problems, and is a high-sensitivity electromagnet characterized by taking the following technical means. That is, the present invention relates to an electromagnet provided with a truncated cone cavity formed in one of a fixed iron core or a movable iron core and the other conical cone iron core opposite to the truncated cone cavity, and the minimum diameter top surface of the truncated cone cavity and its axially adjacent Non-magnetic part, provided with a stopper that defines the adsorption position between the movable iron core and the fixed iron core, and the operating gap at the adsorption position between the fixed iron core and the movable iron core at a predetermined magnetomotive force that does not cause magnetic saturation of the iron core magnetic path A high-sensitivity electromagnet characterized in that the ratio between the permeance value and the sliding gap permeance value is set within a certain range.

円錐台空洞の最小径頂面及びその軸方向隣接部とは、円錐台空洞の小径部より外方の小径部と同径の円筒形の部分をいう。また非磁性体としては、空洞（空気が非磁性）とするか、非磁性の物質が充填されている状態をいう。ストッパは、可動鉄心と固定鉄心とが吸着接触する直前に、微小間隔を介して可動鉄心の吸着を妨げる停止機構を云い、例えば可動鉄心の外周にフランジを設け、このフランジが当接する停止部を固定側に設けるとか、可動鉄心の先端部が当接する部分に設けた非磁性体緩衝材等である。 The minimum-diameter top surface of the truncated cone cavity and the axially adjacent portion refer to a cylindrical portion having the same diameter as the smaller-diameter portion outside the smaller-diameter portion of the truncated-cone cavity. In addition, the non-magnetic material is a state in which a cavity (air is non-magnetic) or a non-magnetic substance is filled. The stopper is a stop mechanism that prevents the movable iron core from being adsorbed through a minute interval immediately before the movable iron core and the fixed iron core are brought into contact with each other. It is a non-magnetic cushioning material or the like provided on the fixed side or provided on the portion where the tip of the movable iron core abuts.

また動作間隙とは、可動鉄心と固定鉄心の吸着面間の間隙を云い、摺動間隙とは可動鉄心の外周と、これに近接したヨークの部分との間隙を云う。ヨークは作動コイルを囲繞し固定鉄心から可動鉄心を通る磁路を形成する部材である。 The operating gap refers to the gap between the adsorbing surfaces of the movable iron core and the fixed iron core, and the sliding gap refers to the gap between the outer periphery of the movable iron core and the portion of the yoke adjacent thereto. The yoke is a member that surrounds the working coil and forms a magnetic path that passes from the fixed iron core to the movable iron core.

上記本発明によれば、
（ａ）円錐台形の動作突起の頂面が対向する相手方への鉄心の部分を数ｍｍ以上の軸方向長の非磁性体とすることにより、円錐台傾斜面を主作動面とし円錐台頂面からの漏洩磁束を最小限にすると共に、鉄心磁路の不必要な磁気飽和を防止する。 According to the present invention,
(A) By making the part of the iron core to the opposite side opposite the top face of the frustoconical operation protrusions into a non-magnetic material having an axial length of several millimeters or more, the truncated cone inclined surface becomes the main working surface and the top face of the truncated cone As well as minimizing the leakage flux from the core, unnecessary magnetic saturation of the iron core magnetic path is prevented.

（ｂ）ストッパを設けることにより、吸着時に適正動作間隙を保持し、ストッパ作動直前に適切な吸引力を得る。 (B) By providing a stopper, an appropriate operation gap is maintained during suction, and an appropriate suction force is obtained immediately before the stopper is activated.

（ｃ）動作間隔パーミアンスと摺動間隙パーミアンスとの比ｋを適正に選択した設計により、吸着時の吸引力の適正化を図る。このｋの値は電磁石の構造、寸法及び所要ストローク等にもよるが０．７〜４とすればよい。
という手段により、可動鉄心と固定鉄心の吸着時の吸引力の値を適正に設定し、小型高感度の電磁石を得ることができる。 (C) By optimizing the ratio k between the operation interval permeance and the sliding gap permeance, the suction force during adsorption is optimized. The value of k depends on the structure, dimensions, required stroke, etc. of the electromagnet, but may be 0.7-4.
By this means, it is possible to appropriately set the value of the attractive force at the time of attracting the movable iron core and the fixed iron core, and obtain a small and highly sensitive electromagnet.

また上記電磁石において、前記円錐台可動鉄心の円錐面と軸直交面との傾斜角度を７５〜８５度とすると電磁石始動時の好適な吸引力を設定できる。 In the electromagnet, when the inclination angle between the conical surface and the axis perpendicular to the frustum movable iron core is 75 to 85 degrees, a suitable attractive force at the time of starting the electromagnet can be set.

さらに、前記円錐台空洞の大径に対して、前記円錐台鉄心の大径を同一寸法又は小径とする円柱部径を設定して、吸着開始時の吸引力が適切な小型高感度の電磁石を得ることができる。 Furthermore, a small-size and high-sensitivity electromagnet with an appropriate attractive force at the start of suction is set by setting a cylindrical part diameter having a large diameter of the truncated cone core equal to or smaller than the large diameter of the truncated cone cavity. Can be obtained.

また、前記円錐台空洞の円錐面と軸直交面との傾斜角度に対して、前記円錐台鉄心の円錐面と軸直交面との傾斜角度を大きく設定して電磁石の吸引力特性を好適に選定することができる。 Further, the attractive force characteristic of the electromagnet is suitably selected by setting the inclination angle between the conical surface and the axis orthogonal surface of the truncated cone iron core larger than the inclination angle between the conical surface and the axis orthogonal surface of the truncated cone cavity. can do.

本発明によれば、小型軽量で、微小電力によって所要の吸引力特性を発揮する高感度電磁石を、安価に提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the highly sensitive electromagnet which is small and lightweight, and exhibits a required attraction force characteristic with micro electric power can be provided at low cost.

以下図面を参照して本発明を実施するための最良の形態について説明する。 The best mode for carrying out the present invention will be described below with reference to the drawings.

図１は本発明の実施例の断面図を示し、中心線より上半分は可動鉄心１１が始動時の状態（１１ａ）、下半分は可動鉄心１１が固定鉄心２１に吸着した時の状態（１１ｂ）を示している。固定鉄心２１は、ヨーク２２、２３を介して連結する柱状可動鉄心１１と磁路を形成している。可動鉄心１１は円柱部１３と鉄心断面縮小部（円錐台部）１２を備えている。コイル３１はボビン３２に巻回されており、可動鉄心が固定鉄心２１に吸着状態（下半分）における動作間隙２５、摺動間隙２６が形成されている。また、可動鉄心１１にはストッパ１４が設けられている。このストッパ１４は可動鉄心１１が吸着されたとき固定側に当接して可動鉄心１１を所定位置に停止させる。 FIG. 1 shows a cross-sectional view of an embodiment of the present invention. The upper half of the center line is a state when the movable iron core 11 is started (11a), and the lower half is a state when the movable iron core 11 is attracted to the fixed iron core 21 (11b). ). The fixed iron core 21 forms a magnetic path with the columnar movable iron core 11 connected via the yokes 22 and 23. The movable iron core 11 includes a cylindrical portion 13 and a core cross-section reduced portion (conical frustum portion) 12. The coil 31 is wound around a bobbin 32, and an operating gap 25 and a sliding gap 26 are formed when the movable iron core is attracted to the fixed iron core 21 (lower half). The movable iron core 11 is provided with a stopper 14. When the movable iron core 11 is attracted, the stopper 14 contacts the fixed side and stops the movable iron core 11 at a predetermined position.

図２は可動鉄心２の円錐台部１２と円柱部１３とに段差のない形式の実施例の模式構造断面図を示したものである。この例は円錐台空洞の大径に対して、円錐台鉄心に連設する円柱状鉄心径を同一寸法又は小径としたものである。図３は固定鉄心２１とヨーク２２との関係形状を変形させた例である。 FIG. 2 is a schematic structural cross-sectional view of an embodiment in which there is no step between the truncated cone part 12 and the cylindrical part 13 of the movable iron core 2. In this example, the diameter of the columnar core connected to the truncated cone core is the same or smaller than the larger diameter of the truncated cone cavity. FIG. 3 shows an example in which the relationship between the fixed iron core 21 and the yoke 22 is changed.

図４は可動鉄心１１を中空の円筒状にし、その先端側に先開きの円錐台空洞１５を設け、固定鉄心２１の形状を円錐台空洞１５内に挿入する円錐台突起２７としたものである。また図５は、可動鉄心１１を円錐台空洞部１５だけの長さの短いものとし、中空円筒部を省略したものである。ストッパ１４は可動鉄心１１の先頭端部に設けている。 In FIG. 4, the movable iron core 11 is formed in a hollow cylindrical shape, a tip-open truncated cone cavity 15 is provided on the tip side thereof, and the shape of the fixed iron core 21 is a truncated cone protrusion 27 which is inserted into the truncated cone cavity 15. . FIG. 5 shows the movable iron core 11 having a short length of the truncated cone cavity 15 and omitting the hollow cylinder. The stopper 14 is provided at the leading end of the movable iron core 11.

なお、図１に示す実施例では可動鉄心１１の円錐台部１２と円柱部１３とは段差を有しているが、図２〜図３の実施例は図１と同様に可動鉄心が中実の柱状部と円錐台突起とから成る電磁石であって、可動鉄心の柱状部の径を、固定鉄心の円錐台空洞の大径と同一又はそれより小径とした実施例である。 In the embodiment shown in FIG. 1, the truncated cone portion 12 and the cylindrical portion 13 of the movable core 11 have a step, but the embodiment of FIGS. This is an example in which the diameter of the columnar portion of the movable iron core is the same as or smaller than the large diameter of the truncated cone cavity of the fixed core.

図１６（ａ）〜図１６（ｃ）に掲げる従来技術の電磁石の作用説明図を参照して、従来技術の問題点を検討する。図１６（ａ）は可動鉄心１１と固定鉄心２１とがストロークｘだけ離隔した状態を示し、図１６（ｂ）はストローク方向の動作間隙がｘのときの状態を示し、図１６（ｃ）は可動鉄心１１と固定鉄心２１とが吸着した状態、すなわち可動鉄心１１と固定鉄心２１のストローク方向の動作間隙ｘがゼロ（又はその近傍）の状態を示している。 The problems of the prior art will be examined with reference to the operation explanatory diagrams of the prior art electromagnets shown in FIGS. 16 (a) to 16 (c). FIG. 16A shows a state where the movable iron core 11 and the fixed iron core 21 are separated by a stroke x, FIG. 16B shows a state where the operation gap in the stroke direction is x, and FIG. The state where the movable iron core 11 and the fixed iron core 21 are adsorbed, that is, the operation gap x in the stroke direction between the movable iron core 11 and the fixed iron core 21 is zero (or in the vicinity thereof).

前記（１）式に示すとおり、動作間隙がｘのとき円錐台の円錐面の軸直交面に対する傾斜角度θを一定値とすると、電磁石の吸引力は、円錐台部挿入部鉄心の平均半径ｒ_mに比例し、動作間隙に作用する起磁力Ｕ_xの二乗に比例する。平均半径ｒ_mは図１６（ｂ）、図１６（ｃ）に示すように、円錐台部１２の頂部の円の半径ｒ₄と円錐台部１２が円錐台空洞に挿入されている部分の円の最大半径ｒ₂の算術平均値である。 As shown in the above equation (1), when the operating gap is x and the inclination angle θ of the conical surface of the truncated cone with respect to the axis perpendicular to the axis is a constant value, the attractive force of the electromagnet is the average radius r of the truncated cone portion insertion core. _It is proportional to _m and proportional to the square of the magnetomotive force U _x acting on the operating gap. As shown in FIGS. 16B and 16C, the average radius r _m is a radius r ₄ of the circle at the top of the truncated cone part 12 and a circle at a part where the truncated cone part 12 is inserted into the truncated cone cavity. is the arithmetic mean value of the maximum radius r ₂ of the.

さて従来技術では、電磁石部品組立の便宜上、可動鉄心１１の円柱部半径ｒ₁と固定鉄心２１の外半径ｒ₇とを略同一径として構成することが一般的であり、また円錐台空洞の加工技術の制約から、固定鉄心２１の円錐台空洞の大径側と固定鉄心２１の外周との差は、片肉寸法ｔを０．５ｍｍ以下に成型することは困難と考えられていた。 In the prior art, for the convenience of assembling the electromagnet parts, it is common to configure the cylindrical portion radius r ₁ of the movable iron core 11 and the outer radius r ₇ of the fixed iron core 21 to have substantially the same diameter. Due to technical limitations, it was considered difficult to mold the single-wall dimension t to 0.5 mm or less because of the difference between the large diameter side of the truncated cone cavity of the fixed iron core 21 and the outer periphery of the fixed iron core 21.

従って、図１６（ｂ）に示すように、可動鉄心１１の円錐台底部半径ｒ₃を、円柱部半径ｒ₁に比して縮小した形状とせざるを得なかった。このため、鉄心磁路断面縮小部（図１６（ａ）のｔの近傍部分あるいは円錐台鉄心の頂面近傍部分）に磁気飽和が発生し、また、可動鉄心１１の円錐台部１２の平均半径ｒ_mの減少等によって電磁石の吸引力が低下するという問題点を招来する。 Therefore, as shown in FIG. 16B, the truncated cone radius r ₃ of the movable iron core 11 has to be reduced to a shape smaller than the column radius r ₁ . For this reason, magnetic saturation occurs in the iron core magnetic path cross-sectional reduced portion (a portion near t in FIG. 16A or a portion near the top surface of the truncated cone core), and the average radius of the truncated cone portion 12 of the movable core 11 attraction force of the electromagnet to lead to problems of a decrease by a decrease in r _m.

次に、図８（ａ）〜図８（ｃ）に本発明の作用説明図を掲げた。固定鉄心２１の円錐台空洞頂面に隣接する部分を同一径の柱状空洞とするかまたはこの部分に非磁性体を配設した。この手段は、固定鉄心２１の円錐台空洞の円錐面に磁束を集め、円錐台空洞の頂面からの漏洩磁束をなくすることを目的としている。このことにより、不適切な動作間隙のパアミアンス値の増大を規制すると共に、可動鉄心と固定鉄心間に適切な動作間隙離隔長δ_xを形成し、両鉄心吸着時の動作間隙に作用する起磁力Ｕ_xを保証して的確な吸引力を発生させることができる。また、上記両鉄心の吸着位置を規制するストッパを設けた。このストッパとして、固定鉄心２１の円錐台空洞頂面に隣接する部分に円柱状の非磁性体を配置してこの非磁性体に可動鉄心を停止させるストッパを兼用させると好適である。以上の手段により、両鉄心吸着時のパアミアンス値を的確に調整することができる。 Next, FIG. 8 (a) to FIG. 8 (c) show action explanatory views of the present invention. A portion adjacent to the top surface of the truncated cone cavity of the fixed iron core 21 is a columnar cavity having the same diameter, or a nonmagnetic material is disposed in this portion. This means aims to collect magnetic flux on the conical surface of the truncated cone cavity of the fixed iron core 21 and eliminate the leakage magnetic flux from the top surface of the truncated cone cavity. As a result, an increase in the improper operating gap permeance value is controlled, and an appropriate operating gap separation length δ _x is formed between the movable iron core and the fixed iron core, and the magnetomotive force acting on the operating gap when both iron cores are attracted. U _x can be guaranteed and an accurate suction force can be generated. Moreover, the stopper which controls the adsorption | suction position of the said both iron cores was provided. As this stopper, it is preferable that a cylindrical nonmagnetic material is disposed in a portion of the fixed iron core 21 adjacent to the top surface of the truncated cone and the nonmagnetic material is also used as a stopper for stopping the movable iron core. By the above means, the permeance value at the time of adsorption of both iron cores can be adjusted accurately.

次に、本発明では、可動鉄心１１の摺動間隙の対向面積及びまたは摺動離隔長を選定して、両鉄心吸着時の動作間隙パアミアンス値に対する摺動間隙のパアミアンス値の比を選定して、前記の両鉄心吸着時の吸引力を設定する。 Next, in the present invention, the opposed area and / or sliding separation length of the sliding gap of the movable iron core 11 is selected, and the ratio of the sliding gap permeance value to the operating gap permeance value at the time of adsorption of both iron cores is selected. The suction force at the time of adsorbing both iron cores is set.

図７に、動作間隙起磁力Ｕ_xの算定グラフを示した。このグラフは電磁石のパアミアンス比ｋ＝Ｐ_x／Ｐ_sを横軸にとり、Ｕ_x／Ｕの値を縦軸にとって描いたものであり、起磁力係数がηのときと起磁力係数がη²のときを示している。動作問隙に作用する起磁力Ｕ_xは、電磁石のパアミアンス比ｋ＝Ｐ_x／Ｐ_sの値が小さいほど増加し、さらに前記（１）式を参照すると、動作間隙に作用する吸引力Ｆ_xは、種々の試作実験の結果、近似的に起磁力係数ηの２乗に比例して変化することが明らかである。 FIG. 7 shows a calculation graph of the operating gap magnetomotive force U _x . This graph is drawn with the electromagnet's permeance ratio k = P _x / P _s on the horizontal axis and the value of U _x / U on the vertical axis. The magnetomotive force coefficient is η and the magnetomotive force coefficient is η ² . Shows the time. The magnetomotive force U _x acting on the operating gap increases as the value of the electromagnet's permeance ratio k = P _x / P _s decreases. Further, referring to the equation (1), the attractive force F _x acting on the operating gap As a result of various prototype experiments, it is apparent that the ratio changes approximately in proportion to the square of the magnetomotive force coefficient η.

従って、電磁石磁路の摺動間隙の対向面積及びまたは摺動離隔長（可動鉄心外周とヨークとの隙間寸法）を調整して、仮定磁路法に従って磁路のパアミアンス比ｋ値を選定する手段を適用することにより、前記両鉄心吸着時の所要吸引力の適切な選定を容易に行うことができる。 Therefore, the means for selecting the permeance ratio k value of the magnetic path according to the hypothetical magnetic path method by adjusting the facing area of the sliding gap of the electromagnet magnetic path and / or the sliding separation length (gap size between the outer periphery of the movable core and the yoke) By applying the above, it is possible to easily select an appropriate suction force at the time of attracting both iron cores.

上記磁路のパアミアンス比ｋ値は、動作間隙のパアミアンス値Ｐ_xに比例し摺動間隙のパアミアンス値Ｐ_sに逆比例する。従って摺動間隙の磁極面離隔長に逆比例し、摺動間隙磁極対向面積に比例する。 The magnetic path permeance ratio k value is in proportion to the operating gap permeance value P _x and inversely proportional to the sliding gap permeance value P _s . Therefore, it is inversely proportional to the magnetic pole surface separation length of the sliding gap and proportional to the sliding gap magnetic pole facing area.

しかしながら、摺動間隙の離隔長（可動鉄心外周とヨークとの間隙寸法）は、鉄心磁路の磁気飽和を調整する必要と加工上の問題から、通常０．１ｍｍ以下に縮小することが困難であり、また電磁石の外形寸法の制約から、摺動間隙の磁極対向面積の増大にも限度がある。 However, the separation length of the sliding gap (gap size between the outer periphery of the movable core and the yoke) is usually difficult to reduce to 0.1 mm or less due to the necessity of adjusting the magnetic saturation of the iron core magnetic path and processing problems. In addition, due to restrictions on the outer dimensions of the electromagnet, there is a limit to the increase of the magnetic pole facing area of the sliding gap.

電磁石の所要設計条件に対応する最適パアミアンス比ｋ値の選定は、前記（１）式の煩雑な演算の繰り返しを実施して最適値を算定することができるが、一般的な電磁石設計のパアミアンス比ｋ値は、所要ストローク長２ｍｍで０．７〜１．５、所要ストローク長６ｍｍの場合には２〜４を基準として、好適な吸引力特性を求めるとよい。 Selection of the optimal permeance ratio k value corresponding to the required design conditions of the electromagnet can be performed by repeating the complicated calculation of the above equation (1) to calculate the optimal value, but the permeance ratio of a general electromagnet design The k value is preferably 0.7 to 1.5 when the required stroke length is 2 mm, and preferably 2 to 4 when the required stroke length is 6 mm.

第２の発明の作用について、図１に模式構造断面図を掲げた実施例について、図８（ｃ）に示す動作間隙離隔長δ_x値の算定グラフ（図９）を参照して説明する。 The operation of the second invention will be described with reference to a calculation graph (FIG. 9) of the operating gap separation length δ _x value shown in FIG.

電磁石の動作間隙離隔長δ_xの値は、前記（３）式
δ_x＝（ｘｃｏｓθ＋ｃ）ｓｉｎθ
に従って算定することができる。この値は図９に示すように、可動鉄心と固定鉄心との作動間隙の寸法ｘを横軸にとり、円錐台の円錐面の軸直交面に対する傾斜角度θをパラメータとして動作間隙離隔長δ_x値算定グラフを作成することができる。 The value of the operating gap separation length δ _x of the electromagnet is expressed by the equation (3) δ _x = ( _x cos θ + c) sin θ.
It can be calculated according to As shown in FIG. 9, this value is obtained by taking the dimension x of the working gap between the movable iron core and the fixed iron core on the horizontal axis, and the operating gap separation length δ _x value with the inclination angle θ of the conical surface of the truncated cone with respect to the axis perpendicular to the axis as a parameter. A calculation graph can be created.

このグラフは、動作間隙のクリアランスｃ値を０．２ｍｍとすれば、電磁石の両鉄心吸着時（可動鉄心と固定鉄心との離隔距離ｘ＝０）の離隔長δ_o＝０．２ｍｍ点を起点とし、各円錐台の円錐面の傾斜角度θ値に対応する直線で表わされ、それぞれのｘの値に対応する動作間隙離隔長δ_x値の変化の状態を示すことができる。 In this graph, when the clearance c value of the operating gap is 0.2 mm, the separation length δ _o = 0.2 mm when the both magnets are attracted to each other (separation distance x = 0 between the movable iron core and the fixed iron core) is the starting point. And a change state of the operating gap separation length δ _x value corresponding to each value of x, which is represented by a straight line corresponding to the inclination angle θ value of the conical surface of each truncated cone.

動作間隙のパアミアンス値Ｐ_xは、動作間隙離隔長δ_x値に逆比例する。図９のグラフに示すように、傾斜角度θが大きいほど動作間隙のパアミアンス値が大きくなり、高吸引力を発生する。しかしその反面、可動鉄心の吸引過程の進行に伴う動作間隙離隔長δ_x値の減少（動作間隙のパアミアンス値Ｐ_xの増加）によって起磁力Ｕ_xが減少し、高吸引力の発生を阻止する作用も増大する。 The operating gap permeance value P _x is inversely proportional to the operating gap separation length δ _x value. As shown in the graph of FIG. 9, the larger the inclination angle θ, the larger the permeance value of the operation gap, and the higher suction force is generated. However, on the other hand, the magnetomotive force U _x decreases due to a decrease in the operating gap separation length δ _x value (increase in the operating gap permeance value P _x ) as the moving iron core attracts, so that the generation of a high attractive force is prevented. The effect is also increased.

因みに本発明の条件を適用して試作した電磁石の吸引力特性曲線の例を、図１０〜図１２に掲げた。 Incidentally, examples of attractive force characteristic curves of electromagnets prototyped by applying the conditions of the present invention are shown in FIGS.

まず図１０に掲げる吸引力特性は、ストロークを６ｍｍとした実施例の設計仕様の電磁石において、円錐台の円錐面の軸直交面に対する傾斜角度θを８０度（一定値）として、磁路のパアミアンス比ｋ値をパラメータとし、パアミアンス比ｋ値を２．３乃至４．４の範囲に変更した場合の、それぞれの吸引力特性の変化状況を示すものである。 First, the attractive force characteristics shown in FIG. 10 are as follows. In the electromagnet of the design specification of the embodiment with a stroke of 6 mm, the inclination angle θ of the truncated cone with respect to the axis perpendicular to the axis is 80 degrees (constant value), and the magnetic path permeance The ratio k value is used as a parameter, and when the permeance ratio k value is changed to a range of 2.3 to 4.4, the change state of each suction force characteristic is shown.

ｋ＝２．３では吸引時（ｘ＝０近傍）の吸引力は非常に大きいが、磁路のパアミアンス比ｋ値が小さくなると、前記摺動間隙のパアミアンスＰ_xが増加し、磁束密度の増大によって鉄心磁路の磁気飽和を誘起する。 At k = 2.3, the attractive force at the time of attraction (near x = 0) is very large. However, when the magnetic path permeance ratio k value decreases, the permeance P _{x of the} sliding gap increases and the magnetic flux density increases. Induces magnetic saturation of the iron core magnetic path.

図１０に示すパアミアンス比ｋ値の設定値が２．３の場合、磁束密度を検討すると磁束密度の値は２．０ｗｂ／ｍ²に達している。鉄心やヨークの材質にもよるが、磁束密度の値が１．５ｗｂ／ｍ²以上では磁気飽和領域である。従って、この場合の吸引力特性は、鉄心磁路の磁気飽和を考慮に入れると、実用的なパアミアンス比ｋ値の設定値は、磁束密度が飽和に達しない３．０乃至４．０の範囲に設定するのがよく、そうすると磁束密度が１．５ｗｂ／ｍ²未満となり、所要の吸引力特性を選定することができるので適切である。 When the setting value of the permeance ratio k value shown in FIG. 10 is 2.3, when the magnetic flux density is examined, the magnetic flux density value reaches 2.0 wb / m ² . Although depending on the material of the iron core and the yoke, the magnetic saturation region is obtained when the magnetic flux density is 1.5 wb / m ² or more. Therefore, in this case, the attractive force characteristic takes into consideration the magnetic saturation of the iron core magnetic path, and the practical setting value of the permeance ratio k value is in the range of 3.0 to 4.0 where the magnetic flux density does not reach saturation. This is suitable because the magnetic flux density is less than 1.5 wb / m ² and the required attractive force characteristics can be selected.

次に、図１１はストロークが４ｍｍの実施例の電磁石において、円錐台の円錐面の軸直交面に対する傾斜角度θを８０．１度（一定値）として、磁路のパアミアンス比ｋ値をパラメータとして描いた吸引力Ｆの変化を示すものである。この場合、ｋ値が１．５より小さい領域では磁気飽和が生ずる。 Next, FIG. 11 shows an example of an electromagnet having a stroke of 4 mm. The inclination angle θ of the truncated cone with respect to the axis orthogonal plane is set to 80.1 degrees (constant value), and the magnetic path permeance ratio k value is used as a parameter. The change of the drawn suction force F is shown. In this case, magnetic saturation occurs in a region where the k value is less than 1.5.

次に図１２はストロークが１．２ｍｍの実施例の電磁石における傾斜角度８０度における磁路のパアミアンス比ｋ値をパラメータとした吸引力Ｆの変化を示すものである。ｋ値が０．７より小さい領域では磁気飽和が生ずる。 Next, FIG. 12 shows changes in the attractive force F with the parameter of the magnetic path permeance ratio k value at an inclination angle of 80 degrees in the electromagnet of the embodiment having a stroke of 1.2 mm. Magnetic saturation occurs in the region where the k value is less than 0.7.

以上のように本発明の実施例の電磁石はストロークと、ストロークの進行に伴う吸引力の変化に応じて、パアミアンス比ｋ値はそれぞれ適切な値が存在し、総合すると０．７〜４の範囲において、好適である。すなわち、コイル通電による起磁力Ｕとストロークに応じて、０．７〜４の範囲内の適切な値を採用することにより磁気飽和を生ずることなく吸引力を高めた高感度の電磁石を得ることができる。 As described above, according to the electromagnet of the embodiment of the present invention, the permeance ratio k value has an appropriate value according to the stroke and the change in the attractive force with the progress of the stroke. In, it is suitable. That is, it is possible to obtain a highly sensitive electromagnet having an increased attractive force without causing magnetic saturation by adopting an appropriate value within a range of 0.7 to 4 according to the magnetomotive force U and stroke caused by energization of the coil. it can.

図１３に傾斜角度θ値選定グラフを掲げた。図１３はｘを横軸にとり実施例の電磁石においてパアミアンス比ｋ値を３．３（一定値）とし、傾斜角度θをパラメータとして７５〜８４度の範囲で変更し、吸引力Ｆ_xを描いたものである。図１３に示すように、電磁石の可動鉄心始動時（ｘ＝６ｍｍ）に所要の高吸引力を発生して、可動鉄心吸引過程（ｘ＝６→０へ移動過程）でも適切な吸引力の発生を保証する円錐台鉄心円錐面の傾斜角度θの最適値は８２〜８４度であり、高感度電磁石の設計に当たっては、傾斜角度θを適切に選定することが必要である。 FIG. 13 shows an inclination angle θ value selection graph. FIG. 13 shows the attractive force F _x by changing x to the horizontal axis and changing the permeance ratio k value to 3.3 (constant value) in the electromagnet of the embodiment and the inclination angle θ as a parameter in the range of 75 to 84 degrees. Is. As shown in FIG. 13, the required high suction force is generated at the time of starting the movable core of the electromagnet (x = 6 mm), and the appropriate suction force is generated even in the movable core suction process (movement process from x = 6 → 0). The optimum value of the inclination angle θ of the conical surface of the truncated cone core that guarantees is 82 to 84 degrees, and it is necessary to appropriately select the inclination angle θ when designing a highly sensitive electromagnet.

上記の最適傾斜角度θの選定は、電磁石の所要設計条件に対応して、前記（１）式の繰り返し演算によって算定することができ、電磁石の形状、寸法その他の条件に対応して７５度以上８５度以下の範囲に選定すると好適である。 The selection of the optimum inclination angle θ can be calculated by the repetitive calculation of the equation (1) corresponding to the required design conditions of the electromagnet, and 75 degrees or more corresponding to the electromagnet shape, dimensions and other conditions. It is preferable to select a range of 85 degrees or less.

なお、円錐台空洞の円錐面と軸直交面との傾斜角度に対して、円錐台鉄心の円錐面と軸直交面との傾斜角度を若干大きく設定して、吸引力特性の改善を図ることができる。図１４はこれを示すもので、円錐台空洞１５の軸直交面との傾斜角度θ₂に対して円錐台鉄心の円錐台１２の円錐面と軸直交面との傾斜角度θ₁との関係をθ₁＞θ₂とすることにより、吸引力特性が改善される。 Note that it is possible to improve the attractive force characteristics by setting the inclination angle between the conical surface of the frustum core and the axis perpendicular to the axis orthogonal to the inclination angle between the conical surface of the frustum cavity and the axis orthogonal to the axis. it can. FIG. 14 shows this, and the relationship between the inclination angle θ ₁ between the cone surface of the truncated cone 12 and the axis orthogonal surface of the truncated cone iron core with respect to the inclination angle θ _{2 with} respect to the axis orthogonal surface of the truncated cone cavity 15 is shown. By satisfying θ ₁ > θ ₂ , the attractive force characteristics are improved.

ここで、傾斜角度θの増加に伴う鉄心磁路の磁束密度の増大は、パアミアンス比ｋ値が一定値であるため、傾斜角度８４度ではの場合には鉄心磁路の磁気飽和を誘起せず、傾斜角度８５度を超過すると磁気飽和の影響を考慮する必要が生ずる。 Here, the increase of the magnetic flux density of the iron core magnetic path with the increase of the tilt angle θ does not induce magnetic saturation of the iron core magnetic path when the tilt angle is 84 degrees because the permeance ratio k value is a constant value. When the inclination angle exceeds 85 degrees, it is necessary to consider the influence of magnetic saturation.

従って、実用的な円錐台傾斜角度の設定値は、７５度乃至８５度の範囲として、始動時（ｘ＝６ｍｍ）に所要の吸引力を発生する電磁石の吸引力特性を選定することができる。 Therefore, the practical setting value of the truncated cone tilt angle can be in the range of 75 to 85 degrees, and the attractive force characteristics of the electromagnet that generates the required attractive force at the start (x = 6 mm) can be selected.

以上のように、本発明によれば適切なパアミアンス比ｋ値の設定によって両鉄心吸着時の吸引力を適切に選定し、そして適切な円錐傾斜角度θの設定によって始動時の適正な吸引力を選定して、電磁石の所要の吸引力特性を選択することができる。 As described above, according to the present invention, the suction force at the time of attracting both iron cores is appropriately selected by setting an appropriate permeance ratio k value, and the appropriate suction force at start-up is set by setting an appropriate cone inclination angle θ. The required attractive force characteristics of the electromagnet can be selected.

さて、図２及び図３に示す本発明の実施例では、図１に示す実施例と異なり、可動鉄心の円柱状部１３の径が固定鉄心２１の円錐台状空洞の底面径と同一径、またはより小径に形成されている。この例は電磁石の外形寸法を縮小し、所要吸引力の発生を可能とする電磁石構成の実施例を示している。 2 and 3, the embodiment of the present invention shown in FIGS. 2 and 3 is different from the embodiment shown in FIG. 1 in that the diameter of the columnar portion 13 of the movable iron core is the same as the bottom diameter of the frustoconical cavity of the fixed iron core 21. Or it is formed in a smaller diameter. This example shows an embodiment of an electromagnet configuration that reduces the outer dimensions of the electromagnet and enables generation of a required attraction force.

すなわち図２の模式構造断面図を参照して、磁束の通過する半径ｒ_mの円錐台磁路断面積と、動作間隙磁路断面積（半径ｒ_mで軸方向長ｈの磁極面の面積）を等しくすると、
πｒ_m ²＝２πｒ_mｈｒ_m＝２ｈ
となる。 That with reference to schematic structural cross-sectional view of FIG. 2, a truncated conical cross-sectional area of magnetic path of radius r _m to pass the magnetic flux, the operation gap magnetic path cross-sectional area (area of the pole face axial length h in radius r _m) Are equal,
πr _m ² = 2πr _m h r _m = 2h
It becomes.

ここで、鉄心磁路の磁束密度許容値を１．５ｗｂ／ｍ²以下、そして動作間隙磁束密度を鉄心磁束密度許容値の半分である０．７５ｗｂ／ｍ²以下に設定し、鉄心磁路の磁束密度を均等化すると、上記式を下記の実用的な式に変換することができる。 Here, the magnetic flux density allowable value of the iron core magnetic path is set to 1.5 wb / m ² or less, and the operating gap magnetic flux density is set to 0.75 wb / m ² or less, which is half of the iron core magnetic flux density allowable value. If the magnetic flux density is equalized, the above equation can be converted into the following practical equation.

ｒ_m＝ｈ ……（４）
例えば、電磁石鉄心磁路の磁気飽和の影響を考慮して、円錐台頂面を同一径の柱状空洞または柱状非磁性体に形成すると、鉄心磁路の各部分の磁束密度の均等化を図ることができ、電磁石の円錐台鉄心を形成する柱状鉄心の半径を、所要ストローク長と略同一に縮小し、電磁石の小型軽量化を容易に実施できることを示す。 r _m = h (4)
For example, when the top surface of the truncated cone is formed into a columnar cavity or columnar nonmagnetic material having the same diameter in consideration of the magnetic saturation effect of the electromagnetic core magnetic path, the magnetic flux density of each part of the core magnetic path is equalized. This shows that the radius of the columnar core forming the frustoconical core of the electromagnet is reduced to be substantially the same as the required stroke length, and the electromagnet can be easily reduced in size and weight.

図１０〜図１３に掲げる電磁石吸引力特性曲線のグラフ及び上記（４）式を参照して、下記の結論を取り纏めることができる。 The following conclusions can be summarized with reference to the graphs of the electromagnet attractive force characteristic curves shown in FIGS.

（１）電磁石の吸着時（ｘ＝近傍）の吸引力は、磁路のパアミアンス比ｋ値が小さいほど大きい。しかし、過少なパアミアンス比ｋ値の設定では、動作間隙に作用する起磁力Ｕ_xの減少を招き、電磁石の両鉄心吸着時の吸引力を低下させる。 (1) The attraction force when the electromagnet is attracted (x = near) is larger as the permeance ratio k value of the magnetic path is smaller. However, when the permeance ratio k value is set too low, the magnetomotive force U _x acting on the operating gap is reduced, and the attractive force at the time of attracting both iron cores of the electromagnet is reduced.

（２）電磁石の始動時（ｘ＝６ｍｍ）の吸引力は、円錐台の円錐面の軸直交面に対する傾斜角度θの設定値が９０度に接近するほど高吸引力を発生するが、同時に動作間隙に作用する起磁力Ｕ_xの減少を招き、磁気飽和により電磁石の吸引力特性を却って低下させる恐れが発生する。 (2) The attraction force when starting the electromagnet (x = 6 mm) generates a higher attraction force as the set value of the inclination angle θ of the truncated cone with respect to the axis perpendicular to the axis approaches 90 degrees, but operates simultaneously. The magnetomotive force U _x acting on the gap is reduced, and there is a possibility that the attractive force characteristic of the electromagnet is deteriorated due to magnetic saturation.

（３）これらの事情を勘案して、それぞれの所要ストローク長に対応する、磁路のパアミアンス比ｋ値の選定と、円錐台の円錐角θ値の適切な設定によって、容易に電磁石の所要吸引力特性を選択をすることができる。 (3) Taking these circumstances into account, the required suction of the electromagnet can be easily achieved by selecting the permeance ratio k value of the magnetic path corresponding to each required stroke length and appropriately setting the cone angle θ value of the truncated cone. Force characteristics can be selected.

（４）一般的な電磁石では、電磁石の所要ストローク長に対応して、電磁石磁路のパアミアンス比ｋ値を０．７〜４の範囲とし、円錐台の円錐面の傾斜角度θを７５度以上８５度以下の範囲に選定することが望ましい。 (4) In a general electromagnet, the permeance ratio k value of the electromagnet magnetic path is in the range of 0.7 to 4 corresponding to the required stroke length of the electromagnet, and the inclination angle θ of the conical surface of the truncated cone is 75 degrees or more. It is desirable to select within the range of 85 degrees or less.

（５）円錐台空洞の頂面を同一径の柱状空洞または柱状非磁性体に形成し、鉄心磁路の磁束密度の均等化を図り、電磁石の鉄心径を所要のストローク長と略同一の寸法に縮小すれば電磁石の小型軽量化を図ることができる。 (5) The top surface of the truncated cone cavity is formed in a columnar cavity or columnar non-magnetic material with the same diameter to equalize the magnetic flux density of the iron core magnetic path, and the iron core diameter of the electromagnet is approximately the same as the required stroke length. If the size is reduced, the size and weight of the electromagnet can be reduced.

実施例の電磁石の構造を示す断面図である。It is sectional drawing which shows the structure of the electromagnet of an Example. 実施例の電磁石の構造を示す断面図である。It is sectional drawing which shows the structure of the electromagnet of an Example. 実施例の電磁石の構造を示す断面図である。It is sectional drawing which shows the structure of the electromagnet of an Example. 実施例の電磁石の構造を示す断面図である。It is sectional drawing which shows the structure of the electromagnet of an Example. 実施例の電磁石の構造を示す断面図である。It is sectional drawing which shows the structure of the electromagnet of an Example. 電磁石磁路の等価回路図である。It is an equivalent circuit diagram of an electromagnet magnetic path. Ｕ_xの算出グラフである。It is a calculated graph of U _x. 実施例の作用説明図である。It is operation | movement explanatory drawing of an Example. 実施例の作用説明図である。It is operation | movement explanatory drawing of an Example. 実施例の作用説明図である。It is operation | movement explanatory drawing of an Example. δ_x値算出グラフである。It is (delta) _x value calculation graph. 吸引力のグラフである。It is a graph of suction power. 吸引力のグラフである。It is a graph of suction power. 吸引力のグラフである。It is a graph of suction power. 吸引力のグラフである。It is a graph of suction power. 実施例の傾斜角度の関係を示す説明図である。It is explanatory drawing which shows the relationship of the inclination angle of an Example. 従来技術の断面図である。It is sectional drawing of a prior art. 従来技術の作用説明図である。It is operation | movement explanatory drawing of a prior art. 従来技術の作用説明図である。It is operation | movement explanatory drawing of a prior art. 従来技術の作用説明図である。It is operation | movement explanatory drawing of a prior art.

符号の説明Explanation of symbols

１０電磁石
１１（１１ａ，１１ｂ）可動鉄心
１２円錐台部
１３円筒部
１４ストッパ
１５円錐台空洞
２１固定鉄心
２２、２３ヨーク
２４凹凸空洞部
２５動作間隙
２６摺動間隙
２７円錐台突起
３１コイル
３２ボビン DESCRIPTION OF SYMBOLS 10 Electromagnet 11 (11a, 11b) Movable iron core 12 Frustum part 13 Cylindrical part 14 Stopper 15 Frustum cavity 21 Fixed iron core 22, 23 Yoke 24 Concavity and convexity part 25 Operation gap 26 Sliding gap 27 Frustum protrusion 31 Coil 32 Bobbin

Claims

固定鉄心又は可動鉄心の一方に形成した円錐台空洞とこれに対向する同軸の他方の円錐台鉄心を設けた電磁石において、円錐台空洞の最小径頂面及びその軸方向隣接部を非磁性体とし、可動鉄心と上記固定鉄心との吸着位置を規制するストッパを設け、かつ、鉄心磁路の磁気飽和を発生しない所定起磁力における固定鉄心と可動鉄心の吸着位置の動作間隙パアミアンス値と摺動間隙パアミアンス値との比を一定範囲内に定めたことを特徴とする高感度電磁石。 In an electromagnet provided with a truncated cone cavity formed in one of a fixed iron core or a movable iron core and the other conical cone iron core facing the same, the minimum diameter top surface of the truncated cone cavity and its axially adjacent portion are made non-magnetic. A stopper that regulates the adsorption position between the movable iron core and the fixed iron core, and an operating gap permeance value and a sliding gap at the adsorption position of the fixed iron core and the movable iron core at a predetermined magnetomotive force that does not cause magnetic saturation of the iron core magnetic path. A high-sensitivity electromagnet characterized in that the ratio to the permeance value is set within a certain range.

前記比の一定範囲は電磁石の所要ストロークに応じて０．７〜４であることを特徴とする請求項１記載の高感度電磁石。 The high-sensitivity electromagnet according to claim 1, wherein the constant range of the ratio is 0.7 to 4 according to a required stroke of the electromagnet.

前記円錐台の円錐面と軸直交面との傾斜角度を７５〜８５度としたことを特徴とする請求項１又は２記載の高感度電磁石。 The highly sensitive electromagnet according to claim 1 or 2, wherein an inclination angle between the conical surface of the truncated cone and the axial orthogonal surface is set to 75 to 85 degrees.

前記円錐台空洞の大径に対して、前記円錐台鉄心に連設する円柱状鉄心径を同一寸法又は小径としたことを特徴とする請求項１〜３の何れかに記載の高感度電磁石。 The high-sensitivity electromagnet according to any one of claims 1 to 3, wherein the diameter of the cylindrical iron core connected to the truncated cone iron core is the same or smaller than the large diameter of the truncated cone cavity.

前記円錐台空洞の円錐面と軸直交面との傾斜角度に対して、前記円錐台鉄心の円錐面と軸直交面との傾斜角度を大きく設定したことを特徴とする請求項１〜４の何れかに記載の高感度電磁石。 5. The tilt angle between the conical surface of the truncated cone core and the axis perpendicular to the axis is set larger than the inclination angle between the conical surface of the frustoconical cavity and the axis orthogonal to the axis. A high-sensitivity electromagnet as described in the above.