JP2001358014A - High-sensitive electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and light high-sensitive electromagnet which provides a suction force stronger than a conventional one with less electric input. SOLUTION: A gap 9 of larger diameter different from a normal slide gap is provided between an outer peripheral surface of a moving iron core 4 and an inner peripheral surface of an opening part 2 of a yoke 2 where the moving iron core 4 is away from a fixed iron core 3, or between counter surfaces, and a normal narrow gap (slide gap 6) is provided between counter surface, or between the outer peripheral surface of the moving iron core 4 and the inner peripheral surface of the opening part 2 of the yoke 2 where the moving iron core 4 contacts the fixed iron core 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet which generates a mechanical force when energized, and more particularly to a high-sensitivity electromagnet which generates a strong attraction force by a minute electric input and aims at reducing the size and weight.

[0002]

2. Description of the Related Art The conventional plunger type electromagnet shown in the schematic structural sectional view of FIG. 10 is a functional component for converting electric energy into mechanical force, and is characterized by its simple and sturdy structure and low manufacturing cost, which are important for social activities. It is used in a wide variety of fields.

A plunger type electromagnet shown in FIG. 10 has a coil 1 in which an electric wire is wound around a bobbin, a yoke 2 having a coaxial opening at one end of the bobbin hole to form a magnetic path outside the coil, and a bobbin hole. A fixed iron core 3 arranged at the other end and connected to the yoke, and a movable iron core 4 movably inserted from the opening of the yoke into the bobbin hole are provided. The lower half of FIG. 10 shows a first position where the movable core 4 contacts the fixed core 3, and the upper half shows a second position where the movable core 4 is separated from the fixed core 3. When the movable core 4 is in the second position, the space between the movable core 4 and the fixed core 3 is an operating gap 5.

The attraction force F of the electromagnet is represented by the following formula, where U is the magnetomotive force acting on the magnetic path by energizing the coil, P is the reciprocal of the magnetic resistance of the magnetic path, P, and x is the displacement of the movable core. It can be calculated by the equation 1).

[0005] F = The ^{(U 2/2) dP /} dx ......... (1), the magnetic circuit of the plunger type electromagnet, ignoring the slight magnetic low anti value of the core portion, the magnetic resistance of the operating gap 5 To _Ro
And then, the magnetic resistance of the sliding gap 6 between the outer and the opening inner peripheral surface of the yoke of the movable iron core and R _i, the magnetomotive force due to energization of the coil as E, be represented as an equivalent electrical circuit set forth in FIG. 12 it can. Power W of the magnetic resistance R _o of the operation gap 5 which corresponds to the magnetic attraction force of the electromagnet, can be calculated by the following equation.

W = R _o (E / R _o + R _i ) ² (2) The above equation (2) gives the magnetomotive force E and the magnetic resistance R _{i of the} sliding gap.
Was a constant value, the magnetic resistance R _o of the operation gap, it can be converted as a variable magnetic resistance R _i (3) where the relationship is established, the following formula (4).

R _o = ηR _i (3) W = E ² / R _i ｛η / (η + 1) ² ｝ (4) Then, the above equation (4) shows that W = E ² / R _i 100% value
As, η = R _o / R _i values of W corresponding to the change of the value, that is, the formula to calculate the variation condition of the attraction force F of the electromagnet corresponding to the change in magnetic low anti value R _o of operation gap, From the equation (4), the impedance matching graph shown in FIG. 15 can be obtained. Figure 15 Referring to impedance matching graph listed, the occurrence of the maximum suction force of the plunger-type electromagnet, requires establishment of the condition of R _o ≒ R _i, R _o
It is apparent that the suction force under the condition of <R _i decreases sharply with the decrease of the η value.

A technical problem of the conventional plunger type electromagnet will be described with reference to a schematic structural sectional view of FIG. FIG. 10 shows the position of the movable core at the start (second position) in the upper half, and the position of the movable core at the completion of suction (first position) in the lower half. First, Paamiansu value 1 / R _o of the operation the gap 5 shown is increased, the movable iron core to generate a suction force F of the equation (1) by energization of the coil according to movement in the right direction of the movable iron core 4 Is driven to the right of the axis to maintain the first position (the state shown in the lower half of FIG. 10).

On the other hand, the sliding gap 6 corresponds to the sliding gap shown in FIG.
As shown in the enlarged view of FIG.
The inner peripheral surface 11 and the opening of the yoke 2 are coaxial with each other through a gap δ.
Radius r inserted through_pOn the outer peripheral surface 13 of the cylindrical movable iron core 4
And the p-amiance value P is
Is the value of the ratio of the area of the pole face to _p
It is proportional to t / δ and is not related to the axial movement of the movable core 4.
It can be calculated as a predetermined value. Therefore,
Of the differential value dP / dx of the Pamiance value P of the sliding gap 6 of
The value is zero.
It is clear that no attractive force F occurs.

That is, a conventional plunger type electromagnet is
Pamiance value 1 of working gap 5 due to movement of movable core 4
/ R _o fluctuation, the sliding gap 6 has a pamiance value of 1
/ R _i always shows a constant value, and it is difficult to satisfy the above-described condition of impedance matching of R _o ≒ R _i . Further, the sliding gap 6 has technical problems such as the necessity of passing an ineffective magnetic flux that does not generate any attraction force in the axial direction.

FIG. 13 shows a conventional electromagnet with a magnetic attraction pole plate. In FIG. 13, the lower half has the movable iron core at the first position, and the upper half has the movable iron core at the second position. A study will be made with reference to the schematic structural sectional view of FIG. The electromagnet with an attractive magnetic pole plate is attached to a movable iron core 4 of a conventional plunger-type electromagnet shown in FIG. 10 so as to come into contact with and separate from an axial orthogonal surface of a yoke 2 as the movable iron core moves in the axial direction. 7
Are arranged. The operating gap 5 of the electromagnet with the attraction magnetic pole plate has the same configuration and the same function as the above-mentioned conventional plunger type electromagnet. As shown in an enlarged view in FIG. 14, the sliding gap 6 of the electromagnet with the attraction magnetic pole plate is slid by reducing the separation dimension x between the axis perpendicular to the yoke 2 and the attraction magnetic pole plate accompanying the displacement of the movable iron core 4. 1 / R _i , which is the permeance value of the dynamic gap 6, is increased, and an energizing coil generates an attractive force F in the axial direction.

[0012] Now, Paamiansu value of the gap of the yoke surface of the shaft perpendicular to the and the suction pole plate, the size of the gap between the suction pole plate and the yoke plane x, the radius of the disk-shaped suction pole as r _a, It is proportional to the value of (r _a -r _p ) ² / x.

Accordingly, the permeance value of the sliding gap 6 shown in FIG. 13 is determined by the radius r which is coaxially inserted into the opening of the yoke having the axial length t via the gap length δ.
_As a magnetic path parallel to the magnetic path of the cylindrical movable iron core of _p , 2r _p
It is proportional to the numerical value of the equation of t / δ + (r _a −r _p ) ² / x. Then, according to the above equation (1), in this sliding gap 6, the differential equation dP / dx of the above equation (r _a -r _p /
x) Generates an axial suction force F proportional to ² .

[0014] However, each of the above formula, for the first time sufficient effect by setting the value of the radius r _a of the suction pole plate 7 sufficiently large value than the radius r _p and displacement amount x of the movable iron core 4 It is important to note that it can be used. That is, the conventional suction pole fitted with electromagnet displacement amount x of the movable iron core to be effective by the occurrence of conditions that are very small compared to the value of the radius r _a of the suction pole plate. Therefore, it is unavoidable to increase the size of the attraction magnetic pole plate 7 and increase the complexity of the configuration due to the increase in the required displacement x.

[0015]

SUMMARY OF THE INVENTION The present invention is an improvement over the prior art as described above, and is intended to achieve a demand for a small and light-weight and energy-saving device or machine using an electromagnet. Another object of the present invention is to provide a high-sensitivity electromagnet capable of increasing the sensitivity of the performance of the electromagnet, that is, generating a strong attractive force by a minute electric input and reducing the size and weight of the electromagnet.

[0016]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies and completed the present invention. That is, the present invention provides a coil 1 in which an electric wire is wound around a bobbin, a yoke 2 having a coaxial opening at one end of the bobbin hole to form a magnetic path outside the coil, and a yoke 2 disposed at the other end of the bobbin hole. And a movable core 4 that moves between a first position that is movably inserted from the opening of the yoke into the bobbin hole and contacts the fixed core and a second position that is separated from the fixed core. Type electromagnet,
A gap is provided between opposing surfaces of the movable core outer peripheral surface and the yoke opening inner peripheral surface at the second position, and a gap is provided between the opposing surfaces of the movable iron core outer peripheral surface and the yoke opening inner peripheral surface at the first position. It is a high-sensitivity electromagnet characterized by the following. Here, the gap refers to a gap having a large diameter difference different from the sliding gap formed between the inner peripheral surface of the opening of the yoke and the outer peripheral surface of the movable core. A gap similar to the gap.

The gap may be formed with a large diameter on the inner peripheral surface of the yoke opening, and the narrow gap may be formed with a large outer diameter on the movable core. May be formed with a small outer diameter of the movable core in a portion facing the above. Preferably, the end of the gap on the side opposite to the fixed core is located at the outer end face position of the yoke opening at the second position, and furthermore, the separation dimension of the narrow gap is set with the movement of the movable core in the fixed core direction. One or both of the inner peripheral surface of the yoke opening and the outer peripheral surface of the movable core facing each other with a small gap may be formed as an inclined surface with respect to the axial direction so as to improve the suction force characteristics acting on the movable core. it can.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an embodiment of the present invention. In the upper half, the movable core has a starting position (second position),
The lower half shows the position (first position) at the time of completion of suction of the movable iron core. FIG. 2 is a front view of FIG.

The embodiment shown in FIG. 1 includes a coil 1 in which an electric wire is wound around a bobbin, a yoke 2 having a coaxial opening at one end of the bobbin hole and forming a magnetic path outside the coil, and a bobbin hole. Fixed core 3 arranged at the other end and connected to yoke
And a movable iron core 4 which is movably inserted into the bobbin hole from the opening of the yoke and comes into contact with and separates from the fixed iron core. And an operating gap 5 between the end faces of the fixed iron core 3 and the movable iron core 4,
This is an improvement over a conventional plunger-type electromagnet in which a sliding gap 6 is formed between an inner peripheral surface 11 of an opening of a yoke and an outer peripheral surface 13 of a movable iron core. The feature is that the movable iron core 4 is the second
A gap 9 is provided between the outer peripheral surface 13 of the movable core 4 and the inner peripheral surface 11 of the opening of the yoke 2 at the position (the upper half of FIG. 1). In the (state), the gap 6 is formed between the opposing surfaces of the outer peripheral surface 15 of the large diameter portion 4 of the movable core and the inner peripheral surface 11 of the opening of the yoke 2. It is desirable that the axial length of the inner surface of the opening of the yoke 2 be set in accordance with the required stroke length of the electromagnet.

The inner circumference of the opening of the yoke 2 of the embodiment shown in FIG.
FIG. 3 schematically shows a portion where the surface and the movable core 4 face each other.
Was. The embodiment shown in FIG. 1 is similar to the prior art plug shown in FIG.
The sliding gap 6 of the jagged electromagnet is changed to a gap 9
is there. That is, as shown in FIG.
The diameter of the inner peripheral surface 11 is increased, and the inner peripheral surface of the opening of the yoke 2 is increased.
11 and a radius r coaxially inserted therethrough_pOf movable iron core 4
The gap 9 was provided between the outer peripheral surface 13 and the outer peripheral surface 13. And movable iron core 4
Is in the first position, the yoke 2
The large diameter portion 8 facing the inner peripheral surface 11 of the opening
Provided. This large diameter portion 8 has a radius r of the movable iron core._pGreater than
Radius r_bHas a large diameter portion outer peripheral surface 15. Gap 9 is movable iron
When the core 4 is in the second position, the inner peripheral surface of the opening of the yoke 2
11 and an outer peripheral surface 13 of the movable iron core 4.
When the movable iron core 4 moves to the first position, the yoke 2
Inner peripheral surface 11 of the opening and outer peripheral surface 1 of large diameter portion 8 of movable core 4
5 is a narrow gap having a minute gap δ. others
The normal diameter r of the movable core 4 _pPart and large diameter part r_bPart of
When the movable iron core 4 is at the second position,
The end of the gap 9 on the side opposite to the fixed core is the outer end face of the yoke 2.
Optimally, it is equal to 12.

From the viewpoint of the above-described paierance alignment, it is apparent that it is desirable to form the permeance value of the gap 9 when the movable iron core moves in the axial direction so as to substantially match the permeance value of the operating gap 5. is there.

Here, there are three types of representative shapes of the through-type (see FIG. 11), the attracting magnetic pole type (see FIG. 14), and the insertion type (see FIG. 3), and the relative values of the path ambience and the attractive force are shown. Table 1 compares the formulas for calculating the values.

Therefore, the path ambience value of the through gap magnetic path is expressed by the following equation: P = r with respect to the axial displacement x of the movable core.
by _p t / [delta], if the separation distance of the axial length t and gap radius r _p and the gap of the movable iron core [delta] is constant, irrespective shows a constant value displacement amount X, the movable iron core in the through-shaped gap magnetic path Since the magnetic attraction force acting on (1) satisfies the attraction force proportional expression dP / dx = 0, it is apparent from the above equation (11) that it is zero and does not act.

Next, the path ambience of the attraction magnetic pole type gap magnetic path is described.
The value is expressed by a relational expression P = (r) with the amount of displacement x in the axial direction of the movable core.
_a-R_b)^Two/ X gives r_aThe value of the parameter and
And r _b= 1 and listed in the graph of FIG.
The magnetic attractive force acting on the movable core in this gap is
Attraction force proportional expression dP / dx = ｛(r_a-R_b) / X)｝^TwoTo
Therefore r_aParameter to the value of and r_bCalculated as = 1
FIG. 17 shows a graph.

Further, the magnetic path of the embodiment shown in FIG. 1 forms a push-type gap magnetic path shown in FIG. 3, and is formed between the inner peripheral surface 11 of the opening of the yoke and the outer peripheral surface 15 of the large diameter portion of the movable core. The path ambience value is expressed as P, where x is the displacement of the movable iron core 4 in the axial right direction.
= (R _b ０．５0.5δ) x / δ proportional to the value calculated by the formula,
The differential equation dP / dx is the radius r _b of the movable iron core large diameter portion parameters, and by the formula of the gap dimension K = not related to displacement x of the movable iron core a [delta] as a variable (r _b + 0.5δ) / δ It can be calculated and shown in the graph of FIG.

[0026] Now, the electromagnet of the present invention listed in Figure 1, the formula for calculating the suction force proportional value and Pasumiansu value of the gap magnetic circuit, the movable iron core large diameter portion of the radius r _b and gap dimension δ of selecting means It applied to, against Pasumiansu value P _a behavior gap 5 to increase with the axial direction of the displacement of the movable iron core 4, the gap 9
Impedance matching means for substantially matching the path immunity value P of the
= (R _b ten 0.5δ) / δ
It can be superimposed on the axial suction force generated in the working gap 5.

That is, the electromagnet of the present invention shown in FIG. 1 can be a high-sensitivity electromagnet which can generate a high attractive force by a smaller electric input than the electromagnet of the prior art.

FIG. 4 shows that the shape of the end of the gap 9 on the side opposite to the fixed core is inclined by the inclined surface 21 provided on the inner peripheral surface of the opening of the yoke 2 and the inclined surface 41 provided on the movable core 4. In this case, the effect of generating a strong suction force with the small electric power is equivalent. FIG. 5 shows an example in which a larger-diameter attracting magnetic pole plate 7 is attached to the outside of the large-diameter portion 8 of the embodiment of FIG.

Next, in the embodiment shown in FIG. 6, in the plunger-type electromagnet, when the movable iron core 4 is at the second position, the movable iron core faces the inner peripheral surface 11 of the opening of the yoke 2 via a gap. A part of the outer peripheral surface 13 of the iron core 4 is coaxial with the small diameter portion 1.
4 is an electromagnet formed with a gap 9.

The gap 9, as shown in the schematic enlarged view in FIG. 7, when the movable iron core 4 is in the second position, the small-diameter portion 14 having a radius r _c to the outer peripheral surface 13 of the movable iron core 4 of a radius r _p It is formed. With such a simple configuration, an operation similar to that of the embodiment shown in FIG. 1 is performed, and a high-sensitivity electromagnet can be provided. However, the movable iron core 4 shown in FIG.
The radius r _p is preferably set to a larger radius than the shaft perpendicular magnetic pole surface radius of the tip of the fixed iron core 3 facing the operating gap 5.

As shown in FIG. 8, one or both of the inner peripheral surface 11 of the opening of the yoke 2 and the outer peripheral surface 13 of the movable core 4 which faces the inner peripheral surface 11 of the opening with a gap therebetween, as illustrated in FIG. It may be formed as an inclined surface 21 and / or 41 with respect to the axial direction. The formula dP / dx = (r _b +
0.5Deruta) As shown in / [delta], the suction force acting on the movable core 4, since it can be selected by the setting value of the radius r _b and gap length [delta] of the movable iron core 4, the inclination and shape of the form slopes 21, 41 by properly selecting the angle, it is possible to adjust the change of the radius r _b and gap length δ of the movable iron core 4 with the movement of the movable iron core 4, to select the required suction force characteristics.

Note that the configuration of the present invention shown in FIG.
As shown in (1), the attracting magnetic pole plate 7 may be attached to further improve the suction holding force of the movable iron core 4.

[0033]

[Table 1]

[0034]

According to the electromagnet of the present invention, compared with the electromagnet of the prior art, a strong attraction force is generated by a minute electric input, so that it is possible to contribute to a reduction in the size and weight of an apparatus or a machine and energy saving. .

The electromagnet of the present invention has the following advantages: (a) The attraction force is doubled with an electromagnet having the same external shape and the same electric input as compared with the electromagnet of the prior art.

(B) With an electromagnet having the same electric power and the same attractive force, the outer dimensions can be reduced by half.

(C) With an electromagnet having the same external force and the same attractive force, the electric input is reduced by half. It has an excellent effect that enables it.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment.

FIG. 2 is a front view of the embodiment.

FIG. 3 is a partial explanatory view of FIG. 1;

FIG. 4 is a partial explanatory view of FIG. 1;

FIG. 5 is a schematic sectional view of an electromagnet according to an embodiment of the present invention.

FIG. 6 is a schematic sectional view of an electromagnet according to another embodiment of the present invention.

FIG. 7 is a partial explanatory view of FIG. 6;

FIG. 8 is a partial explanatory view of FIG. 6;

FIG. 9 is a partial explanatory view of FIG. 6;

FIG. 10 is an explanatory diagram of a conventional electromagnet.

FIG. 11 is an explanatory diagram of a conventional electromagnet.

FIG. 12 is an explanatory diagram of an equivalent electric circuit of a magnetic path of a conventional electromagnet.

FIG. 13 is an explanatory diagram of another conventional electromagnet.

FIG. 14 is an explanatory diagram of another conventional electromagnet.

FIG. 15 is an explanatory graph of impedance matching.

FIG. 16 is a graph showing a relationship between a displacement x and a Pamiance P.

FIG. 17 is a graph showing a relationship with a displacement dP / dx.

FIG. 18 shows the sliding gap δ and (r _p + 0.5δ) / δ
6 is a graph showing a relationship with the graph.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coil 2 Yoke 3 Fixed iron core 4 Movable iron core 5 Working gap 6 Sliding gap 7 Attraction pole plate 8 Large diameter portion 9 Gap 11 Opening inner peripheral surface 12 Yoke outer end surface 13 Movable iron core outer peripheral surface 14 Small diameter portion 15 Large diameter outer peripheral surface 21, 41 Inclined surface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuneo Uehara Hara 3-9-1, Shirahata, Urawa-shi 2-601 F-term (reference) 3H106 DA23 DB02 DB12 DB23 DB32 EE16 EE22 GA11 GA15 GA21 5E048 AA08 AD04 CA04

Claims (5)

[Claims] A coil having a wire wound around a bobbin;
A yoke 2 having a coaxial opening at one end of the bobbin hole to form a magnetic path outside the coil, a fixed iron core 3 disposed at the other end of the bobbin hole and connected to the yoke, In a plunger-type electromagnet comprising a first position which is freely movable through and contacts a fixed core and a movable core 4 which moves between a second position separated from the fixed core, the plunger-type electromagnet includes an outer peripheral surface of the movable core at the second position. A high-sensitivity electromagnet, wherein a gap is provided between opposing surfaces of an inner peripheral surface of a yoke opening and a gap is provided between an outer peripheral surface of a movable core and an inner peripheral surface of a yoke opening at the first position. 2. The high-sensitivity electromagnet according to claim 1, wherein the gap is formed with a large diameter on the inner peripheral surface of the yoke opening, and the narrow gap is formed with a large outer diameter of the movable iron core. . 3. The high-sensitivity electromagnet according to claim 1, wherein the gap is formed by making the outer peripheral surface of the movable iron core at a portion facing the inner peripheral surface of the yoke opening small. 4. An end portion of the gap on the side opposite to the fixed core in a position axially coincident with an outer end surface of the yoke opening at the second position. High sensitivity electromagnet as described. 5. One or both of the inner peripheral surface of the yoke opening and the outer peripheral surface of the movable core, which are opposed to each other by the small gap, so that the separation dimension of the small gap decreases with the movement of the movable core in the fixed core direction. The high-sensitivity electromagnet according to any one of claims 1 to 4, wherein the high-sensitivity electromagnet is formed as an inclined surface with respect to the axial direction.