JPH0516647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a polarized electromagnet suitable for use in relays and the like.

BACKGROUND ART FIG. 7 is a perspective view showing the structure of a polarized electromagnet according to the prior art. The polar electromagnet 51 includes a pair of U-shaped yokes 52 and 53 disposed facing each other, a permanent magnet piece 54 held and fixed between the yokes 52 and 53, and the yokes 52 and 53. end portions 58a and 58b; It is installed so that it can be freely angularly displaced. Furthermore, due to the magnetic poles N and S of the permanent magnet piece 54, each end 5 of the yokes 52 and 53
8a, 58b and 59a, 59b have N, S
For example, the magnetic poles of the armature 55 are formed as shown in FIG.
It is wound perpendicularly to the longitudinal direction of 5.

FIGS. 8 1 and 8 2 are diagrams for explaining the operation of a conventional polarized electromagnet 51. 81 and 82 are both plan views of the polarized electromagnet 51 shown in FIG. 7, and corresponding parts are given the same reference numerals. York 52, 53
At each end 58a, 58b; 59a, 59b,
The same magnetic poles N and S as shown in FIG. 5 are formed, respectively, and the respective ends 58a, 58b;
b and both ends 60, 61 of the armature 55,
Four voids 62, 63, 64, and 65 are formed.

When a current i is passed through the coil 57 in the directions indicated by arrows a and b in FIG. As a result, among the four voids 62 to 65, the void 62,
A repulsive force is generated at 65, and an attractive force is generated at the voids 63 and 64, respectively. As a result, Amachiya 55
One end 60 (right side in Fig. 8 1) is indicated by the arrow Fa
The other end 61 (Fig. 8
) is subjected to the force indicated by arrow Fb. Force Fa,
Since Fb is equal in size and opposite in direction,
The armature 55 supported by the pivot 56 acts as a couple. Therefore, the armature 55 is angularly displaced about the pivot 56, and its one end 60 is connected to the end 59a of one yoke 53 and the other end 61.
are in pressure contact with the end portion 58b of the other yoke 52, respectively.

FIG. 8 2 is a diagram for explaining the operation when a current i in the opposite direction to that in the case of FIG. 8 1 described above is passed through the coil 57. Since the current i flows in the direction opposite to that shown in FIG. 81, the armature 55 receives forces in the directions indicated by arrows Fc and Fd, contrary to that shown in FIG. 81.
Therefore, Amachiya 55, contrary to Fig. 8 1,
One end 60 of the yoke 52 is connected to one end 58a of the yoke 52.
The other end 61 is in pressure contact with one end 59b of the yoke 53. In this way, a plate spring (not shown) having a movable contact is moved by the armature 55 which can be freely angularly displaced,
By providing a fixed contact (not shown) corresponding to the movable contact, a relay that operates when the coil 57 is energized can be realized.

In this way, the polarized electromagnet 51 according to the prior art is
A current is passed through a coil 57 wound around the armature 55 to magnetize the armature 55, and a desired operation is performed using the repulsive force and attractive force generated between the coil 57 and the yokes 52 and 53 having magnetic poles. .

However, such a polar electromagnet is operated using only the attractive force or repulsive force generated between the armature 55 and the yokes 52 and 53. Therefore, in order to increase the operating speed, the suction force must be increased, and the suction force F is given by F=1/2·φ ² /P ² ·dP/dx (1). Here, φ is magnetic flux, and P is permeance, which is the reciprocal of magnetic resistance. From the first equation, the suction force F
In order to increase the magnetic flux φ, the magnetic flux φ may be increased or the area of the opposing magnetic poles may be increased. On the other hand, using a ferromagnetic magnet (rare earth or archon) to increase the magnetic flux φ increases the cost. A configuration in which the area of the magnetic poles is increased to increase the number of magnetic fluxes has the problem of increasing the size and cost.

FIG. 9 is a graph showing the relationship between the displacement amount (stroke) of the armature 55 of the polarized electromagnet 51 and the attraction force according to the prior art. In FIG. 9, the repulsive force acting on the armature 55 is shown as an attractive force in the negative direction. When increasing the area or increasing the magnetic flux φ in order to increase the attraction force in order to increase the operating speed, the attraction force characteristics will be the same as the previous reference 11.
The solid line graph indicated by 1 is displaced to the dotted chain line graph indicated by reference numeral 112, and the amachia 55
As is displaced and approaches end A or B, the rise or fall of the suction force characteristics becomes steeper, and the difference g from the suction force up to that point becomes larger.

When a polarized electromagnet with such characteristics is used in a relay, etc., the amount of displacement (stroke) of the armature
The ratio of change in attraction force to change in is too large, making it difficult to match with the leaf spring load. Although a method is used to suppress the rate of change in attraction force at the end by attaching a resistive plate to the contact surface, in the case of frequently used polarized electromagnets, etc., the problem of wear of the plate arises. Changes in characteristics become large. Therefore, there has been a demand for a polarized electromagnet that does not significantly change the attractive force with respect to changes in the displacement (stroke) of the armature and that can operate at high speed.

Purpose The purpose of the present invention is to solve the above-mentioned technical problems and provide a polarized electromagnet that increases the attractive force for high-speed operation and that has a gentle change in the attractive force with respect to the displacement (stroke) of the armature. It is to be.

Embodiment FIG. 1 is a perspective view showing the structure of a polarized electromagnet according to an embodiment of the present invention. The polar electromagnet 1 includes a pair of L-shaped yoke members 2 and 3;
3, and an armature 5 which is attached so as to be angularly movable around the vertical axis of FIG. has been done.

One end of each of the yoke members 2 and 3 is connected to one magnetic pole of the permanent magnet piece 4, and is formed integrally with the permanent magnet piece 4, forming a U-shape as a whole. The other end portions 7 and 8 of the yoke members 2 and 3 as magnetic pole tips are provided with a first magnetic pole according to the magnetic poles N and S of the permanent magnet piece 4, respectively.
Magnetic poles N and S are formed as shown.

The armature 5 includes an armature main body 9, and a pair of legs 10, 11; 12, 12, 12,
13, facing legs 10, 11; 1
Recesses 14 and 15 are formed between 2 and 13. A first coil 20 is wound along the longitudinal direction of the armature main body 9 between the recesses 14 and 15, and a second coil 22 is wound around the center of the armature main body 9 perpendicular to the first coil 20. and both ends are shorted. Furthermore, the ends 7, 8 of the yoke members 2, 3 mentioned above are interposed in the recesses 14, 15.
This allows the ends 7, 8 and the legs 10 to 1 to
Between 3 and 4 spaces 16, 17, 18, 19
is formed. What should be noted in this example is:
A second coil 22 is wound perpendicularly to the first coil 20. Its effect will be described later.

FIGS. 2 1 and 2 are diagrams for explaining the operation of the polarized electromagnet 1 according to this embodiment. Second
FIG. 1 is a plan view of the polarized electromagnet 1 shown in FIG. 1, and FIG. 2 is an enlarged view of the vicinity of one leg 10, 11 of the armature 5. In both figures, parts corresponding to those in FIG. 1 are given the same reference numerals. However, for convenience of explanation, the first coil 20 shown in the first diagram is omitted and not shown in FIGS. The cross section at 15 is shown as reference numerals 21a and 21b, and the cross section of the second coil 22 is also shown as 23a and 23b. Also, the ends 7, 8 of the yoke members 2, 3
It is assumed that the same magnetic poles N and S as in FIG. 1 are formed. Next, the operation will be explained with reference to FIGS. 1 and 2.

2. In FIG. 2, a current i is applied to a coil (not shown) wound along the longitudinal direction of the armature main body 9 (horizontal direction in FIG. 2) in the direction indicated by an arrow R.
When passed through, the armature 5 is magnetized and magnetic poles N and S as shown appear on the armature main body 9 and legs 10, 11, 12, and 13, respectively. Therefore, there is a repulsive force in the gaps 16 and 19, and the gap 1
Attractive force acts on 7 and 18, and since the ends 7 and 8 are fixed, armature 5 receives forces in the directions indicated by arrows f1 and f2, resulting in an angular displacement about pivot axis 6. At this time, what should be noted first is the magnetic field within the recesses 14 and 15 and the conductive wires 21a and 21.
This is the electromagnetic force generated by the current i flowing through b.

FIG. 2 shows one leg 10,1 of the armature 5.
FIG. 1 is a diagram showing an enlarged view of one neighborhood. In the recess 14, a plurality of conductive wires 21a are arranged in a plurality of rows in a direction perpendicular to the page, and the direction of current i during operation is from the back to the front of the page.

It is assumed that one end 7 of the yoke member 2 is magnetized by a permanent magnet 4 (not shown) and forms a magnetic pole N. Therefore, a magnetic flux φ is generated from the end 7 toward the other end 8 (not shown), and this magnetic flux φ is perpendicular to the conducting wire 21a.

Now, when a current i is passed through the conductor 21a in the direction shown in the figure (direction from the back to the front of the paper), the conductor 21
Due to the above-mentioned magnetic flux φ and current i, a receives an electromagnetic force F1=Bil (2) according to Fleming's left-hand rule. However, l is a value obtained by multiplying the length of the recess 14 portion of the conducting wire 21a, that is, the length corresponding to the thickness of the armature 5, by the number of turns. The direction of the electromagnetic force F1 shown in the above Table 2 equation is the same direction as the arrow f1, that is, upward in FIG. 2, and this is the same direction as the force f1 shown in FIG. It is. The electromagnetic force F2 generated in the other recess 15 (not shown) is generated in the same manner, and its direction is opposite to the above-mentioned electromagnetic force F1 and is in the same direction as the arrow f2 shown in FIG. 2.

Figure 3 shows the coil 20 wound around the armature 5.
3 is a diagram showing the operation when the current i flowing in the direction (not shown) is set in the direction indicated by the arrow L opposite to that shown in the second figure (from the right to the left in FIG. 3). FIG. Since the current i is in the opposite direction, the magnetic pole generated in the armature 5 is also opposite,
An attractive force acts on the gaps 16 and 19, and a repulsive force acts on the gaps 17 and 18. Also, the conductor 2 in the recess 14
Electromagnetic forces F3 and F4 act on the conductive wire 21d in the recess 15 in accordance with Fleming's left-hand rule, and act on the conductive wire 21d in the recess 15 in accordance with Fleming's left-hand rule.

In this way, the air gap 5 has the voids 16 to 16.
In addition to the attraction force generated on the armature 19, electromagnetic forces F1, F2 or F3, F4 according to Fleming's left hand rule are applied, so the attraction force acting on the armature 5 increases.

What should be further noted in this embodiment is that a first coil 20 and a second coil 22 perpendicular to the first coil 20 are wound around the armature 5 to form a mutual induction circuit, and both ends of the second coil 22 are short-circuited. This is what is being done.

FIG. 4 is an equivalent circuit diagram showing the relationship between the first coil 20 and the second coil 22. L1 is the inductance of the first coil 20, R1 is its internal resistance, L
2 represents the inductance of the second coil 22, R2 represents its internal resistance, and M represents the coupling constant in the mutual induction circuit. Further, i1 is a current flowing through the first coil 20 (hereinafter referred to as coil current), i2 is a second coil current induced in the second coil 22, and E is a power supply voltage. The coupling constant M is expressed as M=√12...(3), and in this example, for example, M=
It is 1. If the switch SW is now closed, the following relationships will be established in the circuit shown in the fourth diagram: L1di1/dt+Mdi2/dt+R1i1=E...(4) L2di2/dt+Mdi1/dt+R2i2=0...(5). From equations 3 to 5 above, it(t)=E/R1[1-(1-L2/L2+R2L1/R1)exp(- αt)...(6) Here, α=R1R2/R1L2+R2L1... (7) The second coil 22 is short-circuited, and in FIG.
When R2=0, the sixth equation becomes i1(t)=E/R1 (8), which eliminates the influence of the inductance of the circuit. On the other hand, in the case of the conventional technology that does not provide the second coil 22, the circuit includes an inductance L1, and L1di1/dt+R1i1=E......(9) i1(t)=E/R1[1-exp(-R1/L1t )] ...(10) That is, by winding the second coil 22 and short-circuiting both ends thereof, the excitation current i is no longer affected by the inductance of the first coil 20, and rises quickly.

FIG. 5 is a graph showing a comparison of coil currents between this embodiment and the prior art. The solid line indicated by reference numeral i1 indicates the coil current according to the present embodiment, and the two-dot chain line indicated by reference numeral i2 indicates the coil current according to the prior art. 2 also denoted by reference i3
The dashed line indicates the induced current flowing through the second coil 22. When the second coil 22 is provided according to the present embodiment and its both ends are short-circuited, the coil current i quickly reaches a steady current value, but in the prior art, due to the influence of the inductance of the coil wound in the amphitheater, It can be seen that it takes time to reach the steady current value, and in the process, the coil current fluctuates due to the influence of the displacement of the armature.

FIG. 6 is a graph showing the relationship between the displacement (stroke) of the armature 5 of the electromagnet 1 and the attraction force according to this embodiment. In FIG. 6, the repulsive force acting on the armature 5 is shown as an attractive force in the negative direction.

When the current i flowing through the armature 5 (hereinafter referred to as coil current i) is 0, the solid line indicated by reference numeral 11 indicates that the two-dot chain line indicated by reference numerals 12 and 14 opposes the coil current i having the same value. This shows the case where only the suction force is applied when flowing in the direction, and the tendency is the same as that shown by reference numeral 111 in FIG. 9 described in the section of the prior art. On the other hand, in this embodiment, as mentioned above, in addition to the conventional attractive force, electromagnetic force F according to Fleming's left-hand rule is added, so the overall attractive force increases by Δf, as shown by the solid lines indicated by reference marks l3 and l5. , indicating an increasing trend in suction power. Furthermore, this tendency does not result in steep rises and falls as in the prior art at the ends A and B, but follows a nearly parallel movement, making it easy to match the leaf spring load when responding to a relay or the like. Fluctuations and variations in the suction force at the ends A and B are reduced, and high-speed operation is realized by increasing the suction force.

Effects As described above, according to the present invention, by energizing the coil wound around the armature, the armature is magnetized in the direction in which its contact ends are arranged.
A magnetic repulsion force and a magnetic attraction force are generated between the magnetic pole generated in the armature due to this magnetization and the magnetic pole end of the yoke facing the magnetic pole. By switching the current direction to the coil, the armature is angularly displaced around an axis perpendicular to the arrangement direction.
Due to the energization and the magnetic flux of the permanent magnet piece, a force according to Fleming's left-hand rule acts on a portion of the coil in a direction perpendicular to the direction in which both magnetic pole ends of the yoke are connected. The angular displacement is also achieved by this force. In other words, we were able to significantly speed up the operation of this armature.

Furthermore, by short-circuiting the second coil that is wound across the first coil, the inductance of the first coil is reduced and the coil current is made more responsive, thereby improving the operation of the armature. Further speed-up is realized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a polarized electromagnet according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining the operation of this embodiment, and FIG. 4 is an equivalent diagram of this embodiment. The circuit diagram, FIG. 5 is a graph comparing the coil current of this embodiment and the conventional technology, FIG. 6 is a graph showing the relationship between the displacement amount (stroke) of the armature 5 of this embodiment and the attraction force, and FIG. The figure shows the prior art, Figure 8 is a diagram for explaining the operation of the prior art, and Figure 9 shows the prior art.
The figure is a graph showing the relationship between the displacement amount (stroke) of the armature 55 and the suction force in the prior art. 1,51...Polarized electromagnet, 2,3...Yoke member, 4,54...Permanent magnet piece, 5,55...Amateur, 6,56...Pivot, 20,57...First coil, 22 ...Second coil, 57...Coil.

Claims (1)

[Scope of Claims] 1. A yoke having a permanent magnet and having a pair of magnetic pole tips having opposite polarities, and an armature portion extending on both sides of each magnetic pole tip extending between the magnetic pole tips. and a first armature supported so as to be angularly displaceable around an axis perpendicular to the arrangement direction connecting the pair of armature ends, and a first armature around which a wire is wound around the armature main body so as to extend along the arrangement direction. A polarized electromagnet comprising: a coil; and a second coil wound to intersect with the first coil.