JPS6134246B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a rotary solenoid.

(B) Conventional technology Conventional so-called rotary solenoids have a structure in which the same number of teeth are cut on the inside of the yoke and the outside of the rotor, or a permanent magnet with an even number of magnetic poles is used in the rotor like a step motor. The structure consists of a yoke with the same number of teeth,
In both cases, the rotor is supported by a bearing, and by energizing an appropriately wound drive coil (hereinafter simply referred to as a coil), magnetic energy is supplied to the magnetic gap created between the yoke and the rotor, and rotational torque is applied to the rotor. This is the common format. Since the rotational torque applied to the rotor is proportional to the square of the magnetic flux density generated in the magnetic gap, in order to increase the rotational torque, the magnetic flux density in the magnetic gap must be increased. In the former type, the magnetic flux density b is generated only by the magnetomotive force generated by energizing the coil, so if the magnetomotive force is small, that is, the input power is small, sufficient rotational torque cannot be generated. In the latter type, it is proportional to the sum of the magnetic flux density B generated by the magnetomotive force of the permanent magnet and the magnetic flux density b generated by the magnetomotive force of the coil, that is, the square of (B+b).

That is, the rotational torque T is as shown in equation (1).

T∞(B+b) ² = B ² +2Bb+b ² ...(1) The first term on the right side of equation (1) is an amount proportional to the rotational torque generated by the permanent magnet, but it does not increase with the input current. do not have. The second and third terms are quantities proportional to the rotational torque generated by the magnetomotive force of the coil. According to equation (1), in order to increase the rotational torque T, it is necessary to increase both the magnetic flux densities B and b, but in the latter type mentioned above, the magnetic flux due to the magnetomotive force of the coil passes through a permanent magnet with low magnetic permeability. This becomes an obstacle to increasing the magnetic flux density b due to the magnetomotive force of the coil, making it difficult to increase the efficiency of the rotary solenoid.

The drawings will be explained in detail below. 1st, 2nd,
Figures 3 and 4 are schematic structural diagrams of conventional rotary solenoids, Figures 1 and 2 are horizontal and side sectional views of a type that does not use permanent magnets, and Figures 3 and 4 are horizontal cross-sectional views of a type that uses permanent magnets in the rotor. and a side sectional view. In FIGS. 1 to 4, 1 is a yoke that also serves as a case, 2 is a coil, 3 and 4 are rotors, 5 is a rotating torque extraction shaft, and 6 is a bearing. The yoke 1 is made of a magnetic material with high magnetic permeability and has yoke teeth 7. The rotor 3 is also made of a high permeability magnetic material and has the same number of rotor teeth 8 as the yoke teeth 7. The rotor 4 is diametrically magnetized with a permanent magnet and has the same number of magnetic poles N and S as the rotor teeth 7.
have.

In Figures 1 and 2, when the coil 2 is energized, magnetic flux flows as shown by the arrow in the magnetic path 9 seen from the coil.
The magnetic flux also passes through the gap 10 created by the yoke teeth 7 and the rotor teeth 8. If the magnetic flux density of the air gap 10 is B, a rotational force proportional to b ² acts on the rotor 3 in the direction of the arrow 11, and rotational torque can be transmitted to an external load via the shaft 5.

In Figures 3 and 4, magnetic flux first flows through the permanent magnet rotor 4 along its magnetic path 12 in the direction of the arrow, and also passes through the gap 13 formed by the yoke teeth 7 and 7' and the rotor 4. . If the magnetic flux density due to the permanent magnet rotor 4 in the air gap 13 is B, a rotational torque proportional to B ² acts on the rotor 4 in the direction of the arrow 14.

Therefore, when the coil 2 is held in this position with a suitable stopper and the coil 2 is energized in the direction shown in FIGS. 3 and 4, a magnetic flux passes in the opposite direction to the arrow along the magnetic path 12 seen from the coil 2. Yoke tooth part 7 is N pole,
The yoke tooth portion 7' becomes the south pole. If the magnetic flux also passes through the air gap 13 and its magnetic flux density is b, then the magnetic poles N-S of the rotor 4 will reach the horizontal position on the paper (B-b) ²
After that, a rotational torque proportional to (B+b) ² acts in the opposite direction to the arrow 14. But coil 2
The magnetic path 12 seen from above includes the permanent magnet rotor 4 .

In general, the magnetic permeability of permanent magnet materials is low, approximately 1 for ferrite and rare earth magnets (that is, approximately the same as air), and at most 10th for alnico magnets. Therefore, if the magnetic resistance of the magnetic path is large and the magnetomotive force is the same, the air gap 1 will be smaller than that of a magnetic path that does not include a permanent magnet.
The magnetic flux density b of No. 3 is small, and an efficient rotary solenoid cannot be expected.

(c) Problems to be Solved by the Invention The present invention has been made to alleviate the above-mentioned drawbacks of the conventional art.

(d) Means for solving the problem The features of the present invention are that the yoke teeth are made of a high permeability material and have two yoke tooth ends, and the high Consisting of a rotor with rotor teeth made of a magnetically permeable material and a driving coil wound around the yoke teeth, the rotor teeth span adjacent yoke tooth ends to form a magnetic gap. It is in.

(E) Function In the present invention, the magnetic path is separated into a permanent magnet magnetic path and a coil magnetic path, including the two-part yoke tooth end portion and the rotor tooth portion made of a high magnetic permeability material. The path is a parallel magnetic path with a magnetic path that includes a permanent magnet and a magnetic path that does not include a permanent magnet, and the magnetic flux due to the magnetomotive force of the coil mainly passes through the magnetic path that does not include a permanent magnet. Magnetic energy is transferred to the magnetic air gap that generates rotational torque. It is designed to supply

(f) Examples The drawings will be explained in detail below.

5 and 6 are horizontal and side sectional views showing one embodiment of the rotary solenoid of the present invention. In the figure, 15, 15' are the yoke teeth of the yoke 1, and the tips thereof are the yoke teeth ends 16, 17, 16', 1.
It is divided like 7'. A rotor 18 is composed of a rotor core 19, rotor teeth 20, 20', and permanent magnets 21, 21'. N,S
are the magnetic poles of the permanent magnets 21, 21'. 2, 5 and 6 are the same as in FIGS. 1 to 4, and the rotor core 19,
The rotor teeth 20, 20' are made of high magnetic permeability material. Here, the rotor core 19 and permanent magnets 21, 2
Even if the permanent magnet is integrated with 1', the operation described below will not change.

The structural feature of the present invention is that unlike conventional rotary solenoids, the yoke teeth and the rotor teeth do not correspond one-to-one, but as shown in FIG. Adjacent yoke tooth ends 16, 16' and 17, 1 of sections 15 and 15'
7'.

7 and 8 are cross _- sectional views for explaining the operation _of the rotary solenoid of the present invention together with FIG. . FIG. 9 shows an example of actually measuring the number of magnetic fluxes passing through each part with respect to the rotation angle of the rotor 18. The horizontal axis represents the rotation angle θ of the rotor 18, and the vertical axis represents the number of magnetic fluxes φ caused by the permanent magnets 21 and 21'. and the number of magnetic flux φ when a constant current is passed through the coil 2.

In the figure, solid lines 15 (Φ), 15' (Φ), 16
(Φ), 17' (Φ) and 17 (Φ), 16' (Φ)
The number of magnetic fluxes due to the permanent magnets 21, 21' passing through the yoke teeth 15, 15', the yoke teeth ends 16, 17', and 17, 16', respectively, is indicated by the two-dot chain line 1.
6 (φ), 17 (φ), dashed line 17 (φ), 1
6' (φ) and three-dot chain line 21 (φ), 21' (φ)
These are the yoke tooth ends 16, 17', 1, respectively.
7, 16' and the permanent magnets 21, 21' due to the magnetomotive force of the coil 2. 1 in the diagram
For 5(Φ) and 15'(Φ), the direction of the magnetic lines of force is reversed depending on the sign of θ, but due to space limitations, they are written on the positive side of φ.

The magnetic flux directly related to the operation is carried out at the yoke tooth end 16,
17' and 17, 16'. 1
6 (Φ), 17' (Φ) and 17 (Φ), 16'
Focusing on (Φ), in the state of θ=0, that is, in Fig. 7, 21 → 20 → air gap 20-16 → 16 → 17 →
A magnetic path a that goes around the air gap 17-20' → 20' → 21' → 19 → 21, and 21 → 20 → air gap 20-1
6'→16'→17'→Gap 17'-20'→20'→
Divided into magnetic path b that goes around from 19 to 21, approximately the same number of magnetic fluxes 16 (Φ), 17' (Φ) and 17 (Φ), 1
6' (Φ), and almost no magnetic flux flows through the yoke teeth 15, 15'.

As shown in Figures 5 and 8, when θ=〓θ ₀ , the magnetic flux is divided into the two magnetic paths a and b, but θ=-θ
At ₀ , the magnetic flux passing through air gaps 20-16' and air gaps 17-20' is greater than the magnetic flux passing through air gaps 20-16 and air gaps 17'-20'. This causes the magnetic flux passing through the magnetic paths a and b to the air gaps 20-16 and 17'-20' to be newly added to 21→20→air gaps 20-16'→1
6'→15'→1→15→17→Gap 17-20'
→ 20' → 21' → 19 → Magnetic flux 15 (φ) and 15' (φ) are added to magnetic path c that goes around 1
This is because they become 7(φ) and 16'(φ). θ=+
The same goes for the case of θ ₀ , newly changing 21 → 20 → air gap 20.
-16→16→15→1→15'→17'→Gap 1
The magnetic fluxes 15 (Φ) and 15' (Φ) of the magnetic path d that goes around 7'-20' → 20' → 21' → 19 → 21 are connected to the air gap 2.
0-16 and void 17'-20' plus 16
(Φ), 17'(Φ).

The number of magnetic fluxes due to the magnetomotive force of coil 2 is 17 (φ), 1
Focusing on 6' (φ), 16 (φ), and 17' (φ), if θ=O, that is, the state shown in Figure 7, and the direction of the current flowing through the coil 2 is selected as shown in Figure 5, 15' → 1
6'→Gap 16'-20→20→Gap 20-16→
Permanent magnet 2 that goes around 16 → 15 → 1 → 15'
Magnetic path e that does not include 1, 21' and 15'→17'→
The air gap 20'-17→17→15→1→15' is divided into a magnetic path f that does not include the permanent magnets 21 and 21', and approximately the same number of magnetic fluxes 16 (φ), 17 (φ), and 17 ( φ), 16'(φ) pass through, permanent magnet 2
There is almost no flow in the magnetic paths a and b including 1 and 21'.

As shown in Figs. 5 and 8, when θ=〓θ ₀ , the magnetic flux is divided into the above two magnetic paths e and f, but θ=-θ
At ₀ , the magnetic flux through air gaps 20-16' and air gaps 17-20' is slightly larger than the magnetic flux through air gaps 20-16 and air gaps 17'-20'. This is because the magnetic flux 21 of the magnetic path c, which includes the permanent magnets 21 and 21' that are parallel to the magnetic path e, is added to the magnetic flux passing through the magnetic paths e and f and the air gap 20-16 and the air gap 17'-20'. (φ) and 21' (φ) are the gap 20-16' and the gap 17-
This is because they are added to 20' and become 17 (φ) and 16' (φ). Similarly, when θ=+θ ₀ , the magnetic fluxes 21(φ), 21'(φ) of the magnetic path d parallel to the magnetic path f are newly added.
is added to the gaps 17'-20' and 20-16, resulting in 16(φ) and 17'(φ). However, magnetic paths c and d are both made of permanent magnets 21 and 21' with low magnetic permeability.
Since the magnetic resistance seen from coil 2 is
The magnetic paths e and f are larger than those of the
21 (φ) and 21' (φ) are very small, and it can be assumed that the magnetic flux due to the magnetomotive force of the coil 2 is actually determined by the magnetic paths e and f. Thus, if the coil 2 is energized in the direction shown in FIG.
(Φ) and 16 (φ) and 17' (Φ) and 17'
(φ) sum of 16 (Φ + φ) and 17' (Φ + φ)
The magnetic flux passes through the air gap 16'-20 and the air gap 17-
20' has 16' (Φ), 16' (φ) and 17
The difference between (Φ) and 17 (φ) is 16' (Φ - φ) and 1
7(Φ-φ) of magnetic flux passes through.

Next, the outer radius of the rotor 18 is R, the thickness is H, the air gaps 16-20, 17'-20', and the air gap 17-2.
The length along the arc of 0', 16'-20 is l ₁₆ ≒ l ₁₇
′ and l ₁₇ ≒ l ₁₆ ′, and now suppose that the rotor teeth 20, 2
The length along the arc of 0' is 4Rθ ₀ , θ=-θ ₀
If l ₁₆ ≒ l ₁₇ ′=O, θ=+θ ₀ and l ₁₇ ≒ l ₁₆ ′=O, then l ₁₆ ≒ l ₁₇ ′ and l ₁₇ ≒ l ₁₆ ′ are expressed by equation (2) l ₁₆ ≒ l ₁₇ ′ =R(θ ₀ +θ), l ₁₇ ≒l ₁₆ ′=R(θ ₀ -θ) ...(2). Therefore, the permanent magnets 21, 2 in each gap
The magnetic flux density due to 1′ is B ₁₆ ≒B ₁₇ ′ and B ₁₇ ≒B ₁₆ ′,
And the magnetic flux density due to the magnetomotive force of coil 2 is b ₁₆ ≒ b _1
7 ' and b ₁₇ ≒ b ₁₆ ', the rotational torque T of the rotor 18 in the direction in which θ increases is given by equation (1): T∞2 {(B ₁₆ + b ₁₆ ) ² − (B ₁₇ + b ₁₇ ) ² } =22/ ^R2H2 [{16(Φ-φ)/( ^θ0 _- θ
)} ² − {17 (Φ − φ) / (θ ₀ − θ)} ² ] ...(3) The rotational torque T _M due to the permanent magnets 21 and 21' is θ
is between −θ ₀ and +θ ₀ , l ₁₆ +l ₁₇ is constant as l ₁₆ +l ₁₇ =2Rθ ₀ (4), so the permanent magnets 21, 2
The magnetic resistance as viewed from 1' is approximately constant and B ₁₆ ≒ B ₁₇ . Therefore, since the increase in the volume of the gaps 16-20, 17'-20' is the same as the decrease in the volume of the gaps 17-20, 16'-21', the rotational torques of both gaps are balanced, and the shaft 5 The rotational torque of is almost 0. In the range of θ<-θ ₀ , the gap lengths of the gaps 16-20 and 17'-20' become large and no magnetic flux passes through them. On the other hand, in the air gaps 16'-20 and 17-20', l ₁₆ '≒l ₁₇ gradually increases from 2Rθ, and the magnetic flux density B
gradually decreases as θ decreases, so the rotating torque on shaft 5 in the direction shown by arrow 22 gradually decreases and becomes θ=-90
It becomes 0 at °. Similarly, in the range θ>+θ ₀ , the rotational torque shown by the arrow 23 gradually decreases in the direction in which θ increases, and reaches 0 at θ=+90°.

Fig. 10 shows an example of actually measured rotational torque T _M due to the permanent magnets 21, 21' as a solid line. is the arrow 23, and the negative side represents the rotational torque in the direction shown by the arrow 22.

In order to examine the rotational torque T _C due to the magnetomotive force of the coil 2, equation (3) [ ] is calculated as shown in equation (5).

T∞ [{16 (Φ) / (θ ₀ + θ)} ² − {17 (Φ
)/(θ ₀ −θ)} ² +216(Φ)×16(φ)/(θ ₀ +θ) ² +1
7(Φ)×17(φ)/(θ ₀ −θ) ² +{16(φ)/(θ ₀ +θ)} ² −17(φ)/
(θ ₀ -θ)} ² ]...(5) The first and second terms of equation (5) represent the rotational torque caused by the permanent magnets 21 and 21', as described above. The third and fourth terms and the fifth and sixth terms are the rotational torque due to the magnetomotive force of the coil 2, and the third and fifth terms are the air gaps 16-20 and 17-2.
The rotational torque generated at 0, the 4th and 6th terms are air gap 1
6'-20 and 17-20'.

Now, considering the range of θ from -θ ₀ to +θ ₀ , at θ=-θ ₀ , (θ ₀ +θ)≒0, so the third and fifth terms become abnormally large and are added, and the arrow 2
Obtain the rotational torque T _C in three directions. As θ gradually increases, the rotational torque Tc gradually decreases, but when θ=+ _θ0 , (θ−θ)≈0 again, so the rotational torque _Tc increases. However, it is smaller than the value of θ=−θ ₀ .
In the range where θ decreases from −θ ₀ , the rotational torque T _C
suddenly becomes O, and in the range where θ increases from +θ ₀ , the rotational torque T _C gradually decreases while taking a value slightly larger than the rotational torque T _M due only to the permanent magnets 21 and 21'. In Fig. 10, an example of the actual measured rotational torque T _C when a constant current is applied to the coil 2 is shown by a dotted line. The rotational torque T _C shown in Fig. 10 is θ = θmax where the rotational torque T _C is maximum in one actual measurement example.
does not always appear at the +θ ₀ position.
Furthermore, since it is possible to eliminate θ=θmin at which the rotational torque T _C is minimum, it is also possible to obtain a characteristic in which the rotational torque T _C gradually decreases.

Next, if the direction in which the coil 2 is energized is reversed, rotational torque in the direction shown by the arrow 22 will be generated, as is clear from the above description.

Now, in the rotary solenoid of the present invention, when the coil 2 is not energized, the stable points are at θ=±90° and near θ≒0.

If θ is within ±θ ₀ , rotational torque can be applied to the rotor 18 in the clockwise or counterclockwise direction depending on the current direction to the coil 2. However, if θ is stable at ±90°, the rotational torque to the coil 2 can be applied. Rotational torque cannot be applied unless a fairly large current is passed.
Therefore, it is necessary to provide a stopper that prevents the rotor 18 from decreasing or increasing by more than θ= _〓θ0 . Set the stopper position to θ=〓θ around ₀ |θ|<|θ
If it is provided at a position of ₀ |, it can be stably stopped at each position by the rotational torque T _M generated by the permanent magnets 21 and 21'. When it is stationary at θ≒-θ ₀ , if the coil 2 is energized in the direction shown in FIG. 5, the rotor 18 will rotate in the direction of arrow 23, and θ≒+θ _0.
Stop at the stopper position. Next, when a current is applied to the coil 2 in the direction opposite to that shown in FIG. 5, the rotor 18 rotates in the direction of the arrow 22 and comes to rest at the stopper position where θ≈− _θ0 . That is, the rotary solenoid of the present invention is a bistable rotary solenoid.

FIG. 11 is a cross-sectional view showing another embodiment of the rotary solenoid of the present invention, and the reference numerals are the same as those in FIG. 5.

FIG. 11 shows a stopper 24 made of a high magnetic permeability material approximately in the center of the inner surface of the yoke tooth ends 16, 17, 16', 17' which are divided into two parts of the yoke teeth 15 and 15'.
24' is fixed, and spacers 25, 25' made of non-magnetic material are attached to the end faces thereof. With this structure, even if the rotor 18 has a rotation angle θ≒±θ ₀ , the stoppers 24, 24' and the rotor teeth 2
0 and 20' are attracted, so the rotor 18 is moved to the fifth position.
It can be held more stably than the case shown in the figure. The degree of suction force can also be appropriately selected depending on the thickness of the spacers 25, 25'.

FIG. 12 is a cross-sectional view showing another example of application of the rotary solenoid of the present invention. 1 and 5 in the figure
are the yoke and rotating torque extraction shaft as in Fig. 5,
29, 30, 31 and 32 are yoke teeth;
9', 29'', 30', 30'', 31', 31'' and 3
2', 32'' are the yoke tooth ends of the yoke tooth parts 29, 30, 31, and 32, respectively; 33 is the rotor; the rotor core 34, the rotor tooth parts 35, 35', 36, 36', and the permanent magnets 37, 37; ', 38, 38', and N and S are the magnetic poles.The yoke, yoke teeth, yoke tooth ends, rotor teeth, and rotor core are all made of high magnetic permeability material.39 ,39'
and 40, 40' are driving coils. As is clear in the figure, the rotor teeth 35, 36, 35' and 36' are connected to the adjacent yoke teeth ends 29'', 3, respectively.
0', 30'', 31', 31'', 32' and 32'', 2
9' to form a magnetic gap.

(G) Effects of the Invention As explained above in detail with reference to the drawings, in the rotary solenoid of the present invention, the magnetic path seen from the drive coil is parallel to the magnetic path including the permanent magnet and the magnetic path not including the permanent magnet. The magnetomotive force of the drive coil passes through a magnetic path that does not include a permanent magnet, increasing the magnetic flux density in the air gap that generates rotational torque. Therefore, it is possible to obtain a large rotating torque in harmony with the magnetic flux density generated in the air gap by the permanent magnet, and there is no need to use a return spring, thereby providing an efficient power-saving rotary solenoid. I can do it. Furthermore, not only can clockwise and counterclockwise rotational torque be obtained by simply changing the polarity of the current applied to the drive coil, but it can also be used as a bistable rotary solenoid. Although not shown in the drawings, since the stopper can be mounted externally, it becomes easier to take measures to reduce impact noise, which has significant practical advantages such as the ability to reduce operating noise.

[Brief explanation of the drawing]

1 and 5 are horizontal and side sectional views showing structural examples of a conventional rotary solenoid that does not use a permanent magnet,
Figures 3 and 4 are horizontal and side sectional views showing structural examples of a rotary solenoid using conventional permanent magnets;
and 6 are lateral and side sectional views showing an embodiment of the rotary solenoid of the present invention, 5, 7 and 8 are cross sectional views for explaining the operation of the rotary solenoid of the present invention, and 9 and 10 are 5 Figures 11 and 12 are cross-sectional views showing other embodiments of the rotary solenoid of the present invention. 1...Yoke, 2, 39, 39', 40, 4
0'... Coil, 3, 4, 18, 33... Rotor, 5... Shaft, 6... Bearing, 7, 7', 15, 1
5'29, 30, 31, 32...Yoke teeth, 1
6,16'17,17',29',29'',30',
30'', 31', 31'', 32', 32''... Yoke tooth end, 20, 20', 35, 36, 35'36'
...Rotor teeth, 4, 21, 21', 37, 3
7', 38, 38'...Permanent magnet, 24, 24'...
...stopper, 25, 25'...spacer.

Claims (1)

[Scope of Claims] 1. A rotary solenoid in which the yoke and the rotor each have an even number of teeth, the yoke tooth portion made of a high magnetic permeability material having two yoke tooth end portions, and a rotating magnet. It consists of a rotor with rotor teeth made of a high magnetic permeability material fixed to the N and S poles, and a drive coil wound around the yoke teeth. A rotary solenoid characterized by a magnetic gap being formed. 2. A patent claim characterized in that a stopper made of a high magnetic permeability material with a spacer made of a non-magnetic material fixed to both ends is provided at approximately the center of the inner side of the yoke tooth end portion which divides the yoke tooth portion into two. The rotary solenoid according to item 1 in the range.