JP2002317838A - Electromagnet and braking device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnet of a small noise in operation and a braking device using the same. SOLUTION: This braking device is provided with a field coil 12, a fixed iron core 3 provided with the field coil 12, a movable iron core 14 mounted oppositely to the fixed iron core 3, and attracted to the fixed iron core 3 when the field coil 12 is energized, and a spring 15 energized in the direction opposite to the attraction direction of the movable iron core 14. As the field coil 12 is mounted on a position shifted from a center of the fixed iron core 3, the electromagnetic attraction force acting on the movable iron core 13 is different in each part, so that the movable iron core 14 is moved while being rotated, the electromagnetic attraction force is partially used in the rotation of the movable iron core 14, and an average speed of the movable iron core 14 is lowered, whereby the hitting sound can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, an electromagnetic magnet for an electromagnetic brake and a braking device using the same.

[0002]

2. Description of the Related Art FIG. 28 is a sectional view of a main part showing the structure of a conventional electromagnetic magnet, and FIG. 29 is a view taken along the line XXIX-XXIX in FIG. FIG. 30 is a sectional view of a main part showing a holding state of a conventional braking device using an electromagnetic magnet, and FIG. 31 is a sectional view of a main part showing an open state of a braking device using a conventional electromagnetic magnet.

In these figures, a conventional electromagnetic magnet 11 is provided with a field coil 12, a fixed iron core 13 in which the field coil 12 is fitted, and a fixed core 13 opposed to the fixed iron core 13. The movable iron core 14 is moved by an electromagnetic force generated by energizing the movable iron core 14, and a spring 15 is an elastic body that urges the movable iron core 14 in a direction opposite to the direction of movement of the movable iron core 14 by the electromagnetic force. Further, the braking device 21 using the conventional electromagnetic magnet is provided with a fixed iron core 1.
3 is a fixed base 22 fixed by bolts 27, and a movable base 2 is fixed to the movable iron core 14 by bolts 27.
3 and a brake shoe 24 fixed to a surface of the movable base 23 opposite to the side to which the movable iron core 14 is fixed.
And a rotary drum 25 provided opposite to the brake shoe 24. Further, a movable portion 26 is constituted by the movable iron core 14, the movable base 23 and the brake shoe 24.

[0004] The fixed iron core 13 has an opposing surface opposing the movable iron core 14, and as shown in FIG. 28, a coil groove 16 formed in parallel to the left and right sides is provided as shown in FIG. Therefore, the opposing surface is divided by the coil groove 16 into an inner opposing surface 17 on the inside and a first outer opposing surface 18a and a second outer opposing surface 18b on both sides thereof. The area of the inner facing surface 17 is the first outer facing surface 18.
It is configured to be equal to the sum of the area of a and the area of the second outer facing surface 18b. The left and right symmetric annular field coils 12 are fitted into these coil grooves 16 so as to surround the inner facing surface 17 as shown in FIG. Further, an electromagnetic force generated by energizing the field coil 12 acts as a force for attracting the movable iron core 14 to the fixed iron core 13 side. Is set.

The spring 15 includes a fixed base 22 and a movable base 2.
3, the left side spring 15a and the right side spring 15b are symmetrically provided on both sides of the field coil 12, the fixed iron core 13, and the movable iron core 14. Further, one end of the spring 15 is fixed to the fixed base 22, and the other end is fixed to the movable base 23. The spring 15 is oriented so that the fixed base 22 and the movable base 23 are separated from each other in a contracted state. It is energizing.

The rotating drum 25 is a rotating body provided on a shaft (not shown) of, for example, an electric motor, and the rotation of the rotating drum 25 is braked by braking the rotation of the rotating drum 25. This rotating drum 2
The brake shoe 24 is used to brake the rotation of the
The elastic drum 5 comes into pressure contact with the rotary drum 25. The rotation of the rotary drum 25 is braked by the frictional force generated by this pressure contact. Therefore,
The repulsive force of the spring 15 is applied to the brake shoe 24 when pressed.
The frictional force between the rotary drum 25 and the rotary drum 25 is adjusted so as to have a magnitude that quickly brakes the rotation of the rotary drum 25.

The electromagnetic magnet 11 constructed as described above
Operates as follows. When the rotating drum 25 is in a stopped state, that is, in a holding state, the brake shoe 24 is in pressure contact with the rotating drum 25. When the rotating drum 25 rotates from this state, the field coil 12 is energized, and the electromagnetic force generated in the fixed iron core 13 by this energization attracts the movable iron core 14 toward the fixed iron core 13. The attracted movable core 14 moves in the direction of the fixed core 13 against the elastic repulsive force of the spring 15. The movable core 14 that has moved contacts the inner facing surface 17, the first outer facing surface 18a, and the second outer facing surface 18b of the fixed iron core 13 at the same time. At this time, since the area of the inner facing surface 17 is equal to the sum of the area of the first outer facing surface 18a and the area of the second outer facing surface 18b, the magnetic flux in each magnetic path is substantially uniform in density and the leakage flux is small. .

Further, since the field coil 12 and the fixed core 13 are symmetrical, the electromagnetic attraction generated in the movable core 14 is also symmetrical as shown in FIG. It moves in parallel toward and comes into contact with the inner facing surface 17, the first outer facing surface 18a, and the second outer facing surface 18b at the same time. When the movable iron core 14 moves toward the fixed iron core 13, the movable base 23 and the brake shoe 24 integrated with the movable iron core 14 also move toward the fixed iron core 13, and the brake shoe 24 separates from the rotating drum 25 and is opened. become. In the open state, the rotating drum 25 is free because the frictional force due to the pressure contact of the brake shoe 24 is removed, and the rotating drum 25 rotates by the rotation of the shaft of the electric motor or the like.

On the other hand, when braking the rotary drum 25 from the state in which the rotary drum 25 is rotating, that is, from the open state, when the energization of the field coil 12 is cut off, the electromagnetic attraction generated in the fixed iron core 13 disappears, and the spring is released. The movable core 14 separates from the fixed core 13 due to the elastic repulsion force of the movable core 15 and the movable core 1
The movable base 23 and the brake shoe 24 which are integrated with 4 also separate from the fixed iron core 13 and the brake shoe 24 comes into contact with the rotating rotary drum 25.

FIG. 33 is a graph showing the relationship between the magnitude of the current flowing through the field coil 12 from the point A when the power supply is cut off, the average speed of the movable portion 26, and the time from the point A when the power supply is cut off. is there. In FIG. 33, when the power supply to the field coil 12 is cut off, the current supplied to the field coil 12 gradually decreases. When the magnitude of the electromagnetic attraction force of the fixed core 13 generated by the energizing current falls below the magnitude of the elastic repulsive force of the spring 15, at the point B, the movable core 14 separates from the fixed core 13 and starts moving. This movable iron core 14
Since the electromagnetic attraction force is symmetrical in the left and right directions, the movable iron core 14 has an inner facing surface 17 of the fixed iron core 13 and a first outer facing surface 18a.
And the second outer facing surface 18b at the same time,
The movable part 26 including the four moves in parallel. The movable portion 26 that moves in parallel is accelerated by receiving the elastic repulsive force of the spring 15, and when the brake shoe 24 comes into contact with the rotating drum 25, the movable portion 26 is rapidly decelerated and stops at the point C. The movable part 26 moves and the brake shoe 24
When the rotating drum 25 is pressed by the elastic repulsive force of No. 5, a frictional force is generated by the pressing, and the rotating rotating drum 25 is braked.

[0011]

In the braking device 21 using such an electromagnetic magnet 11, when the rotating drum 25 is braked, the movable iron core 14 has the inner facing surface 17, the first outer facing surface 18a and the second outer facing surface 18a. The springs 15 on both sides simultaneously move away from the opposing surface 18b and push up while moving the entire movable portion 26 in parallel with the elastic repulsive force. In addition, at this time, the inner facing surface 17, the first outer facing surface 18a, and the second outer facing surface 18b no longer have an electromagnetic attraction force exceeding the elastic repulsion force of the spring 15, so that they can be moved at a stroke. The portion 26 is accelerated by the elastic repulsive force of the spring 15, and the brake shoe 24 of the movable portion 26 collides with the rotating drum 25 at high speed, generating a loud collision sound.

When the rotary drum 25 is rotated, the movable iron core 14 is simultaneously moved to the inner facing surface 17, the first outer facing surface 18a, and the second outer facing surface 18b by the electromagnetic attraction of the fixed iron core 13 at a high speed. Collision generates loud collision noise.

Therefore, there is a problem that measures such as mounting a soundproof wall are required to reduce the noise due to the collision sound.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an electromagnetic magnet with low noise during operation and a braking device using the same.

[0015]

According to the present invention, there is provided an electromagnetic magnet comprising: a fixed core; an annular coil provided on one surface of the fixed core;
An electromagnetic magnet comprising: a movable iron core that moves by an electromagnetic force generated by energizing the coil; and an elastic body that urges the movable iron core in a direction opposite to a moving direction of the movable iron core by the electromagnetic force. The coil is provided eccentrically with respect to the fixed core, the electromagnetic force acts unequally on the movable core, and the movable core rotates in the direction of the movement together with the movement of the movable core. It is something like that.

Further, the fixed core has an inner facing surface facing the movable core and surrounded by the coil, and an outer facing surface facing the movable core and outside the coil,
The area of the inner facing surface is equal to the area of the outer facing surface.

The outer facing surface surrounds the inner facing surface.

Further, the outer facing surface is divided into two on both sides of the coil, and the areas of the outer facing surfaces on both sides are different.

Further, the coil is arranged so as to fit within the outer shape of the fixed core when viewed along the direction in which the movable core is attracted.

The fixed core has a rectangular parallelepiped shape having a coil groove for accommodating the coil on a surface facing the movable core.

The fixed core has a cylindrical shape having a coil groove for accommodating the coil on a surface facing the movable core.

The fixed iron core has a thickness such that the thickness of the fixed iron core around the coil is such that a magnetic flux density in a cross section of a magnetic path through which a magnetic flux formed by a current flowing through the coil passes is constant.

The movable iron core has a thickness such that the movable core has a constant magnetic flux density in a cross section of a magnetic path through which a magnetic flux formed by a current flowing through the coil passes.

Further, a braking device according to the present invention is a braking device using the electromagnetic magnet according to the present invention, wherein a braking shoe fixed to the movable iron core and a rotating shoe provided opposite to the braking shoe are provided. A drum, wherein the movable iron core reciprocates in a direction substantially perpendicular to a contact surface of the rotating drum, and the brake shoe comes into contact with and separates from the rotating drum.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a cross-sectional view of a main part showing the configuration of an electromagnetic magnet according to Embodiment 1 of the present invention, and FIG. 2 is a view taken along the line II-II in FIG. 1 and 2, the electromagnetic magnet 1 includes a fixed iron core 3. Although the fixed iron core 3 is provided with the coil grooves 6 in parallel, unlike the conventional coil groove 16, the fixed iron core 3 is not provided at a symmetric position in the fixed iron core 3,
In the figure, they are provided shifted to the right. The field coil 12 is fitted in the coil groove 6. That is,
The axis P of the fixed core 3 and the axis Q of the field coil 12 do not coincide with each other and are eccentric. The area of the inner facing surface 7 of the fixed core 3 is equal to the sum of the area of the first outer facing surface 8a and the area of the second outer facing surface 8b.
Is different from the area of the second outer facing surface 8b. In the figure, the area of the first outer facing surface 8a is larger than the area of the second outer facing surface 8b. The other configuration of the electromagnetic magnet 1 is the same as the conventional configuration, and the other configuration of the braking device 20 using the electromagnetic magnet 1 is also the same as the conventional configuration.

In the electromagnetic magnet 1 having such a configuration, the position of the field coil 12 is not symmetrical in the fixed iron core 3 and the area of the first outer facing surface 8a and the area of the second outer facing surface 8b are smaller. Since the sizes are different, the magnitude of the electromagnetic attraction force acting on the movable core 14 is not symmetrical as shown in FIG. 3, and acts on the portion of the movable core 14 facing the first outer facing surface 8a. The first electromagnetic attraction force 4a, the inner electromagnetic attraction force 4c acting on the portion facing the inner facing surface 7, and the second electromagnetic attraction force 4b acting on the portion facing the second outer facing surface 8b have a magnitude of 4a. , 4c, 4
It becomes smaller in the order of b.

Therefore, the braking device 20 using the electromagnetic magnet 1 performs the following operation. That is, when the rotating drum 25 is rotating, the braking device 20 is in an open state, and the movable iron core 14 is fixed against the elastic repulsive force of the spring 15 by the electromagnetic attraction generated by energizing the field coil 12. The core 3 is in contact with the inner facing surface 7, the first outer facing surface 8a, and the second outer facing surface 8b. When braking the rotating drum 25, the brake shoe 24 is moved to the rotating drum 25 by cutting off the power supply to the field coil 12, extinguishing the electromagnetic attraction force, and pushing up the movable portion 26 by the elastic repulsive force of the spring 15. The rotation of the rotary drum 25 is braked by the frictional force caused by the contact. This operation will be described in detail below.

FIG. 4 is a partial cross-sectional view showing a state of the braking device 20 immediately after the movable core 14 has completely moved away from the fixed core 13 by interrupting the power supply to the field coil 12, and FIG. The magnitude of the current flowing through the field coil 12 from the point A, the average speed of the movable portion 26, and
It is a graph which shows the relationship with time from a point. FIG.
At point D, when the movable part 26 starts to have a speed,
Point E indicates the time when the brake shoe 24 is in pressure contact with the rotating drum 25 to be in a holding state. As shown in FIG. 5, when the power supply to the field coil 12 is cut off,
2 is gradually reduced. The first electromagnetic attraction force 4 acting on the movable iron core 14 as the conduction current decreases
a, the second electromagnetic attraction force 4b and the inner electromagnetic attraction force 4c are reduced.

Here, as shown in FIG. 3, the first electromagnetic attraction force 4a is the largest among the electromagnetic attraction forces acting on the movable iron core 14, and
Although the second electromagnetic attraction force 4b is the smallest, the first outer facing surface 8
a is larger than the conventional first outer facing surface 18a, and the area of the second outer facing surface 8b is larger than the conventional second outer facing surface 18b.
Therefore, the first electromagnetic attraction force 4a is large and the second electromagnetic attraction force 4b is small as compared with the conventional electromagnetic attraction force. Therefore, when the current supplied decreases and these electromagnetic attractive forces decrease at the same rate, the second electromagnetic attractive force 4
b cannot withstand the elastic repulsion of the spring 15 earlier than the conventional electromagnetic attraction force, and the first electromagnetic attraction force 4a
Can withstand the elastic repulsion of the spring 15 until a point later than the conventional electromagnetic attraction.

From this, when the movable iron core 14 starts to have a speed after the power supply is cut off, the point D is set to the second outer facing surface 8.
This is the time when the movable iron core 14 starts to move away from the point b. This point D is earlier than the point A at which the power supply is interrupted than the conventional point B.
The speed of the movable portion 26 including the movable core 14 that has started to move at the point D is given by the elastic repulsive force of the right spring 15b on the second outer facing surface 8b side. At this time, the first electromagnetic attraction force 4a
And the inner electromagnetic attraction force 4c has a sufficient attraction force to attract the movable iron core 14 against the elastic repulsive force of the spring 15, so that the movable iron core 14 comes into contact with the corner on the first outer facing surface 8a side. While rotating, the speed is increased only more slowly than in the prior art because it is attracted by the first electromagnetic attraction force 4a and the inner electromagnetic attraction force 4c.

Thereafter, the respective electromagnetic attractive forces decrease with the energizing current, and when the first electromagnetic attractive force 4a falls below the elastic repulsive force of the spring 15, the movable core 14 is entirely separated from the fixed core 3 and the movable portion 26 Moves toward the rotating drum 25.

Therefore, at a point earlier than the point A where the power supply was cut off, the movable core 14 begins to separate from the fixed core 3 at a point D, and the elastic energy of the right spring 15b starts to be released. Since the movable core 14 has an electromagnetic attraction force that attracts the fixed iron core 3 against the elastic repulsive force of the right-side spring 15b until the movable iron core 3 is completely separated from the movable iron core 3, the energy is required to resist the electromagnetic attraction force. Is consumed, and the amount of elastic energy of the right side spring 15b applied to the movable portion 26 is smaller than that of the prior art. Further, the left spring 15a emits elastic energy from the time when the movable iron core 14 is completely separated from the fixed iron core 3. At this time, the right spring 15b is already slightly extended and the elastic repulsive force is smaller than the initial state. Therefore, the movable portion 26 does not accelerate as compared with the conventional art, and draws a velocity curve as shown in FIG.

Further, the elastic repulsion of the right side spring 15b is used for rotating the movable portion 26, and is not used for the movement toward the rotary drum 25. Therefore, until the movable portion 26 comes into contact with the rotary drum 25. Takes longer than prior art.

Thereafter, the brake shoe 24 of the movable portion 26
Is in contact with the rotating drum 25, a frictional force is generated between the brake shoe 24 and the rotating drum 25, and the frictional force brakes the rotation of the rotating drum 25.

On the other hand, when the rotating drum 25 rotates from the holding state, the electric field is supplied to the field coil 12 and the movable core 14 is rotated.
An electromagnetic attraction force acts on the fixed iron core 3 to move the movable part 26 toward the fixed iron core 3 so that the brake shoe 24 separates from the rotary drum 25 and the rotary drum 25 rotates.

At this time, when the power supply is started, the supplied current gradually increases, contrary to the case where the power supply is interrupted. The first electromagnetic attraction force 4a exceeds the elastic repulsion force of the left spring 15a by a current amount that is smaller than the amount of current that the conventional electromagnetic attraction force exceeds the elastic repulsion force of the spring 15, and the movable portion 26 moves toward the fixed iron core 3. Begin to. On the other hand, since the second electromagnetic attraction force 4b and the inner electromagnetic attraction force 4c are smaller than the elastic repulsive force of the right spring 15b, the brake shoe 24 remains in contact with the rotating drum 25. Therefore, since the movable portion 26 is pressed by the elastic repulsive force of the right spring 15b, the speed of the movable portion 26 gradually increases. The second electromagnetic attraction force 4b is applied to the right spring 15b.
Above the elastic repulsion of the rotating drum 25
, And moves toward the fixed iron core 3, but since the first electromagnetic attraction force 4a is larger than the second electromagnetic attraction force 4b, the movable portion 26 moves while rotating and tilting. Thereafter, the movable core 14 comes into contact with the first outer facing surface 8a of the fixed core 3 and then comes into contact with each facing surface of the fixed core 3.

Therefore, the first electromagnetic attraction force 4a is
Are not used for the movement toward the fixed core 3, and the movable portion 26 is inclined from the start of the contact of the movable core 14 to the end of the contact when the movable core 14 comes into contact with the fixed core 3. Therefore, it takes longer to move the same distance than in the related art.

In the braking device 20 using the electromagnetic magnet 1 having such a configuration, when braking the rotation of the rotary drum 25 from the open state, the elastic energy of the right spring 15b causes the first electromagnetic attractive force 4a and the inner electromagnetic attractive force. The elastic energy partially consumed by the force 4c and given to the movable part 26 becomes smaller than the elastic energy given to the movable part 26 according to the prior art,
Further, since the movable portion 26 rotates, the rotating drum 2 is
Since it takes time to move toward 5, the speed of the movable portion 26 is reduced and the kinetic energy is reduced as compared with the related art. Therefore, it is possible to reduce the collision noise caused by the collision of the movable portion 26 with the rotating drum 25.

Also, when the rotary drum 25 is rotated from the holding state, the movable portion 26 is rotated by the first electromagnetic attraction force 4a, and all the electromagnetic attraction force is not used for the movement toward the fixed core 3, and the fixed core is not used. Also, when the movable member 26 contacts the third member 3 while being inclined, it takes time to move the movable portion 26, and the speed of the movable portion 26 is reduced and the kinetic energy is reduced as compared with the related art. Therefore, it is possible to reduce a collision sound caused by the movable portion 26 colliding with the fixed iron core 3.

The springs 15 are desirably the same, but may be different as long as the movable portion 26 can be rotated.

The field coil 12 may be shifted to the left or right of the fixed core 3.

The same effect can be obtained even if the field coil 12 is provided only on the movable iron core 14 or on both the movable iron core 14 and the fixed iron core 3.

FIG. 6 shows the fixed core 3 and the movable core 14.
FIG. 7 is a schematic view showing the distribution of magnetic flux in the fixed iron core 3. As shown in FIG. 6, the fixed iron core 3 has a backside thickness which is a distance from the bottom surface of each coil groove 6 to the fixed iron core 3, Are identical to each other. As for the magnetic flux around the field coil 12 fitted in each coil groove 6, the magnetic flux on the first outer facing surface 8a having a larger area is larger than the magnetic flux on the second outer facing surface 4b. At this time, if the magnetic path cross-sectional area at the back side thickness portion and the movable core 14 is smaller than the area of the first outer facing surface 8a, the magnetic flux density B1 at the back side thickness portion and the movable core 14 increases, and the magnetic saturation decreases. The first electromagnetic attraction force 4a may be lowered. On the contrary, if the magnetic path cross-sectional area at the back side thickness portion and the movable core 14 is larger than the area of the second outer facing surface 8b, the back side thickness portion and the movable core 1
4, the magnetic flux density B2 is reduced, and the iron core material is wasted. Therefore, as shown in FIGS. 7 and 8, the fixed core 3 and the movable core 14 are connected to the first outer facing surface 8a.
Thickness t ₁₀ , t ₁₁ and movable iron core thickness t ₂₀ , which are the magnetic path cross-sectional areas corresponding to the area of the second outer facing surface 8b and the area of the second outer facing surface 8b.
If you have a t _21, as shown in FIG. 9, becomes approximately equal uniform magnetic flux density B1 and B2, there is no fear that an electromagnetic attraction force is reduced by magnetic saturation, also eliminates waste of the core material.

Embodiment 2 FIG. 10 is a cross-sectional view of a main part showing a configuration of an electromagnetic magnet according to Embodiment 2 of the present invention, and FIG. 11 is a view along an arrow XI-XI in FIG. FIG. 10 is also a cross-sectional view taken along the line XX of FIG. 10 and 11, the inner facing surface 71
Has a vertical width smaller than the vertical width L of the fixed core 31, and when the field coil 121 is fitted around the inner facing surface 71, the outer shape of the field coil 121 is fixed core 31 in FIG.
It fits within the outer shape of. Other configurations are the same as in the first embodiment.

With this configuration, the same effect as that of the first embodiment can be obtained, and since the field coil 121 does not protrude from the fixed iron core 31, a larger electromagnetic attraction force is generated within the limited dimensions. be able to.

The inner facing surface 71 is the first outer facing surface 8
a and the second outer facing surface 8b may be provided anywhere, for example, as shown in FIGS. 12 and 13, may be shifted in the vertical width direction and the second outer facing surface 8b side, When the inner facing surface 71 is displaced from inside the fixed core 31 as in this case, the area of the first outer facing surface 8a and the area of the second outer facing surface 8b may be the same. In this case, for example, the springs 15 are arranged at the four corners around the movable iron core 14 and the fixed iron core 31 to control the operation of the movable part 26 not three-dimensionally but three-dimensionally, and to reduce the kinetic energy of the movable part 26. The noise can be further reduced to reduce the noise.

As shown in FIGS. 14 and 15, the fixed core 31 and the movable core 14 have a magnetic path cross-sectional area corresponding to the area of the first outer facing surface 8a and the area of the second outer facing surface 8b. Thicknesses t ₁₃ and t ₁₄ and movable core thicknesses t ₂₃ and t ₂₄
As in the first embodiment, there is no possibility that electromagnetic attraction due to magnetic saturation is reduced, and no waste of iron core material occurs.

Embodiment 3 FIG. 16 is a front view showing a configuration of an electromagnetic magnet according to Embodiment 3 of the present invention, and FIG. 17 is a view taken along the line XVII-XVII in FIG. 16 and 17, when viewed along the direction in which the movable core 14 is attracted, the field coil 122 surrounds the inner facing surface 72, and the outer facing surface 81 is the inner facing surface 72 and the field coil. 122. Also, the area of the inner facing surface 72 and the outer facing surface 81
, The inner facing surface 72 is provided at a position shifted from the center of the fixed iron core 32, and the outer facing surface 81 is not symmetrical. Other configurations are the same as in the first embodiment.

With this configuration, the same effect as that of the second embodiment can be obtained, and since the outer facing surface 81 surrounds the field coil 122, the leakage magnetic flux can be further suppressed, and the facing surface is the same. The electromagnetic attraction in the area increases.

As shown in FIGS. 18 and 19, the inner facing surface 72 and the field coil 122 are shifted in both the vertical width direction and the horizontal width direction of the fixed iron core 32 in FIG. If the configuration is not symmetrical in both the width direction and the width direction, for example, the spring 1
5 is arranged at the four corners around the fixed iron core 32 and the movable iron core 14, so that the operation of the movable iron core 14 is three-dimensionally, not two-dimensionally, by the electromagnetic attractive force acting on the movable iron core 14 and the spring 15 arranged around the movable iron core 14. Since the control can be performed, the average speed of the movable core 14 can be further reduced, and the noise caused by the movable core 14 colliding with the fixed core 32 or the rotating drum 25 can be reduced.

As shown in FIG. 20 and FIG.
The fixed iron core 32 and the movable iron core 14 have an area of the outer facing surface 81.
For the backside thickness part corresponding to the magnetic flux and the magnetic path cross section of the movable core
Thickness t so that the magnetic flux density in the
_{twenty five}, T₂₆And movable core thickness t ₁₅, T₁₆To adjust
Therefore, there is no possibility that the electromagnetic attraction force is reduced by magnetic saturation,
There is no waste of iron core material.

Embodiment 4 FIG. FIG. 22 is a cross-sectional view of main parts showing a configuration of an electromagnetic magnet according to Embodiment 4 of the present invention, and FIG. 23 is a view taken along the line XXIII-XXIII in FIG. 22 and 23, the fixed core 33 has a cylindrical shape, the inner facing surface 73 has a circular shape, and the field coil 12 has a circular shape.
Reference numeral 3 denotes an annular shape. Also, the inner facing surface 73 and the field coil 1 are arranged so that the center of the inner facing surface 73 and the center of the field coil 123 do not coincide with the center of the circular outer shape of the fixed iron core 33.
23 are shifted, and an outer facing surface 82 is formed between the circular outer shape of the fixed iron core 33 and the outer shape of the field coil 123. Accordingly, the outer facing surface 82 is formed in an annular shape having an uneven thickness. Further, the movable iron core 141 also has a cylindrical shape. Other configurations are the same as those of the first embodiment.

With this configuration, the same effects as those of the third embodiment can be obtained, and since the field coil 123 is annular, it is easy to manufacture.

As shown in FIG. 24, when the spring 15 is arranged on a straight line, the fixed core 33 is fixed to the fixed base 22 such that the centers of the fixed core 33 and the inner facing surface 73 are located on the straight line. 25, the balance between the elastic repulsive force of the spring 15 and the electromagnetic attraction force acting on the movable core 141 can be efficiently reduced, and the average speed of the movable core 141 can be efficiently reduced. As shown, when the springs 15 are arranged at the four corners around the fixed iron core 33 and the movable iron core 141, by slightly rotating the fixed iron core 33, the circular outer shape of the fixed iron core 33 and each center point of the inner facing surface 73 are set. The fixed iron core 33 is easily arranged so that the straight line connecting the two does not coincide with the diagonal line connecting the four corner springs 15, so that the operation of the movable iron core 141 can be easily adjusted three-dimensionally.

As shown in FIGS. 26 and 27, the thickness of the back side of the fixed iron core 33 and the thickness of the movable iron core 141 are thicknesses corresponding to the area of the outer facing surface 82, and The magnetic flux densities are the same. In this case, since the width of the outer facing surface 82 gradually changes, the amount of magnetic flux passing through the thickness portion on the back side of the fixed core 33 and the movable core 141 also gradually changes. Accordingly, the thickness of the back side and the thickness of the movable core 141 are also gradually changed in accordance with the amount of magnetic flux. In this way, the magnetic flux density can be made uniform and the iron core material is used efficiently, so that the waste of the iron core material can be saved and the magnetic attraction force acting on the movable iron core 141 due to the magnetic saturation can be prevented from lowering. it can.

[0056]

As is apparent from the above description, according to the present invention, the electromagnetic magnet according to the present invention comprises: a fixed iron core; an annular coil provided on one surface of the fixed iron core;
A movable core that is provided opposite to the fixed core and moves by an electromagnetic force generated by energizing the coil; and an elasticity that urges the movable core in a direction opposite to a moving direction of the movable core by the electromagnetic force. An electromagnetic magnet having a body, wherein the coil is provided eccentrically with respect to the fixed iron core, and the electromagnetic force acts unequally on the movable iron core,
Since the movable core is configured to rotate in the direction of the movement together with the movement of the movable core, the elastic repulsive force of the elastic body is partially used to rotate the movable core, and Not all are used in the direction of movement, and the speed of the direction of movement of the movable core is reduced, so that noise due to collision can be reduced.

The fixed iron core has an inner facing surface facing the movable iron core and surrounded by the coil, and an outer facing surface facing the movable iron core and outside the coil, and has an area of the inner facing surface. Since is equal to the area of the outer facing surface, the leakage magnetic flux is reduced, and the magnetic flux densities of the inner facing surface and the outer facing surface can be made uniform.

Further, since the outside facing surface surrounds the inside facing surface, the leakage magnetic flux can be reduced as much as possible.

Further, the outer facing surface is divided into two on both sides of the coil, and the areas of the outer facing surfaces on both sides are different, so that the electromagnetic attractive force acting on the movable iron core is reduced. The movable core is separated from the fixed core at a position where the electromagnetic force is small, and the movable core can be rotated with a simple configuration.

Further, since the coil is arranged so as to fit within the outer shape of the fixed core when viewed along the direction in which the movable core is attracted, the coil is effectively prevented from protruding from the fixed core. We can utilize space.

The fixed iron core has a rectangular parallelepiped shape having a coil groove for accommodating the coil on a surface facing the movable iron core, so that processing is easy and space can be effectively utilized.

Further, since the fixed core has a cylindrical shape having a coil groove for accommodating the coil on a surface facing the movable iron core, the eccentric direction of the coil can be changed only by rotating around the center axis of the cylindrical shape. Can be easily changed,
This makes it possible to easily adjust the movement of the movable iron core by changing the position where the electromagnetic force is generated.

In the fixed core, the thickness of the fixed core around the coil is such that the magnetic flux density in the cross section of the magnetic path through which the magnetic flux formed by the current flowing through the coil passes is constant. The fixed core is less likely to cause magnetic saturation, and waste of core material can be eliminated.

In the movable iron core, the thickness of the movable iron core around the coil is such that the magnetic flux density in the cross section of the magnetic path through which the magnetic flux formed by the current flowing through the coil passes is constant. The movable core is less likely to cause magnetic saturation, and waste of core material can be eliminated.

A braking device according to the present invention is a braking device using the electromagnetic magnet according to the present invention, wherein a braking shoe fixed to the movable iron core and a rotating drum rotating around a rotating shaft are provided. Since the movable iron core moves in a direction substantially perpendicular to the contact surface of the rotary drum and the brake shoe comes into contact with and separates from the rotary drum, the movable iron core rotates to The speed in the direction is reduced, and noise generated when the brake shoe contacts the rotating drum and when the movable core contacts the fixed core is reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a configuration of an electromagnetic magnet according to Embodiment 1 of the present invention.

FIG. 2 is an arrow view along the line II-II in FIG.

FIG. 3 is a conceptual diagram showing a distribution of an electromagnetic attractive force acting on a movable iron core of the electromagnetic magnet according to Embodiment 1 of the present invention.

FIG. 4 is a partial cross-sectional view showing a configuration of a braking device using the electromagnetic magnet according to Embodiment 1 of the present invention.

FIG. 5 is a graph showing the relationship between the magnitude of the current flowing through the field coil and the average speed of the movable part after the power supply is cut off and the time from when the power supply is cut off.

FIG. 6 is a conceptual diagram illustrating a magnetic flux distribution when the backside thickness of the fixed iron core is the same.

FIG. 7 is a configuration diagram showing a fixed core and a movable core having the same thickness on the back side of the fixed core and the thickness of the movable core, where the magnetic flux density in each magnetic path in FIG. 1 is the same.

FIG. 8 is a view along arrow VIII-VIII in FIG. 7;

FIG. 9 is a conceptual diagram showing a magnetic flux distribution generated in the fixed iron core and the movable iron core of FIG.

FIG. 10 is a partial cross-sectional view illustrating a configuration of an electromagnetic magnet according to Embodiment 2 of the present invention.

FIG. 11 is a view along arrow XI-XI in FIG. 10;

12 is a partial cross-sectional view showing a configuration of an electromagnetic magnet in which the center of the inner facing surface of the fixed iron core of FIG. 10 is shifted.

FIG. 13 is an arrow view along the line XIII-XIII in FIG. 12;

14 is a configuration diagram showing a fixed core and a movable core having the same thickness of the back side and the movable core of the fixed core having the same magnetic flux density in each magnetic path of FIG. 10;

FIG. 15 is a view along arrow XV-XV in FIG. 14;

FIG. 16 is a front view showing a configuration of an electromagnetic magnet according to Embodiment 3 of the present invention.

FIG. 17 is a view taken along the line XVII-XVII in FIG. 16;

18 is a front view showing the configuration of the electromagnetic magnet in which the center of the inner facing surface of the fixed iron core of FIG. 16 is shifted.

FIG. 19 is a view along arrow XIX-XIX in FIG. 18;

20 is a configuration diagram showing a fixed core and a movable core having the same thickness of the back side and the movable core of the fixed core having the same magnetic flux density in each magnetic path of FIG. 16;

21 is a view as viewed from the direction of the arrows along the line XXI-XXI in FIG. 20;

FIG. 22 is a partial cross-sectional view showing a configuration of an electromagnetic magnet according to Embodiment 4 of the present invention.

FIG. 23 is a view taken along the line XXIII-XXIII in FIG. 22;

24 is a partial cross-sectional view of the braking device when springs are arranged on both sides of the fixed iron core of FIG. 23.

FIG. 25 is a partial cross-sectional view of the braking device when springs are arranged at four corners around the fixed iron core of FIG. 23;

26 is a configuration diagram showing a fixed core and a movable core having the same thickness on the back side of the fixed core and the thickness of the movable core where the magnetic flux densities in the respective magnetic paths in FIG. 22 are the same.

FIG. 27 is a view taken in the direction of arrows along the line XXVII-XXVII in FIG. 26;

FIG. 28 is a partial cross-sectional view showing a configuration of a conventional electromagnetic magnet.

FIG. 29 is a view taken along the line XXIX-XXIX in FIG. 28;

FIG. 30 is a cross-sectional view of a main part showing a holding state of a braking device using a conventional electromagnetic magnet.

FIG. 31 is a cross-sectional view of a main part showing an open state of a braking device using a conventional electromagnetic magnet.

FIG. 32 is a conceptual diagram showing a distribution of electromagnetic attraction acting on a conventional movable iron core.

FIG. 33 is a graph showing the relationship between the magnitude of the current flowing through the field coil and the average speed of the movable part after the power supply to the conventional field coil is cut off and the time since the power supply was cut off.

[Explanation of symbols]

1 electromagnetic magnet, 12, 121, 122, 123
Field coil (coil), 3,31,32,33 Fixed iron core, 14,141 Movable iron core, 16 Coil groove, 7,7
1, 72, 73 inner facing surface, 8a first outer facing surface,
8b 2nd outer facing surface, 81, 82 outer facing surface, 15
Spring (elastic body), 20 braking device.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 3J058 AA07 AA13 AA17 AA29 AA38 BA21 CC13 CC72 CC77 GA92 5E048 AA04 AB06 AD07 BA01 CA01 CB07

Claims (10)

[Claims] A fixed core, an annular coil provided on one surface of the fixed core, a movable core provided opposite to the fixed core and moved by an electromagnetic force generated by energizing the coil, An electromagnetic magnet comprising an elastic body that urges the movable core in a direction opposite to a direction of movement of the movable core by the electromagnetic force, wherein the coil is provided eccentrically with respect to the fixed core. An electromagnetic magnet characterized in that the electromagnetic force acts unequally on the movable core, and the movable core rotates in the direction of the movement when the movable core moves. 2. The fixed core has an inner facing surface facing the movable core and surrounded by the coil, and an outer facing surface facing the movable core and outside the coil. The electromagnetic magnet according to claim 1, wherein a surface area is equal to an area of the outer facing surface. 3. The electromagnetic magnet according to claim 2, wherein the outer facing surface surrounds the inner facing surface. 4. The electromagnetic field according to claim 2, wherein the outer facing surface is divided into two on both sides of the coil, and the outer facing surface on each of the two sides has a different area. magnet. 5. The fixed core according to claim 1, wherein the coil is arranged so as to fit within the outer shape of the fixed core when viewed along a direction in which the movable core is attracted. An electromagnetic magnet according to any of the above. 6. The electromagnetic device according to claim 1, wherein the fixed core has a rectangular parallelepiped shape having a coil groove for accommodating the coil on a surface facing the movable core. magnet. 7. The electromagnetic device according to claim 1, wherein the fixed iron core has a cylindrical shape having a coil groove for accommodating the coil on a surface facing the movable iron core. magnet. 8. The fixed iron core is characterized in that the thickness of the fixed iron core around the coil is such that the magnetic flux density in the cross section of the magnetic path through which the magnetic flux formed by the current flowing through the coil passes is constant. The electromagnetic magnet according to any one of claims 1 to 7, wherein 9. The movable core according to claim 1, wherein the movable core has a thickness such that a magnetic flux density in a cross section of a magnetic path through which a magnetic flux formed by a current flowing through the coil passes is constant. An electromagnetic magnet according to claim 8. 10. A braking device using the electromagnetic magnet according to claim 1, wherein the braking device is provided to face the brake shoe fixed to the movable iron core. With a rotating drum,
The brake device wherein the movable iron core reciprocates in a direction substantially perpendicular to a contact surface of the rotating drum, and the brake shoe comes into contact with and separates from the rotating drum.