JPH1174115A - Linear electromagnetic solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly reduce the noise of a linear electromagnetic solenoid by respectively forming magnetic pole pieces extended along the moving direction of a mover on both sides of the opened end of the magnetic patch of a yoke. SOLUTION: A yoke 2 has a through-hole 11b of a coil bobbin 11, inserting holes 2a and 2b respectively formed through the upper and lower bottoms of its cylindrical body, and magnetic pole pieces 5a and 5b which are partially inserted into the through-hole 11b of the bobbin 11 and extended along the peripheral edges of the inserting holes 2a and 2b. In addition, a cylindrical mover guide 12 is provided across the magnetic pole pieces 5a and 5b in a state, where the guide 12 is inscribed to the pieces 5a and 5b. A mover 3 makes linearly advancing motions while the mover 3 slides on the internal peripheral surface of the guide 12, so that the mover 3 does not collide with other members. In addition, since the facing areas of the magnetic pole pieces 5a and 5b to the mover 3 are made large by oppositely facing the pieces 5a and 5a to the side faces of the mover 3, the thrust applied to the whole body of the mover 3 is made relatively stronger. As a result, a low-noise high-output linear electromagnetic solenoid can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear electromagnetic solenoid used for an actuator for driving electric equipment, a driving unit for a massage machine, and the like.

[0002]

2. Description of the Related Art As a conventional linear electromagnetic solenoid of this type, there is a configuration shown in FIG. This linear electromagnetic solenoid has a configuration in which a cylindrical coil 1 is housed in a yoke 2 and a mover 3 made of a magnetic material is inserted into a center hole of the coil 1. Further, a stator 4 magnetically coupled to the yoke 2 is provided in one end of the coil 1 so as to apply an attractive force to the mover 3 by exciting the coil 1. The mover 3 is movable in the axial direction of the coil 1, and the stator 4 is arranged so as to face one end surface of the mover 3 in the moving direction.

In this configuration, a part of the mover 3 is
When the coil 1 is excited in a state where the movable member 3 is separated from the stator 4 and the movable member 3 is separated from the stator 4, the movable member 4 is moved in a direction in which the magnetic resistance of the magnetic path formed by the yoke 2, the movable member 3 and the stator 4 is reduced. Moves, and the mover 3 is attracted to the stator 4.

[0004]

By the way, in the above configuration, since the stator 4 is disposed so as to face the mover 3, if the mover 3 moves, it will collide with the stator 4. An impulsive sound is produced. In particular, if magnetic saturation does not occur in the above-described magnetic path, a force acts between the mover 3 and the stator 4 in inverse proportion to the square of the distance between them.
Immediately before the mover 3 collides with the stator 4, a very large thrust acts on the mover 3, and the impact sound increases accordingly.

It has been considered to provide a buffer made of an elastic material in order to reduce such an impact sound.
And the stator 4 collides with each other, the effect of the shock absorber is insufficient, and there is a problem that loud noise is generated during operation. In addition, it is considered that the mover 3 is operated in a magnetic saturation region, and as shown in FIG.
With a short stroke, the thrust can be kept almost constant. In the characteristics shown in the figure, the stroke is indicated by the distance of the mover 3 with respect to the stator 4, and it can be seen that the thrust (static thrust) is kept almost constant up to about 7 mm. If designed to obtain such characteristics, the impact noise is reduced to some extent, but the mover 3 still collides with the stator 4, and sufficient noise reduction cannot be achieved.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a linear electromagnetic solenoid with low noise.

[0007]

A first aspect of the present invention is directed to a direction connecting a coil, a yoke magnetically coupled to both poles of the coil and having a part of a magnetic path opened, and an open end of the magnetic path in the yoke. And a mover made of a magnetic body that can move linearly, and magnetic pole pieces extending along the moving direction of the mover are formed on both sides of the open end of the magnetic path in the yoke. According to this configuration, since the mover moves without colliding with another member, only a friction noise is generated when the mover moves, and noise can be significantly reduced as compared with the conventional configuration. In addition, since the pole piece extends in the moving direction of the mover, the opposing area between the mover and the pole piece is relatively large, thereby increasing the magnetic efficiency, and consequently obtaining a relatively large thrust. it can.

[0008] The invention of claim 2 is characterized in that, in the invention of claim 1, the mover is cylindrical. This configuration is a preferred embodiment. According to a third aspect of the present invention, in the first aspect of the present invention, at least one of the magnetic pole piece and the front end of the mover located on the front side when the mover moves along with the excitation of the coil, An inclined portion is formed so that the distance between each other is increased toward the front. According to this configuration, it is possible to set various relations between the movement of the mover and the thrust by adjusting the inclination angle of the inclined portion. For example, if the inclination angle of the inclined portion is increased, the thrust of the mover does not become extremely large near the final stop position of the mover, and the range of change in the thrust can be reduced, thereby facilitating control. Further, if the inclination angle of the inclined portion is reduced, the maximum value of the thrust acting on the mover is increased, so that the movable member can be used for applications requiring a large thrust in a short time.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the inclined portion is shorter than the pole piece in the moving direction of the mover. According to this configuration, when the mover is moved to the desired position, no reverse force acts on the mover,
Thrust can be increased. According to a fifth aspect of the present invention, in the first aspect of the present invention, the movable element is located at the rear side when the movable element moves with the excitation of the coil at the time of the maximum thrust acting on the movable element by the excitation of the coil. The rear end of the pole piece and the rear end surface of the mover are flush with each other,
The size of the mover is set. In this configuration, the movable element has a minimum size in which a force in a direction opposite to the direction in which the movable element is to be moved does not act. In other words, thrust acts on the mover by the magnetic force between one end of the mover and the magnetic pole piece, but does not contribute to the thrust at the other end of the mover, and the mover shorter than the above size If there is, when the thrust acting on the mover is maximized, a force opposite to the thrust acts on the mover. Thus, by setting the above dimensions, it is possible to use a mover having a minimum dimension within a range in which a force in the direction opposite to the thrust does not act.
A lightweight linear electromagnetic solenoid can be provided.

According to a sixth aspect of the present invention, in the first aspect of the present invention, at the time when the maximum thrust is applied to the movable element by the excitation of the coil, a rear side of the movable element moving with the excitation of the coil. The dimension of the mover is set such that the rear end of the mover extends rearward from the rear end of the pole piece located at the position (1). According to this configuration, a sufficiently long movable element is used, so that a force opposite to the thrust does not act on the movable element.

According to a seventh aspect of the present invention, in the first aspect of the present invention, at least one end of the mover is provided with a connecting member for coupling to a load to be controlled. With this configuration, coupling with a load becomes easy. According to an eighth aspect of the present invention, in the first aspect, the yoke is formed by coupling a yoke main body magnetically coupled to the coil and a magnetic pole member having a magnetic pole piece. Since the yoke is composed of the yoke main body and the magnetic pole member as described above, machining and assembling becomes relatively easy even if the shapes of the coil, the yoke, and the magnetic pole piece are complicated.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the yoke is formed in a shape surrounding the coil, a pole piece is extended inside, and the mover is inserted into the yoke. Things. This configuration is a preferred embodiment, since the yoke surrounds the coil and the pole pieces and the mover are provided inside the yoke, the leakage of magnetic flux is reduced and the magnetic efficiency is increased.

According to a tenth aspect of the present invention, in the first aspect of the invention, the yoke is formed in a cylindrical shape surrounding the coil, a pole piece is extended in the cylinder, and the movable element is inserted in the cylinder. Is what it is. This configuration is a desirable embodiment, since the yoke surrounds the coil and the pole piece and the mover are provided in the cylinder of the yoke, the leakage of magnetic flux is reduced and the magnetic efficiency is increased.

According to an eleventh aspect of the present invention, in the ninth or tenth aspect of the present invention, the yoke is provided with a vent hole penetrating in and out. With this configuration, heat from the coil, frictional heat generated due to the movement of the mover, and the like can be released from the ventilation holes, thereby facilitating measures against heat.
According to a twelfth aspect of the present invention, in the first aspect of the invention, the yoke and the movable element are connected via a spring. According to this configuration, a return force can be applied to the mover by the spring, and there is no restriction on the direction in which the mover is used.

According to a thirteenth aspect, in the twelfth aspect, the spring is selected so that resonance does not occur in a vibration system including the spring. According to this configuration, since the resonance does not occur, the cycle of the reciprocating operation of the mover can be freely selected. In other words, it is suitable for applications involving a change in the cycle of the reciprocating motion of the mover. According to a fourteenth aspect, in the twelfth aspect, the spring is selected such that resonance occurs in a vibration system including the spring. According to this configuration, the thrust of the mover can be increased by utilizing the resonance.

According to a fifteenth aspect of the present invention, in the first aspect of the present invention, a treatment element for massage is attached to at least one end surface of the movable element. According to this configuration, a massage effect can be obtained by bringing the treatment element into contact with the human body and reciprocating the movable element.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) As shown in FIG. 1, a coil 1 formed by winding a coil around a coil bobbin 11 of a non-magnetic material (usually using a synthetic resin) having flanges 11a at both ends is formed in a cylindrical shape. It is stored in the yoke 2. The coil bobbin 11 is formed in a cylindrical shape, and a through hole 11b is formed in the center.
The yoke 2 has a cylindrical shape, and through holes 2a and 2b are formed on the upper bottom surface and the lower bottom surface coaxially with the through hole 11b of the coil bobbin 11, and the coil bobbin 1 is formed around the insertion holes 2a and 2b.
Pole pieces 5a and 5b inserted into a part of one through hole 11b
Is extended. Further, a cylindrical mover guide 12 extending between the pole pieces 5a and 5b is provided so as to be inscribed in the pole pieces 5a and 5b. The mover 3 is provided in the mover guide 12.
Are inserted in such a manner that their movement is restricted so that only linear movement is possible in the axial direction of the mover guide 12.

Now, it is assumed that the mover 3 has been pulled up slightly above the state shown in FIG. 1, and the peripheral surface of the other end of the mover 3 faces the magnetic pole piece 5a. When the coil 1 is energized by energizing the coil 1 in this state, the magnetic flux generated by the coil 1 reduces the magnetic resistance of the magnetic path formed by the yoke 2 and the mover 3 and the mover 3 and the magnetic pole piece. Since the suction force acts between the movable member 3 and the movable member 5b, the mover 3 moves downward. That is, the mover 3 receives the downward thrust and moves downward while sliding on the mover guide 12. FIG. 2 shows a magnetic flux distribution when the mover 3 is stopped. Thus, the yoke 2, the pole pieces 5a and 5b,
Since the closed magnetic path is formed by the mover 3, high magnetic efficiency and high output can be obtained.

If the above-described configuration is adopted, the mover 3 moves straight while sliding on the inner peripheral surface of the mover guide 12, so that the mover 3 does not collide with other members and generates only frictional noise. Therefore, noise during operation can be significantly reduced as compared with the conventional configuration. Moreover, the pole piece 5
a, 5b are opposed to the side surface of the mover 3, and the pole piece 5a
Since the opposing area between the armature 3 and the mover 3 is large, the thrust acting on the entire mover 3 can be relatively large. That is, a low-noise and high-output linear electromagnetic solenoid can be obtained. In this embodiment, a member for applying a return force to the mover 3 is not described. However, when the movable member 3 is used upside down from the state shown in FIG. 1, it can be returned by gravity. Further, as described later, a return spring can be provided as needed.

Embodiment 2 In this embodiment, as shown in FIG. 3, a taper (inclined portion) 15 is formed at one end of each mover 3. The taper 15 is formed on the front side (lower side in FIG. 3) when the movable element 3 is operated by applying a thrust, and is formed in a shape in which the diameter of the movable element 3 becomes smaller toward the front.

In this case, the thrust of the mover 3 has characteristics as shown in FIG. As shown in FIG. 5, the angle θ of the taper 15 is shown as an angle with respect to the front end face of the mover 3, assuming that the mover 3 has a constant diameter of 0 °. FIG. 4 shows that the smaller the angle θ of the taper 15 is, the narrower the section in which thrust occurs is, but the larger the maximum value of thrust is.
That is, as shown in FIG. 6, the maximum value of the thrust is largest when the taper 15 is not formed. A linear electromagnetic solenoid that can obtain high output in a short time can be configured. On the other hand, when the taper 15 is provided, the maximum value of the thrust is reduced, but the change in the thrust is reduced as a whole, so that a linear electromagnetic solenoid that can be easily controlled can be configured.

In the configuration shown in FIG. 3, the length of the taper 15 in the vertical direction (that is, the moving direction of the mover 3) is shorter than that of the pole piece 5b. In other words, if the length of the taper 15 in the vertical direction is longer than the pole piece 5b, a force in the direction opposite to the thrust acts on the mover 3, but this is prevented to increase the thrust of the mover 3 and increase the output. Becomes possible. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 3) In the present embodiment, as shown in FIG. 7, at the position where the thrust of the mover 3 is maximized, the surface of the mover 3 that does not contribute to the thrust (upper side in FIG. 7) is removed. The length of the mover 3 is set so as to be flush with the upper end of the pole piece 5a. This length is the shortest dimension that does not generate a force in the direction opposite to the thrust between the pole piece 5a and the mover 3 when the thrust of the mover 3 is maximum, and is small while ensuring high output. In addition, it is possible to provide a lightweight linear electromagnetic solenoid. In addition, an increase in the material cost of the mover 3 can be prevented. Other configurations and operations are the same as those of the second embodiment.

When miniaturization and weight reduction are not particularly necessary and a slight increase in material cost is not a problem, as shown in FIG. 8, when the thrust of the mover 3 is maximum, the upper end of the mover 3 is closed. The length may be long enough to protrude from the pole piece 5a. In this case, a force in a direction opposite to the thrust does not act on the mover 3 in a wide moving range, and the thrust is improved as a whole.

(Embodiment 4) In this embodiment, as shown in FIG. 9, a connecting member 7 to be coupled to a load to be controlled is fixed to one end (the lower end in the illustrated example) of the mover 3. . The connecting member 7 has a rod shape and can be easily connected to another load. By providing such a connecting member 7, an output can be easily given to a load. Other configurations and operations are the same as those of the second embodiment.

(Embodiment 5) As described above, the yoke 2 is provided with the pole pieces 5a and 5b,
Since a and 5b are inserted inside the coil bobbin 11, if the yoke 2 is formed by one member, complicated processing is required. Therefore, as shown in FIG. 10, a cylindrical yoke main body 16 and a pair of annular magnetic pole members (magnetic pole pieces 5 a and 5 b) having a substantially L-shaped cross section, which are separate from the yoke main body 16.
It is desirable that the yoke 2 is configured by combining the yoke 2 with a member provided with the above. With this configuration, the coil 1 can be easily assembled by storing the coil 1 in the yoke 2 and then coupling the magnetic pole members. Further, the yoke main body 16 and the magnetic pole member can be processed relatively easily. The yoke body 1
Since it is necessary to house the coil 1 in the yoke 6, it is desirable to form the yoke main body 16 by connecting a flat base plate 16a and a cylindrical cap 16b. Other configurations and operations are the same as those of the second embodiment.

(Embodiment 6) In each of the embodiments described above, a cylindrical yoke 2 as shown in FIG. 11 is provided, and the coil 1 is built in the yoke 2. The mover 3 is also arranged in the yoke 2. As described above, since the coil 1 is surrounded by the yoke 2 which is a magnetic material, and the mover 3 and the pole pieces 5a and 5b are provided inside the yoke 2, the yoke 2 functions as a magnetic shield. Accordingly, magnetic flux leakage to the outside of the yoke 2 is reduced. That is, the small magnetic flux leakage leads to high magnetic efficiency and consequently high output. here,
It is considered that, by disposing the coil 1 and the mover 3 in the yoke 2, it is difficult to release the heat of the coil 1 and the frictional heat accompanying the movement of the mover 3. Therefore, in the present embodiment, as shown in FIG. 12, a ventilation hole 17 is formed at an appropriate position of the yoke 2 so that heat generated inside the yoke 2 is easily released to the outside. By adopting such a configuration, measures against heat are facilitated. Other configurations and operations are the same as those of the second embodiment.

(Embodiment 7) In each of the above embodiments,
Although the yoke 2 is formed in a cylindrical shape, in this embodiment, as shown in FIG. 13, the yoke 2 is formed in a rectangular cylindrical shape.
With this configuration, the same effect as when the cylindrical yoke 2 is used can be obtained. Other configurations and operations are the same as those of the second embodiment.

(Embodiment 8) In this embodiment, as shown in FIG. 14, a spring 8 composed of a coil spring is provided for returning the mover 3. That is, the yoke 2 and the mover 3 are connected via the spring 8. The mover 3 is moved by the excitation of the coil 1, but returns to its original position by the spring 8 when the energization of the coil 1 is stopped.
When the return force by the spring 8 is applied in this manner, the movable element 3 can be returned regardless of the mounting direction, and the mounting direction is less restricted.

Here, if the spring 8 is selected with a spring constant such that the resonance frequency determined by the mass of the mover 3 does not coincide with the frequency at which the mover 3 reciprocates, the operating frequency range of the mover 3 can be adjusted. Thus, the actuator can be used without resonance and is suitable for applications involving a change in operating frequency. Further, if the spring constant of the spring 8 is selected so that the operating frequency and the resonance frequency coincide with each other, a large thrust can be obtained by resonance, and the spring 8 can be used for applications requiring a large thrust.

The above-described linear electromagnetic solenoid is shown in FIG.
As shown in (1), by attaching a massager 9 to the distal end of the connecting member 7, the massager can be used. As a massage machine, for example, FIG.
Or a foot massager for massaging the sole as shown in FIG. This device includes a housing 20 for placing on a floor or the like, and two linear electromagnetic solenoids 21 described above are housed in the housing 20. The treatment element 9 is connected to the connection member 7 of each linear electromagnetic solenoid 21. The treatment element 9 has a large number of protrusions 9a protruding from a portion that comes into contact with the sole of the foot. The operation of the linear electromagnetic solenoid 21 is controlled by a control circuit built in the housing 20, so that the treatment element 9 is hit on the sole of the foot. Stimulation and vibration stimulation can be given. These operations are performed by the switch group 2 provided on the upper surface of the housing 20.
2 is selected.

[0032]

According to the first aspect of the present invention, there is provided a coil, a yoke magnetically coupled to both poles of the coil and having a part of a magnetic path opened.
A movable element made of a magnetic material that can move straight in the direction connecting the open ends of the magnetic path in the yoke, and magnetic pole pieces extended along the moving direction of the movable element on both sides of the open end of the magnetic path in the yoke. Since the mover moves without colliding with other members, only a frictional noise is generated when the mover moves, and the noise can be significantly reduced as compared with the conventional configuration. There is an advantage. In addition, since the pole piece extends in the moving direction of the mover, the opposing area between the mover and the pole piece is relatively large, thereby increasing the magnetic efficiency, and consequently obtaining a relatively large thrust. There is an advantage that you can. That is, a high-output and low-noise linear electromagnetic solenoid can be provided.

According to the third aspect of the present invention, at least one of the pole piece located on the front side and the front end of the mover when the mover moves along with the excitation of the coil, the distance between the pole piece and the front end of the mover increases. In the case where the inclined portion is formed so as to be widened, there is an advantage that various relations between the movement of the mover and the thrust can be set by adjusting the inclination angle of the inclined portion.

In the case where the inclined portion is shorter than the pole piece in the moving direction of the mover as in the fourth aspect of the present invention, no reverse force acts on the mover when the mover is moved to a desired position. ,
There is an advantage that the thrust can be increased. According to a fifth aspect of the present invention, the rear end of the pole piece located on the rear side when the mover moves along with the excitation of the coil at the time of the maximum thrust on the mover due to the excitation of the coil and the mover When the size of the mover is set so that the rear end surface is flush with the mover, the mover is the smallest size that does not act in the direction opposite to the direction in which the mover is to be moved. There is an advantage that a lightweight linear electromagnetic solenoid can be provided.

According to a sixth aspect of the present invention, at the time when the maximum thrust is applied to the mover by the excitation of the coil, the rear end of the pole piece located on the rear side when the mover moves with the excitation of the coil. Also, as the rear end of the mover extends rearward,
When the size of the mover is set, a sufficiently long one is used as the mover, so that there is an advantage that a force opposite to the thrust does not act on the mover.

As described in the seventh aspect of the present invention, at least one end of the mover is provided with a connecting member for coupling to a load to be controlled, which has an advantage that coupling to a load is facilitated. According to an eighth aspect of the present invention, when the yoke is formed by coupling the yoke main body magnetically coupled to the coil and the magnetic pole member having the magnetic pole piece, the shapes of the coil, the yoke, and the magnetic pole piece are changed. There is an advantage that machining and assembling becomes relatively easy even for a complicated shape.

According to the ninth aspect of the present invention, the yoke is formed to surround the coil, the pole piece is extended inside, and the mover is inserted into the yoke.
Since the yoke surrounds the coil and the pole piece and the mover are provided inside the yoke, there is an advantage that leakage of magnetic flux is reduced and magnetic efficiency is increased. According to a tenth aspect of the present invention, when the yoke is formed in a cylindrical shape surrounding the coil, the magnetic pole piece is extended in the cylinder, and the mover is inserted in the cylinder, the yoke surrounds the coil, and Since the pole piece and the mover are provided in the cylinder of the yoke, there is an advantage that leakage of magnetic flux is reduced and magnetic efficiency is increased.

According to the eleventh aspect of the present invention, when the yoke is formed with a ventilation hole penetrating inside and outside, the heat from the coil and the frictional heat generated by the movement of the mover are released from the ventilation hole. This has the advantage that heat measures can be made easier. When the yoke and the mover are connected via a spring as in the invention of claim 12, the return force can be applied to the mover by the spring, and there is no restriction on the direction in which the mover is used. Has the advantage of expanding.

According to the thirteenth aspect of the present invention, when the spring is selected so as not to cause resonance in the vibration system including the spring, the resonance does not occur, so that the period of the reciprocating operation of the movable element can be freely selected. Therefore, there is an advantage that it becomes suitable for an application involving a change in the cycle of the reciprocating operation of the mover. In the case where the spring is selected so that resonance occurs in the vibration system including the spring as in the invention of claim 14, there is an advantage that the thrust of the mover can be increased by utilizing the resonance.

According to the fifteenth aspect of the present invention, the massager is attached to at least one end surface of the movable element, and the massage effect can be obtained by bringing the movable element into contact with the human body and reciprocating the movable element. There is an advantage that can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is an operation explanatory view of the above.

FIG. 3 is a sectional view showing a second embodiment.

FIG. 4 is an operation explanatory view of the above.

FIG. 5 is an explanatory diagram showing an angle of a taper of the above.

FIG. 6 is a sectional view showing another example of the above.

FIG. 7 is a sectional view showing a third embodiment.

FIG. 8 is a sectional view showing another example of the above.

FIG. 9 is a sectional view showing a fourth embodiment.

FIG. 10 is a sectional view showing a fifth embodiment.

11A and 11B show a basic configuration of a sixth embodiment, in which FIG. 11A is a plan view and FIG. 11B is a cross-sectional view.

FIG. 12 is a plan view showing a sixth embodiment.

FIG. 13 is a plan view showing a seventh embodiment.

FIG. 14 is a sectional view showing an eighth embodiment.

FIG. 15 is a sectional view showing an application example of the present invention.

FIG. 16 is a sectional view showing an application example of the present invention.

FIG. 17 is a side view of the same.

FIG. 18 is a front view of the same.

FIG. 19 is a front view showing a state where the housing is opened.

FIG. 20 is a sectional view showing a conventional example.

FIG. 21 is an explanatory diagram of the above operation.

[Explanation of symbols]

 Reference Signs List 1 coil 2 yoke 3 mover 5a, 5b magnetic pole piece 7 connecting member 8 spring 9 treatment element 15 taper 16 yoke main body 17 ventilation hole

Continued on the front page (72) Inventor Hironori Iwamoto 1048 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (15)

[Claims] 1. A coil, a yoke magnetically coupled to both poles of the coil and having a part of a magnetic path opened, and a movable element made of a magnetic body movable linearly in a direction connecting open ends of the magnetic path in the yoke. And a magnetic pole piece extending along the moving direction of the mover is formed on both sides of the open end of the magnetic path in the yoke. 2. The linear electromagnetic solenoid according to claim 1, wherein said mover has a cylindrical shape. 3. The at least one of the magnetic pole piece located on the front side and the front end of the mover when the mover moves along with the excitation of the coil so that the distance between them is increased toward the front. The linear electromagnetic solenoid according to claim 1 or 2, wherein an inclined portion is formed. 4. The linear electromagnetic solenoid according to claim 3, wherein said inclined portion is shorter than said pole piece in the moving direction of said mover. 5. The rear end of the pole piece located on the rear side when the mover moves along with the excitation of the coil at the time when the maximum thrust is applied to the mover by the excitation of the coil and the movable end. 2. The linear electromagnetic solenoid according to claim 1, wherein the size of the mover is set such that the rear end surface of the mover is flush with the rear end surface of the mover. 6. A rear end of the magnetic pole piece, which is located at a rear side when the mover moves along with the excitation of the coil at a time when a maximum thrust is applied to the mover by the excitation of the coil, 2. The linear electromagnetic solenoid according to claim 1, wherein the size of the mover is set such that a rear end of the mover extends rearward. 7. The linear electromagnetic solenoid according to claim 1, wherein at least one end of said mover is provided with a connecting member for coupling to a load to be controlled. 8. The linear electromagnetic solenoid according to claim 1, wherein the yoke is formed by coupling a yoke main body magnetically coupled to a coil and a magnetic pole member having a pole piece. 9. The linear electromagnetic device according to claim 1, wherein said yoke is formed in a shape surrounding said coil, a pole piece is extended inside, and said mover is inserted inside said yoke. solenoid. 10. The apparatus according to claim 1, wherein the yoke is formed in a cylindrical shape surrounding the coil, a pole piece is extended in the cylinder, and the mover is inserted in the cylinder.
The described linear electromagnetic solenoid. 11. The linear electromagnetic solenoid according to claim 9, wherein a ventilation hole penetrating in and out of the yoke is formed in the yoke. 12. The linear electromagnetic solenoid according to claim 1, wherein said yoke and said mover are connected via a spring. 13. The linear electromagnetic solenoid according to claim 12, wherein the spring is selected so that resonance does not occur in a vibration system including the spring. 14. The linear electromagnetic solenoid according to claim 12, wherein the spring is selected so that resonance occurs in a vibration system including the spring. 15. The linear electromagnetic solenoid according to claim 1, wherein a massage treatment element is attached to at least one end surface of the movable element.