JP2001251835A - Linear vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid decline in the efficiency of a linear vibration actuator. SOLUTION: Rolled surfaces of electromagnetic steel plates, of which a yoke 124 of a mover 120 and a yoke 133 (particularly main poles 133b) of an electromagnet (stator) 130 are composed, are arranged approximately in parallel with the moving direction of the mover 120, and bobbins 131b and 132b are made of aluminum and have slits formed in their axial directions. With this constitution, a magnetic reluctance of a magnetic circuit can be reduce, and further eddy currents sin the bobbins 131b and 132b can be avoided, while temperature rises of excitation coils 131a and 312a are suppressed, so that efficiency of a linear vibration actuator can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear vibration actuator for directly giving a linear reciprocating motion to a mover by an electric input without using any conversion mechanism. The present invention is effective when applied to a linear compressor applied to a chiller-type refrigerator such as a pulse tube refrigerator or a Stirling refrigerator that cools an object to be cooled by expansion and compression.

[0002]

2. Description of the Related Art A linear vibration actuator vibrates a mover by periodically changing the polarity of an electromagnet. An actuator including a permanent magnet (magnet) in a magnetic circuit uses an electric current supplied to the electromagnet. Can be obtained, and a thrust that is constituted only by electromagnets can obtain a thrust in proportion to approximately the square of the supplied current.

[0003]

By the way, the present inventors have conducted various trial production studies to improve the efficiency of the linear vibration actuator (= output work / input power). As a result, the efficiency of the linear vibration actuator is reduced. The following points were discovered as the cause.

FIG. 13 and FIG. 14 show a linear vibration actuator which the inventors of the present invention have studied on a trial basis.
FIG. 3 is a view showing a cross section orthogonal to the movement direction of the mover of the linear vibration actuator. Reference numeral 120 denotes a mover that reciprocates in a direction perpendicular to the paper surface and includes a mover core (yoke) and a magnet 122, and reference numeral 130 denotes a stator that includes solenoid coils 131a and 132a and a stator core (yoke) 133. And both iron cores 12
4, 133 to prevent eddy currents from being generated
The two cores 12 are formed by laminating thin electromagnetic steel sheets in the direction perpendicular to the paper surface.
4 and 133.

The magnetic flux flowing through the magnetic gap (gap) δg between the stator core (stator) and the mover core (stator) has a uniform magnetic flux density as shown in FIG. Instead of flowing between the two cores, the flow direction is changed so as to concentrate on a corner (edge) on the movement direction side of the mover 120 and flows between the two cores.

[0006] Since the magnetic properties of the magnetic steel sheet in the direction perpendicular to the rolling surface are significantly worse than the magnetization characteristics in the direction parallel to the rolling surface, the lamination direction of the two iron cores is set to the movable element as in the above prototype. In this case, the magnetic flux flowing through both iron cores must be turned to the direction perpendicular to the rolling surface and concentrated on the corners of both iron cores.

Therefore, the magnetic resistance as a whole of the magnetic circuit increases, and the magnetic flux density at the corners in the direction of movement of the two iron cores decreases. Decrease. Hereinafter, this problem is referred to as a first problem.

The solenoid coil is formed by winding an electric wire (winding) around a resin winding frame. When the solenoid coil is energized, the solenoid (joule loss / iron loss) generated at the time of energization generates a solenoid. The temperature of the coil increases. Then, when the temperature of the solenoid coil rises, the electric resistance of the solenoid coil rises, so that the current value flowing through the solenoid coil decreases,
The magnetomotive force (magnetic field intensity) induced by the solenoid coil decreases. Therefore, the thrust for moving the mover is reduced, and the efficiency of the linear vibration actuator is reduced. Hereinafter, this problem is referred to as a second problem.

[0009] As shown in FIG.
The magnet 122 is embedded between the non-magnetic spacers 125. As described above, the magnetic flux flowing between the two cores concentrates on the corners of the two cores and flows between the two cores. For this reason, the change in the magnetic flux density near the corners of the movable iron core becomes large, so that an eddy current is generated in the spacer located near the movable iron core, and the efficiency of the linear vibration actuator is reduced. Hereinafter, this problem is referred to as a third problem.

[0010] In view of the above, it is an object of the present invention to prevent the efficiency of a linear vibration actuator from decreasing.

[0011]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a first magnetic field-inducing magnetic field is provided by using a movable iron core (124). A movable element (120) having a magnetic field generating means and reciprocating;
Movable element (120), facing movable element (120)
And a stator (130) having a second magnetic field generating means for generating a magnetic field with a stator iron core (133b) made of a magnetic material extending in a direction perpendicular to the direction of movement of the first magnetic field. By periodically changing the polarity of at least one of the induced magnetic field and the magnetic field induced by the second magnetic field generating means, the mover (120) reciprocates, and further, the stator core (133b) And at least one of the mover iron cores (124) is formed by laminating thin rolled steel plates (124a, 133a), and the rolling surface of the rolled steel plates (124a, 133a) and the movement of the mover (120). The direction is substantially parallel.

As a result, the magnetic flux changes its direction of flow in a plane parallel to the rolling surface, so that the magnetic resistance in the direction in which the magnetic flux flows is smaller than that of the prototype. Therefore, since the first problem is solved, the thrust for moving the mover (120) increases,
The efficiency of the linear vibration actuator is improved.

According to the second aspect of the present invention, the movable element (120) that induces a magnetic field and reciprocates and faces the movable element (120), and is orthogonal to the direction of movement of the movable element (120). And a stator (130) having a magnetic field generating means for generating a magnetic field having a stator core (133b) made of a magnetic material extending to the magnetic field, and periodically changing the polarity of the magnetic field induced by the magnetic field generating means. This causes the mover (120) to reciprocate, and further, the stator core (133b) is formed by laminating a thin rolled steel plate (13a), and is movable with the rolling surface of the rolled steel plate (133a). The movement direction of the child (120) is substantially parallel.

Thus, the magnetic flux changes its direction of flow in a plane parallel to the rolling surface, so that the magnetic resistance in the direction in which the magnetic flux flows becomes smaller than that of the prototype. Therefore, since the first problem is solved, the thrust for moving the mover (120) increases,
The efficiency of the linear vibration actuator is improved.

According to a third aspect of the present invention, there is provided an electromagnet (130) having a solenoid coil (131a, 132a) formed by winding an electric wire around a cylindrical winding frame (131b, 132b) and inducing a magnetic field. And a movable element (120) that induces a magnetic field and reciprocates, causing the movable element (120) to reciprocate by periodically changing the polarity of the magnetic field induced by the electromagnet (130). The winding frames (131b, 132b) are made of metal, and the winding frames (131b, 132b) are provided with an electrical insulating portion (S) extending in the axial direction.

Thus, the solenoid coil (131)
a, 132a) to the winding frames (131b, 13a).
Since heat can be quickly radiated through 2b), the temperature rise of the solenoid coil 13 (1a, 132a) can be suppressed.

Further, since the electric insulating portion (S) is provided, eddy current can be prevented from being generated in the winding frames (131b, 132b), and the efficiency of the linear vibration actuator can be improved.

The electric insulating portion may be constituted by a slit (S) for cutting the winding frames (131b, 132b) in the axial direction, as in the invention of the fourth aspect.

According to the fifth aspect of the present invention, the movable element (120) having a plurality of first magnetic field generating means for reciprocating and inducing a magnetic field, the movable element (120), and the movable element (120). And a stator provided with a second magnetic field generating means for generating a magnetic field in a direction orthogonal to the direction of movement of the first magnetic field generating means.
The movable element (12) is sandwiched by a spacer (125) made of a non-magnetic material.
0) are arranged in series in the direction of movement, and further, at the corner (125a) of the spacer (125) facing the stator core (133b) and the first magnetic field generating means, an electrical insulating portion (125b) is provided. It is characterized by being provided.

Thus, it is possible to prevent an eddy current from being generated in the spacer (125) located near the first magnetic field generating means, so that the third problem can be solved and the efficiency of the linear vibration actuator can be reduced. Can be improved.

[0021] The electric insulating portion is formed by the stator core (1) of the spacer (125).
33b) and the corner (125) facing the first magnetic field generating means.
It may be provided by removing a).

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
The linear vibration actuator according to the present invention is applied to a linear compressor for a pulse tube refrigerator (hereinafter abbreviated as a compressor). FIG. 1 shows a pulse tube refrigerator. The operation of the pulse tube refrigerator as a whole is described in Japanese Patent No. 269.
Since it is the same as the invention described in No. 9957, the description of the operation of the pulse tube refrigerator itself is omitted in this specification.

[0024] 100 is a compressor according to the present embodiment (the fluid drive unit), the working fluid (specifically within畜冷200 to be described later by the compressor 100, H _e, N _2,
Expansion and compression of H ₂ , Ar, Ne, etc. (generating standing wave components)
At the same time, a displacement (traveling wave component) is given to the working fluid. The detailed structure of the compressor 100 will be described later.

Reference numeral 200 denotes a regenerator that transfers heat to and from the working fluid. When the working fluid flowing through the regenerator 200 is compressed, the regenerator 200 quickly absorbs heat from the working fluid, and , At the time of expansion, it is necessary to quickly give the absorbed heat to the working fluid,
It is made of a material having a heat capacity sufficiently larger than that of the working fluid and a relatively high thermal conductivity.

Specifically, a metal mesh (metal mesh) made of stainless steel, copper, a copper alloy, or the like is laminated, or a metal ball of stainless steel, lead, or the like is sealed in an airtight container. At this time, the regenerator 20
When heat is transferred to a cooling unit 210 described later through 0, the cooling capacity of the cooling unit 210 is reduced. Therefore, it is necessary to suppress heat conduction in the regenerator 200 as much as possible. For this reason, when configuring the animal cooler 200 with a metal mesh, the stacking direction of the metal mesh state is the displacement direction of the working fluid (the axial direction of the cool storage device 200).
It is preferable to set

At the end of the regenerator 200, there is provided a cooling unit 210 for cooling a body to be cooled (such as a superconductor or an infrared sensor) by directly contacting the cooling unit.
Is formed of a metal having high thermal conductivity such as copper and indium.

Reference numeral 300 denotes a regenerator 2 adjacent to the cooling unit 210.
The pulse tube 300 is arranged so as to communicate with the internal space 00. The pulse tube 300 is formed of a thin metal pipe made of stainless steel, titanium, a titanium alloy or the like.

Reference numeral 400 denotes a buffer tank for temporarily storing the working fluid displaced from the inside of the pulse tube 300. The pressure difference between the pulse tube 300 and the buffer tank 400 is predetermined between the buffer tank 400 and the pulse tube 300. First relief valve 50 configured to open when a value is reached
0 and a second relief valve 600 (fluid displacement control valve device) are arranged.

Further, the first relief valve 500 is configured to close the working fluid displaced from the pulse tube 300 to the buffer tank 400, and the second relief valve 600 is configured to close the pulse tube 300 from the buffer tank 400.
It is configured to close the working fluid that is displaced to.

The compressor 100, the regenerator 200, the cooling section 210, the pulse tube 300, the two relief valves 500,
600 and the buffer tank 400 are arranged in series in the displacement direction of the working fluid (in a one-dimensional model),
The regenerator 200, the cooling unit 210, and the pulse tube 300 (FIG. 1)
Are enclosed in a vacuum vessel (not shown) for heat insulation from the outside.

Reference numeral 700 denotes a double inlet pipe (pipe) connecting the buffer tank 400 side of the pulse tube 300 and the compressor 100 by bypassing the regenerator 200. The double inlet pipe 700 gives the working fluid to the working fluid by the compressor 100. The pressure is input into the pulse tube 300 from the buffer tank 400 side of the pulse tube 300.

An electromagnetic valve (fluid compression control valve device) 800 is disposed in the double inlet pipe 700, and the communication state of the double inlet pipe 700 is controlled by opening and closing the electromagnetic valve 800.

Next, the compressor 100 will be described.

FIG. 2 is a schematic view of the compressor 100. The compressor 100 includes a refrigerator 200 and a discharge port 1 of the compressor 100.
11 (symmetrical piston-type structure).

Numeral 110 denotes the animal cooler 200 through a pipe 900.
A pressure vessel made of stainless steel and formed in a round pipe shape communicating with the inside of the vessel.
10 is a substantially cylindrical mover 120 that reciprocates in the longitudinal direction.
Are arranged.

At one end in the longitudinal direction of the mover 120 (on the side of the discharge port 111), the cylindrical piston portion 12 positioned with a small gap with respect to the inner wall of the pressure vessel 110 is provided.
1 is provided.
The working fluid expands and compresses by reciprocating integrally with 20. Incidentally, the piston portion 1 of the pressure vessel 110
The part where the reciprocating operation 21 is performed is particularly called a cylinder, and this cylinder is formed of a material having a linear expansion coefficient substantially equal to that of the piston part 121.

The piston 12 of the mover 120
A plunger portion 123 in which a disk-shaped permanent magnet 122 is fixed (buried) is provided on the other end side in the longitudinal direction from 1. The plunger portion 123 and the piston portion 121
Screw-connected.

It should be noted that both sides of the permanent magnet 122 (N pole / S
On the pole side), a rolled steel sheet made of a magnetic material such as a thin electromagnetic steel sheet or a silicon steel sheet is laminated in order to gather magnetic fluxes induced by the permanent magnets 122 on both pole sides and increase the magnetic flux density at both poles. The yoke 124 and the permanent magnet 122 are provided with a yoke (mover iron core) 124 formed in this way, and the yoke 124 and the permanent magnet 122 sandwich the spacer 125 made of a nonmagnetic material such as stainless steel or an aluminum alloy. (Left-right direction).

On the other hand, out of the magnetic field (magnetic field) induced by the permanent magnet 122, the first and second
One set of electromagnets (stators) 131 and 132 (hereinafter, the first and second electromagnets 131 and 132 are referred to as electromagnets 130)
A plurality of sets (2 × 2 sets in the present embodiment) of the electromagnet 1
30 are arranged in the longitudinal direction of the pressure vessel 110,
Together with 10, it is fixed to a pedestal 140.

As shown in FIG. 3, the electromagnet 130 has a yoke (fixed) that forms a magnetic path of a magnetic flux induced by the first and second excitation coils 131a and 132a and both excitation coils (solenoid coils) 131a and 132a. Child iron core)
The yoke 133 is made of a magnetic material such as a thin electromagnetic steel plate or a silicon steel plate in order to suppress the generation of eddy current in the yoke 133. Formed by laminating rolled steel plates 133a. The dual excitation coil 131
Reference numerals a and 132a are formed by winding windings such as copper wires (electric wires) around bobbin (winding frames) 131b and 132b in the shape of a resin square pipe (square tube).

The mover 120 of the yoke 133
And extends in a direction perpendicular to the direction of movement of the mover 120 (perpendicular to the paper surface) (both excitation coils 131a, 132a
Main pole 133b and the mover 120
Rolled steel plates 133a, 124a constituting the yoke 124 of FIG.
Are stacked such that the rolling surface thereof and the moving direction of the mover 120 are substantially parallel. Incidentally, in the present embodiment,
The rolled steel plates 133a of the yoke 133 other than the main pole 133b (ring-shaped portion) are stacked such that the rolling surface is orthogonal to the moving direction of the mover 120.

In the present embodiment, the movable element 12 is attached to the main magnetic pole 133b by the electromagnet 130 (second magnetic field generating means).
A magnetic field in a direction substantially perpendicular to the movement direction of 0 is induced, and the magnetic path forms a magnetic circuit (radial magnetic flux type) flowing in a plane substantially perpendicular to the movement direction of the mover 120.

As shown in FIG. 2, the mover 120 is provided with a thin plate at both ends in the longitudinal direction so that the piston 121 and the plunger 123 do not come into contact with the inner wall of the pressure vessel 110. Is supported by a support member 150 on which a plate-shaped leaf spring 151 is laminated.
50 is housed in a stainless steel support member case 160 formed in a round pipe shape.

Then, each leaf spring 151 of the support member 150
As shown in FIG. 4, the plate spring 151 is formed in a narrow shape at the center so that the maximum stress in each portion in the longitudinal direction of the leaf spring 151 is substantially equal. Incidentally, in FIG. 4, hatched portions are fixing portions for fixing the respective leaf springs 151 to the support member case 160.

In this embodiment, the piston 121
Does not have a sealing means such as a piston ring or the like for maintaining airtightness while sliding, the piston portion 121 and the pressure vessel 1 are not provided.
By making the gap between the inner wall 10 and the inner wall 10 small, a kind of mechanical seal is formed to maintain the airtightness, so that the internal pressure also acts on the space of the pressure vessel 110 on the plunger 123 side. Therefore, the support member case 160 communicates with the pressure vessel 110, and thus functions as a pressure vessel in which an internal pressure acts together with the pressure vessel 110.

Incidentally, the mover 120 (piston portion 121)
And the plunger portion 123) reciprocate without contacting the inner wall of the pressure vessel 110, but when the mover 120 vibrates due to external vibration or the like, the piston (clearance) with the pressure vessel 110 is small. The part 121 is
There is a possibility of contact with the inner wall of the pressure vessel 110. Therefore,
In the present embodiment, the outer peripheral wall of the piston 121 is coated with a resin to protect the piston 121 and the inner wall of the pressure vessel 110.

The compressor 100 (electromagnet 130)
Is controlled by a controller (electronic control device) 900. The controller 900 has a frequency equal to the natural frequency of the vibration system in consideration of the elastic characteristics of the working fluid in the mover 120, the support member 150, and the pressure vessel 110. An alternating current is applied to the electromagnet 130 to periodically change the polarity of the electromagnet 130, so that the electromagnet 130 and the mover 1
The movable element 120 is reciprocated by periodically reversing the directions of the attractive force and the repulsive force generated between the movable element 120 and the permanent magnet 122 embedded in the movable member 120.

In the compressor according to the present embodiment, the mover 120 has a top dead center (when the piston 121 is closest to the discharge port 111) and a bottom dead center (when the piston 121 is farthest from the discharge port 111). (Hereinafter, the position of the mover 120 at this time is referred to as the center of the amplitude), the rate of change of the permeance between the permanent magnet 122 and the electromagnet 130 becomes maximum. As described above, the permanent magnet 122 and the electromagnet 130 are arranged. For this reason,
In the compressor according to the present embodiment, the thrust acting on the mover 120 is maximum at the center of the amplitude.

Next, the features of this embodiment will be described.

As shown in FIG. 5, the magnetic flux flowing through the magnetic gap (gap) δg between the main magnetic pole 133b and the yoke 124 is, as shown in FIG. 5, a corner (edge) 133c on the moving direction side of the mover 120 of the main magnetic pole 133b. The direction of the flow is changed so as to concentrate on the main pole 133b and the yoke 124 of the mover 120 in the present embodiment.
Since the rolling surfaces a and 124a are stacked so that the rolling surface and the moving direction of the mover 120 are substantially parallel, the magnetic flux changes the direction of the flow in a plane parallel to the rolling surface.

Therefore, the magnetic resistance in the direction in which the magnetic flux flows is smaller than that of the prototype, so that the main pole 1
The magnetic flux density at the corner 133c of 33b and the corner 124b in the direction of movement of the yoke 124 increases. In the end,
Since the first problem is solved, as shown in FIG. 6, the thrust for moving the mover 120 is increased, and the efficiency of the compressor (linear vibration actuator) is improved.

In this embodiment, as shown in FIG. 3, the rolled steel plate 133a of the portion (ring-shaped portion) 133d of the yoke 133 other than the main magnetic pole 133b has its rolling surface in the moving direction of the mover 120. However, since the magnetic flux in the portion 133d changes its flow direction in a plane parallel to the rolling plane, the problem that the magnetic resistance increases in the portion 133d does not occur. Incidentally, the main magnetic pole 133b and the ring-shaped portion 13
3d is joined by joining means such as laser welding.

In this embodiment, the permanent magnet 12
2 and the yoke 124 constitute a first magnetic field generating means for inducing a magnetic field.
The first magnetic field generating means may be constituted by only 22.

In this embodiment, both the rolled surface of the main pole 133b and the rolled surface of the yoke 124 are movable
Although the movement direction of the movable member 20 is substantially parallel to the movement direction of the mover 120, only one of the rolling surfaces may be substantially parallel to the movement direction of the mover 120.

(Second Embodiment) In the first embodiment, only the rolled surface of the main magnetic pole 133b is substantially parallel to the direction of movement of the mover 120. In this embodiment, as shown in FIGS. The entire rolling surface of the yoke 133 is configured to be substantially parallel to the moving direction of the mover 120.

The yoke 133 according to this embodiment is
It is manufactured in the same manner as the transformer core. First, as shown in FIG. 9A, a rolled steel plate is wound around a jig, and the rolled steel plate is joined.
As shown in (b), it is manufactured by cutting and removing a portion where the mover 120 is mounted.

(Third Embodiment) In the first and second embodiments,
Although the bobbins 131b and 132b made of resin are employed, in the present embodiment, the bobbins 131b and 132b are made of metal (in this embodiment, aluminum) having higher thermal conductivity than resin, and as shown in FIG. , Bobbin 131b,
The bobbins 131b and 13 extend in the axial direction of 132b.
A slit S (electrically insulating portion) for cutting 2b is provided.

As a result, the excitation coil 131
a, 132a to the bobbins 131b, 132b
The heat can be quickly dissipated via the first coil, so that the temperature of the exciting coils 131a and 132a can be prevented from rising.

Therefore, the solenoid exciting coil 131
Since the magnetomotive force (magnetic field strength) induced by a and 132a can be prevented from decreasing, the second problem can be solved, and the thrust for moving the mover 120 increases, and the compression force increases. Machine (linear vibration actuator) efficiency is improved.

When the bobbins 131b and 132b are made of metal, the energizing coils 131a and 132a are energized, as shown in FIG.
An eddy current that flows around the outer peripheral wall of the shaft 132b in the axial direction is generated, and on the contrary, the efficiency of the compressor (linear vibration actuator) may be reduced.

On the other hand, in the present embodiment, the bobbin 1
Bobbin 131 so as to extend in the axial direction of 31b and 132b.
Since slits S for cutting b and 132b are provided, it is possible to prevent the eddy current flowing around the axial direction from flowing.

Accordingly, in the present embodiment, the bobbin 1 is prevented from increasing in temperature of the exciting coils 131a and 132a.
Since it is possible to prevent eddy currents from being generated in the compressors 31b and 132b, the compressor (linear vibration actuator) is more reliably provided.
Efficiency can be improved.

In the present embodiment, the rolled surface of the main pole 133b is configured to be substantially parallel to the direction of movement of the mover 120, the bobbins 131b and 132b are made of metal, and the bobbins 131b and 132b Slits S for cutting the bobbins 131b and 132b are provided so as to extend in the axial direction of the main body 133b.
And the bobbins 131b and 132b are made of metal and extend in the axial direction of the bobbins 131b and 132b.
A slit S for cutting 1b and 132b may be provided.

In place of the slit S, the bobbin 131
An electrical insulator may be embedded in the b and 132b so as to extend in the axial direction.

(Fourth Embodiment) In this embodiment, as shown in FIG. 12, a corner 125a of a spacer 125 facing a main magnetic pole 133b and a yoke 124 is cut and removed, and an electrical insulating portion is formed on the corner 125a. 125b is provided.

As a result, eddy current can be prevented from being generated in the spacer 125 located near the yoke 124, so that the third problem can be solved and the efficiency of the compressor (linear vibration actuator) can be improved. Can be done.

In this embodiment, in this embodiment,
The rolling surface of the main pole 133b is configured to be substantially parallel to the direction of movement of the mover 120, and the bobbins 131b and 132b are made of metal and cut off so that the bobbins 131b and 132b extend in the axial direction of the bobbins 131b and 132b. And a corner 125 of the spacer 125 is provided.
a is provided with the electrical insulating portion 125 b, but in the present embodiment, at least the electrical insulating portion 1
25b may be provided.

Further, in the present embodiment, the first magnetic field generating means for inducing a magnetic field by the permanent magnet 122 and the yoke 124 is formed.
The first magnetic field generating means may be constituted by only the first magnetic field generating means.

(Other Embodiments) The application of the linear vibration actuator according to the present invention is not limited to a compressor for a pulse tube refrigerator, but an actuator for a machine tool or a compressor for a Stirling refrigerator. And so on.

In the above embodiment, the movable member 12
Although the permanent magnet 122 is buried in 0, an electromagnet may be used instead of the permanent magnet 122 to supply an alternating current to the electromagnet. In this case, whether a DC current is applied to the electromagnet 130 disposed outside the pressure vessel 110,
Alternatively, it is necessary to shift the phase of the alternating current flowing between the electromagnet provided on the movable member 120 and the electromagnet 130, or to use a permanent magnet instead of the electromagnet 130.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a pulse tube refrigerator using a linear vibration actuator according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a compressor according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a front view of the leaf spring according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a magnetic flux flow in the linear vibration actuator according to the first embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the thrust generated in the mover and the position of the mover (the amount of deviation from the state of zero applied voltage).

FIG. 7 is a sectional view of a linear vibration actuator according to a second embodiment of the present invention.

FIG. 8 is a sectional view of a linear vibration actuator according to a modification of the second embodiment of the present invention.

FIG. 9 is an explanatory view showing a method of manufacturing a yoke applied to the linear vibration actuator according to the second embodiment of the present invention.

FIG. 10 is a perspective view of a bobbin used in a linear vibration actuator according to a third embodiment of the present invention.

FIG. 11 is a schematic diagram of an eddy current flowing in a bobbin.

FIG. 12A is a sectional view of a mover used in a linear vibration actuator according to a fourth embodiment of the present invention, and FIG. 12B is a side view.

FIG. 13 is a cross-sectional view of a prototype linear vibration actuator.

FIG. 14 is a cross-sectional view of a prototype linear vibration actuator.

[Explanation of symbols]

Reference numeral 120: mover, 122: permanent magnet, 124: yoke (mover core), 130: electromagnet (stator), 131a, 132a: exciting coil, 133: yoke (stator core), 133b: main magnetic pole.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AA03 AE08 5H633 BB08 BB11 GG02 GG04 GG05 GG09 GG13 GG17 HH03 HH04 HH09 HH18 HH21 HH22 HH24 JB03 JB04

Claims (6)

[Claims] 1. A reciprocating mover (120) having a mover iron core (124) made of a magnetic material and inducing first magnetic field, and facing the mover (120). And a stator (130) having a stator core (133b) made of a magnetic material extending in a direction perpendicular to the direction of movement of the mover (120) and having second magnetic field generating means for generating a magnetic field. The movable element (120) reciprocates by periodically changing the polarity of at least one of the magnetic field induced by the first magnetic field generating means and the magnetic field induced by the second magnetic field generating means. Further, at least one of the stator core (133b) and the mover core (124) is formed by laminating a thin rolled steel plate (124a, 133a), and A linear vibration actuator, wherein a rolling surface of a rolled steel plate (124a, 133a) and a moving direction of the mover (120) are substantially parallel. 2. A mover (120) that induces a magnetic field and reciprocates, and is made of a magnetic material that faces the mover (120) and extends in a direction perpendicular to the direction of movement of the mover (120). A stator (130) having a magnetic field generating means for generating a magnetic field with the stator core (133b) of the above, wherein the polarity of the magnetic field induced by the magnetic field generating means is periodically changed to produce the magnetic field. The mover (120) is reciprocated, and the stator core (133b) is formed by laminating a thin rolled steel plate (13a), and the rolling surface of the rolled steel plate (133a) and the movable surface A linear vibration actuator, wherein a movement direction of a child (120) is substantially parallel. 3. A solenoid coil (131) formed by winding an electric wire around a cylindrical winding frame (131b, 132b).
a, 132a) and an electromagnet (13
0) and a movable element (12) that reciprocates while inducing a magnetic field.
0), the movable element (120) is reciprocated by periodically changing the polarity of the magnetic field induced by the electromagnet (130), and the winding frames (131b, 132b) are made of metal. A linear vibration actuator characterized in that the winding frames (131b, 132b) are provided with an electric insulating portion (S) extending in the axial direction. 4. The electric insulation part includes a winding frame (131).
b, 132b) in the axial direction (S)
The linear vibration actuator according to claim 3, wherein 5. A mover (120) having a plurality of first magnetic field generating means for reciprocating and inducing a magnetic field.
And a stator (130) facing the mover (120) and having a second magnetic field generating means for generating a magnetic field in a direction orthogonal to the direction of movement of the mover (120). The first magnetic field generating means are arranged in series in the movement direction of the mover (120) with a spacer (125) made of a non-magnetic material interposed therebetween. (133b) and a corner (125a) facing the first magnetic field generating means is provided with an electric insulating portion (125b). 6. The electrical insulating section includes a spacer (12).
5) The linear vibration actuator according to 5), wherein a corner (125a) facing the stator core (133b) and the first magnetic field generating means is removed.