KR101356765B1 - Linear actuator - Google Patents

Abstract

The present invention relates to a linear actuator, capable of bidirectionally operating a plunger by the switch of an electrical input without a mechanical structure like a spring by forming an iron core with a rectangular parallelepiped shape on a stator with a multistage structure to be partially overlapped, increasing the stroke of the plunger, and continuously moving the plunger at a preset distance by successively applying a current to a coil of the stator with the multistage structure.

Description

[0001] The present invention relates to a linear actuator,

The present invention relates to a linear actuator, and more particularly, the stator iron core is composed of a multi-stage structure of two or more stages, thereby enabling bidirectional operation of the plunger by switching electrical inputs without a mechanical structure such as a spring, and increasing the stroke distance of the plunger. It is about a linear actuator which can be made.

A general linear actuator is composed of a coil through which an electric current flows to generate a magnetic field, an iron core magnetized by the coil, and a plunger pulled by an excited magnetic force and returned to its original state by a spring.

In the conventional linear actuator, when a current is applied, the plunger, which is spaced apart from the iron core by a predetermined distance, moves toward the iron core while overcoming the elastic force of the spring by the magnetic force of the iron core. In the case of interrupting the current, the plunger moves unidirectionally by returning to its original position by the restoring force of the spring.

However, the conventional linear actuator has to design the magnitude and magnetic force of the input current in consideration of the restoring force of the spring, and there is a problem that the structure is complicated and the manufacturing cost is high. In addition, since the moving distance between the iron core and the plunger cannot be increased by a certain limit or more, the situation is limited to the short-range use of light loads.

In addition, the Republic of Korea Patent No. 0865635 (registered on October 22, 2008) is used as part of the return path to the outer shell of the hollow cylindrical tube structure, two permanent magnets installed in the hollow portion of the outer shell, magnetic circuit A linear actuator consisting of a short soft magnetic pole piece and a long soft magnetic pole piece, and a coil installed around the coil base, wherein the coil base enables bi-directional movement in the axial direction with respect to the outer shell. It is.

In the case of the linear actuator of the patent, permanent magnets of the same pole are disposed to face each other at both ends in the axial direction, and the moving coil can be operated in both directions by switching the polarity of the current according to the direction of movement.

However, the linear actuator of the registered patent cannot operate with a constant force with respect to the entire stroke, and there is a problem that the force decreases linearly with respect to the direction of movement.

The present invention is to solve the above problems, the present invention is composed of a stator iron core in a multi-stage structure of two or more stages to enable bi-directional operation of the plunger by switching the electrical input without a mechanical structure such as a spring and stroke of the plunger It is also an object of the present invention to provide a linear actuator that can increase the distance and to continuously move the plunger by a predetermined distance by applying a sequential current to the coil of the stator having a multi-stage structure.

Linear actuator according to the present invention for achieving the above object, the stator base; A plurality of first iron cores protruding from one surface of the stator base and arranged at regular intervals in one direction on the stator base; A plurality of second iron cores protruding from one side of the first iron core and disposed between the first iron cores and partially overlapping with the first iron cores so as to overlap with the first iron cores at one side of the first iron cores; A first coil wound around the first iron cores to magnetize the first iron cores as a current is applied; A second coil wound around the second iron cores to magnetize the second iron cores as a current is applied; One side of the stator base is installed to be movable relative to the stator base, the current is applied to the first coil or the second coil relative to the stator base by the magnetic force generated by the magnetization of the first iron core or the second iron core And a moving plunger.

The linear actuator according to the present invention selectively applies power to the first coil and the second coil of the iron core stage consisting of two or more stages without a mechanical structure such as a conventional spring, and selectively magnetic force to the first iron core and the second iron core. By generating, it is possible to operate the plunger in both directions and increase the stroke distance of the plunger.

In addition, since the structure can be simplified, it is easy to manufacture, and there is an advantage of improving productivity.

1 is a partially cutaway perspective view showing a first embodiment of a linear actuator according to the present invention.
FIG. 2 is a partially cutaway perspective view showing the plunger of the linear actuator of FIG. 1.
3 is a cross-sectional view of the linear actuator of FIG. 1.
4 is a partially cutaway perspective view of a second embodiment of a linear actuator according to the present invention.
5 is a partially cutaway perspective view showing a third embodiment of a linear actuator according to the present invention.
FIG. 6 is a partially cutaway perspective view showing the plunger of the linear actuator of FIG. 5.
FIG. 7 is a cross-sectional view of the linear actuator of FIG. 5.
8 is a partially cutaway perspective view showing a fourth embodiment of the linear actuator according to the present invention.
FIG. 9 is a partially cutaway perspective view showing the plunger of the linear actuator of FIG. 8.
10 is a cross-sectional view of the linear actuator of FIG. 8.
11 is a partially cutaway perspective view showing a fifth embodiment of a linear actuator according to the present invention.
12A and 12B are graphs and tables showing values obtained by three-dimensional finite element analysis of the force acting in the axial direction according to the magnetic force when a current is applied to the coil of the stator core of the linear actuator according to the present invention.
13A and 13B are side and perspective views, respectively, of a sixth embodiment of a linear actuator according to the present invention.
14A and 14B are side and perspective views, respectively, of a seventh embodiment of a linear actuator according to the present invention.
15A and 15B are side and perspective views, respectively, of an eighth embodiment of a linear actuator according to the present invention.
16A and 16B are side and perspective views, respectively, of a ninth embodiment of a linear actuator according to the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of a linear actuator according to the present invention will be described in detail with reference to the accompanying drawings.

First, the first embodiment of the linear actuator according to the present invention will be described with reference to FIGS. 1 to 3. The linear actuator according to the first embodiment of the present invention includes a stator base 10, a first iron core 21, and a second embodiment. It consists of the structure containing the iron core 31, the 1st coil 22, the 2nd coil 32, and the plunger 40. As shown in FIG.

In this embodiment, the stator base 10 is made of a hollow cylindrical shape with the top and bottom open in the drawing, but alternatively, the stator base 10 has either the top or the bottom, or both the top and the bottom of the structure. It can be made in a cylindrical shape. In the form in which both the top and bottom of the stator base 10 are closed, an elongated long slot is formed along the axial direction at the side surface of the stator base 10, through which the plunger is connected to an external linear motion object. Can be. The stator base 10 is placed in the circumferential direction by inserting the iron core of the rectangular parallelepiped that protrudes and protrudes into the hollow cylindrical stator iron core, or each of the divided "tt" shaped iron cores are connected to each other to make a cylindrical Can lose.

The first iron cores 21 are formed to protrude radially on the inner surface of the stator base 10, and are arranged at a predetermined interval along the circumferential direction at the bottom of the stator base 10. The first iron cores 21 have a rectangular parallelepiped shape extending in the axial direction of the stator base 10.

The second iron cores 31 protrude from the top of the stator base 10 and are arranged at regular intervals along the circumferential direction of the stator base 10. The second iron core 31 has the same rectangular parallelepiped shape as the first iron core 21, and is disposed between the first iron cores 21, and a portion (a lower portion of the drawing part) is the first iron core 21. Are overlapped with a portion of the first iron core 21 so as to overlap with a portion of the upper portion of the figure.

The first coil 22 is wound around the respective first iron cores 21. The first coils 22 wound around the first iron cores 21 are electrically connected to each other, and coils are alternately wound and are electrically connected to an external control device (not shown) to apply a current. Receive.

The second coil 32 is wound around the second iron cores 31, and is electrically connected to each other like the first coil 22, and the coils are alternately wound. The second coil 32 is also electrically connected to an external control device (not shown) to receive a current from the control device.

The first coil 22 and the second coil 32 are solenoid type coils, and generate a magnetic field as a current is applied from a control device (not shown), so that the first iron core 21 and the second iron core 31 are formed. Will act to magnetize them.

The plurality of first iron cores 21 and the first coil 22 form a first iron core end 20, and the plurality of second iron cores 31 and the second coil 32 may include a second iron core end ( 30).

As described above, the linear actuator of the present invention includes a first iron core 20 composed of the first iron core 21 and the first coil 22, and a second iron core composed of the second iron core 31 and the second coil 32. Stage 30 is arranged in a two-stage structure along the axial direction of the stator base 10, the first iron core 20 and the portion of the second iron core 30 has a structure arranged while overlapping each other.

The plunger 40 is formed of a circular rod made of a magnetic material to move by magnetic force, and is installed to be movable in the axial direction inside the hollow part of the stator base 10. The plunger 40 has an outer circumferential surface spaced apart from the first iron core 21 and the second iron core 31 by a predetermined interval so as to selectively generate magnetic force at the first iron core 20 and the second iron core 30. By the stator base 10 is moved in the axial direction. Although not shown in the drawing, the plunger 40 is connected to the linear motion object to be moved linearly to function as a driving body for linear movement of the linear motion object.

The length of the plunger 40 is preferably formed to be equal to or longer than the length of the first iron core 21 or the second iron core 31.

The linear actuator having the above configuration operates as follows.

The lower end of the plunger 40 is in an overlapping state with the upper end of the first iron core 21 in a state where the plunger 40 is positioned at the position corresponding to the second iron core 31, that is, the upper part of the stator base 10. This is because the length of the plunger 40 is formed to be equal to or slightly longer than the length of the first iron core 21 or the second iron core 31.

In this state, when power is supplied from the control device (not shown) to the first coil 22 and current flows in the first coil 22, a magnetic field is generated in the first coil 22 to generate the first iron core 21. Is magnetized. Accordingly, the plunger 40 moves downward in the axial direction by the attraction force with the first iron core 21 to move to the position corresponding to the first iron core 21.

At this time, in order for the plunger 40 to perform the upward movement again after the downward movement, power is applied to the second coil 32 so that a current flows, and a magnetic field is generated in the second coil 32, thereby causing the second iron core ( 31) is magnetized. Accordingly, the plunger 40 positioned below moves upward in the axial direction by the attraction force with the second iron core 31 to move to the position corresponding to the second iron core 31. The power applied to the exciting coil after the up or down movement of the plunger 40 is maintained or cut off depending on the external load.

As the power is alternately applied to the first coil 22 and the second coil 32 as a current flows, a magnetic field is alternately generated in the first coil 22 and the second coil 32 so as to generate a first coil. Magnetic force is generated alternately in the iron core 20 and the second iron core 30. Accordingly, the plunger 40 moves axially in the stator base 10 to reciprocate to a position corresponding to the first iron core end 20 and a position corresponding to the second iron core end 30.

Meanwhile, in the first embodiment described above, the first iron core stage 20 and the second iron core stage 30 are arranged alternately with each other, so that the iron core stages are all composed of two stages. However, as shown in FIG. 4, the first iron core end 20 including the first iron core 21 and the first coil 22 is disposed at the lower end of the stator base 10, and the second iron core ( 31)-the second iron core end 30 is formed of the second coil 32, and the third iron core 51-third coil core consisting of the third coil (52) on the upper end of the iron core It is also possible to configure all three stages. Here, the third iron core end 50 composed of the third iron core 51 and the third coil 52 is formed of the first iron core end 20 formed of the first iron core 21 and the first coil 22. Can be interpreted as repetition. That is, the linear actuator of this embodiment can be interpreted as consisting of three stages of the first iron core stage 20, the second iron core stage 30, and the first iron core stage 20. Of course, the iron core and the coil may be further added to make the iron core end in four or more stages along the axial direction of the stator base 10.

When the iron core is configured in three stages as in this embodiment, power may be sequentially applied to the first coil 22 at the lower end, the second coil 32 at the middle, and the third coil 52 at the upper end. The first coil 22 at the bottom and the third coil 52 at the top may be paired to simultaneously apply power. Of course, if the core core consists of four stages, the first and third coils of the first and third iron core ends are paired, and the second and fourth coils of the second and fourth iron core ends are paired, and power is supplied to each pair. It may be authorized. When the paired operation is performed in this way, the structure of the plunger 40 is composed of a magnetic part-nonmagnetic part-magnetic part-nonmagnetic part, the magnetic part corresponding to the first and third iron cores, and the nonmagnetic part It is located in correspondence with 2, 4 iron core end. At this time, the force acting on the plunger 40 is proportional to the number of stages of the excited stator iron core.

5 to 7 show a third embodiment of a linear actuator according to the invention, in which the linear actuator has another auxiliary stator in the center of the stator base 10. That is, the linear actuator of the third embodiment has a shape corresponding to the first iron core 21 on the sub stator base 60 installed at the center of the stator base 10 and the lower outer surface of the sub stator base 60. And a plurality of first auxiliary cores 61 installed to face the first iron cores 21 and the first auxiliary cores 61 and wound around the first auxiliary cores 61 to be applied with a current from a control device. The first auxiliary coil 62 to magnetize and a plurality of second auxiliary coils formed on the upper outer surface of the auxiliary stator base 60 to face the second iron core 31 and installed to face the second iron core 31. And a second auxiliary coil 72 wound around the iron core 71 and the second auxiliary iron cores 71 to magnetize the second auxiliary cores 71 as a current is applied from a control device.

In addition, the plunger 40 is formed in a cylindrical shape having a hollow tube structure formed along the axial direction of the hole 43 in which the auxiliary stator base 60 is received at a central portion thereof, such that the stator base 10 and the auxiliary stator base 60 are formed. And move axially in the space between them.

In the linear actuator of the third embodiment configured as described above, power is simultaneously applied to the first coil 22 and the first auxiliary coil 62 to generate a magnetic field as a current flows, and the first iron core 21 and the first auxiliary core ( 61 is simultaneously magnetized to generate magnetic force. Thereafter, power is simultaneously applied to the second coil 32 and the second auxiliary coil 72 to generate a magnetic field as a current flows, and the second core 31 and the second auxiliary core 71 are simultaneously magnetized to generate magnetic force. Will be generated.

Since the linear actuator of the third embodiment generates magnetic force at the outside and the inside of the plunger 40 at the same time, the plunger 40 moves, so that the same specification may move the plunger 40 with a relatively larger force than the first embodiment described above. There is an advantage to this.

8 to 10 show a linear actuator according to a fourth embodiment of the present invention, in which the linear actuator includes the first iron core 21 and the first coil 22 and the second iron core 31. And a second coil 32 installed on the inner and outer surfaces of the stator base 10 to correspond to each other.

That is, the first iron core 21 and the first coil 22 are configured to be symmetrical to each other on both sides of the stator base 10, that is, the inner and outer surfaces, and the second iron core 31 and the second coil 32 ) Are configured to be symmetrical to each of the inner and outer surfaces of the stator base 10 so that magnetic forces are generated at the same time inside and outside the stator base 10.

The plunger 40 has a double tube structure including an inner plunger portion 41 inserted into the stator base 10 and an outer plunger portion 42 surrounding the outside of the stator base 10.

Meanwhile, in the above-described embodiments of the linear actuator, the first iron core 21 and the first coil 22, the second iron core 31 and the second coil (on both the inner surface of the stator base 10 or both surfaces of the inner and outer surfaces thereof) Although 32) is installed, the first iron core 21 and the first coil 22, and the second iron core 31 and the second coil 32 are installed in a two-stage structure only on the outer surface of the stator base 10. And the plunger 40 may be configured to linearly move in a hollow tube structure surrounding the outer surface of the stator base 10.

11 shows a linear actuator according to a fifth embodiment of the present invention. The linear actuator of this embodiment has a basic configuration similar to that of the first embodiment described above, except that the plunger 40 has a ring-shaped permanent magnet 45. There is a difference in this point of installation.

The permanent magnet 45 is a component for increasing the axial force by increasing the magnetic flux density, the magnetizing direction of the permanent magnet 45 may be selectively used in the axial direction of the upper side (arrow direction in the drawing) or axially lower side. . As shown in FIG. 11, when the magnetization direction is applied to the permanent magnet 45 having the upper side (↑) as shown in the drawing, when power is applied to the first coil 22 and the second coil 32 at the same time. The second iron core 31 is magnetized to the N pole to generate the repulsive force with the N pole of the plunger 40, and the N pole of the first iron core 21 generates the S pole of the plunger 40 and the attraction force. The plunger 40 is pushed with the second iron core 31 and pulled with the first iron core 21 so that the plunger 40 moves downward with a stronger force.

As described above, the structure in which the permanent magnets 45 are mounted to the plunger 40 may be applied to the linear actuators of the second embodiment, the third embodiment, and the fourth embodiment.

12A illustrates a case in which a current is applied to the first coil 22 of the first iron core end 20 when the plunger 40 of the linear actuator according to the first embodiment corresponds to the second iron core 31. The force acting in the axial direction according to the magnetic force is obtained by 3D finite element analysis. 12B illustrates a magnetic force when a current is applied to the second coil 32 of the second iron core 30 when the plunger 40 of the linear actuator according to the first embodiment corresponds to the first iron core 21. The force acting in the axial direction according to is obtained by 3D finite element analysis. The linear actuator used in the finite element analysis has a length of 40 mm in the axial direction of the first iron core 21 and the second iron core 31, respectively, and a length in which the first iron core 21 and the second iron core 31 overlap each other. Is 10 mm, and the axial length of the plunger 40 is 40 mm.

As can be seen from the finite element analysis results of FIGS. 12A and 12B, it can be seen that the forces in the axial direction of the plunger 40 are the same with respect to the moving direction of the plunger 40. It can be seen that the 40 can be moved long distances.

Meanwhile, in the above-described embodiments of the linear actuator, the stator base 10 and the plunger 40 have a cylindrical shape, but the stator base 10 and the plunger 40 are illustrated in other embodiments in FIGS. 13A to 16B. ) May be in the form of a rectangular flat plate. 13A and 13B are cut out and extended from the stator base 10 and the plunger 40 of the linear actuator (see FIGS. 1 to 3) of the first embodiment described above, and the first iron core (not shown) in the stator base 10. 21 and the first coil 22, the second iron core 31 and the second coil 32 are alternately arranged in two stages, and one side of the plunger 40 is formed to face each other at a predetermined distance apart from each other. .

14A and 14B show the same shape as the linear actuator cut out and unfolded in the third embodiment (see FIGS. 5 to 7), and the first iron core 21 and the first coil 22 on the stator base 10. The second iron core 31 and the second coil 32 are alternately arranged in two stages, and the first auxiliary core 61 and the first auxiliary coil 62 are disposed on one side (upper side in the drawing) of the stator base 10. ), And the second stator core 71 and the second auxiliary coil 72 are alternately arranged in two stages, and a stator base 60 is installed between the stator base 10 and the auxiliary stator base 60. It has a structure in which the plunger 40 of the form is arranged.

15A and 15B show the linear actuator cut out and unfolded in the fourth embodiment described above (see FIGS. 8 to 10), wherein the first iron core 21 and the first coil 22 are formed on both sides of the stator base 10. ), The second iron core 31 and the second coil 32 are alternately arranged in two stages, and two sets of plungers 40 are disposed to face each other. That is, the first plunger 41 is disposed on one side (upper side in the drawing), and the second plunger 42 is disposed on one side (lower side in the drawing) on the opposite side.

16A and 16B are cut and unfolded linear actuators of the fifth embodiment (see FIG. 11) described above, wherein the first iron core 21 and the first coil 22 are formed on one surface of the stator base 10; The second iron core 31 and the second coil 32 are alternately arranged in two stages, and one side of the plunger 40 is installed to face each other at a predetermined distance from each other, and a permanent magnet in the middle of the plunger 40. It forms a structure equipped with (45).

As described above, the linear actuator according to the present invention selectively applies power to the first coil 22 and the second coil 32 of the iron core end having multiple stages without a mechanical structure such as a conventional spring, thereby providing a first iron core ( 21) and the second iron core (31) by selectively generating a magnetic force has the advantage that it is possible to drive the plunger in both directions and increase the stroke distance of the plunger.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. And it is to be understood that such modified embodiments belong to the scope of protection of the present invention defined by the appended claims.

10: stator base 20: first iron core end
21: first iron core 22: first coil
30: second iron core 31: second iron core
32: second coil 40: plunger
41, 42: inner and outer plunger portion 43: hole
45: permanent magnet 50: the third iron core
51: third iron core 52: third coil
60: auxiliary stator base 61: first auxiliary core
62: first auxiliary coil 71: second auxiliary core
72: second auxiliary coil

Claims (10)

A stator base 10;
A plurality of first iron cores 21 protruding from one surface of the stator base 10 and arranged at regular intervals in one direction on the stator base 10;
Protruding from one side of the stator base 10 on one side of the first iron core 21 is disposed between the first iron core 21, but only a part of the first iron core 21 overlaps with the first iron core 21 A plurality of second iron cores 31 alternately arranged with the iron cores 21;
A first coil 22 wound around the first cores 21 to magnetize the first cores 21 as a current is applied;
A second coil 32 wound around the second cores 31 to magnetize the second cores 31 as a current is applied;
One side of the stator base 10 is installed to be relatively movable with respect to the stator base 10, and a current is applied to the first coil 22 or the second coil 32 so that the first iron core 21 or the first one. The linear actuator, characterized in that it comprises a plunger (40) which moves relative to the stator base (10) by the magnetic force generated as the two core (31) is magnetized. According to claim 1, wherein the first iron core 21 and the first coil 22, the second iron core 31 and the second coil 32 are respectively installed on both sides of the stator base 10 to correspond to each other Linear actuator, characterized in that. The linear actuator according to claim 2, wherein the plunger (40) is installed at both sides of the stator base (10) so as to face both sides of the stator base (10). The method of claim 1, further comprising: an auxiliary stator base (60) installed at one side of the stator base (10);
A plurality of first auxiliary cores 61 installed on the auxiliary stator base 60 so as to face the first iron core 21 while having a shape corresponding to the first iron core 21;
A first auxiliary coil 62 wound around the first auxiliary cores 61 to magnetize the first auxiliary cores 61 as a current is applied;
A plurality of second auxiliary iron cores 71 formed on the auxiliary stator base 60 so as to face the second iron core 31 while having a shape corresponding to the second iron core 31;
A second auxiliary coil 72 wound around the second auxiliary cores 71 to magnetize the second auxiliary cores 71 when a current is applied;
The plunger (40) is a linear actuator, characterized in that the movable installation in the space between the stator base (10) and the auxiliary stator base (60). The linear actuator according to any one of claims 1 to 4, wherein the plunger (40) is provided with a permanent magnet (45). A linear according to any one of claims 1 to 4, wherein the first iron core (21) and the second iron core (31) are in the form of a rectangular parallelepiped extending in the axial direction of the stator base (10). Actuator. 5. The first iron core end 20 formed by the plurality of first iron cores 21 and the first coils 22 and the plurality of second iron cores 31. And the second iron core ends 30 formed by the second coil 32 are alternately arranged along the axial direction of the stator base 10, so that the first iron core end 20 and the second iron core end 30 are three or more stages. Linear actuators, characterized in that arranged in. The linear actuator according to any one of claims 1 to 4, wherein the length of the plunger (40) is longer than or equal to the length of the first iron core (21) and the second iron core (31). 5. The linear actuator as claimed in claim 1, wherein the stator base and the plunger are cylindrical. 6. The linear actuator as claimed in any one of the preceding claims, characterized in that the stator base (10) and the plunger (40) are flat.

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