KR20040090206A - Core for linear motor and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A core and a manufacturing method thereof are provided to allow for ease of manufacture of core, and reduce manufacturing costs and weight of the core. CONSTITUTION: A core comprises a core stacked unit where a plurality of core sheets(22) are radially stacked into a cylindrical shape; and a core frame(21) made of a plastic material, and which covers the inner surface of the core stacked unit. The core frame is formed by an insert injection process or an extrusion process. A method for manufacturing a core comprises a step of forming a core stacked unit by radially stacking a plurality of core sheets; and a step of forming a core frame by insert injecting a plastic material such that the core frame covers the inner surface of the core stacked unit.

Description

Core for linear motor and manufacturing method {CORE FOR LINEAR MOTOR AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor core and a method for manufacturing the same, and more particularly, to a liner motor core and a method for producing the core frame having improved materials and manufacturing methods.

In general, a linear motor converts the flux of a normal motor having a three-dimensional structure into a flat shape, and the movable part of the flat shape moves on the plane according to the change of the magnetic flux formed on the fixed part of the plane. It is to move linearly.

1 and 2 illustrate an example of a linear motor. As shown in the drawing, the linear motor has a cylindrical shape to be inserted into an outer core 10 and an outer core 10 formed in a cylindrical shape. Between the stator 1 comprising the inner core 20 formed therein, the winding coil coupled to the inner and outer cores 10 or 20, and the permanent magnet, between the outer core 10 and the inner core 20. And a mover inserted to be movable in the. In the drawing, the winding coil is coupled to the outer core 10.

When the current flows in the winding coil, such a linear motor has a magnetic flux formed around the winding coil by the current flowing in the winding coil, and the formed magnetic flux is a closed loop along the outer core 10 and the inner core 20. Will form. The magnetic fluxes formed in the outer core 10 and the inner core 20 are axially forced by the magnetic flux formed by the permanent magnets, that is, by the interaction of the magnetic fluxes. Linear motion in the axial direction between the (20). At this time, if the direction of the current applied to the winding coil is alternately changed, the mover linearly reciprocates.

The outer core 10 is formed by radially stacking a plurality of core sheets 22 formed of a thin plate having a predetermined shape to form a cylinder. Here, when the winding coil is coupled to the outer core, a bobbin (not shown) is used for electrical insulation and simplicity of manufacture.

The inner core 20 is formed by radially stacking a plurality of core sheets 22 formed of a thin plate having a predetermined shape to form a cylindrical shape. The cylindrical inner core 20 is inserted into the outer core 10 at predetermined intervals.

The core frame 21 is inserted inside the inner core 20. The core frame 21 has a cylindrical shape, the outer peripheral surface thereof is in contact with the inner peripheral surface of the core frame 21 to support the cylindrical core laminated portion 25. End portions of the core frame 21 and the core stacked portion 25 are fixed by a method such as welding.

By the way, in the conventional inner core 20 formation method, the manufacturing process of the metal core frame 21 and the process of fixing the core laminated part 25 to the outer peripheral surface of the core frame 21 are performed individually, etc. The process of forming the inner core 20 is complicated and there is a problem of increasing the manufacturing cost.

In addition, by using the metal core frame 21, the weight of the inner core 20 is heavy, there is a problem to increase the overall weight of the linear motor.

Accordingly, it is an object of the present invention to provide a linear motor core and a method of manufacturing the same, which are easy to manufacture the core for the linear motor, reduce the manufacturing cost and reduce the weight thereof.

1 is a schematic cross-sectional view of a general linear motor,

2 is a front view of an inner core of the linear motor of FIG. 1,

3 is a schematic diagram of an insert injection molding machine for a core frame of an inner core according to an embodiment of the present invention;

4 to 9 is a view showing a process of forming a core laminated portion of the inner core of the present invention,

10 is a schematic diagram of an insert injection molding machine for a core frame of an inner core according to an embodiment of the present invention;

11 is a perspective view of a core sheet according to another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1: stator 2: permanent magnet

3: winding coil 10: outer core

20: inner core 21: core frame

22: core sheet 23: fixing groove

25 core stacking part 26

27: hanging jaw ball 28: retaining ring

29: fixing protrusion 30: horizontal alignment jig

31: alignment groove 40: outer diameter guide jig

50: inner diameter guide jig 60: tape

The object is, according to the present invention, a core stacking portion laminated radially so that a plurality of core sheets having a predetermined shape to form a cylindrical shape; It is achieved by a core for a linear motor comprising a core frame formed of a plastic material so as to surround the inner peripheral surface of the core laminated portion.

Here, the core frame is preferably formed by insert injection molding so that the plastic material surrounds the inner circumferential surface of the core stacking portion.

In addition, the core frame may be formed by extruding the plastic material.

In addition, fixing grooves are formed at both ends of the core sheet forming the core stacking portion, and a fixing protrusion inserted into the fixing groove is formed in the core frame.

In addition, the inner circumferential surface of the core laminated portion is formed with a locking projection protruding toward the core frame, it is preferable that the locking jaw accommodation hole is formed in the core frame surrounding the locking projection.

On the other hand, the above object, according to another field of the present invention, in the method for manufacturing a core for a linear motor having a cylindrical core frame and a plurality of core sheets core laminated portion radially laminated so as to surround the outer periphery of the core frame. The method of claim 1, further comprising: forming a core stack by radially stacking the plurality of core sheets to form a cylindrical shape; It can be achieved by a method for manufacturing a core for a linear motor, comprising the step of inserting a plastic material to surround the inner peripheral surface of the core laminated portion to form a core frame.

The forming of the core stacking portion may include: linearly stacking the plurality of core sheets in parallel with each other; Attaching an adhesive tape such that the core sheets are interconnected along one side of the linearly aligned core sheets; Radially aligning the core sheets to which the adhesive tape is attached to form a cylindrical shape; It is preferable to include the step of inserting the fixing ring in the circular groove formed by the fixing groove formed on both ends of the core sheets radially aligned to form a cylindrical shape.

The linear stacking of the plurality of core sheets in parallel and linear alignment may include linearly aligning the core sheets by inserting the core sheets into a horizontal alignment jig in which alignment grooves having a shape corresponding to the plate surface of the core sheets are formed. Making a step; Preferably, the linearly aligned core sheets are pressed in a stacking direction by a predetermined pressure.

Here, the number of the core sheets to be radially laminated to the outer periphery of the core frame is preferably determined by the stacking thickness of the core sheets linearly laminated by a predetermined pressure in the alignment groove of the horizontal alignment jig. Do.

In addition, the method may further include inserting a cylindrical injection preventing member into the core sheets radially aligned to form a cylindrical shape.

In addition, the core sheet is preferably formed with a taping groove to which the adhesive tape is attached.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the structure of a linear motor is demonstrated with reference to FIG.

The linear motor according to the present invention includes a stator 1 composed of an outer core 10 formed in a cylindrical shape and an inner core 20 formed in a cylindrical shape so as to be inserted into the outer core 10. And a winding coil coupled to the inside of the outer core 10 or the inner core 20, a permanent magnet, and a mover inserted to be movable between the outer core 10 and the inner core 20.

The outer core 10 is formed by radially stacking a plurality of core sheets 22 formed of a thin plate having a predetermined shape to form a cylinder. Here, when the winding coil is coupled to the outer core 10, a bobbin (not shown) is used for electrical insulation and simplicity of manufacture.

The inner core 20 is formed of a plastic material so as to surround the inner circumferential surface of the core stacking portion 25 and the core stacking portion 25 stacked radially so that a plurality of core sheets 22 having a predetermined shape have a cylindrical shape. And a frame 21.

Since the core stacked part 25 is formed by a plurality of core sheets 22, the area of the magnetic path flowing between the core stack 22 and the outer core 10 disposed at predetermined intervals on the outer circumferential surface thereof is increased to improve the efficiency of the motor. 3 and 4 illustrate the core sheet 22 having an approximately square shape as an example, but may have other shapes as necessary.

The fixing grooves 23 cut inwardly are formed at both ends of the core sheet 22. The fixing groove 23 forms a circular groove 24 at both ends of the core laminated portion 25 when the plurality of core sheets 22 form the cylindrical core stacked portion 25. The circular retaining ring 28 is inserted into the groove 24 of the core stack 25 to maintain the shape.

The core frame 21 has a cylindrical shape and supports the core stack 25 disposed along its outer circumference. The inner space of the core frame 21 guides linear movement of the drive shaft of the driver inserted into the inner space.

The core frame 21 according to the present invention is preferably formed by insert injection molding so that the plastic material surrounds the inner circumferential surface of the core laminated portion 25. The mold for forming the core frame 21 has a cylindrical shape corresponding to the shape of the core frame 21, as shown in FIG. The core laminated portion 25 is disposed along the outer circumferential surface of the cylindrical mold, and the core frame 21 is formed along the inner circumferential surface of the core laminated portion 25 during injection molding.

In addition, the mold for forming the core frame 21 is a plastic material is injected into the circular groove 24 formed by the fixing grooves 23 of the core sheets 22 at both ends of the core laminated portion 25 during injection molding. It is provided so that, when the core frame 21 is formed an annular fixing protrusion 29 is inserted into the circular groove 24 formed at both ends of the core laminated portion 25. Accordingly, in the core frame 21 formed by injection molding, a fixing protrusion 29 inserted into the fixing grooves 23 of the core sheets 22 is formed to support the circular shape of the core stacking portion 25. .

On the other hand, on the inner circumferential surface of the core laminated portion 25, as shown in FIG. 10, a locking projection 26 protruding toward the core frame 21 may be formed. As a result, when the core frame 21 is formed by injection molding, the locking jaw accommodation hole 27 is formed to surround the locking jaw 26 formed on the inner circumferential surface of the core stack 25, thereby forming the core stacked part 25. Can be more firmly supported on the core frame 21.

Hereinafter, a method of manufacturing the inner core 20 according to the present invention will be described with reference to FIGS. 3 to 6.

First, a plurality of core sheets 22 formed of a thin plate of a predetermined shape are prepared. Here, as described above, the fixing grooves 23 are formed at both ends of the core sheets 22, and the extension flanges are formed such that the locking jaw 26 is formed on the inner circumferential surface of the core stack 25.

Then, a plurality of core sheets 22 to form a core stacked portion 25 is radially stacked to form a cylindrical shape. At this time, a circular fixing ring 28 is inserted into the circular groove 24 formed by the fixing grooves 23 of the core sheets 22 at both ends of the core stacking portion 25 so that the core stacking portion 25 is formed. Keep it cylindrical.

Then, after inserting the cylindrical core laminated portion 25 into the mold for insert injection, by forming the core frame 21 through the insert injection, the production of the inner core 20 is completed.

Here, the cylindrical core laminated portion 25 is preferably formed through the formation process as follows.

First, a plurality of core sheets 22 formed of thin plates of a predetermined shape are provided. Here, fixing grooves 23 are formed at both ends of the core sheet 22 as described above. Then, the predetermined number of core sheets 22 are stacked in parallel and aligned linearly. Here, it is preferable to use a horizontal alignment jig 30 for linear alignment of the core sheets 22. An alignment groove 31 having a shape corresponding to the plate surface of the core sheet 22 is formed in the horizontal alignment jig 30, and the core sheets 22 are inserted by inserting the core sheets 22 into the alignment groove 31. Can be linearly aligned.

In general, even if the stacked core sheets 22 are laminated with the same number of core sheets 22 due to mutual elasticity or thickness errors in manufacturing the core sheets 22, the stacking thickness of the core sheets 22 is changed. In the present invention, the number of core sheets 22 laminated to a desired thickness is determined while pressing the plurality of core sheets 22 inserted and stacked in the horizontal alignment jig 30 in the stacking direction of the core sheets 22 by a constant pressure. do. As a result, the lamination thickness of the core sheets 22 laminated at a constant pressure can be maintained at every production, and the constant lamination thickness of the core sheets 22 determined by this method is such that the inner core 20 has a cylindrical shape. The inner and outer diameters can be kept constant when they are stacked radially. Here, it is preferable to use a pressure gauge so as to press the stacked core sheets 22 at a constant pressure.

The adhesive tape 60 is attached to each other so that the core sheets 22 are interconnected along one side of the core sheets 22 which are stacked to a predetermined thickness and linearly aligned by the above method. Then, the core sheets 22 to which the adhesive tape 60 is attached are removed from the horizontal alignment jig 30 and then inserted into the cylindrical outer diameter guide jig 40 to align the stacked core sheets 22 in the cylindrical shape. As a result, the core sheets 22 have the same shape as the core stacking portion 25 of the inner core 20 that is radially stacked. Here, the inner diameter of the outer diameter guide determines the outer diameter of the inner core 20.

Then, a cylindrical inner diameter guide jig 50 is inserted into the cylindrical inner space formed by the core sheets 22 in the outer diameter guide jig 40 to form a cylindrical inner circumferential surface formed by the core sheets 22. Sort it. As a result, the inner diameter and the outer diameter of the cylindrical core sheets 22 are constantly aligned by the outer circumferential surface and the inner circumferential surface of the inner diameter guide jig 50 and the outer diameter guide jig 40.

At this time, the fixing grooves 23 formed at both ends of the core sheets 22 are circularly stacked at both ends of the core stacking portion 25 as the core sheets 22 are radially stacked to form a cylindrical shape. The shape of the core laminated portion 25 is maintained by inserting the circular fixing ring 28 into the circular groove 24. Here, the cylindrical core laminated portion 25 is formed by removing the outer diameter guide jig 40 and the inner diameter guide jig 50.

On the other hand, the manufacturing method in the inner core 20 according to the present invention is the core laminated portion 25 in the step before forming the core frame portion 25 by insert injection on the inner peripheral surface of the core laminated portion 25 arranged in a cylindrical shape, It is preferable to further include the step of inserting a cylindrical injection prevention member not shown in the interior. As a result, the liquid plastic material forming the core frame 21 during injection molding can be prevented from being injected between the core sheets 22 forming the core laminated part 25.

In addition, in the core sheet 22a according to the present invention, as illustrated in FIG. 11, a taping groove 22b to which the adhesive tape 60 is attached may be formed. As a result, the core sheets 22a are linearly aligned by the horizontal alignment jig 30 and then the adhesive tape 60 is attached to the taping grooves 22b, thereby forming the inner circumferential surfaces of the core sheets 22 arranged in a cylindrical shape. When aligning, it is possible to minimize the error due to the thickness of the adhesive tape (60). Here, the depth of the taping groove 22b formed in the core sheet 22a is preferably formed deeper than the thickness of the adhesive tape 60.

In the above-described embodiment, the core frame 21 is formed by insert injection, of course, the plastic material may be formed through extrusion.

As such, the core stacking portion 25 having a plurality of core sheets 22 having a predetermined shape radially stacked to form a cylindrical shape, and the core frame 21 formed of a plastic material to surround the inner circumferential surface of the core stacking portion 25 ), The core for the linear motor can be easily manufactured, and the manufacturing cost can be reduced, while the weight thereof can be reduced.

As described above, according to the present invention, a linear motor core and a method of manufacturing the same are provided which are easy to manufacture the core for the linear motor, reduce the manufacturing cost, and reduce the weight thereof.

Claims (11)

A core stacking portion stacked radially such that a plurality of core sheets having a predetermined shape form a cylindrical shape; And a core frame formed of a plastic material to surround the inner circumferential surface of the core stacking portion. The method of claim 1, The core frame is a core for a linear motor, characterized in that the plastic material is formed by insert injection so as to surround the inner peripheral surface of the core laminated portion. The method of claim 1, The core frame is a core for a linear motor, characterized in that formed by extruding the plastic material. The method of claim 2, Fixed grooves are formed at both ends of the core sheet forming the core stacking portion, and the core frame has a fixing protrusion inserted into the fixing groove. The method of claim 2, The inner circumferential surface of the core stacking portion is formed with a locking projection protruding toward the core frame, the core frame for a linear motor, characterized in that the locking projection receiving hole surrounding the locking projection is formed. In the manufacturing method of the core for a linear motor having a cylindrical core frame and a plurality of core sheets are laminated in a radially laminated core so as to surround the outer periphery of the core frame, Forming a core stack by radially stacking a plurality of the core sheets to form a cylindrical shape; And inserting a plastic material so as to surround the inner circumferential surface of the core lamination part to form a core frame. The method of claim 6, Forming the core laminated portion, Stacking and arranging the plurality of coresheets in parallel to each other; Attaching an adhesive tape such that the core sheets are interconnected along one side of the linearly aligned core sheets; Radially aligning the core sheets to which the adhesive tape is attached to form a cylindrical shape; And inserting a fixing ring into a circular groove formed by fixing grooves formed at both ends of the core sheets radially aligned to form a cylindrical shape. The method of claim 7, wherein The stacking of the plurality of core sheets parallel to each other and linearly aligned, Linearly aligning the core sheets by inserting the core sheets into a horizontal alignment jig in which alignment grooves having a shape corresponding to the plate surface of the core sheets are formed; And pressing the linearly aligned core sheets in a lamination direction by a predetermined pressure. The method of claim 8, The number of the core sheets radially laminated on the outer periphery of the core frame is determined by the stacking thickness of the core sheets linearly stacked by a predetermined pressure in the alignment groove of the horizontal alignment jig. Manufacturing method of core for linear motor. The method of claim 8, And inserting a cylindrical injection preventing member into the core sheets radially aligned to form a cylindrical shape. The method of claim 1, The core sheet is a core for a linear motor, characterized in that the taping groove to which the adhesive tape is attached.