KR101592472B1 - Rotor - Google Patents

Abstract

The present invention relates to a rotor, a mold for stacking the same, and an injection molding apparatus having the mold and, more specifically, to a rotor which has a core for a rotor having a magnet hole where a magnet is inserted, a first hole located on the center, and a second hole located on the outer boundary than the first hole, and integrally forms first and second covers formed on each of the upper surface and the lower surface of the core, a first connection part formed in a space between the magnet hole and the magnet, and a second connection part formed on the second hole; a mold for stacking the same; and an injection molding apparatus having the mold, and manufacturing the rotor by injection molding a plastic material on the core of the rotor. The mold stacking the core for the rotor is formed with a lower mold and an upper mold; a first core supporting protrusion inserted into the lower part of the second hole of the core is formed on the lower mold; and a second core supporting protrusion inserted into the upper part of the second hole of the core is formed on the upper mold. So a separation space where the rotor is separated from the lower surface of the lower mold and the upper surface of the upper mold is formed, thereby, when first and second covers are formed on the upper surface and the lower surface of the core by injection molding of a plastic material, easily forming the first and second covers.

Description

Rotor {ROTOR}

The present invention relates to an injection molding machine for manufacturing an electric motor having a rotor for an electric motor having a magnet, a metal mold for mounting the metal mold and the metal mold, and a plastic material injected into the core of the rotor.

In the related art of a magnet synchronous motor having a rotor inside a stator, conventionally, as a method of inserting and fixing a magnet into a magnet hole of a core of a rotor, the magnet is adhered to the magnet hole using an adhesive or the like, And a cover which is rivet-bonded on the upper and lower surfaces of the core was used.

However, if the magnet is adhered to the magnet hole formed in the core by using an adhesive, the magnet can be separated from the core due to high centrifugal force during operation of the motor, and when the cover is provided on the upper and lower surfaces of the core , There is a problem that noise and vibration are generated when the rotor rotates due to the tolerance between the magnet hole formed in the core and the magnet.

Therefore, in order to solve the conventional problems, techniques for preventing noise and vibration while fixing the magnets firmly in the magnet insertion grooves of the cores have been developed. These techniques are disclosed in Korean Patent Publication No. 2012-7029157 1 "), Korean Laid-Open Patent Application No. 2015-0077468 (hereinafter referred to as Patent Document 2) and Korean Patent No. 1262390 (hereinafter referred to as Patent Document 3).

The body of the rotor of Patent Document 1 is partially surrounded by a coupling sleeve having a chamber wall, said chamber wall defining at least one chamber in which at least one permanent magnet element is disposed with a support surface, A coupling sleeve secures the position of the permanent magnet element in a radial direction on the body and a locking element is molded on the body, the locking element sealing the chamber so that axial movement of the permanent magnet element And has a rotor structure for fixing the position.

In the case of Patent Document 2, the rotor has a cylindrical core made of a ferromagnetic laminated body or a ferromagnetic powder metal, a shaft fixed to the core to form a rotation shaft, and a shaft hole disposed at the center of the core and supporting the shaft A hub, at least one pole segment disposed all around the hub, at least one magnet slot disposed between the pole segments, at least one magnetic slot tangentially magnetized and disposed within the magnet slot and extending radially outwardly, And two end rings made of a nonmagnetic material such as a magnet and plastic or aluminum and fixed on the front and rear surfaces of the core by an injection molding method.

In the case of Patent Document 3, the rotor includes a cylindrical central core surrounded by a plurality of permanent magnets. As a method of manufacturing such a rotor, a plurality of arrangement sheets for the permanent magnets are formed between the base end and the open end, Comprising the steps of: arranging a cup-shaped body having a plurality of passing longitudinal grooves; inserting the central core into a cup-shaped body and arranging the permanent magnets on the placement sheet; And a column extending between the opposed bottoms and received in the grooves, the cage-like structure comprising:

However, in the case of Patent Documents 1 to 3, when the rotor rotates and centrifugal force is applied, the web of Patent Document 1, the bar of Patent Document 2, and the column of Patent Document 3 are repeatedly The web, the bar, and the column may be damaged.

Also, by connecting the locking member of Patent Document 1 formed on the upper and lower surfaces of the core with only the web, connecting the end ring of Patent Document 2 with only the bar, and connecting the opposite bottoms of Patent Document 3 with only the column, Since the load is concentrated on the web or the like, the web or the like may be more easily broken due to repetitive use of the rotor.

Korea Patent Publication No. 2012-7029157. Korean Patent Publication No. 2015-0077468. Korean Patent No. 1262390.

SUMMARY OF THE INVENTION The present invention is conceived to solve the above-described problems, and it is an object of the present invention to provide a rotor core having a magnet hole into which a magnet is inserted, a first hole located at the center and a second hole located outside the first hole, And a second connecting portion formed in a space between the magnet hole and the magnet, and a second connecting portion formed in the second hole, the first and second covers being formed on the upper surface and the lower surface of the core, And an injection molding machine having a mold and a mold for loading the rotor.

The mold according to one aspect of the present invention is a die for loading a rotor core having a magnet hole into which a magnet is inserted, a first hole located at the center, and a second hole located outside the first hole, A lower mold into which a lower portion of the core is inserted; An upper mold disposed on an upper portion of the lower mold to cover an upper portion of the core; And an injection hole formed in one of the upper mold and the lower mold, wherein the lower mold includes: an insertion portion into which a lower portion of the core is inserted; A first circular protrusion inserted into a lower portion of the first hole; A first core supporting protrusion inserted into a lower portion of the second hole such that a space is formed on a lower surface of the core and an upper surface of the lower mold; And a magnet supporting protrusion for supporting a lower portion of the magnet inserted in the magnet hole, wherein the upper mold includes: a second circular protrusion inserted into the upper portion of the first hole; And a second core supporting protrusion inserted into the upper portion of the second hole so that a space is formed in the upper surface of the core and the lower surface of the upper mold.

According to an aspect of the present invention, there is provided a rotor including: a core having a first hole formed therein; A plurality of second holes formed in the outer periphery of the first hole; A magnet hole formed in the core; A magnet inserted into the magnet hole; First and second covers formed on upper and lower surfaces of the core, respectively; And first and second connection portions connecting the first and second covers, wherein the first and second covers and the first and second connection portions are integrally formed by injection of a plastic material, The magnet is formed in a space between the magnet hole and the magnet, and the second connection portion is formed in at least one of the plurality of second holes.

The plurality of magnet holes may be formed so that one side thereof is convex in the direction of the first hole and the other side is concave, A plurality of magnet holes are formed to be respectively inserted into the plurality of magnet holes, one side thereof being convex and the other side being concave.

According to one aspect of the present invention, there is provided an injection molding machine including a rotor core having a magnet hole into which a magnet is inserted, a first hole located at the center, and a second hole located outside the first hole, 1. An injection molding machine for injecting plastic, comprising: a main body; A mold installed in the main body to load the core; An injection nozzle for injecting and injecting plastic into the mold; And a movable member located at a lower portion of the mold, wherein the mold includes a lower mold into which the core is inserted, and an upper mold positioned at an upper portion of the lower mold to cover an upper portion of the core, The lower mold includes an insertion portion into which a lower portion of the core is inserted; A first circular protrusion inserted into a lower portion of the first hole; A first core supporting protrusion inserted into a lower portion of the second hole such that a space is formed on a lower surface of the core and an upper surface of the lower mold; And a magnet supporting protrusion for supporting a lower portion of the magnet inserted in the magnet hole, wherein the upper mold includes: a second circular protrusion inserted into the upper portion of the first hole; A second core supporting protrusion inserted into an upper portion of the second hole such that a space is formed in an upper surface of the core and a lower surface of the upper mold; And an injection hole through which the plastic injected from the injection nozzle flows into the magnet hole, wherein the moving member is horizontally movable so as to be in contact with a lower surface of the lower mold.

The first and second slides are horizontally moved from both sides of the main body to the lower side of the lower mold, First and second cylinders; First and second pistons respectively installed in the first and second cylinders; And first and second blocks respectively coupled to the first and second pistons and in contact with the lower surface of the lower mold, wherein a lower surface of the lower mold is convex downward, The first and second inclined surfaces contacting the lower surface of the convex lower mold are respectively formed.

As described above, the rotor of the present invention and the injection molding machine having the mold and the mold for loading the rotor have the following effects.

Wherein a mold for loading a rotor core is formed of a lower mold and an upper mold, a first core supporting projection inserted into a lower portion of a second hole of the core is formed in the lower mold, The second core supporting projection inserted into the upper portion of the hole may be formed so that the rotor is spaced apart from the lower surface of the lower mold and the upper surface of the upper mold. When the first and second covers are formed on the upper and lower surfaces of the core, the first and second covers can be easily formed.

Further, since the magnet supporting protrusions are formed on the lower mold, the magnet inserted into the cores can be supported, and the first and second covers can be formed on the upper and lower surfaces of the core more stably.

The magnet hole formed in the core of the rotor and the magnet inserted into the magnet hole are convex on one side and concave on the other side so that the distance from the center of the core to the core is smaller than that of the conventional rectangular magnet structure There is an effect that the magnet having a wider area can be disposed.

Further, since the outer side of the core, that is, the magnet hole and the other side of the magnet are concave, a force applied to the first connecting portion, which is in contact with the other side of the magnet when the rotor rotates and centrifugal force acts, So that it is possible to prevent breakage or the like of the first connection portion.

Further, when the plastic material is injected by the injection molding machine to form the first connection part in the magnet hole, the area in which the first connection part contacts the magnet becomes larger, and the first connection part further strengthens the magnet There is an effect that it can be fixed.

The first and second slides are horizontally movable on both sides of the main body of the injection molding machine having the mold so that when the plastic material is injected into the mold through the injection nozzle and the injection hole of the injection molding machine, Is horizontally moved from both sides of the main body to the lower direction of the lower mold, thereby preventing the mold from being pushed downward by the injection pressure.

1 is a perspective view of a rotor according to a preferred embodiment of the present invention;
Fig. 2 is a view showing the combination of the core and the magnet in Fig. 1; Fig.
3 is a cross-sectional view showing the first connection portion of Fig.
4 is a cross-sectional view of the second connection portion of Fig.
5 is a view showing a core loaded on a mold according to a preferred embodiment of the present invention;
Fig. 6 (a) is a front view of the lower mold of Fig. 5; Fig.
6 (b) is a plan view of the lower mold of Fig. 5;
7 (a) is a front view of the upper mold of Fig. 5; Fig.
7 (b) is a bottom view of the upper mold of Fig. 5;
8 is a front view of an injection molding machine according to a preferred embodiment of the present invention.
Fig. 9 is a view showing that the first and second slides of Fig. 8 are horizontally moved in the lower direction of the lower mold; Fig.
10 is a side view of Fig. 8; Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view of a rotor according to a preferred embodiment of the present invention, FIG. 2 is a view showing a combination of a core and a magnet in FIG. 1, FIG. 3 is a cross- FIG. 5 is a view illustrating a core mounted on a mold according to a preferred embodiment of the present invention. FIG. 6 (a) is a front view of the lower mold of FIG. 5 5 is a front view of the upper mold of Fig. 5, Fig. 7 (b) is a bottom view of the upper mold of Fig. 5, and Fig. 8 FIG. 9 is a front view of the injection molding machine according to a preferred embodiment of the present invention. FIG. 9 is a view illustrating the first and second slides of FIG.

1 to 4, a rotor 100 according to a preferred embodiment of the present invention includes a core 110 formed with a first hole 111 at a center thereof, a core 110 formed at a periphery of the first hole 111, A magnet 120 inserted in the magnet hole 115 and a plurality of second holes 113 formed in the upper and lower surfaces of the core 110, And first and second connectors 135 and 137 for connecting the first and second covers 131 and 133 and the first and second covers 131 and 133.

The core 110 has a cylindrical shape and a first hole 111 is formed at the center so as to penetrate the upper and lower surfaces of the core 110 so as to insert a shaft (not shown).

The second hole 113 is formed so as to pass through the upper and lower surfaces of the core 110 and is formed in a plurality of outsides of the first hole 111.

In this case, the plurality of second holes 113 are inserted into the first and second core support projections 215 and 235 of the mold 200 to be described later, and the core 110 is connected to the upper mold 230 and / And serves to separate the lower mold 210 from the lower mold 210 or to provide a space in which the second connection part 137 is formed.

2, six second holes 113 are formed in the core 110. However, it is needless to say that the number of the second holes 113 may be varied according to the size and usage of the core 110. [

A plurality of magnet holes 115 are formed on the outer periphery of the second hole 113, one side of which is convex in the direction of the first hole 111, and the other side of which is concave.

The magnet 120 also has a convex shape on one side and an arch shape on the other side, like the shape of the magnet hole 115.

The magnets 120 are formed in the same number as the magnet holes 115 and inserted into the magnet holes 115, respectively.

The magnet 120 can be fixed to the magnet hole 115 by the first connection portion 135 even if the magnet 120 does not have the same size as the magnet hole 115, have.

The magnet hole 115 and the shape of the magnet 120 can provide a magnet having a larger area at a distance closer to the central axis of the core 110 than the conventional rectangular magnet structure.

Since the outer side of the core 110, that is, the other side of the magnet hole 115 and the magnet 120 is concave, when the rotor 100 rotates and centrifugal force acts, the other side of the magnet 120 The force applied to the first connecting part 135 to be brought into contact with the first connecting part 135 can be dispersed, thereby preventing the first connecting part 135 from being damaged.

When the plastic material is injected into an injection molding machine 300 to be described later and the first connection part 135 is formed in the magnet hole 115, the contact area of the first connection part 135 with the magnet 120 is large So that the first connection part 135 can secure the magnet 120 more firmly.

The first and second covers 131 and 133 are respectively formed on the upper and lower surfaces of the core 110 and have a circular shape such as an upper surface and a lower surface of the core 110.

The first connection part 135 fills a space formed between the magnet hole 115 and the magnet 120 to connect between the first and second covers 131 and 133. Therefore, the number of the first connection portions 135 is equal to the number of the magnet holes 115.

The second connection portion 137 is formed in the first hole 111 to connect between the first and second covers 131 and 133.

In this case, the number of the second connection portions 137 may vary depending on the number of the first and second core support protrusions 215 and 235 of the mold, which will be described later in detail.

The first and second covers 131 and 133 and the first and second connection portions 135 and 137 are integrally formed by injection of a plastic material.

Therefore, unlike the conventional rotor cover, there is no need to join the first and second covers 131 and 133 by means of rivets or the like, and due to the characteristics of the plastic injection, Vibration and noise due to the tolerance between the magnet hole 115 and the magnet 120 can be prevented by forming the space formed between the magnets 120. [

A detailed description of the process and method of forming the first and second covers 131 and 133 and the first and second connection portions 135 and 137 using the plastic material will be described later.

Hereinafter, a mold 200 according to a preferred embodiment of the present invention for mounting the rotor 100 will be described.

In this case, the mold 200 is used to load the core 110 of the rotor 100 and the first and second covers 131 and 133 (not shown) are formed in the core 110 by injection of the plastic material of the injection molding machine 300 And fixing the core 110 to the injection molding machine 300 so as to form the first and second connection portions 135 and 137.

5 to 7, the mold 200 according to the preferred embodiment of the present invention includes the upper mold 230 and the lower mold.

6A and 6B, the lower mold 210 includes an insertion portion 211 into which a lower portion of the core 110 is inserted, a first hole 111 in the core 110, A first circular protrusion 213 inserted in a lower portion of the core 110 and a second hole 113 of the core 110 so that a space (A in FIG. 5) is formed on the upper surface of the lower mold 210 and the lower surface of the core 110, And a magnet supporting protrusion 217 for supporting a lower portion of the magnet 120 inserted into the magnet hole 115 of the core 110. The first core supporting protrusion 215 is inserted into the lower portion of the core 110,

In addition, the lower surface of the lower mold 210 may be convex downward, and detailed effects thereof will be described later.

The insertion portion 211 is formed on the upper surface of the lower mold 210 and is formed into a circular groove having the same size as the lower portion of the core 110 so that the insertion of the core 110 is facilitated.

Therefore, since the core 110 is inserted into the insertion portion 211 and is seated, the lower mold 210 can easily fix the core 110. [

The first circular protrusion 213 has a cylindrical shape and protrudes upward from the center of the upper surface of the lower mold 210 so that the first hole 111 of the core 110, into which the shaft (not shown) So that the core 110 is fixed and supported.

A first step 214 may be formed at a lower portion of the first circular protrusion 213 so as to contact a part of the lower surface of the core 110. The first step 214 may support the lower surface of the core 110 And also prevents the plastic material from being injected into the first hole 111 when the second cover 133 is formed on the lower portion of the core 110 by the injection of the plastic material.

In this case, it is preferable that the diameter of the first circular protruding portion 213 is formed to be the same as that of the first hole 111. The length of the first circular protrusion 213 is formed so as not to contact the second circular protrusion 233 of the upper mold 230 when the upper mold 230 is positioned on the lower mold 210 .

The first core support protrusion 215 is inserted into the lower portion of the second hole 113 of the core 110 and is formed on the upper surface of the lower mold 210 so as to be located outside the first circular protrusion 213 do.

The lower surface of the core 110 is separated from the upper surface of the lower mold 210 by inserting the first core support protrusion 215 into the lower portion of the second hole 113 of the core 110. [

In this case, the number of the first core support protrusions 215 may vary depending on the design of the rotor 100, but is preferably less than the number of the second holes 113 of the core 110. That is, the second connection part 137 can not be formed in the second hole 113 in which the first core supporting protrusion 215 is inserted, so that the first core supporting protrusion 215 is inserted into all the second holes 113 The second connection portion 137 of the core 110 does not exist. 2, the number of the second holes 113 of the core 110 is preferably 6, and the number of the first core support protrusions 215 is preferably 3, It is preferable that the number of the second connection portions 137 of the first connector 110 is also four. Of course, even if the number of the first core supporting protrusions 215 is two, the number of the first core supporting protrusions 215 is two, and the number of the first core supporting protrusions 215 of the second connecting portion 137 The number may be four.

A second step (not shown) may be formed in the lower portion of the first core supporting protrusion 215 and the second step may be in contact with the lower surface of the core 110 around the second hole 113, Not only the lower surface of the lower mold 110 is separated from the upper surface of the lower mold 210 but also the plastic material is prevented from being injected into the second hole 113 into which the first core supporting protrusion 215 is inserted .

 A plurality of the magnet supporting protrusions 217 are formed in a number equal to the number of the magnet holes 115 and the number of the magnets 120. When the core 110 is inserted into the inserting portion of the lower mold 210, The first core supporting protrusion 215 is located at the lower side of the first core supporting protrusion 215.

The magnet supporting protrusion 217 supports the lower surface of the magnet 120 inserted into the magnet hole 115 so that the magnet 120 can move downwardly when the first connecting portion 135 is formed by injection of the plastic material, That is, it functions to prevent the lower mold 210 from falling downward.

Therefore, it is preferable that the size of the magnet supporting protrusion 217 is formed to be smaller than the lower surface of the magnet 120, and the height of the magnet supporting protrusion 217 is formed to be equal to the thickness of the second cover 133 to be formed by injection of the plastic material .

7A and 7B, the upper mold 230 includes a second circular protrusion 233 inserted into the upper portion of the first hole 111 of the core 110, A second core supporting protrusion 235 inserted into an upper portion of the second hole 113 so as to form a spacing space (B in FIG. 5) on the upper surface of the upper mold 230 and the lower surface of the upper mold 230, And an injection hole (237 in Fig. 10) formed so as to penetrate the upper and lower surfaces of the frame.

The upper mold 230 has a shape having an outer wall 231 protruding downward and the outer wall 231 contacts the outer side of the lower mold 210 so that the core 110 contacts the lower mold 210, The upper mold 230 may be positioned on the upper portion of the lower mold 210 so as to surround the lower mold 210. That is, the lower mold 210, the core 110, and the upper mold 230 are stacked in this order from the bottom to the top, so that the core 110 is stacked on the mold 200.

In this case, the third step 232 may be formed on the inner side of the outer side wall 231 of the upper mold 230, and the third step 232 may contact the upper side of the lower mold 210, The mold 230 may be positioned on the upper portion of the lower mold 210.

The second circular protrusion 233 has a cylindrical shape and protrudes downward from the center of the lower surface of the upper mold 230 so that the first circular hole 111 of the core 110, into which the shaft (not shown) So that the core 110 is fixed and supported.

A fourth step 234 may be formed on the upper portion of the second circular protrusion 233 to contact a part of the upper surface of the core 110 and a fourth step 234 may be formed on the upper surface of the core 110 And prevents the plastic material from being injected into the first hole 111 when the first cover 131 is formed on the top of the core 110 by the injection of the plastic material.

In this case, it is preferable that the diameter of the second circular protrusion 233 is formed to be the same as the diameter of the first hole 111. The length of the second circular protrusion 233 is formed so as not to contact the first circular protrusion 213 of the lower mold 210 when the upper mold 230 is positioned on the lower mold 210 .

The second core supporting protrusion 235 is inserted into the upper portion of the second hole 113 of the core 110 and is formed on the lower surface of the upper mold 230 so as to be located outside the second circular protrusion 233 do.

The upper surface of the core 110 is separated from the lower surface of the upper mold 230 by inserting the second core supporting protrusion 235 into the upper portion of the second hole 113 of the core 110. [

In this case, the second core support protrusion 235 is preferably formed at a position opposite to the first core support protrusion 215 described above, and thus the number of the second core support protrusions 235 is equal to the number of the above- The number of the core supporting protrusions 215 is preferably equal to the number of the core supporting protrusions 215.

A fifth step (not shown) may be formed on the upper portion of the second core support protrusion 235. The fifth step may contact the upper surface of the core 110 around the second hole 113, Not only does the upper surface of the upper mold member 110 be separated from the lower surface of the upper mold 230 but also prevents the plastic material from being injected into the second hole 113 into which the first core supporting protrusion 215 is inserted .

The injection hole 237 is formed through the upper surface and the lower surface of the upper mold 230 and serves to flow the plastic material injected from the injection nozzle 330 of the injection molding machine 300 to be described later.

The injection hole 237 is formed to be positioned directly above any one of the plurality of magnet holes 115 formed in the core 110 when the core 110 is loaded on the mold 200 , It is preferable that the area of the injection hole 237 is formed to be smaller than the area of the magnet hole 115 so that the plastic material injected from the injection nozzle 330 can easily flow into the magnet hole 115.

Hereinafter, an injection molding machine 300 according to a preferred embodiment of the present invention having the mold 200 having the above-described structure will be described.

8 and 10, the injection molding machine 300 according to the preferred embodiment of the present invention includes a main body 310, a mold 200 installed on the main body 310 and loading the core 110, An injection nozzle 330 for injecting and injecting the plastic into the mold 200, and a moving member located under the mold 200.

The main body 310 is provided with a mold 200 for loading the core 110 and a movable member capable of moving horizontally from both sides of the main body 310. An injection hole 237 are formed with an injection nozzle 330 for injecting a plastic material.

The mold 200 includes an upper mold 230 and a lower mold 210. The upper mold 230 is installed on the upper portion of the main body 310 and the lower mold 210 is mounted on the lower portion of the main body 310 And is fixed to the main body 310 by a support bar 320 installed on the main body 310.

In this case, the mold 200 can be eccentrically installed in either the front or rear direction of the main body 310 to facilitate the flow of the plastic material injected by the injection nozzle 330.

The upper mold 230 may be installed up and down in the direction of the lower mold 210 by a hydraulic cylinder (not shown).

Since the shapes and configurations of the upper mold 230 and the lower mold 210 have been described above, their explanation is omitted.

As described above, the injection nozzle 330 is formed on the upper part of the main body 310, and functions to inject the plastic material into the injection hole 237 of the upper mold 230 described above.

The moving member is composed of first and second slides (350, 370) provided on both sides of the main body (310).

The first slide 350 is installed on the left side of the main body 310 and includes a first cylinder 351 for horizontally moving the first slide 350 in the downward direction of the lower mold 210, And a first block 353 coupled to the first piston 350. The first piston 353 is coupled to the first piston 350. [

The first cylinder 351 is preferably a hydraulic cylinder, and the structure of the first cylinder 351 and the first piston may be the same as that of the conventional cylinder structure, so that a description thereof will be omitted.

The first block 353 has one end coupled to the end of the first piston and the first block 353 also moves horizontally when the first piston moves horizontally within the first cylinder 351 And is moved downward of the lower mold 210 to be brought into contact with the lower surface of the lower mold 210 which is convex downward as described above.

In this case, a first inclined surface 354 inclined downward toward the other end is formed on the upper surface of the other end of the first block 353, and a first inclined surface 354 is formed on the lower surface of the lower mold 210 .

The second slide 370 is installed on the right side of the main body 310 and includes a second cylinder 371 for horizontally moving the second slide 370 in the lower direction of the lower mold 210, And a second block 373 coupled to the second piston. The second piston 373 is coupled to the second piston.

The second cylinder 371 and the first cylinder 351 are preferably hydraulic cylinders and the structure of the second cylinder 371 and the second piston may be the same as those of the conventional cylinder structure , And a description thereof will be omitted.

The second block 373 has one end coupled to the end of the second piston 370 and the second block 373 is also moved in the horizontal direction when the second piston 370 is moved in the horizontal direction inside the second cylinder 371 And is moved downward of the lower mold 210 to be brought into contact with the lower surface of the lower mold 210.

In this case, a second inclined surface 374 inclined downward toward the other end is formed on the upper surface of the other end of the second block 373, and the second inclined surface 374 is formed on the upper surface of the lower mold 210 having the convex shape .

When the plastic material is injected into the mold 200 through the injection nozzle 330 and the injection hole 237 due to the structure of the first and second slides 350 and 370 described above, 370 are horizontally moved in the lower direction of the lower mold 210 from both sides of the main body 310 to prevent the mold 200 from being pushed.

That is, the first and second inclined surfaces 354 and 374 of the first and second blocks 353 and 373 of the first and second slides 350 and 370 are brought into contact with the lower surface of the lower mold 210 which is convex downward, It is possible to prevent the mold 200 from being pushed down by the injection pressure applied to the mold 200.

In this case, the angle of the first and second inclined surfaces 354 and 374 (? In Fig. 8) can be defined by Equation 1 below.

'Equation 1: Cylinder pressure = (tan? X injection pressure) x 1.5'

Therefore, it is preferable that the angle [theta] of the first and second inclined surfaces 354 and 374 is determined by the cylinder pressure and the injection pressure as described in the above-mentioned 'Equation 1'.

The first and second covers 131 and 133 and the first and second connection portions 135 and 135 are formed in the rotor 100 of the preferred embodiment of the present invention by using the injection molding machine 300 according to the preferred embodiment of the present invention. , 137 are injection-molded.

The first circular protrusion 213 of the lower mold 210 is inserted into the first hole 111 of the core 110 and the first core support protrusion 215 is inserted into the second hole 113 of the core 110 The lower portion of the core 110 is inserted into the inserting portion 211 of the lower mold 210. In this case, since there are three first core support projections 215 as shown in Figs. 10A to 10C, the first core support protrusions 215 are formed at the lower part of the three second holes 113 of the six second holes 113, (215) is inserted.

When the lower portion of the core 110 is inserted into the insertion portion 211 of the lower mold 210 and is seated thereat, the first step 214 of the first circular protrusion 213 is inserted into the lower mold 210 210 and the core 110 supports the insertion portion 211 of the lower mold 210, the first circular protrusion 213, the first core support protrusion 215, and the first step 214, The spacing A is formed on the lower surface of the core 110 and the upper surface of the lower mold 210 by the first core supporting protrusion 215. [

When the core 110 is fixed to the lower mold 210, the magnet 120 is inserted into the magnet hole 115 of the core 110. In this case, the lower surface of the magnet 120 is brought into contact with the upper surface of the magnet supporting protrusion 217 of the lower mold 210, so that the magnet 120 is placed on the lower surface of the core 110 and the upper surface of the lower mold 210 So that it is prevented from going down to the formed spacing space (A).

After the magnet 120 is inserted into the magnet hole 115 of the core 110, the upper mold 230 is lowered in the direction of the lower mold by the above-described hydraulic cylinder (not shown).

The second circular protrusion 233 of the upper mold 230 is inserted into the first hole 111 of the core 110 so that the fourth step 234 of the second circular protrusion 233 is inserted into the core 110, And the second core supporting protrusion 235 of the upper mold 230 is inserted into the upper portion of the second hole 113 into which the first core supporting protrusion 215 is inserted.

The second core support protrusion 235 forms a spacing space B on the upper surface of the core 110 and the lower surface of the upper mold 230.

After the lowering of the upper mold 230 is completed, the plastic material is melted at the injection nozzle 330, and then the plastic material is injected into the injection hole 237 of the upper mold 230.

In this case, in order to prevent the mold 200 from being pushed down by the injection pressure of the plastic material injected from the injection nozzle 330, the first and second slides 350, The first and second blocks 353 and 373 are horizontally moved in the lower direction of the lower mold 210 from both sides of the main body 310.

The plastic material is injected into the mold 200 along the magnet hole 115 located at the lower portion of the injection hole 237 to fill the space between the magnet hole 115 and the magnet 120, 135 are formed.

The plastic material flows into the spaced space A formed on the lower surface of the core 110 and the upper surface of the lower mold 210 to form the second cover 133, And the first cover 131 is formed by the second cover 130. The first cover 131 is formed in the upper surface of the upper mold 230 and the second space formed in the lower surface of the upper mold 230, And the second connection part 137 is formed.

After the first and second covers 131 and 133 and the first and second connection portions 135 and 137 are formed, the first and second slides 350 and 370 are horizontally moved in the direction of both sides of the main body 310 The upper mold 230 is lifted, and the injection molding process is finished.

The rotor 100 having undergone the injection molding using the injection molding machine 300 has the structure of the rotor 100 and the structure shown in FIG.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the following claims Or modified.

100: rotor 110: core
111: first hole 113: second hole
115: Magnet hole 120: Magnet
131: first cover 133: second cover
135: first connection part 137: second connection part
200: mold 210: lower mold
211: insertion portion 213: first circular protrusion
214: first step 215: first core supporting projection
217: Magnet support protrusion 230: Upper mold
231: outer wall 232: third stage
233: second circular protrusion 234: fourth step
235: second core support projection 237: injection hole
300: injection molding machine 310:
320: support bar 330: injection nozzle
350: first slide 351: first cylinder
353: first block 354: first inclined plane
370: second slide 371: second cylinder
373: second block 374: second inclined surface

Claims (5)

delete A core having a first hole formed at its center;
A plurality of second holes formed in the outer periphery of the first hole;
A magnet hole formed in the core;
A magnet inserted into the magnet hole;
A first and a second cover each formed at an upper surface and a lower surface of the core by injection of a plastic material while a core supporting protrusion of the metal mold is inserted into at least one of the plurality of second holes; And
And first and second connecting portions formed integrally with the first and second covers by injection of the plastic material to connect the first and second covers,
Wherein the first connecting portion is formed in a space between the magnet hole and the magnet and the second connecting portion is formed in a remaining hole of the plurality of second holes in which the core supporting protrusion of the metal mold is not inserted. .
3. The method of claim 2,
The plurality of magnet holes are formed in the periphery of the first hole,
Wherein the plurality of magnet holes are each formed so that one side thereof is convex in the direction of the first hole and the other side is concave,
Wherein the plurality of magnets are formed to be respectively inserted into the plurality of magnet holes, one side of which is convex and the other side is concave.
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