KR20210103795A - Suite of molds for forming coating layer of core and forming method of core coating layer using thereof - Google Patents

Abstract

The present invention relates to a pair of molds for forming a coating layer of a core and a core coating layer forming method using the same and, more specifically, the objective of the present invention is to provide uniformity of the thickness of a coating layer of a core as a whole while forming the coating layer on the entire surface, such as the inner peripheral surface of a hollow hole of a cylindrical core, the outer peripheral surface of the core, the upper and lower surface, and the like, through a synthetic resin injection molding process. According to the present invention, the pair of molds comprise: a first mold (100) having a first cavity (130) formed on an interface between a first lower mold (110) and a first upper mold (120) to form a first coating layer (11) which is a part of a coating layer; and a second mold (200) having a second cavity (230) formed on an interface between a second lower mold (210) and a second upper mold (220) to form a second coating layer (12) which is the remaining portion of the coating layer except for the first coating layer (11). Accordingly, the synthetic resin coating layers (11, 12) are formed on wall surfaces including the inner peripheral surface, the outer peripheral surface, the upper surface and the lower surface of a hollow hole of a cylindrical core (10).

Description

A set of molds for forming a coating layer of a core and a method for forming a coating layer of a core using the same

The present invention relates to a set of molds for forming a covering layer of a core and a method for forming a covering layer of a core using the same, and more particularly, to an armature core in which an electric coil is wound, on the surface of an iron core made of a metal material, electrically separated from the electric coil It relates to a set of molds for molding the coating layer of the core for injection molding the insulating coating layer for the following purpose, and a method for molding the coating layer of the core using the same.

In general, an armature core refers to a circuit element in which an electric coil such as a copper wire is wound around an outer peripheral surface of an iron core made of a metal material, and electromagnetic is induced by a current flowing in the electric coil to form a magnetic field. Electrical coils must be electrically isolated from each other and insulated.

There are various types of such an armature core depending on the shape of the iron core and the winding shape of the electric coil. In order to insulate the electric coil and the iron core of the armature core, a coating layer should be formed on the entire surface of the upper and lower surfaces, including the inner and outer peripheral surfaces of the iron core.

As an example of such a method for forming a coating layer of an armature core, in Korean Patent Registration No. 0554700, an iron core is formed into a ring-shaped core, a protective cap is placed on the upper and lower surfaces of the core, and an insulating coating material such as varnish is coated on the outer surface. A toroidal core is formed, a secondary coil is tightly wound along the outer periphery of the toroidal core, and an insulating film made of a synthetic resin material with strong insulating properties is wrapped around the entire coil, and the insulated For power savers that manufacture a toroidal coil by winding a primary coil made of an insulated wire consisting of a stranded wire divided into several strands in the same winding direction as the secondary coil along the outer peripheral surface of the insulating film wound and insulated around the secondary coil It has been proposed in a method for manufacturing a Trojan coil (Patent Document 1).

However, since the insulating structure as in Patent Document 1 is made of a form of coating an insulating coating material or enclosing an insulating film, manufacturing is complicated and takes a lot of time, so productivity is not high, and the thickness of the insulating coating layer is not uniform in the manufacturing process Therefore, there is a problem that the insulating quality is not uniform.

In order to solve this problem, a method of manufacturing the coating layer by injection molding with a synthetic resin may be considered. The injection molding method has the advantage that productivity can be increased and the defect rate is very low because the manufacturing process is simple and the manufacturing time is short.

As an example of the related art, in Korean Utility Model Publication No. 1999-004347 (Patent Document 2), plastic resin is injection-molded on the front and rear surfaces of the core body of the armature core and the inner surface of the coil receiving groove to integrally cover the insulation part. It has been proposed in the armature core and its insulation method.

Since the armature core of Patent Document 2 has a structure in which a coating layer is not formed on the outer circumferential surface of the iron core, when the armature core is inserted into the cavity of the injection mold, the outer circumferential surface of the armature core can be inserted in contact with the inner surface of the cavity. Since it is possible to prevent the flow of the armature core, the coating layer can be easily formed on a desired portion.

However, as described above, when the coating layer needs to be formed on the entire surface of the cylindrical iron core, when the iron core is inserted into the cavity of the injection mold, the condition that the entire outer surface of the iron core must be spaced apart from the inner surface of the cavity must be satisfied. The molding structure is limited in that it cannot form the coating layer of the cylindrical core.

1. Korean Patent Registration No. 0554700 Patent Publication 2. Korean Utility Model Publication No. 1999-004347 Public Utility Model Publication

The present invention for solving the problems implied by the above prior art is to form a coating layer through a synthetic resin injection molding process on the entire surface, such as the inner peripheral surface of the hollow hole, the outer peripheral surface of the core, the upper surface and the lower surface of the cylindrical core, but the coating layer of the core An object of the present invention is to provide a set of molds for molding the coating layer of the core so that the thickness of the core can have uniformity as a whole, and a method for molding the coating layer of the core using the same.

A set of molds for forming the coating layer of the core for achieving the above object,

The synthetic resin melt is injected into the cavity formed on the interface between the lower mold and the upper mold to form a synthetic resin coating layer on the wall including the inner peripheral surface, the outer peripheral surface, the upper surface and the lower surface of the hollow hole of the cylindrical core accommodated in the cavity. As a mold,

a first mold having a first cavity formed on an interface between the first lower mold and the first upper mold for forming a first covering layer, which is a part of the covering layer;

a second mold having a second cavity formed on the interface between the second lower mold and the second upper mold to form a second covering layer, which is a portion of the covering layer excluding the first covering layer; characterized in that it consists of

Here, in order to expand the contact area of the respective interfaces of the first and second covering layers, the first cavity forming the interface of the first covering layer in the first mold may form a concave-convex surface.

In addition, the first covering layer may include an inner circumferential coating layer covering the inner circumferential surface of the core; an upper inner covering layer connected to an upper end of the inner peripheral surface covering layer and covering an inner portion of an upper surface of the core; a lower inner covering layer connected to a lower end of the inner circumferential covering layer and covering an inner portion of a lower end surface of the core; including,

The first lower mold may include a first cavity for accommodating the core; a plurality of lower support pins protruding upward from the lower end surface of the first cavity to support the lower end surface of the core; includes,

The first upper mold may include a plurality of upper support pins that cover the top surface of the core and protrude downward from the top surface of the first cavity to support the top surface of the core; including,

When the synthetic resin melt is injected, the support end of the upper support pin may be moved to be spaced a predetermined distance from the top surface of the core, so that the synthetic resin melt may be filled.

In addition, the second covering layer, the outer peripheral surface covering layer covering the outer peripheral surface of the core; an upper outer covering layer connected to an upper end of the outer circumferential covering layer and covering the remaining portion of the upper surface of the core except for the upper inner covering layer; a lower outer covering layer connected to a lower end of the outer circumferential covering layer and covering the remaining portion of the lower end surface of the core except for the lower inner covering layer; including,

A second cavity for accommodating the core on which the first covering layer is formed is formed on the interface between the second lower mold and the second upper mold,

A synthetic resin melt may be injected into the second cavity to form a second coating layer in which the first coating layer and the interface are coupled.

In addition, the first upper mold may further include a support mold disposed on the upper support pin, and a gap is formed between the upper support pin and the support mold so that the upper support pin moves by the gap when the upper support pin moves up and down. It is possible, and the upper support pin may be returned after movement by the elastic force of the elastic body.

A method for forming the coating layer of a core using a set of molds having these characteristics,

a first step of inserting a core into a first cavity formed on an interface of a first mold composed of a first lower mold and a first upper mold;

a second step of injecting a synthetic resin melt into the first cavity to form a first coating layer that is a part of the coating layer;

a third step of inserting the core on which the first covering layer is formed into a second cavity formed on an interface of a second mold composed of a second lower mold and a second upper mold;

a fourth step of injecting a synthetic resin melt into the second cavity to form a second covering layer, which is the remaining portion of the covering layer except for the first covering layer; characterized in that it consists of

According to the present invention, when the synthetic resin coating layer is formed on the inner peripheral surface of the hollow hole of the cylindrical core, the outer peripheral surface of the core, and the wall including the upper surface and the lower surface, a part of the coating layer is injection molded in the first mold, and the remaining part is not molded By injection molding in the second mold, it is possible to minimize the non-uniform molding of the coating layer thickness and at the same time to minimize the defect rate, so that high-quality armature coils can be produced and productivity can be improved.

1 is a plan view schematically showing a first mold among the coating layer molding molds according to the present invention.
2 is a cross-sectional view taken along line 'A-A' of FIG. 1;
3 is an operation state diagram of a first mold among the coating layer forming molds according to the present invention.
4 is a perspective view of a core showing a state in which the first coating layer is molded by the first mold among the coating layer molding molds according to the present invention;
5 is a plan view schematically showing a second mold among the coating layer molding molds according to the present invention.
6 is a cross-sectional view taken along line 'B-B' of FIG. 5;
7 is an operation state diagram of a second mold among the coating layer forming molds according to the present invention.
8 is a perspective view of a core showing a state in which a second coating layer is molded by a second mold among the coating layer molding molds according to the present invention;
9 is a plan view of a core and a coating layer for explaining a modified example of the present invention.

Since the present invention can have various modifications and can have various embodiments, preferred embodiments of the present invention will be exemplified below, and the present invention will be described in detail based thereon. However, this is not intended to limit the present invention to only the illustrated embodiments, and it should be understood that the spirit and scope of the present invention includes ordinary modifications or equivalents to substitutes of the illustrated forms.

In addition, throughout the specification, that a part is 'connected' to another part includes a case in which it is 'directly connected' or 'indirectly connected' with an element, and 'includes' a certain element is a description that is specifically opposed. It means that other components can be added, not excluding other components unless there is.

1 is a plan view schematically showing a first mold among the coating layer molding molds according to the present invention, FIG. 2 is a cross-sectional view taken along line 'A-A' of FIG. 1, and FIG. 3 is a coating layer molding mold according to the present invention. It is an operation state diagram of the first mold, and FIG. 4 is a perspective view of a core showing a state in which the first coating layer is molded by the first mold among the coating layer molding molds according to the present invention.

5 is a plan view schematically showing a second mold among the coating layer molding molds according to the present invention, FIG. 6 is a cross-sectional view taken along line 'B-B' of FIG. 5, and FIG. 7 is a coating layer molding according to the present invention. 8 is a perspective view of a core showing a state in which the second coating layer is molded by the second mold among the coating layer forming molds according to the present invention.

The present invention injects a synthetic resin melt into a cavity formed on the interface between the lower mold and the upper mold, and the hollow hole of the cylindrical core 10 accommodated in the cavity is made of synthetic resin on the wall including the inner peripheral surface, the outer peripheral surface, the upper surface and the lower surface. It includes a first mold 100 and a second mold 200 for separately molding the first covering layer 11 and the second covering layer 12, respectively.

The operation method of a mold for injection molding of synthetic resin is sufficient if a general structure is applied, so a detailed description thereof will be omitted, and hereinafter, as in the present invention, for uniformly molding the coating layer 20 on the outer surface of the cylindrical core 10 as in the present invention. The characteristic structure of the set of molds 100 and 200 will be described in detail.

For forming the first covering layer 11, which is a part of the covering layers 11 and 12, on the interface PL of the first lower mold 110 and the first upper mold 120 of the first mold 100 While the first cavity 130 is formed, on the interface PL of the second lower mold 210 and the second upper mold 220 of the second mold 200 except for the first covering layer 11 . A second cavity 230 for forming the remaining portion of the second covering layer 12 is formed.

More specifically, as shown in FIGS. 1 to 4 , the first mold 100 is mounted on the first lower mold 110 mounted on the fixed side plate of the synthetic resin injection device, and on the moving side plate of the injection device. and a first upper mold 120 that moves to be coupled to or separated from the first lower mold 110, and the interface between the first lower mold 110 and the first upper mold 120 in the coupled state. On the (PL), the first cavity 130 into which the cylindrical core 10 is inserted is formed.

When the synthetic resin melt is injected into the injection port 121 at a high pressure, the synthetic resin melt flows into the first cavity 130 through the gate 123 via the runner 122, and the synthetic resin melt flows through the outer surface of the core 10. After filling the space between the inner surface of the first cavity 130 and hardening, the first coating layer 11 integral with the core 10 is formed.

In an embodiment, the first covering layer 11 includes an inner peripheral surface covering layer 11a covering the inner peripheral surface of the core 10 , and an upper end of the inner peripheral surface covering layer 11a and connected to the upper surface of the core 10 . It may include an upper inner covering layer 11b that covers the inner portion, and a lower inner covering layer 11c that is connected to the lower end of the inner peripheral surface covering layer 11a and covers the inner portion of the lower surface of the core 10. (See Figures 3 and 4).

In order to form the first covering layer 11 , the first lower mold 110 has a first cavity 130 accommodating the core 10 , and protrudes upward from the lower end surface of the first cavity 130 . and a plurality of lower support pins 111 for supporting the lower end surface of the core 10 .

In addition, the first upper mold 120 covers the top surface of the core 10 and at the same time protrudes downward from the top surface of the first cavity 130 to support the top surface of the core 10 . of the upper support pin 124 .

Four of the lower support pins 111 and the upper support pins 124 may be disposed at a 90° angle as in the example shown, or three may be disposed at an angle of 120° differently from the illustrated example, and the size of the core 10 . As a result, the quantity may increase further.

When the synthetic resin melt is injected into the first cavity 130 , the support end (lower end surface) of the upper support pin 124 moves upward a predetermined distance from the upper surface of the core 10 so that the synthetic resin melt is transferred to the upper support pin 124 . The spaced space between the supporting end of the core 10 and the top surface of the core 10 is filled.

A support mold 125 integrated with the first upper mold 120 is provided on an upper portion of the upper support pin 124 , and a gap (the gap is It is preferable to have a distance equal to the thickness of the upper inner covering layer 11b.] to allow the upper support pin 124 to move up and down by the gap with respect to the support mold 125, at this time An elastic body 126 is interposed between the upper support pin 124 and the support mold 125 so that the upper support pin 124 is supported by an elastic force. In this case, after the upper support pin 124 moves by the gap distance in the direction of the support mold 125 by an external force (the injection pressure of the synthetic resin melt), when the external force is removed, it returns to its original position by the elastic force of the elastic body 126 .

Although the drawing illustrates a form in which the lower support pin 111 is fixed to the first lower mold 110 , according to the present invention, it is also possible to make the lower support pin 111 reciprocate in the vertical direction. That is, the upper support pin 124 has a structure that is vertically symmetrical with a structure in which the upper support pin 124 can move by the gap in the vertical direction so that the lower support pin 111 can move up and down by the gap with respect to the lower mold 110, and the lower support pin ( When the 111) is supported by the elastic force of the elastic body, the lower support pin 111 can move downward by the gap distance by the external force, and when the external force is removed, it can return to the original position by the elastic force of the elastic body.

Meanwhile, as shown in FIGS. 5 to 8 , the second mold 200 includes a second lower mold 210 mounted on a fixed side plate of the synthetic resin injection device, and a moving side plate of the injection device. and a second upper mold 220 that moves to be coupled to or separated from the second lower mold 210, and a boundary surface between the second lower mold 210 and the second upper mold 220 in the coupled state On the PL), a second cavity 230 into which the core 10 on which the first covering layer 11 is formed is inserted is formed.

When the synthetic resin melt is injected into the injection port 221 of the second mold 200 at high pressure, the synthetic resin melt flows into the second cavity 230 through the gate 223 via the runner 222 and flows into the first coating layer. After filling the space between the outer surface of the core 10 and the inner surface of the second cavity 230 except for (11), the second covering layer 12, which is cured to form an integral body with the first covering layer 11 and the core 10, is formed. do.

In one embodiment, the second covering layer 12 is connected to an outer circumferential covering layer 12a covering the outer circumferential surface of the core 10 , and an upper end of the outer circumferential covering layer 12a and is connected to the top surface of the core 10 . of the upper outer covering layer 11b that covers the remaining portion except for the upper inner covering layer 11b, and the lower inner covering layer 11c of the lower end surface of the core 10 connected to the lower end of the outer circumferential covering layer 12a It may include a lower outer covering layer 12c covering the remaining portion except for (see FIGS. 7 and 8).

A second cavity ( 230) is formed (see FIG. 6).

When the synthetic resin melt is injected into the second cavity 230 in a state in which the core 10 on which the first covering layer 11 is formed is inserted into the second cavity 230, the outer surface of the core 10 has a first covering layer 11 The second coating layer, which is the remaining part except for, may be molded (12).

In this way, when the coating layers 11 and 12 of the core 10 are partially injected, the structure of the injection mold is simple, so that it is easy to manufacture and the coating layer having a uniform thickness can be easily molded.

Since the first covering layer 11 and the second covering layer 12 are each separately divided and molded, the first covering layer 11 and the second covering layer 12 are made of the same material to increase the bonding force of the interface 13 therebetween. It is preferable to consist of

9 is a plan view of a core and a coating layer for explaining a modified example of the present invention.

As another method for increasing the bonding force of the interface 13 of the first covering layer 11 and the second covering layer 12, each boundary surface 13 is formed with a zigzag shape or a corrugated surface as shown in FIG. 9 . It is also possible

To this end, when the first cavity 130 forming the interface of the first covering layer 11 in the first mold 100 is manufactured to have a concave-convex shape, the first covering layer 11 formed in the first cavity 130 is formed. ) may form an uneven surface, and then, when the synthetic resin melt for forming the second coating layer 12 is injected into the second cavity 230, the uneven interface 13 of the first coating layer 11 is filled. Since it is hardened while increasing, the contact area of each interface 13 can be increased.

In the above drawings, the interface 13 between the first covering layer 11 and the second covering layer 12 is disposed on the top and bottom surfaces of the core 10, and the first covering layer 11 and the second covering layer 12 are placed inside. and the outward segmentation have been illustrated, but the present invention is not limited thereto, and the interface 13 is, for example, a core 10 spanning the outer and inner peripheral surfaces of the first covering layer 11 and the second covering layer 12 . It is also possible to segment up and down with respect to the core (10).

In addition, although it has been exemplified that four cores 10 are mounted on each of the first mold 100 and the second mold 200 and a coating layer can be formed on the four cores 10 through one injection process, each The number of cavities 130 and 230 formed in the molds 100 and 200 may be increased or decreased in consideration of the size of the core.

Although the above description has been described as a limited embodiment showing the technical idea of the present invention, the present invention is not limited to a specific embodiment or shape and numerical value, and the gist of the present invention, such as changing and mixing some of the components of the embodiments, is not limited. Various modifications and variations may be implemented by those of ordinary skill in the art to which the invention pertains without departing from, and such modifications and variations should not be individually understood from the technical spirit or prospect of the present invention.

10... Core 11... First coating layer
12... Second coating layer 13... Interface
100... First mold 110... First lower mold
111... Lower support pin 120... First upper mold
121... Inlet 122... Runner
123... gate 124... upper support pin
125... support mold 126... elastomer
130... 1st cavity 200... 2nd mold
210... Second lower mold 220... Second upper mold
221... Inlet 222... Runner
223... Gade 230... 2nd cavity

Claims (6)

The synthetic resin melt is injected into the cavity formed on the interface between the lower mold and the upper mold to form a synthetic resin coating layer on the wall including the inner peripheral surface, the outer peripheral surface, the upper surface and the lower surface of the hollow hole of the cylindrical core accommodated in the cavity. As a mold,
a first mold having a first cavity formed on an interface between the first lower mold and the first upper mold for forming a first covering layer, which is a part of the covering layer;
a second mold having a second cavity formed on an interface between the second lower mold and the second upper mold to form a second covering layer, which is a portion of the covering layer excluding the first covering layer;
A set of molds for forming the coating layer of the core, characterized in that consisting of. The method according to claim 1,
In order to expand the contact area of the respective interfaces of the first and second covering layers, the first cavity forming the interface of the first covering layer in the first mold has an uneven shape. bee mold. The method according to claim 1 or 2,
The first covering layer may include an inner circumferential coating layer covering the inner circumferential surface of the core; an upper inner covering layer connected to an upper end of the inner circumferential covering layer and covering an inner portion of an upper surface of the core; a lower inner covering layer connected to a lower end of the inner circumferential covering layer and covering an inner portion of a lower end surface of the core; including,
The first lower mold may include a first cavity accommodating the core; a plurality of lower support pins protruding upward from the lower end surface of the first cavity to support the lower end surface of the core; includes,
The first upper mold may include a plurality of upper support pins that cover the top surface of the core and protrude downward from the top surface of the first cavity to support the top surface of the core; including,
A pair of molds for molding the coating layer of a core, characterized in that when the synthetic resin melt is injected, the support end of the upper support pin is moved to be spaced apart from the top surface of the core by a predetermined distance to be filled with the synthetic resin melt. 4. The method according to claim 3,
The second covering layer may include an outer circumferential covering layer covering the outer circumferential surface of the core; an upper outer covering layer connected to an upper end of the outer circumferential covering layer and covering the remaining portion of the upper surface of the core except for the upper inner covering layer; a lower outer covering layer connected to a lower end of the outer circumferential covering layer and covering the remaining portion of the lower end surface of the core except for the lower inner covering layer; including,
A second cavity for accommodating the core on which the first covering layer is formed is formed on the interface between the second lower mold and the second upper mold,
A set of molds for molding the coating layer of the core, characterized in that the synthetic resin melt is injected into the second cavity to form a second coating layer that is coupled to the first coating layer and the interface. 4. The method according to claim 3,
The first upper mold may further include a support mold disposed on the upper support pin, and a gap is formed between the upper support pin and the support mold to move the upper support pin by the gap when the upper support pin moves up and down. and the upper support pin is a pair of molds for molding the coating layer of the core, characterized in that it is possible to return after moving by the elastic force of the elastic body. A method for forming a coating layer of a core, wherein a synthetic resin coating layer is formed on a wall surface including an inner peripheral surface, an outer peripheral surface, an upper surface and a lower surface of the hollow hole of the core using the set of molds according to any one of claims 1 to 5,
a first step of inserting a core into a first cavity formed on an interface of a first mold composed of a first lower mold and a first upper mold;
a second step of injecting a synthetic resin melt into the first cavity to form a first coating layer that is a part of the coating layer;
a third step of inserting the core on which the first covering layer is formed into a second cavity formed on an interface of a second mold composed of a second lower mold and a second upper mold;
a fourth step of injecting a synthetic resin melt into the second cavity to form a second covering layer that is the remaining portion of the covering layer except for the first covering layer;
A method for forming the coating layer of the core using a set of molds, characterized in that consisting of

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