KR20200143769A - Injection molding machine for dust cap - Google Patents

Abstract

Disclosed in the present specification relates to the provision of a molding apparatus that improves the internal cooling efficiency of a dust cap during an injection molding process of the dust cap. According to an embodiment of the present disclosure, a molding apparatus for molding a dust cap having a space formed between a side wall and an inner wall includes: a lower mold including a cooling unit in which a spiral passage is formed inside an outer wall surrounding a hollow and a cooling line inserted into the hollow in a cylindrical shape in which an inner space is formed; a first upper mold including a sliding core surrounding the cooling unit; and a second upper mold capable of going up and down from an upper portion of the first upper mold towards upper and lower portions and having an injection hole for injecting a raw material into a lower surface thereof. When the second upper mold is lowered and the raw material is injected toward the upper portion of the cooling unit, the raw material is injected between the sliding core and the cooling unit and between the cooling unit and the cooling line to form the dust cap.

Description

Molding device for dust cap {INJECTION MOLDING MACHINE FOR DUST CAP}

The content disclosed in the present specification relates to a molding apparatus, and to a molding apparatus for manufacturing a molded article through an injection mold method.

Unless otherwise indicated herein, the contents described in this identification item are not prior art to the claims of this application, and description in this identification item is not admitted to be prior art.

In general, a vehicle is equipped with a steering device to control the direction of the vehicle at the discretion of the driver while driving, and a hydraulic power steering system to improve the steering wheel's operation power because the tire's grounding resistance is high in large vehicles or vehicles using low pressure tires. Use.

In the case of hydraulic power steering, a valve body housing that opens and closes the valve by receiving a twist signal from the steering wheel to form a flow path for hydraulic oil, and a dust cap is mounted on the upper part of the valve body housing to contain external dust and water. Prevent it from penetrating.

However, although the existing dust cap manufacturing method is manufactured through injection molds, the cooling efficiency in the narrow space between the inner wall formed inside and the outer wall covering the outside is remarkably low, causing molding shrinkage on the surface of the dust cap. There is this.

In this regard, Korean Patent Publication No. 10-1850054 discloses a dust cap injection molding mold, and Korean Patent Publication No. 10-2015-0111622 discloses a dust cap assembly structure of an automobile steering system.

However, the existing inventions do not disclose a technology for improving the cooling efficiency inside the dust cap.

It is to provide a molding apparatus that improves the internal cooling efficiency of the dust cap during the injection molding process of the dust cap.

In addition, it is not limited to the technical problems as described above, and it is obvious that another technical problem may be derived from the following description.

According to an embodiment of the disclosure, in the molding apparatus for molding a dust cap having a space formed between the side wall and the inner wall, the molding apparatus includes a cooling part having a spiral passage formed inside an outer wall surrounding a hollow and a cylinder having an inner space A lower mold including a cooling line inserted into the hollow in a form, a first upper mold including a sliding core surrounding the cooling part, and an upper and lower mold from the top of the first upper mold, and raw materials are injected into the bottom surface And a second upper mold having an injection hole formed therein, and when the second upper mold is lowered and the raw material is injected toward the upper portion of the cooling unit, the raw material is transferred between the sliding core and the cooling unit and between the cooling unit and the cooling line. The dust cap is molded by injection.

In addition, the upper portion of the cooling unit is formed in a cylindrical shape in which the inner space is opened upward and downward, and is inserted into the space, and the lower portion is formed in a plate shape to form discharge lines and inlet lines connected to the passage.

In addition, the passage has one end connected to the inlet line and the other end forming the same pitch, while the first line and one end extending toward the top and surrounding the hollow spirally are connected to the other end of the first line, and the other end While forming the same pitch as the first line, a second line extending helically toward the bottom on different horizontal lines may be formed to be connected to the discharge line.

In addition, the passage has one end coupled to the other end of the first line, the other end extending toward the other end of the first line, and then a third line formed to be connected to one end of the second line may be formed. have.

In addition, the cooling unit may be manufactured by being laminated through a 3D metal printer.

In addition, the sliding core has a semicircular cross section and is recessed toward one side in a form extending toward the lower side to surround one side of the cooling unit, and a first side core coupled to the lower mold so as to slide toward one side or the other side. And a semicircle in cross section and extending toward the lower side, which is recessed toward the other side, surrounds the other side of the cooling unit, is in close contact with the first side core, and is coupled to the lower mold so as to slide toward one side or the other side. It may include a second side core.

In addition, the molding device is formed in the shape of a rectangular parallelepiped, and in the center is recessed from the top to the bottom to form an upper hollow into which the cooling unit is inserted, and a portion of the bottom surface surrounding the position corresponding to the lower portion of the upper hollow is recessed toward the top. It may further include an upper core formed so as to surround the cooling unit and the sliding core.

According to an embodiment disclosed in the present specification, the molding apparatus has an advantage of effectively improving the cooling effect inside the dust cap, which is molded with high residual stress after the molding is completed, since the cooling effect is low through the cooling unit manufactured by 3D printing.

In addition, the molding apparatus improves the quality of the dust cap by manufacturing a cooling unit having an internal passage that is difficult to process with a general processing unit through 3D metal printing, and the cooling efficiency is remarkably extended through the passage formed in a coil shape by extending in a spiral shape There is an advantage to be improved.

In addition, since the effects of the present invention described as described above are naturally exerted by the composition of the contents described regardless of whether the inventor recognizes or not, the above-described effects are only a few effects according to the contents described, and all effects that the inventor grasp or exist It should not be recognized as describing

In addition, the effect of the present invention will have to be further grasped by the overall description of the specification, and even if it is not described in an explicit sentence, a person having ordinary knowledge in the technical field to which the described content belongs will have such an effect through the present specification. If it is an effect that can be recognized as the effect will be seen as the effect described in the present specification.

1 is a perspective view and a cross-sectional view of a dust cap used in a vehicle steering system.
Figure 2 is a perspective view of a molding apparatus according to an embodiment of the content disclosed in the present specification.
3 and 4 are exploded perspective views showing the molding apparatus of FIG. 2.
5 is a perspective view of the cooling unit of FIG. 4 and a cross-sectional view taken along line II′.
6 is a cross-sectional view taken along line II-II′ of the molding apparatus of FIG. 3.
7 is an image showing the flow analysis experiment results of the dust cap produced through the molding apparatus of FIG. 2.

Hereinafter, with reference to the accompanying drawings looks at the configuration, operation, and effects of the molding apparatus according to a preferred embodiment. For reference, in the drawings below, each component is omitted or schematically illustrated for convenience and clarity, and the size of each component does not reflect the actual size, and the same reference numerals refer to the same component throughout the specification. And reference numerals for the same configuration in individual drawings will be omitted.

1 is a perspective view and a cross-sectional view of a dust cap used in a steering system of a vehicle.

Referring to FIG. 1, the dust cap 10 is a device that is mounted on a steering device of a vehicle to block foreign substances from flowing into the steering device, and is generally manufactured through an injection molding method.

Inside the hollow (1) of the dust cap 10, an inner wall (2) is formed that extends in a cylindrical shape toward the upper or lower portion and surrounds the hollow (1), and the side wall (3) is formed on the outer surface of the dust cap (10). It is formed and is spaced apart from the side wall 3 with a space 4 formed in a cylindrical shape therebetween.

However, on the inner side of the dust cap 10 at a position corresponding to the inner wall 2 and the upper part of the space 4, a cooling device for cooling the dust cap 10 manufactured through injection molding has an insertion problem. There is a disadvantage in that the side wall 3 or the inner wall 2 due to the reduction of the effect is caused to shrink.

Therefore, in order to improve the cooling efficiency of the space 4 between the inner wall 2 and the side wall 3 formed inside the dust cap 10, it is possible to insert it into the space 4 while the cooling water is movable therein. It is necessary to develop a cooling unit in which a passage is formed.

2 shows a perspective view of a molding apparatus according to an embodiment of the present disclosure. 3 and 4 are exploded perspective views showing the molding apparatus of FIG. 2.

2 to 4, the molding apparatus 100 includes a lower mold 200, a first upper mold 400 and a second upper mold 600.

The molding apparatus 100 is an injection molding apparatus that manufactures the dust cap 10 by injecting and cooling raw materials into the lower mold 200 in which the dust cap 10 type frame is disposed. Some are manufactured through 3D metal printing, and passages for cooling water are formed therein.

Specifically, the lower mold 200 includes a lower block 220, a cooling unit 240 and a cooling line 260.

The lower mold 200 has a rectangular parallelepiped groove formed at the top to form a cooling unit 240 inserted into the dust cap 10, and passages through which the coolant moves through the front or rear of the lower mold 200 It is connected to the cooling unit 240.

The lower side of the lower block 220 is formed in a rectangular parallelepiped shape that extends long toward the front or rear, and the upper side surrounds a rectangular parallelepiped-shaped groove formed in the center by extending the front and rear portions of the lower side by a predetermined distance toward the top. .

Guide pins are formed on the upper part of the upper part corresponding to the front and rear corners of the upper part of the lower block 220, and when the second upper mold 600 descends, it is inserted into the second upper mold 600 to be inserted into the second upper part. Guide the movement of the mold 600.

The cooling unit 240 includes a cooling core 242, a cooling plate 244, an inlet line 246 and an outlet line 248.

The cooling unit 240 is formed in a cylindrical outer wall surrounding the hollow 50 that extends long toward the upper or lower part and rotates toward the upper or lower part in a spiral manner, and a passage extending therethrough is formed in the dust cap 10 forming process. It improves the cooling efficiency inside the dust cap 10.

Specifically, the cooling plate 244 is formed in a plate shape, and a portion of a circular shape is recessed in the center to form a hollow 50 connecting the upper and lower portions of the cooling plate 244, and a hollow 50 is formed inside. The surrounding cooling passages are formed to surround the hollow 50 on different horizontal lines.

One end of the cooling core 242 is formed in a cylindrical shape surrounding the hollow 50 at the upper center of the cooling plate 244 and connected to the cooling plate 244, and the other end is in a cylindrical shape by a predetermined distance toward the top. After being reduced and extended, it is extended toward the top while maintaining the same outer diameter to surround the hollow 50.

Inside the outer wall of the cooling core 242 surrounding the hollow 50, a passage extending toward the upper or lower portion in the form of a screw or coil is formed to surround the hollow 50, and the passage enclosing the cooling plate 244 It is connected to the passing lines to receive cooling water.

The cooling core 242 is manufactured by a 3D metal printing method, and is stacked and extended by a predetermined distance from the upper surface of the cooling plate 244 toward the upper part, thereby making it easy to manufacture the minute passages that are difficult to process. have.

On the other hand, the cooling core 242 and the cooling plate 244 are integrally manufactured through a 3D metal printing method to reduce manufacturing cost and improve durability against damage that may be caused by driving the molding apparatus 100 I can make it.

The inlet line 246 passes through the cooling plate 244 from the rear of the cooling plate 244, extends forward, and then is bent upward to connect to an opening of the passage opened from the bottom of the cooling core 242.

The discharge line 248 passes through the cooling plate 244 from the rear of the cooling plate 244 in a state spaced apart from the inlet line 246 and extends toward the front, and is then bent toward the top to be bent at the bottom of the cooling core 242 It is connected to the outlet of the open passage to discharge the high-temperature cooling water discharged from the outlet to the outside.

One end of the cooling line 260 is formed in a cylindrical shape with an open inner space toward the upper or lower portion, and is disposed at the lower center of the lower block 220, and the other end extends toward the upper in a cylindrical shape and inserted into the hollow 50 And, the top of the other end is sealed at a position corresponding to the other end of the cooling core 242.

The first upper mold 400 includes a sliding core 420 and an upper core 440, and the sliding core 420 includes a first side core 422 and a second side core 424.

The first upper mold 400 is disposed in a groove formed above the lower mold 200, is coupled to the cooling unit 240 to be detachable or attached, and between the cooling unit 240 and the first upper mold 400 A space in which the dust cap 10 is molded is formed.

Specifically, the sliding core 420 is formed in a shape surrounding the cooling unit 240 and is coupled to the cooling unit 240 to be detachable or attached, and between the cooling unit 240 and the sliding core 420, dust A space in which the cap 10 is molded is formed.

The first side core 422 has a semicircular shape protruding toward one side in cross section and extends from the top to the bottom, and is recessed from one end of the first side core 422 toward one side of the cooling core 242. A first groove surrounding one side is formed.

The other end of the first side core 422 extends obliquely from one end toward the lower side of the first side by a predetermined distance, and then a part extends toward the lower side in a rectangular parallelepiped shape to surround the top and one side of one side of the cooling plate 244 .

The first side core 422 is coupled to the lower block 220 so as to be slidable toward one side or the other side, and when sliding toward the other side, one end of the first side core 422 is cooled through the first groove. It surrounds one side of the core 242.

The second side core 424 has a semicircular cross-section protruding toward the other side and is extended from the top to the lower side, and is recessed from one end of the second side core 424 toward the other side of the cooling core 242. A second groove surrounding the other side is formed.

The other end of the second side core 424 extends obliquely from one end toward the lower side of the other side by a predetermined distance, and then a portion extends toward the lower side in a rectangular parallelepiped shape to surround the upper and one side of the other side of the cooling plate 244 .

The second side core 424 is coupled to the lower block 220 to enable sliding movement toward one side or the other side, and when sliding toward one side, one end of the second side core 424 is cooled through the second groove. It surrounds the other side of the core 242 and is coupled to one end of the first side core 422 to be detachable or attachable.

The inner surface of each of the first and second side cores 422 and 424 located in the first and second grooves connected to each other by combining the ends of each of the first and second side cores 422 and 424 The silver cooling core 242 is spaced apart by a predetermined distance to form a space in which the side wall 3 of the dust cap 10 is molded.

The upper core 440 is formed in the form of a rectangular parallelepiped that extends long toward the front or the rear, and an upper hollow 442 is formed in the center of which the cooling unit 240 is inserted by being recessed from the top to the bottom.

A portion of the front and rear bottom surfaces of the upper core 440 corresponding to the lower portion of the upper hollow 442 are recessed toward the upper portion to form a lower groove 444 connected to the upper hollow 442, and the upper core 440 The cooling plate 244 is inserted in a state coupled to the cooling unit 240.

Therefore, the upper core 440 surrounds the front and rear sides of the sliding core 420 and the cooling unit 240 at the same time while the sliding core 420 surrounds the cooling core 242. ) Is coupled to be detachable or attachable to stably fix the sliding core 420.

In addition, after the dust cap 10 formed in the expanded shape of the lower and upper portions is formed, the upper core 440 is separated from the cooling unit 240 and the sliding core 420, and the first side surface 422 And by separating each of the second side cores 424 from the cooling unit 240, the dust cap 10 may be conveniently separated from the cooling unit 240.

5 is a perspective view of the cooling unit of FIG. 4 and a cross-sectional view taken along line II′. 6 is a cross-sectional view of the molding apparatus of FIG. 3 taken along II-II'.

5 and 6, the cooling unit 240 further includes cooling passages 280 and 282, and the passages include a first line 250, a second line 252, and a third line ( 254).

The cooling passages 280 are inserted at a relatively high position inside the cooling plate 244 and are coupled to each other around the hollow 50 to connect the inner space in a rectangular shape, and the cooling water supplied from the outside is the cooling passage 280 It is discharged to the outside after circulating through the duct.

The cooling passages 282 are inserted at a relatively low position inside the cooling plate 244 and are coupled to each other around the hollow 50 to connect the inner space in a rectangular shape, so that the cooling water supplied from the outside is the cooling passage 282 It is discharged to the outside after circulating through the duct.

Accordingly, the cooling passages 280 and 282 have an advantage of improving the molding quality of the dust cap 10 formed by effectively cooling the lower portion of the dust cap 10 formed on the lower side of the cooling core 242.

One end of the first line 250 is connected to the inlet line 246 from the inside of the cooling plate 244, and the other end maintains a cylindrical shape at one end, and the same pitch from the inside of the outer wall of the cooling core 242 toward the top of the outer wall. It extends in the forward direction in the form of a coil formed of a plurality of turns spaced apart by

One end of the second line 252 is connected to the other end of the first line 250 from the top of the other end of the first line 250 through the third line 254, and the other end of the second line 252 is a cooling core. The outer wall of 242 extends downward in the form of a coil consisting of a plurality of turns spaced at the same pitch as the first line 250.

The second line 252 crosses the first line 250 in each of the spaces corresponding to the pitch of the first line 250 and extends in a reverse direction toward the bottom so that the first and second lines 250 and 252 The passage is formed in an overlapping form.

Therefore, each of the first and second lines 250 and 252 surrounds the hollow 50 in the form of coils overlapping each other inside the outer wall of the cooling core 242, so that the inside of the first and second lines 250 and 252 The cooling efficiency inside the dust cap 10 is effectively improved by the moving cooling water.

One end of the third line 254 is connected in a cylindrical shape to the other end of the first line 250 inside the outer wall of the cooling core 242, and the other end is in a cylindrical shape and faces directly above the other end of the first line 250. After being extended, it is bent and connected to the other end of the second line 252.

The third line 254 is formed in a cylindrical shape bent in a semicircular shape in a direction spaced apart from the other end and one end of each of the first and second lines 250 and 252 and the inner wall 2 of the dust cap 10 and Cooling water is supplied to the space corresponding to the upper side of the side wall (3).

Therefore, the third line 254 connects the first and second lines 250 and 252, and at the same time, the dust cap 10 is formed on the inner wall 2 and the side wall 3, which have relatively low cooling efficiency. Since the corresponding space is cooled, the molding quality of the dust cap 10 is improved.

7 shows images showing the flow analysis experiment results of the dust cap manufactured through the molding apparatus of FIG. 2.

As shown in (a) and (b) of FIG. 7, the experimental result of the dust cap 10 shown in (a) and (b) is a dust cap 10 manufactured through a conventional molding apparatus. As the experimental result of (a), the temperature result immediately after molding and the experimental result of (b) indicates the residual stress immediately after molding.

As shown in (c) and (d), the experimental result of the dust cap 10 shown in (c) and (d) is the experiment of the dust cap 10 manufactured through the molding apparatus 100 As a result, the test result in (c) shows the temperature result immediately after molding, and the test result in (d) shows the residual stress immediately after molding.

As shown in (a) and (c), the temperature of the space corresponding to the top of the inner wall 2 of the dust cap 10 of (a) is the upper of the inner wall 2 of the dust cap 10 of (c) It is relatively higher than the temperature of the space corresponding to.

Therefore, it can be seen that the dust cap 10 molded through the molding apparatus 100 effectively cools the upper portion of the inner wall 2 under the influence of the cooling core 242 manufactured by the 3D printing method.

As shown in (b) and (d), the residual stress of the space corresponding to the upper inner wall (2) of the dust cap 10 of (b) is the inner wall (2) of the dust cap 10 of (d) It is relatively higher than the residual stress of the space corresponding to the upper part.

Therefore, the dust cap 10 molded through the molding apparatus 100 effectively cools the upper portion of the inner wall 2 under the influence of the cooling core 242 manufactured by the 3D printing method. It can be seen that the quality of the dust cap 10 is improved by effectively reducing the residual stress after the molding is completed.

Although preferred embodiments of the present invention have been described with reference to the accompanying drawings, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and represent all the technical ideas of the present invention. Since it is not, it should be understood that there may be various equivalents and modifications that may be substituted for them at the time of application. Therefore, the embodiments described above should be understood as illustrative and non-limiting in all respects, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and the All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

100: molding device 200: lower mold
400: first upper mold 600: second upper mold

Claims (7)

In the molding apparatus for forming a dust cap with a space formed between the side wall and the inner wall,
A lower mold including a cooling unit in which a spiral passage is formed inside the outer wall surrounding the hollow and a cooling line inserted into the hollow in the form of a cylinder having an inner space;
A first upper mold including a sliding core surrounding the cooling unit; And
Including; a second upper mold capable of raising and lowering from an upper portion of the first upper mold toward the upper and lower portions, and having an injection hole for injecting a raw material into a lower surface thereof,
When the second upper mold is lowered and the raw material is injected toward the upper portion of the cooling unit, the raw material is injected between the sliding core and the cooling unit and between the cooling unit and the cooling line to form the dust cap. Molding device.
The method of claim 1, wherein the cooling unit,
The molding apparatus, characterized in that the upper end portion is formed in a cylindrical shape in which the inner space is opened toward the upper and lower portions, and is inserted into the space, and the lower portion is formed in the form of a plate to form discharge lines and inlet lines connected to the passage.
The method of claim 2, wherein the passage,
One end connected to the inlet line and the other end forming the same pitch, a first line spirally surrounding the hollow and extending toward the top, and
One end is connected to the other end of the first line, and the other end forms a second line connected to the discharge line by helically extending downward on different horizontal lines while forming the same pitch as the first line. Molding device.
The method of claim 2, wherein the passage,
A molding apparatus, wherein one end is coupled to the other end of the first line, the other end extends directly above the other end of the first line, and a third line is formed to be connected to one end of the second line. .
The method of claim 1, wherein the cooling unit,
A molding apparatus, characterized in that it is laminated and manufactured through a 3D metal printer.
The method of claim 1, wherein the sliding core,
A first side core having a semicircular cross-section and extending toward a lower side and being depressed toward one side to surround one side of the cooling unit, and coupled to the lower mold to enable sliding movement toward one side or the other side; And
The cross-section is a semicircle and extends toward the lower side, is recessed toward the other side, surrounds the other side of the cooling unit, is in close contact with the first side core, and is coupled to the lower mold to enable sliding movement toward one side or the other side. Forming apparatus comprising a; two side core.
The method of claim 1,
It is formed in the shape of a rectangular parallelepiped, and in the center is formed an upper hollow in which the cooling unit is inserted by being recessed from the top to the bottom, and a portion of the bottom surface surrounding a position corresponding to the lower portion of the upper hollow is formed to be recessed toward the top, and the cooling Molding apparatus further comprising a; upper core surrounding the portion and the sliding core.

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