KR101468717B1 - A manufacturing method of an air duct for air conditioning system of automobile and the air duct manufactured therefrom - Google Patents

Abstract

The present invention relates to a method of manufacturing an air duct for an air conditioning apparatus for an automobile and an air duct manufactured therefrom, which is an air conveyance passage, and, in accordance with the present invention, It is possible to easily manufacture an air duct molding formed with a hollow portion (v) to be an air transfer passage inside by an automated process. The manufactured air duct is lightweight, excellent in heat insulation, and has a shape suitable as an air duct.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an air duct for an air conditioner of an automobile and an air duct manufactured therefrom,

The present invention relates to a method of manufacturing an air duct for an air conditioner of an automobile, which is a conveyance passage for air.

 The present invention is also directed to an air duct manufactured using such a manufacturing method.

In an air conditioner of an automobile, a refrigerant compressed by a compressor driven by an engine is typically flowed into a condenser, heat-exchanged by forced blowing of the cooling fan, condensed, and then passed through a receiver dryer, an expansion valve and an evaporator An apparatus for cooling indoor air of a vehicle by exchanging air blown by a blowing fan of a blower unit with a refrigerant passing through an evaporator and flowing into a room in a cool state during a process of being introduced into a compressor; And a heating device for heating the interior of the automobile by flowing the air blown by the blowing fan into the room in a warm state by exchanging heat with the cooling water passing through the heater core in the process of returning the cooling water of the engine to the engine through the heater core.

In other words, the air conditioning system installed in a car is a main function to provide a comfortable environment for the passengers who ride in the cabin under various climatic and driving conditions.

In an air conditioner of an automobile, air to be blown is moved along an air duct which is a conveyance passage of air. The air vent is connected to one end of the air duct and is blown into the interior of the vehicle.

Such air ducts for air conditioners of automobiles are usually manufactured by blow molding molding a polyethylene resin. However, a solid type air duct manufactured by molding polyethylene has a density of about 1, which is heavy, which is an obstacle to the weight reduction of automobiles. In addition, solid type air ducts are poor in heat insulation and condensation phenomenon occurs, which lowers the cooling and heating efficiency of automobiles, resulting in an increase in carbon dioxide emissions, resulting in poor fuel efficiency of automobiles. Accordingly, the non-woven fabric is attached to the outer portion of the air duct of the solid type to improve the heat insulation and reduce the noise. However, there is still a problem due to the above-mentioned weight and a manufacturing process is also added.

In order to solve these problems, the applicant of the present invention has continued research to manufacture an air duct by using a foam which is foamed by a foaming agent and is light and has excellent heat insulation property.

The technical object of the present invention is to provide a method of manufacturing an air duct for an air conditioner of an automobile and an air duct manufactured therefrom, which is lightweight and has excellent heat insulation property, contributing to weight reduction of a vehicle and improvement of cooling and heating efficiency .

According to another aspect of the present invention, there is provided a method of manufacturing an air duct for an automotive air conditioner,

(S1) introducing a foam raw material composition comprising polypropylene and a foaming agent into an extruder and melt extruding the extruded sheet to produce an extruded sheet;

(S2) crosslinking the polypropylene by irradiating the extruded sheet with an electron beam;

(S3) heating the resultant of (S2) to foam the foaming agent to form a foamed sheet of crosslinked polypropylene;

(2) of the crosslinked polypropylene on the upper and lower surfaces (11) and (13) of the frame having the 'C' shape opened at the front end (16)

(2) is pressed against the frame by using a pressurizing cylinder provided so as to correspond to at least the rear end (19) and the front end (16) of the frame so that the foam sheet (1) A step of tightly fixing;

(S6) heating the foam sheet (1) (2) using a heater; And

(S7) After moving the upper mold and the lower mold to press the foam sheets 1 and 2 to form a closed system, the foam sheets 1 and 2 are vacuum-molded to form a hollow portion v) is formed.

The step (S6) may include inflating the foam sheet by injecting high-temperature air into the space s2 formed by the foam sheet (1) 2, the frame, and the pressurizing cylinder.

The step (S7) may include cooling the air duct molding by injecting cooling air into the hollow v.

After the step (S7), a trimming knife mounted on one of the upper mold and the lower mold may be operated to cut the edge of the air duct molding.

The present invention has the following effects.

First, two foam sheets can be vacuum-formed in a closed system to form an air duct molding having a hollow portion serving as a transfer passage for air therein.

Second, the manufacturing process of the air duct molding can be automated.

Third, by pressing the foam sheet by using the press block having the inclined face 12 at the front end of the frame and having the inclined face 53 that cooperates with the inclined face 12, the stroke of the press block is reduced, 1) and (2) are folded at right angles.

Fourthly, the closed space s2 is formed by using the frame, the moving means and the pressure block, and the high-temperature air is injected into the space s2 to expand the foam sheet 1 (2) . Accordingly, the thickness deviation of the produced air duct molding is reduced, productivity is improved, and defective folding can be reduced.

Fifth, it is possible to make automobile air duct which is light and excellent in heat insulation.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention. And should not be construed as limiting.
1 is a plan view showing an air duct forming apparatus according to a preferred embodiment of the present invention.
Fig. 2 is a front view showing a foam sheet mounted on a frame provided in the air duct molding apparatus shown in Fig. 1; Fig.
3 is a plan view showing a foam sheet mounted on a frame provided in the air duct molding apparatus of FIG.
Fig. 4 is a cross-sectional view showing a pressurizing cylinder provided in the air duct molding apparatus of Fig. 1 pressing the frame. Fig.
Fig. 5 is a front view showing the formation of an air duct molding by vacuum-forming a foam sheet in a state where upper and lower molds provided in the air duct molding apparatus of Fig. 1 are closed by pressing a foam sheet.
FIG. 6 is a front view showing a part of a trimming knife provided in the upper mold of FIG. 1; FIG.
Fig. 7 is a plan view showing an air duct molding produced by the air duct molding apparatus of Fig. 1; Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

A method for manufacturing an air duct for an air conditioner of an automobile according to the present invention will be described in detail as follows.

First, a foam raw material composition containing polypropylene and a foaming agent is put into an extruder and melt extruded to produce an extruded sheet (Step S1).

The content ratio of the polypropylene and the foaming agent in the foam material composition can be appropriately selected by those skilled in the art in consideration of the foamability of the foaming agent, the density of the desired foam, and the like. In addition, in order to improve the processability of the foam raw material composition, polyethylene may be further added in an amount of 50 parts by weight or less based on 100 parts by weight of polypropylene, for example. Further, a flame retardant may be further added to the foam material composition for imparting flame retardancy, and a crosslinking aid may be further added to assist the electron beam crosslinking of the polypropylene. It is needless to say that other resin may be added to the foam raw material composition in addition to the polypropylene resin to the extent that the object of the present invention is not impaired.

 Examples of blowing agents for forming fine and uniform bubbles include azodicarbonamide, N, N'-dinitrosopentamethylene tetramine, oxybis (benzenesulfonylhydrazide Known blowing agents such as P, P'-oxybis (benzenesulfonyl hydrazide) and P, P'-toluenesulfonylhydrazide can be used.

As a foaming aid for improving foaming power, a cadmium compound, a calsium compound, a zinc compound, a magnesium compound, an iron compound, a copper compound copper compound, etc. may be further added.

Subsequently, the extruded sheet is irradiated with an electron beam to crosslink the polypropylene (step S2). For example, by irradiating an electron beam at an irradiation dose of electron beam of 1 to 10 Mrad, all the polypropylene of the extruded sheet is crosslinked to obtain a foam having a uniform and small cell size in a foaming process described below.

Then, the resultant product of (S2) is heated and foamed to form a foamed sheet of crosslinked polypropylene (step S3). In the foaming process, for example, the result of (S2) is injected into an oven at 200 to 300 ° C to foam, and the heating temperature can be controlled according to the type of the foaming agent. However, if the heating temperature is too high, the crosslinked polypropylene may be thermally decomposed, so that it is maintained at a proper temperature or lower.

The steps (S1) to (S3) described above are well known in the art as a conventional method for producing a foamed sheet of crosslinked polypropylene.

Hereinafter, the method for producing the air duct of the present invention using the obtained foamed sheet of polypropylene will be described in detail. Prior to the description of the manufacturing method, the molding apparatus used for forming the air duct will be described in detail first.

FIG. 1 is a plan view showing an air duct molding apparatus according to a preferred embodiment of the present invention, and FIG. 2 is a front view showing a foam sheet mounted on a frame of the air duct molding apparatus.

Referring to the drawings, the air duct forming apparatus includes a frame 10 for mounting foam sheets 1 and 2, a moving means for moving a foam sheet 1 (2) mounted on a frame 10, A heater 20 (25) for heating the mold 1 (2), an upper mold 30 and a lower mold 40, and a pressurizing cylinder (not shown) for pressurizing the foam sheet 1 50).

The frame 10 is installed in a space (s1 in Fig. 4) between the upper and lower dies 30, The frame 10 is opened at its tip end 16 and has a "C" shape. The tip 16 is opened so that the foam sheet 1 or 2 can be moved forward after molding is completed.

The frame 10 has an upper surface 11, a lower surface 13, a tube 15 formed at the center, and a nozzle 17. Although a rectangular frame having a 'C' shape is shown in the drawing, the frame may have various structures depending on the shape of the air duct molding to be formed, such as a circular shape, an elliptical shape, etc.,

As shown in Figs. 2 and 3, the frame 10 has an inclined surface 12 at its tip. The inclined surface 12 has a structure in which the inclined surface 12 and the inclined surface 53 of the pressing cylinder 50 cooperate with each other to fix the foam sheet 1 and the foam sheet 2 in close contact with each other. The pressing cylinder 50 is operated so that the inclined surface 53 presses the foam sheet 1 against the inclined surface 12 so that the space s2 between the foam sheets 1 and 2 is sealed This point is further explained below. It is preferable that the slopes 12 and 53 have an inclination of about 45 degrees.

The reason that the tip end 16 forms the inclined surface 12 is to improve the hermeticity of the space (s2 in FIG. 4) and to reduce the stroke of the pressurizing cylinder 50 as compared with the case where the tip end 16 forms a vertical surface. The distance by which the block 51 is moved up and down) can be reduced to increase the productivity, and there is an advantage that the foam sheets 1 and 2 are prevented from being folded at a right angle.

The passage (15) is formed to penetrate the frame (10). Accordingly, as shown in FIG. 5, the upper and lower dies 30 and 40 can be in close contact with each other to form a closed system.

The nozzle 17 injects air into the space s2 formed by the foam sheet 1 and the foam sheet 1 and the frame 10 and the pressure blocks 51 and 52. [ The air injected through the nozzle 17 inflates the foam sheet 1 of the upper face 11 upward and inflates the foam sheet 2 of the lower face 13 so as to perform vacuum molding well. When the air is not injected, the foam sheet 1 on the upper face 11 is lowered, and the thickness variation of the vacuum-formed air duct molding becomes large. Air is injected and the foam sheet 1 of the upper face 11 So that the vacuum molding can be performed well and productivity can be improved.

Air at room temperature may be injected into the space s2 through the nozzle 17, but air of high temperature, preferably about 80 to 130 degrees, may be injected. The high-temperature air makes it possible to shorten the heating time by the heaters 20 and 25 by heating the foam sheet 1 (2).

The moving means are provided on the upper side and the lower side of the frame 10, respectively. The moving means is provided with a trajectory 60 provided on both sides of the frame 10 and a needle portion 62 provided so as to protrude from the trajectory 60.

The trajectory 60 is provided on both sides 18 of the frame 10 in the longitudinal direction of the frame 10 and is rotated in an endless track by a drive motor (not shown).

The orbital 60 can bring the foam sheet 1 or 2 into close contact with the frame 10 in the state that the needle portion 62 is inserted into the foam sheet 1 or 2 and accordingly the space s2 ) Can be sealed. Since the trajectory 60 is rotated in an endless track by a motor or the like, it is a commonly used constitution, and a detailed description thereof will be omitted.

The needle portion 62 is a sharpened portion that can be inserted into the foam sheet 1 (2), and when the orbit 60 is rotated, the needle portion 62 is inserted into the foam sheet 1 (2) The foam sheet 1 or 2 can be moved out of the foam sheet 1 or 2 when the foam sheet 1 or 2 is moved after the orbit 60 is rotated.

The heaters 20 and 25 may be installed on one side of the upper and lower dies 30 and 40. [ The heaters 20 and 25 are capable of reciprocating with respect to the space s1. That is, when the foam sheet 1 (2) is moved by the moving means to be mounted on the frame 10 and the foam sheet 1 (2) is brought into close contact with the frame 10 by the pressing cylinder 50, 20) 25 moves to the space s1 to heat the foam sheet 1 (2), and then returns to the original position. In addition to the heating, hot air may be injected through the nozzle 17.

The movement of the heaters 20 and 25 may be performed by a cylinder (not shown in the drawing) or a motor (not shown in the figure), and this will be easily understood by those skilled in the art, Description thereof will be omitted.

The heaters 20 and 25 may include an upper heater 20 disposed on the upper surface 11 and a lower heater 25 disposed below the lower surface 13. The upper heater 20 heats the foam sheet 1 provided on the upper surface 11 and the lower heater 25 heats the foam sheet 2 provided on the lower surface 13. [

As the heaters 20 and 25, an infrared heater and a halogen heater having a wavelength of about 1.5 mu m may be used, but the present invention is not limited thereto.

The upper and lower molds 30 and 40 are reciprocated vertically by a cylinder (not shown). That is, as described above, when the heaters 20 and 25 move to the space s1 to heat the foam sheet 1 and 2, and then the heaters 20 and 25 retreat to their original positions, The mold 30 descends and the lower mold 40 rises to press the foam sheet 1 or 2 to form a closed system as shown in Fig.

The upper mold 30 is provided with a first recessed portion 31, a trimming knife 33, and a suction pipe 35.

The first recessed portion 31 is a portion formed to be recessed in the lower surface of the upper metal mold 30 and is a space for allowing the foamed sheet 1 to be vacuumed and inflated upward.

The trimming knife 33 is installed around the first yaw groove 31 in the upper mold 30 so as to be movable up and down by a vertically movable cylinder (not shown). The trimming knife 33 is lowered to be inserted into the groove 43 of the lower mold 40, so that the edge of the air duct molding is cut. The structure in which the trimming knife 33 is moved up and down by the cylinder will be easily understood by those skilled in the art, and therefore, a description thereof will be omitted.

The suction pipe 35 is a pipe connected to an external vacuum pump (not shown). When the vacuum pump is operated after the upper and lower molds 30 and 40 form a closed system, the foam sheet 1 is inflated upward and brought into close contact with the surface of the first recessed portion 31, And is brought into close contact with the surface of the second recessed groove 41 to form a hollow portion v which serves as a conveyance passage for air.

The lower mold 40 has a second recessed portion 41, a groove 43, and a suction pipe 45.

The second recessed portion 41 is a space formed to be recessed in the upper surface of the lower mold 40 and is a space for vacuuming the foam sheet 2 to be inflated downward (struck).

The groove 43 is formed around the second recessed groove 41 on the upper surface of the lower mold 40 and has a shape in which at least a part of the trimming knife 33 can be inserted.

The suction pipe 45 is connected to an external vacuum pump (not shown) and has the same structure and function as the suction pipe 35 described above.

The structure and shape of the first and second recessed grooves 31 and 41 are determined depending on the shape of the air duct molding to be formed. Although the first and second recessed grooves 31 and 41 are shown as ellipses in the figure, the shape formed by the first and second recessed grooves 31 and 41 is not limited to this, Square, and the like.

The trimming knife 33 is provided on the upper mold 30 and the groove 43 is formed on the lower mold 40. However, when the trimming knife is installed on the lower mold 40, The grooves may be formed.

As shown in Fig. 6, it is preferable that the trimming knife 33 is formed by repeatedly forming the mountain 33a and the valley 33b. When the trimming knife 33 having such a structure is inserted into the groove 43, the foam sheets 1 and 2 are cut at predetermined intervals. That is, as shown in Fig. 7, the cutting grooves 3 are formed at predetermined intervals by the trimming knife 33 around the molded product f. The cutting groove 3 facilitates the subsequent separation of the molded product f from the foam sheet 1 (2).

The pressurizing cylinder 50 is installed so as to correspond to the front end 16 and the rear end 19 of the frame 10. The pressurizing cylinder 50 is formed by the foam sheet 1 (2), the frame 10 and the moving means by pressing the foam sheet 1 (2) against the front end 16 and the rear end 19 Thereby sealing the space s2.

The pressurizing cylinder (50) has press blocks (51) (52) provided at its end. The pressing block 51 provided so as to correspond to the front end 16 of the frame 10 has the inclined surface 53. [

More preferably, the pressing block 51 has a horizontal surface 54 formed to extend from the end of the inclined surface 53. When the pushing block 51 of the upper and lower pressing cylinders 50 is operated to press the foam sheet 1 or 2, the horizontal surface 54 prevents the air in the space s2 from leaking to the outside prevent.

The steps (S4) to (S7) for manufacturing the air duct molding using the above-described air duct molding apparatus will be described below.

First, the foamed sheets 1 and 2 of the crosslinked polypropylene formed in the above-described steps (S1) to (S3) are prepared. The foam sheet 1 (2) is moved to the rotor frame 10 by a supply unit (not shown in the drawing, using a roller or the like to move the sheet). The movement is carried out by a moving means. The foam sheet 1 (2) is moved as the orbit 60 rotates in the state that the needle portion 62 is inserted into the sheet 1 (2). At this time, it is preferable that the trajectory 60 closely adheres the foam sheet 1 (2) to the frame 10.

Subsequently, the pressurizing cylinder 50 is operated to press the foam sheet 1 (2) against the frame 10 to thereby pressurize the press block 51, 52, the orbit 60, the sheet 1, So that the space s2 is sealed by the frame 10. Heating the foam sheet (1) (2) after the heater (20) (25) advances to the space (s1), following or during the above operation of the pressurizing cylinder (50).

At this time, when the air is injected through the nozzle 17, the foam sheet 1 is inflated upward and the foam sheet 2 is inflated downward, which is advantageous for a subsequent vacuum molding operation. Specifically, since the foam sheet 1 (2) is inflated, the thickness variation and folding defects of the vacuum-formed air duct molding (f) can be reduced and the productivity can be improved.

On the other hand, when air of a high temperature, for example, 80 to 130 degrees, is injected through the nozzle 17, the foam sheet 1 (2) 1) (2) Since the heating time can be shortened, the productivity can be increased.

When the heating is completed, the heaters (20) and (25) are returned to the home position.

Subsequently, the upper and lower dies 30 and 40 are moved so that the upper and lower dies 30 and 40 press the foam sheets 1 and 2 to form a closed system.

Next, a vacuum pump (not shown in the figure) is operated to cause the foam sheet 1 to be inflated upward and the foam sheet 2 to be inflated downward. After the vacuum forming, the cooling air can be injected through the nozzle 17. The cooling air shortens the process time by cooling the air duct formed product (f).

Then, the trimming knife 33 is operated to cut the rim of the air duct formed product f.

When the cutting is completed, the pressure cylinder 50 is returned to the home position and the foam sheet 1 or 2 is advanced by one pitch using the moving means. Since the frame 10 has a 'C' shape with its tip end 16 opened, the formed airfoil f can be moved forward.

When the foam sheet 1 (2) advances by one pitch, a new portion of the foam sheet 1 (2) is placed on the frame 10.

1, 2: foam sheet 10: frame
20: upper heater 25: lower heater
30: upper mold 40: lower mold
50: pressurizing cylinder 60: orbital
62: Needle portion

Claims (9)

(S1) introducing a foam raw material composition containing polypropylene and a foaming agent into an extruder and melt-extruding the extruded sheet to produce an extruded sheet;
(S2) crosslinking the polypropylene by irradiating the extruded sheet with an electron beam;
(S3) heating the resultant of (S2) to foam the foaming agent to form a foamed sheet of crosslinked polypropylene;
The foamed sheet 1 of the crosslinked polypropylene (hereinafter referred to as " foamed sheet 1 ") is formed on the upper and lower surfaces 11 and 13 of the frame having a flat cross- 2;
The foam sheet 1 or 2 is pressed against the frame by using a pressurizing cylinder provided so as to correspond to the rear end 19 and the front end 16 of the frame S5 to closely contact the foam sheet 1, ;
(S6) heating the foam sheet (1) (2) using a heater; And
(S7) After moving the upper mold and the lower mold to press the foam sheets 1 and 2 to form a closed system, the foam sheets 1 and 2 are vacuum-molded to form a hollow portion v) formed therein;
The tip 16 of the frame has an inclined surface 12 that is inclined so that the thickness of the tip 16 decreases from the rear of the tip 16 to the front of the tip 16,
The pressing cylinder provided so as to correspond to the tip end 16 of the pressurizing cylinder has a pressing block 51 having an inclined surface 53 which cooperates with the inclined surface 12,
Characterized in that the inclined surfaces (12) and (53) cooperate with each other to fix the foam sheet (1) (2) when the pressure block (51) presses the tip (16) Gt; The method according to claim 1,
The step (S6)
And inflating the foam sheet by injecting high-temperature air into the space s2 formed by the foam sheet (1) (2), the frame, and the pressurizing cylinder to manufacture an air duct for an air conditioner for an automobile Way. The method according to claim 1,
The step (S7)
And cooling the air duct molding by injecting cooling air into the hollow part (v). The method according to claim 1,
After the step (S7)
Further comprising the step of cutting a rim of the air duct molding by operating a trimming knife mounted on one of the upper mold and the lower mold. The method according to claim 1,
And a moving means provided in the frame for moving the foam sheet (1) (2) provided on the upper surface (11) and the lower surface (13)
The moving means,
An orbital installed on both sides (18) of the frame in the longitudinal direction of the frame and rotating in an infinite orbit; And
And a needle portion provided in the orbit and inserted into the foam sheet (1) (2)
Wherein the foam sheet (1) (2) is moved by movement of the orbit in a state where the needles are inserted into the foam sheet (1) (2). 6. The method of claim 5,
Wherein the trajectory causes the foam sheet (1) (2) to be in close contact with the frame. delete The method according to claim 1,
Wherein the foam raw material composition further comprises polyethylene in an amount of not more than 50 parts by weight (excluding 0 parts) based on 100 parts by weight of polypropylene. delete

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