JP2020163997A - Duct and method for manufacture thereof - Google Patents

Abstract

To effectively use a curved part of a duct.SOLUTION: A duct 10 comprises: an opening 18 formed through a curved part 14a which is curved so that an air circulation direction is changed in a duct wall part 14 which defines an air circulation channel 12; and a porous body 20 which closes the opening 18, and is joined to an external surface of the duct wall part 14 across bending of the curved part 14a. In the porous body 20, a closing surface 20a thereof, which closes the opening 18, is previously formed in accordance with bending of the curved part 14a in the duct wall part 14.SELECTED DRAWING: Figure 1

Description

The present invention relates to a duct used in, for example, a vehicle and a method for manufacturing the duct.

Vehicles that use electric energy, such as electric vehicles and hybrid vehicles, are equipped with a secondary battery at the bottom of the passenger compartment. Since the secondary battery generates heat, the air taken in from the vehicle interior is guided by a duct, and the air is blown onto the secondary battery to cool the secondary battery (see, for example, Patent Document 1). For example, one end of the duct is connected to the intake port side that opens to the lower front surface of the rear seat, and the other end is opened to the battery mounting portion of the secondary battery arranged under the rear seat. In addition, a blower is installed between the intake port and the battery mounting part to take in the air in the passenger compartment from the intake port and positively send the air to the battery mounting part through the duct. ing.

The battery cooling structure disclosed in Patent Document 1 has a shape in which a duct forming a cooling pipeline connected to an intake port provided in the vehicle interior has a curved portion, so that the vehicle interior and the luggage compartment have a curved portion. Effective use of space is being planned. In addition, by attaching a sound absorbing material made of fiber material to the opening provided in the curved part of the duct, the sound generated from the blower is absorbed by the sound absorbing material, and noise is prevented from leaking from the intake port to the passenger compartment. are doing.

Japanese Unexamined Patent Publication No. 2005-71759

If the sound absorbing material is attached to a bent portion of the duct so that the direction of the air flow direction changes, the plate-shaped sound absorbing portion is deformed according to the bent portion of the bent portion. At this time, the sound absorbing portion may be wrinkled due to the deformation, the sound absorbing portion may be compressed to deteriorate the sound absorbing performance, or the deformed sound absorbing portion may protrude from the opening to the inside of the duct to obstruct the air flow. Problems such as occur. Therefore, in Patent Document 1, even if the sound absorbing portion is attached to the bent portion of the bent portion, the sound absorbing portion is not deformed by providing an opening in the straight portion connected to the upstream side of the bent portion in the air flow direction. I have no choice but to install it.

The present invention has been proposed in view of the above-mentioned problems related to the prior art, and has been proposed to suitably solve these problems, and provides a duct that effectively utilizes the curved portion of the duct wall portion and a method for manufacturing the duct. The purpose is.

In order to overcome the above-mentioned problems and achieve the intended purpose, the duct according to the present invention is used.
An opening formed through a curved portion that bends so as to change the direction of air flow in the duct wall portion that defines the air flow passage,
A porous body that closes the opening and is joined to the outer surface of the duct wall portion across the bend of the curved portion.
The gist of the porous body is that the closed surface that closes the opening is formed in advance in accordance with the bending of the curved portion.

In order to overcome the above-mentioned problems and achieve the desired object, the method for manufacturing a duct according to the present invention is:
When a duct wall portion having a curved portion that bends so as to change the direction of air flow is molded by a molding die, the duct wall is formed so as to close an opening formed through the porous body. It is a method of manufacturing a duct that joins to one side of a part.
A closed surface that closes the opening in the porous body is formed in accordance with the bending of the curved portion.
The porous body having the closed surface shaped to match the curved portion is housed in the molding mold.
The gist is to join the porous body and the duct wall portion by supplying a synthetic resin to the cavity of the molding mold to mold the duct wall portion.

According to the duct according to the present invention, the curved portion of the duct wall portion is effectively used.
According to the method for manufacturing a duct according to the present invention, it is possible to easily obtain a duct that effectively utilizes the curved portion of the duct wall portion.

It is explanatory drawing which shows the intake structure by the duct which concerns on embodiment of this invention. It is a schematic perspective view which shows the duct of an Example. It is the schematic perspective view which shows the duct of an Example in the state which removed the porous body. The porous body indicated by the alternate long and short dash line represents the state before joining to the duct wall portion. It is explanatory drawing which shows the manufacturing process of the duct of an Example. It is explanatory drawing which shows the manufacturing process of the duct of an Example. It is a top view which shows the duct of the modification example.

Next, the duct and the method for manufacturing the duct according to the present invention will be described below with reference to the accompanying drawings with reference to suitable examples.

As shown in FIG. 1, the duct 10 according to the embodiment is a tubular body provided with an air flow passage 12 through which air flows. One end of the duct 10 is connected to the intake port Sa side that opens to the lower front surface of the rear seat S, and the other end is connected to the blower B arranged below the rear seat S. The duct 10 takes in air from the passenger compartment through the filter F from the intake port Sa by the negative pressure created by the blower B, and is placed in the battery mounting portion of the secondary battery (not shown) arranged under the rear seat S. It is designed to guide the air toward. The duct 10 of the embodiment is a synthetic resin molded product obtained by injection molding or the like, using a solid resin (solid synthetic resin) such as polypropylene (PP) or high-density polyethylene (HDPE) as a material. The side of the duct 10 facing the air flow passage 12 is referred to as the inside, and the opposite side thereof is referred to as the outside.

As shown in FIGS. 1 and 2, in the duct 10, the air flow passage 12 is formed wider on the intake port Sa side than on the secondary battery side, and the duct wall portion 14 defining the air flow passage 12 is formed. However, it has a curved portion 14a that bends so that the direction of the air flow direction changes. Further, the duct wall portion 14 is provided with a linear portion 14b extending linearly on both the upstream side in the air flow direction and the downstream side in the air flow direction of the curved portion 14a.

As shown in FIG. 1, the duct 10 has an opening 18 formed so as to penetrate the duct wall portion 14 defining the air flow passage 12, and an outer surface of the duct wall portion 14 so as to close the opening 18. It is provided with a porous body 20 bonded to. In the duct 10, the porous body 20 that closes the opening 18 becomes a functional part having functions such as sound absorption, heat insulation, and weight reduction due to its characteristics, and in the embodiment, noise from a blower B or the like that sucks air is taken in. It is set as a sound absorbing part to prevent leakage from the mouth Sa side. In the duct 10, an opening 18 is formed in the curved portion 14a of the duct wall portion 14, and the porous body 20 closes the opening 18 and straddles the bend of the curved portion 14a to form the duct wall portion 14. It is joined to the outer surface. In the duct 10 of the embodiment, the opening 18 is formed over the straight portion 14b connected to the upstream side and the downstream side of the curved portion 14a of the duct wall portion 14 in the air flow direction, and the porous body 20 is formed of the straight portion 14b and the curved portion 14b. It is provided over the shaped portion 14a. Further, in the duct 10 of the embodiment, when the duct wall portion 14 made of the synthetic resin R is formed, the opening 18 is formed and the porous body 20 is joined to the outer surface of the duct wall portion 14.

The porous body 20 has elasticity to return to its original shape when the compressed and deformed state is released. Further, if it is used for sound absorption described above, it is preferable that it has breathability. As the porous body 20, for example, a polyurethane foam, a foam such as an olefin-based foam such as polypropylene foam, or a material produced by an extraction method for extracting a nucleating agent to be a cell can be used. Among these, it is preferable to use a polyurethane foam having an open cell structure. In the examples, as the porous body 20, a polyurethane foam having an open cell structure having a restoration rate of 92% or more after 50% compression is used.

As shown in FIG. 3, the duct wall portion 14 includes a crosspiece 22 formed so as to bridge the opening 18, and the crosspiece 22 has a plurality of openings 18 (two in the embodiment) opening regions 18a. It is divided into. The porous body 20 is joined to the opening edge of the opening 18 and the crosspiece 22 in the duct wall portion 14, and the joint portion 24 is thinner than the general portion 26 corresponding to the central portion of the opening region 18a. .. The porous body 20 is formed so that the general portion 26 projects from the joint portion 24 toward the side opposite to the duct wall portion 14 (see FIG. 2). Further, in the porous body 20, the closing surface 20a on the duct wall portion 14 side that closes the opening 18 extends so as to imitate the surrounding duct wall portion 14 in the air flow direction, and the closing surface that closes the opening 18 is closed. 20a constitutes an air guide surface continuous with the surroundings. The joint portion 24 of the porous body 20 is joined at the time of molding the duct wall portion 14. Therefore, the joint portion 24 is melted by contact with the molten synthetic resin R (FIG. 5A) that becomes the duct wall portion 14, and the duct wall portion 14 and the joint portion 24 joined to the duct wall portion 14 are joined. Is in a fused state. In the figure, the boundary between the joint portion 24 of the porous body 20 and the duct wall portion 14 is shown for convenience, but it is considered that the boundaries between them are ambiguous.

As shown by the alternate long and short dash line in FIG. 3, in the porous body 20, the closing surface 20a that closes the opening 18 is formed in advance in accordance with the bending of the curved portion 14a. The closed surface 20a of the porous body 20 is formed so as to bend according to a change in the direction of the air flow direction in the curved portion 14a in a state before being joined to the duct wall portion 14, and is formed to the duct wall portion 14. It is not attached by bending it according to the shape of the curved portion 14a at the time of joining. The closed surface 20a of the porous body 20 of the embodiment has not only a bend that matches the shape of the curved portion 14a, but also a straight surface that matches the straight portion 14b that is continuous with the curved portion 14a.

The duct 10 according to the embodiment is obtained by insert molding in which the duct wall portion 14 is molded in a molding die 30 in which the porous body 20 formed in a predetermined shape is set (see FIGS. 4 and 5). As shown in FIGS. 4 and 5, the molding die 30 is composed of a first mold portion 32 and a second mold portion 34 configured to be openable and closable relative to the first mold portion 32, and the mold is closed. At that time, a cavity 36 that matches the shape of the duct wall portion 14 is formed between the first mold portion 32 and the second mold portion 34. The first mold portion 32 is provided with a recess 38 in accordance with the formation position of the opening region 18a of the opening 18. Further, in the first mold portion 32, a porous body 20 set in the second mold portion 34 is provided in the opening region 18a of the opening 18 corresponding to a position adjacent to the opening edge of the opening 18. A compression portion 40 that can be compressed by being sandwiched between the mold portion 32 and the mold portion 32 is provided. In the embodiment, the compression unit 40 is provided over the position corresponding to the opening edge of the opening 18 and the position corresponding to the crosspiece 22, and the position of the joint portion 24 in the porous body 20 is also determined by the compression unit 40. It is configured so that it can be pressed toward the second mold portion 34. The second mold portion 34 is provided with a convex portion 42 corresponding to the opening region 18a of the opening portion 18.

As shown in FIGS. 4 and 5, when the mold is closed, the molding die 30 is adjacent to the joining portion 24 to be joined to the duct wall portion 14 in the porous body 20 between the compression portion 40 and the convex portion 42. The adjacent portion 28 is sandwiched between the adjacent portions 28, and the adjacent portion 28 can be sandwiched in a compressed state. In the molding die 30, the distance between the concave portion 38 and the convex portion 42 is set to be smaller than the plate thickness of the general portion 26 corresponding to the central portion of the opening region 18a of the opening 18 in the porous body 20. The molding die 30 is configured so that when the mold is closed, the general portion 26 of the porous body 20 can be sandwiched between the concave portion 38 and the convex portion 42 in a compressed state. Here, in the molding die 30, the degree of compression of the adjacent portion 28 of the porous body 20 by the compression portion 40 and the convex portion 42 is higher than the degree of compression of the general portion 26 of the porous body 20 by the concave portion 38 and the convex portion 42. Is also set large.

The method for manufacturing the duct 10 using the molding die 30 described above is as follows. A plate-shaped porous body 20 is prepared (see FIG. 4A). The closed surface 20a side that closes the opening 18 in the porous body 20 is formed in accordance with the bending of the curved portion 14a of the duct wall portion 14 that is the attachment portion of the porous body 20 (see FIG. 4B). In the embodiment, the porous body 20 is cut diagonally to form the closed surface 20a of the porous body 20 in accordance with the curved portion 14a that bends between the intersecting straight line portions 14b.

Next, as shown in FIG. 4C, the porous body 20 formed in advance into a predetermined shape is set in the molding die 30. Specifically, the general portion 26 corresponds to the recess 38, the adjacent portion 28 corresponds to the compression portion 40, and the porous body 20 is set in the second mold portion 34. By closing the molding die 30, the adjacent portion 28 is sandwiched between the compression portion 40 of the first mold portion 32 and the convex portion 42 of the second mold portion 34 in the plate thickness direction, and the adjacent portion 28 is compressed. (See FIG. 4 (d)). In this way, the porous body 20 is housed in the molding die 30 with the adjacent portion 28 sandwiched between the molding dies 30 in the plate thickness direction and compressed, and the joint portion 24 facing the cavity 36. At this time, the compressed adjacent portion 28 has a higher density than the general portion 26 and the joint portion 24.

The synthetic resin R in a molten state is supplied to the cavity 36 of the molding die 30 facing the joint portion 24 while applying pressure. Then, while sealing the synthetic resin R with the compressed adjacent portion 28, the duct wall portion 14 having the opening 18 is formed in the cavity 36 (see FIG. 5A). Here, the joint portion 24 arranged so as to face the cavity 36 in the porous body 20 melts and melts when it comes into contact with the high temperature synthetic resin R. At this time, the molten synthetic resin R tries to impregnate the porous body 20 from the joint portion 24, but since the adjacent portion 28 adjacent to the joint portion 24 is compressed and has a high density, the synthetic resin R is joined. It is possible to prevent impregnation from the portion 24 beyond the adjacent portion 28. By cooling and solidifying the molten synthetic resin R, the duct wall portion 14 is formed, the joint portion 24 of the porous body 20 and the duct wall portion 14 are joined, and the porous body 20 is the opening region of the opening 18. The 18a is integrally fixed to the duct wall portion 14 in a closed state.

The molding die 30 is opened, and the duct 10 in which the porous body 20 is integrated is taken out (see FIG. 5B). In the porous body 20, the adjacent portion 28 and the general portion 26 compressed by the molding die 30 are restored by their own elasticity. On the other hand, in the porous body 20, the joint portion 24 is integrated with the duct wall portion 14, and the thickness is thinner than the original (before joining) plate thickness.

In the duct 10, since the closing surface 20a that closes the opening 18 in the porous body 20 is formed in advance in accordance with the bending of the curved portion 14a of the duct wall portion 14, the porous body 20 is bent in the curved portion 14a. It is not necessary to bend along the line. As a result, the porous body 20 is wrinkled due to the bending of the porous body 20, the performance peculiar to the porous body 20 is deteriorated due to the compression of the porous body 20, and the deformed porous body 20 is formed. It is possible to avoid the occurrence of problems such as the 20 protruding from the opening 18 to the inside of the air flow passage 12 and obstructing the flow of air. According to the duct 10 described above, the performance peculiar to the porous body 20 is exhibited, functions such as sound absorption can be obtained, and the cross-sectional area of the air flow passage 12 is secured, so that the pressure loss is suppressed and a predetermined value is obtained. Ventilation performance can be ensured. As described above, since the performance of the duct 10 does not deteriorate even if the porous body 20 is arranged in the curved portion 14a, the curved portion of the duct wall portion 14 in which the porous body 20 could not be arranged in the past is not deteriorated. An opening 18 can be provided in 14a to arrange the porous body 20. Therefore, since the curved portion 14a can be effectively used as an arrangement space for the porous body 20, the degree of freedom in the arrangement of the porous body 20 is increased, and the function such as sound absorption by the porous body 20 is enhanced. It becomes possible.

In the duct 10, the porous body 20 corresponds to the linear portion 14b formed across the linear portions 14b and 14b connected to the upstream side and the downstream side of the curved portion 14a in the duct wall portion 14 in the air flow direction. , 14b and the curved portion 14a. In this way, by effectively utilizing the curved portion 14a as an arrangement space for the porous body 20 and arranging the porous body 20 over a wide range, the function such as sound absorption by the porous body 20 is enhanced. Can be done.

The duct 10 is formed by a simple process of forming the closed surface 20a of the porous body 20 according to the bending of the curved portion 14a before molding the duct wall portion 14 with the molding die 30 in which the porous body 20 is set. The porous body 20 can be arranged in the curved portion 14a without deteriorating the performance of the porous body 20. In particular, when the closed surface 20a is formed by cutting the side of the plate-shaped porous body 20 that becomes the closed surface 20a that closes the opening 18, the porous body 20 is bent when the closed surface 20a is formed in accordance with the bending of the curved portion 14a. Therefore, it is possible to reduce the time and effort required to place the mold 30 on the curved portion 14a.

(Change example)
The configuration is not limited to the above, and may be changed as follows, for example.

(1) In the embodiment, the closed surface 20a that closes the opening 18 in the porous body 20 is formed in accordance with the bent curved portion 14a of the duct wall portion 14, but as shown in FIG. 6, the duct wall portion is formed. The closed surface 20a of the porous body 20 may be formed in accordance with the curved curved portion 14a of 14, and the porous body 20 may be arranged on the curved portion 14a. At this time, it is also possible to arrange the porous body 20 over at least one straight line portion 14b on the upstream side and the downstream side in the air flow direction of the curved curved portion 14a. Further, as shown in FIG. 6, the porous body 20 can be arranged in the curved portion 14a that bends in a convex shape, instead of the curved portion 14a that bends in a concave shape as in the embodiment.
(2) The porous body 20 is not limited to a configuration in which only the closing surface 20a side that closes the opening 18 is formed in accordance with the curved portion 14a (left side in the drawing of FIG. 6), and the opening 18 in the porous body 20 is not limited. The closed surface 20a and the surface opposite to the closed surface 20a may be formed so as to match the curved portion 14a (right side in the drawing of FIG. 6).

(3) In the embodiment, the entire duct is molded at once in the molding die, but the present invention is not limited to this, and a plurality of divided bodies may be combined to form the duct.
(4) The present invention can be applied to various ducts such as a cooling duct for guiding air for cooling a battery and an intake duct for guiding air to an engine or the like.

10 ducts, 12 air flow passages, 14 duct walls, 14a curved parts,
14b straight part, 18 openings, 20 porous body, 20a closed surface, 30 molding mold,
36 Cavity, R Synthetic resin

Claims (4)

An opening formed through a curved portion that bends so as to change the direction of air flow in the duct wall portion that defines the air flow passage,
A porous body that closes the opening and is joined to the outer surface of the duct wall portion across the bend of the curved portion.
The porous body is a duct characterized in that a closed surface that closes the opening is formed in advance in accordance with the bending of the curved portion. The opening is formed over a straight portion extending upstream or downstream in the air flow direction of the curved portion of the duct wall portion.
The duct according to claim 1, wherein the porous body is provided over the curved portion and the straight portion so as to close the opening. When a duct wall portion having a curved portion that bends so as to change the direction of air flow is molded by a molding die, the duct wall is formed so as to close an opening formed through the porous body. It is a method of manufacturing a duct that joins to one side of a part.
A closed surface that closes the opening in the porous body is formed in accordance with the bending of the curved portion.
The porous body having the closed surface shaped to match the curved portion is housed in the molding mold.
A method for manufacturing a duct, characterized in that the porous body and the duct wall portion are joined by supplying a synthetic resin to the cavity of the molding mold to mold the duct wall portion. The method for manufacturing a duct according to claim 3, wherein the closed surface is formed in accordance with the bending of the curved portion by cutting the side of the plate-shaped porous body that becomes the closing surface that closes the opening.

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