JP2010236838A - Connection structure for air conditioning duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure for an air conditioning duct facilitating connection of the air conditioning duct and having good adhesion without increasing the number of components and work processes. <P>SOLUTION: In the connection structure 10 for the air conditioning duct, a second duct 14 is fitted to a first duct 12, and conditioned air is made to flow within the first and second ducts 12, 14. At least one of the first duct 12 and the second duct 14 is formed of thermoplastic resin, and in at least one of the first duct 12 and the second duct 14, a spiral part having a projection and a recess arranged in the circumferential direction is formed in a predetermined range in the longitudinal direction from the opening end. The first duct 12 and the second duct 14 are fitted to each other via the projection while spirally coming into contact with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a connection structure for an air-conditioning duct for circulating conditioned air sent from a ventilation air conditioner.

  A ventilation air conditioner (HVAC: Heating Ventilating and Air-Conditioning System) sends air that has been conditioned into a room through an air conditioning duct. This air-conditioning duct is arranged with a predetermined length for convenience in manufacturing, convenience of piping, etc., and is connected to a duct connection port of one end ventilation air conditioner, and the other end is directly or other air-conditioning duct. Is connected to the air outlet. The air conditioning duct is generally a metal or hard plastic molded product or a composite product thereof.

  Conventionally, as a connection structure between an air conditioning duct and a ventilation air conditioner or a connection structure between air conditioning ducts, there is a packingless structure as shown in FIG. 6 (Patent Document 1). A duct-to-duct connection structure 1 shown in FIG. 6 includes two ducts 2 and 3 to be connected formed of materials having different elastic coefficients, and when they are fitted, a duct 2 having a small elastic coefficient (hereinafter referred to as soft). (Referred to as a duct) is elastically deformed and is in close contact with the other duct 3 (hereinafter referred to as a hard duct). The duct connection structure 1 functions to seal between the two ducts. In addition, the connection part of the soft duct 2 is formed with a wave-shaped insertion connection part 2a, which has a structure that improves the adhesion between them.

Japanese Patent Laid-Open No. 2002-144846

  However, in the connection structure of the air conditioning duct shown in Patent Document 1, since the bellows-like waveform is formed in the insertion connection portion of the soft duct, when the hard duct is inserted, the bellows portion of the soft duct is Since it is easy to buckle or deform, there is a risk of breaking, and there is a problem that workability at the time of insertion is remarkably lowered.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a connection structure for an air conditioning duct that is easy to connect and that has excellent resistance to buckling and deformation of a duct connection portion. .

  In order to achieve the above-described object, the air-conditioning duct connection structure according to the present invention has the second duct fitted into the first duct, and the air-conditioned air flows through the first and second ducts. A duct connection structure, wherein at least one of the first duct or the second duct is formed of a foam of a thermoplastic resin, and at least one of the first duct or the second duct has an opening end thereof. A spiral portion in which convex portions and concave portions are arranged in a spiral shape is formed in a predetermined range in the longitudinal direction, and the first duct and the second duct are in spiral contact with each other through the convex portion. It is characterized by being fitted by.

  Moreover, the connection structure for an air conditioning duct according to the present invention is characterized in that the foamed thermoplastic resin has closed cells.

  Furthermore, the air-conditioning duct connecting structure according to the present invention is a cross-linked polyethylene having a foaming ratio of 2 to 40 times of the thermoplastic resin.

  Furthermore, the air duct connection structure according to the present invention is characterized in that the spiral portion is formed on at least an inner peripheral surface of the first duct or the second duct.

  Furthermore, the air duct connection structure according to the present invention is characterized in that the spiral portion is formed on at least the outer peripheral surface of the first duct or the second duct.

  Furthermore, in the connection structure for an air-conditioning duct according to the present invention, the spiral portion has a curved portion on the connecting portion end face side of the convex portion that is curved more gently than a curved portion on the terminal end side of the spiral portion of the convex portion. It is characterized by being.

  Furthermore, the connection structure for an air conditioning duct according to the present invention is characterized in that the first duct and the second duct are fitted in a state in which the first duct and the second duct are in contact with each other on the main body side from the end of the spiral portion. is there.

  According to the air conditioning duct of the present invention, since the first duct and the other duct are brought into contact with each other in a spiral shape, the contact resistance at the time of insertion is lowered, and the insertion workability can be improved. . Further, since the connection portion has a spiral structure, buckling and deformation can be suppressed as compared with the bellows-like structure, and workability can be further improved.

(A), (b) is sectional drawing which shows Embodiment 1 of this invention typically. (C) is sectional drawing which shows the modification of Embodiment 1 typically. (A) is sectional drawing which shows typically the modification of Embodiment 1, (b) is the partially expanded view of (a). (A), (b) is sectional drawing which shows Embodiment 2 of this invention typically. It is sectional drawing which shows typically the modification of Embodiment 2 of this invention. It is sectional drawing which shows typically the connection structure regarding embodiment of this invention. It is sectional drawing which shows the conventional Example typically.

  Hereinafter, the connection structure of the air-conditioning duct according to the embodiment of the present invention will be described.

  An automobile air conditioning system performs indoor air conditioning by introducing air conditioned by HVAC into a room through an air conditioning duct. The air conditioning duct is installed on the back side of an instrument panel (hereinafter referred to as an instrument panel), a floor console, a ceiling, etc., which is a member in an automobile, and connects a ventilation air conditioner and an air outlet provided in the instrument panel, etc. Yes.

  FIG. 1A is a cross-sectional view showing an embodiment of a connection structure 10 for an air conditioning duct according to the present embodiment. The air-conditioning duct connection structure 10 according to the present embodiment has a structure in which the second duct 14 is fitted to one end of the first duct 12 and the connection part 16 is formed. The first duct 12 is connected at the other end to an air outlet through which conditioned air is circulated between a driver seat and a passenger seat provided in an instrument panel (not shown). It is attached to the back of the unit and modularized. The second duct 14 is modularized with the other end connected to a ventilation air conditioner (not shown).

  Next, each structure of the 1st duct 12, the 2nd duct 14, and the connection part 16 is demonstrated with FIG. 1 (a), (b), (c). FIG.1 (b) is sectional drawing before the fitting of the 1st duct 12 and the 2nd duct 14 of the duct 10 for an air conditioning shown by Fig.1 (a). In addition, FIG.1 (c) is a modification of Fig.1 (a). First, the first duct 12 will be described.

  The first duct 12 is formed by forming a foamable resin sheet into a tubular shape. The foamable resin sheet is not particularly limited, but a foamed polyethylene sheet or foamed polypropylene sheet having a closed cell structure, particularly a foamed polyolefin sheet such as a crosslinked foamed polyethylene sheet or a crosslinked foamed polypropylene sheet is preferably used. it can. In addition, the foamable resin sheet can also be expected to have secondary effects such as weight reduction and improvement in heat insulation due to the foamability of the material. Moreover, the crosslinking type of the crosslinked foamed polyolefin sheet among the foamable resin sheets is not particularly limited, and may be selected by a production method such as a chemical method or an electron beam method.

  Furthermore, the expansion ratio of the foamable resin sheet is preferably 2 to 40 times, and more preferably 5 to 20 times. If the expansion ratio is less than 2, the effects of weight reduction, insertability and sealability are reduced. On the other hand, when the expansion ratio exceeds 40 times, the weight reduction and the heat insulation effect are increased, but the rigidity is lowered, and particularly the reliability for mounting on an automobile may be lowered.

  Furthermore, the cell diameter of the closed cells of the foamed resin sheet is preferably 0.2 to 2.0 mm, and more preferably 0.7 to 1.2 mm. If the cell diameter of the closed cells is less than 0.2 mm or more than 2.0 mm, it may be difficult to obtain a suitable expansion ratio, heat insulation and rigidity.

  As described above, the first duct 12 has a foamable resin sheet formed in a tubular shape, and a spiral portion 12c is formed on the inner peripheral surface and the outer peripheral surface thereof. . The spiral portion 12c is formed in a predetermined range from the opening end portion 12a of the first duct 12 toward the duct main body 12b, and is formed to have a length of 50 mm from the opening end portion 12a, for example.

  The first duct 12 shown in FIGS. 1 (a) and 1 (b) has a structure in which a spiral portion 12c is formed on the inner and outer peripheral surfaces in the vicinity of the opening end portion 12a, but as shown in FIG. 1 (c). In addition, the spiral portion may be formed only on the inner peripheral surface. Furthermore, the inner diameter A of the spiral portion 12c (the inner diameter when the surface connecting the portions contacting the outer peripheral surface of the second duct 14 is the inner peripheral surface) must be smaller than the outer diameter B of the second duct 14. This is because when the second duct 14 is fitted to the first duct 12, the first duct 12 is elastically deformed and the both ducts are brought into close contact with each other. If the thickness of the spiral portion 12c is, for example, 0.5 mm to 3.0 mm, the adhesion can be improved.

  Furthermore, it is preferable that the pitch interval of the convex part which the spiral part 12c adjoins is 5 mm-25 mm. Since the spiral portion 12c has this pitch interval, the insertability is improved.

  As a modification of the first duct 12, as shown in FIGS. 2A and 2B, the uneven shape of the cross section of the spiral portion 12c formed on the inner peripheral surface of the second duct 12 is shown in FIG. It is good also as a thing different from the shape (shape in which each recessed part and convex part become a cross-sectional left-right symmetry in FIG. 1). As shown in the enlarged sectional view of the spiral portion 12c in FIG. 2B, the concave-convex shape of the cross-section is such that the curved portion R1 on the end surface side of the convex portion is more than the curved portion R2 on the terminal side of the spiral portion of the convex portion. Due to the uneven shape which is gently curved, the second duct 14 shown in FIG. 2 can be easily inserted into the first duct 12 and can be easily pulled out.

Next, a method for forming the spiral portion 12c at the opening end of the first duct 12 will be described. Although there is no limitation in particular in the method of forming a foamable resin sheet in the shape of a tube, the method described in European Patent Application Publication No. 0445592 (EP 0445592 A2) can be suitably employed. This method includes the following steps (1) to (4).
(1) One or two foamed resin sheets are heated to a temperature higher than the softening temperature of the foamed resin sheet, and then placed in a split mold. The temperature is 130 to 200 ° C, preferably 150 to 170 ° C.
(2) By closing the split mold, they are joined together along the edge of the foamed resin sheet, and the intermediate space between the foamed resin sheets is sealed to a considerable extent.
(3) By introducing the fluid under pressure into the intermediate space between the foamed resin sheets, the foamed resin sheet is pressed against the wall of the split mold to adjust the shape.
(4) After the part is cooled, the molded product is removed.
Moreover, you may employ | adopt the method similarly shape | molded with a split mold using the foaming parison which consists of polypropylene resin or polyethylene resin other than said method. In (3), the fluid under pressure is introduced into the middle between the foamed resin sheets. However, evacuation may be performed from the wall surface of the split mold, or both may be performed.

  The portion corresponding to the spiral portion 12c is formed in the same manner as described above by providing irregularities corresponding to the spiral shape on the inner surface of the split mold.

  Next, the second duct 14 will be described. As shown in FIG. 1A, the second duct 14 is a tubular body made of unfoamed polyethylene, unfoamed polypropylene, or the like, one of which is connected to a ventilation air conditioner. The second duct 14 is formed of a material having a larger elastic coefficient than that of the first duct 12. This is because when the spiral portion 12c (first duct 12) is fitted into the second duct 14, the spiral portion 12c is elastically deformed, and this elastic force improves adhesion to the second duct.

  As a modified form of the second duct 14, as shown in FIGS. 3A and 3B, a spiral portion 14 c is formed on the outer periphery of the second duct 14 from the opening end portion 14 a toward the duct body 14 b side. It may be formed. The second duct 14 has a structure in which the spiral portion 14c is formed only on the outer periphery in the vicinity of the opening end portion 14a, but a spiral portion similar to the outer periphery may be formed on the inner periphery (not shown).

  3A and 3B, when the spiral portion 14c is formed in the second duct 14, it is not necessary to form the spiral portion 12c (see FIG. 1) in the first duct 12. However, as shown in FIG. 4, a spiral portion 12 c corresponding to the spiral portion 14 c of the second duct 14 may be formed. In this case, since the first duct 12 and the second duct 14 are fitted in a screwed state, the adhesion can be further improved.

  3 and 4, both the outer diameter D of the spiral portion 14c (the outer diameter when the surface connecting the portions contacting the inner peripheral surface of the first duct 12 is the outer peripheral surface), D ′ (The outer diameter when the surface connecting the portion contacting the inner peripheral surface of the first duct 12 is the outer peripheral surface) is the inner diameter C, C ′ of the first duct 12 (the outer peripheral surface of the second duct 14 is in contact). The inner diameter must be larger than the inner peripheral surface of the surface connecting the parts. This is because when the second duct 14 is fitted to the first duct 12, the first duct 12 is elastically deformed and the both ducts are brought into close contact with each other.

  In the above description, the second duct 14 is formed of a material having a larger elastic coefficient than that of the first duct 12. However, the present invention is not limited to this, and the second duct 14 may be made of the same material as the first duct. That is, the second duct 14 may be a foamed resin sheet formed in a tubular shape.

  Next, the connection unit 16 will be described. As shown in FIGS. 1 to 4, the connecting portion 16 is fitted by inserting the second duct 14 into the first duct 12, and the first duct 12 is elastically deformed on the outer periphery of the second duct 14. Thus, both the ducts 12 and 14 are in close contact with each other, and the air flowing through the duct is prevented from leaking out of the duct.

  As shown in FIG. 5, as the structure of the connecting portion 16, the tip end 14 a of the open end portion 14 a of the second duct 14 is positioned closer to the duct body 12 b than the rear end 12 d of the spiral portion 12 c of the first duct 12. It is preferable to make it fit. By adopting this structure, the adhesion (sealability) between the two is further improved, and there is no need to interpose a seal member (not shown).

DESCRIPTION OF SYMBOLS 10 Air conditioning duct 12 1st duct 12a Open end part 12b Duct main body 12c Spiral part 12d Rear end 14 Second duct 14a Open end part 14b Duct main body 14c Spiral part 14d Front end 16 Connection part

Claims (7)

A connection structure of an air conditioning duct in which the second duct is fitted to the first duct and the air-conditioned air circulates in the first and second ducts,
At least one of the first duct or the second duct is formed of a thermoplastic resin foam,
At least one of the first duct or the second duct is formed with a spiral portion in which a convex portion and a concave portion are spirally arranged in a predetermined range in the longitudinal direction from the opening end portion thereof,
A connection structure for an air conditioning duct, wherein the first duct and the second duct are fitted in a spiral contact state via the convex portion.   The air-conditioning duct connection structure according to claim 1, wherein the thermoplastic resin foam has closed cells.   The air-conditioning duct connection structure according to claim 2, wherein the thermoplastic resin is a cross-linked polyethylene having an expansion ratio of 2 to 40 times.   2. The air duct connection structure according to claim 1, wherein the spiral portion is formed on at least an inner peripheral surface of the first duct or the second duct.   2. The air duct connection structure according to claim 1, wherein the spiral portion is formed on at least an outer peripheral surface of the first duct or the second duct.   2. The spiral part is characterized in that the curved part on the end face side of the connecting part of the convex part is curved more gently than the curved part on the terminal side of the spiral part of the convex part. The connection structure for an air conditioning duct according to any one of 5.   The air conditioning according to any one of claims 1 to 6, wherein the first duct and the second duct are fitted in a state in which the first duct and the second duct are in contact with each other on the main body side from the end of the spiral portion. Duct connection structure.

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