JP2005090593A - Intake duct with bellows - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance performance of an intake duct with bellows. <P>SOLUTION: In the intake duct, a bellows is formed in a multiple structure (2), which is provided with a void layer (2a). Thereby, the strength of the bellows can be enhanced while maintaining special properties of the bellows. The void layer can absorb noise generated by fluid passing through the bellows. As a result, inexpensive intake duct with a bellows which materializes low noise and high strength can be offered. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blow-molded hollow body having a bellows structure, and can be used for ducts, hoses, pipes and the like for introducing a gas such as air. In particular, it can be used for intake ducts, hoses, pipes, and the like required for automobile engines that use air, and is suitable for ducts, hoses, and pipes that need to prevent noise generated during intake.

  In engine intake system parts for automobiles, blow molded hollow products are used for intake ducts that introduce air into the engine and turbo pipes that send air supplied by a turbocharger. In addition, a bellows portion is provided for the purpose of absorbing vibrations between parts connecting the ducts and pipes (for example, between parts on the engine side and the vehicle body side) and for improving attachment.

  In addition, the bellows part provided in the intake duct or turbo pipe generally takes a thinner structure than the duct or pipe body part in order to improve the stretchability and flexibility of the bellows. The bellows performance is demonstrated by the effect.

  On the other hand, the noise generated in automobile engines and turbochargers is also emitted to the outside from these intake ducts and turbo pipes as radiated noise, but from the thin bellows part, the radiation is transmitted because it is thin. There is a lot of noise, and there is a problem with noise reduction, and various husbands have been made to eliminate this noise.

  For example, a sheet-like foamed urethane or foamed rubber is wrapped around the bellows of an intake duct or turbo pipe that generates noise and fixed with tape to reduce radiation noise from the bellows, or the entire circumference of the bellows Is covered with a foamed urethane layer by RIM molding (reaction injection molding), and radiation noise is absorbed by this foamed urethane layer. These conventional methods use the noise absorbing effect of the foam in any case, but the cost of parts such as the foam and the processing cost are high.

  In the above conventional method, in order to reduce the radiation noise from the bellows part of the intake duct or the turbo pipe, foams are used, and they are added to the bellows part by various methods. There has been a demand for a simpler and more effective method with high component costs and additional processing costs.

  An object of the present invention is to solve the above-mentioned conventional drawbacks and to provide an intake duct or a turbo pipe having a bellows part that has a function of reducing radiation noise from the bellows part easily and inexpensively. .

  Specifically, the accordion portion of the intake duct or turbo pipe has a multi-layer structure, and an intermediate layer (air gap) made of an air layer is provided in the accordion portion of the multi-layer structure. The noise emitted from the inside of the bellows portion is generated.

  The method of the present invention formed by blow molding is a method of forming a bellows portion having an air layer (void) by superimposing and integrating the multiple bellows component portions of two blow molded products each having a multiple bellows component portion. A blow molded product having an internal forming portion for forming an air layer is inserted into a blow molded product having an external bellows for forming an air layer, and an intermediate air layer is formed at the bellows portion. At the same time, the two are integrated by means such as heat welding and adhesion, and a bellows portion having a desired shape and function is provided as a duct or pipe having a multiple structure.

  As a method for forming a multi-structure bellows having an air layer, for example, a bellows of a bellows duct having a spiral shape with a small outer diameter at the same bellows pitch on a bellows portion of a duct having a spiral shape and an externally formed bellows having a large outer diameter. Screwing the part, forming a gap with an air layer at the different height of each bellows crest part, and heat welding, bonding or partial overmolding the screwed end Insert the multi-structure bellows internal formation part of the duct with multi-structure bellows internal formation part into the bellows part of the bellows duct with the bellows forming the external bellows or the bellows forming the external bellows, and heat-welding the overlapping ends Duct with multiple structure on bellows part with desired shape and radiation noise prevention effect by means of integration by means such as bonding or partial overmolding By producing pipe is to provide a product which attained high cost reliable.

  The effects achieved by the present invention are as follows.

  In the intake duct and pipe having the bellows structure, (1) noise transmitted through and radiated from the bellows portion of the duct and pipe can be reduced. (2) Since the bellows portion has a multi-layer structure and absorbs noise by the intermediate air layer, a product that is inexpensive and effective can be obtained. (3) A multi-structure having a noise prevention effect can be manufactured with a simple and simple process and structure. (4) Since the bellows portion has a multiple structure, the strength of the bellows portion is increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic external view of an intake duct having a bellows portion to which an embodiment according to the present invention is applied. The intake duct 1 has a vehicle body side assembly portion 1a and an engine side (turbocharger side) assembly portion 1b. The bellows portion 1c is provided to absorb the vibrations on the vehicle body side and the engine side and the relative displacement during traveling of the assembly portion. A connector pipe 1d for returning the engine blow-by gas is provided at the center of the duct.

  FIG. 2 is a schematic partial cross-sectional view showing a multi-structure bellows formed by overlapping a bellows having a spiral shape in a first example in which the embodiment according to the present invention is applied to the duct bellows portion 1c of FIG.

  The multi-structure bellows 2 includes a duct 3 having a spiral structure at the end of the duct and an externally formed bellows 3a having a large outer diameter, and a spiral-shaped inner portion having the same pitch at the end of the duct and a low peak. The duct 4 having the formation bellows part 4a is formed by screwing each other. The internally formed bellows portion 4a and the externally formed bellows portion 3a have the same bellows pitch and the ridge height is changed so that a part of the outer periphery of the internally formed bellows portion 4a contacts the inside of the externally formed bellows portion 3a. An intermediate air gap layer 2a for forming an air layer is provided between the two.

  The two blow-molded ducts are integrated by screwing the spiral bellows part into the duct end part 3b of the duct 3 having the externally formed bellows part 3a and the duct weld part 4b of the duct 4 having the internally formed bellows part 4a. It welds and the airtightness and joining strength are maintained by the welding part 5. FIG.

  FIG. 3 is a partial cross-sectional schematic diagram showing an example (a cylindrical structure in the case of the illustrated example) in which the internal forming part of the multilayer structure bellows part is a non-bellows structure in a second example to which the embodiment according to the present invention is applied. is there.

  The multi-structure bellows portion 22 includes a duct 6 having an externally formed bellows portion 6a having a large outer diameter at the duct end, and a cylindrical inner portion having an outer diameter at the duct end that is smaller than the inner diameter of the bellows portion formed inside the duct 6. The duct 7 having the forming portion 7a is inserted and formed. The intermediate gap layer 22a having the air layer of the multiple structure bellows part 22 is formed by a gap formed between the duct 6 having the externally formed bellows part 6a and the internal formation part 7a of the duct 7, and this multiple structure is formed. The duct 6 and the duct 7 to be formed are integrated by welding the end portion 6b of the duct 6 and the welded portion 7b of the duct 7, and the airtightness and joint strength of the duct 6 and the duct 7 joined by the welded portion 55 are joined. Hold.

  Radiant noise generated from the inside of the duct was absorbed by the air layer formed by the intermediate gap layer 22a, and a better noise reduction effect was brought about compared to a single bellows structure.

  In this embodiment, the bellows forming portion 6a of the duct 6 provided outside has sufficient flexibility and flexibility, so that the inside forming portion 7a of the duct 7 is made of a soft resin and the bellows of the duct 6 provided outside. Desired functions and effects can be obtained by using a resin having flexibility that does not impair the function of the portion 6a.

  The reduction effect of the radiated noise obtained by the above-described embodiment of the present inventors is 10 to 40% lower than that of the conventional single-layer bellows structure, and a desired radiated noise reduction effect is obtained. It was.

  The above embodiment is an example of an embodiment of the present invention, and includes a blow molded hollow molded body in which a multi-structure bellows portion of an intermediate void air layer having various structures and shapes in addition to the above embodiment is formed. It goes without saying that the air intake duct or the like can be provided by a method other than the above embodiment.

  Further, the product according to the present invention can be used not only as an intake duct or pipe having an automobile or other internal combustion engine but also as a duct or pipe of a mechanism generating noise, and has a higher reliability than conventional methods. Of course, it can be provided inexpensively and efficiently.

1 is a schematic external view of an intake duct having a bellows portion to which an embodiment according to the present invention is applied. The partial cross-section schematic which shows the multiple structure bellows by the spiral-shaped bellows in the Example 1 by this invention. The partial cross-section schematic which made the internal formation part of the multilayer structure bellows part the non-bellows structure in the Example 2 by this invention.

Explanation of symbols

1: Intake duct 1c: Bellows part 2: Multiple structure bellows part 2a: Intermediate gap layer

Claims (2)

  An air intake duct having a bellows portion formed by blow molding, wherein the bellows portion has a multiple structure and a gap layer is provided in the multiple structure portion.   2. The air intake duct having a bellows portion formed by blow molding according to claim 1, wherein the void layer has a sound absorbing effect.

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