JP2008297936A - Duct for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light weight duct for an automobile capable of controlling quantity of air flow by increasing rigidity and making breakage during manufacturing not easily occur without increasing the unit weight and thickness of a porous body. <P>SOLUTION: This duct for the automobile is formed out of a laminated body having the porous body 31 laminated and integrated on one surface of a synthetic resin sheet 21 having a large number of through holes 22. The porous body 31 has a coarse structure at a position of the through holes 22 of the synthetic resin sheet 21 then other positions, and is thicker with entering the through holes 22 than other positions. The synthetic resin sheet 21 is put at an inner side of the duct for the automobile and the porous body 31 is put at an outer side of the duct for the automobile to inhibit increase of resistance of a pipe wall when air passes through the inside of the duct for the automobile. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automobile duct.

  Conventionally, the following are known as automobile ducts used as an intake duct of an engine, an air duct of an air conditioner, or the like. For example, a non-woven fabric containing a thermoplastic binder is heated and pressed to form a half body having a substantially concave cross section, and the half body is joined at its side part, and a film is laminated on one side of the nonwoven fabric. A car duct formed by forming a half body having a substantially concave cross section with a heating press or the like, and then joining the half bodies on the side so that the plastic film is on the outside, or a plastic hollow There is an automobile duct manufactured by a blow molding method that is frequently used as a method for molding a cylindrical body.

  However, the automotive duct in which the nonwoven fabric containing the thermoplastic binder is heated and pressed is heated until the nonwoven fabric is softened and shaped by pressing. May be torn. In order to prevent the nonwoven fabric from being broken during pressing, increasing the fabric weight of the nonwoven fabric increases the time required for heating and pressing, increasing the molding time, increasing the weight of the automobile duct, and increasing the product cost. There arises a problem that the sound absorption performance of the automobile duct is lowered due to an increase in air permeability or a decrease in air permeability.

  On the other hand, automotive ducts, which are laminated with a film on one side of a non-woven fabric and heated and pressed, have a problem that the product cost increases due to the lamination of the plastic film and the sound absorption performance is lowered because air permeability is almost lost.

  Moreover, since the duct for motor vehicles manufactured by the blow molding method is comprised with the hard plastic with no air permeability, there exists a problem that a sound absorption property and heat insulation are low.

JP-A-11-343938 JP 2002-302858 A JP-A-9-264487 JP 63-53029 A

  The present invention has been made in view of the above points, and in an automobile duct using a porous body such as a nonwoven fabric or a synthetic resin foam, the rigidity of the duct without increasing the basis weight or thickness of the porous body. The purpose of the present invention is to provide a duct for automobiles that can prevent tearing during manufacturing by increasing the pressure and that is lightweight and capable of controlling the air flow rate.

  The invention according to claim 1 is formed from a laminate in which a porous body is laminated and integrated on one side of a synthetic resin sheet having a large number of through-holes, and the porous body is positioned at the holes of the synthetic resin sheet. The present invention relates to an automobile duct characterized in that it has a thickness greater than that of other positions.

  According to a second aspect of the present invention, in the first aspect, the density of the porous body is coarser at the positions of the through holes of the synthetic resin sheet than at other positions.

  The invention of claim 3 is characterized in that, in claim 1 or 2, the synthetic resin sheet is inside the duct, and the porous body is outside the duct.

  The invention of claim 4 is characterized in that, in any one of claims 1 to 3, the synthetic resin sheet and the porous body are heated and integrated and shaped by a press.

  The invention according to claim 5 is the invention according to claim 4, wherein the synthetic resin sheet has a lower melting point than the porous body, and the synthetic resin of the synthetic resin sheet enters the porous body and enters the porous body. It is characterized by being tangled.

  According to the first aspect of the present invention, the automobile duct is formed from the laminate in which the porous body is laminated and integrated on one surface of the synthetic resin sheet having a large number of through holes. Then, when shaping the synthetic resin sheet and the porous body by pressing, the rigidity increases due to the presence of the synthetic resin sheet compared to the case of only the porous body, so the thickness of the porous body can be increased. When using non-woven fabric as the porous body, it is possible to prevent tearing at corners, etc. without excessively increasing the basis weight of the non-woven fabric, and to make automobile ducts of good quality and light weight be able to. Furthermore, according to the invention of claim 1, since the synthetic resin sheet has a large number of through holes in the automobile duct, air permeability can be secured through the porous body at the through hole portion of the synthetic resin sheet. The sound absorption can be improved by the air permeability. In addition, air permeability can be controlled by the size and number of through holes. In addition, since the porous body enters the through-hole at the position of the through hole of the synthetic resin sheet and is thicker than other positions, the sound in the duct passes through the porous body at the position of the through-hole. In addition to suppressing leakage to the outside, sound absorption can be enhanced. In addition, since the porous body has entered the through hole at the position of the through hole of the synthetic resin sheet, the integrity of the porous body and the synthetic resin sheet is high, and the rigidity of the tube wall of the automobile duct can be increased. it can.

  According to the invention of claim 2, since the density of the porous body is coarser than the other positions at the positions of the through holes of the synthetic resin sheet, the thickness of the porous body is the position of the through holes of the synthetic resin sheet. Even if it becomes large, it is possible to prevent a shortage of air permeability necessary for improving sound absorption.

  According to the invention of claim 3, since the synthetic resin sheet is inside the duct and the porous body is outside the duct, the porous body is exposed in the duct only at the through-hole portion of the synthetic resin sheet. In other words, when the air passes through the duct, an increase in air passage resistance due to contact with the irregularities on the surface of the porous body can be suppressed, and the air flow in the duct can be improved.

  According to the invention of claim 4, since the synthetic resin sheet and the porous body are heated and integrated and shaped by pressing, the automobile duct can be manufactured easily and inexpensively.

  According to the invention of claim 5, since the synthetic resin sheet is made of a material having a lower melting point than the porous body, the heating temperature at the time of pressing is higher than the melting point of the synthetic resin sheet and lower than the melting point of the porous body. By doing so, it is possible to prevent the porous body from being melted and deformed, and to prevent a decrease in air permeability and sound absorption due to the melt and deformation of the porous body. Moreover, since the synthetic resin of the synthetic resin sheet enters the porous body and is entangled with the porous body, the integration of the synthetic resin sheet and the porous body can be strengthened.

  Hereinafter, embodiments of the present invention will be described in detail. 1 is a perspective view showing an automobile duct according to an embodiment of the present invention, FIG. 2 is a perspective view showing a part of the automobile duct of FIG. 1, FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. Is a perspective view of the synthetic resin sheet and the porous body, FIG. 5 is a schematic view of the manufacturing apparatus, FIG. 6 is a cross-sectional view showing the time of pressing, and FIG. 7 is a cross-sectional view showing the time of joining the duct halves.

  The automobile duct 10 according to one embodiment of the present invention shown in FIGS. 1 to 3 is a tubular structure in which halves 11 having a substantially concave cross section are joined by a flange portion 12 on the side so that the concave surface 11a is inside. The inside of the tubular body is an air flow passage 17 (shown in FIG. 3). The flange 12 is joined by fusion or the like. The automobile duct 10 has an appropriate cross-sectional shape and bent shape depending on the automobile to which the automobile duct 10 is mounted.

  The half body 11 is formed of a laminated body 41 in which a porous body 31 is laminated and integrated on one surface of a synthetic resin sheet 21 having a large number of through holes 22. FIG. 4 shows a synthetic resin sheet 21 having the numerous through holes 22. The synthetic resin sheet 21 having a large number of through holes 22 is a synthetic resin sheet in which a large number of through holes 22 are formed at predetermined intervals, and is also referred to as a synthetic resin net (or net). The synthetic resin sheet 21 and the porous body 31 are integrated and shaped by being heated and pressed.

  The through hole 22 may be formed at the time of manufacturing the synthetic resin sheet, or may be formed by punching or the like after manufacturing the synthetic resin sheet. The shape, size, and number of the through-holes 22 are set as appropriate. Examples of the through-holes 22 include a square having a side of about 3 to 10 mm and a center interval between the through-holes and the through-holes of about 5 to 10 mm.

  The thickness of the synthetic resin sheet 21 is determined in consideration of moldability when the half body 11 is molded, rigidity in the automobile duct 10, and the like. As an example, the thickness is about 1 to 4 mm.

  The synthetic resin sheet 21 is made of a thermoplastic synthetic resin such as polyethylene or polypropylene, and preferably has a melting point lower than that of the porous body 31. If the melting point of the synthetic resin sheet 21 is lower than the melting point of the porous body 31, when the half body 11 is molded by heating and pressing, the heating temperature is equal to or higher than the melting point of the synthetic resin sheet 21. If the temperature is lower than the melting point of the material 31, the porous material 31 is melted and deformed at the time of pressing to impair the porous property, whereby the air permeability and sound absorbing property of the porous material, that is, the air permeability and sound absorbing property of the duct. It is possible to prevent the performance from deteriorating. Further, since the synthetic resin of the synthetic resin sheet 21 is heated and pressed, it enters the porous body 31 during pressing and is entangled with the skeleton and fibers of the porous body 31, thereby the synthetic resin sheet 21 and the synthetic resin sheet 21. The integration of the porous body 31 is strong.

  The porous body 31 is made of a non-woven fabric or a synthetic resin foam having an open cell structure. An example of the synthetic resin foam having the open cell structure is a polyurethane foam. Although the thickness of the porous body 31 varies depending on the material, about 1 to 5 mm is given as an example. Further, as shown in FIG. 3, the porous body 31 enters the through hole 22 at the position of the through hole 22 of the synthetic resin sheet 21 and is thicker than other positions. With this configuration, the sound in the duct can be prevented from leaking to the outside through the porous body 31 at the position of the through hole 22, and the sound absorption can be enhanced. Further, since the porous body 31 enters the through hole 22 at the position of the through hole 22 of the synthetic resin sheet 21, the integrity of the porous body 31 and the synthetic resin sheet 21 is high, and the duct for automobiles. The rigidity of the ten tube walls can be increased.

  Furthermore, the porous body 31 is uncompressed at the position of the through hole 22 of the synthetic resin sheet 21 or is compressed to a lower degree than the other positions, so that the penetration of the synthetic resin sheet 21 is achieved. The density of the porous body 31 is coarser at the positions of the holes 22 than at other positions (in the case of the nonwoven fabric, the spacing between the fibers is coarse, whereas in the case of the foam, the density is low). Therefore, even if the thickness of the porous body 31 is large at the position of the through hole 22 of the synthetic resin sheet 21, it is possible to prevent a shortage of air permeability necessary to improve sound absorption. it can.

  In the automobile duct 10, it is preferable that the synthetic resin sheet 21 is inside the duct and the porous body 31 is outside the duct. With this configuration, the porous body 31 is exposed in the duct only at the through-hole 22 portion of the synthetic resin sheet 21, and contact with the irregularities on the surface of the porous body 31 when air passes through the duct. It is possible to suppress an increase in the air passage resistance due to this, and to improve the flow of air in the duct.

  A method for manufacturing the automobile duct 10 will be described. The manufacturing method of the automobile duct 10 includes a heating process, a pressing process, and a half body bonding process.

  An example of a manufacturing apparatus used for manufacturing the automobile duct 10 is shown in FIG. A manufacturing apparatus 51 shown in FIG. 5 is for continuously manufacturing the half body 11 and supplies the synthetic resin sheet 21 having the numerous through holes 22 and the porous body 31 in one direction. A supply unit 53; a heating unit 55 provided in the middle of supplying the synthetic resin sheet 21 and the porous body 31; and a forward direction of the synthetic resin sheet 21 and the porous body 31 with respect to the heating unit 55. It consists of a concave mold 57 and a convex mold 59. In the illustrated example, the supply means 53 is configured by a drive roller that is rotated in one direction by a drive motor (not shown), and the synthetic resin sheet 21 placed on the drive roller. The porous body 31 is supplied in the rotation direction of the drive roller.

  The synthetic resin sheet 21 having the numerous through-holes 22 and the porous body 31 are such that the synthetic resin sheet 21 has a lower melting point than the porous body 31, and is on the porous body 31 having a higher melting point. The synthetic resin sheet 21 having a high melting point is placed and supplied in one direction.

  A heating step is performed at the position of the heating means 55. In the heating step, at least the synthetic resin sheet 21 is heated. The heating means 55 is composed of an appropriate heating device such as an electric heater, and is arranged vertically so as to sandwich the synthetic resin sheet 21 and the porous body 31 as shown in the figure, and the synthetic resin sheet 21 and the In addition to heating both of the porous bodies 31, they may be arranged only on one side (upper side) so as to heat only the synthetic resin sheet 21 side. The heating temperature by the heating means 55 is set to be higher than the melting point of the synthetic resin sheet 21 and lower than the melting point of the porous body 31 so that the porous body 31 is not melted and deformed. The heated synthetic resin sheet 21 and the porous body 31 are supplied to the positions of the concave mold 57 and the convex mold 59. At the time of supply, the synthetic resin sheet 21 having a temperature higher than the melting point due to the heating is placed on the porous body 31 having a temperature lower than the melting point due to the heating. The synthetic resin sheet 21 can be supported by the porous body 31 from below and the synthetic resin sheet 21 can be prevented from being deformed by its own weight, and the synthetic resin sheet 21 and the porous sheet are interposed between the concave mold 57 and the convex mold 59. The body 31 can be arranged correctly.

  In the pressing step, cold pressing is performed. That is, as shown in FIG. 6, the synthetic resin sheet 21 heated in the heating step and the porous body 31 are stacked and pressed with the concave mold 57 and the convex mold 59 to perform integration and shaping. The concave mold 57 is positioned below the synthetic resin sheet 21 and the porous body 31, while the convex mold 59 is positioned above, and the synthetic resin sheet 21 is disposed toward the convex mold 59. The porous body 31 is arranged toward the concave mold 57, and the synthetic resin sheet 21 and the porous body 31 are pressed by bringing the concave mold 57 and the convex mold 59 close to each other. The concave mold 57 forms the outer surface side of the automobile duct 10, and the convex mold 59 forms the inner surface side of the automobile duct 10.

  In the skeleton portion 24 (shown in FIG. 4 and the like) other than the through hole 22 in the synthetic resin sheet 21 by the pressing, the porous body 31 is pressed against the skeleton portion 24 and compressed, while the through hole 22 is compressed. In this part, the degree of compression is made lower or uncompressed than the part of the porous body 31 in which the porous body 31 enters the through-hole 22 and is in pressure contact with the skeleton portion 24. Thereby, in the skeleton part 24 other than the through hole 22 in the synthetic resin sheet 21, the synthetic resin of the synthetic resin sheet enters the porous body 31 and becomes entangled with the porous body 31. The integration of 21 and the porous body 31 becomes strong. On the other hand, in the portion of the through hole 22 in the synthetic resin sheet 21, the porous body 31 has a coarser structure and a larger thickness than the skeleton portion 24 other than the through hole 22.

  After the pressing step, the periphery of the portion formed by the concave mold 57 and the convex mold 59 is cut to obtain the duct half body 11 having a substantially concave cross section. Next, a half body joining step is performed. In the half-body joining step, as shown in FIG. 7, the duct halves 11 are joined and integrated at the flange portion 12 on the side so that the concave surfaces 11a face each other, and are shown in FIG. A duct 10 is obtained. The joint integration is performed by a method of fusing the flange portions 12 by overlapping the flange portions 12 in the two duct halves 11 and pressing them with the hot plate 71.

  The production of the automobile duct is not limited to the method using the continuous production apparatus as shown in FIG. 5, and is produced in a unit or a predetermined number of units using a synthetic resin sheet and a porous body cut into a predetermined size. It may be a method to do.

A 2 mm thick synthetic resin sheet made of polyethylene resin (melting point 135 ° C.) in which square through holes of 5 mm × 5 mm are formed at intervals of 7 mm (center distance between the through holes), and a basis weight of 50 g / m ² as a porous body, Using a non-woven fabric (PP fiber, melting point 160 ° C.) having a thickness of 1 mm, the heating temperature is 140 ° C., the concave mold is positioned on the lower side, the convex mold is positioned on the upper side, and the porous body is placed on the porous body. The synthetic resin sheets were stacked and pressed with the concave mold and the convex mold to perform integration and shaping. And the circumference | surroundings of the shaped part were cut | disconnected and the duct half body of cross-sectional substantially concave shape was obtained. Next, the duct halves are overlapped with each other at the side flange portion, and the flange portion is pressed and fused with a hot plate at 180 ° C., thereby a straight tubular automobile having a length of 600 mm and a square cross section of 75 mm × 80 mm. Ducts were manufactured. The obtained automobile duct was lightweight without tearing at the corners.

It is a perspective view which shows the duct for motor vehicles based on one Embodiment of this invention. It is a perspective view which shows a part of duct for motor vehicles of FIG. FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. 2. It is a perspective view of a synthetic resin sheet and a porous body. It is the schematic of a manufacturing apparatus. It is sectional drawing which shows the time of a press. It is sectional drawing which shows the time of joining of duct halves.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automotive duct 11 Duct half body 12 Flange part 21 Synthetic resin sheet 22 Through-hole 31 Porous body 55 Heating means 57 Concave type 59 Convex type

Claims (5)

  It is formed from a laminate in which a porous body is laminated and integrated on one side of a synthetic resin sheet having a large number of through holes, and the porous body enters the through holes at the positions of the through holes of the synthetic resin sheet. An automobile duct having a thickness greater than that of the position.   2. The automobile duct according to claim 1, wherein the density of the porous body is coarser at the positions of the through holes of the synthetic resin sheet than at other positions.   The automobile duct according to claim 1 or 2, wherein the synthetic resin sheet is inside the duct and the porous body is outside the duct.   The automobile duct according to any one of claims 1 to 3, wherein the synthetic resin sheet and the porous body are heated and integrated and shaped by a press.   5. The synthetic resin sheet is made of a material having a lower melting point than the porous body, and the synthetic resin of the synthetic resin sheet enters the porous body and is entangled in the porous body. A duct for automobiles as described in 1.

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