JP2007247461A - Intake duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake duct formable by insert blow molding, and capable of restraining and reducing an increase in intake resistance. <P>SOLUTION: A connecting part 11 continuing with the intake flow passage upstream side of at least a part in the peripheral direction of a flange holding part 10, and a guide part 12 continuing with the intake flow passage upstream side of the connecting part 11, are arranged in an upstream part 1 of the cylindrical intake duct having the upstream part 1 and a downstream part 2 and integrating the upstream part 1 into the downstream part 2 by blow molding by a mold placed with the downstream part 2 molded in advance. An outside surface of the guide part 12 is formed on the inner peripheral side more than an outer peripheral surface of the connecting part 11. Among an inner surface of the guide part 12, an end part on the intake flow passage downstream side is continuously adjacently formed on an inner peripheral surface of a flange 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake duct that forms a part of an intake system of an automobile or the like.

  An intake duct for an automobile is a cylindrical member and constitutes a part of an intake system of the automobile. Some intake ducts are formed by integrating two or more parts made of different materials. For example, a portion (downstream portion) attached to the engine side component in the intake duct is generally made of a soft material. In the intake duct, the portion other than the downstream portion (upstream portion) is generally made of a hard material. This is because the downstream portion is required to ensure sufficient sealing performance and assembling performance for engine-side parts, and the upstream portion is required to sufficiently ensure negative pressure resistance. This type of air intake duct is generally formed by insert blow molding. That is, one of the downstream portion and the upstream portion is molded in advance and placed inside the blow mold. And the other of an upstream part and a downstream part is blow-molded with this blow molding die, and the downstream part and the upstream part are integrated (for example, refer patent documents 1-2).

  By the way, in the intake duct formed by insert blow molding, turbulent flow may occur at the boundary portion between the upstream portion and the downstream portion. FIG. 9 is a cross-sectional view schematically showing a conventional air intake duct formed by insert blow molding.

In the conventional air intake duct shown in FIG. 9, the upstream portion 101 is blow-molded with a blow molding die on which a pre-formed downstream portion 102 is placed. The downstream portion 102 of the conventional intake duct shown in FIG. 9 has a flange 120 at the end on the upstream side of the intake flow path. This is to ensure a sufficient bonding area between the downstream portion 102 and the upstream portion 101. The upstream portion 101 has a flange holding portion 110 that wraps the outer periphery of the flange at the downstream end of the intake flow path. The flange holding part 110 extends while expanding in diameter toward the outer peripheral side of the inner peripheral surface of the flange 120. Therefore, the inner surface of the portion near the flange holding portion 110 in the upstream portion 101 has a larger diameter than the inner peripheral surface of the flange 120. For this reason, in the vicinity of the flange holding portion 110, the intake air flowing out to the inner peripheral portion of the flow flange 120 along the inner surface vortexes and turbulence of the intake air is generated. When the turbulent flow of the intake air occurs, the intake resistance of the intake duct may increase.
Japanese Patent No. 2631525 JP 2005-282449 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an intake duct that can be formed by insert blow molding and can suppress an increase in intake resistance.

  The air intake duct of the present invention that solves the above problems has a cylindrical downstream portion that has a flange at one end and the inside forms a downstream portion of the intake flow passage, and a flange holding portion that wraps the outer periphery of the flange, and the inside is on the intake flow passage. A cylindrical intake duct having a cylindrical upstream portion constituting the flow side portion, the upstream portion being blow-molded by a molding die on which a pre-formed downstream portion is placed and integrated with the downstream portion. The upstream portion has a connecting portion that is continuous with at least a part of the upstream side of the intake passage in the circumferential direction of the flange holding portion, and a guide portion that is continuous with the upstream side of the intake passage of the connecting portion. The outer surface is formed on the inner peripheral side with respect to the outer peripheral surface of the connecting portion, and the inner surface of the downstream end portion of the intake passage of the guide portion is formed at least partially adjacent to the inner peripheral surface of the flange. It is characterized by being.

The intake duct of the present invention preferably includes any of the following configurations (1) to (3). It is desirable to provide a plurality of configurations (1) to (3).
(1) The upstream portion has one end opened in the axial direction and the other end closed, and the flange holding portion is formed on the peripheral wall. The upstream portion is located upstream of the intake passage of the guide portion. It has a general part that is located and at least partially continuous with the guide part, and a portion of the inner surface of the guide part on the upstream side of the intake passage smoothly continues to the inner surface of the general part.
(2) In the case of (1), the guide portion is formed at the end portion on the closed side in the upstream portion, and has an intersection with the axis of the general portion.
(3) The distance between the end of the flange holding portion on the upstream side of the intake passage and the end of the guide portion on the downstream side of the intake passage is 10 mm or less.

  In the intake duct of the present invention, the upstream portion has a guide portion formed on the upstream side of at least a part of the flange holding portion. The outer surface of the guide portion is formed on the inner peripheral side with respect to the outer peripheral surface of the connecting portion, and at least a part of the inner surface of the downstream end of the intake passage on the guide portion is continuously adjacent to the inner peripheral surface of the flange. Is formed. Therefore, the intake air flowing in the vicinity of the flange holding portion is guided toward the inner peripheral side of the flange by the inner surface of the guide portion. Therefore, according to the intake duct of the present invention, the generation of the turbulent flow described above can be suppressed, and an increase in intake resistance can be suppressed.

  When the intake duct of the present invention has the above-described configuration (1), the upstream portion is formed in such a shape that one end in the axial direction is open and the other end is closed, and a flange is held on the peripheral wall downstream of the intake passage in the upstream portion. Also when forming a part, generation | occurrence | production of the turbulent flow mentioned above can be suppressed more reliably, and the increase in intake resistance can be suppressed more reliably. That is, when the upstream portion is formed in a shape in which one end in the axial direction is opened and the other end is closed, and the flange holding portion is formed on the peripheral wall on the downstream side of the upstream intake passage, The flow changes abruptly in a portion near the flange holding portion. Therefore, in this case, the above-described turbulent flow is more likely to occur. In the intake duct of the present invention having the above configuration (1), the portion on the upstream side of the intake passage in the inner surface of the guide portion is smooth on the inner surface of the general portion that is further on the upstream side of the intake passage than the guide portion. It is continuous. For this reason, the flow of the intake air in the vicinity of the flange holding portion can be smoothly adjusted by the guide portion. Therefore, the intake duct of the present invention having the configuration (1) can more reliably suppress the occurrence of turbulence.

  When the intake duct of the present invention has the above configuration (2), the generation of the turbulent flow described above can be more reliably suppressed, and the increase in intake resistance can be more reliably suppressed. The portion of the upstream portion that is the inner surface of the closed end and the intersection with the axis of the general portion is the portion where the intake air flowing along the inner surface of the general portion is associated. Therefore, the formation of the turbulent flow can be more reliably suppressed by forming the guide portion at least in this portion.

  When the intake duct of the present invention has the above configuration (3), the intake air flowing in the vicinity of the flange holding portion can be reliably guided toward the inner peripheral side of the flange by the inner surface of the guide portion. Therefore, generation | occurrence | production of the turbulent flow mentioned above can be suppressed more reliably.

  In the intake duct of the present invention, the upstream portion and the downstream portion may extend straight or be curved. The upstream portion and the downstream portion may be made of the same material or different materials. For example, both the upstream portion and the downstream portion may be formed of a hard material, and both the upstream portion and the downstream portion may be formed of a soft material.

  The intake duct of the present invention can be formed by a known insert blow molding method. The guide surface may be formed when the upstream portion is insert blow molded. Moreover, you may form a guide part by shaping the molded object obtained by insert blow molding.

  Hereinafter, an intake duct according to the present invention will be described with reference to the drawings.

Example 1
The intake duct of the first embodiment includes the above configurations (1) to (3). The intake duct of the first embodiment constitutes a part of the intake system of the automobile. FIG. 1 is a perspective view schematically showing the intake duct of the first embodiment. FIG. 2 is a cross-sectional view schematically showing a state where the intake duct of the first embodiment is cut along AA ′ in FIG. FIG. 3 is a top view schematically showing the intake duct of the first embodiment. Hereinafter, in Example 1, the terms “up”, “down”, “left”, “right”, “front”, and “rear” refer to “upper, lower, left, right, front, and rear” illustrated in FIG.

  As shown in FIG. 1, the intake duct of the first embodiment has a cylindrical upstream portion 1 and a cylindrical downstream portion 2. As shown in FIG. 2, the inside of the upstream portion 1 and the inside of the downstream portion 2 communicate with each other. The inside of the upstream portion 1 constitutes an intake flow channel upstream side portion of the intake duct. The inside of the downstream portion 2 constitutes a portion on the downstream side of the intake passage in the intake duct. The downstream portion 2 has a cylindrical shape extending straight and has a flange 20 at the end. As shown in FIG. 2, the center O of the flange 20 is on the axis L <b> 2 of the downstream portion 2. The flange 20 is integrated with the upstream portion 1. As shown in FIG. 3, the axis L2 of the downstream portion 2 is on the axis L1 of the general portion 13, and the axis of the downstream portion 2 and the axis of the upstream portion 1 are orthogonal to each other.

  The upstream part 1 has a flange holding part 10, a communication part 11, a guide part 12, and a general part 13. The upstream portion 1 has a bottomed cylindrical shape with an open rear end and a closed front end. In the intake duct of the first embodiment, the rear portion (upstream portion of the intake passage) of the upstream portion 1 is the general portion 13. A flange 20 is integrally held on the peripheral wall of the upstream portion 1. Specifically, an opening 15 is formed in the peripheral wall on the lower front side of the upstream portion 1, and the peripheral edge of the opening 15 wraps around the outer periphery of the flange 20 (FIG. 2). The peripheral edge portion of the opening 15 becomes the flange holding portion 10. The flange holding portion 10 has a substantially annular shape that wraps around the entire outer periphery of the flange 20, and fixes the flange 20.

  The outer peripheral side portion of the flange holding portion 10 extends outward from the outer periphery of the flange 20. As shown in FIG. 3, in the intake duct of the first embodiment, the front end portion of the upstream portion 1 (the end portion on the downstream side of the intake passage) has two planes (plane a, plane) including the axis L2 of the downstream portion 2. A region surrounded by b) is formed, and this region is recessed as shown in FIG. The angle formed by the plane a and the axis L1 of the general portion 13 is 45 °, and the angle formed by the plane b and the axis L1 of the general portion 13 is 45 °. That is, the angle formed by the plane a and the plane b is 90 °. In the intake duct of the first embodiment, the recessed area serves as the guide portion 12. The guide part 12 has an intersection with the axis L1 of the general part 13.

  As shown in FIG. 2, in the intake duct of the first embodiment, the outer surface 12 a of the guide portion 12 is formed on the inner peripheral side of the outer peripheral surface 10 a of the flange holding portion 10 and the outer peripheral surface 11 a of the connecting portion 11.

  In the inner surface 12 b of the guide portion 12, the end portion on the downstream side of the intake flow path is formed continuously adjacent to the inner peripheral surface 20 b of the flange 20. In the intake duct of the first embodiment, the end portion on the downstream side of the intake flow passage in the inner surface 12 b of the guide portion 12 is formed on a surface extending from the inner peripheral surface 20 b of the flange 20. An end portion of the guide portion 12 on the downstream side of the intake flow channel and an end portion of the flange holding portion 10 on the upstream side of the intake flow channel are communicated with each other by a connecting portion 11. The distance W between the end on the downstream side of the intake passage of the guide portion 12 and the end on the upstream side of the intake passage of the flange holding portion 10 is 10 mm, and between the guide portion 12 and the flange holding portion 10, A cavity 30 defined by the inner surface of the connecting portion 11 is formed. A part of the general portion 13 on the downstream side of the intake flow passage is continuous with the guide portion 12 and partially continuous with the flange holding portion 10. The portion on the upstream side of the intake flow passage in the inner surface 12 b of the guide portion 12 smoothly continues to the inner surface 13 b of the general portion 13. The intake duct of Example 1 is insert blow molded. Specifically, first, the parison 5 is hung between the molding dies 4 in a state where the previously formed downstream portion 2 is placed on the molding dies 4 that are opened (FIG. 4). Next, the mold 4 is closed while blowing air into the parison 5, and the upstream portion 1 is molded with the cavity surface 40 of the mold 4. At this time, the flange holding portion 10, the connecting portion 11, and the guide portion 12 are formed, and the downstream portion 2 is integrated with the upstream portion 2 (FIG. 5). In some cases, the connecting portion 11 and the guide portion 12 may be formed after the portion excluding the connecting portion 11 and the guiding portion 12 in the upstream portion 1 is blow-molded.

  In the intake duct of the first embodiment, the end portion on the downstream side of the intake flow passage in the inner surface 12 b of the guide portion 12 is formed continuously adjacent to the inner peripheral surface 20 b of the flange 20. Therefore, the intake air flowing in the vicinity of the flange holding portion 10 is guided toward the inner peripheral side of the flange 20 by the inner surface 12 b of the guide portion 12. Therefore, the intake duct of the embodiment can suppress the occurrence of turbulent flow and suppress an increase in intake resistance.

  Further, in the intake duct of the first embodiment, the portion on the upstream side of the intake flow passage in the inner surface 12 b of the guide portion 12 smoothly continues to the inner surface 13 b of the general portion 13. For this reason, the flow of the intake air near the flange holding part 10 can be smoothly adjusted by the guide part 12. Therefore, the intake duct of the first embodiment can more reliably suppress the occurrence of turbulent flow.

  Further, in the intake duct of the first embodiment, the intersection with the axis L1 of the general portion 13 that is the portion close to the intake flow path in the upstream portion 1, that is, the inner surface of the closed end portion. The guide part 12 is provided in the part to include. Therefore, the intake duct of the first embodiment can more reliably suppress the occurrence of turbulent flow.

  In the intake duct of the first embodiment, the distance W between the end of the flange holding portion 10 on the upstream side of the intake passage and the end of the guide portion 12 on the downstream side of the intake passage is 10 mm, and they are sufficiently close to each other. ing. For this reason, in the intake duct of the first embodiment, the intake air flowing in the vicinity of the flange holding portion 10 can be reliably guided toward the inner peripheral side of the flange 20 by the inner surface 12b of the guide portion 12. Therefore, the intake duct of the first embodiment can reliably suppress the occurrence of turbulent flow.

  In the intake duct of the first embodiment, the end on the upstream side of the intake passage of the flange holding portion 10 and the end on the downstream side of the intake passage of the guide portion 12 are separated from each other. May be. That is, the cavity 30 shown in FIG. 2 may be eliminated. In this case, since the intake air guided by the inner surface 12b of the guide portion 12 does not enter the cavity 30, there is an advantage that generation of turbulent flow can be suppressed more reliably.

  In the intake duct of the first embodiment, the angle formed by the two planes (plane a and plane b) defining the guide portion 12 is 90 °, but the angle formed by the plane a and the plane b may be less than 90 °. It may be 90 ° or more. When the angle formed by the plane a and the plane b is 90 ° or more, the guide portion 12 is arranged in almost the entire portion of the upstream portion 1 where turbulent flow is likely to occur. There is an advantage that it can be more reliably suppressed.

(Example 2)
The intake duct of the second embodiment includes the configuration (3). The intake duct of the second embodiment has the same downstream portion as the intake duct of the first embodiment, but the shape of the upstream portion 1 is different from the intake duct of the first embodiment. FIG. 6 is a cross-sectional view schematically showing the intake duct of the second embodiment.

  The upstream portion 1 in the intake duct of the second embodiment has a cylindrical shape with both ends opened and curved. The flange holding part 10 is formed at one end of the upstream part 1. The outer surface 12 a of the guide portion 12 is formed on the inner peripheral side with respect to the outer peripheral surface 10 a of the flange holding portion 10 and the outer peripheral surface 11 a of the connecting portion 11. In the inner surface 12 b of the guide portion 12, the end portion on the downstream side of the intake flow path is formed continuously adjacent to the inner peripheral surface 20 b of the flange 20. The portion on the upstream side of the intake flow passage in the inner surface 12 b of the guide portion 12 is smoothly continuous with the inner surface 13 b of the general portion 13.

  The intake duct of the second embodiment is different from the intake duct of the first embodiment in the shape of the upstream portion 1, but, like the intake duct of the first embodiment, the intake air flowing in the vicinity of the flange holding portion 10 is supplied to the inner surface of the guide portion 12. By 12b, it can guide reliably toward the inner peripheral side of the flange 20. Therefore, similarly to the intake duct of the first embodiment, the intake duct of the second embodiment can reliably suppress the occurrence of turbulent flow.

(Comparative example)
The intake duct of the comparative example is a conventional intake duct shown in FIG. That is, the intake duct of the comparative example is the same as the intake duct of the first embodiment except that it does not have a guide portion.

(Pressure loss measurement test)
The air intake duct of Example 1 and the air intake duct of the comparative example are attached to the air blower on the upstream side of the intake flow path, and the flow rates of 2 m ³ / min, 4 m ³ / min, 5 m ³ / min, and 6 m ³ / min are supplied to each intake duct. Then, air was circulated and the pressure loss (pressure loss) of the intake air through each intake duct was measured. Specifically, the pressure of air flowing into each intake duct and the pressure of air flowing out from each intake duct were measured, and the difference between the two was taken as the pressure loss of the intake air through each intake duct. FIG. 7 shows a graph representing the pressure loss due to the intake duct of Example 1 and the intake duct of the comparative example.

As shown in FIG. 7, the pressure loss due to the intake duct of Example 1 is smaller than the pressure loss due to the intake duct of the comparative example. This result shows that the intake duct of the present invention can suppress an increase in pressure loss, that is, an increase in intake resistance. For reference, a graph showing the pressure loss reduction rate of the intake duct of Example 1 is shown in FIG. The pressure loss reduction rate of the intake duct of Example 1 is a value based on the intake duct of the comparative example, and was calculated as follows.
Reduction rate of pressure loss of intake duct of Example 1 (%)
= 100-pressure loss of the intake duct of the first embodiment (kPa) / pressure loss of the intake duct of the comparative example at the same flow rate (kPa) × 100

As shown in FIG. 8, the pressure loss reduction rate of the intake duct of Example 1 increases as the air flow rate increases, and exceeds 10% when the air flow rate is 6 m ³ / min. In other words, when the air flow rate is 6 m ³ / min, the pressure loss of the intake duct of Example 1 is 10% or more lower than the intake duct of the comparative example. From this result, it is clear that the pressure loss can be greatly reduced and the increase of the intake resistance can be suppressed according to the intake duct of the present invention.

FIG. 3 is a perspective view schematically illustrating an intake duct according to the first embodiment. It is sectional drawing which represents typically a mode that the air intake duct of Example 1 was cut | disconnected by AA 'in FIG. FIG. 3 is a top view schematically illustrating an intake duct according to the first embodiment. It is sectional drawing which represents typically a mode that the air intake duct of Example 1 is insert blow molded. It is sectional drawing which represents typically a mode that the air intake duct of Example 1 is insert blow molded. FIG. 6 is a cross-sectional view schematically illustrating an intake duct according to a second embodiment. It is a graph showing the pressure loss by the intake duct of Example 1, and the intake duct of a comparative example. 6 is a graph showing a pressure loss reduction rate of the intake duct of the first embodiment. It is sectional drawing which represents the conventional air intake duct typically.

Explanation of symbols

1: upstream part, 2: downstream part, 20: flange, 10: flange holding part, 11: communication part, 12: guide part, 13: general part

Claims (4)

A cylindrical downstream portion having a flange at one end and the inside constituting a downstream portion of the intake flow path, and a cylindrical upstream portion having a flange holding portion for wrapping the outer periphery of the flange and the inside constituting the upstream portion of the intake flow path And the upstream portion is a cylindrical intake duct that is blow-molded with a molding die on which the pre-formed downstream portion is placed and integrated with the downstream portion,
The upstream portion has a connecting portion that is continuous to at least a part of the intake passage upstream in the circumferential direction of the flange holding portion, and a guide portion that is continuous to the upstream side of the intake passage of the connecting portion,
The outer surface of the guide portion is formed on the inner peripheral side with respect to the outer peripheral surface of the connecting portion,
An intake duct characterized in that at least a part of the end portion on the downstream side of the intake passage in the inner surface of the guide portion is formed continuously adjacent to the inner peripheral surface of the flange. The upstream portion has one end in the axial direction opened and the other end closed, and the flange holding portion is formed on the peripheral wall.
The upstream portion has a general portion that is located on the upstream side of the intake passage of the guide portion and at least part of which is continuous with the guide portion,
2. The intake duct according to claim 1, wherein a portion on the upstream side of the intake passage in the inner surface of the guide portion smoothly continues to the inner surface of the general portion.   The intake duct according to claim 2, wherein the guide portion is formed at an end portion on a closed side in the upstream portion, and has an intersection with the axis of the general portion.   2. The intake duct according to claim 1, wherein a distance between an end portion on the upstream side of the intake passage of the flange holding portion and an end portion on the downstream side of the intake passage of the guide portion is 10 mm or less.

Images