JP2021076076A - Intake duct of on-vehicle internal combustion engine - Google Patents

Abstract

To reduce noise in an engine room.SOLUTION: An intake duct of an on-vehicle internal combustion engine comprises a first dividing body 20 and a second dividing body 40 which divide a peripheral wall 11 thereof in a peripheral direction. The first dividing body 20 and the second dividing body 40 respectively have a first connection section 24 and a second connection section 44 connected to each other at respective edges 22a in the peripheral direction. The second dividing body 40 is made of a textile compact produced through compression molding and has an extended section 45 outwardly extended from the second connection section 44. The extended section 45 has a first low compression section 47 produced through the compression molding with a lower compression ratio than the second connection section 44 so as to ensure airflow.SELECTED DRAWING: Figure 1

Description

The present invention relates to an intake duct of an in-vehicle internal combustion engine.

An intake duct having a tubular side wall is provided in the intake passage of the in-vehicle internal combustion engine (see, for example, Patent Document 1). The side wall of the intake duct described in Patent Document 1 is divided into two in the circumferential direction by a first divided body made of a synthetic resin molded body and a second divided body made of a non-woven fabric molded body. Flange portions are formed at both ends of the side wall in each of the first and second divided bodies in the circumferential direction. By welding the flange portion of the first split body and the flange portion of the second split body, the first split body and the second split body are joined. According to this intake duct, since the side wall of the second split body has a certain degree of air permeability, the generation of standing waves is suppressed by passing a part of the sound wave of the intake air through the side wall, and the intake noise. Is reduced.

Japanese Unexamined Patent Publication No. 2000-73895

By the way, in the engine room of a vehicle, in addition to the above-mentioned intake noise, other noise generated by the operation of the internal combustion engine is generated. However, the intake duct described in Patent Document 1 does not take such a point into consideration, and there is room for improvement in reducing noise in the engine room.

An object of the present invention is to provide an intake duct of an in-vehicle internal combustion engine capable of reducing noise in an engine room.

The intake duct of the vehicle-mounted internal combustion engine for achieving the above object is provided with a tubular peripheral wall, and has a first divided body and a second divided body formed by dividing the peripheral wall in the circumferential direction. A first joint portion and a second joint portion for joining each other are provided at the ends of both the first divided body and the second divided body in the circumferential direction, and the second divided body is compressed. It is made of a molded fiber molded body and has an extension portion extending outward from the second joint portion, and the extension portion has a lower compression ratio than the second joint portion. It has a breathable low compression part molded by.

According to the same configuration, the sound wave of noise generated by the operation of the internal combustion engine vibrates the fiber when passing through the low compression portion provided in the extension portion. At this time, a part of the kinetic energy of the sound wave is converted into the thermal energy of the fiber. As a result, the sound pressure, which is the pressure of the sound waves in the engine room, is reduced. Therefore, the noise in the engine room can be reduced.

The perspective view which shows the intake duct of the in-vehicle internal combustion engine in this embodiment. The exploded perspective view which shows the 1st division body and the 2nd division body of FIG. 1 separated from each other. A cross-sectional view taken along the line 3-3 of FIG. The perspective view which shows the modification example of an intake duct. (A) and (b) are cross-sectional views showing other modified examples of the intake duct. Sectional drawing which shows the other modification example of an intake duct.

Hereinafter, an embodiment of an intake duct (hereinafter, intake duct) of an in-vehicle internal combustion engine will be described with reference to FIGS. 1 to 3. Hereinafter, the upstream side and the downstream side in the intake air flow direction in the intake duct are simply referred to as the upstream side and the downstream side, respectively.

As shown in FIG. 1, the intake duct has a square tubular peripheral wall 11 as a whole, an introduction port 12 for introducing intake air is provided at the upstream end, and is connected to an air cleaner or the like at the downstream end. A connection port 14 is provided. The peripheral wall 11 extends so as to connect the introduction port 12 and the connection port 14. Hereinafter, the extending direction of the peripheral wall 11 will be described as the extending direction Y.

The peripheral wall 11 is composed of a first divided body 20 and a second divided body 40. The first divided body 20 and the second divided body 40 are configured by dividing the peripheral wall 11 into two in the circumferential direction.
<First split body 20>
As shown in FIGS. 1 to 3, the first divided body 20 is made of a resin molded body such as PP (polypropylene), and has a rectangular bottom wall 21 in a plan view and a short side direction of the bottom wall 21 (FIG. 3). It has a pair of side walls 22 that are bent from both ends in the left-right direction and extend toward the second divided body 40, and have a gutter shape. Hereinafter, the short side direction of the bottom wall 21 will be described as the width direction W.

Each end 22a in the circumferential direction of each side wall 22 is provided with a pair of first flanges 23 protruding from the end 22a toward the outer peripheral side. Further, each end 22a is provided with a contact portion 26 that protrudes toward the second divided body 40 and is brought into contact with the second divided body 40.

Each first flange 23 projects along the width direction W and is provided over the entire side wall 22 in the extending direction Y.
At the center of each of the first flanges 23 in the projecting direction, a first joint portion 24 projecting toward the second divided body 40 is provided. The first joint portion 24 is provided over the entire first flange 23 in the extending direction Y.

At the tip of each of the first flanges 23 in the protruding direction, a protrusion 25 that protrudes toward the side away from the second divided body 40 is provided.
<Second split body 40>
As shown in FIGS. 1 and 3, the second divided body 40 is made of a fiber molded body and has a main body portion 41 facing the bottom wall 21 of the first divided body 20 and forming the top wall of the peripheral wall 11. There is. The length of the main body 41 in the width direction W is slightly shorter than the distance between the inner surfaces of the pair of side walls 22. The peripheral wall 11 is composed of the main body 41 of the second divided body 40 and the bottom wall 21 and the side wall 22 of the first divided body 20.

As shown in FIGS. 1 to 3, a pair of second flanges 43 projecting to the outer peripheral side are provided at both ends of the main body 41 in the width direction W. Each second flange 43 is provided over the entire main body 41 in the extending direction Y.

Each second flange 43 has a second joint portion 44 joined to the first joint portion 24, and an extension portion 45 extending outward from the second joint portion 44. The second joint portion 44 and the extension portion 45 are provided over the entire second flange 43 in the extension direction Y.

The second joint 44 is a non-breathable, highly compressed portion. The first joint portion 24 of the first split body 20 and the second joint portion 44 of the second split body 40 are joined by, for example, vibration welding. A space S that functions as a burr pool is provided between the inner portion 24a of the first joint portion 24 and the contact portion 26 (see FIG. 3).

As shown in FIG. 2, the second joint portion 44 and the main body portion 41 are connected to each other on the inner surface of the second divided body 40 via a step 41a.
Here, at the time of vibration welding, the first divided body 20 is positioned with respect to the fixing jig of the vibration welding device. More specifically, the pair of protrusions 25 of the first divided body 20 are hooked on the edges of the jig. On the other hand, the second divided body 40 is restrained by the movable jig of the device. The movable jig is positioned in a state where a part of the main body 41 including the step 41a in the thickness direction is fitted between the pair of side walls 22 of the first divided body 20. Although not shown, the first joint portion 24 of the first split body 20 has a higher protrusion height than the contact portion 26 before vibration welding. Subsequently, the movable jig is vibrated in the extending direction Y in a state where the first joint portion 24 and the second joint portion 44 are in pressure contact with each other. As a result, the first joint portion 24 and the second joint portion 44 are joined to each other.

As shown in FIGS. 1 to 3, the extending portion 45 is provided with a base portion 46 and a breathable first low compression portion 47 formed at a compression rate lower than that of the base portion 46.
The base 46 is a non-breathable, highly compressed portion. The base portion 46 projects along the width direction W and is provided over the entire second joint portion 44 in the extending direction Y.

The first low compression portion 47 is formed with a lower compression rate than the second joint portion 44. The first low compression portion 47 is provided over the entire extension portion 45 in the extension direction Y.
As shown in FIG. 3, the first low compression portion 47 is located on the base portion 46 side and protrudes along the width direction W from the portion 47a and the side opposite to the base portion 46, that is, on the tip end side of the second flange 43. It is located and has a portion 47b that protrudes toward the first divided body 20 along the vertical direction (vertical direction in the figure). The parts 47a and 47b are curved and connected in an arc shape. The lower end of the portion 47b is located on the outer peripheral side of the side wall 22. As a result, the first divided body 20 is covered from the outer peripheral side by the second divided body 40.

The first low compression portion 47 and the base portion 46 are connected via a step on the inner surface of the second divided body 40, while are connected flat on the outer surface.
Breathable second low compression portions 42A are provided at both ends of the main body portion 41 in the width direction W. The second low compression portion 42A is provided over the entire main body portion 41 in the extending direction Y.

As shown in FIGS. 1 and 2, non-breathable high compression portions 42B are provided between the pair of second low compression portions 42A at both ends of the main body portion 41 in the extending direction Y.
The high compression portion 42B and the second low compression portion 42A are connected to each other via a step on the outer surface of the second divided body 40, while are connected flat on the inner surface.

Further, as shown in FIGS. 1 and 2, the portion of the main body portion 41 surrounded by the second low compression portion 42A and the high compression portion 42B is formed by a plurality of breathable second low compression portions 42C. It has a plurality of non-breathable high compression portions 42D. The second low compression section 42C is formed at the same compression rate as the second low compression section 42A. Further, the second low compression portions 42A and 42C are molded at the same compression rate as the first low compression portion 47.

In the present embodiment, each of the second low compression sections 42C and each high compression section 42D has a square shape in a plan view of the same size, and is arranged alternately in a checkered pattern.
The high compression section 42D and the second low compression sections 42A and 42C are connected via a step on the outer surface of the second divided body 40, while are connected flat on the inner surface.

In the present embodiment, the entire outer surface of the second divided body 40 is a design surface.
Next, the structure of the fiber molded body constituting the second split body 40 will be described.
The fiber molded body is made of a well-known core-sheath type composite fiber having, for example, a core made of PET (polyethylene terephthalate) and a sheath made of modified PET having a lower melting point than the PET fiber (both not shown). It is composed of a non-woven fabric and a non-woven fabric made of PET fibers. The modified PET forming the sheath of the composite fiber functions as a binder for binding the fibers to each other. In the present embodiment, the melting point of the resin of the fiber molded product constituting the second divided body 40 is higher than the melting point of the resin of the resin molded product constituting the first divided body 20.

The blending ratio of the modified PET is preferably 30 to 70%. In the present embodiment, the blending ratio of the modified PET is 50%.
In addition, such a composite fiber may have PP (polypropylene) having a melting point lower than that of PET. However, in this case, the melting point of the resin of the fiber molded product having PP needs to be higher than the melting point of the resin of the resin molded product constituting the first divided body 20.

Basis weight of the fibrous form ^is preferably ^{500g / m 2 ~1500g / m 2} . In the present embodiment, the basis weight of the fiber molded product is 800 g / m ² .
The second divided body 40 is formed by heat-compressing (heat-pressing) the above-mentioned non-woven fabric sheet having a predetermined thickness (for example, 30 to 100 mm).

The air permeability (JISL1096, A method (Frazier type method)) of the above-mentioned high compression portion (second joint portion 44 and high compression portion 42B, 42D) is set to be approximately 0 cm ³ / cm ² · s. The plate thickness of the highly compressed portion is preferably 0.5 to 1.5 mm. In the present embodiment, the plate thickness of the high compression portion is 0.7 mm.

The air permeability of the low compression section (first low compression section 47 and second low compression section 42A, 42C) is set to 3 cm ³ / cm ² · s. The plate thickness of the low compression portion is preferably 0.8 to 3.0 mm. In the present embodiment, the plate thickness of the low compression portion is 1.0 mm.

Next, the operation of this embodiment will be described.
In the intake duct of the present embodiment, the sound waves of noise generated by the operation of the internal combustion engine vibrate the fibers when passing through the first low compression section 47 provided in the extension section 45. At this time, a part of the kinetic energy of the sound wave is converted into the thermal energy of the fiber. As a result, the sound pressure, which is the pressure of the sound waves in the engine room, is reduced.

Next, the action and effect of this embodiment will be described.
(1) The second split body 40 is made of a compression-molded fiber molded body, and has an extending portion 45 extending outward from the second joining portion 44. The extending portion 45 has a breathable first low compression portion 47 formed at a lower compression rate than the second joint portion 44.

According to such a configuration, the noise in the engine room can be reduced because the above-mentioned action is obtained.
(2) The first low compression portion 47 is provided in the entire extension direction Y in the extension portion 45.

According to such a configuration, the surface area of the first low compression portion 47 can be increased. Therefore, the noise in the engine room can be further reduced.
(3) The second joint portion 44 is provided at both ends of the second divided body 40 in the circumferential direction, and the extension portions 45 are provided on both of the second joint portion 44, and the first low compression portion. 47 are provided on both sides of the extension portion 45.

According to such a configuration, the extension portions 45 are provided on both of the second joint portions 44, and the first low compression portion 47 is provided on both of the extension portions 45. Therefore, the surface area of the first low compression portion 47 can be increased. Therefore, the noise in the engine room can be further reduced.

(4) The outer surface of the second divided body 40 is the design surface.
According to such a configuration, the extending portion 45 of the second divided body 40 makes it difficult to visually recognize the joint portion between the first joint portion 24 and the second joint portion 44. Therefore, the design of the intake duct is improved.

(5) The first divided body 20 is made of a resin molded body.
According to the same configuration, as compared with the case where the first divided body 20 is molded by the fiber molded body, it becomes easier to form a complicated shape such as a peripheral wall having a curved intake passage.

(6) The melting point of the resin constituting the fiber molded body is higher than the melting point of the resin constituting the resin molded body, and the extending portion 45 covers the first divided body 20 from the outer peripheral side.
According to such a configuration, the radiant heat from a heat source such as an internal combustion engine is directly transferred to the extending portion 45 of the second divided body 40 having a relatively high melting point, so that the first divided body 20 having a relatively low melting point 20 It becomes difficult to convey to. Therefore, the heat resistance of the first divided body 20 is improved.

(7) The second divided body 40 has a main body portion 41 constituting the peripheral wall 11, and the main body portion 41 is a breathable second body formed at a lower compression rate than the second joint portion 44. It has low compression sections 42A and 42C.

According to such a configuration, the generation of standing waves in the intake passage can be suppressed by the second low compression portions 42A and 42C provided in the main body portion 41 of the second divided body 40. Therefore, the intake noise can be reduced.

<Change example>
The above embodiment can be modified and implemented as follows, for example. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

The second low compression sections 42A and 42C and the first low compression section 47 can have different compression rates as long as they are breathable.
The first divided body 20 may be covered from the outer peripheral side by a portion of the extending portion 45 other than the first low compression portion 47 such as the base portion 46.

-The shape of the extension portion 45 can be changed as appropriate. For example, in the first low compression portion 47 shown in FIG. 3, a portion 47b extending in the vertical direction may be further extended downward to cover the entire side wall 22 of the first divided body 20 in the vertical direction. Further, the extending portion 45 may have a configuration in which the portion 47b is omitted.

-In the engine room, the intake duct can be arranged so that the outer surface of the bottom wall 21 of the first divided body 20 is the design surface. Even in this case, the extension portion 45 directly transfers the radiant heat from a heat source such as an internal combustion engine to the extension portion 45 of the second divided body 40 having a relatively high melting point, so that the melting point is relatively high. It becomes difficult to transmit to the first divided body 20 having a low melting point.

In the above embodiment, at both ends of the main body 41 in the extending direction Y, the portion between the pair of second low compression portions 42A is the high compression portion 42B, but the intake duct shown in FIG. 4 is illustrated. As described above, the portion may be a low compression portion.

The shape of the first joint portion 24 is not limited to that illustrated in the above embodiment. For example, as shown in FIGS. 5A and 5B, it may have a cross-sectional shape that tapers toward the second divided body 40. According to such a configuration, the contact area between the first joint portion 24 and the second joint portion 44 becomes smaller. As a result, the frictional heat during vibration welding increases. Therefore, the weldability is improved.

Further, as shown in FIG. 6, the first joint portion 24 and the contact portion 26 in the first flange 23 of the above embodiment are omitted, and the entire surface of the first flange 23 facing the second joint portion 44 is the first. It may be 1 joint portion 24. In this case, the first joint portion 24 and the second joint portion 44 can be joined to each other with an adhesive.

-The high compression portions 42B and 42D of the main body portion 41 may be omitted. That is, the main body 41 can be configured only by the low compression section.
-The second low compression portions 42A and 42C of the main body portion 41 may be omitted. That is, the main body 41 can be configured only by the high compression section.

-The step 41a may be omitted. That is, the second joint portion 44 and the main body portion 41 may be arranged so as to be flatly connected to each other on the inner surface of the second divided body 40.
-Only one extending portion 45 may have a first low compression portion 47.

-It may be configured that only one second joint portion 44 has an extension portion 45.
The first low compression portion 47 may be partially provided in the extending direction Y of the extending portion 45. Further, a plurality of such first low compression portions 47 may be provided at intervals in the extending direction Y of the extending portion 45.

-The first divided body 20 may be made of a fiber molded body.

11 ... peripheral wall, 12 ... introduction port, 14 ... connection port, 20 ... first split body, 21 ... bottom wall, 22 ... side wall, 22a ... end, 23 ... first flange, 24 ... first joint, 24a ... inside Part, 25 ... Protrusion part, 26 ... Contact part, 40 ... Second split body, 41 ... Main body part, 41a ... Step, 42A, 42C ... Second low compression part, 42B, 42D ... High compression part, 43 ... 2 flanges, 44 ... second joint, 45 ... extension, 46 ... base, 47 ... first low compression, 47a, 47b ... parts.

Claims (7)

In the intake duct of an in-vehicle internal combustion engine equipped with a tubular peripheral wall
It has a first divided body and a second divided body formed by dividing the peripheral wall in the circumferential direction.
At the ends of both the first divided body and the second divided body in the circumferential direction, a first joint portion and a second joint portion for joining each other are provided, respectively.
The second divided body is made of a compression-molded fiber molded body, and has an extending portion extending outward from the second joining portion.
The extension portion has a breathable low compression portion formed at a lower compression rate than the second joint portion.
Intake duct for in-vehicle internal combustion engine. When the extending direction of the peripheral wall is the extending direction,
The low compression portion is provided in the entire extending direction of the extending portion.
The intake duct of an in-vehicle internal combustion engine according to claim 1. The second joints are provided at both ends of the second split body in the circumferential direction.
The extending portion is provided on both sides of the second joint portion, and the extending portion is provided on both sides.
The low compression portion is provided on both sides of the extension portion.
The intake duct of the vehicle-mounted internal combustion engine according to claim 1 or 2. The outer surface of the second divided body is a design surface.
The intake duct of an in-vehicle internal combustion engine according to any one of claims 1 to 3. The first divided body is made of a resin molded body.
The intake duct of an in-vehicle internal combustion engine according to any one of claims 1 to 4. The melting point of the resin constituting the fiber molded product is higher than the melting point of the resin constituting the resin molded product.
The extending portion covers the first divided body from the outer peripheral side.
The intake duct of the vehicle-mounted internal combustion engine according to claim 5. When the low compression section is used as the first low compression section,
The second divided body has a main body portion constituting the peripheral wall, and has a main body portion.
The main body portion has a breathable second low compression portion molded at a lower compression rate than the second joint portion.
The intake duct of an in-vehicle internal combustion engine according to any one of claims 1 to 6.

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