JP2022144027A - Engine intake duct - Google Patents

Abstract

To surely discharge water droplets in an intake duct for taking air into an air cleaner.SOLUTION: A duct unit 6 is formed by welding two pieces of left and right shell-shaped members 18, 19, and comprises a first vertically-long part 20a and a horizontally-long part 20c. A drain chamber 24 formed by extending the first vertically-long part 20a, and a guide part 34 for covering the drain chamber 24 from above are formed at a corner part. A slit 35 in which water droplets flow down is formed at the guide part 34. Air is smoothly guided, and exchanged in a direction from the first vertically-long part 20a to the horizontally-long part 20c. The water droplets flow down to the drain chamber 24 from the slit 35. Therefore, water can be removed while largely suppressing a pressure loss. Since the water which has entered the drain chamber 24 cannot be blown and returned, a downward protrusion dimension of the drain chamber 24 can be reduced, and the duct unit can be arranged even in a narrow space.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to an intake duct provided as an accessory to an engine (internal combustion engine) for an automobile or the like.

Gasoline and diesel engines require an air cleaner that takes in and purifies the air, and the air is taken in by the air cleaner through the air intake duct. Therefore, the intake duct is provided with drain means for removing the water without reaching the air cleaner.

As an example, in Patent Document 1, an air intake duct is formed with a bent portion having a vertical portion and a horizontal portion branched from the bent portion, and the vertical portion is extended downward from the horizontal portion to form a drain chamber. It is disclosed that a drain port is provided at the lower end of the valve and a vacuum operated valve body is mounted thereon, and a small hole for air entry is provided at the upstream end of the horizontal portion that is connected to the vertical portion.

In Patent Document 1, when the engine is running, the valve body receives negative pressure and closes. drained. Further, as a function of the small holes, Patent Document 1 explains that since air also enters through the small holes, the flow velocity of the air flowing through the vertical portion is reduced, which makes it easier for water to flow into the drain chamber.

Microfilm of Jitsukaihei 2-4612

There is no doubt that Patent Document 1 has a function of discharging water, but there are also some problems. For example, since the drain chamber is formed in the vertical section and the horizontal section is perpendicular to the vertical section, the direction of the air flowing through the vertical section is suddenly changed and directed toward the horizontal section. , it is undeniable that the air flow resistance increases. That is, it is considered that the smoothness of the air flow is remarkably lacking.

In addition, since the drain chamber is open at the bottom of the vertical part, the air tends to enter directly into the drain chamber. There is also a concern that the water droplets will atomize and enter the air cleaner, and the significance of providing the drain chamber will be lost.

Furthermore, in Patent Document 1, a small hole is made in the horizontal part in order to suppress violent collision of air and water droplets with the drain chamber, but there is also a problem that water may enter through the small hole. In particular, if the intake duct is exposed in the engine room, which is installed on the underfloor of a cab-over type automobile (for example, a one-box type light van), rainwater or water splashed up during driving tends to hit the horizontal part of the intake duct. , the small hole can become a water intrusion hole, which is a big problem.

The invention of the present application was made in response to such a situation, and aims to provide an air intake duct that suppresses the flow resistance of air and has an excellent drainage effect.

The intake duct of the present invention is
"Comprising a vertically elongated part through which air flows downward and a horizontally elongated part into which the air passing through the vertically elongated part changes direction and flows in,
a drain chamber formed by extending the vertically elongated portion downward at a corner portion where the vertically elongated portion and the horizontally elongated portion are connected; and a guide portion that covers the drain chamber from above and changes the direction of air to the horizontally elongated portion. is provided, and a drainage port consisting of a slit or a hole is opened in the guide part.
It is configured.

In the present invention, the horizontally elongated portion may be directly connected to the body case (dirty chamber) of the air cleaner, or as in the embodiment, the horizontally elongated portion may be provided with a second vertically elongated portion facing upward, and the second vertically elongated portion may be attached to the air cleaner. may be connected.

In the present invention, since the curved guide portion is provided at the corner where the vertically long portion and the horizontally long portion are connected, the air flowing down the vertically long portion is prevented from violently colliding with the drain chamber and directed toward the horizontally long portion. can redirect the airflow to Therefore, the air flow resistance can be greatly reduced and the air flow can be smoothed. As a result, airflow resistance can be reduced, contributing to improved fuel efficiency and driving stability.

Moreover, since the water contained in the air flows into the drain chamber through the water drain port such as the slit, the water drain effect is also excellent. In other words, since water has a large specific gravity and a high straightness in the vertically long portion, it is possible to make the water droplets enter the water drain port accurately by utilizing gravity and air flow. Excellent for The same is true for grains of sand.

In addition, since a small hole such as that in Patent Document 1 is not required, when it is applied to an automobile, even if it is exposed in the engine room or the like, water or sand grains will not flow into the air intake duct from the middle part (water and Even if a grain of sand enters, it will only enter from the intake port at the top of the vertical part).

Furthermore, in Patent Document 1, since the air goes straight into the drain chamber, even if water flows into the drain chamber, it may be blown back from the drain chamber by the countercurrent of the air. functions as a lid for the drain chamber, preventing or significantly suppressing blowback of water and sand grains that have entered the drain chamber. It can greatly improve functionality. Therefore, it is suitable for an air intake system such as a cab-over type light van, in which the air intake duct is exposed downward in the engine room provided on the underfloor of the automobile.

As described above, it is preferable to provide the second vertically elongated portion at the downstream end of the horizontally elongated portion so that the water droplets (or grains of sand) that could not be collected in the drain chamber are less likely to flow into the air cleaner. be.

It is the perspective view which looked at the intake device from the diagonally upward direction. It is the perspective view which looked at the intake device from the downward direction. FIG. 4 is a separated front view of the state in which two shell-shaped members are spread out (state in which mating surfaces are exposed); (A) is a perspective view with the air cleaner omitted, (B) is a bottom view of the drain chamber, and (C) is a perspective view of the check valve. (A) is a perspective view of the second shell-shaped member with a part of the structure omitted, (B) is a cross-sectional view taken along line VB-VB of FIG. 1, and (C) is a partially enlarged view of (B). . BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the motor vehicle to which embodiment is applied, (A) is a side view of the whole, (B) is a partially broken enlarged view of (A).

Next, embodiments of the present invention will be described based on the drawings. Although a cab-over type van (for example, a one-box type light van) is shown in FIG. 6, the intake system 1 of the present embodiment can be installed in this cab-over type van.

That is, the cab-over type van has a front compartment (driver's cab) 2 in which front seats 2a are arranged and a luggage compartment space 3 behind it, and an engine 4 is arranged in the space below the front seats 2a. However, the intake device 1 of the present embodiment is surrounded by a portion near the front passenger seat (side members (underframes) of the vehicle body, a floor, and an underbody (outer plate) in the lower rear portion of the front seat 2a). space) (may be placed on the side of the driver's seat).

The engine 4 is arranged vertically with the crankshaft directed in the front-rear direction of the vehicle, and the cylinder bore axis is greatly slant so as to approach the horizontal side. In addition, the side of the air intake is placed upward. 4a shown in FIG. 6B is a transmission case, and 4b is a dry light.

In the following description, the terms front, rear, left, and right are used to specify directions, and these directions are the same as the front, rear, left, and right directions of the vehicle. That is, it is the same as the front, rear, left, and right directions as seen from the driver.

(1) Overview As shown in FIG. 1, the air intake system 1 comprises an air cleaner 5 and a duct unit 6 located mostly below it, and the air cleaner 5 has a dirty chamber positioned below it. It has a main body case 7 made of synthetic resin, a cover case 8 made of synthetic resin that forms a clean room and overlaps the main body case 7 from above, and a filter element (not shown) sandwiched between them.

The cover case 8 has a downwardly open tray shape, and each corner is fixed to the main body case 7 by a substantially C-shaped clip 9 . Therefore, the cover case 8 of this embodiment is detachable. Therefore, an enclosing rim 10 is arranged outside the opening edge of the cover case 8, and the clip 9 is hooked on the rim 10 against elasticity. A purified air outlet 11 protrudes from the left side surface of the cover case 8 . In addition, the cover case 8 may be of an opening/closing type that rotates about one side thereof as a fulcrum.

The main body case 7 of the air cleaner 5 has a box-like shape with an upward opening. is locked at the point of A bracket portion 13 for fixing to the vehicle body frame is integrally formed on the outer surface and the inner corner portion of the body case 7 . The bracket portion 13 is fixed to a vehicle body frame (not shown) with bolts 14 via anti-vibration grommets.

As shown in FIGS. 4 and 5, the duct unit 6 includes a receiving plate 15 on which the main body case 7 is overlapped and fixed. It forms an outlet 16 . The receiving plate 15 and the bottom surface of the main body case 7 are fixed (bonded) by welding such as vibration welding. As shown in FIG. 4A, grid-like ribs 17 for welding or the like are formed on the upper surface of the receiving plate 15 (only a portion of the ribs 17 are shown in FIG. 5A). not).

As shown in FIGS. 3 to 5, the duct unit 6 is made up of a pair of shell-shaped members, a left shell-shaped member 18 and a right shell-shaped member 19. Both shell-shaped members 18 and 19 are overlapped and welded by vibration welding or the like. It has an intake duct 20 and first and second resonators 21 , 22 . Accordingly, both shell-shaped members 18 and 19 are formed with a bulging portion forming the intake duct 20 and a bulging portion forming the resonators 21 and 22 . The above-described receiving plate 15 is integrally formed on the upper end of the right shell-shaped member 19 .

In FIGS. 3 and 5, the welded surfaces (overlapping surfaces) of both shell-shaped members 18 and 19 are indicated by hatching (thus, in FIGS. 3 and 5, hatching does not indicate a cross section). Although not shown, grooves are formed in the welding surfaces of both shell-shaped members 18 and 19 .

As shown in FIGS. 1, 3, and 5, the air intake duct 20 has a first vertically elongated portion 20a with an air intake port 23 open at the upper end through which air flows downward, and an outlet port 16 that opens at the upper end. It has a second vertically elongated portion 20b through which air flows upward, and a horizontally elongated portion (bottom portion) 20c that is connected to the lower ends of both of the vertically elongated portions 20a and 20b and through which air flows in a substantially horizontal direction. Therefore, the air intake duct 20 has a substantially U-shaped configuration when viewed from the side, and the resonators 21 and 22 are arranged in a space surrounded by the vertically elongated portions 20a and 20b and the horizontally elongated portion 20c.

A drain chamber 24 for discharging water protrudes downward at a corner portion where the first vertically elongated portion 20a and the bottom portion 20c are connected to each other. Therefore, in this embodiment, the first vertically elongated portion 20a is the vertically elongated portion described in the claims.

Since the upper end of the second vertically elongated portion 20b is open to the receiving plate 15, the second vertically elongated portion 20b is inevitably arranged below the air cleaner 5, but the upper end of the first vertically elongated portion 20a is above the air cleaner 5. It is almost the same height as the top. For example, as can be understood from FIG. 2, the intake port 23 opens in a substantially horizontal direction (lateral direction) toward the cover case 8 of the air cleaner 5 .

Therefore, although the upper half of the first longitudinally elongated portion 20a is arranged in front of the air cleaner 5, the resonators 21 and 22 are arranged below the air cleaner 5, so the lower half of the first longitudinally elongated portion 20a is arranged in the lower half. , is bent so as to enter below the air cleaner 5 .

The first vertically elongated portion 20a is bent at a gentle angle, and the radius of curvature of the connecting portion between the first vertically elongated portion 20a and the horizontally elongated portion 20c is made as large as possible. Furthermore, the connecting portion between the laterally elongated portion 20c and the second longitudinally elongated portion 20b is largely curved, and the second longitudinally elongated portion 20b itself is also curved so as to bulge outward from the vehicle body.

The first resonator 21 is arranged close to the first vertically elongated portion 20a, and its lower end communicates with the horizontally elongated portion 20c through the first communication passage 25. As shown in FIG. On the other hand, the second resonator 22 is housed in a recess formed by outwardly curving the second vertically elongated portion 20b, and its lower end is connected to the second resonator 22 via a second communicating passage 26. It communicates with the lower portion of the vertically elongated portion 20b. As shown in FIGS. 3 and 5A, inside the resonators 21 and 22, vertical and horizontal internal ribs 27 are formed to intersect each other in a grid pattern when viewed from the side. As shown in FIGS. 1 and 3 , the right shell-shaped member 19 and the receiving plate 15 are connected by a large number of ribs 29 .

(2) Drain Structure As can be understood from FIGS. 3 and 5, the drain chamber 24 is formed by extending the first vertically elongated portion 20a downward, and therefore protrudes downward beyond the horizontally elongated portion 20c. The drain chamber 24 has a bottom plate 30 and a check valve 31 is attached to the bottom plate 30 of the right shell member 19 . The check valve 31 is closed by being attracted to the bottom plate 30 when the engine is running and the intake duct 20 is in a negative pressure state, and is opened when the operation is stopped and the intake duct 20 becomes atmospheric pressure. there is

The check valve 31 of this embodiment is clearly shown in FIG. 4(C). That is, the check valve 31 is made of a moderately elastic soft material such as rubber or elastomer. ) and the engaging projection 31b. On the other hand, as shown in FIG. 4B, for example, the engagement projection 31b of the check valve 31 is fitted into the bottom plate 30 of the right shell-shaped member 19 from below against its elasticity and is held so as not to fall off. and a plurality of (three) drain holes 33 formed around the mounting hole 32 .

When the engine is running, the check valve 31 is sucked upward by the negative pressure, and the valve plate 31a is in close contact with the lower surface of the bottom plate 30. When the engine is stopped, the check valve 31 is pulled up by its own weight and drains. It is moved downward by the hydraulic pressure of the water accumulated in the chamber 24. - 特許庁Then, the drain hole 33 is released from the check valve 31, and the water accumulated in the drain chamber 24 is discharged downward.

In the embodiment, the check valve 31 is of a lifting type, but the valve plate 31a may be bent and deformed by the weight of water, as indicated by the dashed line in FIG. 5(C). Alternatively, the structure may be such that the valve plate 31a is in an open state indicated by the dashed line in FIG. 5(C) when the engine is stopped, and the valve plate 31a is rotated upward by the suction action of the negative pressure during operation.

In the case of the elevating type check valve 31, the material does not have to be made of an elastic material, and plastic or metal can also be used. A check valve using a spring or a plate spring can also be used, but the use of an elevating or rotating check valve as in the present embodiment has the advantage of simplifying and reducing the thickness of the structure.

The attachment hole 32 and the drain hole 33 may be formed by drilling, or the shell-shaped members 18 and 19 may be molded with these holes formed.

An eave-like guide portion 34 that covers the drain chamber 24 is formed above the drain chamber 24 . The connecting portion between the first vertically elongated portion 20a and the horizontally elongated portion 20c is largely curved, but the guide portion 34 is curved in a shape that matches the same degree of curvature of the connecting portion between the first vertically elongated portion 20a and the horizontally elongated portion 20c. ing.

A slit 35 that opens toward the tip of the guide portion 34 is formed as a drain port in the guide portion 34 . Although only one slit 35 is formed at the joint surface of both shell-shaped members 18 and 19, a plurality of slits 35 may be arranged in front and behind, or one or a plurality of small holes may be formed as drain holes. You may In addition, in this embodiment, the guide portion does not touch the horizontally long portion 20c, but is interrupted in front of the horizontally long portion 20c. Since it is located at the lower end, water (grains of sand) entering the intake duct 20 always flows into the drain chamber 24. - 特許庁

As described above, in the present embodiment, since the guide portion 34 is formed at the corner portion, the air flowing down the first vertically elongated portion 20a smoothly changes direction at the guide portion 34 and flows to the horizontally elongated portion 20c. go. Therefore, it is possible to suppress the pressure loss and contribute to the improvement of fuel consumption, and realize stable operation.

Even if water droplets are contained in the air, the water droplets pass through the slit 35 and flow into the drain chamber 24 where they accumulate. be. Sand grains can be discharged in the same way. In the present embodiment, even if water droplets pass through the drain chamber 24 , they can be prevented or significantly suppressed from entering the air cleaner 5 because of the presence of the second vertically elongated portion 20 b. Water that has returned to the laterally elongated portion 20c without being able to rise through the second longitudinally elongated portion 20b can be discharged back to the drain chamber 24 when operation is stopped by the arrangement of the duct and the drain chamber described above. It can also be evaporated.

In this embodiment, the drain chamber 24 is covered with the curved guide portion 34 almost entirely except for the end of the guide portion 34, so that the air is smoothly guided to the laterally elongated portion 20c without flowing into the drain chamber 24. Moreover, since the guide portion 34 functions as a lid for the drain chamber 24, the water that has flowed into the drain chamber 24 does not blow back. Therefore, water can be stored in the drain chamber 24 while minimizing the downward projection dimension of the drain chamber 24 as much as possible. Therefore, even if the installation space for the air intake parts is narrow, such as in a one-box light van, the air intake parts can be arranged without impairing the function.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, it can also be applied to an L-shaped air intake duct consisting of one vertically elongated portion and one horizontally elongated portion.

The present invention can be embodied in an intake system for an engine. Therefore, it can be used industrially.

REFERENCE SIGNS LIST 1 intake device 4 engine 5 air cleaner 6 duct unit 18 left shell-shaped member 19 right shell-shaped member 20 intake duct 20a first vertically elongated portion 20b second vertically elongated portion 20c horizontally elongated portion (bottom portion)
21, 22 resonator 23 intake port 24 drain chamber 31 check valve 34 guide portion 35 slit

Claims (1)

A vertically elongated portion through which air flows downward, and a horizontally elongated portion into which the air passing through the vertically elongated portion changes direction and flows in,
a drain chamber formed by extending the vertically elongated portion downward at a corner portion where the vertically elongated portion and the horizontally elongated portion are connected; and a guide portion that covers the drain chamber from above and changes the direction of air to the horizontally elongated portion. is provided, and the guide portion has a drain opening consisting of a slit or a hole,
Intake duct for the engine.

Images