JPH09280124A - Air intake device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the easy mounting and removing operation of a carburetor and reduce air intake noises and increase a sound insulation effect in an air intake device. SOLUTION: In an air intake device of an engine which connects an intake air outlet port 6a of an air cleaner 6 or an intake air inlet port 4a of a carburetor 4 with a flexible carburetor boot 9, the peripheral surface of the carburetor boot 9 is wrapped by a division-type boot cover 10 via vibration damping member 13, 14. If the division-type boot cover 10 is removed, the carburetor 4 can be easily removed by using the flexibility of the carburetor boot 9. If the boot cover 10 is mounted via the vibration damping member 13, 14, air intake noises are reduced. In an engine having a plurality of cylinders, the boot cover 10 is composed of a pair of cover members 11, 12 which are made by integrally connecting in parallel half cylindrical portions corresponding to each carburetor boot 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine intake system in which an intake port of an air cleaner and an intake port of a carburetor are connected by a carburetor boot, and more particularly,
The present invention relates to an intake device suitable for an engine, such as a motorcycle, in which a space for disposing a carburetor or an air cleaner is limited.

[0002]

2. Description of the Related Art In a motorcycle or the like in which an engine space is limited, a flexible carburetor boot is generally mounted in order to ensure workability when the carburetor is assembled. The carburetor is connected by bending it to, and after connection, it is returned to its normal position. As a related technique, there is JP-A-62-91648.

[0003]

However, when the carburetor boot is made of a flexible material, the carburetor boot vibrates greatly due to engine vibration during engine operation, and the intake pulsation from the inside of the crankcase causes the carburetor boot to move. It is propagated to the outside through the wall surface and causes noise to increase. The same applies to the transmitted sound of the intake noise of the air cleaner.

On the other hand, if the carburetor boot is made of an inflexible material, it becomes difficult to attach the carburetor. Especially, it becomes difficult to remove only the carburetor for inspection and repair of the carburetor.

[0005]

An object of the present invention is to suppress the vibration of the carburetor boot and to prevent the intake pulsation in the engine from being propagated to the outside through the carburetor boot, while ensuring the workability of mounting the carburetor as before. The purpose is to prevent the transmitted sound of the intake noise from the boot and to increase the sound insulation effect.

[0006]

In order to achieve the above object, the invention according to claim 1 of the present application is an intake device for an engine in which an intake outlet of an air cleaner and an intake inlet of a carburetor are connected by a flexible carburetor boot. In the air intake device of the engine, the outer peripheral surface of the carburetor boot is wrapped with a split type boot cover via a damping material such as sponge or rubber.

The invention according to claim 2 is characterized in that a damping material is attached to the inner peripheral surface of the boot cover in order to facilitate the mounting work of the boot cover. It is a device.

According to a third aspect of the present invention, in the intake system for an engine according to the first aspect including a plurality of cylinders and carburetors for each cylinder, the boot cover has a half-cylindrical portion corresponding to each carburetor boot. An intake device for an engine, comprising: a pair of cover members integrally connected in parallel.

[0009]

1 to 5 show an example in which the present invention is applied to an intake system of a four-cylinder engine for a motorcycle,
In FIG. 1 showing a plan view, four intake ports for each cylinder are formed on the rear surface of the engine 1 on the same straight line, for example, and a carburetor 4 is connected to each intake port via an insulator 3, respectively. ing.

The air cleaner 6 is arranged further rearward of the carburetor 4 and has an intake inlet 4 of each carburetor 4.
A and the outlet 6a of the air cleaner 6 are connected by a cylindrical carburetor boot 9 made of a material having flexibility such as butyl rubber.

A boot cover 10 for enclosing the four carburetor boots 9 has a pair of upper and lower cover members 11 and 12 and a pair of upper and lower damping materials 13 and 1 as shown in FIG.
4, the cover members 11 and 12 are made of hard resin plastic, and the vibration damping members 13 and 14 are made of plastic.
Is made of sponge.

The upper cover member 11 includes four downward-opening half-split cylindrical portions 11a, a flat connecting portion 11b for connecting the lower ends of these half split cylindrical portions 11a, and horizontal end portions 11c. And both ends 11c
Long holes 15 for fastening are formed in each of them. The upper damping material 13 is stretched over the entire inner peripheral surface (lower surface) of the upper cover member 11, and its thickness t is equal to the half-cylindrical portion 11.
A is uniformly thick (for example, 10 mm to 20 mm), and is thinner (for example, about 5 mm) at the connecting portion 11b and the end 11c.

In FIG. 4, the inner diameter of the damping material 13 is set smaller than the outer diameter of the carburetor boot 9 in the free state (non-wearing state).
When mounted on the boot 9, a compression margin of about 2 to 4 mm is secured so that the boot 9 comes into close contact with the outer peripheral surface thereof.

Lower cover member 12 and lower damping material 14
Has a vertically symmetrical shape except that the upper cover member 11 and the upper damping material 13 are provided with a protrusion 18 that engages with the elongated hole 15 as a fastening means.
It has two half-cylindrical portions 12a, a planar connecting portion 12b for connecting them, and horizontal end portions 12c. The protrusion 18 projects upward and has an engaging bulge 18a as shown in FIG. 5, and the bulge 18a is formed with an inclined surface that expands outward as it goes downward.

When the carburetor 4 is attached, the boot cover 10 is not attached. Therefore, the carburetor boot 9 is bent in a convenient direction to connect the carburetor 4, and after the connection, the carburetor 4 is attached. Return to the normal position as shown in 2.

Next, as shown in FIG. 4, the upper and lower cover members 11 and 12 are inserted from the side into the upper and lower spaces of the carburetor boot 9, respectively, and are wrapped around the outer peripheral surface of the carburetor boot 9 as shown in FIG. By fitting and engaging the projections 18 at both ends with the elongated holes 15, both cover members 11, 1
Combine 2 permanently. When engaging the protrusion 18 with the elongated hole 15, the protrusion 18 passes through the elongated hole 15 while bending toward the half-divided cylindrical member side in FIG. 5, and after the insertion, the bulging portion 18 is inserted.
Returns to its original posture and engages with the edge of the elongated hole 15.

In the mounted state, the damping materials 13 and 14 are
The outer boot covers 11 and 12 are pressed and compressed with a constant pressure, and thereby, they are in close contact with the outer peripheral surface of the carburetor boot 9.

If the boot cover 10 is to be removed, FIG.
While pushing the bulging portion 18a of the protrusion 18 toward the half-divided cylindrical member side, the protrusion 18 is removed from the elongated hole 15.

[0019]

[Other Embodiments]

(1) Needless to say, the present invention can be applied to a single-cylinder engine or a multi-cylinder engine other than four-cylinder engine. Also in the case of a single cylinder, as in the case of a plurality of cylinders, it is composed of a pair of cover members having a half-split cylindrical portion,
It is not limited to the upper and lower halves but may be the right and left halves.

(2) FIG. 6 shows an example in which the damping material 23 is independently attached to the carburetor boot 9 without being attached to the inner peripheral surface of the boot cover 11. The damping material 23 is for each boot 9
Is formed into a cylindrical shape for use with a cut 23a,
The boots 9 are fitted to the outer circumference of the boots 9, respectively. And
A pair of upper and lower cover members 1 are provided on the outer periphery of the damping material 23.
1 and 12 are fitted so as to compress the damping material 23 with a constant pressure.

Since the damping material 23 itself is made of sponge or a similar material, the boot covers 11, 12
It is possible to bend together with the carburetor boot 9 and the damping material 23 by removing only the carburetor boot 9. Therefore, even if the damping material 23 is attached, the carburetor 4 can be easily attached and detached. Further, the damping material 23 can be detached from the boot 9 by itself by opening it from the cut 23a.

(3) In the structure in which the damping material is attached to the inner peripheral surface of the boot cover, the damping material may be attached only to the inner peripheral surface of the half-cylindrical portion.

(4) The means for connecting the upper and lower boot covers are
The long hole and the projection are not limited, and various combinations such as a dovetail groove and a streak-like projection fitted into the dovetail groove are conceivable.

(5) The boot cover is not limited to the hard plastic made of resin, and may be made of metal.

As the damping material, soft rubber can be used in addition to sponge.

[0026]

As described above, according to the present invention, (1) flexible carburetor boot 9 and damping material 1
Since the boot cover 10 that wraps it through 3.14 is a separate body, and the boot cover 10 is a split type, the boot cover 10 must be removed when installing and removing the carburetor 4. By freely bending the carburetor boot 9 in a desired direction, the carburetor 4 can be easily attached and detached.

(2) Since the boot cover 10 is fitted to the outer periphery of the carburetor boot 9 via the damping materials 13 and 14, engine vibration and boot vibration due to intake pulsation can be suppressed, and intake noise can be reduced. Suppresses the transmitted sound of
Moreover, the sound insulation effect can be increased.

(3) That is, as in the effect (1), the intake noise can be reduced as in the effect (2) while maintaining the ease of the work of attaching and detaching the carburetor.

(4) Since the boot cover 10 is of a split type, the boot cover 10 can be easily removed from the outside even when the carburetor 4 is attached, which is suitable for a motorcycle having a large space limitation.

(5) When the damping materials 13 and 14 are attached to the inner surface of the boot cover 10 as in the second aspect of the invention, the boot cover 10 and the damping materials 13 and 14 can be mounted simultaneously. The mounting work becomes easier.

(6) As in the third aspect of the invention, in a multi-cylinder engine, the upper and lower parts 1 formed by integrally connecting the half-split cylindrical parts corresponding to the carburetor boots 9 in parallel
When the boot cover 10 is configured by the pair of cover members 11 and 12, the effect of suppressing the vibration of each boot 9 is further improved, and the boot cover 10 is easily attached to the plurality of cylinders.

[Brief description of drawings]

FIG. 1 is a plan view of an intake device to which the present invention is applied.

FIG. 2 is a side view of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is an exploded vertical sectional view of FIG.

FIG. 5 is an enlarged cross-sectional view taken along line VV of FIG. 1;

FIG. 6 is an exploded vertical sectional view similar to FIG. 4 showing a modified example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 engine 4 carburetor 4a intake inlet 6 air cleaner 6a intake outlet 9 carburetor boot 10 boot cover 11 upper cover member 11a half-cylindrical part 12 lower cover member 12a half-cylindrical part 13 upper damping member 14 lower damping Vibration material 23 Damping material

Claims (3)

[Claims] 1. In an intake system for an engine, wherein an intake port of an air cleaner and an intake port of a carburetor are connected by a flexible carburetor boot, the outer peripheral surface of the carburetor boot is of a split type via a damping material. An air intake system for an engine, which is characterized by being wrapped in a boot cover. 2. The intake system for an engine according to claim 1, wherein a damping material is attached to the inner peripheral surface of the boot cover. 3. The intake system for an engine according to claim 1, further comprising a plurality of cylinders and carburetors for the respective cylinders, wherein the split type boot cover has half-cylindrical portions corresponding to the respective carburetor boots integrated in parallel. An engine intake device comprising a pair of cover members connected to each other.