JP3409691B2 - Engine soundproof structure and soundproof cover - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine soundproof structure and a soundproof cover for reducing engine noise.

[0002]

2. Description of the Related Art As an engine is operated, various noises such as an explosion sound due to combustion of fuel in a cylinder and operating noises of intake and exhaust valves are generated from the engine. Conventionally, a soundproof cover has been used to prevent such noise from leaking to the outside. For example, actual Kaihei 5
In the "engine sound insulation device" described in JP-10755, the engine is covered with the sound insulation cover by fixing the sound insulation cover to the engine with a plurality of bolts.

By attaching the soundproof cover to the engine, it is possible to reduce the noise emitted from the engine, but the soundproof cover vibrates due to the vibration of the engine. There is a possibility that it may become a noise source.

Therefore, conventionally, when fixing the soundproof cover, a rubber mount is used to elastically support the soundproof cover to reduce the vibration of the engine propagating to the soundproof cover.

[0005]

However, such a structure in which the soundproof cover is elastically supported is effective in blocking the propagation of high frequency components of the vibration components of the engine, but the so-called "chattering". The effect of blocking the propagation of low frequency components that cause "sound" is relatively small. Also,
If a rubber mount with a relatively low elastic modulus is adopted, the chatter noise reduction effect can be improved, but considering that it is necessary to securely fix the soundproof cover to the engine, these measures are naturally necessary. There is a limit.

Therefore, in order to reliably reduce chattering noise, in addition to the elastic support structure as described above, the number of fixing portions of the soundproof cover is increased to increase the support rigidity thereof, or the thickness of the soundproof cover is increased. It is necessary to take measures to increase the rigidity and increase the rigidity. However, if the number of fixing portions of the soundproof cover is increased or the thickness of the soundproof cover is increased in this way, the number of parts such as bolts and the weight of the soundproof cover are increased.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce chatter noise generated in the soundproof cover without increasing the number of parts and the weight of the soundproof cover. It is to provide a soundproof structure and a soundproof cover for an engine.

[0008]

In order to achieve the above object, according to the invention as set forth in claim 1, in an engine soundproof structure including a soundproof cover fixed to the engine so as to cover the engine, at least one of the soundproofing covers, wherein the solid stereotactic location a respective different positions and
The soundproof cover is provided with a contact portion which is formed at a position where the vibration amplitude is maximized and which comes into contact with the other of the engine and the soundproof cover. In the present specification, the "engine" includes not only the engine body but also members constituting the intake system and the exhaust system connected to the engine, and the components attached to or near the engine. Included are the auxiliary equipment etc.

With the above arrangement, since the contact contact portion formed on at least one of the engine and the soundproof cover is in contact with the other of the engine and soundproof cover, the support rigidity of the soundproof cover is increased, the vibration in the soundproof cover The occurrence will be suppressed. Then, in order to further enhance the inhibitory effect on the occurrence of such vibration, it is desirable that the front SL contact portion is formed at a position where the amplitude of the vibration of the sound insulation cover is maximized.

[0010] In the invention according to claim 2, in soundproof structure for an engine according to claim 1, the contact portion is assumed to form a convex shape. According to the above configuration, the claims
In addition to the effect of the invention described in 1, the contact surface pressure between the contact portion and the other of the engine and the soundproof cover increases, so that the vibration of the soundproof cover is further suppressed.

[0011] In the invention according to claim 3, also claim 1
In the engine soundproof structure described in No. 2 , the contact portion is in contact with the other of the engine and the soundproof cover through the elastic member.

According to the above construction, in addition to the operation of the invention described in claim 1 or 2 , the vibration propagating from the engine to the soundproof cover is damped by the elastic member. According to the invention described in claim 4 , in the soundproof structure for an engine according to claim 3 , the elastic member is a sound absorbing material provided on a surface of the soundproof cover that covers the engine.

According to the above construction, in addition to the function of the invention described in claim 3 , it is not necessary to separately provide an elastic member. In the invention according to claim 5, in soundproof cover which is fixed to the engine so as to cover the engine, before Symbol
Solid and place a respective different position and the soundproof cover of the vibration
A contact portion is formed at a position where the amplitude is maximized and comes into contact with the engine.

With the above arrangement, since the contact contact portion is in contact with the engine, the support rigidity of the soundproof cover is increased, occurrence of vibration in soundproof cover is suppressed.
Then, in order to further enhance the inhibitory effect on the occurrence of such vibration, it is desirable that the front SL contact portion is formed at a position where the amplitude of the vibration of the sound insulation cover is maximized.
According to the sixth aspect of the invention, in the engine soundproof cover according to the fifth aspect , the contact portion has a convex shape.

According to the above construction, in addition to the action of the invention described in claim 5 , the contact surface pressure between the contact portion and the engine increases, so that the vibration of the soundproof cover is further suppressed. .

In the invention described in claim 7 , the invention according to claim 5 or
In the engine soundproof cover described in 6 , the contact portion is covered with an elastic member. According to the above configuration, in addition to the action of the invention described in claim 5 or 6 , the vibration propagating from the engine to the soundproof cover is damped by the elastic member.

According to the invention described in claim 8 , the elastic member is a sound absorbing member provided on the surface covering the engine. According to the above configuration, in addition to the effect of the invention described in claim 7 , it is not necessary to separately provide an elastic member.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 is a side view showing an engine 10 and a soundproof cover 20 attached so as to cover an upper portion of the engine 10, and FIG.
FIG. 3 is a perspective view showing the soundproof cover 20.

As shown in FIG. 1, an engine 10 in this embodiment is a V-type engine mounted on a vehicle, and is provided in a cylinder block 11, a left bank 10L and a right bank 10R of the cylinder block 11, respectively. Cylinder heads 12L, 12R, both banks 10L, 1
The intake manifold 13 provided between 0R, the resonator 14 connected to the intake manifold 13, and the like are provided.

A plurality of cylinders (not shown) are formed inside each of the banks 10L and 10R.
An intake valve and an exhaust valve (both not shown) are provided in L and 12R corresponding to each of these cylinders. These valves are cylinder heads 12L and 12R.
Intake camshafts 15L and 15R respectively provided in the
And is opened and closed by the exhaust camshafts 16L and 16R.

Further, the intake camshafts 15L, 15R
Is connected by a timing belt 18 to a crankshaft 17 that rotates in synchronization with the reciprocating movement of a piston (not shown) provided in each cylinder. On the other hand, the exhaust camshafts 16L and 16R are connected to the corresponding intake camshafts 15L and 15R by gears (not shown). Therefore, when the crankshaft 17 rotates, each camshaft 15L, 15R, 16L,
16R rotates, and further, each cam shaft 15L, 1
Each bank 10 in synchronization with the rotation of 5R, 16L, 16R
The intake valves and the exhaust valves of L and 10R are opened and closed at a predetermined timing.

The intake manifold 13 is the engine 1
It constitutes a part of the intake system of 0 and is connected to a throttle body (not shown) via an intake pipe 13a. The intake air introduced into the intake manifold 13 via the throttle body is supplied to each bank 10
It is adapted to be introduced into each cylinder (not shown) formed in L and 10R.

The resonator 14 has a substantially rectangular parallelepiped shape as a whole, and is connected to the intake pipe 13a by a connection pipe 14a. The resonator 14 is for reducing intake noise generated when intake air passes through the intake system by a resonance action.

The soundproof cover 20 is intended to prevent noise such as the operating noise of the intake valve and the exhaust valve and the explosion noise of the fuel in the cylinder from leaking above the engine 10. The soundproof cover 20 is a polyamide resin having excellent heat resistance. It is formed of a synthetic resin material such as. As shown in FIG. 2, the soundproof cover 20 includes a rectangular upper plate 21 and a rectangular upper plate 2.
1 and a side plate 22 extending downward from the peripheral edge portion. A rectangular opening 21a is formed in the center of the upper plate 21, and a plurality of mounting holes 21b are formed around the opening 21a. As shown in FIG. 1, the upper plate 21 is partially tightened and fixed to the intake manifold 13 by bolts 26 inserted into the mounting holes 21b. Further, by mounting the soundproof cover 20 on the engine 10 in this manner, a part of the intake manifold 13 is exposed from the opening 21a.

The lower surface of the upper plate 21, that is, the engine 10
A sheet-shaped sound absorbing material 28 is attached to the surface that covers the entire surface so as to cover almost the entire surface. The sound absorbing material 28 is formed of a felt material made of synthetic resin such as polyester resin having excellent heat resistance.

FIG. 3 is a partial sectional view showing the shape of the soundproof cover 20 in the vicinity of the resonator 14, and FIG. 4 is a sectional view taken along line 4-4 of FIG. As shown in these drawings, the surface of the upper plate 21 that covers the engine 10 is
A pair of protrusions 25 protruding toward the intake manifold 13 side
a and 25b are integrally formed at a predetermined interval. Each of these convex portions 25a and 25b is covered with a sound absorbing material 28. The lower surfaces of the respective convex portions 25a and 25b are in contact with the upper surface of the resonator 14 via the sound absorbing material 28. Further, when the bolts 26 are tightened, the portions of the sound absorbing material 28 sandwiched between the convex portions 25a and 25b and the resonator 14 are elastically deformed.

The protrusions 25a and 25b serve to suppress the vibration of the soundproof cover 20 by increasing the supporting rigidity of the soundproof cover 20. Therefore, it is preferable that the convex portions 25a and 25b are formed at positions where the amplitude of the vibration becomes maximum when the soundproof cover 20 vibrates while being attached to the intake manifold 13, and more specifically, Is preferably formed at a position fixed to the intake manifold 13, that is, at a position sufficiently separated from the mounting hole 21b. In consideration of these points, in the present embodiment, each of the convex portions 25a and 25b is formed near the peripheral portion of the upper plate 21.

According to the present embodiment configured as described above, the following effects can be obtained. (1) In the present embodiment, since the convex portions 25a and 25b are brought into contact with the resonator 14 via the sound absorbing material 28,
Since the support rigidity of the soundproof cover 20 is increased, the soundproof cover 20
The generation of vibrations in the will be suppressed. Therefore,
In order to suppress the occurrence of vibration in the soundproof cover 20,
For example, it is not necessary to increase the number of parts fixed to the intake manifold 13 to increase the support rigidity of the soundproof cover 20, or increase the thickness of the soundproof cover 20 to increase the rigidity of the soundproof cover 20 itself. As a result, according to this embodiment, the chatter noise generated in the soundproof cover 20 can be reduced without increasing the number of parts and the weight of the soundproof cover 20.

(2) In particular, in this embodiment, the portion of the soundproof cover 20 to be brought into contact with the resonator 14 (the convex portion 2).
5a, 25b) are formed in a convex shape projecting to the resonator 14 side, the soundproof cover 20 and the resonator 14 can be compared with, for example, a configuration in which the soundproof cover 20 is brought into contact with the entire upper surface of the resonator 14. The surface pressure at the contact portion with increases. As a result, the occurrence of vibration in the soundproof cover 20 is further suppressed, and chatter noise can be reduced more reliably.

(3) Further, in the present embodiment, since the convex portions 25a and 25b which come into contact with the resonator 14 are covered with the sound absorbing material 28, the vibration propagating between the resonator 14 and the soundproof cover 20 absorbs sound. The material 28 attenuates. As a result, according to this embodiment, the chatter noise can be reduced more reliably.

(4) In order to damp the vibration propagating between the resonator 14 and the soundproof cover 20 as described above, an elastic member such as rubber having a large damping property is provided between the convex portions 25a and 25b and the resonator 14. It is also possible to adopt a configuration in which

In this respect, in this embodiment, since the sound absorbing material 28 of the soundproof cover 20 covers each of the convex portions 25a and 25b, it is not necessary to separately provide such an elastic member. Therefore, according to the present embodiment, the structure of the soundproof cover 20 can be simplified.

(5) Further, in order to effectively suppress the vibration of the soundproof cover 20, it is desirable that the contact surface pressure between the convex portions 25a and 25b and the resonator 14 is large. For example, in the side plate 22 of the soundproof cover 20, the resonator 14
Even if the convex portion projecting from the resonator 14 is formed at a portion (indicated by an arrow A in FIG. 3) facing to the resonator 14 and the convex portion abuts on the resonator 14, the soundproof cover 20 vibrates. Can be suppressed. However, in such a configuration, the contact surface pressure between the convex portion and the resonator 14 becomes small, and the vibration suppressing effect thereof becomes relatively small.

In this respect, in the present embodiment, by tightening the bolts 26, it is possible to press the respective convex portions 25a and 25b against the resonator 14, so that the respective convex portions 25 are formed.
The contact surface pressure between a and 25b and the resonator 14 can be set sufficiently large. As a result, according to the present embodiment, it is possible to effectively suppress the vibration of the soundproof cover 20 and reliably reduce chatter noise.

The above-described embodiment described above can be modified in configuration as follows. -In the said embodiment, the convex parts 25a and 2 are attached to the soundproof cover 20.
5b is formed, and the convex portions 25a and 25b are brought into contact with the resonator 14 via the sound absorbing material 28. On the other hand, a convex portion may be formed on the upper surface of the resonator 14, and the convex portion may be brought into contact with the soundproof cover 20 via the sound absorbing material 28. Further, portions corresponding to the convex portions 25a and 25b may be formed on both the soundproof cover 20 and the resonator 14. Even with this configuration, it is possible to achieve the same effects as the present embodiment.

The convex portions 25a and 25b are members other than the resonator 14, for example, members constituting an intake system or the engine 1.
0 may be attached to or may be brought into contact with an accessory device or the like arranged in the vicinity thereof.

The convex portions 25a and 25b are not necessarily limited to the shapes shown in FIGS. 3 and 4, and may be, for example, cylindrical or the like, and the number thereof may be arbitrary. Also,
The convex portions 25a and 25b may be brought into contact with different members.

The material for forming the soundproof cover 20 and the sound absorbing material 28 may be a material other than the exemplified polyamide resin or polyester resin as long as it has excellent heat resistance. Further, the engine 10 is not limited to one mounted on a vehicle, and may be, for example, a marine engine or a stationary power engine. Furthermore, the engine is not limited to the V-type engine, and may be, for example, an in-line engine.

[0039]

In the invention described, according to the present invention in claim 1, the engine and at least one of the soundproof cover is solid localization location A of each different position of the engine and the soundproof cover and soundproof cover
Is provided at a position where the amplitude of the vibration is maximized, and the contact portion comes into contact with the other of the engine and the soundproof cover. Therefore, when the contact portion comes into contact with the other of the engine and the soundproof cover, the support rigidity of the soundproof cover is increased, and the vibration of the soundproof cover is suppressed. As a result, the chatter noise generated in the soundproof cover can be reduced without increasing the number of parts and the weight of the soundproof cover. Further, since the upper SL contact portion which may be formed on the position where the amplitude of the vibration of the sound insulation cover is maximized, generation of vibration in the soundproof cover is to be further suppressed.

In particular, according to the second aspect of the invention, since the contact portion has a convex shape, the contact surface pressure between this contact portion and the other of the engine and the soundproof cover increases. As a result, the occurrence of vibration in the soundproof cover is further suppressed, and chatter noise can be reduced more reliably.

Further, in the invention described in claim 3 , since the contact portion is brought into contact with the other of the engine and the soundproof cover through the elastic member, the vibration propagating from the engine to the soundproof cover is elastic member. Will be attenuated by. As a result, in addition to the effect of the invention described in claim 1 or 2 , chatter noise can be further reliably reduced.

Further, in the invention described in claim 4 , since the elastic member is a sound absorbing material provided on the surface of the soundproof cover that covers the engine, it is not necessary to separately provide an elastic member and the structure is simplified. be able to.

[0043] In the invention as set forth in claim 5, a respective different position from the solid-localization location of the engine and the vibration of the sound insulation cover
Has a contact portion that is formed at a position where the amplitude of is maximum and that contacts the engine. Therefore, when the contact portion comes into contact with the engine, the support rigidity of the soundproof cover increases, and the occurrence of vibration in the soundproof cover is suppressed. As a result, the chatter noise generated in the soundproof cover can be reduced without increasing the number of parts and the weight of the soundproof cover. Further, since the upper SL contact portion which may be formed on the position where the amplitude of the vibration of the sound insulation cover is maximized, generation of vibration in the soundproof cover is to be further suppressed.

Particularly, in the invention described in claim 6 , since the contact portion has a convex shape, the contact surface pressure between the contact portion and the engine increases. As a result, the occurrence of vibration in the soundproof cover is further suppressed, and chatter noise can be reduced more reliably.

Further, in the invention described in claim 7 , since the contact portion is brought into contact with the engine through the elastic member, the vibration propagating from the engine to the soundproof cover is damped by the elastic member. As a result, the claims
In addition to the effect of the invention described in 5 or 6 , chatter noise can be reduced more reliably.

Further, in the invention described in claim 8 , since the elastic member is a sound absorbing material provided on the surface of the soundproof cover that covers the engine, it is not necessary to separately provide an elastic member, and the structure is simplified. be able to.

[Brief description of drawings]

FIG. 1 is a side view of an engine having a soundproof cover attached thereto.

FIG. 2 is a perspective view of a soundproof cover.

FIG. 3 is a partially enlarged sectional view showing a contact portion formed on the soundproof cover.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

[Explanation of symbols]

10 ... Engine, 10L ... Left bank, 10R ... Right bank, 11 ... Cylinder block, 12L, 12R ... Cylinder head, 13 ... Intake manifold, 13a ... Intake pipe, 14 ... Resonator, 14a ... Connection pipe, 15L, 15R ... Intake Camshaft, 16L, 16
R ... Exhaust camshaft, 17 ... Crankshaft, 18
... Timing belt, 20 ... Soundproof cover, 21 ... Top plate,
21a ... Opening part, 22 ... Side plate, 21b ... Mounting hole, 25
a, 25b ... convex portion, 26 ... bolt, 28 ... sound absorbing material.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02B 77/13 F02B 77/11

Claims (8)

(57) [Claims] 1. A soundproof structure for an engine, comprising a soundproof cover fixed to the engine so as to cover the engine, wherein at least one of the engine and the soundproof cover is provided.
Wherein the solid stereotactic location a respective different position and the soundproof cover
The soundproof structure for an engine, comprising a contact portion formed at a position where the amplitude of the vibration is maximized and contacting the other of the engine and the soundproof cover. 2. The soundproof structure for an engine according to claim 1, wherein the contact portion has a convex shape . 3. The contact portion is provided with an elastic member through the end portion.
The soundproof structure for an engine according to claim 1 or 2, wherein the soundproof structure contacts the other of the gin and the soundproof cover . 4. The soundproof cover is provided with the elastic member.
The soundproof structure for an engine according to claim 3 , wherein the soundproof structure is a sound absorbing material provided on a surface that covers the engine. 5. An engine fixed to cover the engine.
In the soundproof cover that is specified, separate from the fixed position
Position and the vibration amplitude of the soundproof cover is the largest.
Contacting portion formed at a closed position and contacting the engine
A soundproof cover for an engine, which is provided with. 6. The contact portion has a convex shape.
A soundproof cover for an engine according to claim 5 . 7. The soundproof cover for an engine according to claim 5, wherein the contact portion is covered with an elastic member . 8. The elastic member is provided on a surface that covers the engine.
The sound absorbing material provided, according to claim 7,
Soundproof cover for the engine.