GB2543333A

GB2543333A - Acoustic cover

Info

Publication number: GB2543333A
Application number: GB1518255.3A
Authority: GB
Inventors: Donna Davide; Ruotolo Romualdo
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2015-10-15
Filing date: 2015-10-15
Publication date: 2017-04-19
Also published as: GB201518255D0

Abstract

The present invention relates to an acoustic cover 100, in particular for a vehicle or an internal combustion engine, in particular of a vehicle, comprising a body with a surface 110 which is divided into a number of portions 11-16 by slots (21-25, fig.1) filled at least partially with an elastic filler 3 in particular Polyacrylate rubber or Ethylene acrylic rubber. The acoustic cover is essentially flat and made up of metal, a light metal alloy or in particular aluminium alloy and is contoured by forming, in particular stamping. The slots are configured such that the portions vibrate in counter phase with respect to one another if excited by at least one critical frequency of the vehicle of combustion engine. At least two of the slots draw a 30 degree angle at most and in particular at a least essentially align with one another. The slots are formed by molding.

Description

Acoustic Cover

Description

The present invention relates to an acoustic cover, in particular for an internal combustion engine and/or a vehicle, a drive engine comprising the cover, a vehicle comprising the cover and a method for manufacturing the cover respectively.

From JP 2010-236412 A an engine cover structure for covering a cylinder block of an internal combustion engine is known which is composed of three or more component surfaces, which are different in height so as to obtain a radiation suppression effect.

One object of the present invention is to provide an, in particular improved, reduction of noise, in particular of an internal combustion engine and/or a vehicle.

Said object is solved in particular by an acoustic cover according to present claim 1. Claims 10,12 and 13 refer to a drive engine comprising an acoustic cover as described herein, a vehicle comprising a cover, in particular a drive engine, as described herein and a method for manufacturing an acoustic cover as described herein respectively, sub-claims refer to advantageous embodiments.

According to one embodiment of the present invention an acoustic cover, in particular an acoustic cover for, in particular of, a vehicle or for, in particular of, an internal combustion engine, in particular an acoustic cover for, in particular of, an internal combustion engine of a vehicle, comprises a body with a surface which is divided or split respectively into a number of portions by slots, in particular cuts, which are fully or partially filled with an elastic filler.

According to one embodiment such portions, due to the elastic filler within the slots dividing the portions, can vibrate in counterphase one respect to the adjacent, thus providing an advantageous noise reducing effect according to one embodiment. Accordingly, two or more of the portions are configured so as to be able to vibrate in counterphase one respect to the adjacent according to one embodiment.

According to one embodiment the elastic filler can provide a damping effect, thus further reducing noise according to one embodiment.

According to one embodiment the surface is divided or split respectively into an even number of portions by slots, in particular cuts, which are fully or partially filled with the elastic filler. Additionally or alternatively the surface is divided or split respectively into two, four or more portions.

According to one embodiment due to an even number of portions the portions can compensate one another pairwise, thus further reducing noise according to one embodiment. According to one embodiment two or more portions may further reduce noise.

According to one embodiment the surface or cover respectively comprises one or more pairs of adjacent portions defined or divided by said slots respectively. According to one embodiment the adjacent portions of at least one such pair differ in size or surface area respectively not more than 50%, in particular not more than 30%, in particular not more than 20% from one another. According to one embodiment the adjacent portions of a first pair differ in size or surface area respectively not more than 50%, in particular not more than 30%, in particular not more than 20% from one another and the adjacent portions of at least one second pair differ in size or surface area respectively not more than 50%, in particular not more than 30%, in particular not more than 20% from one another. According to one embodiment one portion of the first pair and one portion of at least one such second pair differ in size or surface area respectively not more than 50%, in particular not more than 30%, in particular not more than 20% from one another according. Additionally or alternatively one portion of the first pair and one portion of at least one such second pair differ in size or surface area respectively for at least 20%, in particular for at least 30%, in particular for at least 50% from one another according to one embodiment. If the surface or cover respectively comprises two or more pairs of adjacent portions defined or divided by said slots respectively, one portion of one pair may be adjacent to one portion of at least one other, adjacent pair according to one embodiment. Thus, according to one embodiment there may just for example be four consecutive portions which define two adjacent pairs of adjacent portions accordingly.

According to one embodiment such portions can compensate one another pairwise, thus further reducing noise according to one embodiment. According to one embodiment similar sizes or surface areas respectively may further reduce noise due to vibration in counterphase. According to one embodiment different sizes or surface areas respectively between pairs of portions may further reduce noise with respect to different frequencies.

According to one embodiment one or more of the slots are through-holes reaching or going through the body or open into or connecting said surface which is divided into said portions and an opposite surface of the body respectively.

According to one embodiment this may allow larger amplitudes of the portions vibrating, in particular in counterphase one respect to the adjacent, thus further reducing noise according to one embodiment.

Additionally or alternatively one or more of said slots may be blind holes or pockets or closed with respect to a surface opposite to said surface which is divided into said portions. According to one embodiment also such dividing at one surface alone may already reduce noise according to one embodiment, in particular by defining or supporting according vibration patterns.

According to one embodiment the cover, in particular the body, is, at least essentially, flat. In particular its extension into one (height) direction, in particular perpendicular to said surface which is divided into said portions, may be smaller than 10%, in particular 1%, of its extension into two perpendicular (length and width) directions according to one embodiment.

According to one embodiment dividing a flat cover(‘s surface) or body(‘s surface) respectively into a number of portions by slots which are filled (at least partially) with an elastic filler may provide an advantageous noise reducing effect, in particular since portions may, at least essentially, vibrate in the same plane according to one embodiment.

According to one embodiment the slots or portions respectively are configured such that portions vibrate in counterphase one respect to the adjacent if excited by one or more critical frequencies of the vehicle or internal combustion engine respectively, in particular with the cover attached thereto. Such configuration may be found in particular by simulation and/or experiment according to one embodiment.

According to one embodiment a critical frequency of the vehicle or internal combustion engine respectively is a resonance or eigenfrequency and/or a machine order of the vehicle or internal combustion engine respectively, in particular with the cover attached thereto.

According to one embodiment the slots or portions respectively are configured such that an, in particular even, plurality of portions predominantly vibrate in counterphase one respect to the adjacent if excited by one critical frequency of the vehicle or internal combustion engine respectively and another, in particular even, plurality of portions predominantly vibrate in counterphase one respect to the adjacent if excited by another critical frequency of the vehicle or internal combustion engine respectively.

In other words the cover, in particular its slots and portions respectively, may be tuned in order to magnify a noise reduction effect at one or more critical frequencies of the vehicle or internal combustion engine respectively, in particular the most critical frequency/frequencies, according to one embodiment by configuring the slots accordingly, in particular by simulation and/or experiment.

According to one embodiment this may provide an advantageous noise reducing effect.

According to one embodiment the body is made one-piece, in particular single-layer. According to one embodiment the cover is made single-layer, said layer defined by the body.

According to one embodiment this may advantageously reduce weight and/or improve the noise reducing effect.

Additionally or alternatively the body is made from a metal, in particular a light metal alloy, in particular an aluminum alloy, according to one embodiment.

According to one embodiment the elastic filler comprises, in particular is, rubber.

According to one embodiment the rubber is molded and/or Polyacrylate rubber (“ACM”) and/or Ethylene Acrylic rubber (“AEM”).

According to one embodiment two or more, in particular adjacent, slots draw an angle of 30° at most, in particular of 10° at most, with one another. In particular two or more slots may at least essentially align with one another according to one embodiment. Additionally or alternatively two or more slots drawing an angle of 30° at most, in particular of 10° at most, with one another may be spaced apart from one another perpendicular to a lengthwise direction of the slots according to one embodiment. Additionally or alternatively two or more, in particular adjacent, slots draw an angle of at least 60°, in particular of at least 80°, with one another according to one embodiment. In particular at least two slots drawing an angle of 30° at most, in particular of 10° at most, with one another may be arranged on opposite sides of a further slot drawing an angle of at least 60°°, in particular of at least 80°, with these two slots according to one embodiment.

According to one embodiment this may improve the noise reducing effect, in particular provide an advantageous vibration pattern.

According to one embodiment the cover comprises two or more rows of two or more lines of adjacent portions defined or divided by said slots respectively.

According to one embodiment one or more slots are closed at both ends in lengthwise or extending direction of the slot or a direction parallel to the surface respectively. In particular one or more slots are arranged completely within the body and do not open into a border or edge of the body respectively according to one embodiment.

According to one embodiment this may improve the stability of the cover and/or the noise reducing effect.

According to one embodiment one or more slots are configured as straight lines. Additionally or alternatively one or more slots may be configured as curved lines and/or single- or multi-angled lines, in particular exhibit a meandering pattern.

According to one embodiment one or more portions each covers or comprises at least 5%, in particular at least 10%, of the surface respectively. Additionally or alternatively one or more portions, in particular one or more of said portions each covering at least 5%, in particular at least 10%, each covers or comprises 30% at most, in particular 20% at most, of the surface respectively. In particular one or more portions each cover between 5%, in particular 10%, and 30%, in particular 20%, of the surface respectively according to one embodiment. According to one embodiment a surface of two or more, in particular adjacent, portions differs less than 25%, in particular less than 10%.

According to one embodiment this may improve stability of the cover and/or improve the noise reducing effect.

According to one embodiment the body may be contoured by forming, in particular stamping, deep drawing or the like.

According to one embodiment the cover is attached to the internal combustion engine, in particular by bonding, form fit, friction fit, in particular screws, or the like, in particular at least or only along a circumference of the cover.

According to one embodiment this may improve the noise reducing effect, in particular increase amplitudes of non-attached portions vibrating in counterphase one respect to the adjacent according to one embodiment.

According to one embodiment the internal combustion engine may be part of a drive engine or train respectively of a vehicle, in particular a passenger car.

According to one embodiment noise radiation to the insider and/or outside of the vehicle may be reduced thereby.

According to one embodiment the cover is arranged, in particular at least or only, at a front face of the internal combustion engine.

According to one embodiment such front cover may provide an advantageous noise reducing effect.

According to one embodiment the cover is attached to another component of the vehicle like in particular a wall, roof, bottom or the like, in particular by bonding, form fit, friction fit, in particular screws, or the like, in particular at least or only along a circumference of the cover.

According to one embodiment the slots are created within the body(‘s surface) and fully or partially filled with the elastic filler.

According to one embodiment the slots are created by material removing, in particular by cutting or stamping, in particular while contouring the body, in particular forming depressions and/or further holes.

According to one embodiment this may reduce manufacturing effort.

According to another embodiment the slots are created, in particular by material removing, in particular by cutting or stamping, within the already contoured, in particular stamped, body respectively.

According to one embodiment this may allow to vary the slot pattern between identically contoured bodies.

According to one embodiment the slots are filled with the elastic filler by molding, in particular overmolding the slots with the elastic filler, in particular as it is basically known from dynamic lip seal bonding or edge molded gaskets respectively.

According to one embodiment said filler is arranged at least essentially only at slots. In other words in particular the inner parts of portions may be at least essentially free from said elastic filler according to one embodiment.

According to one embodiment this may reduce weight.

According to another embodiment also other areas of the cover or its surface respectively may be covered, in particular overmolded, by the elastic filler. In particular the complete cover may be at least essentially covered, in particular overmolded, by the elastic filler according to one embodiment.

According to one embodiment at least two adjacent portions are defined or divided respectively by one single of said slots. Additionally or alternatively at least two adjacent portions are defined or divided respectively by two or more of said slots according to one embodiment. Thus, in particular adjacent portions may be connected by one or more partition walls limiting the slot(s) between said portions which are closed at both ends in lengthwise of the slot(s) according to one embodiment.

According to one embodiment this may provide an advantageous noise reducing effect and/or enhance stability.

Further features of the present invention are disclosed in the sub-claims and the following description of preferred embodiments. Thereto it is shown, partially schematically, in:

Fig. 1 a body of a semi-manufactured cover according to an embodiment of the present invention;

Fig. 2 the completely manufactured cover;

Fig. 3 a drive engine for a vehicle with the cover; and

Figs. 4-7 covers according to other embodiments of the present invention.

Fig. 1 shows a body 1 of a semi-manufactured cover according to an embodiment of the present invention in top view, Fig. 2 the completely manufactured cover 100. A surface 110 of the essentially flat body 1 looked upon in Figs. 1,2 is divided into six portions 11 -16 forming three pairs (11,12), (13,14) and (15,16) of adjacent portions by slots 21 - 25 which are filled with an elastic filler 3 so as to be able to vibrate in counterphase one respect to the adjacent. One or more, in particular all, of said slots 21 -25 may be through-holes or blind holes.

Slots 21-25 and portions 11-16 are configured such that portions vibrate in counterphase one respect to the adjacent if excited by one or different critical frequencies of the internal combustion engine.

Body 1 is made one-piece from an aluminum alloy, the cover 100 is made single-layer from said body 1.

Elastic filler 3 is molded ACM or AEM in the embodiment.

Slots 21, 22 and slots 23, 24 draw an angle of 30° at most with one another. Also slots 21, 23 and slots 22,24 draw an angle of 30° at most with one another. In particular slots 21, 22 essentially align with one another in the embodiment. Additionally slots 21, 23 and slots 22, 24 drawing an angle of 30° at most with one another are spaced apart from one another perpendicular to a lengthwise direction of said slots in the embodiment. Slot 25 and slots 21 - 24 draw angles of at least 60° with one another in the embodiment, wherein the two slots 21,22 and the two slots 23, 24 drawing an angle of 30° at most with one another are arranged on opposite sides of further slot 25 drawing an angle of at least 60° with these slots 21 - 24.

Cover 100 comprises three rows (horizontally in Fig. 1) of two lines (vertically in Fig. 1) of adjacent portions 11-16.

Slots 21 - 25 each are configured as straight lines and closed at both ends in lengthwise direction of the respective slot or a direction parallel to surface 110 respectively.

Body 1 is contoured by stamping.

As can be understood from the sequence of Figs. 1, 2, slots 21 - 25 are created by material removing, in particular by cutting, within already contoured body 1 (see Fig. 1).

Afterwards slots 21 - 25 are filled with elastic filler 3 by overmolding slots 21 -25.

Finally, completely manufactured cover 100 as shown in Fig. 2 is attached to a front face of an internal combustion engine 200 for a vehicle by screws reaching through screw holes 4 along a circumference of the cover 100 as it is schematically shown in Fig. 3.

Fig. 4 shows a cover 100 according to another embodiment of the present invention in top view. Corresponding features are indicated by the same reference sign. Thus, reference is made to the foregoing description while only differences are addressed in the following.

The surface 110 of cover 100 looked upon in Fig. 4 is divided into portions 11 - 18 by two slots 21,22 filled with the elastic filler 3. One or both slots 21, 22 may be through-holes or blind holes. Portions (11,12), (13,14), (15,16) and (17,18) form four pairs of adjacent portions.

Both slots 21, 22 are configured as multi-angled lines and exhibit a meandering pattern.

Slots 21, 22 and portions 11-18 are configured such that an even plurality of portions 11-14 predominantly vibrate in counterphase one respect to the adjacent if excited by one critical frequency of the internal combustion engine and another even plurality of portions 15-18 predominantly vibrate in counterphase one respect to the adjacent if excited by another critical frequency of the internal combustion engine. In other words cover 100, in particular its slots 21,22 and portions 11-18 respectively, are tuned in order to magnify a noise reduction effect at two different, in particular most, critical frequencies of the internal combustion engine. This is indicated schematically by “+” and in Fig. 4, indicating counterphase vibration (amplitudes).

Also slots 21 - 25 and portions 11-16 respectively of the embodiment according to Fig. 2 may be configured such that different portions predominantly vibrate in counterphase one respect to the adjacent if excited by different, in particular most, critical frequencies of the internal combustion engine.

Fig. 5 shows a cover 100 according to another embodiment of the present invention in top view. Corresponding features are indicated by the same reference sign, Thus, reference is made to the foregoing description while only differences are addressed in the following.

The surface 110 of cover 100 looked upon in Fig. 5 is divided into an even number of four portions 11 - 14 by three slots 21 - 23 filled with the elastic filler 3. One or more, in particular all, of said slots 21 - 23 may be through-holes or blind holes. Portions (11,12) and (13,14) or alternatively portions (11,13) and (12,14) form two pairs of adjacent portions.

One should note that the two slots 21, 22 on opposite sides of slot 23 are closed at both ends in lengthwise direction (horizontally in Fig. 5), i.e. both end before slot 23 in the embodiment. However, elastic filler 3 filling slots 21 - 23 by overmolding may form a cross with connected legs in the embodiment.

Fig. 6 shows a cover 100 according to another embodiment of the present invention in top view. Corresponding features are indicated by the same reference sign. Thus, reference is made to the foregoing description while only differences are addressed in the following.

The surface 110 of cover 100 looked upon in Fig. 6 is divided into portions 11 -14 by one multi-angled slot 21 filled with the elastic filler 3 and exhibiting a meandering pattern. Said slot 21 may be a through-hole ora blind hole. Portions (11,12) and (13, 14) form two consecutive pairs of adjacent portions.

As indicated also in Fig. 4 by “+” and indicating a vibrational pattern of said portions 11-14, these portions vibrate in counterphase one respect to the adjacent if excited by a, in particular most critical, critical frequency of the internal combustion engine or are configured thereto respectively.

Fig. 7 shows a further surface 110 of a cover 100 according to one embodiment of the present invention in a top view corresponding to Fig. 2. Again corresponding features are indicated by the same reference sign and reference is made to the foregoing description while only differences are addressed in the following.

In the embodiment of Fig. 7 the surface 110 is divided into portions 11,12 forming a pair of adjacent portions by a plurality of slots 21,22. The complete surface 110 or at least the slots 21, 22 are overmolded by rubber.

While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.

REFERENCE NUMBERS

Claims

1. An acoustic cover (100), in particular for a vehicle or an internal combustion engine (200), in particular of a vehicle, comprising a body (1) with a surface (110) which is divided into a number of portions (11 -18) by slots (21 - 25) filled at least partially with an elastic filler (3).

2. An acoustic cover (100) according to the preceding claim, wherein said cover (100) is, at least essentially, flat.

3. An acoustic cover (100) according to one of the preceding claims, wherein said slots (21-25) are configured such that portions (11-18) vibrate in counterphase one respect to the adjacent if excited by at least one critical frequency of the vehicle or internal combustion engine (200).

4. An acoustic cover (100) according to one of the preceding claims, wherein said body (1) is made one-piece and/or from a metal, in particular a light metal alloy, in particular an aluminum alloy.

5. An acoustic cover (100) according to one of the preceding claims, wherein said elastic filler (3) comprises, in particular molded, rubber, in particular Polyacrylate rubber and/or Ethylene Acrylic rubber.

6. An acoustic cover (100) according to one of the preceding claims, wherein at least two, in particular adjacent, slots (21-25) draw an angle of 30° at most, in particular at least essentially align, with one another, and/or at least two, in particular adjacent, slots (21-25) draw an angle of at least 60° with one another.

7. An acoustic cover (100) according to one of the preceding claims, comprising at least one pair of adjacent portions (11-18), in particular at least two rows of at least two lines of adjacent portions (11-18).

8. An acoustic cover (100) according to one of the preceding claims, wherein at least one slot (21-25) is closed at both ends in lengthwise direction of the slot (21-25).

9. An acoustic cover (100) according to one of the preceding claims, wherein the body (1) is contoured by forming, in particular stamping.

10. A drive engine, in particular for a vehicle, comprising an internal combustion engine (200) and an acoustic cover (100) according to one of the preceding claims attached to said internal combustion engine (200).

11. A drive engine according to the preceding claim, wherein said cover (100) is arranged at a front face of the internal combustion engine (200).

12. A vehicle, in particular a passenger car, comprising an acoustic cover (100), in particular a drive engine, according to one of the preceding claims.

13. A method for manufacturing an acoustic cover (100) according to one of the preceding claims, wherein the slots (21-25) are created and at least partially filled with the elastic filler (3).

14. A method according to the preceding claim, wherein the slots (21-25) are created by material removing, in particular cutting or stamping, in particular while contouring the body (1).

15. A method according to one of the preceding claims, wherein the slots (21-25) are filled with the elastic filler (3) by molding.