This application claims priority to Japanese Patent Application No. 2020-152506 filed on Sep. 11, 2020, which is incorporated herein by reference in its entirety including the specification, claims, drawings, and abstract.
The present disclosure relates to a sound insulation structure that reduces noise transmission from outside a vehicle cabin to the vehicle cabin and to a structure of a vehicle component.
Battery electric vehicles driven by a motor are widely used in recent years. The battery electric vehicles including no engines emit less noise than conventional vehicles driven by an engine. Therefore, the interior noise of a battery electric vehicle is mainly road noise between tires and a road surface or wind noise, of which the road noise may enter the vehicle cabin along a propagation path from below a vehicle door through an inner weather strip of a belt line of the vehicle. JP 2001-301469 A, for example, proposes a structure including a sound-absorbing material attached to seal a space between seal lips of the inner weather strip.
However, the structure disclosed in JP 2001-301469 A is produced by pressing and attaching the sound-absorbing material, such as synthetic fiber felt, nonwoven fabric, or urethane foam rubber, for example, to a base part of the weather strip during extrusion molding of rubber, or by forming the weather strip by extrusion molding and then attaching the sound-absorbing material to the base part of the weather strip with an adhesive. Thus, the weather strip disclosed in JP 2001-301469 A includes the rubber weather strip having a base part and the sound-absorbing material made of a material other than rubber attached on the base part, and therefore has a complicated structure.
Embodiments of the disclosure are therefore aimed at reducing entrance of noise from outside the vehicle cabin to the vehicle cabin with a simple configuration.
In one aspect of the disclosure, a sound insulation structure is to be disposed in a space between vehicle components to reduce noise transmission through the space, and the space forms a propagation path of noise from outside a vehicle cabin into the vehicle cabin. The sound insulation structure includes a base, and a plurality of protrusions disposed on a surface of the base.
Sound waves entering a recess between the plurality of protrusions are reflected at the bottom of the recess to interfere with sound waves external to the protrusions. This configuration lowers the sound pressure level to thereby reduce entrance of noise from outside the vehicle cabin into the vehicle cabin.
In the sound insulation structure, the base may be part of a seal member to be attached to a first component of the vehicle components defining the space to seal the space, and the plurality of protrusions may be integral with the seal member.
The base and the protrusions are integrally formed, as described above. Entrance of noise from outside of the vehicle cabin into the vehicle cabin can therefore be reduced with a simple configuration.
In the sound insulation structure, the seal member may be a weather strip that is a longitudinal component to seal the space of the vehicle, and the seal member may include a body part to be attached to the first vehicle component defining the space, and seal lip rising on the body part to protrude toward a second vehicle component of the vehicle components defining the space and come into contact with the second vehicle component at tip of the seal lip. The base may be the body part of the weather strip, and the plurality of protrusions may protrude toward the second vehicle component and extend longitudinally.
As described above, it is possible to produce the protrusions protruding toward the second vehicle component and extending along the length of the weather strip which is a longitudinal component, at the time of producing the weather strip by extrusion molding of rubber. This configuration enables simple production of the protrusions for reducing entrance of noise into the vehicle cabin.
In the sound insulation structure, the weather strip may be a belt line weather strip to be attached to a door member to seal a space between the door member and a door glass, and may include at least two seal lips. The plurality of protrusions may be disposed on the body part between the seal lips.
This configuration lowers the sound pressure level in the space between the seal lips to thereby reduce entrance of the noise through the seal lips into the vehicle cabin.
In the sound insulation structure, the protrusions may be disposed on a first surface of each of the seal lips opposite a second surface that comes into contact with the second vehicle component.
This configuration can effectively lower the sound pressure level in the space between the seal lips to thereby reduce entrance of the noise through the seal lips into the vehicle cabin.
In the sound insulation structure, the protrusions may have a cross section having a wedge shape with a tapered tip.
The protrusions having a wedge shape cross section reflect sound waves entering between the protrusions repeatedly at the surfaces of opposing protrusions and thus attenuate the sound waves. Thus, entrance of noise from outside the vehicle cabin into the vehicle cabin is reduced with a simple configuration.
In the sound insulation structure, the protrusions may have a planar shape.
This enables reduction of entrance of noise from outside the vehicle cabin into the vehicle cabin with a simple configuration.
In the sound insulation structure, the protrusions may have a surface on which a sound-absorbing material is attached.
This configuration effectively reduces entrance of noise from outside the vehicle cabin into the vehicle cabin.
In a further aspect of the disclosure, a vehicle component is configured to define a space with a further vehicle component, and the space forms a propagation path of noise from outside a vehicle cabin into the vehicle cabin. The vehicle component includes a base part, and a plurality of protrusions rising on a surface of the base part to extend toward the further vehicle component to reduce transmission of noise through the space.
As described above, the plurality of protrusions disposed on a portion of the vehicle component opposite the further vehicle component reduce entrance of noise through the space between the vehicle component and the further vehicle component into the vehicle cabin.
In the vehicle component, the plurality of protrusions may be integral with the base part.
As described above, a simple configuration including the base part integral with the protrusions can reduce entrance of noise from outside the vehicle cabin into the vehicle cabin.
The present disclosure enables reduction in entrance of noise from outside the vehicle cabin into the vehicle cabin with a simple configuration.
Embodiments of the present disclosure will be described by reference to the following figures, wherein:
Various weather strips to which sound insulation structures according to embodiments are applied will be described by reference to the drawings. In each drawing, arrows FR, UP, and LH indicate frontward (forward), upward, and leftward of a vehicle 10, respectively. The directions opposite the arrows FR, UP, and LH are rearward, downward, and rightward of the vehicle, respectively. In the following description, unless specified otherwise, simple description of front and rear, right and left (widthwise), and above and below refers to directions with regard to a vehicle.
In the vehicle 10 illustrated in
As illustrated in
As will be described below, noise outside the vehicle cabin enters the vehicle cabin 14 through the space 28, or through the space 27 and the space 28. The outer belt line weather strip 30 and the inner belt line weather strip 40 are therefore disposed in the spaces 27 and 28, respectively, between components of the vehicle 10 forming a propagation path of noise from outside of the vehicle cabin to inside of the vehicle cabin.
The outer belt line weather strip 30 is a longitudinal component including a body part 31 to be attached to the door outer panel 21, an upper seal lip 32 and a lower seal lip 33 rising on the body part 31, and a belt molding 34 covering an upper end of the door outer panel 21. The upper seal lip 32 and the lower seal lip 33 each include a flock material 35, 36 on the undersurface facing the door glass 24. The upper seal lip 32 and the lower seal lip 33 protrude toward the door glass 24 to bring the flock materials 35 and 36 on tip ends into contact with the door glass 24, thereby sealing the space 27 between the door glass 24 and the door outer panel 21. The outer belt line weather strip 30 is a component produced by extrusion molding of rubber. The space 27 of the vehicle 10 is defined by two components: the door outer panel 21 to which the outer belt line weather strip 30 is to be attached and the door glass 24 with which the flock materials 35 and 36 on the tip ends of the upper seal lip 32 and the lower seal lip 33 come into contact. The body part 31 forms a base.
The inner belt line weather strip 40 is a longitudinal component including a body part 41 to be attached to the door interior member 23, an upper seal lip 42 and a lower seal lip 43 rising on the body part 41, and protrusions 44 having a wedge shape cross section. The upper seal lip 42 and the lower seal lip 43 protrude toward the door glass 24. The upper seal lip 42 and the lower seal lip 43 each include a flock material 45, 46 on the undersurfaces facing the door glass 24. The flock materials 45 and 46 on tip ends of the upper seal lip 42 and the lower seal lip 43 come into contact with the door glass 24 to seal the space 28 between the door glass 24 and the door interior member 23. The space 28 of vehicle 10 is defined by two components: the door interior member 23 to which the inner belt line weather strip 40 is to be attached and the door glass 24 with which the flock materials 45 and 46 on the tip ends of the upper seal lip 42 and the lower seal lip 43 come in contact. The body part 41 forms a base.
The inner belt line weather strip 40 is a longitudinal component produced by extrusion molding of rubber. As illustrated in
Referring now to
Road noise generated between tires and a road surface enters a space between the door outer panel 21 and the door inner panel 22 (see
Part of the noise that has reached the space 28 is absorbed by the flock material 46 of the lower seal lip 43, while another part of the noise is reflected by the lower seal lip 43, as indicated by an arrow 91 in
The space 47 is enclosed by the upper seal lip 42, the lower seal lip 43, the body part 41, and the door glass 24. As the space 47 is a closed region in which the sound waves are reflected repeatedly, the sound pressure level would increase in the space 47 unless any countermeasures are taken. In this embodiment, the inner belt line weather strip 40 includes the protrusions 44 on the body part 41 between the upper seal lip 42 and the lower seal lip 43. As illustrated in
The sound wave entering the recess 44a of the protrusions 44, reflected on the bottom of the recess 44a, and then reflected from the protrusions 44 toward the space 47, interferes with a sound wave in the space 47 to thereby reduce the sound pressure level in the space 47.
As described above, the protrusions 44 reduce the sound pressure level in the space 47. Such a configuration of the protrusions 44 reduces the sound entering the vehicle cabin 14 from the space 47 through the upper seal lip 42 as indicated by a dashed line arrow 95 in
The protrusions 44 thus attenuate the sound entering the space 47 to reduce the sound pressure level of the space 47. This configuration regulates noise transmission through the space 28 between the door glass 24 and the door interior member 23 and reduces entrance of noise from outside the vehicle cabin into the vehicle cabin. Further, the protrusions 44, which are integral with the body part 41, the upper seal lip 42, and the lower seal lip 43, reduce entrance of the noise from outside the vehicle cabin to the vehicle cabin with a simple configuration. While in the above example, the inner belt line weather strip 40 is an extrusion molded rubber component, the inner belt line weather strip 40 may be formed by any other molding methods in which the protrusions 44 are integrally formed with the body part 41, the upper seal lip 42, and the lower seal lip 43, with any materials other than rubber, such as a resin.
A drive mechanism for the door glass 24 may be configured to press the door glass 24 in a full open state outward of the vehicle cabin. This configuration reduces a contact pressure between the door glass 24 and each of the flock materials 45 and 46 of the upper seal lip 42 and the lower seal lip 43 of the inner belt line weather strip 40, making noise likely to enter the vehicle cabin through the space between the door glass 24 and each of the flock materials 45 and 46 of the upper seal lip 42 and the lower seal lip 43. In this embodiment, the protrusions 44 of the inner belt line weather strip 40 reduce the sound pressure level in the space 47 between the upper seal lip 42 and the lower seal lip 43 to thereby reduce noise transmission through the space 28 and reduce entrance of noise from outside the vehicle cabin to the vehicle cabin.
While in the embodiment described above, the protrusions 44 of the inner belt line weather strip 40 include five protrusions arranged vertically on the body part 41 between the upper seal lip 42 and the lower seal lip 43, the number of protrusions in the protrusions 44 may be any number that is two or greater, such as two or three. The height or width of the protrusions 44 may also be modified in accordance with the frequency to be reduced.
While in the above embodiment, the inner belt line weather strip 40 includes two seal lips: that is, the upper seal lip 42 and the lower seal lip 43, the number of seal lips may be any plural number other than two, such as three or four, for example. In this configuration, the inner belt line weather strip 40 may be configured to include a plurality of protrusions 44 between each pair of seal lips.
While in the above embodiment, the inner belt line weather strip 40 is attached to the door interior member 23, the inner belt line weather strip 40 may be attached to the door inner panel 22.
While in the embodiment described above, the protrusions 44 are disposed on the body part 41 of the inner belt line weather strip 40, protrusions having the same configuration may be disposed on the body part 31 of the outer belt line weather strip 30.
Referring now to
The inner belt line weather strip 140 illustrated in
A sound wave that has entered a slit 48a between the flat protrusions 48 from the space 47 between the upper seal lip 42 and the lower seal lip 43 of the inner belt line weather strip 140 is reflected at a bottom face 48b of the slit 48a and returns to the space 47 to interfere with the sound wave in the space 47, thereby reducing the sound pressure level in the space 47. This configuration reduces noise transmission through the space 28 to reduce entrance of noise from outside the vehicle cabin to the vehicle cabin.
Referring now to
As illustrated in
The inner belt line weather strip 240 according to this embodiment includes a great number of protrusions 44 and 49, and therefore significantly reduces the sound pressure level of the space 47. This configuration further enables reduced noise transmission through the space 28 to thereby reduce entry of noise from outside the vehicle cabin into the vehicle cabin.
Referring further to
As illustrated in
The inner belt line weather strip 340 of this embodiment absorbs sound entering recesses 44c of the flock material 44b with the flock material 44b to thereby significantly reduce the sound pressure level of the space 47 between the upper seal lip 42 and the lower seal lip 43. This configuration reduces noise transmission through the space 28 to thereby enable reduced entrance of noise from outside the vehicle cabin into the vehicle cabin. While in this embodiment, the inner belt line weather strip 340 includes, as a sound-absorbing material, the flock material 44b, the sound-absorbing material is not limited to a flock material and may be felt, unwoven fabric, or urethane, for example, attached to the surface of the protrusions 44 with an adhesive.
Referring further to
As indicate by a dashed line arrow 97 in
The door weather strip 50 and the opening weather strip 60 attenuate the sound pressure of the sound that has entered the tubular seal lips 52 and 62, with the protrusions 53 and 63, respectively, to thereby reduce the sound pressure level of the seal lips 52 and 62. This configuration enables reduction in noise transmission through the space 57 to reduce entrance of the noise from outside the vehicle cabin into the vehicle cabin.
As described above, the inner belt line weather strip 40, the door weather strip 50, and the opening weather strip 60 including the body parts 41, 51, 61, the seal lips 42, 43, 52, 62, and the protrusions 44, 48, 49, 53, 63 which are distinct from the seal lips 42, 43, 52, 62, respectively, are described as example sound insulation structures, by reference to
For example, the inner belt line weather strip 40 described above by reference to
Referring to
The upper surface of the front end 72 of the instrument panel 70 is formed into a plurality of protrusions 73 having a wedge cross section protruding into the space 75 toward the windshield glass 12. The protrusions 73 are formed from the same resin as the instrument panel 70 and are integrally formed with the instrument panel 70 during manufacturing by resin molding.
Noise generated in the front compartment 15 enters through the dash panel 16 into the interior of the instrument panel 70. The noise entering the interior of the instrument panel 70 transmits through the seal member 18 and is propagated through the space 75 between the upper surface of the front end 72 of the base part 71 and the lower surface of the windshield glass 12 into the vehicle cabin 14. Thus, the instrument panel 70 is a vehicle component that defines, with another component; that is, the windshield glass 12, the space 75 forming a propagation path of the noise from the outside the vehicle cabin into the vehicle cabin.
Similar to the protrusions 44 of the inner belt line weather strip 40 described above by reference to
While in the above example, the protrusions 73 are disposed on the instrument panel 70, the protrusions 73 may be disposed on other interior components produced by resin molding. Further, while in the above example, the front end 72 of the base part 71 of the instrument panel 70 is attached, via the seal member 18, to the top face of the upper panel 17, the front end 72 of the base part 71 of the instrument panel 70 may be attached directly to the upper panel 17.
Further, while in the above example, the instrument panel 70 itself includes the protrusions 73, a sound insulation structure including only the body part 41 and the protrusions 44 of the inner belt line weather strip 40 described above by reference to
In the embodiments described above, the protrusions 44, 53, 63, and 73 of the inner belt line weather strip 40, the door weather strip 50, the opening weather strip 60, and the instrument panel 70, respectively, are integral with and made of the same material as the respective body parts 41, 51, and 61 or the base part 71. This simple configuration enables reduction in entrance of the noise from the outside the vehicle cabin into the vehicle cabin with reduced costs.
Number | Date | Country | Kind |
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2020-152506 | Sep 2020 | JP | national |