JP6588324B2 - Resin exterior parts for vehicles - Google Patents

Description

  The present invention relates to a resin exterior product for a vehicle, and more particularly to a resin exterior product for a vehicle that can advantageously reduce noise outside the vehicle.

  Conventionally, in vehicles such as automobiles, noise (road noise) generated due to contact between a tire and a road surface during traveling, engine noise reflected on the road surface, and the like (noise outside the vehicle) Noise). In order to suppress the deterioration of the living environment caused by such outside noise, in recent years, it has been required for vehicles to satisfy predetermined outside noise regulations, and further reinforcement of outside noise regulations is planned in the future. ing.

  On the other hand, recently, a member (glass wool) for absorbing outside noise in a vehicle exterior such as a fender liner attached in a wheel house or a floor cover arranged to cover a lower part (under the floor) of a vehicle body. For example, Japanese Unexamined Patent Application Publication No. 2003-112661 (Patent Document 1) discloses a vehicle exterior product using a nonwoven fabric. Proposed. In such a vehicular exterior product, the sound absorption effect is exhibited by the minute cells configured by the network structure of the nonwoven fabric.

  Further, the applicant of the present application also has an exterior product body provided with a through hole and a vibrating body fixed to the exterior product body in Japanese Patent Application Laid-Open No. 2012-008458 (Patent Document 2). A vehicle exterior product in which an air chamber is formed so as to be surrounded by the exterior product body and the vibrating body is clarified. In such a vehicular exterior product, a vibration type sound absorber that absorbs sound by vibration of a vibrating body and a Helmholtz type sound absorber that absorbs sound by resonating in an air chamber are formed. These vibration type sound absorbers And the Helmholtz type sound absorber can absorb the noise sufficiently and reliably.

JP 2003-112661 A JP 2012-008458 A

  However, it is difficult to strictly control the network structure that exhibits the sound absorbing effect and the minute cells formed thereby in the vehicle exterior product composed of the nonwoven fabric as described above, and therefore the desired frequency. There is a problem that a sound absorption effect in a band (particularly a relatively low frequency band) cannot be obtained sufficiently. In addition, since the vehicle exterior product made of such a nonwoven fabric has low rigidity, it may be deformed relatively easily by an external force such as wind pressure when mounted on the vehicle. There are also problems such as complicating the manufacturing process and increasing the material cost.

  Further, in the above-described vehicle exterior product proposed by the applicant of the present application and the vehicle exterior product provided with the sound absorbing material, a plurality of members including the exterior product main body, the vibrating body, the sound absorbing material, and the like are used. In view of reducing the manufacturing cost and material cost by further simplifying the structure while maintaining the desired sound absorption performance, it is still possible to reduce the weight of the vehicle exterior product. There was room for improvement.

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is that the structure is simple and the sound absorption effect in a desired frequency band can be advantageously exhibited. Accordingly, an object of the present invention is to provide a vehicle exterior resin product that can advantageously reduce outside noise.

  And in this invention, in order to solve this subject, it has the structure which absorbs a vehicle exterior noise in which several through-holes are formed in the resin-made plate-shaped main body at predetermined intervals mutually. A resin exterior product for a vehicle, wherein a flange portion integrally rising from a peripheral portion of the through hole at a predetermined height is formed, and at least a part of the flange portion is caused by sound pressure of the outside noise. The gist of the present invention is a resin exterior product for a vehicle in which a membrane vibration part having a thickness smaller than the plate thickness of the plate-like main body is formed.

  In addition, according to one of desirable aspects of the resin exterior article for a vehicle according to the present invention, the thickness of the flange portion is gradually decreased from the base side to the tip side, and the tip of the flange portion is The side portion is the membrane vibrating portion.

  In the present invention, preferably, another vehicle component is disposed around the plate-shaped main body, and the plate-shaped main body is formed at a portion where the distance from the other vehicle component is large. Further, the opening area of the through hole is made larger than the opening area of the through hole formed in a portion where the distance between the plate-like main body and the other vehicle component is small.

  As described above, in the vehicle exterior resin article according to the present invention, in addition to exhibiting the sound absorption effect by the plurality of through-holes formed in the plate-like main body, it is integrated from the peripheral portion of the through-holes. Since a membrane vibration part that is vibrated by sound pressure is formed on at least a part of the flange part that rises at a predetermined height, sound that causes external noise is advantageous due to such vibration of the membrane vibration part. Will be absorbed. That is, the noise outside the vehicle is advantageously reduced by combining the sound absorption effect by the through hole and the sound absorption effect by the predetermined membrane vibrating portion.

  Moreover, in the vehicle exterior resin article according to the present invention, the through hole is formed in the plate-shaped main body, and the flange portion including the membrane vibrating portion is integrally formed from the peripheral portion of the through hole. In other words, since the flange portion is formed integrally with the plate-like main body, the structure of the vehicle exterior resin product is simplified.

It is plane explanatory drawing which shows the fender liner as an example of the resin-made exterior products for vehicles according to this invention. It is AA cross-section explanatory drawing in FIG. It is the B section enlarged explanatory view in FIG. FIG. 2 is a partial cross-sectional explanatory view schematically showing a front portion of the vehicle to which the fender liner shown in FIG. 1 is attached. FIG. 5 is a partial cross-sectional explanatory view schematically showing a part of a vehicle to which a floor cover as another example of a resin exterior product for a vehicle according to the present invention is attached. FIG. 6 is an enlarged explanatory view of a CC cross section in FIG. 5. FIG. 4 is a cross-sectional explanatory view corresponding to FIG. 3, showing another example of a vehicle exterior resin article according to the present invention.

  Hereinafter, in order to clarify the present invention more specifically, representative embodiments of the present invention will be described in detail with reference to the drawings.

  First, in FIG. 1 and FIG. 2, a fender liner of an automobile as an embodiment of a resin exterior product for a vehicle having a structure according to the present invention is shown in a planar form or a sectional form, respectively. Here, the entire fender liner 10 is formed using a resin material such as polyethylene, and is not damaged by the collision of pebbles or the like that the tire jumps up with sufficient rigidity not to be deformed by wind pressure generated when the vehicle travels. It is configured with sufficient strength.

  More specifically, the fender liner 10 has a wheel arch portion 12 as a plate-like main body that exhibits a substantially arc-shaped curved plate shape in a side view. At both ends of the wheel arch portion 12 in the length direction (left and right direction in FIGS. 1 and 2), attachment pieces 14 and 14 are integrally formed. The wheel arch portion 12 and the attachment pieces 14 and 14 are formed with a plurality of insertion holes 16 for inserting fasteners such as bolts and screw grommets when the fender liner 10 is attached to the vehicle.

  The wheel arch portion 12 is disposed in the thickness direction (plate) on a substantially half portion on one side in the length direction of the wheel arch portion 12, here, on a substantially half portion on the vehicle rear side in an attached state to the vehicle described later. A large number of through holes 18 (small diameter holes 18a and large diameter holes 18b) penetrating in the thickness direction) are formed. These many through holes 18 have a circular hole shape, and are arranged so as to be arranged side by side in the longitudinal direction and the lateral direction at intervals in the length direction and the width direction of the wheel arch portion 12.

  The large number of through-holes 18 formed in the wheel arch portion 12 of the fender liner 10 as described above is composed of a small-diameter hole 18a and a large-diameter hole 18b which are two types of through-holes having different hole diameters (opening areas). That is, as shown in FIG. 3, the hole diameter: d2 of the large diameter hole 18b among the large number of through holes 18 is made larger than the hole diameter: d1 of the small diameter hole 18a.

  In the fender liner 10, as clearly shown in FIGS. 1 and 2, the small-diameter hole 18 a is the length of the wheel arch portion 12 in the portion where the through hole 18 of the wheel arch portion 12 is formed. On the both sides in the direction (hereinafter also referred to as small-diameter hole forming portions 20 and 20), respectively, while the large-diameter hole 18b is sandwiched between the small-diameter hole forming portions 20 and 20 (hereinafter referred to as the small-diameter hole forming portions 20 and 20). (Also referred to as a large-diameter hole forming portion 22).

  As shown in FIGS. 2 and 3, in the fender liner 10, a substantially cylindrical flange portion 24 that integrally rises at a predetermined height from the peripheral portion of each through hole 18 (18 a and 18 b). Is formed. The inner diameters of the flange portions 24 are substantially the same as the inner diameters of the corresponding through holes 18a and 18b.

  Furthermore, as shown in detail in FIG. 3, the thickness of such a flange portion 24 is gradually reduced from the base side (wheel arch portion 12 side) toward the distal end side. As a result, a membrane vibrating portion 26 having a thickness smaller than the plate thickness of the wheel arch portion 12 is formed at the tip side portion of the flange portion 24. The membrane vibrating portion 26 is configured to be vibrated by sound pressure by being thin and having a free end at the tip.

  The base portion side portion of the flange portion 24 is a thick portion 28 that is thicker than the thickness of the membrane vibrating portion 26. The thick portion 28 has higher rigidity than the membrane vibrating portion 26 and is difficult to vibrate due to sound pressure.

  And the fender liner 10 of this embodiment which has such a structure is arrange | positioned in the vehicle front part as schematically shown in FIG. Here, the fender liner 10 is mounted on the vehicle body in a state where the wheel arch portion 12 in which a large number of through-holes 18a and 18b are formed is arranged so as to cover the tire 32 from above in the wheel house of the vehicle 30. ing. In such a mounting state of the fender liner 10 to the vehicle 30, the through holes 18a and 18b formed in the wheel arch portion 12 are exposed to the outside (road surface side) of the vehicle body, and the flange portion 24 is formed. It is extended toward the inside of the car body.

  Further, other vehicle parts are disposed around the wheel arch portion 12 of the fender liner 10. In FIG. 4, such other vehicle parts are disposed above the fender liner 10. A metal apron 34 and a metal fender protector 36 disposed behind the fender liner 10 are schematically shown. The apron 34 and the fender protector 36 are arranged at a predetermined distance from the fender liner 10. As a result, a space (back air layer 38) is formed between the fender liner 10 (wheel arch portion 12), the apron 34, and the fender protector 36.

  Here, in the vehicle 30, the distance between the wheel arch portion 12, the apron 34, and the fender protector 36 (the size of the back air layer 38) depends on the design factors such as the shape and arrangement of each vehicle component. It is different depending on. In the present embodiment, as shown in FIG. 4, the distance S2 between the large-diameter hole forming portion 22 of the wheel arch portion 12 and the apron 34 is the small-diameter hole forming portion on the vehicle front side of the wheel arch portion 12. The distance between 20 and the apron 34: S1, and the distance between the small-diameter hole forming portion 20 on the vehicle rear side of the wheel arch portion 12 and the fender protector 36: larger than S3. In other words, the size of the back air layer 38 formed between the large-diameter hole forming portion 22 of the wheel arch portion 12 and the apron 34 is such that the small-diameter hole forming portions 20 and 20 of the wheel arch portion 12 and the apron 34 or The size of the back air layer 38 formed between the fender protector 36 and the fender protector 36 is larger.

  For the fender liner 10 attached to the vehicle 30 in this manner, as schematically shown by thin line arrows in FIG. The sound (road noise) (N1) generated by the contact of the engine, the engine sound (N2) reflected on the road surface, and the like are input. And the various sound absorption effects in the fender liner 10 will be exhibited with respect to such a sound. In the following, “sound” is used to mean “sound wave” and “vibrated air”.

  First, when sound input to the fender liner 10 passes through the through holes 18a and 18b, part of the sound energy is heated due to friction between the vibrated air and the inner peripheral surfaces of the through holes 18a and 18b. By being consumed as energy, the energy of sound is reduced. In addition, the energy consumed by friction increases by increasing the flow velocity of air in the through holes 18a and 18b, and the air flow instantaneously spreads after passing through the through holes 18a and 18b, thereby generating a vortex. Thus, the energy of the sound is advantageously reduced by instantaneously losing energy.

  Further, a sound absorption structure constituted by combining a wheel arch portion 12 in which a large number of through holes 18a and 18b are formed, and a back air layer 38 formed between the wheel arch portion 12 and the apron 34 and the fender protector 36. The sound absorbing effect by the structure is also exhibited. That is, when sound is input to the fender liner 10, the air inside the through holes 18 a and 18 b can reciprocate the inside of the through holes 18 a and 18 b many times by the spring action of the back air layer 38. Thus, friction occurs with the inner peripheral surfaces of the through holes 18a and 18b, and sound energy can be reduced by being converted into thermal energy.

  Furthermore, in the fender liner 10 of the present embodiment, when the sound input to the fender liner 10 passes through the flange portion 24 through the through holes 18a and 18b, the membrane vibrating portion 26 is vibrated by the sound pressure. It will be. The vibration of the membrane vibrating portion 26 converts sound energy into kinetic energy, and is also consumed and reduced as thermal energy due to internal friction of the membrane vibrating portion 26. It is.

  As is clear from the above description, in the present embodiment, the flange portion 24 is integrally formed with a predetermined height from the peripheral edge portion of the through-hole 18 (18a, 18b), and a sound pressure is formed in a part thereof. Since the membrane vibrating portion 26 that is vibrated by the above is formed, the sound absorbing action due to the vibration of the membrane vibrating portion 26 advantageously absorbs the sound that causes the outside noise. That is, in addition to the sound absorbing action by the through holes 18a and 18b as described above, the sound absorbing action by the membrane vibrating portion 26 is exhibited, and by combining them, the outside noise is advantageously reduced. .

  Moreover, in the fender liner 10, the through holes 18 a and 18 b are directly formed in the wheel arch portion 12 as a plate-like main body, and the flange portion 24 including the membrane vibrating portion 26 is a peripheral edge of the through holes 18 a and 18 b. The fender liner 10 that exhibits an advantageous sound absorbing action is formed from the parts that are integrally formed from the part, that is, the flange part 24 is formed integrally with the wheel arch part 12 as a plate-like body. It is configured in a simple structure without increasing.

  The sound absorption effect of the through holes 18a and 18b in the fender liner 10 is adjusted by appropriately adjusting the frequency band of the sound to be absorbed by adjusting the hole diameters (opening areas) of the through holes 18a and 18b. Is possible.

  Further, since the entire fender liner 10 is made of resin, there are advantages that it is lightweight, has a high degree of freedom in shape, and has a low material cost. In addition, since the resin material is relatively excellent in flexibility, it is possible to easily form the membrane vibration part 26 that vibrates by sound pressure, and to effectively exhibit the sound absorbing action.

  Further, in the fender liner 10, the thickness of the flange portion 24 is gradually reduced from the base portion side toward the distal end side, and the distal end side portion of the flange portion 24 is the membrane vibration portion 26. In other words, the thin film vibrating portion 26 is formed integrally with the wheel arch portion 12 via the thick portion 28 formed on the base side portion of the flange portion 24. Therefore, it is advantageously prevented that the flange portion 24 is damaged on the base side and the membrane vibration portion 26 is dropped from the fender liner 10.

  Further, conventionally, by adjusting the plate thickness of the plate-like main body, the frequency band of the sound to be absorbed is adjusted. In particular, the plate thickness of the plate-like main body is increased, that is, the length of the inner peripheral surface of the through hole It is known that by increasing the length, the frequency band of the absorbed sound shifts to the low frequency side. However, in the fender liner 10, if the plate thickness of the wheel arch portion 12 as the plate-like main body is uniformly increased, there arises a problem that the fender liner 10 itself increases in weight and material cost. On the other hand, in the fender liner 10 of the present embodiment, the base portion of the flange portion 24 is the thick portion 28, which is substantially the same as increasing the plate thickness of the wheel arch portion 12. The effect of can be obtained. Therefore, due to the presence of such a thick portion 28, as shown in FIG. 3, the length L of the substantially inner peripheral surface of the through hole 18 (18a, 18b) is set to the plate thickness of the wheel arch portion 12. : By making the length longer than t, it is possible to appropriately adjust the frequency band of the sound to be absorbed.

  By the way, in the present embodiment, as described above, the wheel arch portion 12 in which a large number of through holes 18a and 18b are formed, and the wheel arch portion 12 and the apron 34 when the fender liner 10 is attached to the vehicle 30. In addition, the sound absorbing action is also exhibited by the sound absorbing structure configured by combining the rear air layer 38 formed between the fender protector 36 and the fender protector 36.

  Here, conventionally, the sound absorption characteristic of the sound absorbing structure in which the plate-like member having such a through hole and the back air layer is combined has a mountain-shaped characteristic centered on a predetermined frequency (peak). It has been known. In general, the inventor and the like within the range of the frequency band of the sound to be absorbed in the vehicle and the range of the distance (the size of the back air layer) that can be set between the vehicle components. As a result of paying attention to the change in sound absorption characteristics when the hole diameter (opening area) and the back air layer are changed, if the back air layer is enlarged with the opening area of the through-holes kept constant, the sound absorption peak will be on the low frequency side It has been found that the peak of sound absorption shifts to the high frequency side when shifting and by increasing the opening area of the through-hole while keeping the size of the back air layer constant. That is, in a resin exterior product for a vehicle, in order to advantageously obtain sound absorbing performance in a desired frequency band, it is preferable to relatively increase the opening area of the through hole in a portion where the back air layer becomes large. However, it became clear.

  In short, in the present embodiment, the wheel arch portion 12 has a large diameter that is a through-hole formed in a portion (here, the large-diameter hole forming portion 22) having a large distance from the apron 34 that is another vehicle component. The opening area of the hole 18b (hole diameter: d2) is a part of the wheel arch portion 12 where the distance from the apron 34 or the fender protector 36, which is another vehicle component, is small (here, the small diameter hole forming portions 20 and 20). It is made larger than the opening area (hole diameter: d1) of the small diameter hole 18a which is the formed through hole. As a result, in the large-diameter hole forming portion 22 of the wheel arch portion 12, the sound absorption peak that tends to shift to the low frequency side due to the increased distance from the apron 34 (the back air layer 38) is caused to pass through the through-hole 18 b. By making the hole diameter of each of these holes relatively large, the frequency is corrected to the high frequency side, thereby preventing the peak of sound absorption in each of the through holes 18a and 18b from deviating significantly from the desired frequency. Therefore, it is possible to advantageously maintain the sound absorbing performance in.

  In the fender liner 10, it is preferable that the through holes 18 a and 18 b have a diameter of about 1 mm to 2 mm. This is because if the hole diameter is smaller than 1 mm, the incidence of sound due to irregular reflection is reduced, making it difficult for the sound absorbing action by the through holes 18a and 18b to be effectively exhibited, and the formation process of the through holes 18a and 18b (drilling process). On the other hand, if the hole diameter exceeds 2 mm, foreign matter may enter through the through holes 18a and 18b, or snow may enter the through holes 18a and 18b. This is because problems such as being unable to satisfy the evaluation of icing due to intrusion and sticking / depositing occur.

  The exemplary embodiments of the present invention have been described in detail above. However, the embodiments are merely examples, and the present invention is limited in any way by specific descriptions according to such embodiments. It should be understood that it is not interpreted.

  FIGS. 5 and 6 show a vehicle floor cover as another embodiment of a resin exterior article for a vehicle having a structure according to the present invention, in a partially cross-sectional form or a cross-sectional form, respectively, in a state of being attached to a vehicle. It is shown. In addition, in the floor cover 40 shown in FIGS. 5 and 6, the same reference numerals are given to the parts of the structure corresponding to the fender liner 10 according to the previous embodiment, and detailed description will be omitted. To do.

  The floor cover 40 has a cover main body portion 42 as a plate-like main body having a substantially flat plate shape, and a plurality of through holes 18 (18c, 18d, and 18e described later) are formed in the cover main body portion 42. Yes. Such a floor cover 40 is disposed so as to cover the lower part (under the floor) of the vehicle 30, and each through hole 18 is exposed to the outside of the vehicle body, and as shown in detail in FIG. A flange portion 24 having a distal end side portion as a membrane vibration portion 26 is formed from the inside toward the inside of the vehicle body.

  The floor cover 40 is inputted with a sound (N3) that causes noise outside the vehicle, as schematically shown by the thin arrow in FIG. On the other hand, in the floor cover 40, the sound absorbing action by the numerous through holes 18 formed in the cover main body part 42 is exhibited, and the sound absorbing action by the membrane vibrating part 26 of the flange part 24 is exhibited. This makes it possible to advantageously reduce outside noise.

  Further, as schematically shown in FIGS. 5 and 6, a floor panel 44 is disposed as another vehicle component above the floor cover 40 (inside the vehicle). Such a floor panel 44 has a panel body portion 46 having a substantially flat plate shape, and the panel body portion 46 and the cover body portion 42 of the floor cover 40 are arranged so as to face each other.

  More specifically, as shown in FIG. 6, the cover main body 42 of the floor cover 40 is provided for the purpose of rectifying traveling wind flowing under the vehicle body (under the floor) and reinforcing the floor cover 40 itself. An uneven shape (bead shape) is formed. The floor panel 44 is also formed with a concavo-convex shape to meet the strength and layout requirements. Thereby, the distance between the floor cover 40 (cover main body portion 42) and the floor panel 44 (panel main body portion 46), that is, the size of the back air layer 38 formed between the floor cover 40 and the floor panel 44. However, it is different depending on the part.

  In the floor cover 40, the hole diameters of the through holes 18c, 18d, and 18e are respectively set so as to correspond to the distances between the cover main body 42 and the floor panel 44: S4, S5, and S6. It is. Specifically, corresponding to the distance between the cover main body 42 and the floor panel 44 increasing in the order of S4, S5, and S6, the hole diameter of the through hole 18c: d3 and the through hole 18d. The hole diameter: d4 and the hole diameter: d5 of the through hole 18e are increased in that order.

  Therefore, in the floor cover 40 of the present embodiment, the sound absorption performance in the desired frequency band is prevented by preventing the sound absorption peak from deviating significantly from the desired frequency due to the difference in the size of the back air layer 38. Thus, it is possible to advantageously maintain the noise, and thus it is possible to advantageously reduce the noise outside the vehicle.

  The vehicle exterior resin article having a structure according to the present invention is not limited to the fender liner and floor cover as described above. For example, the structure of the present invention is disposed on the engine under cover or the vehicle rear side. The present invention can also be applied to a rear floor cover or the like. By the way, in recent years, as a result of mainly reducing the noise of the power unit system, it is important to reduce the noise generated at the contact portion between the tire and the road surface. Under such circumstances, in order to effectively reduce the noise outside the vehicle, the resin exterior product for vehicles having the structure according to the present invention can be used particularly advantageously as a fender liner or floor cover disposed in the lower part of the vehicle. It becomes.

  In addition, the fender liner 10 and the floor cover 40 as described above can be formed by vacuum forming or pressure forming on a resin panel (resin sheet) extruded using a known resin material such as polyethylene material, By performing compression molding by heating such a resin panel, the wheel arch part 12 and the cover main body part 42 are formed as a plate-like main body, and then the through hole 18 and the flange are formed by drilling with a pin or the like. By forming the portion 24, it can be easily manufactured.

  In particular, when drilling with a pin is performed, the through hole 18 is formed, and the thickness is gradually reduced from the base side toward the tip side by utilizing the elongation of the resin material. The flange portion 24 whose portion is the membrane vibration portion 26 can be easily formed. In addition, by adopting such a manufacturing method, it is possible to use the product shape (flange portion 24) as it is without removing the burr shape that has been removed in the subsequent process in relation to the appearance and other parts. This is possible, and there is also an advantage that the manufacturing cost of the resin exterior product for vehicles can be advantageously reduced.

  In addition, as a manufacturing method of the resin exterior product for a vehicle, it is possible to adopt a known method such as injection molding, and it is also possible to integrally mold the plate-shaped main body, the through hole, and the flange portion at the same time. . Further, the formation method of the through hole 18 is not limited to the drilling process using the pin as described above, and a known technique such as drilling process using a drill or burring process after forming the lower hole is used. Can be adopted.

  Further, the through hole 18 is not limited to a circular hole as illustrated, and may be, for example, a polygonal hole. In addition, as a tool (a pin, a drill, etc.) for forming the through-hole 18, the thing corresponding to a circular hole has an advantage that a cost is cheap, and the drilling process itself is easier for a circular hole.

  In the above embodiment, the thickness of the flange portion 24 is gradually reduced toward the distal end side, and the membrane vibrating portion 26 is formed on a part of the flange portion 24 (the distal end side portion). On the other hand, as shown in FIG. 7, the entire flange portion 24 may be formed with a thickness that can be vibrated by sound pressure so that the entire flange portion 24 becomes the membrane vibration portion 26. .

  Furthermore, in the resin exterior product for a vehicle, the flange portion 24 having the entire membrane vibrating portion 26 and the flange portion 24 having the thick portion 28 in which a part (tip side portion) is the membrane vibrating portion 26; May be mixed. For example, for the through hole 18 in which the hole diameter (opening area) cannot be further reduced, a flange part 24 having a thick part 28 is provided to substantially extend the length of the through hole 18. As a result, the sound absorption peak to be shifted to the high frequency side in relation to the back air layer 38 is corrected to the low frequency side, and the sound absorbing action by the membrane vibrating portion 26 is exhibited, while an appropriate hole diameter (opening area) is set. For the settable through hole 18, by providing the flange portion 24 composed only of the membrane vibrating portion 26, the sound absorbing action by the membrane vibrating portion 26 is exerted. This makes it possible to exhibit advantageous sound absorbing performance in the frequency band.

  In the present embodiment, the hole diameter (opening area) of the through hole 18 (18a and 18b or 18c and 18d and 18e) corresponds to the size of the back air layer 38 and is divided into two or three stages. However, the present invention is not limited to such an embodiment, and the opening areas of all the through holes 18 can be made substantially constant. Conversely, the opening areas of these through holes 18 are set to the rear air layer 38. It is also possible to set in more stages depending on the size of the.

  In addition, although not listed one by one, the present invention can be carried out in an embodiment to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Fender liner 12 Wheel arch part 18 (18a, 18b, 18c, 18d, 18e) Through-hole 20 Small diameter hole formation part 22 Large diameter hole formation part 24 Flange part 26 Membrane vibration part 28 Thick part 34 Apron 36 Fender protector 38 Behind Air layer 40 Floor cover 42 Cover body 44 Floor panel

Claims (3)

Resin plate-shaped body made of resin, a plurality of through holes formed at a predetermined interval from each other, a vehicle exterior resin product having a structure for absorbing outside noise,
A plate of the plate-like main body having a flange portion integrally rising from a peripheral edge portion of the through-hole at a predetermined height, and being caused to vibrate at least a part of the flange portion by sound pressure of the outside noise. A resin exterior product for a vehicle, wherein a membrane vibration part having a thickness smaller than the thickness is formed.   The resin outer packaging for vehicles according to claim 1, wherein the thickness of the flange portion is gradually reduced from the base side toward the tip side, and the tip side portion of the flange portion is the membrane vibration portion. . Other vehicle parts are arranged around the plate-shaped main body, and the opening area of the through-hole formed in a portion where the distance between the plate-shaped main body and the other vehicle parts is large is the plate-shaped body. The resin exterior product for a vehicle according to claim 1 or 2, wherein the exterior exterior part of the vehicle is made larger than an opening area of the through hole formed in a portion where the distance from the other vehicle component of the main body is small.

Images