JP7269116B2 - Composite member and its manufacturing method - Google Patents

Description

The present invention relates to a composite member used for an engine undercover of a vehicle, an instrument panel undercover, etc., and a manufacturing method thereof.

2. Description of the Related Art Vehicles such as automobiles include composite members such as engine undercovers and instrument panel undercovers, in which a porous sheet material is spread in a resin frame to provide sound absorption. Some improved inventions have also been proposed (for example, Patent Document 1).

JP 2017-77637 A

Patent Document 1 describes that "a plate-shaped fibrous body made of nonwoven fabric is sandwiched between the mold surfaces of a closed mold and compressed in the plate thickness direction, and the closed mold is defined between the fibrous body and the A method for manufacturing a composite member in which a cavity is filled with a resin raw material and a resin molded body is molded", and the invention secures rigidity with the resin molded body and exerts a sound absorbing effect with the fiber body.

However, when the composite member of Patent Document 1 is used for, for example, an engine undercover, the single-layer fiber sheet has a high sound absorbing effect against high-frequency noise exceeding 2 kHz emitted from the engine side, but the noise is lower than 2 kHz. When it comes to frequency sound, the sound absorption performance is lowered. When Phase 3 regulations begin, it will become necessary to take measures to absorb low-frequency sound (800Hz to 2kHz) emitted from running tires near the engine. In the first place, it was difficult to absorb low-frequency sounds.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to provide a composite member effective against low-frequency noise generated from tire noise and the like, and a manufacturing method thereof.

In order to achieve the above object, the gist of the invention as set forth in claim 1 is a porous sheet member formed by laminating a plurality of porous sheet members having air permeability and different air flow resistances while maintaining the porous structure. a sound-absorbing panel portion and a frame portion surrounding the sound-absorbing panel portion and integrally formed therewith, and forming a hardened portion by penetrating and hardening in the sound-absorbing panel portion to form front and back surfaces of the sound-absorbing panel portion an injection-molded part made of synthetic resin in which convex portions are respectively formed on both panel surfaces, and the plurality of porous sheet members are used as inserts, and the injection-molded part is integrally molded, Further, the composite member is characterized in that the convex portion restrains the movement of the panel surface related to the sound absorbing panel portion in the outward direction of the convex portion at that point. The composite member according to claim 2 is the composite member according to claim 1, wherein the convex portion formed on one panel surface of the sound absorbing panel portion forms a hardened portion that is hardened by penetrating into the sound absorbing panel portion. , crossing over one panel surface of the sound absorbing panel portion and connecting both end portions to the frame portion to form a first crosspiece, while the sound absorbing panel portion is formed on the other panel surface of the sound absorbing panel portion. A convex portion forms a hardened portion by entering and hardening in the sound absorbing panel portion, crosses the other panel surface related to the sound absorbing panel portion, and connects both end portions to the second crosspiece connected to the frame portion. characterized by becoming The composite member according to claim 3 is the composite member according to claim 1 or 2, wherein the sound absorbing panel part is provided with a through hole penetrating from one panel surface in contact with the first crosspiece to the other panel surface, and the second crosspiece Instead, the through-hole is filled with a hardened portion of a shaft-shaped resin, and the head portion of the tip protrudes into the peripheral portion of the through-hole on the other panel surface to form a hardened protrusion. do. The composite member according to the invention of claim 4 is the composite member according to claims 1 to 3, wherein the sound absorbing panel part is formed of the two porous sheet members having different airflow resistances, and the porous sheet member constituting one panel surface side It is characterized in that the porous sheet member constituting the other panel surface side has a greater airflow resistance than the porous sheet member, and the two are stacked and shaped. The composite member according to the invention of claim 5 is the composite member according to claim 4, wherein the first crosspieces are arranged and formed in a grid pattern on the one panel surface, and the second crosspieces sandwiching the sound absorbing panel portion with the first crosspieces. are arranged in a grid pattern on the other panel surface. The composite member according to the invention of claim 6 is the composite member according to claims 1 to 5, wherein the porous sheet members are both made of nonwoven fabric, and the nonwoven fabric forming one panel face side of the sound absorbing panel portion is on the other panel face side. The nonwoven fabric forming the is made to have a larger basis weight and a smaller thickness, and the two are laminated in two layers and shaped. The composite member according to the invention of claim 7 is the composite member according to claims 1 to 6, wherein the plurality of porous sheet members are laminated and shaped by adhesively fixing a part of their lamination interfaces. .
The gist of the invention according to claim 8 is that the cavity for the panel portion of the sound absorbing panel portion is formed by the porous sheet member by mold clamping, and the cavity for the synthetic resin frame portion surrounds the cavity for the sound absorbing panel portion. Further, a first groove for a first rail is formed on the cavity surface of the sound absorbing panel portion cavity of one of the split molds, and a first groove for the first crosspiece is formed on the cavity surface of the sound absorbing panel portion cavity of the other split mold. , using an injection molding machine equipped with a pair of split molds formed with a second groove for the second crosspiece or a recess for the protrusion, and laminating a plurality of the porous sheet members having air permeability and different air resistance. and set it in one of the split molds, then the mold is clamped to form a sound absorbing panel portion that maintains a porous structure, and then the cavity for the frame portion, the first groove, and the second A composite member characterized by injecting a synthetic resin raw material into the two grooves or the recess, and injection molding the frame, the first crosspiece, the second crosspiece, or the protrusion integrated with the sound absorbing panel. in the manufacturing method. The method for manufacturing a composite member according to the ninth aspect of the invention is characterized in that, in the eighth aspect, both the porous sheet members are made of nonwoven fabric, and the nonwoven fabric forming one panel side of the sound absorbing panel portion is closer to the other panel side than the other panel side. The nonwoven fabric forming the is made to have a larger basis weight and a smaller thickness, two layers are stacked, set in one of the split molds, and then the mold is clamped to form the sound absorbing panel portion. Characterized by

The composite member and its manufacturing method of the present invention can effectively absorb low-frequency sound of about 800 Hz to 2 kHz emitted from tires, etc., and in addition to the original role of cover members such as engine undercovers, low-frequency noise It has excellent absorption effect.

1 is a perspective view of a composite member viewed from the back side, in one embodiment of the composite member and the manufacturing method thereof of the present invention. FIG. FIG. 2 is a perspective view showing only a resin molded portion without the sound absorbing panel portion of FIG. 1; (A) is a perspective view of a porous sheet member before shaping, and (B) is a perspective view of a sound absorbing panel portion. It is an IV-IV line cross section of FIG. FIG. 5 is a partially enlarged view of FIG. 4; (A) is a partial enlarged view of FIG. 4, and (B) is a reference drawing replacing FIG. 6(A). (a) is another embodiment diagram replacing FIG. 2, and (b) is a cross-sectional view taken along the line VII-VII of (a). (a) is another view in place of FIG. 2, and (b) is a partial sectional view of (a). FIG. 2 is a cross-sectional view of a main part of an injection molding machine used for manufacturing a composite member; FIG. 4 is an explanatory cross-sectional view of laminating porous sheet members and setting them in a movable mold. It is explanatory sectional drawing which closes a mold and inject|pours a resin raw material. It is explanatory sectional drawing which finished injection molding of a resin molding part. FIG. 2 is another aspect diagram that replaces FIG. 1;

The composite member and the manufacturing method thereof according to the present invention will be described in detail below. 1 to 13 show an embodiment of the composite member and its manufacturing method of the present invention, FIG. 1 is a perspective view of the back side of the composite member, FIG. A) is a perspective view of the porous sheet member, (B) is a perspective view of the sound absorbing panel part, FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, and FIGS. , FIG. 6(b) is a reference drawing, FIG. 7(a) is another aspect diagram replacing FIG. 2, (b) is a cross-sectional view of (a), and FIG. , (B) is a cross-sectional view of (A), FIG. 9 is a cross-sectional view of the main parts of an injection molding machine used for manufacturing a composite member, and FIG. 10 is a cross-sectional view of laminating porous sheet members and setting them in a movable mold. 11 is a cross-sectional view of injecting the resin raw material, FIG. 12 is a cross-sectional view after molding of the resin molded portion, and FIG. In order to make each drawing easy to understand, the drawings are simplified and the main part of the invention is emphasized.

(1) Composite Member Manufacturing Method The composite member 1 includes a sound absorbing panel portion 2 formed by laminating a plurality of porous sheet members 3 having air permeability and having different airflow resistances, and a synthetic resin frame. It is a vehicle product that is surrounded by a portion 5 to retain its shape. The laminated porous sheet member 3 becomes a three-dimensionally shaped sheet-like sound absorbing panel portion 2, for example, as shown in FIG.
The composite member 1 of this embodiment is applied to an engine undercover (FIGS. 1 to 6). In this manufacturing method, an injection molding machine 7 having a mold T as shown in FIG. 9 is used.

In the composite member manufacturing method, prior to this, an injection molding machine 7 having a porous sheet member 3 and a mold T for the composite member 1 is prepared (FIGS. 3 and 9).

The porous sheet member 3 is a sheet-like body having a sound-absorbing porous structure such as non-woven fabric or foam (a in FIG. 3). Thermoplastic resin non-woven fabrics such as polyethylene terephthalate (PET) and polypropylene (PP), foam sheets of polyurethane and polypropylene, and the like are used. The present invention includes felts in nonwovens. Felt is also considered a non-woven fabric for the purposes of this invention. The "sheet" of the porous sheet member 3 includes a plate-like one. A plurality of porous sheet members 3 having air permeability and different air resistance and cut into a predetermined size having substantially the same shape in a plan view are laminated and used for manufacturing the composite member 1 .

For the engine undercover of this embodiment, two types of porous sheet members 3 having different ventilation resistances are prepared ((a) in FIG. 3). Porous sheet members 3 with different airflow resistances may be referred to as porous sheet members 3 with different airflow rates. When used as the sound absorbing panel part 2, the porous sheet member 3 on the side of the surface 2a on the road surface side is an outer porous sheet member 3A (basis weight) made of high-density fibers with an air permeability of 18 cm ³ /cm ² /sec. The porous sheet member 3 on the side of the rear surface 2b on the engine side is the inner porous sheet member 3B (small basis weight, small thickness) made of low-density fibers with an air permeability of 55 cm ³ /cm ² /sec. large). The ventilation rate was measured with a stationary FX3300 ventilation rate tester manufactured by Takayama Reed Co., Ltd. Both porous sheet members 3, which are one size larger than the frame opening 50, are superimposed and set in the mold T. As shown in FIG.
Even if the outer porous sheet member 3A and the inner porous sheet member 3B change from the initial thicknesses t2 and t1 to the gap width of the cavity C2 of the sound absorbing panel part 2 by compression, the sound absorbing porous structure is maintained. (Fig. 11). For the porous sheet member 3, for example, a two-component composite nonwoven fabric in which a low-melting point material and a high-melting point material are mixed can be used. There is a non-woven fabric having a sheath-core structure in which each fiber has a core made of a high-melting-point material and a sheath made of a low-melting-point material, and this may be used. After heating the outer porous sheet member 3A and the inner porous sheet member 3B made of the non-woven fabric to soften the sheath, they are set in a mold T and clamped to thermally bond the sheath at the heating temperature. , can be formed into a predetermined shape at the core.

The injection molding machine 7 has a mold T consisting of one split mold 8 (here, movable type) and the other split mold 9 (here, fixed type) (FIG. 9). A cavity C of the composite member 1 is formed by clamping the movable mold 8 and the fixed mold 9 . A panel portion cavity C2 of the sound absorbing panel portion 2 by the porous sheet member 3 is formed in the center under the mold clamping, and a synthetic resin frame portion cavity C5 surrounds and communicates with the sound absorbing panel portion cavity C2. It is formed. There is no partition between the two. Furthermore, a first crosspiece first groove 861 is formed on the cavity surface 82 of the sound absorbing panel portion cavity C2 of one of the split molds 8, and the cavity surface 92 of the sound absorbing panel portion cavity C2 of the other split mold 9 is formed with: A second groove 962 for the second rail or a depression (not shown) for the projecting portion 63 is formed.

In this embodiment, along with the formation of the frame portion cavity C5 surrounding the sound absorbing panel portion cavity C2 in which the porous sheet members 3 that become the sound absorbing panel portion 2 are stacked, the first crosspiece cavity C61 formed by the first groove 861 is formed. is formed on the movable mold 8 side, and a second rail cavity C62 formed by the second groove 962 is formed on the fixed mold 9 side. Even if the sound absorbing panel portion 2 exists as an insert in the cavity C, the first and second crosspiece cavities C61 and C62 are electrically connected to the frame cavity C5 at both end portions 611 and 621, respectively.
A first groove 861 for the band plate-like first crosspiece 61 serving as a framework is dug into the cavity surface 82 for the sound absorbing panel portion of the movable mold 8 in a groove shape that is raised in the band width direction. The groove-like lines are formed so as to intersect in a grid pattern on the cavity surface 82 for the sound absorbing panel portion. In addition, a second groove 962 for the band plate-like second crosspiece 62 is dug into the cavity surface 92 of the fixed mold 9 in a groove shape with the band width direction raised. The first crosspiece 61 and the second crosspiece 62, which are assembled in a grid pattern, are displaced from each other in a plan view as shown in FIG. (Fig. 4). By clamping the mold, the first groove 861 and the second groove 962 form first crosspiece and second crosspiece cavities C61 and C62.
When the mold T is opened, after stacking and setting a plurality of porous sheet members 3 having different airflow resistances, the mold is clamped, and the stacked porous sheet members 3 are compressed in the plate thickness direction to form a porous structure. is shaped into the sound absorbing panel part 2 that maintains the After that, a synthetic resin raw material g (hereinafter also simply referred to as “resin raw material”) is injected into the cavity C5 for the frame portion, the cavity C61 for the first crosspiece, and the cavity C62 for the second crosspiece. It is an injection molding machine 7 capable of molding a synthetic resin injection molding part 4 .

Using the porous sheet member 3 and the injection molding machine 7, the composite member 1 is manufactured, for example, as follows. FIGS. 9 to 12 used for the following description show respective manufacturing process diagrams in the cross-sectional view of the composite member 1 in FIG.

First, the mold T is opened, and two types (plurality) of porous sheet members 3 having different airflow resistances, which are softened by heating to a predetermined temperature, are laminated and set on the cavity surface 82 for the sound absorbing panel part of the movable mold 8. (Fig. 10). An outer porous sheet member 3A having a large airflow resistance and an inner porous sheet member 3B having a small airflow resistance cut to the required size of the sound absorbing panel part 2 are laminated, and a stopper (not shown) is attached to the movable mold 8. Lock set. The thickness t2 of the outer porous sheet member 3A is smaller than the thickness t1 of the inner porous sheet member 3B.

Next, the fixed mold 9 and the movable mold 8 are clamped to form the sound absorbing panel portion 2 (FIG. 11). While the molds are clamped, the gap between the cavity surface 82 for the sound absorbing panel section of the movable mold 8 and the cavity surface 92 for the sound absorbing panel section of the fixed mold 9 opposed thereto is set to the thickness t2 of the outer porous sheet member 3A. It is set smaller than the value added with the thickness t1 of the member 3B.
The sound absorbing panel cavity surface 82 of the movable mold 8 and the sound absorbing panel cavity surface 92 of the fixed mold 9 sandwich and compress the laminate of the inner and outer porous sheet members 3B and 3A. The inner and outer porous sheet members 3B and 3A are compressed in the thickness direction while leaving the sound absorbing porous structure, compression hardening progresses, and the sound absorbing panel portion 2 with the thickness t forms the slope shown in FIG. shaped. The sound absorbing panel portion 2 is molded in the sound absorbing panel portion cavity C2 by mold clamping. remains. In addition, the first crosspiece cavity C61 remains on the side of the movable mold 8 that is the back side of the sound absorbing panel portion 2 due to the first groove 861, and the second groove 962 is left on the side of the fixed mold 9 that is the side of the front surface 2a of the sound absorbing panel portion 2. A second rail cavity C62 remains (FIGS. 9 and 11).
Reference numeral 85f denotes a biting protrusion formed on the frame portion, 861f a biting protrusion formed on the first crosspiece, and 962f a biting protrusion formed on the second crosspiece. By injecting the resin raw material g into the cavity C after mold clamping, the resin raw material g is unnecessary into the sound absorbing panel part 2 from the cavities C5, C61, C62 of the frame part 5, the first crosspiece 61, and the second crosspiece 62. prevent intrusion.

Subsequently, the synthetic resin raw material g is injected into the frame cavity C5, the first groove 861, and the second groove 962 or the recess (FIG. 11), and the frame 5 integrated with the sound absorbing panel 2, the second One crosspiece 61 and second crosspiece 62 or projecting portion 63 are injection molded.
In this embodiment, the resin raw material g is injected under a mold clamping state, and the frame portion 5, the first crosspiece 61, and the second crosspiece 62 for retaining the shape of the sound absorbing panel portion 2 are integrally molded with the sound absorbing panel portion 2. . After clamping, the resin material g is injected into the cavities C5, C61 and C62 for the frame portion 5, the first crosspiece 61 and the second crosspiece 62 to mold the synthetic resin injection molded portion 4 (Fig. 12). . A resin raw material g is injected into the cavity C from a nozzle 74 of the injection molding machine 7 through a runner 72 and a gate 71 (FIG. 11). Here, polypropylene resin raw material g is used. The resin raw material g is injected into the cavity C from the side gate 71 leading to the frame cavity C5, and the resin raw material g enters the first and second crosspiece cavities C61 and C62 from the frame cavity C5, The frame portion 5, and further the first crosspiece 61 and the second crosspiece 62 as the convex portion 6 are formed.

The resin raw material g tries to penetrate from the outer peripheral portion 22 of the sound absorbing panel portion to the main body of the sound absorbing panel portion 2 which is maintained in a porous structure, but is blocked by the biting protrusions 85f formed on the frame portion 5. FIG. The resin raw material g tries to enter the main body of the sound absorbing panel portion 2 from the root portions of the cavities C61 and C62 for the first crosspiece 61 and the second crosspiece 62, but the bite projections 861f for forming the first crosspiece 61 and the second crosspiece 62, Blocked by 962f. That is, in the mold clamping, the projections 85f, 861f, and 962f bite into the sound absorbing panel portion 2 by the amount that protrudes toward the sound absorbing panel portion 2 from the cavity surfaces 82, 85, and 92 around them, and the sound absorbing structure of the porous structure The portion of the panel portion 2 is further compressed to have a high density to prevent permeation of the resin raw material g. The projections 85f, 861f, and 962f prevent the leakage of the resin raw material g, which deteriorates the sound absorption performance, into the main body area of the sound absorbing panel portion 2 beyond the projections 85f, 861f, and 962f.

In the frame cavity C5, the biting protrusion 85f for forming the frame portion 5 is formed around the outer periphery of the sound absorbing panel portion 2 so as to be one size smaller than the outer periphery of the sound absorbing panel portion 2. A resin infiltration hardened portion 51 in which the resin raw material g is infiltrated and hardened in the network structure of the limited region is formed on the peripheral edge portion of the frame portion opening 50 . A combined area 15 is formed in which the resin infiltration hardening portion 51 and the sound absorbing panel portion outer peripheral portion 22 are integrated.

On the other hand, in the cavities C61 and C62 for the first crosspiece 61 and the second crosspiece 62, the groove mouths of the first groove 861 and the second groove 962 are closed with the sound absorbing panel portion 2, and the sound absorbing panel portion 2 has a porous structure. Since it is maintained, hardened portions 615 and 625 where the resin raw material g penetrates and hardens are formed in the portions of the sound absorbing panel portion 2 that are in contact with the mouths of the first and second grooves 861 and 962, and the first crosspiece 61 and the second crosspiece are formed. 62 is integrated with the sound absorbing panel section 2 . The first crosspiece 61 provided on the back surface 1b side of the composite member 1 is a low-density panel layer 2B (hereinafter also referred to as "back panel layer") formed by the inner porous sheet member 3B forming the back surface 2b of the sound absorbing panel portion. ), and the second crosspiece 62 provided on the surface 1a side of the composite member 1 is a high-density panel portion layer 2A (hereinafter referred to as “front panel portion (Also referred to as "layer").
Here, as shown in FIGS. 1 and 6(a), the first crosspiece 61 is arranged on the back surface 2b of the sound absorbing panel part 2, and the first crosspiece 61 is joined and integrated with the back surface, whereby the sound absorbing panel part 2 can maintain the shape of one panel surface 2b side. However, if there is no second crosspiece 62, the inner and outer porous sheet members 3B and 3A are simply laminated, and depending on the running of the vehicle, the front panel layer 2A may become the back panel as shown in FIG. 6(b). It invites a situation in which it rises from the interface 2K with the sublayer 2B. Even if the base of the first crosspiece 61 can be penetrated and hardened into the back panel layer 2B, it is difficult to penetrate and harden the front panel layer 2A.
Therefore, in order to solve such a situation, the present invention integrates the second crosspiece 62 with the front panel layer 2A so that the second crosspiece 62 as the convex portion 6 prevents the floating.

As for the second crosspiece 62, instead of FIG. 2, the first crosspiece 61 and the second crosspiece 62 may be arranged to face each other via the sound absorbing panel portion 2 as shown in FIG. Further, instead of the second crosspiece cavity C62, a through hole 20 is provided that penetrates the sound absorbing panel portion 2 that forms the recess and is interposed between the recess and the first crosspiece cavity C61. The hardened resin portion 631 is filled, and the head portion 632 at the tip thereof protrudes into the through-hole peripheral portion 21 on the other panel surface 2a to form a hardened projecting portion 63 (FIG. 8). Incidentally, in the porous sheet member 3 and the sound absorbing panel portion 2 of FIG. does not have the through holes 20 and 30.

In this manner, injection molding is performed in which the resin raw material g enters the sound absorbing panel portion 2, the frame portion cavity C5, the outer peripheral portion 22 of the sound absorbing panel portion 2, and the first and second crosspiece cavities C61 and C62. The composite member 1 is formed by integrating the first crosspiece 61 and the low-density panel layer 2B, and integrating the second crosspiece 62 and the high-density panel layer 2A.
A plurality of porous sheet members 3 having different airflow resistances are laminated by mold clamping to form a sound absorbing panel part 2. - 特許庁After that, the sound absorbing panel portion 2 (porous sheet member 2) is used as an insert product, and the resin raw material g is injected into the cavity C. , and the first crosspiece 61, the second crosspiece 62, and the hardened portions 615, 625 that penetrate the resin into the sound absorbing panel portion 2 at the base of these, to form the desired composite member 1 get

(2) Composite member 1
The composite member 1 (here, "engine undercover") obtained by the manufacturing method or the like shown in FIGS. ).

The sound absorbing panel part 2 is a sheet-like body formed by laminating a plurality of porous sheet members 3 having air permeability and different air resistance. A plurality of porous sheet members 3 are formed by compressing the sheet thickness and maintaining the porous structure and air permeability.
In this embodiment, an outer porous sheet member 3A having a high density (large basis weight) and a small thickness, and an inner porous sheet member 3B having a lower density (lower basis weight) and a larger thickness than the outer porous sheet member 3A. , the sound absorbing panel portion 2 is molded (FIGS. 3 and 5). The sound absorbing panel portion 2 is extended so as to close the frame opening 50 of the frame portion 5 .

The sound absorbing panel part 2 is formed of the two porous sheet members 3 having different airflow resistances, and the airflow resistance of the outer porous sheet member 3A is made larger than that of the inner porous sheet member 3B, so that both are separated. It is laminated in two layers and shaped while maintaining a porous structure. Specifically, two porous sheet members 3 having different air permeability are both formed of nonwoven fabric. The nonwoven fabric 3 arranged on the side of the outer surface 3a is made larger in basis weight and smaller in thickness than the nonwoven fabric 3 arranged on the side of the inner surface 3b, and the sound absorbing panel part 2 is formed by laminating them in two layers. there is As shown in FIG. 5, the front side panel layer 2A formed of the outer porous sheet member 3A is arranged on the composite member front surface 1a side, and the back side formed of the inner porous sheet member 3B is arranged on the composite member back surface 1b side. A panel section layer 2B is arranged.

Here, the plurality of porous sheet members 3 may be adhesively fixed at a portion of their lamination interfaces 2K. The laminated and shaped sound absorbing panel portion 2 is more preferable as long as the sound absorbing effect is not deteriorated. This is because it is possible to prevent one panel layer from rising from the other panel layer. A portion of the interface 2K between the front panel layer 2A and the back panel layer 2B may be partially bonded with an adhesive or the like, but in this embodiment, the front panel layer 2A and the back panel layer 2B only overlap each other. Therefore, no adhesive or the like is used to bond the two to the joint interface 2K. An injection-molded portion 4 is provided so that the front side panel layer 2A and the back side panel layer 2B are not separated from each other and the shape of the sound absorbing panel section 2 is maintained.

The injection molded part 4 includes a frame part 5 and a convex part 6, and surrounds the sound absorbing panel part 2. The injection molding part 4 is integrally formed with the sound absorbing panel part 2 so that the panel surface is not deformed. This is the molding processing section.

The frame portion 5 is a main portion of the injection molded portion 4 formed integrally with the sound absorbing panel portion 2 by forming an infiltration hardened portion 51 in the outer peripheral portion 22 of the sound absorbing panel portion. During the injection molding, the frame portion 5 is joined to the sound absorbing panel portion 2 by part of the resin raw material g entering the sound absorbing panel portion 2 from the outer peripheral contact surface of the sound absorbing panel portion 2 and hardening. The resin-infiltrated hardened portion 51 of the frame portion 5 that enters the sound-absorbing panel portion outer peripheral portion 22 and hardens forms the combined area 15 with the sound-absorbing panel portion 2 . A frame portion 5 is integrally formed surrounding the sound absorbing panel portion 2 . In this embodiment, the composite member 1 is substantially rectangular in plan view, and the sound absorbing panel section 2 is spread out within the frame opening 50 of the rectangular frame section 5 . A reference numeral 53 denotes a frame reinforcement forming portion having a U-shaped cross section on the outer periphery of the frame portion 5 .

The convex portion 6 is part of the injection-molded portion 4 that is connected to the frame portion 5 and molded simultaneously with the molding of the frame portion 5 . A cured portion is formed by infiltrating the resin raw material g into the sound absorbing panel portion 2 from the root portion, and convex portions 6 are formed on the panel front surface 2a and the panel back surface 2b of the sound absorbing panel portion 2, respectively. The injection-molded portion 4 is integrally molded using the plurality of porous sheet members 3 as inserts. I'm trying to stop it from moving in the direction.

In this embodiment, the convex portion 6 formed on one panel surface of the sound absorbing panel portion 2 (on the panel back surface 2b of the sound absorbing panel portion 2) penetrates into the sound absorbing panel portion 2 from the root portion and hardens. A hardened portion 615 is formed to form a first crosspiece 61 that traverses the panel rear surface 2b of the sound absorbing panel portion 2 and has both end portions 611 connected to the facing portions of the frame portion 5, respectively. In addition, the convex portion 6 formed on the other panel surface (the panel surface 2a of the sound absorbing panel portion 2) related to the sound absorbing panel portion 2 penetrates into the sound absorbing panel portion 2 from the root portion and is hardened to form a hardened portion 625. , which traverses the panel surface 2 a of the sound-absorbing panel portion 2 , and the end portions 621 of which are joined to the facing portions of the frame portion 5 to form a second crosspiece 62 .
The band plate-like first crosspiece 61 and second crosspiece 62 are not only connected to the frame 5 at both ends 611 and 621, but also penetrated and hardened by entering the resin raw material g into the sound absorbing panel 2 from the base portion. The portions 615 and 625 hold the strip-shaped sheet in the width direction more firmly upright. It is possible to prevent the panel surface of the sound absorbing panel part 2 from partially swelling or floating. A first crosspiece 61 is arranged and formed in a grid pattern on the panel back surface 2b of the sound absorbing panel part 2, and a second crosspiece 62 sandwiching the sound absorbing panel part 2 with the first crosspiece 61 is arranged in a grid pattern on the panel surface 2a. formed (FIGS. 2-6).
Although the lattice-like bodies of the first crosspiece 61 and the second crosspiece 62 are staggered as shown in FIG. can also be arranged opposite each other.

Regarding the second crosspiece 62, a through hole 20 is provided that penetrates from the back surface 2b of the sound absorbing panel portion 2 that contacts the first crosspiece 61 to the front surface 2a. The head portion 632 of the tip protrudes into the peripheral edge portion 21 of the through hole 20 on the panel surface 2a, and can be replaced with a hardened projecting portion 63 (FIG. 8B). Unlike the second crosspiece 62, only the rivet head-shaped head portion 632 protrudes on the side of the sound absorbing panel portion surface 2a, so that the appearance of the product design side is improved. Both the projecting portion 63 and the second crosspiece 62 may be provided as the convex portion 6 on the sound absorbing panel portion surface 2a side. Of course, the projecting portion 63 can also be provided on the side of the rear surface 2b of the sound absorbing panel portion.

In this manner, the injection-molded portion 4 is integrally molded with a plurality of porous sheet members 3 as inserts, and the convex portion 6 is positioned on the panel surface of the sound-absorbing panel portion 2 . The desired composite member is finished in which movement in the outward direction of the convex portion is restrained.
The rest of the configuration is the same as the content described in (1), so the description thereof is omitted. The same reference numerals as (1) indicate the same or corresponding parts. Reference numeral 32 denotes the outer peripheral portion of the porous sheet member 3, reference numeral 5a denotes the front surface of the frame portion 5, and reference numeral 5b denotes the back surface of the frame portion 5. As shown in FIG.

(3) Effect According to the composite member and the manufacturing method thereof configured as described above, the sound absorbing panel portion 2, which is the main portion formed by shaping the porous sheet member 3 having air permeability, remains a porous structure. So it retains its sound absorbing properties. In addition, when a plurality of porous sheet members 3 having air permeability and different air resistance are laminated to maintain a porous structure, the sound absorbing panel section 2 can withstand low frequency sounds of about 800 Hz to 2 kHz. can effectively absorb sound. The sound absorption performance of the sound absorbing panel portion 2 is improved by stacking the panel portion layers 2A and 2B of porous bodies having different air permeability. If it is used for the engine undercover of the embodiment, in addition to the original role of the engine cover member, it exhibits an excellent effect of absorbing low-frequency sound emitted from the surrounding running tires and the like.

More specifically, as in claims 1 and 8, when the sound absorbing panel portion 2 is formed by laminating a plurality of porous sheet members 3 having different airflow resistance, the porous sheet member 2 with low airflow resistance is formed. A spring-mass model can be formed in which the panel layer 2B made of the sheet member 3 corresponds to the spring, and the panel layer 2A made of the porous sheet member 3 with high airflow resistance corresponds to the mass (mass). Therefore, the panel portion layer 2A made of the porous sheet member 3 with high airflow resistance is shaken by the panel portion layer 2B made of the porous sheet member 3 with low airflow resistance, and compared to the high frequency sound, it sounds like a tire sound. It can absorb low-frequency sound (800Hz to 2kHz) with large energy at low cost. It is effective in absorbing external noise generated from tire noise, etc. while the vehicle is running.

Further, convex portions 6 are formed on both the front and back panel surfaces 2a and 2b of the sound absorbing panel portion 2, respectively, and the convex portions 6 are formed on the panel surfaces of the sound absorbing panel portion 2 at the points. By restraining the movement in the 6-side direction, it is possible to maintain the overlapping state of the panel part layers with different ventilation resistances, so that the low-frequency sound is stably and effectively absorbed. If each panel portion layer laminated with different air resistance is separated from the contact state, the spring mass model cannot be formed. In the present invention, the projection 6 prevents separation and retains the spring mass model. The convex portion 6 suppresses the partial expansion of the panel front surface 2a and the panel back surface 2b. Even with the panel section layers 2A and 2B having a two-layer structure as in the present embodiment, if the convex portion 6 is provided, they will not separate or float. As a result, low frequency sound can be continuously absorbed.

As in claims 2 and 8, when the convex portion 6 is formed by the first crosspiece 61 and the second crosspiece 62, the convex portion of the panel surface related to each panel layer constituting the sound absorbing panel portion 2 is formed. Movement in the lateral direction, that is, movement in the direction perpendicular to the panel surface can be efficiently and reliably restrained, so low-frequency sound (800 Hz to 2 kHz) can be stably absorbed. When both end portions 611 and 621 of the first crosspiece 61 and the second crosspiece 62 are connected to the frame portion 5 respectively, the first crosspiece 61 and the second crosspiece 62 are formed by injecting into the frame portion 5 in manufacturing the composite member 1 . Since the resin raw material g thus obtained can enter the cavities C61 and C62 for the first crosspiece and the second crosspiece through the both end portions 611 and 621, the molding of the frame portion 5 and the first crosspiece 61 and the second crosspiece 62 is facilitated. . Since the first crosspiece 61, the second crosspiece 62 and the frame part 5 are integrated, the shape retention of the sound absorbing panel part 2 is excellent.

As in claim 3, when the through hole 20 and the projecting portion 63 are provided, the projecting portion 63 appearing on the surface 2a of the sound absorbing panel portion 2 can be only a head portion 632 such as a rivet head, and the composite member which becomes the design surface side. The convex portion 6 on the surface 1a can be made inconspicuous.
As in claim 4, when the sound absorbing panel portion 2 is formed of two porous sheet members 3 having different ventilation resistances, the structure can be simple and low frequency sound can be absorbed. When the airflow resistance of the outer porous sheet member 3A is made larger than that of the inner porous sheet member 3B, and both are laminated in two layers to form the sound absorbing panel portion 2, the panel portion layer 2A having a high density becomes the sound absorbing panel. Since it is on the surface 2a side of the portion 2, the sound absorbing panel portion 2 is protected against external force, and the composite member 1 having excellent strength can be obtained.

When the first crosspieces 61 and the second crosspieces 62 are arranged in a grid pattern on the panel surface of the sound absorbing panel portion 2 as in claim 5, the movement of the panel surface in the vertical direction can be effectively restrained.
As in claims 6 and 9, when the two porous sheet members 3 having different air permeability are both formed of nonwoven fabric, the porous sheet member 3 is moved to the sound absorbing panel portion 2 maintaining the porous structure by clamping. and can be easily shaped. Both of the porous sheet members 3 are made of nonwoven fabric, and the nonwoven fabric forming the other panel surface side of the sound absorbing panel portion 2 is made larger in basis weight and thicker than the nonwoven fabric forming the other panel surface side. If the two sheets are made small and laminated in two layers and shaped, sound absorption adjustment for low-frequency sounds (800 Hz to 2 kHz) can be easily performed.
As in claim 7, when the plurality of porous sheet members 3 are bonded and fixed at a part of their lamination interfaces 2K to form a laminated and shaped sound absorbing panel portion 2, the panel portion layers having different airflow resistances are formed. does not separate from the adhesive fixing portion, so low-frequency sound can be stably and effectively absorbed.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention according to the purpose and application. Composite member 1, sound absorbing panel part 2, porous sheet member 3, injection molding part 4, frame part 5, convex part 6, injection molding machine 7, mold T, etc. The shape, size, number, material, etc. can be selected as appropriate. Although the composite member 1 of the present embodiment is used as an engine undercover, it can of course be applied to a battery cooling duct shown in FIG. 13 as well as an instrument panel undercover. In FIG. 13, reference numeral 10 denotes a duct connection port, and the same reference numerals as in the embodiment indicate the same or corresponding portions. In the embodiment, the porous sheet member 3 is heated (preheated) prior to being set in the mold T and then shaped into the sound absorbing panel portion 2, but the heating is not always required.

1 composite member 2 sound absorbing panel 2a other panel surface (surface)
2b One panel side (back side)
3 Porous sheet member (nonwoven fabric)
4 injection molding part 5 frame part 6 convex part 615 infiltration hardening part 625 infiltration hardening part 631 infiltration hardening part 7 injection molding machine 8 one mold (movable mold)
9 Other type (fixed type)
C cavity g resin raw material

Claims (9)

a sound absorbing panel section in which a plurality of porous sheet members having air permeability and different air resistance are laminated ;
A frame portion integrally formed to surround the sound absorbing panel portion, and convex portions respectively formed on both front and back panel surfaces of the sound absorbing panel portion, wherein the frame portion and the convex shape A composite member comprising : a synthetic resin portion having a hardened portion which is formed by infiltrating and hardening into the sound absorbing panel portion on both of the portions . 2. The sound absorbing panel according to claim 1, wherein said convex portion formed on one panel surface of said sound absorbing panel portion includes a first crosspiece which traverses said one panel surface and whose both end portions are respectively coupled to said frame portion. Composite member. 3. The projecting portion formed on the other panel surface of the sound absorbing panel portion includes a second crosspiece that traverses the other panel surface and has both end portions coupled to the frame portion. Composite member. 4. The composite member according to claim 3, wherein said first crosspieces are arranged in a grid pattern on said one panel surface, and said second crosspieces are arranged in a grid pattern on said other panel surface. A through hole penetrating from the one panel surface to the other panel surface is provided in the sound absorbing panel portion,
The through hole is filled with a cured resin portion, and the tip of the through hole protrudes from the peripheral portion of the through hole on the other panel surface to form a projecting portion as the convex portion formed on the other panel surface. 3. The composite member of claim 2 formed. Both of the porous sheet members are made of nonwoven fabric, and the nonwoven fabric forming the other panel surface side of the sound absorbing panel part has a larger basis weight and a smaller thickness than the nonwoven fabric forming the other panel surface side. A composite member according to any one of claims 1 to 5. An article comprising the composite member according to any one of claims 1 to 6,
The article is selected from an engine undercover, an instrument panel undercover, and a battery cooling duct. A pair of molds for forming a panel portion cavity of the sound absorbing panel portion by the porous sheet member and a frame portion cavity surrounding the sound absorbing panel portion cavity and communicating with the sound absorbing panel portion cavity. split type,
A first groove for a first crosspiece is formed on the cavity surface of the cavity for the sound absorbing panel portion of one of the split molds,
A mold in which a second groove for a second rail or a recess for a projecting portion is formed on the cavity surface of the cavity for the sound absorbing panel portion of the other split mold. A method for manufacturing a composite member using the mold according to claim 8,
a setting step of stacking the porous sheet members and setting them in the cavity for the sound absorbing panel;
a mold clamping step of clamping the split mold after the setting step;
After the mold clamping step, a synthetic resin raw material is injected into the cavity for the frame portion, the first groove for the first crosspiece, and the second groove for the second crosspiece or the recess for the protrusion, and integrated with the sound absorbing panel portion. and a molding step of injection-molding the frame portion, the first crosspiece, and the second crosspiece or the projecting portion.

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