JP2007114617A - Sound absorbing cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase of metal mold cost for molding a base material and to stably hold a sound absorbing material on a rear face of the base material without using other component such as a washer, in a sound absorbing cover in which the base material and the sound absorbing material are not connected. <P>SOLUTION: A socket section 3 for attaching is projected from the rear face of the base material 1, and in the socket section 3, an aperture 30 which becomes undercut when molding the base material 1 is formed, and a hook section 34 which extends to the same direction of an opening of the aperture 30, with a holding face 35 which is approximately parallel to the rear face of the base material 1 is provided. The sound absorbing material 2 includes a through hole 22 which the socket section 3 can penetrate. The socket section 3 penetrates the through hole 22, and the sound absorbing material 2 is pinched and held by the holding face 35 of the hooking section 34 and the rear face of the base material 1. The hooking section 34 can be molded only by carving an existing metal mold. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a soundproof cover used for an engine cover or the like.

  In recent automobiles, a block side cover and an under cover are disposed around or below the engine to shield noise from the engine, and an engine cover is disposed on the upper surface of the cylinder block. These soundproof covers are made of, for example, a hard base material (sound insulation material) made of resin or steel plate and urethane foam laminated on the engine side surface of the base material, as seen in Japanese Patent Application Laid-Open No. 10-205352. And a sound absorbing material made of molecular foam. In this soundproof cover, the base material shields the sound from the engine, and the sound absorbing material absorbs the sound from the engine.

  That is, the sound wave emitted from the engine as the sound source is absorbed to some extent by the sound absorbing material when passing through the sound absorbing material, and the remaining sound wave reaches the substrate. Since it is difficult for the sound wave to pass through the hard base material, it is reflected by the base material and passes through the sound absorbing material again. Therefore, since the sound wave is repeatedly reflected between the engine and the base material and is absorbed every time it passes through the sound absorbing material, it is possible to effectively prevent sound.

  However, since the base material has a hard plate shape, there is a problem that when the base material itself vibrates, it becomes a noise generation source. Therefore, by making the sound absorbing material thick, it is also possible to prevent sound waves from reaching the base material and vibrating the base material. Such a soundproof cover is used by arranging a sound absorbing material in contact with a sound source, or being fixed to the engine or the vicinity of the engine via a vibration-proof member such as a rubber mount.

  By the way, the sound-absorbing material is generally used by being joined to the back surface of the base material by a double-sided tape, an adhesive or the like, or when the sound-absorbing layer is urethane, it is generally formed by integral foaming with the base material. However, when double-sided tape and adhesive are used, man-hours for joining the base material and the sound absorbing material are required, and in the case of integral foam molding, it is difficult to separate the base material and the sound absorbing material. There is a problem above. In order to avoid such a problem, it is necessary to unbond the base material and the sound absorbing material.

  However, if the base material and the sound absorbing material are not joined, when the soundproof cover is assembled to the mating member, the sound absorbing material hangs down from the base material, making it difficult to assemble, or part of the sound absorbing material may be There is a case where it is caught and assembled in an excessively deformed state. Therefore, it is conceivable to physically fix the sound absorbing material to the base material. For example, a socket that protrudes on the back side of the base material is formed, a through hole is formed in the sound absorbing material, a socket is inserted into the through hole, and then a washer is fitted and fixed to the tip of the socket protruding from the sound absorbing material. Has been done.

However, when the fixing socket is formed on the base material, another part such as a washer is required, and there is a problem that the cost is increased including the mounting man-hour. In addition, when a hook for fixing the sound-absorbing material is formed during the injection molding of the base material, there is a problem that undercut processing such as a slide core is newly required and the mold cost (mold cost) for base material molding increases. was there.
JP-A-10-205352

  The present invention has been made in view of the above circumstances, and in the soundproof cover in which the base material and the sound absorbing material are not joined, while preventing the mold cost for base material molding from increasing, another part such as a washer is provided. An object to be solved is to stably hold the sound absorbing material on the back surface of the base material without using it.

The feature of the soundproof cover of the present invention that solves the above-mentioned problem is composed of a hard base material formed by injection molding and a sound absorbing material laminated in a non-bonded state on the back surface side of the base material, and the back surface of the base material From the socket part for mounting to the mating member protrudes so as to penetrate the sound absorbing material, the socket part is a soundproof cover having an undercut part when molding the base material,
The socket portion includes a hook portion having a holding surface that extends in the same direction as the slide core used when forming the undercut portion of the base material and faces the back surface of the base material. That is, it is held between the holding surface and the back surface of the substrate.

  It is desirable that the hook portion has a tapered surface that is continuous with the holding surface and is inclined toward the socket portion.

Further, another feature of the soundproof cover of the present invention that solves the above problems is composed of a hard base material formed by injection molding, and a sound absorbing material laminated in a non-bonded state on the back side of the base material, A soundproof cover having ribs engageable with slits formed in the sound absorbing material on the back surface of the base material,
A part of the rib is provided with a hook portion extending in the same direction as the die-cutting direction when forming the base material and having a holding surface facing the back surface of the base material, and the sound absorbing material is provided between the holding surface of the hook portion and the base material. That is, it is held between the back and the back.

  The holding surface is preferably a tapered surface inclined in the direction of narrowing the gap with the back surface of the substrate.

  According to the soundproof cover of the present invention, since the base material and the sound absorbing material are not joined, recycling is possible, and earth resources can be saved. And since the sound absorbing material is held on the base material by physically engaging with the hooking part, problems such as drooping or entangled when assembled to the mating member are prevented in advance. it can.

  Furthermore, the hook part extends in the same direction as the moving direction of the slide core for forming the socket part, or extends in the same direction as the die-cutting direction at the time of molding the base material. Molding is possible just by engraving. Therefore, an increase in mold cost can be prevented. And if a taper surface is formed in a hook part, the workability | operativity at the time of hold | maintaining a sound-absorbing material to a base material will improve.

  The soundproof cover of the present invention comprises a hard base material formed by injection molding and a sound absorbing material laminated in a non-bonded state on the back surface side of the base material. Various materials such as PP, PE, PA, and ABS can be used as the material of the base material. The sound absorbing material is a soft porous body, and is formed from urethane foam, felt, or the like so as to follow the back surface of the substrate.

  In the soundproof cover of the first invention, a socket part for attachment to the mating member protrudes from the back surface of the base material, and the socket part is provided with, for example, an opening that becomes an undercut when the base material is molded. In the case of an engine cover, a flange that can hold a grommet to which a protrusion protruding from the cylinder block is fitted can be used as the socket. Since the collar portion includes an undercut portion that becomes an undercut when the base material is molded, the collar portion is molded using the slide core.

  The socket portion includes a hook portion that extends in the same direction as the slide direction of the slide core and has a holding surface facing the back surface of the base material. In other words, the hook portion does not undercut the slide core that forms the undercut portion of the socket portion. Therefore, by engraving the mold surface of the slide core or the mold surface that is in sliding contact with the slide core, the hook portion can be formed, so that it is not necessary to manufacture a new mold and the increase in mold cost can be suppressed. .

  The hook portion does not need to be newly formed for fixing the sound absorbing material, and the mold cost can be saved by using the existing socket portion. The other sound-absorbing material has a through-hole through which the socket part can penetrate. And when laminating | stacking a sound absorption material on a base material, a socket part penetrates a through-hole, and a sound absorption material is pinched | interposed and hold | maintained by the holding surface of a hook part, and the back surface of a base material. As a result, the sound absorbing material can be stably held on the base material, and problems such as drooping or being caught when assembled to the counterpart member can be avoided.

  It is desirable that the hook portion has a tapered surface that is continuous with the holding surface and is inclined toward the socket portion. Since the sound absorbing material is guided by the tapered surface, the workability when the socket portion is inserted into the through hole is improved.

  In the soundproof cover according to the second aspect of the invention, a rib is provided on the back surface of the substrate. A part of the rib is provided with a hook portion that extends in the same direction as the die cutting direction when the base material is molded. Therefore, the hook portion is not undercut. And since a hook part can be shape | molded by carving a mold surface, it is not necessary to manufacture a metal mold | die newly and the increase in mold cost can be suppressed.

  The other sound-absorbing material has a slit with which the rib can be engaged, and the hook is engaged with the slit and is held by the base material.

  The rib extends to the end portion of the base material, and the hook portion can be a protrusion formed at the tip of the rib and having a gap with the back surface of the base material. In this way, the sound absorbing material can be hooked on the protrusion at the end of the slit, and the sound absorbing material can be held on the substrate. In this case, it is desirable that the protrusion has a tapered surface (holding surface) that is inclined in the direction of narrowing the gap. In this way, the sound absorbing material is guided by the tapered surface to improve workability, and the sound absorbing material that has entered the gap is compressed by the tapered surface. Therefore, the sound absorbing material is in a state of being pressed against the back surface of the base material, and can be held more stably.

  Hereinafter, the present invention will be described specifically by way of examples.

  The engine cover which is a soundproof cover of a present Example is shown in FIGS. This engine cover includes both the first invention and the second invention.

  The engine cover is composed of an ABS base material 1 manufactured by injection molding and a urethane foam sound absorbing material 2 manufactured by closed foam molding. Both the base material 1 and the sound absorbing material 2 have a container shape with a shallow bottom.

  The substrate 1 includes a substantially rectangular bottom 10 and an edge 11 rising from four sides of the bottom 10. The sound absorbing material 2 is formed in a size that can be arranged along the inner peripheral surface of the base material 1, and includes a bottom portion 20 and an edge portion 21 that rises from four sides of the bottom portion 20. Since the base 1 is assembled so that the bottom 10 side faces the engine, the surface of the bottom 10 is hereinafter referred to as “the back of the base 1” and the opposite surface is referred to as “the surface of the base 1”. . The surface of the substrate 1 becomes the design surface.

  On the back surface of the substrate 1, a socket portion 3 is projected. As shown in an enlarged view in FIG. 2, the socket portion 3 includes a leg portion 31 having a U-shaped cross section that protrudes from the back surface of the base material 1 and has an opening 30 on one surface, and a flange portion formed at the tip of the leg portion 31. It consists of 32. The collar portion 32 includes a holding groove 33 that opens to the opening 30 side. The holding groove 33 holds a grommet described later.

  Further, hook portions 34 extending in the same direction as the opening direction of the opening 30 are formed on both sides of the opening 30 on the pair of wall portions of the leg portion 31 constituting the opening 30. The hook portion 34 has a holding surface 35 extending in parallel with the back surface of the substrate 1 and a tapered surface 36 inclined from the tip of the holding surface 35 toward the leg portion 3 and is formed in a substantially triangular shape. The hook portion 34 has the same thickness as the leg portions 31 on both sides of the opening 30 and extends in the same direction as the opening direction.

  The hook portion 34 is originally undercut with respect to the die-cutting direction (vertical direction in FIG. 1) of the mold for molding the base material 1, but originally has a slide core mechanism for forming the flange portion 32. Therefore, it is not necessary to newly provide a slide core mechanism. Then, the hook portion 34 can be formed simply by carving the mold surface of the slide core for forming the collar portion 32.

  Furthermore, on the back surface of the base material 1, a plurality of ribs 4 extending from the surface of the bottom portion 10 along the surface of the edge portion 11 to reinforce the base material 1, and reinforcing ribs formed along the surface of only the bottom portion 10. 5 is formed. As shown in an enlarged view in FIG. 3, the rib 4 has a tip extending to the end of the edge 11, and a protrusion (hook portion) 41 having a gap 40 between the surface of the edge 11 is formed at the tip. ing. The protrusion (hooking portion) 41 is formed with a tapered surface (holding surface) 42 that extends in an inclined manner in the direction of narrowing the gap 40.

  Since this protrusion (hanging part) 41 extends in parallel with the die-cutting direction of the mold for forming the base material 1, it does not undercut.

  On the other hand, in the sound absorbing material 2, as shown in FIG. 1, a through hole 22 that penetrates the bottom portion 20 is formed at a position corresponding to the socket portion 3. Further, on the outer surface of the edge portion 21, a plurality of slits 23 are formed at positions corresponding to the ribs 4, and a plurality of slits 24 are formed at positions corresponding to the ribs 5. Further, at the end portion of the edge portion 21, a recess portion 25 communicating with each slit 23 is formed.

  When assembling the sound absorbing material 2 to the base material 1, as shown in FIG. 4, the socket portions 3 are fitted into the respective through holes 22 of the sound absorbing material 2. Since the sound-absorbing material 2 is soft, it is easily elastically deformed when the hook portion 34 is pressed, and the hook portion 34 easily passes through the through hole 22 when guided by the tapered surface 36. When the hook 34 passes through the through hole 22 and protrudes from the back surface of the sound absorbing material 2, the holding surface 35 comes into contact with the surface of the sound absorbing material 2 as shown in FIG. The state is sandwiched between the back surface of the substrate 1 and the holding surface 35. The rib 5 is engaged with the slit 24. Thereby, the sound absorbing material 2 is stably held in a state in which the sound absorbing material 2 is in contact with the bottom 10 of the substrate 1.

  On the other hand, as shown in FIG. 6, at the edge portion 11, the rib 4 is engaged with the slit 23, but it is difficult to hold the sound absorbing material 2 on the edge portion 11 as it is. Therefore, the end of the sound absorbing material 2 is pulled, and a protrusion (hook) 41 at the tip of the rib 4 engaged with the slit 23 is inserted into the recess 25 from the slit 23. Then, as shown in FIG. 7, a part of the tip of the edge portion 21 is engaged with the gap 40 while being guided by the taper surface (holding surface) 42, and the edge portion 11 of the base material 1 is cut by the tapered surface (holding surface) 42. Pressure contacted. As a result, the edge 21 of the sound absorbing material 2 is stably held in a state where it is in contact with the edge 11 of the substrate 1.

  In the soundproof cover of this embodiment, the grommet 6 is attached to the flange 32 as shown in FIG. 8, and is pressed toward the spherical protrusion 7 protruding from the cylinder head. Thereby, the spherical protrusion 7 penetrates the grommet 6, and the base material 1 is fixed to the cylinder block via the grommet 6. At the time of this assembling work, since the entire sound absorbing material 2 is prevented from being separated from the base material 1 by the socket portion 3 and the rib 4, the sound absorbing material 2 does not hang down and workability is not deteriorated. There is no trouble such as 2 entrainment.

  When the vehicle is scrapped, the base material 1 and the sound absorbing material 2 can be easily separated, so that they can be recycled and save earth resources.

  In the embodiments, the present invention is applied to the engine cover. However, the soundproof cover of the present invention is not limited to the engine cover, and any use is possible as long as the sound absorbing material is laminated non-bonded to a hard base material. There is no limit.

It is a disassembled perspective view which shows the structure of the soundproof cover of one Example of this invention. It is a principal part expansion perspective view of the socket part in the soundproof cover of one Example of this invention. It is a principal part expansion perspective view of the rib in the soundproof cover of one Example of this invention. In the soundproof cover of one Example of this invention, it is principal part sectional drawing which shows a mode that a socket part and a sound-absorbing material are assembled | attached. In the soundproof cover of one Example of this invention, it is principal part sectional drawing which shows the state which assembled | attached the socket part and the sound-absorbing material. It is principal part sectional drawing which shows a mode that a rib and a sound-absorbing material are assembled | attached in the soundproof cover of one Example of this invention. In the soundproof cover of one Example of this invention, it is principal part sectional drawing which shows the state which assembled | attached the rib and the sound-absorbing material. It is principal part sectional drawing shown in the state which assembled | attached the soundproof cover of one Example of this invention to the cylinder block.

Explanation of symbols

1: Base material 2: Sound absorbing material 3: Socket part 4: Rib 5: Rib 6: Grommet
10, 20: Bottom 11, 21: Edge 22: Through hole
23: Slit 25: Recess 30: Opening
32: Saddle 34: Hook 35: Holding surface
36: Tapered surface 40: Clearance 41: Protrusion (hook)
42: Tapered surface (holding surface)

Claims (4)

A hard base material formed by injection molding, and a sound absorbing material laminated in a non-bonded state on the back surface side of the base material, and a socket portion for mounting to a mating member is provided from the back surface of the base material Projecting so as to penetrate the sound absorbing material, the socket portion is a soundproof cover having an undercut portion when the base material is molded,
The socket portion includes a hook portion having a holding surface that extends in the same direction as the slide direction of the slide core used when the undercut portion of the base material is molded and faces the back surface of the base material.
The sound-absorbing cover, wherein the sound-absorbing material is sandwiched and held between the holding surface of the hook portion and the back surface of the base material.   The soundproof cover according to claim 1, wherein the hook portion has a tapered surface that is continuous with the holding surface and is inclined toward the socket portion. A hard base material formed by injection molding, and a sound-absorbing material laminated in a non-bonded state on the back side of the base material, and a slit formed in the sound-absorbing material on the back side of the base material. A soundproof cover with matable ribs,
A part of the rib includes a hook portion having a holding surface that extends in the same direction as the die-cutting direction when molding the base material and faces the back surface of the base material,
The sound-absorbing cover, wherein the sound-absorbing material is sandwiched and held between the holding surface of the hook portion and the back surface of the base material.   The soundproof cover according to claim 3, wherein the holding surface is a tapered surface inclined in a direction of narrowing a gap with the back surface of the base material.

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