JP6287124B2 - Cover for automobile parts and method for producing cover for automobile parts - Google Patents

Description

  The present invention relates to a cover for automobile parts and a method for manufacturing a cover for automobile parts.

Conventionally, there is an engine under cover disposed below an engine as one of the parts of an automobile.
The engine undercover is primarily responsible for protecting the engine, but it also reduces air resistance, absorbs engine noise, blocks engine noise, prevents oil leaks, There are various roles such as preventing entry.

  And the technique for improving the sound insulation of such an engine undercover is disclosed (for example, refer patent document 1).

  In the engine undercover of Patent Document 1, since a sheet-like porous material is stuck between the resin upper surface plate portion and the resin lower surface plate portion while leaving an air layer, by driving the engine It is considered that the generated noise can be effectively suppressed.

JP 2013-95314 A

  Here, in order to ensure sound insulation, the specific gravity and mass (mass = specific gravity × volume) of the sound insulation material are important factors. That is, in order to improve the sound insulation, a thicker and heavier member is generally suitable than a thin and lighter member.

  Therefore, in order to improve sound insulation, it is preferable to apply a metal having a large specific gravity to the sound insulation material. In this regard, since the technology of Patent Document 1 achieves sound insulation using an air layer, sound insulation is not sufficient with air having a specific gravity smaller than that of metal or the like.

  Thus, since the metal with a large specific gravity is excellent in sound insulation, it is also conceivable to change the engine undercover itself from a resin member to a metal plate. However, with an engine undercover made of only metal plates, it is difficult for workers on the automobile assembly line to carry around, so it is desirable to avoid the construction of only metal plates.

  Therefore, in order to improve the workability of workers, it is conceivable to wrap the metal plate with some resin material, but because the fundamental raw material is different between the metal plate and the resin member, it is difficult to weld. There's a problem.

  Accordingly, an object of the present invention is to provide a technique capable of ensuring good sound insulation and improving workability and facilitating manufacture.

  In order to solve the above problems, the present invention employs a cover for automobile parts and a method for manufacturing a cover for automobile parts. In addition, the wording in the parenthesis shown below is an illustration to the last, and this invention is not limited to this.

[Auto Parts Cover]
Solution 1: The automobile component cover of the present solution includes a sound insulating material, a holding member, and a resin member. For this reason, the automotive component cover of the present solution mainly uses three members.

  The sound insulating material has a specific gravity (for example, 2.0 to 11.5) of a predetermined value (for example, 2.0) or more. When the numerical range of such specific gravity is a value less than the lower limit value, the sound insulation performance is lowered, and when the value range is larger than the upper limit value, the sound insulation material becomes too heavy. The predetermined value can be determined according to the sound insulation performance to be realized. For example, if the predetermined value is set to a high value, the sound insulation is improved accordingly, and if the predetermined value is set to a low value, the sound insulation is reduced. Thus, having a specific gravity of a predetermined value or more means a member having a certain sound insulation property. The same applies to the following specific values.

Holding member has a defined value below the apparent density (e.g., is preferably 0.9 g / cm ³ or less, more preferably 0.01 to 0.5 g / cm ^3), the desired resin (PP, PE, etc.) can be bonded, and the sound insulating material is wrapped and held. For this reason, the sound insulating material is covered with the holding member. Moreover, when the numerical value range of the density is less than the lower limit value, it is difficult to procure materials, and manufacturing becomes difficult, and when the value is larger than the upper limit value, the anchor effect cannot be sufficiently exerted. End up. Here, the apparent density is the mass per unit volume according to the external dimensions. Further, the adhesion includes welding by heat and fixation by an anchor effect.

  The resin member has a specific gravity (for example, 0.8 to 1.1) equal to or higher than a specific value (for example, 0.8), is configured of a desired resin (PP, PE, etc.), and holds the sound insulating material. Encloses the member. For this reason, the holding member enclosing the sound insulating material is covered with the resin member. Therefore, in the automotive part cover of the present solution, the sound insulating material is arranged at the center, the holding member is arranged around it, and the resin member is arranged around it. In addition, if the numerical value range of the specific gravity is a value less than the lower limit value, the sound insulating property is lowered, and if the value range is larger than the upper limit value, the resin material becomes too heavy.

  Thus, according to this solution, since the sound insulating material having a specific gravity equal to or higher than a predetermined value is used, sufficient sound insulating properties can be ensured as compared with sound insulating by an air layer.

  In this solution, each of the three members, the sound insulating material, the holding member, and the resin member, can exhibit sound insulating properties, and the three members can synergistically improve the sound insulating properties.

  Furthermore, according to this solution, since the outermost layer is a resin member, the cover for automobile parts is easier to carry compared to the state in which the sound insulating material is exposed, and the Workability can be improved.

  Furthermore, according to this solution, since the sound insulating material is wrapped in the holding member, the sound insulating material and the resin member are connected via the holding member even if the sound insulating material cannot be bonded to the resin member. Can be integrated. For this reason, it is not necessary to consider the adhesiveness (weldability) with the resin member when selecting the sound insulating material, and an arbitrary sound insulating material can be selected and used according to the required degree of sound insulation.

  In addition, according to this solution, since the holding member and the resin member are securely bonded, the holding member is firmly positioned inside the resin member, and the position of the holding member is shifted inside the resin member after bonding. It will not happen.

Solution 2: The sound insulating material is a metal plate or a high-density resin sheet.
According to this solution, since the sound insulating material is a metal plate or a high-density resin sheet, the specific gravity can be set higher than that of a general resin material. Then, by setting the specific gravity value of the sound insulating material high, the sound insulating property of the sound insulating material is increased, and as a result, the sound insulating property of the entire automobile part cover can be improved.

  Here, the holding member serves as a medium for integrating the sound insulating material and the resin member. Such a role of the holding member is more effective when a metal plate is used for the sound insulating material. On the other hand, when a high-density resin sheet is used for the sound insulating material, since the sound insulating material and the resin member are made of resin, compared to a metal plate, the sound insulating material and the resin member are more easily bonded, and the holding member It seems that the need for is lower than when metal plates are used.

Although this point depends on the molding method, a certain degree of connectivity can be ensured if the high-density resin sheet and the resin member can be brought into close contact with each other at a considerably high temperature. However, when a molding method is adopted in which the resin member is extruded into a sheet shape and molded in a state where the sheet resin is suspended, if the sheet resin becomes too hot, the sheet shape is in the suspended state. Since the resin melts and extends and falls, the melting temperature that can be molded is limited to a narrow range. Then, even if it is a case where a high-density resin sheet is employ | adopted with respect to a sound insulating material, stable bondability can be provided by interposing a holding member in between.

  In addition, when a high-density resin sheet is used for the sound insulating material, the sound insulation is inferior to that when a metal plate is used for the sound insulating material. Suitable when requested.

Solution 3: The holding member is a foam material, glass wool, or nonwoven fabric.
According to this solution, since the holding member is a foam material, glass wool, or non-woven fabric, there are relatively large irregularities on the surface of the holding member. For this reason, the molten resin member can easily enter the surface of the holding member (an anchor effect is easily generated), and the adhesion between the holding member and the resin member can be improved.

Solution 4: The resin member is a resin containing talc, mica, or glass fiber.
According to this solution, since the resin member contains an inorganic filler such as talc, mica, glass fiber, or the like that has a higher density (higher specific gravity) than a general resin, Specific gravity also becomes large and the sound insulation of a resin member can be improved.

Solution 5: The automobile parts cover is an engine undercover disposed below the automobile engine.
According to this solution, the cover for automobile parts can be applied to the engine under cover, and the phenomenon that the engine sound can be heard outside the vehicle from below the engine can be reduced.

Here, the automobile parts cover may be a truck engine undercover disposed below the truck engine.
In general, in the case of a passenger car, the sound absorption is regarded as important, such as the sound absorption of the engine sound and the sound of the running sound, but the engine sound is larger than that of the passenger car in the truck, so the sound absorption of the engine sound is called. Rather than that, sound insulation of engine sound is required.

  And by applying the cover for automobile parts to the engine undercover for trucks, it is possible to reduce the phenomenon that the engine sound can be heard from the lower side of the truck engine by enhancing the sound insulation of the engine sound. .

Solution 6: The resin member has an opening exposing a part of the holding member.
According to this solution, since a part of the holding member can be exposed through the opening formed in the resin member, a portion where the resin member is not formed can be provided. And it can avoid that the resin member melt | dissolves with a heat | fever by matching the opening position with the site | part which needs heat resistance.

[Method of manufacturing a cover for automobile parts]
Solution 7: The method of manufacturing a cover for automobile parts according to the present solution includes a drooping process, an arrangement process, and an adhesion process.

  In the drooping step, the molten sheet-like first resin and second resin are drooped downward between the divided molds arranged at a predetermined interval. The first resin and the second resin may be the same material resin or different resin materials. The first resin and the second resin are suspended at a predetermined interval while facing each other.

In the arranging step, the holding member is arranged between the first resin and the second resin that are suspended. The holding member wraps and holds a sound insulating material having a specific gravity (for example, 2.0 to 11.5) equal to or higher than a predetermined value (for example, 2.0), and has an apparent density (for example, 0.9 g / It is preferably cm ³ or less, more preferably 0.01 to 0.5 g / cm ³ ), and can be bonded to the first resin and the second resin.

  In the bonding step, the first mold and the second resin that are suspended are bonded to the holding member by clamping the divided mold.

  Thus, in this solution, the first resin and the second resin are suspended downward in the hanging process, and the holding member that wraps the sound insulating material is disposed between the first resin and the second resin in the placing process. Since the first resin and the second resin are bonded to the holding member in the bonding step, a holding member that wraps the sound insulating material is prepared and placed between the first resin and the second resin. With a simple process as described above, a cover for an automobile part having a complicated configuration can be easily manufactured.

  Solution 8: In this solution, a packing process is included before the drooping process. The packing step is a step of wrapping the sound insulating material with the holding member by fitting the sound insulating material into the concave storage portion formed on the holding member. In this case, the holding member can be divided into two members.

  Thus, in this solution, since the sound insulating material is wrapped by the holding member by fitting the sound insulating material into the holding portion of the holding member, it is not necessary to bond the sound insulating material and the holding member. That is, the sound insulating material and the holding member can be integrated by a fitting structure. As a result, it is possible to avoid a situation in which the adhesive is affected by heat at the time of bonding (welding) and the bonded state between the sound insulating material and the holding member cannot be maintained.

  According to the present invention, since the sound insulating material is wrapped with the holding member, and further, the holding member is wrapped with the resin member, the workability is good while ensuring excellent sound insulation, and the manufacturing can be facilitated. Yes.

It is a side view of a motor vehicle provided with the engine undercover of this embodiment. It is sectional drawing of an engine undercover. It is a figure which shows roughly the shaping | molding apparatus of an engine undercover. It is process drawing explaining the manufacturing method of an engine undercover. It is a schematic diagram explaining the manufacturing method of an engine undercover (1/4). It is a schematic diagram explaining the manufacturing method of an engine undercover (2/4). It is a schematic diagram explaining the manufacturing method of an engine undercover (3/4). It is a schematic diagram explaining the manufacturing method of an engine undercover (4/4). It is a figure which shows roughly the test method about the sound insulation of an engine undercover.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of an automobile provided with the engine under cover of the present embodiment.

〔Automobile〕
The automobile 10 is a vehicle that travels on the road by rotating wheels using the power of a prime mover such as an engine. The automobile 10 is a small, medium, or large truck, and includes a driver's cab (cab) 12 disposed in front and a cargo bed 14 disposed in the rear.

  An engine 20 is disposed below the cab 12 and the driving force of the engine 20 is transmitted to the front wheels 16 or the rear wheels 18 via an axle (not shown).

Further, an engine under cover 30 for trucks as a cover for automobile parts is disposed below the engine 20, and covers the lower region of the engine 20 as a whole.
The shape of the engine under cover 30 is a shape along the shape of the lower surface of the engine 20.

Next, the laminated structure of the engine under cover 30 will be described.
FIG. 2 is a cross-sectional view of the engine undercover 30. Note that the thickness and shape of each member in the following drawings are exaggerated for easy understanding.

[Sound insulation]
A sound insulating material 32 is disposed at the center of the engine under cover 30.
The sound insulating material 32 is a member having a specific gravity (for example, 2.0 to 11.5) equal to or higher than a predetermined value (for example, 2.0), and is, for example, a metal plate or a high-density resin sheet. Examples of the metal plate include iron sheet metal, and examples of the high-density resin sheet include a composite plastic sheet (for example, PVC: Poly Vinyl Chloride).

  The thickness of the sound insulating material 32 is preferably 0.4 to 2.0 mm, more specifically, the thickness of the metal plate is preferably 0.4 to 1.0 mm, and the thickness of the high-density resin sheet Is preferably 0.8 to 2.0 mm.

[Holding member]
A holding member 34 is disposed around the sound insulating material 32.
Holding member 34 has a prescribed value below the apparent density (e.g., is preferably 0.9 g / cm ³ or less, more preferably 0.01 to 0.5 g / cm ^3), a resin member 36 can be welded (adhered), and the sound insulating material 32 is wrapped and held.

  The holding member 34 is a foam material, glass wool, or a nonwoven fabric, for example. Examples of the foam material include 10 to 30 times EPP (Expanded PolyproPyrene). Examples of the non-woven fabric include those using PET (PolyEthylene Terephthalate) and PP (PolyPropylene).

  Moreover, it is preferable that the thickness of the holding member 34 is 5.0-20.0 mm. Here, when the engine undercover 30 is required to have heat resistance, it is desirable to apply a nonwoven fabric (PET fiber) using glass wool or PET to the holding member 34.

(Resin member)
A resin member 36 is disposed around the holding member 34.
The resin member 36 has a specific gravity (for example, 0.8 to 1.1) equal to or higher than a specific value (for example, 0.8), and encloses the holding member 34 that encloses the sound insulating material 32. The resin member 36 is, for example, PET or PP containing about 20 to 30% of an inorganic filler such as talc, mica, or glass fiber. By including the inorganic filler, the specific gravity of the resin member 36 can be 1.1 or more, and thereby the sound insulation can be further improved. Moreover, it is preferable that the thickness of the resin member 36 is 1.0-2.5 mm.

  The resin member 36 may have an opening that exposes a part of the holding member 34. By forming an opening in the resin member 36, a part of the holding member 34 disposed inside the resin member 36 can be exposed to the outside. It is possible to avoid the resin member 36 from being melted by heat by adjusting to a higher temperature part).

[Molding equipment]
Next, an apparatus for forming the engine under cover 30 will be described.
FIG. 3 is a diagram schematically showing a molding device for the engine undercover 30.
The molding device 40 includes two extrusion devices 50 and a mold clamping device 70 disposed below the extrusion device 50.
The molding device 40 sends the molten sheet-shaped resin P extruded from the extrusion device 50 to the mold clamping device 70, and the mold clamping device 70 shapes the molten sheet-shaped resin P.

[Extruder]
The two extrusion apparatuses 50 are arrange | positioned along with right and left, and can droop the two sheet-like resin P. FIG.

  The extrusion device 50 includes a cylinder 54 to which a hopper 52 is connected, a screw (not shown) provided in the cylinder 54, a hydraulic motor 56 connected to the screw, an accumulator 58 in which the cylinder 54 and the inside communicate with each other, and an accumulator 58. And a plunger 60 provided therein.

The hopper 52 is charged with resin pellets as a raw material for the resin member 36.
The resin pellets introduced from the hopper 52 are melted and kneaded by the rotation of the screw by the hydraulic motor 56 in the cylinder 54, and the molten resin is transferred into the accumulator 58 and stored in a certain amount, and the plunger 60 is driven. Is sent in a melted state toward the T die 62.

  The melted resin is extruded as a continuous sheet-shaped resin P through the slit-shaped extrusion port 64, and is moved downward while being sandwiched by a pair of rollers 66 arranged at a predetermined interval. 72 is suspended.

  Since the extrusion port 64 provided in the T die 62 is arranged vertically downward, the sheet-like resin P is directed vertically downward from the extrusion port 64 to the pair of rollers 66. The extrusion port 64 is provided with a thermal expansion type or mechanical type gap adjusting device (not shown). And the thickness of the sheet-like resin P can be changed by changing the space | interval of a slit with this clearance gap adjustment apparatus.

[Clamping device]
The mold clamping device 70 includes two divided molds 72 arranged side by side and a mold driving device (not shown) that moves the divided mold 72 in a direction substantially orthogonal to the supply direction of the sheet-like resin P. Have.

  The two split molds 72 are arranged with the cavities 74 facing each other, and the longitudinal directions of the cavities 74 are arranged in a substantially vertical direction. The shape of the cavity 74 is a concavo-convex shape corresponding to the outer shape and surface shape of the engine undercover 30 formed based on the sheet-like resin P.

  A pinch-off portion 76 is formed around the cavity 74 of the two split molds 72. The pinch-off part 76 is formed in an annular shape around the cavity 74 and protrudes toward the opposed split mold 72. Accordingly, when the two divided molds 72 are clamped, the tip portions of the respective pinch-off portions 76 come into contact with each other.

  The mold driving device is a device that drives the two divided molds 72 in the horizontal direction. For example, when in the open position, the sheet-shaped resin P can be disposed between the two divided molds 72, When in the closed position, the pinch-off portions 76 of the two split molds 72 can be brought into contact with each other to form a sealed space inside the two split molds 72.

  In addition, a vacuum suction chamber (not shown) is provided inside the split mold 72. The vacuum suction chamber communicates with the cavity 74 through the suction hole, and the sheet-like resin P can be adsorbed on the inner wall of the cavity 74 by sucking air from the vacuum suction chamber through the suction hole. The sheet-like resin P finally becomes the resin member 36 (see FIG. 2).

Next, a method for manufacturing the engine undercover 30 according to the present embodiment will be described with reference to FIGS.
FIG. 4 is a process diagram illustrating a method for manufacturing the engine undercover 30, and FIGS. 5 to 8 are schematic diagrams illustrating a method for manufacturing the engine undercover 30.

In the manufacturing method of the present embodiment, in the primary molding (extrusion molding), the two sheet-shaped resins P are molded and the two sheet-shaped resins P are suspended.
Then, in secondary molding (vacuum molding), a resin molded product is molded through clamping of the split mold 72 using the two sheet-like resins P extruded downward.

  Furthermore, in this secondary molding, a hollow portion is formed inside the two sheets of sheet-like resin P, and a holding member 34 that encloses a sound insulating material 32 separately prepared in the hollow portion is disposed, and the sound insulating material 32 is provided. A sandwich molded product in which the holding member 34 that is wrapped is sandwiched between two sheet-like resins is manufactured. The manufacturing method of the engine undercover 30 of this embodiment proceeds by executing the following steps.

[Preparation process: Step S100]
In the preparation step, as shown in FIG. 5A, a material used for the sound insulating material 32 is prepared. This preparatory process (step S100) and the next packing process (step S110) are performed as a pre-process before using the shaping | molding apparatus 40 mentioned above.

[Packing process: Step S110]
In the packing process, the sound insulating material 32 is wrapped by the holding member 34.
Specifically, first, as shown in FIG. 5B, a first holding member 34a having a concave portion 35a in the periphery and a concave storage portion 35b for storing the sound insulating material 32 in the center. Is prepared, and the sound insulating material 32 is fitted into the storage portion 35b.

  Next, as shown in FIG. 5C, a second holding member 34b having a convex portion 35c in the periphery and a concave storage portion 35d for storing the sound insulating material 32 in the center is prepared.

  Finally, as shown in FIG. 5D, the concave portion 35a of the first holding member 34a and the convex portion 35c of the second holding member 34b are fitted together, and the sound insulating material 32 is wrapped by the holding member 34. The sound insulating material 32 is fitted and fixed to the storage portions 35b and 35d of the holding member 34, but is not bonded. Thereby, the holding member 34 enclosing the sound insulating material 32 is completed.

[Dropping step: Step S120]
In the dripping process, as shown in FIG. 6E, two strips of the sheet-like resin P in a molten state are dripped between the divided molds 72 arranged at a predetermined interval. In addition, from this dripping process, it becomes the process using the shaping | molding apparatus 40 mentioned above.

  Specifically, the sheet-like resin P extruded from the extrusion port 64 of the extrusion apparatus 50 is sent downward by the rotation of a pair of rollers 66 (see FIG. 3). Thereby, the sheet-like resin P is disposed between the two divided molds 72. The sheet-like resin P may be held by a frame member (not shown).

[Contact process: Step S130]
In the contact process, as shown in FIG. 6F, a mold driving device (not shown) is operated to bring the divided mold 72 into close contact with the sheet-like resin P.
Specifically, the mold driving device is operated to bring the pinch-off portion 76 of the split mold 72 into contact with the sheet-like resin P. Thereby, a sealed space is formed by the sheet-like resin P, the cavity 74, and the pinch-off portion 76.

[Suction process: Step S140]
In the suction step, as shown in FIG. 6G, the sheet-like resin P is brought into close contact with the inner wall of the split mold 72 by sucking air from a vacuum suction chamber (not shown) through a suction hole.
As a result, the inside of the sealed space is sucked through the respective divided molds 72, the corresponding sheet-shaped resin P is pressed against the cavity 74, and the sheet-shaped resin P is molded into a shape along the inner wall of the cavity 74.

[Insertion process: Step S150]
In the inserting step, as shown in FIG. 7H, the holding member 34 held by the suction disk 80 of the manipulator (not shown) is inserted between the two divided molds 72 from the side. The holding member 34 is the holding member 34 manufactured in the previous packing step (step S110), and the holding member 34 encloses the sound insulating material 32.

[Pressing step: Step S160]
In the pressing step, as shown in FIG. 7 (I), the sheet-shaped resin adsorbed in the cavity 74 of the right split mold 72 by moving the manipulator in the horizontal direction toward the right split mold 72. The holding member 34 enclosing the sound insulating material 32 is pressed against P. Thereby, the holding member 34 enclosing the sound insulating material 32 and the sheet-like resin P are welded. Note that this pressing step also corresponds to the welding step in terms of welding the holding member 34 and the sheet-like resin P.

[Evacuation process: Step S170]
In the retracting process, as shown in FIG. 7J, the suction by the suction plate 80 is released, and the manipulator is moved in the horizontal direction toward the left split mold 72.

[Drawing process: Step S180]
In the drawing process, as shown in FIG. 7 (K), the manipulator is drawn from between the two split molds 72 to prepare for mold clamping.

[Welding process: Step S190]
In the welding process (bonding process), as shown in FIG. 8L, the two divided molds 72 are moved toward each other by a mold driving device, and the molds are clamped. Accordingly, the holding member 34 welded to one sheet-like resin P (right side in the figure) is welded to the other sheet-like resin P (left side in the figure), and the peripheral edges of the sheet-like resins P are welded. The Although not particularly illustrated, a parting line made of the sheet-like resin P is formed in a portion where the pinch-off portions 76 are in contact with each other.

[Sampling process: Step S200]
In the extraction step, as shown in FIG. 8 (M), the two split molds 72 are moved away from each other by the mold driving device to open the mold, and the engine undercover 30 of the finished product is extracted. Although not specifically shown, the removal of burrs and the like formed on the engine under cover 30 thereafter completes the manufacture of the engine under cover 30.

〔Test method〕
FIG. 9 is a diagram schematically showing a test method for sound insulation of the engine undercover.
In the sound insulation test, first, as shown in FIG. 9A, a sound insulation box 90 is installed in an anechoic chamber.
The sound insulation box 90 includes a box member 92 having an opening at the top, and a sound absorbing material 94 such as a sponge disposed inside the box member 92.

  Next, as shown in FIG. 9B, the speaker S is placed on the bottom surface inside the sound insulation box 90, the current product sample is placed at a position covering the opening of the box member 92, and a predetermined height is raised from the surface of the current product sample. The sound collecting microphone M is fixed at a position X (for example, 5 to 10 mm). The current product sample is obtained by flattening the engine under cover 30 shown in FIG. 2 and eliminating the sound insulating material 32.

Thereafter, the current product sample is removed, a sound is generated from the speaker S, and the volume is set to about 90 dB (decibel).
Then, a sample of the engine under cover 30 is placed at a position covering the opening of the box member 92, and a gap between the sound insulation box 90 and the sample of the engine under cover 30 is filled with a sealing material 96 such as clay so that no sound leaks. The engine undercover 30 sample is obtained by flattening the engine undercover 30 shown in FIG. 2, and the material, layer structure, and the like are the same.

  Then, the sound collector main body (not shown) connected to the sound collecting microphone M is operated, and the sound insulation property of the sound generated from the speaker S on the average for 30 seconds is measured.

The following test results were obtained by such a test method.
Since the volume of sound when using the current product sample was 66.0 to 68.4 dB, it was found that the sound insulation rate was 23.6 to 26.3%.

  On the other hand, since the loudness when the sample of the engine undercover 30 was used was 51.2 to 56.6 dB, it was found that the sound insulation rate was 36.8 to 42.8%. Note that the range of the numerical value of the test result is wide because the thickness of the sound insulating material 32 and the material used are changed and tested.

  Therefore, it was found that when the sound insulating material 32 is inserted into the center portion of the engine under cover 30, the sound insulating property is improved as compared with the current product in which the sound insulating material 32 is not inserted.

Thus, according to this embodiment, there are the following effects.
(1) Since the sound insulating material 32 has a specific gravity equal to or higher than a predetermined value, sufficient sound insulating properties can be ensured as compared with sound insulation by an air layer or the like.

(2) The sound insulating material 32, the holding member 34, and the resin member 36 can each exhibit sound insulating properties, and the three members can synergistically improve the sound insulating properties.

(3) Since the outermost layer of the engine undercover 30 is the resin member 36, the engine undercover 30 is easier to carry than the state in which the sound insulating material 32 is exposed, and the work of the automobile assembly line The workability of workers can be improved.

(4) Since the sound insulating material 32 is wrapped in the holding member 34, the sound insulating material 32 and the resin member 36 are connected via the holding member 34 even if the sound insulating material 32 cannot be welded to the resin member 36. Can be integrated. For this reason, it is not necessary to consider the weldability with the resin member 36 when selecting the sound insulating material 32, and it is possible to select and use any sound insulating material 32 according to the required degree of sound insulating properties.

(5) Since the holding member 34 and the resin member 36 have a combination that can be welded in advance, the holding member 34 and the resin member 36 are reliably welded. For this reason, the holding member 34 is firmly positioned inside the resin member 36, and the position of the holding member 34 is not displaced inside the resin member 36 after welding.

(6) Since the sound insulating material 32 is a metal plate or a high-density resin sheet, the specific gravity value can be set higher than that of a general resin material. And by setting the specific gravity value of the sound insulating material 32 high, the sound insulating property of the sound insulating material 32 is increased, and as a result, the sound insulating property of the engine undercover 30 as a whole can be improved.

(7) Since the holding member 34 is a foam material, glass wool, or non-woven fabric, relatively large irregularities exist on the surface of the holding member 34. For this reason, the molten sheet-like resin P easily enters the surface of the holding member 34 (is easy to adhere), and the adhesion between the holding member 34 and the resin member 36 can be improved.

(8) Since the resin member 36 contains an inorganic filler such as talc, mica, glass fiber or the like having a higher density (higher specific gravity) than a general resin, the specific gravity of the resin member 36 is also high. As a result, the sound insulation property of the resin member 36 can be improved.

(9) In this embodiment, since the engine under cover 30 is for trucks, the engine under cover 30 can be suitably used for trucks that require further sound insulation of engine sound, and the engine sound of the truck can be heard outside the vehicle. Can be reduced.

(10) According to the manufacturing method of the present embodiment, a complicated configuration is obtained by a simple process of preparing the holding member 34 enclosing the sound insulating material 32 and arranging it between the molten sheet-like resins P. The engine under cover 30 can be easily manufactured.

(11) According to the manufacturing method of the present embodiment, since the sound insulating material 32 is wrapped by the holding member 34 by fitting the sound insulating material 32 into the storage portions 35b, 35d of the two holding members 34a, 34b, There is no need to bond the material 32 and the holding member 34. As a result, it is possible to avoid a situation in which the adhesive is affected by heat at the time of welding, and the coupled state between the sound insulating material 32 and the holding member 34 cannot be maintained.

[Deformation]
The present invention can be implemented with various modifications and substitutions without being limited to the above-described embodiment.
Although the cover for automobile parts has been described as an example applied to an engine undercover, the cover for other automobile parts such as a transmission undercover can also be used as a sound insulation cover.

  Although the cover for automobile parts has been described in the example of being disposed below the engine, it may be disposed above or on the side of the engine.

  Although the cover for automobile parts has been described as an example applied to a truck, it can also be widely applied to large vehicles other than trucks, buses, small passenger cars, and the like.

  In the embodiment described above, the example in which the engine undercover 30 is manufactured by the molding apparatus 40 has been described. However, the method for manufacturing the engine undercover 30 is not limited to this, and other manufacturing apparatuses and molding apparatuses are used. The engine under cover 30 may be manufactured.

  The configurations and raw materials of the engine undercover 30 described in the above-described embodiments are all preferable examples, and can be implemented by appropriately modifying them.

DESCRIPTION OF SYMBOLS 10 Automobile 20 Engine 30 Engine under cover 32 Sound insulation material 34 Holding member 36 Resin member 40 Molding device 50 Extruding device 70 Clamping device 72 Split mold 74 Cavity 76 Pinch-off part 80 Suction plate P Sheet-like resin

Claims (1)

A dripping step of dripping the melted sheet-like first resin and second resin downward between the divided molds arranged at a predetermined interval;
A sound insulating material having a specific gravity of 2.0 to 11.5 is wrapped and held between the first resin and the second resin that are suspended in the drooping step, and has an apparent density of a specified value or less. And an arrangement step of arranging a holding member that can be bonded to the first resin and the second resin;
An adhesion step of bonding the first resin and the second resin suspended in the dripping step and the holding member arranged in the arrangement step by clamping the split mold;
A method of manufacturing a cover for automobile parts, comprising: a packaging step of wrapping the sound insulating material with the holding member by fitting the sound insulating material into a concave storage portion formed on the holding member before the hanging step. .

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