Undertray for a vehicle and method of manufacturing the same

Abstract

Provided is a vehicle under cover having good balance of rigidity. A vehicle under cover (10) includes a plate-shaped body (12) made of a porous material such as a fiber body or a foamed body; and a support body (14) that supports the plate-shaped body (12). The support body (14) has a first frame portion (20) having a groove shape, the first frame portion (20) having a horizontal plate (20a) and vertical plates (20b, 20b) extending from both edges of the horizontal plate (20a). In addition, the support body (14) has a second frame portion (22) disposed so as to cross the first frame portion (20) and protrude toward the inside of the vehicle, the second frame portion (22) having a dimension smaller than that of the first frame portion (20).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an under cover for a vehicle such as an engine under cover and a manufacturing method of an under cover for a vehicle. BACKGROUND

[0002] As shown in Patent Literature 1, an under cover is installed on the lower side of a vehicle body. The under cover of Patent Literature 1 is a plate-shaped body made of synthetic resin and is installed to the vehicle body by a bolt or a nut or the like.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Laying-Open No. 2014-58178 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The under cover needs to have rigidity not to be broken even when water is accumulated on a road surface on which the vehicle runs. However, even if the rigidity of the under cover is set to be excessively high, in a case where an external force is applied to the under cover, stress is concentrated on a fastening portion installed to the vehicle body, resulting in breakage of the fastening portion and easy detachment from the vehicle body.

[0008] One aspect of the present disclosure is proposed in order to appropriately solve the problems in view of the related art, and an object thereof is to provide an under cover for a vehicle having required rigidity and not easily detached from a vehicle body and a manufacturing method of an under cover for a vehicle.

[0009] MEANS FOR SOLVING PROBLEMS

[0010] One aspect of the under cover for a vehicle of the present disclosure is characterized by comprising:

[0011] a porous plate-shaped body; and

[0012] a support body that supports the plate-shaped body,

[0013] the support body has:

[0014] a first frame portion of a groove shape having a horizontal plate and vertical plates extending from both edges of the horizontal plate; and

[0015] a second frame portion that is provided so as to cross the first frame portion and has a dimension protruding to the inside of the vehicle smaller than that of the first frame portion.

[0016] One aspect of the manufacturing method of an under cover for a vehicle of the present disclosure is characterized by comprising:

[0017] A porous plate-shaped body is disposed in a molding die;

[0018] In the molding die, a synthetic resin-made support having a first frame portion in a groove shape formed by a horizontal plate and vertical plates extending from both edges of the horizontal plate, and a second frame portion provided so as to cross the first frame portion and protrude toward the inside of a vehicle and having a size smaller than that of the first frame portion, are molded.

[0019] A vehicle under cover in which the plate-shaped body and the support are joined is obtained.

[0020] Effects of Invention

[0021] According to one aspect of the vehicle under cover of the present disclosure, a vehicle under cover having a required rigidity and being less likely to fall off from a vehicle body is obtained.

[0022] According to one aspect of the manufacturing method of the vehicle under cover of the present disclosure, a vehicle under cover having a required rigidity and being less likely to fall off from a vehicle body can be easily obtained. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a plan view showing an engine under cover of a first embodiment of the present disclosure.

[0024] Figure 2 is a schematic perspective view showing a part of the engine under cover of the first embodiment from the upper side (the inside of the vehicle).

[0025] Figure 3 is a schematic perspective view showing a part of the engine under cover of the first embodiment from the lower side (the outside of the vehicle).

[0026] Figure 4A is an end view cut at a position corresponding to the A-A line in Figure 1

[0027] Figure 4B is an enlarged view of the B part of Figure 4A

[0028] Figure 5 is an end view cut at a position corresponding to the C-C line in Figure 1

[0029] Figure 6A is an end view cut at a position corresponding to the D-D line in Figure 1

[0030] Figure 6B is an enlarged view of the E part of Figure 6A

[0031] Figure 7A ​​​​​is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0032] Figure 7B is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0033] Figure 7C is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0034] Figure 8A is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0035] Figure 8B is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0036] Figure 8C is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0037] Figure 9 is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0038] Figure 10 is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0039] Figure 11 is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0040] Figure 12 is a end view cut along the A-A line in Figure 11 .

[0041] Figure 13 is a end view cut along the B-B line in Figure 11 .

[0042] Figure 14 is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0043] Figure 15A is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0044] Figure 15B is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0045] Figure 15C is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment.

[0046] Figure 15D is a explanatory view showing a manufacturing process of the engine under cover of the first embodiment. Detailed Implementation

[0047] Hereinafter, preferred embodiments of the vehicle undercover and its manufacturing method according to the present disclosure will be described with reference to the accompanying drawings. The vehicle undercover of the present disclosure can be suitably used as an engine undercover, floor undercover, fender liner, or other vehicle exterior components or vehicle structural components. It should be noted that, in this embodiment, an engine undercover installed on the lower side of the engine compartment of a vehicle is illustrated as an example. In the engine undercover described in the following embodiments, the inner side of the vehicle is considered upper, and the outer side of the vehicle is considered lower. Figure 1 and Figure 9 In the arrows shown, X1 is the front of the vehicle, X2 is the rear of the vehicle, X3 is the right side of the vehicle, X4 is the left side of the vehicle, X5 is the top side, and X6 is the bottom side.

[0048] Example

[0049] (First Implementation)

[0050] like Figures 1-4A As shown, the engine cover (vehicle cover) 10 of the first embodiment includes a plate-shaped body 12 and a support body 14 supporting the plate-shaped body 12. The plate-shaped body 12 is constructed primarily of a porous material. The support body 14 is made of synthetic resin. In the engine cover 10, the plate-shaped body 12 and the support body 14 are joined together. A mounting portion 16 is provided on the support body 14. The engine cover 10 is mounted to the vehicle body using the mounting portion 16 of the support body 14. In the first embodiment, the engine cover 10 is mounted to the vehicle body using fastening members such as bolts or rivets in the hole-shaped mounting portion 16. Reference numeral 18 indicates a drainage hole that extends vertically through the plate-shaped body 12 and the support body 14.

[0051] As a porous material, for example, a fibrous body or a foam can be used. The plate-shaped body 12 performs the required functions such as sound absorption or heat insulation by utilizing the properties derived from the porous material. The engine cover 10 uses the plate-shaped body 12 to suppress external noise such as engine noise or driving noise. As a fibrous body, non-woven or woven fabrics formed from polyester fibers, polyolefin fibers, aramid fibers, glass fibers, cellulose fibers, nylon fibers, vinylon fibers, synthetic fibers, etc., can be used. In addition, as a foam, polyurethane-based, polyolefin-based, polystyrene-based, etc., foams can be used. Furthermore, from the perspective of sound absorption, the plate-shaped body 12 is preferably a porous material with air permeability.

[0052] The plate-shaped body 12 can be composed of one layer or two or more layers. For example, the plate-shaped body 12 can be a multi-layer structure including a first layer and a second layer disposed overlapping the first layer. For example, the first layer can perform the main function required by the plate-shaped body 12 (sound absorption in the embodiment). In addition, the second layer can perform an auxiliary function attached to the plate-shaped body 12 (water repellency in the first embodiment). In this case, the water repellency of the second layer can be ensured by setting the density of the second layer to be higher than that of the first layer. In addition, water repellency can also be ensured by imparting a water-repellent material such as silicone resin or fluororesin to the second layer. In this way, by imparting water repellency to the second layer, which is the outer side of the vehicle, in the plate-shaped body 12, it is possible to prevent water from penetrating into the plate-shaped body 12, or to prevent snow from adhering to the plate-shaped body 12, or to prevent ice from forming on the plate-shaped body 12, which is therefore preferred. It should be noted that sheets such as non-woven fabric or foam can also be disposed overlappingly on a part or the entire surface of the upper side (inner side of the vehicle) of the engine cover 10.

[0053] The support 14 is a molded product obtained by injection molding or other processes using synthetic resin. Synthetic resins that can be used include polypropylene (PP), polyethylene (PE), acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polyamide (PA).

[0054] like Figure 1 As shown, the support body 14 has multiple intersecting frame portions 20 and 22. Specifically, the support body 14 includes a first frame portion 20 and a second frame portion 22. The first frame portion 20 extends in the longitudinal direction of the vehicle. The second frame portion 22 extends in a direction intersecting the first frame portion 20 (lateral direction in the vehicle). In addition, the support body 14 includes an outer frame portion 24 that forms the outer edge of the engine cover 10. The first frame portion 20 and the second frame portion 22 are connected to the inner side of the outer frame portion 24 and are arranged in a mesh pattern. Moreover, a plate-like body 12 is arranged on the inner side of multiple regions formed by the first frame portion 20 and the second frame portion 22, or by the first frame portion 20, the second frame portion 22 and the outer frame portion 24 arranged in a longitudinal, lateral, and left-right manner. It should be noted that the support body 14 is a molded product integrally formed from the first frame portion 20, the second frame portion 22 and the outer frame portion 24. In the case where the outer frame portion 24 forming the front edge of the engine cover 10 on the front side of the vehicle is specifically distinguished, it is referred to as the front outer frame portion 24A. When the outer frame portion 24 constituting the rear edge of the engine cover 10 on the vehicle's rear side is specifically distinguished, it is referred to as the rear outer frame portion 24B. When the outer frame portion 24 constituting the side edge of the engine cover 10 on the vehicle's transverse side is specifically distinguished, it is referred to as the transverse outer frame portion 24C.

[0055] like Figure 2 , Figure 6A and Figure 6BAs shown, the first frame portion 20 is formed in a groove shape. The first frame portion 20 has a horizontal plate 20a and vertical plates 20b extending from the left and right edges of the horizontal plate 20a, respectively. In the first frame portion 20, the plate-like body 12 is connected to the lower end of the vertical plates 20b. In the first frame portion 20, the horizontal plate 20a extends out at a position higher than the upper surface of the plate-like body 12. In other words, the first frame portion 20 is recessed from the lower side (outer side of the vehicle) toward the upper side (inner side of the vehicle). The left and right vertical plates 20b in the first frame portion 20 open downwards between each other. In the first embodiment, there is one first frame portion 20 extending in the front-rear direction, but multiple first frame portions 20 may also be arranged in series in the front-rear direction.

[0056] like Figure 5 As shown, in the engine cover 10, the groove shape of the first frame portion 20 is formed such that it extends in the longitudinal direction of the vehicle. The first frame portion 20 opens towards the front of the vehicle. Specifically, the front outer frame portion 24A of the support body 14 extends upward (inward) than the plate-shaped body 12 (and the horizontal plate 20a). The horizontal plate 20a and the vertical plate 20b are connected to the vertical wall of the front outer frame portion 24A. Moreover, the first frame portion 20 penetrates the vertical wall of the front outer frame portion 24A. Thus, the first frame portion 20 does not have a wall that closes the front of the vehicle. It should be noted that when multiple first frame portions 20 are arranged in series in the longitudinal direction, only the first frame portion 20 located at the front of the vehicle needs to open towards the front of the vehicle.

[0057] like Figure 5 As shown, the first frame portion 20 may also include an inclined portion 20c that slopes outward from the front of the vehicle toward the rear. The inclined portion 20c is formed connected to the cross plate 20a. In the first embodiment, the inclined portion 20c is provided at the rear edge of the first frame portion 20 connected to the rear outer frame portion 24B. It should be noted that the inclined portion 20c may also be provided at a midpoint in the front-rear direction of the first frame portion 20. The first frame portion 20 may also be formed with an opening toward the rear of the vehicle. When it is necessary to erect a wall on the inner side of the groove shape, the aforementioned inclined portion 20c is preferred.

[0058] like Figure 1 As shown, the second frame portion 22 is disposed between the left and right adjacent first frame portions 20, 20. The second frame portion 22 is configured to have lower stiffness than the first frame portion 20. Figure 2 As shown, for example, the upward protrusion of the second frame portion 22 (inside the vehicle) is smaller than that of the first frame portion 20. More specifically, the second frame portion 22 includes a base 22a and an upright portion 22b that rises upward from the base 22a (inside the vehicle) (see reference). Figure 4A and Figure 4B). In the first embodiment, the first frame portion 20 is a "U"-shaped cross section formed by the horizontal plate 20a and the left and right vertical plates 20b, 20b. In contrast, the second frame portion 22 is a "T"-shaped cross section formed by the plate-shaped base portion 22a and the plate-shaped upright portion 22b. The dimension of the upright portion 22b in the up-down direction is smaller than the dimension of the vertical plate 20b in the first frame portion 20. The upper end of the upright portion 22b is located at a position lower than the horizontal plate 20a (the vehicle outer side). In the first embodiment, although the upper end of the upright portion 22b is located at a position lower than the upper surface of the plate-shaped body 12 (the vehicle outer side), it can be located at a position higher than the upper surface of the plate-shaped body 12. Note that in the first embodiment, the same rib shape as the upright portion 22b is provided in the horizontal outer frame portion 24C.

[0059] As shown in Figure 2 , in the second frame portion 22, the base portion 22a is connected to the lower end of the vertical plate 20b of the first frame portion 20. The upright portion 22b is connected to the vertical plate 20b. In addition, the base portion 22a is connected to the plate-shaped body 12 (see Figure 4A and Figure 4B ). In the first embodiment, the base portion 22a is impregnated in the plate-shaped body 12 and integrated with the plate-shaped body 12. The upright portion 22b is provided so as to overlap the plate-shaped body 12. The first frame portion 20 is provided between the left and right plate-shaped bodies 12, 12 that are separated from each other. The left and right adjacent plate-shaped bodies 12 are supported by the first frame portion 20. On the other hand, the second frame portion 22 is provided so as to overlap the plate-shaped bodies 12 that are continuous in the front-rear direction. The plate-shaped bodies 12 are supported by the second frame portion 22.

[0060] As shown in Figure 4A and Figure 4B , in the second frame portion 22, the front-rear dimension of the base portion 22a is formed to be larger than the dimension of the upright portion 22b. The second frame portion 22 has a joint portion that is joined to the vertical plate 20b of the first frame portion 20. The width of the lower portion of the joint portion in the second frame portion 22 is formed to be wider than the upper portion of the second frame portion 22. As shown in Figure 3 , the portion of the base portion 22a that is joined to the vertical plate 20b is wider than the intermediate portion of the base portion 22a between the first frame portions 20, 20, so as to widen the width of the vertical plate 20b side of the base portion 22a.

[0061] As shown in Figure 4A , the edge of the rear outer frame portion 24B is formed in a groove shape. The groove shape of the rear outer frame portion 24B, like the first frame portion 20, protrudes to the upper side and is open to the lower side. The dimension of the protrusion to the upper side in the groove shape of the rear outer frame portion 24B is set to be smaller than the dimension of the first frame portion 20. The rigidity of the groove shape of the rear outer frame portion 24B is smaller than the rigidity of the first frame portion 20. As shown in Figure 6AAs shown, the edge of the lateral outer frame portion 24C is formed in a groove shape. The groove shape of the lateral outer frame portion 24C, like the first frame portion 20, projects upward and is open downward. The dimension of the upward projecting portion of the groove shape of the lateral outer frame portion 24C is set to be smaller than that of the first frame portion 20. The rigidity of the groove shape of the lateral outer frame portion 24C is smaller than that of the first frame portion 20.

[0062] As shown in Figure 4A , Figure 4B , Figure 6A and Figure 6B , a compressed portion 26 is provided at the portion of the plate-shaped body 12 to which the frame portions 20, 22 are connected. The compressed portion 26 is recessed in a manner that is open upward from the upper surface of the plate-shaped body 12. The compressed portion 26 is thinner than the central portion of the plate-shaped body 12. The density of the compressed portion 26 is higher than that of the central portion of the plate-shaped body 12. The synthetic resin that forms the frame portions 20, 22 is difficult to penetrate into the compressed portion 26.

[0063] The engine under cover 10 of the first embodiment is obtained by insert molding in which the support body 14 is molded in the molding die 30 provided with the sheet S that becomes the plate-shaped body 12 (see Figure 7A , Figure 7B , Figure 7C , Figure 8A , Figure 8B and Figure 8C ). The engine under cover 10 is integrated with the plate-shaped body 12 and the support body 14 by the bonding force of the support body 14 itself formed by curing the synthetic resin.

[0064] Specifically, the engine under cover 10 can be manufactured in the following manner. First, the sheet S that becomes the plate-shaped body 12 is prepared (see Figure 7A and Figure 8A ). For example, the sheet S in which a weak portion Sa formed by an opening or a slit, or the like is formed at a position corresponding to the first frame portion 20 is prepared (see Figure 8A ). The sheet S is disposed in the molding die 30 after opening. Alternatively, a plurality of sheets S that are formed to be slightly wider than the dimension between the left and right adjacent first frame portions 20, 20 are prepared. Then, the strip-shaped sheet S can also be disposed in the molding die 30 after opening. For example, the sheet S can be formed by blanking processing using a Thomson blade or the like. Note that the weak portion Sa only needs to be formed in conformity with the cutting of the outer shape.

[0065] The weak portion Sa of the sheet S is disposed in matching with the first frame-forming protrusion 32a that forms the lower surface of the first frame portion 20 in the first die 32 (see Figure 8A ). At this time, the sheet S is disposed in overlapping with the portion of the first die 32 that forms the lower surface of the second frame portion 22 (see Figure 7A). When the molding die 30 is closed, the fragile portion Sa is pressed by the first frame-forming protrusion 32a. In addition, the fragile portion Sa is pressed by the opening edge of the first frame-forming recess 34a in the second die 34 that forms the upper surface of the first frame portion 20. Thereby, the fragile portion Sa is broken. Then, the sheet S is divided while sandwiching the first frame-forming protrusion 32a (refer to Figure 8B ). The end portion of the divided sheet S is compressed and held between the opening edge of the first frame-forming recess 34a and the first die 32. By closing the molding die 30, the sheet S is compressed and held in the second frame-forming portion 34b in the second die 34 that forms the upper surface of the second frame portion 22 (refer to Figure 7B ).

[0066] By closing, a cavity 36 corresponding to the first frame portion 20 is formed between the first frame-forming protrusion 32a and the first frame-forming recess 34a. The end portion of the sheet S enters the cavity 36. In addition, a cavity 36 corresponding to the upright portion 22b of the second frame portion 22 is formed between the second frame-forming portion 34b and the sheet S.

[0067] A resin material is injected into the cavity 36 from an unillustrated gate provided at a plurality of portions to injection-mold the support 14 (refer to Figure 7C and Figure 8C ). At this time, the resin material flows, for example, from the cavity 36 corresponding to the outer frame portion 24 to the cavity 36 corresponding to the first frame portion 20 or the second frame portion 22. The resin material flows from the cavity 36 corresponding to the first frame portion 20 to the cavity 36 corresponding to the second frame portion 22. The resin material flows from the cavity 36 corresponding to the second frame portion 22 to the cavity 36 corresponding to the first frame portion 20. In this way, the resin material flows in various paths, thereby permeating throughout the entire cavity 36.

[0068] The end portion of the plate-shaped body 12 (the sheet S) enters the cavity 36 between the first frame-forming protrusion 32a and the first frame-forming recess 34a. In this state, the first frame portion 20 is formed. At this time, the vicinity of the first frame portion 20 in the plate-shaped body 12 (the sheet S) is compressed by the opening edge of the first frame-forming recess 34a. Thus, the penetration of the resin material into the plate-shaped body 12 can be suppressed. The upright portion 22b of the second frame portion 22 is formed in the cavity 36 between the second frame-forming portion 34b and the sheet S. In addition, the resin material penetrates in the sheet S to form the base portion 22a. At this time, the vicinity of the second frame portion 22 in the plate-shaped body 12 (the sheet S) is more compressed than the portion corresponding to the base portion 22a. Thus, the penetration of the resin material into the plate-shaped body 12 can be suppressed. The first frame portion 20 is formed between the plate-shaped bodies 12 adjacent in the left-right direction. In addition, the second frame portion 22 is formed in a manner of overlapping the plate-shaped body 12. Then, the obtained engine under cover 10 is taken out of the molding die 30 after the mold is opened. According to the manufacturing method described above, the engine under cover 10 in which the plate-shaped body 12 is supported by the support body 14 can be simply obtained.

[0069] In the engine under cover 10, the relatively soft plate-shaped body 12 is supported by the support body 14. The support body 14 has the first frame portion 20 having a groove shape and the second frame portion 22 protruding to the inside of the vehicle and having a size smaller than that of the first frame portion 20. By providing the first frame portion 20 with the groove shape having the horizontal plate 20a and the vertical plate 20b extending from both edges of the horizontal plate 20a, sufficient rigidity can be ensured using the shape characteristics thereof. In addition, by providing the second frame portion 22 with a size smaller than that of the first frame portion 20, the rigidity of the second frame portion 22 can be made smaller than that of the first frame portion 20. In this way, the engine under cover 10 can release the load due to the water carried when running on a water-accumulated road or the vibration or the like during running, or the load due to the collision with a curbstone or ice and snow on the road, by the deformation of the second frame portion 22. Thus, the excessive load applied to the mounting portion 16 of the vehicle body can be suppressed. Therefore, the engine under cover 10 has the required rigidity and is less likely to be detached from the vehicle body.

[0070] Since the engine under cover 10 can ensure the rigidity by the support body 14, it is not necessary to obtain the rigidity by compressing the plate-shaped body 12 or the like. For example, since the thickness or the void of the plate-shaped body 12 can be ensured, the sound absorption or the like performance can be improved. In addition, the cost can be reduced by reducing the unit volume mass.

[0071] The first frame portion 20 has a groove shape that is recessed from the vehicle outer side toward the vehicle inner side. The groove shape of the first frame portion 20 extends in the front-rear direction of the vehicle. In addition, the groove shape of the first frame portion 20 is open to the vehicle front side. In this way, in the engine under cover 10, since the first frame portion 20 having the groove shape extends in the front-rear direction of the vehicle, the first frame portion 20 can obtain the effect of rectifying air on the lower side of the vehicle. Thereby, it is advantageous in terms of aerodynamic characteristics. In addition, since the first frame portion 20 is open to the vehicle front side, air is easily made to pass through the inside of the groove of the first frame portion 20. Thereby, the rectifying effect of the first frame portion 20 can be more effectively obtained.

[0072] The first frame portion 20 has an inclined portion 20c formed in connection with the horizontal plate 20a. The inclined portion 20c is inclined to the vehicle outer side as it goes from the vehicle front side toward the vehicle rear side. With the inclined portion 20c, air in the engine under cover 10 is easily made to be discharged to the vehicle rear side from the first frame portion 20 having the groove shape. Thereby, the rectifying effect of the first frame portion 20 is made to be more effective, and it is more advantageous in terms of aerodynamic characteristics.

[0073] The first frame portion 20 is provided between the plate-shaped bodies 12, 12 adjacent in the left-right direction. In addition, the first frame portion 20 having relatively high rigidity connects the plate-shaped bodies 12, 12. Thereby, the plate-shaped bodies 12 can be appropriately supported. The second frame portion 22 is provided so as to overlap the plate-shaped bodies 12. Thereby, even the second frame portion 22 having relatively low rigidity can appropriately support the plate-shaped bodies 12. The first frame portion 20 is formed between the plate-shaped bodies 12, 12 adjacent in the left-right direction. By forming the first frame portion 20 in this way, the plate-shaped bodies 12 (the sheet material S) can be easily connected. In addition, the second frame portion 22 is formed so as to overlap the plate-shaped bodies 12. Thereby, the time required to divide the sheet material S can be saved. Therefore, the sheet material S can be easily set in the molding die 30.

[0074] The second frame portion 22 has a connecting portion that connects the longitudinal plate 20b of the first frame portion 20. The lower portion of the connecting portion is formed to be wider than the upper portion of the connecting portion. Thereby, the strength of the connecting portion of the second frame portion 22 that connects the first frame portion 20 can be improved. In addition, when the support body 14 is formed, the resin material can easily flow between the cavity 36 corresponding to the second frame portion 22 and the cavity 36 corresponding to the first frame portion 20. Therefore, the mass of the engine under cover 10 obtained can be stabilized.

[0075] (Second Embodiment)

[0076] As Figures 9-11As shown, the engine cover 110 of the second embodiment includes a support body 112 made of synthetic resin and a sound-absorbing portion 116, which is a plate-like body supported by the support body 112. The sound-absorbing portion 116 is provided in each opening portion 114 to close the opening portion 114 divided by the support body 112. In the engine cover 110, the support body 112 and the sound-absorbing portion 116 are connected by means of integral molding of the support body 112, bonding with adhesive, or welding by heat. In the engine cover 110, the rigidity is mainly ensured by the support body 112, which is more rigid than the sound-absorbing portion 116. The engine cover 110 is mounted to the vehicle body using a mounting portion provided on the support body 112.

[0077] The support 112 is a molded product obtained by injection molding or other methods using synthetic resin. Synthetic resins that can be used include polypropylene (PP), polyethylene (PE), acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polyamide (PA).

[0078] like Figures 9-11 As shown, the support body 112 of the second embodiment includes an outer peripheral portion 118 and frame portions 120, 122 formed inside the outer peripheral portion 118. A mounting portion for the vehicle body is formed on the outer peripheral portion 118. The frame portions 120, 122 are formed in a grid pattern extending in the front-rear and left-right directions. An opening portion 114 is formed by four frame portions 120, 122, or by the outer peripheral portion 118 and the frame portions 120, 122. In the support body 112 of the second embodiment, a plurality of opening portions 114 are arranged in a front-rear and left-right configuration.

[0079] The sound-absorbing part 116 is breathable. The sound-absorbing part 116 can be made of a porous material such as non-woven fabric or foam. The engine cover 110 suppresses external noise such as engine noise or driving noise through the sound-absorbing part 116, which has multiple pores. As the non-woven fabric, non-woven fabrics made of polyester fibers, polyolefin fibers, aramid fibers, glass fibers, cellulose fibers, nylon fibers, vinylon fibers, synthetic fibers, etc., can be used. As the foam, polyurethane-based, polyolefin-based, polystyrene-based, etc., foams can be used. The thickness of the sound-absorbing part 116 is, for example, set to approximately 7.5 mm to 32 mm.

[0080] like Figure 12 and Figure 13As shown, the lower surface of the sound absorbing portion 116 has a fused layer 124 having lower air permeability than other portions of the sound absorbing portion 116. The fused layer 124 is a layer formed by fusing and solidifying a surface (one surface) of the porous body constituting the sound absorbing portion 116. The fused layer 124 has air permeability in the thickness direction (up-down direction) of the sound absorbing portion 116. The air permeability of the fused layer 124 is lower than that of the portion above the fused layer 124 in the sound absorbing portion 116. In addition, the density of the fused layer 124 is higher than that of the portion above the fused layer 124 in the sound absorbing portion 116. Further, the fused layer 124 is harder than the portion above the fused layer 124 in the sound absorbing portion 116. The surface roughness of the lower surface of the fused layer 124 (the lower surface of the sound absorbing portion 116) is lower than that of the upper surface of the sound absorbing portion 116 where the fused layer 124 is not formed. The lower surface of the fused layer 124 is smooth. For example, the surface roughness of the lower surface in the fused layer 124 is about 50 μm or less.

[0081] The sound absorbing portion 116 of the second embodiment is constituted by a fibrous body such as a nonwoven fabric. As shown in FIG. 2, the sound absorbing portion 116 has a first fibrous layer 126 constituting the upper side of the sound absorbing portion 116 and a second fibrous layer 128 constituting the lower side of the sound absorbing portion 116. Further, the fused layer 124 constitutes the lower portion of the second fibrous layer 128. The fused layer 124 of the second embodiment is formed by fusing the lower portion of the second fibrous layer 128. The fused layer 124 covers the lower side of the second fibrous layer 128. In the second embodiment, the first fibrous layer 126 is thickest in the sound absorbing portion 116. In the sound absorbing portion 116, the fused layer 124 is thinnest. Note that the thickness of the fused layer 124 is about 0.1 mm to 0.9 mm. The air permeability of the sound absorbing portion 116 decreases in the order of the first fibrous layer 126, the second fibrous layer 128, and the fused layer 124. Figure 12 13 As shown, the sound absorbing portion 116 has a fused layer 124 having lower air permeability than other portions of the sound absorbing portion 116 on the lower surface of the sound absorbing portion 116. The fused layer 124 is a layer formed by fusing and solidifying a surface (one surface) of the porous body constituting the sound absorbing portion 116. The fused layer 124 has air permeability in the thickness direction (up-down direction) of the sound absorbing portion 116. The air permeability of the fused layer 124 is lower than that of the portion above the fused layer 124 in the sound absorbing portion 116. In addition, the density of the fused layer 124 is higher than that of the portion above the fused layer 124 in the sound absorbing portion 116. Further, the fused layer 124 is harder than the portion above the fused layer 124 in the sound absorbing portion 116. The surface roughness of the lower surface of the fused layer 124 (the lower surface of the sound absorbing portion 116) is lower than that of the upper surface of the sound absorbing portion 116 where the fused layer 124 is not formed. The lower surface of the fused layer 124 is smooth. For example, the surface roughness of the lower surface in the fused layer 124 is about 50 μm or less.

[0082] The thickness of the first fibrous layer 126 is set to, for example, about 7 mm to 30 mm. In addition, the unit volume mass of the first fibrous layer 126 is, for example, about 600 g / m 2 to 1800 g / m 2 . Further, the density of the first fibrous layer 126 is, for example, about 0.02 g / cm 3 to 0.25 g / cm 3 .

[0083] The thickness of the second fibrous layer 128 is set to, for example, about 0.5 mm to 2 mm. In addition, the unit volume mass of the second fibrous layer 128 is, for example, about 200 g / m 2 to 600 g / m 2 . Further, the density of the second fibrous layer 128 is, for example, about 0.1 g / cm 3 to 1.2 g / cm 3 . ​

[0084] The second fiber layer 128 has a higher water repellency than the first fiber layer 126. As a method of ensuring water repellency, for example, imparting a water repellent material such as a silicone resin or a fluorine resin to the second fiber layer 128, or forming the second fiber layer 128 with a material such as a fiber having water repellency, and the like are cited. In addition, the water repellency can also be increased by making the density (mass per unit volume) of the second fiber layer 128 higher than the density of the first fiber layer 126.

[0085] Next, the manufacturing method of the engine under cover 110 described above will be explained. The engine under cover 110 can be obtained by insert molding that forms the support body 112 in a molding die 136 provided with a sheet S that becomes the sound absorbing portion 116. The sheet S is a sound absorbing sheet. First, as shown in FIG. 9, a sheet S having a first fiber layer 126 and a second fiber layer 128 is prepared. The sheet S is passed between a pair of rollers 130, 132. Here, the second roller 132 that contacts the second fiber layer 128 is heated in the pair of rollers 130, 132. By this, a portion in the thickness direction of the second fiber layer 128 is melted on one surface of the sheet S, forming a melted layer 124. Note that the other surface of the sheet S is still the first fiber layer 126. Figure 14

[0086] Next, the sheet S on which the melted layer 124 is formed is cut processed by using a Thomson blade or the like. At this time, a slit 134 (refer to FIG. 10) is formed in the sheet S so as to coincide with the positions at which the frame portions 120, 122 are to be formed. In addition, a link portion is provided so as not to cut the intersection between the longitudinal frame portion 120 and the transverse frame portion 122 in the sheet S, and the like. By this, the sheet S is maintained in a state in which it is connected as one piece. Figure 15A

[0087] The sheet S on which the melted layer 124 and the slit 134 are formed is set in the molding die 136 (refer to FIG. 11). The molding die 136 is closed. At this time, a portion of the opening edge of the slit 134 in the sheet S faces the cavity 138 (refer to FIG. 12) of the support body 112. When the molding die 136 is closed, the link portion that links the sheet S can also be broken by the concavities and convexities of the die surface of the molding die 136. Then, the support body 112 is injection molded in a state in which a portion of the sheet S faces the cavity 138 in which the support body 112 is formed (refer to FIG. 13). Figure 15A Figure 15B Figure 15C ​​​​). At this time, the connecting portions of the connecting sheet S can also be melted and broken by the molten resin at a high temperature. Thus, the end portions (part of) of the sound absorbing portions 116 obtained by dividing the sheet S are fused in a state of entering the inside of the support body 112. Thus, the end portions of the sound absorbing portions 116 are integrated with the support body 112. Then, the engine under cover 110 is taken out of the molding die 136. In the obtained engine under cover 110, the opening portions 114 are closed by the sound absorbing portions 116 divided by each opening portion 114 of the support body 112 (refer to FIG. 1). Figure 15D

[0088] The engine under cover 110 has the fused layer 124 in the sound absorbing portion 116. Thus, sound can be absorbed in a wide frequency band from a low frequency band to a high frequency band. Therefore, the sound absorbing performance of the engine under cover 110 can be improved. The engine under cover 110 can particularly appropriately absorb road noise in a frequency band of 1000 Hz to 1250 Hz. For example, the thinner the fiber diameter of the sound absorbing portion 116, the higher the sound absorbing performance, but also results in a higher cost of the sound absorbing portion 116. According to the engine under cover 110 of the second embodiment, by forming the fused layer 124, even if a fiber body having a thick fiber diameter and a low cost is used, the desired sound absorbing performance can be ensured.

[0089] The engine under cover 110 has the fused layer 124 in the sound absorbing portion 116. By the fused layer 124 having a higher density than the other portions of the sound absorbing portion 116, the rigidity of the sound absorbing portion 116 can be improved. Therefore, the sound absorbing portion 116 can be set wider in the engine under cover 110, and thus the sound absorbing performance can be improved. In the engine under cover 110, by the fused layer 124 having a higher density than the other portions of the sound absorbing portion 116, the resistance to chipping and the wear resistance of the lower surface of the sound absorbing portion 116 can be improved. Therefore, even if a flying stone or the like hits the engine under cover 110, the sound absorbing portion 116 is less likely to be damaged, and the durability is excellent. Since the engine under cover 110 has the fused layer 124 in the sound absorbing portion 116, the lower surface of the sound absorbing portion 116 becomes smooth. Therefore, the wettability of the lower surface of the sound absorbing portion 116 can be reduced, and for example, icing on the sound absorbing portion 116 or water immersion into the sound absorbing portion 116 can be prevented. Thus, the engine under cover 110 can prevent the sound absorbing performance of the sound absorbing portion 116 from being degraded due to water immersion, or the sound absorbing portion 116 from being damaged due to icing, and the like.

[0090] Since the fused layer 124 is a layer formed by surface fusion and solidification of the porous body constituting the sound absorbing portion 116, the man-hours for pasting the fused layer 124 to the sound absorbing portion 116 or the like are not required. Therefore, the sound absorbing performance of the sound absorbing portion 116 can be easily improved.

[0091] ​The lower side of the sound absorbing portion 116 is provided with a second fiber layer 128 having better water repellency than the first fiber layer 126. In this way, by providing the second fiber layer 128 having good water repellency, the wettability of the lower side of the sound absorbing portion 116 can be reduced. For example, it is possible to prevent ice from forming on the sound absorbing portion 116 or water from being absorbed into the sound absorbing portion 116. Thus, the engine under cover 10 can prevent a decrease in sound absorbing performance of the sound absorbing portion 116 due to water absorption or damage to the sound absorbing portion 116 due to ice formation, and the like.

[0092] In the manufacturing method described above, when the support body 112 is molded in the molding die 136, the sheet material S is divided to form the sound absorbing portion 116 corresponding to the opening portion 114 of the support body 112. Thus, it is not necessary to prepare the sound absorbing portions 116 in the number or shape corresponding to the plurality of opening portions 114 in the support body 112, but it is only necessary to prepare one sheet material S. In addition, it is only necessary to set the one sheet material S in the molding die 136, and it is not necessary to spend time and effort to set a plurality of sound absorbing portions 116 corresponding to the plurality of opening portions 114 in the support body 112 in the molding die 136. In this way, according to the manufacturing method described above, by forming the molten layer 124 on one surface of the sheet material S in advance, it is possible to easily obtain the engine under cover 110 in which the sound absorbing portion 116 divided by each of the opening portions 114 of the support body 112 is connected to the support body 112.

[0093] (MODIFIED EXAMPLE)

[0094] Not limited to the above, for example, the following can also be the case. Note that the description is not limited to the above-described embodiments and the following modified examples.

[0095] (1) The structure in which the rigidity of the second frame portion is lower than the rigidity of the first frame portion is not limited to the embodiments. For example, the rigidity of the second frame portion can be made lower than the rigidity of the first frame portion by making the wall thickness of the second frame portion thinner, or the like.

[0096] (2) A portion of the under cover for a vehicle can be cut off, an opening portion for maintenance can be provided, and a closable cover portion can be installed in the opening portion.

[0097] (3) A resin material can be impregnated around the drain hole provided in the plate-shaped body. In addition, a guide path that guides water to the drain hole can be provided on the plate-shaped body by impregnating a resin in the plate-shaped body and molding by a mold at the time of insert molding.

[0098] (4) The upper surface of the sound absorbing portion can be constituted by a second molten layer having higher air permeability than the molten layer of the lower surface. For example, if it is the layer structure of the embodiments, it is only necessary to melt the upper portion of the first fiber layer to form the second molten layer. In this way, by providing the second molten layer on the upper surface of the sound absorbing portion, it is possible to make it difficult for water adhering to the under cover to be absorbed into the sound absorbing portion.

[0099] (5) The sound absorbing portion is not limited to a three-layer structure, and can be a two-layer structure of a fusion layer and another layer, or a four or more layer structure.

[0100] (6) The under cover for a vehicle can be obtained by adhering the sound absorbing portion to the support body with an adhesive, or by fusion bonding the sound absorbing portion to the support body by ultrasonic waves or the like after the support body is molded.

[0101] (7) The fusion layer is not limited to being formed by a hot roller, and can be formed by, for example, hot pressing by placing a mold at a high temperature.

[0102] (8) The fiber layer is not limited to being composed of a single fiber, and can be composed of a plurality of fibers, or other materials can be mixed in the fiber. As the other material, for example, glass or the like can be given.

[0103] An under cover for an engine is provided on the lower side of the engine in a vehicle to reduce engine sound (see, for example, Japanese Patent Laid-Open No. 2013-86599). Such an under cover for an engine is composed by compression molding a fiber to achieve the purpose of absorbing engine sound or the like.

[0104] To ensure the quietness of a vehicle, it is required that the under cover for an engine exhibit sound absorbing performance in a wider frequency band.

[0105] In the present disclosure, as a solution to the above other problem, one example of an under cover for a vehicle in the following manner is described.

[0106] An under cover for a vehicle, the under cover for a vehicle comprising:

[0107] a support body; and

[0108] a sound absorbing portion provided to close an opening portion divided by the support body, and having air permeability;

[0109] wherein a lower surface of the sound absorbing portion is composed of a fusion layer having lower air permeability than other portions in the sound absorbing portion.

[0110] The under cover for a vehicle in the above manner is excellent in sound absorbing performance.

[0111] In the present disclosure, as a solution to the above other problem, a manufacturing method of an under cover for a vehicle in the following manner is described.

[0112] A manufacturing method of an under cover for a vehicle, the manufacturing method of an under cover for a vehicle comprising:

[0113] forming a fusion layer on one surface of a sound absorbing sheet having air permeability by heating and fusing one surface of the sound absorbing sheet.

[0114] After the sound absorbing sheet is disposed in a molding die, a support body is molded, and a sound absorbing portion that closes an opening portion divided by the support body is formed from the sound absorbing sheet.

[0115] According to the manufacturing method of the under cover for a vehicle according to the above-described aspect, the under cover for a vehicle having excellent sound absorbing performance can be obtained.

[0116] This disclosure is based on the priority of Japanese Patent Application No. 2021-6700 filed in Japan on January 19, 2021, Japanese Patent Application No. 2021-96706 filed in Japan on June 9, 2021, and the contents described in the above applications are incorporated into the present specification. In addition, the contents described in the patents, patent applications, and documents cited in the present disclosure are incorporated into the present specification.

[0117] Explanation of Reference Numerals

[0118] 10, 110 under cover for a vehicle; 12 plate-shaped body, 14 support body; 20 first frame portion; 20a horizontal plate; 20b vertical plate; 20c inclined portion; 22 second frame portion; 112 support body; 114 opening portion; 116 sound absorbing portion; 124 molten layer; 126 first fiber layer; 128 second fiber layer; 136 molding die

Claims

1. A vehicle underbody cover, said vehicle underbody cover comprising: Porous plate-like bodies; and Support body, the support body supporting the plate-like body The support body has: A first frame portion in the shape of a groove, the first frame portion in the shape of a groove having a horizontal plate and vertical plates extending from two edges of the horizontal plate; and The second frame portion is configured to intersect with the first frame portion, and the dimension of the second frame portion protruding into the vehicle is smaller than the dimension of the first frame portion; The first frame portion is a groove shape that is recessed from the outside of the vehicle to the inside of the vehicle and opens to the front of the vehicle, and extends along the front-rear direction of the vehicle. The first frame portion has an inclined portion that is connected to the cross plate and tilts outward from the front of the vehicle toward the rear of the vehicle.

2. The vehicle underbody cover according to claim 1, wherein, The first frame portion is disposed between the plate-like bodies. The second frame portion is disposed overlapping the plate-like body.

3. The vehicle underbody cover according to claim 1, wherein, The second frame portion has a connecting portion that connects to the longitudinal plate of the first frame portion. The lower part of the connecting portion is wider than the upper part of the connecting portion.

4. A vehicle underbody cover, said vehicle underbody cover comprising: Porous plate-like bodies; and Support body, the support body supporting the plate-like body The support body has: A first frame portion in the shape of a groove, the first frame portion in the shape of a groove having a horizontal plate and vertical plates extending from two edges of the horizontal plate; and The second frame portion is configured to intersect with the first frame portion, and the dimension of the second frame portion protruding into the vehicle is smaller than the dimension of the first frame portion; The vehicle underbody has an opening portion defined by the support body. A sound-absorbing portion is provided in the plate-like body to close the opening. The sound-absorbing part is breathable. The lower surface of the sound-absorbing part is composed of a molten layer with lower air permeability than other parts of the sound-absorbing part.

5. The vehicle underbody cover according to claim 4, wherein, The molten layer is a layer formed by melting and solidifying the surface of the plate-like body.

6. The vehicle underbody cover according to claim 4 or 5, wherein, The sound-absorbing part includes: A first fiber layer, the first fiber layer constituting the upper side of the sound-absorbing portion; and The second fiber layer forms the lower side of the sound-absorbing part, and the water repellency of the second fiber layer is better than that of the first fiber layer. The molten layer forms the lower part of the second fiber layer.

7. The vehicle underbody cover according to claim 4, wherein, The upper surface of the sound-absorbing part is composed of a second molten layer that has higher air permeability than the molten layer.

8. A method for manufacturing a vehicle underbody cover, the method comprising: A porous plate-like body is placed in a molding die; In the molding die, a support body made of synthetic resin is formed, the support body made of synthetic resin having a first frame portion in the shape of a groove formed by a cross plate and longitudinal plates extending from the two edges of the cross plate; And a second frame portion that is configured to intersect with the first frame portion and protrude toward the inside of the vehicle, with a dimension smaller than that of the first frame portion; A vehicle underbody is obtained by joining the plate-like body and the support body.

9. The method for manufacturing a vehicle underbody cover according to claim 8, wherein, The first frame portion is formed between the plate-like bodies. The second frame portion is formed by overlapping the plate-like body.

10. The method for manufacturing a vehicle underbody according to claim 8 or 9, wherein, The lower part of the second frame portion in the connecting portion between the longitudinal plates of the second frame portion and the first frame portion is wider than the upper part of the second frame portion.

11. The method for manufacturing a vehicle underbody cover according to claim 8, wherein, A molten layer is formed on one surface of the plate-like body by heating and melting one surface that is permeable to air. When the support body is formed in the molding die in which the plate-shaped body is provided, a sound-absorbing part is formed from the plate-shaped body to close the opening portion divided by the support body.

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