JP7709864B2 - Hole seal material for automobile doors and its manufacturing method - Google Patents

Description

The present invention relates to a hole seal material that seals the opening of the inner panel of an automobile door and a method for manufacturing the same.

In the space between the inner panel and outer panel of an automobile door, various parts such as a speaker device and a door lock device are provided, and an opening is formed in the inner panel for the installation of these various parts. This opening is then sealed using a hole sealant such as those described in Patent Documents 1 and 2.

In the structures of Patent Documents 1 and 2, the hole sealant is made of a sheet-like seal body made of a foam material and a synthetic resin film laminated and fixed to the seal body, and the peripheral portion of the synthetic resin film is bonded to the peripheral portion of the opening of the inner panel with a butyl sealant, and the opening is closed with the hole sealant.

JP 2018-2094 A JP 2018-58402 A

In addition to the structures of Patent Documents 1 and 2, a door hole seal structure for sealing the opening of an inner panel can also be considered, as shown in FIG. 6, in which a hole seal material 101 is formed from the same molding material, a foamed main body portion 102 made of foamed resin, and a peripheral lip portion 103 mainly made of unfoamed resin, and the hole seal material 101 is positioned to close the opening 202 of the inner panel 201, and the tip portion 104 of the peripheral lip portion 103 of the hole seal material 101 is elastically pressed against the peripheral portion 203 of the opening 202 of the inner panel 201 to ensure sealing.

As shown in FIG. 7(a), such a hole seal material 101 can be formed by filling a cavity 300 defined by fixed molds 301 and 302 and a movable mold 303 with a foamable molten resin, and then core-backing the movable mold 303 in the direction of the thick arrow in the figure.

However, in the hole seal material 101 formed with a core back, when the movable mold 303 is cored back, a non-contact area 105 that does not come into contact with either the movable mold 303 or the fixed mold 302 is generated. In the foam resin molding of the core back, the resin in the area that is in contact with the mold is cooled by contact with the mold, whereas the resin in the non-contact area 105 is not cooled and remains at a high temperature. Therefore, when the hole seal material 101 molded with a core back is naturally cooled, the outer peripheral lip portion 103 is deformed so that it warps more than the intended shape due to the thermal contraction of the non-contact area 105, as shown by the two-dot chain line in Figure 7 (b).

In a hole sealant 101 that has been significantly deformed by heat in this way, it becomes difficult to ensure sealing by elastically pressing the tip 104 of the outer lip portion 103 against the outer periphery 203 of the inner panel 201, so a hole sealant that can minimize deformation of the outer lip portion due to thermal contraction is desired. In addition, even when forming an unfoamed resin portion, such as an attachment point of the hole sealant, in an area surrounded by a doughnut shape with a foamed resin portion, the same non-contact area as described above occurs, and deformation into an unintended shape occurs due to thermal contraction, so it is also desired to prevent such deformation.

The present invention has been proposed in light of the above problems, and aims to provide a hole sealant and a manufacturing method thereof that can minimize unintended deformation of the shape due to thermal shrinkage at the boundary between the unfoamed resin and the foamed resin.

The hole seal material for an automobile door of the present invention is characterized in that a foamed resin portion and an unfoamed resin portion are formed from the same molding material , a vertical wall portion is provided at the boundary between the foamed resin portion and the unfoamed resin portion, and an unfoamed vertical wall portion made of unfoamed resin is formed at a position closer to the unfoamed resin portion of the vertical wall portion.
According to this, the area that is not in contact with the mold during core back and becomes hotter than the contact area is blocked by the vertical wall, and the effect of thermal shrinkage can be significantly reduced. Therefore, unintended deformation of the shape due to thermal shrinkage at the boundary between the unfoamed resin and the foamed resin can be suppressed as much as possible, and a hole seal material for an automobile door with the intended shape can be reliably obtained.

The hole seal material for automobile doors of the present invention is a same molded material having a foamed main body portion made of foamed resin and an outer peripheral lip portion made of unfoamed resin, and is fixed so that the tip of the outer peripheral lip portion is pressed against the outer peripheral portion of the opening of an inner panel by elastic force and abuts against it, characterized in that a vertical wall portion is provided around the outside of the core back trace groove of the foamed main body portion, an unfoamed vertical wall portion made of unfoamed resin is formed near the outer side of the vertical wall portion, and the outer peripheral lip portion is formed so as to protrude outward from the unfoamed vertical wall portion.
According to this, by providing a vertical wall portion having an unfoamed vertical wall portion on the outer side of the core back trace groove of the foamed main body portion, the area that is not in contact with the mold during core back and has a higher temperature than the contact area can be kept inside the vertical wall portion, and the influence of thermal contraction on the outer peripheral lip portion can be significantly reduced by blocking it with the vertical wall portion. Therefore, it is possible to suppress the deformation of the outer peripheral lip portion due to thermal contraction as much as possible, in other words, it is possible to suppress the occurrence of unintended deformation of shape due to thermal contraction at the boundary between the unfoamed resin and the foamed resin as much as possible, and it is possible to provide a hole seal material that can reliably press the outer peripheral lip portion against the inner panel with elastic force. In addition, the vertical wall portion can prevent the area of foamed resin formed by the core back from extending to the vicinity of the root of the outer peripheral lip portion, and it is possible to prevent the formation of a foamed resin portion on the outer peripheral lip portion and a decrease in strength. In addition, in the door hole seal structure formed by the hole seal material, the tip of the outer peripheral lip of the hole seal material is elastically biased against the outer peripheral part of the opening of the inner panel, so that a surface pressure is constantly applied without any gaps, and the tip of the outer peripheral lip is pressed against the outer peripheral part of the inner panel with a pressure exceeding the excitation force of external vibration to suppress vibration, thereby preventing the occurrence of abnormal noise (buzzing noise) or rattling due to external forces. Furthermore, the synthetic resin film bonded around the opening of the inner panel does not vibrate to generate abnormal noise, and the occurrence of abnormal noise due to the hole seal material can be prevented. Furthermore, in this door hole seal structure, the tip of the outer peripheral lip is elastically biased against the outer peripheral part of the opening of the inner panel to maintain the abutting state, so that the sealing property and waterproofing between the outer peripheral part of the hole seal material and the outer peripheral part of the opening of the inner panel can be ensured.

The hole seal material for an automobile door of the present invention is characterized in that the outer peripheral lip portion is composed of a standing wall extending in the thickness direction of the foamed main body portion, a lip edge formed by sloping outward from the standing wall toward the inner panel side, and a bridging portion composed of unfoamed resin that connects the unfoamed standing wall portion and the standing wall so as to form a roughly H-shape in cross section.
According to this, the strength of the outer periphery of the hole seal material including the outer periphery lip portion can be increased by the cross-sectional H-shape consisting of the unfoamed upright wall portion, the upright wall, and the bridging portion, which are made of unfoamed resin. Furthermore, this cross-sectional H-shape increases the elasticity of the outer periphery lip portion, and the elastic force and surface pressure with which the tip of the outer periphery lip portion is elastically pressed against the outer periphery of the opening of the inner panel can be increased. Therefore, the door hole seal structure consisting of this hole seal material can more reliably prevent the generation of abnormal noise and ensure sealing and waterproofing.

The method for manufacturing a hole seal for an automobile door of the present invention is a method for manufacturing a hole seal for an automobile door of the present invention, and is characterized in that it comprises a first step of forming a cavity consisting of the outer peripheral lip portion, the vertical wall portion, and a hollow surrounded by the vertical wall portion and corresponding to a substrate having a thickness thinner than the height of the vertical wall portion, using a fixed mold and a movable mold, placing the fixed mold on the receding surface of the movable mold in the cavity shaped like the vertical wall portion, and placing a side surface of the movable mold on the inner surface of the cavity shaped like the vertical wall portion, a second step of filling the cavity with a foamable molten resin, and a third step of core-backing the movable mold to foam the foamable molten resin and form the hole seal.
According to this, when the movable mold is cored back to foam the foamable molten resin, the portion that foams corresponding to the movable mold is formed while being in contact with and integrated with the resin that becomes the vertical wall portion located on the outside. Therefore, the area that is not in contact with the mold and becomes high temperature, which corresponds to the core-back trace groove formed on the surface of the hole seal material on the side where the movable mold is retreated, can be made very small, and the influence of thermal contraction on the outer peripheral lip portion can be greatly reduced. In addition, since the high-temperature non-contact area corresponding to the core-back trace groove is formed adjacent to the vertical wall portion whose other than the inside is in contact with the mold, cooling of the non-contact area can be promoted during core-back, and from this point of view, the influence of thermal contraction on the outer peripheral lip portion can be greatly reduced.

The present invention makes it possible to obtain a hole sealant that can minimize unintended deformation caused by thermal shrinkage at the boundary between the unfoamed resin and the foamed resin.

1 is a front view of an automobile door having a door hole seal structure using a hole seal material according to an embodiment of the present invention; 1 is a cross-sectional view of a door hole seal structure using a hole seal material according to an embodiment of the present invention. 3A is an enlarged view of part A in FIG. 2 , and FIG. 3B is an enlarged view of part B in FIG. 2 . 5A to 5C are process explanatory views illustrating a manufacturing process of the hole sealing material according to the embodiment. 5A to 5C are enlarged views of parts corresponding to (a) to (c) in FIG. 4, respectively. FIG. 13 is a cross-sectional explanatory view showing a state in which an outer peripheral lip portion of the hole seal material of the comparative example is pressed against an inner panel. 5A is a cross-sectional view illustrating a manufacturing process of a hole seal material of a comparative example, and FIG. 5B is a cross-sectional view illustrating thermal deformation of an outer peripheral lip portion of the hole seal material of the comparative example.

[Hole seal material for automobile doors according to an embodiment]
1 to 3, a hole seal material 5 for an automobile door according to an embodiment of the present invention is used in a door hole seal structure provided in an inner panel 4 disposed between an outer panel 2 and a door trim 3 in an automobile door 1. The hole seal material 5 is composed of the same molding material, that is, a foamed main body portion 6 made of foamed resin and an outer peripheral lip portion 7 made of unfoamed resin.

The foamed main body 6 of the hole seal material 5 is composed of a foamed core layer 61 and a skin layer 62 formed on the outside of the foamed core layer 61. A standing wall 63 is formed on the outer periphery of the foamed main body 6, and the outer side of the standing wall 63 is an unfoamed standing wall 631 made of unfoamed resin. The standing wall 63 is provided on the outside of a circumferential groove, a core back trace groove 64, provided in the foamed main body 6.

The outer peripheral lip portion 7 is formed so as to protrude outward from the unfoamed standing wall portion 631, and is composed of a standing wall 71 extending in the thickness direction of the foamed main body portion 6, a lip edge 72 formed by slanting outward from the standing wall 71 toward the inner panel 4 side, and a bridging portion 73 made of unfoamed resin that connects the unfoamed standing wall portion 631 and the standing wall 71 so as to form a roughly H-shaped cross section. The lip edge 72 in the illustrated example is formed so as to be curved and slanted in a roughly arc shape from the end of the standing wall 71, and its tip portion 721 is disposed at a position that becomes the periphery of the hole seal material 5 and is formed in a bead shape. In addition, the bridging portion 73 in the illustrated example is formed at a position closer to the inner panel 4 side than the center of the unfoamed standing wall portion 631 in the thickness direction of the foamed main body portion 6, and is bridged between the unfoamed standing wall portion 631 and the standing wall 71.

In this embodiment, the surface of the foam body 6 facing the inner panel 4 has a plurality of predetermined locations on which are provided fastener engagement holes 65 consisting of a portion protruding in a substantially U-shape, and fastener hooks 66 formed with their claws facing outward, and are integrally formed as part of the skin layer 62 of the foam body 6. A separate fastener 8 is inserted into the fastener engagement holes 65 and engaged.

The hole seal material 5 is arranged to close the opening 41 of the inner panel 4, and the foamed main body 6 is mechanically fixed to the inner panel 4. In this embodiment, the hook 66 is hooked to the inside of the periphery 42 of the opening 41 of the inner panel 4, and the tip hook 81 of the hook 8 that engages with the hook engagement hole 65 is hooked to the inside of the periphery 42 of the opening 41 of the inner panel 4 and fixed (see Figures 2 and 3). In other words, the foamed main body 6 is hooked and fixed to the periphery 42 of the opening 41 of the inner panel 4 by applying a force that pulls the foamed main body 6 toward the opening 41 of the inner panel 4.

The tip 721 of the outer peripheral lip portion 7 of the hole seal material 5, which is mechanically fixed to the inner panel 4 by hook fixing, is elastically biased against the outer peripheral portion 43 of the opening 41 of the inner panel 4, and the abutting state is maintained. In the illustrated example, the bead-shaped tip 721 is elastically biased against the outer peripheral portion 43 of the opening 41 of the inner panel 4, which is formed so as to be inclined so as to be curved in an approximately arc toward the vehicle interior from the periphery 42 extending in an approximately vertical direction outward, and the abutting state is maintained.

When manufacturing the hole seal material 5 used in the door hole seal structure of this embodiment, as shown in Figures 4(a) and 5(a), for example, a cavity 90 consisting of an outer peripheral lip portion 7, a vertical wall portion 63, and a cavity surrounded by the vertical wall portion 63 and having a shape corresponding to a substrate with a thickness thinner than the height of the vertical wall portion 63 is formed by partitioning with fixed molds 91, 92 and a movable mold 93. When molding the foamable molten resin, the movable mold 93 retreats in the direction of the thick dashed double-dashed arrow in Figure 4(a), and the fixed mold 92 is placed on the surface 901 of the movable mold 93 on the retreating side in the cavity shaped like the vertical wall portion 63, and the side of the movable mold 93 is placed on the inner surface 903 of the cavity shaped like the vertical wall portion 63.

4(b) and 5(b), the foamable molten resin MR is injected into the cavity 90 through an injection path for the foamable molten resin (not shown) to fill the cavity 90. Any suitable material applicable to the hole seal material 5 of the automobile door 1 can be used for the foamable molten resin.
For example, it is preferable to use olefin resins such as PP (polypropylene) and PE (polyethylene), amorphous resins such as ABS (acrylonitrile butadiene styrene copolymer) and a mixed resin of PC (polycarbonate) and ABS, thermoplastic elastomers such as olefins, or synthetic rubbers such as EPDM (ethylene propylene diene rubber), SBR (styrene butadiene rubber), CR (chloroprene rubber), and NBR (nitrile rubber). In this embodiment, a gap 911 corresponding to the shape of the approximately U-shaped portion constituting the fastener engagement hole 65 and a gap 912 corresponding to the shape of the hook 66 are provided in the fixed mold 91, and the gaps 911 and 912 are also filled with the foamable molten resin MR. A metal bar that can be moved forward and backward within the fixed mold 91 or that can be attached and detached from the fixed mold 91 is provided in the portion corresponding to the fastener engagement hole 65, and is blocked by the metal bar when the foamable molten resin MR is injected or filled, so that a shape corresponding to the fastener engagement hole 65 is formed.

Then, as shown in Fig. 4(c) and Fig. 5(c), the movable mold 93 is cored back in the direction of the thick arrow in the figure to foam the foamable molten resin MR, and a hole sealant 5 consisting of a foamed main body 6 and an outer peripheral lip 7 is formed. At this time, in this embodiment, a substantially U-shaped portion constituting a hook engagement hole 65 and a hook hook 66 are also formed in the formed hole sealant 5. In the hole sealant 5 thus formed, a cored back trace groove 64 is formed on the surface of the foamed main body 6 facing the movable mold 93 at a position corresponding to the side of the movable mold 93, and a standing wall portion 63 having an unfoamed standing wall portion 631 and an outer peripheral lip portion 7 are formed on the outside of the cored back trace groove 64.

According to the hole seal material 5 of the automobile door 1 of this embodiment, the standing wall portion 63 having the unfoamed standing wall portion 631 on the outer side is provided around the outside of the core back trace groove 64 of the foam main body portion 6, so that the area that is not in contact with the mold during core back and becomes hotter than the contact area can be kept inside the standing wall portion 63, and the influence of thermal contraction on the outer peripheral lip portion 7 can be blocked by the standing wall portion 63 and significantly reduced. Therefore, the deformation of the outer peripheral lip portion 7 due to thermal contraction can be suppressed as much as possible, and the outer peripheral lip portion 7 can be reliably pressed against the inner panel 4 by elastic force. In addition, the standing wall portion 63 can prevent the area of foamed resin formed by the core back from extending to the base of the outer peripheral lip portion 7, and the strength of the outer peripheral lip portion 7 can be prevented from being reduced by the formation of a foamed resin portion on the outer peripheral lip portion 7.

In addition, in the door hole seal structure composed of the hole seal material 5, the tip 721 of the outer peripheral lip portion 7 of the hole seal material 5 is elastically biased against the outer peripheral portion 43 of the opening 41 of the inner panel 4, so that a surface pressure is constantly applied without any gaps. The tip 721 of the outer peripheral lip portion 7 is pressed against the outer peripheral portion 43 of the inner panel 4 with a pressure exceeding the excitation force of external vibration to suppress vibration, and the occurrence of abnormal noise (buzzing noise) or rattling due to external forces can be prevented. Furthermore, the synthetic resin film bonded around the opening 41 of the inner panel 4 does not vibrate to generate abnormal noise, and the occurrence of abnormal noise due to the hole seal material 5 can be prevented. Furthermore, in this door hole seal structure, the tip 721 of the outer peripheral lip portion 7 is elastically biased against the outer peripheral portion 43 of the opening 41 of the inner panel 4 to maintain the abutting state, so that the sealing and waterproofing between the outer peripheral portion of the hole seal material 5 and the outer peripheral portion 43 of the opening 41 of the inner panel 4 can be ensured.

The H-shape in cross section, which is made up of the unfoamed upright wall portion 631, the upright wall 71, and the bridging portion 73, which are made of unfoamed resin, enhances the strength of the outer periphery lip portion 7 or the outer periphery of the hole seal material 5. This H-shape in cross section also enhances the elasticity of the outer periphery lip portion 7, and further enhances the elastic force and surface pressure with which the tip portion 721 of the outer periphery lip portion 7 is elastically pressed against the outer periphery 43 of the opening 41 of the inner panel 4. Therefore, the door hole seal structure made up of the hole seal material 5 can more reliably prevent the generation of abnormal noise and ensure sealing and waterproofing.

In addition, according to the method for manufacturing the hole seal material 5 of the above embodiment, when the movable mold 93 is cored back to foam the foamable molten resin MR, the portion that foams corresponding to the movable mold 93 is formed while being in contact with and integrated with the resin that becomes the vertical wall portion 63 located on the outside. Therefore, the area that is not in contact with the mold and becomes hot, corresponding to the core-back trace groove 64 formed on the retreating side surface of the movable mold 93 of the hole seal material 5, can be made very small, and the effect of thermal contraction on the outer peripheral lip portion 7 can be greatly reduced. In addition, since the high-temperature non-contact area corresponding to the core-back trace groove 64 is formed adjacent to the vertical wall portion 63 whose entire surface except the inside is in contact with the mold, cooling of the non-contact area can be promoted during core-back, and from this point of view, the effect of thermal contraction on the outer peripheral lip portion 7 can be greatly reduced.

[Scope of the invention disclosed herein]
The inventions disclosed in this specification include, in addition to the inventions and embodiments listed as inventions, those specified by changing partial contents of these to other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects can be obtained, and specifying them as a higher-level concept. The inventions disclosed in this specification also include the following modified examples and added contents.

For example, in the door hole seal structure using the hole seal material 5 in the above embodiment, the foam body 6 is hooked and fixed to the inner panel 4, but when using the hole seal material 5 of the present invention to form a door hole seal structure, any suitable fixing structure can be used within the scope of the present invention. In particular, it is preferable to use mechanical fixing such as hook fixing, bolting, screwing, caulking, or press-fitting, in other words mechanical fixing, but it is also possible to provide a partial protrusion on the inner panel side of the foam body of the hole seal material in the present invention and chemically fix this protrusion to the periphery of the opening of the inner panel by adhesive or the like.

In addition, the shape of the tip 721 of the outer peripheral lip portion 7 in the above embodiment is beaded from the viewpoints of improving strength, preventing breakage, and increasing the contact area when it comes into contact with the inner panel 4, but the present invention also includes shapes of the tip of the outer peripheral lip portion other than beaded. In addition, the shape of the outer peripheral lip portion protruding outward from the unfoamed vertical wall portion in the present invention may be any shape within the scope of the spirit of the present invention, and is not limited to the approximate H-shape in cross section of the above embodiment.

In the above embodiment, the foamed resin portion is a foamed main body portion made of foamed resin, and the unfoamed resin portion is an outer peripheral lip portion made of unfoamed resin. However, the hole seal material for the automobile door of the present invention includes a suitable hole seal material for the automobile door in which a vertical wall portion is provided at the boundary between the foamed resin portion and the unfoamed resin portion, and an unfoamed vertical wall portion made of unfoamed resin is formed at a position closer to the unfoamed resin portion of the vertical wall portion. For example, when an unfoamed resin portion such as an attachment portion of the hole seal material is formed in an area surrounded by a donut shape by the foamed resin portion, the hole seal material for the automobile door may be structured such that a vertical wall portion is provided at the boundary between the foamed resin portion and the unfoamed resin portion, and an unfoamed vertical wall portion made of unfoamed resin is formed at a position closer to the unfoamed resin portion of the attachment portion of the hole seal material of the vertical wall portion. According to such a hole seal material for the automobile door of the present invention, it is possible to minimize the occurrence of unintended deformation of the shape due to thermal contraction at the boundary between the unfoamed resin and the foamed resin.

The present invention can be used as a hole sealant to close the opening of the inner panel of an automobile door.

LIST OF SYMBOLS 1...Automobile door 2...Outer panel 3...Door trim 4...Inner panel 41...Opening 42...Periphery 43...Outer periphery 5...Hole sealant 6...Foamed main body 61...Foamed core layer 62...Skin layer 63...Upright wall 631...Unfoamed upright wall 64...Core back trace groove 65...Hanging tool engagement hole 66...Hanging hook 7...Outer periphery lip 71...Upright wall 72...Lip edge 721...Tip 73...Bridge 8...Hanging tool 81...Tip hook 90...Cavity 901...Surface on side where movable mold retracts 902...Inner surface 91...Fixed mold 911, 912...Gap 92...Fixed mold 93...Movable mold MR...Foamable molten resin 101...Hole sealant 102...Foamed main body 103...Outer periphery lip 104...Tip 105: non-contact area 201: inner panel 202: opening 203: outer periphery 301, 302: fixed mold 303: movable mold

Claims (3)

A hole seal material for an automobile door, which is made of the same molding material having a foamed body portion made of a foamed resin and an outer peripheral lip portion made of an unfoamed resin, and a tip portion of the outer peripheral lip portion is elastically biased against and fixed to an outer peripheral portion of an opening of an inner panel,
A vertical wall portion is provided around the outer side of the core back trace groove of the foam body portion,
An unfoamed upright wall portion made of unfoamed resin is formed on the outer side of the upright wall portion,
13. A hole seal material for an automobile door, comprising: a peripheral lip portion formed so as to protrude outward from said unfoamed upright wall portion. 2. The hole seal material for an automobile door as described in claim 1, characterized in that the outer peripheral lip portion is composed of an upright wall extending in the thickness direction of the foamed main body portion, a lip edge formed by sloping outward from the upright wall toward the inner panel side, and a bridging portion composed of unfoamed resin that connects the unfoamed upright wall portion and the upright wall so as to form an approximately H -shaped cross section. A method for producing a hole seal material for an automobile door according to claim 1 or 2 , comprising the steps of:
a first step of forming a cavity, which is defined by a fixed mold and a movable mold, and which is composed of the outer peripheral lip portion, the vertical wall portion, and a hollow having a shape corresponding to a substrate and a thickness thinner than the height of the vertical wall portion, by partitioning the cavity with the fixed mold and a movable mold, and disposing the fixed mold on a receding surface of the movable mold in the hollow having the shape of the vertical wall portion, and disposing a side surface of the movable mold on an inner surface of the hollow having the shape of the vertical wall portion;
A second step of filling the cavity with a foamable molten resin;
and a third step of core-backing the movable mold to foam the foamable molten resin and form the hole seal.