This application claims priority to Japanese patent application serial number 2004-242281, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to devices for blocking spaces defined within hollow structures. In particular to blocking devices that include expandable members expanding by external heat to form foam members for blocking the spaces.
2. Description of the Related Art
For example, Japanese Laid-Open Patent Publication No. 2001-79845 teaches a device for blocking a space defined within a hollow structure, such as a hollow panel of an automobile body (e.g., a pillar, a rocker panel, a roof side panel, or a wheel housing), by a foam member in order to improve the damping and sound insulating properties of the hollow structure.
The device disclosed in the above publication has a blocking member constituted by an expandable member that is expanded by external heat to form a foam member and a holder plate for holding the expandable member within the space of the hollow structure. The blocking member is mounted within the space by means of clips that are made of synthetic resin and are integrated with the holder plate.
In the case in which the hollow structure is a hollow panel, the hollow panel may be dipped into a bath containing a liquid coating material for forming electro-deposition coatings on both the internal and external surfaces of the hollow panel. After the internal and external surfaces are coated with the electro-deposition coatings, the hollow panel may be conveyed into a heating furnace where the coatings are baked. The expandable member retained by the holder plate may then expand to form a foam member as a result of the heat applied during the baking process, so that the foam member blocks the space within the hollow structure.
However, according to the blocking device of the above publication, the blocking member of the blocking device is mounted to the wall surface of the hollow structure by means of clips made of synthetic resin. Therefore, there has been a problem in that the mounting strength of the blocking member to the wall of the hollow structure is not sufficient. Thus, in the event that the coating material for electro-deposition surges into the space of the hollow structure, there is a possibility that the clips are forcibly removed from the corresponding mounting holes formed in the wall of the hollow structure. In some cases, the blocking member of the blocking device may fail (e.g., breaking of mounting structures, or being moved to an incorrect position or orientation) due to the pressure of the flow of the coating material. When this occurs, the expandable member may expand in an unintended direction. Consequently, it may be impossible to reliably block the space with the expanded foam member so as to not result in any significant clearance between the blocking device and the walls of the hollow structure.
It is accordingly an object of the present invention to teach improved techniques for reliably fixing the bodies of the blocking devices in position within a space of a hollow structure.
In one aspect of the present teachings, blocking devices for mounting within a space defined within a hollow structure are taught. The hollow structure may have a wall portion extending within the space. The blocking device may include a blocking member and a fixing device. The blocking member may be disposed on one side of the wall portion within the space. The blocking member may include an expandable member and a holder for holding the expandable member. The expandable member may be expandable by heat to form a foam member. The fixing device may include a fixing member that may be disposed on the other side of the wall portion within the space. The fixing device further may include a connecting member(s) that may extend through an insertion hole(s) formed in the wall portion. The connecting member(s) connects the blocking member and the fixing member.
With this arrangement, the blocking member may be fixed in position by the fixing member via the connecting member that extends through the insertion hole formed in the wall portion of the hollow structure. Therefore, the blocking member can be reliably fixed in position in comparison with the known fixing device utilizing clips. In addition, the blocking member may be reliably prevented from failing within the space of the hollow structure, even in the event that a liquid coating material for electro-deposition surges into the space of the hollow structure.
In one embodiment, the expandable member has a first side and a second side opposite to each other. The holder includes a first holder plate and a second holder plate respectively disposed on the first side and the second side of the expandable member. The first holder plate has an engaging member(s). The second holder plate has an engaging hole(s) positioned to correspond to the engaging member(s). The connecting member has a latching hole, so that the first engaging member is engageable with the engaging hole while the engaging member extends through the latching hole.
With this arrangement, the engaging member for assembling the first holder plate to the second holder plate can also be used as a latching member that may prevent the connecting member from being removed from the blocking member. Therefore, the manufacturing cost of the blocking device can be reduced.
In another embodiment, an engaging claw is formed integrally with a circumferential edge of the engaging hole in order to prevent the engaging member from being accidentally removed from the engaging hole. Therefore, it is possible to reliably prevent the first and second holder plates from being accidentally removed from each other. In other words, it is possible to prevent the expandable member from expanding at an unintended position or orientation within the space.
In a further embodiment, the connecting member(s) may have an engaging member(s) disposed on an end portion(s) of the connecting member(s). The blocking member may have an engaging hole(s) for engagement with the engaging member(s). The engaging hole may have an engaging portion formed on an inner wall of the engaging hole and may be engageable with the engaging member for preventing the engaging member from being accidentally removed from the engaging hole. Therefore, it is possible to easily prevent the connecting member from being accidentally removed from the blocking device. The engaging member(s) may be formed integrally with the holder and the connecting member(s) may be formed integrally with the fixing member.
In a further embodiment, the holder plate has at least one rib for preventing the blocking member from falling down within the space of the hollow structure. Therefore, even in the event that a liquid coating material for electro-deposition surges into the space of the hollow structure, the ribs may reliably hold the blocking member in an upright position.
In a further embodiment, the fixing member may have a second expandable member and a second holder for holding the second expandable member. The expandable member is expandable by heat so as to form a second foam member. With this arrangement, the fixing member can also serve as a second blocking member. Therefore, the fixing member can further reliably fix the blocking member in position by the fixing member. In addition, it is possible to simultaneously block both sides of the wall portion within the space. This arrangement is particularly advantageous if the wall portion is a partition wall extending within the space in the longitudinal direction of the hollow structure in order to separate the space into a first space and a second space. Thus, the blocking member may be disposed within the first space to block the first space and the fixing member may be disposed within the second space to block the second space.
FIGS. 8(a) is a plan view of an end portion of a connecting member having an engaging member according to a first modification of an engaging device between the connecting member and a blocking body; and
Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved blocking devices for hollow structures and methods of manufacturing such blocking devices. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with one another, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful embodiments of the present teachings.
A representative embodiment will now be described with reference to FIGS. 1 to 7. Referring to
The construction of the blocking member 20 will be described first. Referring to
As shown in
In addition, as shown in
The expandable member 24 may be made of any suitable expandable material. However, the expandable member 24 may preferably be made of synthetic-resin-based expanding material containing an expanding agent mixed therewith for producing foams when externally heated. More preferably, as a main component, the expandable member 24 may have a synthetic resin material having adhesion properties to metal surfaces and/or synthetic resin surfaces. A fibrous material such as glass fibers may be mixed with the synthetic resin material. With this composition, the expanding member 24 may expand to form a foam member when heated during the baking process of the coatings on an automobile body (e.g. at a temperature of about 110° C. to about 190° C.). Such expandable materials having adhesion properties are disclosed, for example, in Japanese Laid-Open Patent Publication No. 9-176356, the contents of which are incorporated herein.
The construction of the fixing member 30 will now be described. The construction of the fixing member 30 is generally the same as the construction of the blocking member 20. Thus, the fixing member 30 has a holder 33 and an expandable member 34 that is held by the holder 33 within the space of a hollow structure. The holder 33 includes a pair of a first holder plate 31 and a second holder plate 32 that may preferably be made of a heat-resisting thermoplastic resin, such as 66-nylon, and molded by an injection molding process. More specifically, the first and second holder plates 31 and 32 are configured to substantially conform to the shape of a circumferential portion of the cross-section of the space within the hollow structure. In this representative embodiment, the first and second holder plates 31 and 32 have substantially elongated U-shaped configurations. The first holder plate 31 and the second holder plate 32 are positioned opposite to each other and are joined together at joint portions 35a and 35b. The connecting members 40a and 40b respectively extend from the joint portions 35a and 35b. The connecting members 40a and 40b have elongated flat plate-shaped configurations and respectively have latching holes 41a and 41b. A clip 36 is integrally formed with the joint portion 35b and is adapted to temporarily engage a corresponding engaging hole formed in the inner wall of the hollow structure.
The constructions of the fixing member 30 and the blocking member 20 will now be described in relation to the connection between the fixing member 30 and the blocking member 20. As shown in
In
The operation of the above first representative embodiment will now be described in relation to the mounting operation of the blocking device 10 within the space of the hollow structure. Referring to
As shown in
In this way, according to the blocking device 10 of the first representative embodiment, the blocking member 20 may be fixed in position by the connecting members 40a and 40b that extend through the mounting holes 55a and 55b formed in the reinforcement panel 53 or by the fixing member 30 that is connected to the blocking device 10 via the connecting members 40a and 40b. Therefore, the blocking member 20 may be reliably and fixedly mounted within the first space 54a. As a result, even in the event that a liquid coating material for electro-deposition (known as a ED liquid) has surged into the space 54 of the hollow structure 50, the blocking member 20 may be effectively prevented from failure due to the pressure of the coating material.
Further, as shown in
In case that the hollow structure 50 is a hollow panel of an automobile body (e.g., a pillar, a rocker panel, a roof side panel, or a wheel housing), the internal surface and the external surface of the automobile body or the hollow panel may be coated with an electro-deposition coating. The automobile body may then be conveyed into a heating furnace where the coatings are baked. Therefore, the expandable members 24 and 34 of the blocking device 10 shown in
As described above, according to the blocking device 10 of this representative embodiment, the blocking member 20 may be reliably prevented from failing within the first space 54a. Therefore, it is possible to prevent the expandable member 24 from expanding in an unintended direction within the first space 54a. As a result, the formed foam member 24a can reliably block the first space 54a.
In addition, the fixing member 30 used for fixing the blocking member 20 in a correct position also can serve to block an interior space. As a result, in the case that the space 54 of the hollow structure 50 is divided into a first and second space 54a and 54b by a reinforcement panel 53 or a partition extending along the longitudinal direction of the hollow structure 54, the fixing member 30 can block the second space 54b while the blocking member 20 blocks the first space 54a. In this way, the two separate spaces within the hollow structure 54 can be simultaneously blocked.
In the above representative embodiment, the connecting members 40a and 40b of the fixing member 30 have respective latching holes 41a and 41b through which the clips 43a and 43b extend in order to prevent the connecting members 40a and 40b from being inadvertently removed from the blocking member 20. However, the present invention may not be limited to this construction. For example, the connecting members 40a and 40b may be formed with other clips or engaging members that may prevent them from being removed from the expandable member 24 of the blocking member 20. A variety of examples of such modifications (modifications 1 to 3) will be hereinafter described. For the purpose of illustration, these modifications will be described in relation to only one connecting member. Of course, the same modification may be applied to a number of connecting members.
(Modification 1)
According to Modification 1 shown in FIGS. 8(a) and 8(b), a clip or a resilient engaging member 61 is integrally formed with an end portion of a connecting member 60. As shown in
(Modification 2)
According to Modification 2 shown in FIGS. 9(a) and 9(b), a pair of resilient engaging members 71 that may form a clip together are formed integrally with an end portion of a connecting member 70. As shown in
(Modification 3)
According to Modification 3 shown in FIGS. 10(a) and 10(b), an end portion of a connecting member 80 is configured as a clip or an engaging member 85 having a rounded front end. Stepped portions 81 are formed on the rear side of the engaging member 85. Correspondingly, resilient engaging members 82 are integrally formed with the upper and lower walls, as viewed in FIGS. 10(a) and 10(b), of an insertion hole 83 that is formed in an expandable member 84 of the blocking member 20. Therefore, the engaging members 82 may engage with the stepped portions 81 of the engaging member 85 when the connecting member 80 has been inserted into the insertion hole 83 as shown in
(Other Possible Modifications)
In the above representative embodiment, a pair of holder plates 31 and 32 and the expandable member 34 constitute the fixing member 30. However, the fixing member 30 may not be limited to this construction. Since a primary function of the fixing member 30 may be to fix the blocking member 20 in position within the space of the hollow structure, the fixing member 30 may be constructed so as to be dedicated to this specific function. For example, the fixing member 30 may consist entirely of a single element molded from thermoplastic resin, such as 66-nylon.
In addition, although the above representative embodiment has been described in relation to the hollow structure 50 that may be a pillar, a rocker panel, a roof side panel, or a wheel housing of an automobile body for example, the present invention may also be applied to any other hollow structures in addition to those of automobiles. For example, the present invention may be applied to the hollow structures of houses, buildings, boats, and ships.
Number | Date | Country | Kind |
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2004-242281 | Aug 2004 | JP | national |