The present invention relates to a mounting structure of two members with different thermal expansion coefficients.
When the external wall of a chassis made of metal is mounted on the internal wall of a panel made of resin, the internal wall of the panel is conventionally brought into intimate contact with the external wall of the chassis (for example, see Patent Document 1).
Patent Document 1: JP-A-2000-102093
However, because of a difference in thermal expansion coefficient between the metal and the resin, upon thermal contraction, the panel having a larger shrinkage cannot contract since the chassis having a smaller shrinkage is brought in intimate contact with the internal wall thereof, so that a crack occurs in a portion thereof on which stress is concentrated to be damaged, which poses a problem.
The present invention is made to solve the above-mentioned problem, and an object of the invention is to prevent the breakage of a panel upon thermal contraction.
Amounting structure according to the invention is amounting structure for mounting an external wall of a chassis made of metal on an internal wall of a panel made of resin, and an abutting portion for providing partial contact between the panel and the chassis is provided in a position separate from corners of the panel and the chassis.
According to the invention, owing to an arrangement of the abutting portion for providing partial contact between the panel and the chassis, stress concentration on the corner of the panel is released, which enables to prevent the damage thereof upon thermal contraction.
Embodiments of the present invention will now be described with reference to the accompanying drawings in order to explain the present invention in more detail.
A mounting structure shown in
Abutting portions 13 to 16 in the shape of a projection are formed on the internal wall of the panel 10 such that an internal wall 11 of the panel 10 comes in partial contact with an external wall 21 of the chassis 20 to reduce a contact area. Further, in order to avoid stress from being concentrated on the corner 12 upon thermal contraction, the abutting portions 13, 14, and the abutting portions 15, 16 are placed separate from the corners 12. Since these abutting portions 13 to 16 create clearances between the corners 12 of the panel 10 and the corners 22 of the chassis 20, the panel 10 is not hindered from being deformed as shown in
Furthermore, since the abutting portions 13 to 16 provide clearances between the internal wall on the corner 12 of the panel 10 and the external wall on the corner 22 of the chassis 20, the corner 12 can have an increased curvature radius R. Therefore, further stress relaxation thereof can be expected.
Next, an application example of the mounting structure will be discussed. Note that in
The abutting portions 16a, 16b, and 15a have arrangements similar to those of the abutting portions 13a, 13b, and 15a, respectively, and thus illustrations thereof will be omitted.
As discussed above, in accordance with the first embodiment, the mounting structure for mounting the external wall 21 of the chassis 20 made of metal on the internal wall 11 of the panel 10 made of resin is arranged such that the abutting portions 13 to 16 for providing partial contact between the panel 10 and the chassis 20 are provided in positions separate from the corners 12 of the panel 10 and the corners 22 of the chassis 20. For this reason, the stress concentration on the corners 12 of the panel 10 is released, which enables to prevent the damage thereof upon thermal contraction.
Further, since the arrangement of the abutting portions 13 to 16 can form clearances between the corner 12 of the panel 10 and the corner 22 of the chassis 20, the corner 12 of the panel 10 can have a curvature radius larger than that of the corner 22 of the chassis 20. In such a way, further stress relaxation thereof can be achieved.
Hereupon, in the first embodiment, the abutting portions 13 to 16 are formed on the panel 10; however, abutting portions may be formed on the chassis 20 reversely. As illustrated in
Moreover, the abutting portion may have any shape; for example, it may be formed in a hemispheric projection to render a point contact therebetween.
As discussed above, since the mounting structure according to the present invention is arranged such that partial contact is provided between the internal wall of the panel made of resin and the external wall of the chassis made of metal by using the abutting portion, it is suitable for use in a vehicle-mounted apparatus and so on used in a temperature environment where there is a possibility that resin thermally contracts.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2010/002115 | 3/25/2010 | WO | 00 | 5/29/2012 |