JP2010023326A - Synthetic resin platy body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin platy body able of securing a sufficient rigidity without increasing plate thickness. <P>SOLUTION: An aerodynamic cover 1 is produced by a synthetic resin injection molding which injects a molten synthetic resin in a cavity formed by a movable die and a fixed die, where many projections 2 are formed in an alignment so that planar sections between the projections 2 would not remain in straight line while the projections 2 express round shape in planar view and circular arc in cross section. Further, projection height H/projection width W1 is regarded as suitable when it is in the range of 12% to 20.0% considering satisfactory rate of performance improvement although optimum value of the projection height H/projection width W1 is about 16.3% which exemplifies just before slowdown starts in the rate of performance improvement. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a synthetic resin plate-like body formed with a large number of projections, and in particular, aerodynamic cover that covers the bottom of an automobile to reduce air resistance, and a composition such as an automobile protector fender and undercover. The present invention relates to a resin plate.

This type of synthetic resin plate is generally manufactured by synthetic resin injection molding in which molten synthetic resin is injected into a cavity formed by a movable mold and a fixed mold, and the thickness of the sheet is reduced. Generally, rigidity is ensured by increasing the thickness or forming a bead.
Japanese Patent Laid-Open No. 2002-60878

  However, there is a problem that increasing the thickness of the synthetic resin plate-shaped body inevitably results in an increase in weight and an increase in cost, and when unevenness is formed, the flat plate portion is arranged so that it remains linear between the concave grooves. Therefore, sufficient rigidity cannot be secured.

  Therefore, the present invention solves such problems, and an object of the present invention is to provide a synthetic resin plate-like body capable of ensuring sufficient rigidity without increasing the plate thickness.

  Therefore, the first invention is a synthetic resin plate-like body formed with a large number of convex portions, and the convex portion has a height H of the convex portion / width W1 of the convex portion of 12% or more to 20%. It is formed by synthetic resin injection molding so that the flat plate portion is not linearly left between the convex portions.

  The second invention is a synthetic resin plate-like body formed by forming a large number of convex portions, and the convex portion has a height H of the convex portion / width W1 of the convex portion of 12% or more and within 20% or less. It was formed by resin panel press molding so that it may be formed and it may be arranged so that a flat plate part may not remain linearly between convex parts.

  The third invention is characterized in that, in the first or second invention, a width W1 of the convex portion is 10 mm or more and 16 mm or less.

  4th invention is 1st or 2nd invention. WHEREIN: The space | interval C of the said convex parts is 75% or less of the base width W2 which is the sum of space | interval C / 2 and the width W1 of the said convex part. It is characterized by.

  A fifth invention is characterized in that, in the first or second invention, the convex portion has a hexagonal shape in plan view, and a longitudinal section passing through a vertex forming a diagonal has an arc shape.

  A sixth invention is characterized in that, in the first or second invention, the convex portion has a circular shape in plan view, and a longitudinal section thereof has an arc shape.

  The present invention can provide a synthetic resin plate-like body capable of ensuring sufficient rigidity without increasing the plate thickness.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an aerodynamic cover 1 in which convex portions 2 are formed, FIG. 2 is a partial perspective view of the aerodynamic cover 1 in which convex portions 2 are formed, and FIG. 3 is a portion of the aerodynamic cover 1 in which convex portions 2 are formed. It is a top view.

  The aerodynamic cover 1 as a plate-like body is a member for protecting the bottom surface side and reducing the air resistance on the bottom surface side by being fixed so as to cover the bottom surface side of a vehicle body such as an automobile. The aerodynamic cover 1 has a number of convex portions 2 formed on the flat portion except for the peripheral edge portion 3 thereof. And this aerodynamic cover 1 inserts a volt | bolt in the attachment hole 5 formed in the attachment piece 4 formed in the peripheral part 3, and uses the surface where the convex part 2 protruded as an upper surface, and a recessed part is outside air. It is attached to the bottom of the car body so that it touches.

  The aerodynamic cover 1 is manufactured by synthetic resin injection molding in which a molten synthetic resin is injected into a cavity formed by a movable mold and a fixed mold. In this case, a large number of convex portions are formed on the flat plate portion in an array state such that the flat plate portion does not remain linearly between the convex portions. Although the convex portions are formed at equal intervals, the plan view has a circular shape, the longitudinal section has an arc shape, and forms a part of a sphere.

  In the process of manufacturing as described above, the plate thickness of the synthetic resin plate is 0.3 mm, the width W1 of the convex portion 2 is 8 mm, the base width W2 is 10 mm, and the plane dimension (C / 2) is 1 mm. As a result, the performance improvement rate was investigated from the maximum amount of displacement of many examples manufactured by changing the height H of the convex portion 2 every 0.1 mm between 0.8 mm and 3.0 mm. The optimum value of the convex portion height H / the convex portion width W1 was an example of about 16.3% immediately before the start of the slowdown of the performance improvement rate, but the satisfactory performance improvement rate is considered to be 105% or more. Further, it is considered that the convex portion height H / the convex portion width W1 is within a suitable range of 12% to 20.0%.

  Next, as described above, the optimum value of the convex height H / the convex width W1 is about 16.3% in the performance improvement rate, but the convex height H / the convex width W1 is If the optimum value is determined, the optimum width W1 of the convex portion 2 should exist, and even if this width W1 is too small, the absolute height will be insufficient and the strength will not be high, but it is too large. However, since it is considered that the planar element becomes stronger with respect to the plate thickness and the strength is lowered, the plate thickness of the synthetic resin plate-like body is set to 0.35 mm, and the width W1 of the convex portion 2 is set to 6 mm to 20 mm. The performance difference with respect to the base was investigated from the maximum displacement amount of the example manufactured by changing every 2 mm.

  According to this investigation, when the convex portion width W1 is changed, the ratio of the amount of displacement being reduced at a certain width W1 is reduced, and the convex portion width W1 for which improvement of performance can be expected is an example of 12 mm. The satisfactory protrusion width W1 is considered to be an appropriate range of 10 mm to 16 mm.

  Finally, the density of the convex portions 2 will be described. However, if the interval between the convex portions 2 is increased, the rigidity is lowered accordingly. Therefore, verification is made by paying attention to rigidity (small displacement). That is, the plate thickness of the synthetic resin plate is 0.3 mm, the convex width W1 is 8.0 mm, the convex height H is 0.8 mm, and the convex height H / the convex width W1 is 10.0. %, The performance improvement rate was investigated from the maximum displacement amount of the example of every 1 mm between the base width W2 and 10 mm to 16 mm.

  According to this investigation, the amount of displacement tends to decrease as the density of the convex portions 2 increases, that is, as the planar dimension decreases. However, when the base width W2 is 15 mm (a little less than twice the convex portion width W1), the performance improvement rate is reversed, and this area is considered the upper limit. Accordingly, it is considered appropriate that the interval (6.0 mm) between the convex portions 2 that is twice the plane dimension (C / 2) is 75% or less of the base width W2 (8.0 mm).

  In addition, regarding the material elongation when changing the density, the absolute amount is extremely small in the range of the convex portion to be implemented, and there is no significant influence on the moldability. It is desirable to make the value small and zero. However, a plane portion is necessary for actual production processing. In addition, since the planar portions are arranged so as not to remain linearly between the convex portions 2 (see FIG. 3), the dynamic directionality is lost and the rigidity can be greatly improved.

  The second embodiment is based on FIG. 4, which is a partial perspective view of the aerodynamic cover 1 in which the convex portion 20 is formed, and FIG. 5, which is a partial plan view of the aerodynamic cover 1 in which the convex portion 20 is formed. Will be described.

  The protrusions 20 formed on the aerodynamic cover 1 are formed at equal intervals in an arrayed state so that the flat plate portions do not remain linearly between the protrusions 20. The protrusions 20 have a regular hexagonal shape in plan view. The longitudinal section passing through the apex forming the corner has an arc shape. In this case, the regular hexagon is also an efficient shape that can narrow the distance between them as much as possible.

  However, in the second embodiment, similarly to the first embodiment, the convex portion height / the convex portion width W3 is 12% to 20.0%, and the convex portion width W3 is 10 mm to 16 mm. The interval between the convex portions 20 that is twice the plane dimension (C / 2) is 75% or less of the base width W4.

  When the convex portions 2 and 20 are formed as in the first and second embodiments described above, a 0.4 mm thick synthetic resin plate that does not form a convex portion is formed even if a 0.3 mm thick synthetic resin plate is formed. It can exhibit the same or higher rigidity as the plate. Therefore, even when the bead cannot be sufficiently protruded or when the bead cannot be formed on the entire plate surface, by forming the convex portion, it is possible to ensure the necessary rigidity without increasing the plate thickness, Increase in weight and cost can be avoided. In particular, if the flat plate portion is not left in a straight line between the convex portions, the dynamic directionality is lost, and the rigidity can be greatly improved.

  The present invention can be applied not only to the case where the aerodynamic cover 1 is formed by the synthetic resin injection molding as described above, but also to the case where an automobile protector fender, an under cover, or the like is manufactured by resin panel press molding. For example, it is produced by heating a resin sheet containing glass fibers and press-molding with a mold, but in this case as well, by synthesizing by forming convex portions as in the third embodiment described above, Even in a resin plate-like body, necessary rigidity can be ensured without increasing the plate thickness, and an increase in weight and an increase in cost can be avoided.

  In addition, even if a large number of embossed projections are formed on an aluminum heat insulator that can be suitably used for heat insulation of automobile catalytic converters and mufflers, the same effect can be obtained. May be.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various alternatives described above without departing from the spirit of the present invention. It includes modifications or variations.

It is a perspective view of the aerodynamic cover in which the convex part of 1st Embodiment was formed. It is a fragmentary perspective view of the aerodynamic cover in which the convex part of 1st Embodiment was formed. It is a fragmentary top view of the aerodynamic cover in which the convex part of 1st Embodiment was formed. It is a fragmentary perspective view of the aerodynamic cover in which the convex part of 2nd Embodiment was formed. It is a partial top view of the aerodynamic cover in which the convex part of 2nd Embodiment was formed.

Explanation of symbols

1 Aerodynamic cover 2, 20 Convex part

Claims (6)

  It is a synthetic resin plate-like body formed with a large number of protrusions, and the protrusions are formed such that the height H of the protrusions / the width W1 of the protrusions is 12% or more and within 20%. A synthetic resin plate-like body produced by synthetic resin injection molding so that the flat plate portions are not linearly left between the convex portions.   It is a synthetic resin plate-like body formed with a large number of convex portions, and the convex portions are formed such that the height H of the convex portions / the width W1 of the convex portions are within a range of 12% to 20%. A synthetic resin plate-like body produced by resin panel press molding so that the flat plate portions are not linearly left between the convex portions.   The synthetic resin plate-like body according to claim 1 or 2, wherein a width W1 of the convex portion is 10 mm or more and 16 mm or less.   3. The composition according to claim 1, wherein the interval C between the convex portions is 75% or less of a base width W <b> 2 that is a sum of the interval C / 2 and the width W <b> 1 of the convex portion. Resin plate.   3. The synthetic resin plate-like body according to claim 1, wherein the convex portion has a hexagonal shape in a plan view, and a longitudinal section passing through a vertex forming a diagonal has an arc shape. . 3. The synthetic resin plate-like body according to claim 1, wherein the convex portion has a circular shape in a plan view and a vertical cross section has an arc shape.

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