JPH037494B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for molding a door mirror bracket for an automobile.

<Conventional technology> Door mirror brackets generally have 3rd and 5th brackets.
As shown in the figure, a glass storage groove 3 is formed by covering an insert 1 with a U-shaped cross section with an elastic polymer, and mirror mounting holes (three in the example shown) 5 are formed across the glass storage groove 3. The mirror mounting part 7 is formed by extending the insert 1 downward, and the mounting leg part 9 is fixed to the door sheet metal. Here, the insert 1 is generally a sheet metal, and the elastomer material is CR, EPDM, etc.
Use rubber such as, or soft plastic such as PVC or polyolefin.

The molding of the mirror bracket as described above is usually carried out by injection or transfer as described below (see FIGS. 1 and 2).

One side of the outer surface of the mounting part 7 is shaped by a fixed mold 14 and a movable mold 15, and the glass storage groove 3 is shaped by a core 17, and the mirror mounting hole 5 is shaped by one of the fixed mold 14 or the movable mold 15. In the illustrated example, the pillars 19 protrude from the movable mold 15 to form the respective shapes. At this time, the column portion 19 is fitted into the through hole 21 formed in the core 17. In addition, the pillar portion 19
The shape of the mounting hole 19 is formed corresponding to the shape of the mounting hole 19, and is usually a cylinder, but it may also be a square cylinder.

<Problems to be Solved by the Invention> During this molding, a cylindrical gap 23 is usually formed between the pillar portion 19 and the through hole 21;
Cylindrical burrs 25 occur on the molded product. This cylindrical burr 25 is cut by the movement of the core 17 in the direction of the white arrow during mold release, but since the thickness of the cylindrical burr 25 is substantially constant in the axial direction, the cutting location is not constant. Therefore, as shown in FIG. 3, when inserting the mounting boss 29 of the mirror body from one end of the mounting hole 5 and fixing it with the screw 31, the burr 25 will form on the mounting boss 29 as shown in FIG. There was a risk that it would become wedged between the female thread 29a and the screw 31, making assembly impossible. For this reason, it is usually necessary to remove the cylindrical burrs after molding. This removal work was troublesome because the cylindrical burr was located inside the glass storage groove.

<Objective of the Invention> In view of the above, the object of the present invention is to eliminate the risk of cylindrical burrs generated during molding for forming mounting holes biting into mounting mating members such as screws, resulting in poor mounting. An object of the present invention is to provide a method for molding a mirror bracket.

<Means for Solving the Problems> The mirror bracket molding method of the present invention is characterized in that, in the above-mentioned method, a pillar protruding from either the fixed mold or the movable mold for the shape with mounting holes; of the cylindrical gap formed by the through-hole of the core into which it fits,
The above problem is solved by forming one end of the mirror mounting boss on the side opposite to the insertion side as a minute gap.

<Example> Hereinafter, an example of the present invention will be described based on drawings. It should be noted that the same parts as in the conventional example are given the same reference numerals and the explanation will be omitted.

A column part 19 protrudes from either the fixed mold 14 or the movable mold 15, in the illustrated example, from the movable mold 15, and the pillar part 1.
One end of the cylindrical gap 23 formed with the through hole 21 of the core 17 into which the mirror mounting boss 29 is inserted, opposite to the insertion side of the mirror mounting boss 29 (in the illustrated example, the upper end thereof) is connected to the minute gap 2.
As 3a, mold into pillars. In the illustrated example, this minute gap is formed by an annular protrusion 21a formed on the inner circumferential wall of the upper end of the through hole 21 of the core, but the annular protrusion 21a
A continuous wart-like projection may be provided instead of 1a.
Conversely, these annular protrusions or continuous wart-like protrusions may be formed on the upper peripheral wall of the column portion 19. By the way,
When the general interval A of the cylindrical gap 23 is 0.3 mm, the interval a of the minute gap 23a is 0.15 to 0.1 mm, and the height h is
When the thickness was 0.5 to 1.5 mm, the effects described below could be reliably achieved without causing problems such as the pillar portions 19 biting into the through holes 21 of the core when the mold was closed.

<Actions and Effects of the Invention> The method for molding a door mirror bracket of the present invention includes:
a pillar portion 19 for shaping the mirror mounting hole 5;
A minute gap 23 is formed around the entire circumference of one end of the cylindrical gap 23 formed with the through hole 21 of the core 17 into which the column part 19 fits, on the side opposite to the insertion side of the mirror mounting boss.
By forming the cylindrical burr 25 as shown in FIG. Therefore, during demolding (when moving the core 17), the cylindrical burr 25 is reliably cut at one end on the side opposite to the insertion side of the attachment boss 29. Therefore, when installing the mirror body 27,
There is no risk that the cylindrical burr 25 will dig into a mounting pair member such as a screw, specifically between the mounting boss 29 and the screw 31, thereby making the mounting impossible. Therefore, the troublesome work of removing cylindrical burrs after molding, as in the conventional method, becomes unnecessary.

[Brief explanation of the drawing]

Figures 1 to 3 illustrate the present invention, Figure 1 is a schematic cross-sectional view of a mold (before material injection) used in the method of molding a door mirror bracket of the present invention, and Figure 2 shows the material in the mold of Figure 1. Enlarged cross-sectional view of main parts after injection, 3rd
The figure is a schematic cross-sectional view of the mirror attached to the mirror bracket molded with the mold shown in Figure 1, Figure 4 is a cross-sectional view showing problems when attaching the mirror to the mirror bracket molded by the conventional method, and Figure 5 is FIG. 3 is a rear view showing an example of a mirror bracket to which the molding method of the present invention can be applied. 1...Insert, 3...Glass storage groove, 5...
...Mirror mounting hole, 7...Mirror mounting part, 9...
...Mounting leg portion, 14...Fixed type, 15...Movable type, 17... Core, 19... Pillar portion, 21... Through hole, 23... Cylindrical gap, 23a... Minute gap. 2
9...Mirror installation boss.

Claims (1)

[Claims] 1. A U-shaped cross-sectional insert is covered with an elastic polymer to form a glass storage groove, and a mirror mounting hole into which a mirror mounting boss is inserted is formed across the glass storage groove. When molding a door mirror bracket equipped with a mirror mounting part, one side of the outer surface of the mounting part is shaped with a fixed mold and a movable mold, and the glass storage groove is formed with a core, and the mirror mounting hole is formed with a core. The mirror is shaped by a column protruding from either a fixed type or a movable type, and has a cylindrical gap formed by the column and a through hole of the core into which the column fits. A method for molding a door mirror bracket for an automobile, characterized in that one end on the side opposite to the insertion side of the mounting boss is injection molded with a minute gap around the entire circumference.