JPS5936566B2 - Mounting holes for synthetic resin products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a mounting hole through which a metal fixture such as a rivet or bolt is inserted, and expansion and contraction deformation due to changes in ambient temperature occurs in the radial direction perpendicular to each other of the mounting hole. The present invention relates to various synthetic resin products that are becoming increasingly popular, and particularly to improvements in their mounting holes.

Conventionally, as shown in FIG. 1, synthetic resin guide members 10 and 2 have been used in vehicle window glass guide devices.
0 is fixed to the substrate P fixed to the lower end of the window glass W, and is attached to the support rod L so as to be slidable in the vertical direction. As only the guide member 10 is shown in FIG. 1, metal rivets R (metal bolts may also be used) are used.
Therefore, in the fixing means using this rivet R, as shown in enlarged view at A in FIG.
0 is provided with a mounting hole 11' having an inner diameter slightly larger than the outer diameter of the rivet R in consideration of ease of assembly. However, in this case, when the guide member 10 expands due to a rise in ambient temperature, the inner wall surface of the mounting hole 11' deforms into an elliptical shape as shown in B in FIG. do. Then, both the upper and lower ends of the mounting hole 11' as shown in the drawing come into pressure contact with the outer peripheral surface of the rivet R, and this pressure contact portion is plastically deformed.
Therefore, when the ambient temperature returns to normal temperature, the inner wall shape of the mounting hole 11' becomes a vertically elongated ellipse as shown in C in FIG. A large gap or play in the radial direction occurs between the outer peripheries of R (this play causes the window glass W to vibrate due to vibrations of the vehicle, causing abnormal noise). In addition, in order to prevent the occurrence of this backlash, a method is adopted in which the inner diameter of the mounting hole 11' is made smaller than the outer diameter of the rivet R and the rivet R is press-fitted into the mounting hole 11'. Needless to say, problems such as poor assembling performance and the formation of cracks around the mounting hole 11' due to the difference in shrinkage rates between synthetic resin and metal when the ambient temperature decreases will occur.
Even in this method, play may occur in the same manner as described above when the ambient temperature rises. The present invention has been made to deal with such problems, and one embodiment thereof will be described below with reference to the drawings.

4 and 5 show a horizontally elongated synthetic resin guide member 10 according to the present invention, which exhibits remarkable expansion and contraction deformation due to changes in ambient temperature in the longitudinal direction and the direction orthogonal thereto.
Attachment holes 11, 11 into which the repets R are inserted are provided at both ends of the guide member 10, respectively. As shown in the enlarged view in FIG. 6, the mounting hole 11 has a rivet R.
It has an inner diameter slightly larger than an outer diameter, and four protrusions 12 to 12 are formed protruding from its inner wall surface at equal intervals along the axial direction. Each protrusion 12 is provided at an angle of 45 degrees with respect to the longitudinal direction of the guide member 10, and has a predetermined protrusion amount such that its tip comes into close contact with the outer peripheral surface of the rivet R when the rivet R is inserted. are doing. When the guide member 10 configured in this way is fixed to the substrate P of the window glass W of the vehicle shown in FIG. 1 with rivets R, R,
At each fixed portion, when the ambient temperature is normal temperature, the tip of each protrusion 12 is in close contact with the outer circumferential surface of the rivet R, as shown in A in FIG. A slight, substantially uniform gap D is formed between the surfaces, and the guide member 10 is fixed by the rivet R without play.

When the guide member 10 expands due to an increase in ambient temperature, the inner wall surface of the mounting hole 11 deforms into a horizontally long inertia circle as shown at B in FIG. 7. At this time, each protrusion 12 comes into close contact with the outer peripheral surface of the rivet R to prevent the inner wall surface of the mounting hole 11 from abnormally deforming inward and coming into pressure contact with the outer peripheral surface of the rivet R. Therefore, when the ambient temperature reaches normal temperature, the shape of the inner wall surface of the mounting hole 11 returns to its original shape, as shown by C in FIG. Further, when the guide member 10 contracts due to a decrease in the ambient temperature, the inner wall surface of the mounting hole 11 becomes a vertically long freewheel as shown by D in FIG.

At this time, each protrusion 1
In order to prevent the inner wall surface of the mounting hole 11 from abnormally deforming inward due to the rivet R coming into close contact with the outer peripheral surface of the rivet R, when the ambient temperature reaches normal temperature, the inner wall surface shape of the mounting hole 11 changes as shown in FIG. C of
As shown in , it returns to its original shape. In the above embodiment, an example will be described in which four protrusions 12 are provided on the inner wall surface of the mounting hole 11, and each of these protrusions 12 is positioned at an angle of 45 degrees with respect to the longitudinal direction of the guide member 10. However, this is because when a synthetic resin product with a horizontally long shape such as the guide member 10 is thermally deformed, it deforms greatly in the longitudinal direction and in a direction perpendicular thereto, and each protrusion 12 is placed at an angle of 45 degrees with respect to the longitudinal direction where deformation is less. This is based on experimental results showing that the above-mentioned effect of the present invention can be reliably obtained over a long period of time if the present invention is installed in the same position.When implementing the present invention on various other synthetic resin products, It is desirable to measure (or predict) thermal deformation in advance and provide a protrusion in a portion of the mounting hole where thermal deformation is small.

As detailed above, in the present invention, as exemplified in the above embodiment, in the synthetic resin guide member 10 in which expansion and contraction deformation due to changes in ambient temperature appears significantly in the mutually orthogonal radial direction of the mounting hole 11, Two pairs of protrusions 12 that can be brought into close contact with the outer circumferential surface of the rivet R (metal fixture) are formed along the axial direction at positions approximately 45 degrees from the expansion/contraction deformation direction of the inner wall surface of the mounting hole 11, and these protrusions 12 Its structural feature lies in the fact that a slight gap D is provided between the inner wall surface of the mounting hole 11 and the outer peripheral surface of the rivet R.

Therefore, in the present invention, thermal deformation (expansion/contraction deformation due to changes in ambient temperature) of the mounting hole 11 is not restricted by the outer circumferential surface of the rivet R due to the gap D formed by the protrusion 12. can be prevented from being plastically deformed due to changes in ambient temperature. Moreover, the two pairs of protrusions 12 are
It is formed at a position approximately 45 degrees from the direction of expansion/contraction deformation due to changes in ambient temperature, and is hardly affected by expansion/contraction deformation, so it does not come into strong pressure contact with the outer peripheral surface of the rivet R. Therefore, the protrusion 12 will not be deformed or worn out for a long time, and the above-mentioned effect can be expected for a long time. As a result, for a long period of time, no looseness occurs in the close contact portion between the protrusion 12 and the outer peripheral surface of the rivet R, that is, the fixed portion, and the guide member 10 is fixed by the rivet R without any looseness.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a vehicle window glass guide device equipped with a synthetic resin guide member to which the present invention is applied, Fig. 2 is an enlarged cross-sectional bottom view taken along line 2-2 in Fig. 1, and Fig. 3 is a An explanatory diagram showing the thermal deformation of the conventional mounting hole in the 3-3 sectional view of FIG.
FIG. 4 is a front view of a synthetic resin guide member embodying the present invention, FIG. 5 is a bottom view of the same, FIG. 6 is an enlarged rear view as seen from arrow 6 in FIG. 5, and FIG. FIG. 3 is an explanatory diagram showing thermal deformation of a mounting hole according to the present invention corresponding to FIG. Explanation of symbols, 10...Synthetic resin guide member, 1
1...Mounting hole, 12...Protrusion, R...
...Rivet (metal fixture), D...Gap between guide member and rivet.

Claims (1)

[Claims] 1. In synthetic resin products that are provided with mounting holes through which metal fixtures such as rivets and bolts are inserted, and in which expansion and contraction deformation due to changes in ambient temperature is noticeable in the radial direction perpendicular to each other of the mounting holes, Two pairs of protrusions that can be brought into close contact with the outer peripheral surface of the fixture are formed along the axial direction at positions approximately 45 degrees from the expansion/contraction deformation direction on the inner wall surface of the hole, and these protrusions allow the inner wall of the mounting hole to be A mounting hole for a synthetic resin product, characterized in that a slight gap is provided between a wall surface and an outer peripheral surface of the fixture.