JPH0130254Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the mounting structure of resin parts, such as automobile hood louvers.

Conventionally, the resin hood louvers that are attached to automobiles are attached to the vehicle body as shown in Figure 1.
A stud bolt 2 is embedded in the lower surface of the hood louver 1, the bolt is inserted into the hood panel 3, and a nut 4 is screwed together to attach it.Alternatively, as shown in FIG. A hood louver with a protruding leg 5, a self-threading nut 6 fitted into the leg, and tightened while cutting a thread in the leg, or a hood louver as shown in FIG. There was a model in which a cylindrical leg part 7 was provided on the lower surface of the bolt 1 and was attached with a tapping screw 8, but in the model shown in Fig. 1, the axial force due to tightening the nut is applied directly to the stud bolt. Inevitably, the size L of the implanted part becomes large, which tends to cause sink marks on the surface of the mounting part, and it is difficult to move from side to side because it is tightly tightened, especially in the case of large parts etc. The resin part and the member to be mounted are difficult to move. Due to errors in thermal expansion, there are problems such as warping or twisting of the resin parts, which have lower rigidity than the steel plate-like member to which they are attached. In other words, the linear expansion coefficient of a steel plate (iron) is approximately 1 × 10 ^-5 , and that of resin is (approximately 5 to 10) × 10 ^-5 , and if it is 500 mm long and heated at 50°C. If the temperature rises, the amount of elongation will be approximately 0.25 mm for iron and approximately 0.25 mm for resin.
The difference is 1.25 to 2.5 mm, and a difference of 1 to 2.25 mm causes warping or twisting on the resin part side. In addition, in the case shown in Fig. 2, the usable allowable tightening torque is small, so there are problems such as not being able to perform work with good workability such as air tools, and making it impossible to perform many attachment and detachment operations. In the case shown in Fig. 3, there were problems such as the allowable tightening torque was small, the legs required a thick wall, sink marks were likely to occur on the surface of the mounting part, and the drawing process of the mounting panel became deep.

The present invention was made to solve the above-mentioned conventional problems, and it has a simple structure and is easy to install, and it also prevents sink marks from occurring on the mounting surface or warping from the resin parts. The object of the present invention is to provide a structure for attaching resin parts without any problems.

The present invention will be described below with reference to illustrative embodiments.

A is a hood panel showing an example of a member to be attached; a
is the mounting opening 11 bored in the hood panel A.
The hood louver is a resin part that is attached to the hood louver, and a plurality of mounting holes 12 are bored at appropriate intervals near the periphery of the mounting opening 11. A boss part 13 that is freely inserted into the mounting hole 12 is integrally formed in the part corresponding to the mounting hole 12 on the back side of a, and the boss part 13 has a collar with a diameter larger than the diameter of the threaded part 14a. A stud bolt 14 having a portion 14b is inserted so that its collar portion 14b comes into contact with the distal end surface of the boss portion 13. 15 is a nut screwed onto the stud bolt 14, and 16 is a stepped portion 16.
The washer 16 is made of steel and has a cap shape, and a rubber washer 17 having elasticity is fitted into the washer 16. The height of the rubber washer 17 is made slightly larger than the gap H between the stepped portion 16a of the washer 16 and the back surface of the hood panel A when the washer 16 is fastened. It is compressed and held between the back surface of the Reference numeral 19 denotes a protrusion formed near the periphery of the boss portion 13 on the back side of the hood louver a.

Now, in order to attach the hood louver a to the hood panel A, first loosely fit the washer 16 with the rubber washer 17 fitted into the threaded portion 14a of the stud bolt 14, then screw the nut 15 on and tighten it. The bottom of the stud bolt 14 is pressed against the collar 14b of the stud bolt 14, and is interposed and held between the collar 14b and the nut 15, and the protrusion 19 abuts against the surface of the hood panel A. Installation is complete at this point. At this time, since the rubber washer 17 is compressed and held between the hood panel A and the washer 16, the boss portion 13 of the hood louver a has a
Only the reaction force due to the compression of the rubber washer 17 and the tightening torque of the nut 15 are loaded, and the high axial force due to tightening the nut is applied to the stud bolt 14.
This occurs on the contact surface of the collar portion 14b.

In the above embodiment, a stepped cap-shaped steel washer 16 was used to attach the hood louver a, but the washer 16 is not limited to this, and a flat washer 18 as shown in FIG. 8 may also be used. good. Further, although the above embodiment describes the attachment of the hood louver a, the present invention is not limited to this and can be applied to attachment of other resin products to steel plates or the like.

As described above, according to the present invention, a boss portion that is inserted into the mounting hole is bored on the back side of the portion of the resin component that corresponds to the mounting hole of the member to be mounted, and the boss portion is inserted into the mounting hole. forming a protrusion near the periphery of the part that comes into contact with the attached member when attached to the attached member;
A stud bolt having a collar portion having a diameter larger than the diameter of the threaded portion is inserted into the boss portion, and an elastic rubber washer is interposed and sandwiched between the attached member and the steel washer, and ,
The center part of the washer is sandwiched between the nut screwed onto the stud bolt and the collar of the stud bolt, so that the collar of the stud bolt receives the high axial force caused by tightening the nut. Only the reaction force due to the compression of the rubber washer and the tightening torque are applied to the boss part of the resin part, thereby reducing the force applied to the boss part of the resin part. can be simplified. Therefore, since the wall thickness L of the boss portion can also be reduced, sink marks on the surface of the resin component are less likely to occur.

Further, since the nut tightening is completed when the steel washer is crimped onto the collar of the stud bolt, the nut tightening torque can be maintained uniformly without variations.

Further, according to the present invention, the resin part is provided with a protruding boss portion that is inserted into the mounting hole in the part corresponding to the mounting hole of the mounted member, so that the resin part cannot be removed from the mounted member. The amount of protrusion can be reduced.

Further, according to the present invention, a protrusion is formed on the back side of the resin part, and when the resin part is attached to the member to be attached, only the protrusion comes into contact with the surface of the member to be attached. The contact area between the resin part and the mounted member is small, and since the resin part is fixed by the compression reaction force of the rubber washer, the load applied to point P, where the protrusion and the mounted member are in contact, is also small. . Therefore, the resin part and the attached member are easy to slide against each other and can move even if dimensional expansion/contraction due to thermal expansion or water absorption occurs, so the resin part does not warp or twist. .

Additionally, when a painted steel plate is used as the member to be mounted, a rubber washer is interposed between the steel plate and the steel washer during installation, which may damage the back side of the painted steel plate. Since there is no rubber washer, the painted surface can be protected, rust will not occur, and even if the vehicle body etc. vibrates, it is held down by the compression reaction force of the rubber washer, so it has the effect of not rattling. It is something.

[Brief explanation of drawings]

Figures 1 to 3 are partial side sectional views showing the conventional hood louver mounting structure, Figure 4 is a perspective view of the hood panel showing the mounting position of the hood louver, and Figure 5 is the installation of the hood louver according to the present invention. FIG. 6 is an enlarged perspective view of the stud bolt, FIG. 7 is an enlarged perspective view of the special nut, and FIG. 8 is a partial side sectional view showing another embodiment of the present invention. . A is a hood panel, a is a hood louver, 13 is a boss part, 14 is a stud bolt, 14b is a collar part, 15 is a nut, 16 and 18 are washers, 17
is rubber washer.

Claims (1)

[Scope of utility model registration request] A boss part that is inserted into the mounting hole is provided on the back side of the part of the resin part that corresponds to the mounting hole of the mounted member, and a boss part that is inserted into the mounting hole is provided near the periphery of the boss part to be mounted on the mounted member. A stud bolt having a flange portion having a diameter larger than the diameter of the threaded portion is inserted into the boss portion, and a stud bolt that comes into contact with the attached member is formed when the stud bolt is made of steel. An elastic rubber washer is interposed and sandwiched between the washer and the washer, and the center portion of the washer is interposed and sandwiched between a nut screwed to the stud bolt and the collar of the stud bolt. A mounting structure for resin parts featuring: