JPH0356644Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to objects to be coated with welded nuts or weld bolts, and particularly to objects to be coated with threaded portions to be coated.

(Prior art) A structure made entirely of metal members and welded with welt bolts and weld nuts.
For example, in the case of car bodies, they are painted to improve their corrosion resistance and aesthetic appearance. In this case, the entire surface of the vehicle is coated, and in particular, with electrodeposition coating, which is often used as an undercoat, the entire surface of the vehicle is reliably coated, including the back surface of the vehicle body and the inside of the holes.

(The problem that the invention aims to solve) However, when every corner of the car body is completely painted, the weld bolts and weld nuts that are integrally attached to the car body are also completely painted, and the screws The paint film adheres thickly to the grooves and threads. When a bolt or nut is tightened to attach a predetermined member to such a threaded portion, a tightening torque is generated before the axial tightening amount for complete tightening is reached. Alternatively, if the tightening torque is increased to obtain the tightening amount, particularly thin weld bolts may break and no longer function as proper tightening means. SUMMARY OF THE INVENTION The object of the present invention is to provide an object to be painted with a threaded part that can prevent a paint film from adhering to a threaded part that is welded to the part to be painted.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is such that a fastening member having a threaded portion is welded in a pre-painting step, and in particular, the threaded portion is made of porous metal. The porous metal is characterized in that the inside of the porous metal is impregnated with oil.

(Function) Since the threaded portion is formed of porous metal and its interior is impregnated with oil, the oil on the threaded portion prevents paint from adhering.

(Example) FIG. 1 shows a painted body with a threaded portion as a first example of the present invention. The object to be painted with the threaded portion is a part of the vehicle body, and here is the rear end panel 1 of a passenger car. The upper end of this rear end panel 1 contacts the trunk lid 2, and the lower end is welded to the rear end of the rear floor panel 3. A weld nut 5 for attaching the license plate P is welded to the central reinforcing plate 4.

The weld nut 5 has a cubic shape with a screw hole 6 formed in the center, and as shown in FIG. 2, one end serving as a base is welded to a reinforcing plate 4 serving as a portion to be painted. The weld nut 5, which is a fastening member having a threaded portion, is entirely made of porous sintered metal, and the inside thereof is impregnated with oil.

Note that materials other than sintered metals can be similarly used as the porous metal. Furthermore, in place of the weld nut 5 shown in FIG. 2, the weld nut 7 shown in FIG. 3 may be used as the fastening member. In this case, the weld nut 7 is formed of a screw main body 9 made of sintered metal with a screw hole 8 formed therein, and a frame 10 into which the main body 9 is fitted, and these are integrally connected.

It is assumed that a vehicle body equipped with such a rear end panel 1 is first acid-washed, then the entire surface is coated using an electrodeposition coating device, and then an intermediate coat and a top coat are applied using a spray coating method.

First, the oil in the screw hole 6 is also removed by pickling,
Immediately, oil oozes out from the surface of the screw grooves and screw threads due to surface tension and the resulting capillary phenomenon. Therefore, even if electrodeposition coating and subsequent intermediate coating or top coating are performed by spraying, adhesion of the coating film to the screw holes 6 and 8 of the weld nut is prevented. Therefore, when attaching the license plate P using the weld nuts 5, 7, the tightening with the attaching bolts (not shown) is reliably and smoothly performed.

In place of the rear end panel shown in Figure 1, various inner panels are equipped with weld nuts for fixing various equipment installed in other parts of the vehicle body, such as the weld nuts for fixing various types of equipment installed in the engine compartment, and the weld nuts for attaching various panels in the vehicle interior. The present invention can be similarly applied to.

Furthermore, another embodiment of the present invention is shown in FIG.
Front fender 1 as the object to be painted with this screw
1 includes a weld bolt 13 having a boss portion 12 as a base portion welded to a front lower end thereof as a portion to be painted. The weld bolt 13 is inserted into a mounting hole on the front skirt 16 side, and is used when connecting both panels with a nut (not shown).
The weld bolt 13, which is a fastening member, has a thread main body 14 made of porous metal, which is impregnated with oil.

This weld bolt 13 can also prevent paint from adhering during the car body painting process, and when tightening the nut, the tightening operation can be performed smoothly with a specified torque.

In the above, the vehicle body has been explained as the object to be painted, but this book also applies to metallic structures that are equipped with weld bolts and weld nuts as fastening members and are to be entirely painted. Can apply ideas.

(Effects of the invention) As described above, the object to be painted with a threaded part according to the invention prevents paint from adhering to the threaded part by exuding oil, so nuts and bolts can be tightened smoothly later. It also becomes easier to manage the tightening torque and tightening amount.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of a rear end panel as an embodiment of the present invention, Fig. 2 is a perspective view of a weld nut on the same panel, and Fig. 3 is a weld bolt used in place of the weld nut in Fig. 1. and FIG. 4 are schematic partial sectional views of a front fender as another embodiment of the present invention, respectively. 1...Rear end panel, 4...Reinforcement plate, 5,
7...Weld nut, 9, 14...Screw part main body, 10...Frame part, 11...Front fender,
12...Boss department.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a to-be-painted object to which a fastening member having a threaded portion is welded in a pre-painting process, the threaded portion is formed of a porous metal, and the inside of the porous metal is A painted body with a threaded portion, characterized in that it is configured to be impregnated with oil. 2. The object to be painted with a threaded portion according to claim 1, wherein the fastening member is a weld nut. 3. The object to be painted with a threaded portion according to claim 1, wherein the fastening member is a weld bolt.