JPS6338708A - Method of connecting vibration-damping steel plate member - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a method of fastening vibration-damping steel plate members.

<Prior art and its problems> As shown in the cross section of FIG. 1, a damping steel plate is made by sandwiching a viscoelastic resin 2 with a thickness of about 0.05 to 0.15 m+a between two steel plates 1. The viscoelastic resin 2 imparts an allocation effect.

If such damping steel plates are fastened together with bolts, the intermediate viscoelastic resin 2 will change over time (a type of creep) and its thickness will become smaller, resulting in a significant decrease in axial force (tightening force). (See Figure 2 A)! ``There were four problems.'' Therefore, in the past, it was necessary to increase the initial axial force so that sufficient axial force could be maintained even after the axial force had decreased, so bolts with higher strength than necessary or bolts with larger sizes had to be used. However, this has caused an increase in cost and space.

Therefore, in view of such circumstances, an object of the present invention is to provide a method for fastening damping steel plates in which the axial force does not decrease over a long period of time.

Means for Solving the Problems> The structure of the present invention for achieving the above-mentioned object is a method of bolting a damping steel plate member formed by sandwiching a viscoelastic resin between two steel plates, in which the viscoelastic resin is The two steel plates are pressed together by pressing around the bolt hole of the damping steel plate member at a temperature at which the damping steel plate member is melted and does not deteriorate, and then the two steel plates are fastened together.

In the above structure, since the thickness of the viscoelastic resin in the bolted part of the damping steel plate member becomes almost zero and the two steel plates are crimped together, after the bolt is fastened, the viscoelasticity of the bolted part is 4.1 lIN. There is no decrease in axial force due to changes over time.

Embodiment Hereinafter, a preferred embodiment of the present invention will be described based on the drawings.

FIGS. 1(a), fb), (C1 are explanatory diagrams showing the working process of this example. As shown in these diagrams, first, a viscoelastic resin is sandwiched between two steel plates 1. The area around the bolt hole 3 of a 10 m damping steel plate member in which the bolt hole 3 was formed is compressed by a press 4 at a temperature at which the viscoelastic resin melts and does not deteriorate, so that the thickness of the viscoelastic resin 2 becomes almost zero. The two steel plates 1 are crimped together to form a damping steel plate member 10b.Here, the temperature at which the viscoelastic resin 2 melts and does not deteriorate is 180 to 250°C; In this case, even if the viscoelastic resin 2 temporarily melts, once it returns to room temperature and hardens, its properties will completely return to their original state.

The damping steel plate member 10b formed in this way is attached to another member 7.
Fasten with bolts 5 and nuts 6. At this time, since the thickness of the viscoelastic resin 2 at the fastening portion is approximately zero, there is no loosening of the bolt 5 due to changes in the viscoelastic resin 2 over time.

Such a tightening method can be applied to bolting vibration-damping steel plate members such as automobile wiper motor brackets, pop-up motors, and electric antenna motors.

Here, a test example showing the effect of the method of the present invention will be shown.

As shown in Fig. 3, a vibration damping steel plate 10 is sandwiched between a load cell 8 and fastened with bolts 5 and nuts 6, at a temperature of 23°C and a humidity of 5°C.
The sample was left at 0%, and changes in axial force were measured using a load cell 8.

Here, as the damping steel plate 10, the conventional example A1 of the damping steel plate member 10b of the damping steel plate member 10a of the above embodiment was used as the example B of the present invention. At this time, the thickness of the steel plate 1 was 0.4 mm, the thickness of the viscoelastic resin 2 was 0.08+ms, and the size of the bolt 5 was M6XP1.0.

The results at this time are shown in FIG. As shown in the figure, according to the method of the present invention, there is some initial loosening of tightening, but there is no loosening due to changes in the viscoelastic resin 2 over time.

<Effects of the Invention> As explained above in detail with the examples, if the method of the present invention is used when fastening damping steel plate members with bolts, the viscoelasticity is 4! Since there is no decrease in axial force due to changes in fat over time, stable axial force can be maintained over a long period of time.

[Brief explanation of drawings]

Figure 1 (al~[C1 is an explanatory diagram showing the work process of the method of fastening vibration-damping steel plate members according to the present invention, Figure 2 is a graph showing the relationship between axial force and elapsed time, and Figure 3 is a test method Fig. 4 is a sectional view showing a damping steel plate. In the drawing, 1 is a steel plate, 2 is a viscoelastic resin, and 3 is a bolt hole. Patent applicant: Mitsubishi Motors Corporation. person

Claims (1)

[Claims] In a method of bolting a vibration-damping steel plate member in which a viscoelastic resin is sandwiched between two steel plates, the periphery of the bolt hole of the vibration-damping steel plate member is tightened at a temperature at which the viscoelastic resin melts and does not deteriorate. A method of fastening vibration-damping steel plate members, which comprises pressing two steel plates together and then fastening them.