JPH1086271A - Resin composite type damping metal panel excellent in peel resistance at time of high speed deep draw forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composite type damping metal panel reduced in the processing peel caused by the shift of a metal panel at the time of high speed deep draw press molding. SOLUTION: A damping metal panel is constituted by holding a viscoelastic resin layer between two metal plates. When thickness of the thicker metal panels is set to t(mm), the yield strength thereof is set to Y(MPa) and the min. value of shearing densityx strength at the stress speed 10<2> -10<5> MPa/S of the viscoelastic resin layer is set to τ(MPa), the relation of H $ 12, but, H=Y×t<2> /τ is satisfied. By this constitution, processing peel at the time of high speed deep drawing can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material having a vibration absorbing performance in which a viscoelastic resin is sandwiched between two metal plates. The present invention relates to a resin composite type vibration damping metal sheet having excellent resistance to processing peeling during drawing.

[0002]

2. Description of the Related Art A resin composite type vibration damping metal plate is a material in which a viscoelastic resin is interposed between two metal plates to absorb vibration applied to the metal plate due to its viscoelastic properties. This material has been increasingly applied to automotive parts such as engine oil pans due to the recent tightening of noise regulations for automobiles.

[0003] In the production of engine oil pans for automobiles and the like, high-speed deep drawing press molding at a molding speed (speed of change in height of molded product) of 10 m / min or more is generally performed. When a high-speed deep drawing press molding of a resin composite type vibration damping metal plate is performed, the viscoelastic resin (damper resin) has a stress rate of 1
An impact shearing force of 0 ² MPa / S or more acts. Under such an impact force, a brittle fracture may occur in the damper resin, and even in a material that does not undergo processing peeling in the case of static press molding, the processing peeling due to the displacement of the skin metal plate. Occurs. If this processing peeling occurs in a wide area of the molded part, the rigidity of the molded part is reduced and the vibration during use becomes severe, resulting in fatigue cracking and deterioration of vibration damping properties. Occurs.

[0004] As means for reducing the process peeling, a method of subjecting a steel plate surface in contact with a damper resin (viscoelastic resin) to a chromate treatment (Japanese Patent Laid-Open No. 5-133800) or specifying the roughness of a steel plate in contact with the damper resin is specified. Within the range (JP-A-63
A method of improving the interfacial adhesive strength between a damper resin and a steel sheet has been proposed. However, these methods have no effect on processing peeling caused by destruction inside the resin layer.

[0005] In addition to the above, methods for limiting the shear deformation resistance of a damper resin (JP-A-63-72535, JP-A-63-72535,
JP-A-63-72536, JP-A-63-153126, JP-A-63-1
No. 53127, JP-A-63-153128), a method of limiting the elastic modulus of the damper resin (JP-A-59-87146),
Methods of increasing the shear adhesion strength of the damper resin to a certain value or more (JP-A-59-57743 and JP-B-5-75578) have been proposed, but these methods are effective for static processing. However, in the case of high-speed deep drawing press molding such as an engine oil pan of an automobile, peeling could not be sufficiently reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and a resin composite vibration-damping metal which is less likely to be peeled off due to displacement of a skin metal plate during high-speed deep drawing press molding. The board is provided.

[0007]

Means for Solving the Problems In the high-speed deep drawing press molding, the present inventors have focused on the impact shear force applied to the damper resin, and have developed a resin composite mold for preventing the occurrence of peeling even by this impact shear force. The structural conditions of the damping metal plate were studied diligently. As a result, the thickness and yield strength of the thicker metal plate of the two resin composite type vibration damping metal plates, and the stress rate of the viscoelastic resin (damper resin) 10 ² to 10 ⁵ MPa
It has been found that by adjusting the minimum value of the shear adhesion strength in / S to fall within a specific range, processing peeling is reduced, and the present invention has been completed.

That is, according to the present invention, in a resin composite type vibration damping metal plate in which a viscoelastic resin layer is sandwiched between two metal plates, the thickness of the thicker metal plate is set to t (mm). , The yield strength is Y (MPa), and the stress rate of the viscoelastic resin layer is 10 ²
The minimum value of the shear adhesion strength at 〜１０10 ⁵ MPa / S
(MPa), H ≦ 12 (1) where H = Y × t ² / τ A resin composite type vibration-damping metal plate excellent in work-peeling resistance at the time of high-speed deep drawing. It is.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Examples of the metal sheet of the present invention include cold-rolled steel sheets, hot-rolled steel sheets, galvanized steel sheets, Al-based, Cr-based, Ni-based, and Sn-based metal-plated steel sheets, Al sheets, stainless steel sheets, and copper sheets. The surface may be subjected to a chemical conversion treatment such as a chromate treatment, a phosphate treatment, and an organic resin coating treatment. The thickness of this metal plate is 0.4 to 1.
0 mm is preferred.

For the viscoelastic resin layer serving as a damper material, epoxy, polyurethane, acrylic, thermosetting polyester, polyethylene and polypropylene resins may be used alone or in combination. A conductive material such as nickel powder, iron powder, copper powder, stainless steel powder, other alloy metal powder, metal fiber, carbon black, and graphite can be added to the resin to provide resistance welding. The thickness of this resin layer is preferably from 35 to 100 μm in consideration of vibration damping properties and cost.

H (Y × t ² / τ) ≦ 12, where t: thickness of the thicker metal plate, Y: yield strength (MPa), τ: stress rate of the viscoelastic resin layer 10 ² to 1
0 ⁵ MPa / minimum shear adhesion strength in S (MP
a) Since this relationship was found by the inventors' experiments, H
When the value is 12 or less, the peeling rate at the time of high-speed deep drawing press molding is reduced, and it is particularly remarkable when the H value is 7 or less. On the other hand, when the H value exceeds 12, the peeling rate increases extremely. Therefore, the range is limited to H ≦ 12.

[0012]

Embodiments of the present invention will be described below. Sheet thickness 0.
A cold-rolled steel sheet having various yield strengths of 4 to 1.2 mm is coated with a rubber-modified acrylic resin or a thermosetting polyester resin in which Ni powder is mixed at 5 wt% with respect to the weight of the damper resin at a resin thickness of 50 μm, Cold rolled steel sheets having various yield strengths having a thickness of 0.4 to 1.2 mm were pressed and heated to produce a resin composite type vibration damping metal plate, which was used as a test material.

The rubber-modified acrylic resin is a resin mainly composed of a rubber component having an unsaturated bond in a molecule, a metal acrylate or a metal methacrylate, and a polymerizable monomer, and is a thermosetting polyester resin. Is a resin whose main component is a copolymerized polyester having an aromatic ring.

Table 1 shows the thickness structure and the yield strength of the cold-rolled steel sheets used in the examples and comparative examples. The resin composite-type damping metal plate manufactured in this manner was processed into the shape shown in FIG.
The sample of the resin composite type damping metal plate shown is 16 m wide.
m, upper metal plate 1 of resin composite type vibration-damping metal plate with a length of 14 mm
A slit is made at a position 6 mm from the edge, and a slit 6 mm is made at the lower metal plate 2 from the opposite edge. After that, 16mm ×
A 6 mm skin metal plate portion was removed to produce a resin composite type vibration damping metal plate with a viscoelastic resin layer 3 interposed.

After that, the resin was attached to a tensile tester shown in FIG. 2, and the shear adhesion strength of the resin at a stress rate of 10, 10 ² PMa / S was measured. In this apparatus, a sample mounting jig 13 is attached between a first bar 11 and a second bar 12, and an end face 2 of a resin composite type vibration damping metal plate processed as shown in FIG. 13, a constant stress rate can be applied to the viscoelastic resin layer 3 (damper resin) by pulling the first bar 11 at a constant load increasing rate by hooking on the key portion 13.

[0016] The sample was mounted on a testing machine that applies Hopkinson bar testing apparatus shown in FIG. 3, 10 ⁵
The shear adhesion strength of the damper resin at a stress rate of MPa / S was measured. In this apparatus, the impact bar 21 is collided from behind the first bar 11 using the compressed gas, and the compression shock wave generated by the collision passes through the first bar 11 and also passes through the sample mounting portion. At this time, since the spacers 23 are inserted so as to form a gap 22 between the sample end face 1 and the sample mounting jig 13 in FIG. 1, the compressive stress is reduced by the viscoelasticity of the resin composite type vibration damping metal plate. Does not add to the resin layer (damper resin). The compression shock wave that has passed through the sample mounting portion reaches the final end of the second bar 12, is reflected at this portion, and becomes a tensile shock wave. This tensile shock wave is transmitted to the sample from the key portion of the sample mounting jig 13 and a shear stress is applied to the damper resin. The transmitted stress during this time is detected by stress detectors 24 and 25 embedded in the first bar 11 and the second bar 12.

Of the shear adhesion strengths at the stress rates of 10 ² and 10 ⁵ MPa / S, τ is the smaller value of the shear adhesion strength, t is the thickness of the larger skin metal plate, and Y is the yield strength. The H value of the above equation (1) was obtained. Table 1 shows the shear adhesion strength and H value at each stress rate.

Further, in order to investigate the peeling resistance of these resin composite type vibration damping metal plates during high-speed deep drawing press molding, a molding speed of 10 m was measured using a hat-shaped molding test machine having a die shape shown in FIG.
/ Min high-speed molding was performed, and the peeling rate of the side wall was examined by peeling the skin metal plate. In the tester shown in FIG. 4, a flat resin composite vibration-damping metal plate is bridged between two dies 31 and 32, pressed by wrinkle pressing plates 33 and 34, and a central portion is pressed by a punch 35. The peeling rate was determined by the area of the peeling region with respect to the area of the entire side wall. This peeling rate is also shown in Table 1.

When Examples 1 to 5 in Table 1 are compared with Comparative Example 1 and Examples 7, 8, and 4, 5, the peeling rate after press molding is higher even if the same resin is used. The peeling rate is extremely high at 93% or more in the comparative example, while it is remarkably changed depending on the sheet thickness and the yield strength of the steel sheet. Further, the stress rate is 10 MPa / S as in Example 6.
Stress rate of 10 even for resin with low shear adhesion strength
The shear adhesion strength increased as the pressure increased to ² , 10 ⁵ MPa / S, and this effect reduced the peeling rate during pressing. Further, when Examples 7 and 8 are compared with Comparative Examples 4 and 5, according to the example, the stress rate is 10 ⁵ MPa / S
In the case of a composite vibration-damping metal plate in which the shear adhesion strength is extremely reduced in a high region, the peeling rate could be reduced by reducing the thickness of the skin metal plate or reducing the steel plate strength. .

FIG. 5 shows the relationship between the H value and the peeling rate.
It was found that when the H value was 12 or less, the peeling rate was small, and when the H value exceeded 12, the peeling rate extremely increased.

[0021]

[Table 1]

[0022]

As described above, the H value (Y × t ² /
By setting τ) to 12 or less, a remarkable effect of reducing work separation during high-speed deep drawing press molding is exhibited.

[Brief description of the drawings]

FIG. 1 is a diagram showing a shape of a sample for measuring a shear adhesion strength of a damper resin.

FIG. 2 is a diagram showing a method for measuring the shear adhesion strength of a damper resin at a stress rate of 10, 10 ² MPa / S.

FIG. 3 is a diagram showing a method for measuring the shear adhesion strength of a damper resin at a stress rate of 10 ⁵ MPa / S.

FIG. 4 is a view showing a hat-shaped forming test method for investigating the resistance to processing peeling of a damping steel sheet.

FIG. 5 is a diagram showing a relationship between an H value and a peeling rate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Upper metal plate, 2 ... Lower metal plate, 3 ... Viscoelastic resin layer, 11
... First bar, 12 ... Second bar, 13 ... Sample mounting jig, 21 ... Shock bar, 22 ... Gap, 23 ... Spacer,
24, 25 ... Stress detector.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koji Fujii 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (1)

[Claims] 1. A resin composite type vibration damping metal plate having a viscoelastic resin layer sandwiched between two metal plates, the thickness of the thicker metal plate being t (mm), yield strength Is defined as Y (MPa), and the stress rate of the viscoelastic resin layer is 10 ² to 10 ⁵ MPa / S
Where τ (MPa) is the minimum value of the shear adhesion strength in the above, H ≦ 12 (1) where H = Y × t ² / τ. Excellent resin composite type vibration damping metal plate.