JPS6072724A - Laminated metallic plate having excellent press bending workability and press bending method thereof - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the creation of a laminated metal plate in which a viscoelastic substance is interposed between two metal plates, and has a press bending property that can be subjected to press bending equivalent to that of a normal metal plate. The present invention aims to provide an excellent laminated metal plate and a press bending method for the same.

This type of laminated metal plate with a viscoelastic substance interposed therein (hereinafter referred to as a laminated metal plate) is effective in preventing vibration and noise, especially by interposing a synthetic resin with vibration damping performance. It has been used in many applications as a pollution control measure, and has also been widely used as a lightweight material or as a corrosion-resistant material. In this case, rather than being used as a flat plate, the laminated metal plate is often used after being subjected to some kind of processing.

Therefore, in addition to properties such as vibration damping properties, press workability has become one of the important properties that laminated metal plates should have.

In view of these circumstances, the present inventors have conducted intensive research on the press workability of laminated metal plates, and have discovered that laminated metal plates generate a unique phenomenon during press bending. Sonora will be explained using diagrams.

FIG. 1 is a front view of a commonly used press bending tool.

The workpiece 6 is set between the punch 1 and the die 2,
Press bending is performed. In this case, the die shoulder width (WD) of the die 2 is generally set in a range of 6 to 12 times the thickness (1) of the workpiece 6, and the die shoulder width (WD) and the punch shoulder width (Wp) of the punch 1 are If you don't take it equally,
It is known that the shape of press-formed products is damaged.

If the punch shoulder width (Wp) of the punch 1 is too wider than the die shoulder width (WD) of the die 2, the die shoulders 4, 4' will be damaged as shown in FIG. 2, regardless of the properties of the workpiece 6. A phenomenon in which the flange 5゜5/, which should originally be straight, is bent (
It is known that this phenomenon (referred to as reverse bending phenomenon) occurs. However, the inventors of the present invention discovered that when a laminated metal plate is used, even if the press bending is performed under appropriate conditions using the above-mentioned normal press bending tool, the reverse bending phenomenon still occurs. This is shown in Table 1. Here, the bending angle (θ) is as shown in FIG.

In Table 1, the single-layer metal plate used as a comparative example, the cladding made by laminating single-layer metal plates or thermal diffusion pressure welding 4
None of the laminate metal plates had any bends, whereas the laminated metal plates had large bends.

As is clear from this result, the reverse bending phenomenon of the laminated metal plate during press bending is a phenomenon unique to laminated metal plates.

If such a reverse bending phenomenon occurs during press bending, the appearance of the press-formed product will be significantly impaired, and the press-formed product will not be finished to the specified dimensions and shape. It also poses a major hindrance to assembly. Therefore, the occurrence of this reverse bending phenomenon is a fatal defect in press bending.

The present inventors have diligently investigated the cause of the occurrence of the reverse bending phenomenon during press bending of these laminated metal plates, and have found that the occurrence of the reverse bending phenomenon of laminates and metal plates is caused by press bending, as shown in Figure 4. The neutral axis in which the material itself does not expand or contract within the cross section in the plate thickness direction during processing is the central neutral axis (:!/l
In addition, the punch side neutral axis (-) and the die side neutral axis (Z)
We found that this is caused by the occurrence of

Here, with respect to the center neutral -+(y), the punch side neutral axis (-) has an excessive line length, and conversely, the die side neutral axis (Z) has an insufficient line length. Such excess or deficiency in the wire length causes a bending moment in a direction opposite to the direction in which the bending is originally desired to be performed on the flange on the outside of the bent portion.

Therefore, this reverse bending phenomenon of the laminated metal plate is clearly different from the reverse bending phenomenon that occurs in a single layer metal plate when the conditions of the press bending tool are inappropriate.

The inventors of the present invention, based on this knowledge, have conducted extensive research and have invented a laminated metal plate with excellent press bending properties that does not cause reverse bending during press bending, and a press bending method for the same. This is what led me to do this.

12+1 The present invention is a laminated metal plate in which a viscoelastic substance is interposed between two metal plates, wherein the two metal plates have a plate thickness ("/tb) of more than 1 and less than 10, and have a yield resistance. The strength ratio ('a/σb) is 0.5 to 10, and the viscoelastic material has a thickness (tf) of 0.005 m to 10 cm.
Below, the shear adhesion strength (σf) is 0.05 and 9f/-, the thicknesses ta and tb of the two metal plates, the yield strengths #a and #b, and the thickness of the viscoelastic material. The first invention is a ξ-nate metal plate in which tf and shear adhesion strength σf satisfy the following formula (1), and Q-yu (-2,
85k +45.6tf +30)≦15 ,...
, (11σf2 However, k=c”y)2('n,,b)tb In addition, in the method of press bending the laminated metal plate of the present invention described above using a press bending tool consisting of a punch and a die, The press bending mold tool has the die shoulder width (
WD) from 6 times the thickness (1) of the laminated metal plate to 1
At the same time, the die shoulder width (WD) and the punch shoulder width (Wp) are made equal, and between the punch and die of the press bending tool, a laminated metal plate is punched with the thicker side of the plate. The second invention provides a press bending method for a laminated metal plate, in which the laminated metal plate is set so as to be on the side and press bending is performed on the laminated metal plate.

The metal plates constituting the laminated metal plate of the present invention include steel plates,
Examples include copper plates, aluminum plates, etc., but the type is not particularly critical. In addition, Zn was deposited on these metal plates.
Surface treatment such as metal plating, chemical conversion treatment, coating, etc. with tSn, Cu, N amount + Cr, etc. may be performed. Furthermore, the two metal plates may be of different types.

Next, examples of the viscoelastic substance constituting the laminated metal plate of the present invention include rubber-based, resin-based viscoelastic substances, and the like. This viscoelastic material is selected depending on its purpose; in the case of laminated metal plates for vibration damping, synthetic resins with vibration damping properties (polystyrene, polyisoprene), synthetic rubber, trill rubber, etc. are used. It is desirable to apply.

Next, the reasons for limiting the characteristic values of the laminated metal plate of the present invention will be explained with reference to FIGS. 5 and 6.

Figure 5 shows the flange bending angle of a laminated metal plate when the punch width and die shoulder width are equal during press bending, and the die shoulder width is in the range of 6 to 12 times the thickness of the laminated metal sheet. (θ) and a relational expression Q derived by the present inventors. As is clear from the figure, the smaller the θ value, the smaller the flange bending angle (0), which is more effective in eliminating the reverse bending phenomenon. For practical purposes, it is considered that there is no problem with the 9-angle (0) bend of the flange as long as it is within 2.5°.
The Q value will be 15 degrees or less. Next, the plate thickness ratio (ta/lb) of the two metal plates that most affects the Q value in equation (1) will be described. Figure 6 shows the bending angle (θ) in press bending of a laminated metal plate and the plate thickness ratio (
”/tb) and the square value of That is, as the plate thickness ratio increases, the bending angle (θ) becomes smaller.

Therefore, from these reasons, it is necessary to make a difference in the thickness of the two metal plates, and the lower limit of the plate thickness ratio (''/lb) must exceed 1. Also, the plate thickness ratio a (/l , ) was set to less than 10 because the plate thickness ratio (t
When a/lb) is 10 or more, bending of the laminated metal plate will easily cause breakage at the processed part, and other characteristics required of the laminated metal plate, such as a laminated metal plate for allocation, will be adversely affected. This is because problems such as deterioration of allocation performance occur.

Also, the yield strength (/, b) of the two metal plates is also Q of equation (1).
This is one of the important requirements that influences the value.

As the yield strength ratio (/#b) increases, the bending angle during press bending of the laminated metal plate decreases.However, when the yield strength ratio exceeds 10, the yield strength of the thinner metal plate decreases. keep it very low, or
Alternatively, it is necessary to make the yield strength of the thicker metal plate extremely high, which increases the manufacturing cost of the metal plate and poses a practical problem. Therefore, the upper limit of the yield strength ratio was set to 10 or less.

Moreover, the lower limit of the yield strength ratio was set to 0.3 or more because 0.
If it is less than 3, there will be a conflict with other requirements, and it will be difficult to keep the bending angle (4) within practical limits. However, the shear adhesion strength is 0.05 kg
If it is less than '/-, the two metal plates will easily separate, so the lower limit was set at 0.05 k&'/-'.

Further, the thickness (tf) of the viscoelastic material is related to the welding characteristics (electric resistance welding) required in the use of the laminated metal plate of the present invention. FIG. 7 is a diagram showing the relationship between the thickness of the viscoelastic material (synthetic resin) of the laminated metal plate and the diversion time (15°□2) in spot welding.

As is clear from the figure, when the thickness of the viscoelastic material (synthetic resin) exceeds 0.6 as, the diversion time suddenly becomes longer.

For these reasons, the upper limit of the thickness of the viscoelastic material was set to 6 km or less. In addition, the thickness of the substance is 0.005 kgf/, 2
If it is less than that, it is substantially difficult to evenly interpose the viscoelastic substance between the two metal plates.

Therefore, the lower limit was set to 0.005 kg'/wm2.

In addition, when press bending the laminated metal plate of the present invention using a press bending tool, the die shoulder width (WD) of the press bending tool is determined by the thickness of the laminated metal sheet (1
) in the range of 6 to 12 times and 9, and the die shoulder width (W
The reason why D) and the punch shoulder width (Wp) are made equal is that if these conditions are not met, the shape of the press-formed product will be damaged even if the metal plate alone is used.

Also, the reason why the laminated metal plate is set so that the thicker side of the plate is on the punch side is that if the laminated metal plate is set with the thicker side of the plate on the die side, it will cause the reverse bending phenomenon. This is because the effect of the predetermined press bending process cannot be expected because the occurrence of the bending process cannot be avoided.

Next, an example will be described in which the laminated metal plate of the present invention is subjected to press bending.

[Example 1] In the press bending tool, the shoulder width of the die was in the range of 6 to 12 times the thickness of the laminated metal plate, and the shoulder width of the die was equal to the punch shoulder width of the punch. The opening angle of the die is 90' and the test piece size is 50X1.
(I used a LOM plate and set the thicker side of the laminated metal plate on the punch side.

The test results are shown in Table 2.

As is clear from Table 2, the laminated metal plate of the present invention has a flange bending angle (θ) (degree) of 2.5, which is not a problem in practice, by setting Qff& to 15 or less.
It's below 30 degrees.

On the other hand, all of the comparative materials with a Q value exceeding 15 have high values for the flange bending angle (θ) (degrees).

[Example 2] In press bending of the laminated metal plates A-LB-1 and C-1 of the present invention, the thicker side of the laminated metal plates was set in a die elongation and press bending was performed. Other conditions are the same as in Example 1.

The test results are shown in Table 6.

Table 6 Processing method B-1 - 0 C-1 - 0 Comparison A-1 Thicker die side 12.5 Processing method B-
1. Z5 C-1.8.0 As is clear from Table 6, if the thicker side of the laminated metal plate is placed on the die side, the flange bending angle θ (degrees) will be too high for practical use. I can't provide it.

As described above, the laminated metal plate according to the present invention has the characteristics of the metal plate and the viscoelastic material that are its constituent elements limited, thereby eliminating reverse bending, which is a fatal flaw in conventional press bending of laminated metal plates. Since the occurrence of this phenomenon can be completely prevented, it can be widely applied to applications in which laminated metal plates are press-bent, which was previously thought to be difficult to use, and is an extremely significant invention in industry.

[Brief explanation of the drawing]

Figure 1 is a front view of the press bending tool, Figure 2 is a front view explaining the reverse bending phenomenon, Figure 6 is a front view explaining the reverse bending angle, and Figure 4 is a cross section of the laminated metal plate. Figure, 5th
Figures 7 through 7 are graphs. 1... Punch, 2... Die, 3... Workpiece material,
4, 4'...Die shoulder, 5.5'...Flange agent Patent attorney Mizo Kimura 11- Procedural amendment (voluntary) November 1, 1980 To the Commissioner of the Japan Patent Office 1 Indication of the case Patent Application No. 58-180766 2 Name of the invention Laminated metal plate with excellent press bending properties and its press bending method 3 Relationship with the case of the person making the amendment Name of patent applicant Name (412) Agent of Nippon Kokan Co., Ltd. 4 Hidekazu 2nd Toranomon Building 5, 21-19 Toranomon-chome, Minato-ku, Tokyo 105 Detailed description of the invention and drawings in the specification subject to amendment 1-6 Contents of amendment (1) Page 6 of the specification, table 1. On the bottom line, change "composite board" to "
Corrected as "metal plate". (2) Same, page 8, bottom line "thickness product" is corrected to "thickness ratio". (3) Same, page 9, line 3, rlOmmJ is “06mm
Correct it with J. (4) Same page, lines 3-4, r O, 05kgf/
Insert "more than" after +am2J. (5) Same, page 10, line 19, “Ponchi Kanwa” is changed to “
Correct it with "Ponch shoulder width". (6) Same, page 11, line 5, "θ value" is corrected to "Q value". (7) Same page, line 9, amend "15 degrees or less" to "15 degrees or less." (8) Ibid., page 13, line 2, “By becoming.”
After ``, the higher the shear adhesion strength (σf) of a viscoelastic material, the smaller the Q value in equation (1), so there is no upper limit.'' (9) Same page, line 15, [6mm J to r 0.6
Correct as mm J. (!0) Same page, lines 15-16 and line 18, r O,005kgf/mm2J is r O,005
Correct as mm J. (Figures 2 and 6 are corrected according to the attached revised drawings. Above = 2-

Claims (1)

[Claims] (1) A laminated metal plate in which a viscoelastic substance is interposed between two metal plates, wherein the two metal plates have a plate thickness ratio (/lb) of more than 51 and less than 10, and a yield strength ratio ( 'a/, b) is 0.6 or more and 10 or less, and the viscoelastic material has a thickness (tf) of 0.005HI or more and 0.6 or less, and a shear adhesion strength (#f) of o, o 5kg'7
−z or more, the plate thickness ta+tb and yield strength #a, σb of the two metal plates, and the thickness tf and shear adhesion strength σf of the skeleton viscoelastic material satisfy the following formula (1). A laminated metal plate with excellent press bending properties. Q = Yu (-2,85k +45.6tf + 30)
≦15... (1) A laminated metal plate in which a viscoelastic substance is interposed between two metal plates, where k = (/lh)''(/#b) (2) A laminated metal plate in which a viscoelastic substance is interposed between two metal plates, The metal plate has a plate thickness ratio (ta/lb) of more than 1 and less than 10, and a yield strength ratio (''//, h) of 0.
3 or more and 10 or less, and the viscoelastic substance has a thickness (tf
) is 0.005 or more and 0.61 or less, and the shear adhesion strength (
#f) is 0.05 kgV- or more, and the thickness ta, tb and yield strength #a, ab of the two metal plates, and the thickness tf and shear adhesion strength #f of the viscoelastic material are Q = (-2,85k + 45.6 tf +30
)≦15...River (1) However, = (ta/1b)2(1
A laminated metal plate that satisfies the formulas a/b) is pressed and bent by setting the die shoulder width (vVD) of the molding tool to a range of 6 to 12 times the thickness (1) of the laminated metal plate, Die shoulder width (WD) and punch shoulder width (Wp)
A laminate characterized in that the laminated metal plate is set equally between the punch and the die of a press bending tool, with the thicker side of the laminated metal plate facing the punch side, and press bending is performed. Press bending method for metal plates.