JP2834045B2 - Brazed honeycomb panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum brazed honeycomb panel used as a structural member for vehicles, ships, buildings, and the like.

[0002]

2. Description of the Related Art A brazed honeycomb panel has a profile formed on four sides, a honeycomb core disposed in a region surrounded by the profile, and a honeycomb core sandwiched between upper and lower surfaces of the profile and the honeycomb core. It consists of a face plate arranged in. The honeycomb core and the face plate are made of a brazing sheet in which a brazing material is clad on aluminum, and after each member is assembled in the above-described arrangement, the brazing material is melted by heating in a vacuum or an inert atmosphere to melt each member. Are joined.
Each brazing sheet that constitutes the honeycomb core,
A convex surface and a concave surface along the length direction, and an intermediate surface located between the convex surface and the concave surface are alternately formed in an angular wave shape, and the convex surface and the concave surface of the adjacent brazing sheet are superimposed, A honeycomb core composed of a large number of hexagonal column-shaped cells is formed, and the pressure in each cell of the honeycomb core at the time of brazing is made equal to the pressure of the external atmosphere at each brazing sheet, thereby deforming and brazing the honeycomb core. For the purpose of preventing inconveniences such as defects from occurring, vent holes are provided on intermediate surfaces which are not brazed and joined to each other (Japanese Patent Laid-Open No. 7-1).
No. 44380).

[0003]

However, the study by the present inventors has revealed that the strength of the honeycomb panel is hindered when the vent hole is provided in the intermediate surface of the honeycomb core which is not brazed. . That is, when a shear load is applied to the honeycomb panel in the length direction of the brazing sheet constituting the honeycomb core (hereinafter, referred to as a core L direction), it can bear a certain shear load.
When a shear load is applied in a direction perpendicular to the length direction of the brazing sheet (hereinafter, referred to as a core W direction), there is a problem that the shear strength sharply decreases. Then, the fatigue strength of the honeycomb panel is particularly reduced due to the decrease in the shear strength.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and ensures the air permeability of a brazed honeycomb panel, prevents a decrease in the shear strength of a honeycomb core as in the prior art, and provides a honeycomb panel. The purpose is to improve the fatigue strength of steel.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a plurality of sheets each having a convex surface and a concave surface, and an intermediate surface located between the convex surface and the concave surface, which are alternately continuous along the length direction and are formed in an angular wave shape. A honeycomb core made of a brazing sheet, in which the convex and concave surfaces of the adjacent brazing sheets are overlapped and brazed and joined together, a shape material arranged around the honeycomb core, and the honeycomb core and the shape material arranged on the upper and lower surfaces of the shape material. In the aluminum brazed honeycomb panel made of a face plate joined by brazing, a vent hole is provided in a convex surface and a concave surface of the honeycomb core that are brazed to each other, and a vent hole is not provided in an intermediate surface of the honeycomb core that is not brazed to each other. It is characterized by the following.

Further, the present invention comprises a plurality of brazing sheets in which a convex surface and a concave surface and an intermediate surface located between the convex surface and the concave surface are alternately continuous along the length direction and formed in an angular wave shape. , A honeycomb core in which the convex and concave surfaces of adjacent brazing sheets are overlapped and brazed to each other, a profile material disposed around the honeycomb core, and a brazing sheet interposed between the honeycomb core and the profile material are formed into a wavy shape. And an aluminum brazed honeycomb panel comprising a honeycomb core, a profile, and a face plate provided on the upper and lower surfaces of the spacer and brazed to these, the vent holes are formed in the convex and concave surfaces of the honeycomb core brazed to each other. No ventilation holes are provided in the intermediate surfaces of the honeycomb cores that are not brazed and joined, and further, ventilation holes or ventilation slits are provided in the spacer. And wherein the digit. in this case,
Preferably, the spacer is interposed only on a portion of the brazing sheet parallel to the length direction of the brazing sheet, where the convex or concave surface is in contact with the profile, and the end of the brazing sheet is provided on a surface perpendicular to the length direction. Shall be interposed only in the portion that comes into contact with the profile.

[0007]

1 and 2 are a partially cutaway perspective view for explaining a brazed honeycomb panel of the present invention more specifically, and a plan view for explaining an arrangement of honeycomb cores and the like. As shown in FIGS. 1 and 2, a honeycomb core has a large number of brazing sheets in which a convex surface 1 and a concave surface 2 and an intermediate surface 3 located therebetween are alternately continuous along the length direction and are formed in an angular wave shape. And the convex surface 1 and the concave surface 2 of the adjacent brazing sheet are brazed and joined to each other. Shape members 4a and 4b are arranged around the honeycomb core, and spacers 5a and 5b in which a brazing sheet is formed in a wavy shape are interposed between the shape members 4a and 4b and the honeycomb core. 4b and spacer 5
a, a face plate 6 made of a brazing sheet on the upper and lower surfaces
a, 6b are arranged and brazed.

The spacers 5a and 5b are disclosed in
It is the same as that described in JP-A-92-92. That is,
The spacer 5a is interposed between the profile 4a and one side of the cell of the honeycomb core (the portion where the convex surface 1 or the concave surface 2 and the profile 4a are in contact with each other) on a surface parallel to the length direction of the brazing sheet. A pressing force is applied between the honeycomb core and the profile 4a by the force, and therefore, the profile 4a, the spacer 5
a and the honeycomb core are securely in contact with each other and are firmly brazed. On the other hand, the spacer 5b is provided between the profile 4b and the end of the honeycomb core (a portion where the end of the brazing sheet and the profile 4b abut) on a surface perpendicular to the length direction of the brazing sheet constituting the honeycomb core. Interposed. Since the end of the honeycomb core is fitted in the recess of the spacer 5b, the shape member 4b, the spacer 5b, and the honeycomb core are securely in contact with each other and are brazed firmly.

Although one or both of the spacers 5a and 5b can be interposed over the entire length of the profile members 4a and 4b, they are interposed as intermittent small pieces as shown in FIG. 1 or FIG. Is preferred. The reason is, as described in the above-mentioned publication, to ensure contact even if each cell of the honeycomb core has a dimensional difference, and to prevent unnecessary weight increase. The height of the peak of the spacer 5a can be adjusted by pulling in the longitudinal direction. However, the intermittent small pieces facilitate the adjustment of the height of each cell.

In the above honeycomb panel, the convex surface 1 and the concave surface 2 (hereinafter referred to as brazing surfaces) of the honeycomb core which are brazed to each other are provided with ventilation holes 7, and the intermediate surface 3 (hereinafter referred to as a non-brazed surface) is not brazed. No vent hole is provided in the brazing surface. Here, the ventilation holes 7
Although the diameter and the position in the plane are not particularly limited,
It should not be blocked by the braze that has flowed out during brazing. In addition, ventilation holes 8 are provided in the spacers 5a and 5b. The ventilation hole 8 is a space that loses air permeability by not providing a ventilation hole on the non-brazing surface, that is, a space 9a partitioned by the profiles 4a and 4b and the honeycomb core, and a space 9a partitioned by the profiles 4b and the honeycomb core. Space 9b
Has the meaning of ensuring the air permeability of the spacers 5a and 5b and the meaning of ensuring the air permeability of the internal space of the spacers 5a and 5b itself. In addition,
The ventilation hole 8 may be a ventilation slit as described in the above publication.

Although the honeycomb panels shown in FIGS. 1 and 2 are provided with spacers 5a and 5b, it is not essential in the present invention to provide such spacers. When one or both of the spacers 5a and 5b are not provided, for example, a horizontal hole communicating with the inside and outside of the shape member 4b may be formed to communicate the space with the outside in order to ensure the air permeability of the spaces 9a and 9b.

Next, the reason why the ventilation holes are provided on the brazing surface and the ventilation holes are not provided on the non-brazing surface in the present invention will be described.

The strength characteristics required of the honeycomb panel are as follows:
Tensile strength, bending strength and shear strength.According to the knowledge of the present inventors, the tensile strength and bending strength are determined by the strength and thickness of the face plate, and the influence of the honeycomb core is relatively small. Is determined by the shear strength of the honeycomb core. And when a vent is provided on any surface of the honeycomb core, stress concentration occurs on the surface provided with the vent,
In particular, when the ventilation holes are provided on the non-brazing surface, since only this surface bears the shear load in shearing in the direction of the core W, the reduction of the shear strength becomes large. on the other hand,
In the shearing in the direction of the core L, since both the brazing surface and the non-brazing surface bear the shear load, the decrease in the shear strength is small. This will be described in detail below step by step.

(A) First, in the honeycomb panel shown in FIG. 3, when a shear force F acts in the direction of the core L, the shear stress acting on the non-brazing surface is τ _L1 , and the shear stress acting on the brazing surface is τ _L1 . τ _L2 and shear force F in the core W direction
Is applied, the shear stress acting on the non-brazed surface is τ _W1 , and the shear stress acting on the brazed surface is τ _W2 .

(B) Shear stress in the core L direction When the panel width B is the core pitch P in the W direction, the transmission of the shear stress of the core is as shown by the arrow in FIG. According to FIG. 4, the number of cores sharing the shearing force is two on the non-brazing surface (A-A section) and one on the brazing surface (BB section). Next, when the panel width B is 2P, similarly to the above, the number of cores sharing the shear force is 4 on the non-brazing surface.
The number of books and brazing surfaces is two. Similarly, B = 3P,
Considering 4P, the number N of shearing forces of the core is given by the following equations (1) and (2). Number of non-brazing surface core shear force sharing N _L1 N _L1 = 2 × (B / P) ··· Number of brazing surface core shear force sharing N _L2 N _L2 = 1 × (B / P) ··· and above Is a relational expression when the panel width B is an integral multiple of the core pitch P. When B is sufficiently large with respect to P, even if the number of shear force sharing is determined by the expression and there is no practical problem. Next, assuming that the acting shear force is F, the number of core shear force sharing is N, the core height is H, and the core plate thickness is t,
The shear stress τ is obtained by the following equation. τ = F / (N × H × t) where N = N _{L1 on} the non-brazed surface and N on the brazed surface
= A N _L2, when the thickness of the non-brazed surface and t = t _c, since the thickness of the brazing surface is t = 2t _c, ~
From the formula, the shear stress of the non-brazing surface and the brazing surface is given by the following formula. τ = τ _L1 = τ _L2 = F / {2 × (B / P) × H × t _c } That is, when a shear force acts in the direction of the core L, the non-brazing surface and the brazing surface are applied. Shear stresses are equal.

(C) Shear stress in the core W direction When the panel width B is the core pitch Q in the L direction, the transmission of the shear stress of the core is as shown in FIG. From Fig. 5, the number of cores sharing the shear force is 2 on the non-brazing surface (CC section).
Becomes On the other hand, since the brazing surface is perpendicular to the shearing force, τ _W2 = 0 without sharing the shearing force. Next, when the panel width B is 2Q, the number of cores sharing the shearing force is four on the non-brazing surface, as described above. Similarly, B =
Considering 3Q, 4Q,..., The number N of shearing force sharing of the core is given by the following equation. Non-brazing surface core shear force sharing number N _W1 N _W1 = 2 × (B / Q)... From the above and the formula, the shearing stress of the non-brazing surface is given by the following formula. τ _W1 = F / {2 × (B / Q) × H × t _c }

(D) Shear stress ratio From FIG. 3, if the length of one side of the core is a, P = 3 ^1/2 × a... Q = 3 × a. The relationship of the shear stress is as shown in Table 1 below.

[0018]

[Table 1]

That is, assuming a honeycomb core having a regular hexagonal cell, the shear stress applied to the non-brazing surface when a shear load is applied in the core W direction is 3 ¹ compared to when a shear load is applied in the core L direction. ^{/ 2} times.

(E) Concentrated stress when the core has vent holes The above findings are based on the case where the core is smooth and the stress distribution is average. It is known that when the core has a vent, stress concentration occurs at the vent boundary, and according to studies by the present inventors, `` When an infinite plate having a circular hole is subjected to shearing, Stress concentration "can be applied. Since the stress concentration coefficient α in this case is 4.0, with the help of this, when the non-brazing surface and the brazing surface have ventilation holes,
Table 2 below shows the concentrated stress acting on these surfaces.

[0021]

[Table 2]

(F) Shear Stress and Core Shear Strength As an index for measuring the resistance of the core to shear, the ratio between the shear stress and the shear strength of the core was determined. Assuming that the shear strength per side of the core is T ₀ , (shear stress) / (core shear strength) is as shown in Table 3 below. Since the two brazing surfaces are integrated and the plate thickness is doubled, the shear strength is quadrupled to 4T ₀ , but since the number of sides is reduced by half, the shear strength is regarded as 2T ₀ . On the other hand, when vent holes are not provided on the non-brazing surface and vent holes are provided on the brazing surface as in the present invention, the results are as shown in Table 4 below.

[0023]

[Table 3]

[0024]

[Table 4]

In Tables 3 and 4, (shear stress) /
The smaller the value of (the shear strength of the core) is, the less the core surface is likely to be broken by a shear load. And, as shown in Table 3, when there is a vent on the non-brazing surface, the value of (shear stress) / (shear strength of the core) becomes large especially under the load in the W direction, and this surface is easily broken. It is understood that. On the other hand, as shown in Table 4, when there is no vent hole on the non-brazing surface, the value of (shear stress) / (core shear strength) becomes small. Shear stress) / (shear strength of core)
Is not very large. Therefore, it is understood that the core surface is less likely to break than the case where the vent hole is provided on the non-brazing surface.

[0026]

[0027]

[0028]

EXAMPLE Next, a description will be given of an example in which the provision of no ventilation hole on the non-brazing surface improves the bending fatigue strength as compared with the case where the ventilation hole is provided. In this example, in order to know the relationship between the presence or absence of ventilation holes on the non-brazing surface and the fatigue strength, a honeycomb panel having no ventilation holes on the non-brazing surface, and a honeycomb panel having ventilation holes on the non-brazing surface were used. As shown in FIG. 6 , a four-point bending fatigue test in the core W direction was performed. The honeycomb panel subjected to the fatigue test is an aluminum brazed honeycomb panel including only the face plate and the honeycomb core, and has the dimensions shown in Table 5 below.

[0029]

[Table 5]

FIG . 7 is a diagram showing the relationship between the core average shear stress τ calculated from the bending stress and the fatigue life. As shown here, a non-brazing surface having a vent hole has a shorter life than a non-brazed member due to stress concentration. When compared at the same life, the core average shear stress value when there is a vent is が あ る of that when there is no vent. That is, the fatigue strength can be doubled by omitting the ventilation holes on the non-brazing surface. Incidentally, the honeycomb panel to the non-brazed portions have vent, as shown by an arrow s in FIG. 6 (b), the vent shearing section core break starting, the honeycomb panel has no vent, 6 (C)
As shown by the arrow s, the face plate was broken at the uniformly bent portion.

[0031]

According to the present invention, the air permeability of the brazed honeycomb panel is ensured in the same manner as in the prior art, and at the same time, the conventional reduction in the shear strength of the honeycomb core is prevented, and the fatigue strength of the honeycomb panel is improved. be able to.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view illustrating a honeycomb panel of the present invention.

FIG. 2 is a plan view illustrating an arrangement of honeycomb cores and the like of the present invention.

FIG. 3 is an explanatory diagram for obtaining a shear stress applied to a honeycomb core.

FIG. 4 is an explanatory diagram for obtaining a shear stress in a core L direction.

FIG. 5 is an explanatory diagram for obtaining a shear stress in a core W direction.

FIG. 6A is a plan view of a bending fatigue test piece in a core W direction,
(B), (c) is an AA arrow view of (a), respectively.
(B) is a honeycomb panel having a vent hole in a non-brazing portion.
(C) is a case where the non-brazing portion has no vent hole.
The case of a honeycomb panel is shown.

FIG. 7 is a diagram showing a relationship between core shear stress τ and fatigue life.
is there.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Convex surface 2 Concave surface 3 Intermediate surface 4a, 4b Shaped material 5a, 5b Spacer 6a, 6b Face plate 7 Intermediate surface vent 8 Spacer vent

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masato Kobayashi 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Inside Kobe Steel Research Institute Kobe Research Institute (72) Inventor Shinichiro Takahashi Takatsuka, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Co., Ltd.Kobe Institute of Technology, Kobe Steel Co., Ltd. (72) Inventor Toshihiko Sasaki 14-1, Chofu Minatomachi, Shimonoseki City, Yamaguchi Prefecture Kobe Steel, Ltd. JP-A-6-296877 (JP, A) JP-A-7-1061 (JP, A) JP-A-7-92079 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B21D 47 / 00

Claims (3)

(57) [Claims] 1. A brazing sheet comprising a plurality of brazing sheets in which a convex surface and a concave surface and an intermediate surface located between the convex surface and the concave surface are alternately continuous along the length direction and are formed in an angular wave shape. It consists of a honeycomb core in which the convex and concave surfaces of the sheet are overlapped and brazed to each other, a profile material disposed around the honeycomb core, and a face plate disposed on the upper and lower surfaces of the honeycomb core and the profile material and brazed to these. A brazed honeycomb panel made of aluminum, wherein ventilation holes are provided on a convex surface and a concave surface of the honeycomb core that are brazed to each other, and no ventilation hole is provided on an intermediate surface of the honeycomb core that is not brazed to each other. panel. 2. A brazing sheet comprising a plurality of brazing sheets in which a convex surface and a concave surface and an intermediate surface located between the convex surface and the concave surface are alternately continuous along the length direction and are formed in an angular wave shape. A honeycomb core in which the convex and concave surfaces of the sheet are overlapped and brazed to each other, a profile material disposed around the honeycomb core, and a spacer formed into a wavy brazing sheet interposed between the honeycomb core and the profile material, In an aluminum brazed honeycomb panel comprising face plates which are disposed on the upper and lower surfaces of a honeycomb core, a shape member, and a spacer and brazed to these, a vent hole is provided in a convex surface and a concave surface of the honeycomb core which are brazed to each other. A vent is not provided in an intermediate surface of the core that is not brazed and joined, and a vent or a slit for ventilation is provided in the spacer. And the brazed honeycomb panel. 3. The spacer is interposed only on a portion of the brazing sheet parallel to the length direction of the brazing sheet, where the convex or concave surface is in contact with the profile, and on a surface perpendicular to the length direction of the brazing sheet. The brazed honeycomb panel according to claim 2, wherein the end portion is interposed only in a portion that abuts on the profile.