JP2003130771A - Method of measuring joining strength - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of measuring joining strength by which the joining strengths of jointed surfaces joined by brazing or welding or by using an adhesive in the shear direction can be measured accurately. SOLUTION: In order to the measure the joining strengths of the joint surfaces (B) formed by joining parts of a plate-shaped connecting material (4) to parts of plate-shaped base materials (2 and 2') by respectively putting the parts of the material (4) on the parts of the base materials (2 and 2'), the two base materials (2 and 2') are positioned in a facing state so that the upper surfaces (8) of the materials (2 and 2') may be flushed with each other and the parts of the connecting material (4) are respectively put on the parts of the upper surfaces (8) of the materials (2 and 2') over the space between the materials (2 and 2') and joined to the parts. Then a shear force is caused to act on the joint surfaces by respectively applying tensile loads (F and F') to the base materials (2 and 2') and the tensile loads when the base materials (2 and 2') are sheared from the connecting material (4) are measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding strength measuring method, and more specifically, it accurately measures bonding strength in a shearing direction of a bonding surface where two members are superposed and bonded by brazing, welding or using an adhesive. The present invention relates to a bonding strength measuring method for measuring.

[0002]

2. Description of the Related Art FIG. 2 (a) shows a method conventionally used to measure the joint strength in the shearing direction of a joint surface where two flat plate-shaped test pieces are superposed and joined. As shown in this figure, the test piece 21 and the test piece 22 are overlapped in a certain range from one end thereof, and the overlapped portion is joined by brazing, welding, or an adhesive. In addition, B represents a joining surface, and F and F ′ represent a state in which a tensile load is applied.

In the conventional measuring method shown in FIG. 2, two flat plate-shaped test pieces are joined to each other by applying a tensile load F, F'to almost the center of the surface at each other end and applying a shearing force to the joined surfaces. The joint strength of the joint surface was measured by measuring the tensile load when the surfaces were sheared.

[0004]

However, in the conventional bonding strength measuring method of the type in which two conventional test pieces are superposed and bonded, the action axes of F and F ′ do not coincide with each other. A moment proportional to the displacement H in the height direction (see FIG. 2B) is generated. Therefore, just measuring the magnitude of the tensile load F (= F ′) at the time of shearing cannot make it the accurate joining strength of the joining surface.

That is, when the acting axes of the tensile loads F and F ′ do not coincide with each other and a moment acts on the test pieces 21 and 22, the test pieces are warped as shown in FIG. As a result that everything does not work in the shear direction,
Even if the magnitude of the tensile load at the time of shearing was measured, it could not be used as it was as the bonding strength.

Therefore, in the conventional method, a correction calculation using a correction term is performed on the measured value of the tensile load at the time of shearing to indirectly obtain the joint strength in the shearing direction.

Further, in the case where the test piece is a metal which is weak in bending and has low ductility (brittleness) and the like, and the test piece is strongly bonded, the test piece itself bends before the bonding surface shears ( There was a case where it was broken due to (warp).

The present invention does not indirectly measure the joint strength in the shearing direction of the joint surface by using the correction term by making the action axes of the tensile loads applied to the joint surfaces coincide with each other, and instead of measuring the joint strength in the shearing direction. It is intended to provide a bonding strength measuring method in which the load can be directly adopted as the bonding strength.

[0009]

The bonding strength measuring method of the present invention is a bonding surface (part of a flat plate-shaped base material (2, 2 ') and a flat plate-shaped connecting material (4) which are superposed and bonded. B) A bonding strength measuring method for measuring the bonding strength in the shearing direction, wherein two base materials are positioned so that their upper surfaces (8) are flush with each other, and a connecting material is laid over the upper surfaces. When the base material and the connecting material are joined together, and then a tensile load (F, F ′) is applied to the two base materials to exert a shearing force on the joining surfaces, and the base material is sheared from the joining material. The tensile load of is measured.

According to the bonding strength measuring method of the present invention, the action axes of the tensile loads (F, F ') can be made to coincide with each other, so that the base material (2, 2') and the connecting material (4) are almost warped. The measured value of the tensile load at the time of shearing can be used as it is as the bonding strength without causing the above. According to the law of action and reaction, the action directions of F and F ′ are opposite to each other, and their sizes are the same.

Here, in the bonding strength measuring method of the present invention, it is preferable that the tensile load (F, F ') applied to the base material is applied in substantially the same plane as the upper surface of the base material.

By making the tensile load applied to the base material and the shearing force of the joint surface substantially on the same plane, the joint strength in the shearing direction of the joint surface can be measured more accurately.

In the method for measuring the joint strength of the present invention, it is also preferable that the reinforcing material (12) is joined to the upper surface of the connecting material (4).

When the tensile load applied to the base material and the shearing force acting on the joint surface are not completely on the same plane, a bending moment acts on the connecting material, causing warping of the connecting material.
Along with this, the base material closely bonded to the connecting material also warps. When the base material warps, a shearing force and a tensile force act on the joint surface, so that the tensile load value when the joint surface shears cannot be directly used as the joint strength. Therefore, a reinforcing material is joined to the upper surface of the connecting material to reinforce the connecting material and suppress warpage of the connecting material. As a result, the tensile load value at the time of shearing the joint surface can be directly used as the joint strength. In addition, instead of joining the reinforcing material, thickening the connecting material itself is also effective in suppressing warpage of the connecting material. In that sense, it can be said that the present invention provides a measuring method when a thin flat plate is used as the connecting material itself.

Here, the reinforcing material (12) is a flange-shaped thick plate (14) standing upright in parallel to the pulling direction.
It is preferable.

By mounting a flange-shaped thick plate on the upper surface of the connecting member in parallel with the pulling direction, it is possible to effectively suppress the warpage of the connecting member.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, in each figure, the common part is denoted by the same reference numeral, and the duplicated description will be omitted.

An embodiment of the present invention will be described in detail below with reference to FIG. FIG. 1 shows an embodiment of the bonding strength measuring method of the present invention. Here, FIG. 1A shows a perspective view of an embodiment of the present bonding strength measuring method, and FIG. 1B shows a side view thereof. In this embodiment, the joint strength of the joint surface B is measured.

In order to carry out the bonding strength measuring method of the present invention, two base materials 2 made of thin strip-shaped metal plates,
2'is positioned and positioned on the plane base at a constant interval in a state where the longitudinal axes thereof are aligned and one ends of the short sides are opposed to each other. The base materials 2, 2'here have the same thickness, so that the two base materials are flush with their top surfaces.

A connecting member 4 is provided between the base members 2 and 2 '.
The base members 2, 2'and the connecting member 4 are joined by brazing. The joining of the base materials 2 and 2 ′ and the connecting material 4 is performed within a certain range from the opposite ends of both base materials, and the base material 2 ′ and the connecting material 4 are joined.
The area of the joint surface B ′ of the base material 2 and the connecting material 4 is larger than the area of the joint surface B of the base material 2 and the connecting material 4, and the joining of the base material 2 ′ and the connecting material 4 is the joining of the base material 2 and the connecting material 4. It is done more firmly than. Therefore, when shear occurs at the joint surface, it occurs at the joint surface B between the base material 2 and the connecting material 4.

Here, the connecting member 4 is made of a rectangular metal plate having the same width as the short sides of the base members 2 and 2 '(may be the same metal as the base member or may be a different metal). On the upper surface thereof, two thick plates 14 are welded in a flange shape in parallel to the longitudinal direction of the connected base materials and are erected.

The other end on the short side of the base material 2'is firmly fixed to the fixed wall, and the other end on the short side of the base material 2'is a rod provided in a tension device including a hydraulic cylinder (not shown). It is sandwiched by the chuck mechanism at the tip of the. A tensile load F is applied to the base material 2 by this tensioning device in the same horizontal plane in the longitudinal direction.

When a tensile load F is applied to the base portion 2,
Since a bending moment acts on the connecting member 4, the connecting member tends to have a downwardly convex warp as shown in FIG. However, a flange-shaped thick plate 14 is joined to the upper surface of the connecting member 4 by welding, and the thick plate 14 prevents the connecting member 4 from warping. Therefore, in practice, the connecting member 4
Almost no warp occurs, and therefore, the base materials 2, 2'which are tightly joined to this hardly warp. When the planar state of the connecting member 4 and the base members 2 and 2'is maintained, almost all of the applied tensile load F acts as a shearing force on the joint surface B. When this shearing force exceeds the joint strength, the joint surface B is broken.

Therefore, according to the bonding strength measuring method shown in this embodiment, the tensile load value at break can be directly used as the bonding strength of the bonding surface.

Further, when the base materials 2 and 2'have a certain thickness, it is preferable that the tensile load applied to the base material is applied in substantially the same plane as the upper surface 8 of the base material.

That is, by making the tensile load applied to the base member and the shearing force acting on the joint surface substantially on the same plane, the bending moment acting on the joint member 4 is reduced, and the shearing direction of the joint surface is more accurate. The bonding strength of can be measured.

[0027]

As described in detail above, according to the present invention, the warp occurring in the connecting member is prevented, and the working axes of the tensile loads acting on the joint surfaces are made to coincide with each other, so that the correction term is indirectly used. Further, it is possible to provide a bonding strength measuring method in which the tensile load value at the time of shearing can be directly adopted as the bonding strength in the shearing direction, instead of measuring the bonding strength in the shearing direction of the bonding surface.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a bonding strength measuring method of the present invention.

FIG. 2 is a diagram showing an embodiment of a conventional bonding strength measuring method.

[Explanation of symbols]

2, 2'base material 4 connecting materials 8 upper surface 12 Reinforcement material 14 thick plate 21, 22 test piece B, B'joint surface F, F'tensile load H gap

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nobuhiko Yuki             Ishikawa, 3-5-1, Mukodaicho, Tanashi City, Tokyo             Shimaharima Heavy Industries Ltd. Tanashi factory F-term (reference) 2F051 AB01 BA00                 2G052 AA11 AD32 AD52 FD00 GA03                 2G061 AA01 AA11 AB03 BA01 CB19                       EA01

Claims (3)

[Claims] 1. A method for measuring a joining strength in a shearing direction of a joining surface (B) obtained by overlapping and joining a part of a flat base material (2, 2 ') and a flat connecting material (4). A bonding strength measuring method, wherein two base materials are positioned so that their upper surfaces (8) are flush with each other, and a connecting material is laid over the upper surfaces to bond the base material and the connecting material. Bonding, wherein a tensile load (F, F ') is applied to two base materials to exert a shearing force on the joint surfaces, and the tensile load when the base materials are sheared from the connecting material is measured. Strength measurement method. 2. A reinforcing material (1) is provided on the upper surface of the connecting material (4).
The bonding strength measuring method according to claim 1, wherein the bonding strength is 2). 3. The bonding strength measuring method according to claim 2, wherein the reinforcing material (12) is a flange-shaped thick plate (14) standing upright in parallel with the tensile direction.