JPS6168376A - Method of bonding ferrite magnet and metal material - 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 [Technical Field of the Invention] The present invention relates to a method of bonding a ferrite magnet and a metal material.

[Prior art]

Conventionally, the adhesion between a ferrite magnet and a metal material was as shown in diagram g1.

In the figure, (1) is a ferrite magnet, (2) is a metal material such as iron, and (3) is an adhesive made of epoxy resin. Conventionally, the adhesive (3) has been controlled so that it is uniformly applied to the contact surface and is as thin as possible. However, as shown in Figure 2, the ferrite magnet (1) and the metal material (2)
) and the thermal expansion coefficient (bvr). If the temperature difference between the curing temperature of the adhesive (3) and the operating temperature is large, a large stress will be generated between the ferrite magnet (1) and the metal material I) (2). arise. The second reason is that distortion occurs due to the temperature difference between the ferrite magnet (1) and the metal part (2), which is a cause that cannot be explained. (b) shows the relationship between temperature and elongation on the metal material side. The operating temperature 01 is room temperature.

Since the adhesive (3) is a thermosetting resin material, the adhesive (3) is heated and cured at an adhesive curing temperature θO of 150°C. At the operating temperature θl, there is a large stress difference between the ferrite magnet (b) and the metal material (b). This stress difference is denoted by δ and is expressed as δ.

Figure 8 is a diagram showing a state in which a ferrite magnet cracks, and stress is generated in the metal material (2) in the direction indicated by the arrow in the figure.
A fracture surface (4) is generated in the ferrite magnet (1), and the ferrite magnet (1) is broken near the adhesive surface.

As described above, ferrite magnet (1) <! :Metal material(
Due to the difference in coefficient of thermal expansion between the ferrite magnet and the metal material (2), there is a large temperature difference between the curing temperature of the adhesive and the temperature at which it is used. There was a drawback that the ferrite magnet (1), which is relatively brittle compared to other magnets, could crack.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional method as described above, and provides an adhesion method that prevents the proportion of ferrite magnets by making the contact ytm thinner at the center of the bonding surface and thicker at the edges. The purpose is to

[Invention! Travel example) An embodiment of this invention will be explained below with reference to the drawings.

As shown in Figures 4 to 7, (5) is fephytite,
(6) is a metal material such as iron. Ferrite magnet (5
) The bonding surface of the ferrite magnet (5) or metal material (6) is made into a middle ear shape so that the bonding surface is thin at the center and thick at the ends. By doing this, the strain caused by the difference in thermal expansion between the shift magnet (5>) and the metal material [6] can be absorbed by the elasticity of the adhesive (3) made of epoxy resin, and the strain caused by the difference in thermal expansion between the ferrite magnet (5) and the metal material [6] can be absorbed by the elasticity of the adhesive (3) made of epoxy resin. Cracking can be prevented. In the central part of the adhesive surface where almost no distortion occurs due to the difference in thermal expansion, the adhesive layer must be made thin to ensure adhesive strength, and the thickness of the adhesive layer in this central area must be controlled. It is much more effective than the method of uniformly increasing the overall Wffl, such as being able to manage the ferrite-stone and metal materials. By making the il (ta) thicker at the center of the gripping surface, the elasticity of the adhesive can absorb the strain caused by the difference in thermal expansion, which is effective in preventing cracking of the ferrite magnet.

[Brief explanation of the drawing]

Figure 1 is a model diagram of a conventional ferrite magnet and metal material bonded together, Figure 2 shows the cause of distortion caused by the temperature difference between the ferrite magnet and the metal material, and Figure 3 shows how a ferrite magnet cracks. The figures shown in FIGS. 4 to 7 are diagrams of ferrite sandstone and metal material bonded together, showing a simple embodiment of the present invention. In the figure, (3) is an adhesive and (5) is a ferrite magnet. (6) is a metal material.

Claims (3)

[Claims] (1) When bonding a ferrite magnet and metal, the thickness of the adhesive is thinnest at the center of the ferrite magnet and thickest at the ends of the ferrite magnet. Adhesion method. (2) A method for bonding a ferrite magnet and a metal material according to claim 1, wherein the center portion of the bonding surface of the ferrite magnet is formed into a convex shape. (3) A method for adhering a ferrite magnet and a metal material according to claim 1 or 2, wherein the center portion of the adhesion surface on the metal material side is formed into a convex shape.