JPS60260481A - Structure for bonding ceramic axis and metal axis - 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) The present invention relates to a structure in which a ceramic shaft and a metal shaft are joined by [J-marking].

(Prior art) Ceramics with excellent heat resistance have been used for turbine rotors of automobile turbochargers, etc., but they have poor workability after molding and are weak against local deformation forces, so the impeller is attached to the compressor side. It is difficult to form even the rotor shaft with ceramics. .

Conventionally, as shown in Fig. 3, a shaft (ceramic shaft) 1 formed integrally with a turbine (not shown) is made of ceramic, and a shaft (metallic shaft) 2 made of metal is butted and joined by brazing. A similar method has been proposed (see Japanese Patent Application No. 57-2'20295).

In this case, the abutting portion 4 of the metal shaft 2 is formed to have the same diameter as the abutting portion 3 of the Reramic shaft 1, and these abutting portions 3.4 are welded all around by brazing. Note that a predetermined groove is provided on the ceramic shaft 1 side so as to maintain good bonding force on the ceramic shaft 1 side.

According to this, it becomes easy to perform screw processing to attach the impeller, and it is possible to prevent the screw portion from being damaged.

However, in such a joining structure, since the coefficient of thermal expansion is quite different between ceramic and metal (for example, the coefficient of linear expansion of ceramic is 2.8X10-6, and the coefficient of linear expansion of steel is about 11X10-), - It is unavoidable that a relatively strong contraction ν force is applied to the ceramic shaft 1 during the cooling process described above, and as a result, cracks occur around the circumference of the ceramic shaft 1. Therefore, the number of delinquents was high and the yield rate was worsening.

(Objective of the Invention) The object of the present invention is to prevent such rack damage.

(Disclosure of the Invention) This invention has a structure in which a lamic shaft and a metal shaft of this shaft J: Rimo small (Y) are butt-joined by brazing.
(, form a thin flange part toward the outer periphery at the butt part of the metal shaft (J), and attach this flange part to the semi-metal shaft [
]-Attachment-Rir.

Therefore, the thermal stress J3 and shrinkage stress generated during brazing are absorbed by the flange portion, and can be prevented from being applied to the helical shaft.

(Embodiment) FIG. 1 is a main part 111i side view showing an embodiment of the present invention.
Hashiramic shaft 6 accepts a metal shaft with a smaller shaft diameter than this ceramic shaft 5.

This metal shaft 6 is connected to the abutting portion 7 of the Biramink shaft 5.
The wall becomes thinner from the axial surface toward the outer circumference.

A flange portion 8 is formed.

This flange portion 8 has a J-shaped surface on the metal shaft 6 side and a flat surface on the ceramic shaft 5 side, and the axis (Y and l111 diameter) of the abutment 1 part 9 on the outside (Y is the ceramic axis!'). Ru.

Then, the flange part ε3 or L' is joined to the abutting part 9 of the ramic shaft 5), and their outer peripheries are welded all around by n-f=1.

Once, when I joined the metal shaft 6 etc. to the solder with J:Receramic shaft 6, etc.,
Is it because of the heat stress, or is it because of the shrinkage stress in the culm?
. , it is alleviated.

The occurrence of cracks in the helical shaft 5 can be reliably prevented without causing the strong absorbed stress on the helical shaft 5 to bend (, i), and as a result, Good bonding strength and good appearance are achieved by 4ri, and the yield can be greatly improved.

d3, Fig. 2 shows an IJ type in which the metal shaft 6 side of the flange portion 11 is formed into a concave curved shape so as to smoothly connect with the shaft surface.
In this way, it is possible to prevent the occurrence of cracks and to increase the axial strength against one stress concentration.

(Effects of Excuse) [l- It is possible to prevent the occurrence of cracks by alleviating shrinkage stress, etc., and there is an effect that it is possible to improve the axial strength and the ease of reference.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part of another embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional example. 5...Hiramic shaft, 6...Metal shaft, 7...Abutment part, 8...Flange part, 11...Flange part. %i+ +! 'l Applicant: Nissan Automatic Drawer Co., Ltd. Figure 1 Figure 2 Figure 2

Claims (1)

[Claims] In a structure in which a shaft made of ceramic and a metal shaft with a smaller diameter than the shaft are butt-joined by brazing, a flange part that becomes thinner toward the outer circumference is formed at the butt part of the metal shaft, and this flange part is made of ceramic. A joining structure of a ceramic shaft and a metal shaft characterized by brazing the shaft.