JPH0751257Y2 - Press fitting jig for connecting ceramic turbine rotor and metal shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the case where a convex portion of a turbine rotor made of ceramic is press-fitted into a concave portion of metal, that is, a metal shaft is coaxially held with respect to the concave portion. It relates to a jig used for the work of applying pressure to a metal shaft.

(Prior Art) A rotor made of a ceramic for a turbocharger has a process of press-fitting a metal rotating shaft into a shaft portion of a fired ceramic turbine rotor, as described in, for example, JP-A-60-50204. After that, it becomes a product, but a dedicated jig is indispensable for this process.

A jig of this type is disclosed in Japanese Patent Laid-Open No. 63-139075, but there is a problem in that it is difficult to align the ceramic body and the metal body, and the bottom of the container on which the ceramic body is placed is severely worn. It was

Further, when performing press-fitting under reduced pressure, since the concave portion of the metal shaft and the convex portion shaft of the ceramic rotor are aligned at the time of exhaust, there is a problem that the pressure of the concave portion cannot be reduced in a short time.

(Problems to be solved by the invention) Therefore, it is an object of the invention to provide a press-fitting jig in which the alignment of the ceramic turbine rotor and the metal shaft is easy and reliable, and further, the wear of the bottom of the container is reduced. is there.

(Means for Solving the Problem) The present invention relates to a press-fitting jig in which a convex portion formed at a base end of a turbine rotor made of ceramic is press-fitted into a concave portion opened at an end surface of a metal shaft to be integrated with the turbine rotor. A container having a housing space, a lid that closes the opening of the container, and a guide tube having a housing space for the metal shaft, and the bottom surface of the container is made of ceramic having hardness equal to or higher than that of the turbine rotor or A ceramic turbine rotor with a metal bottom plate, a positioning hole into which the projection at the tip of the turbine rotor is fitted, and a guide tube that is movable forward and backward with respect to the turbine rotor in the container are attached to the lid. It is a press-fitting jig for connecting with a shaft.

(Operation) At the tip of the turbine rotor, a columnar protrusion is formed by so-called reverse center processing so as to be convenient at the stage of polishing finish after firing and the stage of press-fitting the metal shaft into the convex portion of the turbine rotor according to the present invention. Has been formed.

In the container, the protrusion is inserted into the positioning hole to position the turbine rotor at a predetermined position, while the metal shaft is held by the guide cylinder, and thereafter the metal shaft is protruded by the load applied to the guide cylinder. It is possible to easily integrate the two by pressing into the part.

By the way, the site where the stress is most concentrated at the time of press-fitting is around the positioning hole in the bottom surface of the container, and according to experiments by the inventors, when SKD-61 (JIS G4404) was used on the bottom surface of the container, 500 The circumference of the positioning hole was abraded by the repeated press-fitting work, and the load during press-fitting was not evenly applied, resulting in inconvenience in the subsequent work.

Therefore, a ceramic or metal bottom plate having hardness equal to or higher than that of the turbine rotor is placed on the bottom surface of the container, and a positioning hole is provided in this bottom plate to prevent abrasion in a short time. The bottom plate can be replaced according to the worn state. By the way, when a bottom plate made of silicon nitride was used, press-fitting work was possible 1800 times or more.

(Embodiment) FIG. 1 shows an embodiment according to the present invention.

In the figure, 1 is a container for accommodating a turbine rotor 2 therein, 3 is a lid of the container 1, 4 is a guide cylinder for accommodating a metal shaft 5 attached to the lid 3, and the guide cylinder 4 is a turbine in the container 1. It can move back and forth with respect to the rotor 2.

A bottom plate 6 made of ceramic or metal is arranged on the bottom surface of the container 1, and the turbine rotor 2 is placed at the center of the bottom plate 6.
A positioning hole 8 into which the projection 7 of FIG. Further, the side wall of the container 1 is provided with an exhaust port 9 for making the inside of the container 1 a reduced pressure atmosphere.

On the other hand, the guide cylinder 4 is provided with a magnet 10 for fixing the metal shaft 5 in the guide cylinder at the upper part thereof. Reference numeral 11 is an O-ring for ensuring airtightness between the container 1 and the lid 3 and between the lid 3 and the guide tube 4.

In order to connect the turbine rotor 2 and the metal shaft 5 with the jig described above, first, the projection 7 of the turbine rotor 2 is housed in the container 1 in which the bottom plate 6 is set, and the turbine rotor 2 is fitted into the positioning hole 7 of the bottom plate 6. Then, a rust preventive agent is applied to the convex portion 2a of the turbine rotor 2. On the other hand, after attaching the guide cylinder 4 accommodating the metal shaft 5 to the lid 3, after covering the container 1 with the lid 3,
Evacuation from the exhaust port 9 is performed by a vacuum pump. Next, a predetermined press-fitting load is applied to the guide cylinder, and the convex portion 2a of the turbine rotor 2 is pushed into the concave portion 5a of the metal shaft 5 to join the two. Then, the inside of the container 1 is brought to atmospheric pressure, and the combined body inside is taken out.

FIG. 2 shows another embodiment according to the present invention.

The jig shown in the same figure is for performing press-fitting without depressurizing the inside of the container 1, and is an example in which a guide cylinder 4 suitable for the case where the diameter of the metal shaft 5 changes in the middle part and there is a step 5b is provided.

(Effect of the Invention) According to the present invention, it is possible to provide a jig that is suitable for the work of press-fitting the metal shaft into the ceramic turbine rotor. Since the stable setting of the turbine rotor and the uniform application of pressure to the press-fitting points can be achieved, and the center positions of the ceramic rotor and the metal shaft can be easily matched, workability is improved. Further, in press fitting under reduced pressure, since the metal shaft is lifted by the magnet of the guide cylinder, exhaust of the recess of the metal shaft can be made uniform and stable press fitting can be performed.

[Brief description of drawings]

1 and 2 are sectional views of a press-fitting jig according to the present invention. 1 ... Container, 2 ... Turbine rotor 2a ... Projection, 3 ... Lid 4 ... Guide tube, 5 ... Metal shaft 5a ... Recess, 5b ... Step 6 ... Bottom plate, 7 ... Projection 8 …… Positioning hole, 9 …… Exhaust port 10 …… Magnet, 11 …… O ring

Claims (3)

[Scope of utility model registration request] 1. A press-fitting jig in which a convex portion formed on the base end of a turbine rotor made of ceramic is press-fitted into a concave portion opened on an end face of a metal shaft to integrate the container with a housing space for the turbine rotor, A lid for closing the opening of the container, and a guide tube having a space for accommodating the metal shaft, and a bottom plate made of ceramic or metal having hardness equal to or higher than that of the turbine rotor is arranged on the bottom surface of the container. A press-fitting jig for coupling a ceramic turbine rotor and a metal shaft, in which a positioning hole for fitting a projection at the tip of the turbine rotor is provided in the bottom plate, and a guide tube that is movable forward and backward with respect to the turbine rotor in the container is attached to a lid. 2. The press fitting jig according to claim 1, wherein the guide tube has a magnet for fixing a metal shaft inside. 3. The press-fitting jig according to claim 1, wherein the lid has an O-ring at the contact portion with the guide tube, and the container has an exhaust port for vacuuming.