JPS5884927A - Heat treatment of columnar member - Google Patents

Abstract

PURPOSE:To make heat treatments uniform and to prevent generation of thermal strain by irradiating plural laser beams simultaneously to a columnar member to be heat treated from the equidistant positions in a circumferential direction, while rotating the same around the axial center. CONSTITUTION:A revolving shaft 1 which is a columnar member to be treated under heating is rotated around its axial center. Plural laser beams 4 are irradiated simultaneously to the parts 3 to be treated of the shaft 1 from equidistant positions in a circumferential direction. The circumferences in the prescribed positions of the columnar member are annealed annularly. Thus, the member is treated under heating uniformly and the generation of thermal strain is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION l) Technical Field of the Invention The present invention relates to a heat treatment method for performing annular hardening around a predetermined position of a cylindrical member, such as the first rotating shaft of a rotating electric machine.

2) Prior art The single rotation shaft used in electric motors and the like is often subjected to heat treatment to obtain the intended function. For example, in the case of a water pump used in a water pump, an O-ring made of Go^ is used in the bearing box 'R' of the shaft of one revolution.
WI is attached to prevent water from entering the rotating cage ak from the outside. In addition, for the rotating shaft, calculate the required torque, 5ML degree from the belt bending force, and decide the material, IL diameter, etc.
Due to the mechanical strength of the rotating shaft, the rotating shaft usually has a stepped portion. In order to improve the fatigue strength of this stepped part or the wear resistance of the part that is in contact with the 05 ring, hardening treatment is often performed locally in an annular shape. Conventionally, high-frequency induction heating was the most common method for hardening, but depending on the size and shape of the object being heated, it was necessary to replace or adjust the inductor coil, and this was done on the surface side. .

Recently, with the advent of high-output carbon dioxide lasers, their high energy, non-contact processability, ease of manipulation with one numerical operation, etc., have led to rapid expansion of applications to 11k IIJI. ing. Next, a conventional hardening method using a longitudinal acid gas laser will be explained.

Hold the rotating shaft to be hardened in a rotatable chuck,
Spray the black paint that increases heat absorption in advance.
A laser beam with an output of t'1lli is applied to an appropriate spot using a converging lens on the part to be hardened which has a temperature of k. While being irradiated with laser beam A, the chuck is rotated once at a certain circumferential speed. Therefore, the rotating shaft rotates once, and by this operation, the temperature is reduced to the quenching temperature until a certain distance from the surface, and after the laser beam, which is the heat source, passes through, the material is immediately quenched by heating, and the quenching is completed. For example, diameter 4 made of carbon copper 845C of Japanese Industrial Standards (J Engineering 8).
In the case of a rotating shaft of 0.0 mm, it is possible to harden to the required hardness with a radar output of 2.51 mW and a height of 1550 m/min. 3) Problems with the conventional technology However, 4. When 9 seconds have elapsed and the phenomenon t is observed in seconds, an asymmetrical heat input occurs with respect to one rotational axis, and thermal strain due to this occurs, although it is slight. Even the slightest deviation of the axis of rotation must not occur, as this will cause vibration.

4) Purpose of the Invention The object of the present BA is to provide a method for treating a cylindrical member with islands, which uses an easy-to-operate laser beam and is capable of hardening without causing thermal distortion.

5) Structure of the Invention The odor device of the present invention has a plurality of laser beams exposed to heat of J6 m.
Irradiate from positions equally spaced in the circumferential direction for 1 m,
Hardening is performed by rotating the cylindrical #M around the axis 71>.

6) Examples of the Invention Hereinafter, examples of solid noodles of the present invention will be described with reference to FIGS. 1 and 2. The rotary shaft (11), which is a cylindrical member to be hardened, is held in a rotatable chuck (2), and the part to be hardened (3) 42, coated with black paint in the area indicated by the broken line in the IJ1 diagram, is Adjusted ・Ta2
Each of the laser beams (4) is focused on a suitable spot by a converging lens (5) and irradiated from a position symmetrical with respect to the axis 1 of the rotation axis (1). At the irradiation position 11 (6), (6) and all the center lines (7), (7) of this anti-rape, shift by a shift width 1 shown at 511 m in the axial direction,
Spread out the total inside of the part to be hardened (3) to the desired width.

Both laser beams (4) split the laser beam emitted from the laser oscillator (not shown) at l@ into two parts by a beam splitter (not shown), and then divide the laser beam into two parts by the laser beam oscillator (not shown) at the rotating shaft (1). Guide to the side. Since the laser beam power is divided into two, compared to the conventional case where it is not divided, the irradiation spot diameter is the same.
Double the output C: It is necessary to adjust the oscillator t or increase the rotating shaft (110 circumferential speed to 172C). Under these circumstances, the laser beam (4) is irradiated from both sides. By rotating the rotation axis (11) once, the rotation axis (
The hardening of the part (3) to be hardened in No. 11 is completed.

Next, I will explain how it works.

The laser irradiation position is the rotation axis (with respect to the axis C2 of 11,
Since it is unisymmetric, the thermal effects on the rotation axis (first and second) are also symmetrical, and no thermal distortion occurs. Since the accounting island l&onchu is widely controlled by shifting, it becomes possible to perform annular hardening with the desired hardening width for just $1.

Next, with reference to FIG. 3, another embodiment t-#Ql#1 will be explained.
This is the case where the irradiation positions of the lasers on both sides (61, (61) are dispersed at the center line (7). In this case, the rotation axis (
The quenching is completed by half-turning.

In this way, the adjustment range during hardening is limited to the maximum @1i4 of the laser beam spot, but the rotation axis (1st eye:
The fact that there is no risk of thermal distortion is the same as in the embodiments of FIG. 1 and 2.

Helmet 1 The present invention is not limited to the embodiments described above and shown in the drawings; for example, it can be applied to any cylindrical member other than the rotating shaft, and the laser beam (4) is applicable to 2 Even if the number of eyes is more than 1, it is enough to irradiate from equally spaced positions in the circumferential direction. Of course, it can be implemented with various modifications.

7) As described in detail, according to the present invention, a plurality of laser beams are irradiated onto the part to be hardened of a cylindrical member at the same time from equally spaced positions in the circumferential direction. By rotating the columnar member around the axis, the cylindrical shape during hardening becomes symmetrical on the circumference, allowing for non-contact machining without thermal distortion! It is now possible to apply thermal processing using a laser beam, which is easy to use, to a cylindrical member.

[Brief explanation of drawings]

Fig. 111 is a top view showing a case 11 in which an embodiment of the heat treatment method for a cylindrical member of the present invention is being carried out; The state of being
It is a top view shown in t. 1.-Rotating shaft 3, which is a cylindrical member...Target fa II & 11 4..Laser beam A5.--Converged y-z 6..Irradiation position 7..
・Center of irradiation position - Representative Patent Attorney Inoue - Male Figure 1 Figure 2

Claims (2)

[Claims] (1) In a method for heat treatment of a cylindrical member, in which a predetermined position of the cylindrical member is annularly injected, a plurality of lathe beads are placed at equally spaced positions in the circular direction with respect to the portion to be heat treated 42. Simultaneously irradiate the cylindrical member around the axis r, 1
A heat treatment method for seven cylindrical members, characterized by rolling. (2)! The method of heat treating a cylindrical member according to claim 1, characterized in that the irradiation position wtft of the laser bee is shifted in the axial direction to widen the total ripening width.