JPS59163535A - Unbalance correcting method of rotating body - Google Patents

Abstract

PURPOSE:To constitute so that a foreign matter scarcely adheres to a grinding part and no stress concentration is generated, to eliminate a damage of a rotating body, etc., and to raise safety by irradiating a pulsative laser light to the surface of the rotating body, evaporating it, eliminating the greater part of an unbalance quantity of the rotating body, and thereafter, adjusting and irradiating the laser light so that a laser power density becomes power of an extent for melting a little the uneven surface of a grinding part of the surface of the rotating body. CONSTITUTION:A condensing lens 4 is moved horizontally and positioned so as to shift a focal position by a lens driving device 8, and a pulsative laser light 3A is irradiated to a rotating body 1 through the condensing lens 4 and a protective glass 5. Usually, the laser light 3A passing through the condensing lens 4 becomes the maximum and the minimum as to its power density and beam diameter, respectively, in the focal position of the condensing lens 4, therefore, by moving forward and backward the focal position of the condensing lens 4 in this way, a power density of the laser light 3A in the irradiating part of a laser light on the surface of the rotating body 1 drops. As a result, an uneven surface 7 of the rotating body 1 is given a heat quantity by which the concave surface 7 is melted a little, from the laser light 3A, melted a little and not evaporated, therefore, unevenness of the surface of the rotating body 1 dies away, and a smooth grinding surface 9 is formed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for correcting unbalance of a rotating body rotating at high speed by irradiating the rotating body with pulsed laser light. Regarding leaving.

[Technical Background of the Invention] Generally, a rotating body has its own critical speed, and in order to rotate the rotating body at high speed, it is necessary to pass through several critical speed regions. If the rotating body reaches the critical speed and the platform has a large -C unbalance, the rotating body will generate large vibrations when passing through the critical speed area, contact the stationary side, and be unable to pass through the critical speed area. Something happens.

In the conventional method of correcting the unbalance of a rotating body using laser light, when correcting the unbalance of a rotating body, the surface of the rotating body is irradiated with pulsed laser light without stopping the rotating body. The unbalanced amount can be removed by instantaneously dissolving and vaporizing the surface of the body.

FIG. 1 is a conceptual diagram showing an apparatus for explaining such a conventional method of correcting unbalance of a rotating body using laser light.

A pulsed laser beam 3 from a laser generator 2 is directed onto the surface of the rotating body 1 as an irradiation surface by a condenser lens 4. Irradiation is possible through the protective glass 5. Here, the amount of unbalance removed by the laser beam 3 scatters in the opposite direction perpendicular to the incidence of the laser beam as shown by an arrow 6. Therefore, the protective glass 5 can protect the condenser lens 4 from the objects scattered and removed from the rotating body 1.

[Problems with the Background Art] However, in the laser unbalance correction method described above, when the surface of the rotating body 1 is irradiated with the pulsed laser beam 3 to remove the unbalance amount, the laser irradiated portion of the surface of the rotating body 1 instantly The surface of the rotating body becomes rough as shown by the symbol 7τ' in Fig. 2, and the surface of the rotating body 1 becomes rough as shown by the symbol 7τ' in Fig. 2. Foreign matter tends to adhere to the rough surface 7 of the ground portion. This has caused a problem in that even though the unbalance has been removed, the unbalance will occur again if foreign matter lands on the surface. In addition, when the surface of the rotating body 1 is made into an uneven surface 7 state as shown in FIG. 2 and the Ct is 35, there is a problem that the strength of the rotating body 1 decreases due to stress concentration occurring on the uneven surface 7. .

1. Purpose of the invention] The present invention has been made to solve the above problems,
The purpose of this is to prevent the ground surface of the rotating body from becoming rough when the unbalance of the rotating body is removed using a laser beam, thereby preventing foreign matter from adhering to and flying around the surface of the rotating body, and preventing the surface of the rotating body from becoming rough. It is an object of the present invention to provide a method for correcting the unbalance of a rotating body using a laser beam so that stress concentration does not occur on a ground surface.

[Summary of the invention 1 Achieving the above purpose! Therefore, in the present invention, a pulsed laser beam is irradiated onto the surface of a rotating body through a focusing lens and evaporated to remove most of the unbalance of the rotating body, and then the laser beam is irradiated onto the rotating body. The laser beam is adjusted and irradiated so that the laser power density is such that it slightly melts the uneven surface of the grinding portion on the surface of the rotating body, and the uneven surface is melted and then smoothed. A solid surface is formed on the surface.

[Embodiment 1 of the invention An embodiment of the present invention will be described below with reference to FIG.

FIG. 3 is a conceptual diagram of an apparatus for explaining the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals. That is, in FIG. 3, a pulsed laser beam 3A generated from a laser generator 2 is condensed by a condensing lens 4, and is irradiated onto the rotating body 1 through a protective glass 5. Here, the condensing lens 4 and the protective glass 5 are arranged so as to be perpendicular to the optical path of the laser beam 3A, and so that the condensing lens 4 passes through the center of the condensing lens 4. .

A lens driving device 8 is attached to the 7C condenser lens 4 so that it can move back and forth and parallel to the optical path direction of the laser beam 3A.

Next, the operation of the above unbalance correction method for a rotating body will be explained.

According to the above embodiment, after the unbalance of the C rotating body is corrected by the conventional laser unbalance correcting method, the condenser lens 4 is moved horizontally by the lens driving device 8 (positioned so as to shift the focal position). Then, the pulsed laser beam 3A is irradiated onto the C rotating body 1 through the condenser lens 4 and the protective crow 5.Normally, the laser beam 3A that has passed through the condenser lens 4 has a power density at the focal position of the condenser lens 4. is the maximum and the beam diameter is the minimum, so by moving the focal point of the condenser lens 4 back and forth from the surface of the rotating body 1,
The power density of the laser beam 3A at the surface irradiated with the laser beam decreases. As a result, the uneven surface 7 of the rotating body 1
(The laser beam 3A gives enough heat to slightly melt the uneven surface 7, and as a result, as shown in FIG. 4, it melts slightly and does not vaporize, so the unevenness on the surface of the rotating body 1 disappears.) A smooth ground surface 9 is thus formed.

In this case, the condenser lens 4 is positioned so that the above can be achieved.

Similarly, the same effect can be obtained by limiting the output of the laser generator 2 alone. A similar effect can be obtained even when the laser generator 2 and lens drive device 8 are combined. Furthermore, by moving the condensing lens 4, the beam diameter of the laser beam 3A is expanded and becomes larger, so that a wider area of the surface of the rotating body 1 can be processed, leading to a reduction in processing time.

[Effects of the Invention] The method for correcting unbalance of a rotating body according to the present invention has the following excellent effects.

■ The uneven surface of the grinding part formed by laser beam irradiation on the surface of the rotating body evaporates and becomes smooth, and the smoothed surface makes it difficult for foreign matter to adhere to the grinding part. This prevents the balance from being lost.

- By removing the uneven surface formed on the grinding part of the surface of the rotating body, stress concentration becomes less likely to occur, and damage to the rotating body due to stress concentration is eliminated, which helps improve safety.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of a device used to explain the conventional unbalance correction method for a rotating body. 4 is a conceptual diagram of an apparatus for explaining an embodiment of the method for correcting unbalance of a rotating body according to the present invention, and FIG.
FIG. 7 is a cross-sectional view showing the surface state of the rotating body afterward. 1......Rotating body 2...Laser generator 3.3A.
・・Laser beam 4・・・・・・・・・・Condensing lens 5・・・・・・
...Protective glass a, 7A...Uneven surface

Claims (1)

[Claims] (1) After correcting the balance by irradiating the balance correction part on the surface of the rotating body with a pulsed laser beam through a focusing lens, the focal length position of the focusing lens is moved. ←− of the overlapping rotating body, characterized by irradiating the balance correction portion of the rotating body with a pulsed laser beam whose power density is adjusted to be lower than that during the irradiation.
unbalance correction method.