JPS6050298B2 - Dynamic balance adjustment device for rotating bodies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for adjusting the dynamic balance of a rotating body by removing unbalanced parts of the rotating body using a laser beam, and particularly for improving processing quality and processing efficiency. The present invention relates to a dynamic balance adjustment device for a rotating body.

Conventionally, there is a device that adjusts the dynamic balance of a rotating body by rotating a rotating body such as a cylindrical body, detecting an unbalanced portion thereof, and removing the unbalanced portion by irradiating the unbalanced portion with a laser beam.

In this type of apparatus, in order to perform accurate adjustment, the rotational speed of the rotating body is usually changed stepwise in the order of low speed, medium speed, and high speed, and processing is performed at each speed. In order to keep the removal amount uniform at each speed, the laser beam irradiation conditions are set to a narrow pulse width and high peak output at high speeds, and a wide pulse width and low peak output at low speeds. There is. However, when removal processing is performed under the above irradiation conditions, the irradiation spot of the laser beam stays at the same processing point of the rotating body for a long time, especially at low speeds, and this causes a weak heat-affected layer on the surface of the rotating body. may be formed.

This heat-affected layer is extremely undesirable because it may break during medium or high speed rotation, leading to damage to the rotating body. For this reason, a method has been considered that involves repeatedly generating a laser beam with a narrow pulse width to remove a large number of dots only when processing at low speeds.

However, in such a method, a large number of dot-shaped machining marks are formed in the machined area, so that the surface of the rotating body is not flat, resulting in a deterioration in quality. In addition, in the above-mentioned dot-like machining, it takes a lot of time to obtain a predetermined removal amount, and the machining efficiency cannot be improved. The present invention has been made in view of the above circumstances, and its purpose is to suppress the generation of a heat-affected layer in the low-speed rotation region to a low level, and to enable high-quality machining with high machining efficiency. An object of the present invention is to provide a dynamic balance adjustment device for a rotating body.

In the present invention, a reflective optical system that scans the laser beam is provided in the optical path of the laser beam, and the scanning speed of the reflective optical system is varied according to the rotational speed of the rotating body, so that the irradiation spot of the laser beam on the rotating body is The above object is achieved by keeping the moving speed constant regardless of the rotational speed of the rotating body.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a schematic configuration diagram of the dynamic balance adjustment device in the same embodiment, and numeral 1 in the figure indicates a thin-walled cylindrical body as a rotating body. This thin-walled cylindrical body 1 has a shaft 2 swingably supported via a bearing 3 and a spring 4, and is rotationally driven by an electric motor 5. The electric motor 5 is driven and controlled by a motor drive circuit 6. Thus, the thin-walled cylindrical body 1 rotates at a predetermined speed, and if there is a weight imbalance with respect to the rotation axis at this time, it vibrates in that direction. The signal processing unit 7 generates vibration detection signals ASl and AS detected by the vibration detectors 8, 8.
2 and the rotational phase signal BS detected by the phase detector 9, the position of the unbalanced part existing in the thin-walled cylindrical body 1 is detected from these signals, and the position of the unbalanced part existing in the thin-walled cylinder 1 is irradiated with a laser beam. Generates a processing timing signal CS. On the other hand, the laser beam generator 10 includes a laser oscillator 11
a reflecting mirror 13 that deflects and scans the laser beam 12 generated by the oscillator 11; and a condensing lens that focuses the laser beam 12 reflected by the reflecting mirror 13 and irradiates it onto the surface of the thin cylinder 1. It consists of 14. Each of these parts and equipment is mounted on a moving table 15, and is moved by arrow A according to instructions from a table drive control circuit 16.
It is designed to move in the direction. By the way, the reflecting mirror 13 is fixed to the scanner 17. The scanner 17 rotates the laser beam 12 so as to scan the thin-walled cylindrical body 1 in the counter-rotational direction.

The drive control circuit 18 generates a scan control signal DS in synchronization with the reference pulse signal generated by the oscillator 19, and controls the drive of the scanner 5a 17 and the gate circuit 23 using this signal DS. This gate circuit 23
The laser oscillator 11 is activated only during the period in which the scanning control signal DS and the processing timing signal from the signal processing circuit 7 are respectively generated.
With such a configuration, when the motor drive circuit 6 sets the rotational speed and rotates the thin-walled cylindrical body 1, vibration is generated by the unbalanced portion, and the position of the unbalanced portion is detected from this vibration. , a laser beam 12 is applied to this unbalanced part.
The processing timing signal C is sent from the signal processing circuit 7 to irradiate the
S is output.

On the other hand, when the rotational drive speed of the thin-walled cylinder 1 is also set in the oscillator 19 and a reference pulse signal is generated according to this set speed, the scanning control signal DS is generated from the drive control circuit 18 and the reflecting mirror 13 is It is rotated at a predetermined speed corresponding to the rotational drive speed of the cylindrical body 1.

At the same time, the scanning control signal DS is transmitted to the gate circuit 23.
is opened, and the processing timing signal CS from the signal processing circuit 7 is supplied to the laser oscillator 11 to energize it. As a result, a laser beam 12 is output from the laser oscillator 11, and this laser beam 12 is deflected and scanned by a reflecting mirror 13, then focused by a lens 14, and irradiated onto an unbalanced portion of the thin cylinder 1. Figure 2 shows the irradiation state.
That is, the reflecting mirror 13, which was in the state shown by the solid line (A) in the figure at the start of irradiation with the laser beam 12, moves toward the arrow B at a predetermined speed.
rotate in the direction. Therefore, the laser beam 12 is scanned in the direction of arrow C from the solid line (A)'' according to the rotational movement of the reflecting mirror 13, and scanned for the pulse output time of the processing timing signal CS, and one irradiation is completed. Note that the two-dot chain lines ◎ and ◎'' in the figure indicate the positions of the reflecting mirror 13 and the laser beam 12 at the end of irradiation. On the other hand, at this time, the thin cylindrical body 1 is rotating in the direction of arrow D. Therefore, the position of the irradiation spot of the laser beam 12 on the thin cylinder 1 moves at a speed corresponding to the vector sum of the rotation speed of the thin cylinder 1 and the scanning speed of the laser beam 12 by the reflecting mirror 13, As a result, the locus of movement is removed. In Figure 3, the moving table 15 is moved to shift the position to multiple locations (four locations in the figure).
This shows the case where the above-mentioned removal process is applied to the thin-walled cylinder 1. At this time, if the rotational peripheral speed of the thin-walled cylindrical body 1 is Vrl, and the scanning speed of the laser beam 12 is Vm, the moving relative speed of the irradiation spot VLB is VLB=(■r+Vm ) becomes.

Therefore, if the scanning speed Vm of the laser beam 12 is varied so as to keep this VLB constant, the thin cylindrical body 1
It is possible to keep the moving speed of the irradiation spot of the laser beam 12 constant in any rotational speed range.

That is, when the rotational speed of the thin-walled cylindrical body 1 is relatively low, the scanning speed m of the laser beam 12 is set high, and when the rotational speed is high, the scanning speed m is set low. As a result, the laser beam 12
By keeping the pulse output time and output level constant during the entire machining process, the amount removed by machining and the size of the machining trajectory of the unbalanced portion can be made uniform regardless of the rotational speed of the thin-walled cylindrical body 1. In this way, with the device of this embodiment, even when the thin-walled cylindrical body 1 is rotating at a low speed, the moving speed of the irradiation spot of the laser beam 12 can be increased.
Unlike the conventional method, the irradiation spot does not stay at the same processing point for a long time, resulting in the formation of a heat-affected layer with weak properties at the processing site.

As a result, there is no fear that the thin-walled cylindrical body 1 will be damaged even if the rotation speed shifts to high speed, and balance adjustment can be performed stably. Furthermore, according to this embodiment, there is no need to perform a large number of dot-like machining as in the conventional method, and the machining removal locus can be made uniform for all, so the machined surface can be finished flat and aligned with the locus. , can provide high quality products. Also, when rotating at low speed, the laser beam 12
Since there is no need to keep the peak output level low, a large amount of machining removal can be achieved for each pulse, resulting in highly efficient adjustment work. Note that the present invention is not limited to the above embodiments.

For example, the scanning direction of the laser beam 12 is as shown in FIG.
It may also be set in the axial direction of the thin-walled cylindrical body 1 as shown in FIG. In addition, in the above embodiment, the relative speed was controlled to be constant in the direction of increasing the speed using the scanning device, but since the rotating body was moving at a high speed compared to the pulse width of the laser, it was necessary to remove a predetermined thin-walled cylinder during oscillation. It is clear that when machining is performed over an area wider than the machining part, it is also possible to scan the scanning spot in a direction that follows the rotational direction of the rotary body, thereby keeping the relative scanning speed constant and making the machining range of the thin-walled cylinder constant. It is. Furthermore, as the reflective optical system, a reflective prism or the like may be used in place of the reflective mirror, and the means for generating the scanning control signal DS, the type of rotating body, etc. may be modified in various ways without departing from the gist of the present invention. can. As described in detail above, a reflective optical system that scans the laser beam is provided in the laser beam irradiation optical path, and the scanning speed of this optical system is varied according to the rotational speed of the rotating body to irradiate the laser beam on the rotating body. According to the present invention, in which the relative speed of the spot is controlled to be constant regardless of the rotational speed of the rotating body, the generation of a heat-affected zone in the low-speed rotation region can be suppressed to a low level, and the machining efficiency can be increased. It is possible to provide a dynamic balance adjustment device for a rotating body that enables quality processing.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a dynamic balance adjustment device according to an embodiment of the present invention, Figs. 2 and 3 are used to explain the operation of the adjustment device, and Fig. 2 shows the state of laser beam irradiation. FIG. 3 is a schematic diagram showing a machining state, and FIGS. 4 and 5 are schematic diagrams showing a machining state in other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Thin cylindrical body, 11... Loser oscillator, 12... Loser beam, 13... Reflecting mirror, 14... Lens.

Claims (1)

[Claims] 1 A method of rotating a rotating body in which the rotational speed is changed in multiple stages and a laser beam is applied to the peripheral surface of the rotating body in a planar manner at each speed, thereby removing unbalanced parts and adjusting the dynamic balance of the rotating body. A dynamic balance adjustment device includes a reflective optical system disposed in the irradiation optical path of a laser beam and deflects and scans the laser beam, and a scanning speed of the reflective optical system that is varied according to the rotational speed of a rotating body. 1. A dynamic balance adjustment device for a rotating body, comprising a scanning control circuit that controls the relative moving speed of a laser beam irradiation spot to be constant over the entire rotational speed range of the rotating body.