JPS61218822A - Rotor shaft for compressor with laser quenched surface and manufacture thereof - Google Patents

Abstract

PURPOSE:To quench the surface of a crank spirally or concentrically by turning a roller shaft eccentrically making the center line of a crank as the turning center and moving it up and down while keeping the distance between a laser beam and the surface of the crank constant. CONSTITUTION:A jig 13 holding a roller shaft 1 is fitted on a rotary block 12 which has been fixed on a movable block 11 equipped with a mechanism capable of moving vertically at a given velocity on a level block 10 so that the center line of the jig is shifted from the center line of the rotary block 12 by the eccentric distance l between the center line of the shaft 1 and that of the crank 2. Consequently, the prescribed distance t between the surface of the crank 2 and a laser beam 14 during turning of the rotary block is kept constant. The laser beam 14 is set to be in line with the position of the upper end surface of the crank 2, and the rotary block 12 is turned at a given velocity, and at the same time the movable block 11 rises at a given velocity. Accordingly, since the crank 2 rises and turns at a given velocity while receiving the irradiation of laser beam 14, the surface of the crank 2 receives a spiral irradiation of a given pitch.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a rotor shaft of a four-tary compressor.
In particular, the wear resistance of the crank part has been improved. -Relating to a shaft and a method for manufacturing the same.

(Conventional technology and problems) The compressor uses a reciprocating system in which a piston moves reciprocatingly within the cylinder chamber, and a roller that rotates eccentrically within the cylinder chamber. There is a rotary type compressor, but compared to the reciprocating type compressor, which has a complicated structure and many parts, the rotary type compressor is smaller, lighter, and simpler, and is widely used.

．． As shown in Figures 1 and 2, a rotary compressor consists of a cylinder (A) that has a cylindrical space inside, and a cylinder chamber (B) that is formed by side plates (ZL) that seal both sides of the cylinder. It consists of a rotorsha 7) (1) having a crank @ with an eccentric center, a roller (2) in sliding contact with the crank part @, and a blade (support) in sliding contact with the outer peripheral surface of the roller By rotating the rotor ■ eccentrically in the cylinder chamber (→) through the crank part (goods), the blades (a) are raised and lowered, and air is drawn into the cylinder through the intake hole (b) partitioned by the blades (a). compresses the gas etc. in the chamber) and releases the compressed gas through the discharge hole (
7) is discharged from the cylinder chamber (b).

The inner circumferential surface of the roller ■ is in sliding contact with the outer circumferential surface of the crank ■ of the rotor shaft V), and the outer circumferential surface of the roller seven is in sliding contact with the outer circumferential surface of the crank ■ of the rotor shaft V).
B) is in sliding contact. Since the roller ■ comes in sliding contact with both the inner and outer circumferential surfaces, wear resistance is particularly required, and mRa is reduced by quenching and tempering.
It is hardened to around 30%.

On the other hand, the rotor shirt (1) is one of the most expensive compressor components, and has excellent wear resistance and
The material is selected based on strength, sliding properties, and ease of joining with the crank part, but due to cost considerations, regular cast iron has traditionally been used, which reduces wear on the surface of the crank as it slides against the hard rotor. This had problems such as significantly shortening the life of the compressor.

Solving that problem has a wide range of applications. Fully quenching of the roller shaft material is an urgent need for rotary compressors as a wear-resistant measure.

■Only the crank part is hardened using high frequency, etc.

■Methods such as adding alloy materials such as Or and M6 to the roller shaft material have been proposed, but these have not achieved the desired effect despite the large increase in processing costs and material costs. .

(Means for solving the problems) The present invention is a conventional method. In order to effectively solve the problems of rotary compressors, we use the high-output 00 Loser, which has been used in a variety of industrial applications in recent years, and take advantage of the highly economical characteristics of laser hardening! -7.

The roller shaft is rotated eccentrically around the center of the crank to move it up and down while keeping the distance between the laser beam and the crank surface constant.

The laser beam is set and irradiated on the upper end surface (or lower end surface) of the crank. The crank rotates at a constant speed and moves up (or down) at a constant speed. Therefore, the crank surface is irradiated with the beam in a spiral shape with a constant pitch and is hardened.

As is well known, since the laser is a pulse wave, the irradiation time can be freely selected, and the shape of the hardened portion, the distance between the hardened parts, and the ratio of the hardened area can be freely selected.

Further, the size of the hardened portion can be arbitrarily selected by changing the energy density per unit area depending on the aperture amount of the laser beam.

Moreover, the shape of the hardened portion is of course not limited to a spiral shape, but can also be made concentric by moving up and down by a predetermined pitch with each rotation of the crank.

When irradiated with a laser beam, the irradiated surface inevitably bulges out and creates irregularities on the surface, so these portions are removed by polishing to create a smooth circumferential surface.

(Example) Embodiments of the present invention will be described below with reference to the drawings. .

As shown in FIG. In 2), the jig (/3) that grips the roller shaft has an eccentricity E1) between the center of the roller shaft and the center of the crank from the center of the rotary disk.
It is installed eccentrically.

Thereby, the predetermined distance III(t) between the surface of the crank O and the laser beam due to rotation is kept constant.

Grip the roller shaft Q) in the jig (/j). The laser beam is set to match the position of the upper end face of the crank. The rotary disk (/must) rotates at a constant speed and the movable disk (//) rises at a constant speed.Therefore, the crank ■ rotates at a constant speed and rises at a constant speed while being irradiated by the laser beam. Therefore, the crank surface is irradiated in a spiral pattern at a constant pitch.The crank surface irradiated with the laser bulges and creates unevenness, which is removed by polishing to create a smooth surface.

Also, after irradiating the laser beam while rotating the crank,
It is also easy to irradiate and harden concentrically by repeating irradiation after raising/turning by a predetermined pitch.

This implementation was carried out under the following conditions.

Output -21cws using 3KW OO2 laser device
Quenching speed 22 m/mm, 1rm in laser beam light
ms bitch jmm A cross-sectional view of the crank in its hardened state! If
FIG. 5 shows the cross-sectional hardness distribution.

The quenching area at the center ((turn) part of the beam irradiation is deep and the peripheral part (E) is shallow, 0.4Lrnrn and 0.2rn, respectively.
It was m. Also, the hardness (MMV) + 1 center part (A) is approximately 6
Compared to male O, peripheral part (B) j is lower at 70.

Hardened layers (4) and (2) having different depths and hardnesses are formed continuously in the circumferential direction and alternately in the axial direction.

Due to the hardness difference between the central part (4) and the peripheral part (B), during actual operation, the difference in wear resistance causes the peripheral part (B) to wear out more than the central part (A), resulting in a recess. The recess functions as an oil reservoir, improving lubricity and further improving wear resistance.

FIG. 6 shows the results of a wear test on a product hardened by the laser beam of the present invention. The wear amount of the conventional product that is not hardened is 21 m.
In contrast to g, the hardened product of the present invention achieves a large reduction in Jmg, and the wear amount of the mating roller hardened product is 0.2.2 mm, which is 0.77 m, which is the same as that of the rotor shaft. A remarkable effect was obtained in that there was less wear due to the influence of the reduction in the amount of friction powder due to the reduction, and the wear of the mating o-lar was also reduced.

This test was conducted using an Okoshi type abrasion tester using a dry friction method with a final load of 22 mm, a friction speed of 0.301 m/a, and a friction distance of M2.
O0rn, the test piece used a ring with outer diameter x inner diameter x thickness -30 x 2≠XJmm as the crank material, and a rectangular plate with width x length x thickness -jO x 30X/(7 mm) as the mating roller material.

Effect: We use a conventional inexpensive ordinary sabot for the base material of the roller shaft, and the crank surface is irradiated with a laser beam to form a quenched hardened layer that is continuous in the circumferential direction and discontinuous in the rotational direction, making it wear resistant. The durability of the roller shaft has been completely improved. The lifespan of rotary compressors is greatly extended. The practical effect of this method is that it is possible to provide a roller shaft with excellent wear resistance easily and inexpensively with less man-hours than changing the material of the p-rash shaft or hardening with high frequency.

[Brief explanation of the drawing]

Figure 1 is. An illustrative front partial cross-sectional view of the main parts of a rotary compressor. FIG. 2 is a partially sectional illustrative view of the side surface of the same as above. FIG. 3 is an explanatory cross-sectional view of the crank part in a hardened state. Figure 4 is a comparison diagram of the amount of wear between the conventional product and the hardened product.

Claims (2)

[Claims] 1. Laser hardening is applied to the crank surface of the rotor shaft of a rotary compressor to create a highly hardened layer with a deep hardened layer and a hardened layer with a shallow hardened layer and a slightly lower hardness, either continuously or discontinuously in the circumferential direction, and in the axial direction. A rotor shaft for a compressor, characterized in that the rotor shaft is formed discontinuously and alternately. 2. A highly hardened layer with a deep hardened layer and a hardened layer with a shallow hardened layer and a slightly lower hardness are formed by laser hardening on the crank surface of the rotor shaft of a rotary compressor, either continuously or discontinuously in the circumferential direction, or discontinuously in the axial direction. A method for manufacturing a rotor shaft, which is characterized in that the rotor shaft is rotated eccentrically around the center of the crank while being moved up and down, and the surface of the crank is irradiated and hardened with a laser.