JP5423347B2 - Gas laser oscillator and gas laser processing machine - Google Patents

Description

  The present invention relates to a gas laser oscillating device and a gas laser processing machine provided with a blowing means for circulating laser gas.

  In general, the gas laser oscillation device has a pair of electrodes in a sealed casing, and the laser gas sealed in the casing is forcibly circulated by a blowing means such as a blower. The laser gas is excited by the discharge generated by the pair of electrodes, resonated by the partial reflection mirror and the total reflection mirror, and outputs laser light to the outside.

  The gas laser oscillator is used in a gas laser processing machine that performs processing by sending irradiated laser light to a processing head via a plurality of mirrors and irradiating a laser beam positioned on a work on a processing table.

  By the way, the air blowing means for circulating the laser gas in such a gas laser oscillation apparatus is configured to hold the rotating shaft connected to the impeller that blows the laser gas with a bearing, and replace the bearing after judging the life of the bearing in advance. Is required (see Patent Document 1).

  In such a bearing, when the friction inside the bearing increases due to poor lubrication or the entry of foreign matter into the interior, the bearing generates heat. Since this heat generation is a sign of failure, it is possible to perform appropriate maintenance by detecting heat generation at an early stage, and it is possible to extend the life of the bearing, that is, the life of the entire blowing means.

  Therefore, as a method for determining the bearing life of this type of blowing means, there has been a method for detecting the temperature of the bearing.

  FIG. 5 is a configuration diagram of a blowing means of a conventional gas laser oscillation apparatus, and an impeller 101 that sucks laser gas and discharges it by rotation is attached to a rotating shaft 102. A motor rotor 103 is attached to the rotating shaft 102, and a motor stator 104 is disposed at a position facing the motor rotor 103, and the motor stator 104 is fixed to the casing 105.

  In addition, an upper bearing 106 and a lower bearing 107 are arranged at two positions above and below the rotating shaft 102 between the rotating shaft 102 and the casing 105, are rotatably supported, and the casing is in contact with the outer ring of the upper bearing 106. The upper temperature detecting means 108 is disposed in the interior 105, and similarly, the lower temperature detecting means 109 is disposed in the casing 105 so as to be in contact with the outer ring of the lower bearing 107.

Japanese Patent Laid-Open No. 11-311197

  As described above, in the conventional gas laser oscillation apparatus, the upper temperature detecting means 108 and the lower temperature detecting means 109 are attached to the outer rings of the upper bearing 106 and the lower bearing 107 so as to be in direct contact with the upper bearing 106 and the lower bearing 107. Therefore, there is a high possibility that an unbalanced radial load is applied.

  The rotating body including the bearing used for the air blowing means of the gas laser oscillation device rotating at such a speed of several tens of thousands of revolutions has a dynamic balance on the order of several mmg or less in order to suppress the generation of centrifugal force due to high-speed rotation as much as possible. A rotating body that is dynamically balanced in this order is very sensitive to disturbances, and when an unbalanced radial load is applied, it adversely affects the rotation and causes an increase in vibration. As a result, the increase in vibration has shortened the service life.

  The present invention solves this problem and provides a gas laser oscillation device and a gas laser processing machine capable of determining the life of a bearing without shortening the life.

  In order to solve the above problems, a gas laser oscillation apparatus according to the present invention includes: a discharge unit that generates a discharge in a laser gas; and a blower unit that blows the laser gas to a discharge portion by the discharge unit. A non-rotating portion that does not rotate, a bearing is provided between the rotating portion and the non-rotating portion, and an elastic body that biases the temperature detecting means in the direction of the bearing; the bearing and the temperature detecting means A buffer member is disposed between the two.

  With this configuration, the bearing can absorb the external force transmitted from the outside via the temperature detection means by the buffer member, so that it is less affected by the external force and can perform more stable rotation. Since the temperature is transmitted to the temperature detecting means through the buffer member, there is no problem in the temperature detecting function, and the life of the bearing can be determined without shortening the life.

  The gas laser oscillation apparatus of the present invention further includes a discharge unit that generates a discharge in the laser gas, and a blower unit that blows the laser gas to a discharge portion of the discharge unit, and the blower unit does not rotate with the rotating unit. A non-rotating portion, a bearing between the rotating portion and the non-rotating portion, a sliding member arranged coaxially with the rotating portion and freely slidable in the axial direction, and the sliding member of the bearing An elastic body that is pressed against the outer ring is provided, and temperature detecting means is disposed on the sliding member.

  With this configuration, the sliding member is coaxially and slidably arranged in the axial direction by the elastic body, so that there is no eccentricity of the rotating part, and the bearing generates minute vibrations during operation. However, the sliding member follows this vibration by the elastic body and can always contact the bearing with the same surface pressure, so that the contact can be maintained reliably, and the temperature of the sliding member is detected by the temperature detecting means. The temperature can be monitored, and the bearing life can be determined without shortening the life.

  The present invention includes one applied to a gas laser processing machine including any of the gas laser oscillators described above and a driving unit that relatively moves a laser beam irradiated from the gas laser oscillator and a workpiece.

  As described above, the present invention makes it possible to detect the temperature of the bearing in a manner that minimizes disturbance to the rotating part of the air blowing means, extends the life of the whole air blowing means, and has high reliability over a long period of time. Sex can be secured.

Configuration diagram of the air blowing means of the gas laser oscillation apparatus according to Embodiment 1 of the present invention Configuration diagram of gas laser oscillation apparatus according to Embodiment 1 of the present invention The block diagram of the ventilation means of the gas laser oscillation apparatus regarding Embodiment 2 of this invention Configuration diagram of gas laser processing machine according to Embodiment 3 of the present invention Configuration diagram of blowing means of a conventional gas laser oscillation device

  Hereinafter, embodiments for carrying out the present invention will be described with reference to FIGS. 1 to 4.

(Embodiment 1)
FIG. 1 is a configuration diagram of a blowing unit of a gas laser oscillation apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram of the gas laser oscillation apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 2, in the discharge tube 1 made of an insulator such as glass, in this embodiment, a laser gas 2 made of a mixture of nitrogen gas and helium gas containing CO2 gas as a main component is circulated as a laser gas. ing. The discharge tube 1 is provided with electrodes 3, 4, and a power source 5 is connected to the electrodes 3, 4 to form discharge means so as to generate a discharge in the discharge tube 1.

  High-speed electrons generated by this discharge excite nitrogen molecules to raise them to high energy levels, and the excited nitrogen molecules collide with the CO2 molecules and give energy to the CO2 molecules to excite them, resulting in energy levels. At that time, the energy level of nitrogen molecules decreases.

  The inversion-distributed CO2 molecules are amplified in the resonator by the total reflection mirror 6 and the partial reflection mirror 7 disposed so as to face both ends of the discharge tube 1, and stimulated emission of the laser light is performed from the partial reflection mirror 7 to the outside. The laser beam 8 is output.

  The helium gas has a cooling effect, and suppresses the temperature rise of the laser gas 2 and returns the lower level CO2 molecules not related to laser oscillation to the ground state by collision.

  A gas circulation path 9 serving as a circulation path for circulating the laser gas 2 is connected to the discharge tube 1, and a blowing means 10 for blowing the laser gas 2 is disposed in the middle of the gas circulation path 9. The laser gas 2 in the gas circulation path 9 is circulated so that a gas flow of about 100 m / sec in 1 is achieved.

  In this gas circulation path 9, a plurality of heat exchangers 11 are arranged for lowering the temperature of the laser gas 2 that has become hot due to discharge energy and compression heat after passing through the discharge and blower means 10.

  A control means 12 is connected to the blower means 10 and the power source 5 so as to control them. The control means 12 is also connected to an alarm means 13.

  As shown in FIG. 1, the blower means 10 uses a centrifugal blower means in this embodiment, and an impeller 14 that sucks the laser gas 2 and discharges it by rotation is attached to a rotary shaft 15. A motor rotor 16 is attached to the rotating shaft 15, and a motor stator 17 is disposed at a position facing the motor rotor 16, and the motor stator 17 is fixed to a casing 18.

  As described above, the air blowing means 10 is divided into a rotating part and a non-rotating part. The rotating part is composed of an impeller 14, a rotating shaft 15, and a motor rotor 16. The non-rotating part is composed of a motor stator 17 and a casing 18. Has been.

  Further, an upper bearing 19 and a lower bearing 20 of a ball bearing are arranged between the rotating part and the non-rotating part of the air blowing means 10, specifically between the rotating shaft 15 and the casing 18, and are rotatably supported. When AC power is supplied to the motor stator 17, the motor rotor 16 is rotated by the generated rotating magnetic field, and the impeller 14 is rotated via the rotating shaft 15 to blow the laser gas 2.

  Note that a portion of the upper bearing 19 that is in contact with the non-rotating portion, that is, the outer ring is brought into contact with the upper buffer member 21 made of a material having good thermal conductivity, and the upper buffer member 21 is sandwiched between the outer ring of the upper bearing 19. An upper temperature detecting means 22 is arranged, and an upper elastic body 23 for urging the upper temperature detecting means 22 in the direction of the upper bearing 19 is arranged in the casing 18.

  Similarly to the upper bearing 19, the lower cushioning member 24 made of a material having good thermal conductivity is brought into contact with a portion of the lower bearing 20 that contacts the non-rotating portion, that is, the outer ring, and the lower cushioning member 24 is brought into contact with the lower bearing 20. The lower temperature detecting means 25 is arranged at a position sandwiched between the outer ring and the lower elastic body 26 for urging the lower temperature detecting means 25 in the direction of the lower bearing 20 is arranged in the casing 18.

  Then, a signal from the upper temperature detection means 22 and a signal from the lower temperature detection means 25 are input to the control means 12, and a value corresponding to a preset temperature is compared with the input signal to compare the upper bearing 19 and the lower bearing 20. If the temperature exceeds the predetermined temperature, the power supply 5 and the air blowing means 10 are stopped and the alarm means 13 is operated to indicate that maintenance is required. To let you know.

  As described above, according to the present embodiment, the discharge means including the electrodes 3 and 4 for generating the discharge in the laser gas 2 and the power source 5 and the blower means 10 for blowing the laser gas 2 to the discharge portion by the discharge means are provided. The means 10 has a rotating part composed of an impeller 14, a rotating shaft 15, and a motor rotor 16, and a non-rotating part composed of a motor stator 17 and a casing 18, which does not rotate. An upper bearing 19 and a lower bearing 20 are provided therebetween, and an upper elastic body 23, a lower elastic body 26, and an upper bearing that urge the upper temperature detecting means 22 and the lower temperature detecting means 25 in the direction of the upper bearing 19 and the lower bearing 20. 19, an upper cushioning member 21 and a lower cushioning member 24 are arranged between the lower bearing 20, the upper temperature detection means 22, and the lower temperature detection means 25. With this configuration, the upper bearing 19 and the lower bearing 0 can absorb the external force transmitted from the outside through the upper temperature detecting means 22 and the lower temperature detecting means 25 by the upper shock absorbing member 21 and the lower shock absorbing member 24, and is less affected by the external force and more stable. In addition, the temperature of the upper bearing 19 and the lower bearing 20 is transmitted to the upper temperature detecting means 22 and the lower temperature detecting means 25 through the upper buffer member 21 and the lower buffer member 24. There is no problem, and the life of the bearing can be determined without shortening the life.

  In this embodiment, rubber O-rings are used as the upper buffer member 21 and the lower buffer member 24. However, the present invention is not limited to this, and an elastic member made of a resin material or metal having good thermal conductivity is used. It can also be used.

  In this embodiment, coil springs are used as the upper elastic body 23 and the lower elastic body 26. However, the present invention is not limited to this, and a resin elastic body such as a leaf spring or rubber can also be used.

(Embodiment 2)
FIG. 3A is a configuration diagram of the blowing means of the gas laser oscillation apparatus according to the second embodiment, and FIG. 3B is a perspective view of a sliding member to be described later. In the second embodiment, the same as the first embodiment. Constituent parts are denoted by the same reference numerals and description thereof is omitted.

  The feature of the present embodiment is that, instead of the lower cushioning member 24 and the lower elastic body 26 in the first embodiment, it is coaxial with the rotating portion, that is, coaxial with the rotating shaft 15 and slidable freely in the axial direction. The moving member 27 is disposed, and an elastic body 28 that presses the sliding member 27 against the outer ring of the lower bearing 20 at a level that does not affect the rotation of the rotating portion is provided, and the lower temperature detecting means 25 is provided on the sliding member 27. It is a point attached.

  Also in this embodiment, the signal from the upper temperature detection means 22 and the signal from the lower temperature detection means 25 are input to the control means 12, and the value corresponding to the preset temperature is compared with the input signal. It is determined whether the upper bearing 19 and the lower bearing 20 are above a predetermined temperature. If the temperature is higher than a predetermined temperature, the power supply 5 and the air blowing means 10 are stopped and the alarm means 13 is operated to perform maintenance. The operator is informed that it is necessary.

  Since the sliding member 27 is arranged coaxially and slidably in the axial direction by the elastic body 28 because it is configured in this way, the rotating part is not eccentric, and the lower bearing 20 is not operated during operation. Although minute vibrations are generated, the sliding member 27 follows this vibration by the elastic body 28 and can always contact the lower bearing 20 with the same surface pressure. Therefore, the temperature of the upper bearing 19 and the lower bearing 20 can be monitored, and the life of the bearing can be determined without shortening the life.

  In the present embodiment, a rubber O-ring is used as the upper buffer member 21, but the present invention is not limited to this, and an elastic member made of a resin material or metal having good thermal conductivity can also be used.

  In the present embodiment, a coil spring is used as the elastic body 28, but the present invention is not limited to this, and a resin elastic body such as a leaf spring or rubber can also be used.

(Embodiment 3)
The gas laser oscillation apparatus according to the first and second embodiments of the present invention having the above-described configuration can be used in the gas laser processing machine shown in FIG. 4, and the schematic configuration will be described with reference to FIG.

  In this figure, the laser beam 8 output from the gas laser oscillation apparatus according to the embodiment of the present invention described above is changed by reflecting the traveling direction in the direction of the work 29 by the reflecting mirror 30, and provided in the torch 31. The laser beam 8 is condensed into a high-density energy beam by the condensing lens 32 and irradiated onto the work 29.

  The workpiece 29 is fixed on the machining table 33, and the torch 31 is moved relative to the workpiece 29 by the driving means of the X-axis motor 34 or the Y-axis motor 35, thereby processing a predetermined shape. Is configured to do.

  The gas laser oscillation device and the gas laser processing machine according to the present invention can detect the temperature of the bearing while minimizing the disturbance to the rotating part of the air blowing means, extend the life of the whole air blowing means, It is useful as a gas laser oscillation device and a gas laser processing machine that can ensure high reliability.

2 Laser gas 3, 4 Electrode 5 Power supply 8 Laser light 10 Blowing means 14 Impeller 15 Rotating shaft 16 Motor rotor 17 Motor stator 18 Casing 19 Upper bearing 20 Lower bearing 21 Upper buffer member 22 Upper temperature detecting means 22
DESCRIPTION OF SYMBOLS 23 Upper elastic body 24 Lower buffer member 25 Lower temperature detection means 26 Lower elastic body 27 Sliding member 28 Elastic body 29 Work 34 X-axis motor 35 Y-axis motor

Claims (3)

Discharging means for generating a discharge in the laser gas, and a blowing means for blowing the laser gas to a discharge portion by the discharging means,
The air blowing means has a rotating part and a non-rotating part that does not rotate, and a bearing is provided between the rotating part and the non-rotating part, and an elastic body that biases the temperature detecting means in the direction of the bearing; A buffer member is disposed between the bearing and the temperature detecting means ;
A gas laser oscillating device comprising control means for comparing a temperature signal detected by the temperature detection means via the buffer member with a value corresponding to a preset temperature . Discharging means for generating a discharge in the laser gas, and a blowing means for blowing the laser gas to a discharge portion by the discharging means,
The air blowing means has a rotating portion and a non-rotating portion that does not rotate, and is arranged between the rotating portion and the non-rotating portion so as to be freely slidable coaxially and axially with the rotating portion. A sliding member and an elastic body that presses the sliding member against the outer ring of the bearing; and a temperature detecting means is disposed on the sliding member ;
A gas laser oscillating apparatus comprising a control means for comparing a temperature signal detected by the temperature detection means via the sliding member with a value corresponding to a preset temperature .   A gas laser processing machine comprising: the gas laser oscillator according to claim 1; and a driving unit that relatively moves the laser beam irradiated from the gas laser oscillator and a workpiece.

Images