JP2012094556A - Gas laser oscillation device and gas laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas laser oscillation device in which maintenance of blowing means of the gas laser oscillation device is eliminated by preventing the bearing wear due to lack of grease of the blowing means.SOLUTION: In the gas laser oscillation device, grease replenishment means is provided in the vicinity of the bearing of the blowing means. The gas laser oscillation device includes grease amount detection means that detects a grease amount encapsulated in the bearing directly or indirectly, automatic replenishment of grease can be performed as appropriate using a vacuum force, etc. by the pressure difference between the external and internal of the blowing means based on a signal detected by grease amount detection means or based on a preset amount according to an operation time.

Description

  The present invention relates to a gas laser oscillation device and a gas laser processing machine which are mainly used for sheet metal cutting and welding.

  FIG. 5 shows an example of a schematic configuration of a conventional axial flow type gas laser oscillation apparatus. Hereinafter, a conventional axial gas laser oscillator will be described with reference to FIG.

  In this figure, reference numeral 901 denotes a discharge tube made of a dielectric such as glass, and reference numerals 902 and 903 denote electrodes provided around the discharge tube. Reference numeral 904 denotes a power source connected to the electrode. Reference numeral 905 denotes a discharge space in the discharge tube 901 sandwiched between the electrodes 902 and 903. Reference numeral 906 denotes a total reflection mirror, and reference numeral 907 denotes a partial reflection mirror. The total reflection mirror 906 and the partial reflection mirror 907 are fixedly disposed at both ends of the discharge space 905 to form an optical resonator. Reference numeral 908 denotes a laser beam output from the partial reflection mirror 907. An arrow 909 indicates a laser gas flow, and circulates in the axial flow type gas laser oscillation device. Reference numeral 910 denotes a laser gas flow path, reference numerals 911 and 912 denote heat exchangers for lowering the temperature of the laser gas whose temperature has risen due to discharge in the discharge space 905 and operation of the blower, and reference numeral 913 denotes blowing means for circulating the laser gas. A gas flow of about 100 m / sec is obtained in the discharge space 905 by the means 913. The laser gas flow path 910 and the discharge tube 1 are connected by a laser gas introduction part 914.

  FIG. 6 shows an example of a schematic configuration of a conventional sheet metal cutting laser processing machine. Hereinafter, a conventional laser beam machine will be described with reference to FIG.

  In this figure, the laser beam 908 is reflected by the reflecting mirror 915 and guided to the vicinity of the work 916. The laser beam 908 is condensed into a high-density energy beam by a condensing lens 918 provided inside the torch 917, irradiated onto the workpiece 916, and cutting processing is performed. The workpiece 916 is fixed on the machining table 919, and the X-axis motor 920 or the Y-axis motor 921 moves the torch 917 relative to the workpiece 916 so that a predetermined shape is machined.

  The above is the configuration of the conventional gas laser oscillation device and gas laser processing machine. Next, the operation will be described.

  The laser gas sent out from the blower 913 passes through the laser gas flow path 910 and is introduced into the discharge tube 901 from the laser gas introduction part 914. In this state, discharge is generated in the discharge space 5 from the electrodes 902 and 903 connected to the power source 904. The laser gas in the discharge space 905 is excited by obtaining this discharge energy, and the excited laser gas is brought into a resonance state by an optical resonator formed by the total reflection mirror 906 and the partial reflection mirror 907, and the laser is emitted from the partial reflection mirror 907. A beam 908 is output. This laser beam 908 is used for applications such as laser processing.

  FIG. 7 shows a configuration example of a conventional blowing means. The motor rotor 922 is coupled to the rotation shaft 923, and an impeller 924 is provided at the tip of the rotation shaft 923. A motor stator 926 is disposed coaxially with the motor rotor 922, and the motor stator 926 is fixed to the support member 925. When AC power is supplied from the outside to the motor stator 926, the motor rotor 922 is rotated by the generated rotating magnetic field, and the impeller 924 is rotated via the rotating shaft 923. A laser gas flow 909 is generated by the rotation of the impeller 924.

  The rotating shaft 923 is supported in a rotatable state by bearings 928 arranged at two locations on the upper and lower sides. The bearing 928 is coupled to the rotating shaft 923. The structure of the air blowing means 913 is divided into a rotating part and a non-rotating part, and the rotating part is composed of the motor rotor 922, the rotating shaft 923, the impeller 924 and the bearing 928.

  The outer periphery of the bearing 928 is coupled to a support member 925 that is a non-rotating portion. The bearing 928 contains grease 929 for lubrication.

An example of a conventional technique relating to bearing lubrication is one in which grease replenishment and recovery means are provided in the vicinity of the bearing (see, for example, Patent Document 1).
JP 2005-221042 A

  However, the gas laser oscillation device according to the above prior art has the following problems.

  In the gas laser oscillation device, the air blowing means 913 is one of the regular replacement parts at the user's site. The bearing 928 has the shortest life in the blower 913, and the life of the bearing 928 depends on the amount of the grease 929. Generally, since the grease 929 is a volatile substance, the grease 929 decreases with time. When the grease is reduced, the lubrication performance is lowered, the wear of the bearing 928 is advanced, and the life is reached.

  Originally, if grease can be appropriately supplied to the bearing 928, it is possible to extend the life, but it is difficult to implement at the user's site. Alternatively, if only the bearing is replaced, the blowing means 913 recovers its function, but in order to remove the bearing 928, the entire blowing means 913 is replaced. Therefore, it is necessary for the user to bear the replacement cost of the entire air blowing means 913, resulting in an increase in the cost of periodic inspection costs.

  That is, due to the extension of the life of the bearing 928, the replacement frequency of the air blowing means 913 has been reduced, and the reduction of the periodic inspection cost has been a major issue.

  Further, the technique as disclosed in Patent Document 1 cannot cope with the decrease in grease over time according to the degree of use of the air blowing means.

  In order to solve the above problems, a gas laser oscillation apparatus of the present invention includes a discharge unit that excites laser gas as a laser medium, a blower unit that blows laser gas, and a laser gas between the discharge unit and the blower unit. A gas laser oscillating device comprising a laser gas path forming a circulation path, wherein the blower means is coupled to a rotating shaft provided with an impeller portion at a tip thereof, a driving unit for rotating the rotating shaft, and the rotating shaft A plurality of bearings, grease sealed in the bearings, a grease supply mechanism for supplying grease to the bearings, and a grease amount detection means for directly or indirectly detecting the amount of grease sealed in the bearings. The replenishment is performed according to the amount of grease.

  Alternatively, the gas laser oscillation device is characterized in that a predetermined amount of grease is replenished every predetermined time.

  With the configuration shown in the present invention, it is possible to extend the life of the bearing of the air blowing means, reduce the replacement frequency of the air blowing means, and reduce the periodic inspection cost.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an example of a schematic configuration of an axial flow type gas laser oscillation apparatus of the present invention.

  The axial flow type gas laser oscillation apparatus 100 includes a discharge tube 101, electrodes 102 and 103, a power source 104, a total reflection mirror 106, a partial reflection mirror 107, a laser gas flow path 110, heat exchangers 111 and 112, a blower means 113, and a laser gas introduction section 114. Is provided as a configuration thereof.

  The discharge tube 101 is made of a dielectric material such as glass. The electrodes 102 and 103 are provided around the discharge tube 101, and a power source 104 is connected to each of the electrodes 102 and 103. A discharge space 105 is formed in the discharge tube 101 sandwiched between the electrode 102 and the electrode 103. The total reflection mirror 106 and the partial reflection mirror 107 are fixedly arranged at both ends of the discharge space 105 to form an optical resonator. An arrow 108 symbolically represents the laser beam output from the partial reflection mirror 107.

  An arrow 109 indicates a laser gas flow, and circulates through a laser gas flow path 110 in the axial flow type gas laser oscillation device. The heat exchanger 111 and the heat exchanger 112 lower the temperature of the laser gas whose temperature has risen due to the discharge in the discharge space 105 and the operation of the blower. The air blowing means 113 is for circulating laser gas, and a gas flow of about 100 m / sec is obtained in the discharge space 5 by the air blowing means 113. The laser gas channel 110 and the discharge tube 101 are connected by a laser gas introduction unit 114.

  The above is the configuration of the gas laser oscillator 100 of the present invention. Next, the operation will be described.

  The laser gas sent out from the blowing means 113 passes through the laser gas flow path 110 and is introduced into the discharge tube 101 from the laser gas introduction unit 114. In this state, a discharge is generated in the discharge space 105 from the electrodes 102 and 103 connected to the power source 104.

  The laser gas in the discharge space 105 is excited by obtaining this discharge energy, and the excited laser gas is brought into a resonance state by an optical resonator formed by the total reflection mirror 106 and the partial reflection mirror 107, and the laser is emitted from the partial reflection mirror 107. A beam 108 is output. This laser beam 108 is used for applications such as laser processing.

  FIG. 2 shows in detail an example of the configuration of the blowing means installed in the laser gas flow path 110. In this figure, the motor rotor 122 is coupled to a rotating shaft 123, and an impeller 124 is provided at the tip of the rotating shaft 123. A motor stator 126 is disposed coaxially with the motor rotor 122, and the motor stator 126 is fixed to the support member 125.

  The support member 125 supports each member constituting the air blowing means 113 with respect to the outer wall 110a of the laser gas flow path 110, and is formed so as to secure the flow path of the laser gas flow 109.

  When AC power is supplied to the motor stator 126 from an external wiring (not shown), the motor rotor 122 is rotated by the generated rotating magnetic field, and the impeller 124 is rotated via the rotating shaft 123. A laser gas flow 109 is generated by the rotation of the impeller 124. The rotating shaft 123 is supported in a rotatable state by bearings 128 arranged at two locations above and below.

  The structure of the air blowing means 113 is divided into a rotating part and a non-rotating part, and the rotating part is composed of the motor rotor 122, the rotating shaft 123, the impeller 124 and the inner ring of the bearing 128. The inner ring of the bearing 128 is press-fitted to the rotary shaft 123 and the outer ring is press-fitted to the support member 125 and fixed.

  A grease supply mechanism 130 is disposed adjacent to each of the plurality of bearings 128. Grease 129 is enclosed in the bearing 128. Since there is a gap between the bearing 128 and the outside due to the structure, it is inevitable that grease will volatilize and decrease over time through the gap. When the grease is decreased, the friction performance of the bearing is increased due to a decrease in lubrication performance, and heat generation and vibration are increased. In order to prevent this, the grease supply mechanism 130 supplies the reduced amount of grease.

  The grease replenishment control device 132 detects and replenishes grease. For this purpose, a grease supply path 135 is provided between the grease supply control device 132 and the grease supply mechanism 130. Various means for replenishing grease are conceivable, but a method using vacuum force is used as an example. In the gas laser oscillation device, the gas circulation path including the inside of the blowing means is in a reduced pressure state. On the other hand, the outside of the blowing means is in the atmosphere. Therefore, it is possible to introduce grease into the inside using a vacuum force due to a pressure difference between the outside and the inside of the air blowing means.

  As a different control means for supplying the grease 129, the amount of decrease in grease over time is recorded in advance in the grease replenishment control device 132, and control for replenishing the bearing 128 with a predetermined amount of grease according to the operation time is performed. May be.

  Next, FIG. 3 is an example of a different embodiment of the present invention, and is a configuration diagram of the air blowing means 113 of the gas laser oscillation device. With respect to FIG. 2, the same components are denoted by the same reference numerals, and the description thereof is omitted.

  In this figure, a temperature sensor 131 is provided in the vicinity of the bearing 128, and the temperature sensor 131 and the grease supply mechanism 130 are both connected to the grease supply control device 132. When the grease evaporates over time and decreases, the temperature sensor 131 detects an increase in the bearing temperature due to heat generation, and sends a signal to the grease replenishing mechanism 130 by comparison with a preset value to replenish the grease to the bearing 128. I do.

  Next, FIG. 4 is an example of a different embodiment of the present invention, and is a configuration diagram of the air blowing means 113 of the gas laser oscillation device. With respect to FIG. 2, the same components are denoted by the same reference numerals, and the description thereof is omitted.

  In this figure, the support member 125 is provided with a vibration sensor 133, and the vibration sensor 133 and the grease supply mechanism 130 are both connected to the grease supply control device 132. When the grease evaporates and decreases with time, the vibration sensor 133 detects an increase in vibration, and sends a signal to the grease replenishing mechanism 130 by comparison with a preset value to replenish the bearing 128 with grease.

  In the present embodiment, the example in which the air blowing means 113 is installed in the laser gas flow path 110 is shown. However, the portion near the air blowing means in the outer wall 110a of the laser gas flow path is made detachable from the entire apparatus. In addition, the illustrated portion of the laser gas flow path may be installed as a unit.

  Further, in the case of unitization, the laser gas flow path may be formed into a unit in such a form that only members that generate a laser gas flow, for example, the rotating shaft 123 and the impeller 124 are installed in the laser gas flow path. . In this way, the influence of grease on the laser gas can be reduced, and the ease of maintenance of the blowing means can be improved.

  According to the configuration of the present invention described above, an appropriate amount of grease can be appropriately supplied to the bearing of the blowing means, thereby extending the life of the bearing, reducing the replacement frequency of the blowing means, and reducing the periodic inspection cost. It becomes possible.

  The gas laser oscillating device and gas laser processing machine according to the present invention can reduce the necessity of maintenance of the air blowing means by automatically replenishing grease to the bearing, greatly reduce the periodic inspection cost of the entire device, and have high cost performance. It is useful as an oscillation device and a gas laser processing machine.

Schematic configuration diagram of a gas laser oscillation apparatus according to an embodiment of the present invention Sectional drawing which shows the structure of the 1st example of the ventilation means which concerns on embodiment of this invention Sectional drawing which shows the structure of the 2nd example of the ventilation means which concerns on embodiment of this invention Sectional drawing which shows the structure of the 3rd example of the ventilation means which concerns on embodiment of this invention Configuration diagram of gas laser oscillation device according to prior art Configuration diagram of a gas laser processing machine according to the prior art Configuration diagram of blower in gas laser oscillation device according to prior art

DESCRIPTION OF SYMBOLS 100 Gas laser oscillator 101 Discharge tube 102 Electrode 103 Electrode 104 Power supply 105 Discharge space 106 Total reflection mirror 107 Partial reflection mirror 108 Laser beam 109 Laser gas flow 110 Laser gas flow path 110a Outer wall of laser gas flow path 111 Heat exchanger 112 Heat exchanger 113 Air blowing Means 114 Laser gas introduction part 122 Motor rotor 123 Rotating shaft 124 Impeller 125 Support member 126 Motor stator 128 Bearing 129 Grease 130 Grease replenishment mechanism 131 Temperature sensor 132 Grease replenishment control device 133 Vibration sensor 135 Grease replenishment path

Claims (6)

A gas laser oscillating apparatus comprising: discharge means for exciting laser gas as a laser medium; blower means for blowing laser gas; and a laser gas path forming a laser gas circulation path between the discharge means and the blower means. ,
The air blowing means includes a rotating shaft provided with an impeller portion at a tip thereof, a driving unit that rotates the rotating shaft, a plurality of bearings coupled to the rotating shaft, grease sealed in the bearing, and the bearing A gas laser oscillating apparatus comprising: a grease replenishing mechanism for replenishing grease; and a grease amount detecting means for directly or indirectly detecting the amount of grease enclosed in the bearing, and performing replenishment according to the amount of grease. 2. The gas laser oscillation apparatus according to claim 1, wherein the grease replenishing mechanism replenishes the grease by utilizing a vacuum force due to a pressure difference between the outside and the inside of the air blowing means. 3. The gas laser oscillation apparatus according to claim 1, wherein the grease amount detection means is a temperature detection means provided near the bearing. 3. The gas laser oscillation apparatus according to claim 1, wherein the grease amount detection means is vibration detection means provided near the bearing. A gas laser oscillating apparatus comprising: discharge means for exciting laser gas as a laser medium; blower means for blowing laser gas; and a laser gas path forming a laser gas circulation path between the discharge means and the blower means. ,
The air blowing means includes a rotating shaft provided with an impeller portion at a tip thereof, a driving unit that rotates the rotating shaft, a plurality of bearings coupled to the rotating shaft, grease sealed in the bearing, and the bearing A gas laser oscillation apparatus comprising a grease replenishing mechanism for replenishing grease, and replenishing a predetermined amount of grease every predetermined time. A gas laser processing machine comprising the gas laser oscillation device according to claim 1.

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