JPH0424974A - laser oscillator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a highly reliable gas laser oscillator that generates laser light for cutting, welding, heat treatment, and the like.

2. Description of the Related Art The configuration of a typical gas laser oscillator will be explained with reference to FIG. A discharge tube group 1 consisting of one or more discharge tubes includes an anode 21L for each discharge tube.

In the example of FIG. 6, two sets of discharge tubes are formed, and the two sets of discharge tubes are arranged symmetrically to form discharge tube group 1. and power is supplied to each from the high voltage power supply 4. -! In addition, output mirrors 6. are provided at both ends of the discharge tube group 1. A termination mirror 6 is arranged to form an optical resonator. Furthermore, the cathodes at both ends of the discharge tube group 10 are used as electrodes 31L, and the anode electrodes 21L are placed near 3b and in the center.

2b are connected by an approximately X-shaped circulation tube to form a gas circulation path, and this circulation tube 7 is equipped with a blower 8 for circulating gas and a plurality of heat exchangers 9 for cooling the gas. It is set up. Further, the discharge tube group 1 includes the anodes 2a, 2b and the cathode 3 for each discharge tube! A discharge starting auxiliary ring 102L, 10b electrically connected to the anode 22L2b or the cathode 3a, 3b on the outer periphery of the discharge tube between L and 3b.
is provided.

Next, FIG. 7 shows an enlarged view of the discharge starting auxiliary ring 10 and its vicinity in a conventional example used to prevent ignition errors during pulse oscillation (state of periodic intermittent output in the form of a pulse train). The figure shows only the left half of the discharge tube group. As is clear from FIG. 7, the discharge starting auxiliary ring 10a is directly attached to the discharge tube.

Further, FIG. 8 shows a conventional connection state between the discharge starting auxiliary ring 101L and the anode 2a. As is clear from FIG. 8, the discharge starting auxiliary ring 101L
and an electric conductor 11a between the anode 2a or the cathode 3a,
11b is connected through the vicinity of the surface of the discharge tube.

In a laser oscillator configured in this way, the gas flow direction, the discharge direction, and the oscillation axis of the laser beam are coaxial, so when viewed from the optical axis direction, the discharge and the gain distribution formed by the discharge are Concentric and symmetrical. Therefore, it is said that the machining performance is good when machining is performed using the output laser light.

Problems to be Solved by the Invention However, in order to prevent ignition during pulse oscillation, the anode 2a is installed between the anode 2a and the cathode 3a and between the anode 2b and the cathode 3b.

2b or the cathode 3a, ab, the discharge starting auxiliary ring 10! L, 10b is the discharge start auxiliary ring 10! An electric field is generated around L and 10b, and the discharge contracts due to the influence of the electric field, causing discharge starting auxiliary rings 10a and 10b.
A streamer is formed in the center of the nearby discharge area. The first problem is that fluctuations in discharge current increase, laser output ripple increases, and machined surface quality deteriorates. Further, the discharge starting auxiliary rings 10a, 10b and the anode 2 are attached between the anodes 2a, 2b and the negatives 413m, 3b.
When the electric conductors 111L and 11b that are electrically connected to the cathodes 3a and 3b are connected through the discharge tube surface which is 2 mm or less from the discharge tube surface, the electric conductors 111L,
The second problem is that the discharge contracts under the influence of the electric field generated from 11b and is drawn toward the electrical conductors 111L and 11b, increasing fluctuations in the discharge current, increasing laser output ripple, and roughening the machined surface. There was an issue.

Means for Solving the Problems In order to solve the first problem, the present invention provides a discharge starting auxiliary ring connected to the anode or the cathode with an electric conductor on the outer periphery of the discharge tube between the anode and the cathode. Attach the discharge starting auxiliary ring to the outer periphery of the discharge tube with a thickness of 2ff~
It is attached via a 2off electrical insulator 12.

Furthermore, in order to solve the second problem, the present invention provides an electric conductor that connects between the anode or the cathode and a discharge starting auxiliary ring attached to the outer periphery of the discharge tube between the anode and the cathode. They are arranged with a gap of 2 mm or more between them.

Therefore, according to the present invention, there is a gap between 211f and the outer wall of the discharge tube.
Since the discharge starting auxiliary ring is attached via an electrical insulator having a thickness of f~2Qfl, the discharge current ripple rate is reduced and the machining quality is improved.

Furthermore, by arranging the electrical conductor that connects the cathode or anode and the discharge starting auxiliary ring with two or more gaps from the surface of the discharge tube, the discharge current ripple rate is reduced and the machining quality is improved.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 shows the left half of the discharge tube group, and shows an example of how to install the discharge starting auxiliary ring 101L in the present invention, and FIG. An example of a connection method using an electric conductor 112L is shown.

In FIG. 1, 12 is an electrical insulator, which serves as a spacer for the discharge starting auxiliary ring 10&. As is clear from a comparison with FIG. 7, in the present invention, the discharge starting auxiliary ring 10
a. Electric insulator 12 with a thickness of 2MM or more using 1ob as a discharge tube
Attached via, discharge start auxiliary ring 1OA, 101
) By weakening the influence of the electric field generated by the laser, the discharge current ripple rate is reduced and the laser output is further stabilized.

Figure 3 shows the relationship between the thickness of the electrical insulator 12 and the discharge current ripple rate. It can be seen that when the thickness of the faint binding material 12 becomes 2H or more, the discharge current ripple rate decreases as the thickness of the electrical insulator 12 increases. Further, FIG. 5 shows the relationship between the discharge current ripple rate and the machined surface roughness, and it can be seen that as the discharge current ripple rate increases, the machined surface roughness increases and the machined surface quality deteriorates. From the above, discharge start auxiliary ring 10! L, 10b is an electrical insulator 12 with a thickness of 2 mm or more
By attaching the discharge tube to the discharge tube via the wire, it is possible to reduce the discharge current ripple rate and improve the machined surface quality.

However, if the thickness of the electrical insulator exceeds 20 mm, the discharge starting voltage will increase, the effect of the discharge starting auxiliary ring will be lost, and ignition errors will occur, so the upper limit for the thickness of the electrical insulator is 2 ( It becomes If.

In FIG. 2, as is clear from a comparison with FIG. 8, the gap from the surface of the discharge tube of the electric conductor 11a connecting the discharge starting auxiliary ring 10a and the anode 2 or the cathode 3 is smaller than that of the conventional one shown in FIG. It can be seen that it is very large compared to the structure. By arranging the electrical conductor 11a connecting the discharge starting auxiliary ring 1oIL and the anode 2a or the cathode 3a with a gap distance of 2M or more from the surface of the discharge tube, the discharge current ripple rate can be reduced. This makes it possible to further stabilize the laser output.

Figure 4 shows the relationship between the gap distance between the connecting conductor and the surface of the discharge tube and the discharge current ripple rate.
By setting the gap distance between 11b and the surface of the discharge tube to 2ff or more, it is possible to reduce the discharge current ripple rate, and from the relationship between discharge current ripple and machined surface roughness shown in Fig. 5, the machining quality can be improved. It is clear that it is possible to improve

In addition, according to the present invention, the discharge current ripple rate is expressed by the following formula.As described above, according to the present invention, the thickness of the discharge starting auxiliary ring is 2 to 20+! ff to the discharge tube via an electrical insulator, and the electric conductor connecting the discharge starting auxiliary ring and the anode or cathode to the discharge tube surface 21R'j1
Both of these methods reduce discharge current ripple,
Processing quality can be improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing the configuration of the discharge starting auxiliary ring and the anode or cathode in one embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view showing the configuration of the discharging starting auxiliary ring and the anode or cathode in one embodiment of the present invention. A schematic cross-sectional view showing the arrangement of the electrical conductors to be connected. Figure 3 shows the discharge. Figure 4 shows the relationship between the distance between the electrical conductor connecting the discharge starting auxiliary ring and the anode or cathode and the surface of the discharge tube and the discharge current. Figure 5 is a graph showing discharge current ripple and machined surface roughness, Figure 6 is a configuration diagram of a conventional gas laser oscillator, and Figure 7 is a conventional example where the discharge starting auxiliary ring is attached to the discharge tube. A schematic cross-sectional diagram showing the state of
FIG. 8 is a schematic cross-sectional view showing the state of connection between the discharge starting auxiliary ring and the anode or cathode in a conventional example. 1...Leave tube group, 2a, 2b...Anode, 31L. 3b...Cathode, 4...High voltage power supply, 6
...Output mirror, 6...Terminal mirror,
7...Circulation pipe body, 8...Blower, 9.
... Heat exchanger, 10a, 10b ... Discharge start auxiliary ring, 11a, 11b ... Electric conductor, 12 ... Insulator. Name of agent: Patent attorney Shigetaka Awano and 1 other person Figure / - 1 Mosquito Electric VZV 2L - Base / Z - Cell Binding I Tree Figure Figure 1 - View detailed diagram +! Thickness of the unconscious bat
s sail) Fig. e 1t5 Ripple base (%) /--One flag 11F fee, 2b...-3L of food, 3b--Kisou 4--Mr. Takao'' 15 original 5-・-Mirror 6- Terminal mirror 7- Ill salary 8- 1L collection 9- Heat exchanger I?

Claims (2)

[Claims] (1) A discharge tube group consisting of one or more discharge tubes having at least one pair of discharge electrodes consisting of an anode and a cathode, a mirror for laser resonance disposed at both ends of this discharge tube group, and the vicinity of the discharge electrode. A circulation pipe body connected to the discharge tube group and forming a gas circulation path together with the discharge tube group, and a blower device for circulating gas as a laser medium in the gas circulation path, and consisting of the anode and the cathode. A discharge starting auxiliary ring electrically connected to an anode or a cathode is provided on the outer periphery of the discharge tube located between the discharge electrodes, and the discharge starting auxiliary ring is provided with an electrical insulator having a thickness of 2 mm to 20 mm around the outer periphery of the discharge tube. A laser oscillator characterized by being installed through the (2) The laser oscillator according to claim 1, wherein the electric conductor connecting the discharge starting auxiliary ring and the anode or the cathode is arranged with a gap of 2 mm or more from the surface of the discharge tube.