JP2022111509A - laser oscillator - Google Patents

Abstract

To provide a compact laser oscillator with a low price, which is low in failure risk even if the oscillator is directly connected to a switchboard without a transformer therebetween.SOLUTION: A laser oscillator 1 emitting a laser beam includes: a feeder circuit 10 receiving power supply from an external power supply 2; and a plurality of branch circuits 20-n which is branched from the feeder circuit 10 and to each of which power from the external power supply 2 is distributed via the feeder circuit 10. The feeder circuit 10 has a breaker 11 connected to the external power supply 2, and a current-limiting fuse 12 connected between the breaker 11 and a branch point P of the plurality of branch circuits 20-n from the feeder circuit 10. Each of the plurality of branch circuits 20-n has: a power supply unit 21 to generate power for laser beam emission on the basis of, power distributed from the feeder circuit 10 via the branch point P; and a laser cavity unit 22 which is connected to an output side of the power supply unit 21 and which emits a laser beam on the basis of, the power for laser beam emission.SELECTED DRAWING: Figure 1

Description

The present invention relates to laser oscillators.

A laser oscillator is used, for example, to supply a laser beam to a laser processing apparatus. The laser oscillator generates laser light based on power supplied from an external power source and outputs the laser light to the outside. The laser oscillator is composed of a feeder circuit that receives power from an external power supply and a plurality of branch circuits branched from the feeder circuit, and each branch circuit is provided with a laser cavity unit that outputs laser light. .

For example, in Patent Document 1, "The laser device 1 includes an LD module 2, a cavity 3, a power source section 4, a power cutoff section 5, and a laser light control section 6 as a group of components for outputting laser light." , "The LD module 2 is a laser light source that generates laser light. The LD module 2 is composed of a plurality of laser diodes. A laser beam is generated, and the laser beam generated by each laser diode is transmitted to the cavity 3 through an optical fiber cable.” and “The cavity 3 amplifies the laser beam transmitted from the LD module 2. Laser light generated by each laser diode is amplified in the cavity 3 and output to an external laser processing device 51 via an optical fiber cable."

For example, Patent Document 2 states that "SPDs are devices intended to limit transient overvoltages and shunt surge currents to ground, and contain non-linear elements."

The AC voltage supplied from the switchboard differs depending on the country or region. Depending on the specific country or region, in order to use laser oscillators mass-produced according to certain standards, the AC voltage supplied from the switchboard is stepped down or reduced using a transformer so that it is within the range of the rated input voltage of the laser oscillator. Sometimes you have to step up. For example, if a laser oscillator with a rated input voltage of 200 V AC is to be operated under an AC input voltage of another magnitude (for example, 400 V AC or 480 V AC), a transformer should be provided on the AC input side of the laser oscillator. The AC input voltage of the laser oscillator must be stepped down to match the rated input voltage. On the other hand, transformers are physically large, heavy, and expensive, so we designed the laser oscillator's rated input voltage to match the voltage of the switchboard so that the laser oscillator can be directly connected to the switchboard without going through a transformer. By doing so, the introduction cost of the laser oscillator is also suppressed.

JP 2019-047017 A JP 2010-074971 A

If the laser oscillator is directly connected to the switchboard without a transformer, there is a high risk that the laser oscillator and its peripheral devices will break down due to overcurrent that occurs during a short circuit, ground fault, or lightning strike. For example, Industrial Control Panels for the US are required to display SCCR (Short-Circuit Current Rating) values in accordance with US electrical installation standards. SCCR refers to the limit current value that each power circuit device can withstand short-circuit current, and this "withstand" means "even if the device breaks down, it does not harm other adjacent devices". means. Laser oscillators are required to have a high SCCR of, for example, 50 kA or more. Therefore, in order to avoid the risk of failure caused by directly connecting a laser oscillator to a switchboard without going through a transformer, conventionally, each of the feeder circuit and the branch circuit , was provided with a current-limiting fuse. However, since the current-limiting fuse is expensive, there is a drawback that the laser oscillator is expensive. In addition, if the current-limiting fuse melts due to overcurrent, it will be necessary to replace the current-limiting fuse. During the replacement work, the operation of the laser oscillator will stop, and the operating efficiency of the device equipped with the laser oscillator will decrease. There is a drawback.

In addition, when designing a laser oscillator assuming that it will be directly connected to a switchboard without a transformer, it is necessary to secure a sufficient insulation distance within the laser cavity unit, which is one of the components of the laser oscillator. There is a drawback that the size of the cavity unit is increased, which in turn increases the size of the laser oscillator.

Therefore, there is a demand for a small, low-cost laser oscillator that has a low risk of failure even if it is directly connected to a switchboard without a transformer.

According to one aspect of the present disclosure, a laser oscillator that outputs laser light includes a feeder circuit that receives power supply from an external power source and a plurality of branch circuits branched from the feeder circuit, wherein the plurality of branch circuits Each of the circuits comprises a branch circuit to which power from an external power source is distributed via a feeder circuit, the feeder circuit having a breaker connected to the external power source and a plurality of branch circuits from the breaker and feeder circuit. and a current limiting fuse connected between the branch point, wherein each of the plurality of branch circuits generates power for laser light output based on power distributed from the feeder circuit via the branch point. and a laser cavity unit that is connected to the output side of the power supply unit and that outputs laser light based on power for laser light output.

According to one aspect of the present disclosure, it is possible to realize a small, low-cost laser oscillator that has a low risk of failure even if it is directly connected to a switchboard without a transformer.

1 illustrates a laser oscillator according to a first embodiment of the present disclosure; FIG. Fig. 3 shows a laser oscillator according to a second embodiment of the present disclosure; Fig. 3 shows a laser oscillator according to a third embodiment of the present disclosure; FIG. 4 illustrates a laser oscillator according to a fourth embodiment of the present disclosure; It is a perspective view which illustrates a branch terminal block.

A laser oscillator will be described below with reference to the drawings. In order to facilitate understanding, the drawings are appropriately scaled. Moreover, the form shown in drawing is one example for implementing, and it is not limited to the illustrated form.

FIG. 1 is a diagram showing a laser oscillator according to a first embodiment of the present disclosure; FIG.

A laser oscillator 1 according to the first embodiment of the present disclosure and second and third embodiments described later is a device that supplies a laser beam to a laser processing device 3 . The laser processing device 3 is a device that processes a workpiece by emitting a laser beam from a processing head (not shown). The external power supply 2 is a commercial AC three-phase power supply, and generally supplies power of a predetermined voltage (for example, AC 200 V, AC 400 V, or AC 480 V) to electrical equipment such as the laser oscillator 1 via a switchboard. do. In the following description, the switchboard may be treated synonymously with the external power supply 2 .

The laser oscillator 1 according to the first embodiment of the present disclosure and the second and third embodiments described later includes a feeder circuit 10 and a plurality of branch circuits 20-1 to 20-n (where n is an integer of 2 or more, hereinafter Similarly.) and provided. The feeder circuit 10 receives power supply from the external power source 2 . The feeder circuit 10 may be directly connected to the external power supply 2 (i.e., the switchboard) without a transformer if the voltage supplied from the external power supply 2 (i.e., switchboard) falls within the rated voltage range of the laser oscillator. . A plurality of branch circuits 20-1 to 20-n are configured by branching from the feeder circuit 10 at a branch point P. FIG. Power from the external power supply 2 is distributed to each of the plurality of branch circuits 20-1 to 20-n via the feeder circuit 10. FIG.

In laser oscillator 1 according to the first embodiment of the present disclosure, feeder circuit 10 has breaker 11 and current limiting fuse 12 . An external power source 2 is connected to one end of the breaker 11 and a current limiting fuse 12 is connected to the other end. The current-limiting fuse 12 is connected between one end of the breaker 11 to which the external power supply 2 is not connected and a branch point P between the feeder circuit 10 and the plurality of branch circuits 20-1 to 20-n.

The breaker 11 has a function of opening and closing a current path from the external power supply 2 to the current limiting fuse 12 . Formation of a current path from the external power supply 2 to the current-limiting fuse 12 is realized by closing the contact of the breaker 11, and interruption of the current path from the external power supply 2 to the current-limiting fuse 12 when an overcurrent occurs. It is realized by opening the contacts of the breaker 11 . A current-limiting fuse 12, which is a type of power fuse, is a protective device that generates an arc resistance, breaks the short-circuit current in the rising half cycle, and current-limits and breaks a fault current flowing in an electric circuit.

In the laser oscillator 1 according to the first embodiment of the present disclosure, each of the plurality of branch circuits 20-1 to 20-n has a power supply unit 21 and a laser cavity unit 22. For example, in the first branch circuit 20-1, the power supply unit 21 is connected between the branch point P between the feeder circuit 10 and the first branch circuit 20-1 and the laser cavity unit 22. The laser cavity unit 22 is connected to the output side of the power supply unit 21 . The connection relationship between the power supply unit 21 and the laser cavity unit 22 in the second branch circuit 20-2 to the n-th branch circuit 20-n is the same as the connection relationship in the first branch circuit 20-1.

In each of the plurality of branch circuits 20-1 to 20-n, the power supply unit 21 is distributed from the feeder circuit 10 via the branch point P in accordance with a control signal sent from a laser light control section (not shown). Based on the power, power for laser light output is generated and supplied to the laser cavity unit 22 . The power supply unit 21 is composed of a coil, a capacitor, a switching element or a transformer, and the like. The laser cavity unit 22 includes an LD module (not shown) that generates laser light having an intensity corresponding to the amount of power for laser light output supplied from the power supply unit 21, and an optical fiber cable (not shown) from the LD module. and a cavity (not shown) for amplifying the laser light sent out via the laser. The cavities in the laser cavity units 22 of the plurality of branch circuits 20-1 to 20-n are respectively connected to the beam combiner 50 via optical fiber cables. The laser beams amplified in each cavity are combined by a beam combiner 50 and then supplied to the laser processing device 3 via an optical fiber cable.

Thus, in the laser oscillator 1 according to the first embodiment of the present disclosure, the breaker 11 is provided in the feeder circuit 10 before the current limiting fuse 12 . Since the breaker 11 cuts off an overcurrent generated at the time of a short circuit, ground fault, or lightning strike, the current-limiting fuse 12 can be prevented from blowing. In addition, since the breaker 11 itself also has a function of limiting an overcurrent, the laser oscillator 1 according to the first embodiment of the present disclosure can be compared with the conventional case in which a current-limiting fuse is provided alone in the feeder circuit. to accommodate larger overcurrents. Even if the laser oscillator 1 according to the first embodiment of the present disclosure is directly connected to the external power supply 2 (distribution board) without a transformer, overcurrent caused by a short circuit, a ground fault, or a lightning strike may cause the laser oscillator 1 and its components to malfunction. Low risk of peripheral device failure. Therefore, according to the first embodiment of the present disclosure, even if the laser oscillator 1 is directly connected to the external power supply 2 (for example, a switchboard) without a transformer, the safety of the laser oscillator 1 and its peripheral devices can be ensured. can. According to the first embodiment of the present disclosure, the laser oscillator 1 can be used by directly connecting to the external power supply 2 without going through a transformer that is physically large, heavy, and expensive. The introduction cost of the laser oscillator 1 can be suppressed, and the size and weight of the device provided with the laser oscillator 1 can be reduced.

Further, the breaker 11 protects the current-limiting fuse 12 and a plurality of branch circuits 20-1 to 20-n in the succeeding stage from overcurrent, and the current-limiting fuse 12 itself also limits overcurrent (for example, from 50 kA to 10 kA). Therefore, according to the first embodiment of the present disclosure, current-limiting fuses conventionally provided on branch circuits to meet high SCCR requirements can be eliminated or reduced in size. can. According to the first embodiment of the present disclosure, since it is not necessary to provide a current limiting fuse in each of the plurality of branch circuits 20-1 to 20-n, the cost of the laser oscillator 1 can be reduced. Since current-limiting fuses are not provided in each of the plurality of branch circuits 20-1 to 20-n, the frequency of replacement work for the current-limiting fuses is lower than in the conventional art. can be prevented. Even if a current-limiting fuse is provided in each of the plurality of branch circuits 20-1 to 20-n, it can be small and inexpensive, so it can be used in each of the plurality of branch circuits 20-1 to 20-n. It is possible to reduce the cable diameter of the power line to be used, and to reduce the price of the laser oscillator 1 . Also, the power supply unit 21 provided in each of the plurality of branch circuits 20-1 to 20-n can be made to have a low SCCR, so that the laser oscillator 1 can be made low-priced, small-sized, and light-weight. be able to.

FIG. 2 is a diagram illustrating a laser oscillator according to a second embodiment of the present disclosure;

The laser oscillator 1 according to the second embodiment of the present disclosure further includes an electromagnetic contactor 23 in each of the plurality of branch circuits 20-1 to 20-n in the laser oscillator 1 according to the first embodiment. . According to the second embodiment of the present disclosure, for example, in the first branch circuit 20-1, the electromagnetic contactor 23 includes the branch point P between the feeder circuit 10 and the first branch circuit 20-1 and the power supply unit 21 is connected between the input side of . The connection relationship between the electromagnetic contactor 23, the power supply unit 21, and the laser cavity unit 22 in the second branch circuit 20-2 to the n-th branch circuit 20-n is also the connection relationship in the first branch circuit 20-1. It is the same. Circuit components other than the electromagnetic contactor 23 are the same as the circuit components shown in FIG. .

The electromagnetic contactor 23 has a function of opening and closing a current path from the branch point P to the power supply unit 21 . The formation of the current path from the branch point P to the power supply unit 21 is realized by closing the contacts of the electromagnetic contactor 23, and the interruption of the current path from the branch point P to the power supply unit 21 when an overcurrent occurs is It is realized by opening the contacts of the electromagnetic contactor 23 .

According to the second embodiment of the present disclosure, the electromagnetic contactor 23 provided in the front stage of the power supply unit 21 in each of the plurality of branch circuits 20-1 to 20-n is set at the time of a short circuit, a ground fault, or a lightning strike. can protect against overcurrent. Here, since the breaker 11 and the current limiting fuse 12 have a current limiting function, the magnetic contactor 23 provided in each of the plurality of branch circuits 20-1 to 20-n can be of low SCCR. Therefore, the laser oscillator 1 having the function of opening and closing the current path to the power supply unit 21 can be made low-priced, small-sized, and light-weight.

FIG. 3 is a diagram illustrating a laser oscillator according to a third embodiment of the present disclosure;

The laser oscillator 1 according to the third embodiment of the present disclosure further includes a surge protector 13 in the feeder circuit 10 of the laser oscillator 1 according to the first embodiment. According to the third embodiment of the present disclosure, the feeder circuit 10 has a surge protector 13 whose one end is connected to the connection point Q between the breaker 11 and the current limiting fuse 12 and whose other end is grounded. Since circuit components other than the surge protector 13 are the same as those shown in FIG. 1, the same circuit components are denoted by the same reference numerals, and detailed description of the circuit components is omitted.

The surge protector 13 is also called an SPD (Serge Protection Device), an arrester, or a lightning arrester. The surge protector 13 comprises non-linear elements such as MOVs (metal oxide varistors), GDTs (gas-filled discharge tubes), ABDs (avalanche breakdown diodes), or TSSs (surge protection thyristors). A nonlinear element has the characteristic that its resistance value changes depending on the voltage across the element. When the voltage across the element is low, the resistance is high and there is almost no conduction. Become. Surge protector 13 uses these properties of nonlinear elements to limit transient overvoltages and shunt surge currents to ground.

The surge protector 13 does not allow current to flow to the ground side because the nonlinear element has a high resistance with respect to the voltage in normal use, but when a very large voltage such as a lightning surge is applied, the nonlinear element becomes active. The low resistance allows surge current to flow to the ground side and suppresses overvoltage. Even if the magnitude of the voltage applied from the external power supply 2 to the laser oscillator 1 does not reach the voltage that causes the breaker 11 to open, the surge protector 13 allows the overcurrent to flow to the ground side and suppresses the overvoltage. The current limiting fuse 12 and subsequent branch circuits 20-1 to 20-n can be protected from overcurrent and overvoltage. Therefore, the capacity of the current-limiting fuse 12 can be reduced, and the price and size of the laser oscillator 1 can be further reduced. Of course, when the magnitude of the overvoltage reaches the voltage at which the breaker 11 opens, the current path from the external power supply 2 to the current-limiting fuse 12 is cut off, so that the current-limiting fuse 12 and the branch circuit 20- 1 to 20-n can be protected from overcurrent and overvoltage. Thus, the laser oscillator 1 according to the third embodiment of the present disclosure, in addition to the effects of the laser oscillator 1 according to the first embodiment, has the current-limiting fuse 12 and the branch circuits 20-1 to 20-n in the subsequent stages. can be more reliably protected from overcurrent and overvoltage. In addition, since the current-limiting fuse 12 in the feeder circuit 10 can be more reliably protected from overcurrent and overvoltage, the possibility of failure of the current-limiting fuse 12 is reduced, and the frequency of replacement work for the current-limiting fuse 12 is also reduced. Therefore, it is possible to prevent the operating efficiency of the apparatus including the laser oscillator 1 from being lowered.

FIG. 4 is a diagram illustrating a laser oscillator according to a fourth embodiment of the present disclosure;

A fourth embodiment of the present disclosure is a combination of the second and third embodiments. That is, in the laser oscillator 1 according to the fourth embodiment of the present disclosure, the feeder circuit 10 includes a surge protector 13 whose one end is connected to the connection point Q between the breaker 11 and the current limiting fuse 12 and whose other end is grounded. have Further, in each of the plurality of branch circuits 20-1 to 20-n, the electromagnetic contactor 23 is provided between the branch point P between the feeder circuit 10 and each branch circuit 20-1 to 20-n and the power supply unit 21. connected to Circuit components other than the surge protector 13 and the electromagnetic contactor 23 are the same as the circuit components shown in FIG. Description is omitted. The laser oscillator 1 according to the fourth embodiment of the present disclosure has the effects of the laser oscillators 1 according to the first to third embodiments.

In the first to fourth embodiments described above, if the power supply unit 21 includes a transformer, the transformer insulates the input side and the output side of the power supply unit 21 . As a result, the insulation distance in the laser cavity unit 22 can be designed to be shorter than before, the size of the laser cavity unit 22 can be reduced, and the size of the laser oscillator 1 can be reduced. For example, under IEC61010-1 (safety of electrical equipment for measurement, control and laboratory use), which is a standard established by the International Electrotechnical Commission, Category III (equipment that takes in electricity directly from a switchboard The laser cavity unit 22 can be designed according to the regulations of Category II (electrical circuits of equipment with a power cord that connects to an outlet), rather than the electrical circuit from the primary side of the power supply and the branch to the outlet). For example, the insulation distance in the laser cavity unit 22 can be shortened from 3 mm to 1.5 mm.

Further, in the first to fourth embodiments described above, branching between the feeder circuit 10 and the plurality of branch circuits 20-1 to 20-n at the branch point P may be performed via a branch terminal block. FIG. 5 is a perspective view illustrating a branch terminal block. The shape of the branch terminal block shown in FIG. 5 is merely an example, and other shapes may be used. Generally, in the branch terminal block 30 , a plurality of terminal screws 32 are provided on the support base 31 , and the terminal screws 32 arranged in the lateral direction are electrically connected inside the support base 31 . A desired branch path can be formed by appropriately connecting the terminal screws 32 arranged in the longitudinal direction of the branch terminal block 30 with a short bar. Since the branch terminal block 30 tightens the terminal screw 32 with a predetermined torque, it has the advantage of less likely to cause poor contact than the branch connector. Such a branch terminal block 30 may be provided at the branch point P to realize the connection relationship between the feeder circuit 10 and each of the branch circuits 20-1 to 20-n.

Reference Signs List 1 laser oscillator 2 external power supply 3 laser processing device 10 feeder circuit 11 breaker 12 current limiting fuse 13 surge protector 20-1 to 20-n branch circuit 21 power supply unit 22 laser cavity unit 23 electromagnetic contactor 30 branch terminal block 31 support base 32 Terminal screw 50 Beam combiner

Claims (5)

A laser oscillator that outputs laser light,
a feeder circuit that receives power from an external power supply;
a plurality of branch circuits branched from the feeder circuit, each of the plurality of branch circuits to which power from the external power source is distributed via the feeder circuit;
with
The feeder circuit has a breaker connected to the external power supply, and a current-limiting fuse connected between the breaker and branch points of the plurality of branch circuits from the feeder circuit,
Each of the plurality of branch circuits is connected to a power supply unit that generates power for laser light output based on the power distributed from the feeder circuit via the branch point, and an output side of the power supply unit. a laser cavity unit that outputs laser light based on the power for light output;
laser oscillator. 2. The laser oscillator according to claim 1, wherein each of said plurality of branch circuits has an electromagnetic contactor connected between said branch point and said power supply unit. 3. The laser oscillator according to claim 1, wherein said feeder circuit has a surge protector having one end connected to a connection point between said breaker and said current limiting fuse and the other end grounded. 4. The laser oscillator according to claim 1, wherein said feeder circuit and each of said plurality of branch circuits are connected via a branch terminal block on said branch point. 5. The laser oscillator according to claim 1, wherein said power supply unit is insulated between an input side and said output side of said power supply unit by a built-in transformer.

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