Laser processing device

Abstract

Provided are: a laser light source that oscillates laser light; a transmission optical fiber that transmits the laser light oscillated from the laser light source; a laser light irradiation section that irradiates the laser light transmitted through the transmission optical fiber toward an object; a power supply that receives input of an alternating voltage, generates a drive voltage for setting the laser light source in a state in which the laser light can be oscillated, and applies the drive voltage to the laser light source; a semiconductor switch that is provided on a path of the drive voltage between the power supply and the laser light source; a mechanical relay that is provided on a path of the alternating voltage to the power supply; and a control section that monitors a control signal including an on signal for setting the semiconductor switch in an on state and an off signal for setting the semiconductor switch in an off state to cut off the path of the drive voltage.

Description

Technical Field

[0001] This invention relates to a laser processing apparatus. Background Technology

[0002] Patent Document 1 describes an interlock circuit consisting of a relay connected in series between a DC power supply and a load, and a control switch for driving the relay. In this interlock circuit, a semiconductor switch is connected in series between the DC power supply and the relay, and a delay drive circuit is connected to the semiconductor switch, thereby preventing the relay contacts from melting due to inrush current.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-215772 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in laser processing apparatuses used for laser processing of objects, for example when the protective housing is opened for the loading and unloading of objects, an interlocking function is incorporated to prevent radiation exposure to the operator. As an example of such an interlocking function, a mechanical shutter for cutting off the laser beam can be installed inside the laser irradiation section used to direct the laser from the laser source onto the object.

[0008] However, when using a transmission optical fiber connected to the laser irradiation unit as the optical transmission path between the laser source and the laser irradiation unit, the transmission optical fiber is considered as an optical delivery system. Therefore, a mechanical gate is required at the front end of the transmission optical fiber, i.e., inside the laser source (sometimes a cutting device is required at the entrance of the optical delivery system). However, it is difficult to install a mechanical gate inside the laser source. Therefore, in the case of optical fiber transmission, an alternative interlocking function needs to be considered.

[0009] As an additional interlocking function in laser processing apparatuses using optical fibers for transmission, one could consider replacing a mechanical gate by setting the interlocking circuit described in Patent Document 1 at the power supply of the laser source to cut off the power. However, in the case of laser processing apparatuses with high processing output, for example, the opening and closing of the protective housing accompanying the frequent handling of objects requires frequent operation of the interlocking circuit. Therefore, using a mechanical relay as described above is undesirable due to its lifespan, requiring frequent replacement.

[0010] Therefore, the objective of this invention is to provide a laser processing apparatus with a long lifespan and a highly reliable interlocking function.

[0011] Technical means to solve the problem

[0012] The laser processing apparatus of the present invention comprises: a laser source that causes laser oscillation; a transmission optical fiber that transmits the laser oscillated from the laser source; a laser irradiation unit that irradiates an object with the laser transmitted through the transmission optical fiber; a power supply that accepts an input AC voltage, generates a driving voltage for setting the laser source to a state capable of laser oscillation, and applies it to the laser source; a semiconductor switch disposed between the power supply and the laser source on the path of the driving voltage; a mechanical relay disposed on the path of the AC voltage to the power supply, i.e., the AC path; and a control unit that monitors a control signal, the control signal including an on signal for setting the semiconductor switch to an ON state and an off signal for setting the semiconductor switch to an OFF state to cut off the signal path, the control unit monitoring the output voltage of the semiconductor switch, and, if it determines that the semiconductor switch is abnormal by comparing the control signal and the output voltage, setting the mechanical relay to an OFF state, thereby cutting off the AC voltage path.

[0013] This laser processing apparatus transmits laser light from a laser source to the laser irradiation unit via a transmission optical fiber. Therefore, as an interlock function, the power supply to the laser source is cut off. Specifically, in this laser processing apparatus, a semiconductor switch is installed on the voltage supply path between the power supply and the laser source. By setting this semiconductor switch to the off state, the voltage supply path (i.e., the power supply) is cut off, and the laser oscillation of the laser source is stopped. Generally, semiconductor switches have a longer lifespan than mechanical relays. Therefore, a long-life interlock function is achieved. On the other hand, a mechanical relay is installed at the source of the voltage supply in the power supply, i.e., the AC voltage supply path. Then, when the semiconductor switch malfunctions, the control unit cuts off the AC voltage to the power supply by setting the mechanical relay to the off state. Therefore, even if the semiconductor switch malfunctions, voltage supply from the power supply to the laser source is prevented, maintaining the interlock function. Therefore, reliability is improved. Furthermore, while this laser processing apparatus also uses mechanical relays, these relays only operate when the long-life semiconductor switch malfunctions, and their operation frequency is extremely low. Therefore, the impact on the lifespan of the mechanical relays, which serve as the interlocking function, is minimal. As described above, this laser processing apparatus possesses a long-life and highly reliable interlocking function.

[0014] The laser processing apparatus of the present invention may also include: a first semiconductor switch and a second semiconductor switch, which are connected in series between a power supply and a laser source; a control unit, when both control signals to the first and second semiconductor switches are off signals, and when it detects that both the first and second semiconductor switches are in an on state based on their output voltages, determines that the first and second semiconductor switches are malfunctioning, and sets a mechanical relay to an off state. In this case, the interlocking function effectively operates as long as either of the two series-connected semiconductor switches is functioning normally. Furthermore, since the mechanical relay only operates when both semiconductor switches are malfunctioning, the operating frequency of the mechanical relay is further reduced. Therefore, a longer lifespan can be achieved, and reliability is further improved.

[0015] The laser processing apparatus of the present invention may also include a first mechanical relay and a second mechanical relay connected in series in the power path as mechanical relays, wherein the control unit sets both the first mechanical relay and the second mechanical relay to the off state when it determines that there is an abnormality in the semiconductor switch. In this case, further improvement in reliability can be achieved.

[0016] In the laser processing apparatus of the present invention, the control unit may send a power-off signal to the power supply to turn off the power supply when outputting a power-off signal to the semiconductor switch, and send a power-on signal to turn on the power supply to turn on the power supply after outputting a power-on signal to the semiconductor switch. The power supply includes a slow-start circuit, which gradually increases the driving voltage value when receiving the power-on signal from the control unit. In this case, the generation of inrush current when the power supply is turned on is suppressed, and adverse conditions such as the melting of the fuse of the laser source are suppressed. Therefore, a long lifespan can be reliably achieved.

[0017] The effects of the invention

[0018] According to the present invention, a laser processing apparatus with a long lifespan and a highly reliable interlocking function can be provided. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the laser processing apparatus of this embodiment.

[0020] Figure 2 This is a diagram illustrating an example of the internal logic circuitry of a safety controller.

[0021] Figure 3 To indicate Figure 2 A table summarizing the combinations of inputs and outputs of the logic circuit shown.

[0022] Figure 4 This is a diagram used to illustrate surge current. Detailed Implementation

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a schematic diagram illustrating the laser processing apparatus of this embodiment. Figure 1 As shown, the laser processing apparatus 1A is a device for processing an object W and is housed in a protective housing Q. It includes a laser body (laser source) 10, a transmission optical fiber 20, a laser optics unit (laser irradiation unit) 30, and a power supply unit 100. The laser body 10 includes, for example, a laser element such as a laser diode, and is a laser source for oscillating the laser L.

[0024] The laser body 10 has a laser power supply 11 and a control power supply 12 inside. The control power supply 12 supplies power to a circuit that controls the conditions related to laser oscillation (e.g., laser output, frequency, pulse width, and start / stop of laser oscillation) as commanded by an external device C. In the laser body 10, when a driving voltage Vs2 (e.g., DC 24V) from the power supply unit 100 is input to the laser power supply 11, the laser drive circuit of the laser body 10 enters an oscillation state, enabling the oscillation of the laser L.

[0025] The transmission fiber optic cable 20 is optically connected at one end to the laser body 10 and at the other end to the laser optics unit 30 via the laser output unit 21. The transmission fiber optic cable 20 transmits the laser L output from the laser body 10.

[0026] The laser optics unit 30 is configured to face the object W to be laser-processed and to irradiate the object W with the laser L transmitted through the transmission fiber 20. Therefore, the laser optics unit 30 may include various optical elements such as a focusing lens for focusing the laser L towards the object W. The transmission fiber 20 and the laser optics unit 30 constitute the optical transmission system D. Therefore, the entrance to the optical transmission system D is the entrance to the transmission fiber 20.

[0027] The power supply unit 100 includes a first power supply 41 and a second power supply (power supply) 42. An external device C is connected to the input side (primary side) of both the first power supply 41 and the second power supply 42. The first power supply 41 receives an AC voltage Ps (e.g., AC 200V) from the external device C and generates a DC voltage Vs1 (e.g., DC 24V). The first power supply 41 applies the DC voltage Vs1 to the control power supply 12 of the laser body 10. The second power supply 42 receives an AC voltage Ps (e.g., AC 200V) from the external device C and generates a DC drive voltage Vs2 (e.g., DC 24V). The second power supply 42 applies the drive voltage Vs2, which enables laser oscillation, to the laser power supply 11 of the laser body 10. Additionally, the second power supply 42 includes a slow-start circuit 43.

[0028] The power supply unit 100 has a first semiconductor switch (semiconductor switch) 51 and a second semiconductor switch (semiconductor switch) 52 disposed between the second power supply 42 and the laser body 10 on the output side (secondary side) of the second power supply 42. The first semiconductor switch 51 and the second semiconductor switch 52 are configured, for example, as solid state relays (SSRs). The first semiconductor switch 51 and the second semiconductor switch 52 are connected in series in this order along the path of the driving voltage Vs2 from the laser body 10 side. Therefore, by setting at least one of the first semiconductor switch 51 and the second semiconductor switch 52 to the off state, the path of the driving voltage Vs2 toward the laser body 10 can be cut off. In this case, in the laser processing apparatus 1A, the oscillation of the laser L in the laser body 10 is stopped.

[0029] The power supply unit 100 includes a first mechanical relay 61 and a second mechanical relay 62 disposed on the input side (primary side) of the second power supply 42. The first mechanical relay 61 and the second mechanical relay 62 are connected in series in the path of AC voltage Ps from the external device C to the second power supply 42, from the branch point of the path from the external device C to the first power supply 41 towards the second power supply 42. Therefore, by operating at least one of the first mechanical relay 61 and the second mechanical relay 62, the path of AC voltage Ps to the first power supply 41 can be maintained and the path of AC voltage Ps to the second power supply 42 can be cut off. In this case, in the laser processing apparatus 1A, the oscillation of the laser L in the laser body 10 is also stopped.

[0030] The power supply unit 100 includes a safety controller (control unit) 70. The safety controller 70 can use components designated as safety circuits. The safety controller 70 monitors a control signal C1, which includes an oscillation stop command sent from an external device C to each of the first semiconductor switch 51 and the second semiconductor switch 52. The control signal C1 includes an on signal for setting each of the first semiconductor switch 51 and the second semiconductor switch 52 to an on state, and an off signal for setting each of the first semiconductor switch 51 and the second semiconductor switch 52 to an off state, thereby cutting off the path to the drive voltage Vs2.

[0031] Furthermore, the safety controller 70 sends a control signal Sr to each of the first mechanical relay 61 and the second mechanical relay 62 to the respective first mechanical relay 61 and the second mechanical relay 62. Additionally, the safety controller 70 sends a control signal Ss to the second power supply 42, which includes a power-on signal for turning on the second power supply 42 and a power-off signal for turning off the second power supply 42.

[0032] On the other hand, the safety controller 70 receives a monitoring signal Sm for monitoring the output voltage of each of the first semiconductor switch 51 and the second semiconductor switch 52. Thus, the safety controller 70 is configured to monitor the output voltage of the first semiconductor switch 51 and the second semiconductor switch 52.

[0033] In addition, the safety controller 70 transmits and receives signals with the external device C. More specifically, the safety controller 70 receives a control signal C1 containing an oscillation stop command for the laser L from the external device C, and sends a signal C2 containing an oscillation stop report for the laser L, a fault in the first semiconductor switch 51 and the second semiconductor switch 52, a broken signal line, or a fault in the safety controller 70 to the external device C. The signal C2 consists of multiple signal lines, but is represented as a single line for simplicity. The control signal C1 is sent to the safety controller 70, for example, when the door Qs of the protective housing Q is opened to move the object W into the interior of the protective housing Q. The control signal C1 is an important signal line related to safety functions, and therefore consists of two or more wires. If one of the wires is cut, the states of the two signal lines are different, and the safety controller 70 can detect the breakage of the control signal line by detecting this state. Signal C2, which serves as an oscillation stop report, is sent to external device C when the safety controller 70, upon receiving control signal C1, sets the first semiconductor switch 51 and the second semiconductor switch 52 to the off state, thus cutting off the path to the drive voltage Vs2 and stopping the oscillation of laser L. The oscillation stop report in signal C2 is a crucial safety feature and is therefore composed of two or more wires. If one of the wires is cut, the states of the two signal lines differ; therefore, by detecting this state through the controller on the external device C side, a break in the control signal line can be detected.

[0034] Thus, in the laser processing apparatus 1A, firstly, the external device C sends a control signal C1 concerning an oscillation stop command to each of the first semiconductor switch 51 and the second semiconductor switch 52. The safety controller 70 receives (monitors) the control signal C1.

[0035] Next, the safety controller 70 monitors the output voltages of the first semiconductor switch 51 and the second semiconductor switch 52 by receiving the monitoring signal Sm. If the output voltage is, for example, 0V, and it is determined that the first semiconductor switch 51 and the second semiconductor switch 52 are in the off state, it sends a signal C2 reporting the oscillation cessation to the external device C. The external device C opens the door Qs of the protective housing Q based on the receipt of the signal C2. As described above, in the laser processing apparatus 1A, the safety controller 70 detects that the first semiconductor switch 51 and the second semiconductor switch 52 are operating normally and that the oscillation of the laser L has stopped, thus enabling the safe opening of the door Qs of the protective housing Q.

[0036] Here, the laser processing apparatus 1A performs fault detection on the first semiconductor switch 51 and the second semiconductor switch 52, and has the function of stopping the oscillation of the laser L even when the first semiconductor switch 51 and the second semiconductor switch 52 are faulty.

[0037] That is, in the laser processing apparatus 1A, the safety controller 70 monitors the output voltage of the first semiconductor switch 51 and the second semiconductor switch 52, and compares the control signal C1 to the first semiconductor switch 51 and the second semiconductor switch 52 with the output voltage, thereby determining whether the first semiconductor switch 51 and the second semiconductor switch 52 are abnormal.

[0038] Then, if the safety controller 70 determines that the first semiconductor switch 51 and the second semiconductor switch 52 are malfunctioning, it sends a control signal Sr to each of the first mechanical relay 61 and the second mechanical relay 62 to turn them off. As a result, the safety controller 70 cuts off the path of the AC voltage Ps to the second power supply 42 by turning off the first mechanical relay 61 and the second mechanical relay 62. Consequently, the oscillation of the laser L stops, ensuring safety.

[0039] Figure 2 This is a diagram illustrating an example of the internal logic circuitry of a safety controller. (See diagram for example.) Figure 2 As shown, in the safety controller 70, the control signal C1 to the first semiconductor switch 51 and the second semiconductor switch 52 is input to the NAND circuit A2 via the NOT circuit A1, and the outputs of each of the first semiconductor switch 51 and the second semiconductor switch 52 are input to the NAND circuit A2. The outputs of the first semiconductor switch 51 and the second semiconductor switch 52 can be detected by the monitoring signal Sm. Then, the output of the NAND circuit A2 is input to the first mechanical relay 61 and the second mechanical relay 62.

[0040] Figure 3 To indicate Figure 2 A table summarizing the input and output combinations of the logic circuits shown. Figure 3 In this configuration, control signal C1 is set to "0" when the first semiconductor switch 51 and the second semiconductor switch 52 are turned off to stop the oscillation of laser L, and set to "1" when the first semiconductor switch 51 and the second semiconductor switch 52 are turned on to allow laser L to oscillate. The outputs of the first semiconductor switch 51 and the second semiconductor switch 52 are set to "0" for example, at 0V, and set to "1" for 24V. Furthermore, the first mechanical relay 61 and the second mechanical relay 62 are set to the on state when set to "1" and to the off state when set to "0", thus cutting off the path to AC voltage Ps.

[0041] like Figure 3As shown in Case 4, in the safety controller 70, when the control signal C1 is "0", that is, when the outputs of the first semiconductor switch 51 and the second semiconductor switch 52 are "1", it is determined that there is an abnormality (short circuit) in both the first semiconductor switch 51 and the second semiconductor switch 52. Therefore, in Case 4, the first mechanical relay 61 and the second mechanical relay 62 are set to the off state ("0"), and as a result, the driving voltage Vs2 to the laser power supply 11 is cut off (set to "0"). In this case, the safety controller 70 sends a failure output indicating a short circuit fault in the first semiconductor switch 51 and the second semiconductor switch 52 to the signal line of signal C2.

[0042] Regarding other cases, see the table below. Specifically, in case 1, since control signal C1 is "0" and the outputs of both the first semiconductor switch 51 and the second semiconductor switch 52 are "0", both the first and second semiconductor switches 51 and 52 are functioning normally. Therefore, the first mechanical relay and the second mechanical relay 62 are maintained in the open state ("1"). In this case, the safety controller 70 outputs a signal indicating an oscillation stop report to the signal line of signal C2.

[0043] Furthermore, in case 3, although control signal C1 is "0" and the output of the first semiconductor switch 51 is "0", the output of the second semiconductor switch 52 is "1", indicating a short circuit only in the second semiconductor switch 52. However, the first semiconductor switch 51 operates normally, achieving the cutoff of the drive voltage Vs2. Therefore, the first mechanical relay and the second mechanical relay 62 are maintained in the open state ("1"). In this case, the safety controller 70 does not send a failure output indicating a short circuit fault in the second semiconductor switch 52 to the signal line of signal C2, nor does it send a report indicating the oscillation stop of the laser L. Since the oscillation stop signal is not sent, an operational anomaly can be detected on the external device C side. In addition, in case 2, the output of the second semiconductor switch 52 on the upstream side (the second power supply 42 side) is "0", therefore, the output of the first semiconductor switch 51 on the downstream side cannot be "1", which is an impossible situation.

[0044] Furthermore, in case 5, although the control signal C1 is "1", the outputs of both the first semiconductor switch 51 and the second semiconductor switch 52 are "0", indicating that at least the second semiconductor switch 52 is open-circuited. In this case, the drive voltage Vs2 to the laser power supply 11 is cut off, thus unintentionally causing the oscillation of the laser L to stop, but without causing any safety issues. Therefore, the first mechanical relay 61 and the second mechanical relay 62 are kept in the open state ("1"). In this case, a failure output indicating an open-circuit fault in the second semiconductor switch 52 is sent to the signal line of signal C2, thus allowing an abnormal operation to be detected on the external device C side.

[0045] In case 7, although control signal C1 is "1" and the output of the second semiconductor switch 52 is "1", the output of the first semiconductor switch 51 is "0", indicating that only the first semiconductor switch 51 is open-circuited. In this case, the driving voltage Vs2 to the laser power supply 11 is also cut off, thus unintentionally causing the oscillation of the laser L to stop, but without causing a safety problem. Therefore, the first mechanical relay 61 and the second mechanical relay 62 are kept in the open state ("1"). In this case, the safety controller 70 sends a failure output indicating an open-circuit fault of the first semiconductor switch 51 to the signal line of signal C2. In addition, in case 6, the output of the second semiconductor switch 52 on the upstream side (on the second power supply 42 side) is "0", therefore, the output of the first semiconductor switch 51 on the downstream side cannot be "1", which is an impossible situation.

[0046] In addition, in case 8, the control signal C1 is "1" and the outputs of the first semiconductor switch 51 and the second semiconductor switch 52 are "1", which can be considered as normal operation. Therefore, the first mechanical relay 61 and the second mechanical relay 62 are kept in the open state ("1").

[0047] As described above, when the safety controller 70 detects that the control signal C1 to both the first semiconductor switch 51 and the second semiconductor switch 52 is a turn-off signal, and both the first semiconductor switch 51 and the second semiconductor switch 52 are in the open state, it determines that the first semiconductor switch 51 and the second semiconductor switch 52 are abnormal, and sets the first mechanical relay 61 and the second mechanical relay 62 to the turn-off state.

[0048] In addition, such as Figure 1As shown, in the safety controller 70, when a turn-off signal, i.e., a control signal C1, is sent to the first semiconductor switch 51 and the second semiconductor switch 52 to stop the oscillation of the laser L, a control signal (power-off signal) Ss for turning off the second power supply 42 can also be sent simultaneously. Thus, the first semiconductor switch 51 and the second semiconductor switch 52 become off, and the second power supply 42 also becomes off, with the output becoming 0 (e.g., attenuated by 50% over 400ms).

[0049] Furthermore, in the safety controller 70, after sending an on signal, i.e. a control signal C1, to the first semiconductor switch 51 and the second semiconductor switch 52 to start the oscillation of the laser L (for example, after 100ms), it is possible to send a control signal (power on signal) Ss to turn on the second power supply 42.

[0050] Here, a fuse (not shown) is provided in the laser body 10. Generally, it is common for power supply units to have capacitors at the input stage to prevent significant fluctuations in output current or voltage even with load-side variations. If a capacitor is present at the input stage, it needs to be charged when power is applied to the power supply unit; therefore, if... Figure 4 As shown, a current greater than the fuse's rated current RC flows until a stable current Ic is reached. This current is the surge current Ip. The fuse's lifespan is calculated by multiplying the square of the instantaneous surge current Ip by the pulse width I. 2 T and the definition of power surge number n (I) 2 (t-T characteristic). If the power supply is switched on approximately once a day, the fuse will not blow in a short period of time. However, if the surge frequency of the power supply increases, this limitation does not apply.

[0051] In contrast, the second power supply 42, as described above, has a slow-start circuit 43. Therefore, in the second power supply 42, when it is turned on upon receiving a control signal Ss from the safety controller 70, the slow-start circuit 43 prevents a sharp increase in the driving voltage Vs2, causing it to increase gradually. This suppresses the generation of surge current Ip and prevents the fuse from blowing.

[0052] As explained above, the laser processing apparatus 1A uses a transmission optical fiber 20 to transmit the laser L from the laser body 10 to the laser optics unit 30. Therefore, as an interlock function, the power supply to the laser body 10 is cut off. Specifically, in this laser processing apparatus 1A, semiconductor switches (first semiconductor switch 51 and second semiconductor switch 52) are provided on the path of the driving voltage Vs2 between the second power supply 42 and the laser body 10, and by setting these semiconductor switches to the off state, the path of the driving voltage Vs2 (i.e., the power supply) is cut off and the laser oscillation of the laser body 10 is stopped. Simultaneously, the safety controller 70 monitors the output voltage of these semiconductor switches.

[0053] Generally, semiconductor switches have a longer lifespan compared to mechanical relays. Therefore, a long-life interlocking function is achieved. On the other hand, mechanical relays (first mechanical relay 61 and second mechanical relay 62) are installed at the source of the drive voltage Vs2 in the second power supply 42, i.e., on the supply path of the AC voltage Ps. Then, when the semiconductor switch malfunctions, the safety controller 70 cuts off the AC voltage Ps to the second power supply 42 by setting these mechanical relays to the off state.

[0054] Therefore, even assuming a malfunction in the semiconductor switch, the application of a driving voltage Vs2 from the second power supply 42 to the laser body 10 is prevented, maintaining the interlock function. Thus, reliability is improved. Furthermore, while a mechanical relay is also used in this laser processing apparatus 1A, the mechanical relay only operates in the event of a malfunction in the long-life semiconductor switch, and its operation frequency is extremely low. Therefore, the impact on the lifespan of the mechanical relay, which serves as the interlock function, is minimal. As described above, this laser processing apparatus 1A possesses a long-life and highly reliable interlock function.

[0055] Furthermore, the laser processing apparatus 1A includes a first semiconductor switch 51 and a second semiconductor switch 52, which are connected in series between the second power supply 42 and the laser body 10, and are configured as semiconductor switches. Then, when the control signal C1 sent to both the first semiconductor switch 51 and the second semiconductor switch 52 is a turn-off signal, and the safety controller 70 detects that both the first semiconductor switch 51 and the second semiconductor switch 52 are in an open state based on the output voltage of the first semiconductor switch 51 and the second semiconductor switch 52, it determines that the first semiconductor switch 51 and the second semiconductor switch 52 are abnormal and sets the mechanical relay to the turn-off state.

[0056] Therefore, the interlocking function works effectively as long as either the first semiconductor switch 51 or the second semiconductor switch 52, which are connected in series, is functioning normally. The mechanical relay only operates when either the first semiconductor switch 51 or the second semiconductor switch 52 malfunctions, thus further reducing the operating frequency of the mechanical relay. Therefore, a longer lifespan can be achieved, and reliability can be further improved.

[0057] Furthermore, the laser processing apparatus 1A includes a first mechanical relay 61 and a second mechanical relay 62 connected in series in the path of the AC voltage Ps to the second power supply 42. Then, when the safety controller 70 determines that there is an abnormality in the semiconductor switch, it sets both the first mechanical relay 61 and the second mechanical relay 62 to the off state. Therefore, further improvements in reliability can be achieved.

[0058] Furthermore, in the laser processing apparatus 1A, the safety controller 70 sends a power-off signal (control signal Ss) to the second power supply 42 to turn it off when outputting a power-off signal to the semiconductor switch, and sends a power-on signal (control signal Ss) to turn the second power supply 42 on after outputting a power-on signal to the semiconductor switch. The second power supply 42 includes a slow-start circuit 43, which gradually increases the driving voltage Vs2 when receiving a power-on signal from the safety controller 70. Therefore, the generation of surge current Ip when the second power supply 42 is turned on is suppressed, and the occurrence of adverse conditions such as fuse blowing in the laser body 10 is suppressed. Therefore, a long lifespan can be reliably achieved.

[0059] The above embodiments illustrate one aspect of the laser processing apparatus 1A of the present invention. Therefore, the laser processing apparatus 1A of the present invention can be arbitrarily deformed.

[0060] For example, in the above embodiment, an example was described in which the laser processing apparatus 1A has a first semiconductor switch 51 and a second semiconductor switch 52 connected in series on the path of the driving voltage Vs2 between the second power supply 42 and the laser body 10. However, the number of semiconductor switches provided by the laser processing apparatus 1A is not limited to two; it may be one or more than three.

[0061] Similarly, in the above embodiment, an example was described in which the laser processing apparatus 1A has a first mechanical relay 61 and a second mechanical relay 62 connected in series on the path of the AC voltage Ps to the second power supply 42. However, the number of mechanical relays provided by the laser processing apparatus 1A is not limited to two, but may be one or more than three.

[0062] Additionally, in the safety controller 70, such as Figure 3 As in cases 3 or 7, if an abnormality (short circuit or open circuit fault) is detected in one of the first semiconductor switch 51 and the second semiconductor switch 52, at least one of the first mechanical relay 61 and the second mechanical relay 62 can be set to the off state. That is, in the safety controller 70, if it is determined that at least one of the plurality of semiconductor switches is abnormal, at least one of the plurality of mechanical relays can also be set to the off state. Furthermore, the safety controller 70 can be omitted from the power supply unit 100, and the safety controller (not shown) of the external device C can have the function of the safety controller 70.

[0063] Industrial availability

[0064] A laser processing device with a long lifespan and high reliability interlocking function is provided.

[0065] Explanation of symbols

[0066] 1A…Laser processing apparatus, 10…Laser body (laser source), 11…Laser power supply, 12…Control power supply, 20…Transmission optical fiber, 21…Laser output unit, 30…Laser optics unit (laser irradiation unit), 41…First power supply, 42…Second power supply, 43…Slow start circuit, 51…First semiconductor switch, 52…Second semiconductor switch, 61…First mechanical relay, 62…Second mechanical relay Mechanical relay), 70… Safety controller (control unit), 100… Power supply unit, A1… NOT circuit, A2… NAND circuit, C… External device, C1… Control signal, C2… Signal, L… Laser, Ps… AC voltage, Q… Protective housing, Qs… Door, Sm… Monitoring signal, Sr… Control signal, Ss… Control signal, Vs1… DC voltage, Vs2… Drive voltage, W… Object, Ic… Stabilizing current, Ip… Surge current, RC… Fuse rated current.

Claims

1. A laser processing apparatus, wherein, have: A laser source that causes the laser to oscillate; An optical fiber for transmission, which transmits the laser oscillating from the laser source; A laser irradiation unit that irradiates an object with the laser beam transmitted through the transmission optical fiber; A power supply that accepts an AC voltage input, generates a driving voltage for setting the laser source to a state capable of laser oscillation, and applies it to the laser source; A semiconductor switch disposed on the path of the driving voltage between the power supply and the laser source; A mechanical relay disposed on the path of the AC voltage supplied to the power source; and The control unit monitors control signals, which include an on signal for setting the semiconductor switch to the on state and an off signal for setting the semiconductor switch to the off state and cutting off the path of the driving voltage. The control unit monitors the output voltage of the semiconductor switch, and if it determines that the semiconductor switch is abnormal by comparing the control signal and the output voltage, it sets the mechanical relay to the off state, thereby cutting off the path of the AC voltage.

2. The laser processing apparatus as described in claim 1, wherein, It includes: a first semiconductor switch and a second semiconductor switch, which are connected in series between the power supply and the laser source. When the control signal sent to the first semiconductor switch and the second semiconductor switch is both the off signal, and the control unit detects that both the first semiconductor switch and the second semiconductor switch are in the on state based on the output voltage of the first semiconductor switch and the second semiconductor switch, it determines that the first semiconductor switch and the second semiconductor switch are abnormal, and sets the mechanical relay to the off state.

3. The laser processing apparatus as described in claim 1, wherein, The system includes a first mechanical relay and a second mechanical relay connected in series in the path of the AC voltage as the mechanical relays. If the control unit determines that the semiconductor switch is abnormal, it sets both the first mechanical relay and the second mechanical relay to the off state.

4. The laser processing apparatus as described in claim 2, wherein, The system includes a first mechanical relay and a second mechanical relay connected in series in the path of the AC voltage as the mechanical relays. If the control unit determines that the semiconductor switch is abnormal, it sets both the first mechanical relay and the second mechanical relay to the off state.

5. The laser processing apparatus according to any one of claims 1 to 4, wherein, When the control unit outputs the off signal to the semiconductor switch, it sends a power off signal to the power supply to set the power supply to off; and after outputting the on signal to the semiconductor switch, it sends a power on signal to the power supply to set the power supply to on. The power supply includes a slow-start circuit, which gradually increases the value of the driving voltage when the power supply is received from the control unit.

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