JP7756335B2 - Laser emission device and optical fiber attachment/detachment method - Google Patents

Description

The present invention relates to a laser emission device and a method for attaching and detaching an optical fiber.

Patent Document 1 describes a laser emission unit in which shielding gas is injected from an injection port, traverses the optical path space along the incident surface of the collimating lens, and is then exhausted to the outside from an exhaust port directly opposite, forming an air curtain that covers the incident surface of the collimating lens.

In the invention of Patent Document 1, an air curtain is used to prevent dust and dirt that has entered the optical path space through the optical fiber insertion port from adhering to the collimating lens.

Patent No. 6150612

However, the invention of Patent Document 1 injects shielding gas along the incident surface of the collimating lens, which can result in large amounts of dust particles that cannot be blown away by the flow of shielding gas alone adhering to the collimating lens.

The present invention was made in consideration of these issues, and its purpose is to prevent dust from adhering to the optical components located inside the head body.

The first invention is a laser emission device that emits laser light transmitted through an optical fiber, and includes a head body having a fiber connection port for detachably connecting the optical fiber and a maintenance opening that opens in a direction intersecting the fiber connection port; an optical component located downstream of the maintenance opening in the head body in the emission direction; an air blowing unit that blows air into the internal space in the head body between the optical component and the fiber connection port; and a cover member that is detachably attached to the head body and closes the maintenance opening.

In the first invention, air is blown into the internal space between the optical components and the fiber connection port in the head body, creating a positive pressure in the internal space. The air blown into the internal space is then exhausted to the outside through the fiber connection port, preventing dust from entering through the fiber connection port.

Specifically, in a configuration in which an air curtain is formed by circulating gas across the fiber connection port, as in conventional inventions, the gas flow creates a negative pressure in the internal space, allowing outside air to flow in through the fiber connection port. While most of the dust contained in the outside air is exhausted through the exhaust port, large amounts of dust that cannot be blown away by the gas end up adhering to the collimating lens, which is an optical component, so it is undesirable for outside air to flow into the head body.

In contrast, with the present invention, the air blown into the internal space of the head body is exhausted to the outside through the fiber connection port, preventing outside air from flowing in through the fiber connection port. As a result, dust contained in the outside air can be prevented from adhering to optical components.

A second invention is a laser emission device according to the first invention, wherein the cover member includes a first cover member and a second cover member replaceable with the first cover member, the first cover member having a first cover body that closes the maintenance opening, and the second cover member having a second cover body that closes the maintenance opening and a protective plate provided on the second cover body that overlaps the optical component when viewed from the fiber connection port.

In the second invention, the first cover member and the second cover member are interchangeable. Specifically, when the laser emission device is in operation, the first cover member closes the maintenance opening, while when the optical fiber is being attached or detached, the second cover member closes the maintenance opening.

In this way, when attaching or detaching the optical fiber, the protective plate is positioned so that it overlaps the optical component when viewed from the fiber connection port. Therefore, even if large amounts of dust that cannot be blown away by air enter the internal space through the fiber connection port, the dust can be caught by the protective plate, preventing it from adhering to the optical component. After attaching or detaching the optical fiber, the dust caught by the protective plate can be collected by removing the second cover member.

The third invention is the laser emission device of the second invention, wherein a recess is formed in the surface of the protective plate facing the fiber connection port, where the protective plate is partially recessed.

In the third invention, by forming a recess on the surface of the protective plate facing the fiber connection port, dust that has entered the internal space can be easily collected by being contained within the recess in the protective plate.

A fourth aspect of the present invention is a laser emission device according to the second or third aspect, wherein the protective plate is made of a glass material that transmits the laser light.

In the fourth aspect of the invention, by constructing the protective plate from a glass material, the second cover member can remain attached to the head body even when the laser emission device is in operation. This means that by having only the second cover member on hand, it can be used both when the laser emission device is in operation and when the optical fiber is being attached or detached, making inventory management easier.

The fifth invention is a method for attaching and detaching an optical fiber in a laser emission device according to any one of the second to fourth inventions, and includes the steps of blowing air into the internal space, removing the first lid member from the head body and then attaching the second lid member, connecting the optical fiber to the fiber connection port, removing the second lid member from the head body and then attaching the first lid member, and stopping the blowing of air into the internal space.

In the fifth invention, by blowing air into the internal space to create a positive pressure in the internal space, it is possible to prevent outside air from flowing in through the fiber connection port. Furthermore, by replacing the first cover member with the second cover member, it is possible to catch large amounts of dust particles that have entered the internal space through the fiber connection port with the protective plate. Furthermore, by stopping the air blowing after replacing the second cover member with the first cover member, it is possible to collect the dust caught by the protective plate and prevent dust from adhering to optical components.

This invention makes it possible to prevent dust from adhering to the optical components arranged inside the head body.

1 is a schematic configuration diagram of a laser beam emission device according to an embodiment of the present invention; FIG. 2 is a diagram showing the internal configuration of a laser processing head. FIG. 10 is a flowchart showing the procedure for attaching and detaching an optical fiber. FIG. 2 is a diagram showing the laser processing head at the time of product shipment. FIG. 10 is a diagram showing the state in which the cap is removed and air is blown into the internal space. 10A and 10B are diagrams showing a state in which the first cover member is removed and the second cover member is attached. FIG. 4 is a perspective view showing the configuration of a second cover member. FIG. 10 is a diagram showing a state in which optical fibers are connected. 10 is a view showing a state in which the second cover member is removed and the first cover member is attached. FIG. FIG. 10 is a diagram showing a state in which air blowing is stopped.

Embodiments of the present invention will now be described with reference to the drawings. Note that the following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

<Configuration of laser emission device>
As shown in FIG. 1 , the laser emission device 1 includes a laser oscillator 10 , an optical fiber 11 , a robot 15 , a control unit 16 , and a laser processing head 20 .

The laser oscillator 10 emits laser light LB. The laser oscillator 10 can be, for example, a solid-state laser light source, a gas laser light source, or a fiber laser light source. The laser oscillator 10 can also be a semiconductor laser light source that directly uses light emitted from a semiconductor laser, or a semiconductor laser array equipped with multiple laser light emitters.

The laser oscillator 10 is connected to the input end of the optical fiber 11. The laser processing head 20 is connected to the output end of the optical fiber 11. The laser light LB emitted from the laser oscillator 10 is transmitted to the laser processing head 20 via the optical fiber 11.

The laser processing head 20 is attached to the robot 15. By operating the robot 15, the laser processing head 20 can change the emission position and focal position of the laser light LB relative to the workpiece W.

The control unit 16 is connected to the laser oscillator 10, laser processing head 20, and robot 15. In addition to the movement speed of the laser processing head 20, the control unit 16 controls the start and stop of the output of the laser light LB, the output intensity of the laser light LB, etc.

<Configuration of laser processing head>
As shown in FIG. 2, the laser processing head 20 has a head body 21, a collimator lens 24 as optical components, a focus lens 25, and an air blowing unit 26.

The head body 21 is formed in a cylindrical shape extending in the direction of emission of the laser light LB. The head body 21 has a fiber connection port 22, a maintenance opening 23, and a laser emission port (not shown). The laser emission port opens on the surface facing the workpiece W in Figure 1.

The optical fiber 11 is detachably connected to the fiber connection port 22. Specifically, a fiber connector 12 is provided at the output end of the optical fiber 11. The optical fiber 11 is connected to the head body 21 by inserting the fiber connector 12 into the fiber connection port 22.

The maintenance opening 23 opens in a direction that intersects with the fiber connection port 22. Specifically, the maintenance opening 23 opens in the side wall of the head body 21, perpendicular to the emission direction of the laser light LB.

The collimating lens 24 is positioned downstream of the maintenance opening in the head body 21 in the emission direction of the laser light LB. The collimating lens 24 collimates the laser light LB emitted from the emission end of the optical fiber 11.

The focus lens 25 focuses the laser light LB that has been collimated by the collimator lens 24. The laser light LB focused by the focus lens 25 passes through the laser emission port and is emitted onto the workpiece W.

An internal space S is provided in the head body 21. The internal space S is the space between the collimator lens 24 and the fiber connection port 22 in the head body 21. A head nozzle 29 is provided at the bottom end of the head body 21. An air pipe 27 is detachably connected to the head nozzle 29. An air supply unit 28 is connected to the air pipe 27. The air supply unit 28 is, for example, an air pump.

Here, during laser processing, the head nozzle 29 is connected to the air supply unit 28 via the air piping 27. The head nozzle 29 blows air supplied from the air supply unit 28 downstream in the emission direction of the laser light LB. This prevents spatter generated at the processing point of the workpiece W from entering the inside of the head main body 21.

An air blowing section lid 30 is removably attached to the air blowing section 26. Here, during laser processing, the air blowing section lid 30 is attached to the air blowing section 26 to close it. Note that, as will be described in detail later, when attaching or detaching the optical fiber 11, the air blowing section lid 30 is removed from the air blowing section 26. The air piping 27 is reattached from the head nozzle 29 to the air blowing section 26.

The air blowing section 26 is located below the maintenance opening 23 on the side wall of the head body 21. The air blowing section 26 blows air supplied from the air supply section 28 into the internal space S of the head body 21.

A first cover member 31 is removably attached to the maintenance opening 23. The first cover member 31 has a first cover body 32 that closes the maintenance opening 23. When the laser emission device 1 is in operation, the first cover member 31 closes the maintenance opening 23. As will be described in more detail below, the first cover member 31 is replaced with a second cover member 35 when the optical fiber 11 is to be attached or detached.

<Optical fiber attachment/detachment method>
Incidentally, the optical fiber 11 may be temporarily removed from the head main body 21 during product shipping or replacement of the optical fiber 11, leaving the fiber connection port 22 of the head main body 21 open. In this case, dust 40 (see FIG. 4 ) contained in the outside air may enter the internal space S of the head main body 21 through the fiber connection port 22 and may adhere to the collimator lens 24.

If the laser light LB is emitted when dust 40 is attached to the collimator lens 24, there is a risk of burnout at the location on the collimator lens 24 where the dust 40 is attached.

Therefore, in this embodiment, measures are taken to prevent dust 40 from entering through the fiber connection port 22 when attaching or detaching the optical fiber 11.

As shown in FIG. 3, in step ST11, the air blowing unit lid 30 is removed from the air blowing unit 26, and the air pipe 27 connected to the head nozzle 29 is reattached to the air blowing unit 26, and the process proceeds to step ST12. Specifically, as shown in FIG. 4, the air pipe 27 is connected to the head nozzle 29. An air blowing unit lid 30 is attached to the air blowing unit 26. Then, to supply air from the air blowing unit 26 to the internal space S of the head main body 21, as shown in FIG. 5, the air blowing unit lid 30 is removed from the air blowing unit 26, the air pipe 27 is removed from the head nozzle 29, and the air pipe 27 is then connected to the air blowing unit 26.

In step ST12 of Figure 3, the cap 33 is removed from the head body 21 to open the fiber connection port 22, and the process proceeds to step ST13. Specifically, as shown in Figure 4, the optical fiber 11 is removed from the head body 21 at the time of product shipment. A cap 33 is fitted into the fiber connection port 22 to close the fiber connection port 22. A first cover member 31 is attached to the maintenance opening 23 to close the maintenance opening 23. Then, to connect the optical fiber 11 to the fiber connection port 22 of the head body 21, the cap 33 is removed as shown in Figure 5.

In step ST13 of Figure 3, air is blown out from the air blowing section 26 into the internal space S, and the process proceeds to step ST14. Specifically, as shown in Figure 5, air supplied from the air supply section 28 is blown out from the air blowing section 26 into the internal space S. This creates a positive pressure in the internal space S. The air blown out into the internal space S is then exhausted to the outside through the fiber connection port 22, thereby preventing dust 40 from entering through the fiber connection port 22.

In step ST14 of Figure 3, the first cover member 31 is removed from the head main body 21, and the process proceeds to step ST15. As shown in Figure 6, removing the first cover member 31 opens the maintenance opening 23. At this time, while the maintenance opening 23 is open, the supply of air to the internal space S continues. Therefore, the air blown into the internal space S is exhausted to the outside through the maintenance opening 23, preventing dust 40 from entering through the maintenance opening 23.

In step ST15 of Figure 3, the second cover member 35 is attached to the head body 21, and the process proceeds to step ST16. As shown in Figures 6 and 7, the second cover member 35 has a second cover body 36 and a protective plate 37. The second cover body 36 is attached to the side wall of the head body 21 and closes the maintenance opening 23.

The protective plate 37 is provided on the second lid body 36 and overlaps the collimator lens 24 when viewed from the fiber connection port 22. A recess 38 is formed on the surface of the protective plate 37 facing the fiber connection port 22, where part of the protective plate 37 is recessed.

As shown in Figure 8, when the second cover member 35 is attached to the head main body 21, the protective plate 37 is positioned so that it overlaps the collimator lens 24 when viewed from the fiber connection port 22. Therefore, even if dust 40 with a large mass that cannot be blown away by air enters the internal space S through the fiber connection port 22, the dust 40 can be caught by the protective plate 37, preventing the dust 40 from adhering to the collimator lens 24.

In step ST16 of Figure 3, the fiber connector 12 of the optical fiber 11 is connected to the fiber connection port 22 of the head main body 21, and the process proceeds to step ST17. As shown in Figure 8, when connecting the optical fiber 11, resistance is encountered from the air exhausted from the fiber connection port 22. Therefore, it is preferable to appropriately adjust the air supply pressure so that the fiber connector 12 can be inserted smoothly.

In step ST17 of Figure 3, the second cover member 35 is removed from the head main body 21, and the process proceeds to step ST18. As shown in Figure 9, large amounts of dust 40 that could not be blown away by air are caught in the recesses 38 of the protective plate 37 of the second cover member 35, and can be collected by removing the second cover member 35. At this time, the maintenance opening 23 is open, but the supply of air to the internal space S continues. Therefore, the air blown into the internal space S is exhausted to the outside through the maintenance opening 23, preventing dust 40 from entering through the maintenance opening 23.

In step ST18 of Figure 3, the first cover member 31 is attached to the maintenance opening 23 of the head main body 21, and then the process proceeds to step ST19. As shown in Figure 10, by closing the maintenance opening 23 with the first cover member 31, it is possible to prevent dust 40 from entering through the maintenance opening 23.

In step ST19 of Figure 3, the operation of the air supply unit 28 is stopped, air blowing from the air blowing unit 26 is stopped, and the process proceeds to step ST20. As shown in Figure 10, the fiber connection port 22 of the head main body 21 is closed by the fiber connector 12, and the maintenance opening 23 is closed by the first cover member 31. This prevents dust 40 from entering the head main body 21.

In step ST20 of Figure 3, the air pipe 27 connected to the air blowing unit 26 is removed and replaced with the head nozzle 29, and the air blowing unit cover 30 is attached to the air blowing unit 26. As a result, as shown in Figure 2, the laser processing device 1 is ready for laser processing, and the attachment and detachment of the optical fiber 11 is completed.

Other Embodiments
The above embodiment may be configured as follows.

In the above embodiment, it is assumed that the protective plate 37 of the second cover member 35 is made of a metal material, but this is not limited to this form.

For example, the protective plate 37 of the second lid member 35 may be made of a glass material that transmits the laser light LB. By making the protective plate 37 out of a glass material in this way, the second lid member 35 can remain attached to the head body 21 even when the laser emission device 1 is in operation. This means that by having only the second lid member 35 on hand, it can be used both when the laser emission device 1 is in operation and when the optical fiber 11 is being attached or detached, making inventory management easier.

As explained above, the present invention has the highly practical effect of preventing dust from adhering to optical components arranged inside the head body, making it extremely useful and highly applicable industrially.

REFERENCE SIGNS LIST 1 Laser emission device 11 Optical fiber 21 Head body 22 Fiber connection port 23 Maintenance opening 24 Collimating lens (optical component)
26 Air blowing portion 31 First cover member (cover member)
32 First lid body 35 Second lid member (lid member)
36 Second cover body 37 Protective plate 38 Recess LB Laser light S Internal space

Claims (5)

A laser emission device that emits laser light transmitted through an optical fiber, comprising:
a head body having a fiber connection port for detachably connecting the optical fiber and a maintenance opening that opens in a direction intersecting the fiber connection port;
an optical component disposed downstream of the maintenance opening in the head body in the emission direction;
an air blowing portion that blows air into an internal space between the optical component and the fiber connection port in the head body;
a cover member that is detachably attached to the head body and closes the maintenance opening,
The cover member includes a first cover member and a second cover member replaceable with the first cover member,
the first cover member has a first cover body that closes the maintenance opening,
The second cover member of the laser beam emission device includes a second cover body that closes the maintenance opening, and a protection plate that is provided on the second cover body and overlaps the optical component when viewed from the fiber connection port. 2. The laser beam emission apparatus according to claim 1,
The laser beam emission device has a surface of the protection plate facing the fiber connection port, the surface being formed with a recess in which part of the protection plate is recessed. 3. The laser beam emission device according to claim 1,
The protection plate is made of a glass material that transmits the laser light. 4. An optical fiber attachment/detachment method for attaching/detaching the optical fiber in the laser beam emitter according to claim 1, comprising:
blowing air into the internal space;
and attaching the second cover member after removing the first cover member from the head body. The optical fiber attachment/detachment method according to claim 4,
a step of connecting the optical fiber to the fiber connection port after attaching the second cover member;
a step of attaching the first cover member after removing the second cover member from the head main body;
and stopping the blowing of air into the internal space.