JPS6121191Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a laser processing device, and more specifically, a laser processing device that can easily adjust the laser beam to focus on a minute spot diameter on the upper surface of a workpiece, etc. This is related to.

In a laser processing apparatus, whether or not a condensing lens that condenses a laser beam is focused at a predetermined position on a workpiece is an important issue in terms of processing accuracy and processing efficiency. However, in laser processing devices, particularly in carbon dioxide laser processing devices, since the carbon dioxide laser emits invisible light, it has been difficult to detect whether the focus of the condenser lens is focused on the upper surface of the workpiece or the like. Therefore, in the past, a visible light source was provided as an auxiliary separate from the carbon dioxide laser oscillation device, and the visible light from this light source was used to determine whether the visible light was focused on the top surface of the workpiece, etc. It is common to confirm that However, in this case, since an auxiliary light source is required, the configuration becomes complicated and expensive. Therefore, sometimes it is necessary to intermittently project a laser beam onto the top of the workpiece and visually observe the flying of sparks from the workpiece to empirically determine whether the focus is on the top of the workpiece. I am doing it. However, in this case, it is based on experience, requires skill, and is not necessarily accurate due to individual differences.

This invention was devised in view of the conventional problems mentioned above, and its purpose is to easily focus the laser beam on a predetermined position on the workpiece, regardless of whether the laser beam is visible light or invisible light. The present invention provides a laser processing device that can perform the following steps.

Yet another purpose is to provide a laser processing device that improves fusing precision and fusing efficiency by accurately focusing on a predetermined position on a workpiece. It will become clear by describing a preferred embodiment of the lever device.

As shown in FIG. 1, the laser processing apparatus 1 according to this invention is composed of a suitable laser oscillation device 3 and a C-shaped main body frame 5. Since the laser oscillation device 3 may be a general laser oscillation device, a detailed explanation of its configuration will be omitted.

The main body frame 5 includes a lower frame 9 that supports a table 7 that movably supports a plate-shaped work W on the upper surface, an upper frame 11 located above the lower frame 9, and a lower frame 9 and an upper frame 11. It is formed into a C-shape by a vertical frame 13 that connects the two.

A plurality of anti-friction devices 7a each having rotatable steel balls are mounted on the upper surface of the table 7 in order to smoothly support the workpiece W. On both the front and rear sides of the table 7 (both the front and back sides of the drawing in FIG. 1), there are Y extending in the left-right direction (left-right direction in FIG. 1).
A shaft guide bar 15 is attached to each Y-axis guide bar 15, and a Y-axis carriage 17 that is movable in the left-right direction along the Y-axis guide bar 15 is attached to each Y-axis guide bar 15, respectively. Both Y-axis carriages 17 are integrally connected to a connecting body 19 extending in the X-axis direction (horizontal direction perpendicular to the Y-axis guide bar 15) with a slight distance between them and the top surface of the table 7. are connected. Therefore,
Both Y-axis carriages 17 move integrally in the Y-axis direction (left-right direction in FIG. 1).

An X-axis guide bar 21 extending in the X-axis direction perpendicular to the Y-axis guide bar 15 is attached to the connecting body 19. A movable X-axis carriage 23 is attached. And this X
A suitable number of work clamps 25 are attached to the shaft carriage 23 and are capable of gripping the edge of the work W movably supported on the upper surface of the table 7.
Therefore, by appropriately moving the X-axis carriage 23 along the X-axis guide bar 21, the workpiece W is moved in the X-axis direction while being held by the workpiece clamp 25. Therefore, as described above, by moving the Y-axis carriage 17 in the Y-axis direction and moving the X-axis carriage 23 in the X-axis direction, the work W can be appropriately moved and positioned in the X-axis direction and the Y-axis direction. It is something that can be done.
The movement and positioning of the Y-axis carriage 17 in the Y-axis direction and the movement and positioning of the X-axis carriage 23 in the X-axis direction are controlled by an appropriate control device (not shown) such as a numerical control device or a computer.
This is done automatically under the control of

A beam bender (reflector) 27 that refracts the laser beam LB from the laser oscillation device 3 perpendicularly to the top surface of the table 7 is mounted near the tip of the upper frame 11 . and,
A focal position adjustment device 29 is mounted at an appropriate lower position of the beam bender 27. This focal position adjustment device 29 is used to adjust the laser beam LB so that it is focused on the upper surface of the workpiece W to a minute spot diameter when the laser beam LB is projected onto the upper surface of the workpiece W. This focal position adjustment device 29 includes a lens holding tube 33 holding a condensing lens 31 for condensing the laser beam LB. It is provided so as to be movable and adjustable in the vertical direction (in the perpendicular optical axis direction of the laser beam LB) by an appropriate configuration such as being screwed together with the laser beam LB. Therefore, even if the thickness of the workpiece W changes, the focus of the condenser lens 31 can always be adjusted to the top surface of the workpiece W by appropriately adjusting the position of the lens holding cylinder 33 in the vertical direction. It is something that can be done. Although not shown,
The focus position adjustment device 29 is provided with a nozzle that jets assist gas toward the laser processing (fusion cutting) position of the workpiece W.

As described above, the laser beam LB from the laser oscillation device 3 is projected onto the workpiece W on the table 7, and assist gas is ejected from the nozzle, and the workpiece W is appropriately moved in the X-axis direction and the Y-axis direction as described above. By doing so, the workpiece W can be laser-processed (fused-cut) into an appropriate shape.

However, it is difficult to detect whether or not the laser beam LB is focused on a minute spot diameter on the upper surface of the workpiece W. Therefore, in this invention, the focus position is adjusted so that the detection can be performed extremely easily. A detection device 37 is suitably mounted on the table 7.

The focal position detecting device 37 detects the lower frame 9 within a table opening 39 provided in the table 7 opposite to the focal position adjusting device 29.
It is removably attached to the That is, a base plate 41 is detachably attached to the lower frame 9 within the table opening 39, and an appropriate number of positioning stops 43 for positioning the base plate 41 are fixed thereto.
The base plate 41 has a laser beam LB.
A guide in which a hole plate 47, which is a hole member equipped with a small hole 45 (see Fig. 2) having approximately the same diameter as the focal spot diameter of the laser beam LB, is supported in a position adjustable in the optical axis direction (vertical direction) of the laser beam LB. A support 49 is vertically erected. Further, the base plate 41 is provided with a laser beam sensing device 51 that outputs an output according to the light intensity of the laser beam LB that has passed through the small hole 45 of the hole plate 47.
is attached, and an appropriate cover 53 is also attached. The laser beam sensing device 51 includes:
It consists of a suitable light sensing element such as a photoelectric element. When the positioning stopper 43 abuts the base plate 41 for positioning, the small hole 45 of the hole plate 47 is exposed to a laser beam.
This acts to align the vertical optical axis of the LB.

Therefore, along the guide column 49, the hole plate 47
Move up and down appropriately, so that the top surface of the hole plate 47 is aligned with the table 7.
After adjusting the position so that it coincides with the upper surface of the work W to be placed on the upper surface, the laser beam LB is projected through the focal position adjustment device 29, and the laser beam LB passes through the small hole 45 of the hole plate 47. The laser beam is irradiated onto the laser beam sensing device 51. Therefore,
The laser beam sensing device 51 outputs an output according to the amount of the irradiated laser beam LB.

By the way, when the focal position of the condensing lens 31 in the focal position adjustment device 29 and the small hole 45 of the hole plate 47 match (position B in FIG. 2), as shown in FIG. All of the laser beam LB that has passed through the condenser lens 31 is irradiated onto the laser beam sensing device 51. However, if the focal position of the condensing lens 31 and the small hole 45 of the hole plate 47 do not match (see A and C in FIG.
As is clear from FIG. 2, a portion of the laser beam LB that has passed through the condenser lens 31 is irradiated onto the laser beam sensing device 51 at this position. Therefore, the aperture lens 31 and the aperture plate 47
The output of the laser beam sensing device 51 is expressed as shown in FIG. 3, with the horizontal axis representing the positional relationship with the laser beam sensing device 51 and the vertical axis representing the output of the laser beam sensing device 51. Therefore, while looking at the instrument panel (not shown) connected to the laser beam sensing device 51, move the lens holding cylinder 33 in the focal position adjustment device 29 in the vertical direction to maximize the output of the laser beam sensing device 51. By adjusting in this manner, the focal position of the condensing lens 31 can be aligned with the upper surface of the workpiece W to be placed on the upper surface of the table 7.

As mentioned above, after adjusting the focus position, in order to avoid interference with the workpiece W placed on the table 7, the focus position detection device 37 is removed from the position of the table opening 39, or ,
It retracts from the top surface of the table 7, and moves linearly or rotationally to a position away from the optical axis of the laser beam LB, and retreats to an appropriate position. In this way, after the focal position detection device 37 is retracted to an appropriate position from the optical axis of the laser beam LB, the workpiece W is placed on the table 7 and held by the workpiece clamp 25.
Laser processing is performed. As mentioned above, the structure for retracting the focal position detection device 37 to an appropriate position can take various structures, so a detailed explanation of the structure will be omitted.

As mentioned above, when adjusting the focal position of the condensing lens 31 using the focal position detection device 37, the output of the laser oscillation device 3 may be lowered or
Alternatively, a slit plate or a half mirror may be inserted in the path of the laser beam LB from the laser oscillation device 3 to the focal position adjustment device 29, so that the laser beam LB enters the laser beam sensing device 51.
It is desirable to attenuate the energy of

As described above, this invention has a focus position adjustment device that projects a laser beam from a laser oscillation device onto the workpiece and can freely adjust the focal point position above a table that movably supports a workpiece on its upper surface. and a base plate mounted on the lower frame facing the focal position adjusting device at a position below the top surface of the table, is appropriately retracted from the optical axis position and the optical axis position of the laser beam from the focal position adjusting device. The base plate is provided with a laser beam sensing device that outputs an output according to the amount of light of the laser beam, and the laser beam is moved between the focal position adjusting device and the laser beam sensing device. Since the hole member is provided with a small hole having approximately the same diameter as the focal spot diameter, the position of the laser beam in the optical axis direction of the laser beam can be freely adjusted. Therefore, it is extremely easy to adjust the laser beam so that it is focused on a minute spot diameter on the upper surface of the workpiece. Therefore, even if the thickness of the workpiece changes, laser processing (fusion cutting) can always be performed with high precision.

Note that this invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments by making appropriate design changes.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing a section of a part of the device according to this invention, and FIG. 2 is an explanatory diagram showing the amount of laser beam passing through depending on the positional relationship between the condenser lens and the aperture plate. FIG. 3 is an explanatory diagram showing the relationship between the positional relationship between the condenser lens and the aperture plate and the output of the laser beam sensing device. Explanation of the symbols representing the main parts of the drawing, 7...
Table, 3... Laser oscillation device, 29... Focus position adjustment device, 9... Lower frame, 41... Base plate, 51... Laser beam sensing device,
45...small hole, 47...hole plate W work, LB...
laser beam.

Claims (1)

[Scope of utility model registration request] A focus position adjustment device that projects a laser beam from a laser oscillation device onto the workpiece and can freely adjust the focus position is disposed above a table that movably supports a workpiece on its upper surface, and A base plate mounted on the lower frame facing the focal position adjusting device at a lower position is provided so as to be movable to an optical axis position of the laser beam from the focal position adjusting device and a retracted position appropriately retracted from the optical axis position. A laser beam sensing device that outputs an output according to the amount of light of the laser beam is attached to the base plate, and a spot having a diameter approximately the same as the focal spot diameter of the laser beam is provided between the focal position adjusting device and the laser beam sensing device. A laser processing device characterized in that a hole member having a small hole is provided whose position can be freely adjusted in the optical axis direction of a laser beam.