A laser rotating cleaning head with an inclined light-emitting scanning focal point arc distribution and a cleaning method

Abstract

The application discloses a laser rotary cleaning head and a cleaning method for scanning focal point arc distribution of inclined light emission, and the laser rotary cleaning head comprises a support frame, a vibrating mirror, a hollow motor, a laser, a rotary reflecting device and a mirror seat; the vibrating mirror and the hollow motor are oppositely arranged on two sides of the support frame, an optical fiber interface is arranged on a light inlet of the vibrating mirror, and an output head of the laser is connected to the optical fiber interface; the rotary reflecting device is arranged on the hollow motor, a positioning indicator lamp is arranged at the center of the bottom of the outer side of the rotary reflecting device; the mirror seat is arranged on the side wall of the rotary reflecting device; a first mirror is arranged in the rotary reflecting device, and a second mirror, a focusing mirror and a protective window lens are sequentially arranged in the mirror seat along the light path propagation direction; the laser emitted by the laser is sequentially irradiated to the part to be cleaned of the workpiece at an inclined angle through the vibrating mirror, the first mirror and the second mirror, the focusing mirror and the protective window lens. The scanning focal point is an arc surface, and the arc surface of the circumferential welding is cleaned without dead angle for 360 degrees.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of laser rotary cleaning head and cleaning method of scanning focal point arc distribution of light obliquely, belong to laser cleaning field. BACKGROUND

[0002] There are usually three cleaning methods for metal material surface to appear rust spot, corrosion, oil stain and other contaminant spots, which are chemical cleaning, mechanical cleaning and laser cleaning. Chemical cleaning needs to use chemical reagent, and with the increasing of people's environmental protection and safety awareness, the requirement of industrial environmental protection in China is also higher and higher, in the case of reaching environmental protection requirement, the types of chemical used in industrial production cleaning are less and less. The method of mechanical cleaning is to use contact cleaning, which has mechanical effect on the surface of the cleaned object, can easily damage the surface layer of the cleaned object, and can also easily cause secondary pollution. And the metal dust produced by contact cleaning can be easily inhaled by workers, affecting the health of workers. Laser cleaning does not need any chemical reagent, no grinding, no stress, no consumables, has the characteristics of no grinding, non-contact, little damage, high efficiency, green and other characteristics, is suitable for cleaning the surface of various materials, is the most reliable and effective metal cleaning method, and has been gradually applied in various fields. The existing cleaning head is perpendicular to the surface of the object to emit light, which is difficult to clean the root of the arc with steps or angles. SUMMARY

[0003] The present application provides a kind of laser rotary cleaning head and cleaning method of scanning focal point arc distribution of light obliquely, simple structure, convenient control, realize 360 ° no dead angle cleaning, can be obliquely 45 ° light, scanning focal point is arc surface, can clean the root of the arc welding position of cylindrical workpiece.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0005] A kind of laser rotary cleaning head of scanning focal point arc distribution of light obliquely, including support frame, galvanometer, hollow motor, laser, rotating reflection device and mirror seat;

[0006] Galvanometer and hollow motor are oppositely installed on both sides of support frame, and the light inlet of galvanometer is provided with a fiber interface, and the output head of laser is connected to the fiber interface;

[0007] Rotating reflection device is pressed on hollow motor and rotates under the drive of hollow motor, and the central part of the bottom of the outer side of rotating reflection device is provided with a positioning indicator light, which can rotate at high speed with unlimited angle, clean the annular weld at high speed, and achieve 360 ° rotary cleaning that ordinary cleaning head cannot complete;

[0008] Mirror seat is installed on the side wall of rotating reflection device and rotates with the rotation of rotating reflection device;

[0009] The first mirror is arranged in the rotating reflection device, and the second mirror, the focusing mirror and the protective window lens are sequentially arranged in the mirror seat along the light path propagation direction; the laser emitted by the laser device sequentially passes through the galvanometer, the first mirror and the second mirror, is focused by the focusing mirror, and finally passes out of the protective window lens and is obliquely irradiated onto the part to be cleaned of the workpiece.

[0010] The second mirror is adjusted to adjust the light direction for different cleaning surfaces.

[0011] The hollow rotating motor, the single-lens focusing and the reflection structure are designed to realize the arc distribution of the scanning focal point, so that the laser is perpendicular to the welding solidification, and the focal point is matched with the arc-shaped welding solidification.

[0012] The support frame and the side surface of the rotating reflection device are provided with light transmission holes, so that the laser emitted by the laser device sequentially passes through the galvanometer, the first mirror and the second mirror, is focused by the focusing mirror, and finally can be obliquely irradiated onto the part to be cleaned of the workpiece.

[0013] The workpiece is an object to be cleaned by the laser. The oblique angle is the included angle between the outgoing light and the axial direction of the workpiece.

[0014] As one of the specific implementation schemes, the first mirror and the second mirror are both arranged at an angle of 45°, and the reflecting surfaces of the first mirror and the second mirror are oppositely arranged, the laser emitted by the laser device sequentially passes through the galvanometer, the first mirror and the second mirror, is focused by the focusing mirror, and finally is obliquely irradiated onto the part to be cleaned of the workpiece at an angle of 45°. The 45° oblique irradiation can effectively utilize the arc-distributed focal point for cleaning. The 45° oblique angle has a wide range of applications and can realize the cleaning of the stepped or angular arc root.

[0015] The above-mentioned 45° is the included angle between the laser propagation direction and the axial direction of the workpiece (usually the vertical direction). The laser of the present application is obliquely irradiated onto the part to be cleaned of the workpiece at an angle of 45°, the scanning focal point is an arc surface, which can clean the arc welding position of the cylindrical workpiece root, and can rotate at an infinite angle and high speed, so that the annular weld is cleaned at high speed, and the 360° arc root rotating cleaning which cannot be completed by the ordinary cleaning head is realized.

[0016] Common optical fiber interfaces include QBH interface, QD interface, QCS interface and RK interface, and different interfaces can be used to adapt to different lasers.

[0017] As one of the specific implementation schemes, the cleaning head further comprises a galvanometer adapter plate, the support frame comprises a horizontal mounting plate, vertical side plates are arranged at both ends of the upper surface of the horizontal mounting plate, and a reinforcing rib is arranged between the side plates and the horizontal mounting plate; the galvanometer is installed on the upper surface of the horizontal mounting plate through the galvanometer adapter plate. In use, the laser rotary cleaning head with the arc distribution of the scanning focal points can be installed on the support column on site by using the side plates.

[0018] In order to facilitate cleaning, the support column is a 7-shaped support frame, the bottom of the 7-shaped support frame is installed on the ground, and the top end of the 7-shaped support frame is connected with the side plates.

[0019] The hollow motor is a DD hollow motor. DD means direct drive; and the positioning indicator light is an infrared indicator light.

[0020] The mirror seat is provided with an adjusting ring for adjusting the focal point position of the focusing lens. The adjusting ring is rotated to adjust the focal point position of the focusing lens. For specific structure, refer to the existing focal length adjusting ring. No special improvement is made in the present application, and thus, no further description is given.

[0021] In order to improve the focusing effect, the focusing mirror is a single focusing mirror, the incident surface of the focusing mirror is a convex surface, the exit surface is a plane, the center thickness of the focusing mirror is 12.7 mm, the curvature radius of the convex surface is 77.30±0.01 mm, and the aperture of the focusing mirror is 74-76 mm. By using the field curvature characteristics of the single lens on the image plane, the scanning focal points are distributed in an arc shape, the focal points are matched with the arc-shaped welding solidification, and the laser energy is concentrated on the concave surface of the cylindrical workpiece to achieve better cleaning effect.

[0022] The material of the focusing mirror is NBK-7, the aperture is 75 mm, and the focal length F is 150 mm; the focusing mirror is coated with a 650-1050 nm anti-reflection film.

[0023] The materials of the protective window lens, the first mirror and the second mirror are all JGS1.

[0024] The cleaning method of the laser rotating cleaning head with the inclined light-emitting scanning focal point circular arc distribution is as follows: the workpiece to be cleaned is translated so that the center position of the workpiece is concentric with the red light indication of the positioning indicator, the height of the workpiece is adjusted so that the surface of the workpiece to be cleaned and the focal point of the laser overlap, and the light-emitting state is observed by opening the low-power laser to determine whether the light-emitting state is the focal point position of the laser (the focal point position can also be adjusted by adjusting the position of the focusing mirror). The motor of the hollow motor (the driving motor is common sense) is started, and the rotation of the red light indication of the laser and the vibration mirror motor (the laser can emit two kinds of light, one is red light indication, and the other is laser, the red light indication is completely consistent with the laser path, and the red light indication is used to determine the cleaning position) is matched, and whether the travel of the red light circle (formed by the red light indication on the laser) rotating one circle meets the cleaning range is observed. After the position of the workpiece is determined, the laser power, the vibration mirror scanning speed and the frequency pulse width of the laser are set through the PLC. The hollow motor is started, the hollow motor drives the rotating reflection device and the mirror seat to rotate, and after a delay, the laser emits light. After the motor rotates one circle, the laser is turned off, and after a delay, the motor stops, and the 360° cleaning without dead angle is completed.

[0025] The setting and control of the PLC of the present application all adopt the prior art, which is a mature technology, and the present application does not have special improvement, therefore, it will not be described in detail.

[0026] A mobile cabinet can be configured, which integrates the laser, the laser power supply, the laser cleaning control card, the touch display screen, the AC contactor, the direct-drive hollow motor driver, the delay relay, the fan, the switching power supply and other components, and specific existing conventional design can be adopted.

[0027] The technologies not mentioned in the present application all refer to the prior art.

[0028] The laser rotating cleaning head with the inclined light-emitting scanning focal point circular arc distribution of the present application has the following beneficial effects:

[0029] 1. 360° cleaning without dead angle, which can be used for pre-welding cleaning to remove oil stains and the like and post-welding cleaning to remove black ash and the like, and the surface cleanliness after cleaning reaches 38 or more according to the detection of a pen;

[0030] 2. Large-aperture focusing mirror and hollow rotating motor for cleaning, large light aperture, and the light aperture is more than 90% of the diameter (aperture) of the mirror;

[0031] 3. Single focusing mirror is adopted, the field curvature characteristics of the single lens are used to make the focal point surface present an arc surface, and the concave arc welding position at the root of the cylindrical workpiece can be well matched;

[0032] 4. The hollow light path of the reflection can rotate at an infinite angle, and the light-emitting scanning is inclined, so that the high-quality cleaning of the circumferential fillet welding seam at the root of the cylinder is realized;

[0033] 5. Fast cleaning speed, high efficiency and high precision;

[0034] 6. Novel structure, adjustable focus;

[0035] 7. The optical axis center is controlled by a galvanometer and uses digital electronic adjustment, making adjustment convenient. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the laser rotating cleaning head with the inclined light-emitting scanning focus arc distribution of the present invention;

[0037] Figure 2 for Figure 1 A three-dimensional image;

[0038] Figure 3 for Figure 1 MM-directed view;

[0039] Figure 4 This is a schematic diagram of the optical path of the laser rotating cleaning head with the tilted light-emitting scanning focus distributed in an arc according to the present invention;

[0040] Figure 5 This is a schematic diagram of the focusing lens of the present invention;

[0041] Figure 6 for Figure 5 View from AA direction;

[0042] Figure 7 This is a schematic diagram of the workpiece to be cleaned.

[0043] Figure 8 for Figure 7 A schematic diagram of the longitudinal section (the arrow points to the surface to be cleaned);

[0044] Figure 9 This is an application scenario diagram for a laser rotary cleaning system;

[0045] In the diagram, 1 is the support frame, 101 is the horizontal mounting plate, 102 is the side plate, 103 is the reinforcing rib, 2 is the galvanometer, 201 is the galvanometer adapter plate, 3 is the hollow motor, 4 is the QCS laser head, 401 is the QCS chuck, 402 is the pressure block on the QCS chuck, 5 is the rotating reflection device, 501 is the first reflecting mirror, 6 is the reflecting mirror base, 601 is the second reflecting mirror, 602 is the focusing mirror, 603 is the protective window lens, 604 is the adjusting ring, 605 is the first pressure ring, 606 is the inner cylinder, 607 is the second pressure ring, 608 is the sponge lens cover, 609 is the reflecting mirror cover, 610 is the outer cylinder, 7 is the positioning indicator light, 8 is the cylindrical workpiece, 9 is the connecting plate, 10 is the L-shaped bracket, and 11 is the protective cover. Detailed Implementation

[0046] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0047] The directional terms used in this application, such as up and down, left and right, horizontal, and vertical, are all based on the relative orientations or positional relationships shown in the attached drawings and should not be construed as absolute limitations on this application.

[0048] Example 1

[0049] like Figures 1-3 As shown, a laser rotating cleaning head with an inclined beam scanning focal point distributed in an arc includes a support frame, an LCS10mm beam galvanometer (LCS2DSC10A-3), a galvanometer adapter plate, a DD hollow motor, a QCS laser head, a rotating reflection device, and a reflector mount.

[0050] The support frame includes a horizontal mounting plate, with vertically arranged and opposite side plates at both ends of the upper surface of the horizontal mounting plate, and reinforcing ribs between the side plates and the horizontal mounting plate; the galvanometer is mounted on the upper surface of the horizontal mounting plate via a galvanometer adapter plate, and the DD hollow motor is mounted on the lower surface of the horizontal mounting plate and is arranged opposite to the galvanometer; the galvanometer has a QCS chuck on its light inlet, and the QCS laser head is connected to the QCS chuck and fixed by the clamping block on the QCS chuck;

[0051] The rotating reflector is mounted on a hollow motor and rotates under the drive of the DD hollow motor. An infrared positioning indicator light is provided at the center of the bottom of the outer side of the rotating reflector.

[0052] The reflector mount is installed on the side wall of the rotating reflector via a connecting plate and rotates as the rotating reflector rotates;

[0053] The rotating reflector is equipped with a first reflector. The reflector base is provided with a second reflector, a focusing mirror, and a protective window mirror in sequence along the direction of light propagation. The reflector base is provided with an adjustment ring for adjusting the focal point of the focusing mirror. The horizontal mounting plate, the galvanometer adapter plate, the side wall of the rotating reflector, and the connecting plate are all provided with light-transmitting holes to ensure that the laser emitted from the QCS laser head passes through the galvanometer, the first reflector, and the second reflector in sequence, and is then focused by the focusing mirror, and finally shines on the part of the workpiece to be cleaned at an inclined angle through the protective window mirror.

[0054] Example 2

[0055] Based on Example 1, the following improvements were made: Both the first and second reflectors are positioned at 45°, and the reflecting surfaces of the first and second reflectors face each other. The laser emitted by the laser passes sequentially through the galvanometer, the first and second reflectors, and is then focused by the focusing lens. Finally, it shines through the protective window lens at a 45° angle onto the part of the workpiece to be cleaned. The optical path diagram is shown below.Figure 4 As shown, there are light-transmitting holes in the center of the horizontal mounting plate, the center of the galvanometer adapter plate, the side wall of the rotating reflector, and the center of the connecting plate. The laser emitted from the QCS laser head propagates vertically downward after passing through the galvanometer, passes through the DD hollow motor, and reaches the first reflector in the rotating reflector. After being reflected horizontally by the 45° first reflector, it reaches the second reflector of the reflector mount. After being reflected again by the 45° second reflector, it passes through the focusing lens and the protective window lens at a 45° angle and then irradiates the part of the workpiece to be cleaned at a 45° angle.

[0056] Example 3

[0057] Based on Example 2, the following improvements were made: Figures 5-6 As shown, the focusing lens is a single-piece lens with a convex incident surface and a flat exit surface. The center thickness of the focusing lens is 12.7 mm, and the radius of curvature of the convex surface is 77.30 mm. The focusing lens is made of NBK-7 material, has a diameter of 75 mm, a focal length of 150 mm, and a light-transmitting aperture > 67.5 mm. The focusing lens is coated with a 900 nm thick anti-reflection coating (double-sided coating, BBAR Ravg < 0.5% FROM 650 nm-1050 nm). The protective window lens, the first reflecting mirror, and the second reflecting mirror are all made of JGS1 material. Figure 4 As shown, the scanning focus after being focused by the focusing lens is a convex arc surface, which matches and fits the welding position of the concave arc surface at the root of the cylindrical workpiece. In this way, the cleaning of the concave arc surface at the root of the cylindrical workpiece can be completed by rotating the hollow motor once.

[0058] like Figure 3 As shown, the reflector mount includes an outer cylinder, an inner cylinder, a reflector cover, and a sponge lens cover. The focusing lens and the protective window lens are both installed inside the inner cylinder. The focusing lens is fixed by a first pressure ring, and the protective window lens is fixed by a second pressure ring. The inner cylinder is installed at the light-emitting end of the outer cylinder. The adjustment ring is located on the outermost side and is used to rotate and adjust the focus position. The structure and principle of the adjustment ring refer to existing focusing technology, and this application has not made any special improvements to it, so it will not be described in detail here. The sponge lens cover is placed on the light-emitting end of the outer cylinder to protect the lens. When focusing and use are required, the sponge lens cover is removed. The reflector cover is installed at the light-inlet end of the outer cylinder, and the second reflector is installed inside the reflector cover.

[0059] Example 4

[0060] Based on Example 3, the following improvements were made: Figure 9 As shown, the laser rotating cleaning head with its tilted scanning focal point distributed in an arc is mounted on the top end of a 7-shaped bracket via a side plate. The bottom of the 7-shaped bracket is mounted on the ground. Figure 9In this design, a protective cover is installed around the laser rotating cleaning head with its tilted, arc-shaped scanning focus. During cleaning, only one laser rotating cleaning head is used, completing one full rotation. The figure shows the dynamic effect during operation; therefore, the rotating part is arranged in a circular array, appearing as multiple cleaning heads, but in reality, it is only one. The workpiece to be cleaned is held and cleaned by a robotic arm, which is not shown in the figure (this application does not make any improvements to the robotic arm). An air knife is installed on the protective cover to blow away sparks and dust generated during cleaning, preventing contamination of the lens and saving costs.

[0061] Figures 7-8 The workpiece to be cleaned is a cylindrical workpiece with a circular arc welded at the root, forming a concave circular arc surface (the surface to be cleaned), made of aluminum alloy. Figure 8 (as indicated by the middle arrow) Figure 9 This diagram illustrates an application scenario for the laser rotary cleaning head with an inclined beam-emitting scanning focal arc distribution. During cleaning, the workpiece to be cleaned is moved so that its center is concentric with the red light indicator. The workpiece height is adjusted so that the surface to be cleaned overlaps with the laser focal point. A low-power laser can be used to observe whether the beam emission is at the laser focal point (the focal point can also be adjusted by adjusting the focusing lens). The hollow motor is started, and in conjunction with the red light indicator on the laser and the rotation of the galvanometer motor, the travel of one revolution of the red light circle (formed by the red light indicator on the laser) is observed to ensure it falls within the cleaning range. Once the workpiece position is determined, the laser power is set to 90% (full power is 300W, 90% is 270W), the galvanometer scanning speed to 10000mm / s, and the laser frequency to 28kHz with a pulse width of 250ns via the PLC. The hollow motor is then started, driving the rotating reflector and reflector mount to rotate. After a delay, the laser emits light immediately. Figure 1 As shown, the light is directed at a 45° angle onto the area of ​​the workpiece to be cleaned. Figure 4 As shown, the laser passes sequentially through a galvanometer, a first reflecting mirror, and a second reflecting mirror, and then is focused by a focusing mirror. The focal surface is a downward-convex arc surface, which matches the concave arc surface at the root of the workpiece. After the motor rotates one revolution, the laser is turned off first, and after a delay, the motor stops, completing 360° cleaning without dead angles. In practice, the arc distribution of the laser beam scanning focal point allows the entire arc welding surface to be cleaned in one revolution of the motor. This cleaning operation covered 500 workpieces, with each workpiece being cleaned by rotating the reflecting mirror mount one revolution. Before cleaning, the surfaces were covered with oil and dust. After cleaning, the surface cleanliness of each workpiece reached a level of 38 mN / m or higher (the standard is 36) as measured by a pen, with a damage rate of 0 (this application defines a damage rate of less than 0.002% as zero damage; if a workpiece shows damage greater than 0.002% on its surface after cleaning, it is defined as a damaged part), no cleaning marks, and a pass rate of 100%.

Claims

1. A laser rotating cleaning head with an inclined beam-emitting scanning focal point distributed in an arc, characterized in that: Includes a support frame, galvanometer, hollow motor, laser, rotating reflector, and reflector mount; The galvanometer and the hollow motor are mounted opposite each other on both sides of the support frame. The galvanometer has an optical fiber interface on its light inlet, and the laser's output head is connected to the optical fiber interface. The rotating reflector is mounted on a hollow motor and rotates under the drive of the hollow motor. A positioning indicator light is provided at the center of the bottom of the outer side of the rotating reflector. The reflector mount is installed on the side wall of the rotating reflector and rotates as the rotating reflector rotates; The rotating reflector is equipped with a first reflector. The reflector base is provided with a second reflector, a focusing mirror and a protective window mirror in sequence along the direction of light propagation. The laser emitted by the laser passes through the galvanometer, the first reflector and the second reflector in sequence, and is then focused by the focusing mirror. Finally, it passes through the protective window mirror and shines on the part of the workpiece to be cleaned at an inclined angle. The focusing lens is a single-element focusing lens with a convex incident surface and a flat exit surface. The center thickness of the focusing lens is 12.7±0.01mm, and the radius of curvature of the convex surface is 77.30±0.01mm. The scanning focus of a laser rotating cleaning head with an inclined beam-emitting scanning focus distributed in an arc is an arc surface.

2. The laser rotating cleaning head with tilted beam-emitting scanning focal point arc distribution as described in claim 1, characterized in that: The first and second reflectors are both set at 45°, and the reflective surfaces of the first and second reflectors face each other. The laser emitted by the laser passes through the galvanometer, the first and second reflectors in sequence, and is then focused by the focusing lens. Finally, it shines on the part of the workpiece to be cleaned at a 45° angle through the protective window lens.

3. The laser rotating cleaning head with an inclined beam-emitting scanning focal point arc distribution as described in claim 1 or 2, characterized in that: It also includes a galvanometer adapter plate, and the support frame includes a horizontal mounting plate. The upper surface of the horizontal mounting plate has vertical and oppositely arranged side plates at both ends, and a reinforcing rib is provided between the side plates and the horizontal mounting plate. The galvanometer is mounted on the upper surface of the horizontal mounting plate through the galvanometer adapter plate.

4. The laser rotating cleaning head with tilted beam-emitting scanning focal point arc distribution as described in claim 3, characterized in that: It also includes a 7-shaped bracket, the bottom of which is installed on the ground, and the top end of which is connected to a side plate.

5. The laser rotating cleaning head with an inclined beam-emitting scanning focal point arc distribution as described in claim 1 or 2, characterized in that: The hollow motor is a DD hollow motor; the positioning indicator is a red light indicator.

6. The laser rotating cleaning head with an arc-shaped distribution of tilted light-emitting scanning focal points as described in claim 1 or 2, characterized in that: The reflector mount is equipped with an adjustment ring for adjusting the focal point position of the focusing lens.

7. The laser rotating cleaning head with an inclined beam-emitting scanning focal point arc distribution as described in claim 1 or 2, characterized in that: The focusing lens is made of NBK-7 material, with a diameter of 75mm and a focal length of 150mm; the focusing lens is coated with an anti-reflection coating with a thickness of 650-1050nm.

8. The laser rotating cleaning head with an inclined beam-emitting scanning focal point arc distribution as described in claim 1 or 2, characterized in that: The protective window lens, the first reflector, and the second reflector are all made of JGS1 material.

9. A laser rotary cleaning method, comprising cleaning using a laser rotary cleaning head with an arc-shaped distribution of tilted beam scanning focal points as described in any one of claims 1-8, characterized in that: The workpiece to be cleaned is moved so that its center position is concentric with the positioning indicator light. The workpiece height and / or the focal point of the focusing lens are adjusted so that the surface of the workpiece to be cleaned and the focal point of the laser overlap. The hollow motor is started, and the hollow motor drives the rotating reflector and the reflector mount to rotate, completing 360° cleaning without dead angles.

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