CN220659538U - Laser focus calibrating device - Google Patents

Abstract

The utility model discloses a laser focus calibration device, which is characterized in that a focus deviation detection device is used for detecting the distance information between the position of a laser beam focus and the upper surface of a workpiece to be processed in real time, and a signal digital display module is used for displaying the distance information, so that an operator can know the position relation between the position of the laser beam focus and the upper surface of the workpiece to be processed without observing the laser beam; the driving device controls the lifting device to move according to the comparison data in real time so as to control the processing platform to move upwards or downwards, and the position relationship between the workpiece to be processed and the laser focus is adjusted in real time.

Description

Laser focus calibrating device

Technical Field

The utility model relates to the field of laser processing, in particular to a laser focus calibration device.

Background

The laser as light source has the features of high directivity, high brightness, high monochromaticity, high energy density, etc. and may be used widely in industrial production, communication, information processing, medical treatment, etc. Laser processing is the most commonly used application of laser systems, including laser welding, laser cutting, surface modification, laser marking, laser drilling, micromachining, photochemical deposition, stereolithography, laser etching, and the like. The technical principle is that the laser beam energy reaches high energy density on a focus after being focused by a lens, and is processed by a photo-thermal effect. In order to ensure the best effect, the best efficiency and the processing stability of the laser processing, the focus of the laser beam after being focused by the lens needs to be ensured to accurately fall on the surface of the product to be processed.

In the prior art, the following disadvantages currently exist: the change of the laser beam focus position cannot be detected on line in real time, so that the position of the laser beam focus cannot be adjusted in real time; the deviation direction of the laser beam focus position cannot be automatically judged, the laser beam focus position cannot be fed back with the upper computer data, and the automation degree is low; the existing laser beam focus position correction operation method is not safe enough, and is usually directly observed and debugged by human eyes, and laser radiation has certain damage to the human eyes; most of similar professional auxiliary devices in the current industry are vision modules, so that the cost is high and commercialization cannot be popularized; the modular structure design cannot be realized, so that the maintenance and replacement cost is high; in the current laser processing technology in industry, the method aiming at the focus debugging and confirmation after focusing is to process conditions with the best effect by repeatedly processing samples, and is complicated and long in debugging period.

Disclosure of Invention

To overcome the above-mentioned drawbacks, an object of the present utility model is to provide a laser focus calibration device.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a laser focus calibration apparatus comprising: the device comprises a laser, a beam expanding device, a focus deviation detecting device, a reflection focusing device, a driving device, a lifting device and a processing platform;

the laser emits a laser beam;

the beam expanding device is used for calibrating and expanding the laser beam;

the focus bias detecting device transmits the laser beam;

the reflection focusing device reflects the laser beam and focuses the laser beam;

placing a to-be-machined piece on a machining platform, machining the to-be-machined piece by the focused laser beam, and generating a radiation beam which reversely propagates along the propagation direction of the laser beam;

the reflection focusing device reflects the radiation beam to the focus deviation detecting device;

the focus deviation detection device detects focus deviation of the radiation beam to obtain detection data, and amplifies the detection data;

the focus deviation detection device displays the amplified detection data, the focus deviation detection device compares the detection data to obtain comparison data, and the comparison data is transmitted to the driving device;

the driving device controls the lifting device to move up or down the processing platform according to the comparison data.

In the technical scheme, the focus deviation detection device detects whether the position of the laser beam focus deviates from the horizontal plane of the surface of the workpiece to be processed, and displays detection data, so that an operator does not need to observe the laser beam to obtain the situation between the position of the laser beam focus and the horizontal plane of the upper surface of the workpiece to be processed, and the damage of the laser beam to human eyes is avoided. The lifting device is controlled by the driving device to automatically debug the distance between the upper surface of the workpiece to be processed and the laser beam focus, so that the laser beam focus and the upper surface of the workpiece to be processed are positioned at the optimal position, and the laser beam focus is automatically calibrated, thereby avoiding the complex operation of repeated comparison in the traditional method and shortening the debugging period. The laser focus calibration device is high in automation degree, and maintenance cost and replacement cost are reduced through the module design of the focus deviation detection device.

In some embodiments, the focus deviation detection device comprises a shell, a beam combining lens, a focusing lens, a half-reflecting half-lens, a first small-hole grating sheet, a second small-hole grating sheet, a first detection device, a second detection device, a signal amplifier module and a signal digital display module;

the device comprises a beam combining lens, a focusing lens, a half-reflecting half-lens, a first small hole grating sheet, a second small hole grating sheet, a first detection device and a second detection device, wherein the focusing lens and the beam combining lens are arranged in a shell, the half-reflecting half-lens and the beam combining lens are arranged in parallel, the first small hole grating sheet, the first detection device and the focusing lens are arranged in parallel, the second small hole grating sheet, the second detection device and the focusing lens are arranged in a 90-degree mode, the first detection device and the second detection device are arranged on the inner wall of the shell, a signal amplifier module is arranged at the bottom of the shell, and a signal digital display module is arranged on the upper side of the shell.

In the technical scheme, the beam combining lens reflects the radiation beam at 45 degrees, so that the track of the radiation beam is changed, the focusing lens can receive the radiation beam, the focusing lens focuses the radiation beam, the focused radiation beam passes through the half-reflecting half-lens, one half of the radiation beam passes through the half-reflecting half-lens and is filtered by the first small hole grating sheet, and the radiation beam is projected to the first detection device; the other half of the radiation beam is reflected by the half-reflecting half-lens and filtered by the second small-hole grating sheet, the radiation beam is projected to the second detection device, the first detection device and the second detection device respectively transmit detection data of the projected radiation beam to the signal amplifier module, the signal amplifier module amplifies and compares the data transmitted by the first detection device and the detection data transmitted by the second detection device, the comparison data are respectively transmitted to the signal digital display module and the driving device, and the signal digital display module directly observes the laser beam by using eyes to obtain the situation of the laser focus position relative to the upper surface position of a workpiece to be processed.

In some embodiments, the radiation beam counter-propagates along the laser beam propagation path to the focus bias detection means;

the beam combining lens is arranged at 45 degrees with the radiation beam, and the beam combining lens reflects the radiation beam at 90 degrees;

the focusing mirror focuses the radiation beam, the half-reflecting half-lens transmits half of the radiation beam before the radiation beam forms a focus to form a first radiation beam, and the first radiation beam passes through the first small hole grating sheet before the first radiation beam forms the focus to be projected to the first detection device;

the half-reflecting half-lens reflects half of the radiation beam by 90 degrees before the radiation beam forms the focal point to form a second radiation beam, and the second radiation beam passes through the second small-hole grating sheet after the focal point is formed and is projected to the second detection device.

In the technical scheme, the beam combining lens reflects the radiation beam at 90 degrees, which is favorable for separating the light path of the radiation beam from the light path of the laser beam, separating the radiation infusion into the first radiation beam and the second radiation beam, and is favorable for further reversely pushing out the relative positions of the focal point of the laser beam and the upper surface of the workpiece to be processed. The arrangement of the first small-hole grating sheet and the second small-hole grating sheet is beneficial to respectively filtering the first radiation beam and the second radiation beam under the condition that the relative positions of the laser beam focus and the upper surface of the workpiece to be processed are not in the same horizontal plane, so that the intensities of the first radiation beam and the second radiation beam irradiated on the first detection device and the second detection device are inconsistent.

In some embodiments, the first detection device and the second detection device are connected with a signal amplifier module, the first detection device obtains first detection data according to the intensity of a first radiation beam projected onto the first detection device, the second detection device obtains second detection data according to the intensity of a second radiation beam projected onto the second detection device, the signal amplifier module amplifies the first detection data and the second detection data and transmits the amplified first detection data and the amplified second detection data to a signal digital display module, and the signal amplifier module performs difference comparison on the first detection data and the second detection data to obtain comparison data.

In the technical scheme, the first detection device and the second detection device are connected with the signal amplifier module, so that the first detection device and the second detection device can transmit first detection data and second detection data to the signal amplifier module respectively, the signal amplifier module amplifies the first detection data and the second detection data, the difference between the first detection data and the second detection data can be displayed conveniently, the signal amplifier module compares the difference between the memory detection data and the second detection data to obtain comparison data, and the relation between the laser focus and a workpiece to be processed can be determined or determined conveniently.

In some embodiments, the signal amplifier module is connected with the signal digital display module and the driving device, the signal amplifier module transmits the amplified first detection data and the amplified second detection data to the signal digital display module, the signal digital display module displays the amplified first detection data and the amplified second detection data, the signal amplifier module transmits the comparison data to the driving device, and the driving device controls the lifting device to lift or move down the processing platform according to the comparison data.

According to the technical scheme, the signal amplifier module transmits amplified detection data to the signal digital display module, the signal digital display module displays the amplified detection data, and an operator can directly observe the data displayed by the signal digital display module to obtain the distance state between the laser beam focus and the upper surface of a workpiece to be processed; the signal amplifier module compares the detection data to obtain comparison data, the comparison data is transmitted to the driving device, and the driving device controls the lifting device to move to control the machining table to move upwards or downwards according to the comparison data, so that the workpiece to be machined is controlled to move upwards or downwards, and the adjustment of the distance between the laser beam focus and the workpiece to be machined is controlled.

In some embodiments, the radiation beam includes a first minimum beam waist point and a second minimum beam waist point, the first minimum beam waist point being located between the first aperture grating sheet and the first detection means, the second aperture grating sheet being disposed between the second detection means and the second minimum beam waist point, the distance between the first detection means and the first minimum beam waist point being equal to the distance between the second and second minimum beam waist points.

In the technical scheme, the first minimum beam waist point is positioned between the first small hole grating sheet and the first detection device, the second small hole grating is arranged between the second detection device and the second minimum beam waist point, so that when the focal position of the laser beam is not in the same horizontal plane with the upper surface of the workpiece to be processed, the first minimum beam waist point position and the second minimum beam waist point position of the radiation beam after passing through the half-reflecting half-lens deviate from the first minimum beam waist point position and the second minimum beam waist point position under the condition that the focal position of the laser beam and the upper surface of the workpiece to be processed are in the same horizontal plane, and the small hole of the grating sheet can filter the radiation beam with larger divergence, so that the intensities of the radiation beams projected onto the first detection device and the second detection device are different; the distance between the first detection device and the first minimum beam waist point is equal to the distance between the second detection device and the second minimum beam waist point, and errors caused by inconsistent light of the radiation beam reaching the first detection device and the second detection device are eliminated.

In some embodiments, the beam combiner transmits the laser beam and the beam combiner reflects the radiation beam.

In the technical scheme, a laser beam normally passes through the beam combining lens and then is processed to be processed, the radiation beam reversely propagates to the beam combining lens, the beam combining lens reflects the radiation beam to the focusing lens, and the propagation direction of the radiation beam is changed.

In some embodiments, the reflective focusing device comprises a galvanometer and a field lens, wherein a reflecting mirror is arranged in the galvanometer and is used for reflecting the laser beam at 90 degrees with the original propagation direction.

In the technical scheme, the reflecting mirror is used for reflecting the laser beam and the radiation beam, and the field lens is used for focusing the laser beam.

In some embodiments, the reflective focusing device comprises a laser cutting head provided with an internal mirror for reflecting the laser beam at 90 ° to the original propagation direction, and a laser focusing mirror for focusing the laser beam.

In this technical scheme, the internal reflection mirror is used for reflecting laser beam and radiation beam, and the focusing mirror is used for focusing the laser beam.

In some embodiments, the lifting device comprises a base and a lifting rod, the processing platform moves up or down along the lifting rod, and the lifting rod is fixed to the base.

In this technical scheme, the base makes laser focus calibrating device more firm place, and the lifter is used for guiding for processing platform's motion.

Drawings

FIG. 1 is a schematic diagram of a galvanometer mode laser focus calibration apparatus according to an embodiment of the utility model;

FIG. 2 is a schematic diagram of a laser focus calibration apparatus for a laser cutting head mode according to an embodiment of the present utility model;

FIG. 3 is a diagram illustrating an internal structure of a vibrating mirror according to an embodiment of the present utility model;

FIG. 4 is a top view of a focus bias detection apparatus according to an embodiment of the utility model;

FIG. 5 is a second plan view of a focus bias detecting device according to an embodiment of the present utility model;

FIG. 6 is a schematic diagram illustrating a path of laser light passing through a beam combiner according to an embodiment of the present utility model;

FIG. 7 is a schematic diagram showing the propagation of a radiation beam with the focal position of a laser beam and the upper surface of a workpiece at the same horizontal plane according to an embodiment of the present utility model;

FIG. 8 is a schematic view illustrating the propagation of a radiation beam with a focal position of a laser beam below the upper surface of a workpiece according to an embodiment of the present utility model;

FIG. 9 is a schematic diagram illustrating the propagation of a radiation beam with a focal position of a laser beam above the upper surface of a workpiece according to an embodiment of the present utility model;

in the figure: 1 laser, 11 laser beams;

2, a beam expanding device;

the device comprises a focus deviation detection device, a shell, a beam combining lens, a focusing lens, a half-reflecting half-lens, a first small-hole grating sheet, a first central aperture, a second small-hole grating sheet, a second central aperture, a first detection device, a second detection device, a signal amplifier module and a signal digital display module, wherein the focus deviation detection device comprises a focus deviation detection device, a shell, a beam combining lens, a focusing lens, a half-reflecting half-lens, a first small-hole grating sheet, a first central aperture, a second small-hole grating sheet, a second central aperture, a first detection device, a signal amplifier module and a signal digital display module;

4 a driving device;

5 lifting device, 51 base, 52 lifting rod;

6 reflection focusing device, 61 vibrating mirror, 611 reflecting mirror, 62 field mirror, 64 laser cutting head, 641 internal reflecting mirror, 65 laser focusing mirror;

7, a processing platform, 71 a to-be-processed workpiece;

81 bottom plates, 82 laser fixing seats, 83 beam expanding device fixing seats;

9 radiation beam, 91 focused radiation beam, 92 first radiation beam, 921 first minimum beam waist point, 93 second radiation beam, 931 second minimum beam waist point.

Detailed Description

The preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present utility model can be more easily understood by those skilled in the art, thereby making clear and defining the scope of the present utility model.

Referring to fig. 1 and 2, the present embodiment provides a laser focus calibration apparatus, and fig. 1 shows that the laser focus calibration apparatus includes: a laser 1, a beam expander 2, a focus deviation detector 3, a driver 4, a lifter 5, a reflection focusing device 6, and a processing platform 7, wherein:

a laser 1, the laser 1 being for emitting a laser beam 11;

the beam expander 2 is arranged in parallel with the laser 1 and the beam expander 2, the center point of the laser 1 and the center point of the beam expander 2 are positioned on the same horizontal straight line, and the beam expander 2 is used for calibrating and expanding the laser beam;

a focus bias detection device 3, wherein the focus bias detection device 3 performs laser focus bias detection to obtain detection data, the focus bias detection device 3 displays the detection data, and the focus bias detection device 3 compares the detection data to obtain comparison data;

a processing platform 7, wherein the processing platform 7 is used for placing a to-be-processed workpiece 71, and the laser beam 11 processes the to-be-processed workpiece 71 to generate a radiation beam 9;

the lifting device 5 is arranged on the processing platform 7, and the lifting device 5 is used for lifting or moving down the processing platform 7;

the driving device 4, the focus deviation detecting device 3 is connected with the driving device 4, the driving device 4 is connected with the lifting device 5, the driving device 4 controls the lifting device 5 to move up or down the processing platform 7, and the focus deviation detecting device 3 transmits contrast data to the driving device 4;

reflection focusing means 6, the reflection focusing means 6 being for reflecting and focusing the laser beam 11 so that the laser beam 11 forms a focus; the reflection focusing means 6 also reflect the radiation beam 9 to the focus bias detection means 3.

The operation of each device is as follows: the laser 1 emits a laser beam 11, the beam expanding device 2 calibrates and expands the laser beam 11, the focus deviation detecting device 3 transmits the laser beam 11, the reflection focusing device 6 reflects the laser beam 11 and focuses the laser beam 11, the workpiece 71 is placed on the processing platform 7, the focused laser beam 11 processes the workpiece 71 and generates a radiation beam 9, the radiation beam 9 reversely propagates along the propagation direction of the laser beam 11, the reflection focusing device 6 reflects the radiation beam to the focus deviation detecting device 3, the focus deviation detecting device 3 detects the focus deviation of the radiation beam 9 to obtain detection data, the detection data is amplified and displayed, the focus deviation detecting device 3 compares the detection data to obtain comparison data, the comparison data is transmitted to the driving device 4, and the driving device 4 controls the lifting device 5 to move up or down the processing platform 7 according to the comparison data.

The focus deviation detecting means 3 detects whether the position of the focus of the laser beam 11 deviates from the horizontal plane in which the surface of the workpiece 71 is located and displays the detection data, so that an operator does not need to observe the laser beam 11 to obtain a situation between the position of the focus of the laser beam 11 and the horizontal plane in which the surface of the workpiece 71 is located, thereby avoiding injury to the human eye caused by the laser beam 11. The lifting device 5 is controlled by the driving device 4 to automatically debug the distance between the surface of the workpiece 71 to be processed and the focal point of the laser beam 11, so that the focal point position of the laser beam 11 and the surface of the workpiece 71 to be processed are in the optimal position, and the automatic calibration of the focal point of the laser beam 11 is realized, thereby avoiding the complex operation of repeated comparison in the traditional method and shortening the debugging period. The laser focus calibration device in the embodiment has high automation degree, and reduces maintenance cost and replacement cost by designing the module of the laser focus calibration device.

With continued reference to fig. 4, 5, and 7, in fig. 4, the focus bias detection apparatus 3 includes, in some embodiments, a housing 30, a beam combiner 31, a focusing lens 32, a half mirror 33, a first aperture grating 34, a second aperture grating 35, a first detection apparatus 36, a second detection apparatus 37, a signal amplifier module 38, and a signal digital display module 39.

The beam combining lens 31, the focusing lens 32, the half-reflecting half-lens 33, the first small-hole grating sheet 34, the second small-hole grating sheet 35, the first detection device 36 and the second detection device 37 are arranged in the shell 30, the focusing lens 32 and the beam combining lens 31 are arranged at 45 degrees, the half-reflecting half-lens 33 and the beam combining lens 31 are arranged in parallel, the first small-hole grating sheet 34, the first detection device 36 and the focusing lens 32 are arranged in parallel, the second small-hole grating sheet 35 and the second detection device 37 are arranged at 90 degrees with the focusing lens 32, the first small-hole grating sheet 34 is provided with a first central aperture 341, the second small-hole grating sheet 35 is provided with a second central aperture 351, the first detection device 36 and the second detection device 37 are arranged on the inner wall of the shell 30, the signal amplifier module 38 is arranged at the bottom of the shell 30, and the signal digital display module 39 is arranged on the upper side of the shell 30.

With continued reference to fig. 3 and fig. 4, in some embodiments, as shown in fig. 3, the workpiece 71 to be processed generates a radiation beam during laser processing, the radiation beam 9 is reflected by the surface of the workpiece 71 to be processed and reversely propagates into the focus deviation detecting device along the propagation direction of the laser, the beam combining mirror forms 45 ° with the radiation beam, the beam combining mirror 31 forms a 90 ° reflection radiation beam, the reflected radiation beam 9 is focused by the focusing mirror 32 to form a focused radiation beam 91, the focused radiation beam 91 passes through the half-reflecting half lens 33, half of the radiation beam passes through the half-reflecting half lens 33 to form a first radiation beam 92, and the first radiation beam 91 passes through the first central aperture 341 of the first small hole grating sheet 34 to be projected onto the first detecting device 36; the other half of the radiation beam 9 is reflected by the half mirror 33 to form a second radiation beam 93, which second radiation beam 93 passes through the second central aperture 351 of the second pinhole grating sheet 35 and is projected onto the second detection device 37.

In some embodiments, the propagation distance of the radiation beam in this example is represented by light, and the light projected by the radiation beam 9 from the focusing mirror 32 to the first detecting device 36 is equal to the light projected by the radiation beam 9 from the focusing mirror 32 to the second detecting device 37, and the first detecting device 36 and the second detecting device 37 detect the light intensity signals of the first detection data and the second detection data according to the intensities of the projected first radiation beam and second radiation beam, respectively.

The first and second detection means transmit the first and second detection data to the signal amplifier module 38, and the signal amplifier module 38 amplifies and compares the first and second detection data.

The signal amplifier module 38 displays the amplified first detection data and the amplified second detection data, and the signal digital display module 39 transmits contrast data obtained by comparing the first detection data with the second detection data to the driving device 4, and the driving controller controls the processing table to move up or down by controlling the movement of the lifting device 5 according to the contrast data transmitted by the signal amplifier module 38.

In some embodiments, the first detecting device 36 and the second detecting device 37 are connected to the signal amplifier module 38, the first detecting device 36 and the second detecting device 37 send the first detecting data and the second detecting data to the signal amplifier module 38, the signal amplifier module amplifies the first detecting data and the second detecting data and transmits the first detecting data and the second detecting data to the signal digital display module, the signal digital display module 39 displays the amplified first detecting data and the second detecting data, and the signal amplifier module 38 compares the difference between the first detecting data and the second detecting data to obtain the comparison data.

In some embodiments, the contrast data is the first probe data minus the second probe data.

For example, the first detection data is x=10 and the second detection data is y=15, but the values of the first detection data and the second detection data are not limited in this application, and the first detection data is 10 and the second detection data is 15. And (3) representing the comparison data by z, setting a difference comparison formula as follows: z=x-y, substituting x=10, y=15 into the formula to calculate: z=10-15, yielding z= -5, i.e. the comparison data is-5.

In the above embodiment, if the comparison data is positive, which means that the laser beam focus is located below the upper surface of the workpiece 71, the driving device 4 controls the lifting device 5 to move up the processing platform 7;

if the comparison data is negative, which means that the laser beam focus is positioned on the upper side of the upper surface of the workpiece 71 to be processed, the driving device 4 controls the lifting device 5 to move down the processing platform 7;

if the comparison data is 0, which means that the laser beam focus is at the same level as the upper surface of the workpiece 71, the processing table 7 is not moved.

For example, setting the moving distance to L, and every 1 increase in the absolute value of z, moving by 2 millimeters, setting the absolute value of z to a, l= 2*a; in the above embodiment, the calculated comparative data is z= -5, the driving device controls the lifting device to move down the processing platform, and a=5, and l= 2*5 is calculated, so as to obtain l=10, that is, the driving device 4 controls the lifting device 5 to move down the processing platform 7 ten millimeters.

In some embodiments, the contrast data is the second probe data minus the first probe data.

For example, the first detection data is x=10 and the second detection data is y=15, but the values of the first detection data and the second detection data are not limited in this application, and the first detection data is 10 and the second detection data is 15. And (3) representing the comparison data by z, setting a difference comparison formula as follows: z=y-x, substituting x=10, y=15 into the formula to calculate: z=15-10, giving z=5, i.e. the comparison data is 5.

In the above embodiment, if the comparison data is positive, which means that the laser beam focus is on the upper side of the upper surface of the workpiece 71, the driving device 4 controls the lifting device 5 to move down the processing platform 7;

if the comparison data is negative, which means that the laser beam focus is at the lower side of the upper surface of the workpiece 71, the driving device 4 controls the lifting device 5 to move up the processing platform 7;

if the comparison data is 0, which means that the laser beam focus is at the same level as the upper surface of the workpiece 71, the processing table 7 is not moved.

For example, setting the moving distance to L, and every 1 increase in the absolute value of z, moving by 2 millimeters, setting the absolute value of z to a, l= 2*a; in the above embodiment, if the calculated comparative data is z=5, the driving device controls the lifting device to move down the processing platform, and a=5, l= 2*5 is calculated, so as to obtain l=10, that is, the driving device 4 controls the lifting device 5 to move down the processing platform by 7 ten millimeters.

In some embodiments, the signal amplifier module 38 is connected to the signal digital display module 39 and the driving device 4, the signal amplifier module 38 transmits the amplified first detection data and the amplified second detection data to the signal digital display module 39, and the signal digital display module 39 displays the amplified first detection data and the amplified second detection data transmitted by the signal amplifier module 38, so that a worker can know the relative position of the focal point of the laser beam 11 with respect to the surface of the workpiece 71 without observing the laser beam 11.

Meanwhile, the signal amplifier module 38 transmits the comparison data of the first detection data and the second detection data to the driving device 4, and the driving device 4 controls the lifting device 5 to move to control the processing platform 7 to move upwards or downwards, so that the distance between the focus of the laser beam 11 and the workpiece 71 to be processed is automatically adjusted.

With continued reference to fig. 5, this embodiment is a second plan view of the focus bias detection device of the present utility model, and fig. 5 shows that after passing through the focusing mirror 32, the radiation beam 9 starts to be focused to form a focused radiation beam 91, and the focused radiation beam 91 will generate a minimum beam waist point, and the radiation beam 9 passes through the focusing mirror 32 and the half mirror 33 to generate two minimum beam waist points because the half mirror 33 splits the radiation beam 9 into two beams, the first radiation beam 92 passing through the half mirror 33 and the second radiation beam 93 reflected by the half mirror 33.

The minimum beam waist point of the radiation beam 9 comprises a first minimum beam waist point 921 and a second minimum beam waist point 931, the first minimum beam waist point 921 is located between the first small hole grating sheet 34 and the first detection device 36, and the second small hole grating sheet 35 is located between the second detection device 37 and the second minimum beam waist point 931, so that when the laser beam focal point position is not at the same horizontal plane as the upper surface of the workpiece, the positions of the first minimum beam waist point 921 and the second minimum beam waist point 931 deviate from the positions of the first minimum beam waist point 921 and the second minimum beam waist point 931 when the laser beam focal point position is at the same horizontal plane as the upper surface of the workpiece, and the intensities of the radiation beams projected onto the first detection device 36 and the second detection device 37 are different after the first small hole grating sheet 34 and the second small hole grating sheet 35 filter the first radiation beam 92 and the second radiation beam 93 respectively.

The distance between the first detecting means 36 and the first minimum beam waist point 921 is equal to the distance between the second detecting means 37 and the second minimum beam waist point 931 for eliminating the influence of the distance variation between the detecting means and the minimum beam waist point.

With continued reference to fig. 5 and 6, in some embodiments, the beam combiner 31 transmits the laser beam 11, the beam combiner 31 reflects the radiation beam, and fig. 5 shows that the radiation beam 9 is reflected by the beam combiner 31 and continues to propagate at 90 ° from the original propagation direction; fig. 6 shows that the laser beam passes through the beam combiner 31 directly and continues to propagate in the original propagation direction.

With continued reference to fig. 1 and 3, in some embodiments, the reflection focusing device 6 employs a galvanometer 61 and a field lens 62, and as shown in fig. 1, after the laser beam 11 propagates to the galvanometer 61, a reflection mirror 611 disposed inside the galvanometer 61 reflects the laser beam 11 by 90 ° with respect to the original propagation direction, and forms a laser beam focus to process the workpiece 71 after focusing by the field lens 62.

With continued reference to fig. 2, in some embodiments, the reflective focusing apparatus 6 employs a laser cutting head 64 and a laser focusing mirror 65, and as shown in fig. 2, after the laser beam 11 propagates to the laser cutting head 64, the laser beam 11 is reflected by an internal mirror 641 provided on the laser cutting head 64, and after being focused by the laser focusing mirror 65, a laser beam focal point is formed to process the workpiece 71.

With continued reference to fig. 1 and 2, in some embodiments, as shown in fig. 1, the lifting device 5 includes a base 51 and a lifting rod 52, and the processing platform 7 moves up or down along the lifting rod 52, and the lifting rod 52 is fixed to the base 51.

With continued reference to fig. 1 and 2, in some embodiments, the laser focus calibration device further includes a base plate 81, a laser fixing base 82, and a beam expander fixing base 83, and in fig. 1, the laser fixing base 82, the beam expander fixing base 83, and the focus deviation detecting device 3 are fixed on the base plate 81, the laser 1 is fixed on the laser fixing base 82, and the beam expander 2 is fixed on the beam expander fixing base 83.

Referring to fig. 7, this embodiment is a schematic view of radiation beam propagation in which the focal position of the laser beam and the upper surface of the workpiece are located at the same horizontal plane, and fig. 7 shows that the focal position of the laser beam 11 and the surface of the workpiece 71 are located at the same horizontal plane, and the radiation beam 9 generated when the laser beam 11 processes the workpiece 71 overlaps with the laser beam 11 and propagates reversely along the propagation direction of the laser beam 11 until the beam combining mirror 31 reflects the radiation beam and forms a focused radiation beam 91 after passing through the focusing mirror 92.

The focused radiation beam 91 passes through the half mirror 33 before creating the minimum beam waist point, the half focused radiation beam 91 passes through the half mirror 33 to form a first radiation beam 92, the first radiation beam 92 starts to diverge after forming the first minimum beam waist point 921 and passes through the first central aperture 341 of the first small aperture grating sheet 34, and the first radiation beam 92 is edge-projected onto the first detector device 36.

The other half of the focused radiation beam 91 is reflected by the half mirror 33 at 90 ° to the original propagation direction of the focused radiation beam 91 to form a second radiation beam 93, the second radiation beam 93 passes through the second central aperture 351 of the second pinhole grating sheet 35 and forms a second minimum beam waist point 931, and the second radiation beam 93 starts to diverge and impinges on the second detection device 37 after forming the second beam waist point 931.

With continued reference to fig. 8, this embodiment is a schematic diagram of radiation beam propagation in which the focal position of the laser beam is located below the upper surface of the workpiece to be processed, and fig. 8 shows that the horizontal plane in which the focal position of the laser beam 11 is located below the horizontal plane in which the surface of the workpiece to be processed 71 is located, so that when the laser beam 11 performs laser processing on the workpiece to be processed 71, the generated radiation beam 9 forms a minimum beam waist point, diverges and propagates reversely along the propagation direction of the laser beam 11 until the beam is reflected by the beam combining mirror 31 by 90 °, and the radiation beam 9 propagates to the focusing mirror 32 to form a focused radiation beam 91.

Before the focused radiation beam 91 forms a minimum beam waist point, it passes through a half mirror 33. One half of the focused radiation beam 91 passes through the half-reflecting half-lens 33 to form a first radiation beam 92, and the first radiation beam 92 passes through the first small-hole grating sheet 34 to form a first minimum beam waist point 921, where the first radiation beam 92, when passing through the first small-hole grating sheet 34, represents the width of the radiation beam in this embodiment of the application by using a beam waist, and then the beam waist of the first radiation beam 92 is smaller than the first central aperture 341 of the small hole of the first grating sheet, so that the first radiation beam 92 can completely pass through the first small-hole grating sheet 34 and be scattered and projected onto the first detection device 36.

The other half of the focused radiation beam 91 is reflected by the half mirror 33 to form a second radiation beam 93, which second radiation beam 93 propagates to the second small aperture plate 35 with a beam waist larger than the second central aperture 351 of the second small aperture plate 35, so that at this time a portion of the second radiation beam 93 larger than the second central aperture 351 of the second small aperture plate 35 will be filtered and the intensity of the radiation beam impinging on the second detector means 37 will be reduced.

With continued reference to fig. 9, this embodiment is a schematic diagram of radiation beam propagation when the focal point of the laser beam is located above the upper surface of the workpiece, and fig. 9 shows that the focal point of the laser beam 11 is located at the upper side of the horizontal plane where the surface of the workpiece 71 is located, so that the laser beam 11 contacts the surface of the workpiece 71 after starting to diverge, and the reflected radiation beam 9 diverges in advance and propagates reversely along the propagation path of the laser beam 11 compared with the radiation beam 9 when the focal point of the laser beam is in the optimal state, until the beam combining mirror 31 reflects the radiation beam 9 by 90 °, and the radiation beam 9 propagates to the focusing mirror 32 to be focused to form the focused radiation beam 91.

Before focusing the radiation beam 91 to create a minimum beam waist point, a half mirror 33 is passed. One half of the focused radiation beam 91 passes through the half mirror 33 to form a first radiation beam 92, the first radiation beam 92 starts to diverge after forming a first minimum beam waist 921, and when the first radiation beam 92 reaches the first small hole grating sheet 34, the beam waist of the first radiation beam 92 is larger than the first central aperture 341 of the first small hole grating sheet 34, so that a portion of the first radiation beam 92 larger than the first central aperture 341 of the first small hole grating sheet 34 will be filtered, and therefore the intensity of the radiation beam 9 impinging on the first detector device 36 after the first radiation beam 92 passes through the first small hole grating sheet 34 will be reduced.

The other half of the focused radiation beam 9 is reflected by the half mirror 33 to form a second radiation beam 93, which second radiation beam 93 has a beam waist when passing through the second small aperture plate 35 which is smaller than the second central aperture 351 of the second small aperture plate 35, so that the intensity of the radiation beam impinging on the second detecting means 37 after the second radiation beam 93 has passed through the second small aperture plate 35 is not reduced.

In summary, the embodiment of the application provides a laser focus calibration device, which detects the horizontal position of the focus position of the laser beam 11 relative to the surface of the workpiece 71 in real time through the focus deviation detection device 3, displays the detection result in real time through the signal digital display module 39, and an operator can know the relative position of the focus of the laser beam 11 relative to the surface of the workpiece 71 through the data displayed by the signal digital display module 39 without directly observing the laser beam 11, thereby avoiding the harm of the laser beam 11 to human eyes; the driving device can simultaneously control the processing platform 7 to move upwards or downwards in real time according to the detected contrast data, so that the relative position of the focus of the laser beam 11 and the workpiece 71 to be processed is at the optimal position, and the excessive display is completed in real time by laser processing equipment, thereby avoiding the complex operation of repeated comparison in the traditional method, shortening the debugging period, having high automation display degree and reducing the maintenance cost and the replacement cost through module design.

The above embodiments are only for illustrating the technical concept and features of the present utility model, and are intended to enable those skilled in the art to understand the content of the present utility model and to implement the same, but are not intended to limit the scope of the present utility model, and all equivalent changes or modifications made according to the spirit of the present utility model should be included in the scope of the present utility model.

Claims (10)

1. A laser focus calibration apparatus, comprising: the device comprises a laser, a beam expanding device, a focus deviation detecting device, a reflection focusing device, a driving device, a lifting device and a processing platform;

the laser emits a laser beam;

the beam expanding device calibrates and expands the laser beam;

the focus bias detection means transmits the laser beam;

the reflection focusing device reflects the laser beam and focuses the laser beam;

placing a to-be-machined piece on the machining platform, machining the to-be-machined piece by the focused laser beam, and generating a radiation beam which is reversely transmitted along the transmission direction of the laser beam;

the reflection focusing device reflects the radiation beam to the focus deviation detecting device;

the focus deviation detection device detects the focus deviation of the radiation beam to obtain detection data, and amplifies the detection data;

the focus deviation detection device displays the amplified detection data, the focus deviation detection device compares the detection data to obtain comparison data, and the comparison data is transmitted to the driving device;

and the driving device controls the lifting device to move up or down the processing platform according to the comparison data.

2. The laser focus calibration device according to claim 1, wherein the focus deviation detection device comprises a housing, a beam combiner, a focusing lens, a half-reflecting half-lens, a first small-hole grating sheet, a second small-hole grating sheet, a first detection device, a second detection device, a signal amplifier module, and a signal digital display module;

the focusing lens is 45 degrees with the beam combining lens, the half-reflecting half-lens is parallel to the beam combining lens, the first small-hole grating sheet, the first detection device is parallel to the focusing lens, the second small-hole grating sheet, the second detection device is 90 degrees with the focusing lens, the first detection device and the second detection device are arranged on the inner wall of the shell, the signal amplifier module is arranged at the bottom of the shell, and the signal digital display module is arranged on the upper side of the shell.

3. The laser focus calibration device according to claim 2, wherein the radiation beam is counter-propagated to the focus bias detection device along the laser beam propagation path;

the beam combining lens is arranged at 45 degrees with the radiation beam, and the beam combining lens reflects the radiation beam at 90 degrees;

the focusing mirror focuses the radiation beam, the half-reflecting half-transmitting mirror transmits half of the radiation beam before the radiation beam forms a focus to form a first radiation beam, and the first radiation beam passes through the first small hole grating sheet before the first radiation beam forms the focus to be projected to the first detection device;

the half-reflecting mirror reflects half of the radiation beam at 90 degrees before the radiation beam forms a focus to form a second radiation beam, and the second radiation beam passes through the second small-hole grating sheet after forming the focus and is projected to the second detection device.

4. The laser focus calibration device according to claim 2, wherein the first detection device and the second detection device are connected to the signal amplifier module, the first detection device obtains first detection data according to the intensity of a first radiation beam projected onto the first detection device, the second detection device obtains second detection data according to the intensity of a second radiation beam projected onto the second detection device, the signal amplifier module amplifies the first detection data and the second detection data and transmits the amplified first detection data and the amplified second detection data to the signal digital display module, and the signal amplifier module performs difference comparison on the first detection data and the second detection data to obtain the contrast data.

5. The laser focus calibration device according to claim 4, wherein the signal amplifier module is connected to the signal digital display module and the driving device, the signal amplifier module transmits the amplified first detection data and second detection data to the signal digital display module, and the signal digital display module displays the amplified first detection data and second detection data; the signal amplifier module transmits the contrast data to the driving device, and the driving device controls the lifting device to lift or move down the processing platform according to the contrast data.

6. The laser focus calibration device of claim 2, wherein the radiation beam comprises a first minimum beam waist point and a second minimum beam waist point, the first minimum beam waist point being located between the first small aperture grating sheet and the first detection device, the second small aperture grating sheet being disposed between the second detection device and the second minimum beam waist point, a distance between the first detection device and the first minimum beam waist point being equal to a distance between the second detection device and the second minimum beam waist point.

7. The laser focus calibration device of claim 2, wherein the beam combiner is transparent to the laser beam, the beam combiner reflecting the radiation beam.

8. The laser focus calibration device according to claim 1, wherein the reflection focusing device comprises a galvanometer and a field lens, wherein a reflecting mirror is arranged inside the galvanometer, and the reflecting mirror is used for reflecting the laser beam at 90 ° to an original propagation direction.

9. The laser focus calibration device according to claim 1, characterized in that the reflection focusing device comprises a laser cutting head provided with an internal mirror for reflecting the laser beam at 90 ° to the original propagation direction and a laser focusing mirror for focusing the laser beam.

10. The laser focus calibration device of claim 1, wherein the lifting device comprises a base and a lifting rod, the processing platform moves up or down along the lifting rod, and the lifting rod is fixed to the base.