CN210548827U

CN210548827U - Laser reducing rotary-cut hole machining optical system

Info

Publication number: CN210548827U
Application number: CN201921405924.4U
Authority: CN
Inventors: 邓磊敏; 乔亚庆; 段军; 熊伟
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2019-08-27
Filing date: 2019-08-27
Publication date: 2020-05-19
Anticipated expiration: 2029-08-27

Abstract

The utility model belongs to the optical design field discloses a laser reducing rotary-cut spot facing work optical system, and this system has the rotation axis to including following the optical element that the light path set up in proper order: the laser beam unidirectional compression assembly comprises a single wedge-shaped mirror (7) for inducing the laser inclination angle, a focusing mirror (8) and a second wedge-shaped mirror group which is composed of two wedge-shaped mirrors with the same wedge angle and is used for adjusting the offset of a focusing light spot. The utility model discloses a composition to each subassembly in the system and the mutual cooperation working relation etc. between each subassembly improve, can realize independently adjusting laser focus from the optical axis volume on a large scale, and then can realize required aperture, and can compensate the laser focus facula from the focus facula distortion that the optical axis slope back arouses because of coma, realize the processing technology of good laser reducing rotary-cut hole of processing effect; in addition, the system can further independently adjust the laser inclination angle and the taper, and realize the independent adjustment of the two aspects of taper and diameter.

Description

Laser reducing rotary-cut hole machining optical system

Technical Field

The utility model belongs to the optical design field, more specifically relates to a laser reducing rotary-cut hole processing optical system, can utilize laser to realize the processing of punching to can further realize the independent regulation of two aspects of reducing the awl.

Background

The development of science and technology continuously provides new challenges for manufacturing technology, and the requirements of manufacturing technical indexes of a plurality of high-end equipment are close to or even exceed the limit of the traditional manufacturing technology, such as an air film hole of an aviation/aerospace engine, an oil nozzle of a direct injection gasoline/diesel engine, a ceramic circuit board array micropore, a novel metamaterial and the like. Taking fuel nozzles and aero-engine gas film holes as examples, in order to ensure the optimal flow field effect, the requirements on the hole type, the hole wall flatness, the hole opening appearance and the like are almost strict. High-quality manufacturing of such holes is difficult to achieve using conventional hole-making techniques, such as mechanical drill machining, electrical discharge machining, ultrasonic machining, and the like. The machining is to drill a hole in a material by using a drill rotating at a high speed, and the drill is generally large in size and relatively suitable for manufacturing a hole with a large diameter. When the aperture required to be prepared is smaller, the drill bit is easy to wear and break, the inclined surface is not easy to process, and the inverted taper hole cannot be manufactured, so that the drill bit is difficult to be used for micropore processing. Meanwhile, the biggest defect of mechanical hole making is that the mechanical hole making belongs to contact type processing, interaction force exists between a workpiece and a drill bit, not only material deformation is caused in the processing process, but also the manufacturing precision is influenced by the generated shaking, and the situation is particularly obvious in the processing process of thin-shell materials such as aircraft engine parts and the like; the electric spark machining is based on the principle of electric spark corrosion, when a tool electrode and a workpiece electrode are close to each other, a pulse spark discharge ablation material is formed between the electrodes, so that the electric spark machining is only suitable for punching holes on metal materials, different punching materials need to be selected, the punching speed is low, the machining precision is reduced due to ablation loss of the electrodes, the efficiency is low, and the like. Meanwhile, the spark erosion process is difficult to control, which is the bottleneck for further improving the precision, so the method is not suitable for manufacturing micropores; ultrasonic machining is special machining in which ultrasonic frequency is used as a tool with small-amplitude vibration, and the grinding material between the tool and a workpiece, which is free in liquid, is used for hammering the machining surface to gradually crush the surface of the workpiece material. The method is only suitable for processing the brittle material, and for metals with higher hardness, toughness and strength, the method has low processing efficiency and poorer forming precision, and the processing of micropores is difficult to realize.

In recent years, high-energy beam manufacturing techniques typified by laser and electron beam have been rapidly developed in the production of micro-holes. Electron beam machining is the machining of materials by the thermal or ionization effect of high energy converging electron beams. However, the high-power acceleration and large-amplitude deflection of the electron beam are difficult to realize, and the processing process needs a full vacuum environment, so that the manufacturing cost is extremely high, the process is very complex, and the manufacturing of the inverted cone hole is difficult to realize; compared with an electron beam, the laser beam has various inherent advantages, such as easy large-scale engineering generation, no need of vacuum environment transmission, easy focusing and shaping, high speed, high efficiency, no tool loss and the like, and therefore, the micro-nano manufacturing is rapidly developed. However, the current laser drilling processing also faces the problem that the hole pattern and the taper are difficult to control, mainly because the laser beam forms extremely high power density on the focus of the beam through the convergence effect of the lens to melt or ablate the material to realize the micropore processing. The light beam formed after focusing has high taper, so that a forward taper hole characteristic that the aperture of an inlet is larger than that of an outlet can be caused in the processing process, and a cylindrical hole, an inverted taper hole or other special-shaped holes can not be obtained.

The european patent EP1656234B1 discloses a method and apparatus for combining laser drilling and cutting with a scanning device, which is characterized by comprising rotatable parallel flat plates, a beam expander, a scanning galvanometer, and a focusing lens. The method uses a scanning galvanometer to carry out punching or other processing applications, and controls the inclination angle of a processing light beam by adjusting the deflection of a parallel flat plate. Due to the limited ability of the parallel plates to deflect the beam and the significant loss of laser energy caused by oblique incidence, this technique requires extremely complex optical design, assembly and control systems, and the ultimate taper control capability of the hole is very limited. Meanwhile, the manufacturing cost of the scheme is too expensive, and the scheme is difficult to be finally applied in large-scale industry; an implementation of a laser drilling device is proposed in the published japanese patent JP4873191B2, which is characterized by comprising elements such as a rotatable plane mirror, a wedge prism, a dove prism, a polygon mirror and a focusing lens. Although the system can realize more light beam deflection functions, because of too many optical elements, the variables needing to be controlled are more, the required aperture and taper ratio can be obtained only by adjusting a plurality of optical elements, and the aperture and taper cannot be simply and independently adjusted, so the practical application is very difficult and the engineering application value is not realized; in the published US9931712 a laser drilling device is proposed, which is characterized by a fast moving and deflecting plane mirror, a rotatable dove prism and two wedge compensating prisms, a focusing lens. The device utilizes a real-time adjustable plane reflector, a dove prism and a compensation wedge mirror to realize the off-axis and deflection of a laser beam together. However, in the high-speed rotating process, it is very difficult to realize the fast real-time control of the position and the inclination angle of the plane mirror, and the processed aperture and the taper can not be adjusted independently; in published US patent US09509106B1, a laser drilling optical system is proposed, which is characterized by comprising a tiltable parallel plate, a pair of rotatable wedge prisms, a rotatable dove prism and a focusing lens, and the device is similar to the device disclosed in the above patent US9931712, except that the position and inclination of the lens are not required to be adjusted in real time during the machining process, but the problem that the machining aperture and taper cannot be adjusted independently exists; the disclosed chinese utility model patents (CN101670486A, CN102218605A, CN103056519A) propose various laser micropore processing devices, which are characterized in that they include a plurality of rotatable wedge prisms and a focusing objective lens, and the above devices can realize the circular diameter scanning of oblique laser, but the processed aperture and taper can not be adjusted independently; the optical scanning system for laser rotation drilling is provided in the currently disclosed chinese utility model patent (CN205380365U), and is characterized in that the optical scanning system comprises a focusing lens, a tiltable parallel plate and a tiltable wedge prism, wherein the parallel plate and the wedge prism are both fixed on a rotating shaft, and rotate along with the rotating shaft to realize drilling processing, but the maximum limitation of the device is that the aperture and taper of the processing cannot be independently adjusted.

The problems of the above-mentioned known punching method and device patents are mainly:

1. except for a galvanometer scanning device (EP1656234B1) which is high in cost and complex to control, other devices cannot realize independent adjustment of two degrees of freedom of a laser incidence angle and a laser focus rotating radius, namely: as the hole radius is adjusted, the hole taper is also changing; similarly, the hole radius is also changing when adjusting the hole taper. The adjustment of the laser beam is very limited and some specific aperture and taper ratios are not even available.

2. The translation capability of optical elements such as a parallel flat plate, a dove prism and the like to a laser focus is limited, if a larger translation amount is required, the inclination angle of the flat plate needs to be increased, even the thickness of the flat plate and the size of the dove prism need to be increased, the optical element with an excessively large thickness can limit the adjustment response speed and the adjustment range of the whole set of system functions, and the inclination angle of the optical element with an excessively large thickness can cause glancing reflection loss of laser energy.

3. The above-mentioned disclosed methods and devices have problems that the laser beam is tilted away from the optical axis and then focused, so that the focused light spot generates coma, which causes distortion of the laser focus, reduction of energy density and uneven distribution, and causes deterioration of the precision and consistency of the drilled hole size. And the larger the inclination angle of the light beam from the optical axis is, the larger the scanning radius is, the more obvious the influence of the coma is, and the larger the influence on the drilling processing precision and quality is. Therefore, the devices have the problem of energy distribution distortion of focusing spots inclined from the optical axis.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects or the improvement requirements of the prior art, the utility model aims to provide an optical system for processing laser reducing rotary cutting holes, wherein, by improving the composition of each component in the optical system and the mutual matching working relationship among the components, the combination of a plurality of wedge-shaped mirrors rotating along the same optical axis and a focusing lens (or a plurality of cylindrical aspheric mirrors) can realize the large-range independent adjustment of the amount of the laser focus away from the optical axis, the required aperture can be realized, the distortion of the laser focusing spot caused by coma aberration after the laser focusing spot inclines away from the optical axis can be compensated, the energy dispersion of the laser focus in the direction away from the optical axis is reduced, the laser power density of the focusing spot inclining away from the optical axis is effectively improved, the punching size precision and consistency are improved, and the laser reducing rotary-cut hole machining process with fine machining effect can be realized; in addition, by further introducing the first wedge-shaped lens group, the system can further independently adjust the inclination angle of the laser and adjust the laser taper, so that the aperture and taper parameters of the focused laser can be flexibly and independently adjusted, and the two aspects of variable taper and variable diameter can be independently adjusted.

To achieve the above object, according to the present invention, there is provided a laser reducing rotary cut hole machining optical system, characterized in that the system has a rotation axis, and includes the following optical elements arranged along a light path in order, and these optical elements are all located in a housing and can rotate synchronously around the rotation axis: the laser beam unidirectional compression assembly comprises a single wedge-shaped mirror (7) for inducing the laser inclination angle, a focusing mirror (8) and a second wedge-shaped mirror group which is composed of two wedge-shaped mirrors with the same wedge angle and is used for adjusting the offset of a focusing light spot; wherein:

the laser beam unidirectional compression component is a compression prism group or a cylindrical surface aspheric lens group, wherein the compression prism group comprises a plurality of wedge-shaped lenses for compression, and the cylindrical surface aspheric lens group comprises a plurality of cylindrical surface aspheric lenses; the laser beam one-way compression assembly is integrally used for compressing an initial incident laser beam in a one-way direction on a laser section vertical to the laser incidence direction, and the propagation direction of the laser is still parallel to the incidence direction of the initial incident laser after being processed by the laser beam one-way compression assembly;

the single-chip wedge-shaped mirror (7) is used for changing the laser propagation direction and inclining the laser propagation direction, so that an inclination angle is generated between the propagation direction of the laser passing through the single-chip wedge-shaped mirror (7) and the laser incidence direction;

the focusing mirror (8) is used for focusing the laser which is induced by the single wedge-shaped mirror (7) to generate an inclination angle, generating a focused laser beam and generating a focused light spot on a focal plane;

the second wedge-shaped lens group is integrally used for enabling the central position of a focusing light spot on a focal plane to deviate, and the propagation direction of laser light is not changed before and after the second wedge-shaped lens group is integrally processed; recording that two wedge-shaped mirrors sequentially arranged along a light path in the second wedge-shaped mirror group are respectively a third wedge-shaped mirror and a fourth wedge-shaped mirror, and arranging a position adjusting component on the third wedge-shaped mirror or/and the fourth wedge-shaped mirror, wherein the position adjusting component can drive the wedge-shaped mirror connected with the position adjusting component to move so as to adjust the distance between the two wedge-shaped mirrors and further adjust the offset of the center of a focusing light spot on a focal plane;

furthermore, the rotation axis coincides with the optical axis of the initially incident laser beam;

when the laser beam one-way compression assembly is a compression prism assembly, the laser compression direction of the compression prism assembly is parallel to the offset direction of the central position of a laser spot, and when the laser beam one-way compression assembly is a cylindrical aspheric lens assembly, the laser compression direction of the cylindrical aspheric lens assembly is parallel to the offset direction of the central position of the laser spot, or the included angle between the straight lines of the laser compression direction of the cylindrical aspheric lens assembly and the offset direction of the central position of the laser spot is not more than 20 degrees, so that the distortion of the focused spot caused by coma aberration after the focused spot inclines away from the optical axis is reduced; based on the action of the single wedge-shaped mirror (7) and the focusing mirror (8), the distance between the center of the focused light spot on the focal plane and the rotating shaft can be adjusted by adjusting the central offset of the focused light spot on the focal plane by using the second wedge-shaped mirror group, so that the processing radius of the focused laser beam is adjusted; based on the integral action of the laser reducing rotary-cut hole machining optical system, the rotary-cut machining of the laser hole with the reducing adjusting effect can be realized.

As a further preferred aspect of the present invention, the system further comprises a first wedge lens group which is composed of two wedge lenses with the same wedge angle and is used for adjusting the offset of the laser beam, the optical element is disposed on the light path between the laser beam unidirectional compression assembly and the single wedge lens (7), so that the system can also realize laser taper adjustment;

the whole first wedge-shaped lens group is used for enabling the central position of a laser spot on a laser section to deviate, the propagation direction of the laser remains unchanged before and after the whole processing of the first wedge-shaped lens group, and the propagation direction of the laser after the whole processing of the first wedge-shaped lens group is still parallel to the incident direction of the initial incident laser; recording that two wedge-shaped mirrors sequentially arranged along a light path in the first wedge-shaped mirror group are respectively a first wedge-shaped mirror and a second wedge-shaped mirror, and then connecting a position adjusting component on the first wedge-shaped mirror or/and the second wedge-shaped mirror, wherein the position adjusting component can drive the wedge-shaped mirror connected with the position adjusting component to move so as to adjust the distance between the two wedge-shaped mirrors and further adjust the offset of the center of a laser spot on the laser section;

the first wedge-shaped mirror group is used for adjusting the offset of the central position of the laser spot on the laser section, and the taper of the focused laser beam obtained by the focusing mirror (8) can be adjusted under the action of the focusing mirror (8).

As a further preference of the present invention, the wedge angle of the single wedge mirror (7) is between 0.01 ° and 42 °;

the wedge angle of the first wedge-shaped mirror is 0.01-42 degrees;

the wedge angle of the third wedge-shaped mirror is 0.01-42 degrees;

the focusing mirror (8) is a spherical focusing mirror or an aspheric focusing mirror.

As the utility model discloses a further preferred, position control subassembly can drive the wedge mirror that is connected with it and remove 0mm to 200mm, and the precision of removal is not inferior to 0.1 mm.

As a further preferred aspect of the present invention, the rotation axis further passes through a center point of each optical element;

the central point of any wedge-shaped mirror is the central point of a vertical optical end face which is 90 degrees in the wedge-shaped mirror.

As a further preferred aspect of the present invention, for the first wedge mirror group, both the vertical optical end surface at 90 ° in the first wedge mirror and the vertical optical end surface at 90 ° in the second wedge mirror are perpendicular to the optical axis of the initial incident laser beam, and the inclined optical end surface inclined at a wedge angle in the first wedge mirror and the inclined optical end surface inclined at a wedge angle in the second wedge mirror are parallel to each other;

for the second wedge-shaped mirror group, both the vertical optical end surface at 90 degrees in the third wedge-shaped mirror and the vertical optical end surface at 90 degrees in the fourth wedge-shaped mirror are perpendicular to the optical axis of the initial incident laser beam, and the inclined optical end surface inclined at the wedge angle in the third wedge-shaped mirror and the inclined optical end surface inclined at the wedge angle in the fourth wedge-shaped mirror are parallel to each other.

As a further preferred aspect of the present invention, the compression prism set includes two wedge mirrors for compression, a wedge angle of each wedge mirror for compression is between 0.01 ° and 42 °, and any one wedge mirror for compression uses a vertical optical end surface that is 90 ° as an incident surface, and uses an inclined optical end surface that is inclined according to the wedge angle as an exit surface, and the vertical optical end surfaces are perpendicular to an optical axis of the initial incident laser beam; remember these two pieces of wedge mirror for compression that follow light path in proper order and successively set up are first piece wedge mirror for compression and second piece wedge mirror for compression respectively, then: the distance between the intersection point of the rear surface of the first piece of wedge-shaped compression mirror and the rotating shaft and the intersection point of the front surface of the second piece of wedge-shaped compression mirror and the rotating shaft is 0-100 mm.

As the utility model discloses a further preferred, the group is including two cylinder aspherical mirror to the cylinder aspherical mirror, and note in proper order along these two cylinder aspherical mirror that the light path successively set up be first piece cylinder aspherical mirror and second piece cylinder aspherical mirror respectively, and wherein, first piece cylinder aspherical mirror has the laser beam folk prescription and converges the effect, and second piece cylinder aspherical mirror has the laser beam folk prescription and diverges the effect.

As a further preferred aspect of the present invention, the laser reducing rotary-cut hole machining optical system is further connected to a hollow rotating device, and is configured to rotate around the rotating shaft under the driving of the hollow rotating device; the rotating speed is 0.1 rpm-6000 rpm.

As a further preferred aspect of the present invention, the hollow rotating device is a hollow rotating device driven by a motor; the shell is a hollow cylinder (12).

Through the utility model discloses above technical scheme who thinks, compare with prior art, the utility model provides a laser reducing rotary-cut spot facing work optical system comprises laser beam folk prescription to compression prism group (or cylinder aspheric surface mirror group), monolithic wedge mirror, a slice sphere focusing mirror (or a slice aspheric surface focusing mirror) and second wedge mirror group to arrange in proper order along laser incident end optical axis. And through further introducing the first wedge lens group, still can realize laser becomes awl reducing rotary cut hole processing optical system, this system is compressed prism group (or cylinder aspheric mirror group), first wedge lens group, monolithic wedge lens, a slice of spherical focusing mirror (or a slice of aspheric focusing mirror) and second wedge lens group by the laser beam unilateral and is constituteed this moment, and arrange in proper order along laser incidence end optical axis.

No matter the diameter is changed or the diameter is changed, since the function of each optical element is basically kept fixed, the laser diameter-changing rotary-cut hole machining optical system using the optical elements is analyzed and explained below, and as long as the optical elements are the same, the laser diameter-changing rotary-cut hole machining optical system also has a corresponding action mechanism.

The unidirectional compression of the laser beam can be achieved in two ways, the first way is to use a compression prism set composed of a plurality of wedge mirrors (e.g. two wedge mirrors with different sizes), and the second way is to use a lens set composed of a plurality of cylindrical aspheric mirrors (e.g. two cylindrical aspheric mirrors). The two lens groups have the functions of compressing the laser focusing light spot in the direction inclined from the optical axis and compensating the focusing light spot distortion caused by coma aberration after the laser focusing light spot is inclined from the optical axis, so that the energy dispersion of the laser focus in the direction from the optical axis is reduced, the laser power density of the focusing light spot from the optical axis is effectively improved, and the punching size precision and consistency are improved. Although compressing the prism assembly causes the input laser beam to be offset parallel to the optical axis by a distance, the beam compressed by the aspherical mirror assembly is still focused on the optical axis. By taking the initial incident laser as a circle, the laser beam unidirectional compression assembly can enable the initial incident laser with the circular light spot cross section to form laser with the elliptical light spot cross section after passing through the laser beam unidirectional compression assembly, and after the laser beam unidirectional compression assembly processes the laser, the propagation direction of the laser is still parallel to the incident direction of the initial incident laser, and the compression lens group is used for correcting coma aberration generated by the optical system in advance. The compression direction of the laser beam one-way compression assembly is preferably parallel to the offset direction of the laser spot center position, and certainly, if the laser beam one-way compression assembly is a cylindrical aspheric lens group, a small-angle included angle (included angle not exceeding 20 °) is allowed to exist between the compression direction of the laser beam one-way compression assembly and the offset direction of the laser spot center position. For the condition that a small-angle included angle exists, the wedge-shaped mirror compression group can deflect the laser when the light beam is compressed, and the non-parallelism of the compression direction can also generate an included angle between the compressed laser deflection direction and the deflection direction of the subsequent first group of wedge-shaped mirrors so as to influence the inclination direction of the laser; however, the propagation direction of the laser after passing through the compression set of the aspherical mirror is still the optical axis direction, so that the compression direction has a certain angular deviation which is acceptable.

The first wedge-shaped lens group consists of two wedge-shaped lenses with the same wedge angle (such as two wedge-shaped lenses with the same wedge angle with larger size), the inclined planes of the two wedge-shaped lenses are opposite to each other by 180 degrees, and the function of the first wedge-shaped lens group is to change the incident angle between the focused laser and the workpiece, namely: the laser is incident into the inclined angle, and the laser beam parallel to the optical axis is still returned to the laser optical axis through the focus of the focusing mirror. The distance between the two wedge-shaped mirrors of the first wedge-shaped mirror group is changed, the incidence inclination angle of the laser can be changed, and thus the hole patterns with different tapers can be obtained. The single wedge-shaped lens is arranged in the optical path in a single piece, and has the function that after the inclined laser beam passing through the first wedge-shaped lens group is focused by the focusing lens, the focus deviates from the optical axis by a certain distance, and when the whole optical system rotates, the deviation distance is the radius of punching processing; the spherical or aspherical focusing mirror functions to focus the inclined laser beam output from the single wedge mirror, resulting in a higher laser energy density. The second wedge-shaped lens group also comprises two wedge-shaped lenses with the same wedge angle (such as two wedge-shaped lenses with the same wedge angle with larger size), the inclined planes of the two wedge-shaped lenses are opposite to each other by 180 degrees and are positioned behind the spherical or aspheric focusing lens; the function of the laser focusing device is to change the distance between the focusing laser focus and the optical axis by adjusting the distance between two wedge-shaped mirrors of the second wedge-shaped mirror group, so that the rotating radius of the laser focus can be independently adjusted, and the requirements of different processing apertures can be met. In addition, the single wedge-shaped mirror enables the laser to generate an inclination angle, so that after passing through the focusing mirror, the laser focus is off-axis towards the lower part of the optical axis to generate a fixed off-axis amount, and the rotation mode of the laser is negative taper rotation at the moment, namely, the single wedge-shaped mirror can also play a role in providing negative taper; the flexible adjustment of the position of the focus compared with the optical axis can be realized by utilizing the matching action of the single wedge-shaped mirror and the second wedge-shaped mirror group; when the focus is below the optical axis, the laser is in a negative taper rotation mode; when the focus is above the optical axis, the laser is in a slight positive taper rotation mode; based on like this the utility model discloses a laser becomes awl reducing rotary cut spot facing work optical system utilizes the cooperation of monolithic wedge mirror and second wedge mirror group, and the rotation mode of laser both can be positive awl, also can be the burden awl, can actually switch in a flexible way.

The whole group of optical elements are sequentially arranged in the hollow cylinder with the same optical axis, the distance between the two groups of wedge-shaped mirrors is adjusted by a position adjusting functional component (such as a small-sized precise adjusting mechanism), and the wedge-shaped mirrors are driven by a hollow motor to rotate with the same optical axis at high speed, so that the laser variable-cone variable-diameter rotary-cutting hole machining optical system device is formed.

Generally speaking, the utility model discloses can gain following effective effect:

1. the utility model provides a laser becomes awl reducing and cuts spot facing work optical system soon can drive the translation of organizing at least a slice wedge mirror in at least one slice wedge mirror and realize respectively through adjusting first wedge mirror group and second wedge mirror group in the interval between two wedge mirrors of cooperation work (this interval accessible position control subassembly), just can realize reaching required aperture and tapering ratio to laser inclination and focus scanning radius's independent regulation to it is convenient, control is simple to adjust. In addition, the special-shaped hole can be machined and formed by conveniently adjusting the taper and the radius.

2. Under the condition of not replacing the lens, the inclination angle of the laser and the scanning radius range of the focus are adjusted to be large, and a larger degree of freedom is provided for laser drilling processing.

3. The two laser beam one-way compression modes can effectively compensate the focusing light spot distortion caused by coma aberration after the laser focusing light spot inclines away from the optical axis, thereby reducing the energy dispersion of the laser focus in the direction away from the optical axis, effectively improving the laser power density of the focusing light spot inclining away from the optical axis and improving the punching size precision and consistency.

4. Furthermore, the utility model discloses well translation volume of laser mainly is decided by three factor. The first is the wedge angle of the wedge-shaped mirror, and the larger the wedge angle is, the stronger the deflection capability of the light beam is; secondly, the distance between the two wedge-shaped mirrors is larger, and the translation amount of the light beam is larger when the distance is larger; the third is the limitation of the translation amount by the size of the two wedge mirrors, wherein the clear aperture of the second wedge mirror cannot be smaller than the sum of the translation amount and the laser radius expected to be obtained. As long as these three factors of reasonable control, just can promote the translation ability to the laser focus greatly, the flexibility of laser focus translation regulation is very good.

Drawings

FIG. 1 is a schematic diagram of an optical system for processing a laser tapered and variable diameter rotary-cut hole by compressing beams of a prism group.

Fig. 2 is a schematic diagram of generation of coma of an off-axis oblique laser focusing beam.

FIG. 3 is a schematic diagram of the operation of beam compression of a prism assembly (i.e., a compressed prism assembly).

Fig. 4 is a schematic diagram of coma aberration caused by compressing the laser spot prism group to compensate the off-axis tilt of the laser beam.

Fig. 5 is a schematic diagram of beam compression of the prism set and independent adjustment of laser drilling taper by negative Y-axis translation of the first set of wedge mirrors (i.e., the first wedge mirror set).

Fig. 6 is a schematic diagram of the action of a prism assembly beam compression, small angle wedge (i.e., a single wedge).

Fig. 7 is a schematic diagram of beam compression of a prism assembly and independent adjustment of the laser drilling radius by a second set of wedge mirrors (i.e., a second set of wedge mirrors).

Fig. 8 is a further schematic diagram of beam compression of the prism assembly and independent adjustment of the laser drilling radius by the second wedge mirror set (i.e., the second wedge mirror set).

FIG. 9 is a schematic view of an aspheric lens group beam compression laser taper-variable diameter-variable rotary-cut hole machining optical system.

Fig. 10 is a schematic diagram illustrating the working principle of beam compression of an aspherical mirror (i.e., a cylindrical aspherical mirror).

Fig. 11 is a schematic diagram of coma aberration caused by off-axis tilting of a compressed compensation beam of the laser spot aspherical mirror group.

Fig. 12 is a schematic diagram of beam compression by an aspherical mirror set and independent laser-drilling taper adjustment by forward Y-axis translation by a first wedge mirror set (i.e., the first wedge mirror set).

Fig. 13 is a schematic diagram of the action of a light beam compression, small angle wedge (i.e., single wedge) lens of an aspherical mirror set.

Fig. 14 is a schematic diagram of beam compression by an aspherical mirror set and independent adjustment of the radius of laser drilling by a second set of wedge mirrors (i.e., a second wedge mirror set).

Fig. 15 is a schematic diagram of beam compression by the aspherical mirror set and independent adjustment of the laser drilling radius by the second wedge mirror set (i.e., the second wedge mirror set).

The meanings of the reference symbols in the figures are as follows: 1 is a laser incidence end optical axis schematic (i.e. an initial incidence laser optical axis), 2 is an initial incidence circular Gaussian distribution laser beam schematic, 3 and 4 jointly form a compression prism group (wherein, 3 is a first wedge-shaped mirror in the compression prism group, 4 is a second wedge-shaped mirror in the compression prism group), 5 and 6 are a first group of large-inclination-angle wedge-shaped mirrors (i.e. a first wedge-shaped mirror group) with the same wedge angle, 7 is a small-inclination-angle wedge-shaped mirror (i.e. a single wedge-shaped mirror), 8 is a focusing mirror (e.g. a spherical focusing mirror or an aspheric focusing mirror), 9 and 10 are a second group of large-inclination-angle wedge-shaped mirrors (i.e. a second wedge-shaped mirror group) with the same wedge angle, 11 is a focusing light spot obtained by unidirectional compression processing, 12 is a hollow cylinder, 13 is a first small-sized precise adjusting mechanism (i.e. a position adjusting component), 14 is a second-sized precise adjusting mechanism (, 15 is a distance between an exit surface and an entrance surface adjacent to each other in the first compression prism group along the optical axis direction, 16 is a distance between an exit surface and an entrance surface adjacent to each other in the second compression prism group along the optical axis direction, 17 is a hollow motor, 18 is a circular gaussian distribution laser beam based on an off-axis tilt laser focusing system and obtained without one-way compression processing, 19 is a laser spot obtained by one-way compression processing, 20 is a prism group beam compression laser variable-taper variable-diameter rotary-cut hole processing optical system (i.e., a laser variable-taper variable-diameter rotary-cut hole processing optical system), 21 is a laser beam emitted after being processed by the first wedge lens group, 22 is an inclination angle, 23 is an inclined laser beam, 24 is a distance by which a laser focus deviates from the optical axis, 25 is a laser focus spot obtained without one-way compression processing based on the off-axis tilt laser focusing system, 26 and 27 are cylindrical aspheric lens groups (wherein, 26 is a first cylindrical aspheric lens, 27 is a second cylindrical aspheric lens), 28 is a laser beam obtained by unidirectional compression, 29 and 30 are a first group of large-inclination wedge lenses (namely, a first wedge lens group) with the same wedge angle, 31 is a laser beam emitted after being processed by the first wedge lens group, and 32 is an aspheric lens group beam compression laser variable-taper variable-diameter rotary cutting hole processing optical system.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features mentioned in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

In order to more clearly illustrate the functions of the first wedge-shaped mirror group, the single wedge-shaped mirror 7 and the second wedge-shaped mirror group, the wedge angles in the first wedge-shaped mirror group and the second wedge-shaped mirror group are set to be large inclination angles, and the inclination angle in the single wedge-shaped mirror 7 is set to be small inclination angles. In practical application, the single wedge-shaped mirror 7 is not required to be a small inclination angle, the wedge angles in the first wedge-shaped mirror group and the second wedge-shaped mirror group are required to be large inclination angles, and the wedge angles can be flexibly arranged; for example, the inclination angles of the wedge-shaped mirrors can be flexibly changed between 0.01 degrees and 42 degrees as long as the wedge angles of the two wedge-shaped mirrors in the first wedge-shaped mirror group are the same, and the wedge angles of the two wedge-shaped mirrors in the second wedge-shaped mirror group are the same.

As shown in fig. 1, the optical system 20 for processing the prism group beam compression laser variable-taper variable-diameter rotary-cut hole comprises two

compression prism groups

3 and 4 with different sizes, a first group of large-inclination wedge mirrors 5 and 6 with the same wedge angle, a small-inclination wedge mirror 7, a spherical or aspheric focusing mirror 8 and a second group of large-inclination wedge mirrors 9 and 10 with the same wedge angle, which are sequentially arranged along the optical axis 1 of the laser incidence end, small-sized

precise adjusting mechanisms

13 and 14 are respectively connected with the wedge mirrors 6 and 10 for adjusting the

distances

15 and 16, and the whole set of device is driven by a hollow motor 17 to perform high-speed rotary laser drilling on the same optical axis 1 in a hollow cylinder 12.

Since the circular gaussian distribution laser beam 2 incident along the optical axis 1 of the laser variable-cone variable-diameter rotary-cutting hole machining optical system 20 deviates from the optical axis 1 along the Y direction and is inclined, as shown in fig. 2, the circular gaussian distribution laser beam 18 is focused by the spherical or aspherical focusing lens 8 to generate coma aberration, so that the size of the laser focus spot 25 in the Y direction is larger than that in the X direction and is no longer a circular spot. Such a focused spot 25 not only causes deterioration in the accuracy and uniformity of the hole size, but also causes a decrease in the laser energy density.

In order to reduce the coma effect, the present invention provides a laser unidirectional compressing device (as shown in fig. 3), which is a prism assembly composed of two

wedge mirrors

3 and 4 with different sizes. The laser beam 2 passes through the first wedge-shaped mirror 3, the propagation direction can be deflected, and then the laser beam passes through the second wedge-shaped mirror 4 to be deflected to the propagation direction parallel to the optical axis 1, and due to the deflection effect of the single direction (Y-axis direction) of the wedge-shaped

mirrors

3 and 4 on the laser beam 2, the light spot size of the laser beam 2 is compressed in the Y direction, while the light spot size in the X direction is kept unchanged, and a laser light spot 19 with the size in the Y direction smaller than that in the X direction is formed, as shown in fig. 4. After the compressed laser beam laser spot 19 is focused by the focusing lens 8, the generated focusing spot 11 can compensate the focusing spot distortion caused by coma aberration after the laser beam deviates from the optical axis 1 and inclines, so that the energy dispersion of the laser focus in the direction from the optical axis 1 is reduced, the punching size precision and consistency of the off-axis inclined focusing spot are effectively improved, and the laser energy density is improved.

In the prism group compression method, the laser spot one-way compression prism group compresses the light beam and simultaneously parallelly shifts the laser 19 from the optical axis 1. Since the laser beam 19 with parallel offset is still parallel to the optical axis 1, the focal point focused by the spherical or aspherical focusing mirror 8 is still on the optical axis 1, and the focused laser beam 11 is inclined by a certain angle, and the larger the parallel offset of the laser beam 19 is, the larger the inclination angle of the focused laser beam 11 is. Therefore, in order to adjust the amount of displacement of the laser beam 19 from the optical axis 1, a first set of large-angled wedge mirrors 5 and 6 of the same wedge angle is introduced, and the inclined surfaces of the large-angled wedge mirrors 5 and 6 are opposed to each other at 180 °, as shown in fig. 5. The working principle is that when a laser beam 19 parallel to the optical axis 1 passes through the large-inclination-angle wedge-shaped mirror 5, refraction towards the negative Y direction is generated, a certain angle is formed between the laser beam and the optical axis 1, then when the laser beam passes through the large-inclination-angle wedge-shaped mirror 6, the laser beam is reversely refracted at the same angle, a laser beam 21 parallel to the optical axis 1 is formed, the offset is reduced, and the inclination angle of a focused laser beam 11 focused by the spherical or aspheric focusing mirror 8 is also reduced. Thus, introducing a first set of large-tilt wedge mirrors 5 and 6 of the same wedge angle can change the tilt angle of the focused laser beam 11. The smaller the distance 15 between the wedge-shaped

mirrors

5 and 6 is, the larger the off-axis translation amount of the laser is, the larger the inclination angle of the focused laser is, and vice versa, so that the wedge-shaped mirror 6 can be adjusted by the precise adjusting mechanism 13 to move back and forth along the Z-axis direction, the distance 15 between the wedge-shaped

mirrors

5 and 6 can be changed, the inclination angle of the focused laser beam 11 can be changed, and the position of the focused laser beam 11 is kept unchanged, thereby realizing the function of independently adjusting the size of the drilling taper.

The small-angle wedge mirror 7 is used for making the laser beam 21 parallel to the optical axis 1 generate a certain inclination angle 22 with the optical axis 1 before focusing to form an inclined laser beam 23, and then focusing is carried out through the focusing mirror 8 to make the laser focus 11 deviate from the optical axis 1 by a certain distance 24 towards the negative direction of the Y axis, as shown in fig. 6. When the entire optical system apparatus is rotated, the offset distance 24 is the radius of the hole being machined.

The spherical or aspherical focusing mirror 8 is used for focusing the laser beam, so that the power density of the laser beam is high enough to meet the requirement of laser drilling processing; in order to change the radius of rotation 24 of the laser focus 11, the present invention introduces a second set of high-tilt wedge mirrors 9 and 10 with the same wedge angle behind the focusing mirror, and the slopes of the high-tilt wedge mirrors 9 and 10 are opposite to each other by 180 °, as shown in fig. 7. The working principle is that after the incident focused laser beam 11 is refracted by the wedge-shaped mirror 9 and refracted by the wedge-shaped mirror 10, the inclined angle of the focused laser beam 11 is kept unchanged and only the rotating radius 24 is changed because the wedge angles of the two wedge-shaped

mirrors

9 and 10 are the same. The size of the change in the radius of rotation 24 is related to the distance 16 between the two wedge-shaped

mirrors

9 and 10. When the distance 16 between the wedge-shaped

mirrors

9 and 10 is gradually increased, the absolute value of the deviation of the rotating radius 24 of the focused laser beam 11 from the optical axis 1 in the negative Y-axis direction is gradually reduced to zero, and the process is that the laser is reversely tapered and rotated to punch holes; further increasing the distance 16, gradually deviating the rotating radius 24 of the focused laser beam 11 from zero to the positive direction of the Y axis from the optical axis 1, as shown in FIG. 8, this process is laser positive cone rotary drilling, adjusting the wedge mirror 10 to move back and forth along the Z axis direction by the precise adjusting mechanism 14, changing the distance 16 between the wedge mirrors 9 and 10, and changing the size and the hole pattern of the rotating radius 24 of the focused laser beam 11, while the laser inclination angle remains unchanged, thereby realizing the function of independently adjusting the drilling radius size and the rotating mode of the laser positive cone and the reverse cone.

As shown in fig. 9, the optical system 32 for processing the variable-taper variable-diameter rotary-cut hole by compressing the light beam with the aspheric lens group comprises two cylindrical

aspheric lens groups

26 and 27 with different sizes, a first group of large-inclination wedge-shaped

lenses

29 and 30 with the same wedge angle, a small-inclination wedge-shaped lens 7, a spherical or aspheric focusing lens 8, and a second group of large-inclination wedge-shaped

lenses

9 and 10 with the same wedge angle, which are sequentially arranged along the optical axis 1 of the laser incidence end, small-sized

precise adjusting mechanisms

13 and 14 are respectively connected with the wedge-shaped

lenses

30 and 10 for adjusting the

distances

15 and 16, and the whole set of device is driven by a hollow motor 17 to perform high-speed rotary laser drilling on the same optical axis 1 in a hollow cylinder 12 with the same optical axis.

Also for reducing the coma effect, the present device provides another laser unidirectional compression device, which is an aspherical mirror set composed of two cylindrical non-curved mirrors 26 and 27, as shown in fig. 10. The laser beam 2 passes through the first aspherical mirror 26 to be converged in the Y direction while being kept constant in the X direction, and then passes through the aspherical mirror 27 to propagate the light in the Y direction in a direction parallel to the optical axis 1, so that the spot size of the laser beam 2 is compressed in the Y direction while the spot size in the X direction is kept constant, and a laser spot 28 having a smaller size in the Y direction than in the X direction is formed, as shown in fig. 11. After the compressed laser beam laser spot 28 is focused by the focusing lens 8, the generated focusing spot 11 can compensate the focusing spot distortion caused by coma aberration after the laser beam deviates from the optical axis 1 and inclines, so that the energy dispersion of the laser focus in the direction from the optical axis 1 is reduced, the punching size precision and consistency of the off-axis inclined focusing spot are effectively improved, and the laser energy density is improved.

Since the exit laser light 28 still propagates along the optical axis 1 in the aspherical mirror compression mode, in order to generate a tilt angle for the focused laser beam 11, a first set of large tilt wedge mirrors 29 and 30 with the same wedge angle are introduced, and the tilt surfaces of the large tilt wedge mirrors 29 and 30 are opposite to each other by 180 °, as shown in fig. 12. The working principle is that when the laser beam 28 transmitted along the optical axis 1 passes through the large-inclination wedge-shaped mirror 29, the forward refraction towards the Y axis is generated to form a certain angle with the optical axis 1, and then when the laser beam passes through the large-inclination wedge-shaped mirror 30, the laser beam is reversely refracted at the same angle to form a laser beam 31 which is parallel to and offset from the optical axis 1. The larger the distance 15 between the wedge mirrors 29 and 30 is, the larger the off-axis translation amount of the laser is, the larger the inclination angle of the focused laser is, and vice versa, so that the precision adjusting mechanism 13 can adjust the wedge mirror 30 to move back and forth along the Z-axis direction, the distance 15 between the wedge mirrors 29 and 30 is changed, the inclination angle of the focused laser beam 11 can be changed, and the position of the focused laser beam 11 is kept unchanged, thereby realizing the function of independently adjusting the size of the drilling taper.

The small angle wedge 7 is used to make the laser beam 31 parallel to the optical axis 1 form an inclined laser beam 23 by a certain inclination angle 22 with the optical axis 1 before focusing, and then focus the laser beam by the focusing mirror 8 to make the laser focus 11 deviate from the optical axis 1 by a certain distance 24 towards the negative direction of the Y-axis, as shown in fig. 13. When the entire optical system apparatus is rotated, the offset distance 24 is the radius of the hole being machined.

The spherical or aspherical focusing mirror 8 is used for focusing the laser beam, so that the power density of the laser beam is high enough to meet the requirement of laser drilling processing; in order to change the radius of rotation 24 of the laser focus 11, the present invention introduces a second set of high-tilt wedge mirrors 9 and 10 with the same wedge angle behind the focusing mirror, and the slopes of the high-tilt wedge mirrors 9 and 10 are opposite to each other by 180 °, as shown in fig. 14. The working principle is that after the incident focused laser beam 11 is refracted by the wedge-shaped mirror 9 and refracted by the wedge-shaped mirror 10, the inclined angle of the focused laser beam 11 is kept unchanged and only the rotating radius 24 is changed because the wedge angles of the two wedge-shaped

mirrors

9 and 10. When the distance 16 between the wedge-shaped

mirrors

9 and 10 is gradually increased, the absolute value of the deviation of the rotating radius 24 of the focused laser beam 11 from the optical axis 1 in the negative Y-axis direction is gradually reduced to zero, and the process is that the laser is reversely tapered and rotated to punch holes; further increasing the distance 16, gradually deviating the rotation radius 24 of the focused laser beam 11 from zero to the positive direction of the Y axis from the optical axis 1, as shown in FIG. 15, this process is laser positive cone rotary drilling, adjusting the wedge mirror 10 to move back and forth along the Z axis direction by the precise adjusting mechanism 14, changing the distance 16 between the wedge mirrors 9 and 10, and changing the size and the hole pattern of the rotation radius 24 of the focused laser beam 11, while the laser inclination angle remains unchanged, thereby realizing the function of independently adjusting the drilling radius size and the rotation modes of the laser positive cone and the reverse cone.

In addition, when the compression prism group is used as the unidirectional laser beam compression assembly, the distance between the intersection point of the rear surface of the first compression wedge-shaped mirror and the rotating shaft and the intersection point of the front surface of the second compression wedge-shaped mirror and the rotating shaft is preferably 0-100 mm, the distance has no influence on the compression of the light beam, but the parallel off-axis amount of the laser deviated from the initial incident optical axis can be changed, and when the wedge angle and the placing angle are fixed, the larger the distance is, the larger the translation amount of the laser is. In the compression mode of the wedge-shaped mirror compression set, the laser can be moved upwards by compressing the light beam, so that the subsequent adjustment of the inclination angle of the light beam is influenced. For example, the distance can be adjusted to make the laser translation amount reach the maximum value that the subsequent lens can bear, and then the distance between the subsequent first group of wedge mirrors can be adjusted to gradually reduce the translation amount, thereby realizing the large-scale adjustment of the beam inclination angle.

Besides, the laser beam unidirectional compression assembly adopts the compression prism group and also can adopt a cylindrical aspheric lens group, and when the compression modes are different, the arrangement mode corresponding to the subsequent first wedge-shaped lens group can be flexibly adjusted. For example, when the wedge-shaped mirror compression set is adopted, the first wedge-shaped mirror set has the function of reducing the upward parallel off-axis amount of the laser, namely the larger the distance between two wedge-shaped mirrors is, the smaller the upward off-axis amount of the laser is; when the aspheric compression lens group is adopted, the laser does not generate off-axis after being compressed, so the first wedge-shaped lens group has the effect of enabling the laser to be off-axis upwards, and the larger the distance between the two wedge-shaped lenses is, the larger the off-axis amount of the laser to be off-axis upwards is.

The following are specific examples:

example 1: processing of 440um thick copper plate prism group compression positive taper hole

A laser having an average power of 60W, a wavelength of 1064nm and a pulse length of 10ps was used as a light source, and the repetition frequency was selected to be 20 kHz. The compression ratio of the laser beam one-way prism compression device is selected from 4: 1; the wedge-shaped prisms with 18-degree 9' wedge angles are selected for the wedge-shaped

mirrors

5 and 6; the wedge angle of the wedge-shaped mirror 7 is 3 degrees 53'; the focusing lens 8 is a focusing lens with an effective focal length of about 50 mm; the wedge angle of the wedge mirrors 9 and 10 is 11 deg. 22'. All lenses were 25.4mm in diameter. The diameter of an input laser beam is 12mm, the length of the input laser beam in the Y direction is compressed to 3mm by 4 times of a laser beam compression system, the distance 15 between the wedge-shaped

mirrors

5 and 6 is 5mm by adjusting the precision displacement adjusting device 13, the inclination angle of the laser beam after passing through the focusing mirror 8 is 5 degrees, the distance 16 between the wedge-shaped

mirrors

9 and 10 is 19.5mm by adjusting the precision displacement adjusting device 14, and the scanning radius of the laser positive cone rotation is 250 um. The laser variable-cone variable-diameter rotary cutting hole machining optical system device is controlled to rotate at the speed of 300 revolutions per minute by the hollow machine. The laser focus is arranged in the middle of the copper plate, and a positive taper hole with the entrance radius of 255um, the exit radius of 214um and the positive taper angle of 5 degrees is processed.

Example 2: processing reverse taper hole of 440um thick copper plate aspheric lens group

A laser having an average power of 60W, a wavelength of 1064nm and a pulse length of 10ps was used as a light source, and the repetition frequency was selected to be 20 kHz. The compression ratio of the laser beam one-way aspherical mirror compression device is selected to be 4: 1; the wedge-shaped

mirrors

29 and 30 adopt wedge-shaped prisms with a wedge angle of 18 degrees and 9 degrees; the wedge angle of the wedge-shaped mirror 7 is 3 degrees 53'; the focusing lens 8 is a focusing lens with an effective focal length of about 50 mm; the wedge angle of the wedge mirrors 9 and 10 is 11 deg. 22'. All lenses were 25.4mm in diameter. The diameter of an input laser beam is 12mm, the length of the input laser beam in the Y direction is compressed to 3mm by 4 times of a laser beam compression system, the distance 15 between the wedge-shaped

mirrors

29 and 30 is 25mm by adjusting the precision displacement adjusting device 13, the inclination angle of the laser beam after passing through the focusing mirror 8 is 5 degrees, the distance 16 between the wedge-shaped

mirrors

9 and 10 is 12.2mm by adjusting the precision displacement adjusting device 14, and the scanning radius of the negative taper rotation of the laser beam is 250 um. The laser variable-cone variable-diameter rotary cutting hole machining optical system device is controlled to rotate at the speed of 300 revolutions per minute by the hollow machine. The laser focus is arranged in the middle of the copper plate, and an inverted taper hole with an entrance radius of 473um, an exit radius of 514um and a taper of minus 5 degrees is processed.

Example 3: 1220um thick nickel-based high-temperature alloy prism group cylindrical hole processing

A laser having an average power of 60W, a wavelength of 1064nm and a pulse length of 10ps was used as a light source, and the repetition frequency was selected to be 20 kHz. The compression ratio of the laser beam one-way prism group compression device is selected from 4: 1; the wedge-shaped prisms with 18-degree 9' wedge angles are selected for the wedge-shaped

mirrors

5 and 6 is 20mm by adjusting the precision displacement adjusting device 13, the inclination angle of the laser beam after passing through the focusing mirror 8 is 1 degree, the distance 16 between the wedge-shaped

mirrors

9 and 10 is 14.7mm by adjusting the precision displacement adjusting device 14, and the scanning radius of the laser positive cone rotation is 243 um. The laser variable-cone variable-diameter rotary cutting hole machining optical system device is controlled to rotate at the speed of 300 revolutions per minute by the hollow machine. The laser focus is positioned on the surface of a processing material, and a cylindrical straight hole with the radius of 250um and the depth of 1200um is obtained by processing.

The utility model discloses can realize becoming the awl and become footpath and adjust, the tapering is adjusted and aperture is adjusted both and can be independently adjusted separately, promptly, the aperture hardly changes when adjusting the tapering, and the tapering also hardly changes when adjusting the aperture. In addition, the above examples are all exemplified by a mirror with a diameter of 1 inch (25.4mm), and the adjustment range of the laser taper and the machining radius can be made larger by using an optical element with a larger diameter; for example, if a two-inch diameter mirror is used instead, the maximum tilt angle of the laser can be twice as large as in the above example, and the adjustment range of the machining radius is expanded without changing the focal length of the focusing mirror.

The utility model discloses the optical axis setting is altogether organized to the whole optical element that adopts, and the optical axis is through each optical element's central point. In addition, regarding the center point of the wedge mirror: because the wedge-shaped mirror has two optical surfaces which can be used as an incident surface or an emergent surface of the laser beam, wherein one optical surface is vertical to the edge of the wedge-shaped mirror (namely, a vertical optical end surface with 90 degrees), and the other surface has a certain inclination angle with the edge of the wedge-shaped mirror (namely, an inclined optical end surface inclined according to a wedge angle); the center point of the wedge-shaped mirror refers to the center point of the surface perpendicular to the edge of the wedge-shaped mirror. The whole device can be driven by a hollow motor or other hollow rotating devices driven by the motor to rotate at the same optical axis at high speed; the distance between the wedge-shaped lenses in the two groups of wedge-shaped lens groups with large inclination angles (namely the first wedge-shaped lens group and the second wedge-shaped lens group) is adjusted by a small-sized precise adjusting mechanism; the small-sized precise adjusting mechanism is a manual precise adjusting mechanism or an electric control precise adjusting mechanism, for example, the movable range of the adjusting mechanism is 0mm to 200mm, and the moving precision is at least not inferior to 0.1mm (of course, the finer the precision is, the better the precision is); the focusing mirror may be a spherical focusing mirror or an aspherical focusing mirror.

The above-mentioned content has been described in detail with respect to the laser variable-taper variable-diameter rotary-cut hole machining optical system, which may be arranged in the same manner, as long as the first wedge lens group is removed.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims

1. The laser reducing rotary cut hole machining optical system is characterized by comprising a rotating shaft and the following optical elements which are sequentially arranged along an optical path, wherein the optical elements are positioned in a shell and can synchronously rotate around the rotating shaft: the laser beam unidirectional compression assembly comprises a single wedge-shaped mirror (7) for inducing the laser inclination angle, a focusing mirror (8) and a second wedge-shaped mirror group which is composed of two wedge-shaped mirrors with the same wedge angle and is used for adjusting the offset of a focusing light spot; wherein:

2. The optical system for laser variable-diameter rotary cut hole machining according to claim 1, further comprising a first wedge lens group consisting of two wedge lenses with the same wedge angle and used for adjusting the offset of the laser beam, wherein the optical element is arranged on the light path between the laser beam unidirectional compression assembly and the single wedge lens (7) so that the system can also realize laser variable-cone adjustment;

3. The optical system for laser variable-diameter rotary cut hole machining according to claim 2, wherein the wedge angle of the single-chip wedge-shaped mirror (7) is 0.01 ° to 42 °;

the wedge angle of the first wedge-shaped mirror is 0.01-42 degrees;

the wedge angle of the third wedge-shaped mirror is 0.01-42 degrees;

4. The optical system for laser variable-diameter rotary cut hole machining according to claim 2, wherein the position adjusting assembly can drive the wedge-shaped mirror connected with the position adjusting assembly to move by 0mm to 200mm, and the moving precision is not inferior to 0.1 mm.

5. The optical system for laser variable diameter rotary cut hole machining according to claim 2, wherein the rotary shaft further passes through a center point of each optical element;

6. The optical system for laser variable diameter rotational atherectomy hole machining according to claim 2, wherein for the first wedge mirror group, both the 90 ° vertical optical end surface of the first wedge mirror and the 90 ° vertical optical end surface of the second wedge mirror are perpendicular to the optical axis of the initial incident laser beam, and the inclined optical end surface of the first wedge mirror inclined at the wedge angle and the inclined optical end surface of the second wedge mirror inclined at the wedge angle are parallel to each other;

7. The optical system for laser variable-diameter rotary cut hole machining according to claim 2, wherein the compression prism group includes two compression wedge mirrors, each compression wedge mirror has a wedge angle of 0.01 ° to 42 °, any one compression wedge mirror has a vertical optical end surface at 90 ° as an incident surface, an inclined optical end surface inclined at the wedge angle as an exit surface, and the vertical optical end surfaces are perpendicular to an optical axis of an initial incident laser beam; remember these two pieces of wedge mirror for compression that follow light path in proper order and successively set up are first piece wedge mirror for compression and second piece wedge mirror for compression respectively, then: the distance between the intersection point of the rear surface of the first piece of wedge-shaped compression mirror and the rotating shaft and the intersection point of the front surface of the second piece of wedge-shaped compression mirror and the rotating shaft is 0-100 mm.

8. The optical system for laser diameter-varying rotary cut hole machining according to claim 2, wherein the cylindrical aspheric lens group includes two cylindrical aspheric lenses, and the two cylindrical aspheric lenses sequentially disposed along the optical path are respectively a first cylindrical aspheric lens and a second cylindrical aspheric lens, wherein the first cylindrical aspheric lens has a function of converging the laser beam in a single direction, and the second cylindrical aspheric lens has a function of diverging the laser beam in a single direction.

9. The optical system for processing rotary cut with laser diameter varying according to claim 1, wherein the optical system for processing rotary cut with laser diameter varying is further connected to a hollow rotating device, and is configured to rotate around the rotating shaft under the driving of the hollow rotating device; the rotating speed is 0.1 rpm-6000 rpm.

10. The optical system for laser diameter-varying rotary cut hole machining according to claim 9, wherein the hollow rotating device is a motor-driven hollow rotating device; the shell is a hollow cylinder (12).