阅读说明：本技术 基于两片透镜的变焦对焦激光切割头 (Zooming and focusing laser cutting head based on two lenses ) 是由 方强 方笑尘 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种基于两片透镜的变焦激光切割头,包括激光输出光纤、光纤封装装置、第一光学透镜、第一透镜框、第二光学透镜、第二透镜框、第一拨杆、第二拨杆和套管；本发明提供的基于两片透镜的变焦激光切割头：将变焦切割头光学系统的结构简化到只有两片,从源头上减少了热杂光；采用自润滑结构,在保证低摩擦力的情况下大幅提高机械结构导热特性；提高了激光切割头的工作功率,延长激光切割头的寿命；降低了变焦激光切割头的成本。(The invention discloses a zoom laser cutting head based on two lenses, which comprises a laser output optical fiber, an optical fiber packaging device, a first optical lens, a first lens frame, a second optical lens, a second lens frame, a first deflector rod, a second deflector rod and a sleeve; the invention provides a zoom laser cutting head based on two lenses, which comprises: the structure of the optical system of the zoom cutting head is simplified to only two pieces, so that the hot stray light is reduced from the source; the self-lubricating structure is adopted, so that the heat conduction characteristic of the mechanical structure is greatly improved under the condition of ensuring low friction force; the working power of the laser cutting head is improved, and the service life of the laser cutting head is prolonged; the cost of the laser cutting head with variable focus is reduced.)

1. The utility model provides a focus laser cutting head zooms based on two lens, characterized by: the optical fiber packaging device comprises a laser output optical fiber (1), an optical fiber packaging device (2), a first optical lens (31), a first lens frame (41), a second optical lens (32), a second lens frame (42), a first deflector rod (51), a second deflector rod (52) and a sleeve (6), wherein: the first optical lens (31) and the second optical lens (32) are arranged on an output optical path of the laser output fiber (1); the laser output optical fiber packaging device (2) wraps and fixes the laser output optical fiber (1); the first optical lens (31) is fixed to the first lens frame (41); the second optical lens (32) is fixed on the second lens frame (42); the first lens frame (41) is arranged at one end of the sleeve (6) close to the laser output optical fiber (1); the second lens frame (42) is arranged at one end of the sleeve (6) far away from the laser output optical fiber (1); a self-lubricating structure is arranged between the outer annular surfaces of the first lens frame (41) and the second lens frame (42) and the sleeve (6); the sleeve (6) is provided with two grooves along the direction parallel to the axis of the sleeve, the first deflector rod (51) is connected with the first lens frame (41) through one groove on the sleeve (6), and the second deflector rod (52) is connected with the second lens frame (42) through the other groove on the sleeve (6); the optical fiber packaging device (2) is fixedly connected with the sleeve (6).

2. The two-lens based laser cutting head with zooming and focusing functions as claimed in claim 1, wherein the first driving lever (51) and the second driving lever (52) respectively drag the first lens frame (41) and the second lens frame (42) and the first optical lens (31) and the second optical lens (32) fixed on the lens frames to move for zooming and/or focusing.

3. A two-lens based zoom and focus laser cutting head as claimed in claim 1 or 2, wherein: the first lens frame (41) and the second lens frame (42) are made of self-lubricating materials, or are composed of a lens frame base body and a self-lubricating coating on the outer surface of the base body, or are composed of a lens frame base body and self-lubricating materials embedded on the lens frame base body.

4. The utility model provides a focus laser cutting head zooms based on two lens, characterized by: the optical fiber packaging device comprises a laser output optical fiber (1), an optical fiber packaging device (2), a first optical lens (31), a first lens frame (41), a second optical lens (32), a second lens frame (42), a second deflector rod (52) and a sleeve (6), wherein: the first optical lens (31) and the second optical lens (32) are arranged on an output optical path of the laser output fiber (1); the laser output optical fiber packaging device (2) wraps and fixes the laser output optical fiber (1); the first optical lens (31) is fixed to the first lens frame (41); the second optical lens (32) is fixed on the second lens frame (42); the first lens frame (41) is fixedly arranged at one end, close to the laser output optical fiber (1), of the sleeve (6); the second lens frame (42) is arranged at one end of the sleeve (6) far away from the laser output optical fiber (1); a self-lubricating structure is arranged between the outer annular surface of the second lens frame and the sleeve; a groove is formed in the wall of the sleeve (6) along the axial direction of the parallel tube, and the second driving lever (52) is fixedly connected with the second lens frame (42) through the groove in the sleeve (6); the optical fiber packaging device (2) is fixedly connected with the sleeve (6).

5. The two-lens based zoom focusing laser cutting head of claim 4, wherein: the second driving lever (52) drags the second lens frame (42) and the second optical lens (32) fixed on the lens frame to move for realizing zooming and/or focusing.

6. A two-lens based zoom and focus laser cutting head as claimed in claim 4 or 5, wherein: the second lens frame (42) is made of a self-lubricating material, or consists of a lens frame base body and a self-lubricating coating on the outer surface of the base body, or consists of a lens frame base body and a self-lubricating material embedded on the lens frame base body.

7. The two-lens based zoom focusing laser cutting head of claim 1, wherein: the lens frame is an annular lens frame.

8. The two-lens based zoom focusing laser cutting head of claim 1, wherein: the first optical lens (31) and the second optical lens (32) both adopt spherical mirrors.

Technical Field

The invention belongs to the technical field of laser processing, and particularly relates to a zooming and focusing laser cutting head based on two lenses.

Background

Laser cutting heads are a key component in laser cutting equipment, which images the light output by a laser onto a surface being cut. For metal plates of different thicknesses, different size spots are often required to improve cutting efficiency, which requires optical zoom capability of the laser cutting head. In reality, however, no laser cutting machine, except the top-level cutting machine, employs a variable-focus cutting head. The optical aspects of this situation are mainly due to:

1. from an optical system point of view, it is extremely expensive. Besides the complicated design of zoom lenses, aspheric mirrors are often used in large quantities to reduce the number of lenses and ensure image quality, for example: the national engineering research center of Huazhong university of science and technology, Gejiaqi et al (2 nd 2019 of the Chinese optical science) provides a lens design of 7 lenses, and 3 aspherical mirrors are adopted in the design; shanghai Jiaqiang automation technology company provides a technical scheme of 4 lenses (Chinese patent application number CN201510566726.6), and 3 aspheric lenses are adopted. Due to the difficulty in processing the aspherical mirror, the laser lens is very expensive.

2. Because the optical glass material has material absorption and scattering, the light absorbed by the lens directly causes the temperature rise of the lens, and the scattered light is used as stray light to heat devices and a shell in a closed cavity of the optical system. In order to reduce the thermal lens effect caused by the temperature rise caused by the absorption of the material, expensive high-purity glass material is adopted.

3. The level of scattered light of the current high-power film is not less than 0.2% due to the imperfect coating technology of the optical lens, which means that the stray light generated by each single glass lens is not less than 0.4%, and obviously, the increase of the number of glass lenses in the optical system means the increase of the stray light generating heat. For example, if the laser power is ten thousand watts and the heating stray light generated by each lens is 40 watts, an optical system composed of 7 lenses needs at least one protective glass, and the power of the heating stray light in the optical system is at least 320 watts. In order to remove the heat from these parasitic lights, the cooling system must be carefully designed, which can reduce the reliability of the optical system if the cooling effect is not good.

The mechanical reasons for this situation are mainly: the mechanical structure and method for realizing the relative movement of the lenses in the zoom lens are as follows: the lenses are fixed on respective lens frames, the lens frames are connected with the guide rail by the linear bearing, and then the lenses are driven to realize relative motion by the cam erected on the bearing, so that the aim of zooming is achieved. The specific structure can be seen in the technical scheme disclosed in Chinese patent application No. 201910637898.6. In a laser optical system, due to absorption and scattering of a lens material and light scattering caused by imperfect coating on the surface of the lens, the temperature of the lens and a lens frame sealed in a cam can be increased, the heat conduction characteristic of a linear bearing is poor, heat on the lens and the lens frame can be transferred to the cam only through air, the cam can also generate heat under the action of light, part of heat on the cam is transferred to a base through the bearing, and the other part of heat is transferred through the air; the traditional structure has poor heat dissipation effect, so that the use power of the zoom lens is limited, or the reliability of an optical system is reduced when the zoom lens is used with high power, and the performance is reduced when the zoom lens is used with high power, such as thermal lens effect; furthermore, this structure results in a mechanical system that is complex, difficult to install and large in size.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a laser cutting head based on two lenses for zooming and focusing, which can reduce the cost of the zooming cutting head; reducing thermal flare in a laser cutting head; the heat conductivity of the mechanical structure of the laser cutting head is improved, and the reliability of the cutting head is improved.

In order to achieve the above object, a zoom and focus laser cutting head based on two lenses adopts the technical scheme that the zoom and focus laser cutting head comprises a laser output optical fiber, an optical fiber packaging device, a first optical lens, a first lens frame, a second optical lens, a second lens frame, a first deflector rod, a second deflector rod and a sleeve, wherein: the first optical lens and the second optical lens are arranged on an output optical path of the laser output optical fiber; the laser output optical fiber packaging device wraps and fixes the laser output optical fiber; the first optical lens is fixed on the first lens frame; the second optical lens is fixed on the second lens frame; the first lens frame is arranged at one end, close to the laser output optical fiber, of the sleeve; the second lens frame is arranged at one end, far away from the laser output optical fiber, in the sleeve; a self-lubricating structure is arranged between the outer annular surfaces of the first lens frame and the second lens frame and the sleeve; the wall of the sleeve is provided with two grooves along the direction parallel to the axis of the tube, the first deflector rod is connected with the first lens frame through one groove of the sleeve, and the second deflector rod is connected with the second lens frame through the other groove of the sleeve; the optical fiber packaging device is fixedly connected with the sleeve.

Further, the first shifting lever and the second shifting lever respectively drag the first lens frame and the second lens frame and the first optical lens and the second optical lens fixed on the lens frames to move, so that zooming and/or focusing are realized.

Further, the first lens frame and the second lens frame are made of self-lubricating materials, or are composed of a lens frame base body and a self-lubricating coating on the outer surface of the base body, or are composed of a lens frame base body and self-lubricating materials embedded on the lens frame base body.

Further, the first optical lens and the second optical lens both adopt spherical mirrors.

The invention provides another zoom focusing laser cutting head based on two lenses, which is characterized in that: the optical fiber packaging device comprises a laser output optical fiber, an optical fiber packaging device, a first optical lens, a first lens frame, a second optical lens, a second lens frame, a second deflector rod and a sleeve, wherein: the first optical lens and the second optical lens are arranged on an output optical path of the laser output optical fiber; the laser output optical fiber packaging device wraps and fixes the laser output optical fiber; the first optical lens is fixed on the first lens frame; the second optical lens is fixed on the second lens frame; the first lens frame is fixedly arranged at one end, close to the laser output optical fiber, in the sleeve; the second lens frame is arranged at one end, far away from the laser output optical fiber, in the sleeve; a self-lubricating structure is arranged between the outer annular surface of the second lens frame and the sleeve; a groove is formed in the wall of the sleeve along the axis direction of the parallel tube, and the second deflector rod is fixedly connected with the second lens frame through the groove in the sleeve; the optical fiber packaging device is fixedly connected with the sleeve.

Further: the second shifting lever drags the second lens frame and the second optical lens fixed on the lens frame to move, so that zooming and/or focusing are realized.

Further, the second lens frame is made of a self-lubricating material, or is composed of a lens frame base body and a self-lubricating coating on the outer surface of the base body, or is composed of a lens frame base body and a self-lubricating material embedded on the lens frame base body.

In the above technical solution, the lens frame is an annular lens frame.

Compared with the prior art, the invention has at least the following beneficial effects: according to the two-lens-based zoom focusing laser cutting head, the structure of the optical system of the zoom cutting head is simplified to only two lenses, so that heat stray light is reduced from the source, a cooling system is prevented from being added in the optical system of the cutting head, the stability of an optical system is improved, and the cost of the laser cutting head is reduced because the two lenses adopt spherical lenses.

Furthermore, the laser head of the invention widely adopts a self-lubricating structure, the self-lubricating structure is preferably graphite, and the graphite is used as a good heat conducting material, so that the heat conducting property of the mechanical structure can be greatly improved under the condition of ensuring low friction force, in the design, the self-lubricating structure realizes surface contact between devices, the heat conducting property is greatly improved, along with the great improvement of the heat problem, the working power of the laser cutting head can be improved, the service life of the laser cutting head is prolonged, and the reliability of the cutting head is improved.

Furthermore, the laser cutting head disclosed by the invention is simple in structure, and compared with the existing laser cutting head, the cost is greatly reduced, so that the universal application of the laser cutting head becomes possible, and the improvement of the laser cutting quality and efficiency can be further promoted.

Drawings

Fig. 1 is a schematic structural diagram of a first zoom and focus laser cutting head based on two lenses according to the present invention.

Fig. 2 is a schematic structural diagram of a second zoom and focus laser cutting head based on two lenses according to the present invention.

Wherein: 1 denotes a laser output fiber; 2, a laser output fiber packaging device, 31, a first lens and 32, a second lens; 41 denotes a first lens frame, 42 denotes a second lens frame; 51 denotes a first lever, and 52 denotes a second lever; and 6 denotes a sleeve.

Detailed Description

The two-lens based zoom focusing laser cutting head of the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural diagram of a first zoom and focus laser cutting head based on two lenses according to the present invention. The laser output optical fiber packaging device comprises a laser output optical fiber 1, a laser output optical fiber packaging device 2, a first optical lens 31, a second optical lens 32, a first lens frame 41, a second lens frame 42, a first deflector rod 51, a second deflector rod 52 and a sleeve. Wherein: the laser output optical fiber packaging device 2 wraps and fixes the laser output optical fiber 2 in the laser output optical fiber packaging device, and is used for performing necessary treatment on the optical fiber and protecting the optical fiber; the first optical lens 31 is fixed on the first lens frame 41, and the second optical lens 32 is fixed on the second lens frame 42; two grooves parallel to the pipe shaft are formed in the sleeve 6 along the direction parallel to the pipe shaft; lens frames 41 and 42 are disposed within the ferrule 6, the first lens frame 41 being adjacent to the laser output fiber; the first shift lever 51 is fixedly connected with the first lens frame 41 through a corresponding groove on the sleeve 6, and the second shift lever 52 is fixedly connected with the second lens frame 42 through a corresponding groove on the sleeve 6; at least one of the outer peripheral surface of the lens frames 41, 42 and the sleeve 6 has a self-lubricating structure. In the cutting head, the first driving lever 51 and the second driving lever 52 are respectively dragged to drive the first lens frame 41, the second lens frame 42 and the first optical lens 31 and the second optical lens 32 fixed on the lens frames, so that the zooming function of the optical system can be realized, and the two driving levers, the lens frames and the lenses fixed together with the driving levers are synchronously dragged, so that the focusing of the optical system can be realized. By combining the zoom data and the focus data, both zoom and focus functions can be performed simultaneously.

In the above system, the self-lubricating structure is generally made on the outer annular surface of the lens frame, which is more convenient. The first lens frame 41 and the second lens frame 42 may be made of a self-lubricating material, may be made of a lens frame base and a self-lubricating coating on the outer surface of the base, or may be made of a lens frame base and a self-lubricating material embedded on the annular lens frame base.

Generally, the lens frame is annular.

Fig. 2 is a schematic structural diagram of a second variable-focus laser cutting head based on two lenses according to the present invention. The laser output optical fiber packaging device comprises a laser output optical fiber 1, a laser output optical fiber packaging device 2, a first optical lens 31, a second optical lens 32, a first lens frame 41, a second lens frame 42, a second deflector rod 52 and a sleeve. Wherein: the laser output optical fiber packaging device 2 wraps and fixes the laser output optical fiber 2 in the laser output optical fiber packaging device, and is used for performing necessary treatment on the optical fiber and protecting the optical fiber; the first optical lens 31 is fixed on the first lens frame 41, and the second optical lens 32 is fixed on the second lens frame 42; a groove parallel to the pipe shaft is formed on the sleeve 6 along the direction parallel to the pipe shaft; the first lens frame 41 is fixedly arranged in the sleeve 6 and close to the laser output optical fiber 1, and the second lens frame 42 is arranged at one end of the sleeve 6 far away from the laser output optical fiber; the second shift lever 52 is fixedly connected with the second lens frame 42 through a corresponding groove on the sleeve 6; at least one of the outer ring surface of the second lens frame 42 and the sleeve 6 has a self-lubricating structure. In the cutting head, by dragging the second shift lever 52 to move the second lens frame 42 and the second optical lens 32 fixed on the lens frame, some specific optical system zooming and focusing can be realized.

In the above system, the self-lubricating structure is generally made on the outer annular surface of the lens frame, which is more convenient. The second lens frame 42 may be made of a self-lubricating material, or may be made of a lens frame base and a self-lubricating coating on the outer surface of the base, or may be made of a lens frame base and a self-lubricating material embedded in the lens frame base.

Generally, the lens frame is annular.

According to the technical scheme shown in fig. 1, a zoom focusing system is designed for outputting laser with a numerical aperture of 0.065, and the core diameter of a laser output fiber 1 can be changed from 2 times to 4 times. Wherein, the two lenses both adopt spherical mirrors, and the focal lengths are 39.84 and 50.75 respectively; the lens frames 41 and 42 are structured by embedding a self-lubricating material (graphite) in an annular metal base, and the lenses are fixed inside the lens frames. In the system, the same amount of driving deflector rods drive the two lenses to move, so that focusing can be realized; the two driving levers are respectively dragged according to the zooming rule, so that zooming can be realized; the amount of movement required for focusing is simultaneously superposed on the basis of the amount of movement for dragging the lens to zoom, and zooming and focusing can be simultaneously realized. The zoom lens structure can enable the cost of the laser cutting head to be even lower than that of a fixed-focus laser cutting head, and greatly improves the market competitiveness of the zoom cutting head.

According to the technical scheme shown in fig. 2, a zoom system is designed for outputting laser with a numerical aperture of 0.065, the core diameter of a laser output optical fiber 1 can be changed from 2 times to 4 times, spherical mirrors are adopted by two lenses, and the focal lengths are 37.51 and 43.76 respectively; the lens frame 42 is formed by embedding a self-lubricating material (graphite) in an annular metal substrate, and the lens is fixed inside the lens frame. The zoom lens structure is an approximate zoom lens structure, and the conjugate distance from a light emitting point of a light source to an image point is changed by only 0.11 mm in the zooming process from 2 times to 4 times through ingenious parameter design, so that the use is not influenced. The two driving levers are respectively dragged according to the zooming rule, zooming can be realized, and the exercise mechanism is simpler than the former scheme.

According to the technical scheme shown in fig. 2, a focusing and zooming related system is designed for a single-mode laser, and the zooming amount can be changed according to the focusing amount through the movement of a lens. The cutting head is suitable for laser output with a numerical aperture of 0.065, and can change the core diameter of a laser output optical fiber from 2 times to 5 times. Wherein, the two lenses both adopt spherical mirrors, and the focal lengths are respectively 34.7 mm and 45.48 mm; the lens frame 42 is formed by embedding a self-lubricating material (graphite) in an annular metal substrate, and the lens is fixed inside the lens frame. The designed change rule of the processing light spot is as follows: the focusing amount is 4.5 mm, and the magnification is 3 times; focusing amount is 0 mm, and magnification is 3.5 times; the focusing amount is minus 5 mm, and the magnification is 3 times; the focusing amount is minus 10 mm, and the magnification is 4 times; the focusing amount is minus 18.2, and the magnification is 5 times.

Compared with the existing commercial products, the zoom laser cutting head based on the two lenses provided by the invention can greatly reduce the cost of the zoom laser cutting head, so that the universal application of the zoom laser cutting head becomes possible, and the improvement of the laser cutting quality and efficiency is further promoted.