CN111299849A

CN111299849A - Laser cutting machine with double swinging heads

Info

Publication number: CN111299849A
Application number: CN201911040568.5A
Authority: CN
Inventors: 钟胜波; 李芝春
Original assignee: Changzhou Conovo Cnc Technology Co ltd
Current assignee: Changzhou Conovo Cnc Technology Co ltd
Priority date: 2015-11-09
Filing date: 2015-11-09
Publication date: 2020-06-19
Also published as: CN105215559A; CN107570885B; CN111299848A; CN107570885A; CN105215559B

Abstract

The embodiment of the invention discloses a laser cutting machine with double swinging heads, wherein a rotating shaft of a B-shaft swinging head is in three stages comprising a B-shaft input shaft, a first-stage B-shaft transmission shaft and a last-stage B-shaft transmission shaft, one end of the B-shaft input shaft is supported in a gearbox box body of the double swinging heads, the other end of the B-shaft input shaft is supported in a cavity of a C-shaft swinging arm, the first-stage B-shaft transmission shaft and the last-stage B-shaft transmission shaft are respectively supported in the cavity of the C-shaft swinging arm, a helical bevel gear pair is respectively engaged between the B-shaft input shaft and the first-stage B-shaft transmission shaft as well as between the first-stage B-shaft transmission shaft and the last-stage B-shaft transmission shaft, and the last. The invention can improve the comprehensive performance of the laser cutting machine.

Description

Laser cutting machine with double swinging heads

The present invention is a divisional application of the chinese patent application having an application number of "201510757120.0" and a name of "double swing head and laser cutting machine with hollow shaft structure" filed on 09.11.2015, and the entire contents of the application are incorporated in the present application.

Technical Field

The invention relates to a laser cutting technology, in particular to a three-dimensional multi-axis numerical control laser cutting technology, and more particularly relates to a double-swing head with a hollow shaft structure and a laser cutting machine.

Background

The laser cutting technology has the characteristics of high cutting size precision, no burr on a cut, no deformation of a cut seam, high cutting speed, no limitation of a processing shape and the like, and is increasingly applied to the field of machining at present. The three-dimensional laser cutting is characterized by being advanced, flexible and rapid, and is widely applied to the fields of aerospace, automobile industry and the like. By using the three-dimensional laser cutting technology, not only can templates and tooling equipment be saved, but also the production preparation period can be greatly shortened.

In order to ensure the cutting quality, the three-dimensional laser cutting machine should meet the following requirements: firstly, the laser beam is always vertical to the cutting curve of the cut workpiece; secondly, the relative positions of the laser beam focus and the workpiece surface are kept unchanged, namely the distance between the cutting nozzle and the workpiece surface is always kept consistent; and thirdly, reflecting the characteristics of the three-dimensional curve simply and quickly and converting the characteristics into laser cutting data. This is not only an important issue that the three-dimensional laser cutting design must solve, but also the most complicated step in the practical application of the three-dimensional laser cutting technology.

The three-dimensional laser cutting machine generally adopts a flying light path design, namely, a workpiece is fixed in the processing process and is completed by the movement of a laser cutting head. A typical laser cutting head is three-dimensional five-axis linkage, and the relationship between the axes is shown in FIG. 1: the laser cutting head has the advantages that the laser cutting head can rapidly move relative to an axis of a workpiece coordinate system X, Y, Z, and the laser cutting head also has the rotation of a C-axis swing arm, the swing of a B-axis swing head and the normal direction (A-axis) follow-up of the laser cutting head. When rotating the C axis or the B axis, the coordinates of the cutting nozzle center point in the workpiece coordinate system should be kept unchanged, namely: the center of the cutting nozzle is fixed, and the laser cutting head moves around the center of the cutting nozzle; when the center of the cutting nozzle is moved, the laser cutting head can move correspondingly. Because the laser cutting head involves multiple movements, the motion control is complicated, and a very complicated algorithm is needed to meet the requirements.

Fig. 2 is a schematic structural diagram of a conventional laser cutting machine. This laser cutting machine has the laser cutting head of installing on two pendulums, and it includes parts such as C axle motor 01, C axle microscope base 02, the counterweight body 03, B axle motor 04, B axle microscope base 05, collision device 06 and cutting head 07: the C-axis motor 01 and the B-axis motor 04 are both DD motors (Direct Driver, Direct drive motors), wherein the C-axis motor 01 is used for driving a C axis to rotate, and the B-axis motor 04 is used for driving a B axis to swing; the counterweight 03 is used for balancing the deflection moment of the cutting head 07 on the B axis. Through the rotation of the shaft C and the swing of the shaft B, the cutting head 07 can process various single-side V-shaped and I-shaped grooves within the range of 0-45 degrees. This laser cutting head device has obvious defect: for example, when the C-axis is rotated, the B-axis is linked, so that the cutting nozzle of the cutting head 07 moves, and the re-alignment is very difficult, thereby affecting the cutting efficiency and the cutting quality; for another example, when the distance between the cutting tip of the cutting head 07 and the workpiece is adjusted, the C axis and the B axis need to be moved integrally, so that the mass is large, the follow-up response of the cutting head 07 is slow, and the efficiency is low; for another example, the C-axis motor 01 and the B-axis motor 04 need to be hollow motors, which are expensive.

At present, the existing products improve the method, and a double-pendulum head structure without coupling motion is adopted to adjust the position of the laser cutting head, so that the C-axis rotation and the B-axis pendulum head can be independently controlled. However, the double-swing head without coupling motion has certain problems; on one hand, the motion control and the tool path planning of the whole laser cutting machine are difficult to realize; on the other hand, the hollow motor, the hollow speed reducer and the encoder are required to be used, otherwise, the hollow shaft structure is difficult to realize, and the price for customizing the hollow parts is high, so that the production cost is not reduced.

In view of the above, there is a need to develop a new dual-swing head structure with a hollow shaft to better meet the overall design requirements of the three-dimensional laser cutting machine.

Disclosure of Invention

Aiming at the defects in the prior art, the embodiment of the invention aims to provide the laser cutting machine with the hollow rotating shaft and the double swinging heads, which is low in price, strong in adaptability and convenient for realizing motion control and cutter planning.

In order to solve the above technical problems, an embodiment of the present invention provides a laser cutting machine configured with a double swing head, where the double swing head includes a C-axis swing arm capable of rotating around a first direction and a B-axis swing head capable of rotating around a second direction, and the B-axis swing head is provided with a laser cutting head; the C-axis input shaft of the C-axis swing arm is connected to a C-axis speed reducer of a C-axis driving motor, the B-axis input shaft of the B-axis swinging head is connected to a B-axis speed reducer of a B-axis driving motor, the B-axis input shaft is connected to the B-axis swinging head through a plurality of stages of B-axis transmission shafts, and each stage of B-axis transmission shaft is installed on the C-axis swing arm; the C-axis input shaft, the B-axis input shaft and all levels of B-axis transmission shafts are provided with axial cavities, the B-axis input shaft is sleeved on the C-axis input shaft, and laser reflectors are respectively arranged at the intersection positions between the B-axis input shaft and the first-level B-axis transmission shaft, between the adjacent levels of B-axis transmission shafts, and between the last-level B-axis transmission shaft and the B-axis swinging head; the C-axis speed reducer is a harmonic speed reducer, a wave generator of the harmonic speed reducer is connected with the C-axis driving motor, a flexible gear of the harmonic speed reducer is fixed, a rigid gear of the harmonic speed reducer is fixedly connected with a C-axis driving gear, and the C-axis driving gear is meshed with a C-axis input gear arranged on the C-axis input shaft; the B axle speed reducer is differential harmonic speed reducer machine, the wave generator of differential harmonic speed reducer machine is connected B axle driving motor, the flexbile gear of differential harmonic speed reducer machine is fixed, the first rigid gear of differential harmonic speed reducer machine has linked firmly B axle drive gear, the second rigid gear of differential harmonic speed reducer machine has linked firmly B axle decoupling zero gear, first rigid gear with the sharing of second rigid gear the wave generator of differential harmonic speed reducer machine with the flexbile gear of differential harmonic speed reducer machine, B axle drive gear with install in the B axle input gear meshing of B axle input shaft, B axle decoupling zero gear with C axle input gear meshing.

Compared with the prior art, the B-axis input shaft and the B-axis transmission shafts at all levels in the double-swing head in the embodiment of the invention are of hollow structures, and the C-axis input shaft and the B-axis input shaft are coaxially arranged, so that the tool path can be conveniently planned. When the C-axis swing arm rotates, the center position of a laser head cutting nozzle on the B-axis swing head is kept unchanged, so that the movement of the laser cutting head is convenient to control, and the cutting quality is favorably ensured.

Specifically, the hollow shaft structure can be realized by adopting a common motor in the embodiment of the invention: the B-axis decoupling gear is arranged and is mounted with the B-axis driving gear in a differential mode, when the C axis rotates, the rotating speed transmitted to the B-axis driving gear by the B-axis input gear is offset with the rotating speed transmitted to the B-axis decoupling gear by the C-axis input gear, and therefore the B-axis following motion caused by the rotation of the C axis is decoupled, and the B-axis driving motor is not affected by the coupling motion between the two axes. Therefore, the embodiment of the invention can decouple the coupling motion between the shaft C and the shaft B only through the decoupling gear which is installed in a differential mode, and compared with a scheme of decoupling through an electric control mode, the decoupling gear has the advantages of more ingenious conception and more compact structure.

Based on the differential decoupling mode of the embodiment of the invention, the double-pendulum head with the hollow shaft structure is easy to obtain. When the double-pendulum head with the hollow shaft structure is applied to a laser cutting machine, at least the following beneficial technical effects can be achieved:

1. and the motion control and the tool path planning are easy to realize. The laser cutting machine adopts a point-to-point structure, the normal vector of the cutter space can be flexibly adjusted through the movement of the two rotating shafts, the three-dimensional coordinate of a cutting point cannot be influenced, on one hand, the movement control is easy to realize, and on the other hand, the cutter path is easier to plan.

2. And the adaptability is strong. The laser cutting head on the double-swing head is flexible in movement mode, can quickly and accurately reach a preset position, and can cut the surface of a workpiece according to the set position, angle and distance, so that the laser cutting head is suitable for processing various workpiece forms.

3. The structure of hollow rotating shaft multi-channel integration is easy to realize. Cables, air flow, light and the like required by the laser cutting head can pass through the hollow structure, so that the optimization of component layout is facilitated, and the product structure is more compact.

4. The price is low. The two rotating shafts of the double-swing head can be driven to move by adopting a common motor, the coupling effect between the two rotating shafts is better eliminated, and the price of the device is relatively low because the specially customized motor, the speed reducer, the encoder and other parts are not needed, thereby being beneficial to reducing the cost. The light path of the laser cutting machine can ensure that the focusing position of the laser beam is not changed when the double-swing head rotates and swings.

The light path of the laser cutting machine provided by the embodiment of the invention can ensure that the focusing position of the laser beam is not changed when the double-swing head rotates and swings. The optical path has fewer related components, short optical path, and is very simple and practical.

Drawings

FIG. 1 is a schematic diagram of coordinate axes of a three-dimensional five-axis laser cutting machine;

FIG. 2 is a schematic diagram of a prior art laser cutting machine;

fig. 3 is a schematic structural diagram of a laser cutting machine according to an embodiment of the present invention, wherein a double-swing head with a hollow shaft structure and a laser cutting head follow-up height adjustment device are shown;

FIG. 4 is a three-dimensional view of the double pendulum head of FIG. 3;

FIG. 5 is a schematic view of the double-pendulum head shown in FIG. 3 with the C-axis swing arm seal plate removed;

FIG. 6 is a three-dimensional view of the double pendulum shown in FIG. 5 from one perspective;

FIG. 7 is a three-dimensional view of the dual pendulum head of FIG. 5 from another perspective;

FIG. 8 is a schematic view of the double-wobble head of FIG. 3 with the gear housing removed;

FIG. 9 is a three-dimensional view of the double pendulum head of FIG. 8;

FIG. 10 is a schematic view of the double-pendulum head of FIG. 8 with the C-axis swing arm seal plate removed;

FIG. 11 is a three-dimensional view of the dual pendulum head of FIG. 10 from one perspective;

FIG. 12 is a three-dimensional view of the dual pendulum head of FIG. 10 from another perspective;

FIG. 13 is a view A-A of FIG. 3;

FIG. 14 is a view B-B of FIG. 3;

FIG. 15 is a view C-C of FIG. 3;

FIG. 16 is a schematic structural diagram of the differential harmonic reducer of FIG. 15;

FIG. 17 is a schematic diagram of the operation of the differential harmonic reducer of FIG. 16;

FIG. 18 is a schematic view of the optical path of FIG. 13;

FIG. 19 is a schematic view of the follow-up height adjustment mechanism for the cutting head of FIG. 3;

FIG. 20 is a left side view of FIG. 19;

FIG. 21 is a right side view of FIG. 19;

fig. 22 is a cross-sectional view of the central symmetry plane of fig. 19.

Detailed Description

For a better understanding of the technical principles and the working processes of the embodiments of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 3 to fig. 22, the laser cutting machine according to the embodiment of the present invention is partially schematic structural diagrams, wherein a double swing head S1 with a hollow shaft structure and a cutting head follow-up height adjustment device S2 are mainly shown; for details, please refer to the related documents in the prior art, and further description is omitted.

The structure, operation principle and operation process of the double-swing head S1 and the cutting head follow-up height-adjusting device S2 will be described in detail with reference to fig. 3 to 22.

1. Double-swing head S1

Referring to fig. 3-18, the double pendulum head S1 is a hollow rotating shaft structure. The double pendulum head S1 includes two axes of rotation such that the double pendulum head S1 can rotate about the C axis on the one hand and can swing about the B axis on the other hand, thereby adjusting the cutting orientation and the tilt angle of the laser cutting head 18. The two axes of rotation can be defined in detail with reference to the coordinate system of fig. 1: first, a C-axis, which is a first direction, is generally parallel to a normal direction of a work surface of the workpiece; second, the B axis, which is the second direction, is generally parallel to or at an acute angle relative to the work surface of the workpiece.

In this embodiment, the double swing head S1 has a C-axis swing arm 6 and a B-axis swing arm 16, which are respectively driven by motors, wherein: the C-axis swing arm 6 is arranged on a frame (not shown) and can rotate around a C axis in a first direction; the B-axis swinging head 16 is arranged on the C-axis swinging arm 6 and can swing around the B axis in the second direction; the cutting head follow-up height adjusting device S2 is arranged on the B-axis swinging head 16, and can enable the laser cutting head 18 to move along the normal direction of the workpiece processing surface, namely the A axis. Thus, in addition to moving with the X, Y, Z axis of the carriage relative to the workpiece, the laser cutting head 18 can also effect rotation in two directions and translation in one direction.

In this embodiment, the motion process of the double swing head S1 is as follows: when the C-axis swing arm 6 rotates, the B-axis swing head 16 and the cutting head follow-up height adjusting device S2 on the B-axis swing head are driven to rotate, and therefore the orientation of the laser head 18 relative to the workpiece processing surface is adjusted; when the B-axis swinging head 16 rotates, the cutting head follow-up height adjusting device S2 is driven to swing, so that the inclination angle of the laser head 18 relative to the processing surface of the workpiece surface is adjusted; when the cutting head follow-up height adjusting device S2 follows up, the laser cutting head 18 is driven to move along the normal direction of the processing surface of the workpiece, so that the distance of the laser head 18 relative to the processing surface of the workpiece surface can be adjusted.

According to the structure, the laser cutting machine can better realize multi-axis linkage, not only can enable the laser cutting head 18 to move along the X, Y, Z axes of the random frame relative to the workpiece, but also can flexibly adjust the postures of the laser cutting head 18 and the workpiece processing surface through the rotation of the C-axis swing arm 6, the swing of the B-axis swing head 16 and the follow-up of the cutting head follow-up height adjusting device S2, thereby being better suitable for processing workpieces with different surface shapes.

In this embodiment, the functions to be implemented by the C-axis swing arm 6 and the B-axis swing head 16 are different, so that the shapes of the two swing arms are greatly different, and the two swing arms are roughly triangular, wherein the specification of the C-axis swing arm 6 is larger than that of the B-axis swing head 16. The rotating shafts of the two also present different structural modes: the rotation axis of the C-axis swing arm 6 is a one-stage straight line shape, and the rotation axis of the B-axis swing head 16 is a multi-stage zigzag shape, which will be further described below.

The rotation axis of the C-axis swing arm 6 is a first-order, i.e., a linear C-axis input shaft 5, and the C-axis input shaft 5 is connected to a C-axis reducer 22 of a C-axis driving motor 19. After the C-axis driving motor 19 is started, the speed is reduced through the C-axis speed reducer 22, and the power is transmitted to the C-axis input shaft 5, so that the C-axis swing arm 6 is driven to rotate around the C axis. After the C-axis swing arm 6 rotates, the B-axis swing head 16 and the cutting head follow-up height adjusting device S2 mounted thereon can be correspondingly driven to rotate, thereby adjusting the orientation of the laser cutting head 18 on the workpiece processing surface.

The rotating shaft of the B-axis swinging head 16 is in a multi-stage fold line shape, the rotating shafts at all stages are configured into fold lines according to a certain angle, and the included angle between the rotating shafts ensures that the laser beam advances along a preset light path. For convenience, the first stage of the rotating shaft of the B-axis swing head 16 is simply referred to as the B-axis input shaft 4, which is connected with the B-axis reducer 28 of the B-axis drive motor 24; other stages are called B-axis transmission shafts, and are arranged in a hollow cavity of the C-axis swing arm 6, so that the spatial layout of all parts can be optimized. Particularly, the B-axis input shaft 4 is meshed with the first-stage B-axis transmission shaft and the adjacent B-axis transmission shafts at all stages through a helical bevel gear pair, so that the B-axis input shaft 4 is connected to the B-axis swing head 16 through the B-axis transmission shafts at all stages, and the transmission structure is very compact. When the power output by the B-axis driving motor 24 is decelerated by the B-axis reducer, the power is transmitted to the B-axis swinging head 16 through the B-axis input shaft 4 and the B-axis transmission shafts at all levels, and finally the B-axis swinging head 16 is driven to swing around the B axis.

The double-pendulum head in this embodiment is a hollow shaft structure, specifically: the C-axis input shaft 5, the B-axis input shaft 4 and all the B-axis transmission shafts are provided with axial cavities, and the B-axis input shaft 4 is sleeved in the C-axis input shaft 5. The advantages of such a hollow structure are: cables, air flow, light and the like can pass through the hollow structure, so that the purposes of optimizing layout and simplifying structure are achieved.

However, the application of the hollow shaft is limited by certain conditions. With the present embodiment, the kinematic coupling factor between the C-axis and the B-axis is an important consideration, and is analyzed below.

If the C-axis drive motor 19, the C-axis reducer 22, the B-axis drive motor 24, the B-axis reducer 28, the encoder, and the like are all configured as hollow components, these components may be mounted on the same axis, and the C-axis input shaft 5 and the C-axis reducer 22, and the B-axis input shaft 4 and the B-axis reducer 28 may be directly connected to each other without any additional transmission elements therebetween. When the C axis rotates, the B axis generates following movement due to inertia and the like, that is, there is movement coupling between the C axis and the B axis, but the coupling movement hardly affects the B axis driving motor 24. In this way, the two hollow motors can be controlled independently without regard to kinematic coupling considerations. As previously mentioned, the cost of customizing these hollow devices is too high to be suitable for this embodiment.

If the C-axis drive motor 19 and the B-axis drive motor 24 are both ordinary motors, they cannot be installed on the same axis with the C-axis and the B-axis, that is: the two driving motors need to be installed eccentrically, a certain transmission device needs to be arranged between the two driving motors and the two rotating shafts, and the influence of inertia coupling factors, conduction coupling factors and the like is large, so that the problem of kinematic coupling between the C shaft and the B shaft cannot be ignored. When the C axis is not moved, there is no coupling motion between the C axis and the B axis. When the C axis rotates, the B axis generates following motion, and the motion between the B axis and the C axis has a relatively obvious coupling relation; at this time, the B-axis input gear 1 on the B-axis input shaft 4 transmits the rotation speed to the B-axis drive gear 27 of the B-axis reducer 28, and further the B-axis motor drive shaft 26 of the B-axis drive motor 24 rotates, which causes the B-axis drive motor 24 to rotate, which is very disadvantageous for the B-axis drive motor 24, and thus needs to be effectively decoupled.

In summary, when the C-axis swing arm 6 and the B-axis swing head 16 are driven by the common motor, the coupling motion between the C-axis and the B-axis must be effectively and reliably decoupled, otherwise the control of the double swing head S1 will be adversely affected. That is, on the premise of using a common motor, the double-swing head S1 with the above structure can be adopted only by overcoming the kinematic coupling between the C-axis and the B-axis; otherwise, it is difficult to realize the hollow shaft structure.

For the kinematic coupling between the C axis and the B axis, decoupling can be performed in an electrical control manner, but the algorithm is complex and not economical. To this end, the present embodiment specifically contemplates a purely mechanical decoupling approach, described in detail below.

As shown in fig. 8 to 15, the C-axis input shaft 5 is fixedly mounted with the C-axis input gear 2, and the C-axis reducer 22 is fixedly mounted with the C-axis drive gear 23, and the C-axis drive gear 23 is engaged with the C-axis input gear 2, that is, the rotation of the C-axis is realized by driving the C-axis input gear 2. The B-axis input shaft 4 is fixedly provided with a B-axis input gear 1, the B-axis reducer 28 is fixedly provided with a B-axis drive gear 27, and the B-axis drive gear 27 is meshed with the B-axis input gear 1, namely, the rotation of the B-axis is realized by driving the B-axis input gear 1.

Since the C-axis input shaft 5 is fixed to the C-axis input gear 2 and the B-axis input shaft 4 is fixed to the B-axis input gear 1, the motions of the C-axis and the B-axis can also be characterized by the motions of the C-axis input gear 2 and the B-axis input gear 1. When there is a coupling motion between the C-axis and the B-axis, if the rotational speed of the B-axis input gear 1 and the rotational speed of the C-axis input gear 2 can be efficiently transmitted to the B-axis reducer 28 at the same time and cancelled, there is a possibility that the coupling motion between the B-axis and the C-axis is decoupled.

Based on the assumption that the rotational speed of the B-axis input gear 1 and the rotational speed of the C-axis input gear 2 are transmitted and cancelled, the present embodiment decouples the coupling motion between the B-axis and the C-axis by providing the B-axis decoupling gear 29 on the B-axis reducer 28. The concrete structure is as follows: the B-axis reducer 28 is provided with a B-axis drive gear 27 and a B-axis decoupling gear 29, wherein: the B-axis drive gear 27 meshes with the B-axis input gear 1, and the B-axis decoupling gear 29 meshes with the C-axis input gear 2. The B-axis decoupling gear 29 and the B-axis driving gear 27 should be installed in a differential manner so as to cancel the rotation speed of the C-axis input gear 2 transmitted by the B-axis decoupling gear 29 and the rotation speed of the B-axis input gear 1 transmitted by the B-axis driving gear 27, so that the coupling motion between the B-axis and the C-axis can be decoupled.

When the C-axis input gear 2 is not moved, the B-axis decoupling gear 29 is kept still, and the B-axis reducer 28 outputs the rotating speed through the B-axis driving gear 27, so as to drive the B-axis input gear 1 to rotate. When the C axis rotates, the B axis generates following motion; the rotational speed of the B-axis input gear 1 is input to the B-axis drive gear 27, while the B-axis decoupling gear 29 simultaneously inputs the reverse rotational speed of the C-axis input gear 2. At this time, the B-axis reducer 28 has two input rotation speeds simultaneously, which can be opposite, and finally the output rotation speed of the B-axis reducer 28 is reduced to even 0, thereby eliminating the rotation speed added to the B-axis motor driving shaft 26, keeping the B-axis driving motor 24 stationary, and finally achieving the purpose of decoupling the coupling motion between the B-axis and the C-axis.

It can be understood that: the decoupling effect is determined by the gear ratios among the C-axis input gear 2, the B-axis decoupling gear 29, the B-axis driving gear 27 and the B-axis input gear 1; complete decoupling can be achieved if the gear ratios between them can be configured appropriately. For the configuration of the gear ratios between the gears, please calculate according to the design requirements of specific products, and the details are not repeated herein.

As previously described, the differential mounting arrangement between the B-axis decoupling gear 29 and the B-axis drive gear 27 in this embodiment may be different. For example, the B-axis decoupling gear 29 and the B-axis drive gear 27 are not coaxially mounted, but a transmission mechanism is provided therebetween, which can also reversely transmit the rotational speed of the C-axis input gear 2. As another example, whether the B-axis decoupling gear 29 feeds back the rotation speed of the C-axis input gear 2 may be controlled by an electric control system. These solutions can achieve the effects of the differential mounting structure described above, but are relatively complex and costly.

For this reason, the present embodiment ingeniously contemplates a fully mechanical way to achieve the above-mentioned decoupling effect, specifically, a differential installation between the B-axis decoupling gear 29 and the B-axis driving gear 27 is achieved through a differential harmonic reducer, which is further described in detail below with reference to the accompanying drawings.

For the sake of easy understanding, the structure and the operation principle of the differential harmonic reducer shown in fig. 16 to 17 will be explained.

As shown in fig. 16, the B-axis reducer 28 in the present embodiment is a differential harmonic reducer. The differential harmonic reducer comprises a wave generator 28-1 (comprising wave generator cams 28-1-1, wave generator bearings 28-1-2, a bearing retainer, a pressurizer 28-1-3 and the like), a flexible gear 28-2, a first steel gear 28-3 (also called steel gear S), a second steel gear 28-4 (also called steel gear D), ball bearings 28-5, C-shaped clamp rings 28-6 for holes, a machine shell 28-7, inner hexagon bolts 28-8 and the like. The differential harmonic reducer has a wave generator, a flexible gear and two steel gears, wherein the two steel gears share the wave generator and the flexible gear, which functionally correspond to two harmonic reducers installed in a special way.

In the differential harmonic reducer: the rigid wheel S and the steel wheel D are rigid gears with inner gear rings and are equivalent to central wheels in a planetary system; the flexible gear 28-2 is a thin-wall gear which can generate large elastic deformation and is provided with an outer gear ring which is equivalent to a planetary gear; the wave generator 28-1 is a rod-shaped member, and ball bearings 28-5 are mounted at both ends thereof to constitute a roller, which corresponds to a planet carrier. The inner hole diameter of the flexible gear 28-2 is slightly smaller than the total length of the wave generator 28-1, so that after the wave generator 28-1 is installed in the flexible gear 28-2, the section of the flexible gear 28-2 can be forced to be changed from the original circle into an ellipse, the teeth near the two ends of the long shaft are completely meshed with the teeth of the rigid gear S and the steel gear D, the teeth near the two ends of the short shaft are completely separated from the rigid gear, and the teeth of other sections on the perimeter are in a transition state of meshing and separation. When the wave generator 28-1 rotates continuously, the flexible gear 28-2 deforms continuously, so that the meshing state of the flexible gear 28-2 with the rigid gear S and the steel gear D is changed continuously, and the meshing, disengaging and re-meshing … … are carried out repeatedly, and the flexible gear 28-2 rotates slowly relative to the rigid gear S and the steel gear D along the opposite direction of the wave generator 28-1.

In the embodiment, the steel gear D and the flexible gear 28-2 have the same tooth number and have the same function as the flexible gear 28-2; the steel wheel S has two more teeth than the flexible wheel 28-2, and is equivalent to a steel wheel of a common harmonic reducer. Thus, because of the different numbers of teeth of steel wheel S and steel wheel D, their rotational speeds are also different, thereby facilitating a differential mounting of B-axis decoupling gear 29 and B-axis drive gear 27. During specific installation, the B-axis decoupling gear 29 and the B-axis driving gear 27 are respectively fixed with one of the steel wheels S and D, so that the differential installation scheme can be realized.

It can be understood that the wave generator 28-1, the flexspline 28-2, and the steel wheel S and the steel wheel D of the differential harmonic reducer can be combined by fixing different components to meet specific input and output requirements. In view of the convenience of installation, the present embodiment performs input and output in a manner of fixing the flexspline 28-2, and the working principle thereof is described with reference to fig. 17:

case ① -input Steel wheel D, output Steel wheel S, fixed wave Generator, reduction ratio now

If the steel wheel D inputs the rotating speed N_DThen the steel wheel S outputs the rotating speed

Situation ②-inputting: a wave generator; and (3) outputting: a steel wheel S; fixing: and (4) a steel wheel D. At this time, the reduction ratio is

If the input rotation speed N of the wave generator_DThen the steel wheel S outputs the rotating speed

Case ③ -

synthetic

① and ②, then the S output speed of the steel wheel

Wherein: "+" indicates that the wave generator and the steel wheel D rotate in the same direction; "-" indicates that the wave generator was rotating in the opposite direction to the steel wheel D.

According to the principle, the B-axis decoupling gear 29 is mounted on the differential harmonic reducer, so that the motion decoupling between the C-axis and the B-axis can be realized, and the following is further described:

as shown in fig. 15, the B-axis reducer 28 in the present embodiment is a differential harmonic reducer in which: the wave generator 28-1 is an input connected to the B-axis motor drive shaft 26 of the B-axis drive motor 24; the flexible gear 28-2 is fixed; the first steel wheel 28-3, namely the rigid wheel S, is fixedly connected with a B-axis driving gear 27; the second rigid wheel 28-4, namely the steel wheel D, is fixedly connected with a B-axis decoupling gear 29. In this way, the B-axis decoupling gear 29 and the B-axis drive gear 27 are differentially mounted to the B-axis reducer 28, and the rotational speed of the C-axis input gear 2 transmitted by the B-axis decoupling gear 29 and the rotational speed of the B-axis input gear 1 transmitted by the B-axis drive gear 27 can be cancelled out.

In the embodiment, the decoupling of the C-axis motion and the B-axis motion is realized by adopting the installation mode of fixing the flexible gear 28-2, additionally installing the B-axis driving gear 27 on the steel wheel S and additionally installing the B-axis decoupling gear 29 on the steel wheel D, and the following is further explained:

when the C-axis driving motor 19 is fixed, the C-axis driving gear 23 and the C-axis input gear 2 are both fixed, and at this time, the B-axis decoupling gear 29 is fixed without input, which is equivalent to the situation ② in fig. 17.

When the C-axis driving motor 19 rotates, after the C-axis driving motor 19 is decelerated by the C-axis reducer 22, the C-axis driving gear 23 drives the C-axis input shaft 5 to rotate, which is equivalent to the movement of the C-axis input gear 2. once the C-axis rotates, the B-axis will be caused to move together, which is equivalent to the movement of the B-axis input gear 1, so that a coupling movement is generated, and a B-axis decoupling gear 29 and a differential harmonic reducer are required to decouple.

When the C shaft rotates, the C shaft input gear 2 moves and drives the B shaft input gear 4 to move, when the B shaft input gear 4 moves, the input and the output are simultaneously realized by the differential harmonic reducer, through a certain reduction ratio conversion, the input and the output can be just as shown as a situation ① in a figure 17, namely, the rotating speed of the C shaft input gear 2 transmitted by the B shaft decoupling gear 29 is counteracted with the rotating speed of the B shaft input gear 1 transmitted by the B shaft driving gear 27, therefore, the B shaft driving motor 24 is kept not to move, and finally, the motion decoupling between the B shaft and the C shaft is realized.

In this embodiment, the B-axis reducer 28 is a differential harmonic reducer for differentially mounting the B-axis decoupling gear 29 and the B-axis drive gear 27. As a harmonic speed reducer, the B-axis speed reducer 28 has the advantages of large transmission speed ratio, strong bearing capacity, good transmission precision, high transmission efficiency, stable motion and the like. Similarly, the C-axis reducer 22 also adopts a harmonic reducer, a wave generator of which is connected with the C-axis drive motor 19, a flexible gear of which is fixed, and a rigid gear of which is connected with the C-axis drive gear 23. In this embodiment, the C-axis reducer 22 and the B-axis reducer 28 both adopt harmonic reducers, and have excellent transmission characteristics, which is very favorable for improving the control accuracy of the laser cutting head.

Referring to fig. 3 to 15, the double-swing head S1 of the present embodiment uses a gear box to mount a power device and accessories, and specifically includes: the shaft coupling mechanism comprises a C-axis input shaft 5, a C-axis input gear 2, a C-axis driving motor 19, a C-axis speed reducer 22, a C-axis driving gear 23, a B-axis input shaft 4, a B-axis input gear 1, a B-axis driving motor 24, a B-axis speed reducer 28, a B-axis driving gear 27, a B-axis decoupling gear 29 and the like, and is compact in structure. The mounting of the various main components involved in the gearbox is as follows.

As shown in fig. 13, the C-axis input shaft 5 and the B-axis input shaft 4 are each partially accommodated in the gear housing 3 so as to mount the respective input gears. The part of the C-axis input shaft 5 in the gear box body 3 is provided with a C-axis input gear 2 which is meshed with a C-axis driving gear 23 and a B-axis decoupling gear 29 in the gear box body 3; the connecting part between the C-axis input shaft 5 and the gear box body 3 is provided with a bearing so as to support the C-axis swing arm 6 to rotate. One end of the B-axis input shaft 4 is supported on the gear box body 3 by a bearing 4-1, and the other end of the B-axis input shaft is supported on the C-axis swing arm 6 by a bearing 4-2, so that the B-axis input shaft 4 can rotate relative to the C-axis swing arm 6; the B-axis input shaft 4 is partially mounted in the gear housing 3 with a B-axis input gear 1 that meshes with a B-axis drive gear 27 also in the gear housing 3.

As shown in fig. 14, the C-axis driving motor 19 is mounted on the gear box top cover 12 through a C-axis driving motor support base 20; the C-axis motor drive shaft 21 is connected to a wave generator of a C-axis reducer 22 through a coupling 21-1, a flexible gear of the C-axis reducer 22 is fixed, a C-axis drive gear 23 is mounted on a steel gear 22-1, and a gear shaft of the C-axis drive gear 23 is supported on the gear box 3 through a bearing 23-1, so that the C-axis reducer 22 and the C-axis drive gear 23 mounted thereon are integrally accommodated in the gear box 3.

As shown in fig. 15, the B-axis driving motor 24 is mounted on the gear box top cover 12 through a B-axis driving motor support 25; a B-axis speed reducer 28 is arranged on the B-axis motor driving shaft 26, a wave generator of the B-axis speed reducer 28 is connected with the B-axis motor driving shaft 26, a flexible gear is fixed, a B-axis driving gear 27 is arranged on a steel wheel 28-3, and a B-axis decoupling gear 29 is arranged on a steel wheel 28-4; shaft sleeves 26-2 and 26-4 are arranged between the B-axis motor driving shaft 26 and a wave generator of the B-axis speed reducer 28, and are supported by bearings 26-1 and 26-3 with the gear box body 3, so that the motor driving shaft 26, the B-axis speed reducer 28, the B-axis driving gear 27 and the B-axis decoupling gear 29 on the motor driving shaft are integrally accommodated in the gear box body 3.

Through above-mentioned mounting means, the gear box can provide the support for main power device and annex, has simplified the structure like this, has reduced the part occupation space.

The double pendulum head S1 based on differential decoupling is described in detail above, and after mechanical decoupling, a hollow shaft structure can be realized by using a common motor. Such a double pendulum is not limited to use in laser cutting machines; in fact, the double-pendulum head structure can also be adopted in equipment (such as a manipulator) which needs to control the movement of two rotating shafts. The present embodiment mainly describes an application scenario of the laser cutting machine, and other application scenarios are not described again.

As shown in fig. 3 to 22, when the embodiment is applied to a laser cutting machine, the B-axis swing head 16 of the double swing head S1 is provided with a laser cutting head 18; a laser transmission pipe 34 is arranged on the gearbox top cover 12 through a laser transmission pipe mounting seat 35, and the B-axis input shaft 4 is communicated with the laser transmission pipe 34 so as to receive an entering laser beam; after entering the cavity of the laser conduction tube 34, the laser beam will travel along the designed optical path and finally be transmitted to the cutting tip of the laser cutting head 18 to cut the workpiece.

In order to ensure that the laser beam reaches the cutting tip of the laser cutting head 18, the optical path needs to be properly designed. Referring to fig. 18, the B-axis input shaft 4 is engaged with the first-stage B-axis transmission shaft 7 and the adjacent B-axis transmission shafts at all stages are engaged through a helical bevel gear pair; in addition, laser mirrors are respectively arranged at the intersection positions between the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7, between the adjacent B-axis transmission shafts at all stages, and between the last-stage B-axis transmission shaft and the B-axis swinging head 16; these laser mirrors are arranged at an angle such that the laser beam is continuously reflected to the cutting tip of the laser cutting head 18 in order to cut the workpiece.

In this embodiment, when the B-axis input shaft 4 and the B-axis transmission shafts are rotated, the focusing position of the laser beam is kept unchanged, which is very convenient for the operation control of the laser cutting head 18. To achieve this, the optical path needs to be specially designed.

A simple and effective solution is: the rotating shaft of the B-axis swinging head 16 is divided into three stages, namely: one end of a B-axis input shaft (a first-stage B-axis rotating shaft) 4 is supported in the gear box body 3 by a bearing 4-1, and the other end of the B-axis input shaft is supported in a cavity of a C-axis swing arm 6 by a bearing 4-2; a first-stage B-axis transmission shaft (a second-stage B-axis rotating shaft) 7 is supported in a cavity of the C-axis swing arm 6 through a bearing 7-1 and a bearing 7-2; a final-stage B-axis transmission shaft (a third-stage B-axis rotating shaft) 10 is supported in a cavity of the C-axis swing arm 6 through a bearing 10-1 and a bearing 10-2; the B-axis input shaft 4 is meshed with the first-stage B-axis transmission shaft 7 through a spiral bevel gear pair 13, the first-stage B-axis transmission shaft 7 is meshed with the last-stage B-axis transmission shaft 10 through a spiral bevel gear pair 9, and the last-stage B-axis transmission shaft 10 is fixedly connected with a B-axis swing head mounting base 16-1. When the B-axis input shaft 4 is rotated, the swing of the B-axis swing head 16 around the B axis is realized through the power transmission of the series B-axis transmission shaft.

In this embodiment, the C-axis swing arm 6 and the B-axis swing head 16 can be assembled by a main body and a sealing plate, and the main bodies of the C-axis swing arm 6 and the B-axis swing head 16 have cavities, so that the hollow all-stage B-axis rotating shafts and all-stage laser mirror assemblies can be mounted. The main body of the C-axis swing arm 6 is provided with detachable mirror base mounting covers 6-1 at some places, so that the B-axis rotating shafts at all levels are convenient to mount, and the mounting parameters of the laser reflector component are convenient to adjust.

The specific installation method is as follows: the light path of laser cutting machine is provided with four levels of laser reflection lenses, wherein: the first-stage laser reflection lens 14 is arranged at the intersection position of the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7 on the C-axis swing arm 6, and the reflection surface of the first-stage laser reflection lens is perpendicular to the bisector of the included angle of the axes of the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7; the second-stage laser reflection lens 8 is arranged at the intersection position of a last-stage B-axis transmission shaft 10 of a first-stage B-axis transmission shaft 7 on the C-axis swing arm 6, and the reflection surface of the second-stage laser reflection lens is perpendicular to the bisector of the axis included angle of the last-stage B-axis transmission shaft 10 of the first-stage B-axis transmission shaft 7; the third-stage laser reflection lens 11 is arranged on the bottom wall of the B-axis swinging head 16 and is close to the outlet position of the final-stage B-axis transmission shaft 10; the fourth-stage laser reflection lens 15 is installed at the reaching position of the laser beam reflected by the third-stage laser reflection lens 11 on the top wall of the B-axis swing head 16, and the fourth-stage laser reflection lens 15 can reflect the laser beam to a cutting nozzle of the laser cutting head 18. The light path can ensure that the laser beam reaches the cutting nozzle of the laser cutting head 18, and the gathering position of the laser beam cannot be changed when the C axis rotates and the B axis swings.

The light path structure is that the axis intersection angle between the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7 is 90 degrees, the axis intersection angle α between the first-stage B-axis transmission shaft 7 and the last-stage B-axis transmission shaft 10 is 45 degrees, the C-axis swing arm 6 is provided with a first-stage reflector seat 14-1 at the position where the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7 intersect, a first-stage laser reflector 14 is mounted on the first-stage reflector seat, the normal line of the first-stage laser reflector is coplanar with the axis of the B-axis input shaft 4 and the first-stage B-axis transmission shaft 7, the incident angle and the exit angle of the laser are 45 degrees, the C-axis swing arm 6 is provided with a second-stage reflector seat 8-1 at the position where the first-stage B-axis transmission shaft 7 and the last-stage B-axis transmission shaft 10 intersect, namely, a normal line of the first-stage B-axis transmission shaft 7 and the last-stage B-axis transmission shaft 10 is provided with a second-stage reflector seat 8, the normal line of the second-stage laser reflector is coplanar with the axis of the first-stage B-axis transmission shaft 7 and the last-stage B-axis transmission shaft 10, the incident angle and the exit angle of the third-stage B-axis transmission shaft 7 and the last-stage B-axis transmission shaft 10, the third-stage B-axis, the second-stage reflector seat is 22.5, the second-stage reflector seat, the second reflector seat is provided with a top wall of the fourth-stage reflector 18-stage reflector seat, the second reflector seat, the top wall of the second reflector 18-stage B-axis of the second reflector seat, the fourth-axis of the fourth reflector seat, the fourth reflector seat 18-stage reflector seat, the fourth reflector seat is provided with the top of the fourth-stage B-axis of the second reflector 18-axis of the second reflector seat, the.

The light path can ensure that the focusing position of the laser beam is not changed when the double-swing head rotates and swings. The optical path has fewer related components, short optical path, and is very simple and practical. It is understood that the optical path in this embodiment may also adopt other designs, and will not be described herein.

A double pendulum head having a hollow shaft structure, which is advantageous for realizing the hollow shaft structure, is described above in detail. The laser cutting machine adopting the double-swinging head has the following outstanding characteristics:

1. by adopting a point-to-point structure, the normal vector of the cutter space can be flexibly adjusted through the movement of the two rotating shafts without influencing the three-dimensional coordinate of the cutting point, so that on one hand, the movement control is easy to realize, and on the other hand, the cutter path is easier to plan.

2. The laser cutting head on the double-swing head is flexible in movement mode, can quickly and accurately reach a preset position, and can cut the surface of a workpiece according to the set position, angle and distance, so that the laser cutting head is suitable for processing various workpiece forms.

3. The structure that cavity rotation axis multichannel is integrated is easily realized, and required cable, air current, light etc. of laser cutting head all can follow hollow structure and pass through, help optimizing the part overall arrangement for the product structure is more compact.

4. The two rotating shafts of the double-swing head can be driven to move by adopting a common motor, the coupling effect between the two rotating shafts is better eliminated, and the price of components is balanced and lower because the components such as a specially customized motor, a speed reducer, an encoder and the like are not needed, thereby being beneficial to reducing the cost.

Besides the adjustment of the orientation and the angle of the laser cutting head 18 by using the double swinging head S1, the distance between the laser cutting head 18 and the workpiece needs to be adjusted, so that the cutting quality can be better ensured. In the present embodiment, the distance between the laser cutting head 18 and the workpiece is increased by the cutting head follow-up height adjustment device S2, which will be described in detail below.

2. Cutting head follow-up height-adjusting device S2

In this embodiment, the laser cutting head 18 is mounted in a relatively compact manner. Please refer to fig. 19-22, and also refer to fig. 3-18. A B-axis swing mounting seat 16-1 on one side wall of the B-axis swing 16 is connected with the final-stage B-axis transmission shaft 10, so that the B-axis swing 16 can swing around the B axis. The bottom wall of the B-axis swinging head 16 is provided with a third laser reflection lens 11, and the top wall of the B-axis swinging head 16 is provided with a fourth laser reflection lens 15. The fourth laser reflection lens 15 is positioned above the laser cutting head 18, reflects the laser beam into a wide-mouth converging tube 18-2 at the top end of the laser cutting head 18, transmits the laser beam through a tapered tube of the laser cutting head 18, and cuts the workpiece after focusing.

As shown in fig. 3-22, the laser cutting machine of the present embodiment has a laser cutting head follow-up height-adjusting device S2, which detects the distance between the cutting tip of the laser cutting head 18 and the workpiece, and generates a corresponding control command by a controller (not shown) to drive the laser cutting head to move.

The cutting head follow-up height-adjusting device S2 mainly comprises a detector, a controller, a driver and the like:

a detector for detecting and outputting a distance signal between the cutting tip of the cutting head 18 and the workpiece;

the controller receives the detection signal and outputs a control instruction according to a preset algorithm so as to control the action of the driver;

and the driver drives the laser cutting head 18 to move towards or away from the workpiece according to the control command.

Specifically, after the cutting head follow-up height-adjusting device S2 is started: when detecting that the distance between the cutting tip of the cutting head 18 and the workpiece is greater than the preset distance, the controller outputs a first control command (pitch reduction driving command), so that the driver of the optical cutting head follow-up height-adjusting device S2 drives the laser cutting head 18 to move towards the workpiece approaching direction; when detecting that the distance between the cutting tip of the laser cutting head 18 and the workpiece is smaller than the preset distance, the controller outputs a second control command (an increase interval driving command), thereby causing the driver of the optical cutting head follow-up height adjusting device S2 to drive the laser cutting head 18 to move away from the workpiece.

In the cutting head follow-up height adjustment device S2 described above: the detector can adopt an eddy current type position sensor and the like, and the detected distance between the cutting nozzle of the laser cutting head 18 and the workpiece is converted into an electric signal to be output; the controller can be a PLC or an embedded chip and can output control instructions according to a preset algorithm, and the control instructions can be PWM (pulse width modulation) signals; the driver is usually a transmission mechanism of a motor, a combination mode of a servo motor and a linear module is generally adopted, and the rotary motion of the servo motor is converted into the linear motion of the module, so that the laser cutting head 18 moves along with the linear motion of the module, and the follow-up height adjustment is realized.

For a laser cutting machine, the follow-up response speed of the laser cutting head 18 is fast. If the motor and the linear module are adopted to convert motion, the rotary motion is converted into linear motion, and high acceleration follow-up is difficult to realize; and because the number of parts of the structure is large, the whole mass of the follow-up system is large, and the follow-up speed is not improved. For this reason, the present embodiment is particularly improved, thereby obtaining a high-acceleration, light-weight cutting-head follow-up height adjusting apparatus S2 described below.

Referring to fig. 19 to 22, the detector of the cutting head follow-up height adjustment device of the present embodiment is a capacitance sensor 30, which is disposed at the bottom end of the cutting tip of the laser cutting head 18 so as to detect and output a distance signal between the cutting tip of the laser cutting head 18 and the workpiece. The capacitance sensor can measure slow change or tiny quantity, has the advantages of large measuring range, high sensitivity, quick dynamic response, good stability and the like, and is very favorable for improving the performance of the cutting head follow-up heightening device of the embodiment.

As shown in fig. 19 to 22, the cutting head follow-up height adjustment device S2 of the present embodiment employs a Voice coil Motor (Voice coil actuator/Motor)17 as a driver for driving the laser cutting head 18 to move. The voice coil motor utilizes the interaction between the magnetic field from the permanent magnetic steel and the magnetic poles in the magnetic field generated by the electrified coil conductor to generate regular motion so as to convert electric energy into mechanical energy, and can realize linear motion and motion with limited swing angle. The voice coil motor is a non-current conversion type power device, and the positioning precision of the voice coil motor is completely dependent on a feedback and control system and is independent of the voice coil motor. When a proper positioning feedback and induction device is adopted, the positioning precision can easily reach 10NM, and the acceleration can reach 300g, so that the design requirements of high acceleration and light weight of the cutting head follow-up height adjusting device are favorable.

In this embodiment, the voice coil motor 17 and the laser cutting head 18 are directly connected together and can slide on the mounting housing 31. As shown in fig. 19-22, the laser cutting head 18 is attached to a voice coil motor 17, and the voice coil motor 17 is mounted to a mounting housing rail 32 of the B-axis yaw 16 via a rail slider 33 to drive the laser cutting head 18 along the mounting housing rail 32 in a manner further described below.

As shown in fig. 19-22, the bottom wall of the B-axis pendulum head 16 is provided with an opening for the laser cutting head 18 and the voice coil motor 17 to pass through; one side wall of the B-axis swinging head 16 is used as a mounting shell 31 of the voice coil motor 17, a shell opening 31-1 is arranged on the mounting shell 31, and mounting shell guide rails 32 are arranged on two sides of the mounting shell 31; the voice coil motor 17 is assembled on the mounting shell guide rail 32 by two guide rail sliding blocks 33, and the two guide rail sliding blocks 33 are connected into a whole by a sliding block connecting rod 33-1 so as to ensure that the voice coil motor 17 runs stably on the shell guide rail 32; the top end of the laser cutting head 18 is provided with an L-shaped laser cutting head connecting sleeve 18-1, the laser cutting head connecting sleeve 18-1 extends into the opening 31-1 of the shell, and the laser cutting head 18 and the voice coil motor 17 are connected into a whole. Thus, the voice coil motor 17 drives the laser cutting head 18 to move together when moving up and down, thereby adjusting the distance between the cutting tip of the laser cutting head 18 and the workpiece. This type of mounting is very compact and ensures that the laser cutting head 18 moves rapidly and smoothly with the voice coil motor 17.

In the above embodiment, the capacitive sensor 30 and the voice coil motor 17 are used to realize the function of the follow-up height adjustment of the laser cutting head 18, the capacitive sensor 30 senses the distance between the cutting head and the workpiece to be cut, and the controller adjusts the stroke of the voice coil motor 17, so as to adjust the distance between the cutting tip of the laser cutting head 18 and the workpiece to realize the function of the follow-up height adjustment of the cutting.

The laser cutting machine of the above embodiment uses the following height-adjusting device of the capacitance sensor + the voice coil motor, and its main advantages include but are not limited to the following aspects:

1. the follow-up acceleration is high. The voice coil motor directly drives the cutting head, so that higher acceleration can be realized;

2. the weight is light. The voice coil motor is adopted to replace a servo motor and a linear module, so that the number of components is greatly reduced, and the mass reduction is obvious.

3. The price is low. The voice coil motor is adopted to replace a servo motor and a linear module, so that the number of parts is reduced, and the price is favorably reduced.

4. The reliability is high. The number of parts is reduced and the failure rate is reduced, which is advantageous for improving the reliability.

The above embodiments illustrate the laser cutting machine of the present invention, wherein the two parts of the double-swing head and the cutting head follow-up height adjusting device with the hollow shaft structure are described in detail. After the improvement measures are taken, the performance of the laser cutting machine is greatly improved, and the laser cutting machine has the advantages of excellent product performance, high reliability, lower price and better market prospect.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto, and variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. A laser cutting machine with double swinging heads comprises a C-axis swinging arm capable of rotating around a first direction and a B-axis swinging head capable of rotating around a second direction, wherein the B-axis swinging head is provided with a laser cutting head; the C-axis input shaft of the C-axis swing arm is connected to a C-axis speed reducer of a C-axis driving motor, the B-axis input shaft of the B-axis swinging head is connected to a B-axis speed reducer of a B-axis driving motor, the B-axis input shaft is connected to the B-axis swinging head through a plurality of stages of B-axis transmission shafts, and each stage of B-axis transmission shaft is installed on the C-axis swing arm; the C-axis input shaft, the B-axis input shaft and all levels of B-axis transmission shafts are provided with axial cavities, the B-axis input shaft is sleeved on the C-axis input shaft, and laser reflectors are respectively arranged at the intersection positions between the B-axis input shaft and the first-level B-axis transmission shaft, between the adjacent levels of B-axis transmission shafts, and between the last-level B-axis transmission shaft and the B-axis swinging head; the double-swing-head gear box is characterized in that a rotating shaft of the B-shaft swing head is three-stage and comprises a B-shaft input shaft, a first-stage B-shaft transmission shaft and a last-stage B-shaft transmission shaft, wherein one end of the B-shaft input shaft is supported in the gear box body of the double-swing head, the other end of the B-shaft input shaft is supported in a cavity of the C-shaft swing arm, the first-stage B-shaft transmission shaft and the last-stage B-shaft transmission shaft are respectively supported in the cavity of the C-shaft swing arm, the B-shaft input shaft is meshed with the first-stage B-shaft transmission shaft and the first-stage B-shaft transmission shaft is meshed with the last-stage B-shaft transmission shaft through a spiral bevel gear pair, and the last-stage B-.

2. The laser cutting machine according to claim 1, wherein the optical path of the laser cutting machine is provided with four stages of laser reflection mirrors, wherein: the first-stage laser reflection lens is arranged at the intersection position of the B-axis input shaft and the first-stage B-axis transmission shaft on the C-axis swing arm, and the reflection surface of the first-stage laser reflection lens is perpendicular to the bisector of the axis included angle of the B-axis input shaft and the first-stage B-axis transmission shaft; the second-stage laser reflection lens is arranged at the intersection position of the last-stage B-axis transmission shaft of the first-stage B-axis transmission shaft on the C-axis swing arm, and the reflection surface of the second-stage laser reflection lens is perpendicular to the bisector of the included angle of the axes of the last-stage B-axis transmission shaft of the first-stage B-axis transmission shaft; the third-stage laser reflection lens is arranged on the bottom wall of the swing head of the B shaft and is close to the outlet position of the transmission shaft of the last-stage B shaft; the fourth-stage laser reflection lens is arranged at the position, on the top wall of the swing head of the B shaft, of the third-stage laser reflection lens, where the laser beam is reflected, and can reflect the laser beam to a cutting nozzle of the laser cutting head.

3. The laser cutter of claim 2, wherein the axis intersection angle between the B-axis input shaft and the first stage B-axis drive shaft is 90 ° and the axis intersection angle between the first stage B-axis drive shaft and the last stage B-axis drive shaft is 45 °; a first-stage laser reflection lens is mounted at the position of the C-axis swing arm where the B-axis input shaft and the first-stage shaft transmission shaft meet, the normal line of the first-stage laser reflection lens is coplanar with the axes of the B-axis input shaft and the first-stage shaft transmission shaft, and the laser incident angle and the laser emergent angle of the first-stage laser reflection lens are respectively 45 degrees; a second-stage laser reflection lens is mounted at the position of the C-axis swing arm, where the first-stage B-axis transmission shaft and the last-stage B-axis transmission shaft meet, the normal line of the second-stage laser reflection lens is coplanar with the axes of the first-stage B-axis transmission shaft and the last-stage B-axis transmission shaft, and the laser incident angle and the laser emergent angle of the second-stage laser reflection lens are 22.5 degrees respectively; a third-stage reflector is arranged on the bottom wall of the B-axis swinging head at the outlet of the last-stage B-axis transmission shaft, the normal line of the third-stage reflector is coplanar with the axes of the last-stage B-axis transmission shaft and the laser cutting head, and the laser incident angle and the laser emergent angle of the third-stage reflector are respectively 45 degrees; and a fourth-stage reflecting lens is arranged on the top wall of the B-axis swinging head above the laser cutting head, the normal line of the fourth-stage reflecting lens is coplanar with the normal line of the third-stage reflecting lens and the axis of the laser cutting head, and the laser incident angle and the reflection angle of the fourth-stage reflecting lens are respectively 22.5 degrees.

4. The laser cutting machine according to claim 1, wherein the C-axis swing arm and the B-axis swing head are assembled by a main body and a sealing plate, respectively, the main bodies of the C-axis swing arm and the B-axis swing head are provided with cavities for mounting hollow B-axis rotating shafts and laser mirror assemblies of each stage, and the main body of the C-axis swing arm is provided with a detachable mirror base mounting cover.

5. The laser cutting machine according to claim 1, wherein the C-axis reducer is a harmonic reducer, a wave generator of the harmonic reducer is connected to the C-axis drive motor, a flexible gear of the harmonic reducer is fixed, a rigid gear of the harmonic reducer is fixedly connected to a C-axis drive gear, and the C-axis drive gear is engaged with a C-axis input gear mounted on the C-axis input shaft; the B axle speed reducer is differential harmonic speed reducer machine, the wave generator of differential harmonic speed reducer machine is connected B axle driving motor, the flexbile gear of differential harmonic speed reducer machine is fixed, the first rigid gear of differential harmonic speed reducer machine has linked firmly B axle drive gear, the second rigid gear of differential harmonic speed reducer machine has linked firmly B axle decoupling zero gear, first rigid gear with the sharing of second rigid gear the wave generator of differential harmonic speed reducer machine with the flexbile gear of differential harmonic speed reducer machine, B axle drive gear with install in the B axle input gear meshing of B axle input shaft, B axle decoupling zero gear with C axle input gear meshing.

6. The laser cutting machine according to claim 5, wherein a drive shaft of the C-axis drive motor is connected to the wave generator of the harmonic reducer through a coupling, and a drive shaft of the B-axis drive motor is connected to the wave generator of the differential harmonic reducer.

7. The laser cutting machine according to claim 5, wherein the double-pendulum head is provided with a gear box, the C-axis input shaft and the B-axis input shaft are respectively supported by a box body of the gear box, the harmonic reducer and C-axis drive gear, the differential harmonic reducer and B-axis drive gear and B-axis decoupling gear, the C-axis input gear and the B-axis input gear are respectively installed in the box body of the gear box, and the C-axis drive motor and the B-axis drive motor are respectively installed on a top cover of the gear box.

8. The laser cutting machine according to claim 7, wherein the C-axis driving motor is mounted to the top cover of the gear box through a C-axis driving motor support; the C-axis motor driving shaft is connected with a wave generator of a C-axis speed reducer through a coupler, a flexible gear of the C-axis speed reducer is fixed, a driving gear is mounted on a steel wheel, and a gear shaft of the C-axis driving gear is supported on a gear box body through a bearing, so that the C-axis speed reducer and the C-axis driving gear mounted on the C-axis speed reducer are integrally accommodated in the gear box body.

9. The laser cutting machine according to claim 7, wherein the B-axis drive motor is mounted to the top cover of the gear box through a B-axis drive motor support; a B-axis speed reducer is arranged on the B-axis motor driving shaft, a wave generator of the B-axis speed reducer is connected with the B-axis motor driving shaft, a flexible gear is fixed, a B-axis driving gear is arranged on a steel wheel, and a B-axis decoupling gear is arranged on the steel wheel; a shaft sleeve is arranged between the B-axis motor driving shaft and a wave generator of the B-axis speed reducer, and the B-axis motor driving shaft and the gear box body are supported by a bearing, so that the motor driving shaft, the B-axis speed reducer, the B-axis driving gear and the B-axis decoupling gear on the motor driving shaft are integrally accommodated in the gear box body.

10. The laser cutting machine according to any one of claims 1 to 9, wherein the laser cutting head is provided with a cutting head follow-up height adjustment device including a detector, a controller, and a driver, wherein: the detector is used for detecting and outputting a distance signal between a cutting nozzle of the laser cutting head and a workpiece; the controller receives the detection signal and outputs a control instruction according to a preset algorithm to control the action of the driver; the driver is arranged on the side surface of the laser cutting head and fixedly connected with the laser cutting head, and drives the laser cutting head to move towards the direction close to or far away from the workpiece according to the control command; when the detector detects that the distance between a cutting nozzle of the laser cutting head and the workpiece is larger than a preset distance, the controller outputs a first control instruction to enable the driver to drive the laser cutting head to move towards the direction close to the workpiece; when the detector detects that the distance between the cutting nozzle of the laser cutting head and the workpiece is smaller than the preset distance, the controller outputs a second control instruction to enable the driver to drive the laser cutting head to move towards the direction far away from the workpiece.