Disclosure of Invention
The invention provides a silicon carbide laser forming processing system, which comprises a processing table, wherein the upper end of the processing table is provided with a fixing unit for fixing a silicon carbide pipe and a laser cutting unit for laser cutting the silicon carbide pipe; the fixing unit comprises an installation groove formed in the upper end of the processing table, two limiting plates which are arranged left and right are arranged at the upper end of the installation groove, round holes for the silicon carbide tubes to pass through are formed in the right limiting plate, a clamping and rotating mechanism for driving the silicon carbide tubes to rotate is arranged on the right side of the limiting plate, a plurality of groups of fixing components which are uniformly arranged left and right are arranged between the left limiting plate and the right limiting plate, the fixing components comprise middle blocks which are arranged in the installation groove, the left side and the right side of the middle blocks are respectively provided with an installation block, an electric push rod is arranged at the upper end of each installation block, supporting blocks are arranged at the upper end of the pushing end of each electric push rod, and auxiliary plates are arranged at the lower ends of the right sides of the rest supporting blocks except for the supporting blocks which are positioned on the right side in the rightmost fixing components; the upper end of the supporting block is provided with clamping assemblies, each clamping assembly comprises arc clamping plates which are arranged at the upper end of the supporting block in a front-back symmetrical mode, and the upper end of the processing table is provided with an adjusting assembly for adjusting the position of the clamping assembly and a driving assembly for driving the front arc clamping plates and the rear arc clamping plates in different clamping assemblies to synchronously move in opposite directions; the laser cutting unit comprises two transverse guide rails which are arranged around the mounting grooves and are mounted at the upper end of the processing table, electric sliding plates are mounted at the upper ends of the transverse guide rails in a sliding mode, an inverted U-shaped frame is mounted between the upper ends of the front electric sliding plate and the rear electric sliding plate, a top plate is arranged below the horizontal section of the inverted U-shaped frame, a hydraulic cylinder with a pushing end fixedly connected with the top plate is mounted on the horizontal section of the inverted U-shaped frame, and an automatic laser cutting machine is arranged at the lower end of the top plate.
In one possible implementation mode, the clamping assembly further comprises sliding grooves which are formed in the upper end of the supporting block in a front-back symmetrical mode, a control board is installed in the sliding grooves in a sliding mode, a moving board which is connected with the upper end of the supporting block in a front-back sliding mode is installed at the upper end of the control board, an arc-shaped clamping plate is installed on one side, close to the moving board, of the front-back moving board, an elastic rubber pad is installed on the inner side of the arc-shaped clamping plate, a bidirectional screw rod which is connected with the control board in a threaded mode is installed in the sliding grooves in a rotating mode, and gears are installed at the front end of the bidirectional screw rod, which penetrates through the supporting block in a rotating mode.
In a possible implementation mode, the driving assembly comprises racks which are meshed with each other on the left side of a gear in each clamping assembly, a connecting plate which is connected with the corresponding racks in a sliding way up and down is installed at the front end on the left side of the supporting block, the racks are installed at the upper end of the same transverse plate in a sliding way left and right, the transverse plate is installed between two vertical guide rails which are fixedly connected with the processing table in a sliding way up and down, and an electric sliding block which is fixedly connected with the upper end face of the transverse plate is installed on the vertical guide rails in a sliding way.
In one possible implementation mode, the rectangular groove which is positioned between the front sliding groove and the rear sliding groove and positioned above the corresponding bidirectional screw is formed in the upper end of the supporting block, the placing block is arranged in the rectangular groove in a vertically sliding mode, the arc-shaped groove is formed in the upper end of the placing block, and the connecting springs which are uniformly distributed left and right are connected between the placing block and the bottom wall of the rectangular groove.
In a possible implementation manner, the adjusting component comprises a bidirectional threaded telescopic rod, the installation block is connected with the installation groove in a left-right sliding mode, the bidirectional threaded telescopic rod is installed on the middle block in the same fixing component, the left-right telescopic ends of the bidirectional threaded telescopic rod are all connected with the corresponding installation block in a rotating mode, and the rear end of the middle block is provided with a scale plate which is located above the processing table and is bilaterally symmetrical.
In a possible implementation manner, the adjusting assembly further comprises a side plate, the middle block is connected with the mounting groove in a left-right sliding mode, the side plate is mounted at the front end of the middle block, threaded holes which are located on the front side of the mounting groove and distributed evenly in the left-right mode are formed in the upper end of the processing table, and bolts in threaded connection with the corresponding threaded holes are rotatably mounted on the side plate.
In a possible implementation mode, the locating plates which are connected with the mounting grooves in a left-right sliding mode are installed at the lower ends of the sides, far away from the limiting plates, of the left side and the right side, square holes which are evenly distributed in the left side and the right side are formed in the positions, corresponding to the locating plates, of the bottom walls of the mounting grooves, and the locating plates are in plug-in connection with the corresponding square holes through square rods.
In one possible implementation manner, the support plates are all installed at the lower ends of the left sides of the support blocks corresponding to the auxiliary plates, the threaded telescopic columns with telescopic ends in rotary connection with the corresponding auxiliary plates are installed at the front sides of the right ends of the support plates, the guiding telescopic columns with telescopic ends in fixed connection with the auxiliary plates are installed at the rear sides of the right ends of the support plates, and the electric push rods are located between the threaded telescopic columns and the guiding telescopic columns.
In one possible implementation mode, the middle part of the front side of the auxiliary plate is provided with elastic telescopic rods, the front ends of the telescopic ends of the elastic telescopic rods are provided with rolling balls, and the front vertical section of the inverted U-shaped frame is provided with clamping grooves matched with the rolling balls.
In one possible implementation mode, rollers which are uniformly distributed up and down are rotatably arranged on the right side of the auxiliary plate, and arc-shaped supporting plates are arranged at the upper end of one side, close to the left limiting plate and the right limiting plate, of the lower end of the right side of the auxiliary plate.
The invention has the beneficial effects that: 1. the continuous and continuous multi-section laser cutting mode of the silicon carbide pipe is different from the traditional feeding laser cutting mode, so that the time required by repeated positioning can be reduced, the overall laser cutting efficiency is improved, the laser cutting point positions and the fixed supporting point positions among different silicon carbide pipe sections can be kept the same, the consistency and the precision of laser cutting among the silicon carbide pipe sections can be improved, in addition, the positions of the fixing component and the clamping component can be flexibly adjusted through the adjusting component, the fixing and laser cutting requirements of the silicon carbide pipes with different lengths can be met, and the applicability is high.
2. The fixing unit adopted by the invention can not only synchronously and uniformly clamp and fix the silicon carbide tube at multiple points, ensure that the silicon carbide tube is kept stable in the laser cutting process and avoid vibration and offset, but also can provide stable support for the two sides of the laser cutting point by utilizing the clamping component to prevent the silicon carbide tube from deforming or shaking when being subjected to laser cutting force and ensure the quality of a laser cutting surface, thereby improving the overall laser cutting quality and the consistency of the laser cutting effects of different points.
In addition to the technical problems, technical features constituting the technical solutions, and beneficial effects caused by the technical features of the technical solutions described above, other technical problems that can be solved by the silicon carbide laser forming processing system provided by the embodiment of the present application, other technical features included in the technical solutions, and beneficial effects caused by the technical features of the technical solutions, a further detailed description will be made in the detailed description of the present application.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms than described below and similarly modified by those skilled in the art without departing from the spirit or scope of the invention, which is therefore not limited to the specific embodiments disclosed below.
Referring to fig. 1, a silicon carbide laser forming processing system comprises a processing table 1, wherein a fixing unit 2 for fixing a silicon carbide tube and a laser cutting unit 3 for laser cutting the silicon carbide tube are arranged at the upper end of the processing table 1.
Referring to fig. 1, fig. 2, fig. 3, fig. 4 and fig. 6, the fixing unit 2 includes a mounting groove 21 formed at an upper end of the processing table 1, two limiting plates 22 arranged left and right are provided at an upper end of the mounting groove 21, round holes for the silicon carbide tube to pass through are formed in the right limiting plate 22, a clamping and rotating mechanism for driving the silicon carbide tube to rotate is provided at a right side of the limiting plate 22, a plurality of groups of fixing components uniformly arranged left and right are provided between the left limiting plate 22 and the right limiting plate 22, the fixing components include a middle block 211 arranged inside the mounting groove 21, mounting blocks 212 are respectively provided at left and right sides of the middle block 211, an electric push rod 213 is mounted at an upper end of the mounting block 212, a supporting block 214 is mounted at an upper end of a pushing end of the electric push rod 213, auxiliary plates 215 are respectively provided at lower ends of the rest supporting blocks 214 except for the supporting blocks 214 positioned at a right side in the rightmost fixing components, rollers 216 are rotatably mounted at a right side of the auxiliary plates 215, a side upper end of the auxiliary plates 215 is close to one side upper end of the left limiting plates 22, lower ends of the auxiliary plates 215 are respectively provided with rollers which are uniformly arranged up and down, an upper end of the auxiliary supporting blocks 215 is provided at a lower end of the auxiliary supporting blocks 215, and a front end of the supporting rods 218 is provided at an elastic telescopic rod. The clamping and rotating mechanism comprises a side motor arranged at the right end of the right limiting plate 22 and a chuck arranged on the output shaft of the side motor and used for clamping the silicon carbide tube.
Referring to fig. 2-6, the clamping assembly includes a sliding groove 221 symmetrically formed on the upper end of the supporting block 214, a control board is slidably mounted in the sliding groove 221, a moving plate 222 slidably connected to the upper end of the supporting block 214 is mounted on the upper end of the control board, an arc-shaped clamping plate 223 is mounted on the side of the moving plate 222, which is close to the moving plate, an elastic rubber pad is mounted on the inner side of the arc-shaped clamping plate 223, a bidirectional screw 224 in threaded connection with the control board is rotatably mounted in the sliding groove 221, and a gear 225 is mounted on the bidirectional screw 224 to penetrate through the front end of the supporting block 214.
Referring to fig. 5, a rectangular groove located between the front and rear sliding grooves 221 and above the corresponding bidirectional screw 224 is provided at the upper end of the supporting block 214, a placement block 226 is slidably mounted in the rectangular groove up and down, an arc groove is provided at the upper end of the placement block 226, and a connecting spring 227 uniformly distributed left and right is connected between the placement block 226 and the bottom wall of the rectangular groove.
Referring to fig. 1,2,3 and 4, an adjusting component for adjusting the position of the clamping component and a driving component for driving the front and rear arc clamping plates 223 in different clamping components to move synchronously and oppositely are disposed at the upper end of the processing table 1, the driving component comprises a rack 228 engaged with the left side of a gear 225 in each clamping component, a connecting plate 229 connected with the corresponding rack 228 in a sliding manner is mounted at the front end of the left side of the supporting block 214, the rack 228 is mounted at the upper end of the same transverse plate 231 in a sliding manner, the transverse plate 231 is mounted between two vertical guide rails 232 fixedly connected with the processing table 1 in a sliding manner, and an electric slider fixedly connected with the upper end surface of the transverse plate 231 is mounted on the vertical guide rails 232.
When in operation, the device comprises: firstly, the silicon carbide pipe to be cut by laser needs to be horizontally placed between the left limiting plate 22 and the right limiting plate 22, the right end of the silicon carbide pipe passes through the round hole and then is clamped and fixed by the chuck, the left end and the right end of the silicon carbide pipe are respectively placed on the corresponding arc-shaped supporting plates 217, the limiting plates 22 can limit the end parts of the silicon carbide pipe, the influence on the laser cutting precision and the laser cutting quality caused by the left-right movement of the silicon carbide pipe during laser cutting is avoided, the arc-shaped supporting plates 217 can provide accurate placement positions for the silicon carbide pipe, stable supporting force can be provided for the end parts of the silicon carbide pipe, the force points of the silicon carbide pipe are increased, and therefore the stability of the silicon carbide pipe in the laser cutting process is improved.
In the initial state, placing block 226 is located the rectangle recess top under the effect of coupling spring 227, before carborundum pipe tip and arc layer board 217 contact, placing block 226 on each bearing block 214 all is in contact with carborundum pipe laminating earlier through the arc recess, the arc recess can carry out the correction in advance to the place position of carborundum pipe, avoid carborundum pipe to take place the skew and influence subsequent centre gripping when placing on the piece 226, place the piece 226 and move down along the rectangle recess through compression coupling spring 227 when placing the piece 226, place the piece 226 this moment and only arc recess part is located bearing block 214 top, and carborundum pipe just contacts with bearing block 214 up end, it is to be noted that coupling spring 227's elasticity is less than carborundum pipe's gravity.
Then, can carry out the centre gripping to the silicon carbide pipe that steadily places fixedly, in this in-process, the electronic slider of accessible left and right sides drives diaphragm 231 along corresponding vertical guide rail 232 and upwards moves, diaphragm 231 drives a plurality of racks 228 and upwards moves along corresponding connecting plate 229 in step, gear 225 rotates clockwise along with corresponding rack 228 is synchronous, the control panel of both sides is synchronous along corresponding slip recess 221 in opposite directions around the gear 225 passes through bi-directional screw 224 drive, the control panel drives movable plate 222, arc splint 223 and elastic rubber pad synchronous movement, until the arc splint 223 of both sides supports tightly the silicon carbide pipe through corresponding elastic rubber pad simultaneously, so as to accomplish the centre gripping fixed to the silicon carbide pipe, the elastic rubber pad not only can prevent too big clamping force damage silicon carbide pipe, still be favorable to increasing the frictional force between arc splint 223 and the silicon carbide pipe, thereby improve the stability of silicon carbide pipe, in addition, the centre gripping subassembly in different positions simultaneously centre gripping silicon carbide pipe, implement the multiple spot centre gripping to the silicon carbide pipe when guaranteeing the centre gripping efficiency, further increase the stability of silicon carbide pipe, simultaneously, two adjacent subassemblies are located just in the centre gripping subassembly of the side and are located and just at the laser cutting pipe section when the laser cutting the cutting quality is close to the silicon carbide pipe, the cutting stability of silicon carbide pipe, the cutting quality is improved, the cutting the silicon carbide pipe is guaranteed, the cutting quality is guaranteed at the cutting the pipe is near the laser pipe, when cutting the pipe is cut to the cutting the pipe is broken.
Referring to fig. 1, 3 and 6, the laser cutting unit 3 includes two transverse rails 31 mounted at the upper end of the processing table 1 and arranged in front and back with respect to the mounting groove 21, an electric slide plate 32 is slidably mounted at the upper end of the transverse rails 31, a reverse-u-shaped frame 33 is mounted between the upper ends of the front and back two electric slide plates 32, a clamping groove matched with the ball 219 is formed on the front vertical section of the reverse-u-shaped frame 33, a top plate is arranged below the horizontal section of the reverse-u-shaped frame 33, a hydraulic cylinder 34 with a pushing end fixedly connected with the top plate is mounted on the horizontal section of the reverse-u-shaped frame 33, an automatic laser cutting machine 35 is arranged at the lower end of the top plate, and the automatic laser cutting machine 35 is an existing laser cutting device.
When in operation, the device comprises: after the silicon carbide tube is fixed, the electric sliding plates 32 on the front side and the rear side can drive the inverted U-shaped frame 33 to move from left to right along the transverse guide rail 31, the inverted U-shaped frame 33 drives the hydraulic cylinder 34, the top plate and the automatic laser cutting machine 35 to move left synchronously until the automatic laser cutting machine 35 moves to a designated first laser cutting position, namely between the upper ends of the left clamping assembly and the right clamping assembly in the leftmost fixing assembly, in the process, the vertical section on the front side of the inverted U-shaped frame 33 gradually contacts with the balls 219 on the elastic telescopic column on the front side of the corresponding auxiliary plate 215, the balls 219 are subjected to the pressing force to enable the elastic telescopic column to shrink synchronously, the balls 219 are clamped into clamping grooves on the vertical section on the front side of the inverted U-shaped frame 33 under the action of the elastic telescopic column, the movement of the inverted U-shaped frame 33 can be limited by utilizing the matching between the clamping grooves and the balls 219, and the automatic laser cutting machine 35 can move to the required laser cutting position accurately along with the inverted U-shaped frame 33, and accordingly the laser cutting precision of the subsequent automatic laser cutting machine 35 can cut the silicon carbide tube.
Then the hydraulic cylinder 34 can push the top plate and the automatic laser cutting machine 35 to move downwards, after approaching the silicon carbide pipe, the automatic laser cutting machine 35 works, meanwhile, the side motor drives the silicon carbide pipe to rotate through the chuck until the automatic laser cutting machine 35 completes the laser cutting of the silicon carbide pipe, then the hydraulic cylinder 34 can drive the top plate and the automatic laser cutting machine 35 to move upwards for resetting, and the electric sliding plate 32 can drive the inverted U-shaped frame 33, the hydraulic cylinder 34, the top plate and the automatic laser cutting machine 35 to move to the next laser cutting position, meanwhile, the electric push rod 213 at the leftmost side can push the supporting block 214 to move upwards, the supporting block 214 can drive the clamping assembly to move upwards synchronously with the silicon carbide pipe after laser cutting, in the process, the connecting plate 229 moves upwards along the rack 228, the rack 228 keeps a static state, the gear 225 which moves upwards along with the supporting block 214 rotates anticlockwise in a meshed manner, the bidirectional screw 224 rotates anticlockwise synchronously along with the gear 225, and drives the front side and rear side control plate 222 and the arc clamping plate 223 to move reversely synchronously away from the cut silicon carbide pipe section until the clamping assembly completely releases the clamping assembly from clamping the cut silicon carbide pipe section, and then the cut silicon carbide pipe section can be removed.
In the process of moving up the bearing block 214, the auxiliary plate 215 moves up synchronously with the bearing block 214 to gradually attach to the cross section of the remaining silicon carbide tube after laser cutting, the elastic telescopic rod 218 drives the ball 219 to move up synchronously, and the auxiliary plate 215 moves up and simultaneously is in rolling contact with the cross section of the remaining silicon carbide tube through the roller 216, so that friction force between the auxiliary plate 215 and the silicon carbide tube is reduced, and when the clamping assembly releases the clamping of the silicon carbide tube section, the arc-shaped supporting plate 217 at the lower end of the auxiliary plate 215 just moves up and contacts with the cross section of the remaining silicon carbide tube (namely, the left end of the silicon carbide tube at the moment) so as to support the left end of the silicon carbide tube.
When the automatic laser cutting machine 35 moves to the next laser cutting point, the automatic laser cutting machine 35 is just located between the upper ends of the left and right adjacent clamping assemblies in the next fixed assembly, at this time, the vertical section at the front side of the inverted U-shaped frame 33 is clamped with the ball 219 on the elastic telescopic rod 218 corresponding to the front side of the auxiliary plate 215 again in the same manner, then the laser cutting of the silicon carbide tube can be completed again in the same manner, the clamping of the clamping assemblies on the silicon carbide tube section after the laser cutting is released by the upward moving bearing block 214, the corresponding auxiliary plate 215 carries out spacing support again on the left end of the silicon carbide tube, and then the laser cutting is carried out on the laser cutting point of the silicon carbide tube from left to right in sequence until the silicon carbide tube is cut into a plurality of sections by laser, and through coherent multi-section laser cutting of the silicon carbide tube, the laser cutting method is not only beneficial to improving the overall efficiency of laser cutting, but also can ensure the consistency of laser cutting between each silicon carbide tube section.
Referring to fig. 2,3 and 4, the adjusting assembly includes a bidirectional threaded telescopic rod 230, the mounting block 212 and the middle block 211 are both slidably connected with the mounting groove 21, the bidirectional threaded telescopic rod 230 is mounted on the middle block 211 in the same fixing assembly, the left and right telescopic ends of the bidirectional threaded telescopic rod 230 are both rotatably connected with the corresponding mounting block 212, the rear end of the middle block 211 is mounted with a scale plate 233 which is positioned above the processing table 1 and is laterally symmetrical, the front end of the middle block 211 is mounted with a side plate 235, the upper end of the processing table 1 is provided with threaded holes 234 which are positioned in front of the mounting groove 21 and are uniformly distributed left and right, and the side plate 235 is rotatably mounted with bolts which are in threaded connection with the corresponding threaded holes 234.
Referring to fig. 2,3, 4 and 6, the lower ends of the sides, far away from the limiting plate 22, of the left and right sides are respectively provided with a positioning plate 236 which is connected with the mounting groove 21 in a left and right sliding manner, square holes 237 which are uniformly distributed left and right are respectively formed in the positions, corresponding to the positioning plates 236, of the bottom wall of the mounting groove 21, the positioning plates 236 are in plug-in fit with the corresponding square holes 237 through square rods 238, support plates are respectively mounted at the lower ends of the left sides of the supporting blocks 214 corresponding to the auxiliary plates 215, telescopic ends are mounted at the front sides of the right ends of the support plates, threaded telescopic columns 241 which are connected with the corresponding auxiliary plates 215 in a rotating manner are mounted at the rear sides of the right ends of the support plates, guide telescopic columns 242 fixedly connected with the auxiliary plates 215 are mounted at the telescopic ends of the right ends of the support plates, and electric push rods 213 are positioned between the threaded telescopic columns 241 and the guide telescopic columns 242.
Referring to fig. 1-6, in operation: when the overall length of the silicon carbide tube changes, the positioning plates 236 on the left side and the right side can be synchronously moved in opposite directions or reversely along the mounting groove 21, the limiting plates 22 synchronously move along with the corresponding positioning plates 236, after the limiting plates 22 move to a proper position, the positioning plates 236 and the limiting plates 22 are fixed in the mounting groove 21 through the cooperation between the square rods 238 and the square holes 237, so that the limiting plates 22 can limit the silicon carbide tubes with different lengths.
When silicon carbide pipe sections with different lengths are needed, the laser cutting points of the silicon carbide pipe need to be adjusted synchronously, in the process, the middle block 211 can be moved to a proper position left and right along the mounting groove 21, the middle block 211 drives the mounting blocks 212 on the left side and the right side of the middle block to move synchronously with the clamping assembly, and then the side plates 235 can fix the middle block 211 in the mounting groove 21 through the matching between the bolts and the threaded holes 234, so that the adjustment of the position of the fixing assembly is completed.
In addition, the left and right telescopic ends of the bidirectional threaded telescopic rod 230 are required to be rotated, so that the mounting blocks 212 on the left and right sides of the middle block 211 synchronously move in opposite directions or synchronously move in opposite directions along the mounting groove 21, the mounting blocks 212 drive the bearing blocks 214 and the clamping assemblies through the electric push rods 213 to synchronously move so as to change the clamping points of the clamping assemblies on the silicon carbide pipe, the clamping assemblies can clamp the silicon carbide pipe section after laser cutting in a centered and stable manner, the positions of the two clamping assemblies in the same fixing assembly are required to be kept symmetrical, the clamping assemblies can effectively clamp and fix and support the silicon carbide pipe with different laser cutting length requirements, in the process, the consistency of position adjustment of the left and right mounting blocks 212 can be ensured by comparing with the left and right graduation plates 233 on the rear side of the middle block 211, thereby improving the accuracy and stability of the clamping assemblies for clamping the silicon carbide pipe, in the process of adjusting the positions of the fixing assemblies or the clamping assemblies, the bearing blocks 214 can drive the corresponding racks 228 to synchronously move in the left and right directions along the transverse plates 231 through the connecting plates 229, and the racks 228 are always meshed with the corresponding gears 225.
When the laser cutting point position of the silicon carbide tube changes, in order to enable the auxiliary plate 215 to be in limit support with the end of the silicon carbide tube after laser cutting all the time, the position of the auxiliary plate 215 can be correspondingly adjusted, at the moment, the threaded telescopic column 241 can be rotated to move left and right to move the auxiliary plate 215, the guide telescopic column 242 synchronously stretches and stretches along with the movement of the auxiliary plate 215, the auxiliary plate 215 drives the elastic telescopic rod 218 to synchronously move with the arc-shaped supporting plate 217, the auxiliary plate 215 is ensured to be attached to the end of the silicon carbide tube after subsequent laser cutting, namely, the position adjustment of the auxiliary plate 215 is completed, and the limit position adjustment of the inverted U-shaped frame 33 by the elastic telescopic rod 218 and the ball 219 is synchronously completed.
In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "connected," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, or slidably connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
The embodiments of the present invention are all preferred embodiments of the present invention, and are not intended to limit the scope of the present invention in this way, therefore: all equivalent changes in structure, shape and principle according to the present invention should be covered in the protection scope of the present invention.