阅读说明：本技术 一种陶瓷pcb自动分板组装用的组装设备 (Equipment that automatic board equipment of dividing of pottery PCB was used ) 是由 李东方 于 2021-09-26 设计创作，主要内容包括：本发明公开了陶瓷PCB自动分板组装用的组装设备,包括组装底座,组装底座顶部对称设有支撑竖柱,两个支撑竖柱顶端共同安装有支撑顶板。本发明启动驱动电机,驱动转轴转动,动力锥齿轮转动,动力锥齿轮啮合有从动锥齿轮,从动锥齿轮转动,蜗杆带动涡轮转动,继而实现安装转轴转动,进而实现正安装螺区、反安装螺区转动,继而实现螺纹动块相向移动,从而实现推动组件带动第一陶瓷PCB板、第二陶瓷PCB板移动,进而将组装卡块与第二陶瓷PCB板上的组装口配合卡接；螺纹区转动,带动梯形座移动,继而实现滑动轮在滑动槽内滑动,触动竖柱向上移动,带动动触片与静触片接触,报警器报警,驱动控制控制器。(The invention discloses an assembling device for automatic board-splitting assembly of a ceramic PCB (printed circuit board), which comprises an assembling base, wherein supporting vertical columns are symmetrically arranged at the top of the assembling base, and supporting top plates are jointly arranged at the top ends of the two supporting vertical columns. The driving motor is started to drive the rotating shaft to rotate, the power bevel gear is meshed with the driven bevel gear, the driven bevel gear rotates, the worm drives the turbine to rotate, then the installation rotating shaft rotates, further the forward installation screw region and the backward installation screw region rotate, and then the threaded moving blocks move in opposite directions, so that the pushing assembly drives the first ceramic PCB and the second ceramic PCB to move, and further the assembly clamping block is matched and clamped with an assembly port on the second ceramic PCB; the thread area rotates to drive the trapezoidal seat to move, then the sliding wheel slides in the sliding groove, the vertical column is touched to move upwards, the movable contact piece is driven to be in contact with the static contact piece, the alarm gives an alarm, and the control controller is driven.)

1. The assembling equipment for automatic board-splitting assembly of the ceramic PCB is characterized by comprising an assembling base (1), wherein supporting vertical columns (2) are symmetrically arranged at the top of the assembling base (1), a supporting top plate (3) is jointly installed at the top ends of the two supporting vertical columns (2), the assembling base (1) is provided with a driving assembly (4), an installation rotating shaft (6) is arranged in an installation cavity (5) of the assembling base (1), and a positive installation screw area (7) and a negative installation screw area (8) are arranged on the installation rotating shaft (6); the threads of the positive mounting screw area (7) and the reverse mounting screw area (8) are opposite;

the screw thread moving block (9) is arranged on the screw thread moving block (9) in the forward installation screw region (7) and the reverse installation screw region (8) in a threaded manner, a through position column (10) is arranged on the screw thread moving block (9), the through position column (10) penetrates through a through position groove (11) of the assembly base (1) to be connected with a power moving column (12), a pushing assembly (13) penetrates through the power moving column (12), the pushing assembly (13) is used for pushing a first ceramic PCB (14) and a second ceramic PCB (15), an assembly clamping block (16) is arranged on the first ceramic PCB (14), and the assembly clamping block (16) is matched with an assembly opening (17) in the second ceramic PCB (15);

supporting roof (3) upper portion is equipped with push cylinder (18), and push cylinder (18) free end is connected with punching press seat (19), and punching press seat (19) lateral wall is equipped with controller (20), and punching press seat (19) lower part is equipped with punching press head (21), and punching press screw (22) have been placed to punching press head (21), and punching press screw (22) are used for assembling the locking of fixture block (16) and fix.

2. The assembly equipment for the automatic board-separating and assembling of the ceramic PCB according to claim 1, wherein the driving assembly (4) comprises a driving seat (41), a driving motor (42) is arranged in the driving seat (41), an output shaft of the driving motor (42) is connected with a driving rotating shaft (43), a power bevel gear (44) is arranged on the driving rotating shaft (43), the power bevel gear (44) is meshed with a driven bevel gear (45), the driven bevel gear (45) is connected with a worm (46), the worm (46) is connected with a worm wheel (47), and the worm wheel (47) is in contact fit with the mounting rotating shaft (6); a threaded area (412) is arranged on the driving rotating shaft (43), a trapezoidal seat (49) is arranged on the threaded area (412), a sliding groove (410) is arranged on the trapezoidal seat (49), a sliding wheel (411) is arranged in the sliding groove (410) in a sliding mode, and the sliding wheel (411) is matched with the trigger piece (48); the driving rotating shaft (43) is provided with a wire spool (412), the wire spool (412) is provided with a rope winding (413), and the rope winding (413) is connected with the pushing assembly (13) through a first guide wheel (414) and a second guide wheel.

3. The assembly apparatus for automatic board separation and assembly of ceramic PCB according to claim 2, the trigger piece (48) comprises a trigger box body (481), a trigger slider (482) is arranged in the trigger box body (481) in a sliding manner, a movable contact piece (483) is arranged at the upper part of the trigger slider (482), the movable contact piece (483) is contacted with a static contact piece (484), the alarm device is used for alarm setting of an alarm (485), a triggering vertical column (486) is arranged at the lower part of the triggering sliding block (482), the triggering vertical column (486) is connected with the sliding wheel (411), a triggering spring (487) is sleeved on the triggering vertical column (486), one end of the triggering spring (487) is connected with the triggering sliding block (482), the other end of the triggering spring (487) is connected with the inner bottom wall of the triggering box body (481), the side part of the touch vertical column (486) is provided with a stabilizing column (488), the stabilizing column (488) is connected with a stabilizing sliding block (489), and the stabilizing sliding block (489) is arranged in a stabilizing sliding groove (4810) in a sliding mode.

4. The assembling apparatus for automatic board-splitting assembly of ceramic PCB according to claim 3, wherein said movable contact piece (483) is in contact with a stationary contact piece (484) for driving the control controller (20).

5. The assembly equipment for the automatic board-splitting assembly of the ceramic PCB as claimed in claim 1, wherein the pushing assembly (13) comprises a pushing sleeve (131), a pushing slider (132) is slidably disposed in the pushing sleeve (131), the pushing slider (132) is connected with a pushing post (133), the pushing post (133) is connected with an extruding block (134), the extruding block (134) is used for pushing the first ceramic PCB (14) and the second ceramic PCB (15), a releasing slider (135) is further slidably disposed in the pushing sleeve (131), the releasing slider (135) is connected with the pushing slider (132) through a releasing spring (136), and the releasing slider (135) is connected with a winding rope (413).

6. The automatic assembly equipment that divides board equipment and use of ceramic PCB of claim 1, characterized by, the punching press head (21) includes punching press seat (211), be equipped with punching press runner (212) on punching press seat (211), punching press runner (212) one side intercommunication has stamping workpiece (213), the piston slider (214) is equipped with to the piston in punching press runner (212), piston slider (214) is connected with punching press post (215), punching press post (215) pass collection hopper (216) and punching press screw (22) cooperation setting, punching press seat (211) lateral part is equipped with pay-off (217), pay-off (217) are used for the pay-off setting of punching press screw (22).

7. The assembly apparatus for automatic board-splitting assembly of ceramic PCB according to claim 6, wherein said stamping part (213) comprises a stamping cylinder (2131), the stamping cylinder (2131) is connected with a stamping block (2132), the stamping block (2132) is slidably disposed in a stamping sleeve (2133), and the stamping sleeve (2133) is communicated with the stamping runner (212).

8. The assembly equipment for the automatic board-splitting and assembling of the ceramic PCB as claimed in claim 6, wherein the feeding member (217) comprises a feeding box (2171), a feeding rack (2172) is arranged on the outer side wall of the feeding box (2171), a double-counter motor (2173) is arranged on the feeding rack (2172), a feeding screw rod (2174) is connected to an output shaft of the double-counter motor (2173), a feeding screw block (2175) is in threaded connection with the feeding screw rod (2174), a linkage sliding column (2176) is arranged at the lower part of the feeding screw block (2175), the linkage sliding column (2176) is connected with a sliding plate (2177), and the sliding plate (2177) is used for pushing the stamping screw (22).

9. The assembly apparatus for automatic board division and assembly of ceramic PCB as claimed in claim 8, wherein said interlocking slide column (2176) is slidably disposed within a feed box (2171).

Technical Field

The invention relates to the technical field of ceramic PCBs, in particular to assembling equipment for automatically separating and assembling ceramic PCBs.

Background

The ceramic substrate refers to a special process plate in which copper foil is directly bonded to the surface (single or double side) of an alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at a high temperature. The manufactured ultrathin composite substrate has excellent electrical insulation performance, high heat conduction characteristic, excellent soft solderability and high adhesion strength, can be etched into various patterns like a PCB (printed circuit board), and has great current carrying capacity. Therefore, the ceramic substrate has become a basic material for high-power electronic circuit structure technology and interconnection technology; the mechanical strength is high enough, and the bearing can be used as a supporting component besides a carrying element; the processability is good, and the dimensional accuracy is high; multilayering is easy to realize; smooth surface, no warp, bend, micro-crack, etc.

When the existing ceramic PCB is assembled, the assembly process is simple, the assembled PCB is poor in installation strength, the installation efficiency is low, and based on the assembly process, further improvement and treatment are needed.

Disclosure of Invention

The invention aims to provide an assembling device for automatically assembling ceramic PCBs (printed circuit boards) in a board splitting manner, so as to solve the problems in the background art.

In order to achieve the purpose, the invention provides the following technical scheme:

the assembling equipment for automatic board-splitting assembly of the ceramic PCB comprises an assembling base, wherein supporting vertical columns are symmetrically arranged at the top of the assembling base, a supporting top plate is jointly installed at the top ends of the two supporting vertical columns, the assembling base is provided with a driving assembly, an installing rotating shaft is arranged in an installing cavity of the assembling base, and a positive installing screw area and a negative installing screw area are arranged on the installing rotating shaft; the threads of the forward installing thread area and the reverse installing thread area are opposite;

the screw thread moving blocks are arranged on the screw thread moving blocks in the forward installation screw area and the reverse installation screw area, the screw thread moving blocks are provided with through position columns, the through position columns penetrate through position through grooves of the assembly base to be connected with the power moving columns, the power moving columns penetrate through pushing assemblies, the pushing assemblies are used for pushing a first ceramic PCB and a second ceramic PCB, the first ceramic PCB is provided with an assembly clamping block, and the assembly clamping block is matched with an assembly port on the second ceramic PCB;

supporting roof upper portion is equipped with push cylinder, and push cylinder free end is connected with the punching press seat, and punching press seat lateral wall is equipped with the controller, and punching press seat lower part is equipped with the punching press head, and punching press screw has been placed to the punching press head, and it is fixed that punching press screw is used for the locking of equipment fixture block.

Preferably, the driving assembly comprises a driving seat, a driving motor is arranged in the driving seat, an output shaft of the driving motor is connected with a driving rotating shaft, a power bevel gear is arranged on the driving rotating shaft and meshed with a driven bevel gear, the driven bevel gear is connected with a worm, the worm is connected with a worm wheel, and the worm wheel is in contact fit with the mounting rotating shaft; the driving rotating shaft is provided with a threaded area, the threaded area is provided with a trapezoidal seat, the trapezoidal seat is provided with a sliding groove, a sliding wheel is arranged in the sliding groove in a sliding mode, and the sliding wheel is matched with the trigger piece; the driving rotating shaft is provided with a wire spool, a winding rope is arranged on the wire spool, and the winding rope is connected with the pushing assembly through a first guide wheel and a second guide wheel.

Preferably, the trigger part comprises a trigger box body, a trigger sliding block is arranged in the trigger box body in a sliding mode, a movable contact spring is arranged at the upper portion of the trigger sliding block and is in contact with a static contact spring for alarm setting of the alarm, a touch vertical column is arranged at the lower portion of the trigger sliding block and is connected with a sliding wheel, a touch spring is sleeved on the touch vertical column, one end of the touch spring is connected with the trigger sliding block, the other end of the touch spring is connected with the inner bottom wall of the trigger box body, a stabilizing column is arranged on the side portion of the touch vertical column and is connected with the stabilizing sliding block, and the stabilizing sliding block is arranged in the stabilizing sliding groove in a sliding mode.

Preferably, the movable contact piece is in contact with the static contact piece for driving the control controller.

Preferably, promote the subassembly including promoting the sleeve, promote to slide in the sleeve and be equipped with and promote the slider, promote the slider and promote the post connection, promote the post and be connected with the extrusion piece, the extrusion piece is used for promoting first pottery PCB board, second pottery PCB board, still slide in the promotion sleeve and be equipped with the release slider, the release slider passes through release spring with the promotion slider and is connected, the setting is connected with the wiring to the release slider.

Preferably, the stamping head comprises a stamping seat, a stamping runner is arranged on the stamping seat, a stamping part is communicated with one side of the stamping runner, a piston slider is arranged in the stamping runner in a piston mode and connected with a stamping column, the stamping column penetrates through the collecting hopper and is matched with the stamping screw, and a feeding part is arranged on the side portion of the stamping seat and used for feeding the stamping screw.

Preferably, the stamping part comprises a stamping cylinder, the stamping cylinder is connected with a stamping block, the stamping block is arranged in a stamping sleeve in a sliding mode, and the stamping sleeve is communicated with the stamping flow channel.

Preferably, the feeding part comprises a feeding box, a feeding frame is erected on the outer side of the feeding box, a double-reverse motor is arranged on the feeding frame, an output shaft of the double-reverse motor is connected with a feeding screw rod, the feeding screw rod is in threaded connection with a feeding screw block, a linkage sliding column is arranged on the lower portion of the feeding screw block and connected with a sliding plate, and the sliding plate is used for pushing a stamping screw.

Preferably, the linkage slide post is arranged in the feeding box in a sliding mode.

Compared with the prior art, the invention has the beneficial effects that:

1. the driving motor is started to drive the rotating shaft to rotate, the power bevel gear is meshed with the driven bevel gear, the driven bevel gear rotates, the worm drives the turbine to rotate, then the installation rotating shaft rotates, further the forward installation screw region and the backward installation screw region rotate, and then the threaded moving blocks move in opposite directions, so that the pushing assembly drives the first ceramic PCB and the second ceramic PCB to move, and further the assembly clamping block is matched and clamped with an assembly port on the second ceramic PCB;

the thread area rotates to drive the trapezoidal seat to move, then the sliding wheel slides in the sliding groove, the vertical column is touched to move upwards, the movable contact piece is driven to be in contact with the static contact piece, the alarm gives an alarm, and the control controller is driven.

2. The drive pivot rotates, it rotates to drive the wire reel, the wiring rotates, and then realize the pulling of release slider, the release spring is tensile, promote telescopic removal simultaneously, thereby realize dorsad further extension release spring, the release spring reaches best tensile state, when the first pottery PCB board of extrusion piece contact, the second pottery PCB board, the release spring further extrudees, thereby the buffering effect of the first pottery PCB board of extrusion piece extrusion has been improved, thereby protect first pottery PCB board, the second pottery PCB board, and then realize buffer protection in pressing from both sides tightly, the device availability factor has been improved.

3. The punching seat moves downwards when the pushing cylinder is started; the stamping cylinder is started to drive the stamping block to move, the stamping sleeve is connected to push the piston slide block to move, then the stamping column penetrates through the collecting hopper to be matched with the stamping screw, and then the assembling fixture block is clamped with the assembling port on the second ceramic PCB; and meanwhile, the double-reverse motor is started, the feeding screw rod rotates to drive the feeding screw block to move, and then the linkage sliding column is matched with the sliding plate, so that the sliding plate is used for pushing the stamping screw, and feeding is realized.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of a driving assembly according to the present invention;

FIG. 3 is an enlarged schematic view of FIG. 2 at A in accordance with the present invention;

FIG. 4 is a schematic view of a pushing assembly according to the present invention;

FIG. 5 is a schematic view of the structure of the punch head of the present invention;

FIG. 6 is a schematic view of the structure of the punching screw of the present invention;

fig. 7 is a schematic structural view of the feeding member of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

referring to fig. 1-7, the assembly equipment for automatic board separation assembly of ceramic PCBs in the present invention includes an assembly base 1, wherein support vertical posts 2 are symmetrically arranged on the top of the assembly base 1, a support top plate 3 is installed on the top ends of the two support vertical posts 2, the assembly base 1 is provided with a driving assembly 4, an installation rotating shaft 6 is arranged in an installation cavity 5 of the assembly base 1, and a positive installation screw region 7 and a negative installation screw region 8 are arranged on the installation rotating shaft 6; the threads of the positive installing thread area 7 and the reverse installing thread area 8 are opposite;

the screw thread moving block 9 is arranged on the screw thread moving block 9 in the forward installation screw region 7 and the screw thread moving block 9 in the reverse installation screw region 8, the through position column 10 is arranged on the screw thread moving block 9, the through position column 10 penetrates through the through position groove 11 of the assembly base 1 to be connected with the power moving column 12, the power moving column 12 is penetrated with a pushing assembly 13, the pushing assembly 13 is used for pushing a first ceramic PCB 14 and a second ceramic PCB 15, an assembly clamping block 16 is arranged on the first ceramic PCB 14, and the assembly clamping block 16 is matched with an assembly opening 17 on the second ceramic PCB 15;

supporting roof 3 upper portion is equipped with push cylinder 18, and push cylinder 18 free end is connected with punching press seat 19, and punching press seat 19 lateral wall is equipped with controller 20, and punching press seat 19 lower part is equipped with punching press head 21, and punching press screw 22 has been placed to punching press head 21, and punching press screw 22 is used for assembling fixture block 16's locking fixed.

The driving assembly 4 of the embodiment comprises a driving seat 41, a driving motor 42 is arranged in the driving seat 41, an output shaft of the driving motor 42 is connected with a driving rotating shaft 43, a power bevel gear 44 is arranged on the driving rotating shaft 43, the power bevel gear 44 is meshed with a driven bevel gear 45, the driven bevel gear 45 is connected with a worm 46, the worm 46 is connected with a worm wheel 47, and the worm wheel 47 is in contact fit with the mounting rotating shaft 6; a threaded area 412 is arranged on the driving rotating shaft 43, a trapezoidal seat 49 is arranged on the threaded area 412, a sliding groove 410 is arranged on the trapezoidal seat 49, a sliding wheel 411 is arranged in the sliding groove 410 in a sliding mode, and the sliding wheel 411 is arranged in a matching mode with the trigger 48; a wire spool 412 is arranged on the driving rotating shaft 43, a rope 413 is arranged on the wire spool 412, and the rope 413 is connected with the pushing assembly 13 through a first guide wheel 414 and a second guide wheel.

The driving motor 42 is started, the rotating shaft 43 is driven to rotate, the power bevel gear 44 rotates, the power bevel gear 44 is meshed with the driven bevel gear 45, the driven bevel gear 45 rotates, the worm 46 drives the worm wheel 47 to rotate, the installation rotating shaft 6 rotates, the forward installation screw region 7 and the reverse installation screw region 8 rotate, the threaded moving blocks 9 move oppositely, the pushing assembly 13 drives the first ceramic PCB 14 and the second ceramic PCB 15 to move, and the assembly clamping block 16 is matched and clamped with the assembly port 17 in the second ceramic PCB 15;

the threaded area 412 rotates to drive the trapezoidal seat 49 to move, so that the sliding wheel 411 slides in the sliding groove 410, the vertical column 486 is triggered to move upwards, the movable contact piece 483 is driven to be in contact with the static contact piece 484, the alarm 485 gives an alarm, and the control controller 20 is driven;

the triggering part 48 of the present embodiment includes a triggering box 481, a triggering slider 482 is slidably disposed in the triggering box 481, a movable contact 483 is disposed on the upper portion of the triggering slider 482, the movable contact 483 contacts with a stationary contact 484 for setting an alarm of an alarm 485, a triggering upright 486 is disposed on the lower portion of the triggering slider 482, the triggering upright 486 is connected to a sliding wheel 411, a triggering spring 487 is sleeved on the triggering upright 486, one end of the triggering spring 487 is connected to the triggering slider 482, the other end of the triggering spring 487 is connected to an inner bottom wall of the triggering box 481, a stabilizing column 488 is disposed on the side portion of the triggering upright 486, the stabilizing column 488 is connected to a stabilizing slider 489, and the stabilizing slider 489 is slidably disposed in a stabilizing sliding groove 4810.

The movable contact piece 483 of the present embodiment is in contact with the stationary contact piece 484 for driving the control controller 20.

The pushing assembly 13 of this embodiment includes a pushing sleeve 131, a pushing slider 132 is slidably disposed in the pushing sleeve 131, the pushing slider 132 is connected to a pushing post 133, the pushing post 133 is connected to an extruding block 134, the extruding block 134 is used for pushing the first ceramic PCB 14 and the second ceramic PCB 15, a releasing slider 135 is further slidably disposed in the pushing sleeve 131, the releasing slider 135 is connected to the pushing slider 132 through a releasing spring 136, and the releasing slider 135 is connected to a winding rope 413.

Drive shaft 43 rotates, drive wire reel 412 and rotate, the wiring 413 rotates, and then realize releasing slider 135 pulling, release spring 136 is tensile, promote the removal of sleeve 131 simultaneously, thereby realize dorsad further extension release spring 136, release spring 136 reaches best tensile state, when extrusion piece 134 contact first ceramic PCB board 14, second ceramic PCB board 15, release spring 136 further extrudees, thereby the buffering effect of extrusion piece 134 extrusion first ceramic PCB board 14 has been improved, thereby protect first ceramic PCB board 14, second ceramic PCB board 15, and then realize the buffer protection in pressing from both sides tightly, the device availability factor has been improved.

The stamping head 21 of the embodiment comprises a stamping seat 211, a stamping runner 212 is arranged on the stamping seat 211, one side of the stamping runner 212 is communicated with a stamping part 213, a piston slider 214 is arranged in the stamping runner 212 in a piston mode, the piston slider 214 is connected with a stamping column 215, the stamping column 215 passes through a collecting hopper 216 and is matched with a stamping screw 22, a feeding part 217 is arranged on the side portion of the stamping seat 211, and the feeding part 217 is used for feeding the stamping screw 22.

The stamping part 213 of the embodiment includes a stamping cylinder 2131, the stamping cylinder 2131 is connected with a stamping block 2132, the stamping block 2132 is slidably arranged in a stamping sleeve 2133, and the stamping sleeve 2133 is communicated with a stamping runner 212.

The feeding member 217 of the embodiment comprises a feeding box 2171, a feeding frame 2172 is arranged on the outer wall of the feeding box 2171, a double-reaction motor 2173 is arranged on the feeding frame 2172, an output shaft of the double-reaction motor 2173 is connected with a feeding screw 2174, the feeding screw 2174 is in threaded connection with a feeding wire block 2175, a linkage sliding column 2176 is arranged at the lower part of the feeding wire block 2175, the linkage sliding column 2176 is connected with a sliding plate 2177, and the sliding plate 2177 is used for pushing the stamping screw 22.

The ganged slide 2176 of this embodiment is slidably disposed within the feed tray 2171.

The pushing cylinder 18 is started, and the punching seat 19 moves downwards; the stamping cylinder 2131 is started to drive the stamping block 2132 to move, the stamping sleeve 2133 is connected to push the piston slide block 214 to move, then the stamping column 215 penetrates through the collecting hopper 216 to be matched with the stamping screw 22, and then the assembling fixture block 16 is clamped with the assembling port 17 on the second ceramic PCB 15;

meanwhile, when the double-reverse motor 2173 is started, the feeding screw 2174 rotates to drive the feeding screw block 2175 to move, and then the linkage sliding column 2176 is matched with the sliding plate 2177, so that the sliding plate 2177 is used for pushing the stamping screw 22, and feeding is realized.

The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.