CN109660082B

CN109660082B - Motor assembly process

Info

Publication number: CN109660082B
Application number: CN201910095482.6A
Authority: CN
Inventors: 吴林; 梁伯军; 刘益
Original assignee: Chongqing Knvan Electronics Co ltd
Current assignee: Chongqing Knvan Electronics Co ltd
Priority date: 2019-01-31
Filing date: 2019-01-31
Publication date: 2023-10-20
Anticipated expiration: 2039-01-31
Also published as: CN109660082A

Abstract

The invention relates to the field of motor assembly, in particular to a motor assembly process, which comprises the following steps: step 1: preparing a device for assembling a motor; step 2: after transferring the lower shell in the discharging tray into the arrangement seat, calibrating the welding tray on the lower shell to face the same direction through a calibrating unit, and then transferring the lower shell in the arrangement seat into the mounting seat through a transferring unit; step 3: after the positioning unit positions the soft board, the assembling unit pastes the soft board to the bottom of the lower shell; then coating the adhesive on the bottom of the lower shell; then, the soft board is protected; step 4: after the magnetized magnetic steel is stuck to the bottom of the lower shell, the contact position of the magnetic steel and the adhesive is solidified; step 5: detecting the height of the electric brush, then assembling the rotor on the lower shell, and injecting engine oil into the rotor bearing; step 6: the upper shell is assembled on the lower shell and then riveted and fixed. By adopting the technical scheme, the motor assembly rate can be improved.

Description

Motor assembly process

Technical Field

The invention relates to the field of motor assembly, in particular to a motor assembly process.

Background

The miniature motor is generally applied to the mobile phone to generate a vibration effect, specifically, a group of adjustable eccentric blocks are respectively arranged at two ends of a rotor bearing of the miniature motor, and excitation force is obtained by utilizing centrifugal force generated by high-speed rotation of a shaft and the eccentric blocks, so that vibration is generated. The miniature motor is small in size and capacity, but relates to various components, such as a lower shell, a soft board (an electric brush is arranged on the soft board), magnetic steel, a rotor, an upper shell and the like, and the traditional assembly process is basically carried out by manually assembling, after the lower shell is placed on a mounting seat, a welding disc on the lower shell is positioned, then the soft board is manually torn off from a carrier sheet and stuck to the bottom of the lower shell, so that the assembly efficiency is extremely low, and the production requirement is not met.

Disclosure of Invention

The invention aims to provide a process for automatically assembling partial working procedures in the miniature motor assembly process.

In order to achieve the above purpose, the technical scheme of the invention provides a motor assembly process, which comprises the following steps:

step 1: the equipment for assembling the motor comprises a discharging mechanism, a transfer calibration mechanism and a positioning assembly mechanism, wherein the discharging mechanism comprises a discharging disc and an arrangement seat, the transfer calibration mechanism comprises a transfer unit and a calibration unit, and the positioning assembly mechanism comprises a positioning unit and an assembly unit;

step 2: after transferring the lower shell in the discharging tray into the arrangement seat, calibrating the welding tray on the lower shell to face the same direction through a calibrating unit, and then transferring the lower shell in the arrangement seat into the mounting seat through a transferring unit;

step 3: after the positioning unit positions the soft board, the assembling unit pastes the soft board to the bottom of the lower shell; then coating the adhesive on the bottom of the lower shell, wherein the adhesive is positioned around the soft board; then, coating the welding head of the lead on the soft board with the strong adhesive;

step 4: after the magnetized magnetic steel is stuck to the bottom of the lower shell, the contact position of the magnetic steel and the adhesive is solidified;

step 5: detecting the height of the electric brush on the soft board through observation, then manually assembling the rotor on the lower shell, and injecting engine oil into the rotor bearing;

step 6: after the upper shell is assembled on the lower shell, the contact position of the upper shell and the lower shell is riveted and fixed.

The technical effect of this scheme is: after the lower shell in the discharging tray is transferred into the arrangement seat, the welding tray on the lower shell is aligned to face the same direction through the alignment unit, and then the lower shell in the arrangement seat is transferred into the mounting seat through the transfer unit, so that the time for positioning the lower shell can be greatly prolonged, and after the lower shell is positioned, the lower shell is kept motionless in the subsequent process, and the assembly can be facilitated; meanwhile, after the positioning unit positions the soft board, the assembly unit pastes the soft board to the bottom of the lower shell, so that the assembly efficiency is improved, and the assembly unit meets the requirement of efficient production more compared with the case that the soft board is pasted to the bottom of the lower shell manually.

Further, in the step 1, the assembling unit includes a shrinking member and a plurality of adsorption heads, and an elastic member is connected between two adjacent adsorption heads; in the step 3, in the process that the assembling unit pastes the soft board to the bottom of the lower shell, the contraction part pushes the adsorption heads to be close and then adsorbs the soft board, and after the contraction part separates the adsorption heads, the soft board on the adsorption heads is pasted to the bottom of the lower shell. The technical effect of this scheme is: because a plurality of adsorption heads are mutually close in the process of adsorbing the soft plates, a certain distance is not required to be arranged between two adjacent soft plates on the carrier sheet, and therefore the problem of waste of carrier material materials which is not paid attention to by manufacturers at present is solved.

Further, before the positioning unit performs positioning on the flexible board in step 3, the flexible board is placed at the positioning unit through the ball screw pair, the cutting mechanism and the clamping mechanism. The technical effect of this scheme is: after the clamping mechanism clamps the edge of the carrier sheet, the ball screw pair drives the carrier sheet to move to the positioning unit, and the cutting cylinder cuts the carrier sheet, so that the carrier sheets are automatically transported to the positioning unit in batches, the labor intensity is reduced, and the cost is saved.

Further, the ball screw pair comprises a screw, one end of the screw is provided with a brush, and the brush is positioned at the positioning unit and is separated from the bearing piece of the soft board in the process of rotating the screw. The technical effect of this scheme is: in the process of screw rotation, the screw drives the hairbrush to rotate, so that the bearing piece separated from the soft plate at the positioning unit is cleaned, the bearing piece is not required to be cleaned manually, and the assembly rate is improved.

Further, in step 1, the calibration unit includes a calibration column and a push rod eccentrically fixed on an end surface of the calibration column, in step 2, after transferring the lower casing in the discharging tray into the arrangement seat, the transfer unit transfers the lower casing onto the calibration column, and in a process of rotating the calibration column, the welding tray on the lower casing is calibrated to face the same direction through the push rod. The technical effect of this scheme is: the orientation of welding dish is unified automatically to the in-process push rod of calibrating post pivoted, has improved the speed of lower casing location.

Drawings

FIG. 1 is a top view of a transfer calibration mechanism and a portion of a discharging mechanism in an embodiment of the present invention;

FIG. 2 is a front view of the second support block of FIG. 1;

FIG. 3 is a top view of the discharge chute;

FIG. 4 is a top view of a positioning assembly mechanism according to an embodiment of the present invention;

FIG. 5 is a half-sectional view in the direction A of FIG. 4;

FIG. 6 is a partial enlarged view at B in FIG. 5;

fig. 7 is a left side view of the clamping unit of fig. 6;

FIG. 8 is a schematic view of the suction head of FIG. 5 after being drawn together (with part of the structure omitted);

FIG. 9 is a left side view of the suction head of FIG. 5;

fig. 10 is a schematic view of a stamping mechanism.

Detailed Description

The following is a further detailed description of the embodiments:

reference numerals in the drawings of the specification include: the device comprises a supporting table 1, a conveyor belt 2, a mounting seat 3, a lower casing 4, a welding disc 5, a push-pull cylinder 6, a lifting cylinder 7, a contraction cylinder 8, an adsorption head 9, a stretching flat bar 10, a supporting plate 11, a sliding rod 12, a first spring 13, a pushing cylinder 14, a placing seat 15, a separating frame 16, a through groove 17, a servo motor 18, a screw 19, a nut seat 20, a brush 21, a cutting cylinder 22, a cutting knife 23, a pressing cylinder 24, a first clamping bar 25, a second clamping bar 26, a boss 27, a bearing sheet 28, a soft plate 29, a discharging slideway 30, an arrangement seat 31, a discharging cylinder 32, an upper rolling part 33, a first shifting cylinder 34, a second shifting cylinder 35, a third shifting cylinder 36, a first supporting block 37, a second supporting block 38, an adsorption disc 39, a stepping motor 40, a conveyor belt 41, a calibration column 42, a push rod 43, a punching machine 44, a punching tube 45, a second spring 46 and a pushing block 47.

The motor assembly process comprises the following steps:

step 1: an apparatus for assembling a motor is prepared, which includes a transfer alignment mechanism and a discharging mechanism as shown in fig. 1, 2, 3, and a support table 1, a conveyor belt 2, a positioning assembly mechanism as shown in fig. 4, 5, and a punching mechanism as shown in fig. 10. Wherein also be provided with brace table 1 and conveyer belt 2 in fig. 1, brace table 1 passes through the bolt to be installed in the frame, and conveyer belt 2 runs through whole motor assembly line, and conveyer belt 2 is used for conveying mount pad 3 as shown in fig. 1, and it has circular slot and standing groove to open in the mount pad 3, and the circular slot is used for placing down casing 4, and the standing groove is used for placing the welding dish 5 on the casing 4 down, and the positive center of casing 4 is provided with the protruding needle down.

As shown in fig. 1 and 3, the discharging mechanism comprises a discharging tray (not shown in the drawings), a discharging slideway 30, an arrangement seat 31 and a discharging cylinder 32, a rotating plate is arranged at the bottom of the discharging tray, the rotating plate is driven to rotate by a torque motor, the lower casing 4 is contained in the discharging tray, a spiral channel is arranged on the side wall of the discharging tray and communicated with the discharging slideway 30, and a winding part 33 is arranged at the bottom of the discharging slideway 30.

As shown in fig. 1, a discharging cylinder 32 is mounted on a supporting table 1 (the supporting table 1 is not shown in fig. 1) through bolts, an arrangement seat 31 is welded with an output shaft of the discharging cylinder 32, the arrangement seat 31 is slidably arranged on the supporting table 1, eight grooves are formed in the arrangement seat 31, and intervals are formed between adjacent grooves; the side walls of the grooves and the outer side walls of the arrangement seats 31 are provided with channels, the grooves are communicated with the discharging slide ways 30 through the channels, and the channels can only be used for the single lower casing 4 to pass through, and the lower casing 4 is prevented from being stacked due to the fact that the lower casing 4 is too thin.

The transfer calibration mechanism comprises a transfer unit and a calibration unit, wherein the transfer unit comprises a first transfer cylinder 34, a second transfer cylinder 35, a third transfer cylinder 36, a first support block 37 and a second support block 38, the first support block 37 and the second support block 38 are connected and then welded with an output shaft of the first transfer cylinder 34, the second transfer cylinder 35 is arranged on the first support block 37, and the third transfer cylinder 36 is arranged on the second support block 38. As shown in fig. 2, a connecting plate is welded to the third transfer cylinder 36, and eight adsorption disks 39 are welded to the connecting plate.

As shown in fig. 2, the calibration unit includes a stepping motor 40, a conveyor belt 41 and eight calibration columns 42, the calibration columns 42 are rotatably disposed on a frame, a push rod 43 is eccentrically fixed on an upper end surface of the calibration columns 42, the stepping motor 40 is mounted on the frame by bolts, and an output shaft of the stepping motor 40 and the eight calibration columns 42 are connected by the conveyor belt 41.

The positioning and assembling mechanism shown in fig. 4 comprises a positioning unit, an assembling unit, a ball screw pair, a cutting mechanism and a clamping mechanism. As shown in fig. 4 and 5, the assembling unit includes a push-pull cylinder 6, a lifting cylinder 7, a shrinking cylinder 8 and eight adsorption heads 9, the adsorption heads 9 provide adsorption force for the adsorption heads through a vacuum generator, as shown in fig. 9, bending-shaped stretching flat bars 10 are welded on the adsorption heads 9, and since a convex welding disc 5 is arranged on the lower casing 4, a placing groove is correspondingly arranged on the mounting seat 3, so that when the lower casing 4 is placed on the mounting seat 3 through a manipulator, the welding disc 5 and the placing groove are not aligned, the edge of the welding disc 5 is slightly curled due to pressure generated in the placing process of the manipulator, which affects the quality of a motor in the following processes of motor assembly, wire welding and the like, other manufacturers do not pay attention to the problem at present, and can roll the welding disc 5 while assembling the soft board 29 by installing the stretching flat bars 10 on the adsorption heads 9. The push-pull cylinder 6 is mounted on the frame through bolts, and the lifting cylinder 7 is welded with an output shaft of the push-pull cylinder 6; the lifting cylinder 7 is fixedly provided with a supporting plate 11 through a pin, and the contracting cylinder 8 is fixedly arranged on the supporting plate 11.

As shown in fig. 5, one suction head 9 on the far right side is welded with a support plate 11, and a slide bar 12 is welded on the suction head 9, and the other suction heads 9 are slidably connected with the support plate 11 and the slide bar 12. The output shaft of the contracting cylinder 8 is welded with the leftmost suction head 9, and two adjacent suction heads 9 are connected through a first spring 13.

As shown in fig. 4 and 5, the positioning mechanism comprises a pushing cylinder 14, a placement seat 15 and a separation frame 16, wherein the pushing cylinder 14 and the separation frame 16 are fixedly installed on the supporting table 1, a through groove 17 for inserting the adsorption head 9 is formed in the separation frame 16, the placement seat 15 is slidably arranged on the supporting table 1, and the placement seat 15 is welded with an output shaft of the pushing cylinder 14.

The ball screw assembly comprises a servo motor 18, a screw 19 and a nut seat 20, wherein the servo motor 18 is arranged on the supporting table 1, the left end of the screw 19 is welded with an output shaft of the servo motor 18, a hairbrush 21 is fixed at the right end of the screw 19 through an iron wire, the hairbrush 21 has plasticity, the nut seat 20 is in threaded connection with the screw 19, and a guide rod (not shown in the figure) for guiding the nut seat 20 is arranged on the frame. The cutting mechanism comprises a cutting cylinder 22 and a cutting knife 23, the cutting cylinder 22 is fixedly arranged on the supporting table 1, and the cutting knife 23 is welded with an output shaft of the cutting cylinder 22.

The clamping mechanism comprises two clamping units, as shown in fig. 6 and 7, each clamping unit comprises a pressing cylinder 24, a first clamping strip 25 and a second clamping strip 26, the pressing cylinders 24 are welded on the nut base 20 through bolts, the first clamping strips 25 are welded with a shell of the pressing cylinders 24 through supporting rods, the middle parts of the second clamping strips 26 are hinged with the middle parts of the first clamping strips 25 through pin shafts, and the right ends of the second clamping strips 26 are hinged with an output shaft of the pressing cylinders 24 through pin shafts. As shown in fig. 5 and 6, the supporting table 1 is provided with a boss 27, the carrier sheet 28 is placed on the boss 27, and the width of the boss 27 is smaller than that of the carrier sheet 28, so that the edges of the carrier sheet 28 are conveniently clamped by the first clamping strip 25 and the second clamping strip 26 shown in fig. 7.

As shown in fig. 10, the punching mechanism includes a punch 44 and a punch 45, the punch 44 is mounted on the frame, the punch 45 is welded coaxially with an output shaft of the punch 44, a second spring 46 is welded on the output shaft of the punch 44, a push block 47 is welded at a lower end of the second spring 46, and the push block 47 is slidably connected with an inner pipe wall of the punch 45.

Step 2: in the process that the torque motor drives the rotary plate at the bottom of the discharging disc to rotate, the lower casing 4 in the discharging disc enters the discharging slideway 30 along the spiral channel shown in fig. 1, and as the convex needle is arranged at the center of the lower casing 4 and the upper rolling part 33 is arranged at the bottom of the discharging slideway 30 shown in fig. 3, the lower casing 4 passing through the discharging slideway 30 is provided with the convex needle with one surface facing upwards; in the process that the lower casing 4 enters the groove of the arrangement seat 31 along the discharging slide way 30 shown in fig. 1, the discharging cylinder 32 is started to push the arrangement seat 31 to move leftwards, so that the lower casing 4 is sequentially arranged in the groove of the arrangement seat 31;

then, the first transfer cylinder 34 shown in fig. 1 is started to push the first support block 37 and the second support block 38 to move downwards, and after the first support block 37 is aligned with the lower casing 4 on the arrangement seat 31, the second transfer cylinder 35 is started, so that the lower casing 4 on the arrangement seat 31 is adsorbed by the adsorption disc 39, and after the first transfer cylinder 34 and the second transfer cylinder 35 are reset, the second transfer cylinder 35 is started again to transfer the lower casing 4 on the adsorption disc 39 to the calibration column 42 shown in fig. 2; after the first transfer cylinder 34 is started again, after the adsorption disc 39 on the third transfer cylinder 36 is aligned with the calibration column 42 as shown in fig. 2, the third transfer cylinder 36 is started and drives the adsorption disc 39 to contact with the lower casing 4, at this time, the stepping motor 40 is started and drives the calibration column 42 to rotate for one circle, and after the push rod 43 on the calibration column 42 contacts with the welding disc 5 on the lower casing 4, the welding disc 5 on the lower casing 4 is pushed to face the same direction; after the first transfer cylinder 34 is reset again, as shown in fig. 1, the adsorption disc 39 on the third transfer cylinder 36 transfers the lower casing 4 to a position aligned with the mounting seat 3, and then the third transfer cylinder 36 is started to transfer the lower casing 4 into the mounting seat 3;

step 3: after the carrier sheet 28 with the plurality of flexible boards 29 adhered to it is placed on the boss 27 as shown in fig. 5, the pressing cylinder 24 shown in fig. 7 is started to push the right end of the second clamping bar 26 to rotate downward, so that the left ends of the first clamping bar 25 and the second clamping bar 26 clamp the edge of the carrier sheet 28;

then the servo motor 18 is started, the output shaft of the servo motor 18 rotates forward to drive the screw 19 to rotate forward, so that the nut seat 20 is driven to pull the pressing cylinder 24, the first clamping strip 25, the second clamping strip 26 and the bearing sheet 28 to move rightwards, when the bearing sheet 28 moves into the placing seat 15, the cutting cylinder 22 shown in fig. 4 is started to drive the cutting knife 23 to cut the bearing sheet 28, the cut bearing sheet 28 falls into the placing seat 15, and only eight soft plates 29 are arranged on the cut bearing sheet 28. Then the pushing cylinder 14 is started to push the placing seat 15 to slide into the separating frame 16;

in the process of sliding the placement seat 15 into the separation frame 16, the push-pull air cylinder 6 shown in fig. 4 is started to push the lifting air cylinder 7, the supporting plate 11, the shrinkage air cylinder 8 and the eight adsorption heads 9 to move downwards to the position of the placement seat 15, and in the process, the shrinkage air cylinder 8 is started to push the eight adsorption heads 9 shown in fig. 8 to be mutually close; when the eight adsorption heads 9 move to the position above the placement seat 15, the lifting cylinder 7 is started to drive the supporting plate 11, the shrinkage cylinder 8 and the eight adsorption heads 9 to move downwards, and the eight adsorption heads 9 pass through the through grooves 17 to adsorb the soft plates 29 on the carrier sheet 28; then the lifting cylinder 7 is reset, the soft plate 29 is separated from the bearing piece 28 under the blocking action of the separating frame 16, and the bearing piece 28 is left in the placing seat 15. Then the push-pull cylinder 6 drives the placement seat 15 to reset, and meanwhile, the servo motor 18 also reversely rotates as shown in fig. 5, so that the brush 21 is driven to rotate in the process of driving the screw 19 to reversely rotate, and the brush 21 is further used for cleaning the carrier sheet 28 in the placement seat 15;

when the push-pull air cylinder 6 drives the lifting air cylinder 7, the shrinkage air cylinder 8 and the eight adsorption heads 9 to reset to the state shown in fig. 4, the lifting air cylinder 7 is started again, so that the supporting plate 11 and the adsorption heads 9 are driven to move downwards, and the soft plate 29 on the adsorption heads 9 is adhered to the lower casing 4 on the installation base 3 shown in fig. 1 because the installation base 3 is positioned on the conveyor belt 2 (at the moment, the installation base 3 shown in fig. 1 is operated to be right below the adsorption heads 9 shown in fig. 5);

step 3: manually coating a circle of adhesive on the bottom of the lower shell 4, wherein the adhesive is positioned around the soft board 29; then, applying a strong adhesive (such as UV adhesive) to the welding joint of the wires on the flexible board 29;

step 4: then the magnetized magnetic steel is stuck to the bottom of the lower shell 4, and the contact position of the magnetic steel and the adhesive is heated and cured, wherein the heating and curing temperature is 55 ℃;

step 5: the mounting seat 3 carries the lower casing 4, in the moving process, the electric brush on the soft board 29 is shot through the camera, then the soft board 29 is imaged on the screen, and the height of the electric brush is judged to be within a reasonable range by observing the upper and lower marked lines which are arranged on the screen in advance manually; then manually assembling the rotor to the lower casing 4, and injecting engine oil into the rotor bearing;

step 6: after the upper casing is assembled on the lower casing 4, the upper casing and the lower casing 4 are placed on a supporting table 1 shown in fig. 10, then a punching machine 44 is started, an output shaft of the punching machine 44 drives a punching pipe 45 to move downwards in the process of extending downwards, after the inner pipe wall of the punching pipe 45 is contacted with the side wall of the upper casing, the upper casing and the lower casing 4 are pressed and riveted, the motor assembly is completed, and a second spring 46 is compressed in the process; during the upward movement of the output shaft of the punch 44, the second spring 46 is reset, so that the motor is punched out of the punch tube 45 by the push block 47.

Claims

1. The motor assembly process is characterized by comprising the following steps of:

the transfer calibration mechanism comprises a transfer unit and a calibration unit, wherein the transfer unit comprises a first transfer cylinder, a second transfer cylinder, a third transfer cylinder, a first support block and a second support block, the first support block and the second support block are connected and then welded with an output shaft of the first transfer cylinder, the second transfer cylinder is arranged on the first support block, the third transfer cylinder is arranged on the second support block, a connecting plate is welded on the third transfer cylinder, and eight adsorption discs are welded on the connecting plate;

the calibration unit comprises a stepping motor, a conveyor belt and eight calibration columns, the calibration columns are rotatably arranged on the frame, a push rod is eccentrically fixed on the upper end face of each calibration column, the stepping motor is mounted on the frame through bolts, and an output shaft of the stepping motor is connected with the eight calibration columns through the conveyor belt;

the positioning and assembling mechanism comprises a positioning unit, an assembling unit, a ball screw pair, a cutting mechanism and a clamping mechanism, wherein the assembling unit comprises a push-pull cylinder, a lifting cylinder, a contraction cylinder and eight adsorption heads, the adsorption heads provide adsorption force for the adsorption heads through a vacuum generator, bent stretched flat strips are welded on the adsorption heads, a convex welding disc is arranged on a lower shell, a placing groove is correspondingly arranged on a mounting seat, and the welding disc is flattened while a soft board is assembled; the push-pull cylinder is arranged on the frame through a bolt, and the lifting cylinder is welded with an output shaft of the push-pull cylinder; the lifting cylinder is fixedly provided with a supporting plate through a pin, and the contracting cylinder is fixedly arranged on the supporting plate;

one adsorption head at the rightmost side is welded with the support plate, a slide bar is welded on the adsorption head, and the other adsorption heads are connected with the support plate and the slide bar in a sliding way; an output shaft of the shrinkage cylinder is welded with the leftmost adsorption head, and two adjacent adsorption heads are connected through a first spring;

the positioning unit comprises a pushing cylinder, a placing seat and a separating frame, wherein the pushing cylinder and the separating frame are fixedly arranged on the supporting table, a through groove for the insertion of the adsorption head is formed in the separating frame, the placing seat is arranged on the supporting table in a sliding manner, and the placing seat is welded with an output shaft of the pushing cylinder;

2. The motor assembly process of claim 1, wherein: the assembling unit in the step 1 comprises a contraction piece and a plurality of adsorption heads, and an elastic piece is connected between two adjacent adsorption heads; in the step 3, in the process that the assembling unit pastes the soft board to the bottom of the lower shell, the contraction part pushes the adsorption heads to be close and then adsorbs the soft board, and after the contraction part separates the adsorption heads, the soft board on the adsorption heads is pasted to the bottom of the lower shell.

3. The motor assembly process of claim 2, wherein: and 3, before the positioning unit positions the soft board, the soft board is placed at the positioning unit through the ball screw pair, the cutting mechanism and the clamping mechanism.

4. A motor assembly process according to claim 3, wherein: the ball screw pair comprises a screw, one end of the screw is provided with a brush, and the brush is positioned at the positioning unit and is cleaned with a bearing piece separated from the soft board in the process of rotating the screw.

5. The motor assembly process of claim 4, wherein: in the step 1, the calibration unit comprises a calibration column and a push rod eccentrically fixed on the end face of the calibration column, in the step 2, after the lower casing in the discharging tray is transferred into the arrangement seat, the transfer unit transfers the lower casing onto the calibration column, and the welding tray on the lower casing is calibrated to face the same direction through the push rod in the process of rotating the calibration column.