JPS6347324B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an iron core manufacturing apparatus for manufacturing iron cores for reactors, transformers, etc.

Generally, as shown in Figure 1, the core of a three-phase internal iron type transformer is such that one end of each leg iron 1, 2, and 3 is connected by each yoke 4, 5, and each leg iron 1 to 3 is connected to one end of each leg iron 1, 2, and 3. After the coils 6, 7, and 8 are arranged, the other ends of the leg irons 1 to 3 are connected with the respective yokes 9, 10.

Each leg iron 1 to 3, each yoke 4, 5, 9, 10 is the second
As shown in Figures and Figure 3, 45 strip-shaped iron core members are
It is made up of pieces cut at an angle of . That is, the leg irons 1 and 3 have holes 11a, 12a, 13a, 1
Each core piece 11, 12, 13, 14 with 4a
The leg iron 2 has holes 15a, 16a in each core piece 15, 16, and the leg irons 4, 5 have holes 17a, 18a,
Each core piece 17, 18, 1 with 19a, 20a
9 and 20, and the yokes 9 and 10 are each iron core pieces 21 and 2.
2, 23, and 24 are laminated as shown in FIGS. 4 to 6, respectively. In addition, each leg iron 1 to 3
As shown in FIG. 7, the cross section of the iron core piece is formed by stacking iron core pieces of different widths to form a substantially circular shape.

When stacking as described above, leg irons 1 to 3 are cut in the shapes shown in Figures 2 and 3 in advance.
Iron core piece for yoke 4, 5 and yoke 9,
After sorting into 10 core pieces, they are transported to a surface plate for assembly and stacked by multiple people.

Another method is to replace the iron core pieces for leg irons 1 to 3 with the 4th
As shown in the figure, the iron cores are arranged at predetermined intervals, and sent by chute into the assembly jig of the surface plate for lamination in the next step, where they are brought to a natural stop by the frictional resistance between the cores. As shown in FIG. 1, the final positioning of each core piece and the stacking of yokes 4 and 5 were performed manually. In this case, in order to stack the stacks as shown in Figure 7, the positioning jig for the next core piece must be set each time the stacking work for each layer is completed, which is a cumbersome work. Ta.

As described above, the conventional laminating method has the drawback that most of the work is done manually, which requires a lot of time. In addition, there was a drawback that each core piece was distorted when handled, leading to an increase in iron loss.

This invention was made to solve the above-mentioned drawbacks, and the core pieces for the leg irons and the yoke are conveyed in the longitudinal direction of each iron core piece from one end side of the stacking table to the other end side. To provide an iron core manufacturing device in which cores for leg irons are stacked on a stacking table, cores for yoke are conveyed to the other end of the stacking table, rotated 90 degrees horizontally by a robot, and then combined with those for leg irons.

The figures will be explained below. In FIGS. 8 to 10, reference numeral 25 denotes a horizontally arranged stacking cart for stacking iron cores, which has wheels 25a for running. 26
27 is a jack that moves the support rod 26 up and down; 28 is a drive mechanism for the jack 27; 29 is a running rail for the stacked cart 25; 30 is a jack for moving the stacked cart 25 to the left in the drawing A stopper 31 for preventing movement is a gate-shaped support cart arranged to straddle the stacked cart 25, and has wheels 31a for running. 32 is a running rail for the frame body 31, and 33 and 34 are adjustment tables arranged on the upper surface of the laminated truck 25, which are configured to be movable in the left and right directions with respect to the traveling direction of the laminated truck 25. 35a, 3
5b is an adjustment rod screwed together with the adjustment tables 33 and 34;
Each adjustment table 33 is driven by a drive device (not shown),
34 in the direction of approaching or moving away.
Numerals 36a and 36b are pins whose upper ends are configured as shown in FIG. 11 and are fitted into the laminated cart 25 and adjustment tables 33 and 34, into which the holes of the respective iron core pieces 11 to 16 can be fitted. Reference numeral 37 denotes a transport carriage mounted on the support carriage 31 and movable in the left and right directions with respect to the traveling direction of the support carriage 31, and is driven by a drive device (not shown).
Reference numeral 38 denotes a suspension trolley that is suspended from the carrier 37 via wheels 39 and is movable in the left and right directions with respect to the traveling direction of the support carrier 31; 40 is a frame fixed to the carrier 37; 41 is the carrier 37; Hanging trolley 38
The spacing between the hanging carriage 38 and the frame 40 can be adjusted by rotating the adjustment rod screwed together. 42 is a first conveyor mounted on a suspension cart 38; 43 is a second conveyor mounted on a frame 40;
It is a conveyor. In addition, both conveyors 42, 43
As shown in Figures 12 to 14, 44~
50. 44 is suspension trolley 3
8 and a bearing fixed to the frame 40, 45 is a pulley supported by a bearing 44, and is driven by a drive device not shown. 46 is a belt suspended on pulley 44, 47 and 48 are N and S poles, respectively.
A pair of permanent magnets whose poles face the belt 46; 49 is a magnetic force adjustment plate having magnetism attracted to the permanent magnets 47 and 48; 50 is a holding plate that presses the belt 46 downward; It is made to be slidable. 51 is a connecting rod connecting two pairs of permanent magnets 47, 48, and 52 is a lifting link connected to connecting rod 51, which is driven by a drive device (not shown) to lift and lower the permanent magnets 47, 48. A first sensor 53 is fixed to the suspension cart 38 and the frame 40 and detects when the core pieces have fallen from both conveyors 42 and 43. The sensor 53 is composed of a beam switch and the like that detects the distance by reflecting light. There is. 54
A second sensor composed of a beam switch or the like fixed to the hanging truck 38 and the frame 40 detects the distance to the core pieces stacked on the stacked truck 25. A third sensor 55 is fixed to the suspension truck 38 and the frame 40 and is composed of a beam switch or the like, and detects the front end of the iron core piece conveyed by both conveyors 42 and 43. Reference numeral 56 indicates a movable platform provided on the suspension vehicle 38 and the frame 40 and is movable in the left-right direction as shown in FIG. The feed screw 59 is screwed into the base 56, and is a handle fixed to the feed screw 58, which is rotatably supported by the suspension cart 38 or the frame 40. Reference numerals 60 and 61 indicate a fourth sensor and a fifth sensor, which are fixed to the movable table 56 and constituted by a beam switch, etc., and detect holes in the iron core piece. 62 is a third conveyor that conveys the core pieces 11 to 16 for leg irons 1 to 3; 63 is both conveyors 42;
43 and a guide arranged between the third conveyor 62,
64 is a fourth conveyor that conveys the core pieces 17 to 20 for the yokes 4 and 5; 65 is a flapper that sends each core piece to the third conveyor 62 or the fourth conveyor 64; and 66 is the upper part of the support cart 31. A fifth conveyor 67 provided between the fourth conveyor 64 and the fifth conveyor 66 is a sixth conveyor provided between the fourth conveyor 64 and the fifth conveyor 66, and conveys the iron core piece while holding it with a permanent magnet 67a. 68 is a fixed frame with four supporting columns 69
It is supported by Reference numerals 70 and 71 refer to first and second parts supported by the fixed frame 68 so as to be movable in the vertical direction.
The table has grooves in the longitudinal direction, as shown in FIG. 15, and is arranged in upper and lower stages so that the holes in the core can be easily detected. 72 is both tables 7
A lifting cylinder that drives 0.71 in the vertical direction.
It is provided on the fixed frame 68. 73 is a shooter that transfers the core piece to the lower right, 74 is both tables 7
This is a pinch roller provided between the shutter 73 and the shutter 73, and is driven by a variable speed motor (not shown). 75 is a sixth sensor composed of a beam switch and the like arranged opposite to the shooter 73;
The rear end of the iron core passing through the shooter 73 is detected. A workbench 76 is supported by a support column 69 and driven in the vertical direction by a drive device (not shown). 7
7 and 78 are robots that take out core pieces from the respective tables 70 and 71, transport them to predetermined positions on the stacking cart 25, and stack them.The main parts are 79 to 86 as shown in FIGS. 16a and 16b. It is arranged in correspondence with each lower leg iron. In FIGS. 16a and 16b, rotating arms 79 and 80 are rotatably connected to each other, and a holding arm 81 is rotatably connected to the tip of the rotating arm 80. The holding arm 81 is provided with a vacuum pad 82 that attracts the iron core piece. A first
As shown in Figure 6, the 7th to 7th stages detect holes in the iron core.
Ten sensors 83-86 are provided. In addition,
The robots 77, 78 are controlled by a computer and servo motors (not shown), and each rotating arm 79, 80
and the holding arm 81 are configured to rotate by a predetermined angle. Reference numerals 87 and 88 designate positioning devices provided on the workbench 76, which in detail are comprised of 89 to 91 as shown in FIG. 17a, and are arranged in pairs with the respective robots 77 and 78. In Figure 17a, 89
90 is an alignment member fixed to the tip of the operating arm 89, and has a horizontal surface portion 90a that receives the iron core piece, and a horizontal surface portion 90a that receives the iron core piece, It has a vertical portion 90b that comes into contact with the end surface of the laminated core pieces. A proximity switch 91 detects the end of the core piece, and is fixed to the alignment member 90.

As shown in FIG. 21, which will be described later, the iron core pieces for the leg irons 1 and 3 are attached to the horizontal surface portion 9 of each positioning device 87 and 88.
If the horizontal surface portion 90 slides on the upper surface of 0a and then falls after being positioned by the conveyors 42 and 43, that is, in the state shown in FIG.
If there is no a, the state shown in FIGS. 17b and 17c will change to the state shown in FIGS. 17d and 17e, and the already laminated yoke core pieces will be pushed out, or Alternatively, a problem arises in that the leg iron core pieces are stacked with their tips bent. In other words, for complete automation, the horizontal surface section 90a
plays an important role.

Next, the operation will be explained. An example of assembling the E-shaped core shown in FIG. 1 using the core pieces shown in FIGS. 2 and 3 will be described. Figures 8 to 16 a, b and 1
In FIG. 7a, the iron core piece 11 processed in the cutting and drilling line in the previous process is sent to the flapper 65. At this time, the flapper 65 is operating downward, and the iron core piece 11 is sent over the upper surface of the third conveyor 62 and delivered to the lower surface of the first conveyor 42. In this case, both conveyors 42, 62 are operated at the same speed, the first conveyor 42 being at speed V ₁ as shown in FIG. Then, when the front end of the iron core piece 11 passes the third sensor 55, the servo motor driving the first conveyor 42 enters a stopping process at a predetermined deceleration. At this time, the core piece 11 is similarly decelerated and stopped at a predetermined position as shown in FIG. 19. The core piece 11 is attracted to permanent magnets 47 and 48 via a belt 46, and is adjusted to have an appropriate strength so that it will not slip between the belt 46 and the core piece 11 even when the speed is reduced. If the attractive force of this permanent magnet is too strong, the energy for driving the belt 46 will increase. Furthermore, there is a drawback that when the permanent magnet is raised and the iron core piece is dropped, a large upward stroke must be taken. For this purpose, the attractive force of the permanent magnets is first strongly magnetized, and as shown in Fig. 14, both permanent magnets are
An adjusting plate 49 made of a magnetic steel strip is attached to the upper part of the magnetic steel strips 7 and 48. By changing the thickness of this steel strip, the magnetic force generated at the lower ends of the permanent magnets 47, 48 can be adjusted. Now, fast V ₁
As shown in Figure 18, the iron core sent at is decelerated at point E and stopped at point F after _T1 seconds. This stopped state is shown in FIG. 19. At this time, the stopping position due to high-speed feeding, that is, the distance L between the tip of the iron core piece and the right end of the first conveyor 42, is made as small as possible, and the state shown in FIG. Shorten the sending distance at medium speed V ₂ shown. This will reduce the overall lamination time. For this purpose, as shown in FIG.
5 and the right end surface of the first conveyor 42, the high speed is V ₁ , the deceleration _is α, and the maximum width of the iron core piece is H
Then, each cut plane is at 45 degrees and detection is performed at the center in the width direction, so L ₁ = 1/2H + V ² / ₁ /2α. Alternatively, if the time until stopping is _T1 , then _L1 =1/2×(H+ _V1 × _T1 ).

When the first conveyor 42 stops, the carriage 37 moves by a distance l in the direction of the arrow as shown in FIG. 20, and the second conveyor 43 is moved to the center position. Note that this movement is under NC control so that no impact is applied during acceleration or deceleration. This dimension l is determined for each leg iron 1 as shown in FIGS. 1 and 6.
Equal to the distance between ~3. While the carriage 37 is moving from the position shown in FIG. 19 to the position shown in FIG. 20 in T ₂ seconds, the second conveyor 43 starts moving and reaches a speed of V ₁ . When the movement of the transport vehicle 37 is completed, the operating arm 89 of the positioning device 87 is moved to the stacking vehicle 2.
Move forward in the direction of 5. Subsequently, the iron core piece 11
It is sent forward at a medium speed V ₂ as shown in Figure 8. At this time,
Since the tip of the iron core piece 11 is removed from the position facing the permanent magnets 47, 48, the tip hangs down due to its own weight and can slide on the upper surface of the horizontal surface portion 90a of the positioning device 87, as shown in FIG. If the hole 11a of the iron core piece 11 passes the fourth sensor ₆₀ during this process, the 18th
As shown in the figure, the speed becomes low V ₃ .

Furthermore, when the hole 11a is detected by the fifth sensor 61 while moving forward at the speed of _V3 , the first conveyor 42
stops. At this time, the time T ₃ at the speed V ₃ is set to the shortest time during which various different iron core pieces are conveyed and there is no variation in stopping accuracy. In other words, the distance L ₂ between the fourth sensor 60 and the fifth sensor 61 is L ₂ = 1/2α × (V ² ₁ −V ² ₂ ) + V ₃ ×T ₃ .

In addition, in order to shorten the conveyance time by the conveyors 42 and 43, it is desired to position the iron core at a high speed of speed V ₁ compared to speed V ₂ , but since the conveyors 42 and 43 do not have guides in the width direction of the iron core, It may shift slightly laterally during transportation. Therefore, in cases where the fourth sensor 60 does not detect holes, etc.
If the sensor malfunctions or holes are not drilled in the cutting and drilling line in the previous process, the core piece will fly out of the conveyor at a high speed of _V1 . This means that the iron core piece is 0.3mm or 0.35mm.
It is so thin that the blade seems to come out.

If a worker acts on behalf of the robot 77 to stack the yokes faster than the robot 77,
This is a very dangerous investigation. For this reason, the speed _V2 is such that the tip of the core piece moves downward under its own weight and naturally falls in front of the worker.

On the other hand, since the stop from V ₁ in the conveyors 42 and 43 is detected by the end face of the iron core piece, it will not jump out at high speed unless the third sensor 55 fails.

If the third sensor 55 fails to detect a malfunction, a safety measure is taken so that the next fourth sensor 60 issues an emergency stop command and automatically stops.

When the iron core piece 11 stops at a predetermined position as shown in FIG. 22, the four sets of permanent magnets 4 of the conveyor 42
7 and 48 rise at the same time. Then, the iron core piece 11
Since the attraction between the permanent magnets 47 and 48 is eliminated,
The core pieces 11 fall one after another so as to be peeled off from the tip, and the holes 11a of the core pieces 11 enter the two pins 36b and are stacked at predetermined positions. In this case, hole 1
The positions of 1a and pin 36b are adjusted by turning the handle 59. In order to maintain this falling distance at about 80 mm, the height of the stack is detected by the second sensor 54. When this second sensor 54 turns ON, it drives the jack 27 that raises the stacked truck 25,
It is lowered until the second sensor 54 turns OFF and then stopped. Further, confirmation that the core piece 11 has fallen is performed by the first sensor 53, and when it is turned off, the transport carriage 37 can be moved.

As shown in FIG.
When the lateral movement is completed in step 7, the loading of the core piece 15 for the central leg iron 2 begins. First, the iron core piece 15 is carried into the second conveyor 43 at high speed.
is stopped inside the second conveyor 43 as shown in FIG. As soon as the stop is complete, at medium speed _V2 ,
The iron core piece 15 is fed again by a predetermined amount and becomes as shown in FIG. 23, and then the iron core piece 15 falls. In other words, in the case of the core piece 15 for the leg iron 2, all other operations are the same as the core piece 11 except that there is no lateral movement. When the core piece 15 falls and the first sensor 53 turns OFF, the second conveyor 43 starts rotating at high speed, and when it reaches a speed of _V1 , the core piece 12 for the leg iron 1 enters. forgive. During this time, the core piece 21 for the upper yoke 9 is automatically taken out at the rear of the cutting line, which is the previous process. Subsequently, the flapper 65 moves to the upper position to cut and drill the core piece 1 for the lower yoke 4.
7 passes through the fourth conveyor 64, the sixth conveyor 67, and the fifth conveyor 66, and slides on the shooter 73, and the rotating pinch roller 7
4, and is sent to the upper surface of the first table 70 located at the lower stage for taking out the yoke. At this time, the sixth sensor 75 detects the rear end of the iron core piece 17 and applies a predetermined deceleration to the pinch roller 74.
The protrusion of the iron core piece 17 is controlled and the first
The final speed of the pinch roller 74 is adjusted so that it stops on the side of the table 70 closer to the pinch roller 74. When the iron core piece 17 is placed on the first table 70, the first table 70 descends and the robot 77
Alternatively, it stops at a position where it is easy for the operator to take it out. When the robot 77 stops, it starts the basic operation stored in advance and moves in the direction of arrow D in FIG. 16a, searching for the hole 17a in the core piece 17. Then, all four sensors 83 to 86
When the OFF state is reached, the rotating arms 79, 80 and the holding arm 81 are lowered, and the vacuum part 82 is attached to the core piece 1.
When it comes into contact with 7, it starts vacuuming and attracts the iron core piece 17. Subsequently, the rotating arms 79, 80 and the holding arm 81 rise by a predetermined amount, and the arrow E in FIG.
It moves as follows and comes to the pre-memorized position. At this time, the hole 17a of the iron core piece 17 is
It comes to the center position of the pin 36a shown in the figure. continue,
If only the holding arm 81 is rotated in the direction of arrow F and the side surface of the core piece 17 activates the proximity switch 91 of the positioning device 87, the rotation of the holding arm 81 is stopped and air is put into the vacuum pad 82 to remove the core. Drop piece 17. At this time, the iron core piece 17 is
2, both ends are hanging down, so there is a gap at the joint with the core pieces 11 and 15 for the leg irons 1 and 2, and the core piece 1 falls as soon as it falls.
Since 7 is stretched, it is easy to match the seams. However, in order to align the stacked end faces, it is necessary to position the proximity switch 91 slightly to the rear of the stack so that the core pieces are slightly protruding, and then, when stacking the core pieces for the next yoke, position them. It is more effective to align them on the side surface of the vertical portion 90b of the device 87.

Further, as shown in FIG. 16a, the operation of the robot 77 from taking out each core piece from the first table 70 to stacking the core pieces is such that the robot 77 only needs to horizontally rotate each core piece by 90 degrees. . In other words, it is a feature of the present device that the material is fed to the flapper 65 in the cutting order as shown in FIGS. 2 and 3.

Now, by the time the iron core pieces 17 for the yoke 4 have been stacked, the iron core pieces 12 for the leg iron 3 will be placed in the positions shown in FIGS. 24 to 25.
After passing through the state shown in the figure, the state shown in FIG. 26 is reached. At this time,
Like the core piece 21, the iron core piece 22 for the upper yoke 10 is automatically taken out by the cutting fin in the previous process. Subsequently, the core piece 18 for the lower yoke 5 rides on the second table 71 via each conveyor 64, 67, 66. Incidentally, when the first table 70 is lowered, the second table 71 lowers a little to receive the iron core piece passing through the pinch roller 74. In other words, the second table 71 descends once more and is delivered to the robot 78, so it performs a two-stage operation when descending. In this way, by the time the other robot 78 takes out the core piece 18, the core piece 16 for the next layer, the central leg iron 2, has been brought in, as shown in FIG. As shown in FIG. 27, they are dropped into predetermined positions and stacked. By the time the robot 78 stacks the core pieces 18, the core piece 13 for the next leg iron 1 has been stopped in the first conveyor 42 as shown in FIG. 27, and this state is as shown in FIG. It's the same. continue,
As shown in FIG. 20, the core pieces 13 are then dropped to a predetermined position and stacked as shown in FIG. 28. During this time, the iron core piece 14 for the leg iron 3 is carried into the transport vehicle 3.
7 moves horizontally. At this time, the iron core pieces 19 for the lower leg iron 4 are laminated by the robot 77. This state is similar to that of the core piece 17 shown in FIG. Thereafter, the first layer, that is, the second layer is also laminated in the same way as the laminated state shown in FIG. 4, and thereafter the state of the first layer and the second layer are repeated and laminated. In other words, during one reciprocation of the transport vehicle 37, the iron cores are stacked one layer at a time in numerical order. When a predetermined height is reached, the iron core width is changed and further stacking is performed, and the stacking is completed in the final state shown in FIG. When the stacking operation is completed, as shown in FIG. 29, the support cart 31 moves to the left in the figure to open the upper part of the stacking cart 25 and take out the pins 36a and 36b. Pins 36a, 36b
When it is removed, the work platform 76 is raised, and the stacking cart 25 moves on its own to the right in the figure and goes to the core framing station for the next process, where it is framed. Note that the straight part that serves as a guide for the core hole is about 20 mm, and when the stacking cart 25 is placed on the running rail 29 after the core stacking is completed, the straight part at the tip of the pins 36a and 36b will come off the core hole. , the pins 36a and 36b can be easily pulled out upward. In other words, if there is a straight line that touches the core hole over the entire height of the stack, it will be extremely difficult to pull out due to frictional force.

For example, if a failure occurs in the equipment during lamination work, or if a plate with irregularities called an oil duct is inserted between each lamination when large width core pieces are laminated, or if the iron core When checking the stacking state of the pieces, that is, whether the dimensions of the E-shape are accurate, whether the iron core is not tilted, etc. for each stack, move the support cart 31 to the 29th position.
Perform the work by moving it as shown in the diagram.

According to this invention, the core pieces for the leg irons are conveyed in the longitudinal direction of the core pieces from one end side of the stacking table and stacked on the stacking table, the iron core pieces for the yoke are conveyed to the other end side of the stacking table, By rotating it 90 degrees horizontally using a robot and then combining it with the leg iron, it is possible to ensure reliable positioning and facilitate automation. Furthermore, since the iron core is not distorted during handling, deterioration of the characteristics of the iron core can be prevented.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the completed lamination of the E-shaped core, Figures 2 and 3 are plan views showing the cut shape of the core piece, Figure 4 is a plan view of the first layer, and Figure 5 is a plan view of the 2nd layer.
A plan view of the layers, FIG. 6 is a plan view showing the laminated state of the first and second layers, FIG. 7 is a sectional view taken along the - line in FIG. 1, and FIG. 8 shows an embodiment of the present invention. 9 is a partially broken front view of FIG. 7, FIG. 10 is a sectional view taken along the - line in FIG. 9, and FIG. 12
The figure is a front view of the conveyor, Fig. 13 is a side view of Fig. 12, Fig. 14 is a sectional view taken along the line XI-XI of Fig. 12, Fig. 15 is a sectional view taken along the - line of Fig. 16, and Fig. Figure a is a plan view of the robot, Figure 16b
is a plan view showing the main part of FIG. 16a, FIG. 17a is a front view of the positioning devices 87 and 88, and FIG. FIG. 17C is a front view of FIG. 17B, and FIG. 17D is a plan view showing the completed state of stacking the leg iron core pieces without the positioning devices 87 and 88. e is a front view of FIG. 17d, FIG. 18 is an explanatory diagram showing the conveyance speed of the conveyor, FIG. 21 is an explanatory diagram showing the operating status of the positioning device, FIG. 22 is a diagram showing the stopping position of the iron core piece, FIGS. 19, 20, and 23 to 28 are explanatory diagrams showing the operating status of the conveyor, and FIG. 29 is an explanatory diagram showing the state after the stacking operation is completed. In the figure, 1 to 3 are leg irons, 4 and 5 are yoke, 11 to 16 are core pieces for leg irons, 17 to 20 are iron core pieces for yoke,
25 is a stacking truck, 31 is a support truck, 37 is a transport truck, 42 is a first conveyor, 43 is a second conveyor, 76 is a workbench, 77 and 78 are robots, 8
7 and 88 are positioning devices. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1 The first and second parts carried into one end of the stacking table
The core pieces for the leg irons are conveyed on the stacking table in the longitudinal direction of the iron core pieces by a first conveyor so that the longitudinal directions of the iron core pieces face each other and a predetermined distance is maintained between the two leg irons. The core pieces for the yoke are stacked and carried into one end of the stacking table, and the core pieces for the yoke are placed on the other end of the stacking table so that the longitudinal direction thereof is approximately parallel to the longitudinal direction of the iron core pieces for the leg iron. The iron core piece for the yoke is conveyed by a conveyor, and rotated horizontally by 90 degrees by a robot placed on the other end side of the stacking table to combine it with the iron core piece for the double leg iron. Iron core manufacturing equipment.