Winding apparatus and method which deforms the wire during winding

A winding apparatus for winding a coated wire on the drum for making a coil which is used for a stator or an alternator. A sectional shape of the wire which is introduced to the winding apparatus is circular, and the wire is deformed in order to make the sectional shape of the wire polygonal, so that the polygonal wire is fed to the bobbin in order to be wound on the bobbin. The resulting coil wound by the apparatus has an increased density.

FIELD OF THE INVENTION 
The present invention relates to a winding apparatus for winding a wire in 
order to make a coil useful, for instance, as a solenoid coil of a stator 
or a rator coil of an alternator. 
BACKGROUND OF THE INVENTION 
A conventional type of the winding apparatus winds the wire the sectional 
shape of which is circular on a bobbin 21 as shown in FIG. 15. Since the 
coil is required to have a high density of wires in order to decrease the 
volume of the equipment which uses the coil, the wire 20 is wound to be 
aligned. The coil shown in FIG. 15, however, cannot make the density of 
wire maximum even though the wire 20 is aligned in the correct order. 
Since the sectional shape of the wire 20 is circular, at least a certain 
amount of space remains between the wires adjacent to each other. 
In order to reduce the void between the adjacent wires, a wire the 
sectional shape of which is square (square wire) may be used instead of a 
circular wire. According to the present inventors' study, a coil wound 
with square wire has the following disadvantages. Since the square wire 
should be uncoiled from a drum in order to be supplied to the bobbin, and 
since twisting of the square wire should be carefully avoided, the drum 
must be rotated when the square wire is uncoiled from the drum in order to 
avoid twisting of the square wire. Hence, such uncoiling apparatus is 
complex and requires much capital cost. The position of the square wire 
should be carefully controlled in order to align the square wire on the 
bobbin. Therefore, the orientation of the square wire from the uncoiler to 
the bobbin must be carefully controlled. Furthermore, since the end 
portion of the wire must be connected to the bobbin by the end of the wire 
being wound around the terminal of the bobbin, it is difficult to avoid 
twisting the wire after the end portion of the wire is wound on the 
terminal of the bobbin. Consequently, it is difficult to align the square 
wire on the bobbin. As described above, the square wire can be adapted 
only on the special shape of the coil. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide the winding apparatus for 
winding a wire the sectional shape of which is polygon on the bobbin. 
Another object of the present invention is to avoid the disadvantage that 
such polygonal shaped wire is twisted on the bobbin. 
Further, an object of the present invention is to provide winding apparatus 
which can wind the wire on a bobbin in order even though the sectional 
shape of the wire is polygon.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT 
The winding apparatus of the first embodiment of the present invention is 
explained by referring FIG. 1. Numeral 1 represents a motor which rotates 
a bobbin 3, numeral 2 represents a rotating tool for holding the bobbin 3. 
The tool 2 is connected to the motor 1 so that the tool 2 is rotated in 
accordance with the rotation of the motor 1. The bobbin 3 is held between 
the tool 2 and the fixing plate 2a so that the bobbin 3 is rotated in 
accordance with the rotation of the tool 2. Numeral 4 shows a wire the 
sectional shape of which is circular and which is wound on a drum 10. An 
insulating material such as polymide or polyester is coated on the wire 4 
in order to maintain the electric insulation of the wire. The wire 4 of 
the present embodiment is used for a rotor coil of an alternator or for a 
solenoid coil of a magnet switch of a slator. The diameter of the wire 4 
is about 1 mm. 
Numeral 5 shows a holding member. A first shaping roller 6a and a second 
shaping roller 6b are held on the holding member 5 (as shown in FIGS. 1 
and 2). The first shaping roller is connected to a shaft 8a of a motor 8 
which is connected to the holding member 5 at an opposite side from the 
shaping roller 6a, so that the first shaping roller 6a is rotated by the 
motor 8. The shaft 8a is rotatably supported by a bearing held in the 
holding member 5. The second shaping roller 6b is rotatably supported by a 
slide block 12 in such a manner that the rotating shaft 6c of the second 
shaping roller 6b is supported by a bearing held in the slide block 12. 
The slide block 12 is supported in a sliding groove formed in the holding 
member 5, and the sliding block 12 is connected to a sliding cylinder 13. 
Guide nozzles 7a and 7b are respectively connected to arms 5a of the 
holding member 5 in such a manner that an axis of the guide nozzles 7a and 
7b locate in the center of the first and second rollers 6a and 6b. Numeral 
9 shows a motor for rotating a screw member 11 to which the holding member 
5 is connected so that the holding member 5 is moved in a direction 
parallel to the longitudinal axis of the screw member 11 in accordance 
with the rotation of the motor 9. 
The operation of the above winding apparatus above is explained 
hereinafter. The bobbin 3 is held between the rotating tool 2 and the 
fixing plate 2a. The end portion of the wire 4 the sectional shape of 
which is circular and which is uncoiled from the drum 10a is conveyed 
toward the guide nozzle 7a through a guide 10b. The wire passed through 
the guide nozzle 7a is then introduced to the guide nozzle 7b through the 
space between the first shaping roller 6a and the second roller 6b. The 
slide block 12 by which the second shaping roller 6b is supported is moved 
downwardly (shown by arrow B in FIG. 2) by the sliding cylinder 13 to make 
the space between the first shaping roller 6a and the second shaping 
roller 6b larger than the diameter of the wire 4b. The end portion of the 
wire 4 is connected to a T-shaped connecting portion 3a (FIG. 3)in such a 
manner that the end portion of the wire 4 is connected around the 
connecting portion 3a. After the end portion of the circular wire is 
connected to the connecting portion 3a, the slide block 12 is elevated 
(direction of arrow C in FIG. 2) by the pressure of the sliding cylinder 
13 in order to reduce the space between the first shaping roller 6a and 
the second shaping roller 6b for adjusting the deforming amount of the 
wire 4b. 
After the slide block 12 is elevated, the wire 4 is wound on the outer 
surface of the bobbin by the rotation of the motor 1. When the wire is fed 
toward the bobbin 3, the wire is deformed by the first and second shaping 
rollers 6a and 6b as shown in FIG. 4 so that the sectional shape of the 
wire passed the rollers 6a and 6b becomes rectangular. The rotating torque 
of the first shaping roller 6a is so controlled by the rotating motor 8 
that the tension of the wire fed to the bobbin 3 is maintained within the 
predetermined value. Since the wire from the drum 4 (circular wire 4b ) is 
guided by the nozzle 7a, the wire 4b is supplied to the rollers 6a and 6b 
steadily. The wire 7a deformed by the rollers 6a and 6b is fed toward the 
bobbin 3 through the guide 7b in order to be wound on the bobbin 3. Since 
the motor 9 is rotated while the motor 1 is rotated, the holding member 5 
is transferred along the axis of the screw member 11 in such a manner that 
the holding member 5 moves a distance which is an equivalent to the width 
of the wire 4b per one rotation of the bobbin 3. After the wire 4a is 
completely wound on the drum 3, another end portion of the wire is 
connected to another T-shaped connecting portion 3a 1 in such a manner 
that the other end of the wire is convected around the connecting portion 
3a ' (as shown in FIG. 3). The bobbin shown in FIG. 3 is used for a rotor 
of an automotive alternator. 
It is important for the winding apparatus to protect the insulating layer 
coated on the outer surface of the wire 4 when the wire 4 is deformed from 
the circular wire 4b to the square wire 4a. FIG. 5 shows the test results 
about the relationship between the deforming rate of the wire and the 
voltage that the wire can be supplied. The ordinate of FIG. 5 represents 
the deforming rate which is calculated as the expanded amount of the wire 
4 when the wire 4 is deformed by the rollers 6a and 6b. The coordinate of 
FIG. 5 is the voltage. The voltage of 600 V represents as the minimum 
standard which is calculated as 50 times normal automotive voltage 
(battery voltage 12 V). The dots in FIG. 5 represents mean voltage. 
As shown from FIG. 5, it is required for the wire 4 to be deformed less 
than the deforming rate of 17% in order to keep the voltage upper than the 
minimum standard voltage of 600 V. Hence, the shaping rollers 6a and 6b of 
the present invention so deforms the wire 4 so that the expansion rate of 
the wire 4 is less than 17%. 
Since the winding apparatus of the present invention begins to deform the 
wire 4 after the end portion of the wire 4 is connected to the connecting 
portion 3a, namely since the sectional shape of the wire 4 is circular 
when the wire 4b is connected to the connecting portion 3a, twisting of 
the wire is well prevented even though the end portion of the wire 4 is 
connected to the connecting portion 3a. Therefore, the position of the 
square wire 4a is well controlled when the square wire 4a is wound on the 
bobbin 3. Furthermore, since the wire 4 is conveyed to the shaping rollers 
6a and 6b is circular, the wire 4 between the drum 10a to the shaping 
rollers 6a and 6b does not need to be controlled twisting thereof. 
Consequently, the uncoiling device for uncoiling the wire 4 from the drum 
10a of the present embodiment is not required to have a complex mechanism. 
FIG. 6 shows another embodiment of the winding apparatus. The first shaping 
roller 6a is connected at the top end of the shaft 8a of the motor 8. A 
first transmitting gear 15 is connected on the shaft 8a so that the gear 
15 is rotated in accordance with the shaft 8a. A second transmitting gear 
16 is so connected with the first transmitting gear 15 so that the 
rotation of the gear 15 is transmitted to the second gear 16, and the 
rotation of the second gear 16 is transferred to the second shaping roller 
6b through the shaft 17. So that the second shaping roller 6b rotates 
simultaneously with the first shaping roller 6a, the second shaping roller 
is positioned perpendicular to the first shaping roller 6a. Numeral 12a 
shows a first slide block slidably connected with a first cylinder 13a so 
that the first sliding block 12a slides along with the line D shown in 
FIG. 6. A third shaping roller 6c is rotatably connected with the first 
sliding block 12 a. The third shaping roller faces to the first shaping 
roller 6a so that the third shaping roller 6c and the first shaping roller 
6a are aligned. 
Numeral 13b shows a second sliding block which is connected to a second 
sliding cylinder 13b so that the second sliding block 12b can slide along 
with line E in FIG. 6. A fourth shaping roller 6d is rotatably connected 
with the second sliding block 12b, and the fourth shaping roller 6d faces 
the second shaping roller 6b so that the fourth shaping roller 6d and the 
second shaping roller 6b are aligned. Accordingly, a square space 18 is 
formed within the first through the fourth rollers 6a-6d as shown in FIG. 
6. 
Accordingly the circular wire 4b is deformed to be square while the wire 4b 
is transferred through the space 18. The first sliding cylinder 13a and 
the second sliding cylinder 13b slides the third shaping roller 6c and the 
fourth shaping roller 6d respectively in order not to deform the wire 4b 
when the end portion of the wire is connected to the connecting piece 3a. 
After the end portion of the wire is connected to the connecting piece 3a 
the wire is then deformed to be square and the square wire 4c is wound 
around the bobbin 3 in such a manner that the flat surface of the wire 
connects to the outer surface of the bobbin 3. 
Since the rotating direction of the first through fourth rollers 6a-6b 
coincides with the drawing direction of the wire 4c caused by the motor 1, 
the insulating layer coated on the outer surface of the wire is well 
prevented from dropping off the wire 4. The motor 8 so controls the 
rotation of the shaping rollers 6a and 6b that a predetermined tension is 
caused to the wire 4c between the rollers 6a through 6b and the bobbin 3 
in order to tighten the wire wound on the bobbin 3. 
Since the square wire 4c faces the adjacent wire 4c without any gap 
therebetween (shown in FIG. 8), the density of the coil is improved. The 
density of the coil shown in FIG. 8 is 27.4% higher than that of the coil 
of the circular wire shown in FIG. 9. Furthermore, since no groove is 
formed between adjacent wires when the sectional shape of the wire is 
square, the wire 4c can be wound without any influence of the lower layer 
of wire 4c. Namely, a lead groove is formed between adjacent wires if the 
sectional shape of the wire is circular as shown in FIG. 15, and such lead 
groove should cause damage to the coil wound on the lead groove. 
FIG. 10 shows a third embodiment of the winding apparatus of the present 
invention. The apparatus shown in FIG. 10 has a pair of limit switches 19. 
The left and right limit switches 19 are so provided that the holding 
member 5 actuates the left limit switch 19 when the holding member 5 moves 
to the predetermined left position which coincides to the left end portion 
of the bobbin 3. The left limit switch 19 outputs a signal to the sliding 
cylinder 13 (FIG. 2) for controlling the position of the sliding block 12. 
The operation of the apparatus of the third embodiment is explained 
hereinafter. The bobbin 3 locates at the predetermined left position when 
the end portion of the circular wire 4b is connected to the connecting 
piece 3a so that the left limit switch 19 outputs a signal to the sliding 
cylinder 13 for sliding the second shaping roller 6b apart from the first 
shaping roller 6a in order to make the space between the surfaces of the 
first shaping roller 6a and the second shaping roller 6b expand. 
Therefore, the wire 4 is not deformed by the shaping rollers 6a and 6b 
when the left limit switch 19 senses the predetermined left position of 
the holding member 5. 
The holding member 5 deactivates the left limit switch 19 when the drum 
rotates a first predetermined rotation, so that the left limit switch 19 
outputs a signal to the sliding cylinder for sliding the shaping roller 6b 
in order to reduce the space between the first shaping roller 6a and the 
second shaping role 6b. Therefore, the wire 4 is deformed after the 
holding member 5 deactivates the left limit switch 19. The square wire 4a 
is, therefore, fed to the bobbin 3 in order to be wound on the bobbin 3. 
The holding member 5 slides rightwardly as the winding of the wire 4 
progressively rightwardly in order. After the holding member 5 moves to 
the predetermined right position, the holding member 5 activates the right 
limit switch 19. Therefore, the right limit switch 19 outputs a signal for 
moving the shaping roller 6b in order not to deform the wire 4. 
Accordingly, circular wire 4b is supplied to the bobbin at the right end 
position of the line of the wire 4 as shown in FIG. 10. 
The apparatus shown in FIG. 10 ably prevents the disadvantage that the 
position of the square wire 22 is not held properly at the end point 22a 
of the line as shown in FIG. 11. It is difficult to control the 
positioning of square wire 22 when the wire 22 is transferred from a lower 
layer to be on the upper layer. The since the apparatus shown in FIG. 10 
can make the sectional shape of the wire circular when the wire is 
positioned at the end of the line in the bobbin, the wire can be properly 
transferred from a lower layer to an upper layer. 
FIG. 12 shows the fourth embodiment of the winding apparatus of the present 
invention. The apparatus shown in FIG. 12 has the first through the fourth 
shaping rollers 6a-6b inclined in order to incline the square wire 4a. The 
bobbin 3 shown in FIG. 12 has holding grooves 3c coinciding with the 
sectional shape of the square wire 4a. The lead groove 4x the shape of 
which coincides with the sectional shape of the square wire 4a is formed 
between adjacent square wires 4a when the square wire 4a is wound on the 
bobbin 3, so that the square wire of the upper layer can be held in the 
lead groove 4x formed by the square wires of the lower layer. Therefore, 
the wire 4 is guided by the lead groove 4x when the wire is wound on the 
bobbin 3. 
FIGS. 13 and 14 show other embodiments of the shaping rollers. The shaping 
rollers 6e and 6f shown in FIG. 13 has a protruding portion 6e1 and 6f1 
for forming a square space within the upper surfaces of the rollers 6e and 
6f and the side surfaces of the protruding portions 6e1 and 6f1. The 
shaping rollers 6g and 6h shown in FIG. 14 has a triangular groove 6g1 and 
6h1 on the outer surface thereof and the shaping rollers 6g and 6h touched 
each other so that a square space is formed between the grooves 6g1 and 
6h1. 
FIG. 16 shows the fifth embodiment of the winding apparatus of the present 
invention. The apparatus shown in FIG. 16 further has a tension meter 22, 
a control unit 24 and an electropneumatic regulator 26. The tension meter 
22 detects tension acting on the wire rod 4a; and the control unit 24 
receives a signal of the tension detected by the tension meter 22, 
compares it with a given level, and sends a signal to an electropneumatic 
regulator 26. This electropneumatic regulator 21 controls the turning 
torque of the forming roller turning motor 8 in accordance with the signal 
from the control unit 24. 
The operation of the foregoing coil winding apparatus according to the 
present invention is now described. The leading end of wire rod 4b of 
circular shape in cross section is passed through the guide nozzle 7a, 
between the rollers 6a and 6b, and through the guide nozzle 7b, and is 
secured to the bobbin 3 after being wound therearound. Before the above 
step, the roller sliding cylinder 13 is operated to move down the roller 
6b supported thereby (in the direction of arrow B in FIG. 2) such that the 
spacing between the rollers 6a and 6b becomes larger than the diameter of 
the round wire rod 4b. 
Then, the bobbin turning motor 1 is operated to wind the wire rod 4b around 
the bobbin 3. At this time, the slide block 12 (in FIG. 2) is moved up by 
means of the roller sliding cylinder 13 to shift the roller 6b upward (in 
the direction of arrow C in FIG. 2) such that the spacing between the 
rollers 6a and 6b will result in a given degree of deformation. 
Where a copper wire rod 4b of 0.995 mm in diameter, for example, is pressed 
to 0.75 mm to form the wire rod 4a and this wire rod is wound around the 
bobbin 3, a tension of 10 Kgf is imposed on the wire rod 4a between the 
bobbin 3 and the rollers, for example, 6a and 6b. This tension is a force 
acting to stretch the wire rod 4a and is imposed on the wire rod 4a after 
the covered wire 4b is pressed by the rollers 6a and 6b; therefore, 
without the tension control arrangement of the present invention, an 
undesirable twisting force is applied to the cover or coating of the wire 
rod, so that the coating is badly damaged, for example cracked open. 
In view of the above, according to the present invention, as shown in FIG. 
4, a torque T is applied to the roller 6a in the same direction as that of 
the tension F by means of the forming roller turning motor 8, so that the 
tension decreases. That is, the value of the forming resistance of the 
wire rod 4a minus the torque T becomes the tension F acting on the wire 
rod 4a having been formed. Therefore, the tension acting on the wire rod 
4a can be varied by varying the torque T. 
An example of the torque control of the forming roller turning motor 8 is 
as follows. That is, the tension F acting on the wire rod 4a is detected 
by the tension meter 22. The control unit 24 receives the tension F 
detected by the tension meter 22 and delivers an instruction to the 
electropneumatic regulator 26 to vary the air pressure being supplied to 
the forming roller turning motor 8 such that the tension F becomes a given 
level (for example, 4 Kgf). 
In this way, the tension acting on the wire rod 4a is regulated, and the 
round wire rod 4b is continuously pressed under optimum tension, whereby a 
flat or rectangular wire rod 4a is formed as shown in FIG. 3. During this 
forming, the round wire rod 4b is passed through the guide nozzle 7a and 
led stably to a given position between the pair of forming rollers 6a and 
6b. Then, the wire rod thus made flat or rectangular is passed through the 
guide nozzle 7b and led to the bobbin 3. At the same time, the traversing 
motor 9 is also operated, so that the whole wire rod forming section shown 
in FIG. 2 is moved horizontal back and forth by means of the screw member 
11 in synchronization with the rotation of the bobbin 3 (i.e., the 
rotation of the bobbin turning motor 1) at a pitch corresponding to the 
width of the wire rod 4a. 
Further, the tension acting on the wire rod 4a can be set arbitrarily by 
using an air motor as the forming roller turning motor 8 and regulating 
the pressure and flow rate of air being supplied to that motor. Of course, 
the same effect as above can be obtained by using any motor, such as a 
torque motor, whose output torque can be controlled.