JP2709565B2 - Sewing machine lower thread winding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for winding a bobbin thread on a bobbin.

[0002]

2. Description of the Related Art In a conventional lockstitch sewing machine, when a bobbin wound around a bobbin runs out, the bobbin is removed together with the bobbin case from the shuttle, the bobbin is wound around the bobbin, and the bobbin is attached to the shuttle again. or, or had carried out the work, such as replacing the bobbin thread winding already bobbin which had been prepared in advance, a lot of time in the work, in order to take the effort, Japanese Patent Application No.
JP-A-4-188688 (JP-A-6-272)
) , A device for automatically winding a bobbin on a bobbin and automatically cutting a bobbin thread on a bobbin case and cutting a bobbin thread on the bobbin case on which the yarn is hooked has been proposed.

[0003]

However, the apparatus described in Japanese Patent Application No. 4-188688 (JP-A-6-272) has the following problems. That is, in the above-described device, the bobbin and the bobbin clutch are rotated by the rotation of the motor so that the bobbin is wound around the bobbin while the bobbin is held between the bobbin and the bobbin clutch. During rotation, it is not possible to release the bobbin and the bobbin thread at the beginning of winding by the bobbin clutch.
Therefore, the end of the thread at the beginning of the winding that has been pinched remains outside the bobbin case after the completion of the winding.If the final sewing is performed in such a state, the thread at the beginning of the winding remaining outside the bobbin case becomes entangled, Therefore, there was a problem that a good seam could not be formed due to being caught in the gap, and the upper thread might break in some cases.

In the above-mentioned apparatus, a special bobbin and a bobbin case having a special shape different from the conventional bobbin must be used. In addition, there is a problem that the quality of the sewing cannot be maintained because it affects the sewing quality built up in the above, and that the bobbin and the bobbin case are processed, so that the cost is high.

Further, in the above-mentioned apparatus, the lower thread is wound in from the machined thread outlet of the bobbin case. Therefore, there is a problem that the bobbin thread is biased around the bobbin.

Further, in the above-mentioned apparatus, a cam mechanism for moving the thread guide for guiding the lower thread from the thread winding so that the thread guide can be moved in the axial direction during operation is provided. Providing such a cam mechanism is not preferable because the apparatus becomes complicated.

[0007] In view of the above, the present invention makes it possible to wind a lower thread by giving a rotation to a bobbin so that a thread end at the beginning of winding does not remain outside the bobbin case after the winding is completed, and a good seam can be formed and an upper thread can be formed. There is no fear of cuts, and without any or little changes to the bobbin and bobbin case,
SUMMARY OF THE INVENTION It is a first object of the present invention to provide a lower thread winding device for a sewing machine, which can maintain sewing quality and reduce cost, and can align and wind a lower thread neatly on a bobbin without unevenness.

It is a second object of the present invention to provide a sewing machine lower bobbin winding device which can favorably guide a lower bobbin in the axial direction during operation without a moving mechanism such as a cam mechanism. And

A third object of the present invention is to provide a lower thread winding device for a sewing machine in which the tension of the lower thread is made variable and the operation is carried out extremely well.

[0010]

In order to achieve the first object, a lower thread winding device according to the first aspect of the present invention is configured such that a bobbin rotatably supported and a lower thread can be clamped and released. A thread clamp means, a wiper for moving a lower thread clamped by the thread clamp means to an opening of a bobbin case in which the bobbin is housed, and applying a rotation to the bobbin of the lower thread drawn by the wiper. And a take-up shaft that can be wound around the bobbin. When the bobbin bobbin is wound around the bobbin, the thread clamp means is opened.

[0011] In order to achieve the second object, the present invention provides
The bobbin winding device of the second sewing machine includes a bobbin guide for guiding a bobbin thread from the bobbin, and the bobbin thread guide has an elongated hole capable of guiding a bobbin thread that moves in the axial direction during operation. .

[0012] To achieve the third object, the present invention provides
The lower thread winding device of No. 3 was provided with thread tension varying means for varying the tension of the lower thread.

[0013]

According to the lower thread winding device of the first aspect, the lower thread is clamped by the thread clamp means, and the supply side of the clamped lower thread is brought to the opening of the bobbin case by the wiper. . When the take-up shaft rotates, the bobbin thread is wound up on the bobbin in the bobbin case. At this time, the opening end of the thread is automatically stored in the bobbin case by the opening operation of the thread clamping means, and the bobbin case is started. Is not left outside the bobbin case. Accordingly, a good seam can be formed and the occurrence of breakage of the upper thread can be prevented. Further, since the bobbin and the bobbin case are not changed at all or hardly changed, the sewing quality can be maintained and the cost can be reduced, and the bobbin can be wound around the bobbin without deviation.

The lower thread winding device according to the second aspect of the present invention.
According to the arrangement, the lower thread which moves in the axial direction during operation is guided by the long hole of the thread guide. Therefore, a moving mechanism such as a cam mechanism is not required, and the lower thread can be guided in the axial direction with a simple configuration.

The lower thread winding device of the sewing machine according to the third aspect.
According to this arrangement, the tension of the lower thread is varied by the thread tension varying means, and an optimal tension is applied to the lower thread during operation. Therefore, the operation of the apparatus is performed extremely well. Further, for example, the setting of the yarn tension is optimally performed according to the type of the yarn and the thickness of the yarn.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, with reference to FIGS. 18 to 22 , an outline of an automatic lower thread supply device that employs the lower thread winding device of the sewing machine of the present invention will be described.

The bobbin thread automatic supply device is provided with a sewing machine bed 1
Is located in the space where the bottom below is an oil sump,
As shown in FIGS. 18 and 19, bobbin case detaching position A, the residual thread removing position B and bobbin thread winding position C is disposed in the 120 ° intervals around the uniaxial and, as shown in FIGS. 18 to 20 , Bobbin case attaching / detaching position A and other working positions B and C
Is divided into both ends of the one axis, and a column 2 erected in the space, a main base 3 mounted on the column 2, and the single axis horizontally supported by the main base 3. A guide shaft 4, a rotating arm 5 rotatably supported by the guide shaft 4 and slidably supported in the axial direction, and a forward / backward lever for moving the rotating arm 5 forward and backward along the guide shaft 4 6 and a drive unit for rotating the rotating arm 5 forward or backward in increments of 60 °.

As shown in FIG. 21 , the guide shaft 4 is rotatably supported at both ends by an upright portion of the main base 3. As shown in FIG. 22 , the cross section is non-circular, and the shape of the corresponding hole of the boss 5a of the rotating arm 5 is the same. Therefore, the rotating arm 5 can slide along the guide shaft 4 and can rotate together with the guide shaft 4.

The pivot arm 5, as shown in FIG. 18, extends symmetrically refracted slightly to both sides from the center, in the vicinity of each end, as shown in FIG. 21, a built-in bobbin 7 A bobbin case 8 is detachably supported. The bobbin attaching / detaching mechanism in the rotating arm 5 is described in, for example,
No. 92476, automatic lower thread feeding device and Japanese Patent Application No. 5-12
1960 Pat including the pair of electromagnets suction head described in the bobbin exchanging device of a sewing machine of (JP-A 6-304370 discloses), For example JP Gantaira 5-11636
An appropriate device such as a device using a lever claw described in a bobbin exchanging device of a sewing machine disclosed in Japanese Patent Application Laid-Open No. 6-304369 can be employed.

The forward-reverse lever 6, 19, as shown in FIG. 20, and is rotatably supported by a shaft 9 which is erected on the main base 3. A long hole 6a is formed near the free end. The other end is rotatably attached to a shaft 13 fixed to a knuckle 12 at the rod end of an air cylinder 11 attached to the main base 3 by a support plate 10. Then, the long hole 6a of the forward-reverse lever 6, FIG. 21, as shown in FIG. 22, the rotating arm 5
Of the collar 14 rotatably attached to the boss 5a of the
A pin 15 projecting from the surface is engaged. Therefore, when the rod of the air cylinder 11 expands and contracts, the forward / reverse lever 6 rotates forward and backward around the shaft 9. Accordingly, the rotating arm 5 moves forward and backward along the guide shaft 4 via the pin 15 which engages with the long hole 6a of the forward and backward moving lever 6.
That is, the rotating arm 5, FIG. 18, hook 1 shown in FIG. 21
It is possible to move forward and backward along the guide shaft 4 along the bobbin case attaching / detaching position A side and the opposite side (the remaining yarn removing position B and the bobbin winding position C exist), which are the sewing positions provided at 6. it can.

The rotary drive of the rotary arm 5, FIG. 19,
As shown in FIG. 20 , a motor 19 attached to a bracket 18 fixed to a bracket 17 below the main base 3 and a gear 21 fixed to a rotating shaft 20 thereof
A gear 22 that is rotatably supported by the bracket 17 and meshes with the gear 21, a master wheel 23 fixed to one surface of the gear 22, a pin 24, and a driven wheel 25 that is rotatably supported by the bracket 17. The mechanism, a gear 26 coaxially fixed to the driven wheel 25, and a guide shaft 4 (FIG. 2)
1 ) a gear 27 meshing with the gear 26. Therefore, by configuring the gear 26 and the gear 27 at a predetermined gear ratio, the rotating arm 5 is rotated by the Geneva mechanism of the rotary driving device by the motor 19 as a drive source in units of 60 ° via the guide shaft 4. .

[0022] The residual thread removing position B, For example, especially Gantaira 5-2
Appropriate devices such as the bobbin residual yarn removing device disclosed in Japanese Patent No. 03610 (Japanese Patent Application Laid-Open No. 7-80177) can be employed.

In the automatic bobbin thread supplying device constructed as described above, the rotation of the motor 19 causes the rotating arm 5 to repeat forward / reverse rotation in units of 60 °, and forward / backward movement along the guide shaft 4 to repeat. The bobbin case 8 is reliably transported to each of the work positions A, B, and C to execute or receive work.

For example, without holding the bobbin case 8 at one end of the rotating arm 5, holding the bobbin case 8 with a built-in bobbin (described later in detail) 7 by a bobbin winding device at the other end. Assume that one end not holding the bobbin case 8 is waiting at a position D (see FIG. 19 ) between A and B. When predetermined sewing is completed in this state, the rotating arm 5 rotates counterclockwise by 60 ° in FIG. 19 and moves forward to the shuttle side in FIG. 18, and there is a residual thread from the shuttle 16 at the bobbin case attaching / detaching position A. A bobbin case 8 with a built-in bobbin is held at one end of the rotating arm 5.

Next, when the rotating arm 5 retreats to the retracted position of the guide shaft 4 and rotates 180.degree. To move forward, the bobbin case 8 with the bobbin wound on the bobbin held at the other end of the rotating arm 5 is wound. It is attached to the shuttle 16 at the bobbin case attaching / detaching position A. When the rotating arm 5 moves backward and rotates 60 ° clockwise, the bobbin case 8 with a built-in bobbin with a remaining thread held at one end of the rotating arm 5 advances to the remaining thread removing position B, where the remaining thread is removed. Bobbin 7 by thread removing device
Is removed, and the bobbin becomes an empty bobbin without a thread. Thereafter, when the rotating arm 5 rotates counterclockwise by 120 ° and retreats, the bobbin case 8 with the empty bobbin from which the residual yarn has been removed advances to the lower bobbin winding position C, and the bobbin bobbin winding device there turns to the empty bobbin. The bobbin thread is wound. Thereafter, these operations are repeated.

Next, a bobbin winding device, which is a feature of the present invention and is disposed at the bobbin winding position C, will be described with reference to FIGS.
This will be described below with reference to FIG.

This bobbin winding apparatus clamps the bobbin thread, introduces the bobbin thread into the bobbin case, and applies the rotation to the bobbin and releases the clamp, thereby accommodating the bobbin thread which has been wound into the bobbin case. An operation of winding the bobbin thread around the bobbin, and an operation of hooking the bobbin thread wound around the bobbin and led out from the opening of the bobbin case to the bobbin case (slip of the bobbin case).
The leads to the preparative operation) or the like being adapted to be carried out automatically, yet can be optimized to a lower thread tension in the series of operations, and to be able to determine also the upper thread state.

As shown in FIG. 1, the lower thread winding device includes a sub-frame 10 mounted on the main base 3.
One. The sub-frame 101 has a substantially U-shape, and is arranged such that the opening faces downward. Through holes are formed coaxially on both side plates of the subframe 101, and bearings 103 and 104 are respectively mounted in these through holes as shown in FIG.

As shown in FIG. 3, one of the bearings 104 is provided so as to protrude from one surface of the pulley 106 and has a slit 1.
A boss 106c having a shape obtained by symmetrically dividing the cylindrical portion into two parts in the axial direction by 06b is rotatably supported. Pulley 1
A boss 106a having a substantially cylindrical shape is provided on the other surface of
The shaft hole of the pulley 106 and the boss 106c are formed coaxially. As shown in FIG. 2, a winding shaft 107 is inserted into the shaft holes of the boss 106a, the pulley 106, and the boss 106c, and the winding shaft 107 is supported by the pulley 106. I have. A pin hole orthogonal to the axial direction is formed at an end of the winding shaft 107 corresponding to the bearing 104. This pin hole has a pin 1
Reference numeral 08 is fitted and fixed, and both ends of the pin 108 are loosely fitted in the slit 106b.
Therefore, the rotation of the pulley 106 is controlled by the boss 106c and the pin 10
8, the winding shaft 107 can slide in the axial direction at the same time because both ends of the pin 108 can slide in the slit 106b.

On the other bearing 103, a thread clamp shaft 105 as a thread clamp means having a substantially cylindrical shape and having a flange at the left end in FIG. 2 is slidably supported in the axial direction. A part of the winding shaft 107 is inserted into a shaft hole of the yarn clamp shaft 105 on the side opposite to the pulley, and the winding shaft 1
07 is supported by the thread clamp shaft 105 so as to be slidable in the axial direction. The boss 106a is inserted into a shaft hole on the pulley side of the thread clamp shaft 105, and the thread clamp shaft 105 is slidable on the boss 106a.

A flange is formed at the end of the take-up shaft 107 on the side opposite to the pulley. On the surface of this flange portion, a pin 107 a for clutching an existing hole provided in the flange of the bobbin 7 and transmitting the rotation of the winding shaft 107 to the bobbin 7.
Are formed on the peripheral surface, and a large number of convex surfaces are formed at equal intervals on the peripheral surface to prevent the lower thread from slipping on the peripheral surface.

At substantially the center in the axial direction of the winding shaft 107, E
The ring 109 is mounted so as to protrude outward, and compression springs 110 and 111 are provided between the inner wall surface of the clamp shaft 105 and the E ring 109 and between the E ring 109 and the inner wall surface of the pulley 106. Each is arranged. Accordingly, the take-up shaft 107 is urged leftward in FIG. 2 with respect to the pulley 106 by the compression spring 111, and the thread clamp shaft 105 is taken up by the compression spring 110
07 is urged to the left in FIG. That is, the yarn clamp shaft 105 and the winding shaft 107 are always
And the winding shaft 107
The flange of the thread clamp shaft 105 is in pressure contact with the flange of.

As shown in FIGS. 2 and 4, the rotary drive mechanism of the pulley 106 includes a motor 115, a transmission shaft 114 mounted on the output shaft of the motor 115 along the same axis, and a transmission shaft 114. Pulley 1 fixed to 114
13 and a timing belt 112 stretched over the pulley 113 and the pulley 106. Therefore, the rotational driving force of the motor 115 is
4, and transmitted to the pulley 106 via the pulley 113 and the timing belt 112.

As shown in FIG. 1, a flange 105a is formed at the end of the thread clamp shaft 105 on the pulley side, and a roller 136a is applied to the end surface of the flange 105a on the side opposite to the pulley. It is in contact (initial state).
The roller 136a is supported by a lever 136, as shown in FIG.
37 is fixed to one end. The collar 137 is rotatably supported by the support column 2, and one end of a link 138 is fixed to the other end of the collar 137 rotated by 90 ° counterclockwise. One end of a link 139 is pivotally connected to the other end of the link 138, and the other end of the link 139 is pivotally connected to a piston rod of the air cylinder 140. Therefore, the air cylinder 140 is driven (in this embodiment, the piston rod is retracted).
The collar 137 rotates clockwise in FIG. 2, and the roller 136 a causes the flange 1 of the thread clamp shaft 105 to resist the urging force of the spring 110 urging the thread clamp shaft 105.
05a to the pulley side, and as a result, the yarn clamp shaft 105
Is retracted toward the pulley, and a gap is formed between the flange of the thread clamp shaft 105 and the flange of the winding shaft 107.

As shown in FIG. 2, a substantially cylindrical collar 180 is fitted around the outer periphery of the bearing 103. The collar 180 is prevented from coming off in the axial direction by a C-ring 90. Yarns in the top in FIG. 2 Color 180
A separation mounting base 116a is provided to protrude, and this thread
The thread mounting 116a shown in FIG.
Has been fixed.

[0036] The handling member 116 is a rear end V-shaped notches 1 16D to put guide the lower yarn (the far side in FIG. 2)
That has a shape made the rotation plate 116A.

As shown in FIG. 1, a gear 122 is formed on the outer periphery of the collar 180.
22 is a gear 121, a gear 120, a gear 119, a gear 1
18. Motor 1 that can rotate forward and reverse through gear 117
23 is driven to rotate. That is, by driving the motor 123, the collar 180 and the yarn handling 11
6 rotates in forward and reverse directions.

As shown in FIGS. 1, 6, and 7, on the outer periphery of the upper portion of the bearing 103, a thread hook lever 124 is rotatably supported by a stepped screw 124a on a plane perpendicular to the plane of FIG. Have been. This thread hook lever 12
4, a hook 124 is provided at the distal end as shown in FIG.
A and an inclined surface 124B connected to the hook 124A and inclined from upper to lower right in FIG. 6 are formed. The thread hook lever 124 is connected to the torsion spring 12.
5, it is urged in the counterclockwise direction in FIG.
Normally, it is in the state shown by the solid line in FIG.

A wiper 130 is provided on the front side of the winding shaft 107 in FIG. The wiper 130 has a rod shape with a partly bent part,
(See FIGS. 19 and 20 ) A shaft 129 rotatable coaxially with the shaft 129.
Is fixed to its central part. A gear 132 is fixed to an end of the shaft 129. The gear 132 has a gear 133 having an axis in a direction orthogonal to the axis of the gear 132.
Are engaged. The end of the gear 133 has a link 1
One end of 31a is connected. The other end of the link 131a has a link 131 as shown in FIGS.
The other end of the link 131b is pivotally connected to one end of a link 131c. The other end of the link 131c is a rotary air cylinder 1
34. Accordingly, when the air cylinder 134 is driven, the wiper 130 rotates around the shaft 129.

As shown in FIG. 11 and FIG. 13, above the yarn handling 116 and on the near side, as shown in FIG.
The thread guide 92 for guiding the lower thread 150 supplied from the boss (see FIG. 9) is fixedly arranged. The thread guide 92 is formed in a flat plate shape and stands substantially horizontally, and a long hole 92a through which a bobbin thread passes is formed in the plate portion. This long hole 92a
Has a height difference inclined from left to right in FIG. 10, and the lower thread axially moving during operation is
are guided along a.

As shown in FIG. 9, a mechanism is provided between the yarn guide 92 and the bobbin 200 to remove the looseness of the lower thread. This mechanism attaches a lever 201 having a lower thread 150 passed through through holes at both ends, a shaft 203 rotatably supporting the lever 201, and one end (upper end in the figure) of the lever 201 in the right direction in the figure. And a biasing spring 202. With this mechanism, the slack of the lower thread 150 upstream and downstream of the mechanism is removed.

Between the lever 201 and the bobbin 200,
A thread tension varying means 204 for varying the tension of the lower thread 150 is provided. The thread tension varying means 204 includes a tension spring 205 for pressing the lower thread 150 passing therethrough, a screw 206 for adjusting the pressing force of the tension spring 205 by manual operation, and a tension spring 20 disposed in the sewing machine bed 1.
And a solenoid SOL that generates a solenoid thrust against the pressing force of No. 5.

The electric circuit for driving the yarn tension varying means 204 has a configuration in which a power supply V is connected in series to a solenoid SOL, and a switch SW is interposed therebetween.

Therefore, when the switch SW is turned off, the solenoid thrust is not generated, the pressing force of the tension spring 205 is applied to the bobbin thread 150 to the maximum, and the bobbin thread tension is maximized. When the switch SW is turned on, the above-described solenoid thrust is generated to the maximum, and the lower thread 150 is applied with a force obtained by subtracting the solenoid thrust from the pressing force of the tension spring 205, and the lower thread tension is minimized.

The yarn tension varying means 204 and the yarn winding 200
A yarn detector 222 serving as a lower yarn state detecting means for judging the yarn state via the yarn guide 207 is provided between the two. The yarn detector 222 includes a yarn guide 207 and the yarn winding 20.
0 and a substantially cylindrical thread path tunnel 208 formed between
And a through hole 208a penetrating the cylindrical portion of the yarn path tunnel 208 in a direction orthogonal to the axial direction, and a photodiode PD and a phototransistor PT disposed at both ends of the through hole 208a. I have.

As shown in FIG. 15 , a power supply V is connected in series to the photodiode PD via a resistor Ra. The connection point between the power supply V and the resistor Ra is connected to the collector terminal of the phototransistor PT, and the connection point between the power supply V and the photodiode PD is connected to the emitter terminal of the phototransistor PT via the resistor Rb. The collector terminal of the phototransistor PT is connected to the + terminal of the comparator COMP1 via a variable resistor Rc, and the + terminal of the comparator COMP2 via a variable resistor Rd. Has a negative terminal of the comparator COMP1 and a comparator C
The-terminals of OMP2 are connected to each other. The other end of the resistor Re whose one end is grounded is connected to the connection point between the variable resistor Rc and the + terminal of the comparator COMP1, and the one end is grounded to the connection point between the variable resistor Rd and the + terminal of the comparator COMP2. The other ends of the resistors Rf are connected to each other. The output terminals of the comparator COMP1 and the comparator COMP2 are connected to a discriminating means 222a as a control means, and can appropriately generate, for example, an operation stop signal (a pin winding prohibition signal), an alarm signal, and the like.

Here, when there is no yarn in the yarn path tunnel 208, the light of the photodiode PD irradiates the phototransistor PT to the maximum, and the comparators COMP1, CO2
MP2 of - voltage Vs applied to the terminal, as shown in FIG. 16, rise, comparator COM, which is set in advance
The voltages exceed the respective voltages V ₁ and V ₂ applied to the + terminals of P1 and COMP2. Therefore, the comparators COMP1, CO1
Both outputs of MP2 become 0, and the determination means 222a determines that there is no supply yarn, and generates, for example, an operation stop signal for stopping the operation of the lower thread winding device, an alarm warning signal for notifying the operator of the abnormality, and the like. Is done.

When the yarn is normally present in the yarn path tunnel 208, the light of the photodiode PD is transmitted to the lower yarn 1
50 and shielded at an appropriate rate by comparators COMP1,
COMP2 of - voltage Vs applied to the terminal, as shown in FIG. 16, will be present between the voltage _V 1, _{V 2.} Accordingly, the outputs of the comparators COMP1 and COMP2 are 0 and 1, respectively, and the determination unit 222a determines that the supply yarn is passing normally.

Also, the yarn may become abnormally thick because it is spliced on the way, or may become abnormally thick due to, for example, a yarn ball. , The light of the photodiode PD is considerably shielded by the unusually thick thread portion, and the voltage V applied to the minus terminals of the comparators COMP1 and COMP2.
s, as shown in FIG. 16, smaller than the voltage _V 1, _{V 2.} Accordingly, the outputs of the comparators COMP1 and COMP2 are both 1, and the determining means 222a stops the operation of the lower thread winding device, for example, assuming that there is an abnormally thick thread portion in the supplied yarn and good sewing cannot be performed. A stop signal or an alarm signal for notifying the operator of the abnormality is generated.

The reason is that the comparators COMP1, COMP2
Table 1 shows the relationship between the output and the yarn state and the discrimination results as a table.

[Table 1]

Next, the operation of the bobbin thread winding apparatus constructed sewing machine in this way, with reference to FIGS. 10 to 14, will be described below.

First, the rotary arm 5 of the above-described automatic bobbin thread supplying device is rotated, and the bobbin case 8 with the empty bobbin 7 from which the remaining thread has been removed reaches the bobbin thread winding position C.

At this time, the bobbin winding device is in an initial state as shown in FIG.
Numeral 0 is passed through a long hole 92a of the yarn guide 92, and the end thereof is clamped between the flange of the yarn clamp shaft 107 and the flange of the winding shaft 105 by manual operation.
You.

At this time, the switch SW of the thread tension varying means 204 is turned on to generate the above-mentioned solenoid thrust to the maximum and to minimize the lower thread tension.

Next, the rotating arm 5 is moved forward (to the right in the figure), and the pin 107a of the winding shaft 107 is engaged with the existing hole provided in the flange of the bobbin 7. Then, as shown in FIG. 11, the wiper 130 is moved about 18
It is rotated 0 °. Then, the thread portion between the clutched tip portion of the lower thread 150 and the thread guide 92 is hooked on the wiper 130, and the opening 8A of the bobbin case 8 is opened.
Sent to

Next, the motor 115 is driven to rotate the winding shaft 107, and the bobbin thread 150 is wound around the bobbin 7. Then, wiper 1 is
The lower thread 30 is returned to the initial position, and the motor 115 is further driven to wind a small amount of the lower thread 150 around the bobbin 7.

When the bobbin 7 is wound in a small amount on the bobbin 7, the thread clamp shaft 105 is retracted by the air cylinder 140 (moved rightward in the drawing), and the motor 115 is further driven. Then, thread clamp shaft 1
The yarn end at the beginning of the winding, which is clamped between the flange portion 07 and the flange portion of the winding shaft 105, is automatically stored in the bobbin case 8 (see FIG. 12). Then, the driving of the motor 115 is continued, the bobbin thread 150 is wound around the bobbin 7 by a set amount, and the motor 115 is stopped.

After the bobbin thread 150 is automatically wound around the bobbin 7 in this manner, the bobbin case 8 is then threaded (moving the bobbin case 8 to a slit in the bobbin case 8).
Work) .

First, the switch S of the yarn tension varying means 204
W is turned off to eliminate the above-mentioned solenoid thrust and maximize the bobbin thread tension.

Next, the motor 123 is driven to control the yarn handling 1
16 is rotated half a turn. Then, as shown in FIG. 13, the lower thread 15 led out from the opening 8A of the bobbin case 8
0 is caught at the apex of the V-shaped cut portion 116D, and the threading position 8 on the lower thread tension spring side of the bobbin case 8 is
Move toward B.

At this time, the lower thread moving toward the threading position 8B comes into contact with the inclined surface 124B of the threading lever 124 and pushes the threading lever 124 in the traveling direction. As described above, since the torsion spring 125 is urged in the direction opposite to the traveling direction, FIG.
As shown in (2), the lower thread is guided to the slit 8C at the threading position 8B after pushing the threading lever 124 in the advancing direction by a predetermined amount. Then, the handling member 116 by driving the motor 123 is reversely half turn, returns the thread handling 116 to the original position (see FIG. 14).

The supplied lower thread 15 during the above operation is
The state of 0 is constantly monitored by the yarn detector 222. For example, when an abnormality of the yarn breakage or the yarn thickness is detected, the lower yarn winding operation is stopped by the determination means 222a, and the fact is notified to the operator. It is notified by an alarm or the like.

As shown in FIG. 8, a bobbin case 8 used in this embodiment is provided with a thread 150 led out from an opening 8A and a thread hooking position 8B on the lower thread tension spring side of the bobbin case 8. Chamfer 8a to make it easier to move
However, there is no change in the sewing quality due to the chamfer 8a.

As described above, in this embodiment, the bobbin 7 rotatably supported and the thread clamp shaft 10 serving as a thread clamp means capable of clamping and releasing the lower thread 150 are provided.
5, a wiper 130 for moving the bobbin thread 150 clamped by the thread clamp shaft 105 to the opening 8A of the bobbin case 8 in which the bobbin 7 is incorporated, and a bobbin thread 150 drawn by the wiper 130 to the bobbin 7 Winding shaft 107 that can be wound on the bobbin 7 by giving rotation to
When the bobbin 7 is wound around the bobbin 7, the bobbin thread 107 is released. Therefore, the bobbin thread 150 is clamped by the bobbin thread 107, and the clamped bobbin thread 150 is supplied. The side (the side of the bobbin 200) is moved toward the opening 8A of the bobbin case 8 by the wiper 130,
When the take-up shaft 107 rotates, the bobbin thread 150 is taken up by the bobbin 7 in the bobbin case 8. At this time, the opening end of the thread clamp shaft 107 causes the thread end at the start of winding to be automatically placed in the bobbin case 8. So that the thread ends are not left outside the bobbin case 8 as in the prior art. Therefore, it is possible to form a good seam and to prevent the occurrence of upper thread breakage. Also, since the bobbin and the bobbin case are not changed at all or hardly changed, it is possible to maintain the sewing quality and reduce the cost, and it is possible to wind the bobbin around the bobbin without unevenness. It is possible.

The thread guide 92 is provided with a thread guide 92 for guiding the lower thread 150 from the thread spool 200. The thread guide 92 has an elongated hole 92a capable of guiding the lower thread 150 moving in the axial direction during operation.
Is formed, the lower hole 92a guides the lower thread that moves in the axial direction during operation. Therefore, a moving mechanism such as a cam mechanism is not required, and the lower thread
It is possible to provide guidance in 50 axial directions.

Further, since there is provided the yarn tension varying means 204 for varying the tension of the lower thread 150, the yarn tension varying means 2 is provided.
04 makes the tension of the lower thread 150 variable so that an optimal tension is applied to the lower thread during operation. Therefore, it is possible to perform the device operation extremely well.

Further, a yarn detector 222 for detecting the state of the lower cloth arranged in the lower thread supply path, and a discrimination for stopping the winding of the lower cloth based on the state of the lower thread detected by the yarn detector 222. Means 222a.
The yarn detector 222 detects the state of the yarn, for example, the presence or absence of a yarn, the presence or absence of a yarn ball or a seam of a yarn. The lower thread winding operation to the bobbin can be stopped by 222a, and by this stopping operation, for example, a product of stable quality can be provided.

FIG. 17 is a diagram showing another example of an electric circuit to which the yarn tension varying means 204 is applied. In the this example, the solenoid SOL and power supply V is connected in series, between the one terminal a of the power supply V and the solenoid SOL, a series circuit of a switch SW ₁ and the resistor R _1, the switch a series circuit of the SW ₂ and the resistor R _2, a series circuit of a switch SW ₃ and the resistor R _3, circuit connected in parallel is connected.

Therefore, the switches SW ₁ , SW ₂ , SW ₃
Is selectively turned on, the applied voltage applied to the solenoid SOL changes due to the resistance voltage division. That is, the switch S
The solenoid thrust changes according to the selection of W ₁ , SW ₂ , and SW ₃ , and each resistance value and the like are set so that the lower bobbin thread tension is obtained by the change in the solenoid thrust.

Particularly, in this example, the switch S
The selection of W ₁ , SW ₂ , and SW ₃ is made according to the type and thickness of the yarn, so that the lower thread tension can be set more optimally than in the above-described embodiment. I have. Table 2 shows the relationship between the switch, the thread type, and the thread tension.

[Table 2]

The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say, for example, in the above-described embodiment, the yarn detector 222 detects an abnormally thick yarn, for example, the presence or absence of a yarn ball, but the + setting value of the comparator is changed. Alternatively, if a comparator is added, it is possible to detect a case where the yarn is abnormally thin.

Also, in the above embodiment, the bobbin case 8 is chamfered so that the thread 150 led out from the opening 8A can be easily moved to the thread hooking position 8B on the lower thread tension spring side of the bobbin case 8. 8a is performed, but this is for the sake of emergency, and it goes without saying that the effects of the present invention can be obtained without performing the chamfering 8a.

[0073]

As described above, according to the lower thread winding device of the first aspect, the lower thread is clamped by the thread clamp means, and the supply side of the clamped lower thread is opened by the wiper to open the bobbin case. When the take-up shaft rotates, the bobbin thread is wound on the bobbin in the bobbin case. At this time, the yarn end at the beginning of winding is automatically placed in the bobbin case by the opening operation of the thread clamp means. It is stored and the thread ends are not left outside the bobbin case. Accordingly, it is possible to form a good seam and to prevent the occurrence of breakage of the upper thread. In addition, since the bobbin and the bobbin case are not changed at all or hardly changed, it is possible to maintain the sewing quality and reduce the cost, and it is possible to perform the winding of the bobbin on the bobbin neatly without unevenness. Become.

Further, in the lower thread winding device of the sewing machine according to the second aspect,
According to this, the lower thread moving in the axial direction during operation is guided by the long hole of the thread guide. Therefore, it is possible to guide the lower thread in the axial direction with a simple configuration without requiring a moving mechanism such as a cam mechanism.

Further, in the lower thread winding device according to the third aspect of the present invention,
According to this, the tension of the lower thread is varied by the thread tension varying means, and an optimal tension is applied to the lower thread during operation. Therefore,
The device operation can be performed extremely well. Further, for example, it is possible to optimally set the yarn tension according to the type of yarn and the thickness of the yarn.

[Brief description of the drawings]

FIG. 1 is a front view of a lower thread winding device of a sewing machine according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional plan view of FIG.

FIG. 3 is a perspective view of a pulley.

FIG. 4 is a view of FIG. 1 as viewed from the left side.

FIG. 5 is a perspective view of thread handling .

FIG. 6 is a plan view of a thread hook lever.

FIG. 7 is a sectional view of a thread hook lever.

FIG. 8 is a perspective view of a bobbin case employed in the embodiment.

FIG. 9 is a front view of a yarn tension varying means and a yarn detector applied to the embodiment.

FIG. 10 is a front view of a main part showing a yarn clamping operation in an initial state of the device.

FIG. 11 is a front view of a main part showing a bobbin thread winding operation on the bobbin of the above device.

FIG. 12 is a front view of a main part showing a bobbin winding operation and a yarn releasing operation on a bobbin of the same device.

FIG. 13 is a plan view of a main part showing a bobbin thread guiding operation to a slit of a bobbin case of the above device.

FIG. 14 is a plan view of a main part showing a lower thread guiding operation following a lower thread guiding operation to the slit in FIG. 13;

FIG. 15 is an electric circuit diagram to which the yarn detector of FIG. 9 is applied.

FIG. 16 is a diagram illustrating a relationship between a circuit voltage that varies according to a yarn state and a predetermined voltage.

FIG. 17 is a diagram showing another example of the electric circuit to which the yarn tension varying means is applied.

FIG. 18 is a perspective view of a lower thread automatic supply device to which the upper and lower thread winding devices are applied.

FIG. 19 is a front view of FIG. 18 ;

FIG. 20 is a plan view of FIG. 18 ;

FIG. 21 is a side view of FIG. 18 ;

FIG. 22 is a front view showing the relationship between a rotating arm, a forward / reverse lever, and a guide shaft which constitute the automatic upper / lower thread supply device.

DESCRIPTION OF SYMBOLS 7 bobbin 8 bobbin case 8A bobbin case opening 92 thread guide 92a long hole 105 thread clamp means 107 winding shaft 130 wiper 150 bobbin thread 204 thread tension variable means 208 bobbin thread supply path 200 bobbin thread 222 bobbin thread State detection means 222a Control means

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukio Nakamura 8-2, Kokuryo-cho, Chofu-shi, Tokyo Juki Corporation (56) References JP-A-5-192476 (JP, A) JP-A-1 JP-A-91898 (JP, A) JP-A-7-31778 (JP, A) JP-A-53-115461 (JP, A) JP-A-52-92650 (JP, A) Japanese Utility Model Publication No. 54-27855 (JP, U) ) Tokiko Hei 2-2780 (JP, B2)

Claims (3)

(57) [Claims] 1. A bobbin rotatably supported, a thread clamp means capable of clamping and releasing a lower thread, and a lower thread clamped by the thread clamp means is opened to a bobbin case in which the bobbin is built. And a take-up shaft capable of winding the bobbin drawn by the wiper onto the bobbin by applying rotation to the bobbin. And a lower thread winding device for the sewing machine, wherein the thread clamp means is opened. 2. The bobbin thread winding device according to claim 1, further comprising a thread guide for guiding a bobbin thread from the bobbin, which can guide a bobbin thread that moves in an axial direction during operation. Bobbin thread winding device in which a long hole is formed. 3. The lower thread winding device according to claim 1, further comprising a thread tension varying means for varying a tension of the lower thread.