JPH0191898A - Bottom thread winding device in sewing machine - Google Patents

Abstract

PURPOSE: To make automatically windable a bobbin thread to a bobbin and to make removable the bobbin thread remaining on the bobbin by rotating a winding shaft by a second driving means, rotating the bobbin engaged with it and sucking air from the opening part of an air intake pipe near the bobbin. CONSTITUTION: When a bobbin thread winding motor 9 is operated and the winding shaft 12 is rotated together with a turning shaft through gears 10 and 11, the bobbin thread I is wound to the bobbin 5 with a chevron shaped groove 55 guided by the bobbin thread insertion part 13a1 of a guide pin 13a as a winding start position. When a wound thread length reaches a predetermined length, the operation of a driving circuit is stopped and the winding motor 9 is stopped. Then, an advancing/backing motor is rotated in an opposite direction, a guide shaft 13 is backed and the guide pin 13a is pulled out from a housing main body 41. When a scheduled bobbin thread length is used and the sewing of a prescribed cycle is ended, the driving circuit and a relay are operated, an intake source 26 is operated and a slight bobbin thread remaining in the bobbin 5 is sucked out from the opening part 25a of the intake pipe 25 and removed to the outside.

Description

Detailed Description of the Invention [Industrial Application Yf] The present invention relates to a bobbin thread winding device for winding a bobbin thread around a bobbin thread bobbin provided in a lockstitch sewing machine.

[Conventional technology and its problems] Currently, there is a trend in sewing factories to automate various work processes in pursuit of high productivity, and accordingly, industrial sewing machines are also becoming faster and more automated. ing.

However, in the case of sewing machines, which are considered to be the mainstream type of sewing machine*, the bobbin thread must be supplied manually, which prevents complete automation of the sewing process.

In other words, the conventional wood sewing machine has an outer hook that rotates in conjunction with the lower shaft, and an inner hook that is rotatable. A covered bobbin is rotatably mounted.

If the bobbin thread that was wound around the bobbin runs out, remove the bobbin together with the bobbin case from the inner hook, wind the bobbin thread around the bobbin, and attach it to the inner hook again, or use the bobbin thread prepared in advance. It was necessary to perform operations such as replacing the bobbin with a bobbin already wound with the bobbin thread, which required a lot of time and effort.

For this reason, some systems are being considered that automatically supply the bobbin thread as a secondary power source, but in this case,
This requires large-scale modification and addition of mechanisms to the hook and the sewing machine itself, resulting in an extremely complex structure and a significant increase in cost, which is why it has not yet been put into practical use. In addition, in order to completely automate the bobbin thread supply source to the bobbin, in addition to the function that automatically winds the bobbin thread around the bobbin, it is also necessary to automatically remove the small amount of bobbin thread (unused thread) that remains on the bobbin after the sewing operation is finished. Is it necessary to add a function to remove the material outward from the bobbin? For this reason, conventional methods have been proposed to automatically remove the bobbin thread. However, in this case, an extremely complicated mechanism is required and there is a problem in that it is expensive.

The present invention has been made to solve the above-mentioned problems, and it is possible to automatically wind the bobbin thread around the bobbin without having to attach or detach the bobbin, and it requires special changes to the sewing machine itself. Easy to fit into existing sewing machines without the need for
Another object of the present invention is to provide a bobbin thread winding device that can automatically remove bobbin thread remaining on a bobbin with a simple configuration.

[Means for Solving the Problems] The present invention has a bobbin for winding the bobbin that is rotatably supported on an inner hook that is rotatably supported with respect to an outer hook, and A guide shaft for guiding the thread unreeled from the bobbin thread supply source is moved forward and backward by the drive means of 51, and
By advancing the winding shaft, which is held so as to be able to move forward and backward, by the first driving means, the bobbin thread guided by the guide shaft is held between the bobbin and the bobbin, and the bobbin is engaged with the rotation center of the bobbin. an intake pipe having an opening in the vicinity of the bobbin, the winding shaft being rotated by a second driving means, and a bobbin engaged therewith being rotated; The remaining yarn removing means is configured to remove unnecessary yarn remaining on the bobbin by an air suction source that sucks air through the opening of the bobbin.

[Function] In this invention, when the guide shaft and the take-up shaft are advanced by the first driving means, the bobbin thread being let out from the bobbin thread supply source is moved between the bobbin and the take-up shaft that engages with the bobbin. It is held and fixed and guided to the side of the outer peripheral surface of the bobbin. When the second drive means is activated to rotate the winding shaft in this state, the bobbin also rotates, and the bobbin thread starts from the part where it is held and fixed by the bobbin and the winding shaft. It is wrapped around the outer circumferential surface. Furthermore, a small amount of bobbin thread remaining on the bobbin due to the subsequent sewing operation is sucked into the suction pipe by the operation of the suction source and removed outward.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is a lower shaft that rotates according to the rotation of two axes (not shown) that move the needle N up and down, and 2 is an outer hook fixed to this lower shaft l, and a tip 2a on which the needle thread loop is hooked. have Reference numeral 3 denotes an inner hook rotatably supported with respect to the outer hook 2 (see Fig. 11).
h, and then rotate the outer hook 2 around its outer circumference. 4 is the inner pot 3
A hollow cylindrical housing that can be detachably attached to.

Reference numeral 5 denotes a bobbin rotatably supported within the housing 4, and the bobbin 5 and the housing 4 have shapes and configurations as shown in FIGS. 2 to 4.

That is, the outer shell of the housing 4 includes a housing body 41 having a cylindrical shape with a head and a lid portion 42 that closes an opening of the housing body 41. In addition, both members 41 and 42 can be attached and detached from each other, so that they can be assembled and
It also allows for easy internal inspection. Further, the housing main body 41 is provided with a detachable lever 41a and a lock pin 41b that protrude from its outer peripheral surface. After inserting the tip of the detachable lever 41a into the fixing groove 3a formed in the inner pot 3, it is engaged in a predetermined manner. By rotating it to the matching position, the lock bin 41b engages with the inner hook 3, and the housing body 41 is firmly fixed to the inner hook 3.

The winding shaft insertion hole 4]c has a circular shape centered on the rotation center axis C of the bobbin 5, and the slit 41d is formed to communicate the guide shaft insertion hole 41e and the winding shaft insertion hole 41c. has been done. Note that 41h is a lower thread guide for properly guiding the lower thread to a predetermined position during the forward and backward movement of the guide shaft and winding shaft, which will be described later.

The bobbin 5 is rotatably attached via a bearing 51 to a shaft 42a that protrudes inward from the center of the lid portion 42 of the housing 4, and a rotation axis is formed on the side surface thereof. A retaining hole 52 centered at C is formed, and a convex portion 53 is further provided in the engaging hole 52-. Further, the bobbin 5 is provided with a plurality of slits 54 (eight in this case) extending from the side surface to the center of the outer circumferential surface, and furthermore, an annular V-shaped groove 55 is formed in the center of the outer circumferential surface. ing. Note that 56 and 57 are collar portions that prevent the bobbin thread disguised on the bobbin 5 from falling off to the side, and one collar portion 56 has a slit 5 that communicates with the slit 54.
6a is perforated, and the other flange 57 has a
A brake lever 43 provided in the housing yj4 is pressed by a spring 44, which causes the bobbin 5 to
Tension is applied to the bobbin thread being let out from the bobbin 5, and rotation of the bobbin 5 in the opposite direction is prevented.

Note that this pressing force can be adjusted as appropriate by rotating and adjusting the adjustment screw 45, and by pressing the protrusion 43a protruding from the outer peripheral surface of the bobbin body 41 against the spring 44, the brim can be adjusted. The pressing force on the portion 57 can be released.

On the other hand, in FIG. 1, 6 is a base plate 1 provided below the sewing machine bed, 7 is a support stand provided on this base plate 6, and 8 is a rotating wheel rotatably supported by this support stand 7. The take-up motor 9, which is a second driving means supported by the support stand 6, rotates via a gear 10.11, and the center axis of the rotation of the bobbin 5 is It coincides with the dynamic center axis C (see Fig. 5). Reference numeral 12 denotes a winding shaft fitted into the rotating shaft 8, which rotates together with the rotating shaft 8 and can move forward and backward along the same axis 8 (see FIG. 5). Furthermore, the slit 54 of the bobbin 5 is formed on the outer periphery of the tip 12a.
A pin 12a3 is provided which can be engaged with the pin 12a3 (see FIG. 6). Further, reference numeral 13 denotes a guide shaft supported by the support base 7 so as to be movable back and forth, and a guide pin 13a having a bobbin thread insertion portion 13a1 is provided at one end of the guide shaft (see Fig. 5-6).
. The guide pin 13a is located at a position opposite to the guide shaft insertion hole 41e of the housing main body 41, and when the guide shaft 13 moves forward, it is inserted into the guide shaft insertion hole 41e and passes through the bobbin thread insertion portion 13al or the outer circumference of the bobbin 5. It is positioned to the side of the face.

13b is a connecting member that connects the guide shaft 13 and the winding shaft 12, and the connecting member 13b allows both shafts 12 and 13 to move forward and backward.

Reference numeral 14 denotes a forward/reverse motor as a first driving means attached to the support base 7, and the motor shaft includes:
A rack 13c formed in the elongated direction on the guide shaft 13 and +
Four matching gears 14a are fixedly installed (see Fig. 5).

Further, reference numeral 15 denotes a bobbin thread pull-out lever which is rotated about a shaft 17 by a bobbin thread pull-out motor 16 from a lateral position n of the guide pin 13a to a lateral position of the winding shaft 12, and has a V-shaped tip at one end. The bobbin thread hooking portion 15a is formed into a forked shape (see FIG. 11). Reference numeral 18 denotes a cutter provided on the side of the winding shaft 12, and a fitting portion 18a that fits into the bobbin thread hooking portion 15a of the bobbin thread pull-out lever 15 is provided in the center of the cutter.
A knife 18b held by the fitting portion 18a is provided (see FIG. 11).

Reference numeral 19 denotes a bobbin brake release solenoid provided on the lower surface of the base plate 6. A brake release rod 21 protruding from the upper surface of the base plate 6 is fixed to the tip of a plunger 20 provided on the solenoid 19. When the plunger 20 is protruded by the operation of 19, the brake rod 21 is moved to the protrusion 43 of the brake lever 43 provided on the housing 4.
By pressing a, the pressing force applied to the bobbin 5 is released. Note that 22 and 23 pass the bobbin thread I fed out from the bobbin thread supply source 24 to the bobbin thread insertion portion 13a of the guide bin 13a.
This is a bobbin thread guide that guides the thread to l.

In addition, 25 is an intake 2 connected to an external intake source 26.
A tube (see FIG. 16) has a distal end 25a inserted into the guide pin 13 near the guide shaft insertion hole 41e of the housing 4.
It is arranged so as not to interfere with a. Further, in this embodiment, the intake pipe 25 has a shape and configuration as shown in FIG. That is, the intake pipe 25 has a circular intake port 25a, and a plurality of pairs of small holes 25b facing each other are bored at equal intervals in the peripheral wall of the distal end portion.

FIG. 9 is a block diagram showing the control circuit in this embodiment.

In the figure, 27 is the CPU 27a, RAM 27b, RO
A well-known microcomputer comprising M27c and I10 boats 27d, 27d, etc., 28, 28.28 is a drive circuit comprising a transistor array, etc., to which the motors 9.14.16 and solenoid 19 are connected. In addition, 29 is the length of the bobbin thread that should be disguised as the bobbin 5, etc.
There is an operation display device for inputting and displaying various data related to sewing, and the input data is sent to I10 boats 27d and C.
The data is stored in the RAM 27b via the PU 27a. In addition, 3
0 is a thread absence detection sensor that detects whether or not the bobbin 5 is disguised as a bobbin thread. 31 is operated by the drive circuit 28 based on the above configuration, and the operation thereof will now be explained with reference to the flowchart of FIG. 1O and the operation diagrams of FIGS. 11 to 16.

When the automatic motor is set by the operator or by the input device 2t29, step 1), the CPU 27a receives the setting data and initializes each part (step 3), thereby controlling the winding motor 9 and the winding shaft 12. Groove 12a at its tip
1 is aligned and held in a predetermined orientation. Next, the operator pulls out a certain length of the bobbin thread I from the thread supply source 24 and inserts it into each bobbin thread guide 22゜2.
3, the lower thread insertion part 13al of the guide bin 13
is inserted into the groove 12a1 of the winding shaft 12 (see FIG. 11). After this, if the operator sets the length of the bobbin thread ■ that should be disguised as the bobbin 5, for example the length (thread length) required for one cycle of sewing, and inputs that information, the thread length data will be stored in the RAM 27b. (Step 4).

Here, when the bobbin winding start digit is input, the CPU 27a activates the drive circuit 28 to rotate the motor 14 for one forward and backward movement in the forward direction (step 6). Due to this forward rotation, gear 1
4a sends the rack 13c forward to advance the guide shaft 13 and the winding shaft 12 connected thereto. As a result, the winding shaft 12 is inserted into the housing main body 4 through the winding shaft insertion hole 41c, and further engages with the engagement pin 12a3 provided at its tip 12a and the slit 56a of the bobbin 5, and finally winds the winding shaft 12. The concave portion 12a2 of the shaft 12 fits into the convex portion 53 of the bobbin 5. Further, the guide shaft 13 is inserted into the housing main body 4 through the guide pin 13a or the guide shaft insertion hole 41e, and finally the bobbin thread insertion portion 13a1
is located on the side of the outer peripheral surface of the bobbin 5. As a result, the bobbin thread I held in the groove 12a1 of the winding shaft 12 is held and fixed between the convex portion 53 and the concave portion 12a2, and the bobbin thread I is held in the groove 12a1 of the winding shaft 12. It is inserted into the slit 56a and guided to the side of the outer peripheral surface of the bobbin 5 (in this case, to the side of the 7-shaped groove 55) by the lower thread insertion portion 13al of the guide bin 13a (see FIG. 12).

Next, the bobbin thread winding motor 9 is operated, and the gear 10.11 is
The winding shaft 12 is installed together with the rotating shaft 8 through the drive circuit 28 when the camouflaged yarn length reaches a predetermined length.
, and the take-up motor 9 is stopped (step 7). When the take-up motor 9 is stopped, the CPU 27
a operates the drive circuit 28 to rotate the forward/reverse motor 14 in the opposite direction, causing the guide shaft 13 to move backward and move the guide bin 13a.
is pulled out from the housing body 41 (step 8). As a result, as shown in FIG.
It is located on the moving path of the lower thread hooking part 15a. After this,
The CPU 27a operates the drive circuit 28 to drive the bobbin thread pull-out motor 16. As a result, the bobbin thread pull-out lever 15 rotates and moves while hooking the bobbin thread I on the moving path with the bobbin thread hooking part 15a and pulling out the bobbin thread ■ from the bobbin thread supply source 24, as shown in FIG. It fits into the fitting portion 18a of the cutter FlrW18 (step 9).

As a result, the lower thread I is divided by the knife 18b into a portion extending from the lower thread hooking portion 15a to the lower thread supply source 24 and a portion extending to the bobbin, and the portion leading to the lower thread supply source 24 is separated from the winding shaft. It is inserted into the groove 12al formed in the tip 12a of the 12 and held.

With the above steps, the winding operation onto the bobbin 5 is completed.

Thereafter, when the operator starts sewing, the lower shaft 1 rotates together with the upper shaft, and a well-known wood sewing operation is performed (step 10). Then, when the planned bobbin thread length is used and a predetermined cycle of sewing is completed, the CPU 27a causes the drive circuit 28 to
and actuating the relay 31 to actuate the intake source 26,
A small amount of the bobbin thread remaining on the bobbin 5 is sucked out from the opening 25a of the suction pipe 25 and removed to the outside of the bobbin 1 (step 11).
). As a result, the operator can remove the unnecessary bobbin thread ■ remaining on the bobbin 5 without any trouble, and in addition to the automatic thread winding operation described above, the automation can be more fully executed. can. Moreover, in this example,
The small hole 25b provided in the peripheral wall of the intake pipe 25 allows the intake pipe 2
5 to generate turbulence by changing the direction of the airflow inside the bobbin thread I.
It is designed to increase the suction power of.

That is, when the intake pipe 25 without the small hole 25b is used as shown in FIG. 8(c), the intake 'l
? The airflow inside the intake pipe 25 becomes laminar, whereas when the small hole 25b is provided as shown in this embodiment, the airflow inside the intake pipe 25 becomes laminar.
The airflow inside becomes turbulent (see Figure 8 (d) in Figure 5). Generally, when a fluid changes from laminar flow to turbulent flow, the axial direction of objects present in the fluid (in this case, the central axis direction of the intake pipe 25)
The thrust force increases rapidly from the static viscous resistance of the fluid (air in this case) to the resistance force due to dynamic flow energy. Therefore, the suction force is greatly increased compared to the case where the small hole 25b is not provided in the bobbin threader, and the bobbin thread can be removed reliably. Figure 8(e), (D, (g)
) is a diagram showing the situation in which the bobbin thread I is suctioned; (e) shows the state before suction, (f) shows the initial state, and (g)
indicate the state after suction, and in this example, the eighth
In both cases (f) and (g), the effect of increasing attraction is noticeable even in cases of single-person crime.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment of fJS2, the shape of the tip of the intake pipe 25 is circular in the first embodiment, but the shape of the tip is oval, and furthermore, only the short diameter portion of the peripheral wall of the tip is opposed to each other. A plurality of pairs of small holes 25b are bored.

According to this, the initial suction of the yarn at the long diameter portion can be made easier, and since the spacing between the small holes facing each other is small, a more powerful airflow can be sucked from the small holes 25b. The thread gripping force can be improved. In this case, it is desirable to form a curved surface with as large a curvature as possible on the edge of the opening facing outward.

FIG. 18 is a diagram showing a third embodiment of the present invention. In this third embodiment, the pair of small holes 25b or 25b' in the first or second embodiment are shifted in the axial direction from the opposing positions and arranged alternately. According to this, it is possible to generate greater turbulence in the intake pipe 25, and even when using a small diameter intake pipe or using a thick thread, sufficient turbulence can be generated. I can do it.

[Effects of the Invention] As explained above, according to the present invention, the lower thread can be automatically wound around the bobbin without attaching or detaching the bobbin, and there is no need to make any special changes to the sewing machine itself.
It is easily compatible with existing sewing machines, and has the effect of being extremely versatile.Furthermore, it has an extremely inexpensive and simple structure in which the suction tube connected to the suction source is placed on the side of the bobbin, which allows the bobbin thread to be removed. It also has the effect of being able to be removed reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a plan view of a housing and bobbin applied to this embodiment, and FIG. 3 is a partially cutaway side view of the same as shown in FIG. 2. , FIG. 4 is a longitudinal cross-sectional side view of what is shown in FIG. 2, and FIG.
FIG. 1 is a partial cross-sectional side view showing the surrounding structure of the guide shaft and the winding shaft, FIG. 6 is a partial longitudinal side view of the winding shaft shown in FIG. 5, and FIG. 5 is a side view showing the guide pin shown in FIG. 5, and FIG. 8 is a diagram showing the configuration of the suction tube in this embodiment. (C) is an explanatory longitudinal side view showing the flow of airflow in the suction tube without small holes, and (d) is an explanatory longitudinal side view showing the flow of airflow in the suction tube shown in Fig. 1 (a).
Figures (e), (f), and (g) are diagrams showing the lower thread suction state of the machine shown in Figure (a). FIG. 9 is a block diagram showing the control circuit in this embodiment, and FIG.
Flowcharts in this embodiment, FIGS. 11 to 16 are cross-sectional plan views showing the main operations of the system shown in FIG. 1, and FIG. 17 is a diagram showing a second embodiment of the present invention.
Figure (a) is a front view, and Figure (b) is a longitudinal side view. FIG. 18 is a longitudinal sectional side view showing a third embodiment of the invention. 3 ... ... Inner hook 5 ... ... Bobbin 9 ... ... Winding motor (second drive means) 1
2 ... ... Winding shaft 13 ... ... Guide shaft 14 ... ... Forward and backward motor (first drive means) 26 ... ... Air intake source 25 ... ... ... Name of intake pipe applicant Kozo Hanzuka Director of Agency of Industrial Science and Technology Figure 2 41d'' Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 (e) (f) (()
) (Q) (b) Figure 9 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 (a) (b) Figure 18

Claims (3)

[Claims] (1) An inner hook rotatably supported by an outer hook that rotates as the lower shaft rotates, a bobbin for winding the bobbin thread that is rotatably supported by the inner hook, and a predetermined support. a guide shaft that is held in the body so as to be movable back and forth and guides the bobbin thread paid out from the bobbin thread supply source to the side of the outer peripheral surface of the bobbin when moving forward; The bobbin thread is held and rotatably held about the rotation center axis, and when moving forward, one end engages with the bobbin and the bobbin thread guided by the guide shaft is clamped and fixed between the bobbin and the bobbin. a winding shaft, a first driving means for moving the guide shaft and the winding shaft back and forth, and a second driving means for rotating the winding shaft; A residual yarn removing means is provided for removing the residual yarn, and this residual yarn removing means is composed of an intake pipe whose opening end is located near the bobbin, and a suction source that sucks air from the opening of the intake pipe. Features of the sewing machine's bobbin thread winding device. (2) A bobbin thread winding device for a sewing machine according to claim 1, wherein the suction pipe has a small hole formed in the peripheral wall of the distal end thereof. (3) A bobbin thread winding device for a sewing machine as set forth in claim 2, wherein a plurality of small holes are formed at opposing positions on the peripheral wall of the distal end portion.