JP3838681B2 - Lower thread winding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lower thread winding device for winding a lower thread around a bobbin.
[0002]
[Prior art]
In a sewing machine that performs sewing using an upper thread and a lower thread, particularly an industrial sewing machine that performs high-speed sewing work, it is necessary to frequently replace the bobbin around which the lower thread is wound. Generally, when the bobbin thread is consumed or when the remaining capacity is low, the sewing machine operation is temporarily stopped, the bobbin case is removed from the hook, the bobbin remaining thread is removed, and the bobbin is wound around the bobbin. The newly wound bobbin is housed again in the bobbin case, the wound lower thread is threaded onto the bobbin case, and the lower thread led out from the bobbin case is cut to leave a predetermined length. A series of operations such as mounting in the hook are performed manually.
[0003]
In a sewing machine that performs sewing using an upper thread and a lower thread, particularly an industrial sewing machine that performs high-speed sewing work, it is necessary to frequently replace the bobbin around which the lower thread is wound. Generally, when the bobbin thread is consumed or when the remaining capacity is low, the sewing machine operation is temporarily stopped, the bobbin case is removed from the hook, the bobbin remaining thread is removed, and the bobbin is wound around the bobbin. The newly wound bobbin is housed again in the bobbin case, the wound lower thread is threaded onto the bobbin case, and the lower thread led out from the bobbin case is cut to leave a predetermined length. A series of operations such as mounting in the hook are performed manually.
[0004]
However, such residual thread removal work, manual bobbin winding work, bobbin threading work, thread trimming work, and bobbin case replacement work are very inefficient and cause a reduction in productivity. Yes.
Therefore, the present applicant automatically performs the above-described residual thread removing work, lower thread winding work, threading work, thread trimming work, and bobbin case replacement work in JP-A-7-68071 filed earlier. We have proposed an automatic bobbin feeder for the purpose.
[0005]
This bobbin thread automatic supply device includes a bobbin exchanging device that holds a bobbin case containing a bobbin and moves along a predetermined path, and removes the remaining yarn from the bobbin housed in the bobbin case. Bobbin case wound around a bobbin, a bobbin case wound around a bobbin by inserting a bobbin thread from a bobbin case opening through a bobbin case opening by inserting a bobbin thread from a bobbin case opening device A thread hooking device for catching a lower thread led out from an opening and rotating the periphery of the bobbin case so that the lower thread wound around the bobbin is led out from a predetermined position of the bobbin case, and the bobbin case A thread trimming device that cuts the lower thread derived from the predetermined position, leaving a predetermined length.
[0006]
[Problems to be solved by the invention]
In the lower thread winding device described in the above-mentioned JP-A-7-68071, the bobbin and the bobbin case are not separated and the lower thread winding operation is performed in the stored state. However, as is apparent from FIGS. 23 and 24 of Japanese Patent Laid-Open No. 7-68071, the present invention provides a bobbin for entanglement between the thread supply source and the bobbin when winding the lower thread.IsKey-shaped thread hookMaterials andVGrooveIs provided. That is, a bobbin having no versatility is used.
[0007]
Also, when performing the initial work of entwining the lower thread from the thread supply source to the bobbin, and the winding work of rotating the bobbin and winding the lower thread after the lower thread has entangled with the bobbin, U-shaped part engaged with lower threadMaterial (The engaging member is a bobbin cageSusIt is fixed near the opening. However, the initial work of entwining the lower thread around the bobbin differs from the winding work of winding the lower thread by rotating the bobbin. That is, in general, the engagement member should be closer to the bobbin case opening in order to ensure that the initial operation is entangled with the lower thread. On the other hand, in the winding operation, in order to uniformly wind the lower thread around the bobbin, the engaging member should be far from the bobbin case opening.
[0008]
Accordingly, the lower thread winding device described in JP-A-7-68071 is a U-shaped portion.Material (The bobbin thread was not uniformly wound due to the positional relationship between the engaging member) and the bobbin and the special shape of the bobbin. The present invention has been made to solve the above problems. That is, it is a first object to provide a lower thread winding device that uses a general-purpose bobbin to surely entangle a lower thread around the bobbin and uniformly wind the lower thread around the bobbin.
[0009]
In addition, when the lower thread between the bobbin case and the thread supply nozzle is cut after winding the lower thread, a predetermined length of lower thread is secured on the bobbin case side in order to form a seam. A second object is to move the yarn supply nozzle when cutting the yarn so that the lower yarn of a predetermined length is led out from the yarn supply nozzle in order to entangle the yarn supply source and the bobbin.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1
A bobbin case that rotatably supports the bobbin and has an opening at a predetermined position;
Bobbin rotating means for rotating the bobbin mounted on the bobbin case;
The tip side is bent toward the bobbin case opening,From the lower thread sourceThe lower thread is insertedA thread supply nozzle that can lead out the lower thread from the nozzle tip and supply the lower thread to the bobbin;
A motor that rotates around the rear end side of the yarn supply nozzle to move to an initial work position, a winding work position, and a yarn cutting position;
A tension spring that is provided between the lower thread supply source and the thread supply nozzle and applies tension by pressing the lower thread;
A solenoid for generating a thrust against the pressing force of the tension spring;
  A moving knife threading arranged to be rotatable around the bobbin case;,
  A fixed knife capable of cutting a thread in cooperation with the moving knife threading,
A threading step of rotating the moving knife threading to guide the lower thread led out from the bobbin case opening and reaching the thread supply nozzle so as to be led out from the vicinity of the lower thread tension spring hole is performed.In the lower thread winding device,
The yarn supply nozzle,
An initial work position where the yarn guide air is blown and the bobbin shaft is entangled with the lower yarn end portion derived from the tip of the yarn supply nozzle;
One end is entangled with the bobbin shaft, and the other end is wound around the bobbin thread by rotating the bobbin against the bobbin thread led out from the thread supply nozzle.Perform the bobbin winding processWinding work position;
A yarn cutting position for performing a lower yarn cutting step of cutting a lower yarn between the bobbin case and the yarn supply nozzle;And move it to
The winding work position is located at a position spaced apart from the initial work position by a predetermined amount, and the yarn supply nozzle tip is in contact with the bobbin shaft and connects the bobbin case opening end and the bobbin case maximum winding. The second straight line connecting the outer diameter of the bobbin case and the end of the bobbin case opening is located in an area defined by,and,
During the bobbin winding process, the thrust of the solenoid is generated to minimize the bobbin thread tension, and during the threading process, threading is performed in a state where the thrust of the solenoid is eliminated and the bobbin thread tension is maximized. A bobbin thread winding device characterized by that.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
First, an embodiment in which the embodiment of the present invention is applied to a lower thread automatic supply device will be described in detail with reference to the drawings.
As shown in FIG. 1, the lower thread automatic supply device of the present embodiment is schematically configured from a lower thread winding device 162, a residual yarn removing device 161, and a bobbin changing device (bobbin case moving means) 160. The bobbin exchanging device 160 includes a lower thread winding position C of the lower thread winding apparatus 162, a remaining thread removing position B of the remaining thread removing apparatus 161, a shuttle position (bobbin case attaching / detaching position) A, a dummy shaft (bobbin case The bobbin case 2 is moved to the bobbin case attaching / detaching position D of the holding means 6. As shown in FIG. 1, the lower thread winding position C and the remaining thread removal position B are the rotation fulcrum 103 when the sewing machine bed 101 is raised from the upright plane along the range V below the conveying shaft 4 and the coaxial line. It is the range W on the side, and is disposed at a position opposite to the rotation locus of the bobbin case gripping means. The remaining yarn removal position B is arranged below the lower yarn winding position C. Further, the position of the remaining yarn removal position B in the conveyance axis direction (direction perpendicular to the paper surface in FIG. 1) is a position slightly advanced from the retracted position of the bobbin case gripping means (the reflection type optical sensor 500 detects the rotation of the bobbin 7). The position of the lower thread winding position C in the conveyance axis direction is a position where the bobbin case gripping means is slightly advanced from the retracted position at a position advanced as much as possible (details will be described later); a position advanced toward the paper surface in FIG. (Position advanced toward the paper surface in FIG. 1).
[0016]
The lower thread automatic supply device is provided in the lower part of the sewing machine bed 101. First, the bobbin exchanging device 160 will be described below with reference to FIGS.
2 to 6, reference numeral 1 denotes a hook to which the bobbin case 2 is mounted, reference numeral 1 a denotes a hook shaft, and reference numeral 3 denotes a main base attached to the sewing machine body, and is arranged directly below the hook 1. A base plate as a support is shown. A base end 4a of a transport shaft 4 having an axis parallel to the shuttle shaft 1a is fixed to the base plate 3, and the transport shaft 4 is It is in a state where it is cantilevered.
[0017]
A transport block 12 is supported on the transport shaft 4 on the front end 4 b side (on the side opposite to the base plate) so as to be rotatable and slidable with respect to the transport shaft 4. As shown in FIG. 2 in particular, the transport block 12 has a shape formed by cutting the outer peripheral surface of the cylinder at two locations along the axial direction so that the cut surfaces face each other. On each cut surface of the conveyance block 12, one plate-like portion constituting the L-shape of the conveyance plates 10 and 10 bent in an L-shape is fixed. Moreover, the other plate-shaped part which comprises L shape is in the state which mutually opposed across the axis.
[0018]
One end of each of the holding portions 11 and 11 bent so as to extend to the shuttle side along the axial direction is fixed to each of the transport plates 10 and 10. Bobbin case gripping means (not shown) for gripping or opening the bobbin case is fixed to the other end (the end facing the shuttle). As the bobbin case gripping means, for example, an automatic lower thread supply device disclosed in Japanese Patent Application Laid-Open No. 5-192476 or an automatic lower thread supply device of a sewing machine disclosed in Japanese Patent Application No. Hei 5-121960 previously filed by the present applicant. As well as a pair of electromagnet attracting heads that have been used, for example, by means of a lever claw described in the lower thread automatic feeding device of the sewing machine of Japanese Patent Application No. 5-116363 previously filed by the present applicant, etc. What is essential is that the bobbin case 2 can be attached to and detached from the opposing member (for example, the hook 1) as necessary.
[0019]
1 to 6 again, a rotating gear 13 is fixed to the outer periphery of the conveying block 12, and the rotating gear 13 extends along the hook shaft 1a direction as shown in FIG. The drive gear 19 having an elongated shape is engaged. One end of the drive gear 19 is rotatably supported by the portion of the motor fixing plate 21 attached to the base plate 3 that protrudes to the other end of the conveying shaft, and the other end is fixed to the motor fixing plate 21. In this state, the rotation motor 20 is directly connected to the output shaft.
[0020]
Accordingly, when the rotation motor 20 rotates, a rotation arm 70 as a rotation means composed of the conveyance block 12, the conveyance plates 10 and 10, and the holding portions 11 and 11 is connected via the drive gear 19 and the rotation gear 13. It is designed to rotate. In the present embodiment, the rotating arm 70 is rotated when the rotating arm 70 is in the retracted position (see FIGS. 3 to 5). Further, although the transport shaft 4 is cantilevered, since it is guided by the drive gear 19, its supporting strength is sufficient.
[0021]
For example, a stop ring (not shown) is fixed to the fixed end side of the conveying shaft 4 from the rotating gear 13 on the outer periphery of the conveying block 12, and the rotating gear 13 and the stop ring on the outer periphery of the conveying block 12 are fixed. In between, the linear motion collar 14 is rotatably supported.
As shown in FIGS. 2 to 4, one end of a rack 16 supported so as to be movable in parallel with the shuttle shaft 1 a is fixed to the linear movement collar 14, and a pinion is attached to the other end of the rack 16. 17 meshes. The pinion 17 is fixed to the output shaft of the moving motor 18 attached to the base plate 3.
[0022]
Therefore, when the moving motor 18 is driven, the linear collar 14 and the rotating arm 70 are moved along the axial direction of the transport shaft 4 together with the rack 16 via the pinion 17. That is, the rotating arm 70 can rotate with respect to the transport shaft 4 and can slide along the transport shaft 4.
A sensor fixing plate 33 is attached to the open end side of the transport shaft 4, and a rotation sensor 31 including a light emitting element 31 a and a light receiving element 31 b is attached on the sensor fixing plate 33. Further, as shown in FIGS. 2 and 3, a sensor plate 32 is fixed to the rotating arm 70. When the rotating arm 70 rotates, the sensor plate 32 has a light emitting element 31a and a light receiving element 31b. The position of the rotation sensor 31, the sensor fixing plate 33, and the sensor plate 32 is adjusted so as to pass between the two.
[0023]
As shown in FIGS. 2 and 4, a linear motion sensor 41 having the same structure as the rotation sensor 31 is attached to the base plate 3. A sensor plate 15 is fixed to the rack 16, and the sensor plate 15 can pass between the light emitting element 41 a and the light receiving element 41 b of the linear motion sensor 41 when the rotating arm 70 is linearly moved. As described above, the positions of the linear motion sensor 41 and the sensor plate 15 are adjusted.
[0024]
That is, when the bobbin case gripping means is moved to the retracted position, the sensor plate 15 shields between the light emitting element 41a and the light receiving element 41b of the linear motion sensor 41, whereby the bobbin case gripping means is retracted. Movement to is detected. This time, the origin position is searched for at the retracted position. That is, if the bobbin case holding means is rotated at the retracted position and the position where the sensor plate 32 shields between the light emitting element 31a and the light receiving element 31b is set as the origin position, for example, the bobbin case holding means is rotated to this position. Then, it will return to the origin position. Further, when a pulse motor, for example, is used as the rotation motor 20, the bobbin case gripping means is connected to the hook position A, the lower thread winding position C, the remaining thread by counting the number of pulses of the pulse motor. The rotation can be controlled to the removal position B, the first position B1, the second position B2, and the dummy position D.
[0025]
A dummy shaft 6 as a bobbin case holding means is fixed at a position opposite to the rotation trajectory of the bobbin case gripping means on the base plate 3 and at a position D just below the hook 1 as shown in FIG. ing. As shown in FIG. 6, the dummy shaft 6 has the same structure as the inner hook shaft 5 so that the bobbin case 2 can be held by pushing the bobbin case 2 in which the bobbin is accommodated. It has become. Then, the existing bobbin locking claw 2d of the pushed-in bobbin case 2 is configured to engage with a locking groove of a rotation preventing member 5aa projecting in the vicinity of the dummy shaft 6 as shown in FIG. Has been. That is, the bobbin case 2 is positioned and held at a predetermined position.
[0026]
A residual yarn removing device 161 is disposed at the residual yarn removing position B. Regarding this residual yarn removing device 161, Japanese Patent Application No. 7-67026, filed earlier by the present applicant.Figures 47 and 48The following can be used. This is composed of a pair of rollers, a remaining yarn winding motor, and an air-discharge nozzle for guiding the remaining yarn to a predetermined position. When the remaining yarn winding motor rotates in one direction, one of the rollers is separated from the other. When the remaining yarn winding motor rotates in the opposite direction, the pair of rollers approach each other, and eventually both rollers rotate. At this time, the remaining yarn from the bobbin case is sandwiched between the rollers, and the remaining yarn is discharged toward the lower portion of the remaining yarn removing device.
[0027]
Further, a lower thread winding device 162 is disposed at the lower thread winding position C. As the lower thread winding device 162, for example, an apparatus capable of automatically winding the lower thread around the bobbin by rotating the bobbin by driving a motor or the like is employed. The lower thread winding device 162 includes a bobbin drive mechanism E, an air guide mechanism G, and a thread supply detection mechanism F, as shown in a simplified manner in FIG. First, the bobbin driving mechanism E will be described below.
[0028]
9, 10, and 15, reference numeral 50 denotes a winding shaft, and the winding shaft 50 is rotatably supported on the base plate 3. A clutch mechanism 50a that can be engaged with a plurality of holes 7b (see FIG. 7) formed in the bobbin 7 is fixed to one end of the winding shaft 50, and a pulley 50b is fixed to the other end. A bobbin driving motor M2 as a bobbin rotating means is also fixed to the base plate 3. A pulley 52 is fixed to the output shaft of the bobbin drive motor M2, and a belt 51 is stretched between the pulley 52 and the pulley 50b.
[0029]
That is, when the bobbin case 2 that has reached the lower thread winding position C due to the rotation of the rotating arm 70 is slightly advanced by the forward movement of the rotating arm 70 and the bobbin driving motor M2 is driven, the winding shaft 50 rotates. The clutch mechanism 50a and the bobbin 7 are connected. The clutch mechanism is not limited to a configuration that engages with the hole as described above, and may have another configuration.
[0030]
Further, the lower thread winding device 162 includes a thread supply detection mechanism F that detects the entanglement of the lower thread on the bobbin shaft and the amount of lower thread wound around the bobbin. The yarn supply detection mechanism F will be described below. 11 and 12, reference numeral 53 indicates a U-shaped base, and a roller shaft 55 is rotatably spanned between both side plates 53a and 53b of the base 53. An end portion of the roller shaft 55 on the side plate 53b side protrudes outward from the side plate 53b, and a roller 54 around which the lower thread 150 from the thread winding 200 is wound (one turn) is fixed to the end portion. ing.
[0031]
A sensor slit 58 is fixed to a portion of the roller shaft 55 between both side plates 53a and 53b. The sensor slit 58 has a disc shape and is provided with a groove in a part of the outer periphery. A photo sensor 60 is disposed at a position opposite to the sensor slit 58 so that the groove of the sensor slit 58 can be detected. That is, the rotation of the roller 54 can be detected by the photosensor 60.
[0032]
The photosensor 60 is connected to an effective lower thread winding amount detecting means 61 that detects the entanglement of the lower thread 150 on the bobbin shaft and detects the effective lower thread winding amount wound around the bobbin shaft. The effective lower thread winding amount detecting means 61 is connected to a determining means 61B. This determination means 61B is configured to input the lower thread winding amount connected to the outside and set the lower thread winding amount from the means 61A and the lower thread actually wound around the bobbin from the effective lower thread winding amount detection means 61. When the two bobbin thread amounts coincide with each other, it functions to send a drive stop signal to the driver 310a of the bobbin drive motor M2. Such effective lower thread winding amount detection means 61 and determination means 61B are incorporated in a thread winding device control means 401 (not shown).
[0033]
Further, downstream of the yarn supply detection mechanism F, the yarn is inserted to guide the lower thread 150 from the bobbin winding 200 (see FIG. 13) as a lower thread supply source into the bobbin case 2 through the opening 2A of the bobbin case 2. An air guide mechanism G is provided as means. The air guide mechanism G will be described below. 9, 10, and 14, reference numeral 65 indicates a substantially hollow cylindrical thread suction device. As shown in FIG. 14, the thread suction device 65 has a through hole 65 b as a linear path. In addition, a suction hole 65a is formed in the middle of the through-hole 65b so as to be obliquely connected and opened to the outside. As shown in FIGS. 9 and 10, one end of an air tube 66 is connected to the opening on the upstream side of the through hole 65 b, and a flow rate control type electropneumatic is connected to the other end of the air tube 66. A proportional valve 68 is connected to the electropneumatic proportional valve 68 and an air source (not shown) is connected. Further, one end of a yarn supply nozzle (yarn supply means) 67 is connected to the opening on the downstream side of the through hole 65b in the yarn suction device 65, and this yarn supply noseLe (The other end side (tip end side) of the yarn supplying means 67 is bent in a U shape. Furthermore, the nozzle diameter of the yarn supply nozzle 67 is 3 to 4 mm.
[0034]
As shown in FIGS. 9 and 10, the yarn suction device 65 is fixed to the nozzle shaft 34, and the nozzle shaft 34 is rotatably supported by the base plate 3. A nozzle gear 35 is fixed between the yarn suction device 65 and the base plate 3 in the nozzle shaft 34, and a nozzle motor gear 36 is engaged with the nozzle gear 35. The nozzle motor gear 36 is fixed to an output shaft of a stepping motor 37 as an air nozzle retracting motor fixed to the base plate 3.
[0035]
Accordingly, when the stepping motor 37 is driven, the yarn suction device 65 and the yarn supply nozzle 67 rotate with the nozzle shaft 34 as a rotation fulcrum. Further, the rotational position of the yarn supply nozzle 67 at this time is detected by a sensor plate 38 fixed to the nozzle gear 35 and a nozzle sensor 39 which is fixed to the base plate 3 and detects the position of the sensor plate 38. The stepping motor 37 is controlled according to the detection result.
That is, by driving the stepping motor 37, the tip 67a of the yarn supply nozzle (yarn supply means) is moved to the initial work position N1, the winding work position N2, and the yarn cutting work position N5 shown in FIG. The yarn cutting work position N5 is located between the initial work position N1 and the winding work position N2.
[0036]
The initial operation position N1 is a position facing the opening 2A of the bobbin case 2, and performs an operation of entwining the lower thread 150 from the lower thread supply source 200 to the bobbin shaft 7a. By the way, when the lower thread is entangled with the bobbin shaft 7a, the lower thread of a predetermined length is led out from the thread supply nozzle tip portion 67a located at the initial working position. The lower thread length (LL) derived from the thread supply nozzle tip 67a is set to a length necessary for entangled the derived lower thread end with the bobbin shaft. And this required length is {circle around (1)} {(length from the air nozzle at the working position to reach the outer periphery of the bobbin shaft) + [bobbin shaft circumferential length × (1.1 to 2.0)]} It is preferable that it is in the range of {circle around (2)}, {circle around (2)} {(length from the air nozzle at the working position to reach the outer periphery of the bobbin shaft) + [bobbin shaft full length × (1.25 to 1.8)]} More preferably in the range.
[0037]
If it is longer than the range of (1), it will be difficult for the lower thread end portion to enter from the opening 2A of the bobbin case 2 or even if it enters, it will circulate the bobbin shaft 7a one or more times to form its own knot. The bobbin shaft 7a may be bound, and if it is shorter than the range of (1) or (2), the lower thread end portion may be twisted around the bobbin shaft 7a.
In the present embodiment, the required length is set to 55 mm. That is, the distance H between the tip of the air nozzle 67a and the opening 2A of the bobbin case 2 is 7 mm, the length of the bobbin case opening 2A in contact with the outer periphery of the bobbin shaft is 7 mm, and the bobbin shaft periphery is 25 mm × 1.64. I asked for it.
[0038]
The lower thread guide direction (air blowing direction) of the yarn supply nozzle tip 67a located at the initial operation position N1 is on the bobbin shaft lower thread winding side. As shown in FIGS. 16 and 17, the bobbin shaft lower thread winding side referred to here is an outer periphery of the bobbin shaft 7a divided into two by a line segment YY connecting the center of the bobbin shaft 7a and the thread supply nozzle tip 67a. One direction, that is, the side where the lower thread 150 is entangled with the bobbin shaft 7a (the direction indicated by the symbol XX in FIG. 17). The lower yarn guiding direction of the yarn supply nozzle tip 67a is preferably a direction intersecting the outer periphery of the bobbin shaft 7a on the bobbin shaft lower yarn winding side XX, and particularly preferably a direction in contact with the outer periphery of the bobbin shaft 7a.
[0039]
Then, the distance H between the yarn supply nozzle tip 67a (at the initial working position N1) and the opening 2A of the bobbin case 2 stopped at the position opposite to the bobbin case opening 2A (see FIG.16Is preferably 10 mm or less, particularly preferably 3 to 7 mm. By this range, the fluttering of the lower thread 150 due to the blowing air can be suppressed, and a vortex required for the lower thread 150 to be entangled with the bobbin shaft 7a in the bobbin case 2 can be formed.
[0040]
Further, when the surface treatment is performed on the outer periphery of the bobbin shaft 7a, the lower thread entanglement operation (the operation of forming the cross point with the lower thread tip portion turning around the bobbin shaft outer periphery 7a) at the initial operation position N1 becomes more reliable. This surface treatment of the outer periphery of the bobbin shaft is to increase the friction coefficient of the outer periphery of the bobbin shaft. And, for example, sandblasting is performed using abrasive particles # 60 to # 100 on the bobbin shaft of an aluminum alloy, plasma spraying processing is performed on the bobbin shaft to make the outer surface of the bobbin shaft a surface roughness R50 to 100 micrometers, For example, sandpapers Nos. 120 to 240 are attached to the outer periphery of the bobbin shaft.
[0041]
Next, the winding work position N2 will be described with reference to FIG.
In the figure, I indicates the bobbin rotation direction, and 0 indicates the rotation direction of the yarn supply nozzle 67 as the yarn supply means.
This winding operation position N2 is a position where the bobbin rotating means M2 rotates the bobbin 7 to wind the lower thread 150 around the bobbin 7 after the lower thread tangling operation. The winding operation position N2 is the same as the position of the yarn supply nozzle 67 at the time of yarn hooking and standby, which will be described later.
[0042]
The winding work position N2 is located in a region J (a hatched portion in FIG. 20 that extends as far as the lower left direction in the drawing) surrounded by the first straight line K, the second straight line L, and the bobbin case opening 2a. . The first straight line K is a straight line that contacts the bobbin shaft outer periphery 7a and connects the bobbin case opening end 2aa.
The second straight line is a straight line that is in contact with the lower thread maximum winding amount outer diameter P and connects the bobbin case opening end 2ab. The lower thread maximum winding amount outer diameter P is set to a value of 80 to 90% of the bobbin case inner diameter. That is, the bobbin case is not wound uniformly, and the bobbin case inner diameter is set to a value smaller than the bobbin case inner diameter so that the lower thread winding amount outer diameter does not contact the bobbin case inner diameter.
[0043]
Further, the longer the distance Q between the thread supply nozzle tip 67a and the bobbin case opening, the more the lower thread 150 is wound evenly around the bobbin 7. This distance Q is preferably 40 mm or more, and more preferably 80 mm or more.
Then, after performing the lower thread entanglement work (work in which the lower thread tip part goes around the bobbin shaft outer periphery 7a and forms a cross point) at the initial work position N1, the thread supply nozzle 67 is rotated to wind the winding work position N2. To be located. Next, the bobbin 7 is rotated, and the lower thread 150 from the thread supply source is wound around the bobbin 7.
[0044]
At this time, the yarn supply nozzle tip 67a is in the J region and is separated from the bobbin case opening by a predetermined amount Q. For this reason, the lower thread 150 between the bobbin 7 and the thread supply nozzle tip 67a does not come into contact with the bobbin case opening edge or other devices during the winding operation. Is wound. Incidentally, the lower thread winding device 162 is provided with a yarn hooking device. This threading device, FIG.As shown inAs shown in FIG.The bobbin case 2 set at the lower thread winding position C has a moving knife threading 116 disposed around the bobbin case 2. The moving knife threading 116 is rotated around the bobbin case 2. The lower thread 150 from the bobbin winder 200 wound around the bobbin and led out from the bobbin case opening 2A is guided to the thread hooking position 2B via the gap between the open end edge of the bobbin case 2 and the outer periphery of the bobbin 7 to form a slit groove. 2C, and can be led out from the vicinity of the lower thread tension spring hole 2E through the lower thread tension hole 2H below the lower thread tension spring 2D.FIG.reference). Note that the threading device is not limited to the one having the above-described configuration. In short, the bobbin case 2 can be threaded with the lower thread 150 from the thread winding 200 wound around the bobbin and led out from the bobbin case opening 2A. Any yarn hooking device described in Japanese Patent Application Laid-Open No. 7-68071 or the yarn hooking device described in Japanese Patent Application No. 7-65140 filed earlier by the present applicant may be used. From the beginning, appropriate ones can be adopted.
[0045]
The lower thread winding device 162 is further provided with a thread trimming device. In this thread trimming device, the bobbin thread 150 from the bobbin winder 200 led out from the vicinity of the bobbin thread tension spring hole 2E is wound by the rotating operation of the moving knife threading 116, and remains with the fixed knife 91 for a predetermined length. In this way, it can be cut (see FIG. 18).
Here, the lower thread tension spring hole 2E of the lower thread led out from the vicinity of the lower thread tension spring hole 2E of the bobbin case 2 has a lower thread cutting point S (specifically, a moving knife threading knife 116 and a fixed knife 91). The bobbin case 2, the fixing knife 91, the lower thread so that the length of the lower thread up to the point of rubbing; see FIG. 18) is the length necessary for stitch formation by entanglement with the upper thread, that is, about 40 mm. Each arrangement such as the cutting point S is determined.
[0046]
Further, when the yarn supply nozzle tip 67a is located at the yarn cutting position N5, the distance between the lower yarn cutting point S and the tip of the yarn supply nozzle 67a at the time of cutting is as described above as shown in FIG. The bobbin case 2, the lower thread cutting point S, and the thread of the thread supply nozzle 67a so as to substantially match the length LL (about 55 mm in the present embodiment) required for entwining the lower thread around the bobbin shaft 7a. Each arrangement such as the cutting position N5 is determined.
[0047]
The thread trimming device is not limited to the one having the above-described configuration. In short, the thread trimming device is wound around a bobbin and passes through a lower thread lead-out hole 2H below a lower thread tension spring 2D of the bobbin case 2. Any thread can be used as long as it can cut the lower thread 150 from the spool 200 derived from the vicinity of 2E while leaving the predetermined length, for example, a thread trimming device or a book described in JP-A-7-68071. Appropriate ones can be adopted, including the thread trimming device described in the specification of Japanese Patent Application No. 7-65140 previously filed by the applicant.
[0048]
Further, as shown in FIG. 13, a yarn tension varying means 204 for varying the tension of the lower thread 150 is provided between the yarn supply detection mechanism F and the spool 200. This thread tension varying means 204 includes a tension spring 205 that presses the passing lower thread 150, a screw 206 that adjusts the pressing force of the tension spring 205 by manual operation, and a tension spring 205 that is disposed in the sewing machine bed 101. And a solenoid SOL that generates a solenoid thrust that resists the pressing force.
[0049]
The electric circuit for driving the yarn tension varying means 204 has a configuration in which a power source is connected in series to the solenoid SOL and a switch is interposed therebetween.
Accordingly, when the switch is turned off, the solenoid thrust is not generated, the pressing force of the tension spring 205 is applied to the lower thread 150 to the maximum, and the lower thread tension becomes maximum. When the switch is turned on, the solenoid thrust is generated to the maximum. The lower thread 150 is obtained by subtracting the solenoid thrust from the pressing force of the tension spring 205, and the lower thread tension is minimized.
[0050]
Next, the lower thread winding operation of the present invention will be briefly described.
The explanation is made from the state where the bobbin remaining yarn is removed after the operation of the sewing machine is temporarily stopped when the lower thread is consumed or when the remaining amount is low, and the bobbin case is removed from the hook.
Prior to this lower thread winding processing operation, the following operation is performed. First, the bobbin thread 200 and the lower thread 150 from the thread tension varying means 204 are wound around the roller 54 once. At this time, the thread tension varying means 204 is turned on to maximize the solenoid thrust and minimize the lower thread tension.
[0051]
Next, the thread end of the lower thread 150 is inserted into the suction hole 65a of the thread suction device 65, and pushed in a little. Next, the solenoid valve 68 is temporarily turned on to allow air from an air source to flow into the yarn supply nozzle 67, and the lower thread 150 inserted and pushed into the suction hole 65a is guided to the yarn supply nozzle tip 67a by the air flow. The yarn end is exposed and led out from the tip end portion 67a of the yarn supply nozzle. The derived length LL is about 55 mm.
[0052]
Next, the rotating arm 70 is moved backward to move the bobbin case 2 from the remaining thread removing position B to the retracted position, and then rotated to make the bobbin case 2 face the lower thread winding position C.
Next. The rotating arm 70 is moved forward to place the bobbin case 2X at the lower thread winding position C and the bobbin driving motor M2 is temporarily driven to connect the clutch mechanism 50a and the bobbin 7.
[0053]
Next, the bobbin driving motor M2 is driven to rotate the bobbin 7. Then, the yarn supply nozzle retraction motor 37 is driven to move the yarn supply nozzle 67 waiting at the retraction position (winding operation position) N2 to the initial operation position N1.
Next, blowing of yarn guide air is started from the yarn supply nozzle tip portion 67a, and a predetermined time is awaited.
[0054]
Then, as shown in FIG. 16, the lower yarn end portion led out from the yarn supply nozzle tip portion 67a is satisfactorily inserted into the bobbin case 2 from the opening 2A of the bobbin case 2 in a state where flapping is suppressed ( Bobbin shaft lower thread winding side XX(See Figure 17)And is entangled with the bobbin shaft 7a by the cooperation of the rotation of the bobbin shaft 7a and the vortex formed by the air. When the entanglement of the lower thread end with the bobbin shaft is completed, the thread supply nozzle 67 at the initial work position N1 is moved to the winding work position N2.
[0055]
At this time, the bobbin driving motor M2 continues to rotate, and therefore the lower thread is wound around the bobbin shaft 7a. In this way, when the lower thread is wound by increasing the distance between the thread supply nozzle tip 67a and the bobbin shaft 7a, the lower thread 150 is wound substantially uniformly over the entire area of the bobbin shaft 7a. It will be. When the lower thread is wound up to the set lower thread winding amount, the bobbin drive motor M2 is stopped.
[0056]
Next, when the winding operation of the lower thread 150 around the bobbin 7 is automatically performed, the thread tension varying means 204 is turned off, and the thread is hooked in a state where the lower thread tension is maximized by eliminating the solenoid thrust. Do. In other words, the lower thread 150 from the bobbin winder 200 wound around the bobbin 7 and led out from the bobbin case opening 2A is guided to the yarn hooking position 2B through the gap between the open end edge of the bobbin case 2 and the outer periphery of the bobbin 7. It leads to the slit groove 2C and is led out from the vicinity of the lower thread tension spring hole 2E through the lower thread tension hole 2H below the lower thread tension spring 2D.
[0057]
When the yarn is hooked in this way, the yarn supply nozzle 67 is moved from the winding operation position N2 to the yarn cutting operation position N5, and the yarn tension varying means 204 is turned on to generate the solenoid thrust to the maximum. Thread trimming with the lower thread tension minimized. As a result of this thread trimming, the bobbin case 2 side lower thread has a length necessary for stitch formation by entanglement with the upper thread, that is, about 40 mm, as shown in the lower thread tension spring 2D. After passing through 2H, the lower thread tension spring hole 2E is in the state of being led out. On the other hand, as described above, the lower thread on the thread winding 200 side has a length LL necessary to entangle the lower thread around the bobbin shaft 7a, that is, 55 mm. The degree is derived from the tip of the air nozzle 67a.
[0058]
Thus, since the lower thread of the length LL necessary for entanglement of the lower thread with the bobbin shaft 7a is derived from the thread supply nozzle 67, the same as described above is applied to the bobbin for the next transition. If the operation is performed, the lower thread can be wound in the same manner. Then, the yarn supply nozzle 67 is moved from the yarn cutting operation position N5 to the retracted position N2 (also serving as the winding operation position).
[0059]
Then, when the lower thread cutting operation is automatically performed in this way, the rotating arm 70 is retracted to the retracted position, and then rotated so that the bobbin case 2 faces the hook 1 and enters a standby state.
The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the embodiment, the yarn supply nozzle 67 is rotated to the retracted position N2, the initial work position N1, the winding work position N2, and the yarn cutting work position N5 by the rotation of the nozzle retracting motor 37. However, instead of this, it is easily conceivable to move the working positions N2, N1, and N5 linearly by using an air cylinder having a three stop position function. It is also easy to move the working positions N2, N1, and N5 linearly by connecting the motor and a gear or pinion that converts the rotational motion of the motor into a linear motion. Can be considered.
[0060]
When the yarn supply nozzle 67 is moved linearly, the initial operation position N1 and the winding operation position N2 are set to the same positions as when the yarn supply nozzle 67 is rotated, and only the yarn cutting operation position N5 is set after the yarn is cut. It is also conceivable that the thread length necessary for forming the seam from the bobbin case 2 is secured, and that the thread is changed to a linear locus such that a predetermined length of lower thread is derived from the thread supply nozzle. .
[0061]
In the present invention, the bobbin case 2 to which the bobbin 7 is mounted is held at a predetermined position, and the yarn supply nozzle 67 is moved to thereby move the initial work position N1, the winding work position N2, and the yarn cutting work position N5. Got. Instead, the yarn supply nozzle 67 is fixed at a predetermined position, and the bobbin case 2 to which the bobbin 7 is attached is moved to obtain the initial operation position N1, the winding operation position N2, and the yarn cutting operation position N5. It can be easily considered. It is also conceivable to easily obtain the initial operation position N1, the winding operation position N2, and the yarn cutting operation position N5 by moving the yarn supply nozzle 67 and the bobbin case 2 to which the bobbin 7 is attached. . The relative movement in this specification means the above three movements.
[0062]
Further, in the present invention, the yarn supply nozzle 67 capable of inserting the lower yarn from the lower yarn supply source and communicating with the air supply source is used as the yarn supply means. However, instead of this, for example, a pair of rotating rollers for feeding the lower thread from the yarn supply source, a thread guide nozzle for guiding the fed lower thread to a predetermined position, and a thread guide nozzle are used as the initial operation. The bobbin case so that the lower thread end is entangled with the bobbin shaft when the driving means for moving to the position N1, the winding work position N2 and the thread cutting work position N5 and the thread guide nozzle are at the initial work position N1. It is easily conceived to comprise air-discharge means for discharging air from the opening.
[0063]
Further, according to the present invention, the yarn supplying means and the bobbin case on which the bobbin is mounted are moved relatively to the initial work position N1, the winding work position N2, and the thread cutting work position N5. Instead, for example, it is easily conceivable to match the winding work position N2 and the yarn cutting work position N5. That is, even if the cutting work is performed at the winding work position, the thread length necessary to form the seam from the bobbin case is secured after the thread is cut, and the next thread supply source and the bobbin are entangled. For attachment, a fixed knife and a moving knife may be provided at predetermined positions so that the lower thread of a predetermined length is led out from the yarn supply means.
[0064]
【The invention's effect】
As described above, according to the lower thread winding device of claim 1,
The bobbin attached to the bobbin case and the yarn supply means for deriving a predetermined length of yarn from the yarn supply source relatively move their positional relationship. The initial work position where the lower thread is entangled is different from the winding work position where the bobbin is rotated to wind the lower thread around the bobbin case. Therefore, the lower thread can be reliably entangled and the lower thread is uniformly wound around the bobbin. Further, since the lower thread winding work position is set in the region defined in claim 1, the lower thread does not come into contact with the bobbin case opening edge during the lower thread winding work, so that the lower thread is uniformly wound around the bobbin. At the same time, the lower thread is not damaged or the lower thread is not unwound.
[0065]
In addition, after the yarn is cut, the lower yarn of a predetermined length is led out from the yarn supply nozzle in order to entangle the next yarn supply source with the bobbin.
[Brief description of the drawings]
FIG. 1 is a schematic front view illustrating a bobbin thread automatic supply device according to an embodiment of the present invention.
FIG. 2 is a front view of a bobbin exchanging device employed in the automatic upper and lower thread automatic supply device.
FIG. 3 is a plan view of the bobbin exchanging device.
FIG. 4 is a right side view showing a linear motion mechanism portion in the bobbin exchanging device.
FIG. 5 is a right side view showing a rotating mechanism portion in the bobbin exchanging device.
FIG. 6 is a schematic right side view for explaining a dummy position and a dummy shaft of the bobbin exchanging device.
FIG. 7 is a front view of the bobbin used in the present embodiment on the side of rotation detection means.
FIG. 8 is a waveform diagram detected when the bobbin rotates.
FIG. 9 is a top view showing a bobbin driving mechanism and an air guide mechanism of a lower thread winding device employed in the automatic upper and lower thread automatic supply device.
FIG. 10 is a front view of the bobbin driving mechanism and the air guide mechanism.
FIG. 11 is a front view showing a yarn supply detecting mechanism of the upper and lower yarn winding device.
FIG. 12 is a right side view of the same thread supply detection mechanism.
FIG. 13 is a front view showing yarn tension varying means of the upper and lower yarn winding device.
FIG. 14 is a cross-sectional view showing the lower thread suction unit of the air guide mechanism.
FIG. 15 is a perspective view of the bobbin driving mechanism.
FIG. 16 is an explanatory diagram showing a positional relationship with respect to a bobbin case and a bobbin shaft when a lower thread is entangled with a thread supply nozzle for inserting a lower thread.
FIG. 17 is a view for explaining the lower thread winding side of the bobbin shaft.
FIG. 18 is an explanatory diagram showing the positional relationship among the yarn supply nozzle, the yarn trimming device, and the bobbin case of the air guide mechanism during yarn trimming.
FIG. 19 is a perspective view of a bobbin case employed in the embodiment.
FIG. 20 is an explanatory diagram showing the positional relationship between the yarn supply nozzle at the lower yarn winding work position and the bobbin case opening.
[Explanation of symbols]
2 Bobbin case
2a Bobbin case opening
7 Bobbins
67 Yarn supply means (yarn supply nozzle)
M2 bobbin rotating means
N1 Initial work position
N2 winding work position
N5 Thread cutting work position
K first straight line
L 2nd straight line

Claims (1)

A bobbin case that rotatably supports the bobbin and has an opening at a predetermined position;
Bobbin rotating means for rotating the bobbin mounted on the bobbin case;
Wherein the distal end side is bent toward the bobbin case opening, it is inserted bobbin thread from the lower thread supply source, the under thread is derived from the nozzle tip, capable of supplying yarn supplying the lower thread in the bobbin nozzle When,
A motor that rotates around the rear end side of the yarn supply nozzle to move to an initial work position, a winding work position, and a yarn cutting position;
A tension spring that is provided between the lower thread supply source and the thread supply nozzle and applies tension by pressing the lower thread;
A solenoid for generating a thrust against the pressing force of the tension spring;
A moving knife threading arranged to be rotatable around the bobbin case ;
A fixed knife capable of cutting a thread in cooperation with the moving knife threading,
Lower thread winding for performing a threading step of rotating the moving knife threading and guiding the lower thread led out from the bobbin case opening and reaching the thread supply nozzle so as to be led out from the vicinity of the lower thread tension spring hole. In the turning device,
The yarn supply nozzle,
An initial work position where the yarn guide air is blown and the bobbin shaft is entangled with the lower yarn end portion derived from the tip of the yarn supply nozzle;
A winding operation position for performing a lower thread winding step of winding the lower thread by rotating the bobbin with respect to the lower thread led from the thread supply nozzle at one end side entangled with the bobbin shaft;
A thread cutting position for performing a lower thread cutting step of cutting a lower thread between the bobbin case and the thread supply nozzle , and
The winding work position is located at a position spaced apart from the initial work position by a predetermined amount, and the yarn supply nozzle tip is in contact with the bobbin shaft and connects the bobbin case opening end and the bobbin case maximum winding. A second straight line connecting the outer diameter of the bobbin case and connecting the end of the bobbin case opening , and
During the bobbin winding process, the thrust of the solenoid is generated to minimize the bobbin thread tension, and during the threading process, threading is performed in a state where the thrust of the solenoid is eliminated and the bobbin thread tension is maximized. A bobbin thread winding device characterized by that.

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