JP2007167198A - Sewing machine needle-thread feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a needle thread with an appropriate length to be fed in a sewing machine needle-thread feeding device for sewing a fabric with a plurality of sewing needles. <P>SOLUTION: Each of guide eyelets 33b of a thread guide 32 disposed in the front bottom of an arm part 5 is provided individually according to each sewing needle 6 near the bottom of each of guide members 33 fixed on the arm part 5 via a long hole 33a. Each guide eyelet 33b is vertically shiftablly and individually adjustable. The guide eyelet 33b of the guide 32 is positioned below a guide eyelet 31a of a needle cramp thread guide 31 vertically moving together with the needle 6 when the needle 6 vertically moving is disposed in the upper dead point of the vertical movement. Thereby when needle locations of a plurality of the needles 6 are performed to the fabric M individually different from the thickness, the needle thread T with the appropriate length for each needle 6 is fed individually, homogenizing seams to improve sewing quality. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a needle thread feeding device for a sewing machine, and more particularly to a needle thread feeding device for a sewing machine that performs sewing with a plurality of sewing needles.

Conventionally, a needle thread feed of a sewing machine that is provided in a sewing machine having a plurality of sewing needles arranged in parallel along the longitudinal direction of the sewing machine arm portion orthogonal to the cloth feed direction and feeds the needle thread supplied to each sewing needle. An apparatus is known (see, for example, Patent Document 1).
Such a conventional needle thread feeding device for a sewing machine is disposed outside the sewing machine arm portion, and is provided in the middle of a needle thread supply path for guiding the needle thread supplied from the needle thread supply source to the sewing needle.
The needle thread supplied to each sewing needle is fed out by reciprocating the needle thread feeding device of the sewing machine up and down in synchronization with the vertical movement of the sewing needle.
JP 2001-187290 A

By the way, when performing sewing with a plurality of sewing needles, for example, the folded portions and overlapping portions of the fabric are mixed, and the thickness of the fabric (sewing object) conveyed to the needle drop position of each sewing needle is different. In this case, the amount of thread consumption (the amount of thread necessary for sewing) at each sewing needle is different.
In addition, when the thicknesses of the fabrics are different, the resistance between the sewing needle and the fabric when the sewing needle is raised changes, so that the amount of yarn excess above the fabric changes.
However, in the above-described conventional needle thread feeding device for a sewing machine, a plurality of needle threads supplied to a plurality of sewing needles are respectively inserted into a plurality of guide holes provided in a single feeding member, Since each needle thread is fed by swinging the single feeding member up and down, it is not possible to supply the appropriate length of needle thread required for each sewing needle. There was a problem that it was not possible to obtain a good sewing quality.

  An object of the present invention is to provide a needle thread feeding device for a sewing machine that can feed a needle thread of an appropriate length.

In order to solve the above-mentioned problem, the invention according to claim 1
A plurality of sewing needles arranged side by side in a direction perpendicular to the cloth feeding direction and capable of reciprocating in the vertical direction;
A needle vertical movement mechanism for driving the sewing needle up and down;
A needle holder for holding the plurality of sewing needles;
A needle thread guide that is attached to the needle thread and includes a plurality of guide holes respectively corresponding to the sewing needles;
A thread guide that is attached to a lower end of a sewing machine arm portion that houses the needle up-and-down movement mechanism, and has a plurality of guide holes provided corresponding to the respective sewing needles;
When the sewing needle is positioned at the top dead center in the vertical movement, the guide hole of the thread guide is arranged below the guide hole of the needle thread guide to feed each needle thread. ,
At least one of the needle thread guide and the yarn guide has each guide hole formed in an individual member and provided individually adjustable in the vertical direction for each member. Is a needle thread feeding device for a sewing machine.

According to the first aspect of the present invention, the guide hole for the thread guide provided individually corresponding to the plurality of sewing needles is a guide for the needle thread guide when the sewing needle is disposed at the top dead center. It is arranged below the hole. That is, when the sewing needle is disposed at the top dead center, the guide hole for the needle thread guide is disposed above the guide hole for the thread guide. As a result, it is possible to apply a pulling force, that is, a feeding force to the needle thread that is stretched between the guide hole of the needle thread guide that rises toward the top dead center and the guide hole of the thread guide.
In addition, the guide hole provided in at least one of the needle thread guide and the thread guide is configured to be adjustable in the vertical direction, so that the needle thread feed amount is individually adjusted for each needle thread. be able to.
Accordingly, when sewing the workpieces having different thicknesses at the respective sewing needles, it is possible to adjust the needle thread feeding amount for each sewing needle in accordance with the thickness. Thereby, a uniform seam can be obtained and the quality of sewing can be improved.
In addition, the thread guide for adjusting the feeding and the needle thread guide are provided in the vicinity of the sewing needle, and there is no structure that affects the thread between these and the sewing needle, and the adjusted feeding amount is directly set. It can be reflected in the sewing.

Hereinafter, a chain stitch sewing machine 1 according to an embodiment of the present invention will be described in detail with reference to FIGS. The chain stitch sewing machine 1 is used, for example, for sewing around sleeves and hems of clothes, and at the time of sewing, a plurality of fabrics are continuously fed at intervals while forming an empty ring between the fabrics. A sewing machine that performs sewing continuously.
Here, in the following description, the direction parallel to the upper surface of the needle plate 9 described later and parallel to the cloth feeding direction is defined as the X-axis direction, and the direction parallel to the upper surface of the needle plate 9 and perpendicular to the X-axis direction is defined. Each part of the sewing machine will be described with the Y-axis direction and the direction perpendicular to the upper surface of the needle plate 9 as the Z-axis direction. In the state where the chain stitch sewing machine 1 is installed on the horizontal plane, the X-axis direction and the Y-axis direction are in a state along the horizontal plane, and the Z-axis direction is in a state along the vertical vertical movement direction.

(Overall configuration of the embodiment of the invention)
FIG. 1 is a schematic perspective view showing an overall configuration of a chain stitch sewing machine 1 according to the present embodiment.
As shown in FIGS. 1 and 2, a chain stitch sewing machine 1 (hereinafter simply referred to as a “sewing machine 1”) includes a needle holder 7 that holds a plurality of sewing needles 6 arranged in a direction perpendicular to the cloth feeding direction, A needle vertical movement mechanism (not shown) that drives the needle holder 7 up and down, a looper mechanism 10 that individually inserts a looper thread into a loop of a needle thread (sewing thread) T formed by each sewing needle 6, and a thread (not shown) A thread tension mechanism 20 for individually applying a predetermined tension to each needle thread T fed from a supply source, a needle thread feeding device 30 for feeding the needle thread T in synchronization with the vertical movement of the sewing needle 6, and a sewing needle The balance mechanism 40 for fastening the seam formed on the cloth by pulling up the needle thread T sewn on the cloth immediately after the sewing operation by the above, and the main body frame 2 holding the above-described components.
The sewing machine 1 includes a sewing machine motor (not shown) serving as a driving source for the sewing machine operation, an upper shaft (not shown) that is connected to the sewing machine motor, and is rotatably provided. To perform sewing, a cloth pressing mechanism (not shown) for pressing, a cloth feeding mechanism (not shown) for transporting the cloth to be sewn, a lower shaft (not shown) for transmitting driving force to the cloth feeding mechanism, etc. are provided. However, since these are the same as conventionally well-known structures, they will not be described in detail in this embodiment.

(Body frame)
The main body frame 2 includes a bed portion 3 that forms a lower portion of the main body frame 2 and extends along the Y-axis direction, a vertical body portion 4 that is erected from one end of the bed portion 3, and a vertical body portion 4. The arm part 5 extended in the same direction as the bed part 3 from the upper end part is provided, and the whole shape is formed in substantially U shape (refer FIG. 1).
A sewing machine motor (not shown), which mainly serves as a drive source for the vertical movement of the needle bar 8, is built in the upper end portion of the vertical body portion 4, and an upper shaft (rotation driven by the sewing motor) is provided in the arm portion 5. (Not shown) are built in along the Y-axis direction. Further, the bed 3 incorporates a lower shaft (not shown) that is rotationally driven from the upper shaft via a timing belt along the Y-axis direction.
A needle plate 9 is provided along the top surface of the bed portion 3 at the top of the bed portion 3 on the front end side. The needle plate 9 is formed with a plurality of needle holes along the Y-axis direction through which the sewing needles 6 drop needles.
On the throat plate 9 is placed a fabric M, which is a material to be sewn, which is conveyed along the X-axis direction by a cloth feed mechanism (not shown) during sewing.

(Needle vertical movement mechanism)
The needle vertical movement mechanism is a crank mechanism (not shown) that converts the rotational driving force of the upper shaft (main shaft) into a reciprocating vertical movement driving force, and can be reciprocated along the Z-axis direction on the distal end side of the arm portion 5 by this crank mechanism. The needle bar 8 is supported by the needle bar 8.
A needle holder 7 is supported at the lower end of the needle bar 8, and three sewing needles 6 are held in the needle holder 7 in a line along the Y-axis direction.
At the lower end of the needle bar 8, the arrangement interval of the sewing needles 6 in the Y-axis direction and the height of the sewing needles 6 in the Z-axis direction can both be changed by exchanging parts such as the needle holder 7. It has become.
A threading hole is formed at the tip of each sewing needle 6, and a needle thread T guided from a thread supply source (not shown) is inserted individually.

(Looper mechanism)
The looper mechanism 10 is arranged along the Y-axis direction in the bed portion 3 and is provided with a swinging force from a lower shaft (not shown) that rotates in synchronism with the upper shaft and a known transmission mechanism from the lower shaft. And four loopers 11 that swing along the direction (see FIG. 2).
Then, the looper mechanism 10 inserts the looper 11 into the loop of each needle thread T formed when each sewing needle 6 rises from the bottom dead center, and the loop of the looper thread is made when the next sewing needle descends. By inserting the sewing needle, the needle thread T and the looper thread are alternately inserted into the loop, and sewing is performed.

(Thread tension mechanism)
As shown in FIG. 1, the thread tension mechanism 20 is provided with a plurality of thread tensions provided on the side surfaces of the longitudinal body 4 and individually corresponding to the needle threads T supplied to the sewing needles 6. I have. Each of the thread tensions includes a pair of thread tension dishes for holding the thread, an elastic body that presses the thread tension dishes together, and a knob that adjusts the pressure contact force of the elastic bodies. With such a configuration, each thread tension is adjusted to an appropriate pressure contact force by a knob, and each thread is pinched to impart a resistance force in the feeding direction and generate an appropriate tension in each thread.

(Balance mechanism)
The balance mechanism 40 includes a needle bar balance 41 disposed above the tip of the arm unit 5 and a swinging balance 42 disposed on the side of the arm unit 5. The balance mechanism 40 pulls up the needle thread T sewn on the fabric M immediately after the sewing operation by the sewing needle 6 and fastens the seam formed on the fabric M.

(Feeding device)
The needle thread feeding device 30 is attached to the needle thread 7 and has a plurality of guide holes 31a respectively corresponding to the needle threads T supplied to the sewing needles 6, and the distal end side of the arm portion 5. A thread guide 32 provided at the lower end and having a guide hole 33b through which each needle thread T is individually inserted.

  The needle thread guide 31 is a plate-like member attached to the upper part of the needle thread 7 and extends upward, and the upper part is refracted to the upstream side in the cloth feeding direction, that is, the side on which an operator is located during sewing. (See FIGS. 3 and 4). A plurality of guide holes 31a individually corresponding to the sewing needles 6 are formed side by side along the Y-axis direction while penetrating the end edges.

The thread guide 32 includes three guide members 33 each corresponding to each sewing needle 6 and having guide holes 33b formed in the vicinity of the lower ends thereof. Each guide member 33 is plate-shaped, and an upper and lower elongated hole 33a penetrating the guide member 33 is formed at the upper end portion, and a guide hole 33b through which the needle thread T is passed is formed at the lower end portion. ing.
And the guide member 33 in this embodiment is detachably attached to the lower end of the tip of the arm portion 5 via a screw 34 inserted into the elongated hole 33a. That is, the guide member 33 is provided so as to be slidable substantially vertically along the elongated hole 33a in a state where the screw 34 is loosened, and by tightening the screw 34 at a desired vertical position. It is possible to adjust the vertical position of each guide member 33 individually.

Further, the thread guide 32 in this embodiment is driven up and down together with the sewing needle 6 when the sewing needle 6 reciprocated up and down by the needle up-and-down movement mechanism is located at the top dead center in the up-and-down movement. The movement range of the vertical adjustment of each guide member 33 is determined so that the guide hole 33b provided in each guide member 33 of the yarn guide 32 is always positioned below the guide hole 31a of the needle thread guide 31. It has been.
That is, the guide hole 31a of the needle thread guide 31 extends to above the guide hole 33b formed in each guide member 33 of the thread guide 32 when the sewing needle 6 is disposed at the top dead center of the vertical movement. It is possible to reach.
Of the guide holes 31a of the thread guide 32 and the needle thread guide 31, the needle thread T supplied from a thread supply source (not shown) is inserted into the guide holes 31a individually corresponding to the sewing needles 6, respectively. It is configured to be guided by each sewing needle 6.

(Description of the operation of the chain stitch machine)
Next, the operation of the needle thread feeding device 30 of the sewing machine 1 having the above configuration will be described in detail with reference to the drawings.
In the present embodiment, as shown in FIG. 2, the portion where the two sewing needles 6 on the left side are needle-dropped toward the downstream side in the cloth feeding direction is thick because the fabric M is folded and thick, and the one sewing needle 6 on the right side is the needle. The part to be dropped is sewn on the thin fabric M.
When each sewing needle 6 reciprocated up and down by a needle up-and-down moving mechanism (not shown) is lowered toward the bottom dead center in the up-and-down movement, the needle thread T inserted into the threading hole at the tip of each sewing needle 6 is The fabric M is penetrated downward together with the sewing needle 6. That is, when the sewing needle 6 descends toward the bottom dead center in the vertical movement, a pulling force is applied to the needle thread T on the needle thread path in the direction in which the needle thread T is supplied. Therefore, the needle thread T is consumed when the sewing needle 6 descends toward the bottom dead center (see FIG. 4). In particular, the yarn consumption increases when the fabric thickness is thick.
On the other hand, when each sewing needle 6 rises toward the top dead center in its vertical movement, the needle thread T stretched between the thread guide 32 and the needle thread guide 31 is moved upward at the position of the thread guide 32. (See FIG. 3). In the needle thread feeding device 30 according to the present embodiment, the guide holes 31a of the needle thread guide 31 are provided in the guide members 33 of the thread guide 32 when the sewing needle 6 is disposed near the top dead center. It is raised above the guide hole 33b, that is, to a higher position.

Here, the needle thread T sewn on the fabric M by the respective sewing needles 6 has one end of the needle thread T in the middle of sewing, that is, before thread trimming after completion of sewing is performed by a thread trimming device (not shown). In this state, the fabric M is still sewn on. For this reason, when the guide hole 31a of the needle thread guide 31 rises above the guide hole 33b provided in each guide member 33 of the thread guide 32, the needle thread T is supplied to the needle thread T. A pulling force, that is, a feeding force is applied in the direction in which it is applied.
Further, the amount of feeding is adjusted by appropriately adjusting the height difference between the guide hole 33b provided in each guide member 33 of the yarn guide 32 and the guide hole 31a of the needle thread guide 31 by sliding the guide member 33 up and down. You can make fine adjustments.

  Then, as shown in FIG. 2, when sewing the fabric M having a variation in thickness along the Y-axis direction, the sewing needle 6 (see FIG. 2, the guide member 33 of the thread guide 32 corresponding to the two sewing needles 6) from the left side is adjusted to move downward, and the vertical position of the guide hole 33b is adjusted accordingly. By performing such movement adjustment, the needle thread T having an appropriate length corresponding to the cloth thickness of the portion where the needle drop is performed by each sewing needle 6 is fed out.

(Effect of embodiment)
As described above, according to the needle thread feeding device 30 of the sewing machine 1 according to the present embodiment, when the sewing needles 6 are arranged at the top dead center, the sewing needles 6 are individually provided correspondingly. Guide holes 33 b provided in each guide member 33 of the yarn guide 32 can be arranged below the guide holes 31 a of the needle thread guide 31. As a result, the pulling force is applied to the needle thread T spanned between the guide hole 31a of the needle thread guide 31 rising toward the top dead center and the guide hole 33b provided in each guide member 33 of the thread guide 32. That is, a feeding force can be applied.
Further, since the guide hole 33b provided in the thread guide 32 is configured to be slidable in the vertical direction by the screw 34 and the elongated hole 33a, the feeding amount of the needle thread T is individually set for each needle thread T. Can be adjusted.
Accordingly, when the fabric M having different thicknesses is sewn at each sewing needle 6, the feeding amount of the needle thread T for each sewing needle 6 can be adjusted according to the thickness. Thereby, a uniform seam can be obtained and the quality of sewing can be improved.
Further, a thread guide 32 for adjusting the feeding and a needle thread guide 31 are provided in the vicinity of each sewing needle 6, and there is no configuration that affects the thread between these sewing needles 6. The feeding amount can be directly reflected on the sewing.

Note that the present invention is not limited to this embodiment. That is, in the present embodiment, the thread guide 32 provided at the tip of the arm portion 5 and individually provided corresponding to each sewing needle 6 is configured to be individually slidable up and down. The thread guide 32 disposed on the side of the section 5 is fixed, and the needle thread guide 31 provided on the needle holder 7 is provided individually corresponding to each sewing needle 6, and the needle thread guide 31 is provided in the needle holder 7. However, it may be configured such that the vertical movement can be adjusted individually. Also with this configuration, it is possible to adjust the feed amount of the needle thread T for each sewing needle 6 according to the cloth thickness.
Further, the number of sewing needles 6 that can be attached to the needle holder 7 and the number of guide holes 31a and 33b corresponding to each sewing needle 6 are not limited to the present embodiment.

It is a schematic perspective view which shows the whole structure of the sewing machine in this embodiment. It is a front view which shows the needle thread feeding apparatus of the sewing machine in this embodiment. It is a perspective view which shows the needle thread feeding device (top dead center) of the sewing machine in this embodiment. It is a perspective view which shows the needle thread feeding device (bottom dead center) of the sewing machine in this embodiment.

Explanation of symbols

1 Sewing machine (sewing machine)
2 Body frame 3 Bed 4 Vertical body 5 Arm 6 Sewing needle 7 Needle clasp 8 Needle bar 9 Needle plate 10 Looper mechanism 11 Looper 20 Thread tension device 30 Needle thread feeding device 31 Needle thread guide 31a Needle thread guide 31 Guide hole 32 Thread guide 33 Guide member 33a Elongated hole 33b Guide member guide hole 34 Screw 40 Balance mechanism 41 Needle bar balance 42 Oscillating balance M Fabric (clothes)
T Sewing thread (needle thread)

Claims (1)

A plurality of sewing needles arranged side by side in a direction perpendicular to the cloth feeding direction and capable of reciprocating in the vertical direction;
A needle vertical movement mechanism for driving the sewing needle up and down;
A needle holder for holding the plurality of sewing needles;
A needle thread guide that is attached to the needle thread and includes a plurality of guide holes respectively corresponding to the sewing needles;
A thread guide that is attached to a lower end of a sewing machine arm portion that houses the needle up-and-down movement mechanism, and has a plurality of guide holes provided corresponding to the respective sewing needles;
When the sewing needle is positioned at the top dead center in the vertical movement, the guide hole of the thread guide is arranged below the guide hole of the needle thread guide to feed each needle thread. ,
At least one of the needle thread guide and the yarn guide has each guide hole formed in an individual member and provided individually adjustable in the vertical direction for each member. Sewing machine needle thread feeding device characterized by

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