JP4236340B2 - Sewing machine and detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine, and more particularly, to a sewing machine including a loop catcher position adjusting member and a loop catcher position detecting means for easily and reliably aligning a loop catcher of the sewing machine.
[0002]
[Prior art]
A conventionally known sewing machine is rotatably supported by a sewing machine frame and rotates in conjunction with a drive motor. A needle can be attached to and detached from a lower end of the needle and is moved up and down as the spindle rotates. A hook shaft that is rotatably supported by the frame and is connected to the main shaft via a transmission mechanism, and a hook that is fixed to the end of the hook shaft so as to be able to adjust the rotation.
There is also known a sewing machine in which a shuttle is movable with a shuttle shaft by a motor.
[0003]
In such a sewing machine, when the needle passes through the sewing product and descends to the lowest point and then slightly rises, the needle thread sags due to the resistance of the sewing product and forms a needle thread loop. The tip of the hook catches this loop. For this reason, it is necessary to maintain a predetermined positional relationship between the hook tip and the needle. This point will be described in more detail with reference to FIG. FIG. 6 shows the needle and the sword at a position where the needle penetrates the sewing product and descends to the lowest point, and then slightly rises and the needle thread loop is captured by the sword, (A) is a front view, B) is a side view. As shown in FIG. 6A, when the needle 12 is lifted from the lowest point, when the hook tip 10a coincides with the center line 12e of the needle 12, the hook tip 10a moves upward by a predetermined distance S from the needle hole 12f. 6 and the distance t between the edge portion 12d of the needle 12 and the sword tip 10a at this time must be separated by a predetermined amount.
[0004]
[Problems to be solved by the invention]
Since the distance t between the edge portion 12d of the needle 12 and the sword tip 10a needs to be changed according to the type of needle, thread, and sewing product to be used, an operation called hook alignment is required. The conventional hook alignment is a manual operation in which the hook is adjusted to the above-described position by visual inspection and then fixed to the hook shaft, and the operator has a large variation. In addition, since the pot is usually located in a place where the surrounding light is hard to hit, it is often difficult to see, which is particularly difficult for the elderly.
[0005]
Furthermore, as shown in FIG. 6 (A), this operation has to determine the position of the sword tip 10a hidden behind the needle 12, which makes the hook alignment more difficult.
[0006]
The distance t is, for example, 0.05 to 0.1 mm, and it is difficult to accurately obtain such a minute distance due to individual differences or the influence of light shadows in the eye measurement. In many cases, breakage or poor sewing occurred.
[0007]
Similarly, when aligning the looper and needle of the chain stitch sewing machine, the distance between the edge portion 12d of the needle 12 and the tip of the looper must be a predetermined amount when the tip of the looper catches the needle thread loop. However, this alignment has the same problems as the hook alignment.
[0008]
Therefore, the object of the present invention is to reduce variations by the operator during hook alignment, position adjustment of the tip of the looper, etc., and to know the minute distance t as described above. Another object of the present invention is to provide a sewing machine that can reduce the occurrence of needle breakage and poor sewing.
[0009]
Another object of the present invention is to provide a sewing machine that can easily perform hook alignment and position adjustment of the tip of the looper, and can reduce the burden on the operator.
Other objects of the present invention will become apparent from the following description.
[0010]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, a main shaft that is rotatably supported by a sewing machine frame and rotates in conjunction with a drive motor, and a needle can be attached to and detached from the lower end, and is moved up and down as the main shaft rotates. A needle bar, a loop catcher fixed shaft that is supported rotatably or swingably on the sewing machine frame, and is connected to the main shaft via a transmission mechanism, and is fixed to the loop catcher fixed shaft so as to move the needle bar up and down. A loop catcher having a loop catching part for catching the needle thread loop formed therewith, a needle bar attaching part that can be attached to the lower end of the needle bar, and a detection surface corresponding to a needle punching part attached to the needle bar; There is provided a sewing machine comprising: a loop catcher position adjusting member having a loop catcher position detecting means capable of detecting a contact state between the detection surface and the loop catcher of the loop catcher. . With this configuration, it is possible to know a minute predetermined distance between the needle and the loop catcher without visual observation in the positioning work of the loop catcher such as hook alignment.
[0011]
In a typical example, the loop catcher fixed shaft is a hook shaft that is rotatably supported by the sewing machine frame and is connected to the main shaft via a transmission mechanism. The loop catcher can be rotationally adjusted to the end of the hook shaft. It is a fixed hook and the loop catcher is the sword tip.
[0012]
In another example, the loop catcher fixed shaft is a looper shaft that is swingably supported by the sewing machine frame and is connected to the main shaft via a transmission mechanism. The loop catcher is a looper fixed to the looper shaft. And the loop catcher is the tip of the looper. For example, the lower end of the loop catcher position adjusting member is formed in parallel to the movement trajectory of the loop catcher . Preferably, the detection surface is displaced from the needle edge portion mounted on the needle bar by a predetermined amount toward the loop capturing portion.
[0013]
The loop catcher position adjusting member has an insulator between the needle bar mounting portion and the detection surface, and the loop catcher position detecting means is provided between the detection surface of the loop catcher position adjusting member and the loop catcher. When a current is passed and the loop capturing part and the detection surface of the loop capturing device position adjusting member are in contact with each other, the position of the loop capturing device can be detected by detecting the current. In this case, preferably, the loop catcher position detection means includes a display means for displaying the loop catcher and the detection surface of the loop catcher position adjusting member when they come into contact with each other.
[0014]
A motor capable of moving the loop catcher fixed shaft in the horizontal direction; a loop catcher position detecting means; and a control means connected to the motor, the control means being based on a detection signal from the loop catcher position detecting means. The motor drive can be controlled. With such a configuration, it is possible to automate at least the main part of the positioning operation of the loop catcher such as hook alignment.
[0015]
The control means moves the loop catcher in the direction of the loop catcher position adjusting member, and controls driving of the motor so as to return the loop catcher by a predetermined amount after receiving the detection signal from the loop catcher position detecting means. Can do.
Further, the present invention provides a loop catcher position adjusting member having a needle bar mounting portion that can be mounted on the lower end of the needle bar of the sewing machine and a detection surface having a shape corresponding to the needle portion of the needle mounted on the needle bar of the sewing machine, It is an invention relating to a detection device comprising: a loop catcher position detecting means capable of detecting a contact state between the detection surface and a loop catching portion of a loop catcher of a sewing machine.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a sewing machine according to the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 is a perspective view of a sewing machine to which a hook position adjusting member (loop catcher position adjusting member) and a hook position detecting means (loop catcher position detecting means), which are features of the present invention, can be applied. The sewing machine 2 includes a main shaft 4 that is rotatably supported by the sewing machine frame, a needle bar 6 that is vertically moved as the main shaft 4 rotates, a lower shaft 8 that is rotatably supported by the sewing machine frame, and a sewing machine frame. A hook shaft (loop catcher fixed shaft) 20 that is rotatably supported on the hook shaft, and a hook (loop catcher) 10 that is fixed to the end of the hook shaft 20 so as to be rotatable. The main shaft 4 rotates in conjunction with a drive motor (not shown). A needle 12 can be attached to and detached from the lower end of the needle bar 6. Sprockets 14 and 16 are fixed to the main shaft 4 and the lower shaft 8, respectively, and the rotation of the main shaft 4 is transmitted to the lower shaft 8 via the timing belt 18. The lower shaft 8 and the shuttle shaft 20 are connected by gears 22 and 24, and the rotation of the lower shaft 8 is transmitted to the shuttle shaft 20 via the gears 22 and 24.
[0018]
2A is a view showing a needle that can be attached to and detached from the lower end of the needle bar of the sewing machine shown in FIG. 1, and FIG. 2B shows the sewing machine shown in FIG. FIG. 3 is a perspective view showing a hook position adjusting member and a hook position detecting means. FIG. In FIG. 2A, the needle 12 is a shank portion (needle bar mounting portion) 12a mounted on the lower end of the needle bar 6, a needle shaft 12c, and an edge portion for making it easier for the sword tip 10a of the shuttle 10 to catch the needle thread loop. 12d.
[0019]
2B and 3, the shuttle position adjusting member (loop catcher position adjusting member) 30 has a shank portion (needle bar mounting portion) 30 a that can be mounted on the lower end of the needle bar 6 and a detection formed below. The shaft 30c has an insulator 30b provided between the shank portion 30a and the detection shaft 30c, and a detection surface 30d formed at the lower end of the detection shaft 30c. The shank portion 30a, the detection shaft 30c, and the detection surface 30d of the shuttle position adjusting member 30 have shapes corresponding to the shank portion 12a, the needle shaft 12c, and the edge portion 12d of the needle 12, respectively. The detection surface 30d is formed in parallel to the rotation trajectory of the blade tip (loop capturing portion) 10a of the shuttle 10 rotating in the direction of arrow R.
[0020]
The shuttle position detection means (loop catcher position detection means) 32 includes a detector 34, an electric wire 36 connecting the detection shaft 30 c of the hook position adjusting member 30 and the detector 34, and an electric wire 38 connecting the sewing machine frame and the detector 34. It is composed of This detector 34 is, for example, an ammeter and a light bulb provided with a power source, detects a current between the detection shaft 30c of the hook position adjusting member 30 attached to the needle bar 6 and the hook, and the electric current is detected by the light bulb. Display presence / absence. The shank portion 30a of the hook position adjusting member 30 attached to the needle bar 6 is electrically connected to the sewing machine frame via the needle bar 6, and the hook 10 is also electrically connected to the sewing machine frame via the hook shaft 20. However, between the shank part 30a and the detection shaft 30c is insulated by the insulator 30b. For this reason, in a normal state, since no current flows between the detection shaft 30c and the shuttle 10, no current is detected by the detector 34. However, when the sword tip 10a of the hook 10 contacts the detection surface 30d of the hook position adjusting member 30, the sewing machine frame, the hook shaft 20, the hook 10, the detection shaft 30c, the electric wire 36, the detector 34, and the electric wire 38 form a closed circuit. Therefore, a current is detected by the detector 34 and the light bulb emits light. Therefore, the contact state between the hook position adjusting member 30 and the hook point 10a can be detected by the hook position detecting means 32.
[0021]
FIG. 4 is a diagram showing the centerlines 30e and 12e of the hook position adjusting member 30 and the needle 12 in alignment with each other in order to explain the amount of displacement of the detection surface 30d of the hook position adjusting member 30. The detection surface 30d is displaced by a predetermined amount t from the edge portion 12d of the needle 12 attached to the needle bar 6 toward the hook sword tip 10a. Here, the predetermined amount t is the same amount as the distance between the edge portion 12d of the needle 12 and the sword tip 10a that need to be adjusted at the time of hook alignment, and is, for example, 0.05 to 0.1 mm as described above.
[0022]
Next, a hook alignment operation using the sewing machine having the above configuration will be described. First, the hook position adjusting member 30 is attached to the needle bar 6 of the sewing machine 2 in place of the needle 12, and the timing of the hook is adjusted. Then, the screw for fixing the hook 10 to the hook shaft 20 is loosened, and the hook 10 is moved to the needle. I ’m getting closer to 12.
[0023]
When the sword tip 10a of the shuttle 10 comes into contact with the toothed portion 12d of the needle 12, the current is detected by the detector 34 and displayed by a light bulb, so that the contact between the sword tip 10a and the needle 12 is detected as an electrical contact instead of visual inspection. It will be.
[0024]
Since the detection surface 30d of the hook position adjusting member 30 is displaced from the edge portion 12d of the needle 12 by a predetermined amount (t) toward the sword tip 10a of the hook 10, the position where the stylus 10a contacts the needle 12 without pressurizing it. Is the hook alignment position.
[0025]
FIG. 5 is a perspective view of a second sewing machine to which the hook position adjusting member and the hook position detecting means, which are the features of the present invention, can be applied. The second sewing machine 102 is a two-needle sewing machine, and two needles 112 and 113 can be attached to and detached from the lower end of the needle bar 106. A main shaft 104, a lower shaft 108, a first hook shaft 120, a second hook shaft 121, a spline shaft 140, and a horizontal shaft 146 are rotatably supported on the sewing machine frame. The lower shaft 108 is connected to the main shaft 104 via a transmission mechanism (not shown). Gears 122, 124, 142 are fixed to the lower shaft 108, the first hook shaft 120, and the spline shaft 140, respectively, and the gear 124 of the first hook shaft 120 meshes with the gear 122 of the lower shaft 108, and the spline shaft. 140 of the gear 142 meshes with the gear 122 of the lower shaft 108. A first hook 110 is fixed to the tip of the first hook shaft 120. One end of the horizontal shaft 146 has a boss portion 146 a formed with a groove corresponding to the spline groove 140 a of the spline shaft 140. The horizontal shaft 146 is arranged coaxially with the spline shaft 140, and the groove of the boss portion 146a is fitted into the spline groove 140a so that it can slide in the axial direction. A gear 148 is fixed to the other end of the horizontal shaft 146. The gear 148 meshes with a gear 150 fixed to the second shuttle shaft 121. A second hook 111 is fixed to the tip of the second hook shaft 121 so as to face the first hook 110.
[0026]
The horizontal shaft 146 and the second shuttle shaft 121 are configured as a part of the second shuttle unit 152, and the second shuttle unit 152 can be moved in the horizontal direction along the guide 156 by the pulse motor 154. By this movement, the second hook 111 can be moved closer to or away from the second needle 113. The pulse motor 154 is controlled by control means (not shown).
[0027]
The hook position adjusting member 30 shown in FIGS. 2B and 3 can also be used for the two-needle sewing machine 102, and the first needle 112 or the second needle 113 is used during the hook alignment operation. Is attached to the needle bar 106 instead. 3 is used to detect a current between the detection shaft 30c of the hook position adjusting member 30 and the first hook 110 or the second hook 111. When the hooks of the first hook 110 are aligned, the operation is the same as that of the hooks of the sewing machine 2 in FIG. 1, and the same effects can be achieved.
[0028]
When the hooks of the second hook 111 are aligned, the second hook unit 152 can be moved by the pulse motor 154 as described above, so the detector 34 and the control means of the pulse motor 154 are connected. This makes it possible to automate at least the main part of the hook alignment operation. As the hook position adjusting member 30 in this case, as shown in FIG. 4, the detection surface 30d is displaced by a predetermined amount t from the edge portion 12d of the needle 12 attached to the needle bar 6 toward the hook point 10a. Although a configuration may be used, the displacement between the detection surface 30d and the edge portion 12d is set to be zero, and the second hook shaft is controlled by controlling the pulse motor 154 by the control means during the hook alignment operation. 121 is moved closer to the second needle 113, the second hook 111 is returned by a predetermined distance t from the position where the second hook 111 is in contact with the second needle 113, and the sword tip of the second needle 113 and the second hook 111 is moved. A gap t can also be obtained.
[0029]
As mentioned above, although the sewing machine by this invention was demonstrated based on embodiment shown on drawing, this invention is not limited to this but can be variously deformed.
[0030]
For example, as the shuttle position detection means 32, the type that detects current is described, but not limited to this, various types can be used. For example, the same effect can be obtained by using a type that detects the vibration sound generated when the detection shaft 30c of the hook position adjusting member 30 is vibrated and the sword tip 10a of the hook 10 contacts the detection surface 30d. it can. Further, the same effect can be obtained even if the insulator 30b of the shuttle position adjusting member 30 is not used, and the detection shaft 30c is made of a material other than metal, and a type that detects a change in resistance value at the time of contact is used. be able to.
[0031]
Furthermore, after electrically insulating any part from the needle bar 6 to the hook 10, a normal needle 12 is used, and an electric wire 36, a detector 34, and a needle 34 are connected between the needle bar 6 and the hook 10. Even if the electric wire 38 is arranged and the current is detected, the same effect can be obtained.
[0032]
Further, the loop catcher position adjusting member 30 and the loop catcher position detecting means 32 shown in FIGS. 2 to 4 are used not for aligning the hook 10 and the needle 12 but for aligning the looper of the chain stitch sewing machine with the needle 12. be able to. That is, the chain stitch sewing machine is rotatably supported by the sewing machine frame, and rotates with the main shaft, the needle can be attached to and detached from the lower end, and the needle bar is moved up and down as the main shaft rotates, and the sewing machine frame. A looper shaft (loop trap fixed shaft) that is rotatably or swingably supported by the main shaft and connected via a transmission mechanism, and a looper (loop trap) fixed to the looper shaft. The needle thread loop formed with the vertical movement is captured by the looper. The detection surface 30d of the loop catcher position adjusting member 30 is parallel to the movement locus of the tip of the swinging looper (loop catching part) and is displaced by a predetermined amount toward the looper tip. The loop catcher positioning operation in this case is the same as that of the hook alignment operation, and the same effect can be achieved.
4 is formed in a plurality of steps, and the operator selects an optimal detection surface according to the sewing conditions (the vertical mounting position of the hook adjustment member on the needle bar). It is also easy to align the hooks (by changing the).
[0033]
【The invention's effect】
According to the present invention, a loop catcher position adjusting member having a needle bar attaching portion that can be attached to the lower end of the needle bar and a detection surface corresponding to a needle punching portion attached to the needle bar , the detection surface and the loop catcher A loop catcher position detecting means capable of detecting the contact state with the loop catching portion of the loop catcher. Since it is possible to know the predetermined distance without visual observation, it is possible to reduce the variation by the operator, and it is possible to know the minute distance between the loop catcher and the needle reliably and easily without visual observation. This can greatly reduce the burden on the worker. In addition, the occurrence of stitch skips, broken needles, and poor sewing could be reduced.
[0034]
When the detection surface is configured to be displaced by a predetermined amount from the needle edge portion attached to the needle bar to the loop catcher side, the loop catcher must be aligned without pressurizing the needle by the loop catcher. Can do.
[0035]
In addition, a motor capable of moving the loop catcher fixed shaft in the horizontal direction, a loop catcher position detection means, and a control means connected to the motor are provided, and the control means is based on a detection signal from the loop catcher position detection means. When the motor drive is controlled, it is possible to automate at least the main part of the positioning operation of the loop catcher such as hook alignment.
[Brief description of the drawings]
FIG. 1 is a perspective view of a sewing machine to which a hook position adjusting member and a hook position detecting means that are characteristic portions of the present invention can be applied.
2A is a view showing a needle that can be attached to and detached from the lower end of the needle bar of the sewing machine in FIG. 1, and FIG. 2B is a sectional view of a hook position adjusting member that can be attached to and detached from the lower end of the needle bar of the sewing machine in FIG. It is.
FIG. 3 is a perspective view showing a hook position adjusting member and a hook position detecting means.
FIG. 4 is a diagram for explaining a displacement amount of a detection surface of a hook position adjusting member.
FIG. 5 is a perspective view of a second sewing machine to which the hook position adjusting member and the hook position detecting means, which are the features of the present invention, can be applied.
6A and 6B show a needle and a sword tip for explaining a conventional hook alignment operation, in which FIG. 6A is a front view and FIG. 6B is a side view.
[Explanation of symbols]
2 Sewing machine 4 Main shaft 6 Needle bar 8 Lower shaft 10 Hook 10a Knife tip 12 Needle 12a Shank part (needle bar mounting part) 12c Needle shaft 12d Edge section 12e Needle center line 12f Needle hole 14, 16 Sprocket 18 Timing belt 20 Hook shaft 22 , 24 Gear 30 Hook position adjustment member 30a Shank portion (needle bar mounting portion) 30b Insulator 30c Detection shaft 30d Detection surface 30e Hook position adjustment member center line 32 Hook position detection means 34 Detector 36 Electric wire 38 Electric wire 102 Second wire Sewing machine 104 Main shaft 106 Needle bar 108 Lower shaft 110 First hook 111 Second hook 112 First needle 113 Second needle 120 First hook shaft 121 Second hook shaft 122, 124, 142 Gear 140 Spline shaft 140a Spline groove 146 Horizontal shaft 146a Boss portion 148 Gear 150 Gear 152 Second hook unit 1 4 the pulse motor 156 guide 158 control unit

Claims (10)

A main shaft that is rotatably supported by the sewing machine frame and rotates in conjunction with a drive motor; a needle bar that can be attached to and detached from the lower end and is moved up and down as the main shaft rotates;
A loop catcher fixed shaft that is rotatably or swingably supported on the sewing machine frame and is connected to the main shaft via a transmission mechanism;
A loop catcher that is fixed to the loop catcher fixed shaft and has a loop catcher that catches a needle thread loop formed as the needle bar moves up and down;
A loop catcher position adjustment member having a needle bar mounting portion that can be mounted on the lower end of the needle bar and a detection surface corresponding to a needle punching portion mounted on the needle bar ;
A sewing machine comprising: a loop catcher position detecting means capable of detecting a contact state between the detection surface and a loop catching portion of the loop catcher. The sewing machine according to claim 1, wherein
The loop catcher fixing shaft is a hook shaft that is rotatably supported by the sewing machine frame,
The sewing machine according to claim 1, wherein the loop catcher is a hook fixed to the end of the hook shaft so as to be adjustable in rotation, and the loop catcher is a sword tip. The sewing machine according to claim 1, wherein
The loop catcher fixed shaft is a looper shaft that is swingably supported by the sewing machine frame,
The loop catcher is a looper fixed to the looper shaft,
The sewing machine characterized in that the loop catching portion is a tip portion of a looper. In the sewing machine according to any one of claims 1 to 3,
The sewing machine according to claim 1, wherein the detection surface is formed in parallel to a movement trajectory of the loop capturing unit. The sewing machine according to claim 4, wherein
The sewing machine is characterized in that the detection surface is displaced by a predetermined amount from the needle edge portion mounted on the needle bar toward the loop catching portion. In the sewing machine according to any one of claims 1 to 5,
The loop catcher position adjusting member has an insulator between the needle bar mounting portion and the detection surface,
The loop catcher position detection means causes a current to flow between the detection surface of the loop catcher position adjustment member and the loop catcher, and when the loop catcher and the detection surface of the loop catcher position adjustment member are in contact with each other, A sewing machine that detects a position of a loop catcher by detecting a current. The sewing machine according to claim 6, wherein
The loop catcher position detecting means includes a display means for displaying a loop catcher and a detection surface of the loop catcher position adjusting member when they are in contact with each other. In the sewing machine according to any one of claims 1, 2, 4 to 6,
A motor capable of moving the loop catcher fixed shaft in a horizontal direction;
The loop catcher position detecting means and a control means connected to the motor, wherein the control means controls driving of the motor based on a detection signal from the loop catcher position detecting means. sewing machine. The sewing machine according to claim 8, wherein
The control means moves the loop catcher in the direction of the loop catcher position adjusting member, and receives the detection signal from the loop catcher position detection means, and then returns the loop catcher by a predetermined amount. A sewing machine characterized by controlling driving. A loop catcher position adjusting member having a needle bar mounting portion which can be mounted on the lower end of the needle bar of the sewing machine and a detection surface having a shape corresponding to the thread portion of the needle mounted on the needle bar of the sewing machine;
A loop capturing device position detecting means capable of detecting a contact state between the detection surface and a loop capturing portion of a loop capturing device of a sewing machine.

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