JP4332253B2 - Cloth cutting knife device for hole sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cloth cutting knife equipment of stitching machine which is dropped the cloth cutting knife at a predetermined portion of the fabric forming the buttonhole.
[0002]
[Prior art]
With a hole sewing machine equipped with a cloth cutting knife, the sewing machine is formed on the surrounding cloth that becomes the button hole, and the part that becomes the button hole is cut with the cloth cutting knife before or after the formation of the button sewing. Yes.
The cloth cutting knife is fixed to the lower end of a knife bar provided at the arm tip of the sewing machine frame so as to be lifted and lowered, and the button hole is opened by the cloth cutting knife by raising and lowering the knife bar. In order to raise and lower the female bar, for example, a solenoid is arranged above the female bar, and the female bar is lowered by its action, and then the female bar is raised and returned by the elastic return force of the return spring provided on the female bar or solenoid. I was letting.
[0003]
[Problems to be solved by the invention]
As shown in FIG. 6, when the cloth cutting knife 31 descends into the cloth W, the knife guide groove 32a formed on the needle plate 32 below the cloth W after the tip of the cloth cutting knife 31 cuts and penetrates the cloth W. However, normally, the width of the knife guide groove 32 is only slightly wider than the width of the cloth cutting knife 31. For this reason, when the cloth cutting knife 31 penetrates the cloth W, both side portions of the cloth cutting portion are caught and sandwiched between the cloth cutting knife 31 and the knife guide groove 32, and so-called biting occurs. there were.
As described above, since the cloth cutting knife returns and rises by the spring force, when this bite occurs, the resistance force becomes larger than the spring force and the rise cannot be restored, and the sewing machine becomes inoperable. There was a thing.
In order to reliably return the cloth cutting knife without raising, for example, it is necessary to increase the spring force, but if the spring force is increased, the solenoid needs to be enlarged to face it, Problems such as an increase in the size and cost of the sewing machine occurred.
[0004]
In addition, since the solenoid is disposed above the knife bar, that is, above the tip of the arm of the sewing machine, it gives a sense of pressure to the sewing manufacturer working on the front side of the tip of the arm and the operation sound of the solenoid. However, there is a problem in that it is likely to resonate with the worker and makes the worker uncomfortable.
Furthermore, since the sewing machine has a needle bar up-and-down mechanism at the arm tip and, in some cases, a needle swing mechanism, if a large and heavy solenoid is placed at the arm tip, the parts are concentrated on the arm and the weight load on the arm increases. As a result, the balance of the sewing machine head is poor, which may cause vibration.
[0005]
An object of this invention is to provide the cloth cutting knife apparatus which can raise | recover a cloth cutting knife reliably after a cloth cutting | disconnection.
Another object of the present invention is to make the solenoid for lowering the cloth cutting knife small.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the cloth cutting knife device of the sewing machine according to claim 1 of the present invention is provided so as to be movable up and down along the arm tip of the machine head frame, and the cloth cutting knife is fixed to the lower end. With a female bar
A female guide groove formed on a needle plate arranged under the cloth and fitted when the cloth cutting knife is lowered,
Provided inside the arm of the sewing machine head frame, the plunger moves in the horizontal direction, and the cloth cutting knife is moved to the rising position on the needle plate and the cutting position for cutting the cloth in the knife guide groove of the needle plate. A reciprocating solenoid to be moved,
A first link arm provided inside the arm of the sewing machine head frame, one end side of which is connected to the plunger of the reciprocating solenoid, and a center portion of which is rotatably supported by a support shaft;
A second link arm provided inside the arm portion of the sewing machine head frame, having one end side rotatably connected to the other end side of the first link arm and the other end side rotatably connected to the knife bar; And
A return spring that urges the female rod upward through the first link arm and the second link arm;
When the plunger of the reciprocating solenoid is urged in one direction, the cloth cutting knife descends through the first and second link arms and the female bar to cut a predetermined portion of the cloth so that a button hole is formed. When the plunger of the reciprocating solenoid is urged in the reverse direction, the cloth cutting knife is lifted through the first and second link arms and the knife bar.
[0008]
When the plunger of the reciprocating solenoid is urged in the reverse direction, the cloth cutting knife ascends through the first and second link arms and the knife bar. Thereby, the cloth cutting knife is reliably raised on the needle plate, and the cloth cutting knife is not locked in the knife guide groove of the needle plate.
Further, the reciprocating solenoid can be lifted up and down and biased from the lowest point, so that the cloth cutting knife can be moved up and down reliably by controlling the timing and the like.
[0011]
Cloth cutting knife devices stitching machine according to claim 2 of the present invention, Oite to claim 1, the knife drive command signal generated after buttonholing sewing complete, the reciprocating solenoid is driven a predetermined time, the fabric The cutting knife is lowered.
[0012]
According to a third aspect of the present invention, there is provided a cloth cutting knife device for a hole sewing machine according to the second aspect , further comprising a sensor for detecting a predetermined position of the cloth cutting knife, and driving the reciprocating solenoid based on a detection signal of the sensor. It is characterized by controlling.
[0013]
According to a fourth aspect of the present invention, there is provided a cloth cutting knife device for a hole sewing machine according to the third aspect , wherein the sensor detects the lowering position of the cloth cutting knife and the reciprocation is performed on the condition of the lowering position detection signal of the sensor. A solenoid is driven to control the cloth cutting knife to be raised.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment example)
In FIG. 1, reference numeral 1 denotes a sewing machine frame on which constituent members such as a sewing machine motor, a needle bar, a needle bar up-and-down mechanism, and a needle swing mechanism are arranged, but the description thereof is omitted.
[0019]
The sewing machine frame 1 includes a bed 3, a vertical body 1 a that stands up from the bed 3, and an arm 1 b that extends substantially parallel to the bed 3 from the vertical body 1 a.
The cloth cutting knife device 5 according to the present invention includes a knife bar 6 which is provided at the tip end 1c of the sewing machine arm 1b so as to be movable up and down, and has the cloth cutting knife 2 fixed to the lower end thereof, and the rear of the arm 1b. Elevating means 7 and urging means 8 provided on the side surface are provided.
[0020]
The female bar 6 is formed in a vertically long rectangular column shape, and is difficult to slide up and down in a groove 1d formed in the tip 1c of the arm 1b.
The elevating means 7 is configured as follows.
That is, a female drive solenoid (first solenoid) 10 is attached to the rear side surface of the intermediate portion of the arm 1b so that the plunger (first plunger) 10a moves along the horizontal direction. The plunger 10a is pulled in the direction of arrow A when energized.
Further, an inverted L-shaped link is disposed on the right side (FIG. 1) of the female drive solenoid 10, and a link arm 30 is supported at the tip of the plunger 10a of the female drive solenoid 10 so as to be rotatable about a horizontal axis. ing.
Further, an inverted L-shaped link arm 11 is supported on the rear side surface of the arm 1b so that the center portion can be rotated by a horizontal support shaft 11a, and the tip end of the link arm 30 extends to the arm portion 11b extending below the link arm 11. It is connected to be rotatable around a horizontal axis.
[0021]
The upper end of the link arm 12 rotatably supported on the side surface of the intermediate portion of the female bar 6 is connected to the tip of the arm portion 11c extending in the lateral direction of the link arm 11 so as to be rotatable about a horizontal axis. .
A return spring 14 is connected to the pin 13 erected on the arm 1 a and the arm portion 11 b of the link arm 11. The return spring 14 urges the link arm 11 counterclockwise (FIG. 1), raises the arm portion 11c, and constantly urges the female bar upward.
The link arm 11 urged by the return spring 14 is held at that position by abutting against a stopper 15 formed of a screw. By screwing the stopper 15 into a nut 15a fixed to the arm 1a, the position of the stopper 15 can be adjusted.
A sensor (proximity sensor) 16 for detecting that the cloth cutting knife 2 has fallen is provided below the arm portion 11c of the link arm 11. When the link arm 11 rotates clockwise and the arm portion 11c approaches the sensor 16, that is, when the cloth cutting knife 2 is positioned at the lowest point.
[0022]
When the knife driving solenoid 10 is actuated and the plunger 10a is retracted after the sewing machine is formed with a hole stitch, the lifting and lowering means 7 is configured so that the link 11 is supported by the return spring with the support shaft 11a as a fulcrum. 14 rotates clockwise (FIG. 1), whereby the knife bar 6 is lowered via the link arm 12, and the cloth is cut by the cloth cutting knife 2 fixed to the lower end thereof.
[0023]
Also, below the plunger 10a of the knife drive solenoid 10, a knife return solenoid (second solenoid, biasing means) 8 is fixed to the rear side surface of the arm 1a.
The female return solenoid 8 is attached so as to move the plunger (second plunger) 8a horizontally. The female return solenoid 8 pushes the plunger 8a in the direction of arrow B when energized, and the arm portion of the link arm 11 is pushed. 11b engages and presses on the lower end. The female return solenoid 8 has a built-in return spring (not shown) for returning the plunger 8a in the opposite arrow B direction.
[0024]
After the knife bar is lowered by the action of the first solenoid 10 and the cloth is cut by the cloth cutting knife 2, the knife returning solenoid 8 is actuated to push out the plunger 8a, which is rotated clockwise in FIG. The arm portion 11b of the link arm 11 is pressed to rotate the link arm 11 counterclockwise. Accordingly, the female bar 6 is raised through the link arm 11 and the link arm 12. Due to the urging of the knife return solenoid 8, the knife bar 6 is raised by a predetermined amount until the cloth cutting knife 2 is separated from the cloth, and the link arm 11 is further rotated counterclockwise by the elastic force of the return spring 14. Returns to the original ascending position.
[0025]
Next, operation | movement of the cloth cutting knife apparatus of the said structure is demonstrated based on the timing chart of FIG.
When the buttonhole sewing for the cloth is completed, the knife drive timing (female drive command signal is generated) is reached, the knife drive solenoid 10 is energized by an ON signal for a predetermined time (female drive solenoid on time), and the plunger is moved. Retracted and retracted. As a result, the link arm 11 rotates and the cloth cutting knife 2 descends to cut the cloth as described above.
[0026]
At the rotational position of the link arm 11 where the cloth cutting knife 2 is located at the lowest point, the arm portion 11c of the link arm 11 is close to the sensor 16, and the sensor (knife lowering detection SW) 16 generates an ON signal. After the female drive solenoid time elapses, the female drive solenoid 10 is de-energized and deactivated by an OFF signal.
[0027]
The female return solenoid standby time is activated by the OFF signal, and after the standby time has elapsed, the female return solenoid 8 is energized for a predetermined time (female return solenoid on time) based on the ON signal of the sensor 16 by the ON signal. The link arm 11 is pressed and rotated counterclockwise by the plunger 8a.
As a result, the cloth cutting knife 2 is forcibly raised on the needle plate from the lowest point, that is, in a state where it enters the knife guide groove of the needle plate, and thereafter rises and returns to the highest point by the elastic force of the return spring 14. .
[0028]
Further, the operation may be performed based on the timing chart shown in FIG. 3 instead of the timing shown in FIG. According to this, when the link arm 11 is rotated so that the cloth cutting knife 2 is positioned at the lowest point by the bias of the knife driving solenoid 10, the sensor (when the knife lowering detection SW16 is turned on is simultaneously driven by the knife. The solenoid 10 is de-energized.
[0029]
From this state, the knife return solenoid 8 is energized after the waiting time of the knife return solenoid, and the knife return solenoid 8 is de-energized when the sensor (knife lowering detection SW) 16 is turned off.
[0030]
As a result, the cloth cutting knife 2 is raised onto the needle plate by the knife return solenoid 8 and then raised and returned to the highest point by the elastic force of the return spring 14.
[0031]
(Second Embodiment)
The cloth cutting knife shown in FIG. 4 is different from the first embodiment in that each mechanism is arranged inside the arm 1 b of the sewing machine frame 1.
As a result, the same effects as those of the first embodiment can be obtained, and there can be no protrusion outside the frame, and the sewing machine can be made compact.
[0032]
(Third embodiment)
Although not shown, the female drive solenoid 10 may be arranged outside or inside the vertical body 1a of the sewing machine frame 1, and accordingly, the link arm 30 may be longer than that shown in FIG. Good.
With this configuration, weight is not added to the arm 1b, the balance of the sewing machine is improved, and vibration can be reduced.
[0033]
(Fourth embodiment)
Further, although not shown, the female drive solenoid as the first solenoid is a reciprocating solenoid with respect to the configuration of FIG. 1, and the reciprocating solenoid is urged in one direction to rotate the link arm 11 in the clockwise direction. Thereby, the cloth cutting knife 2 is lowered. Further, when the reciprocating solenoid is urged in the reverse direction, the link arm 11 is rotated counterclockwise, whereby the cloth cutting knife 2 is raised. Therefore, in this configuration, the reciprocating solenoid as the knife drive solenoid serves as the knife return solenoid 8.
The reciprocating solenoid can be provided inside or outside the arm portion or the vertical trunk portion of the sewing machine frame as in the second and third embodiments.
Furthermore, instead of the reciprocating solenoid, a latch solenoid capable of reciprocating the plunger may be used.
[0034]
(Fifth embodiment)
The positions of the female return solenoid 8 and the proximity sensor 16 of the first embodiment shown in FIG.
[0035]
(Sixth embodiment)
Next, in FIG. 5, in place of the female return solenoid 8 as the second solenoid described in the first embodiment, a slightly thicker sound absorbing property, durability, and excellent repulsive force (elastic force) are combined. It has the same configuration as the first embodiment except that a return member 20 made of rubber and a metal pressing body 21 that presses the return member 20 are arranged.
The return member 20 is formed in a disc shape centered on a fitting hole having a diameter larger than that of the plunger 10a of the female drive solenoid 10, and the fitting hole is fitted to the plunger 10a to form a frame of the female drive solenoid 10. It is fixed.
The pressing body 21 is fixed to an intermediate portion in the axial direction of the plunger 10a, and when the knife driving solenoid 10 is urged and the cloth cutting knife 2 is positioned at the lowest point, the return member 20 is used as a frame of the knife driving solenoid 10. It arrange | positions so that it may pinch between.
[0036]
With this configuration, when the cloth cutting knife 2 is lowered to the lowest point by the urging of the knife driving solenoid 10, the return member 20 and the pressing body 21 are moved in accordance with the movement of the plunger 10a in the direction of arrow A (FIG. 1). It is pinched between the frames and is compressed and deformed due to its characteristics. When the knife drive solenoid 10 is de-energized, the return member 20 tries to return to the steady state from the compression-deformed state due to the movement of the plunger 10a in the direction of arrow B (FIG. 1), and the pressing body. An action force is generated to move 21 in the direction of arrow B by the return force.
[0037]
For this reason, the cloth cutting knife 2 that has been lowered into the knife guide groove of the needle plate is raised onto the needle plate by the acting force accompanying the restoring force. After that, it is raised by the acting force of the return spring 14 as described above.
[0038]
【The invention's effect】
According to the present invention, the cloth cutting knife can be surely detached and raised from the knife guide groove of the needle plate, and the operating rate of the sewing machine is not lowered. Also, miniaturization of the sewing machine, it is possible to reduce the cost, and reduce the feeling of pressure to the operator can remove the discomfort to the operator, and further, can reduce the vibration of the sewing machine to reduce the load on the machine arm . Moreover, the cloth cutting knife can be lifted and lowered without using a return spring.
[Brief description of the drawings]
FIG. 1 is a perspective view from the rear of a sewing machine according to a first embodiment of the present invention.
FIG. 2 is a timing chart of the cloth cutting knife device of the present invention.
FIG. 3 is a timing chart of another embodiment of the cloth cutting knife device of the present invention.
FIG. 4 is a perspective view from the rear of a sewing machine according to a second embodiment of the present invention.
FIG. 5 is a rear perspective view of a sewing machine according to a third embodiment of the present embodiment.
FIG. 6 is an end view showing a state of a needle plate and a cloth cutting knife of a hole sewing machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sewing machine frame 1a Vertical trunk | drum 1b Arm 1c Surface 2 Cloth cutting knife 3 Sewing head 5 Cloth cutting knife device 6 Female bar 7 Lifting means 8 Energizing means 11, 12, 30 Link arm 14 Return spring 15 Stopper 16 Sensor 20 Return member 21 Pressing body

Claims (4)

A female bar which is provided so that it can be moved up and down at the arm tip of the machine head frame, and a cloth cutting knife is fixed to the lower end;
A female guide groove formed on a needle plate arranged under the cloth and fitted when the cloth cutting knife is lowered,
Provided inside the arm of the sewing machine head frame, the plunger moves in the horizontal direction, and the cloth cutting knife is moved to the rising position on the needle plate and the cutting position for cutting the cloth in the knife guide groove of the needle plate. A reciprocating solenoid to be moved,
A first link arm provided inside the arm of the sewing machine head frame, one end side of which is connected to the plunger of the reciprocating solenoid, and a center portion of which is rotatably supported by a support shaft;
A second link arm provided inside the arm portion of the sewing machine head frame, having one end side rotatably connected to the other end side of the first link arm and the other end side rotatably connected to the knife bar; And
A return spring that urges the female rod upward through the first link arm and the second link arm;
When the plunger of the reciprocating solenoid is urged in one direction, the cloth cutting knife descends through the first and second link arms and the female bar to cut a predetermined portion of the cloth so that a button hole is formed. And the cloth cutting knife ascends through the first and second link arms and the knife bar when the plunger of the reciprocating solenoid is biased in the opposite direction. Cloth cutting knife device. The knife drive command signal generated after buttonholing sewing completion, said reciprocating solenoid is driven a predetermined time, the cloth cutting knife device darning sewing machine according to claim 1, wherein the cloth cutting knife, characterized in that descent . A sensor for detecting a predetermined position of the cloth cutting knife;
The cloth cutting knife device for a boring machine according to claim 2 , wherein the driving of the reciprocating solenoid is controlled based on a detection signal of the sensor. The sensor detects the lowered position of the cloth cutting knife,
4. A cloth cutting knife device for a bobbin sewing machine according to claim 3 , wherein the cloth cutting knife is controlled so as to raise the cloth cutting knife by driving the reciprocating solenoid on the condition of a detection position detection signal of the sensor.

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