JP5859248B2 - Double needle sewing machine - Google Patents

Description

  The present invention relates to a two-needle sewing machine.

The two-needle sewing machine is a sewing machine that forms two parallel seams along a predetermined shape by sewing needles attached to two needle bars arranged side by side.
The conventional two-needle sewing machine has changed the sewing direction by manually pressing the fabric so that the seam is formed in a predetermined shape. However, in recent years, it follows the predetermined shape according to predetermined sewing pattern data. Two-needle sewing machines are being developed to form two seams.
For example, two needle bars are held so that they can move up and down, and a needle bar rotating base supported so as to be able to turn around a vertical axis with respect to the sewing machine frame, and two hooks are supported so as to be able to rotate around a vertical axis. This is planned by controlling so that the alignment direction of the two needles is always aligned in a direction perpendicular to the contour line of the predetermined shape with respect to the cloth that moves along the predetermined shape by the cloth holding frame. A sewing machine has been devised that forms two seams along the shape formed (see, for example, Patent Document 1).

Korean Patent No. 10-2008-0089985

By the way, when sewing along a square shape such as a square, a two-needle sewing machine stops the vertical movement of the inner needle bar at the corner and turns only the outer needle bar to form a seam. It is generally done.
Therefore, in order to perform such sewing, the conventional two-needle sewing machine is provided with a latch mechanism for switching between a state in which each needle bar can be moved up and down and a stop state on the needle bar rotating base. The latch mechanism is operated during sewing to switch between the one-needle state and the two-needle state.

However, in the conventional sewing machine, an actuator for switching the latch mechanism is mounted on the needle bar rotating base. For this reason, the turning weight is increased, which hinders high-speed sewing. Although it is possible to replace the motor for turning the needle bar with a large motor, there is a problem that the sewing machine becomes larger and the cost increases.
Further, when an actuator is mounted on a needle bar rotating base that rotates, such as the above-described sewing machine, wiring for energizing the actuator is difficult, and for example, a special part such as a slip ring is required. As a result, the cost increased.

  An object of the present invention is to enable a simple two-needle turning operation while allowing automatic switching between one-needle and two-needle sewing.

According to the first aspect of the present invention, two needle bars that hold the sewing needle and move up and down along the vertical direction, a needle up-and-down moving mechanism that moves the needle bars up and down, and the two needles A needle bar rotating base that supports the bar so as to be movable up and down and is supported by a sewing machine frame so as to be rotatable about a center line in the vertical direction, and the two needle bars via the needle bar rotating base In a two-needle sewing machine comprising: a needle bar rotation mechanism that rotates the needle bar; and a latch mechanism that holds the two needle bars and transmits an up / down movement by the needle vertical movement mechanism. An operation member that releases the holding state of each needle bar by the latch mechanism by performing a position switching operation on the stand, and is fixed to the sewing machine frame and serves as a drive source for the position switching operation of the operation member. Actuator and front from said actuator A differential transmission mechanism for transmitting the position switching operation to the operating member, and the differential transmission mechanism is rotated around the rotation center by the needle bar rotary base and separated from the needle bar rotary base. An input member that is supported so as to be movable and that receives a rotation operation by the actuator, and is supported by the needle bar rotation table so as to be rotatable about a rotation center thereof, and the operation member by the rotation operation. An output member for providing a position switching operation to the needle bar, and the needle bar rotating table supported by the needle bar rotating table so as to be rotatable about the rotation center and rotating the transmitter around the rotation center line of the needle bar rotating table. A rotation support for supporting movement, and a rotation of the output member by the same angle in the reverse rotation direction when a rotation of a predetermined angle is input to the input member without rotating the rotation support. Reverse the rotational force to transmit And a rotation motor that is a driving source of the rotation operation of the needle bar rotation table by the needle bar rotation mechanism is fixed to the sewing machine frame, and the rotation motor is The rotation operation is individually input to both the needle bar rotation table and the rotation support, and the rotation motor is supplied to the needle bar rotation table when the rotation operation is input to the needle bar rotation table. The output member is rotated in the same direction as the needle bar rotary base at the same rotation angle as the needle bar rotary base by inputting a rotary angle that is half the rotational angle of the needle bar to the rotary support. It is characterized by making it.

  The invention described in claim 2 has the same configuration as that of the invention described in claim 1, and further includes a moving mechanism capable of moving the workpiece in an arbitrary direction on a plane perpendicular to the center line of the needle bar. It is characterized by.

  The invention described in claim 3 has the same configuration as that of the invention described in claim 2, and controls the moving mechanism and the rotation motor to form a two-needle stitch along the shape of a predetermined sewing pattern. The sewing machine according to claim 2, wherein the sewing machine is formed.

  The invention according to claim 4 has the same configuration as that of the invention according to any one of claims 1 to 3, and the differential transmission mechanism is a differential gear mechanism using a bevel gear. It is characterized by.

  The invention according to claim 5 has the same configuration as that of the invention according to any one of claims 1 to 3, and the transmission body of the differential transmission mechanism is provided between the input member and the output member. The rotational force is transmitted using a belt or a combination of a belt and a gear.

According to the first aspect of the present invention, the rotation support that supports the transmission body that reverses and transmits the rotational force between the input member and the output member rotates at half the angle when the needle bar rotation table rotates. Therefore, even if the input member connected to the actuator side does not rotate together with the needle bar rotating base and a rotation angle difference occurs between the input members, the needle is It can be rotated at the same rotation angle in the same direction as the bar rotation table. Therefore, the actuating member mounted on the needle bar rotating base can be prevented from being displaced from a predetermined position due to the rotation of the needle bar rotating base.
That is, it is possible to hold the operating member at the correct position without mounting an actuator serving as a driving source for the position switching operation of the operating member on the needle bar rotating base.
As a result, the turning weight of the needle bar turning table can be reduced, and high speed operation can be performed without increasing the size of the motor that performs the turning operation.
Further, since it is not necessary to mount the actuator on the needle bar rotating base, a special part such as a slip ring for energizing the actuator becomes unnecessary, and the manufacturing cost of the sewing machine can be reduced. .

  According to the second aspect of the present invention, since the workpiece moving mechanism is provided, automatic sewing can be performed while the workpiece is moved by the moving mechanism, and the needle bar rotating base is rotated during the sewing process. Even when the sewing machine is executed, the influence on the position switching operation to the operating member can be avoided, and the needle bar can be properly held or released by the latch mechanism even when the sewing operation involving the movement of the workpiece is performed. Is possible.

  According to the third aspect of the present invention, even when the two needle bars are pivoted to form a two-needle stitch along the shape of a predetermined sewing pattern, the position switching operation to the actuating member is prevented. The influence can be avoided, and the needle bar of the latch mechanism can be properly held or released even when the two-needle stitch having a predetermined shape is formed.

  Since the invention according to claim 4 uses a bevel gear for the differential transmission mechanism, the transmission body between the input member and the output member can be realized by a single bevel gear, and the component is simplified. Cost can be reduced.

  According to the fifth aspect of the present invention, the input sprockets and the rotation center lines of the gears constituting the input member, the output member, and the transmission body are all aligned so that they can be easily arranged in a stacked manner, and the differential transmission It is easy to reduce the thickness of the mechanism in the rotation center line direction.

1 is a perspective view of a two-needle sewing machine according to an embodiment of the invention. It is the perspective view shown about the structure in a sewing machine arm part. It is the side view which showed the structure of the periphery of a needle bar. It is sectional drawing of the periphery structure of a needle bar by the cross section along the center of a needle bar. It is sectional drawing along the TT line in FIG. It is a perspective view of a position switching mechanism and an operation member. FIG. 4 is a cross-sectional view taken along the line U-U in FIG. 3. It is sectional drawing along the VV line in FIG. It is sectional drawing along the WW line in FIG. FIG. 10A is an explanatory view showing the change in position of the small sprocket of the needle bar side differential transmission mechanism during the turning operation of the needle bar turntable, and FIG. 10B shows the change in position of the interlocking gear. It is explanatory drawing and FIG.10 (C) is explanatory drawing which shows the position change of a differential member. It is the block diagram which illustrated schematically the mechanism structure of the power transmission mechanism of a hook, and the hook side differential transmission mechanism. It is the figure which showed an example of the sewing pattern which forms two needle stitches. FIG. 13 is a flowchart showing sewing control for forming a two-needle stitch of the sewing pattern shown in FIG. 12. 14A is a perspective view of the needle bar holding support structure, FIG. 14B is a perspective view of another example of the needle bar holding support structure, and FIG. 14C is another example of the needle bar holding support structure. It is a top view.

[Outline of Embodiments of the Invention]
An embodiment of the present invention will be described with reference to FIGS.
The two-needle sewing machine 1 described below as the present embodiment is a so-called electronic cycle sewing machine, and has a holding frame as a cloth holding portion that holds a cloth that is a sewing object to be sewn. By moving relative to the sewing needle of the book, double stitches are formed on the fabric held by the holding frame along a shape pattern based on predetermined sewing data.
1 is a perspective view of a two-needle sewing machine 1 according to the present invention, FIG. 2 is a perspective view showing a configuration in a sewing machine arm portion 101a described later, and FIG. 3 shows a configuration around needle bars 12 and 12 described later. FIG.
Here, a direction in which two sewing needles 11 and 11 to be described later move up and down is a Z-axis direction (vertical direction), and one direction orthogonal to this is an X-axis direction (left-right direction), A direction orthogonal to both the X-axis directions is defined as a Y-axis direction (front-rear direction).

  The two-needle sewing machine 1 has two needle bars 12 and 12 that move up and down along the Z-axis direction, each holding a sewing needle 11 at its lower end, and a sewing needle using a sewing machine motor 21 as a drive source. Needle up-and-down moving mechanism 20 that moves the needle bar up and down, a needle bar rotating base 15 that supports the two needle bars 12 and 12 so as to move up and down, and the two needle bars 12 and A needle bar rotating mechanism 30 that rotates the needle 12 about the center line C along the Z-axis direction, and a latch mechanism that holds the two needle bars 12 and 12 and transmits the vertical movement operation by the needle vertical movement mechanism 20. 50, a stopper mechanism 90 for holding the needle bar 12 released from the holding state of the latch mechanism 50, an operating member 16 for switching the holding state and the releasing state of the needle bars 12, 12 by the latch mechanism 50, and an operating member A position switching mechanism 60 for switching the positions of 16 and the sewing needles 11; 11 includes two hooks 13 and 13 that entangle a lower thread with an upper thread passed through 11, an input shaft 41 and an output shaft 42 that transmit power from the sewing machine motor 21 to the hooks 13 and 13, and a phase difference between these shafts. The hook-side differential transmission mechanism 40 that can be changed and adjusted, the power transmission mechanism 70 that transmits torque from the sewing machine motor 21 to the input shaft 41 of the hook-side differential transmission mechanism 40, and the cloth is held in the XY plane. A cloth movement mechanism 80 as a movement mechanism for arbitrarily moving and positioning along the sewing machine frame 101 is mainly provided.

[Sewing frame]
As shown in FIG. 1, the two-needle sewing machine 1 includes a sewing machine frame 101 whose outer shape is substantially U-shaped when viewed from the X-axis direction. The sewing machine frame 101 is positioned above and below a sewing machine arm portion 101a that extends above the two-needle sewing machine 1 and extends in the Y-axis direction, and a sewing machine bed portion 101b that extends below the two-needle sewing machine 1 and extends in the Y-axis direction. A longitudinal body 101c that connects the sewing machine arm 101a and the sewing machine bed 101b is provided.

[Needle vertical movement mechanism]
As shown in FIGS. 1 to 3, the needle up-and-down moving mechanism 20 includes an upper shaft 22 that is rotatably supported in a state along the Y-axis direction in the sewing machine arm portion 101 a, and an end portion of the upper shaft 22. A sewing machine motor 21 for applying a rotational force, a needle bar crank 23 provided at the other end of the upper shaft 22, a crank rod 24 having one end connected to an eccentric position with respect to the center of rotation of the needle bar crank 23, and a latch A needle bar holder 25 connected to the needle bars 12, 12 via a mechanism 50, and an annular member 26 for holding the needle bar holder 25 so as to be rotatable about the Z axis are provided.

The upper shaft 22 is directly connected to the output shaft of the sewing machine motor 21 and is driven to rotate. The rotation of the upper shaft 22 is converted into an up and down reciprocating motion by the needle bar crank 23 and the crank rod 24 so that the needle bar holder 25 and the ring It is transmitted to the needle bars 12 and 12 through the member 26.
The needle bar rotating base 15 that supports the needle bars 12 and 12 is supported by the sewing machine frame 101 so as to be rotatable about the Z axis, and is rotated about the Z axis with respect to the needle bars 12 and 12 from the crank rod 24. It is necessary to convey the up and down movement operation while allowing the rotation of.
For this reason, the needle bar holder 25 is formed in a substantially ring shape, and the needle bars 12 and 12, the latch mechanism 50 and the needle bar rotating base 15 are inserted through the central opening thereof, and the needle bar 12 is disposed inside the needle bar holder 25. , 12, two support shafts 251 and 251 along the Y-axis direction are connected to both sides of the latch mechanism 50. With the support shafts 251 and 251, the needle bar holder 25 can move up and down integrally with the needle bars 12 and 12 via the latch mechanism 50.
The needle bar holder 25 has a groove 252 formed on the outer peripheral surface thereof over the entire circumference, and the annular member 26 is fitted into the groove 252 and fitted along the groove 252. The joint member 26 is slidable. The annular member 26 has a semicircular shape. One end portion of the annular member 26 in the diametrical direction is connected to the lower end portion of the crank rod 24 so as to be rotatable around the Y axis, and a rectangular square piece 261 is rotatably attached to the other end portion around the Y axis. Has been. Further, a square piece 241 is provided on the opposite side of the lower end portion of the crank rod 24 from the annular member 26 so as to be rotatable around the Y axis. These square pieces 241 and 261 are fitted into guide grooves (not shown) formed in the sewing machine frame 101 along the Z-axis direction, and the annular member 26 and the needle bar holder 25 are maintained in a horizontal orientation. Vertical movement is guided. As shown in FIG. 14A, which is a schematic perspective view of the support structure for the needle bar holder 25, the annular member 26 has a semicircular shape with a half cut, but the annular member 26 has a ring shape that extends around the entire circumference. You may form in.
With this structure, the vertical movement at the lower end of the crank rod 24 is transmitted to the two needle bars 12 and 12 via the annular member 26, the needle bar holder 25, and the latch mechanism 50, and the needle bar rotating base 15 can be allowed to rotate around the Z-axis.

[Needle bar rotating base]
As shown in FIGS. 2 and 3, the needle bar turning base 15 has an upper portion 151 and a lower portion 152 formed in a block shape, and two upper and lower side portions 153 along the Z-axis direction. , 154 are connected.
The upper portion 151 and the lower portion 152 are each formed with a through-hole penetrating the two needle bars 12, 12 extending along the Z-axis direction, and these are rotatably supported by the sewing machine frame 100. Yes. The rotation center line C of the needle bar rotation base 15 is parallel to the Z-axis direction, and is designed to pass through substantially the middle between the two needle bars 12 and 12 when viewed from above. ing.
In addition, a long hole 155 is formed in the side wall portion 153 along the Z-axis direction, and one support shaft 251 that connects the needle bar holder 25 and the latch mechanism 50 is inserted.

[Latch mechanism]
FIG. 4 is a cross-sectional view of the peripheral structure of the needle bar 12 taken along the center of one needle bar 12.
As illustrated, the needle bar 12 described above is formed with a groove 121 along the Z-axis direction, and an engagement hole 122 for the latch mechanism 50 to hold the needle bar 12 is formed below the groove 121. In the upper part of the groove 121, an engagement hole 123 for the stopper mechanism 90 to hold the needle bar 12 is formed. A swing plate 124 for switching the needle bar holding state by the stopper mechanism 90 to the needle bar holding state by the latch mechanism 50 is provided in the groove 121 so as to be swingable.

  The latch mechanism 50 includes a holding body 51 in which two insertion holes for inserting the two needle bars 12 and 12 are formed in the Z-axis direction, and a circular support hole penetrating from the front surface of the holding body 51 to each insertion hole. Two latch members 52 to be inserted, two follower links 53 for moving each latch member 52 forward and backward individually, and a moving force in the forward direction for each latch member 52 via each follower link 53 individually Two pressing springs 54 to be applied, two locking claws 55 that lock each latch member 52 in a retracted state (retracted position), and two locking claws 55 that press in the locking direction, respectively. Two pressing springs 56 and a release pin 57 capable of inputting an operation for releasing the locking by each locking claw 55 from the outside are provided.

The two insertion holes of the holding body 51 are formed along the X-axis direction, and support the substantially cylindrical latch member 52 slidably along the X-axis direction.
The rear end portion of the latch member 52 is connected to a driven link 53, and the driven link 53 presses the latch member 52 toward the needle bar 12 by a pressing spring 54. The end of the latch member 52 is formed in a shape that can be inserted into the engagement hole 122 of the needle bar 12, and the pressing force of the pressing spring 54 causes the engagement between the latch member 52 and the engagement hole 122 of the needle bar 12. In this state, the needle bar 12 is held by the latch mechanism 50.

Further, when the upper end portion of the driven link 53 is pressed downward, the latch member 52 can be retracted, and the holding state of the needle bar 12 by the latch mechanism 50 can be released.
Further, when the latch member 52 is retracted, the locking claw 55 that is constantly pressed upward by the pressing spring 56 locks the tip of the latch member 52 and restricts the forward movement of the latch member 52. The two locking claws 55 can be released from the latched state of the latch member 52 by being pressed downward by the release pin 57.

The upper end portion of the driven link 53 is supported so as to be slidable in the Y-axis direction on the upper portion 151 of the needle bar rotating base 15 when the needle bar 12 reaches the top dead center in the vertical movement of the needle bar 12, as shown in FIG. It can press by colliding with the protrusion 161 (shown in FIG. 4) of the actuating member 16 shown. That is, the operating member 16 can be moved in the Y-axis direction by a solenoid 61 that can switch the position of three positions, and the position P1 that collides with a driven link 53 that releases the holding state of one needle bar 12. Then, control is performed to switch the position between the position P3 that collides with the driven link 53 that releases the holding state of the other needle bar 12 and the position P2 that collides with the release pin 57. The actuating member 16 releases the holding state of each needle bar by the latch mechanism 50 by performing a position switching operation on the needle bar rotating base 15.
Thereby, it is possible to separately hold and release the two needle bars 12 and 12 in the latch mechanism 50.

[Stopper mechanism]
The stopper mechanism 90 includes two stopper members 91 inserted into two circular insertion holes penetrating from the front surface of the needle bar rotation base 15 to the insertion hole of the needle bar 12 in the upper portion 151 of the needle bar rotation base 15. The two press springs 92 that individually press each stopper member 91 toward the needle bar 20, and the cover body 93 that supports each press spring 92 at the rear and covers and closes the insertion hole of the stopper member 91. .

The insertion holes of the stopper members 91 are all formed along the X-axis direction, and support the substantially cylindrical stopper member 91 so as to be slidable along the X-axis direction.
The distal end portion of the stopper member 91 is formed in a shape that can be inserted into the engagement hole 123 of the needle bar 12, and the pressing force of the pressing spring 92 is engaged between the stopper member 91 and the engagement hole 123 of the needle bar 12. The state is maintained, and the holding force of the needle bar 12 by the stopper mechanism 90 is provided.
However, the pressing spring 92 of the stopper member 91 is set to have a sufficiently smaller pressing force than the pressing spring 54 of the latch member 52, and unless the latch member 52 is in the released state, the swing member 124 causes the latch member 52 to move. The needle bar 12 is not held by the stopper mechanism 90. That is, the stopper mechanism 90 is configured to hold only the needle bar 12 whose holding is released by the latch mechanism 50 when the driven link 53 collides with the protrusion 161 of the operating member 16.

[Needle bar rotation mechanism]
FIG. 5 is a sectional view taken along line TT in FIG.
2, 3, and 5, the needle bar rotation mechanism 30 is provided on a rotation motor 31 that is a driving source of the rotation operation of the needle bar 12 and an output shaft of the rotation motor 31. A main drive sprocket 32; a driven sprocket 33 fixedly mounted on the upper end of the shaft-like portion 156 of the needle bar turntable 15; and a timing belt 34 stretched between the main drive sprocket 32 and the driven sprocket 33. ing. The rotation motor 31 has its motor shaft arranged along the Z direction and fixed to the sewing machine frame.
When the rotation motor 31 is driven, the needle bar rotation table 15 can be rotated around the rotation center line C through the main sprocket 32, the timing belt 34 and the driven sprocket 33.

[Position switching mechanism]
6 is a perspective view of the position switching mechanism 60 and the actuating member 16, FIG. 7 is a cross-sectional view taken along line U-U in FIG. 3, FIG. 8 is a cross-sectional view taken along line V-V in FIG. It is sectional drawing along the WW line in FIG.
The position switching mechanism 60 transmits and applies a position switching operation to the actuating member 16 mounted on the needle bar rotating base 15 that rotates from a solenoid 61 as an actuator fixedly mounted inside the sewing machine frame 101. Mechanism.
The position switching mechanism 60 includes a solenoid 61 that can be stopped at three positions, a rack member 62 that is mounted on a plunger of the solenoid 61, and a needle bar side that transmits a position switching operation from the solenoid 61 to the operating member 16 through the rack member 62. And a differential transmission mechanism 63.

The solenoid 61 can be controlled to selectively stop at three positions, and each stop position corresponds to the switching positions P1 to P3 of the operating member 16 described above.
The rack member 62 can move forward and backward along the Y-axis direction by the solenoid 61, and rack teeth are formed along the forward and backward movement direction.

The needle bar side differential transmission mechanism (differential transmission mechanism) 63 includes an input gear 631 as an input member to which a rotation operation is input from a solenoid 61 as an actuator via a rack member 62, and an operation member by the rotation operation. 16, an output gear 632 serving as an output member that gives a position switching operation to 16, a transmission body 64 that reverses and transmits a rotational force between the input gear 631 and the output gear 632, and the transmission body 64 as a needle bar rotation base. 15 is provided with a rotation support 65 (shown in FIG. 3) that supports the rotation around the rotation center line C.
The input gear 631, the output gear 632, and the rotation support body 65 are all supported so as to be rotatable around the rotation center line C by a shaft-like portion 156 formed at the upper end portion of the needle bar rotation table 15. Has been. The input gear 631 includes an upper first gear portion 631a and a lower second gear portion 631b. The gear portions have different tooth shapes but are integrally formed. The rack member 62 is engaged with the first gear portion 631a, and a belt 644 described later is stretched around the second gear portion 631b (input sprocket).

  The input gear 631 is located below the driven sprocket 33 described above, and, as shown in FIG. 7, the upper first gear portion 631a formed on the outer peripheral surface thereof meshes with the rack member 62 described above. The input gear 631 can be rotated separately from the needle bar rotating base 15.

  The rotation support body 65 shown in FIGS. 3 and 7 is fixed to the upper surface of the support plate 651 that supports the transmission body 64 so as to be rotatable about the Z axis, and is rotated by the rotation motor 31 described above. And a sprocket 652 (not shown in FIG. 6) to which motion is input.

The support plate 651 is circular and is positioned below the input gear 631, and is rotatably supported by the shaft-like portion 156 of the needle bar rotating base 15 shown in FIG.
The transmission body 64 described above includes a rotation shaft 641 along the Z-axis direction, a small sprocket 642 fixed to the upper end portion of the rotation shaft 641, and an interlocking gear 643 fixed to the lower end portion of the rotation shaft 641. I have.
The support plate 651 rotatably supports the rotating shaft 641 of the transmission body 64, and a small sprocket 642 is disposed on the upper surface side, and an interlocking gear 643 is disposed on the lower surface side. On the upper surface side of the support plate 651, a belt 644 is stretched over the small sprocket 642 and the second gear portion 631b of the input gear 631, and the small sprocket 642 and the input gear 631 are interlocked in the same rotational direction. It is designed to rotate. When the small sprocket 642 rotates, the interlocking gear 643 connected by the rotation shaft 641 also rotates at the same angular amount in the same direction.

The sprocket 652 has an opening at the center thereof, and the input gear 631 is loosely inserted therein.
The sprocket 652 is fixed to the upper surface of the support plate 651 with a screw (not shown). The small sprocket 642 described above is disposed inside a recess formed on the upper surface of the support plate 651, and is connected to the second gear portion 631 b of the input gear 631 by a belt 644 below the sprocket 652. .
Further, the sprocket 652 is connected to a main driving sprocket 32 provided in the rotation motor 31 of the needle bar rotation mechanism 30 by a timing belt 653.
That is, the rotation motor 31 simultaneously rotates the driven sprocket 33 that rotates the needle bar rotation table 15 and the sprocket 652 that rotates the rotation support body 65 during the drive. It should be noted that the rotation sprocket 33 and the sprocket 652 are such that the rotation angle amount input to the rotation support body 65 from the rotation motor 31 is exactly ½ of the rotation angle amount input to the needle bar rotation base 15. The effective diameter is set. Moreover, these rotation directions are set to the same direction. That is, the rotation motor 31 inputs a rotation angle that is half of the rotation angle to the needle bar rotation table 15 to the rotation support body 65 when inputting the rotation operation to the needle bar rotation table 15.
In this manner, the sprocket 652 is turned from the turning motor 31, whereby the transmission body 64 supported by the support plate 651 can be moved around the turning center line C.

The output gear 632 is positioned below the support plate 651 and meshes with the interlocking gear 643 of the transmission body 64 as shown in FIG. The ratio of the effective diameters of the input gear 631 and the small sprocket 642 and the ratio of the effective diameters of the output gear 632 and the interlocking gear 643 are designed to coincide with each other.
Thus, when rotation of a predetermined angle is input to the input gear 631 in a state where the rotation support 65 is not rotated, the output gear 632 rotates by the same angle in the reverse rotation direction.

As shown in FIG. 6, the aforementioned operating member 16 has rack teeth formed on one upper surface thereof, and meshes with the output gear 632. The actuating member 16 is supported by the groove portion 151 a of the upper portion 151 of the needle bar rotating base 15 and is slidable along the tangential direction of the circumscribed circle of the output gear 632.
The solenoid 61 can stop the rack member 62 at three positions. When the rack member 62 stops at each position, the protrusion 161 of the operating member 16 needs to be stopped at each of the positions P1 to P3 described above.
On the other hand, the operating member 16 is mounted on a needle bar rotating base 15 that is rotated during sewing. A solenoid 61 that is a driving source for switching the position of the operating member 16 is provided on the sewing machine frame. It is fixed. Therefore, when the needle bar rotating table 15 is rotated, the input gear 631 that meshes with the rack member 62 cannot rotate together with the needle bar rotating table 15, and as a result, the needle bar rotates. A relative rotation operation is performed between the table 15 and the input gear 631.
The needle bar side differential transmission mechanism 63 is configured so that even if a relative rotation angle difference occurs between the needle bar rotary table 15 and the input gear 631 due to the rotation of the needle bar rotary table 15, the needle bar side differential transmission mechanism 63. The position of the operating member 16 with respect to the turntable 15 can be maintained constant.

Hereinafter, the operation state of the needle bar side differential transmission mechanism 63 when the needle bar rotating base 15 is rotated will be described with reference to FIGS. 10 (A) to 10 (C).
Here, a case where the needle bar rotating base 15 rotates 180 ° clockwise with the solenoid 61 stopped is illustrated.
First, as shown in FIG. 10A, when the needle bar turntable 15 is turned 180 ° clockwise by the turn motor 31, the turn support 65 is turned 90 ° in the same direction. Motion is granted. As a result, the small sprocket 642 moves 90 degrees in the clockwise direction. At this time, since the small sprocket 642 is connected to the input gear 631 in a stopped state by the belt 644, the small sprocket 642 itself is counterclockwise (diameter of the input gear 631 / diameter of the small sprocket) × 90 °. Rotation takes place.

Accordingly, as shown in FIG. 10B, the interlocking gear 643 performs the same circular movement and rotation as the small sprocket 642. As a result, the output gear 632 that meshes with the interlocking gear 643 has a clockwise rotation (= 90 °) corresponding to the circular movement of the interlocking gear 643 and a clockwise rotation (= 90 °) due to the rotation of the interlocking gear 643. The output gear 632 is rotated 180 ° in the clockwise direction.
That is, when the needle bar rotating base 15 is used as a reference, the input gear 631 is rotated 180 ° counterclockwise relative to the needle bar rotating base 15, but the output gear 632 is a needle bar. The rotating table 15 is not rotated.

As a result, as shown in FIG. 10C, since the relative angular change between the output gear 632 and the operating member 16 does not occur, the operating member 16 does not move on the needle bar rotating base 15, The protrusion 161 can maintain a fixed position.
Even when the solenoid 61 operates and the input gear 631 is rotated during the rotation of the needle bar rotating table 15, the same can be said as described above. It is possible to position the protrusion 161 of the operating member 16 at the position.

[Power transmission mechanism]
FIG. 11 is a configuration diagram schematically showing the mechanism structure of the hook power transmission mechanism 70 and the hook-side differential transmission mechanism 40.
As shown in FIG. 11, the power transmission mechanism 70 of the two hooks 13, 13 includes a main sprocket 751 coupled to the output shaft of a drive motor 71 that is a rotational drive source of the hook 13, and the hook-side differential transmission mechanism 40. A driven sprocket 752 mounted on the input shaft 41 and a timing belt 753 spanned over the sprockets 751 and 752 in the sewing machine bed portion 101b. Thereby, the rotation of the drive motor 71 is transmitted to each hook 13 via the hook side differential transmission mechanism 40.

[Hook and differential transmission mechanism]
The two hooks 13, 13 are so-called full-rotation horizontal hooks, and are arranged diagonally around the rotation center line C of the needle bar rotation base 15 below the needle plate 16. The hooks 13 and 13 are arranged so that the distance between them is equal to the distance of the sewing needles 11 and 11 so that the upper thread can be captured from the corresponding sewing needles 11 and 11, respectively.
A support shaft 14 is provided at the lower portion of each hook 13, and each support shaft 14 is supported by a hook base (not shown) so as to be rotatable around the Z-axis. The pot base is fixedly mounted on the upper part of the turntable 43 of the hook-side differential transmission mechanism 40, and can be moved around the center line C together with the turntable 43. Rotates around the center line C to perform a turning movement, and can follow the circular movement of the two needle bars 12, 12 by the needle bar rotating base 15.

The shuttle-side differential transmission mechanism 40 is supported by a support frame that is attached to one end portion of the sewing machine bed portion 101 b below the needle bar 12 and is integrated with the sewing machine frame 101.
The hook side differential transmission mechanism 40 transmits the rotational force from the drive motor 71 transmitted from the power transmission mechanism 70 to each hook 13 and rotates it around the support shaft 14, and each hook 13 around the center line C. And the function of correcting the fluctuation of the phase around the support shaft 14 due to the rotation of the position of each hook 13.

  That is, the hook-side differential transmission mechanism 40 has an input shaft 41 to which rotational force is input from the sewing machine motor 21 via the power transmission mechanism 70 and an output that outputs the rotational force transmitted from the input shaft 41 to the hook 13 side. The shaft 42 has a support frame 441 that supports the input shaft 41 and the output shaft 42, and transmits the rotational force between these shafts, and rotates from the output shaft 42 to the support shaft 14 of each hook 13. Rotating operation of the hook transmitting portion 45 for transmitting force, the rotating base 43 that holds the pot base and is rotatably supported around the center line C by the sewing machine frame, and the support frame 441 and the rotating base 43 And a rotation imparting mechanism 46 for imparting the same.

The hook transmission 45 is fixed to the upper end of the output shaft 42 that protrudes from the upper end of the turntable 43, and the lower end of the support shaft 14 of one hook 13 that is adjacent to the main sprocket 451 and that is adjacent to the main drive sprocket 451. A driven sprocket 452 that is fixedly mounted on the portion, a driven sprocket 453 that is adjacent to the driven sprocket 451 on the opposite side of the driven sprocket 452 and fixedly mounted on the lower end of the support shaft 14 of the other shuttle 13, and a top plate A tension pulley 454 supported around the Z-axis on the upper surface of the portion 431, and a both-tooth timing belt 455 spanned between the sprocket and the tension pulley 454 are provided.
With this configuration, when the main sprocket 451 rotates with the output shaft 42, the driven sprockets 452 and 453 rotate in the opposite direction to the main sprocket 451 via the both-tooth timing belt 455.

In the inter-shaft transmission portion 44, the support frame 441 is supported inside the turntable 43 so as to be rotatable around the center line C by the turntable 43, and the support frame 441 supports the input shaft 41 and the output shaft 42. It is rotatably supported around the center line C.
The inter-shaft transmission unit 44 includes a first bevel gear 442 that is fixedly mounted on the opposite end of the input shaft 41 and a second bevel gear 443 that is fixedly mounted on the opposite end of the output shaft 42. A transmission body 445 that pivotally supports a transmission bevel gear 444 that meshes with both the first and second bevel gears 442 and 443 facing each other.
With this structure, the inter-shaft transmission portion 44 forms a so-called differential gear mechanism.

  The rotation imparting mechanism 46 is fixedly installed at the lower end of the support frame 441, and includes a first driven sprocket 461 as a first driven member to which the rotational force to the support frame 441 is input, and the rotation table 43. A second driven sprocket 462 as a second driven member, which is fixedly installed at the lower end portion and receives rotational force to the rotating table 43, and serves as a rotation drive source for the support frame 441 and the rotating table 43. The rotation motor 463, the first main driving sprocket 464 as a first main driving member for inputting the rotational power from the rotation motor 463 to the first driven sprocket 461, and the rotation motor 463 to the second driven sprocket 462. A second main driving sprocket 465 serving as a second main driving member for inputting the rotational force, and a timing base spanned between the first main driving sprocket 464 and the first driven sprocket 461. And bets 466, and a timing belt 467 passed over between the second main driving sprocket 465 and the second driven sprocket 462.

The first driven sprocket 461 and the second driven sprocket 462 have the same effective diameter, and the first main sprocket 464 and the second main sprocket 465 are effective. The size of the diameter is set to 1: 2. That is, the rotation angle imparted to the support frame 441 by driving the rotation motor 463 is half that of the rotation table 43.
Furthermore, since both the first main sprocket 464 and the second main sprocket 465 are fixedly mounted on the output shaft of the rotation motor 463, these sprockets 464 and 465 always rotate together and rotate simultaneously. It has become.

That is, the inter-axis transmission portion 44 has a structure capable of obtaining the same action as the needle bar side differential transmission mechanism 63.
The input gear 631 and the output gear 632 of the needle bar side differential transmission mechanism 63 correspond to the first bevel gear 442 and the second bevel gear 443 of the inter-axis transmission unit 44, and The transmission body 64 corresponds to the transmission bevel gear 444 of the inter-axis transmission unit 44. Further, the needle bar rotation base 15 corresponds to the rotation base 43, and the support frame 441 corresponds to the rotation support body 65.
Thus, when the hooks 13 and 13 are driven, if the two hooks 13 and 13 are turned around the center line C by the turntable 43, the support frame 441 turns at half the angle and the transmission bevel gears. By rotating 444 together with the support frame 441, the phase shift caused by the rotation of the hooks 13 and 13 can be corrected with respect to the output shaft 42 side.
That is, each hook 13 can be swung without causing a phase fluctuation.

[Cloth movement mechanism]
As shown in FIG. 1, the cloth moving mechanism 80 includes a holding frame 81 that holds a sewing object on the upper surface of the sewing machine bed portion 101b, a support arm 82 that supports the holding frame 81 so as to be movable up and down, and a support arm 82. An X-axis motor (not shown) that moves the holding frame 81 in the X-axis direction, and a Y-axis motor (not shown) that moves the holding frame 81 in the Y-axis direction via the support arm 82.
With this configuration, the cloth moving mechanism 80 can move and position the sewing object to an arbitrary position on the XY plane via the holding frame 81, and can perform needle dropping at an arbitrary position for each stitch. It is possible to form a free seam.

[Sewing operation of sewing machine]
A sewing operation for forming a two-needle stitch according to the sewing pattern of FIG. 12 will be described.
First, as a premise, a control unit (not shown) of the two-needle sewing machine 1 has position coordinate data indicating a sewing pattern of one sewing needle 11, and from the position coordinate data to one needle drop position of each stitch. The drive operation amounts of the X-axis motor and the Y-axis motor for dropping the sewing needle 11 are calculated (step S1).

  Further, the progress direction of sewing of each needle is obtained from the data of the drive operation amounts of the X-axis motor and Y-axis motor of each needle, and the needle bars 12 and 12 and the shuttles 13 and 13 are arranged in a direction orthogonal to the travel direction. Each turning angle is calculated (step S3).

  Then, the sewing machine motor 21 is driven to start sewing, the X-axis motor and the Y-axis motor are driven for each stitch to advance the sewing in a predetermined sewing direction, and the needle bars 12, 12 and The rotary motors 31 and 463 are controlled so that the hooks 13 and 13 are arranged in a predetermined direction (step S5).

Further, when the current sewing position is one of the apexes A1 to A4 where the sewing pattern is determined (step S7), the solenoid 61 is released so as to release the holding of the needle bar 12 for performing the inner sewing by the latch mechanism 50. Is controlled (step S9).
As a result, only the needle bar 12 on the outside performs sewing (step S11). That is, the rotation motors 31 and 463 are driven halfway to turn 90 ° to form a corner seam with one needle, and then the holding of the needle bar 12 that has been released by the latch mechanism 50 is resumed. The position of the solenoid 61 is controlled (step S13).

  Then, it is determined whether or not the last needle in the sewing pattern has been reached (step S15), and when the sewing is performed up to the final needle, the driving of all the motors is stopped and the sewing is finished. If the final stitch has not yet been reached, the process returns to step S5 to continue sewing.

[Effect of the embodiment of the invention]
In the two-needle sewing machine 1, as described above, the differential transmission mechanism 63 that transmits the position switching operation from the solenoid 61 to the operating member 16 reverses the rotational force between the input gear 631 and the output gear 632. Since the rotation support body 65 that supports the transmission body 64 that transmits the rotation rotates at a half angle of the needle bar rotation table 15 when the needle bar rotation table 15 rotates, the input gear meshes with the rack member 62. 631 does not rotate with the needle bar rotating table 15, and even if a rotation angle difference occurs between them, on the output gear 632 side, the same in the same direction as the needle bar rotating table 15 by the transmitting body 64. It can be rotated at a rotation angle. Therefore, the operating member 16 mounted on the needle bar rotating base 15 is not displaced by the rotation of the needle bar rotating base 15.
For this reason, even if the solenoid 61 is not mounted on the needle bar rotating base 15, the operating member 16 can be kept in the correct position, and the needle bar 12 can be held and released correctly.
As a result, the turning weight of the needle bar turntable 15 can be reduced, high speed operation can be performed without increasing the size of the turning motor 31 that performs the turning operation, and the sewing speed can be increased. It becomes possible.
Further, since it is not necessary to mount a solenoid on the needle bar rotating base 15, special parts such as a slip ring for energizing the solenoid become unnecessary, and the manufacturing cost of the sewing machine can be reduced. Become.

  Further, the two-needle sewing machine 1 includes a cloth movement mechanism 80, and controls the cloth movement mechanism 80 and each of the rotation motors 31 and 463 to form a two-needle stitch along a predetermined sewing pattern. At this time, the needle bars 12 and 12 are also turned in accordance with the progressing direction of the sewing, but even in this case, the operating member 16 may be displaced due to the rotation of the needle bar rotating base 15. Accordingly, the holding and releasing of the needle bar 12 by the operating member 16 can be correctly executed.

  Further, in the needle bar side differential transmission mechanism 63 of the two-needle sewing machine 1, the transmission body 64 is composed of the small sprocket 642 and the interlocking gear 643 which is a spur gear, and the input gear 631 and the output gear 632 are also spur gears. In addition, since both the sprocket and the gear have their rotation axes oriented in the Z-axis direction, it is easy to reduce the thickness of the needle bar side differential transmission mechanism 63 in the Z-axis direction. For this reason, the needle bar side differential transmission mechanism 63 can be installed even in a limited space around the needle bar 12.

[Others]
In the needle bar side differential transmission mechanism 63, the transmission body 64 is constituted by a small sprocket 642 and an interlocking gear 643 which is a spur gear, and the rotation axes thereof are the same as the rotation axes of the input gear 631 and the output gear 632. Although it is oriented in the axial direction, it is not limited to this structure.
For example, in the differential transmission mechanism 63 on the needle bar side, as in the hook-side differential transmission mechanism 40, the input gear 631 and the output gear 632 are bevel gears concentrically facing each other, and the transmission body 64 is the input gear 631 and A bevel gear that meshes with the output gear 632 simultaneously may be used.
In the case of such a structure, it is not necessary for the transmission body 64 to include a member corresponding to each of the input gear 631 and the output gear 632, and power transmission is performed with a single bevel gear, which is advantageous in terms of reducing the number of parts.

  Conversely, the first and second bevel gears 442 and 443 and the transmission body 445 of the hook side differential transmission mechanism 40 are input gear 631 and output gear 632 like the differential transmission mechanism 63 on the needle bar side. And you may comprise with the same member as the transmission body 64 which consists of the small sprocket 642 and the interlocking gear 643.

  In the above embodiment, as shown in FIG. 14A, the semicircular annular member 26 is fitted in the concave groove 252 of the needle bar holder 25, and the vertical movement of the crank rod 24 is controlled by the needle bar. It was transmitted to Dakimakura 25. Instead, for example, as shown in FIGS. 14B and 14C, an annular member 106 larger than the outer periphery of the needle bar holder 25 and support shafts provided at both ends of the semicircular annular member 106. 107, 107, first square pieces 261, 241 provided outside the support shaft 107, and second square pieces 108, 108 provided inside the support shaft 107 can be easily considered. In this other embodiment, since the second square pieces 108 and 108 support the needle bar holder 25, even if wear or the like occurs, the second square piece 108 may be replaced and maintenance is easy.

DESCRIPTION OF SYMBOLS 1 Two-needle sewing machine 11 Sewing needle 12 Needle bar 13 Hook 14 Support shaft 15 Needle bar rotating base 16 Actuating member 20 Needle up-and-down moving mechanism 30 Needle bar rotating mechanism 31 Rotating motor 40 Hook side differential transmission mechanism 50 Latch mechanism 60 Position switching mechanism 61 Solenoid (actuator)
63 Needle bar side differential transmission mechanism (differential transmission mechanism)
631 Input gear (input member)
632 Output gear (output member)
64 Transmission body 642 Small sprocket 643 Interlocking gear 65 Rotating support body 70 Power transmission mechanism 80 Cloth movement mechanism (movement mechanism)
90 Stopper mechanism 101 Sewing machine frame C Center line

Claims (5)

Two needle bars that hold the sewing needle and move up and down along the vertical direction;
A needle up-and-down movement mechanism for moving up and down each of the needle bars;
A needle bar rotating base that supports the two needle bars so as to be movable up and down and is supported by a sewing machine frame so as to be rotatable around a center line along a vertical direction;
A needle bar rotation mechanism for rotating the two needle bars via the needle bar rotation base;
In a two-needle sewing machine comprising a latch mechanism that holds the two needle bars and transmits the movement of the vertical movement by the needle vertical movement mechanism,
An operation member for releasing the holding state of each needle bar by the latch mechanism by performing a position switching operation on the needle bar rotating base;
An actuator fixed to the sewing machine frame and serving as a drive source for the position switching operation of the operating member;
A differential transmission mechanism that transmits the position switching operation from the actuator to the operating member;
The differential transmission mechanism is
An input member that is pivotally supported by the needle bar pivoting table separately from the needle bar pivoting base and pivoted by the actuator;
An output member that is supported by the needle bar turntable so as to be turnable about its turning center and that gives a position switching operation to the operating member by the turning operation;
A pivot support that is supported by the needle bar pivot base so as to be pivotable about the pivot center, and that supports the transmission body so as to rotate around the pivot center line of the needle bar pivot base. When,
A transmission body that inverts and transmits a rotational force so as to rotate the output member by the same angle in the reverse rotation direction when rotation of a predetermined angle is input to the input member in a state where the rotation support is not rotated; With
While the sewing machine frame is fixedly equipped with a rotation motor that is a driving source for the rotation operation of the needle bar rotation table by the needle bar rotation mechanism,
The rotation motor individually inputs a rotation operation to both the needle bar rotation table and the rotation support,
The rotation motor inputs a rotation angle that is half of the rotation angle to the needle bar rotation table to the rotation support body when the rotation operation is input to the needle bar rotation table. An output member is rotated in the same direction as the needle bar rotation base at the same rotation angle as the needle bar rotation base .   The two-needle sewing machine according to claim 1, further comprising a moving mechanism capable of moving the workpiece in an arbitrary direction on a plane perpendicular to the center line of the needle bar.   The two-needle sewing machine according to claim 2, wherein the two-needle stitch is formed along a predetermined sewing pattern shape by controlling the moving mechanism and the rotation motor.   The two-needle sewing machine according to any one of claims 1 to 3, wherein the differential transmission mechanism is a differential gear mechanism using a bevel gear.   4. The transmission body of the differential transmission mechanism transmits a rotational force between the input member and the output member using a belt or a combination of a belt and a gear. A double needle sewing machine according to claim 1.

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