JP6045392B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine including two needle bars.

In order to perform sewing by selectively using two types of sewing threads with different characteristics such as color and thickness, two needle bars that hold two sewing needles individually are provided, and these are placed at the same needle drop position. 2. Description of the Related Art Sewing machines that perform selective positioning and sewing are conventionally known (for example, see Patent Document 1).
In this sewing machine, a needle bar base that supports two needle bars so as to be movable up and down is provided so as to be horizontally movable with respect to the sewing machine frame, and horizontal movement is imparted by air cylinders connected to the upper and lower parts of the needle bar base. As a result, the positions of the two needle bars were switched.
This sewing machine is also provided with a holding unit that holds the upper thread for each sewing needle so that the upper thread of the sewing needle that has not been sewn is not pulled out of the stitch hole of the sewing needle by pulling the balance. It has been.
These holding units are provided in the middle of the upper thread path from the balance to the sewing needle, and are configured to hold the upper thread by the operation of the air cylinder. And the control which hold | maintains an upper thread with respect to the holding unit of the sewing needle which has not performed sewing was performed.

JP 2010-12271 A

  However, since the conventional sewing machine has a structure in which the horizontal movement operation is given to the upper and lower portions of the needle bar base individually by the air cylinder when the needle bar is switched, the two air cylinders are accurately synchronized. If it does not operate, the needle bar base is inclined and the smooth movement operation is hindered, which may cause malfunction.

  Further, the conventional sewing machine employs a structure that imparts a horizontal movement operation to the needle bar base when the needle bar is switched. For this reason, for example, when a vertical movement operation is applied to each needle bar by the crank mechanism from the upper shaft, the crank rod rotates according to the horizontal movement distance of the needle bar base, and each sewing is performed before and after the needle bar is switched. There was a difference in the height of the needle. Then, a stitch is formed with one hook below the needle plate and the selected sewing needle, but there are differences in the sewing conditions such as the positional relationship between the sewing needle and the sword tip of the hook between the two sewing needles. There was also a problem that would occur.

  Furthermore, since the conventional sewing machine is provided with an upper thread holding unit for each sewing needle, two actuators such as an air cylinder as a driving source are required, and these actuators are individually controlled. There is also a problem that the configuration of the entire apparatus is complicated, the number of parts is increased, and the control system is complicated.

  An object of the present invention is to facilitate the switching operation of two needle bars.

  The present invention provides two needle bars that individually hold sewing needles at the lower end, a needle bar base that supports the two needle bars so as to be movable up and down, and the two needle bars through a needle bar holder. Needle up / down movement mechanism for giving up / down movement operation and a needle bar provided individually for the two needle bars and switching between the holding state of the needle bar by the needle bar base and the holding state of the needle bar by the needle bar holder A stop mechanism, a stop selection mechanism for inputting the switching of the two holding states to each of the needle bar stop mechanisms, and a switching drive mechanism for selecting a needle bar to be used for sewing through the needle bar base. The needle bar base is supported by a sewing machine frame so that the lower end side of the two needle bars can swing, and the switching drive mechanism applies a swing operation to the needle bar base. The two needle bars are selected by To.

  In the above invention, the stop selection mechanism includes a switching member that selects one of the two needle bar stop mechanisms and inputs switching between the two holding states, and the two needles with respect to the switching member. It is good also as a structure provided with the actuator which provides the operation | movement which selects which of the said needle bar stop mechanisms of a bar | burr inputs the switch to the said holding state.

  Further, in the above invention, the switching member of the stop selection mechanism is pivotally supported on a support shaft for the swinging motion of the needle bar base, and the needles of the two needle bars are rotated by the rotation around the support shaft. A configuration may be adopted in which switching to the holding state is individually input to the rod stopping mechanism.

Further, in the above invention, the switching drive mechanism has a fitting groove formed along a rocking radial direction with respect to the needle bar base, a square piece fitted into the fitting groove, and a rocking piece. One end side is fixed to the input arm to which the operation is input, and the cam shaft is provided with an eccentric cam portion attached to the square piece on the other end side;
It is good also as a structure provided with the 2nd actuator which provides rocking | fluctuation motion to the said needle bar base via the said input arm.

Further, in the above invention, in accordance with the selection as the needle bar used for the sewing by the switching drive mechanism, the upper thread supplied to the sewing needle held by the non-selected needle bar is transferred to the sewing needle and the balance. A thread holding device, and the thread holding device includes a movable holding member mounted on the needle bar base and a fixed holding member fixedly mounted on the sewing machine frame, and the fixed holding member Has two opposing portions that oppose each of both ends of the movable holding member in the swinging direction of the needle bar base, and the two opposing portions together with the movable holding member are two needle bars. Each upper thread supplied to the sewing needle may be individually clamped.
The fixed holding member of the above-described yarn holding device has a connecting portion that connects the two facing portions, and two threading holes formed in the connecting portion, and is supplied to the sewing needles of two needle bars. It is good also as a structure which lets each upper thread passed separately.

In the above invention, since the needle bar used for sewing is selected by swinging the needle bar base supporting the two needle bars, the selection operation is given to the needle bar base with one drive source. Is possible.
Therefore, it is not necessary to accurately synchronize the two drive sources as in the case where the two upper and lower portions of the needle bar base are moved horizontally at the same time. It is also possible to improve the reliability of the selection operation.

Conventionally, since the needle bar is selected by horizontally moving the needle bar base, the horizontal movement amount of the needle bar holder in the selection operation is equal to the interval between the sewing needles of the two needle bars. On the other hand, according to the present invention, since the needle bar is selected by swinging the needle bar base, even when the two sewing needles are moved by the distance between them, the needle bar hug located at a position close to the center of swinging. The amount of movement is sufficiently smaller than the interval between the two sewing needles.
This reduces the variation in the sewing needle height when each needle bar is selected, reduces the difference in the sewing conditions, reduces the occurrence of stitch skipping by the hook tip, and improves the sewing quality. It is possible to make it.

  In addition, when the selection operation of the switching member for inputting the switching to the holding state with respect to the needle bar stop mechanism of the two needle bars is provided by the actuator, the operation is independent of the swinging operation of the needle bar base. The selection operation can be controlled, and the selection operation can be performed at an appropriate timing different from the swing operation of the needle bar base.

  In addition, when the switching member of the stop selection mechanism is supported on the support shaft for the swinging motion of the needle bar base, the support shaft can be shared, the number of parts can be reduced, and the device configuration can be simplified. Can be achieved.

  Further, the switching drive mechanism includes a fitting groove on the needle bar base, a square piece to be fitted into the fitting groove, an input arm to which a swing motion is input, one end side fixed to the input arm, and the other end side When the camshaft having the eccentric cam portion mounted on the square piece and the second actuator for imparting the swinging motion to the needle bar base via the input arm are provided, the needle bar base is accurately It can be rocked reliably.

Further, when the needle bar base is provided with the movable holding member of the thread holding device, the movable holding member is moved to one of the fixed holding members by swinging the needle bar base in each direction when the needle bar is selected. The opposing portion and the other opposing portion can be individually brought into contact with each other, and the respective upper threads supplied to the sewing needle held by each needle bar can be clamped by each contact.
Therefore, the yarn holding device does not need one drive source for holding the two upper yarns, and it is possible to simplify the configuration of the entire device, reduce the number of parts, and simplify the control system. Become.
The fixed holding member has a connecting portion that connects two opposing portions and two threading holes formed in the connecting portion, and each upper thread supplied to the sewing needles of the two needle bars is individually When it is configured to allow the thread to pass through the thread, erroneous threading of the left and right threads can be prevented.

1 is a perspective view of a sewing machine according to an embodiment of the invention. It is an expansion perspective view which shows the surface part periphery of a sewing machine. FIG. 3 is an enlarged perspective view of a periphery of a surface portion viewed from a direction different from that in FIG. 2. It is a perspective view of the internal configuration stored in the inside of the surface side tip of the sewing machine arm. It is a front view of a needle bar switching mechanism. It is a perspective view of a needle bar switching mechanism. It is sectional drawing which notched the two needle bars and showed the structure of the internal needle bar stop part. It is a disassembled perspective view which shows the connection state of the cam shaft of a switching drive part, and a needle bar base. It is a front view of a thread | yarn holding device. It is a perspective view of a thread | yarn holding device. It is the block diagram which showed the control system of the sewing machine. FIG. 12A shows a state where the sewing needle of one needle bar is selected as a sewing needle used for sewing, and FIG. 12B shows the sewing needle of the other needle bar used as a sewing needle for sewing. It is a front view of the needle bar switching mechanism showing a selected state. It is a front view of other embodiment of the pushing protrusion of a switching lever. It is a perspective view of other embodiments of a thread holding device. It is the elements on larger scale of other embodiments of a thread holding device. It is detail drawing which looked at other embodiment of the thread | yarn holding | maintenance apparatus from the Y-axis direction.

[Outline of Embodiment]
An embodiment of the present invention will be described with reference to FIGS.
A sewing machine 100 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, and the holding frame is attached to the sewing needle. By relatively moving, a sewing pattern based on predetermined sewing data is formed on the fabric held by the holding frame. The sewing machine 100 has two needle bars 110 and 120, and can be selectively used by switching the needle bars 110 and 120. As a result, for example, two types of upper threads U1, U2 having different characteristics such as color and thickness are inserted into the sewing needles 11, 12 provided on the needle bars 110, 120, respectively, and the sewing patterns are It can be formed from yarn.

FIG. 1 is a perspective view of the sewing machine 100 according to the present invention, FIG. 2 is an enlarged perspective view showing the periphery of the surface portion 105 of the sewing machine 100, and FIG. 3 is an enlarged perspective view of the periphery of the surface portion 105 viewed from a different direction from FIG.
Here, the vertical vertical direction is the Z-axis direction, the horizontal direction perpendicular thereto is the X-axis direction (left-right direction), and the horizontal direction perpendicular to both the Z-axis direction and the X-axis direction is the Y-axis direction (front-rear direction). It is defined as

  The sewing machine 100 includes two needle bars 110 and 120 that move up and down while holding the sewing needles 11 and 12 at their lower ends, and a needle up-and-down movement mechanism 20 that moves the sewing needle up and down using the sewing machine motor 21 as a drive source. A needle bar switching mechanism 30 that switches so that one of the two needle bars 110 and 120 performs a vertical movement operation, and upper threads U1 and U2 that are passed through the sewing needles 11 and 12, respectively. A thread tensioner 131 to 133 that applies a predetermined thread tension, a balance mechanism 14 that pulls up the upper threads U1 and U2 in the same cycle as the needle bars 110 and 120, and a sewing needle 11 or 12 that stops vertical movement. A thread holding device 60 that selectively holds the upper thread U1 or U2 passed through the sewing needle, and a single hook that entangles the lower thread (not shown) with the upper thread U1 or U2 passed through the sewing needle 11 or 12. A hook mechanism (not shown) A cloth moving mechanism 80 as a moving mechanism for holding and positioning the cloth arbitrarily along the XY plane, a sewing machine frame 101 that supports each component of the sewing machine 100, and suppressing the vertical movement of the cloth caused by a needle drop. An intermediate presser 15, first and second thread break sensors 161 and 162 as first and second thread feed detecting means for detecting whether or not the upper threads U1 and U2 are fed, respectively, a thread winding mechanism (not shown), A thread end clamping device 18 that holds the end of the upper thread U1 or U2 that hangs down from the sewing needle 11 or 12 and a control device 90 that serves as an operation control means for controlling the operation of each of the above-described configurations are provided.

[Sewing frame]
As shown in FIG. 1, the sewing machine 100 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 includes a sewing arm portion 102 that extends above the sewing machine 100 in the Y-axis direction, a sewing bed portion 103 that extends below the sewing machine 100 and extends in the Y-axis direction, and the sewing machine arm portion 102 and the sewing bed portion 103. And a vertical body portion 104 for connecting the two.

[Cloth movement mechanism]
As shown in FIG. 1, the cloth moving mechanism 80 includes a holding frame 81 that holds an article to be sewn on the upper surface of the sewing machine bed 103, 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 83 (see FIG. 11) that moves the holding frame 81 in the X-axis direction, and a Y-axis motor 84 (see FIG. 11) that moves the holding frame 81 in the Y-axis direction via the support arm 82. ing.
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.

[Needle vertical movement mechanism]
FIG. 4 is a perspective view of the internal configuration stored inside the front end portion on the surface portion 105 side of the sewing machine arm portion 102.
As shown in the figure, the needle up-and-down moving mechanism 20 applies a rotational force from an upper shaft 22 that is rotatably supported in a state along the Y-axis direction in the sewing machine arm portion 102 and one end portion of the upper shaft 22. The sewing machine motor 21 (see FIG. 11), a counterweight 23 provided at the other end of the upper shaft 22, and a Y-axis around a needle bar crank (not shown) at a position eccentric from the center of rotation of the counterweight 23 A crank rod 24 having one end rotatably connected thereto, and a needle bar holder 25 for selectively holding the needle bar 110 or 120.

In the needle up-and-down movement mechanism 20, the upper shaft 22 is rotated by the output of the sewing machine motor 21, and the rotation operation is converted into the up-and-down movement operation through the counterweight 23, the needle bar crank and the crank rod 24. Then, it is possible to apply a vertical movement operation to any one of the needle bars 110 or 120 held by the needle bar holder 25.
The connection structure between the needle bar holder 25 and the needle bars 110 and 120 will be described later.

[Balance mechanism]
As shown in FIG. 4, the balance mechanism 14 can be rotated to a frame within a bell crank-shaped balance 141 in which a threading hole for inserting the upper threads U <b> 1 and U <b> 2 is formed at one end, and the sewing machine arm section 102. And a balance crank 142 pivotally supported on the shaft. The balance 141 has a base end rotatably supported by the counterweight 23, and an intermediate portion between the base end and the tip is connected to the rotation end of the balance crank 142. As a result, when the upper shaft 22 rotates, the base end portion of the balance 141 performs a revolving motion, and the distal end portion of the balance 141 moves in a predetermined vertical direction with different speeds depending on the ascending operation and the descending operation due to the connection with the balance crank 142. The operation is to be performed.

[First and second thread breakage sensors and thread tensioner]
When the surface portion 105 of the sewing machine arm portion 102 is the front surface, as shown in FIG. 2, the upper yarns U1 and U2 fed out from a thread stand (not shown) are a plurality of yarn guides 171 provided on the right side surface portion of the sewing machine arm portion 102. , 172 form respective yarn paths. In the middle of the yarn path, the first and second yarn breakage sensors 161 and 162, the thread tensioners 131 to 133, and the balance 141 are arranged in this order. It is guided to the respective sewing needles 11 and 12 through a thread holding device 60 (see FIG. 11) provided below 105.

The upper thread U1 is inserted through the first thread break sensor 161, and the upper thread U2 is inserted through the second thread break sensor 162. These thread breakage sensors 161 and 162 are provided with an optical sensor including a light source and a light receiving element at a position where the upper threads U1 and U2 pass. It is possible to detect whether the upper threads U1 and U2 are moving or stopped.
For example, when it is detected by the thread breakage sensors 161 and 162 that the upper threads U1 and U2 that should have been inserted do not exist at the passing position, the thread breakage occurs in the middle of the thread path and the thread breakage occurs. It is expected that the sensor 161 or 162 has fallen off.
In addition, when the upper thread U1 or U2 that should be being sewn is stopped, it is expected that there is a difference in that the upper threads U1 and U2 are not correctly passed through the appropriate sewing needle 11 or 12. Is done.
Conversely, when the upper thread U1 or U2 that is not being sewn is moving, the upper threads U1 and U2 are spangled and the other upper threads U1 and U2 are entangled and fed together. It is expected that
As described above, the first and second thread breakage sensors 161 and 162 can detect various abnormal states in light of surrounding sewing conditions.

The upper thread U1 is stretched over the thread tensioner 131, and the upper thread U2 is stretched over the thread tensioner 132, and individual thread tensions are applied to the upper thread U1 and U2.
Further, the thread tensioner 133 is shared by the upper threads U1 and U2, and the same thread tension is applied thereto.
The above-described balance 141 is arranged so that the tip portion protrudes outside from the right side surface portion of the sewing machine arm portion 102, and the upper yarns U1 and U2 hung on the thread tensioner 133 are placed in the respective threading holes. It is inserted.

[Needle bar switching mechanism: Overall]
FIG. 5 is a front view of the needle bar switching mechanism 30, and FIG. 6 is a perspective view. The needle bar switching mechanism 30 includes a needle bar base 31 that supports the two needle bars 110 and 120 so as to be movable up and down, and a support block 35 that supports the needle bar base 31 in the upper part in the vicinity of the surface portion 105 of the sewing machine arm portion 102. , Needle bar stop portions 32, 32 (shown in the figure) that can be switched between a holding state (vertical movement operation state) with respect to the needle bar base 31 and a holding state with respect to the needle bar holder 25 (top dead center position stop state). 7), the stop selection part 33 that performs the switching operation of the holding state for each needle bar stop part 32, 32, and the sewing needle 11 or 12 of the needle bar 110 or 120 to be used are aligned with a predetermined sewing position. And a switching drive unit (switching drive mechanism) 34 for performing the above operation.

[Needle bar switching mechanism: Needle bar base]
The needle bar base 31 is composed of an upper block 311 and a lower block 312 that are spaced apart from each other in the vertical direction, an erection portion 313 that is connected to the upper block 311 and the lower block 312, and a plate shape that extends further upward from the upper surface of the upper block 311 The support portion 314 is integrally formed.
The needle bar base 31 is supported by the support block 35 so as to be swingable about the Y axis via a support shaft 315 inserted into a support hole formed through the support portion 314 along the Y-axis direction. ing. The support block 35 is fixed to the sewing machine arm portion 102 with screws (not shown).

The upper block 311 and the lower block 312 are vertically arranged at a fixed separation distance by the installation portion 313, and the needle bar 110 and 120 are inserted into the upper block 311 and the lower block 312, respectively. The insertion holes 316 and 316 and the needle bar insertion holes 317 and 317 are formed so as to penetrate vertically.
The needle bar insertion holes 316 and 316 and the needle bar insertion holes 317 and 317 are all penetrating along the longitudinal direction of the needle bar base 31. Therefore, when the longitudinal direction of the needle bar base 31 is in a posture parallel to the Z-axis direction, the needle bar insertion holes 316 and 316 and the needle bar insertion holes 317 and 317 are also substantially parallel to the Z-axis direction. .
Furthermore, one needle bar insertion hole 316 and one needle bar insertion hole 317 are concentric and have the same diameter, and the other needle bar insertion hole 316 and the other needle bar insertion hole 317 are also concentric and have the same diameter. Each is formed.
The upper portion of one needle bar 110 is supported by one needle bar insertion hole 316 and the lower portion is supported by one needle bar insertion hole 317. The other needle bar 120 is supported at its upper part by the other needle bar insertion hole 316 and at its lower part by the other needle bar insertion hole 317.
The needle bar insertion holes 316 and 316 and the needle bar insertion holes 317 and 317 are all provided with sliding bearings (not shown) inside, and the needle bars 110 and 120 smoothly move up and down. It is possible to do. That is, the needle bar base 31 supports the two needle bars 110 and 120 so as to be movable up and down.

[Needle bar switching mechanism: Needle bar stop]
Both the needle bar 110 and the needle bar 120 have a hollow tubular shape, and a part of the configuration of the needle bar stop portion 32 is stored in the inside. FIG. 7 is a cross-sectional view showing the configuration of the needle bar stop portion 32 inside by cutting out the needle bars 110 and 120.
Each needle bar stop portion 32 can switch the needle bar 110, 120 between a holding state with respect to the needle bar base 31 and a holding state with respect to the needle bar holder 25. Then, a stop selection unit 33 described later performs a predetermined external operation on each needle bar stop unit 32, and one needle bar 110 is held by the needle bar holder 25 and the other needle bar 120 is a needle bar base. Switching between the first selection state held by the needle 31 and the second selection state where one needle bar 110 is held by the needle bar base 31 and the other needle bar 120 is held by the needle bar holder 25. Thus, only one of the needle bars 110 or 120 can be selectively moved up and down.

The needle bar stop portions 32 provided on each of the needle bar 110 and the needle bar 120 have the same configuration. In addition, a pin protrusion / retraction hole 111, an upper ball protrusion / retraction hole 112, and a lower ball protrusion / retraction hole 113 provided in the needle bar 110 corresponding to the needle bar stop portion 32, a pin protrusion / retraction hole 121 provided in the needle bar 120, The hole 122 and the lower ball in / out hole 123 (both described later) have the same structure.
Accordingly, only the needle bar stop 32 on the needle bar 110 side will be described, and the description of the needle bar stop 32 on the needle bar 120 side will be omitted.

  The needle bar stop 32 includes a stop bar 321 inserted into the tubular shape of the needle bar 110, a pressing spring 322 that presses the stop bar 321 upward within the needle bar 110, and an outer peripheral surface from the inside of the needle bar 110. Needle bar driving ball 323 and needle bar stop ball 324, which can be fitted into upper ball in / out hole 112 and lower ball in / out hole 113, respectively, and needle bar holding body 25, needle bar 110 is dropped. In order to prevent this, a stopper 325 fixed on the outer periphery is provided.

The stop bar 321 has a pin-shaped part 321a having a smaller diameter than the other parts of the stop bar 321 at the upper end thereof, and the pin-shaped part 321a is normally connected to the needle by pressing upward by the pressing spring 322. The pin 110 protrudes upward and outward from a pin retracting hole 111 formed on the upper end surface of the rod 110.
Further, the stop bar 321 has first and second groove cam portions 321b and 321c formed at two locations on the upper and lower sides. These groove cam portions 321b and 321c are formed with a smaller diameter than other portions of the stop bar 321, and the first groove cam portion 321b located on the upper side has a conical taper formed at the inner lower portion of the groove. The second groove cam portion 321c located on the lower side is formed with a conical taper at the inner upper portion of the groove.

A needle bar drive ball 323 and a needle bar stop ball 324 are accommodated in spaces formed between the inner wall surface of the needle bar 110 and the groove cam portions 321b and 321c, respectively.
Further, an upper ball retracting hole 112 penetrating from the inside to the outside is formed at a position where the needle bar driving ball 323 accommodated in the first groove cam portion 321b of the needle bar 110 is faced. At a position where the needle bar stop ball 324 accommodated in the second groove cam portion 321c faces, a lower ball intrusion hole 113 penetrating from the inside to the outside is formed.
The upper ball retracting hole 112 has a larger diameter than the needle bar driving ball 323 on the inner side of the needle bar 110, and has a diameter slightly smaller than that of the needle bar driving ball 323 on the outer peripheral surface of the needle bar 110. It has become. Further, the inner diameter of the lower ball retracting hole 113 and the needle bar stop ball 324 have the same relationship.

When the pin-shaped portion 321a of the stop bar 321 is in a state where it protrudes to the maximum extent (hereinafter, simply referred to as “projection state”), the first groove cam portion 321b is slightly above the upper ball retracting hole 112. The position is set so that the second groove cam portion 321c is positioned with respect to the lower ball retracting hole 113. In this state, the needle bar drive ball 323 is partially protruded from the upper ball retracting hole 112, and the needle bar stop ball 324 is retracted inward from the lower ball retracting hole 113 (the needle bar of FIG. 7). 120).
In addition, when the pin-shaped portion 321a of the stop bar 321 is pushed in (for example, about half to the full length of the protruding shape of the pin-shaped portion 321a: hereinafter referred to as “push-in state”), The groove cam portion 321b of the second ball cam portion 321b matches, and the second groove cam portion 321c is located slightly below the lower ball retracting hole 113. In this state, the needle bar drive ball 323 is retracted inward from the upper ball in / out hole 112, and the needle bar stop ball 324 is partially protruded from the lower ball in / out hole 113 (the needle bar in FIG. 7). 110).

Then, when the needle bar 110 is located at the top dead center height and the needle bar holder 25 is also at the top dead center position, if the pin-shaped portion 321a of the stop bar 321 is in the protruding state, the needle bar 110 is moved from the upper ball retracting hole 112. The needle bar hug 25 can be sandwiched up and down by the needle bar drive ball 323 and the stopper 325 protruding from the part. Accordingly, the needle bar 110 can be held with respect to the needle bar holder 25, and the vertical movement operation from the needle vertical movement mechanism 20 can be transmitted to the needle bar 110.
Further, a ball stopper 326 is provided on the upper surface of the lower block 312 of the needle bar base 31, and a structure that prevents the needle bar 110 from descending with respect to the needle bar base 31 when a protrusion is present on the outer peripheral surface of the needle bar 110. It has become. However, when the pin-shaped portion 321a is in the projecting state, the needle bar stop ball 324 is retracted to the inside of the lower ball retracting hole 113, so that the vertical movement of the needle bar 110 with respect to the needle bar base 31 is not restricted.
Accordingly, the needle bar 110 is in an up / down motion state.

On the other hand, when the needle bar 110 is positioned at the top dead center height and the needle bar holder 25 is also at the top dead center position, if the pin-shaped portion 321a of the stop bar 321 is pushed in, the needle from the upper ball retracting hole 112 Since the bar drive ball 323 moves backward, the holding state of the needle bar 110 with respect to the needle bar holder 25 is released.
Further, since the needle bar stop ball 324 partially protrudes from the lower ball retracting hole 113 when the pin-shaped portion 321a is in the pushed state, the needle stopper 110 is prevented from descending with respect to the needle bar base 31 by the ball stopper 326. Further, the above-described stopper 325 is disposed so as to contact or be close to the lower surface of the upper block 311 of the needle bar base 31 when the needle bar 110 is located at the top dead center. The needle bar 110 is also prevented from moving above the top dead center position.
Therefore, the needle bar 110 is in a holding state with respect to the needle bar base 31.

  Thus, when the needle bar 110 is at the top dead center, the needle bar stop part 32 holds the needle bar 110 with respect to the needle bar hug 25 by pushing the pin-shaped part 321a of the stop bar 321. It is possible to switch from the (vertical movement operation state) to the holding state (top dead center position stop state) with respect to the needle bar base 31. Further, when the pushing operation of the pin-shaped portion 321a is released, the holding state with respect to the needle bar base 31 can be automatically returned from the holding state with respect to the needle bar base 31 by the pressing spring 322.

[Needle bar switching mechanism: switching drive unit]
In the needle bar switching mechanism 30, the needle 11 or 12 can be selected by swinging the needle bar base 31 about the support shaft 315 around the Y axis.
Therefore, in the switching drive unit 34, the tip of the sewing needle 11 and the top dead center when positioned vertically between the top dead center and the bottom dead center in a perpendicular line perpendicular to the center line of the support shaft 315 and lowered downward. And the needle bar base 31 are swung so that the tip ends of the sewing needles 12 positioned in the middle of the bottom dead center have the same inclination angles. In addition, the state in which the tip of the sewing needle 11 and the tip of the sewing needle 12 are at an inclination angle that coincides with the perpendicular line is referred to as “the sewing needle 11 or the sewing needle 12 is in the sewing position”. Each sewing needle 11, 12 forms a seam by sharing one intermediate presser 15 and one hook.

  As shown in FIGS. 4 to 6, the switching drive unit (switching drive mechanism) 34 includes an air cylinder 341 serving as a drive source for the swinging motion of the needle bar base 31, and one rotating arm as a plunger of the air cylinder 341. , A link body 343 having one end connected to the other rotating arm of the bell crank 342, an input arm 346 having one end connected to the link body 343, and one end to the input arm 346. A cam shaft 344 having a fixed portion connected thereto, an eccentric cam 344a provided on the other end side of the cam shaft, and a square piece 347 (shown in FIG. 8) to which the eccentric cam 344a is attached.

  When the plunger of the air cylinder 341 moves forward and backward, the bell crank 342 rotates and the link body 343 moves forward and backward. The other end portion of the link body 343 is connected to the rotation end portion of the input arm 346, and the rotation operation can be imparted to the input arm 346 by the operation of the air cylinder 341. Note that the air cylinder (second actuator) 341 is swingably supported by the sewing machine frame 101, and the displacement in the X-axis direction generated at the connecting portion with the bell crank 342 is allowed by swinging in the forward / backward movement of the plunger. It is possible to do.

  The cam shaft 344 fixedly connected to the input arm 346 includes a circular eccentric cam 344a that is eccentric with respect to the rotation center. The eccentric cam 344a is inserted into the hole 347a of the square piece 347 as shown in FIG. The square piece 347 is fitted in a fitting groove 318 formed in the lower block 312 of the needle bar base 31. The fitting groove 318 is formed in the lower part of the needle bar base 31 along the longitudinal direction (parallel to the swinging radial direction of the needle bar base 31). Accordingly, when the camshaft 344 rotates via the input arm 346 by driving the air cylinder 341, the square piece 347 moves in the left-right direction (X-axis direction), and the needle bar base 31 can be swung. is there.

  Each configuration of the switching drive unit 34 is such that the sewing needle 11 is in the sewing position when the plunger of the air cylinder 341 is in the forward position, and the sewing needle 12 is in the state where the plunger of the air cylinder 341 is in the retracted position. The dimension of each part is designed so that it will be in the state in a sewing position. In addition, either of the configurations of the needle bar base 31 and the switching drive unit 34 is provided with two stoppers so that the sewing needle 11 can be accurately stopped at the position where the sewing needle 11 is at the sewing position and the position where the sewing needle 12 is at the sewing position. Also good. In that case, the position of each stopper may be adjustable, and the positions of the sewing needles 11 and 12 may be adjustable.

[Needle bar switching mechanism: Stop selection section]
The stop selection unit (stop selection mechanism) 33 performs the first operation by pushing the needle bar stop units 32 and 32 of the needle bar 110 and the needle bar 120 with respect to the respective pin-shaped portions 321a and 321a. The selected state (one needle bar 110 is held by the needle bar holder 25 and the other needle bar 120 is held by the needle bar base 31) and the second selected state (one needle bar 110 is the needle bar base 31). And the other needle bar 120 is held by the needle bar holder 25).

  As shown in FIGS. 5 to 7, the stop selection unit 33 includes an air cylinder (actuator) 331 serving as a drive source for the state switching operation of the needle bar 110 and the needle bar 120, and an input arm 332 a on the plunger of the air cylinder 331. And a switching lever (switching member) 332 connected thereto.

The support block 35 is fixed to the sewing machine arm portion 102. The support shaft 315 is fixed to the support block 35. The support shaft 315 supports the needle bar base 31 and the switching lever 332 so as to be rotatable about the Y axis. The switching lever 332 is disposed close to the upper side of the two needle bars 110 and 120.
The switching lever 332 includes an input arm 332a extending in the radial direction around the support shaft 315, and two push-in protrusions 332b and 332c, both extending in a radial direction different from the input arm 332a. Yes.
The switching lever 332 is rotatably supported by the support shaft 315 with the input arm 332a facing upward. The input arm 332 a is connected to the plunger of the air cylinder 331 supported by the support block 35. The air cylinder 331 is supported by the support block 35 so as to be able to swing, and allows the displacement in the Z-axis direction that occurs at the connecting portion of the switching lever 332 to the input arm 332a by swinging when the plunger moves forward and backward. It is possible.

Further, the two pushing projections 332b and 332c are generally directed downward, and the one pushing projection 332b is located at a position facing the pin-shaped portion 321a projecting from the needle bar 110 by the backward movement of the plunger of the air cylinder 331. The other push-in projection 332c is switched to a position facing the pin-shaped portion 321a protruding from the needle bar 120 by the forward movement of the plunger of the air cylinder 331.
Further, the protruding lengths of the push-in protrusions 332b and 332c are such that when the needle bars 110 and 120 are raised to the top dead center height, the pin-shaped portions 321a and 321a hold the needle bars 110 and 120, respectively. The length is set such that the push-in is performed with the push-in amount capable of switching the state.

The swinging operation of the needle bar base 31 by the switching drive unit 34 and the switching operation to the first or second selection state by the stop selection unit 33 are performed in conjunction with each other.
That is, when the needle bar 110, 120 is switched to the first selection state (the state in which the needle bar 110 moves up and down) by the switching lever 332 of the stop selection unit 33, the switching drive unit 34 is connected to the needle bar base 31. The needle bar 110 is swung so that it becomes the sewing position, and the needle bar 110, 120 is brought into the second selected state (the needle bar 120 moves up and down) by the switching lever 332 of the stop selection unit 33. When switching, the switching drive unit 34 swings so that the needle bar 120 of the needle bar base 31 is in the sewing position.

Therefore, when the respective pushing protrusions 332b and 332c of the switching lever 332 are rotated to positions facing the pin-shaped portions 321a and 321a of the needle bars 110 and 120, the swing angle of the needle bar base 31 is taken into consideration. Therefore, the dimensions of the input arm 332a and the push-in protrusions 332b and 332c of the switching lever 332 and the stroke of the air cylinder 331 are set so as to be in an appropriate position.
Further, two stoppers may be provided so that the pushing protrusions 332b and 332c of the switching lever 332 are accurately stopped at an appropriate position when the air cylinder 331 is operated. In that case, the positions of the stoppers may be adjustable, and the stop positions of the push-in protrusions 332b and 332c may be adjustable.

[Thread end clamp device]
The thread end clamping device 18 has a wiper capable of removing the upper thread end hanging from the needle holes of the sewing needles 11 and 12, a suction port capable of sucking the upper thread end guided by the wiper, and a guide guided to the suction port. A ball that clamps the yarn end, an air cylinder 181 (shown in FIG. 11) that moves the ball toward the suction port, and the like are provided.
At the beginning of sewing, after passing the upper thread through the left and right sewing needles 11 and 12, the operator operates the operation panel (not shown) to drive the wiper and suck the left and right upper threads U1 and U2. Guide to the mouth. At the start of sewing, the left and right upper thread ends are sucked into the suction port. However, since the suction force to the thread is weak, when one needle moves up and down to form a seam, the suction to one thread is released. When several stitches are formed, the ball moves and pinches the upper thread of the other needle that does not form the seam, so that the upper thread of the other needle is not caught and sewn. After the thread trimming, the wiper is automatically driven to suck the upper thread end.

[Thread holding device]
9 is a front view of the yarn holding device 60, and FIG. 10 is a perspective view. The thread holding device 60 holds the upper thread U1 or U2 inserted through the sewing needle 11 or 12 that is not selected as a sewing needle for sewing so that the upper thread U1 or U2 is not pulled out from the sewing needle 11 or 12 by the lifting operation of the balance 141. It is for doing.
The thread holding device 60 includes a movable holding member 61 provided at a front lower end of the needle bar base 31 and two opposing parts 621 that are close to and opposed to the movable holding member 61 on both sides in the swinging direction of the needle bar base 31. , 622 and a fixed holding member 62.

The movable holding member 61 is fixed to the lower part of the needle bar base 31 (on the side of the sewing needles 11 and 12 with respect to the support shaft 315), and a thread holding part 611 formed by bending forward is formed at the lower end part thereof. Has been. The thread holding portion 611 has a rectangular flat plate shape along the XY plane, and both left and right side edge portions 611a and 611b are formed in parallel to the Y-axis direction.
The fixed holding member 62 is fixed to the frame of the surface portion 105, and the facing portions 621 and 622 are all disposed so as to be parallel to the YZ plane.

The movable holding member 61 is arranged in a state where the thread holding portion 611 is loosely inserted between the facing portions 621 and 622 of the fixed holding member 62. One opposing portion 621 of the fixed holding member 62 is closely opposed to one side edge 611a of the yarn holding portion 611 on the left side in the X-axis direction, and is fixedly held to the other side edge 611b of the yarn holding portion 611. The other facing portion 622 of the member 62 is closely opposed on the right side in the X-axis direction.
Further, a gap between one side edge portion 611a of the thread holding portion 611 and one facing portion 621 of the fixed holding member 62 serves as a first threading portion for inserting the upper thread U1 inserted through the sewing needle 11. The upper thread U1 on the way from the balance 141 to the sewing needle 11 is inserted.
Further, the gap between the other side edge 611b of the thread holding portion 611 and the other facing portion 622 of the fixed holding member 62 serves as a second threading portion for inserting the upper thread U2 that is inserted into the sewing needle 12. The upper thread U2 on the way from the balance 141 to the sewing needle 12 is inserted.

The movable holding member 61 is mounted on a needle bar base 31 that reciprocally swings along the X-axis direction. When the needle bar base 31 selects the sewing needles 11 and 12 to be sewn, the needle bar switching mechanism 30 is provided. The switching drive unit 34 gives a swinging motion.
When the sewing needle 11 is selected, the switching drive portion 34 swings the lower end portion of the needle bar base 31 to the right, so that the other side edge portion 611b of the thread holding portion 611 of the movable holding member 61 is fixed to the fixed holding member. 62 contacts the other facing portion 622 side. As a result, the upper thread U2 on the side of the sewing needle 12 that is not used is held between them, and it is possible to prevent the upper thread U2 from being pulled out of the sewing needle 12 against the lifting operation of the balance 141.
When the sewing needle 12 is selected, the switching drive unit 34 swings the lower end portion of the needle bar base 31 to the left, so that one side edge 611a of the thread holding portion 611 of the movable holding member 61 is fixed to the fixed holding member. 62 contacts one of the opposing portions 621 side. As a result, the upper thread U1 on the side of the sewing needle 11 that is not used is held between them, and it is possible to prevent the upper thread U1 from being pulled out of the sewing needle 11 against the lifting operation of the balance 141.

[Center press]
The intermediate presser 15 is provided with a frame-like portion in which the sewing needle 11 or 12 selected at the time of sewing can be loosely inserted, and the frame-like portion moves up and down with a small stroke in synchronization with the sewing needle 11 or 12. This is a member for restraining the fabric from swinging up and down greatly due to friction with the sewing needle 11 or 12, and for more reliably pulling out the sewing needle 11 or 12 from the fabric.
The intermediate presser 15 is supported by an intermediate presser drive mechanism (not shown) provided in the sewing machine arm 102, and the intermediate presser drive mechanism obtains power from the upper shaft 22 and imparts an up / down motion operation of the intermediate presser 15. It is carried out.

[Thread winding mechanism]
A thread winding (not shown) is a mechanism for winding a lower thread around a bobbin provided inside the hook. The bobbin winding mechanism includes a bobbin holding base for setting a bobbin, and a power transmission mechanism for obtaining a power from the upper shaft 22 and applying a rotating operation to the bobbin holding base. The power transmission mechanism includes a detection lever that detects that the bobbin is set on the bobbin holding base, and power is transmitted from the upper shaft 22 to the bobbin holding base when the bobbin is detected by the detection lever. Yes. The detection lever is also configured to cut off power transmission from the upper shaft 22 to the bobbin holding base when a predetermined amount of lower thread is wound around the bobbin.

[Sewing machine control system: control device]
FIG. 11 is a block diagram showing a control system of the sewing machine 100. The sewing machine 100 includes a control device 90 as an operation control means for controlling the operation of each unit and each member described above. The control device 90 includes a ROM 92 that stores a program for controlling operations during sewing, a RAM 93 that is a work area for arithmetic processing, and a nonvolatile data memory 94 that stores sewing data. And a CPU 91 for executing a program in the ROM 92.

The CPU 91 is connected to the sewing machine motor drive circuit 21a, the X-axis motor drive circuit 83a, and the Y-axis motor drive circuit 84a through an interface (not shown), and through these, the sewing machine motor 21, the X-axis motor 83, and the Y-axis motor. 84 is controlled.
The sewing machine motor 21 is a servo motor provided with an encoder (not shown), and the detected angle is output to the CPU 91.
The X-axis motor 83 and the Y-axis motor 84 are stepping motors, and origin search means (not shown) is connected to the CPU, and the CPU 91 can recognize the origin positions of the motors 83 and 84 from the output. .
Further, the CPU 91, via an interface (not shown), the air cylinder 331 of the stop selection unit 33 of the needle bar switching mechanism 30, the air cylinder 341 of the switching drive unit 34 of the needle bar switching mechanism 30, and the air cylinder of the yarn end clamping device 18. 181a is connected to drive circuits 333a, 347a, 182a for controlling electromagnetic valves 333, 347, 182 for operating each of the 181.

Further, only the thread tensioner 133 of the above-described thread tensioners 131 to 133 has a built-in solenoid, and the thread tension can be arbitrarily controlled by the control of the control device 90. Accordingly, the drive circuit 133a of the thread tensioner 133 is also connected to the CPU 91 via an interface (not shown).
Further, the first and second thread breakage sensors 161 and 162 for detecting the state of the upper threads U1 and U2 in other cases during sewing are connected to the CPU 91 via a sensor driver 160a.

In the sewing data stored in the data memory 94, the cloth feed amounts of the X-axis motor 83 and the Y-axis motor 84 for moving the cloth to the needle drop position of each stitch for sewing a predetermined sewing pattern are determined. The cloth feed data, the selection sewing needle data that determines which sewing needle 11 or 12 is used, the thread tension data that determines the thread tension, and the like are recorded. Every time, the setting contents of the sewing data are read, and the operation control of each configuration of the sewing machine is executed.
For example, when the CPU 91 reads the cloth feed data for each needle, the X-axis motor 83 and the Y-axis motor 84 are driven at a predetermined upper axis angle to move the cloth to a target needle drop position. .
Further, when the CPU 91 reads the yarn tension data, the built-in solenoid of the yarn tensioner 133 is driven at a predetermined upper axis angle to drive the target yarn tension.

Further, when the CPU 91 reads the selected sewing needle data during the sewing, “sewing machine motor stop” → “upper and lower thread cutting” → “switching of used sewing needle” is executed in order.
That is, in “stop the sewing machine motor”, the CPU 91 controls to stop the sewing machine motor 21 at a predetermined upper axis angle.
In “upper and lower thread cutting”, the CPU 91 controls a thread trimming motor (not shown) to perform thread trimming of the upper thread and the lower thread that have been sewn.
Further, in the “switching of sewing needles to be used”, the CPU 91 operates the air cylinder 331 of the stop selection unit 33 and the air cylinder 341 of the switching drive unit 34 of the needle bar switching mechanism 30 to switch the switching lever 332 and the needle bar base. 31 is swung.
Thereby, the pushing position of the pin-shaped part 321a which protrudes from the upper end of the needle bar 110 or 120 by the switching lever 332 is switched. Further, the needle bar base 31 swings and the sewing needle 11 or 12 is positioned at the sewing position.

[Switching operation of sewing needle to be used]
The above-described “switching the sewing needle to be used” operation will be described in more detail based on the operation explanatory diagram of FIG.
When the CPU 91 of the control device 90 reads the selected sewing needle data from the sewing data in the middle of sewing to form the sewing pattern, for example, the CPU 91 switches from the sewing needle that has been sewn so far to another sewing needle. Here, a case where the sewing needle 12 is switched to the sewing needle 11 is illustrated.
First, the CPU 91 stops the sewing machine motor 21 so as to stop the rotation of the upper shaft 22 at an upper stop position that is a predetermined upper shaft stop angle. For example, the upper axis angle of the upper stop position is the top dead center of the balance 141 (for example, when the needle bar top dead center is 0 °, the upper axis angle is in the range of 30 to 50 °). At this time, since the sewing machine motor 21 is stopped at a position that has passed the needle bar top dead center, the needle bar 120 that holds the sewing needle 12 that has been sewn so far has a lowering operation somewhat from the top dead center position. . Although FIG. 12A shows a state where the needle bar 120 is greatly lowered, the height difference between the needle bar 110 and the needle bar 120 stopped at the upper stop position is the case of FIG. 12A. Smaller than.

Then, the thread trimming motor (not shown) is controlled in the stopped state to perform thread trimming of the upper thread and the lower thread that have been sewn. Next, the wiper of the thread end clamping device 18 is driven, and the upper thread ends of the left and right sewing needles 11 and 12 are guided to the suction port and sucked.
After that, as shown in FIG. 12B, the air cylinder 341 of the switching drive unit 34 of the needle bar switching mechanism 30 is operated to swing the needle bar base 31 in the direction in which the lower end part is directed rightward. As a result, the sewing needle 11 is switched to the sewing position after the sewing needle 12 is disengaged from the sewing position (the position immediately below the support shaft 315).

In addition, the air cylinder 331 of the stop selection unit 33 is operated so that the pushing protrusion 332c of the switching lever 332 is positioned so as to face the pin-shaped portion 321a of the needle bar 120 of the needle bar base 31 after swinging. 332 is rotated.
At this time, since the needle bar 12 is somewhat lowered, the switching lever 332 can be rotated without causing interference between the push-in protrusion 332 c and the pin-shaped portion 321 a of the needle bar 120.

  As the switching lever 332 rotates, the push-in protrusion 332b deviates from the position facing the pin-shaped portion 321a of the needle bar 110, so that the stop bar 321 inside the needle bar 110 is pushed upward by the pressing spring 322. Arise. As a result, the groove cam portion 321c moves upward, and the needle bar stop ball 324 retracts inward in the lower ball retracting hole 113 (see FIG. 7). Accordingly, the state where the needle bar 110 is held by the needle bar base 31 is released. Since the upper shaft 22 is stopped at a position where the upper shaft angle has passed the needle bar top dead center, the needle bar holder 25 is in a somewhat lowered state. The needle bar drive ball 323 cannot protrude outward from the upper ball retracting hole 112, and the needle bar 110 is not held by the needle bar holder 25.

Then, the CPU 91 controls the sewing machine motor 21 to be driven in reverse rotation so as to return from the upper stop position (balance top dead center) to the needle bar top dead center. As a result, the needle bar 120 and the needle bar holder 25 are raised, and the pin-shaped portion 321a of the needle bar 120 comes into contact with the pushing protrusion 332c of the switching lever 332 and is pushed downward. Therefore, the groove cam portion 321 b of the stop bar 321 inside the needle bar 120 is lowered, and the needle bar drive ball 323 is retracted inward from the upper ball retracting hole 112. Further, the groove cam portion 321c is also lowered, and the needle bar stop ball 324 protrudes from the lower ball in / out hole 113. Accordingly, the needle bar 120 is switched to the state in which the needle bar holder 25 is released from the holding state and is held by the needle bar base 31.
On the other hand, in the needle bar 110, the needle bar driving ball 323 protrudes from the upper ball in / out hole 112 and is held by the needle bar holder 25.

When the needle bar base 31 is rotated from the state shown in FIG. 12A to the state shown in FIG. 12B, in the thread holding device 60, the movable holding member 61 moves to the right. The upper thread U1 held between the left side edge portion 611a and the facing portion 621 is released. Further, the right side edge portion 611b of the yarn holding portion 611 of the movable holding member 61 contacts the facing portion 622, and holds the upper yarn U2 therebetween.
Thereafter, the sewing machine motor 21 resumes rotation in the normal rotation direction, and the needle drop by the sewing needle 11 is performed, but the upper thread U2 of the sewing needle 12 is connected to the side edge 611b and the opposing portion 622 of the thread holding portion 611. Therefore, even if the balance 141 is pulled upward, the pull-out from the sewing needle 12 is prevented. In addition, when several stitches are formed after the start of sewing, the ball of the thread end clamping device 18 moves, and the upper thread of the sewing needle 12 that does not form the seam is clamped. Is prevented from being caught and sewn.

[Effects of Embodiment]
The sewing machine 100 includes two needle bars 110 and 120 that individually hold sewing needles at the lower end, a needle bar base 31 that supports the two needle bars so as to move up and down, and two needle bars through a needle bar holder 25. Needle up / down movement mechanism 20 for imparting up / down movement to the needle bar and two needle bars 110, 120 are individually provided, and the needle bar 110 or 120 is held by the needle bar base 31 and the needle bar holder 25 is used. Needle bar stop portions 32, 32 serving as a needle bar stop mechanism for switching between the holding states of the needle bar 110 or 120, and two holding states (the needles by the needle bar holder 25) are provided for each of the needle bar stop portions 32, 32. The selection operation of the stop selection part 33 as a stop selection mechanism for inputting the switching between the holding state of the bar and the holding state of the needle bar by the needle bar base 31 and the selection operation of the needle bar 110 or 120 used for sewing through the needle bar base 31 As a switching drive mechanism to perform The needle bar base 31 is supported by the sewing machine frame of the sewing machine arm portion 101a so that the lower end side of the two needle bars 110 and 120 can swing. The two needle bars 110 and 120 are selected by applying a swinging motion to the needle bar base 31.

In this way, selection of the needle bar used for sewing (positioning of the sewing needle 11 or 12 to the sewing position) is performed by swinging the needle bar base 31 that supports the two needle bars 110 and 120. A selection operation can be given to the needle bar base 31 with an air cylinder 341 as one drive source.
Therefore, compared with the prior art in which the needle bar is selected by simultaneously moving the upper and lower portions of the needle bar base horizontally by the individual drive sources, the needle bars 110, 120 selection operations can be performed smoothly, and it is possible to reduce malfunctions and improve the reliability of the selection operation.

In addition, when the needle bar is selected by moving the needle bar base horizontally as in the conventional method, the amount of horizontal movement of the needle bar holding in the selection operation is the distance between the sewing needles of the two needle bars. Will be equal. As a result, when the sewing needle 11 is selected and when the sewing needle 12 is selected, a significant difference in height may occur in the needle tip.
On the other hand, in the sewing machine 100, since the needle bars 110 and 120 are selected by swinging around the support shaft 315 of the needle bar base 31, the lower ends of the two sewing needles 11 and 12 are equal to the interval between the sewing needles. Even in the case of movement, since the needle bar holder 25 is located closer to the support shaft 315, the amount of movement of the needle bar holder 25 in the horizontal direction can be made sufficiently smaller than the sewing needle interval.
Accordingly, the height difference between the sewing needle 11 and the sewing needle 12 before and after the selection of the needle bar can be sufficiently reduced as compared with the configuration in which the needle bar base is moved horizontally.
As a result, it is possible to reduce the difference in the sewing conditions that occur before and after selecting the needle bar, to reduce the occurrence of stitch skipping by the sword tip of the hook, and to improve the sewing quality.

In addition, the stop selection unit 33 of the sewing machine 100 selects the needle bar stop units 32 and 32 of the two needle bars 110 and 120 to select two holding states (the holding state of the needle bar by the needle bar holder 25 and the needle bar base). The switching lever 332 as a switching member for inputting the switching of the needle bar holding state by 31 and any of the needle bar stop mechanisms 32, 32 of the two needle bars 110, 120 with respect to the switching lever 332 On the other hand, an air cylinder 331 is provided as an actuator for giving an operation of selecting whether to input the switching to the holding state.
For this reason, the switching selection operation of the holding state of each needle bar stop mechanism 32, 32 can be controlled independently of the swinging operation of the needle bar base 31, and the timing is different from the swinging operation of the needle bar base 31. However, the selection operation can be performed.

  Further, the switching lever 332 of the stop selection unit 33 is pivotally supported on a support shaft 315 for swinging the needle bar base 31, and the needle bars of the two needle bars 110 and 120 are rotated around the support shaft 315. Since it is the structure which selects whether the switch to a holding state is individually input with respect to the stop parts 32 and 32, the needle bar base 31 and the switching lever 332 can share the support shaft 315, It is possible to reduce the number of parts and simplify the device configuration.

  Further, the switching drive mechanism 34 is input to the needle bar base with a fitting groove 318 formed along the rocking radius direction, a square piece 347 fitted into the fitting groove, and a rocking motion. One end is fixed to the input arm 346, and a cam shaft 344 having an eccentric cam portion 344a attached to the square piece 347 on the other end, and a swing motion is applied to the needle bar base via the input arm 346. And an air cylinder 341 as two actuators. With this configuration, the needle bar base 31 can be swung accurately and reliably.

Further, the sewing machine 100 is supplied with the needle thread U1 supplied to the sewing needle 11 or 12 held by the unselected needle bar 110 or 120 according to the selection as the needle bar used for sewing by the switching drive unit 34. Alternatively, a thread holding device 60 that holds U2 between the sewing needle 11 or 12 and the balance 141 is provided.
The thread holding device 60 includes a movable holding member 61 mounted on the needle bar base 31 and a fixed holding member 62 fixedly mounted on the sewing machine frame of the sewing machine arm portion 101a. The fixed holding member 62 is movable. The holding member 61 has two facing portions 621 and 622 facing the side edge portions 661a and 661b located at both ends of the needle bar base 31 in the swinging operation direction. Further, each of the two opposing portions 621 and 622 together with the side edge portions 661a and 661b of the movable holding member 61 respectively supplies the upper threads U1 and U2 supplied to the sewing needles 11 and 12 of the two needle bars 110 and 120, respectively. Are configured to be sandwiched individually.

Since the movable holding member 61 of the thread holding device 60 is mounted on the needle bar base 31, each side edge of the movable holding member 61 is caused by the swinging of the needle bar base 31 in each direction when the needle bar is selected. The portions 661a and 661b can be individually brought into contact with one opposing portion 621 and the other opposing portion 622 of the fixed holding member 62, and the sewing needles 11 held by the needle bars 110 and 120 by the respective contacts are provided. , 12 can be held between the upper threads U1, U2.
For this reason, the yarn holding device 60 does not require a single drive source for holding the two upper yarns U1 and U2, simplifies the configuration of the entire device, reduces the number of parts, and simplifies the control system. Can be achieved.

[Others]
The above-described needle bar switching mechanism 30 is not limited to the electronic cycle sewing machine, and may be applied to various sewing machines such as a so-called lockstitch sewing machine. When applied to a lockstitch sewing machine, it is desirable to provide an input means for an operator to instruct the sewing machine control device 90 to execute switching of the needle bars 110 and 120.

In addition, the switching lever 332 of the stop selection unit 33 has a structure including push-in protrusions 332b and 332c protruding outward in the radial direction, and switches the holding state of the needle bars 110 and 120 in the “switching of sewing needles to be used” operation. At this time, the needle bar 110 or 120 held by the needle bar holder 25 is prevented so that the pin-shaped portions 321a and 321a protruding from the upper ends of the needle bars 110 and 120 do not interfere with the pushing protrusions 332b and 332c. The switch lever 332 is rotated when it is in the upper stop position after passing through the top dead center, and then the upper shaft 22 is rotated in the reverse direction to return to the top dead center position to push in the pin-shaped portion 321a.
Here, as shown in FIG. 13, the push-in protrusions 332b and 332c of the switching lever 332 may be connected by a tapered portion 332d that gradually reduces the diameter, and may be formed in an outer peripheral cam shape. As a result, the switching lever 332 can be rotated without interference between the pin-shaped portion 321a of the needle bar 110 or 120 held by the needle bar holder 25 and the pushing protrusion 332b or 332c.
Accordingly, during the “switching of the sewing needle to be used” operation, the sewing machine motor 21 is stopped not at the upper stop position but at the needle bar top dead center, and in this state, thread trimming, rotation of the needle bar base 31, It is possible to rotate the switching lever 332 to switch the needle bars 110 and 120 and resume sewing as it is. That is, the reverse rotation operation of the sewing machine motor 21 is unnecessary, and the needle bar switching operation can be performed quickly.

[Other examples of thread holding device]
Further, instead of the thread holding device 60 shown in FIG. 9, the sewing machine 100 may be equipped with a thread holding device 60A shown in FIGS.
The thread holding device 60A includes a movable holding member 61A fixedly provided near the right side surface of the needle bar base 31 and two movable holding members 61A that are close to and opposed to the movable holding member 61A on both sides in the swinging direction of the needle bar base 31. And a fixed holding member 62A provided with opposing portions 621A and 622A.

The upper end of the movable holding member 61A is fixed by two screws at the right end of the front surface of the needle bar base 31. A lower end portion of the movable holding member 61A is formed with a yarn holding portion 611A that is bent toward the rear in the Y-axis direction. The thread holding portion 611A has a round bar shape along the Y-axis direction.
The left and right side edge portions 611Aa and 611Ab on the outer peripheral surface of the yarn holding portion 611A are opposed to the facing portions 621A and 622A of the fixed holding member 62A, respectively.

  The fixed holding member 62 </ b> A is disposed near the right side of the needle bar base 31. The two opposing portions 621A and 622A of the fixed holding member 62A are both in a flat plate shape that is parallel to the Y-axis direction and slightly inclined with respect to the Z-axis direction, and is substantially inverted U-shaped when viewed from the Y-axis direction. The upper parts of each other are integrally connected so as to form a shape. The fixed holding member 62A is fixed to the frame of the surface portion 105 by the support portion 625A.

Further, the connecting portion of the two opposing portions 621A and 622A has a semi-cylindrical shape, and penetrates the connecting portion up and down to insert the upper thread U1 on the sewing needle 11 side and the upper side on the sewing needle 12 side. A threading hole 624A through which the thread U2 is inserted is formed.
Both the threading holes 623A and 624A are formed in a slit shape along the X-axis direction. The threading hole 623A is formed in the range from the connecting portion of the facing portions 621A and 622A to the facing portion 621A, and the threading hole 624A is formed in the range from the connecting portion of the facing portions 621A and 622A to the facing portion 623A. Yes.
Thereby, the threading hole 623A guides the upper thread U1 inserted from above to the first threading part between the opposing part 621A and the left side edge part 611Aa on the outer peripheral surface of the thread holding part 611A, The threading hole 624A enables the upper thread U2 inserted from above to be guided to the second threading part between the facing part 622A and the left side edge part 611Ab on the outer peripheral surface of the thread holding part 611A. Yes.

Since the movable holding member 61A is mounted on the needle bar base 31 that reciprocally swings along the X-axis direction, the lower end portion of the needle bar base 31 is positioned at the right when the sewing needle 11 is selected by the switching drive unit 34. When it is swung to the right, the right edge 611Ab of the thread holding portion 611A of the movable holding member 61A comes into contact with the facing portion 622A side of the fixed holding member 62A. As a result, the upper thread U2 on the side of the sewing needle 12 that is not used is held between them, and it is possible to prevent the upper thread U2 from being pulled out of the sewing needle 12 against the lifting operation of the balance 141.
Further, when the sewing needle 12 is selected by the switching drive unit 34, the lower end portion of the needle bar base 31 swings to the left, so that one side edge portion 611Aa of the thread holding portion 611A of the movable holding member 61A is fixed to the fixed holding member. It contacts one opposing portion 621A side of 62A. As a result, the upper thread U1 on the side of the sewing needle 11 that is not used is held between them, and it is possible to prevent the upper thread U1 from being pulled out of the sewing needle 11 against the lifting operation of the balance 141.
In the case of the thread holding device 60A, the entire device can be disposed on the right side of the needle bar base 31 and is in the middle of the upper thread path from the balance 141 to the needle bar thread guide 36 provided in the vicinity of the sewing needles 11 and 12. Therefore, the upper threads U1 and U2 can be smoothly guided.

[Effects of other examples]
Since the movable holding member 61A of the thread holding device 60A is mounted on the needle bar base 31, each side edge of the movable holding member 61A is swung in each direction when the needle bar base 31 is selected. The portions 661Aa and 661Ab can be individually brought into contact with one opposing portion 621A and the other opposing portion 622A of the fixed holding member 62A, and the sewing needles 11 held by the needle bars 110 and 120 by the respective contacts are provided. , 12 can be held between the upper threads U1, U2. For this reason, the yarn holding device 60A does not require a single drive source for holding the two upper yarns U1 and U2, simplifies the configuration of the entire device, reduces the number of parts, and simplifies the control system. Can be achieved.
Further, the fixed holding member 62A has a connecting portion that connects two opposing portions, and two threading holes 623A and 624A formed in the connecting portion, and is supplied to the sewing needles of the two needle bars. It was possible to pass the upper thread individually. For this reason, erroneous threading of the left and right threads can be prevented.

[Other inventions]
The yarn holding device 60 and the yarn holding device 60A are used in a sewing machine having a switching drive mechanism 34 that imparts a swinging motion to the needle bar base 31. However, these thread holding devices 60, 60A have a switching drive mechanism such as an air cylinder, and can be used for a sewing machine that applies a horizontal movement operation to the needle bar base.
For the purpose of simplifying the configuration of the entire apparatus, reducing the number of parts, and simplifying the control system, the following configurations of the invention can be easily considered. In addition, what performs both a rocking | fluctuation operation | movement and a horizontal movement operation | movement is only defined as a movement operation | movement.
The configuration of the invention is as follows. In the following description of the configuration, the case where the yarn holding device 60 is mounted is illustrated, but since the yarn holding device 60A can also be mounted, the configuration when the yarn holding device 60A is mounted is also illustrated by the reference numerals in parentheses. To do.
Two needle bars 110, 120 holding the sewing needles individually at the lower end,
A needle bar base 31 that supports the two needle bars 110 and 120 so as to be movable up and down;
A needle up-and-down movement mechanism 20 that gives up and down movement to the two needle bars 11 and 12 through the needle bar holder 25;
Needle bar stop mechanisms 32, which are individually provided for the two needle bars 110, 120, and switch between the holding state of the needle bars 110, 120 by the needle bar base 31 and the holding state of the needle bars 110, 120 by the needle bar holder 25. 32,
A stop selection mechanism 33 for inputting the switching between the two holding states to each of the needle bar stop mechanisms 32, 32;
In a sewing machine provided with a switching drive mechanism 34 that performs a selection operation of the needle bar 110 or 120 used for sewing through the needle bar base 31,
The needle bar base 31 is supported by the sewing machine frame so that the lower end side of the two needle bars 110 and 120 can swing,
The switching drive mechanism 34 selects two needle bars by giving a movement operation to the needle bar base 31,
According to the selection as a needle bar used for sewing by the switching drive mechanism 34, the upper thread U1 or U2 supplied to the sewing needle 11 or 12 held by the non-selected needle bar is used as the sewing needle and the balance 141. Thread holding device 60 (60A) for holding between
The thread holding device 60 (60A) includes a movable holding member 61 (61A) mounted on the needle bar base 31, and a fixed holding member 62 (62A) fixedly mounted on the sewing machine frame,
The fixed holding member 62 (62A) has two opposing portions 621, 622 (621A, 622A) that are opposed to both ends of the movable holding member 61 (61A) in the swinging direction of the needle bar base 31, respectively.
Two opposing portions 621 and 622 (621A and 622A) individually move the upper threads U1 and U2 supplied to the sewing needles 11 and 12 of the two needle bars 110 and 120 together with the movable holding member 61 (61A). It is characterized by being sandwiched between.
With this configuration, the yarn holding device 60 (60A) does not require a single drive source for holding the two upper yarns U1 and U2, simplifying the overall configuration of the device, reducing the number of parts, and control It becomes possible to simplify the system.
When the thread holding device 60A is mounted, the fixed holding member 62A has a connecting part that connects the two facing parts 621A and 622A, and two threading holes 623A and 624A formed in the connecting part, The upper threads U1 and U2 supplied to the sewing needles 11 and 12 of the two needle bars 110 and 120 can be individually passed. For this reason, erroneous threading of the left and right threads can be prevented.

20 Needle vertical movement mechanism 21 Sewing motor 22 Upper shaft 25 Needle bar holding 30 Needle bar switching mechanism 31 Needle bar base 315 Support shaft 32 Needle bar stop part (needle bar stop mechanism)
33 Stop selection unit (stop selection mechanism)
331 Air cylinder (actuator)
332 switching lever (switching member)
34. Switching drive unit (switching drive mechanism)
341 Air cylinder (second actuator)
35 Support block 60, 60A Yarn holding device 61, 61A Movable holding member 611, 611A Yarn holding part 611a, 611b, 611Aa, 611Ab Side edge part 62, 62A Fixed holding member 621, 622, 621A, 622A Opposing part 80 cloth moving mechanism 90 Control device 100 Sewing machine 101 Sewing machine frame 102 Sewing arm parts 11 and 12 Sewing needles 110 and 120 Needle bar 14 Balance mechanism 141 Balance U1 Upper thread U2 Upper thread

Claims (6)

Two needle bars that individually hold the sewing needle at the lower end,
A needle bar base that supports the two needle bars in a vertically movable manner;
A needle up-and-down movement mechanism that gives up and down movement to the two needle bars through needle bar holding;
A needle bar stop mechanism that is individually provided for the two needle bars, and switches between a holding state of the needle bar by the needle bar base and a holding state of the needle bar by the needle bar holder;
For each needle bar stop mechanism, a stop selection mechanism that inputs two switching of the holding state;
In a sewing machine including a switching drive mechanism that performs a selection operation of a needle bar used for sewing through the needle bar base,
The needle bar base is supported by a sewing machine frame so that the lower end side of the two needle bars can swing,
The switching drive mechanism selects the two needle bars by applying a swinging motion to the needle bar base. The stop selection mechanism is
A switching member that selects one of the two needle bar stop mechanisms and inputs the switching of the two holding states;
And an actuator for giving an operation to the switching member to select which of the needle bar stop mechanisms of the two needle bars to input the switching to the holding state. The sewing machine according to claim 1. The switching member of the stop selection mechanism is pivotally supported on a support shaft for swinging movement of the needle bar base,
3. The sewing machine according to claim 2, wherein switching to the holding state is individually input to the needle bar stop mechanism of the two needle bars by a rotation operation around the support shaft. The switching drive mechanism is
A fitting groove formed along the oscillating radial direction with respect to the needle bar base,
A square piece that fits into the fitting groove;
One end side is fixed to the input arm to which the swing motion is input, and the cam shaft is provided with an eccentric cam portion attached to the square piece on the other end side;
The sewing machine according to any one of claims 1 to 3, further comprising a second actuator that imparts a swinging motion to the needle bar base via the input arm. According to the selection as the needle bar used for the sewing by the switching drive mechanism, the upper thread supplied to the sewing needle held by the unselected needle bar is held between the sewing needle and the balance. A thread holding device,
The thread holding device includes a movable holding member equipped on the needle bar base, and a fixed holding member fixed to the sewing machine frame,
The fixed holding member has two opposing portions that are opposed to both ends of the movable holding member in the swinging direction of the needle bar base,
The said two opposing part pinches | interposes each upper thread supplied to the sewing needle | hook of two needle bars with the said movable holding member separately, The Claim 1 characterized by the above-mentioned. The described sewing machine. The fixed holding member is
A connecting portion connecting the two facing portions;
Having two threading holes formed in the connecting portion;
The sewing machine according to claim 5, wherein the upper threads supplied to the sewing needles of the two needle bars are individually passed.

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