JP3749168B2 - Sewing machine needle bar drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a needle bar drive device provided with a jump mechanism for stopping a needle bar at the top dead center during operation mainly in an industrial sewing machine.
[0002]
[Prior art]
Conventionally, a needle bar drive device having a jump mechanism has been proposed in Japanese Patent No. 2752482. As shown in FIGS. 9 and 10, this conventional apparatus includes a guide shaft 72 parallel to the needle bar 71, and a U-shaped lifting body 73 and a needle bar drive member 74 are supported on the guide shaft 72. A needle bar drive cam 76 is fixed to the upper shaft 75 of the sewing machine, and the elevating body 73 and the needle bar drive member 74 are moved up and down integrally through the crank mechanism 77 by the cam 76. The needle bar driving member 74 is provided with an engaging portion 80 that engages with the pin 79 of the needle bar holder 78, and the needle bar 71 and the needle (not shown) are driven as the needle bar driving member 74 moves up and down.
[0003]
The jump mechanism 82 includes a jump cam 83 fixed to the upper shaft 75, an input lever 85 having a cam follower 84 engaged with the jump cam 83, and a roller 87 engaged with the pressing surface 86 of the needle bar drive member 74. The output lever 88 includes a solenoid 89 having a clutch function for coupling the output lever 88 to the input lever 85 so as to be interlocked. The output lever 88 is rotatably supported by a horizontal shaft 91 concentric with the plunger 90 of the solenoid 89, and the input lever 85 is rotatably connected to an intermediate portion of the output lever 88 by a horizontal pin 92.
[0004]
When a jump signal is output at the time of skipping or the like, the solenoid 89 is excited, the plunger 90 is locked to the protruding end 93 of the input lever 85, and the output lever 88 can be interlocked with the input lever 85 around the horizontal axis of the plunger 90. Combined with At a timing when the needle bar 71 is positioned below the top dead center, the needle bar driving member 74 is rotated around the guide shaft 72 by the roller 87, and at a timing when the needle bar 71 stops at the top dead center, The engaging portion 80 is retracted from the pin 79, and the power transmission from the lifting body 73 to the needle bar 71 is interrupted.
[0005]
[Problems to be solved by the invention]
According to the conventional needle bar drive device, since the needle bar drive member 74 is controlled using the jump cam 83, the vertical movement of the needle bar 71 can be accurately canceled at its top dead center. However, since the output lever 88 is rotated around the horizontal axis and the roller 87 is moved circularly in the vertical plane, the power receiving point of the needle bar drive member 74 changes up and down. For this reason, it is necessary to form the press surface 86 of the needle bar drive member 74 vertically long, and the needle bar drive member 74 and the lifting body 73 that supports the needle bar drive member 74 are increased in size. Therefore, these elevating members not only occupy a large space inside the sewing head, but also increase the inertial mass of the elevating member, increase the sliding area, and decrease the stability during high-speed operation. It was.
[0006]
The object of the present invention is to solve the above-mentioned problems, reduce the size and weight of the lifting body and needle bar drive member, reduce the occupied space inside the sewing head, and improve the stability during high-speed operation. It is to provide a driving device.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, a needle bar drive device for a sewing machine according to the present invention includes a guide shaft erected in parallel with the needle bar, a lifting body supported by the guide shaft, and a lifting body that rotates in a horizontal plane. A needle bar drive member that is movably attached, a power transmission mechanism that transmits the power of the upper shaft of the sewing machine to the lifting body, and a jump mechanism that blocks power transmission from the lifting body to the needle bar. Responding to a jump signal, a jump cam fixed to the upper shaft, an input lever rotated around the vertical axis by the jump cam, an intermediate lever provided to be rotatable around the same axis as the input lever And an output lever that is rotated in a horizontal plane by the intermediate lever during the coupling operation of the clutch means, and a needle bar drive member is connected to the output lever from the needle bar. Evacuated Characterized in that a drive unit which rotates location.
[0008]
Here, the power transmission mechanism is not limited to a specific mechanism, and may be configured by appropriately combining various power transmission members such as a cam, a crank, a link, a gear, a belt, and a chain. The clutch means is not limited to a specific means, and can be configured using an actuator that can be electrically controlled by a control device of the sewing machine, such as a solenoid, an air cylinder, or a motor. The drive unit of the output lever is not limited to a specific shape, but in order to combine the function of retracting the needle bar drive member with the drive unit and the function of raising and lowering the needle bar drive member at the retracted position, It is preferable to form it long in the vertical direction with a length corresponding to the stroke of the lifting body.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in an industrial embroidery sewing machine needle bar driving device will be described with reference to the drawings. As shown in FIGS. 1 to 3, a rotating plate 3 is assembled to the lower end of the frame 1 of the sewing machine head via a bearing metal 2 so as to be rotatable in a horizontal plane, and a plurality of needle bars 4 and cloth are attached to the rotating plate 3. The presser bar 5 is supported vertically. A needle bar head 6 is fixed to the upper end of the needle bar 4, a needle 7 is fixed to the lower end of the needle bar 4, and a presser foot 8 is fixed to the lower end of the presser bar 5. The rotary disk 3 is driven by a known needle bar switching mechanism, and one needle bar 4 is indexed to a sewing position corresponding to a needle hole (not shown) of the sewing machine bed.
[0010]
On the rear side (the right side in FIG. 1) of the needle bar 4, a guide shaft 10 is erected in parallel with the needle bar 4 on the bearing metal 2, and an elevating body 11 is supported on the guide shaft 10. An attachment piece 12 projects from the lower end of the elevating body 11 toward the needle bar 4, and a needle bar drive member 13 is attached to the attachment piece 12 by a vertical pin 14 so as to be rotatable in a horizontal plane. The needle bar driving member 13 is made of a hard resin and thin, and a passive piece 15, a pressing piece 16, and a contact piece 17 (see FIG. 3) are radially projected on the outer peripheral surface. A spring 18 that biases the needle bar drive member 13 to a position where it engages with the needle bar 4 is interposed between the passive piece 15 and the elevating body 11, and the contact piece 17 moves up and down at this engagement position. The pressing piece 16 is fitted into the notch 20 of the needle bar head 6 in contact with the stopper 19 of the body 11.
[0011]
On the rear side of the guide shaft 10, an upper shaft 22 of the embroidery sewing machine is horizontally passed through the head frame 1, and a needle bar drive cam 23 is fixed to the upper shaft 22. A ring portion 25 of the crank rod 24 is fitted to the needle bar drive cam 23, and a lower end of the crank rod 24 is pivotally attached to an intermediate portion of the drive lever 26. The rear end of the drive lever 26 is supported by a fixed shaft 27 of the frame 1, and the front end of the drive lever 26 is connected to the lift body 11 via a link 28. The needle bar drive cam 23, the crank rod 24, the drive lever 26 and the link 28 constitute a power transmission mechanism 29 that transmits the power of the upper shaft 22 to the elevating body 11.
[0012]
Next, the jump mechanism 31 that blocks power transmission from the lifting body 11 to the needle bar 4 will be described. As shown in FIGS. 2 to 6, a jump cam 32 is fixed to the upper shaft 22, and a substrate 33 is horizontally provided on the frame 1. A stopper 34 for stopping the needle bar 4 at the top dead center is attached to the front end of the substrate 33, and a cylindrical vertical axis 35 is vertically fixed to the rear end of the substrate 33. An input lever 36 is supported horizontally on the vertical axis 35, a cam follower 37 is attached to the tip of the input lever 36, and a locking piece 39 projects from a boss portion 38 at the base end. The cam follower 37 is pressed against the end face of the jump cam 32 by a spring 40, and the input lever 36 is rotated around the vertical axis of the vertical axis 35 according to the cam shape.
[0013]
Above the input lever 36, a suction type solenoid 43 is installed on the substrate 33 via a bracket 42, and a rod 46 is coupled to the plunger 44 via a coupling 45. The rod 46 penetrates the vertical axis 35 and is urged downward by a compression spring 47. An arm 48 is fixed to the lower end of the rod 46, and a pin 49 is erected on the arm 48. Between the arm 48 and the input lever 36, the intermediate lever 50 is assembled to the vertical axis 35 so as to be rotatable around the same axis as the input lever 36. A vertical hole 52 extends through the boss 51 of the intermediate lever 50, and a pin 49 is inserted into the vertical hole 52 from below.
[0014]
When the solenoid 43 constitutes a clutch means and the solenoid 43 is excited in response to the jump signal, the rod 46, the arm 48 and the pin 49 are pulled up by the plunger 44, and the upper end of the pin 49 is the boss portion of the intermediate lever 50. 51 protrudes upward from 51 and engages with a locking piece 39 of the input lever 36 (see FIG. 6), and the intermediate lever 50 is coupled to the input lever 36 so as to be interlocked. Further, at the time of normal sewing, the solenoid 43 is demagnetized, the arm 48 is pushed down by the compression spring 47, and the upper end of the pin 49 is immersed in the vertical hole 52 of the intermediate lever 50 and disengaged from the locking piece 39 (see FIG. 4). The power transmission from the input lever 36 to the intermediate lever 50 is interrupted.
[0015]
The intermediate lever 50 is formed in a plane L shape, a connecting roller 54 is attached to the tip of the long side portion, and a spring hook 55 is provided at the tip of the short side portion. A stopper 56 and a spring receiver 57 are fixed to the lower surface of the substrate 33 at a position sandwiching the intermediate lever 50, and a tension spring 58 that biases the intermediate lever 50 toward the stopper 56 between the spring receiver 57 and the spring hook 55. Is stretched. Therefore, when the solenoid 43 is excited, the intermediate lever 50 is reciprocally rotated integrally with the input lever 36 in a state where the upper end portion of the pin 49 is in contact with the locking piece 39 by the urging force of the tension spring 58.
[0016]
Between the intermediate lever 50 and the needle bar driving member 13, an output lever 61 is horizontally supported at the intermediate portion by the vertical shaft 60 on the substrate 33. A notch 62 is formed at the rear end of the output lever 61, and a drive unit 63 is suspended downward at the front end. The coupling roller 54 of the intermediate lever 50 is fitted in the notch 62, and the output lever 61 is rotated in a horizontal plane by the intermediate lever 50 when the solenoid 43 is excited. The driving portion 63 is formed by a pin-like member so as to be long in the vertical direction with a length corresponding to the stroke of the elevating body 11, and is a passive piece as the output lever 61 rotates in one direction (clockwise in FIGS. 3 and 5). 15, the pressing piece 16 is made to escape sideways from the notch 20 of the needle bar head 6, and the needle bar driving member 13 is rotated to a position retracted from the needle bar 4.
[0017]
In the needle bar driving device having the above-described configuration, when one needle bar 4 is indexed to the sewing position by the rotating disk 3, the pressing piece 16 of the needle bar driving member 13 is inserted into the notch 20 of the needle bar head 6. . The elevating body 11 and the needle bar drive member 13 are driven by the upper shaft 22 via the power transmission mechanism 29, and the needle bar 4 and the cloth presser bar 5 are driven up and down by the needle bar drive member 13. At this time, the input lever 36 is rotated by the jump cam 32, but since the solenoid 43 is demagnetized, the power transmission from the input lever 36 to the intermediate lever 50 is interrupted, and the intermediate lever 50 is stopped by the tension spring 58. 56, the output lever 61 is stopped, and the drive unit 63 is held at a position away from the passive piece 15 (see FIG. 3).
[0018]
When a jump signal is output from the control device of the sewing machine during a stitch skipping during sewing, the solenoid 43 is excited, the pin 49 is pulled up by the plunger 44, and the upper end of the pin 49 is connected to the locking piece 39 of the input lever 36. Engage and the intermediate lever 50 is coupled to the input lever 36. Then, according to the cam shape of the jump cam 32, the input lever 36, the intermediate lever 50, and the output lever 61 are rotated in conjunction with each other, and at the top dead center of the needle bar 4, the needle bar driving member 13 is moved to the needle bar by the drive unit 63. 4 is evacuated. Thereby, the power transmission from the lifting body 11 to the needle bar 4 is interrupted, and the lifting body 11 and the needle bar drive member 13 are lowered while the needle bar 4 is stopped at the top dead center.
[0019]
In the section from the lowering of the lifting body 11 to just before the rising end, the cam follower 37 is engaged with the height 32a (see FIG. 5) of the jump cam 32, the needle bar driving member 13 is held at the retracted position by the driving unit 63, And it is guided up and down along the drive part 63. When the elevating body 11 reaches just before the ascending end, the cam follower 37 is engaged with the low portion 32b (see FIG. 3) of the jump cam 32, the intermediate lever 50 and the output lever 61 are returned by the tension spring 58, and the needle The bar driving member 13 is returned by the spring 18 and is engaged with the needle bar 4 at the rising end of the elevating body 11. Thereafter, if the jump signal disappears, the needle bar driving member 13 is held in the engaged position, and if the jump signal continues, the needle bar driving member 13 is retreated from the needle bar 4 immediately before the lifting body 11 is lowered. Is done.
[0020]
According to the needle bar drive device of this embodiment, since the needle bar drive member 13 is controlled using the jump cam 32, the vertical movement of the needle bar 4 can be accurately canceled and restored at its top dead center. it can. Further, since the input lever 36, the intermediate lever 50, and the output lever 61 are all rotated around the vertical axis, and the drive unit 63 is circularly moved in the horizontal plane, the power receiving point of the needle bar drive member 13 is moved in the vertical direction. It does not change. For this reason, the needle bar drive member 13 can be formed thin, and the elevating body 11 that supports the needle bar drive member 13 can be formed small and light. Therefore, the space occupied by these elevating members in the sewing head can be reduced, the inertial mass of the elevating members can be reduced, the sliding area can be reduced, and the stability during high-speed operation can be improved.
[0021]
7 and 8 show another embodiment of the jump mechanism. In the jump mechanism 31, an extrusion-type solenoid 64 is used as a clutch means. The plunger 65 of the solenoid 64 is provided with a stopper 59 and an O-ring 53 that determine the upper limit position. The rod 46 is urged upward by a compression spring 47, and the upper end is pressed against the plunger 65. A pair of support pieces 66 project from the boss portion 51 of the intermediate lever 50, and an arm 67 is swingably supported by the support piece 66 by a horizontal pin 68. The arm 67 is biased by a spring 69 so that the front end of the arm 67 contacts the lower end of the rod 46, and a locking piece 70 that locks the rear end of the arm 67 on the input lever 36 projects downward.
[0022]
When the solenoid 64 is excited in response to the jump signal, the rod 46 is pushed down by the pressing pin 59, the arm 67 is swung by the lower end of the rod 46, and the rear end of the arm 67 is engaged with the locking piece 70. The intermediate lever 50 is coupled to the input lever 36 so as to be interlocked. Further, during normal sewing, the solenoid 64 is demagnetized, the rod 46 is pulled up by the compression spring 47, the rear end of the arm 67 is disengaged from the locking piece 70 by the spring 69, and the power from the input lever 36 to the intermediate lever 50 is increased. Transmission is interrupted. Other configurations and operational effects are the same as those of the above embodiment.
[0023]
In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) The vertical dimension of the notch 20 or the thickness of the pressing piece 16 is appropriately changed so that the pressing piece 16 of the needle bar driving member 13 is loosely fitted into the notch 20 of the needle bar head 6.
(2) Contrary to the above-described embodiment, a protrusion is provided on the needle bar head 6 and a notch into which the protrusion is inserted is formed in the needle bar driving member 13.
(3) The drive part 63 of the output lever 61 is formed short, and the needle bar drive member 13 in the retracted position is guided up and down by a guide member different from the drive part 63.
(4) The present invention is applied to various sewing machines other than an embroidery sewing machine such as a lockstitch sewing machine and a chain stitch sewing machine.
[0024]
【The invention's effect】
As described above in detail, according to the needle bar drive device according to the present invention, the lifting body and the needle bar drive member can be reduced in size and weight, the occupied space inside the sewing head can be reduced, and the stability during high-speed operation can be improved. There is an excellent effect of being able to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a sewing head showing an embodiment of a needle bar drive device according to the present invention.
FIG. 2 is an elevation view showing a jump mechanism of the apparatus.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
4 is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a cross-sectional view showing the action of the jump mechanism.
6 is a cross-sectional view taken along line CC in FIG.
FIG. 7 is a cross-sectional view showing another embodiment of the jump mechanism.
8 is a cross-sectional view taken along the line DD of FIG.
FIG. 9 is an elevational view showing a conventional needle bar driving device.
10 is a cross-sectional view taken along line EE of FIG.
[Explanation of symbols]
1 Frame 4 Needle bar 6 Needle bar head 10 Guide shaft 11 Lifting body 13 Needle bar drive member 14 Vertical pin 22 Upper shaft 23 Needle bar drive cam 29 Power transmission mechanism 31 Jump mechanism 32 Jump cam 35 Vertical axis 36 Input lever 37 Cam follower 39 Locking piece 43 Solenoid 49 Pin 50 Intermediate lever 54 Connecting roller 60 Vertical shaft 61 Output lever 63 Drive part 64 Solenoid 67 Arm 70 Locking piece

Claims (2)

A guide shaft erected in parallel with the needle bar, an elevating body supported by the guide shaft, a needle bar drive member attached to the elevating body so as to be rotatable in a horizontal plane, and the power of the upper shaft of the sewing machine A power transmission mechanism that transmits to the body, and a jump mechanism that blocks power transmission from the lifting body to the needle bar,
The jump mechanism includes a jump cam fixed to the upper shaft, an input lever rotated around the vertical axis by the jump cam, and an intermediate lever provided rotatably around the same axis as the input lever, A clutch means for coupling the intermediate lever to the input lever in response to a jump signal and an output lever that is rotated in a horizontal plane by the intermediate lever when the clutch means is engaged. A needle bar drive device for a sewing machine comprising a drive unit that rotates to a position retracted from the needle bar. The needle bar drive device for a sewing machine according to claim 1, wherein the drive unit is formed to be long in the vertical direction with a length corresponding to the stroke of the lifting body.

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