JP3107860B2 - Needle bar jumping device in sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle bar jumping device for an industrial sewing machine, in which the driving of the needle bar is stopped based on a jumping signal from a control device.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show a conventional needle bar jumping device in an industrial sewing machine. As is apparent from these drawings, a needle bar driving member 94 is provided on the shaft of the base needle bar 40 so as to be able to move up and down in conjunction with the rotation of the sewing machine main shaft 50. A pair of upper and lower engaging projections 96 and 97 are formed on the needle bar driving member 94 on the right side in FIG. Needle bar 1 is attached to these engagement projections 96 and 97.
The protruding pin 22 of the needle bar holder 20 fixed to 8 is engaged in the vertical direction in the drawing. Therefore, the needle bar 18 moves up and down in conjunction with the elevating operation of the needle bar driving member 94.

[0003] A jumping signal from a control device causes a plunger 9 of a solenoid 90 shown in FIG.
2 protrudes to the state shown by the virtual line in the drawing,
The jumping switching surface 100 of the needle bar driving member 94 that has risen along the base needle bar 40 contacts the plunger 92. Then, as the needle bar driving member 94 rises,
The action of the plunger 92 and the slope 101 of the jumping switching surface 100 causes the needle bar drive member 94 to rotate about the axis of the base needle bar 40 in the direction of the arrow in FIG. As a result, the engaging projections 96 and 97 of the needle bar driving member 94 are disengaged from the projecting pins 22 of the needle bar holder 20. As a result,
The raising / lowering operation of the needle bar 18 is stopped regardless of the raising / lowering operation of the needle bar driving member 94, and a jumping state is set.

[0004]

According to the jumping device having the structure shown in FIGS. 8 and 9, when the jumping signal is received, the rotation timing of the needle bar driving member 94 is controlled by the plunger of the solenoid 90. The control is performed based on the position of 92 and the shape of the slope 101 of the switching surface 100 for jumping of the needle bar driving member 94. When the raising / lowering operation of the needle bar driving member 94 shifts from its top dead center to the lowering operation, the needle bar driving member 94 is held at a jumping position for jumping for a certain stroke, and The upper engaging projection 96 is attached to the needle bar holder 20.
It is necessary to avoid getting caught on the protruding pin 22 of the main body. For this purpose, the jumping switching surface 100 has a vertical surface 102 following the slope 101. Therefore, when the rising process of the needle bar driving member 94 during the jumping control is viewed, the vertical surface portion 102 of the switching surface 100 for jumping with respect to the plunger 92 of the solenoid 90 before the needle bar driving member 94 reaches the top dead center. At the corresponding position, the engaging projections 96 and 97 of the needle bar driving member 94 are disengaged from the projecting pins 22 of the needle bar holder 20.

That is, the needle bar 18 is released from being restrained by the needle bar driving member 94 just before its top dead center. As a result, when the jumping signal is input, the needle bar 18 rises due to the elastic force of the needle bar holding spring 24, and its top dead center stopper 26 vigorously hits the lower surface of the horizontal frame 14a of the needle bar case 14 and is received. ,
This causes noise during jumping.
Further, when the needle bar driving member 94 rises during the jumping control, the slope portion 101 of the jumping switching surface 100 strongly contacts the plunger 92 of the solenoid 90. The hitting sound caused by this also contributes to the noise at the time of jumping.

The technical problem of the present invention is to provide a jumper for a needle bar.
It is an object of the present invention to provide a needle bar jumping device in a sewing machine that can reduce noise during sewing.

[0007]

Means for Solving the Problems To solve the above problems, a needle bar jumping device in a sewing machine according to the present invention is configured as follows. That is , the needle bar driving member is moved up and down along the base needle bar in conjunction with the rotation of the sewing machine main shaft, and the needle bar driving member is moved up and down by the operation of the needle bar driving member. in jumping device of the needle bar in the constructed sewing machine such that the driving force transmission from the needle bar drive member to the needle bar is cut off by rotating the parallel axis around jumping position and, jumping signal from the control device A control motor driven based on the needle bar drive unit by driving the control motor
The needle bar drive unit is moved forward and backward with respect to the material and is advanced.
And a jump lever to push the wood to jumping position, constituting Then together to rotate the needle bar drive member to the jumping position by driving of the control motor
The needle bar drive pushed by the jump lever
The pressing surface of the member with respect to the direction of elevation of the needle bar driving member.
The needle bar drive member to the jumping position.
The operation timing of the jump lever that rotates to
It can be changed by the control device.

[0008]

In the above construction, the timing of rotating the needle bar driving member to the jumping position by the jump lever is determined by a jumping signal output from the control device to the control motor. Actuator of the jump lever
Imming is performed by the jump lever on the pressing surface of the needle bar driving member.
Can be changed by the control device in the position where the
it can. Therefore, for example, at the time of a single jump, it becomes easy to rotate the needle bar driving member to the jumping position at the top dead center of the needle bar driving member, that is, at a position as close as possible to the top dead center of the needle bar. As a result, the needle bar when the jumping signal is input is restrained by the needle bar driving member to a position as close as possible to its top dead center. As a result, the dead center stopper on the needle bar, which has been rising is caused by Rukoto been hammered vigorously to the needle bar case
It is possible to prevent the impact noise. Also, continuous Jean
Output mode of the jumping signal from the controller
Set the ming earlier than during the single jump
Thus, it is possible to avoid interference between the needle bar driving member and the needle bar.
it can. This causes interference between the needle bar drive member and the needle bar.
Can be prevented. In addition , the control motor is driven based on a jumping signal output from the control device at a predetermined timing, so that the jump lever moves
Pushes flat pressing surface in the vertical movement direction of rod drive member
By doing so, the needle bar driving member is rotated to the jumping position. Therefore, there is no special impact sound when rotating the needle bar driving member. Therefore,
Noise during jumping of the needle bar can be reduced.

[0009]

Next, one embodiment of the present invention will be described with reference to FIGS. In the following embodiment, the needle bar jumping device of the present invention is applied to a multi-head, multi-needle type industrial sewing machine. FIG. 1 is a longitudinal sectional view of a sewing head H,
FIG. 2 shows a right side view (front view) of FIG. 1 and 2, the sewing machine head H includes an arm 12 and a needle bar case 14. Needle bar case 14
Is disposed on the front surface of the arm 12 (the right side surface in FIG. 1), and is slidably attached to the arm 12 in the left and right direction in FIG. The back of the arm 12 (the left side in FIG. 1) is
It is fixed to. That is, in the sewing machine frame 10,
A plurality of sewing heads H each having the arm 12 and the needle bar case 14 are arranged at predetermined intervals.

A plurality (six in the present embodiment) of needle bars 18 which can be moved up and down are attached to the needle bar case 14 at regular intervals in the left-right direction in FIG. Each needle bar 18
The needle bar holders 20 are fixed at substantially the middle positions of the needle bars 20, respectively. Each of the needle bar holders 20 has a protruding pin 22 on a needle bar driving member 42 side (left side in FIG. 1) described later. A top dead center stopper 26 is fixed above the needle bar holder 20 in each needle bar 18. A needle bar holding spring 24 is provided between the spring receiver 19 at the upper end of each of the needle bars 18 and the upper surface of the horizontal frame 14a of the needle bar case 14 to urge the needle bar 18 in the direction of constantly rising. . Due to the elastic force of the spring 24, each needle bar 18
The needle bar which has not received the driving force from the needle bar driving member 42 described later is located at the top dead center position where the top dead center stopper 26 is pressed against the lower surface of the horizontal frame 14a of the needle bar case 14 via the cushion 28. Is held in.

A sewing needle 32 is provided at a lower end of each of the needle bars 18 by a needle holder 30. A cloth presser 34 is attached to each needle bar 18 so as to move up and down in conjunction with the needle bar 18. As shown in FIG. 1, a balance shaft 39 supported by the needle bar case 14 rotatably supports a balance 38 corresponding to each needle bar 18.

On the other hand, one base needle bar 40 is attached to the arm 12 in parallel with each of the needle bars 18. As is apparent from FIG. 3, a jump base 41 and a needle bar driving member 42 are mounted on the shaft of the base needle bar 40 so as to be able to move up and down while maintaining an integral relationship with each other. Further, the needle bar driving member 42 is rotatable around the axis of the base needle bar 40 in the direction indicated by the arrow in FIG. See Figure 3 for details.
As shown in a perspective view of a needle bar driving member in (a) and a cross-sectional view in (b), a jump base 41 is fixed to a sleeve 48 which is vertically movably inserted into a base needle bar 40. The needle bar driving member 42 is rotatably fitted into the sleeve 48. The needle bar driving member 42 is returned to the rotational position (return position) shown in the drawing by the elasticity of the return spring 46, and the jump base 4
1 and is held at that position by hitting a stopper Z fixed thereto.

A pair of upper and lower engaging projections 43 and 44 are integrally formed on the front side (the right side in FIG. 1) of the needle bar driving member 42. The projecting pin 22 of the needle bar holder 20 of one needle bar 18 is selectively engaged between the engagement projections 43 and 44 by the above-described sliding of the needle bar case 14 with respect to the arm 12. Further, the outer surface of the needle bar driving member 42 has a flat pressing surface 45
Are formed. The pressing surface 45 is pressed by the pressing roller 83 of the jump lever 80 during jumping described later, and the needle bar driving member 42 rotates around the axis of the base needle bar 40 in the direction of the arrow in FIG.

As shown in FIG. 1, the arm 1
A sewing machine main shaft 50 penetrating through the respective machine heads H is positioned inside the sewing machine 2. The main shaft 50 of the sewing machine rotates by receiving a torque of a sewing machine drive motor (not shown).
A needle bar driving cam 52 and a balance driving cam 62 are provided on the shaft of a portion of the sewing machine main shaft 50 located inside the arm 12 so as to rotate together with the sewing machine main shaft 50. The rotation of the needle bar drive cam 52 causes a drive lever 55 connected to the rod 54 via a pin 57 to swing around a support pin 56 through a rod 54 having a ring-shaped portion fitted thereto. And this drive lever 5
5 is moved by the lever 55 and the jump base 4.
The needle bar driving member 42 is moved up and down along the base needle bar 40 through a connecting member 58 rotatably connected to both ends of the needle bar 1 via pins 59 and 60. The balance driving cam 6
The rotation of 2 is transmitted to a selected one of the balances 38 as a well-known swing operation (balance operation).

Next, the needle bar driving member 42 is connected to the base needle bar 40.
3 will be described in the direction of the arrow in FIG. As is clear from FIG. 4 showing a front view of the main part in addition to FIG. 1, a control motor 70 composed of a pulse motor is fixed to the bracket 13 fixed to the side surface of the arm 12. The motor shaft 72 of the control motor 70 passes through the bracket 13 and faces the inside of the arm 12. The jump lever 80 is fixed to the motor shaft 72. The distal end of the jump lever 80 is inclined downward and extends toward the base needle bar 40, and a pressing roller 83 is rotatably attached to the distal end. The pressing roller 83 is positioned so as to be able to contact the pressing surface 45 of the needle bar driving member 42 that moves up and down along the base needle bar 40. However, the elastic force of the return spring 84 acting in the direction of separating the pressing roller 83 from the pressing surface 45 of the needle bar driving member 42 acts on the jump lever 80 as shown in FIG. The jump lever 80 is held at a return position where it hits a stopper 85 fixed to the bracket 13. In this state, the pressing roller 83 slightly separates from the pressing surface 45 of the needle bar driving member 42 that moves up and down. It is kept in the state.

As shown in FIG. 4, a jumping signal is input to the control motor 70 from a control device 74 mainly composed of a microcomputer. The control motor 70 is driven to rotate forward and reverse based on this signal. The jumping signal is output to the control motor 70 based on the result of the control device 74 performing a calculation based on a program for driving and stopping the needle bar 18 in addition to the rotation position and the rotation speed of the sewing machine main shaft 50. You.

In the needle bar jumping device having the above-described structure, the needle bar case 14 is slid in the left-right direction in FIG. Needle bar holder 20 on rod 18
The projection pin 22 of the needle bar driving member 42 is
Engage between 3,44. Then, by the action of the needle bar driving cam 52 rotating together with the sewing machine main shaft 50, the jumping base 41 and the needle bar driving member 42 are moved through the rod 54, the driving lever 55 and the connecting member 58 to the base needle bar 40.
It moves up and down along. As a result, the selected one needle bar 18 is moved up and down, and the cloth presser 34 is moved up and down in accordance with this. The other needle bars 18 are waiting at the position of the top dead center.

The jumping signal from the controller 74 of the sewing machine causes the control motor 70 to rotate forward to rotate the jump lever 80. Therefore, by the rotation of the jump lever 80, the pressing surface 45 of the needle bar driving member 42 is pressed by the pressing roller 83, and the needle bar driving member 42 rotates in the direction indicated by the arrow in FIG. The rotation of the needle bar driving member 42 to the jumping position causes the two engagement projections 43 and 44 to be disengaged from the projection pins 22 of the needle bar holder 20 of the needle bar 18. As a result, transmission of the elevating operation from the needle bar driving member 42 to the needle bar 18 is interrupted, and a jumping state is established.

With respect to the elevating operation of the needle bar driving member 42,
The timing for rotating the needle bar driving member 42 to the jumping position is determined by the control device 74.
It is desirable that the timing is set as close as possible to the top dead center of the needle bar driving member 42. More specifically, as shown in FIG.
FIG. 5A shows the rotational speed of the jump lever 80 driven by the control motor 70 so that the jumper 2 can be rotated to the jumping position at a position as close as possible to the top dead center. Ascending needle bar driving member 42
The pressing roller 8 of the jump lever 80 is
At the position where 3 faces, the normal rotation drive of the control motor 70 is started.

As a result, the projecting pin 22 of the needle bar 18 is restrained by the engaging projections 43 and 44 of the needle bar driving member 42 up to or near its top dead center. Therefore, the phenomenon that the top dead center stopper 26 of the needle bar 18 is strongly hit against the lower surface of the horizontal frame 14a of the needle bar case 14 at the time of jumping to generate noise is avoided. When the needle bar drive member 42 moves down,
Since the needle bar driving member 42 is held at the jumping position, a situation in which the upper engagement projection 43 is caught on the projection pin 22 of the needle bar holder 20 is also avoided. When the needle bar drive member 42 moves downward, the sewing machine main shaft 5
When 0 rotates by a predetermined angle, the control device 74 outputs a reverse rotation drive signal to the control motor 70, and the jump lever 80 returns to the original position by the reverse rotation of the control motor 70. Accordingly, the needle bar driving member 42 rotates to the return position. Note that, in order to reduce the tapping sound with the stopper Z when the needle bar driving member 42 returns to the return position, the control motor 7 is moved immediately before hitting the stopper Z.
The zero reverse acceleration may be reduced.

When the needle bar driving member 42 moves up again and approaches its top dead center, if no jumping signal is input, the needle bar driving member 42 continues to rise as it is, and The slope 43a of 43 interferes with the projecting pin 22 of the needle bar 18 waiting at the top dead center. As a result, the needle bar driving member 42 rotates in the same direction as during jumping, against the spring force of the return spring 46, and returns to the return position when the projecting pin 20 is located between the two engaging projections 43, 44. As a result, when the needle bar driving member 42 moves to the lowering operation, the needle bar 18 also lowers.

According to the control device 74, the needle bar 18
During the first stop (during a single jump) while driving
The control timing of the jump lever 80 can be changed between two or more consecutive jumps following a single jump. That is, as shown in the characteristic diagram of the operation timing of the needle bar and the jump lever in FIG. 6, during the single-shot jump, as shown in FIG.
Is rotated at a position as close as possible to the top dead center of the needle bar driving member 42 to prevent noise caused by the top bar dead center stopper 26 of the needle bar 18 being vigorously hit against the horizontal frame 14a of the needle bar case 14, Also, as shown in (b), the jump lever 80 is rotated earlier than during the single-shot jump during the continuous jump, and the needle bar driving member 4 is rotated.
The interference between the inclined surface 43a of the upper engagement projection 43 and the projection pin 22 of the needle bar 18 may be avoided. In FIG. 6, point A is a point in time when the operation of the jump lever 80 is started, point B is a point in time when the engaging projections 43 and 44 are disengaged from the projecting pin 20, and C
The point is the time when the operation of the jump lever 80 is completed, the point D is the time when the return of the jump lever 80 starts, and the point E is
The point at which the return to 0 is completed is shown.

Further, as shown in the characteristic diagram of FIG. 7 when the return of the jump lever is completed, the jump lever 80
Immediately before the completion of the return (point F in the figure), the supply of the drive signal and the holding current to the control motor 70 is stopped (that is, the motor 70 is completely free), and the jump is performed by the elastic force of the return spring 84. If the lever 80 is returned to the return position, the motor shaft is returned to the origin every time one control is performed even if step-out occurs when the pulse motor as the control motor 70 is subjected to open loop control. It will not be impossible. The broken line in the figure is a characteristic diagram when the jump lever 80 is rotated by the control motor 70 until the return is completed.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various embodiments can be considered. For example, when the pressing surface 45 of the needle bar driving member 42 makes contact with the jump lever 80 during jumping, the needle bar driving member 4
A shape that is always kept constant irrespective of the rotation of 2, that is, a shape whose inclination is changed in the radial direction may be used. In the embodiment, the needle bar driving member 42 is provided on the base needle bar 40 so as to be rotatable around its axis (this is also included around the axis parallel to the base needle bar 40). A parallel axis may be provided separately, and the needle bar driving member 42 may be provided on this axis so as to be rotatable around its axis.

[0025]

Effect of the Invention Thus the present invention is capable of arbitrarily determined actuation tie <br/> timing jump lever to rotate the needle bar drive member to the jumping position by the control device, for example
For example, by setting the operation timing of the jump lever in a single jump as close as possible to the top dead center of the needle bar, the needle bar when a jumping signal is input is moved to the position as close as possible to the top dead center. Up to the needle bar driving member. As a result, it is generated by a vigorous per Rukoto such as in dead center stopper needle bar case on top of the needle bar, which has been rising
Impact noise can be prevented. Also, continuous jump
The jump timing of the jump lever at the time
By setting earlier than at the time of
Interference with the needle bar can be avoided. This allows the needle
It is possible to prevent tapping noise due to interference between the rod drive member and the needle bar.
it can. In addition, the jump lever moves up and down the needle bar drive member.
Since it is configured to push the flat pressing surface with respect to work direction, it is not name with a special impact sound when rotating the needle bar drive member. Therefore, noise generation at the time of jumping of the needle bar can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a sewing head.

FIG. 2 is a schematic front view as viewed from the right side of FIG.

FIG. 3 is an explanatory view of a needle bar driving member.

FIG. 4 is a schematic view of an arm portion of the sewing machine head of FIG. 1 as viewed from the front side.

FIG. 5 shows the operation of a jump lever, and FIG.
It is a V line sectional view.

FIG. 6 is a characteristic diagram showing operation timings of a needle bar and a jump lever.

FIG. 7 is a characteristic diagram when the return of the jump lever is completed.

FIG. 8 is a sectional view showing a conventional sewing head in correspondence with FIG.

FIG. 9 is a schematic view of an arm portion of the sewing machine head of FIG. 8 as viewed from the front side.

[Explanation of symbols]

 18 Needle bar 40 Base needle bar 42 Needle bar drive member 50 Sewing machine spindle 70 Control motor

Continuation of the front page (56) References Japanese Utility Model Sho 51-4549 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) D05B 55/14

Claims (1)

(57) [Claims] 1. A needle bar driving member is moved up and down along a base needle bar in conjunction with rotation of a main shaft of a sewing machine. The operation of the needle bar driving member causes the needle bar to move up and down, and the needle bar driving member is connected to the needle bar driving member. in jumping device of the needle bar in the constructed sewing machine such that the driving force transmission from the needle bar drive member by rotating the base needle bar parallel to the axis around jumping position to the needle bar is cut off, the control device A control motor that is driven based on a jumping signal of the needle bar;
The needle bar is moved forward and backward with respect to the member and is advanced.
And a jump lever to push the member into jumping position, constituting Then together to rotate the needle bar drive member to the jumping position by driving of the control motor
The needle bar drive pushed by the jump lever
The pressing surface of the member with respect to the direction of elevation of the needle bar driving member.
The needle bar drive member to the jumping position.
The operation timing of the jump lever that rotates to
Characterized in that it can be changed by the control device.
Jumping apparatus of the needle bar in that sewing machine.