JP3316022B2 - 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 sewing machine configured to move a work clamp up and down in conjunction with the up and down movement of a sewing needle.

[0002]

2. Description of the Related Art For example, an embroidery sewing machine, which is a sewing machine of this type, has a cloth presser attached to a lower end of a vertically movable cloth presser bar, and the rotational driving force of a sewing machine motor is transmitted through a cloth presser driving cam and a link mechanism. By transmitting the pressure to the presser bar, the cloth presser is moved between the top dead center and the bottom dead center during the sewing operation. In order to change the upper and lower dead points of the presser foot according to the thickness of the work cloth to be sewn, the connection position between the two links constituting the link mechanism or the presser foot of the presser foot is changed. The mounting position for the bar is moved in the vertical direction.

[0003]

However, in the above configuration, if the upper and lower dead points of the work clamp are changed, the retreat position is shifted by the change. As a result, for example, when the retracted position is shifted downward, the cloth presser interferes with the work of attaching and detaching the embroidery frame, and when shifted upward, the needle bar is selectively moved when the color of the embroidery thread is changed. The trouble of getting in the way occurs.

Further, in a configuration in which the connecting position between the two links is moved, it is necessary to form a large opening in the sewing machine main body for exposing the connecting portion of the two links, and accordingly, the processing of the sewing machine main body is troublesome. Met. In addition, the trajectory of the link mechanism changes with the movement of the connection position between the links, and the stroke of the reciprocating motion of the work clamp bar during sewing operation changes. May occur.

The present invention has been made in view of the above circumstances, and has as its object to provide a function of adjusting the upper and lower dead points of the work clamp without special processing of the sewing machine body. Another object of the present invention is to provide a sewing machine capable of preventing the change of the retreat position and the generation of noise due to the adjustment.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a sewing machine having a structure in which a presser foot is moved up and down in conjunction with the up and down movement of a sewing needle. Position adjusting means provided at a portion of the lower end of the presser bar located outside the sewing machine main body to adjust a mounting position of the presser foot with respect to the presser bar in the vertical direction; and provided on the presser foot. And a stopper member for determining a retracting position of the presser foot when the presser bar is raised to the retracted position and hits the sewing machine main body.

According to the above means, the upper and lower dead points of the presser foot can be adjusted by moving the mounting position of the presser foot with respect to the presser bar in the vertical direction by the position adjusting means. Therefore, the stroke of the presser bar during sewing operation does not fluctuate (increase) with the change of the upper and lower dead points, and noise can be prevented from being generated. Moreover, since the position adjusting means is provided outside the sewing machine main body, it is necessary to apply a special processing to the sewing machine main body, unlike the conventional case in which an opening for exposing the connecting portion between the links is formed in the sewing machine main body. There is no. Further, since the retracting position of the presser foot is determined by the stopper member provided on the presser foot hitting the sewing machine main body, the retracted position becomes constant without being affected by the change of the upper and lower dead points.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an embroidery sewing machine will be described below with reference to the drawings. First, in FIG. 2 showing the overall configuration of the embroidery sewing machine, the sewing machine body 1 is
The sewing machine arm 2 is integrally provided on the sewing machine table 2. A needle bar support case 5 having a plurality of needle bars 4 in this case, for example, six needle bars 4 is provided at the tip end of the sewing machine arm 3.

The six needle bars 4 are vertically movably supported in the needle bar support case 5 side by side in the lateral (front-rear) direction. Are provided with sewing needles 6, respectively. Each sewing needle 6 is configured to be supplied with an embroidery thread (not shown), which is an upper thread having a different color and type, from a thread supply source (not shown).

The needle bar support case 5 is mounted on the sewing machine arm 3 so as to be movable in the front-rear direction (the direction in which the needle bars 4 are arranged), and is driven to move by a needle bar selection motor 7. A drive mechanism for transmitting the rotational driving force of the sewing machine motor 8 to the needle bar 4 and moving the needle bar 4 up and down is provided in the sewing machine arm 3. This driving force is transmitted only to the needle bar 4 located at a predetermined use position, and only one of the six needle bars 4 is selectively driven. Is configured.

On the other hand, a sewing machine bed 9 is provided on the sewing machine table 2 below the needle bar 4, and the embroidery frame 1 is cooperated with the sewing needle 6 in the sewing machine bed 9.
For example, a shuttle (not shown) which is a thread catcher for forming an embroidery stitch on the work cloth 11 supported by the work cloth 11 is disposed.
This shuttle is rotated by a sewing machine motor 8 in synchronization with the vertical movement of the sewing needle 6. A needle plate and a needle thread cutting device (both not shown) are provided above the shuttle.
Etc. are provided.

Further, an embroidery frame 1 is provided on the sewing machine table 2.
A horizontal moving mechanism 12 is provided for freely moving and driving 0 in the X-axis direction (front-back direction) and the Y-axis direction (left-right direction). This horizontal moving mechanism 12 is provided with a Y-axis feed motor 1
3 (refer to FIG. 7), a Y-axis direction moving frame 14 driven to move in the Y-axis direction, and an X-axis feed motor 15 (refer to FIG. 7). It is configured.

A presser bar 17 is provided at the tip of the sewing machine arm 3, as shown in FIG. The upper end of the presser bar 17 is fitted to a cylindrical support portion 18 provided at an upper portion in the sewing machine arm portion 3.
By inserting the lower end side into a through hole 19a provided in the lower side wall 19 of the sewing machine arm 3, it is configured to be vertically movable.

The presser bar 1 protruding from the sewing machine arm 3
A cloth presser 20 is attached to the lower end of the cloth 7. At the lower end of the presser foot 20, a presser portion 20a having a through hole through which the sewing needle 6 is inserted is formed, and at the upper portion, a long hole 20b extending vertically is formed. As shown in FIG. 3, the presser foot 20 is fixed by tightening a screw 21 inserted through the elongated hole 20b into the presser foot bar 17. Therefore, by loosening the screw 21 and moving the presser foot 20, the mounting position of the presser foot 20 with respect to the presser foot bar 17 can be adjusted in the vertical direction.
1 functions as a position adjusting means. The upper end bent portion 2 horizontally bent at the upper end of the presser foot 20.
On the upper surface of Od, a cushion member 20c made of a rubber plate and functioning as a stopper member is provided. The rising amount of the presser foot 20 is restricted by the cushion member 20c hitting the locking portion 19b which is a part of the lower side wall portion 19.

At a middle portion of the presser bar 17, there are provided a presser bar hanger 22 fixed by screws and a presser operating member 23 which can be moved up and down. This work clamp foot 2
Reference numeral 3 denotes a vertically long rectangular frame shape, in which the cloth holding rod 17 is inserted into through holes formed in the upper wall part 23a and the lower wall part 23b, and the cloth is placed on the upper surface part of the lower wall part 23b. The lower surface of the holding bar holder 22 is configured to abut on an O-ring 24. A first compression coil spring 25 is provided between the upper wall portion 23a of the presser foot operating body 23 and the upper surface of the presser bar holder 22. The first compression coil spring 25 is always
2 is urged so that the lower surface portion thereof comes into contact with the lower wall portion 23b of the work clamp operating body 23.

The side wall portion 2 on the right side in FIG.
The lower end 26a of the work clamp operating link 26 is rotatably connected to 3c. As shown in FIG. 3, one end 27a of a substantially L-shaped cloth presser drive link 27 is rotatably connected to the upper end 26b of the cloth presser operating link 26. The cloth presser drive link 27 has a shape shown in FIGS. 6A and 6B, and is rotatable around the shaft 28 of the sewing machine arm 3 as shown in FIG. ing.

On the other hand, a main shaft 29 which is rotationally driven by the sewing machine motor 8 is provided in an upper portion in the sewing machine arm portion 3.
0 is attached and fixed so as to rotate integrally. As shown in FIG. 3, a cloth presser cam groove 31a for driving the cloth presser 20 is formed on the outer peripheral surface of the cloth presser driving cam 30, and a balance (not shown) is formed on the left side. A balance cam groove 31b for driving is formed.

A cam follower 32 provided at the other end 27b of the presser foot driving link 27 is fitted and connected in the presser foot cam groove 31a. As a result, the presser foot operation link 26 and the presser foot drive link 27 are connected between the presser foot operation body 23 and the presser foot cam groove 31 a of the presser foot drive cam 30. Further, the upper side wall 33 of the sewing machine arm 3 and the upper wall 23
A second compression coil spring 34 is provided between the first compression coil spring 34 and the second compression coil spring 34.

The second compression coil spring 34 has a spring force stronger than the spring force of the first compression coil spring 25, and by urging the cloth pressing operation body 23 downward,
The cloth presser drive link 27 is urged to rotate in the counterclockwise direction in FIG. 3, and the cam follower 32 is urged to always contact the cam surface of the cam groove 31a (in this case, the left inner surface in FIG. 3). ing.

In this configuration, when the presser foot driving cam 30 is driven to rotate, the cam follower 32 moves right and left according to the shape of the cam surface while abutting on the cam surface of the cam groove 31a. The drive link 27 swings around the shaft 28 as a rotation fulcrum. Then, the swing of the presser foot drive link 27 is transmitted to the presser foot operation body 23 via the presser foot operation link 26, and the presser foot operation body 23 moves up and down.
The presser foot bar 17 and the presser foot 20 reciprocate up and down between a bottom dead center shown in FIG. 3 and a top dead center shown in FIG.

On the opposite side of the cam surface of the cam groove 31a of the cloth pressing drive cam 30, a retracting groove 31c is provided as shown in FIG. The position of the evacuation groove 31c is
Is located at the top dead center shown in FIG. 4, the cam follower 32 moves rightward in FIG. 4, and as shown in FIG.
It is set at a position where it can be retracted into the evacuation groove 31c.

A rotary solenoid 36 is provided on the right side of the right side wall 35 of the sewing machine arm 3 in FIG. The rotary shaft 37 of the rotary solenoid 36 protrudes into the sewing machine arm 3, and the tip end of the rotary shaft 37 is connected to a cloth presser retracting lever 38. An engaging piece 38a bent leftward in FIG. 1 is provided at the lower end of the cloth presser retracting lever 38.
As shown in FIG. 5, when the rotary solenoid 36 is driven, as shown in FIG. 5, a pressing portion 27 c formed on the other end 27 b side of the presser foot driving link 27 (see FIG. 1 and FIGS. 6A and 6B). 4), the pressing portion 27c is pressed rightward in FIG. 4, and the cam follower 32 is retracted into the retracting groove 31c.

FIG. 7 shows the electrical configuration of the embroidery sewing machine.
A control device 3 comprising a microcomputer or the like
9 controls the overall operation of embroidery stitching,
U40, a ROM 41 and a RAM 42, and a bus 43 connecting them.
3, an input interface 44 and an output interface 45 are further connected. ROM 41
An operation control program is stored in the RAM.
Various data such as embroidery data for performing embroidery sewing is stored in M42.

The output interface 45 includes a sewing machine motor 8, an X-axis feed motor 15, and a Y-axis feed motor 1.
3. Motor drive circuits 46 to 49 for driving the needle bar selection motor 7 are connected to each other.
By controlling the driving of each of the motors based on the operation control program in the OM 41 and the embroidery data in the RAM 42, the embroidery sewing operation on the work cloth 11 is executed. In addition, output interface 4
5 includes a display drive circuit 52 for driving a display device 51 for displaying embroidery figures and various messages, and a solenoid drive circuit 53 for driving the rotary solenoid 36.
Is connected.

On the other hand, an input interface 44 detects an external storage device 54 such as a floppy disk for storing embroidery data and the like, a keyboard 55 provided with various input keys such as a start key, and a rotation angle of the spindle 29. Rotating angle sensor 56 is connected. The rotation angle sensor 56 is composed of, for example, a rotary encoder or the like, detects the rotation angle of the main shaft 29 (the rotation angle with the top dead center of the needle bar 4 as the origin (0 °)), and corresponds to the rotation angle. The rotation angle detection signal is output.

Next, the operation of the above configuration will be described with reference to FIG. That is, when the sewing machine motor 8 is energized and driven,
When the needle 9 is rotated, the needle bar 4 and the sewing needle 6 are reciprocated vertically. In this case, the rotary solenoid 36 is not energized and the cam follower 32 is urged by the second compression coil spring 34 to abut the cam surface of the cam groove 31a of the presser foot driving cam 30. . Therefore,
With the rotation of the presser foot driving cam 30, the cam follower 32 moves left and right according to the shape of the cam surface of the cam groove 31a, and the presser foot driving link 27 swings around the shaft 28 as a rotation fulcrum.
The presser foot operating body 23 moves up and down via the presser foot operation link 26.

As a result, in conjunction with the vertical movement of the sewing needle 6, the presser foot bar 17 and the presser foot 20 move from the bottom dead center shown in FIG.
It moves up and down between the top dead centers shown in the figure. And cloth foot 20
Presses the work cloth 11 by the spring force of the first spring 25,
The step 11a of the work cloth 11 is caused by the contraction of the first spring 25.
The sewing operation is performed while absorbing the emblem. Curves A to D in FIG. 8 show the trajectory of the vertical movement of the sewing needle 6, the trajectory of the vertical movement of the presser foot 17, the balance thread amount, and the hook thread amount in this order during the sewing operation. , 0
° indicates the needle bar top dead center, and 180 ° indicates the needle bar bottom dead center.

Thereafter, the sewing operation is completed, and
4 is located at the top dead center shown in FIG. 4, the rotary solenoid 36 is energized and the presser foot retracting lever 38 is turned on.
Is rotated counterclockwise in FIG. Then, the engaging piece 38a of the presser foot retracting lever 38 presses the pressing portion 27c of the presser foot drive link 27 rightward in FIG. 4, so that the presser foot is deformed with the compression deformation of the second compression coil spring 34. The drive link 27 is rotated clockwise. Thereby, as shown in FIG. 5, the cam follower 32 enters the evacuation groove 31c,
The pressure foot 17 is moved further above the top dead center. Then, the presser foot 20 rises integrally with the presser foot bar 17, and the cushion member 20c of the presser foot 20 abuts on the locking portion 19b of the lower side wall portion 19. 20 is moved to a retracted position in contact with the sewing machine main body. In this case, the impact at the time of contact is reduced by the elasticity of the cushion member 20c.

In order to sew a work cloth (not shown) having a thickness different from that of the work cloth 11, first, the screws 21 are loosened and the work presser 20 is moved up and down. The upper and lower dead points are set at positions corresponding to the thickness of the work cloth. Therefore, unlike the related art in which the connection position between the two links is moved, the trajectory of the presser foot operation link 26 and the presser foot drive link 27 is always constant. As a result, the stroke of the presser bar 17 during the sewing operation does not fluctuate (especially becomes large) with the change of the upper and lower dead points of the work clamp 20, and generation of noise can be prevented. Moreover, since the screw 21 is provided outside the sewing machine arm 3, the screw 21 is attached to the sewing machine arm 3.
There is no need to perform special processing such as providing a large opening for exposure.

When the sewing operation of the work cloth (not shown) is completed by the same operation as described above, the rotary solenoid 36 is energized and the cam follower 32 is moved to the evacuation groove 31.
c, the presser foot bar 17 is further moved above the top dead center. The retracted position of the presser foot 20 is, as described above, the cushion member 20 provided on the presser foot 20.
Since c is determined by hitting the locking portion 19b of the lower side wall portion 19, it is always constant without being affected by the movement of the upper and lower dead centers. As a result, the work clamp 20 does not hinder the movement of the sewing needle 6 during the attachment / detachment work of the embroidery frame 10 and the color change, and such work can be performed smoothly.
In the above embodiment, the cushion member 20c provided on the presser foot 20 as the stopper member is used. However, the present invention is not limited to this. The cushion member 20c is omitted, and the upper end bent portion 20d of the presser foot 20 is stopped. It may be a member.

[0030]

As is apparent from the above description, according to the present invention, the upper and lower dead points of the presser foot are changed by adjusting the mounting position of the presser foot with respect to the presser foot bar in the vertical direction . Therefore, the stroke of the presser bar during the sewing operation does not change with the change, and as a result, generation of noise can be prevented. Moreover, since the position adjusting means for adjusting the mounting position is provided outside the sewing machine main body, it is not necessary to perform special processing on the sewing machine main body. Further, the retracting position of the presser foot is determined by applying a stopper member provided on the presser foot to the sewing machine main body, so that the retracting position of the presser foot is fixed without being affected by the fluctuation of the upper and lower dead points. It has an excellent effect that it can be made.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a sewing machine arm showing one embodiment of the present invention.

FIG. 2 is a perspective view of the entire sewing machine.

FIG. 3 is a front view showing a driving mechanism of the presser foot and the presser foot bar.

FIG. 4 is a diagram corresponding to FIG. 3, showing a state where the work clamp has moved to the uppermost position;

FIG. 5 is a view corresponding to FIG. 3, showing a state in which the work clamp has been raised to the retracted position;

6A is a side view of a presser foot driving link, and FIG. 6B is a front view of the presser foot driving link.

FIG. 7 is a block diagram.

FIG. 8 is a view showing a locus of vertical movement of a sewing needle and a work clamp;

[Explanation of symbols]

1 is a sewing machine main body, 6 is a sewing needle, 17 is a cloth presser bar, 20 is a cloth presser, 20c is a cushion member (stopper member), 2
Reference numeral 1 denotes a screw (position adjusting means).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D05B 29/02 101 D05B 29/06

Claims (1)

(57) [Claims] 1. A sewing machine configured to move a presser foot up and down in conjunction with the vertical movement of a sewing needle, comprising: a presser bar provided on the sewing machine body so as to be vertically movable; and a lower end of the presser bar. A position adjusting means provided at a portion located outside the sewing machine main body, for adjusting a mounting position of the presser foot to the presser foot bar in a vertical direction; and A stopper member for determining a retracting position of the presser foot when the sewing machine is lifted to a position.