JPH06269584A - Sewing machine - Google Patents

Abstract

PURPOSE:To provide an inexpensive, compact and simple sewing machine with a larger degree of freedom in designing the operation curve of cloth retainer. CONSTITUTION:Since a cam follower 32 of a movement converting member 29 is brought into pressure contact with a cam face 31c of a cloth retaining drive cam 31 by the energizing force of a spring 34, when the cam 31 is rotated, the member 29 is moved according to the shape of the cam surface 31c, and a cloth retaining rod 17 is moved up and down. Furthermore, since the cam 31 is provided with an escape groove 31e where the cam follower 32 of the member 29 enters, when an escape drive means makes the cam follower 32 retreat in the groove 31e, the rod 17 and a cloth retainer 20 rises to a retreat position.

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 cloth presser up and down in conjunction with the vertical movement of a sewing needle.

[0002]

2. Description of the Related Art In this type of sewing machine, for example, an embroidery sewing machine, a cloth presser is attached to a lower end of a vertically movable cloth presser bar, and a link mechanism as a motion converting member is provided between the cloth presser bar and the sewing machine motor. In the sewing operation, the cloth presser is moved up and down by bending and extending the link mechanism in conjunction with the rotational driving of the sewing machine motor.

[0003]

However, in the above-mentioned conventional structure, the presser foot cannot be raised to the retracted position within the stroke range of the link mechanism. Therefore, the retracting drive means such as a motor is used for the link mechanism. By pulling up the whole, the cloth presser is moved to the retracted position.

Therefore, the link mechanism and the structure for pulling up the link mechanism become complicated, and the retracting drive means becomes large in size due to the fact that the link mechanism having a complicated structure is lifted, and the apparatus is generally costly. It was high. Further, since the operation curve of the work clamp is determined depending on the link mechanism having the complicated configuration, when designing the operation curve of the work clamp, variations in the operation curve are limited, and design freedom is limited. The degree was small.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sewing machine which has a large degree of freedom in designing an operation curve of a presser foot and is inexpensive.

[0006]

SUMMARY OF THE INVENTION According to the present invention, in a sewing machine configured to vertically move a presser foot in conjunction with a vertical movement of a sewing needle, a cloth presser drive cam which is rotationally driven by a sewing machine motor, A cloth presser bar having a lower end to which the cloth presser is attached is vertically movable, and is connected to the cloth presser bar and a cam groove of the cloth presser drive cam, and the rotational movement of the cloth presser drive cam is controlled by the cloth. A motion converting member for converting into a vertical motion of the presser bar, a spring for constantly urging the cam follower of the motion converting member in a direction of abutting the cam surface of the cam groove, and a cam of the cam groove in the cloth pressing drive cam. The retracting groove provided on the opposite side of the surface and the cam follower of the motion converting member are retracted into the retracting groove against the spring force of the spring to raise the cloth pressing rod to the retracted position. With the evacuation drive means It has a feature where was painting.

In this case, when the sewing machine is stopped, a retraction groove is provided at a portion corresponding to the cam follower, and when the sewing machine is stopped, the cloth presser may be located near the highest point of the vertical movement in the sewing operation. .

[0008]

According to the above means, the cam follower of the motion converting member is pressed against the cam surface of the cloth pressing drive cam by the urging force of the spring during the sewing operation. Then, when the presser foot drive cam is rotationally driven, the motion converting member moves in accordance with the shape of the cam surface, and in conjunction with this, the presser foot rod moves up and down.
Therefore, when designing the operation curve of the work clamp, it is only necessary to set the shape of the cam surface according to the operation curve, and the degree of freedom is increased.

Further, since the cloth presser drive cam is provided with the retreat groove into which the cam follower of the motion converting member is inserted, when the retraction drive means retracts the cam follower into the retreat groove, the cloth presser bar and the cloth presser are in the retracted position. To rise to.
In this case, since the structure for pulling up the entire motion conversion member is unnecessary, the structure of the motion conversion member can be simplified correspondingly, and the retracting drive means can be downsized, so that the cost can be reduced as a whole.

In the case where the withdrawal groove is provided in the portion corresponding to the cam follower when the sewing machine is stopped, when the sewing machine is stopped and the sewing work is completed, the cam follower of the motion converting member is put into the withdrawal groove and the cloth is removed. The work clamp can be moved to the retracted position. As a result, when the embroidery frame is detached and the color is changed while the sewing machine is stopped, the cloth presser does not interfere, and the work can be performed without any trouble. When the work clamp is configured to be located near the highest point of the vertical movement in the sewing operation when the sewing machine is stopped, a gap will be created between the work clamp and the cloth when the sewing machine is stopped. The feeding operation and the exchange operation can be performed without any trouble.

[0011]

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. 5 showing the overall structure of the embroidery sewing machine, the sewing machine main 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, for example, six in this case, is provided at the tip of the sewing machine arm 3.

The above-mentioned six needle bars 4 are vertically movably supported side by side in the needle bar support case 5 side by side (forward and backward), and are attached to the lower end portion projecting downward from the needle bar support case 5. Has a sewing needle 6 attached thereto. An embroidery thread (not shown), which is an upper thread having a different color or type, is supplied to each sewing needle 6 from a thread supply source (not shown).

The needle bar support case 5 is attached to 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 moved and driven by the needle bar selection motor 7. A driving 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, the sewing machine table 2 is provided with a sewing machine bed portion 9 located below the needle bar 4, and in the sewing machine bed portion 9 in cooperation with the sewing needle 6, the embroidery frame 1 is provided.
A hook (not shown), which is a thread catcher for forming embroidery stitches, is provided on the work cloth 11 supported by 0.
This shuttle is rotationally driven by a sewing machine motor 8 in synchronization with the vertical movement of the sewing needle 6. In addition, a needle plate and a needle thread cutting device (neither shown) are provided above the shuttle.
Etc. are provided.

Further, the sewing table 2 has an embroidery frame 1 on it.
0 for X-axis direction (front-back direction) and Y-axis direction (left-right direction)
A horizontal movement mechanism 12 for freely moving and driving the head is provided. The horizontal moving mechanism 12 is moved in the Y-axis direction by a Y-axis feed motor 13 (see FIG. 7) and an Y-axis direction moving frame 14 and an X-axis feed motor 15 (see FIG. 7). It is composed of a driven X-axis direction moving frame 16.

As shown in FIG. 4, a cloth pressing rod 17 is provided at the tip of the sewing machine arm 3. The cloth pressing rod 17 has its upper end side fitted to a cylindrical support portion 18 provided in an upper portion inside the sewing machine arm portion 3, and
The lower end side is inserted into a through hole 19a provided in the lower side wall portion 19 of the sewing machine arm 3 so that it can be vertically moved.

Cloth pressing rod 1 protruding from the sewing machine arm portion 3
A cloth retainer 20 is attached to the lower end portion of 7. A cloth pressing portion 20a having a through hole through which the sewing needle 6 is inserted is formed at the lower end of the cloth pressing member 20, and an elongated hole 20b extending vertically is formed at the upper portion. Then, as shown in FIG. 1, the cloth presser 20 is fixed by tightening a screw 21 inserted in the elongated hole 20b into the cloth presser bar 17, and loosens the screw 21 to move the cloth presser 20. As a result, the mounting position of the presser foot 20 can be adjusted according to the thickness of the work cloth 11. Further, a stopper member 20d made of a rubber plate is provided on the upper surface of the upper bent portion 20c of the presser foot 20. The lift amount of the cloth presser 20 is limited by the stopper member 20d hitting the engaging portion 19b which is a part of the lower side wall portion 19.

At the intermediate portion of the cloth presser bar 17, a cloth presser bar holder 22 fixed by screwing and a cloth presser actuating body 23 which can move up and down are provided. This work clamp operating body 2
3 has a vertically long rectangular frame shape, and as shown in FIG. 4, the presser bar 17 is inserted into the through holes formed in the upper wall portion 23a and the lower wall portion 23b, respectively, and the lower wall portion 3 is inserted. 23b to the upper surface of 23b.
It is configured to abut via the ring 24.

A first spring 25, which is a compression coil spring, is provided between the upper wall portion 23a of the cloth pressing member 23 and the upper surface of the cloth pressing rod body 22. This first spring 2
5 always biases the lower surface of the work clamp rod holder 22 so as to contact the lower wall portion 23b of the work clamp operating body 23, and the first spring 25 contracts to cause the work clamp rod 17 to move. The ascending movement of is allowed.

A lower end portion 26a of a cloth pressing operation link 26 is rotatably connected to a right side wall portion 23c of the cloth pressing member 23. Further, as shown in FIG. 1, an upper end portion 26b of the cloth pressing operation link 26 is rotatably connected to one end portion 27a of a cloth pressing drive link 27 which is rotatable about a shaft 28 (a cloth). The detailed shape of the presser foot drive link 27 is shown in (a) and (b) of FIG. 6). The cloth presser operating link 26 and the cloth presser drive link 27 constitute a motion converting member 29.

On the other hand, as shown in FIG. 4, a main shaft 30 which is rotationally driven by the sewing machine motor 8 is arranged in the upper part of the sewing machine arm portion 3, and a cloth is provided at the tip of the main shaft 30. The presser drive cam 31 is attached and fixed so as to rotate integrally. As shown in FIG. 1, a cloth pressing cam groove 31a for driving the cloth pressing member 20 is formed on the outer peripheral surface of the cloth pressing driving cam 31, and a balance (not shown) is driven on the left side. A balance cam groove 31b for forming the balance is formed. A cam follower 32 provided at the other end 27b of the cloth pressing drive link 27 is fitted and connected in the cam groove 31a for cloth pressing. Thereby, the motion converting member 29 is connected between the cloth pressing actuating body 23 and the cloth pressing cam groove 31 a of the cloth pressing drive cam 31.

A second spring 34, which is a compression coil spring, is provided between the upper side wall portion 33 of the sewing machine arm portion 3 and the upper wall portion 23a of the cloth pressing member 23. The second spring 34 has a stronger spring force than the first spring 25, and by biasing the presser foot actuating body 23 downward, the presser foot actuating link 26 causes the presser foot pressing link to move. Two
7 is urged to rotate counterclockwise in FIG.

Therefore, the cam follower 32 of the cloth pressing drive link 27 is always in pressure contact with the cam surface 31c of the cam groove 31a, and when the cloth pressing drive cam 31 is driven to rotate,
The cam follower 32 moves in the left-right direction according to the shape of the cam surface 31c. Then, the cloth pressing drive link 27 swings around the shaft 28 as a fulcrum of rotation, and this swing is transmitted to the cloth pressing working body 23 via the cloth pressing working link 26, and the cloth pressing working body 23 moves up and down.

In this case, the cam surface 3 of the presser foot drive cam 31
A portion 31 of the 1c which the cam follower 32 abuts when the sewing machine motor 8 is stopped and the rotation of the main shaft 29 is stopped.
d is formed so as to bulge to the rightmost side. Therefore, when the sewing machine is stopped, the cam follower 32 is moved to the rightmost side, and the work clamp 20 moves the motion converting member 29 and the work clamp rod 2.
It is configured to move to the highest point (hereinafter referred to as top dead center) shown in FIG.

The cloth presser drive cam 31 has a cam surface 3
A retreat groove 31e is provided on the opposite side of 1c. The withdrawal groove 31e is for the cam follower 32 of the presser foot drive link 27 to enter, and when the sewing machine motor 8 stops and the rotation of the main shaft 29 stops, that is,
When the presser foot 20 and the presser foot bar 17 are located at the top dead center shown in FIG. 1, the cam follower 32 is provided at a position where it can move rightward and retract.

As shown in FIG. 4, the sewing machine arm portion 3 is provided with a retracting drive means, such as a rotary solenoid 36, located on the right side surface of the right side wall portion 35.
A rotary shaft 37 of the rotary solenoid 36 projects into the sewing machine arm portion 3, and a cloth presser retract lever 38 is connected to a tip portion of the rotary shaft 37. An engaging piece portion 38a bent leftward in FIG. 4 is provided at the lower end portion of the cloth pressing retracting lever 38, and when the rotary solenoid 36 is driven, the engaging piece portion 38a is formed. , Foot clamp drive link 2
The pressing portion 27c (see also (a) and (b) of FIG. 6) formed on the other end portion 27b side of 7 is abutted. Then, Fig. 3
As shown in, the pressing portion 27c is pressed to the right, and the cam follower 32 is pushed into the retracting groove 31e.

Next, the electrical construction of the embroidery sewing machine will be described with reference to FIG. A control device 39 including a microcomputer controls the overall operation of embroidery sewing, and includes a CPU 40, a ROM 41 and a RAM 42, and
It is composed of a bus 43 connecting these, and an input interface 44 and an output interface 45 are further connected to the bus 43. An operation control program is stored in the ROM 41 and is stored in the RAM.
Various data such as embroidery data for performing embroidery sewing is stored in 42.

The output interface 45 has 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 respectively driving the needle bar selection motor 7 are connected, and the CPU 40 reads R
The embroidery sewing operation for the work cloth 11 is executed by driving and controlling the motors based on the operation control program in the OM 41 and the embroidery data in the RAM 42. Further, the output interface 45 is connected to a display drive circuit 52 which drives a display device 51 for displaying embroidery figures and various messages, and a solenoid drive circuit 53 which drives the rotary solenoid 36.

On the other hand, the input interface 44 detects the rotation angles of the external storage device 54 such as a floppy disk for storing embroidery data, the keyboard 55 including various input keys such as a start key, and the spindle 30. The rotation 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 30 (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 structure will be described with reference to FIG. That is, when the sewing machine motor 8 is energized and the main shaft 30 is rotated, the needle bar 4 and the sewing needle 6 are reciprocated in the vertical direction. In this case, the rotary solenoid 36
Is not electrically driven, and the cam follower 32 is urged by the second spring 34 and abuts on the cam surface 31c of the cloth pressing cam groove 31a. Therefore, the presser foot drive cam 31
With the rotation of the cam follower 32, the cam follower 32 moves in the left-right direction according to the shape of the cam surface 31c of the cam groove 31a. Then,
The presser foot drive link 27 swings around the shaft 28 as a fulcrum, and the presser foot actuating member 23 moves up and down via the presser foot operation link 26, and as a result, the presser foot is interlocked with the vertical movement of the sewing needle 6. The rod 17 and the presser foot 20 move up and down between the lowest point (bottom dead center) shown in FIG. 2 and the top dead center shown in FIG.

In this case, the behavior of the work clamp 20 is determined by the cam surface 3
Since it is determined depending on the shape of 1c, when designing the operation curve of the work clamp 20 as shown in A of FIG.
It is only necessary to set the shape of the cam surface 31c according to the operation curve A, and there are numerous variations of the operation curve A. Therefore, unlike the conventional case in which the behavior of the presser foot is limited depending on the configuration of the link mechanism, the degree of freedom in designing the operation curve A is increased.

The presser foot 20 presses the work cloth 11 by the spring force of the first spring 25, and the step 11a (for example, an emblem) of the work cloth 11 is contracted by the contraction of the first spring 25.
The sewing work is performed while absorbing the. The curves B to D in FIG. 8 are operation curves of the sewing needle 6 during the above sewing work,
The balance thread amount and the shuttle thread amount are shown in this order, and 0 ° indicates the needle bar top dead center and 180 ° indicates the needle bar bottom dead center.

Further, when the sewing machine is stopped, as shown in FIG. 1, a portion 31d of the cam surface 31c of the presser foot drive cam 31 that protrudes to the right comes into contact with the cam follower 32, and the cam follower 32 is moved to the right to move the cloth. The presser foot 20 moves to the top dead center shown in FIG. 1 via the motion converting member 29 and the cloth presser bar 23. At the same time, the retreat groove 31e is located on the right side of the cam follower 32, and the cam follower 32 can be retracted into the retreat groove 31e.

In this state, the rotary solenoid 3
6 is energized and the presser foot retracting lever 38 is rotated counterclockwise in FIG. Then, the engaging piece portion 38 a of the cloth pressing lever retracting lever 38 is pushed by the pressing portion 27 c of the cloth pressing drive link 27.
Is pressed to the right, the cloth presser drive link 27 is rotated clockwise along with the compressive deformation of the second spring 34. As a result, as shown in FIG. 3, the cam follower 32
Enters the retracting groove 31e, and the work clamp bar 17 is moved further upward from the top dead center. Then, the presser foot 20 is lifted up integrally with the presser foot bar 17, and the stopper member 2 of the presser foot 20
Since 0d hits the locking portion 19b of the lower side wall portion 19,
The lifting of the presser bar 17 is restricted, and the presser bar 20 is moved to the retracted position where it comes into contact with the lower side wall part 19.

In this case, the retracting groove 32e into which the cam follower 32 of the cloth pressing drive link 27 is inserted into the cloth pressing drive cam 31.
Since the above is provided, the swing stroke of the presser foot drive link 27 is correspondingly increased. Therefore, the work clamp 20 can be raised to the retracted position within the stroke of the work clamp drive link 27. As a result, a structure for pulling up the motion converting member 29 as a whole is unnecessary, and the structure of the motion converting member 29 can be simplified accordingly. Moreover, since the rotary solenoid 36 does not need to lift the entire motion converting member 29, the rotary solenoid 36 can be downsized and the cost can be reduced as a whole.

Moreover, since the cloth presser 20 is located at the top dead center when the sewing machine is stopped, a gap can be formed between the cloth presser 20 and the work cloth 11 when the sewing machine is stopped. It is possible to perform the feeding operation and the replacement operation of the cloth 11 without any trouble. Further, since the retreat groove 31c is provided at the portion corresponding to the cam follower 32 when the sewing machine is stopped, the cloth presser 20 is moved to the retreat position when the rotary solenoid 36 is energized at the end of the sewing operation. As a result, when the embroidery frame 10 is detached and the color is changed while the sewing machine is stopped, the work clamp 20 does not get in the way and the work can be performed without any trouble.

[0037]

As is apparent from the above description, the sewing machine of the present invention has the following excellent and excellent effects.

According to the means described in claim 1, the cloth presser is configured to be moved up and down in accordance with the shape of the cam surface of the cloth presser drive cam. Therefore, when designing the operation curve of the cloth presser, its operation is performed. It only needs to set the shape of the cam surface according to the curve, which increases the degree of freedom. Further, since the work clamp is moved to the retracted position within the stroke range of the motion converting member, the structure for pulling up the motion converting member as a whole can be eliminated, and the structure of the motion converting member can be simplified accordingly. . Moreover, since it is not necessary to lift the entire motion conversion member as the retracting drive means, the retracting drive means can be downsized and the cost can be reduced as a whole.

According to the second aspect of the invention, the cloth presser can be moved to the retracted position when the sewing machine is stopped.
As a result, when the embroidery frame is detached and the color is changed while the sewing machine is stopped, the cloth presser does not interfere, and the work can be performed without any trouble. According to the means described in claim 3, when the sewing machine is stopped, a gap can be formed between the cloth presser and the cloth, and as a result, the cloth feeding operation and the cloth replacing operation can be performed without trouble.

[Brief description of drawings]

FIG. 1 is a front view of a main part showing an embodiment of the present invention (showing a state where a presser foot is raised to a top dead center).

FIG. 2 is a view corresponding to FIG. 1 showing a state in which the work clamp is moved to the bottom dead center.

FIG. 3 is a view corresponding to FIG. 1 showing a state in which a work clamp is raised to a retracted position.

FIG. 4 is a vertical sectional side view of a sewing machine arm.

FIG. 5 is a perspective view of the entire sewing machine.

6A is a side view of the work clamp drive link, and FIG. 6B is a front view of the work clamp drive link.

FIG. 7 is a block diagram.

FIG. 8 is a diagram showing the loci of vertical movements of the sewing needle and the presser foot.

[Explanation of symbols]

6 is a sewing needle, 8 is a sewing machine motor, 17 is a presser bar, 20 is a presser foot, 29 is a motion converting member, 31 is a presser foot drive cam,
Reference numeral 31a is a cloth pressing cam groove, 31c is a cam surface, 31e is a retracting groove, 32 is a cam follower, 34 is a second spring (spring), and 36 is a rotary solenoid (retracting drive means).

Claims (3)

[Claims] 1. A sewing machine configured to move a presser foot up and down in conjunction with a vertical movement of a sewing needle, and a presser foot drive cam which is rotationally driven by a sewing machine motor and which is vertically movable and is provided at a lower end. The cloth presser bar having the cloth presser attached thereto is connected to the cloth presser bar and the cam groove of the cloth presser drive cam, and the rotational movement of the cloth presser drive cam is converted into the vertical movement of the cloth presser bar. A motion converting member, a spring that constantly urges the cam follower of the motion converting member in a direction of contacting the cam surface of the cam groove, and a spring that is located on the opposite side of the cam surface of the cam groove to the cloth pressing drive cam. And a retracting drive means for retracting the cam follower of the motion converting member into the retracting groove against the spring force of the spring so as to raise the cloth pressing rod to the retracted position. Characterized by sewing machine. 2. The sewing machine according to claim 1, wherein the retracting groove is provided at a portion corresponding to the cam follower when the sewing machine is stopped. 3. The sewing machine according to claim 2, wherein the presser foot is located near the highest point of the vertical movement in the sewing operation when the sewing machine is stopped.