JP2003326038A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine capable of reducing cycle time thereof without the use of a high-power motor. <P>SOLUTION: This sewing machine 1 is equipped with a presser bar lifter mechanism 30 for making a fabric presser 51 ascend/descend, a thread cutting mechanism 10 for cutting a thread, a stepping motor 70 for driving both the mechanisms 10 and 30, a control means for controlling the rotation of the stepping motor 70, and an operating means for operating the ascent of the fabric presser 51; the fabric presser 51 is made to ascend in accordance with the operation of the operating means; and at the termination of sewing operations, the mechanisms 10 and 30 are sequentially operated so that a thread cutter and the fabric presser 51 can be made to ascend sequentially. By the control means, at least either of the speed limit and acceleration rate of a drive motor in the ascent of the fabric presser 51 at the termination of sewing is controlled so as to be made higher than the speed limit and acceleration rate of the drive motor in the ascent of the fabric presser 51 in accordance with the operation of the operating means. Thus, the cycle time can be reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sewing machine.

[0002]

2. Description of the Related Art A solenoid, for example, has been used as a drive actuator of a sewing machine for forming stitches of zigzag type, but various mechanisms such as thread separating, thread cutting, and presser foot are controlled with higher accuracy. Therefore, motors such as servo motors and pulse motors have come to be used as drive actuators.

[0003]

In a drive system for driving a cloth pressing mechanism that raises and lowers a cloth pressing device by using a motor and a cam together and a thread cutting mechanism that performs thread cutting, the cycle time of the sewing machine is reduced. It is conceivable to increase the rotation speed and the acceleration rate of the motor in order to shorten the speed. However, the rotation speed and the acceleration rate of the motor are limited and limited by the balance between the performance of the motor used and the load. Therefore, it is conceivable to use a high-output motor, but using such a motor leads to an increase in cost, and not only does the motor become larger and the size of the entire apparatus increases, but also the inertia of the motor itself. Also becomes large and the controllability deteriorates.

An object of the present invention is to provide a sewing machine which can shorten the cycle time of the sewing machine without using a high output motor.

[0005]

The invention according to claim 1 is
For example, as shown in FIGS. 1 to 8, a presser foot lifting mechanism (30) for raising and lowering a cloth presser (51), a thread trimming mechanism (10) for thread cutting, and a single unit for driving both of these mechanisms. Drive motor (presser thread trimming pulse motor 70) and control means for controlling the rotation of the drive motor (control device 8)
And the operating means (presser switch 95) for operating the raising of the cloth presser, the cloth presser is raised based on the operation of the operating means, and the thread trimming mechanism and the presser lifting mechanism are provided at the end of the sewing operation. In a sewing machine (1) that sequentially operates to sequentially perform thread cutting and raising of a presser foot, a first operating section (inflection section) that converts a rotational driving force of the drive motor into a thread cutting driving force corresponding to a thread cutting mechanism. X2) and a first cam (61) having a first idle running portion (arc portion X1) that does not transmit the rotational driving force of the drive motor to the thread trimming mechanism, and a first actuating portion of which one end is the first cam. A first connecting member (thread cutting link 11) which is connected to the thread cutting mechanism at the other end when it slides, and transmits the thread cutting driving force to the thread cutting mechanism, and a rotation driving force of the drive motor. The second operating part (elliptical ellipse) that converts the presser foot lifting drive force corresponding to Y2) and a second idle running portion (arc portion Y1) that does not transmit the rotational driving force of the drive motor to the presser lifting mechanism, and is arranged with a predetermined phase difference with respect to the first cam. The cam (62) and a second connecting member (presser lifter) that is connected to the presser foot lifting mechanism when the other end slides on the second operating portion of the second cam and transmits the presser foot lifting drive force to the presser foot lifting mechanism. A link 31), and the control means is such that the second connecting member does not slide on the second idle running portion but slides on the second operating portion when the work clamp is raised based on the operation of the operating means. When the presser foot is lifted at the end of sewing, the first connecting member drives the first idle running part and the first operating part to slide sequentially in order to operate the presser lifting mechanism to The motor is controlled to operate the thread trimming mechanism, and then the second connecting member is connected to the second idle section and the second idle section. The drive motor is controlled so as to sequentially slide with the moving part to operate the presser foot lifting mechanism, and at least one of the speed limit and the acceleration rate of the drive motor when the work clamp is raised at the end of sewing is operated by the operating means. It is characterized in that the control is performed so as to be higher than the speed limit and the acceleration rate of the drive motor when the presser foot is raised.

According to the first aspect of the present invention, when the work clamp is raised by the operation of the operating means, the second connecting member slides on the second operating portion without sliding on the second idle running portion. The drive motor has a torque load for accelerating the rotation speed (hereinafter, simply referred to as “acceleration load” in this paragraph) and a torque load for operating the presser foot lifting mechanism (hereinafter, simply referred to as “presser lift load” in this paragraph). ) Rotate while receiving and. On the other hand, when the work clamp rises at the end of sewing, the first connecting member slides sequentially between the first idle running portion and the first operating portion, and then the second connecting member moves the second idle running portion. Since the second portion and the second operating portion are sequentially slid, the drive motor receives only the acceleration load without the presser foot lifting load while the second connecting member slides the second idle running part. Rotate in the state. That is, when the cloth presser rises at the end of sewing as compared with the case where the cloth presser rises due to the operation of the operating means, there is a period in which the drive motor is driven to run.

According to the first aspect of the invention, at least one of the speed limit and the acceleration rate of the drive motor when the cloth presser rises at the end of sewing is driven when the cloth presser rises based on the operation of the operating means. Since the speed is controlled to be higher than the speed limit and acceleration rate of the motor, the rotation of the drive motor when the work clamp rises at the end of sewing is higher than the rotation of the drive motor when the work clamp rises based on the operation of the operating means. It is possible to operate the presser foot lifting mechanism by rotating at a high speed with a less load. As a result, the cycle time of the sewing machine can be shortened without using a high output motor.

According to a second aspect of the present invention, in the sewing machine according to the first aspect, the control means is configured such that the first connecting member causes the first idle running portion and the first operation at the time of thread cutting at the end of the sewing. Control so that at least one of the speed limit and the acceleration rate of the drive motor when sliding sequentially on the section is made larger than the speed limit and the acceleration rate of the drive motor when the work clamp rises based on the operation of the operating means. It is characterized by doing.

As described above in relation to the first aspect of the invention, when the work clamp is raised by the operation of the operation means,
The drive motor rotates under a torque load for accelerating the rotation speed (hereinafter simply referred to as “acceleration load” in this paragraph) and a torque load for operating the presser foot lifting mechanism. On the other hand, at the time of thread trimming at the end of sewing, the first connecting member slides the first idle running portion and the first operating portion in sequence, so that the first connecting member moves the first idle running portion. While sliding, the drive motor rotates in the state of receiving only the acceleration load without receiving the torque load for operating the thread trimming mechanism. In other words, there is a period during which the drive motor is driven to drive during thread trimming at the end of sewing, as compared with when the cloth presser rises based on the operation of the operating means.

According to the second aspect of the present invention, at least one of the speed limit and the acceleration rate of the drive motor at the time of thread trimming at the end of sewing is adjusted so that the presser foot is raised when the work clamp is raised by the operation of the operating means. Since it is controlled so as to be larger than the speed limit and the acceleration rate of, the rotation of the drive motor at the time of thread trimming at the end of sewing is more than the rotation of the drive motor at the time of raising the work clamp based on the operation of the operating means It is possible to operate the thread trimming mechanism by rotating the thread cutting mechanism at a high speed in a state with less load. As a result, the cycle time of the sewing machine can be shortened without using a high output motor.

According to a third aspect of the present invention, for example, as shown in FIGS. 1 to 8, a storage means (control device 8) for storing a predetermined sewing pattern, and a presser foot lifting mechanism for raising and lowering the cloth presser. A drive motor that drives the presser foot lifting mechanism, a control unit that controls the rotation of the drive motor, and an operation unit that operates the lifting of the cloth presser, and the cloth presser lifts based on the operation of the operation unit. In addition, in the sewing machine in which the presser foot lifting mechanism automatically operates to raise the work clamp foot at the end of the sewing operation according to the sewing pattern, the rotational driving force of the drive motor is converted into the presser foot lifting drive force corresponding to the presser foot lifting mechanism. A cam (second cam 62) having an operating part (elliptical part Y2) and an idle running part (arc part Y1) that does not transmit the rotational driving force of the drive motor to the presser lifting mechanism, and an operating part of the cam at one end. Sliding The other end is connected to the presser foot lifting mechanism and transmits the presser foot lifting drive force to the presser foot lifting mechanism. When the presser foot rises, the drive motor is controlled to operate the presser foot lifting mechanism so that the connecting member does not slide on the idle running portion but slides on the operating portion.
When the work clamp rises at the end of the sewing operation according to the sewing pattern, the drive motor is controlled so that the connecting member sequentially slides between the idle running portion and the operating portion to operate the work clamp lifting mechanism, and the sewing operation according to the above sewing pattern. At least one of the speed limit and the acceleration rate of the drive motor when the work clamp rises at the end is controlled to be larger than the speed limit and the acceleration rate of the drive motor when the work clamp rises based on the operation of the operating means. It is characterized by doing.

According to the third aspect of the present invention, when the presser foot is raised by the operation of the operating means, the connecting member slides on the operating part without sliding on the idle running part. A state in which a torque load (hereinafter simply referred to as "acceleration load" in this paragraph) for accelerating the presser and a torque load (hereinafter simply referred to as "presser lift load" in this paragraph) for operating the presser foot lifting mechanism are received. To rotate. On the other hand, when the work clamp rises at the end of the sewing operation according to the sewing pattern, the connecting member slides on the idle running part and then on the operating part, so the connecting member slides on the idle running part. While
The drive motor rotates under the condition that it receives only the acceleration load without receiving the presser foot lifting load. That is, as compared with the case where the presser foot is raised based on the operation of the operation means, when the presser foot is raised at the end of the sewing operation, there is a period in which the drive motor is driven to run.

Further, in the invention according to claim 3, at least one of the speed limit and the acceleration rate of the drive motor when the cloth presser rises at the end of the sewing operation is set when the cloth presser rises based on the operation of the operating means. Since it is controlled to be larger than the speed limit and acceleration rate of the drive motor,
The rotation of the drive motor when the work clamp rises at the end of the sewing operation is higher than the rotation of the drive motor when the work clamp rises based on the operation of the operating means. Can be activated.
As a result, like the first aspect, the cycle time of the sewing machine can be shortened without using a high-output motor.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a sewing machine of the present invention will be described below with reference to the drawings. However, the scope of the present invention is not limited to the illustrated example. FIG. 1 is a side view of a sewing machine 1 according to this embodiment. The sewing machine 1 has a basic configuration as a sewing machine that performs a lock stitch on a material to be sewn (not shown). That is, the sewing machine 1 includes a bed portion 2 having a substantially horizontal bed surface 2a, a vertical body portion 3 provided upright at a rear end portion of the bed portion 2, and an upper portion of the vertical body portion 3 being substantially parallel to the bed portion 2. So as to extend forward, the arm portion 4, the needle bar 5 extending downward from the front end portion of the arm portion 4, the needle 6 attached to the lower end portion of the needle bar 5, and the bed portion 2. And a half-turn hook (not shown) provided in the internal space of
A spindle motor 7 as a driving source for sewing operation, an operation panel 100 (see FIGS. 8 and 9) used for inputting various data, and a controller 8 for controlling the entire sewing machine 1 (FIG. 8).
), And.

An article to be sewn is placed on the bed surface 2a of the bed portion 2, and the article to be sewn is fed in the front-rear direction and the left-right direction by a feed mechanism (not shown). It should be noted that this feed mechanism includes a feed table (not shown) front and rear feed pulse motor 89 (see FIG. 8).
And a left / right feed pulse motor 91 (see FIG. 8) and the like, and the cloth feeding operation of the workpiece is controlled by the controller 8.

The needle bar 5 is provided so as to be vertically movable.
The needle bar 5 is driven by a spindle motor 7. In other words, the drive extraction shaft of the main shaft motor 7 has a rotatable main shaft (not shown).
Is directly connected, and a crank mechanism (not shown) that converts the rotational movement of the main shaft into the vertical reciprocating motion of the needle bar 5 is connected to the main shaft and the needle bar 5.
Is intervened between. Therefore, when the spindle motor 7 is operated, the movement of the spindle motor 7 is transmitted to the needle bar 5 by the spindle and the crank mechanism, and the needle bar 5 reciprocates up and down. In addition, the encoder 7 is attached to the drive take-out shaft of the main shaft motor 7 or the main shaft.
a (see FIG. 8) is provided. The encoder 7a detects the drive take-out shaft of the main spindle motor 7 and the rotation angle of the main spindle. For example, the drive take-out shaft of the main spindle motor 7 is 1 °.
A pulse signal is output to the control device 8 each time it rotates.

A needle 6 is fixed to the needle bar 5. A threading hole is formed in the lower end portion of the needle 6, and the upper thread guided from the upper thread supply source reaches the needle 6 and passes through the threading hole. On the other hand, a half-turn hook (not shown) is arranged immediately below the needle 6, and the half-turn hook is provided with a sword tip that catches the upper thread from the lowered needle 6. A bobbin around which a bobbin thread is wound is housed in the half-turn hook. The half-rotary hook is configured to reciprocate in half rotation, and is driven by the spindle motor 7. That is, the lower shaft is connected to the half-turn hook, the lower shaft is connected to the transmission mechanism (not shown), and the transmission mechanism is connected to the main shaft. Therefore, when the spindle motor 7 is operated, the movement of the spindle motor 7 is transmitted to the half-rotary shuttle by the main spindle, the transmission mechanism and the lower shaft, and the half-rotary shuttle makes a half-rotation reciprocating motion. In addition, the needle plate 9 is provided on the bed surface 2a of the bed portion 2.
(See FIG. 2) is fixed, and the needle plate 9 has a needle hole 9a.
(See FIG. 2) are formed. The needle 6 has this needle hole 9a
And is inserted into the bed portion 2 through.

While the needle 6 reciprocates up and down once, the half-turn hook makes reciprocating motion once. When the needle 6 descends, the half-turn hook catches the upper thread with the tip of the sword to form an upper thread loop from the stitch to the thread passing hole of the needle 6, and the half-turn hook moves forward to move the upper thread. When the loop expands and the half-turn hook begins to return, the upper thread is released from the tip of the sword and the upper thread is entangled with the lower thread. With the cooperation of the needle 6 and the half-turn hook, the upper thread is entangled with the lower thread, and the stitches of the lock stitch are formed on the material to be sewn. This is an operation related to sewing of the sewing machine 1, and in the following description, the above operation is simply referred to as "sewing operation".

As shown in FIGS. 2 to 4, this sewing machine 1
Includes a thread trimming mechanism 10 that performs thread trimming, a presser foot lifting mechanism 30 that raises and lowers the cloth presser, and a cloth presser mechanism 50 that presses the cloth to be sewn. FIG. 2 shows a perspective view of the thread trimming mechanism 10, the presser foot lifting mechanism 30, and the cloth pressing mechanism 50. FIG. 3 is a plan view showing a part of the members forming the thread cutting mechanism 10 which are hidden by the needle plate 9 in FIG. FIG. 4 shows a perspective view of the cloth pressing mechanism 50.

First, the structure of the thread cutting mechanism 10 will be described. The thread trimming mechanism 10 sews a bobbin from the bobbin to the sewn object placed on the needle plate 9 and an upper thread from the upper thread supply source to the sewn object placed on the needle plate 9. It is cut immediately after the end, and mainly includes the thread cutting link 11,
Thread cutting connecting rod 13, fixed knife member 14, movable knife member 1
It is composed of 5 etc.

The thread cutting link 11 as the first connecting member of the present invention is a member that extends vertically in the vertical body portion 3, and is formed in the shape of an elongated rod slightly bent in the middle.
The bent portion 11b is rotatably attached to the vertical body portion 3 by the support pin 12. A fitting pin 11a slidably fitted in a cam groove 61a of a first cam 61, which will be described later, is provided at the upper end of the thread cutting link 11 (see FIG. 5A).

The lower end portion 11c of the thread cutting link 11 is attached to the mounting plate 16 with a screw 17 in a rotatable state together with the rear end portion of the thread cutting connecting rod 13.
At the end of the mounting plate 16, the light shield plate 1 bent in the horizontal direction is provided.
The light blocking member 18 having 8a is fixed. On the other hand, in the vicinity of the light blocking member 18, a photo interrupter 19 including a light emitting element and a light receiving element is fixed to the bed 2.
The photo interrupter 19 detects the origin position of the thread cutting mechanism 10. When the light blocking plate 18a is located between the light emitting element and the light receiving element of the photo interrupter 19, a signal indicating that the photo interrupter 19 is at the origin position is provided. Is output to the control device 8 (see FIG. 8).

The thread-cutting connecting rod 13 is a member extending back and forth in the bed 2. This thread cutting connecting rod 13
Is a slender rod-shaped member that is bent at a predetermined position so as to gradually move upward, and its tip portion 13a has a needle plate 9
Has reached below. As shown in FIG. 3, the tip 1
A movable knife connecting member 20 is rotatably connected to 3a via a screw 21. Further, the movable knife connecting member 2
The thread trimming lever 23 is fixed on the position 0. The connecting pin 22 fixed to the needle plate 9 is inserted into the movable knife connecting member 20 and the thread trimming lever 23, and the movable knife connecting member 20 and the thread trimming lever 23 can rotate together around the connecting pin 22. Has become. One end 24a of a movable knife link 24 is rotatably connected to the tip of the thread cutting lever 23.

The central portion of the movable knife member 15 is rotatably connected to the other end 24b of the movable knife link 24. The end 15a of the movable knife member 15 has a set screw 2
It is attached rotatably with respect to 5. Set screw 2
5 is fixed to the needle plate 9. At the tip of the movable knife member 15, a thread wiping portion 15b that disengages the upper thread and the lower thread without cutting the thread when performing thread trimming, and a means that captures the upper thread and the bobbin thread dissipated by the thread wiping portion 15b A curved yarn catching portion 15c and a movable blade 15d for cutting the upper yarn and the lower yarn are further formed. A fixed knife member 14 screwed to the needle plate 9 is provided near the movable knife member 15, and a movable blade 15d is provided at the tip of the fixed knife member 14.
Fixed blade 1 for pinching the upper thread and the lower thread between them and cutting them
4a is formed.

Next, the operation of the thread cutting mechanism 10 will be described. The thread trimming mechanism 10 having the above-described configuration is in the state of FIG. 3A during the sewing operation, and when the sewing operation ends, before the presser foot lifting mechanism 30 and the cloth presser mechanism 50 operate, a cam to be described later is performed. The thread cutting link 11 by the member 60
Rotates around the support pin 12 in the counterclockwise direction (direction of arrow A) in FIG. 2, and its lower end moves forward. As a result, as shown in FIG. 3B, the thread trimming connecting rod 13 moves forward, and the movable knife connecting member 20 is moved through the screw 21.
Is pressed, the movable knife connecting member 20 and the thread cutting lever 23 rotate around the connecting screw 22.

By the operation of the thread cutting lever 23, the movable knife link 24 connected to the tip of the thread cutting lever 23 is pushed backward,
The movable knife member 15 rotates clockwise around the set screw 25. By this rotating operation, the bobbin threading part 15b separates the bobbin thread from the bobbin to the sewn object and the upper thread thread from the upper thread supply source to the sewn object. And the fixed blade 14a. This is the operation related to the thread handling of the sewing machine 1, and in the following description, the above-mentioned operation is simply referred to as "thread handling operation".

Next, the thread cutting link 11 is attached to the support pin 12.
When the lower end portion of the thread cutting mechanism 10 is rotated clockwise around the center and returns to the rear, the members constituting the thread trimming mechanism 10 operate in reverse. That is, the movable knife member 15 rotates so as to return from the state of FIG. 3B to the original state, and at that time, the yarn catching portion 15c.
By rotating while capturing the upper thread and the lower thread by
As the lower thread and the upper thread approach the fixed blade 14a,
As shown in (c), the movable blade 15d and the fixed blade 14a are aligned, and the upper thread and the lower thread are cut. The movable knife member 15 continues to rotate as it is and returns to the state of FIG. This is an operation related to thread cutting of the sewing machine 1 performed after the thread spreading operation, and in the following description, the above-mentioned operation is simply referred to as "thread cutting operation".

Next, the structure of the presser foot lifting mechanism 30 will be described. The presser foot lifting mechanism 30 raises and lowers the presser foot 51 before and after the sewing operation, and is mainly composed of a presser foot lifting link 31, a presser foot drive link 32, a presser foot drive arm 35, a presser foot 36 and the like. To be done.

The presser foot link 31 as the second connecting member of the present invention is a member arranged in the vertical body portion 3 and is formed in a substantially dogleg shape. It is rotatably attached to the body 3. A roller 43 (see FIG. 5C, which is hidden behind the presser foot link 31 in FIG. 2) is fixed to the lower end 31c of the presser foot link 31 so as to project to the left. Is the second cam 6 of the cam member 60 described later.
The second outer peripheral surface 62a is in contact with the outer peripheral surface 62a (see FIGS. 5A and 5C).

A winding spring 44 is hooked on the presser foot lifting link 31 and the motor base 70a fixed to the vertical barrel portion 3, and the presser foot lifting link 31 causes the roller 43 to move the roller 43 to the second position. It is constantly urged to come into contact with the cam 62. At the upper end 31a of the presser foot lifting link 31,
One end 32a of the presser drive link 32 is rotatably connected.

The presser drive link 32 is a long flat bar-shaped member extending forward and backward in the arm portion 4, and the other end portion 32b is rotatably connected to the lower end portion of the interlocking arm 33. There is. A light blocking member 41 having a light blocking plate 41a bent in the horizontal direction is fixed to the side surface of the presser drive link 32 near the one end 32a. On the other hand, in the vicinity of the light blocking member 41, a photo interrupter 40 including a light emitting element and a light receiving element is fixed to the arm portion 4. The photo interrupter 40 detects the origin position of the presser foot lifting mechanism 30, and when the light blocking plate 41a is located between the light emitting element and the light receiving element of the photo interrupter 40, a signal indicating that the photo interrupter 40 is at the origin position. Is output to the control device 8 (see FIG. 8).

The interlocking arm 33 has, at its upper end,
A holding member driving arm 35, which is laterally formed on the left side of the interlocking arm 33 with respect to the shaft member 34, is held and fixed to the shaft member 34 rotatably supported by the arm portion 4. Thus, the shaft member 34 swings together with the shaft member 34 as a fulcrum. Therefore, when the interlocking arm 33 swings around the shaft member 34 as a fulcrum, the presser drive arm 35 also interlocks with the swinging of the interlocking arm 33, and the shaft member 3 moves.
It swings around 4 as a fulcrum. At the front end portion 35 a of the presser drive arm 35, the presser drive leg 3 that is long in the vertical direction is provided.
6 is rotatably connected.

The presser foot 36 has a substantially U-shaped cross section in the horizontal direction, and its lower edge 36a comes into contact with a contact pin 55 of a cloth presser mechanism 50, which will be described later, when it descends. ing. In the middle of the presser drive leg 36, one end of a horizontally long support rod 37 is rotatably supported. The other end of this support rod 37 is rotatably attached to the arm 4 via a pin 38, and the direction in which the presser drive leg 36 descends is regulated by the support rod 37.

A space having a predetermined size is provided between the pressing drive leg 36 and the contact pin 55 of the cloth pressing mechanism 50 located below the pressing drive leg 36. Therefore, the presser foot drive leg 36
The contact pin 55 of the presser foot mechanism 50 comes into contact with the contact pin 55 with a delay of this interval after the start of descending.

Next, the structure of the cloth pressing mechanism 50 will be described. As shown in FIGS. 2 and 4, the cloth pressing mechanism 50 is
It comprises a cloth presser 51, a support base 52, a cloth presser drive link 53, and the like.

The support base 52 is provided on the bed portion 2 and functions to support the presser foot drive link 53.
The presser foot drive links 53 are arranged in pairs so as to extend substantially along the left and right side surfaces of the support base 52. The pair of presser foot drive links 53, 53 are rotatably attached to the support base 52 by a shaft member 54. A cloth presser 51 that presses the material to be sewn during the sewing operation is fixed to one end portion 53a of each cloth presser drive link 53. Further, an upper extending portion 53b is provided at a part of each presser foot drive link 53. These two upward extensions 53
A contact pin 55 is provided so as to be bridged between the upper ends of b and 53b, and the contact pin 55 is arranged near the lower part of the presser foot 36 of the presser lifting mechanism 30. .

Further, the support base 52 is provided with two pins 56, 56 protruding in the respective left and right directions.
A winding spring (not shown) is hooked between each pin 56 and the other end 53c of each presser foot drive link 53 so that each pin 56 and each other end 53c approach each other. It is always energized. Therefore, the above-mentioned presser foot drive leg 36 of the presser foot lifting mechanism 30 causes the contact pin 5 to
5 is not in contact with each presser foot drive link 53
The one end portion 53a of the above is in a state of descending around the shaft member 54. That is, when the presser foot drive leg 36 is not in contact with the contact pin 55, the cloth presser 51 fixed to the one end portion 53a of each cloth presser drive link 53 is in the lowered state.

Although not described in detail, in the presser foot mechanism 50 having the above structure, the lower plate 57 is provided near the lower end portion 52a of the support base 52, and the support base 52 is provided.
Can move in the front-rear direction together with the lower plate 57, and can also swing in the left-right direction about the shaft portion 52b.

Next, the presser foot lifting mechanism 30 and the cloth presser mechanism 5
The operation of 0 will be described. In the state shown in FIG.
The presser foot lifting link 31 is shown in FIG.
When it rotates in the counterclockwise direction (direction of arrow B) in, the presser drive link 32 is pulled backward. By this action,
When the interlocking arm 33 swings rearward about the shaft member 34, the presser drive arm 35 also rotates about the shaft member 34 in the clockwise direction in FIG. With the rotation of the presser drive arm 35, the presser drive leg 36 descends while being restricted by the support rod 37.

Here, as described above, the presser foot drive leg 36
Since there is a gap between the pressing pin 55 of the presser foot mechanism 50 and the contact pin 55 of the presser foot mechanism 50, the lowered presser foot 16 comes into contact with the contact pin 55 after a predetermined time elapses after the presser foot 36 starts to descend.
The contact pin 55 is pushed downward by the presser drive leg 16 as it is. Then, when the contact pin 55 is pushed downward, each pin 56 provided on the support base 52 and the other end portion 53c of each presser foot drive link 53 are
Each of the cloth presser drive links 53 rotates counterclockwise in FIG. 2 around the shaft member 54 against the biasing force of the winding spring applied between the cloth presser 51 and the cloth presser 51. This is the operation relating to the lifting of the presser foot 51 of the sewing machine 1. In the following description, the above operation will be simply referred to as the "presser foot lifting operation".

Further, the work clamp lifting operation is performed and the work clamp 5
In the state where 1 is raised, the presser foot lifting link 31 is shown in FIG.
When the cloth presser 51 is rotated clockwise, the operation reverse to the cloth presser raising operation is performed and the cloth presser 51 is lowered. This is an operation relating to the lowering of the cloth presser 51 of the sewing machine 1, and in the following description, the above-mentioned operation is simply referred to as "cloth presser lowering operation".
When the work clamp lowering operation is performed, the contact pin 55
Moves up in contact with the presser drive leg 36, and eventually the contact pin 55 and the presser drive leg 36 are released from contact, and only the presser drive leg 36 moves up. This is because, as described above, a space having a predetermined size is provided between the presser foot 36 of the presser foot lifting mechanism 30 and the contact pin 55 of the cloth presser mechanism 50.

Here, as can be seen from the above description,
When the presser foot lifting mechanism 30 operates, the presser foot lifting mechanism 3
The operation of 0 is transmitted to the cloth pressing mechanism 50, and the cloth pressing mechanism 5
0 works. Then, by operating the cloth pressing mechanism 50, the cloth pressing rising operation and the cloth pressing lowering operation are performed. In other words, by operating the presser foot lifting mechanism 30,
The work clamp lifting operation and the work clamp lowering operation are performed.

Although not described in detail, the sewing machine 1 includes a thread wiping mechanism 5 which operates in conjunction with the presser foot lifting mechanism 30.
9 is provided. The thread wiping mechanism 59 is the thread cutting mechanism 1
After the needle thread is cut by 0 and before the cloth retainer 51 of the cloth retainer mechanism 50 is raised, the needle thread connecting the needle 6 to the workpiece is wiped, and the thread end on the needle 6 side is placed on the workpiece. Withdraw.

As described above, in the thread trimming mechanism 10, the thread trimming link 11 includes the presser foot lifting mechanism 30 and the cloth presser mechanism 5.
At 0, the presser foot lifting links 31 act as starting points respectively. Thread trimming link 11 and presser foot lifting link 31
Is configured so that the rotational driving force of the presser thread cutting pulse motor 70 is transmitted at a predetermined timing via the cam member 60 to operate. Hereinafter, the presser thread cutting pulse motor 70 and the cam member 60 will be described.

The presser thread trimming pulse motor 70 as the drive motor of the present invention includes the motor base 70a and the vertical barrel portion 3a.
It is fixed to. A center portion of a cam member 60, which will be described later, is fixed to an output shaft 71 of the presser thread trimming pulse motor 70.
It is designed to rotate by a predetermined angle.

The presser thread cutting pulse motor 70 is driven and controlled by the CPU 80 of the control device 8 which will be described later. The CPU 80 operates the thread trimming mechanism 10, the presser foot lifting mechanism 30, and the cloth presser mechanism 50 while counting the rotational direction of the presser thread trimming pulse motor 70 and the number of operating pulses. It is designed to be performed by controlling.

The cam member 60, as shown in FIG.
When viewed from the front, the first cam 61 is a substantially circular box whose outer shape includes a part of a straight line, and a second cam 62 integrally provided on the front side of the first cam 61. Note that FIG.
A perspective view of the cam member 60 viewed from the back side is shown in (a).

As shown in FIG. 5A, the first cam 61 has a substantially heart-shaped cam groove 61a formed on the back surface side. The fitting pin 11a of the thread cutting link 11 fits into the cam groove 61a and slides along the surface thereof.

The shape of the cam groove 61a is shown in FIG. 5 (b). For convenience, P1 to P7 indicate angular positions that are points in one round. The cam groove 61a is formed so as to draw an arc whose distance from the rotation center C1 is equal from P2 to P3 to P7. on the other hand,
Between P2 and P7 with P1 as the center, they are formed symmetrically so that the distance from the rotation center becomes shorter toward P1. Hereinafter, a portion from P2 to P3 to P7 will be referred to as an “arc portion X1”, and a portion from P2 to P7 centered on P1 will be referred to as an “inflection portion X2”.

The fitting pin 11a described above moves relatively in the cam groove 61a as the cam member 60 rotates, as schematically shown in FIG. 5 (b). Therefore, for example, when the presser thread trimming pulse motor 70 rotates in the forward direction,
When the fitting pin 11a is moving from P2 which is the arc portion X1 to P7 through P3, the distance between the fitting pin 11a and the rotation center C1 does not change, and the thread cutting link 11 does not rotate. The same applies when the presser thread trimming pulse motor 70 rotates in the opposite direction and goes from P7 to P3 to P2. Therefore, when the presser thread cutting pulse motor 70 rotates and the fitting pin 11a moves in the arc portion X1, the rotational driving force of the presser thread cutting pulse motor 70 is not transmitted to the thread cutting mechanism 10. That is, the arc portion X1 is the first idle running portion in the present invention.

On the other hand, when the fitting pin 11a moves from P7 to P1, it gradually approaches the rotation center C1. As a result, the thread trimming link 11 rotates counterclockwise in FIG. 2 (direction of arrow A), and as described above, the movable knife member 1
5 moves beyond the fixed blade 14a.

Then, when the fitting pin 11a moves from P1 to P2, it gradually moves away from the rotation center C1, the thread cutting link 11 rotates clockwise in FIG. 2, and the movable knife member 15 moves the upper thread and the lower thread. Fixed blade 14a while capturing
Cut the upper and lower threads between and. The same applies when the presser thread trimming pulse motor 70 rotates in the opposite direction and the fitting pin 11a goes from P2 to P1 to P7. That is, the inflection portion X2 is the first operation portion in the present invention.

As shown in FIG. 2, the second cam 62 is integrally fixed to the front side of the first cam 61. FIG. 5 (c)
The shape of the second cam 62 is shown in FIG. As shown in FIG. 5C, the second cam 62 is formed in a substantially daruma shape, and the roller 43 of the presser foot lifting link 31 is in contact with the outer peripheral surface 62a thereof. For convenience, Q1 to Q7 in FIG. 5C indicate angular positions that are points in one round. Outer surface 6
2a is formed so as to draw an arc having the same distance from the rotation center C1 from Q6 to Q3 to Q3.

On the other hand, Q3 to Q4 and Q6 to Q5 are formed symmetrically so that the distance from the center of rotation becomes longer toward Q4 and Q5, respectively. Further, between Q4 and Q5, an arc having the same distance to the rotation center C1 is formed. Below, Q6
From Q1 to Q3 is referred to as "arc section Y1",
The area from Q3 to Q6 including Q4 and Q5 is the "ellipse Y
2 ”.

As shown in FIG. 5 (c), the roller 43 described above is rotated by the rotation of the cam member 60 so that the outer peripheral surface 6
Move relatively along 2a. Therefore, for example, the presser thread trimming pulse motor 70 rotates in the forward direction, and the roller 43
Is moving from Q6 through Q1 to Q3, the distance between the roller 43 and the rotation center C1 does not change, and the presser foot lifting link 31 does not rotate. The same applies when the presser thread trimming pulse motor 70 rotates in the opposite direction and the roller 43 moves from Q3 to Q1 to Q6. Therefore, when the presser thread cutting pulse motor 70 rotates and the roller 43 moves in the arc portion Y1, the rotational driving force of the presser thread cutting pulse motor 70 is not transmitted to the presser lifting mechanism 30 and the cloth pressing mechanism 50. That is, the arc portion Y1 is the second idle running portion in the present invention.

On the other hand, when the roller 43 moves from Q3 to Q4, the roller 43 gradually separates from the rotation center C1. As a result, the presser foot lifting link 31 rotates in the counterclockwise direction (the direction of arrow B) in FIG. 2, the presser foot drive link 32 moves rearward, and the cloth presser foot 51 rises as described above.

When the presser thread trimming pulse motor 70 rotates in the opposite direction and the roller 43 returns from Q4 to Q3, the roller 43 gradually approaches the rotation center C1 and the presser foot lifting link 3
1 rotates clockwise in FIG. 2 and presser foot drive link 3
2 returns to the front, and the presser foot 51 comes down. Q
The same applies between 6 and Q5, and when heading for Q5, roll 43
The presser foot drive link 31 rotates in the counterclockwise direction in FIG. 2 via, and rotates in the clockwise direction in FIG. 2 when moving toward Q6. That is, the elliptical portion Y2 is the second operating portion in the present invention.

The reason why the second cam 62 has an arc between Q4 and Q5 is as follows. In the case of the presser foot 51, basically, the raising and lowering operations are rarely continuously performed, and the operation flow is, for example, after lowering, sewing and raising. Even when the presser thread trimming pulse motor 70 is stopped when the roller 43 reaches Q4 or Q5 and raises the presser foot 51, a mechanical deviation occurs in the rotation stop of the cam member 60 with respect to that, and a slight deviation occurs. May pass Q4 or Q5.
By forming an arc between Q4 and Q5, it is possible to prevent the stop from being delayed and the descent operation to start even if the rotation further exceeds Q4 or Q5.

Further, the first cam 61 and the second cam 62 have a phase relationship with each other and a fitting pin in consideration of performing the thread spreading operation, the thread cutting operation and the cloth presser lifting operation in a desired order. 11a and the contact position of each roller 43 are set. Specifically, between P1-P7, P1-P2
, Q1-Q7, and Q1-Q2 are the same (angle m1), and when the fitting pin 11a goes from P7 to P1 to P2, the roller 43 is just Q.
It goes from 7 to Q1 to Q2. That is, the presser foot lifting mechanism 30 and the cloth presser mechanism 50 do not operate during the thread trimming operation.

Further, while the roller 43 moves upward from Q3 to Q4, the fitting pin 11a moves between P3 and P4 and the thread trimming mechanism 10 does not operate. Roll 43 is Q5-Q6
Even while the space is moved to operate the presser foot lifting mechanism 30 and the cloth presser mechanism 50, the fitting pin 11a moves between P5 and P6 and the thread trimming mechanism 10 does not operate. In addition, roller 43
However, when it is located between Q4 and Q5, the fitting pin 11a is P
It is located between 4-P5.

Further, the cam member 60 is a region (inoperative region) in which the rotational driving force of the presser thread trimming pulse motor 70 is not transmitted to any of the thread trimming mechanism 10, the presser foot lifting mechanism 30 and the cloth presser mechanism 50. ) Is provided. That is, when the fitting pin 11a is between P2-P3 and the roller 43 is between Q2-Q3, and when the fitting pin 11a is P
When the roller 43 is between 6 and P7 and the roller 43 is between Q6 and Q7, none of the thread trimming mechanism 10, the presser lifting mechanism 30 and the cloth pressing mechanism 50 operates. That is, FIG.
Areas between P2-P3 and between P6-P7 in (b), and FIG.
Areas between Q2-Q3 and between Q6-Q7 in (c) are inoperative areas.

Next, the operation of the thread trimming mechanism 10, the presser foot lifting mechanism 30, and the cloth presser mechanism 50 centering on the cam member 60 will be described with reference to FIGS. 6 and 7. 6 and 7 are explanatory diagrams for explaining the operation centered on the cam member 60. Here, the operation of operating the thread trimming mechanism 10, the presser foot lifting mechanism 30, and the cloth presser mechanism 50 in this order will be described.

First, the thread cutting operation is started from the state I shown in FIG. 6 (a). In this state I, the mating pin 1
1a is located in the arc portion X1 of the cam groove 61a of the first cam 61, and the roller 43 is the arc portion Y of the outer peripheral surface 62a of the second cam 62.
It is in contact with 1.

From this state I, the cam member 60 causes the presser thread trimming pulse motor 70 to rotate in the forward direction (see arrow F in FIGS. 6 and 7; the same applies hereinafter), so that the cam member 60 rotates clockwise in FIGS. 2 and 6. Rotate to. The fitting pin 11a has an arc portion X1
While the roller 43 relatively moves the arc portion Y1 as it is, the fitting pin 11a eventually reaches the position of the boundary between the arc portion X1 and the inflection portion X2 (P7 in FIG. 5B). Moved to state II.

From here, the fitting pin 11a begins to move in the inflection portion X2, and the thread cutting mechanism 10 starts to operate. The fitting pin 11a is located at the center of the inflection portion X2 (see FIG. 5B).
In the state III (see FIG. 6 (c)), the movable knife member 15 is in the most moved state in FIG. 3 (b). In addition, when shifting from the state II to the state III, the thread cutting operation by the thread cutting mechanism 10 is performed. Further, in both the state II and the state III, the roller 43 is moving along the arc portion Y1 and the presser foot lifting mechanism 30
And the presser foot mechanism 50 does not operate.

Next, the fitting pin 11a advances from P1 to P2 in the inflection portion X2, and in this process, the movable knife member 15 operates so as to return to its original state. Performs a cutting operation. And the fitting pin 11a
Reaches the end point position (P2) of the inflection portion X2 and enters the state IV shown in FIG. 7 (a). At this time, the operation of the thread cutting mechanism 10 ends. Further, the cam member 60 rotates in the same direction, the fitting pin 11a is between P2 and P3 of FIG. 5B (inoperative region), and the roller 43 is between Q2 and Q3 of FIG. 5C (inoperative region). ) Move. At this time, none of the thread trimming mechanism 10, the presser foot lifting mechanism 30, and the cloth pressing mechanism 50 operates.

Then, as shown in FIG. 7 (b), the roller 43 reaches the elliptical portion Y2 of the outer peripheral surface 62a (position Q3 in FIG. 5 (c)) (state V), and from here, the presser foot lifting link 31 can be seen. Two
Then, the counterclockwise rotation in FIG. 7 starts, the presser foot lifting mechanism 30 and the cloth presser mechanism 50 operate, and the cloth presser mechanism 50 performs the cloth presser lifting operation. Then, as shown in FIG. 7 (c), the roller 43 reaches between Q4 and Q5 to enter the state VI, and the cloth presser lifting operation by the cloth presser mechanism 50 is completed,
At this time, the presser thread trimming pulse motor 70 is stopped. In addition,
In either state V or state VI, the fitting pin 11a
Moves along the arcuate portion X1, so the thread cutting mechanism 10 does not operate.

Next, the configuration of the control device 8 will be described with reference to the block diagram shown in FIG. The control device 8 has, as its basic configuration, a ROM 82 in which a control program for controlling the sewing machine and data used in the control program are stored in advance, a CPU 80 that performs various processes based on the control program, and read from the ROM 82. The RAM 81 in which the data calculated by the CPU 80 based on the data and the control program are stored, and the front and rear direction and the left and right direction of the feed table (the material to be sewn set on the feed table) between the needle drops during the sewing operation. EEPR in which a plurality of predetermined sewing patterns relating to the feed amount in the direction are stored
OM83, and.

The CPU 80 has an interface 84a.
The operation panel 100 is connected via the above. CPU
The reference numeral 80 selects one sewing pattern from the plurality of sewing patterns stored in the EEPROM 83 based on the data input from the operation panel 100, and further changes the sewing pattern. The operation panel 100 will be described later.

Further, a presser switch 95 is connected to the CPU 80 via an interface 84a or the like.
When the input signal is input from the presser switch 95, the CPU 80 controls the presser foot lifting mechanism 30 and the cloth presser mechanism 50 to perform a process of raising the presser foot and lowering the presser foot. The presser switch 95 has a function as an operating means of the present invention, and as described later,
Every time the operator operates (presses) the presser foot switch 95, the cloth presser raising operation and the cloth presser lowering operation are repeatedly performed.

A start switch 96 is connected to the CPU 80 via an interface 84a or the like. When the input signal for instructing the start of sewing is input from the start switch 96, the CPU 80 controls the feed mechanism and other mechanisms based on the above-mentioned sewing pattern to perform the sewing operation, and the sewing operation ends. After that,
Thread trimming mechanism 10, presser foot lifting mechanism 30 and cloth presser mechanism 50
Etc. are controlled to perform a thread spreading operation, a thread cutting operation, a presser lifting operation, and the like.

A drive circuit 85 for driving the presser thread cutting pulse motor 70 is connected to the CPU 80 via an interface 84b or the like. further,
An encoder 72 provided in the presser thread cutting pulse motor 70 is connected to the CPU 80 via an interface 84b, a drive circuit 85, and the like. CPU80 is
The rotation angle of the presser thread trimming pulse motor 70 is controlled by recognizing the rotation angle of the presser thread trimming pulse motor 70 by the input signal input from the encoder 72, and the thread trimming mechanism 10, the presser foot lifting mechanism 30, the cloth presser mechanism 50, etc. Control movements.

Further, the CPU 80 has a photo interrupter 19 and a presser lifting mechanism 30 for detecting the origin position of the thread trimming mechanism 10 via the interface 84b and the like.
A photo interrupter 40 for detecting the origin position of is connected. The CPU 80 is the photo interrupter 1
An input signal indicating whether or not the thread cutting mechanism 10 is located at the origin position is input from 9 and control is performed based on this input signal. Similarly, the CPU 80 receives an input signal indicating whether or not the presser foot lifting mechanism 30 is located at the origin position from the photo interrupter 40, and performs control based on this input signal.

Further, to the CPU 80, drive circuits 86 and 87 for driving the forward / backward feed pulse motor 89 and the left / right feed pulse motor 91 provided in the feed mechanism are connected via the interface 84b and the like.
Reference numeral 80 controls the operation of the feed table of the feed mechanism in the front-rear direction and the left-right direction. Further, the CPU 80 is connected with a forward / backward feed origin sensor 90 and a left / right feed origin sensor 92 for detecting the origin position of the feed base (the position where the sewing operation is started). The CPU 80 receives an input signal from the forward / backward feed origin sensor 90 and the left / right feed origin sensor 92 as to whether or not the feed table is located at the origin position, and performs control based on this input signal.

Further, the CPU 80 has a drive circuit 8 for driving the spindle motor 7 via the interface 84b or the like.
8 is connected. Furthermore, an encoder 7a provided in the spindle motor 7 is connected to the CPU 80 via an interface 84b, a drive circuit 88, and the like.
The CPU 80 recognizes the rotation angle of the spindle motor 7 from the input signal input from the encoder 7a, and determines the spindle motor 7
It controls the rotation of 0, and controls the operation of the needle bar 5 including the main shaft and the lower shaft, the counter rotary hook, and the like.

Next, the operation panel 100 for the operator to select and change the sewing pattern will be described with reference to FIG.

On the operation panel 100, a sewing pattern selection section 101 for selecting one sewing pattern from a plurality of sewing patterns, and a work for preparing a sewing operation are CP.
A preparation key 102, which is operated when the U80 is made to operate, is provided.

The sewing pattern selection unit 101 selects the sewing pattern selected from the plurality of sewing patterns as the pattern No. Sewing pattern display portion 101a displayed as
The pattern No. displayed every time the button is pressed 1 is added to the sewing pattern plus key 101b to change the selected sewing pattern, and the pattern No. displayed every time the key is pressed. And a sewing pattern minus key 101c for changing the selected sewing pattern by subtracting 1.

Next, the processing in the CPU 80 when the sewing machine 1 performs the control operation will be described according to the flowchart of FIG. 10 with reference to FIGS. 5, 6, 7 and 11. Note that FIG. 11A shows the presser thread trimming pulse motor 7
Various operations are schematically shown with respect to a rotation angle of 0 (0 ° to 360 °). In particular, a solid line portion indicates an operation relating to the presser foot lifting mechanism 30 and the cloth presser foot mechanism 50 and a movement amount of the presser foot lifting link 31. The dotted line shows the operation of the thread cutting mechanism 10 and the movement amount of the thread cutting link 11. FIG. 11B shows the rotation speed of the presser thread trimming pulse motor 70 with respect to the rotation angle (0 ° to 360 °).

At each rotation angle shown in FIG. 11, "0
“°” corresponds to the state VI of FIG. 7C, and “Point A” is shown in FIG.
Corresponding to the state I of (a), the "point B" is the state I of FIG. 6 (b).
6C corresponds to state III, and "point C" corresponds to a state between state III in FIG. 6C and state IV in FIG. 7A. Correspondingly, "point D" corresponds to state IV in FIG. 7 (a), "point E" corresponds to state V in FIG. 7 (b), and "360 °" is state VI in FIG. 7 (c). Corresponding to. The presser thread cutting pulse motor 70 is adapted to be rotationally driven from the point A.

First, when the operator turns on the sewing machine 1, it is checked whether the sewing pattern plus key 101b or the sewing pattern minus key 101c of the operation panel 100 has been operated (step S1), and the sewing pattern plus switch 101b is pressed. If the sewing pattern has been pressed, 1 is added to the sewing pattern as the default value, and if the sewing pattern minus key 101c is pressed, 1 is subtracted from the sewing pattern as the default value to update the sewing pattern ( Step S2).

Next, the preparation key 10 on the operation panel 100.
2 is pressed (step S3), and if it is pressed, the feed mechanism is operated to move the feed table to the origin position, and at the same time, the cloth pressing mechanism 50 is operated to press the cloth pressing member 51. Is moved to the origin position (the position where the sewing operation is started) (step S4). In this state, since the presser foot lifting mechanism 30 does not operate, the cloth presser 51 is in a lowered state.

Then, in order to set the material to be sewn at the predetermined position, the work clamp mechanism 50 is operated to perform the work clamp lifting operation (step S5). Here, when the cloth presser lifting operation is performed, the presser thread trimming pulse motor 70 rotates in the reverse direction from the state I of FIG. 6A to the state of FIG. 7C.
Move to VI. Specifically, the roller 43 is Q6 in FIG.
Move the ellipse Y2 to move from Q4 to Q5.
When 3 reaches between Q5 and Q4, the presser thread trimming pulse motor 70 stops. At this time, as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from point A to 0 °, but as shown in FIG. , A torque load for operating the presser foot mechanism 50 so as to raise the presser foot 51 (hereinafter simply referred to as “presser foot lift load”) and a torque load for increasing the rotational acceleration (hereinafter simply referred to as “acceleration load”). .) To rotate while accelerating to the limit speed V1 and to rotate at a constant speed at the limit speed V1 while receiving only the presser foot ascending load, and to further reduce the presser foot ascending load and rotational acceleration. Under the torque load (hereinafter simply referred to as "deceleration load"), the motor rotates while decelerating, and finally stops.

Next, the preparation key 10 on the operation panel 100.
2 is pressed (step S6), and if pressed (step S6: YES), the sewing pattern can be changed again by returning to step S1. If not pressed (step S6) : NO), it is checked whether the presser foot switch 95 has been pressed (step S).
7). If it is pressed, the work clamp mechanism 50 is operated to perform the work clamp lowering operation (step S8). At this time, from the state VI of FIG. 7C, the presser thread trimming pulse motor 7
When 0 rotates in the forward direction, the state transitions to the state I of FIG. 6A, and as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 transitions from 0 ° to point A.

Next, it is checked whether or not the presser foot switch 95 has been pressed (step S9), and if it has been pressed (step S9: YES), the cloth presser lifting operation similar to step S5 is performed (step S10). ), Step S
Return to 7. Here, in the processes from step S7 to step S9, the cloth presser raising operation and the cloth presser lowering operation are repeatedly performed every time the presser switch 95 is pressed, whereby the sewing object is reset to the desired position. You can

When the presser foot switch 95 is not pressed (step S9: NO), it is checked whether or not the start switch 96 is pressed (step S11). If it is pressed, the selected sewing pattern is selected. The sewing operation based on is performed (step S12). Next, in a state of being synchronized with the final rotation operation of the spindle motor 7, the presser thread cutting pulse motor 70 is driven to operate the thread cutting mechanism 10 to perform the thread spreading operation (step S13).

Here, when the thread winding operation is performed, first, the presser thread cutting pulse motor 7 is moved from the state I of FIG. 6A.
When 0 rotates in the forward direction, the state moves to state II in FIG. 6B. Specifically, the fitting pin 11a moves along the arc portion X1 so as to move from P6 to P7 in FIG. 5B, while the roller 43 moves toward the arc portion Y1 from Q6 to Q7 in FIG. 5C. To move. At this time, as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from point A to point B, but as shown in FIG. , Rotates while accelerating to the speed limit V3 while receiving only the acceleration load.

Then, from the state II of FIG. 6B, the presser thread trimming pulse motor 70 continues to rotate in the forward direction, thereby shifting to the state III of FIG. 6C. Specifically, the fitting pin 11a moves in the inflection portion X2 so as to move from P7 in FIG. 5 (b) to P1, while the roller 43 is moved to Q7 in FIG. 5 (c).
The arcuate portion Y1 is moved so as to move from Q1 to Q1. At this time, as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from point B to 180 °, but as shown in FIG.
Rotates at a constant speed at a speed limit V3 under a torque load (hereinafter, simply referred to as "thread spreading load") for causing the thread cutting mechanism 10 to perform the thread spreading operation.

Further, since the presser thread trimming pulse motor 70 continues to rotate slightly in the forward direction from the state III of FIG. 6C, the state III of FIG. 6C and the state IV of FIG. 7A are separated. Transition to the state between. Specifically, the fitting pin 11a moves in the inflection portion X2 so as to move from P1 to P2 in FIG. 5B, and the roller 43 has an arcuate portion so as to move from Q1 to Q2 in FIG. 5C. Move Y1 to move the fitting pin 11a to P
When a predetermined position between 1 and P2 is reached and the roller 4
When 3 reaches the predetermined position between Q1 and Q2, the presser thread trimming pulse motor 70 stops. At this time, FIG.
As shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from 180 ° to point C, but FIG.
As shown in, the presser thread trimming pulse motor 70 rotates at a constant speed at the speed limit V3 in the state of receiving the thread spreading load, and eventually rotates while decelerating in the state of receiving the thread spreading load and the deceleration load, Finally stop. In this state,
The thread handling operation ends.

Then, the presser thread cutting pulse motor 70 is driven again to operate the thread cutting mechanism 10 again to perform the thread cutting operation (step S14). Here, when the thread trimming operation is performed, the presser thread trimming pulse motor 70 slightly rotates in the forward direction from the state between the state III in FIG. 6C and the state IV in FIG. 7A. The state moves to state IV in FIG. Specifically, the fitting pin 11a moves the inflection portion X2 so as to move from the predetermined position between P1 and P2 in FIG. 5 (b) described above to P2, and the roller 43 causes the roller 43 to move as described above in FIG. 5 (c). The circular arc portion Y1 is moved from the predetermined position between Q1 and Q2 toward Q2. At this time, as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from point C to point D, but as shown in FIG. , The thread cutting mechanism 10 rotates while accelerating under a torque load (hereinafter simply referred to as “thread cutting load”) for causing the thread cutting operation and an acceleration load. In this state, the sewing operation and the thread cutting operation are completed.

Then, the work clamp mechanism 50 is operated to perform the work clamp lifting operation (step S15). Here, when the cloth presser lifting operation is performed, the presser thread trimming pulse motor 70 continues to rotate in the forward direction from the state IV of FIG. 7A, thereby shifting to the state V of FIG. 7B. In detail,
The fitting pin 11a moves in the arc portion X1 so as to move from P2 to P3 in FIG. 5 (b), and the roller 43 is moved to FIG. 5 (c).
The arc portion Y1 is moved from Q2 to Q3.
At this time, as shown in FIG. 11A, the rotation angle of the presser thread trimming pulse motor 70 shifts from point D to point E.
As shown in FIG. 11B, the presser thread trimming pulse motor 7
0 rotates while accelerating to the speed limit V2 while receiving only the acceleration load, and eventually rotates at the constant speed V2 at the speed limit.

Then, when the presser thread cutting pulse motor 70 continues to rotate in the forward direction from the state V of FIG. 7B, the state transitions to the state VI of FIG. 7C. Specifically, the fitting pin 11a moves along the arcuate portion X1 so as to move from P3 to P4 in FIG. 5B, and the roller 43 moves toward the elliptical portion Y2 so as to move from Q3 to Q4 in FIG. 5C. Is moved and the fitting pin 11a reaches between P4 and P5, and
When 3 reaches between Q4 and Q5, the presser thread trimming pulse motor 70 stops. At this time, as shown in FIG. 11 (a), the rotation angle of the presser thread cutting pulse motor 70 shifts from point E to 360 °, but as shown in FIG. 11 (b),
The presser thread trimming pulse motor 70 rotates at a constant speed at the speed limit V2 in the state of receiving only the cloth presser rising load, and eventually rotates while decelerating in the state of receiving the cloth presser load and the deceleration load, and finally, Stop. In this state, the work clamp lifting operation is completed.

Then, returning to step S6, it becomes possible to continue the above-described operations of steps S6 to S15 many times.

As described above, in the sewing machine 1 according to the present embodiment, when the presser foot lifting operation is performed based on the operation of the presser switch 95 (see step S9 and step S10 in FIG. 10), the urging force of the winding spring 44 is applied. The presser foot lifting link 31 is rotated against it and the contact pin 55 is pushed down against the biasing force of the winding spring between each pin 56 of the support base 52 and the other end portion 53c of each cloth presser drive link 53. There is. In this case, the presser thread trimming pulse motor 70 rotates under the condition that the cloth presser lifting load including the resistance to the bias of these two winding springs is applied in addition to the acceleration load. On the other hand, when the work clamp lifting operation is performed at the end of the sewing operation (see step S15 in FIG. 10), the presser thread trimming pulse motor 7
No. 0 receives the thread trimming load before the work clamp lifting operation,
After the thread trimming operation, the rotation starts only under the acceleration load without receiving the presser foot lifting load, and when the cloth presser rising load is received, the motor has already been accelerated and It can rotate while receiving only.

Therefore, the acceleration rate of the presser thread trimming pulse motor 70 when the cloth presser lifting operation is performed at the end of the sewing operation is set to the presser thread trimming pulse motor when the cloth presser lifting operation is performed based on the operation of the presser switch 95. It can be controlled to be greater than the acceleration rate of 70. In addition, the speed limit V2 of the presser thread trimming pulse motor 70 when the presser foot lifting operation is performed at the end of the sewing operation is set to the presser thread trimming pulse motor 70 when the presser foot lifting operation is performed based on the operation of the presser switch 95. It is also possible to control the speed to be greater than the speed limit V1. As a result, the cycle time of the sewing machine 1 can be shortened without using a high output motor.

Further, in the sewing machine 1 according to this embodiment, when the thread spreading operation is performed (see step S13 in FIG. 10), at the point B where the rotation angle of the presser thread trimming pulse motor 70 starts the thread spreading operation. Instead, the presser thread trimming pulse motor 70 is controlled so as to stop at point A. This is for the following reason. That is, as described above, the spindle motor 7
It is necessary to drive the presser thread trimming pulse motor 70 in a state of being synchronized with the final rotation operation of the sewing machine 1. In addition, in order to further shorten the cycle time of the sewing machine 1, the presser thread trimming pulse motor 70 It is necessary to start the thread separating operation while rotating the machine as soon as possible.
Therefore, the presser thread trimming pulse motor 70 is stopped so that the rotation angle of the presser thread trimming pulse motor 70 stops at the point A instead of the point B, and the presser thread trimming pulse motor 70 receives only the acceleration load, that is, the presser foot. During the period when the rotation angle of the thread trimming pulse motor 70 shifts from point A to point B,
The rotation of the presser thread trimming pulse motor 70 is controlled so that the thread handling operation is started with the presser thread trimming pulse motor 70 already rotated (in the state of being accelerated to the speed limit V3).

Therefore, when the thread cutting operation is performed at the time of thread cutting at the end of the sewing operation (when the thread cutting mechanism 10 is operated at the end of the sewing operation), the presser thread cutting pulse motor 70 rotates the rotation angle. During the period from point A to point B, the rotation is started only under the acceleration load, and when the torque load for operating the thread trimming mechanism 10 is applied, the motor has already been accelerated. , This thread trimming mechanism 1
It is possible to rotate only under the torque load for operating 0. As a result, the presser thread trimming pulse motor 70 is used when the thread spreading operation is performed at the end of the sewing operation.
The presser thread trimming pulse motor 70 when the presser foot lifting operation is performed based on the operation of the presser foot switch 95 is performed.
It can be controlled to be larger than the acceleration rate of. In addition, the speed limit V3 of the presser thread trimming pulse motor 70 when the thread spreading operation is performed at the end of the sewing operation is set to the value of the presser thread trimming pulse motor 70 when the cloth presser lifting operation is performed based on the operation of the presser switch 95. It can also be controlled to be higher than the speed limit V1. As a result, the cycle time of the sewing machine 1 can be further shortened without using a high output motor.

The embodiment of the sewing machine 1 of the present invention is not limited to the above-described embodiment, but various modifications and design changes are made without departing from the gist of the present invention. Good. For example, in the sewing machine 1 having the above-described configuration, the thread trimming mechanism 10 using the presser thread trimming pulse motor 70 as a drive source is differentiated from the presser lifting mechanism 30 and the cloth presser mechanism 50, and the thread trimming mechanism and the thread trimming mechanism An embodiment in which a drive source and the like are separately provided is also possible. That is, in the sewing machine 1 according to such an embodiment, at the end of the sewing operation of the predetermined sewing pattern (for example, when sewing each side of the label such as labeling, the number of stitches corresponding to the length of each side is set). When the sewing operation for the number of stitches is set in advance) and the work clamp lifting operation is automatically performed. Then, in the sewing machine 1, as described above, the cloth presser lifting operation is automatically performed every time the sewing of each side is completed, but the operator himself needs to handle the label when the cloth presser lifting operation is performed. When the operator rotates the label and operates the presser switch 95 again, sewing according to the next sewing pattern (sewing of the next side) is started.

Here, since the number of stitches on each side is preset when the sewing operation on each side of the label is performed, it is possible to detect the remaining number of stitches and control the timing for performing the work clamp lifting operation. . That is, as in the above-described embodiment, the presser thread trimming pulse motor 70 is preliminarily driven in advance in the process before the presser foot lifting operation is performed, and the presser thread trimming pulse motor 70 is rotated at a higher speed. A raising operation can be performed. Of course, also in this case, at least one of the speed limit and the acceleration rate of the presser thread trimming pulse motor 70 when the presser foot lifting operation is performed at the end of the sewing operation is performed based on the operation of the presser switch 95. The control can be performed so as to be larger than the speed limit and the acceleration rate of the presser thread trimming pulse motor 70 in the case of being released. As a result, the cycle time of the sewing machine 1 can be shortened without using a high output motor.

Further, in the present embodiment, the drive motor is a pulse motor (presser thread trimming pulse motor 70), but needless to say, it is applicable to a servo motor as well as a pulse motor.

[0101]

According to the present invention, the cycle time of the sewing machine can be shortened without using a high output motor.

[Brief description of drawings]

FIG. 1 is a side view showing a sewing machine according to an embodiment.

FIG. 2 is a perspective view showing a thread trimming mechanism, a presser lifting mechanism and a cloth pressing mechanism according to the present embodiment.

FIG. 3 is a plan view showing the operations of the fixed knife member and the movable knife member that form the thread cutting mechanism during thread cutting.

FIG. 4 is a perspective view showing the cloth pressing mechanism.

5A is a perspective view of the cam member according to the present embodiment as seen from the back, FIG. 5B is a plan view showing the first cam of the cam member, and FIG. 5C is the cam. It is a top view which shows the 2nd cam of a member.

FIG. 6 is an explanatory diagram for explaining a thread separating operation, a thread cutting operation, and a work clamp lifting operation of the sewing machine.

FIG. 7 is an explanatory diagram continued from FIG. 6;

FIG. 8 is a block diagram showing a configuration of a control device according to the present embodiment.

FIG. 9 is a front view showing an operation panel according to the present embodiment.

FIG. 10 is a flowchart for explaining a process of the control device.

FIG. 11 is an explanatory diagram for explaining the operation of the presser thread trimming pulse motor according to the present embodiment.

[Explanation of symbols]

1 sewing machine 8 Control device (control means) 10 Thread trimming mechanism 11 Thread cutting link (first connecting member) 11a Mating pin 30 Lifting mechanism 31 Presser foot link (second connecting member) 43 Roll 50 Work clamp mechanism 59 Thread clearing mechanism 60 cam member 61 First Cam 61a cam groove 62 Second Cam 62a outer peripheral surface 70 Presser thread trimming pulse motor (drive motor) 95 Presser switch (operating means) X1 arc part (first free running part) X2 Inflection part (first actuation part) Y1 arc part (second free running part) Y2 Elliptical part (second operating part)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3B150 AA16 CB14 CE01 CE23 CE25                       EA12 EA13 FH02 FH03 FH06                       FH09 GD14 GD22 JA03 JA07                       JA17 JA26 JA28 QA04 QA06                       QA07

Claims (3)

[Claims] 1. A presser foot lifting mechanism for raising and lowering a cloth presser, a thread trimming mechanism for thread cutting, a single drive motor for driving these mechanisms, and a control means for controlling the rotation of the drive motor. An operating means for operating the lifting of the cloth presser, the cloth presser is raised based on the operation of the operating means, and the thread trimming mechanism and the presser foot lifting mechanism are sequentially operated at the end of the sewing operation to perform thread trimming. In a sewing machine that sequentially performs the lifting and raising of the presser foot, a first operating unit that converts the rotational drive force of the drive motor into a thread cutting drive force corresponding to the thread cutting mechanism, and the rotation of the drive motor with respect to the thread cutting mechanism. A first cam having a first idle running portion that does not transmit a driving force, and one end that is connected to a thread cutting mechanism when one end slides on a first operating portion of the first cam, and the other end is connected to a thread cutting mechanism to cut the thread cutting driving force. A first connecting member for transmitting to the mechanism; It has a second operation part that converts the rotational driving force of the motor into a presser foot lifting drive force corresponding to the presser foot lifting mechanism, and a second idle running part that does not transmit the rotational driving force of the drive motor to the presser foot lifting mechanism. The second cam is arranged with a predetermined phase difference with respect to the first cam, and when one end slides on the second actuating portion of the second cam, the other end is connected to the presser lifting mechanism so that the presser lifting driving force is applied. A second connecting member that is transmitted to the presser foot lifting mechanism; and the control means prevents the second connecting member from sliding on the second idle running portion when the cloth presser rises based on the operation of the operating means. When the presser foot lifting mechanism is operated by controlling the drive motor so that it slides on the second operating portion, and the cloth presser rises at the end of sewing, the first connecting member causes the first idle running portion and the first operating portion to move. The thread cutting mechanism is operated by controlling the drive motor so that it slides sequentially. The drive motor is controlled so that the connecting member slides sequentially between the second idle running section and the second operating section to operate the presser foot lifting mechanism, and when the cloth presser rises at the end of sewing, the speed limit of the drive motor and A sewing machine, characterized in that at least one of the acceleration rates is controlled so as to be higher than a speed limit and an acceleration rate of a drive motor when the work clamp is raised based on the operation of the operating means. 2. The speed limit of the drive motor when the first connecting member sequentially operates the first idle running portion and the first operating portion at the time of thread trimming at the end of sewing, 2. The sewing machine according to claim 1, wherein at least one of the acceleration rates is controlled to be higher than a speed limit and an acceleration rate of the drive motor when the work clamp is raised based on the operation of the operating means. 3. Storage means for storing a predetermined sewing pattern, a presser foot lifting mechanism for raising and lowering a cloth presser, a drive motor for driving the presser foot lifting mechanism, and control means for controlling rotation of the drive motor. An operating means for operating the lifting of the cloth presser, the cloth presser is raised based on the operation of the operating means, and the presser foot lifting mechanism is automatically operated at the end of the sewing operation according to the sewing pattern. In a sewing machine in which the rotation of the drive motor is increased, an operating portion that converts the rotational drive force of the drive motor into a presser foot drive force corresponding to the presser foot lift mechanism, and an idle portion that does not transmit the rotary drive force of the drive motor to the presser foot lift mechanism A cam having one end and a connecting member whose one end is connected to the presser foot lifting mechanism when the one end slides on the operating part of the cam and which transmits the presser foot lifting drive force to the presser foot lifting mechanism. The means controls the drive motor to operate the presser foot lifting mechanism so that the connecting member slides on the operating part without sliding on the idle part when the presser foot is raised based on the operation of the operating means, When the work clamp rises at the end of the sewing operation according to the sewing pattern, the drive motor is controlled to operate the presser lifting mechanism so that the connecting member sequentially slides between the idle running portion and the operating portion, and the sewing operation according to the sewing pattern is performed. At least one of the speed limit and the acceleration rate of the drive motor when the work clamp rises at the end is controlled to be larger than the speed limit and the acceleration rate of the drive motor when the work clamp rises based on the operation of the operating means. A sewing machine characterized by: