JPH10263237A - Sewing machine lifting device - Google Patents

Abstract

(57) [Problem] To provide a presser lifting device for a sewing machine which can detect properly that the presser has risen to a predetermined position even when the position of fixing the presser to the presser bar is adjusted. SOLUTION: One end 87a of a lever 87 abuts on the upper end of the presser 11 when the presser 11 rises to the vicinity of the top dead center.
Rocks clockwise. When the lever 87 swings near the position indicated by the solid line in FIG.
The proximity of b is detected. Since the one end 87 a is in direct contact with the presser 11, the actual position of the presser 11 is well reflected in the swinging state of the lever 87. Therefore, even when the fixing position of the presser 11 is adjusted, it is possible to detect satisfactorily that the presser 11 has risen to the vicinity of the top dead center. Further, when the presser 11 is lowered, the lever 87 and the presser 11 are separated from each other, so that the fixing position adjustment work of the presser 11 can be easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-up device for a sewing machine that moves a press-up of the sewing machine up and down, and more particularly to a press-up device for a sewing machine that can detect that the presser has been raised to a predetermined position.

[0002]

2. Description of the Related Art In a sewing machine having a presser for holding a work cloth on a bed, it is conceivable that an actuator is driven to move the presser up and down in accordance with the operation of various switches such as an external push button switch. I have. Conventionally, in this type of sewing machine, a solenoid such as a rotary solenoid has been used as an actuator for vertically moving a presser.

However, the amount of operation cannot be arbitrarily adjusted with an actuator such as a solenoid. Therefore, the following configuration is adopted in order to define the moving position of the presser, particularly the position at the time of ascent. That is, a configuration is employed in which a member integrated with the presser collides against an arm or the like, and the presser is locked at a desired raised position by the collision. However, in this case, a collision sound is generated when the presser foot is raised, which causes noise.

[0004]

Therefore, the applicant of the present application has considered using a stepping motor that can rotate by a desired angle in response to a drive signal instead of a solenoid. In this case, by adjusting the drive signal, the movement position of the presser can be arbitrarily defined without relying on mechanical collision. For this reason, the noise of the sewing machine can be reduced. This example is shown in FIG. 3 as a reference example of the present invention.

FIG. 3 is a side view showing the structure of the sewing machine 1 of the reference example. FIG. 3 shows a state in which a face plate (not shown) of the arm 3 is removed. At the bottom of the arm 3,
A presser bar 5 is disposed slidably in the vertical direction via a sleeve 7, and a presser 11 is fixed to a lower end of the presser bar 5 via a screw 9. The presser 11 has a vertically long hole 11a into which the screw 9 can be inserted.
The fixing position of the presser 11 to the presser bar 5 can be adjusted up and down by the insertion position of the screw 9 in 1a. A presser adjusting screw 13 is screwed into the upper part of the arm 3, and a presser spring 17 is provided between the upper end of the presser bar holder 15 fixed in the middle of the presser bar 5 and the lower end of the presser adjusting screw 13. It is fitted in a resilient manner.

Next, a support plate 19 is attached to the side surface of the arm 3 via a screw 19a.
A presser lifting device 23 having a stepping motor 21 and the like is provided. The presser lifting device 23 includes, in addition to the stepping motor 21, a lever 25 fixed to the rotation shaft 21 a and a link 2 that swings in conjunction with the lever 25.
7 and a sensor unit 31 for detecting the swing position of the lever 25.

The stepping motor 21 is rotatable by a desired angle in accordance with a drive signal input via a signal line 33, and the rotating shaft 21a is oriented in a face plate direction (perpendicular to the plane of FIG. 3). Are fixed to the support plate 19 via screws 35. The lever 25 is fixed to the rotation shaft 21 a in the vicinity of the center, and has a protrusion 25 a at one end for engaging with the notch 27 a of the link 27. Link 27 is
The vicinity of the center is swingably connected to the support plate 19, and an end 27 b opposite to the notch 27 a is in contact with a projection 15 a protruding from the presser bar holder 15 from below. Also,
An operation section 27c is provided vertically below the link 27, and the link 27 can be swung even if the operation section 27c is pressed with a finger. Further, the sensor unit 31 includes a well-known Hall element and the like, and as shown by a solid line in FIG.
Is raised to near the top dead center, the proximity of the other end 25b of the lever 25 is detected.

In the presser lifting device 23 constructed as described above, when the stepping motor 21 rotates counterclockwise in FIG. 3, this rotation is transmitted to the presser bar holder 15 via the lever 25 and the link 27, and 11 rises. Then, when the sensor section 31 detects the proximity of the other end 25b, the stepping motor 21 stops after further rotating by a predetermined pulse in the above direction. Thereby, as shown by the solid line in FIG. 3, the presser foot 11 can be raised to near the top dead center and stopped. In this case, since the presser foot 11 can be stopped without mechanical collision, no noise is generated.

However, in this press-up device 23, when the fixing position of the presser 11 to the presser bar 5 is adjusted by the screw 9, the correspondence between the angle of the lever 25 and the actual height of the presser 11 changes. In this case, the sensor unit 31 does not detect the proximity of the other end 25b until the upper end of the presser 11 collides with the lower end of the arm 3, or the sensor unit 31 is moved to the other end 25b at the time when the presser 11 is hardly raised. Or detecting proximity. Therefore, a collision sound may be generated or the presser foot 11 may not be able to be raised to a sufficient height. Adjusting the position of the sensor section 31 according to the fixed position of the presser 11 can solve these problems, but such adjustment is extremely troublesome and impractical.

Accordingly, the present invention provides a press-up device for a sewing machine, which can properly detect that the presser has risen to a predetermined position even when the fixing position of the presser to the presser bar is adjusted. Made for purpose.

[0011]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the invention according to claim 1 comprises a presser for holding a work cloth on a bed and a driving means for moving the presser up and down. In the sewing machine lifting device provided,
A lever that contacts a part of the presser and moves in accordance with the vertical movement of the presser, and a detecting unit that detects that the presser has risen to a predetermined position based on the movement of the lever;
It is characterized by having provided.

In the present invention having the above-described structure, the lever comes into contact with a part of the presser and moves in accordance with the vertical movement of the presser. Then, the detecting means detects that the presser has been raised to a predetermined position based on the movement of the lever. As described above, according to the present invention, since the lever moves while being in contact with a part of the presser, the actual position of the presser is favorably reflected in the movement of the lever. Since the detection means performs the detection based on the movement of the lever, it is possible to satisfactorily detect that the presser has risen to the predetermined position. For example, even if the fixing position of the presser to the presser bar is adjusted, it is possible to satisfactorily detect that the presser has risen to a predetermined position.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the driving unit includes a stepping motor, and a control unit that controls the stepping motor based on a detection result of the detection unit. It is further characterized by being provided. According to the present invention, since the stepping motor constituting the driving means is controlled based on the detection result of the detecting means, the presser can be moved to a desired position without mechanical collision. Therefore, generation of noise can be favorably prevented. Further, as described above, since the detecting means can detect the actual position of the presser satisfactorily, the collision can be more effectively prevented to prevent the generation of noise, and the presser can be surely moved to a desired position. Can be done. Therefore, in the present invention, in addition to the effects of the first aspect of the present invention, there is an effect that the noise of the sewing machine and the improvement of the reliability can be further promoted.

According to a third aspect of the present invention, there is provided the first or second aspect.
In addition to the configuration described above, the lever is separated from the presser when the presser is lowered, and comes into contact with a part of the presser when the presser rises to near the predetermined position. In the present invention, when the presser is lowered, the lever and the presser are separated from each other, so that various operations related to the structure of the presser or its vicinity, such as adjustment of the fixing position of the presser to the presser bar, can be easily performed. Further, when the presser has risen to the vicinity of the predetermined position, the lever comes into contact with a part of the presser, so that the rise of the presser to the predetermined position can be detected well as described above. Therefore, according to the present invention, in addition to the effects of the first and second aspects of the present invention, there is an effect that the workability of the sewing machine can be further improved with respect to various operations related to the configuration of the presser or its vicinity.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a sewing machine 7 to which the present invention is applied.
1 is a side view illustrating the configuration of FIG. In addition, FIG.
In a state where a face plate (not shown) is removed. Also,
In the sewing machine 71, the configuration from the inside of the arm 3 to the presser 11 is substantially the same as that of the sewing machine 1 of the above-described reference example. Therefore, the reference numerals used in FIG. .

A support plate 73 is provided on the side surface of the arm 3 with screws 7.
The support plate 73 is provided with a presser lifting device 75. The support plate 73 has a rotating shaft 7
7a with the stepping motor 77 turned in the face plate direction.
Are fixed, a link 79 is swingably connected, and a sensor section 81 is provided at the lower end. One end of a lever 83 is fixed to the rotation shaft 77a of the stepping motor 77, and the other end of the lever 83 has a link 7
Nine notches 79a are provided with protrusions 83a. An end 79b of the link 79 opposite to the notch 79a is in contact with a projection 15a protruding from the holding bar holder 15 from below. Further, an operation section 79c is provided vertically below the link 79, and the link 79 can be swung even if the operation section 79c is pressed with a finger.

The other end of the lever 83 is engaged with the other end of a torsion coil spring 85 having one end engaged with a hole 73b formed in the support plate 73. When the lever 83 is swung, the torsion coil spring 85 is inverted as shown by a broken line and a two-dot chain line in FIG. Excessive swing of the lever 83 is suppressed by the torsion coil spring 85, and control of the stepping motor 77 is facilitated. Therefore, the projection 83a does not come off the notch 79a.

A lever 87 is provided at the lower end of the arm 3 so as to be swingable. This lever 87 is
When the presser 1 rises to the vicinity of the top dead center, one end 87a abuts on the upper end of the presser 11 and thereafter swings clockwise in FIG. Furthermore,
The sensor unit 81 includes a well-known Hall element or the like, and detects the proximity of the other end 87b when the lever 87 swings to a position near the position indicated by the solid line in FIG. The presser foot 11
When the lever 87 is lowered, the lever 87 swings counterclockwise in FIG. 1 by its own weight. However, when the fold portion 87c of which one end 87a is bent in a horizontal plane abuts on the lower end of the arm 3 (the two-dot chain line in FIG. 1). The swing is stopped by (indicated by). When the presser 11 further descends, the one end 87 a separates from the presser 11.

Next, the operation of the presser lifting device 75 thus configured will be described. As shown in FIG. 2, the sensor unit 81 inputs a detection signal to the electronic control circuit 91. The electronic control circuit 91 includes a CPU 91a, a ROM 91
b, a well-known microcomputer having a RAM 91c as a main part, and reads the operation state of various switches 93 such as an external push button switch together with a detection signal of the sensor unit 81, and reads the stepping motor 77 as follows.
To output a drive signal.

Normally, as shown by a two-dot chain line in FIG. 1, the presser 11 is moved downward by the elastic force of the presser spring 17, and accordingly, the lever 83 is also swung clockwise in FIG. Moving. When various switches 93 are operated to raise the presser 11, the electronic control circuit 91 rotates the stepping motor 77 counterclockwise in FIG. 1 in accordance with the operation. Then, this rotation is performed by the lever 83 and the link 7.
9 is transmitted to the presser bar holder 15 to raise the presser 11.

The presser 11 rises and one end 87 of the lever 87
When the sensor section 81 detects the proximity of the other end 87b, the electronic control circuit 91 further stops the stepping motor 77 after rotating the stepping motor 77 in the above direction by a predetermined number of pulses. Thereby, as shown by the solid line in FIG. 1, the presser foot 11 can be raised to near the top dead center and stopped. When various switches 93 are operated to lower the presser 11, the electronic control circuit 91 causes the stepping motor 7 to operate.
7 is driven in the clockwise direction in FIG. 1 by a predetermined number of pulses. The number of pulses is set in advance to a value sufficient for the presser 11 to be fully lowered. When the drive control is completed, the presser 11 is pressed onto a work cloth (not shown) on the bed.
Can be pressed according to the resilience of

As described above, in the presser lifting device 75, since the presser 11 is moved up and down in accordance with the rotation of the stepping motor 77, the movement position of the presser 11 can be arbitrarily defined by adjusting the drive signal. . Therefore, the presser 11 can be moved to a desired position without generating a noise without requiring a mechanical collision in order to define the moving position of the presser 11. Moreover, it is detected that the presser foot 11 has risen to the vicinity of the top dead center via the sensor section 81,
Since the stepping motor 77 is controlled based on this, the presser 11 can be accurately stopped at the most appropriate ascending position (for example, just before colliding with the lower end of the arm 3).

In the presser lifting device 75, the lever 87
Since the one end 87a is directly in contact with the presser 11, the actual position of the presser 11 is favorably reflected in the swinging state of the lever 87. For this reason, even when the fixing position of the presser 11 to the presser bar 5 is adjusted by the screw 9, it is possible to detect satisfactorily that the presser 11 has risen to near the top dead center. Therefore, the presser foot 11 can be stopped very accurately at an appropriate ascending position, and the noise reduction and the improvement of the reliability of the sewing machine 71 can be promoted very well.
Further, in the presser lifting device 75, since the lever 87 is separated from the presser 11 when the presser 11 is lowered, various operations relating to the configuration of the presser 11 or its vicinity, such as adjustment of the fixing position of the presser 11 to the presser bar 5, are performed. Easy to do. Therefore, the workability of the sewing machine 71 can be further improved.

In the above embodiment, the stepping motor 77, the lever 83, and the link 79 serve as driving means, the sensor 81 serves as detecting means, and the electronic control circuit 91 serves as detecting means.
Correspond to the control means. In addition, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, as the lever, a lever that keeps contacting until the presser 11 reaches the bottom dead center or a lever that moves up and down in parallel according to the vertical movement of the presser 11 can be used. When a lever that keeps the presser 11 in contact until it reaches the bottom dead center is used, a detection unit that can continuously detect the movement of the lever may be used. In this case, the moving state of the presser 11 can be continuously and accurately detected.

Further, in the above-described embodiment, the stepping motor 77 is rotated by operating the various switches 93, and the presser 11 is moved up and down. 11 may be moved up and down.

Further, in the present invention, the lifting state of the presser 11 detected by the detecting means (sensor section 81) can be used for other than the control of the stepping motor 77. For example, when the sewing machine 71 has a holding frame that moves the work cloth in a plane, such as a pocket setter or an embroidery sewing machine, it is necessary to confirm that the presser foot 11 has risen before permitting the movement of the holding frame. Can be considered. Therefore, the detection signal of the sensor unit 81 may be used for these controls.
Further, in this case, the present invention can be applied even if the sewing machine 71 moves the presser 11 up and down by a solenoid or the like. That is, various means such as a solenoid can be applied as the driving means.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of a sewing machine to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of a control system of a lifting device of the sewing machine.

FIG. 3 is a side view illustrating a configuration of a sewing machine according to a reference example of the present invention.

[Explanation of symbols] 3… Arm 5… Presser bar 9… Screw
11 ... presser 13 ... presser adjusting screw 15 ... presser bar holder 1
7 ... presser spring 71 ... sewing machine 75 ... presser lifting device 7
7 Stepping motor 79 Link 81 Sensor section 8
3: Lever 85: Torsion coil spring 87: Lever 9
1. Electronic control circuit

Claims (3)

[Claims] 1. A press-up device for a sewing machine, comprising: a presser for pressing a work cloth on a bed; and driving means for moving the presser up and down. And a detecting means for detecting that the presser has risen to a predetermined position based on the movement of the lever. 2. The sewing machine according to claim 1, wherein the driving unit includes a stepping motor, and further includes a control unit that controls the stepping motor based on a detection result of the detection unit. Lifter device. 3. The lever according to claim 1, wherein the lever is separated from the presser when the presser is lowered, and comes into contact with a part of the presser when the presser rises to near the predetermined position. The presser lifting device for the sewing machine described in the above.