JPH10263236A - Sewing machine lifting device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a presser lifting device for a sewing machine that can move a presser to a desired position without generating noise. When a stepping motor rotates in a counterclockwise direction in FIG. 1, the rotation is transmitted to a presser bar holder via a lever and a link, and the presser presses the presser.
To rise. When the sensor unit 31 detects the proximity of the other end 25b of the lever 25, the stepping motor 21
Stops after being further rotated by a predetermined pulse in the above direction.
Thus, the presser 11 can be raised to near the top dead center and stopped as shown by the solid line. It is possible to move the presser 11 to a desired position without generating a noise without requiring a mechanical collision to define the moving position of the presser 11. In addition, the stepping motor 21 is inexpensive, small in size and low in noise. Accordingly, the cost, size, and noise of the sewing machine 1 can be further reduced.

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 for vertically moving a presser of the sewing machine.

[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.

[0003]

However, with an actuator such as a solenoid, the operation amount cannot be arbitrarily adjusted. 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.

Accordingly, it is an object of the present invention to provide a presser lifting device for a sewing machine which can move a presser to a desired position without generating noise.

[0005]

Means for Solving the Problems and Effects of the Invention An invention according to claim 1 for achieving the above object is a press-up device for a sewing machine for vertically moving a presser of a sewing machine, the apparatus being adapted to respond to a drive signal. A rotary actuator rotatable by a desired angle and a power transmission mechanism for continuously moving the presser up and down in accordance with the rotation of the rotary actuator are provided.

[0006] In the present invention thus constructed, the rotary actuator can be rotated by a desired angle in response to the drive signal, and the presser is moved up and down to a position corresponding to the angle via the power transmission mechanism. be able to. That is, the adjustment position of the presser can arbitrarily define the movement position of the presser.

Therefore, according to the present invention, the presser can be moved to a desired position without generating any noise without requiring a mechanical collision in order to determine the moving position of the presser. Therefore, the noise of the sewing machine can be reduced. Claim 2
According to the present invention, in addition to the configuration of the first aspect, the rotary actuator is a stepping motor.

In the present invention, a stepping motor is used as the rotation actuator. The stepping motor is easy to control, the cost of the motor itself is low, and it is small and has low noise. Therefore, according to the present invention, in addition to the effects of the first aspect of the present invention, there is an effect that the cost, size, and noise of the sewing machine can be further reduced.

The invention described in claim 3 is the first or second invention.
In addition to the configuration described above, the power transmission mechanism includes a link that swings up and down in accordance with the rotation of the rotary actuator and abuts a member integrated with the presser from below. . The power transmission mechanism of the present invention,
The link, which swings up and down in response to the rotation of the rotary actuator, is brought into contact with a member integrated with the holder from below, thereby moving the holder up and down. For this reason, the presser can be easily pushed up by hand without moving the link, and the operation of the rotary actuator is not affected. If you release your hand, the presser returns to its original position. 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 operability of the sewing machine can be further improved and the control of the rotary actuator can be further facilitated.

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, the power transmission mechanism or the presser is provided near the presser to detect that the presser has risen to a predetermined position. And a control means for controlling a drive signal of the rotary actuator based on a detection result of the detection means.

In the present invention, the detection means detects that the presser foot has risen to the predetermined position, and the control means controls the drive signal of the rotary actuator based on the detection result. For this reason, the drive signal can be accurately controlled according to the actual position of the presser. Therefore, according to the present invention, in addition to the effect of the invention described in any one of the first to third aspects, an effect that the movement position of the presser can be more accurately controlled occurs.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a sewing machine 1 to which the present invention is applied.
It is a side view showing the structure of. FIG. 1 shows a state in which a face plate (not shown) of the arm 3 is removed.

At the lower part of the arm 3, a presser bar 5 is provided slidably in the vertical direction via a sleeve 7, and at the lower end of the presser bar 5, a presser 11 is fixed via screws 9. I have. The presser 11 has a vertically long slot 11a into which the screw 9 can be inserted.
The position where the presser 11 is fixed to the presser bar 5 can be adjusted up and down by the insertion position of. A presser adjusting screw 13 is screwed into the upper portion of the arm 3, and a presser spring 17 is provided between the upper end of the presser bar hanger 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 screws 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. 1). 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.

Next, the operation of the presser lifting device 23 thus configured will be described. As shown in FIG. 2, the sensor unit 31 inputs a detection signal to the electronic control circuit 51. The electronic control circuit 51 includes a CPU 51a, a ROM 51
b, a well-known microcomputer having a RAM 51c as a main part, reads the operation state of various switches 53 such as an external push button switch together with the detection signal of the sensor section 31, and reads the operation state of the stepping motor 21 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 the lever 25 is also swung clockwise in FIG. Moving. When the various switches 53 are operated to raise the presser 11, the electronic control circuit 51 rotates the stepping motor 21 counterclockwise in FIG. 1 in accordance with the operation. Then, this rotation is performed by the lever 25 and the link 2
The pressing force is transmitted to the presser bar holder 15 through 7 to raise the presser 11. Then, when the proximity of the other end 25b is detected via the sensor section 31, the electronic control circuit 51 further stops the stepping motor 21 after rotating the stepping motor 21 in the above direction by a predetermined pulse. 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 the various switches 53 are operated to lower the presser 11, the electronic control circuit 51 drives the stepping motor 21 clockwise 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 applied to a work cloth on a bed (not shown) in accordance with the elasticity of the presser spring 17. Can be pressed.

As described above, in the presser lifting device 23, since the presser 11 is moved up and down in accordance with the rotation of the stepping motor 21, 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 31,
Since the stepping motor 21 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).

The stepping motor 21 is easy to control, the cost of the motor itself is low, and it is small and has low noise. Therefore, in the present embodiment, the cost, size, and noise of the sewing machine 1 can be further reduced. Further, in the present embodiment, the presser 11 is moved up and down by bringing the link 27 into contact with the projection 15a of the presser bar holder 15 from below. Therefore, the presser foot 11 can be easily pushed up by hand without moving the link 27, and the operation of the stepping motor 21 is not affected. When the hand is released, the presser foot 11 returns to the original position.
Therefore, the operability of the sewing machine 1 can be further improved, and the control of the stepping motor 21 can be further facilitated.

FIG. 3 is a side view showing a configuration of a sewing machine 71 according to another embodiment to which the present invention is applied. In the sewing machine 71, the configuration from the inside of the arm 3 to the presser 11 is almost the same as that of the sewing machine 1, and thus the reference numerals used in FIG. A support plate 73 is attached to the side surface of the arm 3 via a screw 73a, and a holding device 75 is provided on the support plate 73. Support plate 73
, A stepping motor 77 is fixed with the rotating shaft 77a facing the face plate direction, 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 77 a of the stepping motor 77, and the other end of the lever 83 is provided with a projection 83 a that engages with the notch 79 a of the link 79. 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.

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 1 rises to near the top dead center, one end 87a abuts on the upper end of the presser 11 and thereafter swings clockwise in FIG. The sensor section 81 detects the proximity of the other end 87b when the lever 87 swings.

In the presser lifting device 75 configured as described above, by controlling the stepping motor 77 based on the detection signal of the sensor section 81, the same operation and effect as in the above-described embodiment can be obtained. Further, in the presser lifting device 75, since the one end 87a of the lever 87 is directly in contact with the presser 11, the position of the presser 11 can be accurately determined even when the fixing position of the presser 11 to the presser bar 5 is adjusted by the screw 9. Can be detected. Therefore, the presser 11 can be more accurately stopped at an appropriate ascending position.

In each of the above embodiments, the lever 25 and the link 27, or the lever 83 and the link 79, serve as a power transmission mechanism, the sensor units 31, 81 serve as detection means, and the electronic control circuit 51 serves as control means. Equivalent to. 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, in the above embodiment, the stepping motors 21 and 77 are controlled based on the detection signals of the sensor sections 31 and 81 when the presser 11 is raised. A so-called open loop control for driving by a predetermined number of pulses may be executed. In this case, the sensor units 31 and 81 can be omitted. In the above embodiment, the stepping motor 21 is rotated by operating the various switches 53 to move the presser 11 up and down. However, the stepping motor 21 is rotated according to the execution of the sewing program, and the presser 11 is automatically moved up and down. You may make it move.

Further, as the power transmission mechanism, various forms such as a mechanism using meshing of a rack and a pinion are conceivable in addition to a mechanism having a link. Further, as a rotary actuator, in addition to a stepping motor, a general A
Various forms such as a C motor and a DC motor are conceivable.

[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 another sewing machine to which the present invention is applied.

[Explanation of symbols]

1, 71 ... sewing machine 3 ... arm 5 ... presser bar 11 ... presser 13 ... presser adjusting screw 15 ... presser bar holder 17
… Holding spring 21, 77… Stepping motor 23, 75…
Presser lifting device 25, 83 ... Lever 27, 79 ... Link
31, 81: Sensor unit 51: Electronic control circuit 87: Lever

Claims (4)

[Claims] 1. A press-up device for a sewing machine for vertically moving a presser of a sewing machine, the rotary actuator being rotatable by a desired angle according to a drive signal, and the presser being continuously turned according to the rotation of the rotary actuator. And a power transmission mechanism for vertically moving the sewing machine. 2. The apparatus according to claim 1, wherein said rotary actuator is a stepping motor. 3. The power transmission mechanism further comprises a link that swings up and down in response to the rotation of the rotary actuator and that contacts a member integrated with the presser from below. Item 3. An apparatus for lifting a sewing machine according to item 1 or 2. 4. A detecting means provided near the power transmission mechanism or the presser for detecting that the presser has risen to a predetermined position, and a drive signal for the rotary actuator based on a detection result of the detecting means. The presser lifting device for a sewing machine according to any one of claims 1 to 3, further comprising: control means for controlling