JP2866014B2 - Sewing machine drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine driving device capable of appropriately controlling a stop position of a sewing needle.

[0002]

2. Description of the Related Art Conventionally, when sewing clothes such as clothes with a sewing machine, in order to sew along the shape of the cloth, the sewing machine needle is stopped at a needle lower position to change the direction of the cloth.
Alternatively, in order to remove the cloth, the cloth was stopped at the position above the needle and the thread was cut to replace the cloth.

Generally, such an operation is performed in a sequence control by operating a pedal by fetching a signal of a detector for detecting a position of a needle provided on a sewing machine.

For example, when the pedal is depressed, the speed of the motor is changed according to the depressed position, when the pedal is returned to the neutral position, the sewing machine needle stops at the needle lower position, and when the pedal is depressed again in the opposite direction, the sewing machine needle is raised. It stopped moving to the position. Generally, a speed control type motor having a built-in encoder is used for driving such a sewing needle.

Further, the positioning of the needles is stopped by rotating the motor at a low speed and receiving a signal from a detector to stop driving the motor.

[0006]

In the above-mentioned conventional construction, the sewing machine is provided with a detector for detecting the position of a dedicated needle for detecting the position of the needle of the sewing machine. When mounting, a person has to assemble the needle while checking the needle position and signal width, and has to make fine adjustments for alignment, which has the problem of requiring labor costs and work time.

Further, since an industrial sewing machine is used in a dusty environment such as cloth dust, a detector provided on a high-speed rotating shaft in the sewing machine generates a turbulent airflow and the cloth entering the sewing machine is generated. Dust such as dust is involved. For this reason, when dust or the like adheres to the detection mirror or the detector, there is a problem that trouble often occurs with respect to the quality and reliability of the detector.

Therefore, the detector of the sewing machine needle has a high reliability that can be easily incorporated even in the manufacturing process and maintenance. In addition, it is possible to easily stop the sewing machine needle at the needle lower position and the needle upper position. What was possible was desired.

An object of the present invention is to solve the above problems.

[0010]

In order to achieve the above object, a sewing machine driving apparatus according to the present invention includes a motor for driving a sewing machine needle, a phase difference pulse for detecting a rotation position of the motor, and one Z-phase per rotation. An encoder for outputting a pulse; a direction discriminating means for discriminating the rotation direction of the motor from the phase difference pulse of the encoder; Counting means for detecting the stop position, stop position setting means in which stop position data indicating the stop position of the sewing machine needle is set in advance, and comparison data between the stop position data and the actual position data upon receiving a stop command from the pedal sensor. Motor control means for decelerating and stopping the motor so as to be zero.

The motor control means receives the stop command of the pedal sensor, decelerates the motor to a predetermined speed, and after maintaining the predetermined speed, decelerates and stops the motor so that the comparison data becomes 0 at a predetermined timing. It is preferred that

Further, the stop position setting means can set at least stop position data at the needle up position of the sewing machine needle and stop position data at the needle down position, and a plurality of stop positions set by the stop position setting means. The provision of the stop position selecting means for selecting data does not require any fine adjustment such as a special detector built-in alignment, and achieves the alignment easily.

[0013]

According to the present invention, the following operations can be performed by the above-mentioned structure. That is, a stop position setting means in which stop position data indicating a stop position of the sewing machine needle is set in advance, and a stop command from a pedal sensor is received so that comparison data between the stop position data and the actual position data becomes zero. By providing motor control means for decelerating and stopping the motor, it is possible to decelerate and stop the sewing machine needle driven by the motor to a preset stop position of the sewing machine needle indicated by the stop position data at a speed according to the comparison data. it can.

Also, counting means for resetting with the Z-phase pulse and counting the number of phase difference pulses of the encoder to detect the actual position data of the motor, and stop position data indicating the stop position of the sewing machine needle are preset. The stop position setting means eliminates the need for a conventional detector and makes it possible to effectively use the encoder built in the normal motor.

Further, the motor control means decelerates the motor to a predetermined speed in response to the stop command of the pedal sensor, and after maintaining the predetermined speed, decelerates and stops the motor so that the comparison data becomes 0 at a predetermined timing. With such a configuration, the stop processing can be performed from a fixed low speed, so that the accurate stop position can be relatively smoothly positioned with a simple control.

If the stop position setting means can set at least stop position data at the needle up position of the sewing machine needle and stop position data at the needle down position, a plurality of stop positions set in the stop position setting means can be set. By having the stop position selecting means for selecting data, the stop position of the needle can be set very accurately within the range of the pulse resolution of the encoder, and fine adjustment such as a special detector built-in alignment is required. And alignment can be easily achieved.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a sewing machine driving device showing an embodiment of the present invention.

A speed control type motor 3 for driving a sewing needle 2 attached to a shaft of the sewing machine 1 via a coupling.
An encoder 4 built in a motor 3 for outputting a phase difference pulse A, B having a phase difference of 90 degrees between A phase and B phase and a Z phase pulse Z for outputting one pulse per rotation; A direction discriminating means 7 for discriminating the rotation direction of the motor 3 by A and B;
And the number of four-times multiplied pulses P4 reset by the Z-phase pulse Z and the direction discrimination signal RD
The counting means 9 counts up and down according to the above, receives the stop command PS from the pedal sensor 12 and the counting means 9 for detecting the actual position data DP of the motor, the stop position setting means 11 in which the stop position data DS is set in advance. And the motor control means 14 for decelerating and stopping the motor so that the comparison data between the stop position data DS and the actual position data DP becomes 0. The sewing machine needle 2 driven by the motor 3 is preset. It decelerates and stops at the stop position.

The specific configuration of the sewing machine driving device configured as described above will be described with reference to FIGS.

The operator sets the cloth on the table of the sewing machine 1 and displaces the pitman rod 25 by depressing the pedal 19 with the foot. This displacement amount is detected by the pedal sensor 12, and a speed command PD that changes according to the depressed position is obtained. The motor control means 14 receives the signal of the speed command PD, and instructs the speed NP according to the displacement amount as the sewing machine speed N shown in FIG.
The motor 3 receiving the supply of the phase power rotates and moves the needle 2 of the sewing machine up and down. The cloth moved by the feed mechanism in synchronization with the vertical movement of the needle 2 is sewn with a sewing thread.

In response to the rotation of the motor 3, 360 rotations per rotation
The encoder 4 that outputs the number of pulses also rotates similarly,
An A-phase pulse and a B-phase pulse are output. These two pulses are input to the direction discriminating means 7 and the quadrupling circuit 17 as phase difference pulses A and B.

FIGS. 2A and 2B show the principle of direction discrimination. The state of the B-phase pulse input to the D terminal of the D-FF is latched at the rising edge of the A-phase pulse at the T terminal and output to the Q terminal. The output thus obtained becomes a direction discrimination signal RD. That is, X in FIG.
The rotation direction of the encoder 4 is reversed at the timing shown by,
At the rising edge of 27, the B-phase pulse is "H", but at the rising edge of 26, it is inverted to "L", and inversion detection is obtained. Although FIG. 2 shows an example in which the direction is determined only by the rising edge of the A-phase pulse for convenience of explanation of the principle, in the embodiment, the B-phase pulse is latched at the timing of the upper and lower edges including the falling edge. Thus, the rotation direction is detected and the direction determination signal RD is output.

Next, in the quadruple circuit section 17 for obtaining the quadruple pulse 4P shown in FIGS.
EX- which becomes “L” when the A-phase pulse and the B-phase pulse coincide with each other.
In the output of the OR (exclusive OR), one is delayed by the resistor R and the capacitor C, and the EX-OR is again taken to obtain the time constant τ1 (R
× C) A quadrupled pulse 4P having a width is obtained. Since the A-phase pulse and the B-phase pulse almost exactly have a phase difference of 90 degrees, if the frequency τ2 of the quadrupled pulse 4P is detected,
The rotation speed of the motor can be easily obtained.

As described above, the direction discrimination signal RD and the quadrupled pulse 4P obtained from the phase difference pulses A and B input to the direction discriminating means 7 and the quadrupling circuit unit 17 are respectively used by the U / D of the counting means 9. Terminal and the CK terminal. In the counting means 9, C
The pulse input to the K terminal is changed by the direction discrimination signal RD to "
In the case of "H", it counts up and the direction discrimination signal RD
Is "L", it counts down.

The Z-phase pulse Z is input to the RST terminal of the counting means 9 to reset the count value once. The reset position indicates the reference position of the motor 3, and the counter value indicates the motor position. Is obtained as actual position data DP.

The actual position data DP is supplied to the stop position setting means 11.

The stop position setting means 11 includes a storage means 23, a switch 22, and a stop position output section 24 shown in FIG.
Constitute stop position means 11, and stop position memory data DM is stored in the storage means 23 in advance.

The setting method of the stop position memory data DM is as follows.
When the operation switch 22 is turned on after manually moving the needle 2 of the sewing machine 1 to, for example, the needle lower position in advance, the actual position data DP at that time is latched and stored in the storage means 23. The storage means 23 is composed of a memory such as an EEPROM that does not lose stored data even when the power is off, and keeps holding the actual position data DP once set.

Similarly, the needle position is also stored in another storage area of the storage means 23 by another switch or the like, although omitted in FIG.

The actual position data DP is a counter value counted up to the needle down position of the sewing needle 2 after being reset by the Z-phase pulse Z.

Therefore, if the count value of the needle down position is stored, if the actual position data DP matches the stored stop position memory data DM, the position always becomes the needle down position.

The difference between the actual position data and the stop position memory data can be converted into the distance to the needle lower position of the needle 2.

The stop position memory data DM stored in this way also stores the data on the needle position as described above, and one of the data is selected and passed to the stop position output section. Then, it is output as the stop position data DS.

The stop position data DS is input to the motor control means 14 together with the actual position data DP.

On the other hand, when the pedal 19 operated by the operator is returned from the depressed state to the neutral state, the speed command PD becomes "1".
0 ", and subsequently, the neutral state of the pedal is detected, and a stop command PS is output to the motor control means 14. In this case, the motor control means 14 receives the stop command PS and reads the stop command PS from the storage means 23 of the stop position setting means 11. The stop position memory data DM at the needle lower position is selected as the stop position, and the stop position data D is selected.
Take out as S.

The motor control means 14 is a block controlled by a microcomputer (CPU), and when the speed command PD = 0 is detected as shown in the time chart of FIG. 4, the rotation speed N of the motor 3 is changed from the high speed NP to the low speed NP. Decelerate to rotation NL. After deceleration, the speed N of the sewing machine becomes the low speed NL and rotates at a constant speed.

FIG. 5 shows a deceleration stop flow.
In 1), the process waits until the speed reaches the low speed NL, and when the speed reaches the low speed NL, the deceleration is stopped and the rotation is performed at the NL speed at a constant speed.

Here, in (S2), the actual position data DP
Becomes "0", and in step (S3), the motor control means 14 compares the stop position data DS input to the motor control means 14 with the actual position data DP. The difference between the stop position data DS and the actual position data DP (DS-D
P) is multiplied by a proportional count P, and a speed signal V = P * (DS-DP) corresponding to the distance difference is output to the driver of the motor 3, so that the motor 3 gradually increases in speed according to the distance difference. At the position of (DS-DP) = 0, that is, at the position of the stop position data DS, the speed signal to the motor 3 becomes "0" and the motor 3 is decelerated and stopped.

Further, when the operator steps back on the pedal 19 with the foot in the reverse direction, the pitman rod 25 is displaced in the reverse direction. This reverse displacement is detected by the pedal sensor 12, and a pedal return command PU is obtained. The motor control means 14 rotates the motor 3 according to the speed command NL. In this case, the motor control means 14 receives the pedal return command PU, selects the stop position memory data DM of the needle up position from the storage means 23 of the stop position setting means 11, and extracts it as the stop position data DS. Thereafter, the same deceleration stop as described above is performed, and the needle 2 stops at the needle upper position.

As described above, according to the above-described embodiment, the needle position detector, which was conventionally required, is no longer necessary, and the encoder 4 built in the motor 3 uses the actual position data DP of the motor.
Is detected and compared with the preset stop position data DS, the vehicle can be decelerated and stopped at the stop position.

The storage means 2 of the stop position setting means 11
3 has a function of storing the actual position data DP.
As a result, the stop position can be easily set, and the man-hour required for the conventional detector mounting adjustment can be improved.

Further, since the encoder 4 has a closed structure, dust such as cloth dust does not enter the encoder, and even if the encoder 4 is rotated at a high speed, the reliability of the conventional detector is not impaired. Absent.

In this embodiment, the motor 3 is provided on the sewing machine shaft. However, the motor 3 may be driven via a belt or the like. Further, the encoder 4 may have a configuration separated from the motor 3. Further, the example in which the deceleration stop is performed after decelerating to a predetermined low speed NL has been described. May be used. In the above embodiment, the data stored in the storage means 23 is set from the actual position data DP. However, the data may be set from a setting device or the like. That is, the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
They are not excluded from the scope of the present invention.

[0044]

According to the present invention, the sewing machine driven by the motor is moved to the stop position of the sewing needle indicated by the stop position data.
The motor can be decelerated and stopped relatively smoothly with simple control, and the encoder built into the motor can be used effectively to easily adjust the position without requiring fine adjustments such as installing a special detector. A achievable sewing machine drive can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 shows the principle of discriminating the direction, in which (a)
Shows a circuit diagram, and (b) shows a timing chart.

FIG. 3 shows the quadrupled pulse, and (a)
Shows a circuit diagram, and (b) shows a timing chart.

FIG. 4 is a time chart showing the operation of the sewing machine.

FIG. 5 is a flowchart showing the deceleration stop method.

FIG. 6 is a block diagram showing the stop position setting means.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sewing machine 2 stitches 3 motor 4 encoder 7 direction discriminating means 9 counting means 11 stop position setting means 12 pedal sensor 14 motor control means 174 multiplication circuit section 19 pedal 22 switch 23 storage means 24 storage data output section

Claims (3)

(57) [Claims] 1. A motor that drives a sewing machine needle, an encoder that outputs a phase difference pulse for detecting the rotation position of the motor and one Z-phase pulse per rotation, and determines the rotation direction of the motor from the phase difference pulse of the encoder. Direction discriminating means, counting means for counting the number of phase difference pulses of the encoder and detecting the actual position data of the motor, reset by the Z-phase pulse, and stop position data indicating the stop position of the sewing machine needle. It is characterized by comprising: a set stop position setting means; and a motor control means for receiving a stop command from a pedal sensor and decelerating and stopping the motor so that comparison data between the stop position data and the actual position data becomes zero. Sewing machine driving device. 2. A motor control means receives a stop command of a pedal sensor, decelerates the motor to a predetermined speed, and after maintaining the predetermined speed, decelerates the motor so that the comparison data becomes 0 at a predetermined timing. The sewing machine driving device according to claim 1, wherein the sewing machine driving device is stopped. 3. The stop position setting means can set at least stop position data at a needle up position of the sewing machine needle and stop position data at a needle down position of the sewing machine needle, and a plurality of stops set in the stop position setting means. 3. The sewing machine driving device according to claim 1, further comprising a stop position selecting means for selecting position data.