JP2001212391A - Control device for sewing machine motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of failure in a sewing machine motor in the case where the sewing machine motor is repeatedly locked in a short time by controlling the sewing machine motor in response to the driving condition of the sewing machine motor. SOLUTION: A control device for sewing machine motor is provided with a lock detecting means for detecting the lock of the sewing machine motor in the case where the lock condition is continued for the predetermined detecting time and a detecting time changing means for changing the predetermined time on the basis of a temperature of the sewing machine motor detected by a motor temperature detecting means 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric sewing machine for operating an industrial sewing machine.

[0002]

2. Description of the Related Art In recent years, an industrial sewing machine has been equipped with an actuator on a sewing machine body to automate sewing operations such as thread trimming and reverse sewing.

FIG. 5 is an external view showing a configuration of a main part of the industrial sewing machine 100. As shown in FIG. In the figure, an industrial sewing machine 100 is shown.
Is a sewing machine body 1, a sewing machine motor 2, a control box 3,
It is roughly constituted by a power switch 4, an operation panel 5, a sewing needle 6, a sewing needle bar 7, a main shaft 8, a belt 9, and a sewing pedal 10.

The power switch 4 connects and disconnects the commercial power to the control box 3 by operating the switch. The operator sets various sewing patterns on the operation panel 5. Further, the operator operates the sewing machine pedal 10.
By operating the controller, a start signal or a stop signal of the sewing machine is transmitted to the control box 3, and the drive of the sewing machine motor 2 is controlled by a control circuit inside the control box 3, so that the power of the sewing machine motor 2 is controlled by a motor shaft (not shown). The power is transmitted to the sewing machine needle 6 through the path of the motor shaft pulley (not shown), the belt 9, the main shaft 8, and the sewing machine needle bar 7.

[0005] The sewing machine motor 2 generally uses an induction motor in the case of an inverter control system and an AC servomotor in the case of an AC servo control system in order to control its rotational position and rotational speed. is there.

FIG. 6 is a circuit block diagram showing a main circuit configuration of a control device of the conventional industrial sewing machine 100. FIG.
In the control box 3, a control circuit for supplying electric power from the commercial AC power supply to the sewing machine motor 2 is included, and the AC power supplied to the control circuit by the ON operation of the power switch 4 is supplied to a rectifying unit shown in FIG. 11, is converted to direct current by the smoothing unit 12.

When the sewing machine motor 2 is an AC servomotor,
When servo control is performed, the sewing machine pedal 10
(See FIG. 5) By the operation, in the control box 3,
The CPU (Central Processi)
ng Unit) 13 is supplied with a sewing machine control signal. The CPU 13 generates a motor rotation command signal LSi and a speed command signal SP based on the sewing machine control signal.
C is output to the motor control means 14.

The motor control means 14 receives the motor rotation command signal LSi and the speed command signal SPC, transmits a drive control signal to a motor driver 15, and converts the electric power converted into direct current by the rectifying unit 11 and the smoothing unit 12. Motor driver 1
5, the sewing machine motor 2 is rotated.

A motor rotation speed detecting means 16 (for example, an encoder circuit in the case of AC servo control) is built in the sewing machine motor 2, and transmits a rotation speed detection signal to the CPU 13. The CPU 13 outputs a speed command signal SPC to the motor control means 14 in accordance with the input rotation speed detection signal so that the rotation speed of the sewing machine motor 2 is optimized.

The motor rotation speed detecting means 16 detects the rotation speed of the sewing machine motor 2, detects the rotation angle of the sewing machine motor 2, and outputs the rotation angle detection signal to the C motor.
It is transmitted to PU13.

The current limiter 18 detects a current flowing through the sewing machine motor 2 by a current detector 18a and outputs a current detection signal to a current comparator 18b. The current comparison unit 18b is configured to compare the current detection signal input from the current detection unit 18a with the reference value Re.
When the current detection signal is larger than the Ref value, an output stop signal is transmitted to the motor control means 14.

The motor control means 14 instantaneously stops energizing the sewing machine motor 2 in response to the output stop signal input from the motor current limiting means 18, so that the maximum value of the current flowing through the sewing machine motor 2 is equal to the reference value Ref. Can be restricted so as not to exceed the reference level set by the user.

The CPU power reset circuit 17 includes a CPU
13 RESET terminal (not shown).
The power supply voltage supplied to the PU 13 is monitored, and
If the voltage is outside the operation compensation voltage range of the PU 13, the CPU
By holding the RESET terminal 13 at a “low” level, malfunction of the CPU 13 outside the operation compensation voltage is prevented.

Further, as means for detecting the temperature of the sewing machine motor, a temperature detecting means 20 constituted by, for example, a thermistor or a thermocouple, is provided by a coil section of the sewing machine motor which generates heat at the highest speed, or a motor flange or an encoder. The temperature of the sewing machine motor is provided directly or indirectly on a substrate or the like, and its output is input to the CPU 13, and when the temperature of the sewing machine motor becomes abnormally high, a stop command is output to the sewing machine motor. In some cases, abnormal heat generation is prevented.

In the conventional sewing machine motor control device configured as described above, the sewing machine shaft is further locked during the output of the motor rotation command Lsi, due to staking of the sewing machine shuttle shaft, sewing of an extremely thick material, winding of a bobbin thread, and the like. Then, when the sewing machine motor is locked, in order to protect the sewing machine motor 12, the rotation speed of the sewing machine motor 2 is changed to a predetermined rotation speed based on the rotation speed detection signal fed back by the motor rotation speed detection means 16. A motor lock protection means is provided, which determines that the motor is in the motor locked state when the speed is lower than the speed for a predetermined time and stops the energization to the sewing machine motor 2 to put the sewing machine into a stopped state.

The motor lock protection means will be described with reference to FIG.

In FIG. 7, when the sewing machine motor 2 is locked at a timing t1, that is, when the sewing machine motor 2 is at a certain rotation speed or less for a specified time T (for example, 2 seconds), a timing t2 is reached. In CP
U13 determines that the motor is in the locked state, and stops the power supply to the sewing machine motor 2 to put the sewing machine motor 2 into the power supply prohibited state. During this time, the maximum current (for example, 20 A) limited by the motor current limiting means 18 continues to flow through the coil of the sewing machine motor 2 during the period T as shown in the waveform of the motor current in FIG. Loss of heat at I2 RT,
The motor internal temperature shifts from the state shown in the figure. Here, I is a current flowing through the sewing machine motor 2, R is a motor coil resistance,
T is the duration of the motor lock state.

During a period between timings t2 and t3 in the drawing, the power supply to the sewing machine control device is cut off and turned on by the operator, so that the CPU 13 is reset and the energized state is released. Sewing machine pedal 10 at timing t3
When the sewing machine motor 2 is started by such an operation as above, motor energization is restarted. At this time, if the cause of the motor lock (such as winding of the bobbin thread) has not been removed, the maximum current limited by the motor current limiting means 18 continues to flow again for T. For this reason, the motor internal temperature increases cumulatively before the start of energization. When these series of operations are repeated, the internal temperature of the sewing machine motor 2 rises indefinitely, which may lead to burnout of the motor coil or demagnetization of the rotor magnet. Further, when the encoder circuit provided inside the sewing machine motor 2 exceeds the operation range of the semiconductor element, there is a possibility that the sewing machine motor 2 may be damaged due to malfunction or the like. Particularly, in the case of a small motor, when the motor is locked due to a small heat capacity of the entire motor, a temperature rise of several tens of degrees may occur in a few seconds.

As a countermeasure, a motor temperature detecting means 20 is provided inside the sewing machine motor 2, and the CPU 13 judges the temperature detection signal and detects an abnormality when the temperature is equal to or higher than a predetermined specified temperature. The energization of the motor 2 is stopped.

In this case, even when the motor lock is repeatedly generated in a short time as described above, the temperature of the motor is constantly monitored, so that the temperature does not rise without limit.

However, when the motor is stopped by this method, the motor temperature has already risen considerably, so that the sewing machine has to be stopped for a long time to cool the motor.

If the sewing machine is started without sufficient cooling time even if no abnormality is detected, it is highly likely that the temperature immediately reaches the predetermined temperature and the power supply is stopped again.

Further, the specified temperature is set to a high temperature within a range in which the motor coil does not burn out so that such an abnormality detection does not frequently occur and the operating rate of the sewing machine does not decrease. If the specified temperature is repeatedly reached, a high-low temperature cycle having a large temperature difference is applied to the motor, which may reduce the reliability of the motor.

[0024]

As described above, in the conventional control of a sewing machine motor, when the cause of the motor lock is not canceled at the time of motor lock and the power is turned on again and the start of the sewing machine is repeatedly performed, The same control is repeated regardless of the internal temperature of the sewing machine motor at the time, and the internal temperature of the sewing machine motor may rise abnormally, resulting in burnout of the motor coil, malfunction of the motor encoder circuit, or reduction in reliability. There was a problem that there is.

An object of the present invention is to provide a sewing machine motor driving device which prevents abnormal rise of the temperature of the sewing machine motor by controlling the sewing machine motor in accordance with the driving state of the sewing machine motor, prevents failures, and has high reliability. That is.

[0026]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a temperature detecting means for detecting a temperature of a sewing machine motor (for example, a temperature detecting means 2 shown in FIG. 6).
0) and lock detecting means for detecting lock of the sewing machine motor (for example, corresponding to steps S8 and S9 in the flowchart shown in FIG. 1; and correspond to steps S108 and S109 in the flowchart shown in FIG. 3),
Control means for stopping the sewing machine motor based on the detection result of the lock detection means to set the power supply to the power-supply prohibited state, and enabling the power supply to the sewing machine motor based on the release of the power-supply prohibited state (for example, a flowchart shown in FIG. 1; A control method changing means for changing a control method of the sewing machine motor by the control means based on the temperature detected by the temperature detecting means. (For example, steps S4 to S6 of the flowchart shown in FIG. 1; corresponding to steps S104 to S106 of the flowchart shown in FIG. 3).

According to the first aspect of the present invention, since the control method of the sewing machine motor is changed according to the temperature of the sewing machine motor, control of the sewing machine motor according to the driving state of the sewing machine motor can be provided. The failure of the motor of the industrial sewing machine can be prevented.

According to a second aspect of the present invention, in the control apparatus for a sewing machine motor according to the first aspect, the lock detecting means is configured such that, when the lock state of the sewing machine motor is continued for a predetermined detection time, (For example, step S8 in the flowchart shown in FIG. 1)
(Corresponding to step S9), wherein the control method changing means changes the predetermined detection time based on the temperature of the sewing machine motor detected by the temperature detecting means. (Corresponding to steps S4 to S6 of the flowchart shown in FIG. 1).

According to the second aspect of the present invention, the detection time changing means changes the time required for the locked sewing machine motor to detect the motor lock by the lock detecting means based on the temperature of the sewing machine motor. Accordingly, the energization time to the locked sewing machine motor is changed, and the rise in the internal temperature of the sewing machine motor due to the motor lock can be controlled according to the temperature of the sewing machine motor at that time. Therefore, even when lock occurs repeatedly in a short time, it is possible to prevent the temperature of the sewing machine motor from accumulating and increasing, and to prevent the failure of the motor of the industrial sewing machine.

According to a third aspect of the present invention, in the sewing machine motor control device according to the second aspect, the detection time changing means is configured to control the temperature of the sewing machine motor detected by the temperature detection means to exceed a predetermined temperature. In this case, the predetermined detection time is set shorter than when the temperature of the sewing machine motor detected by the temperature detection means is equal to or lower than the predetermined temperature (for example, in step S6 of the flowchart shown in FIG. 1). Corresponding).

According to the third aspect of the present invention, when the temperature of the sewing machine motor exceeds the predetermined temperature, the detection time changing means increases the temperature at the time of locking when the temperature of the sewing machine motor is lower than the predetermined temperature. Since the temperature can be set lower than in the case, even if the lock is repeatedly generated in a short time, the temperature of the sewing machine motor does not accumulate and abnormally rise, thereby preventing the failure of the motor of the industrial sewing machine. .

According to a fourth aspect of the present invention, in the control apparatus for a sewing machine motor according to the first aspect, the control apparatus for the sewing machine motor includes a current limiting means for limiting a maximum value of a current flowing through the sewing machine motor. 6, the control method changing means changes the maximum value based on the temperature of the sewing machine motor detected by the temperature detecting means (for example, a maximum current changing means (e.g., Step S1 of the flowchart shown in FIG.
04 to S106).

According to the fourth aspect of the invention, the maximum current changing means changes the maximum value of the current flowing through the sewing machine motor based on the temperature of the sewing machine motor to control the temperature rise of the sewing machine motor. Even when lock occurs repeatedly in a short period of time, it is possible to prevent the temperature of the sewing machine motor from accumulating and increasing due to the motor lock, and to prevent failure of the motor of the industrial sewing machine.

According to a fifth aspect of the present invention, in the control device for a sewing machine motor according to the fourth aspect, the maximum current changing means is configured such that the temperature of the sewing machine motor detected by the temperature detecting means exceeds a predetermined temperature. In this case, the maximum value is set smaller than when the temperature of the sewing machine motor detected by the temperature detecting means is equal to or lower than the predetermined temperature (for example, step S1 shown in the flowchart of FIG. 3).
06).

According to the fifth aspect of the present invention, when the temperature of the sewing machine motor exceeds a predetermined temperature, the maximum value of the current flowing through the sewing machine motor is determined by the maximum current changing means. Since it is possible to control the rise in the internal temperature of the sewing machine motor due to the motor lock in accordance with the temperature of the sewing machine motor at that time by making the temperature smaller than the predetermined temperature or less, even when lock occurs repeatedly in a short time. In addition, it is possible to prevent the temperature of the sewing machine motor from accumulating and increasing, and to prevent the failure of the motor of the industrial sewing machine.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 are diagrams showing a first embodiment of an industrial sewing machine to which the present invention is applied.

First, referring to the flowchart of FIG.
The operation of the CPU 13 according to the first embodiment will be described.

In the present embodiment, since the configuration is the same as that described with reference to FIGS. 5 and 6, illustration and description of the configuration are omitted. Here, the control by the CPU 13 will be described. In the following description, the same parts as those of the conventional industrial sewing machine will be described using the same reference numerals.

First, when the power is turned on, the maximum value of the current flowing through the sewing machine motor 2 (for example, 20
A) is set (step S1). This setting is
13 by outputting the reference value Ref to the current comparison unit 18b of the motor current limiting means 18. And
The maximum value of the current flowing through the sewing machine motor 2 is limited by this set value.

Next, when the operator operates the sewing machine pedal 10, the rotation command is transmitted from the pedal input detecting means 19 to the CP.
Wait for input to U13 (step S2).

When the CPU 13 determines in step S2 that a rotation command has been input (YE in step S2).
S), a temperature detection signal output from the motor temperature detection means 20 is read (step S3), and it is determined whether the temperature of the sewing machine motor 2 exceeds a predetermined temperature (step S4).

In step S4, when the CPU 13 determines that the temperature of the sewing machine motor 2 has not exceeded the predetermined temperature (NO in step S4), the CPU 13 sets the motor lock detection time T to a predetermined time (for example, 2 seconds). (Step S
5) The process proceeds to step S7.

When the CPU 13 determines that the temperature of the sewing machine motor 2 exceeds a predetermined temperature (step S).
4), the motor lock detection time T is set to a value (for example, T = 1 second) shorter than the value set in step S5 (step S6), and the process proceeds to step S7.

Next, the CPU 13 controls the motor control means 14.
The motor rotation command signal LSi and the motor speed command signal S
The PC is output, and the rotation of the sewing machine motor 2 is controlled (step S7).

Next, the processing of the lock detecting means composed of steps S8 and S9 is performed.

That is, the CPU 13 determines whether or not the rotation speed of the sewing machine motor 2 detected by the motor rotation speed detecting means 16 is equal to or lower than a predetermined rotation speed (for example, 100 rpm) (step S8). If it is determined that the rotation speed is equal to or lower than the speed (for example, 100 rpm) (YES in step S8), the process proceeds to step S9, and after the rotation speed is equal to or lower than the predetermined rotation speed, step S5 is performed.
Alternatively, in step S6, it is determined whether the time set as T as the motor lock detection time has elapsed.

Then, the CPU 13 proceeds to step S9.
If it is determined that the motor lock detection time T has not yet elapsed after the rotation speed has become equal to or lower than the predetermined rotation speed (NO in step 9), the process returns to step S8, and the rotation speed of the sewing machine motor 2 is again set to the predetermined rotation speed. It is determined whether the rotation speed is equal to or lower than the rotation speed.

If the rotation speed of the sewing machine motor 2 is continuously lower than the predetermined rotation speed in step S8, the processing of YES in step S8 and the processing of NO in step S9 are repeated until YES is determined in step S9. , That is, until the rotation speed of the sewing machine motor 2 becomes equal to or lower than the predetermined rotation speed and until it is determined that the motor lock detection time T has elapsed (YES in step 9).

Then, the CPU 13 determines in step S9 that Y
If it is determined to be ES, it is determined that the motor is locked, the process proceeds to step S10, the sewing machine motor 2 is stopped, and the process proceeds to step S11 to display an error or prohibit reception of all input signals. Error processing such as disabling power supply to the sewing machine 1 and the sewing machine motor 2 is performed (step S11), and the power supply is awaited.

On the other hand, when it is determined in step S8 that the rotation speed of the sewing machine motor 2 is not lower than the predetermined rotation speed (YES in step S8), that is, the rotation speed of the sewing machine motor 2 Exceeds a predetermined rotation speed (for example, 100 rpm) or once a predetermined rotation speed (for example, 100 rpm).
m), but if it is detected that the rotation speed exceeds a predetermined rotation speed (for example, 100 rpm) before the motor lock detection time T elapses, steps S8 and S9 are performed.
Then, the processing by the lock detecting means constituted by the process is ended, and the routine goes to Step S12.

In step S12, the CPU 13
Determines whether a motor stop command has been input from the pedal input detecting means 19 by the operation of the sewing machine pedal 10 by the operator, and if the motor stop command has not been input (NO in step S12), returns to step S7. To continue the rotation control.

If the CPU 13 determines in step S12 that a motor stop command has been input (YES in step S12), the process proceeds to step S13 to stop the sewing machine motor 2, returns to step S2, and rotates again. Wait for command.

With the above processing, the control device of the sewing machine motor according to the present embodiment, every time a rotation command for the sewing machine motor 2 is input, detects the motor lock by the lock detecting means based on the motor temperature at that time. By changing the time T, the energizing time of the sewing machine motor 2 in the locked state is controlled to prevent the temperature of the sewing machine motor 2 from rising without limit.

Next, how the temperature of the sewing machine motor 2 rises when the above control is repeatedly performed by turning on the power again will be described with reference to a time chart of FIG.

At timing t1, the sewing machine motor 2
Is started, it is determined whether the temperature of the sewing machine motor 2 exceeds a predetermined temperature. At the timing t1, the temperature of the sewing machine motor 2 does not exceed the predetermined temperature, so the motor lock detection time T is set to 2 seconds.

As in FIG. 7, the sewing machine motor 2 is locked at the timing t1, and when two seconds of the motor lock detection time elapse, it is determined that the motor is locked at the timing t2, and the sewing machine motor 2 is stopped.

Next, the power supply to the sewing machine control device is turned off and turned on by the operator between the timing t2 and the timing t3, the power supply prohibition state is released, and the sewing machine motor 2 is started at the timing t3. Here, the temperature of the sewing machine motor 2 at the time of startup is equal to or lower than the predetermined temperature, so that the motor lock detection time T is set to 2 seconds as in the startup at the timing t1.

Then, the same processing as the processing between the timings t1 to t3 is performed until the timing t5. Since the control up to this point is substantially the same as the conventional control, the temperature of the sewing machine motor 2 at the timing t5 is the same as that at the timing t5 in FIG.

Next, at timing t5, the sewing machine motor 2 is started. At this time, since the temperature of the sewing machine motor 2 exceeds the predetermined temperature, the motor lock detection time T is set to one second.

At this time, if the lock state is still established, the motor lock is detected and the sewing machine motor 2 is stopped at a timing t6 one second after the start of the sewing machine motor 2. The temperature rise of the sewing machine motor 2 at this time is smaller than that between the timings t1 and t2 and between the timings t3 and t4. This is because the energization time, that is, the motor lock detection time T is shorter than between the timings t1 and t2 and between the timings t3 and t4.

By repeating the same processing after timing t6, it is possible to prevent an unlimited temperature rise of the sewing machine motor 2 as in the conventional control method even if the motor lock occurs repeatedly.

As described above, in the sewing machine motor driving apparatus according to the present embodiment, the sewing machine motor control method based on the temperature of the sewing machine motor, that is, the time from when the motor is locked to when it is determined that the motor is locked is determined. Since the detection time can be automatically changed to prevent an unlimited rise in temperature, a failure of the sewing machine motor can be prevented.

In this embodiment, the motor lock detection time T is changed by determining that the temperature of the sewing machine motor has exceeded a predetermined temperature. However, the present invention is not limited to this. The motor lock detection time may be changed stepwise or continuously according to the temperature.

[Second Embodiment] First, referring to the flowchart of FIG. 3, the CPU 1 in the second embodiment will be described.
Operation 3 will be described.

In this embodiment, since the present embodiment is implemented with the same configuration as that described with reference to FIGS. 5 and 6, illustration and description of the configuration are omitted. Here, the control by the CPU 13 will be described. In the following description, the same parts as those of the conventional industrial sewing machine will be described using the same reference numerals.

First, when the power is turned on, a motor lock detection time T (for example, 2 seconds) is set as an initial setting (step S101).

Next, when the operator operates the sewing machine pedal 10, the rotation command is transmitted from the pedal input detecting means 19 to the CP.
It waits for an input to U13 (step S102).

CPU 13 determines in step S102 that a rotation command has been input (step S1).
(02: YES), the temperature detection signal output from the motor temperature detection means 20 is read (step S103), and it is determined whether the temperature of the sewing machine motor 2 exceeds a predetermined temperature (step S104).

In step S104, the CPU 13
Determines that the temperature of the sewing machine motor 2 has not exceeded the predetermined temperature (NO in step S104),
Is supplied to the current comparison unit 18b of the current limiting unit 18 by the reference value R.
ef, the maximum value IM of the current flowing through the sewing machine motor 2
Is output to a predetermined current (for example, 20 A).

If the CPU 13 determines that the temperature of the sewing machine motor 2 exceeds a predetermined temperature (step S5).
104), the maximum value IM of the current flowing through the sewing machine motor 2 is set as the reference value Ref in the step S5.
A voltage value that limits the current (for example, 15 A) smaller than the value set in Step S106 is output (Step S106), and Step S106 is performed.
Move to 107.

Next, the CPU 13 controls the motor control means 14.
To output the motor rotation command signal LSi and the speed command signal SPC to execute the rotation control of the sewing machine motor 2 (step S107). The maximum current value flowing through the sewing machine motor 2 at this time is determined in step 105 or step 10.
6 is limited to the current set.

Next, step S108 and step S10
9 is performed by the lock detecting means.

That is, the CPU 13 determines whether or not the rotation speed of the sewing machine motor 2 detected by the motor rotation speed detection means 16 is lower than a predetermined rotation speed (for example, 100 rpm) (step S108). When it is determined that the rotation speed is equal to or lower than the speed (for example, 100 rpm) (YES in step S108), the process proceeds to step S109, and after the rotation speed is equal to or lower than the predetermined rotation speed,
In step S105 or step S106, it is determined whether the time set as T (for example, 2 seconds) as the motor lock detection time has elapsed.

Then, the CPU 13 proceeds to step S109
If it is determined that the motor lock detection time T has not yet elapsed after the rotation speed has become equal to or lower than the predetermined rotation speed (NO in step 109), the process returns to step S108, and again the rotation speed of the sewing machine motor 2 It is determined whether the rotation speed is equal to or lower than a predetermined rotation speed.

In step S108, the sewing machine motor 2
If the rotation speed is continuously below the predetermined rotation speed,
The motor lock detection time T is determined until the processing of YES in step S108 and the processing of NO in step S109 are determined to be YES in step S109, that is, after the rotation speed of the sewing machine motor 2 becomes equal to or lower than the predetermined rotation speed. Until it is determined that has elapsed (YES in step 109)
Is repeatedly executed during

By these processes, the sewing machine motor 2 is in the locked state, and the above-described steps 108 and 1
While step 09 is repeatedly executed, step S10
5, or the maximum current set based on the temperature of the sewing machine motor 2 in step S106 continues to flow through the sewing machine motor 2.

Therefore, when the sewing machine motor 2 is in the locked state and the motor temperature exceeds the predetermined temperature, the current continuously flowing through the sewing machine motor 2 becomes smaller than the current flowing when the motor temperature is lower than the predetermined temperature. When the temperature of the sewing machine motor 2 exceeds the predetermined temperature, the temperature rise after the motor lock can be reduced as compared with when the temperature of the sewing machine motor 2 is equal to or lower than the predetermined temperature.

Then, the CPU 13 proceeds to step S109
If YES is determined in step S110, it is determined that the motor is locked, the process proceeds to step S110, and the sewing machine motor 2 is stopped.
Then, the process proceeds to step S111 to perform error processing such as displaying an error, prohibiting reception of all input signals, and prohibiting power supply to the sewing machine and the sewing machine motor 2 (step S111), and waits for power-off.

On the other hand, if it is determined in step S108 that the rotation speed of the sewing machine motor 2 is not lower than the predetermined rotation speed (NO in step S108), that is, the rotation speed of the sewing machine motor 2 Exceeds a predetermined rotation speed (for example, 100 rpm) or once a predetermined rotation speed (for example, 100 rpm).
rpm) or less, but if it is detected that the rotation speed exceeds a predetermined rotation speed (for example, 100 rpm) before the motor lock detection time T elapses, the lock detection means constituted by step S108 and step S109. The process ends, and the routine goes to Step S112.

In step S112, the CPU 13
Determines whether or not a motor stop command has been input from the pedal input detecting means 19 by the operation of the sewing machine pedal 10 by the operator. If the motor stop command has not been input (NO in step S12), the process returns to step S107. To continue the rotation control.

If the CPU 13 determines in step S112 that a motor stop command has been input (YES in step S112), the process proceeds to step S113 to stop the sewing machine motor 2, returns to step S102, and rotates again. Wait for command.

With the above processing, the control device of the sewing machine motor according to the present embodiment, every time a rotation command for the sewing machine motor is input, based on the motor temperature at that time,
By changing the maximum value IM of the current flowing through the sewing machine motor limited by the current limiting means, it is possible to prevent the temperature of the sewing machine motor from rising without limit when the sewing machine motor is locked. (Refer to the previous sentence and correct the previous one.)

Next, the progress of the temperature rise of the sewing machine motor 2 of this embodiment will be described with reference to the time chart of FIG.

When the sewing machine motor 2 is started at the timing t1, it is determined whether the temperature of the sewing machine motor 2 exceeds a predetermined temperature. At the timing t1, the temperature of the sewing machine motor 2 does not exceed the predetermined temperature as shown by the waveform of the motor temperature in FIG. 4, so that the current maximum value IM is set to 20A.

When the sewing machine motor 2 is locked at the timing t1, the current maximum value I
The current of 20 A set as M continues to flow until 2 seconds of the motor lock detection time has elapsed, and when 2 seconds of the motor lock detection time has elapsed, it is determined that the motor is locked at timing t2, and the sewing machine motor 2 is stopped.

Next, between the timing t2 and the timing t3, the power supply to the sewing machine controller is cut off and turned on by the operator, and at the timing t3, the sewing machine motor 2 is started. Since the temperature at this time is equal to or lower than the predetermined temperature, the current maximum value IM is set to 20 A as in the case of starting at the timing t1.

Thereafter, until the timing t5, the timing t
The same processing as the processing between 1 and timing t3 is performed.
Since the control up to this point is substantially the same as the conventional control, the temperature of the sewing machine motor 2 at the timing t5 is the same as that at the timing t5 in FIG.

Next, at a timing t5, the sewing machine motor 2 is started. At this time, since the temperature of the sewing machine motor 2 exceeds the predetermined temperature, the current maximum value IM is 15
A is set.

At this time, if the motor is still in the locked state, the current of 15 A set as the current maximum value IM continues to flow through the sewing machine motor 2 until 2 seconds of the motor lock detection time has elapsed. Is elapsed, it is determined that the motor is locked at timing t6, and the sewing machine motor 2 is stopped. The temperature rise of the sewing machine motor 2 at this time is as follows.
Between timing t1 and timing t2, and timing t
It is smaller than the case between 3 and timing t4. This is because the energizing current, that is, the current maximum value IM is smaller than between timing t1 and timing t2 and between timing t3 and timing t4.

Similar processing is repeated after timing t6.

As described above, in the sewing machine motor driving apparatus according to the present embodiment, the method of controlling the sewing machine motor based on the temperature of the sewing machine motor, that is, the time from when the motor is locked to when it is determined that the motor is locked is determined. Since the maximum value of the flowing current can be automatically changed to prevent unlimited temperature rise, it is possible to prevent the sewing machine motor from malfunctioning.

In the present embodiment, the maximum value IM of the current flowing through the sewing machine motor is changed by determining that the temperature of the sewing machine motor has exceeded a predetermined temperature. However, the present invention is not limited to this. For example, the maximum value IM may be changed stepwise or continuously according to the temperature of the sewing machine motor.

In the first and second embodiments, the lock detecting means determines that the state in which the rotation speed of the sewing machine motor is equal to or lower than the predetermined rotation speed continues for a predetermined period of time. Although the lock is detected, the detection of the motor lock is not limited to this method.For example, the current flowing through the sewing machine motor is monitored, and it is determined that the state where the current is equal to or more than a predetermined current continues for a predetermined time. It may be configured to detect the motor lock.

Alternatively, instead of detecting the rotation speed of the sewing machine motor, a rotation speed detection means is provided on the sewing machine head,
The rotation speed of the sewing machine output from the detection means may be detected to detect the motor lock.

In the first embodiment and the second embodiment, the predetermined temperature for determining the temperature of the sewing machine motor 2, the motor lock detection time T, and the maximum value IM of the current flowing through the motor are respectively set as follows. The setting means is provided to increase the temperature of the sewing machine motor 2 when energized, heat radiation characteristics, insulation heat resistance of the coil, maximum current flowing through the sewing machine motor 2, characteristics of a driving element used for a motor driver, start-up conditions of the sewing machine motor 2. It is also possible to adopt a configuration in which various settings can be made in accordance with the above.

Further, in the first and second embodiments, the lock detection means detects the motor lock and stops the sewing machine motor 2 (step S10 in FIG. 1; step S110 in FIG. 3). , And error processing (step S11 in FIG. 1; step S111 in FIG. 3)
After the power is turned off, the power supply prohibition state is not released until the power is turned on again.However, a separate reset switch is provided, and the power supply prohibition state is released by operating this switch so that the initial state (FIG. Step S1 of FIG. 1: Step S1) of FIG. 3 may be adopted to enable the power supply to the sewing machine motor without depending on the power supply.

[0098]

According to the present invention, the control method of the sewing machine motor is changed based on the temperature of the sewing machine motor detected by the temperature detecting means of the sewing machine motor.
A method of protecting a sewing machine motor according to the driving state of the sewing machine motor can be provided, and failure of the motor of the industrial sewing machine can be prevented.

According to the second aspect of the present invention, the time until the sewing machine motor in the locked state is determined to be locked by the lock detecting means by the detecting time changing means is:
Since the change is performed based on the temperature of the sewing machine motor, the energization time to the sewing machine motor in the locked state is changed, and the rise in the internal temperature of the sewing machine motor can be controlled according to the temperature of the sewing machine motor at that time. The failure of the motor of the industrial sewing machine can be prevented.

According to the third aspect of the present invention, when the temperature of the sewing machine motor exceeds the predetermined temperature, the temperature rise at the time of locking can be made lower than when the temperature of the sewing machine motor is equal to or lower than the predetermined temperature. Since the rise of the internal temperature of the sewing machine motor can be controlled according to the temperature of the sewing machine motor at that time, the failure of the motor of the industrial sewing machine can be prevented.

According to the fourth aspect of the present invention, the maximum current changing means changes the maximum value of the current flowing through the sewing machine motor according to the temperature of the sewing machine motor. Since the temperature rise can be controlled in accordance with the temperature of the sewing machine motor, the failure of the motor of the industrial sewing machine can be prevented.

According to the present invention, when the temperature of the sewing machine motor exceeds a predetermined temperature, the maximum current changing means determines the maximum value of the current flowing through the sewing machine motor in accordance with the temperature of the sewing machine motor. When the temperature of the sewing machine motor is lower than the predetermined temperature or lower, and when the sewing machine motor is locked, the internal temperature rise of the sewing machine motor can be controlled according to the temperature of the sewing machine motor. The failure of the motor can be prevented.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating control of a sewing machine motor 2 according to a first embodiment.

FIG. 2 is a time chart showing the progress of temperature rise of a sewing machine motor 2 according to the first embodiment.

FIG. 3 is a flowchart illustrating control of a sewing machine motor according to a third embodiment.

FIG. 4 is a time chart showing progress of a temperature rise of a sewing machine motor 2 according to a third embodiment.

FIG. 5 is an external view showing a main part configuration of a conventional industrial sewing machine 100.

FIG. 6 is a circuit block diagram illustrating a main circuit configuration of a control device of the conventional industrial sewing machine 100.

FIG. 7 is a time chart showing the progress of temperature rise of sewing machine motor 2 in conventional industrial sewing machine 100.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Industrial sewing machine 1 Sewing machine main body 6 Sewing machine needle 7 Sewing machine needle bar 8 Main shaft 9 Belt 2 Sewing machine motor 16 Motor rotation speed detecting means 3 Control box 11 Rectification unit 12 Smoothing unit 13 CPU 14 Motor control means 15 Motor driver 16 Motor rotation speed detection Means 17 CPU power reset circuit 18 Current limiting means 18a Detection unit 18b Comparison unit 19 Pedal input detection means 20 Motor temperature detection means 4 Power switch 5 Operation panel 10 Sewing machine pedal

Continuation of the front page F term (reference) 3B150 CA03 CA06 CE08 GD12 GD22 JA02 JA05 JA08 KA01 LA31 LA84 LA85 LB01 MA06 MA17 NA71 NC02 NC04 NC07 PA03 QA04 QA07 5G044 AA04 AA07 AC01 AD01 AD03 AE01 CA07 CB03 CE07 5H550 AB01 BB03 BB03 KK06 LL14 LL22 LL39 LL53 MM06

Claims (5)

[Claims] A temperature detecting means for detecting a temperature of the sewing machine motor; a lock detecting means for detecting a lock of the sewing machine motor; A control device for controlling the sewing machine motor, the control device comprising: a control unit configured to enable the power supply to the sewing machine motor based on the release of the power supply prohibition state. The control unit controls the sewing machine based on a temperature detected by the temperature detection unit. A control method changing means for changing a control method of the motor. 2. The lock detection means detects lock of the sewing machine motor when the lock state of the sewing machine motor has been continued for a predetermined detection time, wherein the control method changing means includes: 2. The control device for a sewing machine motor according to claim 1, wherein the control device is a detection time changing unit that changes the predetermined detection time based on a temperature of the sewing machine motor detected by a temperature detection unit. 3. The detection time changing means detects the predetermined detection time by the temperature detection means when the temperature of the sewing machine motor detected by the temperature detection means exceeds a predetermined temperature. 3. The control device for a sewing machine motor according to claim 2, wherein the set temperature of the sewing machine motor is set shorter than a case where the temperature is equal to or lower than the predetermined temperature. 4. The sewing machine motor control device further includes current limiting means for limiting a maximum value of a current flowing through the sewing machine motor, and the control method changing means includes a current limiting means for detecting the temperature of the sewing machine motor detected by the temperature detecting means. The control device for a sewing machine motor according to claim 1, wherein the control device is a maximum current changing unit that changes the maximum value based on a temperature. 5. The maximum current changing means detects the maximum value when the temperature of the sewing machine motor detected by the temperature detecting means exceeds a predetermined temperature. The sewing machine according to claim 4, wherein the temperature of the sewing machine motor is set to be lower than a case where the temperature is equal to or lower than the predetermined temperature.