KR20120058423A - Control device for sewing machine and sewing machine - Google Patents

Abstract

PURPOSE: An apparatus for controlling a sewing machine is provided to enable power save controlling. CONSTITUTION: An apparatus for controlling a sewing machine comprises a switching device of anode side, a driving circuit(6), and a control unit. The switching device helps access of both ends of the coil of a stepping motor(30) to anode of power. The apparatus comprises a deviation generator, a driving signal generator, and gain regulator. The deviation generator calculates deviation of driving current value. The driving signal generator generates driving signal from the deviation of current value.

Description

CONTROL DEVICE FOR SEWING MACHINE AND SEWING MACHINE}

The present invention relates to a control device for controlling the driving of a stepping motor used in a sewing machine, and a sewing machine having a control device.

Stepping motors are known as electric motors capable of accurately positioning the angle of a rotating shaft, and have been used in sewing machines in recent years. There are many types of stepping motors. Two-phase stepping motors are known in which two coils are operated by exciting at different excitation timings.

As control of a stepping motor, for example, Patent Literature 1 discloses H having two switching elements each connecting both ends of a coil of a stepping motor to an anode of a power supply device, and two switching elements each connecting both ends of the coil to earth. A sewing machine having a bridge circuit and controlling the ON / OFF of the switching element such that when the stepping motor is stopped, the current flowing from the coil flows back to the coil itself by magnetic induction of the coil. A drive of a stepping motor is described.

Japanese Patent Publication No. 2009-095148 (0009,0010)

Since the technique of patent document 1 has low responsiveness at the time of reducing the electric current which drives a stepping motor, the phenomenon which more current flows to a stepping motor than the current command value with respect to a stepping motor may generate | occur | produce. As a result, the technology described in Patent Literature 1 may not be able to sufficiently control the power consumption. This invention is made | formed in view of the said situation, and an object of this invention is to reduce the power consumption of the stepping motor used for a sewing machine.

In order to solve the above problems and achieve the object, the present invention, two anode-side switching elements that can connect both ends of the coil of the stepping motor for driving the predetermined operating device of the sewing machine to the anode of the power supply, respectively, and the coil A driving circuit having two earth-side switching elements each of which is capable of connecting both ends of the earth to earth;

A control device for a sewing machine having control means for controlling the drive circuit,

The control means,

A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;

A drive signal generator for generating the drive signal from the current value deviation;

In the case where the driving circuit is controlled to reflux the current flowing from the coil to the coil itself by magnetic induction of the coil, the absolute value of the driving current value is compared with the absolute value of the current command value, and the gain is obtained. Gain adjustment section to adjust

Characterized in that it comprises a.

In a preferred aspect of the present invention, the gain adjusting unit is further configured such that when the absolute value of the drive current value is greater than or equal to the absolute value of the current command value, the gain adjusting unit is larger than the absolute value of the drive current value than the absolute value of the current command value. It is desirable to increase the gain.

In a preferred aspect of the present invention, the anode-side switching element and the earth-side switching element are controlled such that the stepping motor returns a current flowing from the coil to the coil itself by a magnetic induction of the coil at a predetermined rotation speed or less. It is preferable to be.

In a preferred aspect of the present invention, it is preferable that the operating device is a positioning mechanism for relatively positioning the sewing object with respect to the sewing needle such that the needle falls to an arbitrary position with respect to the sewing object. Do.

In order to solve the above problems and achieve the object, the present invention, specifically, as a control device of the sewing machine for controlling a stepping motor for driving a predetermined operating device of the sewing machine,

A driving circuit having two anode-side switching elements capable of connecting both ends of the coil of the stepping motor to the anode of the power supply, and two earth-side switching elements connecting both ends of the coil to the earth, respectively;

Power saving control for driving the positive electrode side switching element and the earth side switching element to generate a current command value for the stepping motor and to reflow the current flowing from the coil to the coil itself by magnetic induction of the coil; A control signal generation unit for generating a control switching command for execution;

A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;

A driving signal generator for generating a driving signal for driving the stepping motor from the current value deviation and inputting the two anode-side switching elements and the two earth-side switching elements;

In the execution of the power saving type control, when the absolute value of the drive current value is greater than or equal to the absolute value of the current command value, the gain is increased more than when the absolute value of the drive current value is smaller than the absolute value of the current command value. Gain adjustment part to enlarge

Characterized in that it comprises a.

Furthermore, the present invention controls the operation of the stepping motor for driving the positioning mechanism for relatively positioning the sewing object relative to the sewing needle such that the needle falls to an arbitrary position with respect to the sewing object.

In addition, the present invention, the stepping motor for driving a predetermined operating device,

A drive circuit having two anode side switching elements each of which can connect both ends of the coil of the stepping motor to an anode of a power supply, and two earth side switching elements each of which can connect both ends of the coil to earth;

A sewing machine having control means for controlling the drive circuit,

The control means,

A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;

A drive signal generator for generating the drive signal from the current value deviation;

In the case where the driving circuit is controlled to reflux the current flowing from the coil to the coil itself by magnetic induction of the coil, the absolute value of the driving current value is compared with the absolute value of the current command value, and the gain is obtained. Gain adjustment section to adjust

Characterized in that it comprises a.

The present invention can reduce the power consumption of the stepping motor used in the sewing machine.

1 is a schematic diagram showing a stepping motor and a stepping motor control apparatus for a sewing machine according to the present embodiment.
Fig. 2 is a diagram showing the device configuration of the motor control apparatus according to the present embodiment.
3 is an explanatory diagram showing a configuration of a signal calculation unit of the motor control apparatus according to the present embodiment.
4 is an explanatory diagram showing a method of generating a control signal.
5 is an explanatory diagram showing a method of generating a control signal.
6 is a schematic diagram illustrating a method of stepping motor.
Fig. 7 is an explanatory diagram showing the operation of the driving circuit when the stepping motor is driven. In Fig. 7-1, the first anode side element and the second earth side element are in an ON state, and the second anode side element and the first earth are shown. 7-2 shows that the second anode side element and the first earth side element are in the ON state, and the first anode side element and the second earth side element are in the OFF state.
8 is a schematic diagram showing a change in current flowing through a coil of a stepping motor.
9 is a schematic diagram showing a change in current flowing through a coil of a stepping motor.
10 is a schematic diagram illustrating a change in current flowing through a coil of a stepping motor.
Fig. 11 is a diagram for explaining the operation of the driving circuit when executing power saving control.
Fig. 12 is a diagram for explaining the operation of the drive circuit when executing power saving control.
It is a schematic diagram which shows the change of the electric current which flows through the coil of a stepping motor at the time of power saving control.
14 is a schematic diagram showing a change in current flowing through a coil of a stepping motor during power saving control.
Fig. 15 is a conceptual diagram for explaining the setting of gain in the power saving control of the present embodiment.
Fig. 16 is a conceptual diagram for explaining the setting of the gain in the power saving control of the present embodiment.
Fig. 17 is a schematic diagram showing the change of the drive current value in the power saving control of the present embodiment.
18 is a flowchart showing an example of control of a stepping motor by the motor controller.
19 is a perspective view showing an example of a sewing machine provided with a stepping motor controlled by the motor control apparatus according to the present embodiment.
20 is a perspective view showing the positioning mechanism of the sewing machine shown in FIG.

EMBODIMENT OF THE INVENTION The form (embodiment) for implementing this invention is demonstrated in detail, referring drawings. This invention is not limited by the content described in the following embodiment. In addition, the component described below includes what can be easily assumed by those skilled in the art, but what is substantially the same. Moreover, the component described below can be combined suitably. If the sewing machine using a stepping motor for driving in the X-Y direction, the present invention can be applied regardless of industrial sewing machine or home sewing machine.

In the present embodiment, the stepping motor 30 is used to drive the positioning mechanism of the sewing machine. However, the stepping motor 30 may be used to drive other mechanisms of the sewing machine such as a presser foot lift mechanism and a feed amount adjusting mechanism. In the present embodiment, the stepping motor 30 is a so-called PM (Permanent Magnet) type two-phase stepping motor, but is not limited thereto. The stepping motor 30 includes a rotation shaft 31, a rotor 32, a stator 33, core parts 33a and 33b, and coils 34a and 34b.

The rotor 32 is a cylindrical structure connected to the rotating shaft 31 of the stepping motor 30 and rotatably installed by the housing of the stepping motor 30. The rotor 32 is a magnetic body such as a permanent magnet. The stator 33 is a cylindrical magnetic material (for example, iron) provided around the rotor 32. The stator 33 has core portions 33a and 33b that protrude toward the rotor 32 at its inner circumference. The coils 34a and 34b are windings wound around the core portions 33a and 33b. The coils 34a and 34b are excited as current flows and function as electromagnets.

The operation of the stepping motor 30 is controlled by the control device of the sewing machine installed in the sewing machine main body or installed in a control box outside the sewing machine main body (hereinafter referred to as a 'motor control device'; 1).

The motor control apparatus 1 includes a control signal generator 2, a signal calculator 4, and drive circuits 6, 6 corresponding to the respective coils 34a, 34b. The motor controller 1 generates a drive signal corresponding to an excitation pattern according to the command rotation angle with respect to the stepping motor 30, and based on this, excitation of these signals is made by flowing a current to each of the coils 34a and 34b. do. As a result, the rotor 32 of the magnetic material rotates at a rotation angle corresponding to the excitation patterns of the coils 34a and 34b, and is maintained at the rotation angle until the excitation pattern changes.

Direction of current of the coils 34a and 34b flowing by the motor controller 1 (in the example shown in FIG. 1, the coil 34a is the direction indicated by arrows A and B, and the coil 34b is the arrows C and D). Direction) is changed depending on the driving of the driving circuit 6.

Next, the motor control apparatus 1 is demonstrated.

In FIG. 2, the motor controller 1 is a device that controls the stepping motor 30, specifically, the drive circuit 6.

As described above, the motor control apparatus 1 includes a control signal generator 2, a signal calculator 4, and a drive circuit 6. The motor controller 1 has as many drive circuits 6 as the number corresponding to the respective coils 34a and 34b of the stepping motor 30 shown in FIG. 1. Only one driving circuit 6 is shown.

The control signal generator 2 calculates and generates a current command value Ic as a command value for controlling the operation of the stepping motor 30, and transmits it to the signal calculator 4. The current command value Ic is an analog signal. In addition, the control signal generation unit 2 generates control switching commands P1 and P2 for switching the power saving type control and the other control, and transmits them to the signal calculation unit 4.

The power saving type control drive circuit 6 returns the current flowing from the coil 34a (34b) to the coil 34a (34b) itself by magnetic induction of the coil 34a (34b) of the stepping motor 30. ) To control. In other words, the power saving type control drive drives the current flowing from the coil 34a (34b) to be returned to the coil 34a (34b) itself by magnetic induction of the coil 34a (34b) of the stepping motor 30. It is control to drive the anode side switching elements 60a and 60c and the earth side switching elements 60b and 60d which the furnace 6 has. The power saving control will be described later.

The control signal generator 2 is, for example, a CPU (Central Processing Unit) or a MCU (Micro Computer Unit).

The control signal generator 2 executes a computer program for controlling the operation of the stepping motor 30, thereby rotating or stopping the stepping motor 30 or the power saving type described above with respect to the stepping motor 30. Take control.

The control signal generator 2 recognizes the rotational speed of the motor from the pulse frequency, and may generate the control switching commands P1 and P2, and an encoder (not shown) that measures the rotational speed of the stepping motor 30. The number of rotations of the stepping motor 30 can be recognized by the signal from the control signal, and control control commands P1 and P2 may be generated.

The signal calculating section 4 operates the stepping motor 30 on the basis of the current command value Ic generated by the control signal generating section 2, the drive current value Id, and the control switching commands P1 and P2. Drive signals Sd1 and Sd2 for driving are generated.

Then, the signal calculating section 4 applies the generated driving signals Sd1 and Sd2 to the driving circuit 6, thereby passing a current to the coils 34a and 34b of the stepping motor 30 to supply the stepping motor 30 to the driving circuit 6. Rotate or stop That is, the stepping motor 30 is controlled through the driving circuit 6 by the driving signals Sd1 and Sd2 of the signal calculating section 4.

As described above, the driving of the stepping motor 30 in the present embodiment includes both rotating the stepping motor 30 and stopping the stepping motor 30.

The drive signals Sd1 and Sd2 are signals for controlling the stepping motor 30 by PWM (Pulse Width Modulation).

The signal calculating section 4 is a processing device (for example, a microcomputer) for realizing the above-described functions. In this embodiment, a DSP (Digital Signal Processor) is used. DSPs are microprocessors that specialize in specific processes. The details of the signal calculating section 4 will be described later.

The drive circuit 6 includes two anode side switching elements 60a and 60c and a coil (which can connect the conductive portions at both ends of the coil 34a (34b) of the stepping motor 30 to the anode of the power supply 62, respectively). The two earth side switching elements 60b and 60d which can connect the electroconductive parts of the both ends of 34a (34b) to the earth 63, respectively.

In this way, the drive circuit 6 is a full bridge circuit. The drive circuit 6 has diodes 61a and 61c and diodes 61b and 61d connected in parallel with the respective anode side switching elements 60a and 60c and the respective earth side switching elements 60b and 60d, respectively. The diodes 61a and 61c and the diodes 61b and 61d are connected to allow an electric current to flow from the earth 63 toward the anode of the power supply 62.

With this configuration, the current from the power supply 62 does not flow through the diodes 61a and 61c and the diodes 61b and 61d, and the current in the direction opposite to the direction of the current by the power supply 62 has flowed. In this case, this current flows through the diodes 61a and 61c and the diodes 61b and 61d. As the driving circuit 6 is configured in this manner, the current in the opposite direction flows to the diodes 61a and 61c and the diodes 61b and 61d so that the anode-side switching elements 60a and 60c and the earth-side switching element 60b. 60d) is avoided.

That is, the diodes 61a and 61c and the diodes 61b and 61d function as protection circuits of the anode side switching elements 60a and 60c and the earth side switching elements 60b and 60d.

In the present embodiment, the anode side switching elements 60a and 60c and the earth side switching elements 60b and 60d are both FETs (Field Effect Transistors).

The driving signal Sd1 is input to the gates of the anode-side switching elements 60a and 60c, and the driving signal Sd2 is input to the gates of the earth-side switching elements 60b and 60d. Note that the anode-side switching elements 60a and 60c and the earth-side switching elements 60b and 60d are not limited to FETs, but the FETs control the gate voltage, which is preferable when a large current flows through the stepping motor 30. Do.

The anode side switching element 60a and the earth side switching element 60b are connected in series. More specifically, the drain of the anode side switching element 60a and the source of the earth side switching element 60b are electrically connected. Similarly, as the drain of the anode-side switching element 60c and the source of the earth-side switching element 60d are electrically connected, both are connected in series. Therefore, both ends of the coil 34a (34b) are connected between the anode-side switching element 60a and earth-side switching element 60b connected in series, and the anode-side switching element 60c and earth-side switching element connected in series ( 60d), respectively.

Hereinafter, if necessary, the anode-side switching element 60a is the first anode side element 60a, the anode-side switching element 60c is the second anode-side element 60c, and the earth-side switching element 60b is first. The earth side element 60b and the earth side switching element 60d will be referred to as a second earth side element 60d.

Between the coil 34a (34b) and the drive circuit 6, as drive current detection means for detecting a current flowing through the stepping motor 30, more specifically, a current flowing through the coil 34a (34b), The current detection circuits 8a (8b) are connected in series. In addition, it means that the current detection circuit 8a corresponds to the coil 34a, and the current detection circuit 8b corresponds to the coil 34b.

The value of the current detected by the current detection circuit 8a (8b) flows through the stepping motor 30 (more specifically, the coil 34a (34b)) to drive the stepping motor 30 (drive current). Is the drive current value Id, and the drive current is converted into a voltage by a shunt resistor in the current detection circuit 8a (8b) and output.

Therefore, in this embodiment, the drive current value Id is output as a voltage. The signal calculator 4 is used to acquire the drive current value Id and generate the drive signals Sd1 and Sd2.

In the present embodiment, the motor controller 1 may have at least a signal calculator 4, and at least one of the control signal generator 2 and the drive circuit 6 is separate from the motor controller 1. Just be ready.

In addition, when the motor control apparatus 1 has the control signal generation part 2 and the signal calculation part 4, you may prepare these as a separate processing apparatus (for example, a microcomputer) like this embodiment.

In addition, the motor control apparatus 1 integrates the control signal generating unit 2 and the signal calculating unit 4 into one processing apparatus (for example, a microcomputer), and executes a separate computer program by the processing apparatus. It is also possible to realize each function.

Next, the signal calculation unit 4 will be described in more detail.

In FIG. 3, the signal calculator 4 includes a deviation generator 40, a drive signal generator 41, a triangle wave generator 42, and a gain adjuster 43.

In addition, the signal calculating section 4 processes the output section 44 for processing the driving signal Sd generated by the driving signal generating section 41 into the driving signals Sd1 and Sd2 transmitted to the driving circuit 6. Have By these, the signal calculating section 4 has an A / D conversion function and a PWM control function for controlling the current driving the stepping motor 30.

The deviation generator 40 includes a current command value Ic for the stepping motor 30 generated by the control signal generator 2 shown in FIG. 2, and a drive current value Id flowing through the stepping motor 30. Deviation (d (= Ic-Id)) is calculated to generate a current value deviation D (= d × G) in which the predetermined gain G generated by the gain adjusting unit 43 is applied to the deviation d. .

The drive signal generator 41 generates a drive signal Sd for driving the stepping motor 30 from the current value deviation D. At this time, the drive signal generator 41 generates a drive signal Sd by using the triangle wave Vt generated by the triangle wave generator 42. Gain G is the weighting of the current value deviation D. The larger G is, the larger the change in the ON duty of the PWM signal is, and the current responsiveness is improved. However, when G is excessively large, an overshoot occurs when the current changes, resulting in an unstable current. For this reason, G needs to be an appropriate value.

In the present embodiment, when two kinds of gains having different sizes are prepared and the power saving type control described above is executed, when the current flowing through the stepping motor 30 needs to be lowered, Use gain greater than gain.

Next, an example of the method for generating the drive signal Sd will be described.

4 and 5, the triangular wave generator 42 generates a triangular wave Vt.

The drive signal generator 41 compares the triangular wave Vt and the current value deviation D to generate an ON signal when Vt <D (time t1 to t2) and an OFF signal when Vt> D. (Time t2 to t3). The ON / OFF signal obtained by combining the ON signal and the OFF signal thus obtained is the drive signal Sd. One period of the triangular wave Vt corresponds to one period of the drive signal Sd.

As can be seen from FIGS. 4 and 5, when the current value deviation D increases, the ON time in one cycle of the drive signal Sd becomes long, and when the current value deviation D decreases, the drive signal Sd OFF time becomes longer in one cycle. When the driving signal Sd is the ON signal, current flows to the stepping motor 30, and when the driving signal Sd is the OFF signal, no current flows to the stepping motor 30. As the ON time of the drive signal Sd is longer, more current flows through the stepping motor 30. In this way, the drive signal Sd changes the magnitude of the current flowing through the stepping motor 30 according to the length of the ON time (called the pulse width as the interval between the times t1 and t2). PWM control is a control for changing the magnitude of the current flowing through the stepping motor 30 based on the pulse width of the drive signal Sd.

The gain adjusting section 43 is the case where the drive circuit 6 is controlled to return the current flowing from the coil 34a (34b) to the coil 34a (34b) itself by magnetic induction of the coil 34a (34b). Therefore, when it is necessary to reduce the absolute value of the drive current value Id, the gain G is made larger than when it is not necessary to decrease the absolute value of the drive current value Id.

That is, the gain adjusting unit 43, when the above-described power saving control is executed, when the absolute value of the drive current value Id is equal to or greater than the absolute value of the current command value Ic, the absolute value of the drive current value Id. The gain G is made larger than when it is smaller than the absolute value of the current command value Ic.

The output unit 44 acquires the drive signal Sd generated by the drive signal generator 41 and outputs it to the drive circuit 6. The output unit 44 includes a first inversion unit 45, a first AND operation unit 46, a second AND operation unit 47, a second inversion unit 48, and a third inversion unit 49. ).

The first logical product operation unit 46 receives the control switching command P1 and the driving signal Sd from the control signal generation unit 2 shown in Fig. 2, and uses both logical ANDs as the driving signal Sd1. Output

The second AND operation unit 47 receives the control switching command P2 from the control signal generation unit 2 and the driving signal Sd passing through the first inverting unit 45 to drive the AND. It outputs as signal Sd2. The driving signal Sd is inverted by the first inverting section 45.

Hereinafter, for convenience of description, the driving signal Sd1 is referred to as a first driving signal Sd1 and the driving signal Sd2 is referred to as a second driving signal Sd2 as necessary. The first driving signal Sd1 is the same as the driving signal Sd, and the second driving signal Sd2 is the same as the signal inverting the driving signal Sd.

The first driving signal Sd1 output from the first AND product 46 is directly input to the gate of the first anode-side element 60a, and passes through the second inverting unit 48, and then the first earth. It is input to the gate of the side element 60b. The second driving signal Sd2 output from the second AND product 47 is directly input to the gate of the second anode-side element 60c, and passes through the third inverting unit 49 before the second earth signal. It is input to the gate of the side element 60d.

In this manner, the first driving signal Sd1 is input to the gate of the first anode side element 60a and the second driving signal Sd2 is input to the gate of the second anode side element 60c. The signal input to the gate of the first earth-side element 60b is the second drive signal Sd2 because the second inverter 48 outputs the inverted first drive signal Sd1.

The signal input to the gate of the second earth-side element 60d is a signal in which the first inverting unit 45 inverts the driving signal Sd, that is, the second driving signal Sd2 is converted into a third inverting unit ( Since 49 is the output inverted again, it becomes the drive signal Sd, that is, the first drive signal Sd1. In this manner, the first anode side element 60a and the second earth side element 60d are driven by the first drive signal Sd1, and the second anode side element 60c and the first earth side element 60b are driven. Is driven by the second drive signal Sd2.

As described above, the signal calculating section 4 includes the deviation generating section 40, the driving signal generating section 41, the triangular wave generating section 42, the gain adjusting section 43, and the output section 44. We include as wealth.

The signal calculating section 4 implements the functions of these components by executing a computer program stored in its own storage section. That is, the signal calculating section 4 realizes its function by software. For this reason, if the computer program is encrypted, it becomes difficult to analyze the function of the signal calculating section 4, so that the risk of unauthorized modification can be reduced.

In addition, even when the specification of the stepping motor 30, the specification of the sewing machine applied to the stepping motor 30, and the like are changed, it is possible to cope with the same signal operation unit 4 only by rewriting in the corresponding computer program. Convenience is improved.

In FIG. 6, the two-phase bipolar stepping motor 30 shown in FIG. 1 has two coils 34a and 34b. There are several methods (excitation method) of applying current to the coils 34a and 34b of the stepping motor 30, for example, A phase (coil 34a) and B phase (coil 34b). There is a method called 1-2 phase excitation method that alternately converts and flows current. This method has the advantage that the step angle can be halved compared to the one-phase excitation or two-phase excitation and smooth rotation is obtained.

In the case of the 1-2 phase excitation, the combination of the currents flowing through the respective coils 34a and 34b is eight patterns of 0 to 7 as shown in FIG. Stepping motors are excited by exciting the coils 34a and 34b in the order of the combination in steps 0, 1, 2, 3, 4, 5, 6, and 7 and switching the current flowing through the respective coils 34a and 34b. 30) rotate.

Next, the operation of the driving circuit 6 in Figs. 7 to 10 will be described for the A phase, that is, the coil 34a.

The current flowing through the coil 34a in steps 0, 1 and 2 of FIG. 6 is defined as the arrow E direction of FIG. 7-1 (the direction from the anode of the power supply 62 toward the earth 63, hereinafter the + direction). Flows). At this time, the first anode side element 60a and the second earth side element 60d repeat ON / OFF to control the drive current value Id flowing through the coil 34a. In this case, as shown in the ON part of FIG. 8, the drive current value Id which flows through the coil 34a increases.

When the first anode side element 60a and the second earth side element 60d are OFF, the diode 61b and coil 34a of the second earth side element 60b and the first anode side element 60c are turned off. Through the diode 61c, a current flows in the direction of returning to the power supply 62 (direction indicated by arrow F in Fig. 7-2). This is because when the first anode side element 60a and the second earth side element 60d are turned off, the coil 34a tries to flow a current in the direction so far flowd by magnetic induction. In this case, in order to suppress heat generation of the diodes 61b and 61c, the second earth side element 60b and the first anode side element 60c are controlled to ON. Then, as shown in the OFF part of FIG. 8, the drive current value Id which flows through the coil 34a decreases.

In steps 3 and 7 shown in Fig. 6, the current command value Ic becomes 0A (amps). This means that the drive current value Id becomes 0A (amps). At this time, the first anode side element 60a, the second earth side element 60d, and the second anode side element 60c such that the current of the coil 34a flows alternately in the + direction and the opposite direction (-direction). ) And the first earth side element 60b are turned on / off (see FIG. 9). As a result, since the average value of the current flowing through the coil 34a is 0A, the drive current value Id is 0A. In steps 4, 5, and 6 shown in Fig. 6, the direction of the current flowing through the coil 34a becomes the-direction (see Fig. 10).

When the inclination of the current flowing through the coil 34a is positive, the first anode side element 60a and the second earth side element 60d are turned on (Fig. 7-1). When the inclination of the current flowing through the coil 34a is negative, the second anode side element 60c and the first earth side element 60b are turned on (Fig. 7-2).

The inclination depends on the voltage applied to the coil 34a, and this voltage becomes the voltage (power supply voltage; Vcc) of the power supply 62, so that the inclination becomes approximately the same magnitude (Figs. 8 to 9). . The change in current due to the slope becomes substantially the same regardless of the magnitude of the current command value Ic, which causes iron loss. That is, in order to suppress the heat generation of the stepping motor 30, even if the current flowing through the coils 34a and 34b is reduced while the stepping motor 30 is stopped, the copper loss caused by this current can be reduced. However, iron loss cannot be reduced. Therefore, the heat generation of the stepping motor 30 is suppressed by the power saving control described above.

Control for suppressing heat generation of the stepping motor 30 is referred to as power saving control for convenience. 11 to 14, power saving control will be described. The power saving control is executed by the control signal generation unit 2 shown in Figs. 2 and 3 giving the control switching commands P1 and P2 to the signal calculation unit 4.

In addition, the power saving control is carried out when the stepping motor 30 is stopped, but in addition, when the stepping motor 30 rotates at low speed, specifically, when the number of rotations of the stepping motor 30 is 200 rpm or less or 300 rpm or less. You may.

When the power saving control is not executed, that is, during normal rotation of the stepping motor 30, the control switching commands P1 and P2 are all set to one. For this reason, both the control switching command P1 input to the first AND product 46 shown in FIG. 3 and the control switching command P2 input to the second AND product 47 are 1. As a result, inputs other than the control switching commands P1 and P2 are output as they are in the outputs of the first AND product 46 and the second AND product 47. Specifically, the driving signal Sd is output as the first driving signal Sd1 from the first AND product 46 and the driving signal Sd is inverted from the second AND product 47. 2 driving signals Sd2 are output. For this reason, each element of the drive circuit 6 repeats ON / OFF by the first drive signal Sd1 and the second drive signal Sd2.

As shown in Fig. 7-1, when the first anode side element 60a and the second earth side element 60d are ON, and the second anode side element 60c and the first earth side element 60b are OFF. The current flows through the coil 34a (34b) in the direction indicated by the arrow E in Fig. 7-1.

In addition, as shown in Fig. 7-2, the second anode side element 60c and the first earth side element 60b are on, and the first anode side element 60a and the second earth side element 60d are off. In the case of, the current flowing through the coil 34a (34b) is directed from the earth 63 toward the anode of the power supply 62, as indicated by the arrow F.

Next, power saving control will be described. The power saving control is performed, for example, while the stepping motor 30 is stopped or at low speed rotation. In executing the power saving control, when the current flowing through the coils 34a (34b) is in the + direction, the control signal generating unit 2 shown in Fig. 2 controls the control switching command (P1 = 1, P2 = 0). Create In addition, when the current flowing through the coil 34a (34b) is in the-direction, the control signal generator 2 shown in Fig. 2 generates a control switching command (P1 = O, P2 = 1). When the current flowing through the coils 34a and 34b is 0A, the control signal generation unit 2 shown in Fig. 2 generates control switching commands (P1 = 0 and P2 = 0).

11 and 12 show a case where the current flowing through the coil 34a (34b) is in the + direction in the power saving control. At this time, since P1 = 1 and P2 = 0, the first driving signal Sd1 is output from the first AND product 46 of FIG. 3, and 0 is output from the second AND product 47.

Therefore, in the power saving type control, when the current flowing through the coil 34a (34b) is in the + direction, the first anode side element 60a and the first earth side element 60b repeat ON / OFF, and 2 anode side element 60c is always OFF, and 2nd earth side element 60d is always ON. Further, when the first anode side element 60a is ON, the first earth side element 60b is OFF, and when the first anode side element 60a is OFF, the first earth side element 60b is ON. do.

As shown in FIG. 11, in the power saving type control, when the first anode side element 60a is ON and the second earth side element 60d is ON, the current flowing through the coil 34a (34b) is shown in FIG. It flows in the direction indicated by arrow E of 11. When the 1st anode side element 60a is OFF and the 1st earth side element 60b is ON, the 2nd anode side element 60c is OFF and the 2nd earth side element 60d is ON.

For this reason, as shown in FIG. 12, the electric current which flows from the coil 34a (34b) by magnetic induction does not return to the power supply 62 through the diode 61c of the 2nd anode side element 60c, Through the first earth side element 60b and the second earth side element 60d, it is refluxed to the coil 34a (34b) itself (direction indicated by arrow G in FIG. 12).

At this time, since the voltage in the reverse direction that impedes the flow of the current of the coil 34a (34b) is not applied, the decrease in the current is markedly stabilized as shown in FIG.

As a result, the change (current ripple) of the current flowing through the coil 34a (34b) becomes very small compared with the case shown in FIG. As a result, the power saving control has an effect of reducing heat generated by iron loss of the stepping motor 30. Then, when the stepping motor 30 is stopped or at a low speed rotation, power saving control is executed when the current flowing through the stepping motor 30 is in a constant state, thereby at the standby of the sewing machine to which the stepping motor 30 is applied. Can reduce power consumption.

However, at the time of power saving type control, since the responsiveness at the time of reducing the current (driving current) flowing to the stepping motor 30 is low, a current larger than the current command value Ic is the coil 34a of the stepping motor 30. And 34b). This is because, as shown in Fig. 14, since the decrease in the current flowing through the coils 34a and 34b is gentle in the power saving type control, before the driving current value Id is reduced to the current command value Ic, Enters the ON time of PWM control.

In the following PWM control, since the ratio of ON becomes smaller than the previous time, the drive current value Id decreases sequentially, and by repeating the PWM control several times, the drive current value Id becomes the current command value ( Decreases to Ic). When the current flowing through the coils 34a and 34b increases, the responsiveness is not a problem because it increases with the same slope as the control other than the normal control, that is, the power saving control. However, since the responsiveness decreases only when the current flowing through the coils 34a and 34b decreases, there is a case where an extra current flows in the meantime and the power consumption of the stepping motor 30 cannot be sufficiently reduced.

In order to ensure sufficient OFF time of PWM control in the case where the current flowing through the coils 34a and 34b is reduced, the current value deviation D from the signal calculating section 4 shown in Figs. It is effective to enlarge in the (minus) direction. For this purpose, what is necessary is just to enlarge the gain G produced by the gain adjustment part 43 which the signal calculating part 4 has. However, when the gain G is increased, when the current flowing through the coils 34a and 34b increases in normal control and power saving control, the current increases excessively, resulting in overshoot. .

In order to solve such a problem, in the power saving type control of the present embodiment, the gain adjusting unit 43 shown in FIG. 3 needs to reduce the absolute value of the drive current value Id when the drive current value Id is required. The gain G is made larger than when it is not necessary to decrease the absolute value of (e.g., when the current flowing through the coils 34a and 34b increases).

In this way, in the power saving type control, the current value deviation D can be increased only when the current flowing through the coils 34a and 34b decreases, so that the OFF time of the switching element can be increased. For this reason, the fall of the response when reducing the electric current which flows through the stepping motor 30 can be suppressed.

As a result, the power-saving control of the present embodiment can quickly converge the drive current value Id to the current command value Ic, so that excess current flows through the coils 34a and 34b. Thus, power consumption of the stepping motor 30 can be sufficiently reduced.

In addition, the gain adjusting unit 43 compares the absolute value of the drive current value Id with the absolute value of the current command value Ic and needs to reduce the absolute value of the drive current value Id. It may be adjusted to increase (G). Further, when the gain adjusting unit 43 executes the power saving type control, when the absolute value of the drive current value Id is equal to or greater than the absolute value of the current command value Ic, the absolute value of the drive current value Id is reduced. The gain G may be adjusted to be larger than when the current command value Ic is smaller than the absolute value of the current command value Ic.

In this embodiment, when the rotational speed of the stepping motor 30 is below a predetermined rotational speed, power saving type control is executed. Below the predetermined rotation speed, the case where the stepping motor 30 is stopped (rotation speed 0) is also included. Until now, the power saving control has been executed when the stepping motor 30 is stopped, but the power consumption of the stepping motor 30 can be further suppressed by expanding the application of the power saving control even when the stepping motor 30 is rotating. There is a number.

The predetermined rotational speed is a rotational speed for defining the case where the stepping motor 30 is rotating at a relatively low speed, for example, 200 rpm to 300 rpm. The power saving control is performed at a predetermined rotation speed or lower because the response is given priority when the stepping motor 30 is rotating at a high speed.

Next, the power saving control of the present embodiment will be described in detail with reference to FIGS. 15 to 17.

FIG. 15 shows the case where the direction of the current flowing through the coils 34a and 34b is + (P1 = 1, P2 = 0), and FIG. 16 is the case of-(P1 = 0, P2 = 1). The solid line in Fig. 17 is a change in the drive current value Id according to the power saving control of the present embodiment, and the dotted line is a change in the drive current value Id when the gain is made constant. As described above, the power-saving control of the present embodiment uses the absolute value of the drive current value Id rather than the gain G1 when it is not necessary to reduce the absolute value | Id | of the drive current value Id. The gain G2 when it is necessary to reduce Id | is increased (G1 <G2).

15 and 16, when the absolute value | Id | of the drive current value Id is smaller than the absolute value | Ic | of the current command value Ic (the region up to t = t1 and t is t2). Larger area), and it is necessary to increase the absolute value | Id | of the drive current value Id to make the deviation d (= Ic-Id) zero.

At this time, since the gain adjusting unit 43 shown in FIG. 3 sets the gain G = G1, the current value deviation D is d × G1. In the case of | Id | ≥ | Ic | (t = t1 to t2), the absolute value | Id | of the drive current value Id is set to zero the deviation d (= Ic-Id). Need to be reduced. At this time, since the gain adjusting unit 43 sets the gain G = G2 (> G1), the current value deviation D becomes d × G2. In this way, in the power saving type control of the present embodiment, the gain adjusting unit 43 determines that | Id | when the absolute value | Id | of the drive current value Id is equal to or greater than the absolute value | Ic | of the current command value Ic. The gain G is made larger than when is smaller than | Ic |.

In this way, the power saving control of the present embodiment can increase the current value deviation D only when the current flowing through the coils 34a and 34b decreases.

As a result, as shown in FIG. 17, the change (solid line) of the drive current value Id by the power-saving control of this embodiment is compared with the stepping motor (when making the gain G constant (dotted line)). The decrease in the responsiveness when reducing the current flowing through 30 is suppressed, and the procedure is promptly converged on the current command value Ic (0 at the stop of the stepping motor 30).

As a result, since the excess current flowing through the stepping motor 30 can be reduced, the power consumption of the stepping motor 30 can be sufficiently reduced. Next, an example in which the motor controller 1 shown in FIG. 2 controls the operation of the stepping motor 30 will be described.

In FIG. 18, when controlling the operation of the stepping motor 30, the control signal generating unit 2 of the motor control device 1 shown in FIG. 2 is configured with the current command value Ic and the control switching command P1. , P2). In step S101, the signal calculating section 4 acquires the current command value Ic generated by the control signal generating section 2, and in step S102 the driving current value (from the current detecting circuit 8a (8b)). Id) is acquired, and in step S103, control switching commands P1 and P2 generated by the control signal generation unit 2 are obtained. In addition, the order of step S101, step S102, and step S103 is irrelevant.

In step S104, when the control switching command P1 or P2 is 0 (step S104; Yes), the motor controller 1 executes power saving type control. In this case, the flow advances to step S105. In step S105, when P1 = 1 and Id≥Ic (step S105; Yes), the direction of the current flowing through the coils 34a and 34b of the stepping motor 30 is + and | Id | ≥ | Ic | to be. In this case, since it is necessary to reduce the drive current value Id, the process proceeds to step S106, where the deviation generator 40 acquires the gain G2 from the gain adjusting unit 43 and multiplies the deviation d by the gain. Set (G) to G2.

In step S104, when the control switching command P1 or P2 is not 0, that is, when P1 = 1 and P2 = 1 (step S104, No), the motor controller 1 does not execute power saving type control. . In this case, the flow advances to step S107, and the deviation generation unit 40 acquires the gain G1 from the gain adjustment unit 43 and sets the gain G to be multiplied by the deviation d to G1. In step S105, when P1 = 1 and Id≥Ic, that is, when P2 = 1 or Id <Ic (step S105, No), it progresses to step S108. In step S108, when P2 = 1 and Ic≥Id (step S108, Yes), the direction of the current flowing through the coils 34a and 34b of the stepping motor 30 is-and | Id | ≥ | Ic | . In this case, since it is necessary to reduce the drive current value Id, the process proceeds to step S106, where the deviation generator 40 acquires the gain G2 from the gain adjusting unit 43 and multiplies the deviation d by the gain. Set (G) to G2.

In step S108, when P2 = 1 and not Ic≥Id, that is, when P2 = 0 or Ic <Id (step S108, No), the motor controller 1 does not perform power saving control. In this case, the flow advances to step S107, and the deviation generation unit 40 acquires the gain G1 from the gain adjustment unit 43 and sets the gain G to be multiplied by the deviation d to G1.

Next, the flow advances to step S109, and the deviation generator 40 calculates the current value deviation D. Then, in step S110, the drive signal generation unit 41 acquires the triangular wave Vt from the triangular wave generator 42. Next, in the case where D> Vt in step S111 (step S111, Yes), the flow advances to step S112, and the drive signal generator 41 sets the drive signal Sd to one. If D? Vt (step S111, No), the process proceeds to step S113, where the drive signal generator 41 sets the drive signal Sd to zero. In step S111 to step S113, the drive signal generator 41 generates a drive signal Sd which is ON / OFF. This drive signal Sd is a signal for PWM control.

Next, the process proceeds to step S114, and the signal calculation unit 4 shown in FIG. 3 sets the drive signal Sd to the first drive signal Sd1, and drives the signal inverting the drive signal Sd to the second drive. Let signal Sd2 be used. The first inverting section 45 of the signal calculating section 4 inverts the driving signal Sd to be the second driving signal Sd2.

If the control switching command P1 is 1 in step S115 (step S115, Yes), the flow advances to step S116. In step S116, when the control switching signal P2 is 1 (step S116, Yes), the process proceeds to step S117, where the signal calculating section 4 receives the first driving signal Sd1 from the first logical product calculating section 46. Is outputted to the drive circuit 6, and the second drive signal Sd2 is outputted to the drive circuit 6 from the second AND product.

If Yes in steps S115 and S116, since P1 = P2 = 1, the power saving control is not executed and the stepping motor 30 is driven by the normal control.

If the control switching command P1 is not 1 in step S115 (step S115, No), the process proceeds to step S118. In this case, since P1 = 0, the first AND product 46 of the signal calculating section 4 sets the first driving signal Sd1 to zero. Thereafter, the flow advances to step S117, and the signal calculating section 4 executes the above process. In this case, since the first drive signal Sd1 = 0 and the second drive signal Sd2 = 1, the power saving type control in the case where the direction of the current flowing through the coils 34a and 34b of the stepping motor 30 is-in step S117. Is executed.

If the control switching signal P2 is not 1 in step S116 (step S116, No), the flow advances to step S119. In this case, since P2 = 0, the second logical product calculating unit 47 of the signal calculating unit 4 sets the second driving signal Sd2 to zero.

Thereafter, the flow advances to step S117, and the signal calculating section 4 executes the above process. In this case, since the first drive signal Sd1 = 1 and the second drive signal Sd2 = 0, in step S117, the power saving type control in the case where the direction of the current flowing through the coils 34a and 34b of the stepping motor 30 is + is Is executed.

The sewing machine 70 shown in FIG. 19 is an electronic cycle sewing machine. The electronic cycle sewing machine has a holding frame for holding the fabric on which sewing is made, and the holding frame is moved relative to the sewing needle, thereby forming needle stitches based on predetermined sewing pattern data (sewing pattern) on the cloth held by the holding frame. It is a sewing machine.

Here, the direction in which the sewing needle 78, which will be described later, moves up and down is called the Z axis direction (up and down direction), and one direction orthogonal to this is called the X axis direction (left and right direction), and the Z axis direction and the X axis direction The direction orthogonal to both of is defined as the Y-axis direction (front and rear direction).

The electronic cycle sewing machine 70 (hereinafter referred to as the 'sewing machine 70') is provided at the lower side of the sewing machine main body 71 and the sewing machine table T provided on the upper surface of the sewing machine table T and starts and stops sewing. It is provided on the pedal (R) and the sewing machine table (T) for operating the operation panel 90 and the like for performing the input operation by the user. The sewing machine main body 71 has a sewing machine frame 72 having an approximately C shape when viewed from the side.

The sewing machine frame 72 includes a sewing machine arm portion 72a which forms an upper portion of the sewing machine main body 71 and extends in the front and rear directions, and a sewing machine bed portion 72b which forms a lower portion of the sewing machine main body 71 and extends in the front and rear directions. And a vertical body portion 72c connecting the sewing machine arm portion 72a and the sewing machine bed portion 72b. The sewing machine main body 71 has a power transmission mechanism disposed in the sewing machine frame 72, and has a main shaft and a lower shaft that are rotatable and extend in the front-rear direction. The main shaft is disposed inside the sewing machine arm portion 72a, and the lower axis is disposed inside the sewing machine bed portion 72b.

The main shaft is connected to the sewing machine motor, the rotational force is given by the sewing machine motor. In addition, the lower axis is connected to the main axis through the vertical axis, when the main axis is rotated, the power of the main axis is transmitted to the lower axis side through the vertical axis, the lower axis is rotated. The needle bar 78a which moves up and down in the Z-axis direction is connected to the front end of the said main shaft by the rotation of the said main shaft. At the lower end of the needle bar 78a, the sewing needle 78 is installed to be replaceable. With this configuration, the sewing needle 78 moves in the Z-axis direction in accordance with the rotation of the main shaft. The north side is provided in the front end of the said lower shaft. When the lower shaft rotates together with the main shaft, needle stitches are formed by the cooperation of the sewing needle 78 and the bobbin case.

The sewing machine arm portion 72a moves up and down in conjunction with the shanghai dong of the needle bar 78a in order to prevent the fabric from being lifted along the shanghai dong of the sewing needle 78, and also moves around the sewing needle 78. The center presser foot device which has a center presser foot which presses a cloth downward is provided. Moreover, the main body of the said central presser foot apparatus is provided in the inside of the sewing machine arm part 72a, and the sewing needle 78 is inserted in the through-hole formed in the front end side of the said central presser foot.

The cloth panel 80 is provided on the sewing machine bed portion 72b. The holding frame 81 and the sewing needle 78 as the cloth holding part are arranged above the cloth panel 80. The holding frame 81 is attached to the attachment member 83 disposed at the front end of the sewing machine arm portion 72a.

As shown in FIG. 20, the holding frame 81 has a presser foot 86 and a lower plate 87. The presser foot 86 can be vertically driven in accordance with the driving of the presser foot cylinder disposed in the sewing machine arm portion 72a. With this configuration, the presser foot 86 is held by the cloth between the lower plate 87 at the time of its descending.

The attachment member 83 holding the holding frame 81 is supported on the X-axis rail 75 stored and held in the sewing machine frame 72 through a slide unit. The X-axis rail 75 is supported on the Y-axis rail 76 via a slide unit. With this configuration, the holding frame 81 can move arbitrarily on the X-Y plane through the attachment member 83.

In the sewing machine bed portion 72b, a first stepping motor 30A as an X-axis motor and a second stepping motor 30B as a Y-axis motor are provided as X-Y drive means. The first stepping motor 30A rotates the feed shaft 77 through the gear to convey the timing belt 84 connected to the attachment member 83.

Moreover, the 2nd stepping motor 30B rotates the feed shaft 78 via an umbrella gear, and conveys the timing belt 85 connected to the X-axis rail 75. FIG.

With this configuration, when the first stepping motor 30A and the second stepping motor 30B are driven, the attachment member 83 and the holding frame 81 can be positioned at any position in the XY plane by their cooperation. Can be.

Then, the movement of the holding frame 81 and the operation of the sewing needle 78 and the bobbin are interlocked, so that the needle stitches based on the needle stitching data of the predetermined sewing pattern data are formed in the fabric.

The holding frame 81, the attaching member 83, the first stepping motor 30A, and the second stepping motor 30B have a sewing needle 78 when the needle falls to an arbitrary position with respect to the fabric to be sewn. ) And cloth are functioned as positioning mechanism 91 for relatively positioning in the X-axis direction and the Y-axis direction.

The operation of the 1st stepping motor 30A and the 2nd stepping motor 30B is controlled by the motor control apparatus 1 shown in FIG. By doing so, the first stepping motor 30A and the second stepping motor 30B drive the positioning mechanism 91. Then, the positioning mechanism 91 performs relative positioning of the sewing needle 78 and the cloth.

When the first stepping motor 30A and the second stepping motor 30B are stopped or rotating at a predetermined rotational speed or less, the motor controller 1 performs the power saving type control of the present embodiment described above. Run In the power saving type control of the present embodiment, the power consumption of the first stepping motor 30A and the second stepping motor 30B can be reduced, so that the power consumption of the sewing machine 70 can be reduced.

As mentioned above, in this embodiment, when it is necessary to reduce the absolute value of the electric current which flows through a stepping motor in power saving type control, a gain is made larger than other cases. In this way, the OFF time of the switching element can be lengthened in the PWM control, so that the time for reducing the current flowing through the stepping motor can be sufficiently secured. As a result, the fall of the response when the said current decreases can be suppressed, and the power consumption of a stepping motor can be reduced. Further, in the power saving type control, the drive current value is quickly converged to the current command value, so that vibration of the drive current value is reduced. As a result, vibration of the holding frame of the sewing machine and noise of the stepping motor are reduced.

In this embodiment, by setting the signal calculating section to a microprocessor (for example, a DSP), the gain setting can be automatically changed to an appropriate value in each of the power saving type control and the normal control. By doing so, in power-saving control, it is possible to suppress a decrease in response when the current flowing through the stepping motor is reduced. As a result, the extra current flowing through the stepping motor can be reduced, and thus the power consumption of the stepping motor can be reduced.

In addition, in this embodiment, by using a signal processor as a microprocessor, even if the stepping motor controlled by the signal calculator is changed, it can be changed by software so that an optimal gain may be obtained. In this manner, the present embodiment can realize the optimum stepping motor control without replacing the hardware. In addition, by software-making the signal calculating section, by installing security when reading a computer program in the signal calculating section, the possibility of leaking technical information such as gain setting or internal control to a third party can also be reduced. In addition, when the deviation generating unit of the signal calculating unit is constituted by hardware, it can be constituted by a differential amplifier circuit having an OP amplifier and a resistor. In this case, since the gain is set as the resistance ratio, the power saving type control and other cases It was difficult to change the gain at high speed. In the present embodiment, since the deviation generator of the signal calculation unit is softwareized, it is possible to easily realize power saving control and high-speed change of gain in other cases.

As described above, the sewing machine control device and the sewing machine according to the present invention are useful for reducing power consumption.

1: Motor Control Device (Sewing Machine Control Device)
2: control signal generator
4: Signal calculation unit
6: driving circuit
8a, 8b: current detection circuit
30: stepping motor
30A: first stepping motor
30B: Second Stepping Motor
31: rotating shaft
32: rotor
33: stator
33a, 33b: core part
34a, 34b: coil
40: deviation generator
41: drive signal generator
42: triangle wave generator
43: gain adjustment unit
44: output unit
45: first inverting unit
46: first AND product
47: second logical product operation unit
48: second inverting unit
49: third inverting unit
60: drive circuit
60a: anode side switching element (first anode side element)
60b: Earth side switching element (first earth side element)
60c: anode side switching element (second anode side element)
60d: Earth side switching element (second earth side element)
61a, 61b, 61c, 61d: diode
62: power
63: Earth
70: sewing machine (electronic cycle sewing machine)
78: needle
91: positioning mechanism

Claims (10)

Two anode-side switching elements capable of connecting both ends of the coil of the stepping motor for driving a predetermined operating device of the sewing machine to the anode of the power supply, respectively, and two earth-side switching elements for connecting both ends of the coil to the earth, respectively. A driving circuit having
A control device for a sewing machine having control means for controlling the drive circuit,
Wherein,
A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;
A drive signal generator for generating a drive signal from the current value deviation;
In the case where the driving circuit is controlled to reflux the current flowing from the coil to the coil itself by magnetic induction of the coil, the absolute value of the driving current value is compared with the absolute value of the current command value, and the gain is obtained. Gain adjustment section to adjust
Control device of the sewing machine comprising a. The method of claim 1,
The gain adjustment unit,
And when the absolute value of the drive current value is equal to or greater than the absolute value of the current command value, the control device of the sewing machine increases the gain than when the absolute value of the drive current value is smaller than the absolute value of the current command value. 3. The method according to claim 1 or 2,
And the anode side switching element and the earth side switching element are controlled such that the stepping motor returns a current flowing from the coil to the coil itself by magnetic induction of the coil at a predetermined rotation speed or less. 3. The method according to claim 1 or 2,
And the operating device is a positioning mechanism for relatively positioning the sewing object relative to the sewing needle such that the needle falls to an arbitrary position with respect to the sewing object. A control device of a sewing machine for controlling a stepping motor for driving a predetermined operating device of the sewing machine,
A driving circuit having two anode-side switching elements capable of connecting both ends of the coil of the stepping motor to the anode of the power supply, and two earth-side switching elements connecting both ends of the coil to the earth, respectively;
Power saving control for driving the positive electrode side switching element and the earth side switching element to generate a current command value for the stepping motor and to reflow the current flowing from the coil to the coil itself by magnetic induction of the coil; A control signal generation unit for generating a control switching command for execution;
A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;
A drive signal generator for generating a drive signal for driving the stepping motor from the current value deviation and inputting the drive signal to the two anode side switching elements and the two earth side switching elements;
In the execution of the power saving type control, when the absolute value of the drive current value is greater than or equal to the absolute value of the current command value, the gain is increased more than when the absolute value of the drive current value is smaller than the absolute value of the current command value. Gain adjustment part to enlarge
Control device of the sewing machine comprising a. 6. The method of claim 5,
And the operating device is a positioning mechanism for relatively positioning the sewing object relative to the sewing needle such that the needle falls to an arbitrary position with respect to the sewing object. A stepping motor for driving a predetermined operating device;
A drive circuit having two anode side switching elements each of which can connect both ends of the coil of the stepping motor to an anode of a power supply, and two earth side switching elements each of which can connect both ends of the coil to earth;
A sewing machine having control means for controlling the drive circuit,
Wherein,
A deviation generator which obtains a deviation between a current command value for the stepping motor and a drive current value of a current flowing through the stepping motor, and generates a current value deviation in which the predetermined gain is given to the deviation;
A drive signal generator for generating the drive signal from the current value deviation;
In the case where the driving circuit is controlled to reflux the current flowing from the coil to the coil itself by magnetic induction of the coil, the absolute value of the driving current value is compared with the absolute value of the current command value, and the gain is obtained. Gain adjustment section to adjust
Sewing machine comprising a. The method of claim 7, wherein
The gain adjustment unit,
And the absolute value of the drive current value is greater than the absolute value of the current command value, wherein the gain is made larger than when the absolute value of the drive current value is smaller than the absolute value of the current command value. 9. The method according to claim 7 or 8,
And the anode side switching element and the earth side switching element are controlled such that the stepping motor returns a current flowing from the coil to the coil itself by magnetic induction of the coil at a predetermined rotation speed or less. The method of claim 7, wherein
And the operating device is a positioning mechanism for relatively positioning the sewing object with respect to the sewing needle such that the needle falls to an arbitrary position with respect to the sewing object.

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