JPS628789A - Speed controller of motor of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a drive control device for a sewing machine.

In particular, it concerns starting, stopping, and speed setting.

(Prior Art) Basically, a sewing machine is equipped with a switch for specifying whether to stop the sewing machine motor and a speed regulator in the main body of the sewing machine so as to operate the sewing machine at a desired rotational speed. There is something that functions as shown in the circuit diagram in Figure 4.

In the circuit shown in Figure 4, the desired rotation speed is specified by adjusting the variable resistance for speed adjustment (VRo), and when a switch (Swo) is pressed and operated, the sewing machine rotates or stops each time the switch (Swo) is pressed. Yes.

For each of these operations, the output Q of the T-type flip-flop (FFo) is inverted, and for example, at the first push operation, it becomes H level, and the level of the capacitor (Co) gradually rises with a predetermined time constant.2. Along with its rise, the transistor (
TR) emitter.

As the impedance between the collectors increases, the speed setting output voltage (2) receiving the potential VCC increases, thereby accelerating the sewing machine from a stopped state to the desired rotation speed. The specific number in this case is the resistance (R
), : It is determined by the value of the capacitor (Co), and the resistor (R) is adjusted in a semi-fixed manner so that the desired rotation speed is reached in about 1 second, for example. When the switch (SWo)') is operated in these operating states, a flip-flop (FFO) is activated. t L level is reached, the capacitor (Co) is immediately discharged and the sewing machine is stopped.

(Problems to be solved by the invention) However, in a device that functions as described above,
Start and stop are specified alternately and unconditionally each time the switch (swo) is operated.

In particular, if you operate it to stop it and then accidentally operate it again before it has completely stopped, it will start running again, which is not desirable from a safety standpoint.

Further, since the starting conditions are determined at the time the switch (SWo) is operated, a separate and troublesome operation is required to appropriately adjust the low-speed operation time at the start of sewing.

(Means for Solving the Problems and Their Effects) In the present invention, when a switch is pressed, for example, the state setting means
When the sewing machine is in the stop setting, the machine moves to the drive setting and starts the sewing machine motor at a predetermined low speed, and this low speed is maintained for a certain period of time after the release operation at this time, and then the sewing machine motor is maintained at a specified low speed as specified by the speed regulator. When the acceleration characteristics are set based on the nrs steady speed, the vehicle is accelerated to the steady speed, and then switched to its steady speed operation and in these drive settings.

When the switch is pressed and operated, the machine moves to the stop preparation setting and brings the sewing machine motor to a stop. During the stop preparation setting, re-driving by the switch is prohibited, and the stop transition means sets the time for the sewing machine motor to stop. As the time elapses, the state setting means is shifted from the stop preparation setting to the stop setting, thereby making it possible to start the sewing machine motor by subsequent operation of the switch.

(Example) Embodiments of the present invention will be described based on the drawings.

FIG. 3 is an external view of a sewing machine showing an embodiment of the present invention,
The switch (SWs) is used to alternately specify operation and stop of the sewing machine motor (not shown) each time the switch is pressed, and when the switch is released, it returns to its original state. For ease of operation during sewing, it is provided near the attachment portion of the needle bar (2) on the front surface of the sewing machine body (1). Speed regulator (VR
s) is similarly provided at a suitable location on the sewing machine body (1).
By moving up and down in the figure, you can specify the steady speed of the sewing machine motor to be variable from low to high speed.

FIG. 1 is a control block diagram, and the main parts of the series of controls are functioned by a microcomputer built into the sewing machine body (1).

Flip-flop with reset priority (FF1)
(F'F2) constitutes state setting means, and the flip-flop (FFs) is such that when the control power of this control circuit is turned on, the terminal of the capacitor (C+) in the power-on detection circuit (D3) is The inverter (INs) is at L level during the process of being charged to the positive potential VCC.

It is reset by receiving an H level signal to the reset terminal (R) via the OR circuit (OR+), and then the reset terminal (R) is reset.
When R) is at L level, it is set every time the set terminal (S) receives an H level detection signal from the falling edge detection circuit (DFt), and the flip-flop (FF) is set at H level.
At level, AND circuit (ANDI), OR circuit (
It is similarly reset upon receiving the H-level signal via the H-level signal (ORI). When the switch (SWl) is pressed, the falling edge detection circuit (DPI) inputs a positive potential v.
A drop from Cc to ground potential is detected.

The flip-flop (FF) is reset when the stop signal S8, which will be described later, becomes H level, and is set when the stop signal Ss is L level and the flip-flop (FFI) becomes H level.◎This flip-flop (FFI)
The state in which both (FF2) are at the H level is the drive setting for the sewing machine motor (M), which will be described later, and the state in which the flip-flop (FFl) is at the L level and the flip-flop (FF2) is at the H level is the same as the stop preparation setting. The state in which both flip-flops (FFs) (FF2) are at L level is a stop setting.

The firing angle setting counter (CTs) is preset to the numerical value input to its preset terminal (ps), and when the stop terminal (STOP) receives the stop signal Ss, this nf
When it is at JIH level, the count is stopped and the sewing machine motor (M) is stopped, and when it is at L level, the start terminal (S
TART) accepts the signal from the flip-flop (FF1).

When this becomes H level, its clock input terminal (Cp)
is incremented every time it receives a clock with a period of 80 pS from the oscillator (OSCL), and the value is sent to the output terminal (Q
) is set to 0 by the next clock whose value reaches 255, and at this time, the overflow terminal (OF) generates an H level signal and continues to be incremented from 0. Sewing machine motor drive circuit (DV
) fires a thyristor (not shown) every time this overflow terminal (OF) becomes H level, starts the sewing machine motor (M) and continues driving by full-wave rectification of the 50 Hz AC power supply. That's what I do. The oscillator (
O8Ct) is designed to cover one cycle of the AC power supply with 255 pulses.

When the switch (5w1) is pressed and the flip-flop (FF1) goes to H level, the counter (CT4) to be described later is preset and outputs its output terminal (OF).
goes to the L level, and the stop signal s goes to the L level via the AND circuit (AND,) and the OR circuit (OR2).At this time, the counter (CTs) is immediately started and the sewing machine motor (M ) is started so that in this case the sewing machine rotates at a constant low speed of about 120 rpm. The speed at this time is based on the constant low speed data storage device (DATA).The rising edge detection circuit (I) is connected to the switch (S).
When WI) is pressed and then released, H
Outputs level detection signal. When the switch (SWI) is released, if the flip-flop (FFl) is at H level, the counter (CT2) is connected to the AND circuit (AND3).
The value is initially set to 10G by receiving a preset signal through the n%AND circuit (AND4), and is decremented every time the clock terminal (Cp) receives a clock with a period of 10m5 from the oscillator (O8C2). value is O
In this case, the output terminal (OF) becomes H level, and at this time, the inverter (IN), AND circuit (AND,
) and stop the count via 50H as described below.
1 second is set for the sewing machine motor (M) driven by the commercial power source No. 2. At this time, the speed is the same as that of the above-mentioned startup.
The speed regulator (VRI), based on data from AI), in this case adjusts the sewing machine rotation by approximately 1
It is adjustable in the range from 5 Orpm to 80 Orpm, and an A/D converter (A/D) converts each adjustment data into digital using digital values from 0 to 127 for the analog data in the range.

The reset priority flip-flop (FF3) is used to specify acceleration of the sewing machine motor (M) upon completion of low-speed operation at startup, and is reset when the stop signal Ss is at H level, and when the stop signal S3 is The rising edge detection circuit (DR2) detects the counter (CT
Set when the end of counting is detected. The counters (CTs) are initially set to 0 when the counter (C'h) finishes counting, and the flip-flops (FF
When s) is at H level, it increments every time it receives the clock from the oscillator (OSC, ) via the AND circuit (AND5), and when it takes about 1.3 seconds to count up to 127, the terminal (OF) goes to H level. Then, the inverter (lN
5) to stop counting. During this time, the speed setting data storage device (DATA4) is used to accelerate the sewing machine motor (M) with a predetermined acceleration slope.
The speed data is read out sequentially from . Comparator (
COMP) has its count data and speed regulator (VR
When the count data is smaller than the digital data specifying the speed according to I), an L level signal is output, and when the count data is equal or larger, an H level signal is output. The switching circuit (SEL) receives an L level signal at its gate terminal (G) through the comparator (COMP) or the device that detects the coincidence, and at this time, it passes the output data of the counter (CTs). , the speed setting data is sequentially read out from the speed setting data storage device (DATA2) using this as an address.

The switching circuit (Sl:Lt) also switches the sewing machine motor (M) to the specified steady speed for speed adjustment, and when it receives an H level signal at its gate terminal (G),
Pass the data from the A/D converter (A/D) and use this as an address to store the speed setting data storage device (DATA2).
), the steady speed setting data corresponding to the speed adjustment is read out.

The counter (CT) is connected to the rising edge detection circuit (Dna) when the flip-flop ('FF) becomes H level.
When it detects n, it is preset to the numerical value 120, and AN
It is decremented every time it receives a clock from the oscillator (O8Cz) via the D circuit (AND6), and when the value reaches 0 after two seconds, the output terminal (OF) becomes H level. The inverter (IN4) outputs the counter (CT4) when the flip-flop (FF+) is at H level.
count is prohibited and the output terminal (OF) is held at the L level, and the stop signal S3 is set at the L level when the sewing machine motor (M) is started and during each drive period as described above. The counter (CT4) also presses and operates a switch (SWl) to stop the sewing machine, and a flip-flop (F
FI ) is AND circuit (ANDI).

It becomes L level through the OR circuit (OR+), and if the flip-flop (FF2) is at H level at this time, it starts counting, and when the value becomes 0, the inverter (IN)
5) Stop counting via ・And as described later,
During the count, the sewing machine motor (M) is rotated at a low speed based on the data in the constant low speed data storage device (DATA+) in the same way as at the time of starting.

The switching circuit (sEr, , ) is for switching the rotational speed of the sewing machine motor (M) according to each driving step, and when its gate terminal (G) is at H level, the constant low speed data storage device <DATAI ) data to the counter (C
T1) is output to the preset (ps) input system, and when it is at L level, it is output to the speed setting data storage device (DATA2).
) to output the data in the same way. The gate terminal (G) is connected to the inverter (INs) while the switch (SWt) is pressed to start or stop.
), is at H level via the OR circuit (0R3), and for the starting operation, the inverter (IN, ), the OR circuit (ORs ) and is at H level through the flip-flop (FFl) for stop operation.
The AND circuit (
AND, ), is at H level through the OR circuit (ORs), and is at L level during the drive period due to acceleration and steady speed.
This is the level.

The stop position detector (PHA) closes the reed switch (SW) when the upper shaft (3) of the sewing machine reaches a predetermined rotational phase, for example, when the needle bar (2) reaches the top dead center.

At this time, an AND circuit (
AND2), and during the stop preparation setting, if the counter (CT4) has finished counting and the switch (SWs) is released, the top dead center of the needle bar (2) is reached. At this point, the stop signal S8 is set to H level to stop the current supply to the sewing machine motor (M).

The synchronization signal generator (SYN) is O'w between the terminals of the AC power supply.
Every time the signal reaches the L level, a narrow H level rectangular wave signal is generated between that point in time. Rising edge detection circuit (DR4)
, the falling edge detection circuit (DF2) detects the rising edge and the falling edge, respectively. The speed detector (SD) is located on the upper axis (
When the shielding plate (4) fixed to 3) rotates, the first
90 pulses are generated from a photointerrupter (pT) for rotation. The waveform shaping circuit (SH) shapes the waveform into a rectangular wave. The falling edge detection circuit (DF3) outputs an H level signal every time the falling edge position is detected.

The calculator (ACCI) is for calculating the rotation speed of the upper shaft (3), and outputs the number of pulses of the oscillator (O8CI) per each pulse period generated by the speed detector (SD) as shown below. do. The register (REG) has five storage locations, starting from the time immediately after the AC power supply voltage becomes zero.

Each time the speed detector (SD) generates a pulse, its memory location is advanced by 1 to 5, the count value of the counter (CTs) is stored in each memory location, and the data is transferred to the arithmetic unit (ACCI).
). Counters (CTs) are registers (REG
), and is reset to O every time it receives a detection signal from the falling edge detection circuit (DF2). Each time a detection signal is received, the value is incremented and given to the address designation terminal (A) of the register (REG), and when the value reaches 5, the inverter (
INs) to stop counting. Register (R
EG) transfers the counter value transfer circuit (
The count value of the counter (CTr) at each point in time is received from TR, ) and stored in each address. The constant low speed data storage device (DATAI) and the speed setting data storage device (DATAg) store one pulse period of the speed detector (SD) in accordance with each speed classification as each speed setting data, for example, in the low speed classification. The number of pulses of the oscillator (C8C1) set to hit the hit,
The number 1 indicating that this is for a period l is memorized, and the number of similar pulses and periods to be entered per 2 to 4 pulse periods are memorized as the divisions become progressively faster corresponding. Then, the switching circuit (SELz) calculates the number of cycles combined with the speed setting data to the arithmetic unit (ACCs).
is applied to the gate terminal (Gl) of Every time the arithmetic unit (ACCI) receives the detection signal of the rising edge detection circuit (DB) at the gate terminal (G2), that is, immediately before the AC power supply voltage becomes O, the arithmetic unit (ACCI) stores the previously stored register ( R.E.
G) data is accepted, and at this time the gate terminal (G1
For example, if the number of cycles received by ) is 1, the value obtained by subtracting the data of 1 from the data in storage location 2, that is, the number of pulses for one cycle, is calculated and output, and if the number of cycles is 4, then The value obtained by subtracting the data of 1 (this will be called the latter) from the data of storage location 5 (this will be called the former), ie, the number of pulses for 4 cycles, is output. This means that when calculating the deviation between the speed setting data and the measured speed data using the following method,
By using the same number of pulses even at high speeds,
This is to prevent the accuracy from decreasing. In addition, when the former data is smaller than the latter data during the above-mentioned subtraction calculation, the arithmetic unit (ACCl) uses the counter (CT1).
contains data before and after the overflow, so in that case, the number of pulses for the period is calculated using the formula: 255 - the latter data minus the former data + 1.

Arithmetic unit (ACCz), (ACCs), latch circuit (LA).

The ignition data transfer circuit (TR2) is a counter (CTt)
, arithmetic unit (AC(4), constant low speed data storage device (DA)
T.A.).

Together with the speed setting data storage device (niTAz), etc.

It constitutes a feedback circuit for speed control,
Basically, one application and JP-A-57-1 filed by the same applicant.
This is equivalent to the technology in 93986.

The arithmetic unit (ACC,) receives the speed setting data (expressed in the number of pulses n, which is expressed as the number of pulses, Cs (t)) from each storage device (DATAI) or (DATAz) as the speed target data from the switching circuit (SEL,). (t represents time) is received from the computing unit (ACC,), and the measured speed data (represented by the number of pulses) is expressed as Cn(t).
shall be. Note that n represents the number of cycles of each wave of the full-wave rectified power supply)
Then, the deviation (this n is ΔCn(t)) is calculated using the formula Δ
Cn(t)=Cs(t) Calculate by Cn(t).

The computing unit (ACC3) computes the preset value of the counter (CTI) for each wave cycle of the full-wave rectified power supply to set the firing angle of the thyristor in the sewing machine motor behavior circuit (DV). The calculation is performed by adding the amount of change with respect to the preset value in the cycle before the current cycle. The computing units (ACCs) also output data related to the preset value for computing in the next cycle. Starting point arc angle data storage device (DATA)
3) is for providing a preset value for the counter (CTl) at the beginning of startup.
), and when the stop signal Ss reaches H level, it is output to the latch circuit (LA) (n is the number of pulses τ). The ignition data transfer device (TRz) supplies the data of the latch circuit (LA) to the preset terminal (ps) of the counter (Crt) immediately after the AC power supply voltage becomes zero. Since the counter (Crt) immediately starts counting from its preset value, the time it takes to count from this preset value to 0 next to 255 sets the firing phase of the thyristor. The arithmetic unit (ACCs) receives from the latch circuit (LA) data related to the preset for the arithmetic operation described above (this is the number of pulses τ), and at the beginning of startup, the number of pulses τ.′ is the number of pulses τ. is used as is), and the calculation formula is used as a calculation for each frequency of the full-wave rectified power supply, and as a calculation of the preset value of the number of pulses after the next cycle at startup.

It is calculated by τn=255−(τ4+ΔCn(t)). In this formula, the number of pulses τ is calculated based on the number of pulses τIn-1 fed back from the latch circuit (LA) in the previous cycle, and the calculation formula is τn ='n-t+αΔCn( t)
by. Although detailed explanation will be omitted, in this circuit, the deviation ΔCn(t) acts to approach 0. In addition, α
is the transfer constant.

In this case, 172 is used.

The operation of the above configuration will be explained below.

Referring also to the timing chart in FIG. 2, when the power is turned on at time to, the power-on detection circuit (Ds) is initially at L level, and the stop signal Ss becomes H level via the inverter (INr). The counter (CTl) remains stopped.

The sewing machine motor (M) is stopped. The stop signal S8 continues to be at the L level. and starting point arc angle data from the starting point arc angle data storage device (DATAs). =170
is output, and immediately after the AC power supply voltage becomes 0, it is preset in the counter (CT1). Further, each flip-flop (FFI) (FFz) (FFs) is reset.

When the switch (8Wl) is pressed and operated at time t1, the flip-flop (FFr) (FFz) is set. The counter (CTl) is its start f(STAR)
T) becomes H level and starts incrementing from the count value 170. On the other hand, the gate terminal (G) of the switch (SELz) is connected to the inverter (INa) OR circuit (0R3).
becomes H level through constant low speed data storage device (DA).
The data of TAI) is transferred to the arithmetic unit (AC(4) (ACCz)
and the sewing machine motor (M) is fed to the counter (CTI).
) is initially fired with a firing angle determined by the time counting from 170 to 255+1, and thereafter at a constant low speed set by the data in the constant low speed data storage device (DATA+), in this case, the upper shaft (3) of the sewing machine is approximately Rotates at 12 Orpm.

The counter (CT4) is then preset to 120. At time t2, when the switch (5W1) is released, the counter (CT2) is preset to 100. The counter (CTz) is decremented in response to a pulse from the oscillator (OSC2). meanwhile.

The gate terminal (G) of the switch (SEL2) is connected to the inverter (
IN, ) is at H level through the OR circuit (ORs), and the sewing machine motor (M) continues to rotate at a constant low speed.

When one second has passed from time t2, the counter (c'r2) becomes 0 at time t3, and the switching circuit (SEL) thereafter converts the data in the speed setting data storage device (DATA2) to the arithmetic unit (ACCl) (ACC Meanwhile, the flip-flops (FFs) are set and the counter (
CT3) is initially set to 0 and starts incrementing. The comparator (COMP) compares this count value with digital data of the speed setting by the speed regulator (VR+). Then, when a time corresponding to the difference between the digital data and the lowest setting value of this digital data has passed, the counter value still matches the digital data, but until then, the switch (SEL) is set to the speed setting value. Storage device (DA)
Read speed setting data corresponding to acceleration sequentially according to the counter value from TA, ).

Therefore, the sewing machine motor (M) is accelerated.

When the counter value matches the digital data at time t4, the speed setting data corresponding to the digital data is read out thereafter, and constant speed operation is performed.

At time ts, press and operate the switch (5Wl),
In this case, if the switch remains open at time t@, the gate terminal (G) of the switch (SEL) becomes H level, so that the sewing machine motor (M) uses the data in the constant low speed data storage device (DATAI). The vehicle is operated at a constant low speed based on the following conditions. A flip-flop (FFI) is an AND circuit (AND
I) is reset via the OR circuit (0Rt). The counter (CT4) decrements in response to a pulse from an oscillator (OSC, ). and the counter (c'r4
) until the value of ) becomes 0, the input of the AND circuit (AND, ) is kept at L level, and the output of the stop position detector (PHA) is disabled.

At time t7, 1.2 seconds have elapsed from time t5, the output terminal (OF) of the counter (CT4) becomes level ■.Then, at time tBζ, the stop position detector (PHA)
When becomes H level, the stop signal Ss becomes H level via the inverter (IN?), AND circuit (AND2), and OR circuit (O1'h), and the sewing machine motor (M) stops. The flip-flop (FF, ) (FF, ) is reset. On the other hand, for the next start, the start time arc angle data is outputted from the start time arc angle data storage device (DATAs) as described above.

Next, if the switch (5w1) is pressed at time t9, held for a relatively long time, and then released at time tto, the counter (CTz) will start from the release position. , as shown in Figure 2,
After the constant low speed setting time at startup is extended by that amount, the engine is accelerated at one time to t tsz in the same manner as described above.

If the switch (8 size) is pressed at time tts and released at time 1 'tts after being held for a relatively long time, the counter (CT4) is pressed until release.
Even if the output terminal (OF) of the switch becomes H level at time t14, the output of the switch (SWl) is
Since an L level signal is given to Dz), the output of the stop position detector (PHA) is disabled. And the release point tll! At the subsequent time tts, the stop position detector (
When PHA) becomes L level, the sewing machine motor (M) stops.

At the above-mentioned time tts, after pressing the switch (5W1), the sewing machine motor (M)
If the release and push operation is performed at time tly + txs before the flip-flop (F
Since F'z) is set, the flip-flop circuit (FFs) receives the setting signal and at the same time the AND circuit (AND, ).

Since the reset signal is received via the OR circuit (OR+), it is not set, and therefore there is no transition to the re-rotation command.

(Effects of the Invention) As described above, according to the present invention, at the time of starting, the rotation is at a constant low speed while the switch (W, ) is pressed.
When starting sewing from a curved part, you can use the space between them to sew safely and carefully. Furthermore, since a constant slow speed time is set after the switch is released, the time required to transfer one hand to the cloth is uniformly secured, which is safe. The constant low speed time at the end of sewing can also be selected as appropriate. Furthermore, even if the switch is pressed twice by mistake during a stop operation, it is safe because the restart does not occur.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control circuit showing an embodiment of the present invention;
FIG. 2 is a timing chart of its operation, FIG. 3 is an external view of the sewing machine, and FIG. 4 is a control circuit diagram showing a conventional example. In the figure, (SWt) is a switch, a flip-flop (
FF1) (FF2) is the main element of the state setting means, constant low speed setting data storage device (DATAI) is the main element of constant low speed starting means, (VRl) is the speed regulator, flip-flop (FFs), speed setting data storage device (D
ATAz) is the main element of the acceleration means, the comparator (COM
P), the switching circuit (SELF) is the main element of the switching means,
The counter (CT4) is the main element of the stopping means.

Claims (1)

[Scope of Claims] A switch that is attached to the sewing machine body and is activated every time a predetermined mode of operation is performed, and that returns automatically when the operation is released, and that alternately operates and stops the sewing machine motor for each of the above-mentioned operations. a switch for specifying the setting; and a state setting means for setting the sewing machine motor to continue each state of drive setting, stop preparation setting, and stop setting based on the specification by the switch, the state setting means setting the stop setting. state setting means for receiving an operation signal of the switch and setting the drive setting when the switch is in the drive setting, and setting the stop preparation setting in response to the operation signal when the switch is in the drive setting; a low-speed starting means for starting the sewing machine motor when the switch is activated and driving the sewing machine motor at a predetermined low speed over a predetermined period of time after the switch self-returns; a speed regulator; and an acceleration characteristic is set based on the steady speed specified by the speed regulator, and when the predetermined time by the low speed starting means has elapsed, the sewing machine is operated until the sewing machine reaches the steady speed according to the acceleration characteristic. an accelerating means for accelerating the motor; a switching means for switching the sewing machine motor to maintain the steady speed upon completion of said acceleration; and a switching means for changing over a predetermined period of time after said state setting means specifies said stop preparation. A speed control device for a sewing machine motor, comprising stop transition means for shifting the state setting means to the stop setting.