JPS6117517B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation command device for controlling the start-up of a motor of a sewing machine, which is equipped with an operator operating means that can be moved toward and away from the outside of the sewing machine frame.

Recently, sewing machines have been used that are equipped with a foot controller as an operator operation means that can be moved in and out of the sewing machine frame. In order to control the speed,
For example, if the sewing machine is powered on and the foot controller is pressed down, that is, the speed command value sent from the foot controller is high, and the controller is connected to the sewing machine, the sewing machine motor will immediately start at high speed. There was a problem in that the machine began to rotate, creating a great danger to workers.

The present invention has been made in view of the above points, and when the sewing machine is connected to the sewing machine body while the operator operating means of the sewing machine is in the operating state, that is, the high speed command value is given to the sewing machine motor, the high speed command value is To provide an operation command device for a sewing machine motor which maintains the stopped state of the motor without giving any noise to the sewing machine motor, and which does not pose a danger to a worker.

To achieve this object, the present invention provides a signal generating means that generates an operation start signal when the operator operating means changes from a non-operating state to an operating state, and a speed command signal and a stop signal set by the operator operating means. and a supply means for selectively supplying the command signal to the power control means of the sewing machine motor, and switching between supplying the speed command signal and the stop command signal to the power control means in response to generation of the operation start signal. It is composed of

Embodiments of the present invention will be described below based on the drawings.

In Fig. 1 showing the external appearance of the sewing machine, reference numeral 1 denotes a foot controller, which has a built-in variable resistor that increases the resistance value when the foot is pressed, and which can be connected to and disconnected from the plug outlet 3 of the sewing machine body 2 via the plug 4. be. 5 is a speed setting switch capable of setting high speed, medium speed, and low speed, and 6 is an automatic return type start/stop switch, which has a contact point ST to be described later. The plug outlet 3 has a plug switch equipped with a contact PL that is turned on when the plug is inserted, and generates a signal SP1 in a connected or disconnected state as means for detecting contact and disconnection of the foot controller 1.

FIG. 2 shows the logic circuit of the operation command device for the sewing machine motor. 7 is an operator operation means having a foot controller 1 and an A/D converter 8;
The input side of the A/D converter 8 is connected to the positive potential side of a power source via a resistor, and is also grounded via a variable resistor of the foot controller 1. The A/D converter 8 is connected to the foot controller 1
An analog signal generated in accordance with the manipulated variable is output as a digital speed command signal SD1. 9 is an encoder that encodes from the speed setting switch; 10 is a read-only memory (ROM) that is addressed by the output signal of encoder 9 and outputs the speed setting signal SD2 stored at that address; 11 is a comparator The speed command signal SD1 output from the A/D converter 8 and the speed setting signal SD2 from the ROM 10
is received at input terminals A and B, and the two signals are compared, and when SD1>SD2, a signal with a logical value of "1" is output.

12 and 13 are multiplexers, respectively, which select port _P2 when the signal input to the port select terminal PTS has a logical value of "1", and select the logical value of "0".
In this case, port _P1 is selected and the signal input to the selected port is output. The port select terminal PTS of the multiplexer 12 is connected via an OR gate 24 so that the output signal of the comparator 11 and the signal SP1 from the contact PL of the plug switch are applied. 14 is a zero speed setting device that outputs a stop command signal SD3 representing a speed setting value "0" to port P2 of the multiplexer 13; 15;
is a control circuit that controls the amount of power supplied to the sewing machine motor M and serves as power control means. Here, the multiplexer 13 selects the stop command signal SD3 from the zero speed setter 14 that commands the stop of the sewing machine motor, that is, the stop command signal SD3 with the speed setting value "0", and the speed command signal SD1 from the foot controller 1. It serves as a supply means for supplying the control circuit 15 with the current.

16 is a JK flip-flop, and when the rising edge of the output signal of OR gate 17 is input to the clock input terminal CK, a logic value "1" is output from the Q output terminal.
Outputs the signal. To the reset terminal RT of the flip-flop 16, a signal SP1 from the contact PL of the plug switch of the plug receptacle 3 and a pulse signal SN, which is output at the same time as the power is turned on and temporarily rises to a positive potential, are applied via the OR gate 18. .

The OR gate 17 is configured as a multi-input OR gate, and when the digital speed command signal from the A/D converter 8 represents the command value "0" (when the foot controller 1 is in a non-operating state), the OR gate 17 has a logical value. If a signal of "0" is output and the speed command signal represents a command value larger than "0" (when operating the foot controller 1), the logical value is "1".
The OR gate 17 outputs an operation start signal whose logical value changes from "0" to "1" as the foot controller 1 changes from a non-operating state to an operating state. It acts as a signal generating means of the present invention.

The Q output terminal of the JK flip-flop 16 is connected to the port select terminal PTS of the multiplexer 13 via an OR gate 19 and a NOT gate 20. The circuit centered around this JK flip-flop 16 starts operation from the OR gate 17 after the connection status signal when the plug 4 of the foot controller 1 is inserted into the plug outlet 3, that is, the signal SP1 becomes a logic value "0". Until the signal is first generated, the multiplexer 13 selects the stop command signal SD3 from the zero speed setting device 14 and sends that signal to the control circuit 15, and in response to the generation of the operation start signal, the speed is adjusted. Command signal SD1 is sent to control circuit 15
This serves as means for switching between the stop command signal and the speed command signal supplied to the motor.

21 is a T-type flip-flop, and the trigger input terminal T is connected to the contact ST of the start/stop switch 6 that applies a rising signal, and the reset terminal RT receives the pulse signal SN at power-on and the contact PL of the plug switch. An inverted signal of signal SP1 is applied via OR gate 22. The Q output terminal of the T-type flip-flop 21 is connected to the control circuit 15 via an OR gate 23. 25 is a multi-input type OR gate that receives the output signal of the multiplexer 13, and 26 is an AND gate, one input terminal of which is connected to the output terminal of the OR gate 25, and the other input terminal connected to the contact of the plug switch. It is connected to receive an inverted signal of signal SP1 from PL, and its output terminal is connected to control circuit 15 via OR gate 23.

A needle position detector 27 generates a home position signal when the sewing needle 30 reaches a predetermined position above the sewing machine bed 31. 28 is a drive circuit for the sewing machine motor M, and 29 is a control circuit for the sewing machine motor. The drive circuit 28 and the brake circuit 29 are shown in circuit diagrams in FIG.

In FIG. 3, the drive circuit 2 of the sewing machine motor M
8 uses two thyristors D ₁ and D ₂ in a single-phase bridge, and controls the conduction angle of the thyristors D ₁ and D ₂ in the rectifier circuit to control the drive of the motor M. Control circuit 1 on the side
A control pulse from 5 is applied.

The braking circuit 29 is a circuit that applies dynamic braking to the sewing machine motor M to stop it.
The trigger pulse from 1 triggers the thyristor D ₅ connected in parallel to the motor M to short-circuit the input terminals of the motor M, and the braking signal is applied from the control circuit 15 to the primary side of the pulse transformer 31. be done. The control circuit 15 sends either a control pulse or a braking signal to the primary side of the pulse transformers 30, 31 in accordance with the speed command signal from the multiplexer 13, the output signal from the OR gate 23, and the fixed position signal from the needle position detector. It is sufficient to selectively supply one of them, and to employ a known speed control circuit having a function of stopping the sewing needle 30 at a fixed position.

Next, the operation of the motion command device according to the present invention will be explained.

First, when the sewing machine's speed setting switch 5 is set to a certain speed and the plug 4 of the foot controller 1 is not inserted into the plug outlet 3 of the sewing machine main body 2, when the sewing machine is turned on, the JK flip-flop 16 is turned on. The T-type flip-flop 21 receives a pulse signal generated when the power is turned on.
It is reset by SN, outputs a signal of logical value "0" from the Q output terminals of both flip-flops, and presses the start/stop switch 6 to operate as follows.

By a series of operations of pressing the start/stop switch 6 and releasing the pressing, the contact ST is temporarily opened, and the trigger input terminal of the T-type flip-flop 21 changes to T from the logical value "0" to "1". When a signal is input, the holding state of the flip-flop 21 is inverted. In this case, flip-flop 21 inverts the signal from its Q output terminal from a logic value of "0" to "1" and instructs control circuit 15 to start sewing machine motor M.

On the other hand, since the foot controller 1 is not connected to the sewing machine body 2, the voltage level at the input terminal of the A/D converter 8 is equal to the voltage level on the positive potential side of the power supply, and the A/D converter 8 is connected to the sewing machine main body 2. A digital speed command signal SD1 is generated in accordance with the voltage level. The speed command signal SD1 represents a very large speed command value, for example, a numerical value equivalent to "150" in decimal notation. The speed command signal SD1 from the A/D converter 8 is sent to the port of the multiplexer 12.
P ₁ , the input terminal A of the comparator 11 and the input terminal of the OR gate 17 are individually supplied. Since the OR gate 17 supplies a signal with a logic value of "1" to the clock terminal CK of the flip-flop 16, the flip-flop 16 continues to output a signal with a logic value of "0" from its Q output terminal without changing its holding state.

Further, since the foot controller 1 is not connected to the sewing machine main body 2, the contact PL of the plug switch is open and generates an output signal SP1 having a logical value of "1". The OR gate 19 receives the output signal SP1 of "1" and the output signal of "0" from the flip-flop 16, and outputs a signal with a logical value of "1".
0 to '0' and multiplexer 1
The signal is supplied to the port select terminal PTS of the multiplexer 13, thereby selecting the port _P1 of the multiplexer 13. The encoder 9 outputs an address signal corresponding to the speed set by the speed setting switch 5 to the ROM.
10 and specify the address, thereby outputting the speed setting signal SD2 corresponding to the set speed.
Output from ROM10. Its speed setting signal SD
2 represents a higher speed setting value as the set speed is higher; for example, in the case of a high speed setting, it is a value equivalent to ``100'' in decimal notation, and in the case of medium and low speed settings, it is a value equivalent to ``7.0'' in decimal notation, Each represents a numerical value equivalent to "30". The speed setting signal SD2 outputted from the ROM 10 is supplied to the port _P2 of the multiplexer 12 and the input terminal B of the comparator 11. As mentioned above, the value of the speed setting signal SD2 is the speed command signal SD1 corresponding to the power supply voltage level.
(corresponding to "150" in decimal number), the comparator 11 outputs a signal with logical value "1", and the output signal is sent to the port select terminal PTS of the multiplexer 12 via the OR gate 24. is applied to select port P ₂ of multiplexer 12, thereby selecting port P ₂ of multiplexer 12.
The speed setting signal SD2, which is the input signal to
SD2 is applied to port P ₂ of multiplexer 13. Here, since a signal with a logical value of "0" is applied to the port select terminal PTS of the multiplexer 13, the port _P1 is selected in the multiplexer 13, and the speed setting signal SD2 is applied to the control circuit 15 of the sewing machine motor M.

Furthermore, as described above, since the control circuit 15 is supplied with the sewing machine motor start command signal (corresponding to the logical value "1") from the OR gate 23,
The sewing machine motor M is driven at a set speed corresponding to the speed setting signal SD2.

When the start/stop switch 6 is pressed to stop the sewing machine motor M in the above driving state, a rising signal is supplied to the trigger terminal T of the T-type flip-flop 21, and the flip-flop 2
1 inverts the holding state and supplies a signal of "0" to the control circuit 15 via the OR gate 23 to instruct the sewing machine motor M to stop. When the control circuit 15 receives a stop command signal from the OR gate 23, it controls the speed of the sewing machine motor M so that it is driven at an extremely low speed, and detects the needle position while the sewing machine motor M is being driven at an extremely low speed. The braking circuit 29 is operated in response to the home position signal output from the machine 27, thereby rapidly stopping the rotation of the sewing machine motor M and stopping the sewing needle 30 at a predetermined position.

Further, in this embodiment, if the foot controller 1 is connected to the sewing machine main body 2 by mistake while the sewing machine motor M is being driven with the foot controller not connected to the sewing machine main body 2,
The “0” signal SP1 from the contact PL is inverted and passed through the OR gate 22 to the T-type flip-flop 21.
is supplied to the sewing machine motor M and resets its flip-flop 21, thereby causing the control circuit 15 to control the sewing machine motor M.
Upon receiving the stop command signal, the sewing needle 30 is stopped at a predetermined position as described above. The above operation is performed when the sewing machine is operated without using the foot controller 1.

Next, if the sewing machine is operated normally through normal use, that is, when the foot controller 1
is inserted into the plug outlet 3 and the foot controller 1 is inserted in a non-operating state, that is, without stepping on it, the variable resistance value of the foot controller 1 is "0", so the input of the A/D converter is The voltage level is "0", so the speed command signal SD1 becomes a signal representing "0" in decimal notation, and the OR gate 17
The output signal of the JK flip-flop 16 has a logic value of "0", and no rising signal is applied to the CK terminal of the JK flip-flop 16, and the flip-flop 16 maintains the reset state, and the signal from the Q output terminal has a logic value of "0". There is. On the other hand, since the contact PL of the plug switch is closed and grounded, the signal SP1 from the contact PL has a logical value of "0". Therefore, since both input terminals of the OR gate 19 are "0", a signal of "1" is given to the port select terminal PTS of the multiplexer 13 via the NOT gate 20, and the multiplexer 13 receives the stop command from the zero speed setter 14. The signal SD3 is selected, and the signal SD3 is applied to the control circuit 15, and the signal SD3 is applied to the OR gate 25. At this time, logical value "0"
The inverted signal of the signal SP1 is sent to the reset terminal RT of the T-type flip-flop 21 via the OR gate 22.
The flip-flop 21 is reset and outputs a logic value "0" signal from the Q output terminal. The T-type flip-flop 21 maintains the reset state as long as the contact PL of the plug switch is closed and the signal SP1 has a logic value of "0". Therefore, the foot controller 1 is connected to the sewing machine body 2.
, the T-type flip-flop 21 supplies a logic value "0" signal to one input terminal of the OR gate 23 regardless of the operating state of the start/stop switch 6.

On the other hand, the OR gate 25 to which the stop command signal SD3 is supplied gives a signal with a logical value of "0" to one input terminal of the AND gate 26, and the other input terminal of the AND gate 26 receives a signal with a logical value of "0". signal
The inverted signal of SP1 is supplied, and therefore, the AND gate 26 gives a signal of logical value "0" to the OR gate 23. Since the OR gate 23 receives a "0" signal at both input terminals, the control circuit 1
A stop command signal (corresponding to logical value "0") for the sewing machine motor M is supplied to the sewing machine 5, so that the sewing machine motor M does not start.

Next, in the above state, the foot controller 1
Let's explain what happens when you step in. When the foot controller 1 is pressed down, a voltage is applied to the input terminal side of the A/D converter 8 at a level that corresponds to the amount of foot pedaling of the foot controller 1, and the voltage from the A/D converter 8 corresponds to the input voltage level. A speed command signal SD1 is output. Upon receiving this speed command signal SD1, the OR gate 17 causes the output signal to rise from the logical value "0" to "1" and applies the rising signal to the clock input terminal CK of the JK flip-flop 16. Then, the JK flip-flop 16 changes the signal from the Q output terminal from "0" to "1" and provides a "0" signal to the port select terminal PTS of the multiplexer 13 via the OR gate 19 and NOT gate 20.

On the other hand, the comparator 11 compares the speed setting signal SD2 outputted from the ROM 10 in accordance with the speed setting operation of the speed setting switch 5 with the speed command signal SD1, and if the relationship SD1>SD2 is satisfied, "1" is set. ” signal is output, and otherwise it is “0”
Outputs the signal. The output signal of the comparator 11 is applied to the port select terminal PTS of the multiplexer 12 via the OR gate 24, but the signal SP
Since 1 is in the state of "0", comparator 11
The output signal of "1" or "0" is directly applied to the port select terminal PTS, and multiplexer 1
2 selects the speed command signal SD1 that enters the port _P1 when it is "0", and selects the speed setting signal SD2 when it is "1". Therefore, the speed command signal corresponding to a certain speed value determined by the amount of depression of the foot controller 1 is compared with the speed setting signal corresponding to the set speed value of the speed setting switch 5, and the speed value represented by the signal is determined. The smaller one, ie the speed value set to the lower speed, is selected in this multiplexer 12, and this signal, SD1 or SD2, is applied to port _P1 of the next multiplexer 13. As described above, the multiplexer 13 selects the signal SD1 or SD2 that enters the port _P1 since the "0" signal is applied to the port select terminal PTS, and applies this to the control circuit 15.

On the other hand, in the OR gate 23 which gives a motor start or stop command signal to the control circuit 15, a signal SD1 or SD representing a numerical value larger than "0" in decimal number is sent.
2 is applied to one input terminal of the AND gate 26 with the OR gate 25 as a signal of logical value "1",
Since the signal SP1 has a logical value of "0", this AND gate 26 is opened via the NOT gate, and a signal of 1 is input to the OR gate 23, so the motor start signal is controlled regardless of the operation of the start/stop switch 6. The sewing machine motor M is driven by the driving circuit 28 at a certain speed based on the speed command signal SD1 or the speed setting signal SD2 applied to the control circuit 15.

The above explanation is about the operation of the embodiment when the foot controller 1 is operated normally, but it is also about the case where the plug 4 is inserted into the plug outlet 3 while the foot controller 1 is depressed (operating state). This will be explained below.

When the foot controller 1 is connected to the sewing machine body 2, a signal from the plug switch contact PL is generated.
SP1 changes from a logical value of "1" to "0" and is supplied to the OR gate 19. Foot controller 1
On the connection side, the JK flip-flop 16 is reset by receiving the signal SP1 of logical value "1" via the OR gate 18, and even if the signal SP1 changes to the logical value "0" when the foot controller 1 is connected, the JK flip-flop 16 is reset. Flip-flop 16 is its clock input terminal.
Since it does not receive a rising signal on CK, it continues to output a signal with a logic value of "0" from the Q output terminal. Therefore, the OR gate 19 receives signals of "0" at both input terminals and supplies a signal of logical value "1" to the port select terminal PTS of the multiplexer 13, thereby causing the multiplexer 13 to select port P2 and select the port _P2 . A stop command signal SD3 representing a base number "0" is given to the control circuit 15. Further, the stop command signal SD3 is supplied to the AND gate 26 as a signal of logical value "0" via the OR gate 25, and the AND gate 26
6 supplies an output signal of "0" to the control circuit 15 via the OR gate 23 to instruct the sewing machine motor M to stop. The stop command status of this sewing machine motor is as follows:
This continues as long as the foot controller 1 is depressed.

When the worker releases the depressed state of the foot controller 1 and depresses it again, the output signal of the OR gate 17 rises from "0" to "1" as in the normal operation of the foot controller 1 described above. , in response to the rising signal, the flip-flop 16 holds the signal state of the input terminal J, that is, the logic value "1" signal, and outputs it from its Q output terminal, and the inverted "0" signal of the output signal is output. Multiplexer 1
3 selects port P ₁ , and that port
Sewing machine motor M is driven according to signal SD1 or SD2 input to _P1 .

When the foot controller 1 is released from the pedal operation to stop the sewing machine motor M which is being driven while the foot controller 1 is connected to the sewing machine main body 2, the speed command signal SD from the A/D converter 8 is released.
1 is a value corresponding to "0" in decimal notation, and the output signal of the comparator 11 is in the "0" state, selects port P ₁ of the multiplexer 12, and selects the speed command signal SD1 input to that port P ₁ . is the port of multiplexer 13 via multiplexer 12
Supplied to P ₁ . Since the JK flip-flop 16 does not receive a rising signal from the clock input terminal CK, it continues to output a signal with a logical value of "1" from the Q output terminal, and the multiplexer 13 selects port _P1 and sends the speed command signal SD1 to the control circuit. 15. Also, since the speed command signal SD1 represents a numerical value equivalent to decimal number "0",
The OR gate 25 sends a signal of logical value "0" to the control circuit 1 via the AND gate 26 and the OR gate 23.
5 to command the sewing machine motor M to stop, and the sewing needle 30 stops at a predetermined position as described above.

In addition, in this embodiment, the foot controller 1
If the foot controller 1 is accidentally separated from the sewing machine main body 2 while the sewing machine motor M is being driven with the controller connected to the sewing machine main body 2, the AND gate 26 will invert the signal SP1 of "1". Upon receiving the signal, an output signal of "0" is supplied to one input terminal of the OR gate 23. The T-type flip-flop 21 is in a reset state before the foot controller 1 is removed, and the holding state of the flip-flop 21 does not change even after the foot controller 1 is removed, so the OR gate 23 receives a "0" signal at both of its input terminals. The control circuit 15 is commanded to stop the sewing machine motor M, thereby stopping the sewing needle 30 at a predetermined position.

In this way, when the foot controller 1 is connected to the sewing machine body 2, the sewing machine motor M cannot be started regardless of whether the start/stop switch 6 is operated or whether the foot controller 1 is already depressed. When the pedal controller 1 is in the connected state, it can be started by pressing the pedal again.

In addition, in the circuit configuration used in the embodiment, a means for selectively supplying the stop command signal SD3 and the speed command signal SD1 to the control circuit 15, and a JK flip-flop 16 that switches these signals in response to the operating state are used. The switching means can also be implemented by being replaced by a microcomputer.

As described above, the sewing machine motor operation command device according to the present invention includes a signal generating means that generates an operation start signal when the operator operation means changes from a non-operating state to an operating state, and a speed generated by the operation start signal. Supply means for selectively supplying the command signal and the stop command signal to the power control means of the sewing machine motor, the supply means supplying the speed command signal and the stop command signal to the power control means in response to the generation of the operation start signal. Since the sewing machine motor is configured to switch, even if a worker presses down on the foot controller and connects it to the sewing machine, the sewing machine motor will not start, but can be started by releasing the foot controller and then pressing it again. Even when the foot controller is connected to the main body, the sewing machine motor does not start rotating and there is no danger to the operator.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view of a sewing machine, FIG. 2 is a logic circuit diagram of a sewing machine motor operation command device, and FIG. 3 is a driving and braking circuit diagram of the sewing machine motor. 1... Foot controller (operator operation means),
3...Plug outlet (connection/separation detection means), 13...
... Multiplexer (supply means), 14 ... Zero speed setting device, 15 ... Control circuit (power control means), 16
...JK flip-flop, 17...OR gate (signal generation means), M...sewing machine motor, SD1...
…Speed command signal, SD2…Speed setting signal, SD3
...stop command signal.

Claims (1)

[Claims] 1. A sewing machine motor, an operator operation means for generating a speed command signal for the sewing machine motor according to the amount of operation, and power supply to the sewing machine motor according to the speed command signal from the operation means. the sewing machine motor and the power control means are housed within the sewing machine frame, the control means is provided outside the sewing machine frame, and the operating means is electrically connected to the power control means. In the sewing machine, the sewing machine is configured to be able to connect and separate when the operating means is in a non-operating state, the operating means being in a non-operating state, the operating means is in a non-operating state; a signal generating means for generating an operation start signal when the state changes from a state to an operating state; and a stop command signal for commanding the stop of the sewing machine motor and a speed command signal from the operating means to be selectively transmitted to the power control means. supplying means for supplying the stop command signal from the time when the connection state signal is generated until the time when the subsequent operation start signal is first generated; An operation command device for a sewing machine motor, comprising switching means for causing a supply means to supply the speed command signal in response. 2. The switching means is set to the supplying state of the stop command signal in response to the detachment state signal from the contact/separation detecting means, and is set to the supply state of the stop command signal in response to the operation start signal from the signal generating means. Claim 1, further comprising a flip-flop circuit set to a state, wherein the supply means supplies either the stop command signal or the speed command signal according to the state of the flip-flop circuit. The operation command device for the sewing machine motor described in .