JPS628785A - Signal generator 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 signal generator for a sewing machine, and more specifically, a main shaft rotatably driven by a sewing machine motor whose speed is variably controlled within a predetermined range; A sewing needle that can reciprocate up and down as the main shaft rotates and can swing in the horizontal direction;
Needle swing data generating means capable of generating needle swing data for controlling the swing position of the sewing needle; Needle fixed position stopping means operable to stop the sewing needle at a needle-up position on the sewing machine bed. The present invention relates to a signal generating device for a sewing machine equipped with a sewing machine.

[Prior Art 1] A conventional sewing machine generates a timing signal that determines the time point at which the needle swing data is generated during each up-and-down reciprocating motion of [1] and a needle-up position signal that indicates the needle-up position. Therefore, two position detectors for detecting two predetermined rotational positions of the main shaft are provided within the main shaft and the sewing machine frame.

[Problems to be Solved by the Invention] Generally, household sewing machines are required to be downsized, and the space within the machine frame is considerably limited. In this narrow space, it is difficult to arrange the two position detectors on the main shaft and the sewing machine frame, and it is also time-consuming to install them. Furthermore, the use of two expensive detectors was disadvantageous in reducing costs.

[Object of the Invention] Therefore, the present invention has been made to solve the conventional problems, and its purpose is to detect the timing signal and the needle top position signal using a single position detector. An object of the present invention is to provide a signal generating device that can generate both signals and facilitate the placement of a position detector in a limited space within a sewing machine frame.

[Means for solving the problem] In order to achieve the above-mentioned object, the signal generating device of the present invention generates either a timing signal or a needle top position signal during each vertical reciprocating movement of the 81 nails. A position detector that detects the predetermined rotational position of the main shaft to generate data, and a time that sets a short time when the sewing machine motor speed is high and a long time when it is low, and generates time data related to the set time. a data generating means; and a timekeeping means that loads time data in response to one signal from the position detector, performs a timekeeping operation for a time corresponding to the time data, and generates the other signal when the timekeeping operation ends. It is structured with the following characteristics.

[Operation] A single position detector generates either a timing signal or a needle-up position signal during each up-and-down reciprocation of the sewing needle. Further, the time data generating means sets a short time when the speed of the sewing machine motor is high, and sets a long time when the speed of the sewing machine motor is low, and generates time data related to the set time. In response to one signal from the position detector, the timer performs a timer operation for a time corresponding to the time data, and then generates the other signal. The operation of this single position detector and timekeeping means generates both a timing signal and a needle top position signal.

Furthermore, since the set time loaded into the timer is changed according to the speed of the sewing machine motor, the rotational phase of the main shaft is almost constant when the other signal is generated, and the rotational phase of the main shaft is almost constant, making it easy to position the swinging position of the sewing needle or fix the sewing needle. Position stop operation becomes stable.

[Embodiment] An embodiment of the signal generating device of the present invention will be described below with reference to the drawings.

FIG. 2 shows the front appearance of a sewing machine in which the signal generating device of this embodiment is adopted. The upper arm 16 extends horizontally from the pillar portion 14. A pattern display board 22 is fixed on the front surface of the upper arm 16 on which are raised the shapes of a large number of patterns and pattern numbers corresponding to each pattern. Four number input keys 26a to 26d, which can be operated to individually set the two-digit pattern number shown on the pattern display board 22, are provided on the front surface of the pillar section 14, and the keys 26a and 26b are used to input the pattern number. Key 2 acts to set the lower digits of the number.
60,266 acts to set the upper digit number. A numeric display 24 is provided on the front surface of the pillar section 14 to display the two-digit pattern number set by the numeric input keys 26a to 26d. Further, a sewing needle 20 is provided at the head of the upper arm 16, and is capable of reciprocating up and down as the main shaft rotates and swinging in the lateral direction.

A start/stop switch 46 that can be operated to start and stop the sewing machine is disposed on the front surface of the head of the upper arm 16.

Next, the electrical configuration of the sewing machine will be explained with reference to FIG.

In order to select a desired pattern from a large number of patterns, a pattern selection device 30 is provided, and the pattern selection device 30 includes the number display 24 and the number input keys 26a to 26d.
The pattern number signal P1 of the selected pattern is output to the data reading device 32.

The position detector 44 is composed of a disk with an IC slit attached to the main shaft and a photointerrupter that detects the slit, and is located at a predetermined rotational position of the main shaft, that is, a predetermined position HA above the bed top surface BS shown in FIG. sewing needle 20
The structure is such that a timing signal TP is generated when the timing signal TP is reached. The data successive device 32 is composed of an address storage device and an address counter. The address storage device generates a leading address signal corresponding to the desired pattern according to the pattern number signal P1, and the address counter generates a start address signal corresponding to the desired pattern in accordance with the pattern number signal P1. It has a structure in which the leading address signal is loaded and, in response to the timing signal TP, the counted contents are advanced and the counted contents are outputted to the stitch data memory 34 as the address signal P2. The stitch data memory 34 stores 41 swing data and feed data regarding all the patterns raised on the pattern display board 22, and when the address signal P2 from the data reading device 32 is input, The needle swing data is output to the needle swing drive circuit 36, and the feed data is output to the feed drive circuit 40.

In this embodiment, the needle swing data generating means is composed of a data reading device 32 and a stitch data memory 34. The needle swing drive circuit 36 is connected to the stitch data memory 3
The needle swing actuator 3 according to the needle swing data from 4.
8. The needle swing actuator 38 is used to set the horizontal swing position of the sewing needle 2o, and for example, a stepping motor is used.

The feed drive circuit 40 also controls the setting of the swing position of the sewing needle 20 according to the feed data from the stitch data memory 34.
The feed actuator 42 is configured to be driven and controlled with a phase difference of 80 degrees. The feed actuator 42 is for setting the adjustment position of a feed adjuster (not shown).

Further, the start/stop switch 46 is constituted by an automatic return type switch that can be pressed, and has a structure that outputs the operation part @P3 to the operation stop command generation circuit 48 when the switch is pressed. The operation stop command generation circuit 48 is configured to alternately generate a high-level operation signal and a low-level stop signal in response to the operation signal P3 from the start/stop switch 46. In this embodiment, the motor control device 50 constitutes a needle fixed position stopping means, and has a speed setting operation section that can be operated to variably set the speed of the sewing machine motor 54 within a predetermined range. The controller is configured to output a control signal @P5 for controlling the speed of the sewing machine motor 54 to the set speed of the operating section, and while a high-level operation signal is supplied from the operation stop command generating circuit 48, the operating section is It outputs a control signal P5, and when a low-level stop signal is supplied, it outputs a control signal P5 in accordance with a low-speed stop signal P6 from a low-speed setter 56, which will be described later. Further, the motor control rIa device 50 is configured to stop outputting the control signal P5 when a needle up position signal NP is supplied from a counter 76, which will be described later. The sewing machine motor drive circuit 52 operates the sewing machine motor 54 and controls its speed in accordance with the control signal P5 from the motor control device 50, and cuts off the power supply to the sewing machine motor 54 when the output of the control signal P5 is stopped. The sewing machine motor 54 is configured to be stopped when the sewing machine motor 54 is stopped.

Since the sewing machine motor 54 cannot be stopped instantaneously even if the power supply is cut off during high-speed operation, a low speed setting device 56 is provided to set a low speed for stopping at which the sewing machine motor 54 can be stopped instantaneously. Low speed signal P for stopping
6 to the motor control device 50 and the comparator 58. Sewing machine motor speed detector 66
detects the speed of the sewing machine motor 54 as an analog quantity, and sends the speed analog signal P7 to the comparator 58 and the Δ/D converter 6.
It is configured to output on days. The comparator 58 compares the low-speed stop signal P6 from the low-speed setter 56 with the speed analog signal P7 from the sewing machine motor 54, and when the speed analog signal P7 is smaller, it outputs a high level signal, and the speed analog signal When P7 is larger, a low level signal is output to the AND circuit 62.

The inverter 60 has a structure that inverts the signal from the operation stop command generation circuit 48 and outputs it to the AND circuit 62. The AND circuit 62 passes the timing signal TP from the position detector 44 and outputs it to the J terminal of the flip 70 knob 64 when the signals from the inverter 60h1 and others and the signal from the comparator 58 are both at high level. It is configured. When the flip-flop 64 receives a rising signal from the AND circuit 62 at its J terminal, it is set and outputs a high-level signal from its Q terminal, and receives a falling signal from the BR terminal of a counter 76 (described later) to its K terminal. When supplied, the Q terminal is reset and outputs a low level signal from the Q terminal. The oscillator 72 uses a crystal oscillator and is configured to output a high frequency pulse signal to the AND circuit 74. The AND circuit 74 operates when the signal from the Q terminal of the flip-flop 64 is at high level.
Passing a high frequency pulse signal from the oscillator 72,
It has a structure in which it is output to the CK terminal of the counter 76. Also,
The A/D converter 68 is configured to convert the speed analog signal P7 from the sewing machine motor speed detector 66 into a speed digital signal P8 and output it to the time setting memory 70. The time setting memory 70 constitutes the time data generation means in this embodiment, and stores a large number of time data signals P9 each corresponding to the content of the speed digital signal P8 from the A/D converter 68. The time represented by the time data signal P9 is set to be short when the speed of the sewing machine motor 54 is high and long when the speed is low. The time setting memory 7° stores the speed digital signal P8.
A time data signal P corresponding to the content when is input.
9 is output to the counter 76. The counter 76 receives a timing signal T from the position detector 44.
When P is supplied to the LD terminal, the time data signal P9 from the time setting memory 70 is loaded, and each time a high frequency pulse signal is supplied to the OK terminal, the count content is decremented by one, and the count content is When the signal becomes zero, the pulse-like needle up position signal NP shown in FIG. Incidentally, in this embodiment, the time measuring means is the oscillator 72. It consists of an AND circuit 74 and a counter 76.

The operation of the sewing machine having the above configuration will be explained.

First, in order to select a desired pattern, number input keys 26a are used.
When the buttons 26d to 26d are pressed, the pattern selection device 30 outputs the pattern number signal P1 for the desired pattern to the data reading device 32, and the data reading device 32 reads the start address signal related to the desired pattern according to the pattern number signal P1. It is output to the stitch data memory 34 as a signal P2. As a result, a group of needle swing data and feed data related to the desired pattern in the stitch data memory 34 is selected.

Next, in order to form the desired pattern, start/stop switch 4
6 is pressed, the operation signal P3 from the switch 46 is supplied to the operation stop command generation circuit 48, and the generation circuit 48 sends a high level operation signal to the motor control device 5.
Supply to 0. The motor control device 550 outputs a control signal P5 for controlling the speed of the sewing machine motor 54 to the speed set by the speed setting operation section to the sewing machine motor drive circuit 52 according to the operating signal, and the drive circuit 52 outputs the control signal P5 to the sewing machine motor drive circuit 52 according to the control signal P5. Controls the amount of power supplied to the sewing machine motor 54. The position detector 4 is driven by the sewing machine motor 54.
4 generates a timing signal TP and supplies it to a data reading device 32 every time the sewing needle 20 reaches a predetermined position HA of 1° as shown in FIG. Address signals P2 for reading each data in the feed data are sequentially supplied to the stitch data memory 34 in response to each timing signal TP. When the stitch data memory 34 receives the address signal P2 from the data reading device 32, it outputs the needle swing data corresponding to the desired pattern to the needle swing drive circuit 36, and sends the feed data to the feed drive circuit 40. Output.

According to the needle swing data, the needle swing drive circuit 36 drives the needle swing actuator 38 to set the horizontal swing position of the sewing needle 20. Further, the feed drive circuit 40 operates according to the feed data and at the setting operation position of the needle swing position (position HB shown in FIG. 3, which has a phase difference of about 180 degrees from the predetermined position 1-(A) in FIG. 3). , feed actuator 42
to set the adjustment position of the feed adjuster. The operation of setting the swing position of the needle and the operation of setting the adjustment position of the feed adjuster are performed every time the sewing needle 20 moves up and down, and by repeating these operations, a desired pattern is formed.゛When the start/stop switch 46 is pressed to stop forming the desired pattern, the operation stop command generation circuit 48 receives the operation signal P3 from the start/stop switch 46 and sends a low level stop signal to the motor control device 50. supply to. When a low-level stop signal is input, the motor control device 50 inputs a low-speed stop signal P6 from a low-speed setting device 56 and outputs a control signal for controlling the speed of the sewing machine motor 54 to a low speed relative to the signal P6. P5 to sewing machine motor drive circuit 52
The drive circuit 52 reduces the amount of power supplied to the sewing machine motor 54 in accordance with the control signal P5.

Thereafter, when the speed of the sewing machine motor 54 drops to the low speed set by the low speed setting device 56, the comparator 58
Speed analog signal P from sewing machine motor speed detector 66
7 is lower than the stop low speed signal P6 from the low speed setter 56, and outputs a high level signal to the AND circuit 62. The AND circuit 62 receives a high level signal from the comparator 58 and a high level signal obtained by inverting the low level stop signal from the operation stop command generation circuit 48 by the inverter 60, and receives the high level signal from the position detector 44.
The state is such that the timing signal TP from the terminal can be allowed to pass through. Then, the sewing needle 20 is placed at a predetermined position H shown in FIG.
When the position A is reached, the position detector 44 outputs the timing signal TP.
is supplied to the J terminal of the flip 70 via the AND circuit 62.

When the timing signal TP that has passed through the AND circuit 62 is input to the J terminal of the flip-flop 64, the flip-flop 70
The knob 64 is set and outputs a high level signal from the Q terminal. The AND circuit 74 is opened by the high level signal and supplies a high frequency pulse signal from the oscillator 72 to the GK terminal of the counter 76 . On the other hand, the speed of the sewing machine motor 54 is detected as an analog value by a sewing machine motor speed detector 66, converted to a digital value by an A/D converter 68, and supplied to a time setting memory 70. Time setting memory 70 outputs time data signal P9 to counter 76 in accordance with speed digital signal P8 from A/D converter 68. The counter 76 is connected to the position detector 44
When the timing signal TP is input, the time data signal P9 from the time setting memory 70 is loaded, and each time a high frequency pulse signal is supplied from the AND circuit 74, the count contents are subtracted one by one. The subtraction operation is performed until the count becomes zero (Ta between the setting sections, not shown in Figure 3).
When the count reaches zero, the counter 76 outputs a high-level needle up position signal NP to the motor ti control device 150 and also outputs it to the 7-lip-flop 64 as a reset signal. The flip 70 knob 64 is the needle up position signal N
P is reset to close the AND circuit 74 and the counter 76 stops counting. Further, the motor control device 50 responds to the needle up position signal NP and sends a control signal P5 according to the low speed signal P6 for stopping from the low speed setting device 56.
The output of the sewing machine motor drive circuit 52 is thereby stopped.
cuts off the power supply to the sewing machine motor 54. At this time,
The sewing needle 20 has reached the position HC shown in FIG. 3 and stops at this position HC.

Sewing machine Tanabata 5 to stop the sewing needle 20 at the needle up position.
4 at a low speed for stopping, a large load is applied to the sewing machine motor 54 due to differences in the number of sheets of cloth to be processed, etc.
The speed of the sewing machine motor 54 may become lower than the low speed for stopping, and this phenomenon causes the sewing machine motor 54 to move at a speed of 9.7).
This is noticeable when not driving under speed control. Therefore, if the speed of the sewing machine motor 54 is lower than the low speed for stopping when the timing signal TP is generated immediately before the sewing needle 20 stops, the sewing machine motor speed detector 66 detects the low speed and The D converter 68 generates a speed digital signal P8 corresponding to a low speed, the time setting memory 70 outputs a time data signal P9 regarding a long setting time according to the speed digital signal P8, and the counter 76 generates a setting shown in FIG. The subtraction operation is performed for a set time Tl (not shown in FIG. 4) which is longer than the time Ta, and thereafter, as described above, when the sewing needle 20 reaches the position HC, the operation of stopping the sewing needle 20 is performed.

In the signal generating device of the present embodiment described above, a single position detector 44 is used to generate a timing signal TP that determines the point in time at which hand swing data is generated, and a time measuring means Accordingly, the assembly position signal NP indicating the needle up position is generated. Therefore, the generation of needle swing data by the timing signal TP is performed accurately at a predetermined rotational position of the main shaft of the sewing machine regardless of the speed of the sewing machine motor 54, but when the needle up position signal NP is generated, the speed of the sewing machine motor 54 changes. There will be some error due to this. However, the generation of the needle top position signal NP is only related to the stopping of the sewing needle and does not directly affect pattern formation, and some errors are allowed in its generation, so in this embodiment, the pattern can be accurately formed. can be formed.

[Modifications] The present invention is not limited to the embodiments described in detail above, and various changes can be made without departing from the spirit thereof.

For example, in this embodiment, the position detector 44 is used to generate the timing signal TP, and the timing signal T
Although the needle up position signal NP is generated from P, the needle up position signal may be generated by a position detector, and the timing signal may be generated from the needle up position signal by a clock means.

In this embodiment, the speed of the sewing machine motor 54 is once set to a low speed for stopping before stopping the sewing needle 20, but the speed of the sewing machine motor 54 is decelerated from variously set high speeds using a brake means. However, the sewing needle may be stopped at the needle-up position. In this case, since the speed of the sewing machine motor fluctuates over a wider range than in this embodiment at the time when the timing signal is generated just before the sewing needle stops, the number of time data signals stored in the time setting memory is determined according to this fluctuation range. need to be increased.

The portion surrounded by a dashed line in FIG. 1 can be partially or entirely replaced by a microcomputer.

In this embodiment, the time setting memory 70 is used as the time data generating means, but a calculating means that calculates the time from the generation of the timing signal to the generation of the needle top position signal according to the speed of the sewing machine motor may also be used. .

[Effects of the Invention] As is clear from the detailed description above, the present invention uses a single position detector and timekeeping means to generate a timing signal and a needle top position signal. Compared to using multiple position detectors, the position detector can be easily placed in the limited space within the sewing machine frame, and costs can be reduced because only one expensive detector is required. .

In addition, since a time f-ta generating means is provided which sets a short time when the sewing machine motor speed is high and a long time when the sewing machine motor speed is low, even if the speed of the sewing machine motor immediately before the sewing needle stops, the The sewing needle can be accurately stopped at a substantially constant above-the-needle position.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a block diagram showing the electrical configuration of a sewing machine equipped with the signal generator of this embodiment, and FIG. 2 is a front view showing the external appearance of the sewing machine. figure,
FIG. 3 is a drawing showing the movement locus of the sewing needle with respect to the bed top surface BS, and the generation points of the timing signal and the needle top position signal, and FIG. 4 is a drawing showing the state where the speed of the sewing machine motor is reduced just before the sewing needle stops. This is a drawing corresponding to .

Claims (1)

[Claims] 1. A main shaft rotatably driven by a sewing machine motor whose speed is variably controlled within a predetermined range, and a main shaft that performs vertical reciprocating motion as the main shaft rotates and is capable of oscillating in the lateral direction. A sewing needle, a needle swing data generating means capable of generating needle swing data for controlling the swing position of the sewing needle, and a needle fixed position operable to stop the sewing needle at a needle-up position on the sewing machine bed. In the sewing machine, the sewing machine is equipped with a stop means, which includes one of a timing signal that determines when the needle rocking data is generated during each up-and-down reciprocating movement of the sewing needle, and a needle-up position signal that indicates the needle-up position. a position detector for detecting a predetermined rotational position of the main shaft in order to generate a signal; and time data related to the set time, which sets a short time when the speed of the sewing machine motor is high and a long time when the speed is low. and a timer that loads the time data in response to one signal from the position detector and generates the other signal after performing a time measurement operation for a time corresponding to the time data. A signal generating device for a sewing machine including means. 2. The signal of the sewing machine according to claim 1, wherein the position detector detects the rotational position of the main shaft corresponding to the point in time when the needle swing data is generated to generate the timing signal. Generator.