JPH07123352B2 - Sewing machine drive controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a sewing machine drive device having functions such as fixed position stop, automatic thread trimming, automatic tie stitch, or pattern stitching,
More specifically, it relates to the rotation speed control of this drive device.

[Constitution of conventional example and its problems] In recent years, in the sewing industry, functions such as fixed position stop, automatic thread trimming, automatic stop stitching, or pattern sewing are performed to improve sewing efficiency and quality by unskilled persons. Raised sewing machines are popular.

When driving these sewing machines, the work rhythm of the worker,
In order to keep the quality of the sewn product constant, the sewing machine must be driven at a constant rotation speed that is unique to each function.
For example, fixed position stop / automatic thread trimming ... 200r.pm automatic backtacking / pattern sewing ... 2,000rpm.

Further, it is often the case that the diameter of the pulley on the motor side is changed or the maximum speed is changed and used depending on the material and work efficiency of the sewn product or the type of sewing machine. However, even in such a case, each of the above-mentioned natural speeds must be constant.

In order to satisfy the above conditions, conventionally, a speed signal generator is provided on the sewing machine side for speed control.

A conventional sewing machine of this type is shown in FIG. In the figure, 1 is a sewing machine,
Reference numeral 2 is called a detector, which generates a rotation speed signal of the rotating shaft of the sewing machine 1 and a signal of the needle position of the sewing machine. 3 is a motor, 4
Is a control device for the motor 3, 5 is a work plate, 6 is a pulley on the side of the sewing machine 1, 8 is a pulley on the motor side, 7 is a belt spanned by pulleys 6 and 8, and 9 is the rotation speed of the motor 3. It's a pedal.

As described above, in the conventional sewing machine drive device, the signal based on the rotation speed of the rotation shaft of the sewing machine 1 is fed back to the control device 4 to control and drive the motor 3. Was trying to get.

Further, when the method of providing the speed signal generator on the motor side is adopted, readjustment for setting each of the above-mentioned inherent speeds is performed by the speed setting device each time the pulley diameter is changed.

However, in the configuration shown in FIG. 1, in order to maintain the performance required as the sewing machine drive device, it was unavoidable that the size of the detector for generating the speed signal became large, and it protruded from the rotary shaft of the sewing machine. Since the signal generator for speed detection is mounted in this state, there is a problem in that different jigs for mounting and detent methods must be considered and mounted for each type of sewing machine.

In addition, the detector for generating the speed signal is attached so as to project from the sewing machine, so that it is easily damaged, and noise is mixed in from the connecting line between the speed signal generator and the control device, or the belt is damaged. There was also a problem that the connection line was cut when touched.

Also, since the pedal depression amount and the sewing machine speed change curve are constant, when the maximum speed is increased by changing the pulley ratio, when the pedal is depressed for the first time, the initial work speed is up to the specified rotation speed. It changed, making it difficult to adjust the speed with the pedal.

Furthermore, recently, a sewing machine that rotates at 10,000 to 12,000 rpm has been developed as a high-speed sewing machine.In this case, if a detector that detects the rotation speed of the sewing machine and generates a signal is attached to the sewing machine from the outside, Functions and performances that can withstand the high rotational speeds mentioned above are required,
The drawback is that the detector becomes expensive.

On the other hand, if the detector for generating the speed signal is provided on the motor side, the above-mentioned drawbacks can be eliminated, but it takes time and effort to adjust each setting member every time the pulley diameter is changed, and a separate speedometer is required. There was also a drawback that

[Object of the Invention] In order to eliminate the above-mentioned drawbacks, the present invention provides a speed signal generator on the sewing machine side with a small shape and structure by providing a detector for generating a main speed signal on the motor side. West,
At the same time, by sharing the signal with other signals, it is possible to achieve better functionality.

[Configuration of the Invention] In order to achieve these objects, in a sewing machine drive control device of the present invention, in a sewing machine drive device that transmits a rotational force of a motor whose speed is freely controllable to a sewing machine through a transmission mechanism, the rotation of the sewing machine is controlled. First detecting means for detecting the position and speed of the shaft, and second detecting means for detecting the rotation speed of the output shaft of the motor.
Detection means, speed control means for controlling the rotation speed of the motor, rotation speed setting means for the motor, and correction means therefor. The correction means includes an output signal from the first detection means. And a signal obtained by combining the output signals from the second detecting means and the output signal from the speed setting means are input, the gear ratio of the transmission mechanism is calculated from the ratio of these two signals, and the gear ratio is set to the speed. The result obtained by multiplying the output signal of the means is used as an output to the speed control means to control the rotation speed of the motor.

As a result, the absolute value of the sewing machine speed can be maintained without impairing the controllability.

[Description of Embodiments] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing an outline of one embodiment of the sewing machine of the sewing machine drive control device of the present invention.

Reference numeral 10 denotes a sewing machine, which is a first detection means for detecting the position or rotation speed of the rotary shaft, and is built in like 11
Alternatively, an external first velocity signal generator such as 12 is provided.

13 is the sewing machine side pulley, 15 is the motor side pulley, and pulley 1
Belt 14 is stretched between 3, 15 and pulley 13 or pulley
The speed ratio can be changed by replacing 15 with a different one.

Reference numeral 16 is a second speed signal generator as second detecting means for detecting the rotation speed of the output shaft of the motor 17.

Reference numeral 18 is a control device including a speed control means, a speed setting device and a correction means.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention.

Regarding the sewing machine drive control device configured as described above,
The operation will be described below.

First, in the present embodiment, the first velocity signal generator 11 or 12
As a fixed position stop control, the position sensor and its signal are used. That is, the speed and position information of the sewing machine are obtained from the cycle of one stroke of the sewing machine (one rotation of the rotary shaft).

The second speed signal generator 16 is a speed signal generator having high responsiveness and sensitivity used for speed control of a normal sewing machine, and together with speed control means by the control device 18, changes in load of the sewing machine and by a sewing machine operator. It provides a speed control function with good performance that faithfully follows the movement of the pedal.

The correction means by the control device 18 obtains the ratio between the rotation speed of the motor and the speed of the rotary shaft of the sewing machine, and multiplies the result by the speed setting signal. In other words, the rotation axis of the motor is 1,000rp
When the gear ratio of the rotary shaft of the sewing machine is 2,000 rpm at m.
Control the speed by halving the speed setting signal.

If the rotation speed of the rotary shaft of the sewing machine is set to 200 rpm, the rotation speed of the motor rotary shaft is halved to 100 rpm.
control to pm.

As described above, according to the present embodiment, by providing the correction means, in speed control such as normal acceleration / deceleration or constant speed operation, the motor-side speed signal generator 16 can provide a fast response, Only the absolute value of the speed of the rotary shaft of the sewing machine can be obtained from the speed signal generator 11 or 12 on the sewing machine side.

Further, as is clear in this embodiment, since the position signal for fixed position stop and the position signal thereof are used with the speed signal generator 11 or 12 on the sewing machine side, it is possible to add a special signal generator. We were able to achieve compactness and simplification. Therefore,
With such a simple position signal generator 12, the structure is simple, the cost can be realized, and the mounting is easy. Further, the position signal generator 11 can be built in without significantly changing the sewing machine, and the reciprocating motion portion other than the rotary motion of the sewing machine can be used for adaptation.

On the other hand, by incorporating the second speed signal generator 16 on the motor side into the motor, the mixing of noise can be reduced and the bearing can be shared with the motor. Moreover, since the speed of this rotating portion increases only up to the rotation speed of the motor, the structure is simple and can be realized at low cost.

As a second embodiment, the first speed signal generator 11 or 12 and the second speed signal generator 16 of the above-described embodiment are used to generate one or more first speed signal per revolution. The second velocity signal generator may be composed of a signal generator that generates more pulses than the pulse generator. According to this configuration, the correction value is determined by counting the number of pulses of the motor side signal during one cycle of the sewing machine side signal. Therefore, the speed until the correction value is determined need not necessarily be constant, and even if the speed is stopped or moving midway, the correction value is always determined by one cycle of the sewing machine side signal regardless of such a state. There is.

As a third embodiment, as shown in FIG. 3, only the second speed setting device using a pedal may be directly connected to the speed control means without passing through the correction means.

Thus, by removing only the pedal-based speed setting device from the correction means, the relationship between the pedal depression amount and the change in motor speed can be kept constant at all times. Therefore, no matter how the gear ratio is changed, there is an advantage that the entire depression amount of the pedal can be effectively used for adjusting the sewing machine speed.

As a fourth embodiment, in the above-mentioned three embodiments, the correction means is provided with an initial value in advance.

Generally, since the response of the speed signal on the sewing machine side is worse than that on the motor side, the correction value during the first about one revolution becomes infinite, and the sewing machine becomes the highest speed, which is dangerous. , In this case, by giving an initial value, it will be corrected by the initial value until the normal correction value is determined, and it is possible to avoid that the rotation speed of the motor becomes the maximum speed in the initial stage. Can perform safe work.

[Effect of the Invention] The first speed signal generator 11 or 12 is provided on the sewing machine side, and the second speed signal generator 16 is provided on the motor side, and correction means is provided to compare these signals and correct the set speed. As a result, the speed signal generator on the sewing machine side can be downsized and simplified, and its practical effect is remarkable.

[Brief description of drawings]

FIG. 1 is a perspective view showing a conventional sewing machine and a sewing machine drive device, FIG. 2 is a schematic view of one embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of another embodiment. Is. 10 ... Sewing machine, 11 ... Built-in first speed signal generator, 12
...... Externally attached first speed signal generator, 13 …… Sewing machine side pulley, 14 …… Belt, 15 …… Motor side pulley, 16 ・ ・ ・
… Second speed signal generator, 17 …… Motor, 18 …… Control device

Claims (4)

[Claims] 1. A sewing machine drive device for transmitting the rotational force of a speed-controllable motor to a sewing machine via a transmission mechanism, comprising: first detection means for detecting the position and speed of a rotary shaft of the sewing machine; The second detection means for detecting the rotation speed of the output shaft, the speed control means for controlling the rotation speed of the motor, the rotation speed setting means of the motor, and the correction means thereof are provided, and the correction means includes: A signal obtained by combining the output signal from the first detection means and the output signal from the second detection means and the output signal from the speed setting means are input, and the speed ratio of the transmission mechanism is calculated from the ratio of these two signals. And controlling the rotation speed of the motor by using the result obtained by multiplying the output signal of the speed setting means by the gear ratio as an output to the speed control means. 2. The first and second detecting means, during one revolution of each of the rotary shaft of the sewing machine and the output shaft of the motor,
The sewing machine drive control device according to claim 1, further comprising a signal generator that generates a plurality of pulses, respectively. 3. The sewing machine drive control device according to claim 1, further comprising a second speed setting device directly input to the speed control means. 4. The sewing machine drive control device according to any one of claims (1) to (3), wherein the correction means comprises an initial value setting means.