JPS6088585A - Controller 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 [Technical Field of the Invention] The present invention relates to a control device for a sewing machine, and particularly to a load control device.

[Prior art]

An example of a conventional sewing machine control device is shown in FIG. 1 and will be described. In the figure, 1 is a sewing machine control device.

2 is a drive device for driving the sewing machine, 3 is a mode of the sewing machine, 4 is a sewing machine, and 5 is a device that is attached to the rotating shaft of the sewing machine 4 and detects the upper or lower position of the sewing machine 4 and the rotational speed of the sewing machine 4. It is a detector.

Note that CS is a speed command given to the control device 1, CL and BK are clutch signals and brake signals, and PG is a speed detection signal supplied to the control device 1 from the detector 5.

A driving device 2 for driving the sewing machine, a braking means for braking or stopping the sewing machine, a control device 1 for controlling the sewing machine 4 by controlling these driving devices and the braking means, and a needle for the sewing machine 4. The sewing machine includes a detector 5 which detects the upper or lower position of the sewing machine and generates a signal corresponding to this detected position, and a detector 5 which detects the rotational speed of the sewing machine 4 and generates a signal corresponding to the rotational speed of the sewing machine.

In the control device 1 for the sewing machine configured as described above, first, when a speed command C8 is given to the control device 1 from the outside, the control device 1 compares the speed detection signal PG from the detector 5 with the speed command CS. do.

Next, the control device 1 outputs the V-skin difference between the two, and controls the rotational speed of 47740 to a speed corresponding to the speed command C8 by controlling the trigger or brake of the mode model 3 via the drive device 2. The moder 3 always rotates and performs speed control by connecting the clutch or the brake.

However, in such a control system for a sewing machine, the time constant of the clutch coil or brake coil in mode 3 is large, and the control system shown in Fig. 1 is also affected by dead time, resulting in load fluctuations and clutch current fluctuations. In some cases, it has been impossible to follow sudden changes in load torque as shown in FIG. 2, which is an explanatory diagram showing the relationship.

In FIG. 2, the horizontal axis represents time t, and the vertical axis 111 represents torque TQ.

It is expressed by taking the clutch current Ic, 8 indicates torque fluctuation), and b indicates the clutch current.

Now, let b be the clutch current corresponding to the two-point torque shown in a.
If the peak point of the load torque, such as point P, is momentarily busy, the clutch current shown in b becomes P'.
By the time the load torque is about to rise to ', the peak of the load torque has already passed.

As described above, the conventional engine control device is unable to follow the instantaneous fluctuation pressure of the load torque.

Another disadvantage is that speed fluctuations occur, and in the worst case, the sewing machine stops.

[Summary of the invention]

In view of the above points, the present invention has been made to solve such problems and eliminate such drawbacks.The purpose of the present invention is to provide a sewing machine that can cope with rapid load changes and that can be controlled with high precision. An object of the present invention is to provide a city IJ control device. In order to achieve such an object, the present invention extracts the characteristics of the load torque from the load torque fluctuation detection signal from the detector, stores it and reads it out during operation. A feature extraction device is provided, and the control device is equipped with a function of predicting load fluctuations.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below based on one drawing.

FIG. 3 is a block diagram showing an embodiment of the 1tlll'l device of the sewing machine according to the present invention, and only the parts necessary for explanation are shown.

In FIG. 3, the same number 41 as in FIG.
Extract and store the load torque characteristics from the speed detection signal 'Ij l' G from j? 7 is a changeover switch connected to the feature extraction device 6 and used to switch between the learning mode and the driving mode.
This changeover switch T is configured to enter the learning mode when the switch is on.

Next, the operation of the embodiment shown in FIG. 3 will be explained. First, let us assume that load fluctuations as shown in FIG. 2 occur only in special cases such as thread cutting operations.

Since the thread cutting operation is normally performed during a half-turn of the sewing machine from the lower position to the upper position, hereinafter, it is assumed that the feature extraction device 6 operates only during this half-turn.

The operation starts when a thread cutting command (not shown) is input to the control device 1.

Now, consider the learning mode in which the selector switch 1 is turned on. Actually, a thread trimming command is given to make the sewing machine 4 turn half a turn, and the information is sent to the controller 1 through the detector 5, which has both the function of detecting the rotational speed of the torque pickup and the function of detecting the lower or upper position of the sewing machine needle. input. and,
Within the control device 1, the waveform of this load torque fluctuation is sampled at a constant period T, and the time and torque value are stored in a storage device (not shown) within the control device 1.

The format of this memory is shown in the table below.

And the torque a in this table. ＋”l・・・・・・
an is expressed as follows.

In this table, it is assumed that the thread trimming process ends when 5 hours nT have elapsed. Furthermore, the same operation is repeated several times to accumulate data as shown in the table above. Here, this number of times is set in the control device 1 in advance.

Then, the torque value at the first time 0 is a6',
Torque value at second time 04. It is expressed as ♂ and the number of repetitions is m. Then, the average value of m times in each time is a. ...a...
... aI, -1 ... ao.

When this calculation is completed, the control device 1 transfers the data and time shown in the table above to the feature extraction device 6. Then, the changeover switch 7 is turned off and the operation mode is set.
When the control device 1 detects that a thread trimming command has been input, the control device 1 reads out the data in the feature extraction device 6 and extracts the data required for each sampling period T from the time the thread trimming command is input. Since the current corresponding to the torque that is generated can be supplied in advance by taking into consideration the time constant of the clutch coil, it is possible to substantially shorten the dead time, and the current corresponding to the sudden torque shown in Figure 2 can be supplied in advance. It can also respond to fluctuations.

The above explanation is based on the case where the present invention is applied to one sewing machine, but it is not guaranteed that the present invention is applied to one sewing machine, but there are several types of switching switches for selection. It is also possible to respond by memorizing the characteristics of the sewing machine and changing the switch depending on the model of the sewing machine.

〔Effect of the invention〕

As is clear from the above explanation, according to the unexploded QIJ,
A simple configuration in which the IIJ control device of the sewing machine has the function of extracting load torque characteristics can respond to sudden load fluctuations and perform highly accurate control without using complicated means. ); Therefore, the practical effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional sewing machine control device, FIG. 2 is an explanatory diagram showing the relationship between load fluctuation and clutch current to explain the operation of FIG. 1, and FIG. 3 is a block diagram showing an example of a conventional sewing machine control device. It is a block diagram showing one example of four baits one device. 1...control device, 2...drive device, 3...
Model, 4... Sewing machine, 5... Detector, 6...
... Feature extraction device, 7... Changeover switch. Agent Masuo Oiwa Figure 1, Figure 2, Figure 3, Wow, sleeve +Ii,'i (spontaneous)! 'l C
11'i 2G lIt+ill Year Month 1 Meal: 3. Section 5, Detailed Description of the Invention of the Specification Subject to Amendment, to be amended (1) Amend the "Table" on page 7 of the specification as shown in the attached sheet. (2) Correct "like" in the bottom five lines of the same page of the same book to "like". that's all

Claims (1)

[Claims] A drive device for driving the sewing machine, a braking means for braking or stopping the sewing machine, and a control device for controlling the sewing machine, and a control device for controlling the sewing machine, and a braking means for braking or stopping the sewing machine. In a sewing machine equipped with a signal that detects the lower position and generates a signal corresponding to the detected position pressure, and a detector that detects the rotational speed of the sewing machine and generates a signal corresponding to the rotational speed of the sewing machine, the load torque from the detector is 1. A control device for a sewing machine, comprising: a feature extraction device that extracts and stores characteristics of load torque from a fluctuation detection signal and reads them out during operation; and the control device has a function of predicting load fluctuations.