JPS63200791A - Control 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 [Field of Industrial Application] The present invention relates to a method of controlling a sewing machine, and more particularly to a method of controlling a sewing machine suitable for use in binding futons and the like.

"Prior Art" An industrial sewing machine used for binding futons, etc. has a sewing machine head and a base part equipped with a needle, and a sewing machine that is interposed between the sewing machine head part and the base part and is used for sewing futons, etc. Some have a work table that supports the work to be sewn. This type of sewing machine is configured to move the work table in the X-Y directions on a horizontal plane to sew a large number of patterns on the object to be sewn. And in this kind of sewing machine,
In order to beautifully sew complicated patterns, there are some machines in which the directions of the sewing machine head and base are always aligned with the sewing direction, and this has been effective.

Conventionally, the above-mentioned sewing machine control method includes FTP control (P
A method called 'oint-to-Paint) is generally adopted. This FTP control means, as shown in FIG. 4, that the sewing pattern 20 to be sewn on the object to be sewn is set at a number of points P. pl,...PN
In this method, the point P is divided and inputted, and the point P is sequentially interpolated with a straight line to sew onto the object to be sewn.

"Problems to be Solved by the Invention" By the way, the conventional FTP control is a method of approximating the continuous sewing pattern 20 with a set of many points and connecting these points with straight lines. The pattern of the area will be approximated by a set of many straight lines. In other words, when attempting to sew a sewing pattern consisting of complicated curves,
There is a risk that the pattern sewn onto the object to be sewn will be a pattern that is different from the original sewing pattern and has lost its smoothness.

In order to improve the reproducibility of the sewing pattern on the workpiece, it is possible to shorten the interval between the points, but this requires a huge number of points to be input, so the control mechanism It is necessary to store this huge amount of point data.
It was extremely difficult to realize this goal. - For example, when a thread breakage occurs during sewing, the sewing machine head is moved to the operator's position, and after the thread breakage is taken care of, the sewing machine head is returned to the vicinity of the point where the thread breakage occurred and sewing is resumed. However, in the case of the FTP control, it is not easy to search for the thread breakage point from the input sewing data. This also applies to cases where sewing is started in the middle of the sewing pattern.

Furthermore, if there is a jump feed part in the sewing pattern 20, the direction of the sewing machine head and base after the jump feed cannot be predicted in advance. After moving the workpiece,
It is necessary to align the sewing machine head and base with respect to the sewing direction. Therefore, the time required to align the sewing machine head and base in the sewing direction becomes a time loss.

This invention has been made in view of the above-mentioned problems, and its purpose is to realize a sewing machine control method that can reduce the amount of sewing data that needs to be input and can perform efficient sewing. That's true.

"Means for Solving Problems" The present invention divides a sewing pattern to be sewn onto a workpiece into a plurality of steps, and inputs sewing data for drawing the sewing pattern for each step. In this method of controlling a sewing machine, the sewing machine is controlled and driven in accordance with the inputted sewing data of a plurality of steps, during the sewing of the object to be sewn, the sewing machine corresponds to the sewing data of at least two steps ahead of the step being sewn. The above-mentioned problems are solved by a sewing machine control method that calculates the amount of control and drive.

"Operation" According to the present invention, since the sewing data is divided into multiple steps and inputted, the amount of data to be inputted can be reduced. In addition, since the sewing machine is controlled and the drive amount is calculated in accordance with the sewing data of at least two steps ahead while sewing the workpiece, the rotation of the sewing machine head and base section at least two steps ahead is performed. The direction can be predicted in advance.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 are diagrams showing a sewing machine controlled by a sewing machine control method according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral l denotes a frame of the sewing machine, and a sewing machine head part 2 and a base part 3 are each rotatably attached to this frame l.

A pulley 4 is provided above the sewing machine head section 2 and connected thereto, and a pulley 5 is provided below the base section 3 and connected thereto. Reference numeral 6 denotes a drive shaft for driving the sewing machine needle 7, and a pulley 8 is attached to the upper end of the drive shaft 6. The lower part of the drive shaft 6 passes through the narrow part of the pulley 4 and reaches the inside of the sewing machine head 2, where the horizontal rotational force of the drive shaft 6 is converted into vertical rotational force by a gear mechanism (not shown). The vertical rotational force is transmitted to the input shaft of a crank mechanism (not shown) that moves the sewing machine needle 7 up and down. Further, reference numeral 9 denotes a shaft that is connected to the input shaft of the crank mechanism and rotates as the drive shaft 6 rotates.

A hook portion IO is rotatably housed inside the base portion 3, and a drive shaft 1. l are connected. A pulley 12 is attached to the lower end of the drive shaft 11, similar to the drive shaft 6.

Also, on the side of the sewing machine frame l (right side in Figure 2),
Output shaft 13 of sewing machine motor 26 and head motor 28
An output shaft 14 is arranged. These output shafts 13.1
4 are each fitted with two pulleys 15,16. These pulleys 15.15 attached to the output shaft 13 of the sewing machine motor 26 are connected to the sewing machine head via a belt 17 and a pulley 19.19 fixed to a shaft 18 rotatably attached inside the frame l. 2 and a pulley 5 of the base part 3. Pulley 16.16 of output shaft 14 of head motor 28
are also connected to pulleys 8 and 11 via belts 17 and pulleys 19 and 19.

With the above configuration, the driving force of the head motor 28 is transmitted to the sewing machine head section 2 and the base section 3, and the sewing machine head section 2 and the base section 3 are always rotated so that their directions coincide with the sewing direction. It becomes possible to be driven so that the Similarly, the sewing machine needle 7 and hook portion 10
The driving force of the sewing machine motor 26 is transmitted through the pulley 8.11, and the sewing machine needle 7 and hook portion I
O is now synchronized.

Further, reference numeral 21 denotes a control device, which is comprised of a CPU (central processing unit), an operation program ROM, a RAM in which various data are temporarily stored, and controls the entire sewing machine. Reference numeral 22 denotes a device consisting of a numeric keypad and various function keys, which is used to input sewing data 23 and designate the operation mode of the control device 21. Reference numeral 24 is a display device, which commands the designation of the operation mode of the control device 21;
It also displays the input status of the sewing data 23.

A work table 32 is interposed between the sewing machine head section 2 and the base section 3 to which a workpiece to be sewn is attached. This work table 32 has a motor 3 that drives it in the X direction.
A motor 31 that drives in the 0 and Y directions is attached.

Further, reference numeral 25 is a sewing machine motor drive circuit that drives the sewing machine motor 26 based on a control signal supplied from the control device 21, reference numeral 27 is a head motor drive circuit that drives the head motor 28 based on the control signal, and reference numeral 29 is a head motor drive circuit that drives the head motor 28 based on the control signal. is a work table drive circuit that drives the motors 30 and 3l based on the control signal.

With the above configuration, the driving of the sewing machine motor 26, head motor 28, and work table 32 is controlled by the control device 2l. A motor 3 whose drive is controlled and which is a movement mechanism for the work table 32
0 and 3l are also controlled by this control device 2l, and therefore the movement of the work table in the X-Y direction is controlled. In addition, it becomes possible to sew a large number of patterns on the object to be sewn.

Further, numeral 33 is a pulse encoder that detects the rotation of the shaft 9, numeral 34 is a pulse encoder that detects the rotation of the drive shaft 6, and numerals 35 and 36 are pulse encoders that detect the rotation of the motors 30 and 3l, respectively. be. And these encoders 33, 34, 35, 3
The output pulse No. 6 is converted by the counter 37 into the amount of rotation of each rotating shaft. Here, since the rotation of the shaft 9 corresponds to the vertical movement of the sewing machine needle 7 as described above, the encoder 33
The output pulse corresponds to the position information of the sewing machine needle 7. Similarly, the output pulses of the encoder 34 correspond to the rotation angle of the sewing machine head 2, and the output pulses of the encoders 35 and 36 correspond to the moving distance of the work table 32 in the X-Y direction.

Next, a method of controlling the sewing machine having the above configuration will be explained with reference to FIGS. 1 and 3.

Suppose that a sewing pattern is classified into three steps as shown below. That is, ■Dry feed (straight line, no sewing) ■Straight stitch (straight line, with sewing) ■Curve sewing (circular arc, with sewing). Therefore, the following data is sufficient as the sewing data to be input for each step.

■Sewing speed, pattern start and end point position ■Sewing speed, pattern start and end point position ■Sewing speed, pattern start and end point position, radius of arc, direction of rotation, type of arc (large circle, small circle, or entire circumference) Since the end point position of each step corresponds to the start point position of the next step, even if only the end point position of each step is input, the sewing pattern can be uniquely determined as long as the sewing start position is set. Therefore, data on the starting point position is unnecessary in the data to be input.

Therefore, as shown in FIG.
,S! , etc., and the sewing data for drawing each of the straight lines and circular arcs is input to the control device 21 through the input device 22 according to the items described above. That is, for example, step S.

In step S, the end point position P+ and sewing speed are input, and in step S, the end point position P t , sewing speed, arc radius r1, rotation direction Dt, and type of arc (small circle in this case) are input. At the same time, the sewing start position P. Also enter the information. This means that sewing data 23 corresponding to sewing pattern 20 has been input. Here, the classification of steps as described above is merely an example, and it goes without saying that the sewing pattern 20 may be divided and input using any division method.

Next, in order to sew the sewing pattern 20 onto the object to be sewn,
Sequentially from the sewing data 23 of the first step, the amount of rotation of each sewing machine head 2 corresponding to this sewing data 23,
The amount of movement of the work table 32 and the amount of driving of the sewing machine needle 7 are calculated by the control device 21, and these capacities are stored in the control device 21. Here, the sewing speed for straight stitch is usually faster.
The sewing speed is set higher than the sewing speed for curved stitching, but in order to keep the sewing pitch constant in any part of the workpiece and achieve beautiful seams, the movement amount of the work table 32 and the drive of the sewing machine needle 7 are adjusted. It is important to form a synchronous relationship with the quantity. This synchronization relationship is calculated by a program stored in the control device 21 in advance. Then, the control device 21 outputs the capacity corresponding to the step two steps before the step currently input to the control device 21 to each drive circuit 25, 27, and 29, and the sewing machine motor 2
6. Drive the head motor 28 and motors 30 and 31, thereby starting sewing according to the sewing data 23 of the two previous steps. That is, at the stage when the capacity corresponding to the sewing data 23 of the third step S3 has been calculated by the control device 21, sewing according to the sewing data 23 of the first step S1 is started. In this manner, while sewing the object to be sewn, the control device 21 calculates the sewing data 23 of the step two steps ahead of the step being sewn. Then, the above-described method is repeated to sew the sewing pattern 20 on the object to be sewn according to the sewing data 23.

Here, while sewing the object to be sewn, the control device 21 calculates the sewing data 23 of the next step, so for example, if the next step of the step currently being sewn is a skip feed pattern, When moving to the next step of sewing, the amount of rotation of the sewing machine head 2 in the next step has already been calculated and stored, so the sewing machine head 2 can be rotated during this idle feed. For example, the turning operation of the sewing machine head 2 after the end of the empty feed is not necessary, and the sewing operation time can be shortened.

Further, during sewing of a workpiece, the sewn sewing pattern may deviate from the set pattern due to resistance or the like during sewing of the workpiece. In this case, the drive circuit 2
It is necessary to perform feedback control on 5.27.29. This feedback control method is arbitrary, but as an example, the amount of rotation of each rotating shaft obtained from the encoder 33, 34, 35, 36 is monitored at regular intervals, and the deviation between this amount of rotation and the set value is An example of a control method is to correct the output signal output to the drive circuit 25, 27, 29 based on the correction amount obtained from the above.

By the control method described above, the sewing pattern 20 is sewn onto the object to be sewn. Here, each sewing pattern 20 is
The sewing data 23 is divided into a plurality of steps and input into the control device 21 as sewing data 23, and the sewing machine is controlled based on the sewing data 23 consisting of the plurality of steps.
As for the amount of data to be input, only 2 to 5 data are required for each step as described above. Furthermore, while the sewing object is being sewn, the control device 21 calculates the sewing data 23 for the next step, so that the sewing machine head for the step two steps ahead has already been calculated by the time the sewing starts at the next step. The amount of rotation of the section 2, etc. are calculated and stored, so that the sewing work time can be shortened. Therefore, it is possible to realize a sewing machine control method that can reduce the amount of sewing data to be inputted and can perform efficient sewing.

Furthermore, by moving the sewing start position of the inputted sewing pattern 20, it is possible to repeatedly sew the same pattern on the object to be sewn. By performing calculations such as coordinate transformation in 21, it becomes possible to enlarge or reduce the pattern, or to sew the pattern inside out. Furthermore, if you input the appropriate data when inputting the sewing data 20, it is possible to sew with the sewing machine head 2 pointing in any direction with respect to the seam, so there will be no problem with skipped stitches or problems in the future. Even if the mechanical structure of the sewing machine changes, it becomes possible to take immediate action.

Note that the method of controlling a sewing machine according to the present invention is not limited to the above embodiment. - As an example, this method of controlling a sewing machine is also applicable to a sewing machine configured such that the work table 32 is fixed and the sewing machine head 2 and base 3 are freely movable in the horizontal direction.

"Effects of the Invention" As described in detail above, according to the present invention, a sewing pattern to be sewn onto a workpiece is divided into a plurality of steps, and sewing data for drawing the sewing pattern is In a method for controlling a sewing machine in which the sewing machine is controlled and driven in accordance with sewing data of a plurality of steps inputted for each step, during sewing of the object to be sewn, sewing of at least two steps ahead of the step being sewn is performed. Since we have created a sewing machine control method that calculates the sewing machine control and drive amount in accordance with the data, the amount of data that needs to be input is smaller compared to conventional control methods.
Since the sewing data for at least two steps ahead is calculated while sewing the workpiece, the control and drive amount of the sewing machine for the two steps ahead is already calculated before the next step is started. Therefore, the sewing work time can be shortened. Therefore, it is possible to realize a sewing machine control method that can reduce the amount of sewing data to be inputted and can perform efficient sewing.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a sewing machine controlled by a sewing machine control method that is an embodiment of the present invention, Fig. 2 is a schematic diagram showing the main parts, and Fig. 3 is an embodiment of the invention. FIG. 4 is a diagram illustrating FTP control, which is a conventional sewing machine control method. 23... Sewing data.

Claims (1)

[Claims] A sewing pattern to be sewn onto a workpiece is divided into a plurality of steps, sewing data for drawing the sewing pattern is inputted for each step, and the sewing machine is controlled according to the inputted sewing data of the plurality of steps. , a method for controlling a sewing machine to be driven, wherein, while sewing the object to be sewn, a control and driving amount of the sewing machine is calculated in accordance with sewing data of at least two steps ahead of the step being sewn. A method of controlling a sewing machine characterized by: