JPS62277990A - Control method 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 3. Detailed Description of the Invention ``Industrial field +11 This 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 machines include a work table that supports the workpiece 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. In order to sew complex patterns beautifully, some sewing machines of this type have a system in which the direction of the sewing machine head and base are always aligned with the sewing direction, which is highly effective. .

FIG. 2 is a diagram showing the conventional sewing machine.

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

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 axial center 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 or the like (not shown). This 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 driving saw shaft 11 that extends downwardly through the shaft center of the Ha2 pulley 5 is connected to the lower portion of the hook portion IO. There is. 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),
An output shaft I3 of a sewing machine motor and an output shaft 14 of a head motor (not shown) are arranged.

Each of these output shafts 13 and 14 has a pulley 15 on the second side.
．． 16 is attached. Sewing machine motor output shaft I
These pulleys 15.15 attached to the sewing machine head 2 are connected to the pulleys 4 and 3 of the sewing machine head 2 via a belt 17 and a pulley 19.19 fixed to a saw shaft 18 which is pivotably attached to the inside of the frame l. It is connected to a pulley 5 of the base part 3. Pulley 16 of the output shaft 14 of the head motor, I6, belt 17, pulley 19.1
It is connected to pulley 8 and pulley 11 via 9.

With the above configuration, the driving force of the head motor 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 in the same direction as the sewing direction. It can also be driven to Similarly to Mako, sewing machine needle 7 and hook part 10
The driving force of the sewing machine motor is transmitted through pulleys 8 and 11, and the sewing machine needle 7 and hook portion 10 are synchronized.

A work table (not shown) on which a workpiece to be sewn is attached is interposed between the sewing machine head part 2 and the base part 3, and the work table has an X-Y position on the horizontal plane of the sewing machine.
A moving mechanism (not shown) is provided for freely moving it in directions (left and right in FIG. 2 and a direction perpendicular to the plane of the paper). Further, the driving of the sewing machine motor and the head motor is controlled by a control mechanism shown in the figure, which controls the rotation of the sewing machine head section 2 and the base section 3, and the driving of the sewing machine needle 7 and hook section 10. At the same time, the drive of the movement mechanism of the work table is also controlled by this control mechanism, and therefore the movement of the work table in the X-Y direction is controlled.As a result, a large number of patterns are sewn on the workpiece. becomes possible.

Conventionally, the above-mentioned sewing machine control method includes FTP control (P
A method called a1nt-to-Pa1nt) 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, .

"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 part 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 fear that the pattern sewn on the object to be sewn will be different from the original sewing pattern and will be a pattern that 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 was necessary to store this enormous amount of point data, and it was extremely difficult to accomplish this. - For example, when a thread breakage occurs during sewing, the sewing machine head 2 is moved to the operator's position, and after the thread breakage is taken care of, the sewing machine head 2 is returned to the vicinity of the point where the thread breakage occurs and the sewing is continued. However, in the case of the FTP control,
It is not easy to search for the thread breakage point based on the input sewing data. This also applies to the case where sewing is started in the middle of the sewing pattern.

This invention has been made in view of the above-mentioned problems, and its purpose is to sew a complicated sewing pattern onto a workpiece with good reproducibility, and to reduce the amount of sewing data that must be input. The objective is to realize a control method for a sewing machine that is possible.

``Means for Solving the Problems'' The present invention provides a method for controlling a sewing machine for performing pattern stitching on a workpiece according to set sewing data, in which a sewing pattern to be sewn on the workpiece is sewn in a straight line and The sewing machine is divided into a plurality of steps consisting of a combination of circular arcs, and the sewing data for drawing the straight line or circular arc is input, and the sewing machine control unit controls the rotation axis of the sewing machine and the sewing machine drive according to the input sewing data of the multiple steps. Calculating the driving amount of the axis and the moving amount of the moving means in order from the sewing data of the first step, and controlling the turning axis, the sewing machine driving shaft, and the moving means according to the driving amount and the moving amount,
The above-mentioned problem has been solved by configuring a control method for a sewing machine that drives the sewing machine.

Here, it is desirable that the sewing machine head, the sewing machine needle, and the moving means be provided with a detection means for detecting the amount of movement thereof. Further, while sewing the object to be sewn, it is preferable that the sewing machine control section calculates sewing data of at least two steps ahead of the step of the sewing upper.

"Function" In this invention, sewing data is input as a combination of straight lines and circular arcs, so the movement of the sewing machine head and work table becomes smooth, and the amount of data to be input can be reduced.

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

FIG. 1 is a diagram showing a sewing machine controlled by a sewing machine control method according to an embodiment of the present invention, and parts corresponding to those shown in FIG. 2 are given the same reference numerals.

In FIG. 1, reference numeral 21 is a control device (sewing machine control section)
, CPU (Central Processing Unit), operating program RO
It is comprised of a RAM, etc., in which M and various data are temporarily stored, and controls the entire sewing machine. Reference numeral 22 performs input to the device 3, which is composed of a numeric keypad and various function keys, and designation of the operation mode of the control device 2l. Reference numeral 24 denotes a display device, which commands and displays designation of the operation mode of the control device 2l, and also displays sewing data 23.
The input status is displayed and the input status is displayed.

Next, 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, and numeral 27 is a head motor drive circuit that drives the head motor 28 based on the control signal. Reference numeral 29 is a work table drive circuit that drives motors 30 and 31 based on the control signal, the motor 30 drives the work table 32 in the X direction, and the motor 31 drives the work table 32 in the Y direction. In the above configuration, the work table drive circuit 29 and the motors 30, 31 constitute a moving means for freely moving the work table 32 in the horizontal direction.

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 driving shaft 6, and numerals 35 and 36 are pulse encoders that detect the rotation of the motors 30 and 31, respectively. . And these encoders 33.34.35.36
The output pulses are 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 output pulse of the encoder 33 corresponds to the position information of the sewing machine needle 7. Similarly, the output pulse of the encoder 34 is the rotation angle of the sewing machine head 2, and the output pulse of the encoder 35 and 36 is the rotation angle of the work table 3.
This corresponds to the moving distance in the XY direction of No.2. In the above configuration, the pulse encoders 33, 34, 35, 36 and the counter 37 are connected to the sewing machine head section 1. It constitutes a detection means for detecting the movement amount of the sewing machine needle 7 and the movement means.

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

Any sewing pattern can basically be classified into the following three steps. 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. 3, the sewing pattern 20 is created by several step
1, S2, etc., and the sewing data for drawing each of the straight lines and circular arcs is sent to the control device using the input device 22 according to the above-mentioned items. Enter 2+. That is, for example, in step S1, the end point position P, 7 & sewing speed, and in step S2, the end point position P2, sewing speed, arc radius r7, rotation direction D2, arc type (
In this case, enter a small circle). At the same time, the sewing start position P. Also enter the information. This allows the sewing bag to be
This means that the sewing data 23 corresponding to 720 has been input.

Next, when the sewing pattern 20 is sewn onto the workpiece, the amount of rotation of each sewing machine head 2 and the amount of movement of the work table 32 corresponding to the sewing data 23 of the first step are sequentially determined from the sewing data 23 of the first step. and the driving amount of the sewing machine needle 7 are calculated by the control device 21, and each of these values is stored in the control device 21. Normally, the sewing speed for straight stitches is set faster than the sewing speed for curved stitches, but in order to achieve beautiful seams by keeping the sewing pitch constant in all parts of the workpiece, It is important to form a synchronous relationship between the amount of movement of the work table 32 and the amount of drive of the sewing machine needle 7. This synchronization relationship is established in advance by the control device 21.
Calculated by a program stored in Then, the control device 21 selects each member corresponding to the step two steps before the step currently input to the control device 21.
Output to each drive circuit 25, 27, 29 to drive sewing machine motor 26, head motor 28, motor 30, 31,
As a result, sewing according to the sewing data 23 of two steps is started. That is, when each member corresponding to the sewing data 23 of the third step S has been calculated by the control device 21, sewing according to the sewing data 23 of the first step S is started. In this manner, while sewing the object to be sewn, the control device 2I 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. The method of this feed bank control 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 amount of rotation and the set value are An example of a control method is to correct the output signal output to the drive circuit 25, 27, 29 using the amount of correction obtained from the deviation.

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 consisting of a combination of straight lines and circular arcs 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. 2,
The movement of the work table 32 becomes smooth, and the amount of data to be input is only 2 to 5 data for each step as described above. Therefore, it is possible to realize a sewing machine control method that can sew a complex sewing pattern on a workpiece with good reproducibility and can suppress the amount of sewing data to be input.

Furthermore, by moving the sewing start position of the inputted sewing pattern 20, it is possible to repeatedly sew the same number of turns on the workpiece, and also to move the inputted sewing pattern 20 to the sewing position described above. By performing calculations such as coordinate transformation within the control device 21, the pattern can be enlarged, reduced,
It is also possible to sew the reverse side of the pattern. 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. - For example, this method of controlling a sewing machine is applicable to a sewing machine having a structure in which the work table 32 is fixed and the sewing machine head section 2 and head section 3 are freely moved in the horizontal direction. Further, the method of inputting the data is not limited to the above embodiment, and for example, the types of data for drawing a circular arc may be the center and curvature of the circular arc, and the rotation direction.

"Effects of the Invention" As described in detail above, according to the present invention, in the method for controlling a sewing machine for performing pattern stitching on a workpiece according to set sewing data, The sewing pattern consists of a combination of straight lines and circular arcs; it is divided into several steps, and sewing data for drawing circular arcs instead of straight lines is input, and the sewing machine is controlled according to the input sewing data for the number of steps. The section calculates the rotation axis of the sewing machine, the drive amount of the sewing machine drive shaft, and the movement amount of the moving means in order from the sewing data of the first step, and calculates the movement of the rotation axis, the sewing machine drive shaft, and the movement according to the drive amount and movement amount. Since we have constructed a control method for the sewing machine that controls and drives the sewing machine, the movement of the sewing machine, sewing machine, and workpiece table is smoother, and the amount of data that needs to be input is reduced compared to conventional control methods. Less is enough.

Therefore, it is possible to realize a method of controlling a sewing machine that can sew a typical sewing pattern on a workpiece with good reproducibility and can reduce the amount of sewing data that needs to be input.

Further, when the sewing machine head, the sewing machine needle, and the moving means are provided with a detection means for detecting the amount of movement thereof, the amount of movement is monitored during sewing of the object to be sewn, and a zero value is set according to the amount of movement. It is possible to detect the deviation between the sewing pattern and the sewing pattern currently being sewn. Therefore, by using this amount of deviation to perform feedback control of the sewing machine head, etc., it is possible to sew a sewing pattern with better reproducibility.

Further, when the sewing machine control section calculates sewing data for at least two steps ahead of the step being sewn while sewing the object, the sewing work time can be shortened.

[Brief explanation of drawings]

Fig. 1 is a schematic 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. 2...Sewing machine head part, 3...Base part, 4.5...Pulley (swivel axis), 6...
・Drive shaft (sewing machine drive M), 21...control device (sewing machine control section), 23...sewing data,
Two... Work table drive circuit, 30.31...
・Motor (2 above, 30.31 is a means of transportation), 33
．． 34.35.36...Pulse encoder, 3
7... Counter (33.34.35.3
6.37 is a detection means).

Claims (3)

[Claims] (1) Two pivot shafts provided on the sewing machine head and the base, respectively, for aligning and horizontally rotating the sewing machine head and the base, and a sewing machine needle provided on the sewing machine head that can freely move up and down. a sewing machine drive shaft that transmits the driving force of the sewing machine motor to the sewing machine; a work stand interposed between the sewing machine head and the base and to which the workpiece is attached; A sewing machine comprising a moving means for freely moving one of them in the horizontal direction, and a sewing machine control section for controlling and driving the rotation axis, the sewing machine drive shaft, and the moving means, according to set sewing data. A method of controlling a sewing machine for performing pattern stitching on the object to be sewn, the method comprising:
The sewing pattern to be sewn on the object to be sewn is divided into a plurality of steps consisting of a combination of straight lines and circular arcs, and sewing data for drawing the straight lines or circular arcs is input, and the input multi-step sewing is performed. According to the data, the sewing machine control section calculates the driving amount of the rotating shaft, the sewing machine drive shaft, and the moving amount of the moving means in order from the sewing data of the first step, and according to the driving amount and moving amount, the rotating shaft, A sewing machine control method characterized by controlling and driving a sewing machine drive shaft and a moving means. (2) A method for controlling a sewing machine according to claim 1, characterized in that the sewing machine head, the sewing machine needle, and the moving means are provided with detecting means for detecting the amount of movement thereof. (3) While sewing the object to be sewn, the sewing machine control section calculates sewing data for at least two steps ahead of the step being sewn. How to control a sewing machine.