JP2582367B2 - Embroidery frame drive of embroidery machine - Google Patents

Description

Description: Object of the Invention (Industrial application field) The present invention relates to an embroidery frame driving device of an embroidery machine which can satisfactorily drive an embroidery frame in synchronization with a sewing needle which moves up and down by rotation of a main shaft. About.

(Prior Art) Conventional embroidery machines convert the rotation of a main shaft into a vertical movement of a sewing needle via a crank mechanism. Further, an embroidery frame driving device holds an application for performing embroidery in synchronization with the movement of the sewing needle. By driving the embroidery frame, the relative positional relationship between the sewing needle and the fabric is changed to enable embroidery processing.

For this reason, the conventional embroidery frame driving device mounts an encoder for detecting the rotation angle on the main shaft, counts pulse signals input from the encoder, and starts embroidery frame driving while the sewing needle is falling off the fabric. The embroidery frame is moved by a predetermined amount each time a predetermined number of pulse signals are input.

(Problems to be Solved by the Invention) However, the embroidery frame driving device of the embroidery machine as described above is still not enough, and has the following problems.

The main shaft connected to the sewing needle is configured to directly receive a change in load according to the vertical movement of the sewing needle. For example, at the bottom dead center where the sewing needle pierces the fabric and at the top dead center where the sewing needle is lifted up to the top, a large torque is required and the rotation speed decreases, and at other rotation angles a relatively small torque is sufficient, so that the rotation is sufficient. Speed increases. Accordingly, the output pulse of the encoder that detects the rotation angle of the main shaft also has a great difference in pulse period even during one rotation of the main shaft due to the influence of the torque fluctuation.

The conventional embroidery frame driving device that drives the embroidery frame based on the pulse signal having such a variation factor generates vibration in the frame drive because the reference of the driving speed of the embroidery frame fluctuates as a result. In addition to being unable to execute driving, accurate positioning and smooth start-up / braking cannot be performed, and in the worst case, the stepping motor, which is the power source for driving the frame, may lose synchronization.

In addition, in order to smoothly move an object, not limited to the embroidery frame, there are optimal starting, moving, and braking speeds according to the mass of the object and the output of a driving device that drives the object. However, the conventional embroidery frame driving device can only drive completely depending on the pulse signal input by the rotation of the main shaft, and cannot execute the optimal control of the embroidery frame driving.

The present invention has been made in order to solve the above problems, and can control the movement of the embroidery frame smoothly without being affected by the rotation fluctuation of the main shaft, and can drive the embroidery frame accurately and smoothly. It is an object of the present invention to provide an embroidery frame driving device of an embroidery machine that can perform the embroidery frame driving.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the means constructed according to the present invention is, as shown in the basic configuration diagram of FIG. The sewing needle drives an embroidery frame that holds a fabric to be sewn, and an embroidery frame driving device of an embroidery machine that forms a desired embroidery pattern on the fabric outputs a detection signal synchronized with a rotation angle of the main shaft. Spindle rotation angle detection means, average rotation speed calculation means for calculating an average rotation speed of the spindle based on a detection signal of the spindle rotation angle detection means, and average rotation speed calculated by the average rotation speed calculation means Pulse cycle determining means for determining a pulse cycle corresponding to: pulse signal generating means for generating a pulse signal having the pulse cycle determined by the pulse cycle determining means; pulses of the pulse signal generating means And a synchronous drive means for driving the embroidery frame in synchronization with a signal.

(Operation) According to the embroidery frame driving device of the embroidery machine of the present invention, the average rotation speed calculating means determines the average rotation speed of the main shaft based on the detection signal output by the main shaft rotation angle detecting means in synchronization with the rotation angle of the main shaft. Is calculated. Then, the pulse cycle determining means determines a pulse cycle corresponding to the average rotation speed and supplies the pulse cycle to the pulse signal generating means. Then, the pulse signal generating means generates a pulse signal having a pulse cycle corresponding to the average rotation speed of the main shaft. The synchronous driving means drives the embroidery frame in synchronization with the pulse signal.

Here, since the main shaft includes a fluctuation factor during one rotation, the detection signal itself of the main shaft rotation angle detecting means includes a microscopic fluctuation due to the effect of the vertical movement of the sewing needle as described above. Have been. However, according to the present invention, since the average rotation speed of the main shaft is calculated by the average rotation speed calculation means, the influence of such microscopic fluctuation is removed. Therefore, the driving of the embroidery frame by the synchronous driving means becomes stable without being affected by the fluctuation of the rotation of the main shaft.

Hereinafter, the present invention will be described more specifically with reference to examples.

(Embodiment) FIGS. 2 and 3 are explanatory views of the configuration of a multi-needle embroidery machine employing an embroidery frame driving device of the embroidery machine of the embodiment.

As shown in FIG. 2, the two-head type multi-needle embroidery machine 10 analyzes input information by a driver unit 30 to create known one-needle data in order to sew an embroidery pattern input from a controller 20. Then, the embroidery thread is selected from the sewing needles 40 according to the one-needle data to select the embroidery thread, and is moved up and down, and the movement of the embroidery frame 50 in the X-Y direction is controlled in synchronization with the up and down movement.

FIG. 3 is a detailed configuration block diagram of the driver unit 30. In the figure, a needle changing motor 32 serves as a power source for selecting an arbitrary one of the multi-needle sewing needles. The sewing motor 34 is for moving the sewing needle selected by the needle changing motor 32 up and down, and rotates a main shaft connected to the selected sewing needle via a crankshaft to move the sewing needle up and down at a predetermined speed. . In order to detect the rotation state of the spindle, a predetermined rotation angle of the spindle, for example, 5 °
An encoder 35 that outputs a pulse signal every time is mounted on the main shaft. X-axis motor 36 consisting of a stepping motor,
The Y-axis motor 38 is a power source for moving the embroidery frame 50 in the X-axis direction and the Y-axis direction. As is known, X
The axis motor 36 moves the embroidery frame 50 by one unit distance in the X direction each time a step signal is input, and the Y axis motor 38 moves the embroidery frame 50 one unit distance in the Y direction each time a step signal is input. The belt attached to the embroidery frame 50 is rotationally driven via a pulley or the like so as to move only.

Further, as shown, the driver unit 30 of the multi-needle embroidery machine 10 is connected to the controller 20 operated by the user,
This is a digital logic circuit centered on a normal microcomputer that operates while analyzing control data input from the controller 20, and a CPU 30 that executes logical operations.
A, a ROM 30B for storing various programs, and a RAM 30C for temporarily storing information. The output of the above-described encoder 35 is appropriately sent to the CPU via the interface 30D.
Incorporated in 30A. Further, motor controllers 30G to 30I that output drive signals of various motors, that is, an X-axis motor 36, a Y-axis motor 38, a needle changing motor 32, and a sewing motor 34 for moving the embroidery frame 30 in the XY directions, The excitation phase of the motor is appropriately changed according to the control signal from the CPU 30A, and the motor is rotated at a desired speed at a desired rotation angle.
Further, the driver unit 30 of this embodiment includes a pulse generator 30J as a digital element. This is CPU30
When an arbitrary pulse period T is set from A, a pulse signal of the period T is generated regularly thereafter.

The driver unit 30 configured as described above analyzes a control code input from the controller 20 as is known, and drives each motor while monitoring a detection result of the encoder 35 based on the analysis result. A desired embroidery pattern can be applied to the cloth held by the embroidery frame 50.

The driver unit 30 of the present embodiment executes a specific pulse signal generation program and an embroidery frame driving program at the time of drive control of each of the above motors, particularly at the time of controlling the X-axis motor 36 and the Y-axis motor 38. X-
Y drive is being performed. 4 and 5 are flowcharts of the pulse signal generation program and the embroidery frame driving program stored in the ROM 30B.

Hereinafter, the drive control of the embroidery frame 50 will be described in detail with reference to this flowchart.

First, the pulse signal generation program is interrupted by the CPU 30A at predetermined time intervals or at predetermined rotation angles of the spindle. First, the current detection output of the encoder 35 is input (step 100). An average rotation speed N of the main shaft is calculated (step 110). Here, the average rotational speed N of the main shaft is calculated as a macroscopic rotational speed determined by the time required for one or more rotations of the main shaft, and is a fine rotation during one rotation in which rotation fluctuation is large. It does not refer to the rotational speed that is a visual calculation result. After the rotation speed N is calculated in this way, the pulse period T is determined based on the calculation result (step 120). The pulse period T is an average period of a pulse train output when the rotation speed of the main spindle rotating at the rotation speed N is detected by the encoder 35, or a period of a pulse train having a precision twice as high as the average. It is. That is, the pulse period T from the encoder obtained when it is assumed that the current rotational speed N of the main shaft is detected by the encoder 35 or by another encoder having higher precision is determined. The pulse period T thus determined is output to the pulse oscillator 30J (step 130), and thereafter, the pulse oscillator 30J stably oscillates the pulse signal of the period T. After the above series of processing, the processing of this program ends and the CP
U30A starts the processing of another program that has been interrupted again.

On the other hand, the CPU 30A starts executing the embroidery frame driving program when it is necessary to move the embroidery frame 50 by the distance L in the X direction or the Y direction as a result of analyzing the control code from the controller 20. FIG. 5 is a flowchart of the embroidery frame driving program.

When the processing of this program is started, first, the movement distance L of the target embroidery frame 50 is read (step 20).
0) Then, a search process of the pulse interval table based on the moving distance L is executed (step 210).

In order to smoothly move the embroidery frame 50 by the moving distance L, as shown in the explanatory diagram of FIG. 6, the elapsed time is known by inputting the pulse train generated by the pulse generator 30J, and the moving speed is gradually increased at the elapsed time. It is desirable that the embroidery frame 50 be stopped by gradually decreasing the moving speed after completing the movement of about half of the moving distance L. If the movement of the embroidery frame 50 is executed based on the input of the pulse train of the pulse generator 30J in this manner, the movement of the embroidery frame 50 when the rotation speed N of the main shaft increases can be easily adapted. That is, the pulse period T corresponding to the rotation speed N of the main shaft is changed by the pulse generator 30 by the processing of the pulse signal generation program.
Since it is set to J, the movement of the embroidery frame 50 can be easily realized within the period in which the sewing needle is removed from the fabric, judging from the rotation angle of the main shaft. In FIG. 6, (a) shows a case where the rotation speed N of the main shaft is high and the pulse period T generated by the pulse generator 30J is short, and (b) shows a pulse where the rotation speed N of the main shaft is low and the pulse generated by the pulse generator 30J. This shows the relationship between the moving speed of the embroidery frame 50 and the pulse train when the period T is long.

The movement of the embroidery frame 50 as shown in FIG.
The pulse interval table describes data for optimal execution according to the above. The pulse interval table describes the most efficient movement mode corresponding to the movement distance L stored in the ROM 30B in advance based on the correspondence with the pulse signal. Content. As shown, the moving distance is L1, L2, ...
.., LN, in order to move the embroidery frame 50 smoothly, the X-axis motor 36 or Y which controls the movement of the embroidery frame 50 is used.
It is described as information indicating how many pulses of the signal input from the pulse generator 30J should be executed to drive the shaft motor 38 by one unit distance.

When the search of the pulse interval table corresponding to the moving distance L is completed in step 210, a process of sequentially reading the data of the searched table is executed (step 220). For example, to describe a case where the table of the moving distance L1 is searched in step 210, the moving distance L1 is stored in the pulse interval table in FIG.
In the movement, the number of pulse signals to be counted in order to output one step signal is determined over the entire movement distance L1, and the numerical value defined for this movement distance L1, 27, .., 9, 11, 14, and 27 are sequentially read each time this step 210 is processed. In the subsequently executed step 230, it is determined whether or not the sequence of numerical values read out in step 220 has already completed reading of all the numerical value columns, and it is determined whether or not the process has been completed. All processing of this program ends.

On the other hand, if the reading of the sequence of numerical values has not been completed yet, the process proceeds to the next step 240, where the numerical value read this time is compared with the count value of the pulse generated by the pulse generator 30J, and both numerical values are compared. It is determined whether they match. This is because the timing of executing the movement of one unit distance to the X motor 36 or the Y motor 38 is executed in accordance with the pulse signal from the pulse generator 30J as described above.
To explain with the example of the moving distance L1 described above, the numerical value read from the pulse interval table is such that, after executing the movement of one unit distance, executing the movement of the next one unit distance
When 27 pulse signals are input, it indicates that execution is necessary. After that, similarly, after the input of 14 pulses, a step signal for further movement of one unit distance is input, after the input of 11 pulses, the next step movement for the fourth time,.
, And so on.

Therefore, the current value read from the pulse interval table in step 240 is compared with the contents of the counter that counts the number of pulse signals since the previous step signal was output, and until the values match. The process waits, and at the same time when the values match, the process proceeds to the next step 250 to output a step signal to the X-axis motor 36 or the Y-axis motor 38 which needs to move by one unit distance.

After the above series of processing, the processing returns to step 220 again, a new numerical value is read from the pulse interval table, and the same processing is repeated thereafter.

If the step driving of the X-axis motor 36 and the Y-axis motor 38 is executed, the movement of the embroidery frame 50 is controlled as shown in FIG. The figure shows the relationship between the number of pulses counted by the counter at the start of the movement and the one unit movement distance of the embroidery frame 50 for the movement distance L1 shown in the above example. As shown in the figure, the embroidery frame 50 is ideally driven such that the moving speed gradually increases at the beginning of the movement.

The pulse signal that serves as a time reference for the movement of the embroidery frame 50 is an extremely stable pulse train generated by the pulse generator 30J. Therefore, stable movement of the embroidery frame 50 determined by only the numerical value set in the pulse interval table is realized.

The case where the embroidery frame 50 is stably moved has been described above. However, in this embodiment, the moving speed of the embroidery frame 50 can be easily changed to an arbitrary speed. That is, conventionally, the only way to change the moving speed of the embroidery frame 50 is to change the pulse interval table described above.
Prepare multiple ROMs, change the storage contents of the ROM, etc.
The device configuration was complicated and the cost was soaring. However, in this embodiment, the intensity can be easily changed only by changing the value of the pulse period T set in the pulse generator,
Moreover, even in such a case, the movement of the embroidery frame 50 can be smoothly changed by gradually changing the speed so that the movement is not stored in the pulse interval table. For example, if the pulse period T set in the pulse generator 30J is changed even when the rotation speed of the main shaft is constant, the movement of the embroidery frame 50 becomes the reference pulse as shown in FIG. The time required for counting can be easily changed and the desired speed can be controlled.

As described above in detail with reference to the embodiments, the embroidery frame driving device of the embroidery machine of the present invention can smoothly control the movement of the embroidery frame without being affected by the rotation fluctuation of the spindle. In addition, the embroidery frame can be driven smoothly.

Also, when changing the moving speed of the embroidery frame, it is only necessary to execute a simple process of simply changing the pulse period, and the movement of the embroidery frame can be freely controlled.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram showing a basic configuration of an embroidery frame drive device of an embroidery machine of the present invention, FIG. 2 is a schematic configuration diagram of an embroidery machine employing the embroidery frame drive device of the embodiment, and FIG. FIG. 4 is a block diagram of the driver unit, FIGS. 4 and 5 are flowcharts of programs executed in the driver unit, FIG. 6 is a diagram for explaining the relationship between embroidery frame driving and pulse signals, and FIG. 7 is a description of a pulse interval table. FIGS. 8A and 8B are explanatory diagrams of embroidery frame driving according to the embodiment. 20: Controller, 30: Driver unit 30: Pulse generator, 36: X-axis motor 38: Y-axis motor, 35: Encoder 50: Embroidery frame

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Shibata 20 Oka Tsukakoshi, Ichinomiya, Ichinomiya, Aichi Pref. Barudan Co., Ltd. (56) References JP-A-56-130181 (JP, A) JP-A-61-76190 (JP, A)

Claims (1)

(57) [Claims] 1. An embroidery frame drive of an embroidery machine for forming a desired embroidery pattern on the cloth by driving the embroidery frame holding the cloth to be sewn in synchronization with the sewing needle moving up and down by the rotation of the main shaft. In the device, a main shaft rotation angle detection unit that outputs a detection signal synchronized with the rotation angle of the main shaft, and an average rotation speed calculation unit that calculates an average rotation speed of the main shaft based on the detection signal of the main shaft rotation angle detection unit Pulse period determination means for determining a pulse period corresponding to the average rotation speed calculated by the average rotation speed calculation means; and pulse signal generation means for generating a pulse signal having the pulse period determined by the pulse period determination means. An embroidery frame driving device for an embroidery machine, comprising: synchronous driving means for driving the embroidery frame in synchronization with a pulse signal of the pulse signal generating means.