JPS5917386A - Speed control apparatus of embroidering 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 The present invention stores data regarding the amount of movement of the embroidery frame for each stitch in a 7-meter disk or the like, and drives a stellabing morph, etc. based on the amount of movement data read out to the needle. The present invention relates to an embroidery sewing machine in which a stitch is formed by moving an embroidery frame by a means, and in particular to a speed control device for an embroidery sewing machine that controls the driving speed of a motor connected to a main shaft based on read movement amount data.

Conventionally, in an embroidery sewing machine, while the needle is positioned above the fabric, the needle moves upwards and upwards above the throat plate, as shown in Figure 8, at a rotation angle θ0 of the main shaft that is proportional to the amount of movement of the embroidery frame. The stepping motor was driven by generating drive pulses with a constant cycle of The travel time does not change, and therefore, when the amount of movement of the stepping motor increases, the needle may penetrate the fabric before the movement is completed, fall out of its designated position, and form an undesired stitch. However, there were drawbacks such as the fabric being moved while the needle was still stuck in the fabric, causing damage to the fabric or breakage of the needle.

Therefore, if the sewing speed of the sewing machine is slowed down, the waiting time for the needle to penetrate the fabric after the movement of the embroidery frame is completed will be longer when the stepping motor movement distance is small, resulting in lower sewing efficiency. was there.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and improve sewing efficiency by controlling the driving speed of the sewing machine motor to increase in inverse proportion to the amount of movement of the embroidery frame.

Hereinafter, the present invention will be described in detail with reference to the drawings. Reference numeral 1 denotes a table having a flat upper surface 1α, and a sewing machine 2 is placed on the upper surface 1a so that the bed surface 2a is located on the same plane. A main shaft (not shown) moves the needle 3 up and down in conjunction with a motor M installed on the same axis. The motor M is driven by a servo circuit system so that its driving speed can be controlled, as will be described later. Reference numeral 4 denotes a support frame, in which an embroidery frame 5 for holding a stretched cloth is removably supported. The embroidery frame 5 is operated in conjunction with a pair of stepping motors XSTM and YSTM arranged below the table 1, and moves on the upper surface 1α of the table 1 in the Y direction and Y direction along the axial direction of the main shaft of the sewing machine.
in the direction crossing the direction.

It is possible to move in the composite direction with the X direction.

6 is a floppy reading means, and an insertion part 6α into which a floppy disk FP (Fig. 4.6) can be inserted and removed.
It reads data from the inserted floppy disk Fp. 7 is an operation panel, which reads data from the floppy disk FP, sets the sewing speed of the sewing machine,
A key switch for controlling the movement of the support frame 5, etc. is provided.

Next, the control circuit of the present invention will be explained.

As shown in FIG. 4, this control circuit includes a digital processing system DS that performs digital calculations on data read from the floppy disk FP by a CPU (central processing unit), and a stepping motor XSTMYSTM based on the output signal of the digital processing system DS. a stepping motor drive circuit DR that drives the motor M at a constant speed for a predetermined number of steps, and a loop 111- that drives the motor M by servo (analog) control.
- It consists of a drive system SR.

The control operation of the CPH in the digital based system will be explained based on the flowchart of FIG. 5. First, it is determined whether the hand 3 has reached the uppermost position. This determination is made based on a detection signal from a well-known rotation angle detection means, not shown, which is arranged in relation to the main shaft and machine frame of the sewing machine 2. When the needle reaches the highest position, the next movement amount data of the embroidery frame 5, that is, the movement amount data after the next needle drop XJ, YJ (J stands for the number of the needle drop point) is read out from the floppy disk Fp. TeXJ
The amount of movement between and YJ is compared, and the larger value is set as LJ as the parameter of the amount of movement. Next, two known constants α1.1, .alpha.1. α2
, calculate the value WJ-α1α2117LT- which is inversely proportional to the embroidery LJ, and then calculate the D/A (digital/analog) in synchronization with the timing when the needle 3 penetrates the cloth.
□In the latch register for output to the log converter) ωJ Next, the servo amplifier SB will be explained. The servo drive system SR is shown in a block diagram in Fig. 4, and the letters in the block represent the transfer function □ expressed by Laplace transform using parameter 5S. ■ is a variable resistor that can be operated manually.

, has a transfer function G8×1, and drives the motor M.

This is to reduce and adjust the moving speed. DF is a circuit for improving the start-up characteristics of motor M, and uses a differentiation circuit consisting of a resistor and a capacitor to create a transfer function of R1+SG.
2 is a servo amplifier, and has a linear amplification characteristic with a transfer function a4>X. Motor M
has a first-order delay response function 05/(1+TS), where T is the time constant of the rise delay. As is well known, this has a rise characteristic like 1-exp(t7T) (t is time). In this way, when the CPU output (AJ, r) is input via D/A, the response of the entire servo drive system SR is ωJ −G 8 (G1+5G2)O
The analog value G4·G5/(1+TS) is calculated, and the structure is such that this value is directly proportional to the drive speed vJ of the motor M.

Furthermore, CA) J −αl a271:/LJ, and ideally it is set so that the product of G1+5G2 and 1/(1+TS) is almost a constant, that is, the delay in rising is completely eliminated. If it is, G3 (
G1+5G2)/G4G5/(1+TS) can be regarded as a constant, so from now on, for convenience, we will use a predetermined proportionality constant K.
Therefore, the driving speed of motor M is υJ=/LJ.

The present invention has the above configuration, and its operation will be explained next.

In FIG. 3, P1 to P7 indicate needle drop points, and the stitches are assumed to proceed in the order of these numbers.

First, at point 21, since the movement amount data of P 1-) P 2 is Xli Yl and Xi>Yl, based on 70- in FIG. 5, L 1 = , from X 1 to (1) 1-
B1(1,2π/L1, so that the drive speed υ of the motor M) is set to /LL.

Now, when the needle 3 is removed from the cloth at point pt, the stepping motors XSTM and YS are activated based on the movement amount data XI and Yl.
TM drives the embroidery frame 3 from point 21 to point 22
Move in the Y composite direction.

At this time, since Xl>Yl, the movement in the Y direction is
It takes less time to complete than directional movement. After completing the movement in the Y direction (Fig. 9 A1), the needle 3 returns to the uppermost position (No. 31ff).
(corresponding to approximately the midpoint between 1 and B2), the next movement amount data X2. T2 is read from the 70-tube disk FP, and since X2>T2, L2=X2, and this B2 makes ω2=
a1a2T/L2 is calculated. The calculated value of ω2 is immediately stored in a predetermined register and is not immediately input to the D/A. Next, movement in the X direction is completed (Fig. 9 S1)
Then, the needle 3 is located directly above B2, but at this time the needle 3 has not yet penetrated the cloth. When time T1 has elapsed since B1, the needle 3 penetrates the cloth, and in connection with this, the value of ω2 becomes D.
Since it is transferred to the output register to /A, servo drive system 5BK(1)2-alα2π/L2 is set, so the drive speed υ2- of motor M becomes /L2.

Next, when the needle 3 is lifted out of the cloth, the movement amount data is set to X2. Y2
Based on this, the stepping motors XSTM and YSTM are driven to move the embroidery frame 5 from the 22nd point to the 28th point in the composite direction of the direction 5x-y. In this case, since X2>T2, Y
Movement in the direction is completed in a shorter time than movement in the X direction (Fig. 9A)
2) Then, when the needle 3 reaches the uppermost position (corresponding to the midpoint between B2 and B3 in Figure 3), the next movement amount data XS and Y8 are read from the floppy disk FP based on the flow in Figure 5. Since X3>T8, L3=X8
By this B8, (JJ3 = al + z27
1/L2 is calculated.

Now, in Fig. 3, since Xi>X2, the stepping motors XSTM, YSTM,
The time to move from Pl to B3 is shorter than the time to move from Pl to B2, and the stepping motor
Since the driving speed of the YSTM is constant, the time from point P2 until the needle 3 lifts up and the next stepping motor It is reduced to the value of the time until stopping multiplied by X 2 / X 1. However, the driving speed of motor M between P 2 - P 11 v 2 =
K/L2=/X2, and the driving speed of motor M between PI and P2 is v1=K/L1=
Since K/X was 1, motor M between B2 and B8
The driving speed v2 of
1 / There isn't.

Next, when the needle 3 penetrates the cloth, the servo drive system SR
Since 1α271/L8 is set, the drive speed U8 of motor M becomes /L3, and as shown in FIG. 3, X2>X
8, so v 8 / v 2 = X 2 / X
8 to v8>112, that is, as the distance to the next needle drop point decreases, the driving speed of the motor M gradually increases in inverse proportion to the length of the distance, so x
a > x4 > Waiting time until 3 penetrates the cloth Tll, T4
．． T5... will not increase.

In the above embodiment, a circuit DF having a transfer function of G1+5G2 is incorporated in the servo drive system 3B in order to improve the start-up characteristics of the motor M, but such a circuit is omitted and the improvement of the above-mentioned start-up characteristics is described below. It may also be possible to process it in software in the CPU as follows. In other words, the response ωJ of the servo drive system SR is 8・(G1+5()2) OG4・G5/(1+
TS) (t is time), ωJ = a1a2π/LJ to ωJ
(G1+5G2)-cl a2'Ir+1→LJ-1-
It changes discretely like 2...

Therefore, as long as the time Δt of one cycle of the motor M is detected, the 70-chart of the program is converted into the log amount shown in FIG. 7 and inputted to the servo drive system SB shown in FIG.
It is possible to obtain improved start-up characteristics of the motor M that are substantially equivalent to those in FIG.

As described above, according to the present invention, by inputting a value inversely proportional to the value of the needle drop point movement amount data to the servo drive system via the D/A, the needle drop point can be inversely proportional to the needle drop point movement amount. Since the driving speed of the motor M is controlled according to the embroidery frame, the driving speed of the motor M is set to a high speed when the distance between the needle drop points is narrow, and the driving speed of the motor M is set to a low speed when the distance between the needle drop points is wide. This prevents the needle from penetrating the fabric before the embroidery frame stops, which prevents needle breakage and misalignment of the needle drop point, and also reduces the time it takes for the needle to penetrate the fabric after the embroidery frame stops. Since the optimum sewing speed is set even for long embroidery stitches, the sewing efficiency can be improved.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the embroidery sewing machine, Figure 2 is a diagram of embroidery pattern "A", Figure 3 is an enlarged view of part Q in Figure 2, Figure 4 is a block diagram of the control circuit, and Figure 5 is a diagram of the embroidery pattern "A". Flowchart of the CPU program, FIG. 6 is a block diagram of the control circuit of another embodiment, FIG. 7 is a flowchart of the program of another embodiment, and FIG. 8 is the conventional movement of the needle up and down and driving of the stepping motor. FIG. 9 is a time chart showing the relationship between the vertical movement of the hand and the driving of the stepping motor in this embodiment. DS...Digital processing system, SB...Name of servo drive system agent Patent attorney Nagoya - Figure 5, Figure 7

Claims (1)

[Claims] A sewing machine 2 placed on a table 1, a motor M connected to the main shaft of the sewing machine that moves the needle up and down, and whose driving speed can be electrically adjusted, parallel to a specific straight line on the table. an embroidery frame 5 supported on a table so as to be movable in the X direction and the Y direction perpendicular to the a readout means for reading the movement amount data of the storage means for each stitch in connection with the detection of a specific rotation angle of the main shaft; is related to the rising of the embroidery hoop at a constant speed x
, drive means XSTM, YSTM that move in the X direction, and a control circuit Cp that adjusts and controls the drive speed of the motor so that it is inversely proportional to the amount of movement based on the read amount of movement data.
U. A speed control device for an embroidery sewing machine. and