JPS5955290A - Drive apparatus 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 provides variable speed control of a sewing machine according to the separation distance of a pedal from a predetermined position, and also controls the sewing machine at a predetermined speed as the pedal moves to a predetermined position. The present invention relates to a sewing machine drive device having a so-called hook position stopping function that positions and stops the needle at the needle position.

Structure of conventional example and its problems Conventionally, as a method of stopping the needle at a fixed position, a method as shown in the time chart of FIG. 1 has been generally adopted.
was.

Normally, a sewing machine is driven by a motor via a belt or directly, and by operating the pedal of the sewing machine, the sewing machine operates the motor through a sharpening section, and then the variable speed control (control) of the sewing machine. ) Alternatively, a series of operations such as completing a predetermined sewing product while stopping the needle at a fixed position is performed.

Generally, when the sewing machine leaves the pedal in an open state (hereinafter referred to as neutral) where no force is applied by the sewing worker, the sewing machine remains in a stopped state, and when the pedal is depressed for a predetermined distance or more, The sewing machine does not have a variable speed control from a low speed to a maximum speed depending on the distance the sewing machine is driven.

In FIG. 1, when the pedal is fully depressed, the sewing machine is running at maximum speed.

When the sewing worker returns the pedal to the neutral position from such a state, the pedal position is detected and the signal +I P N I+ is switched to L'', uH++ without being turned off.
In response to the signal "PN'", the sewing machine operates at a low speed uHL11 for positioning (hereinafter referred to as position speed).
If the settings are not set, the speed will suddenly slow down. Next, after reaching the position speed IIN, I+, the sewing machine is positioned and stopped when the needle position signal "ND" indicating the position to be stopped is confirmed.

The second operation is performed, and after reaching the position speed TANL, the needle position signal ++ND
The time II TLI+ at 1 to check I+ requires a time equivalent to one rotation at the longest position speed, and the rotational angle position when reaching the position speed is l: less than the longest time. There will be various changes.

The time It TLI+ is the position speed II N
, "'" are very long because of their low speed, and are a serious factor that significantly reduces sewing efficiency. In addition, the above-mentioned time ++TLI+ changes every time sewing is performed, and the rhythm of sewing does not mesh with each other, and the sewing operation cannot be carried out smoothly, which also causes disadvantages.

In order to improve sewing efficiency, in the conventional method, there is no choice but to increase the position speed ttNLllk, and on the other hand, if the speed is increased, the stop position during positioning will be affected by speed fluctuations, voltage fluctuations, etc. As a result, the needle position can vary greatly depending on various factors, and the needle position cannot be determined and the function of stopping the needle in the fixed position cannot be achieved, which hinders sewing work and causes problems and limits. was there.

-1- As mentioned above, the conventional method has the drawback that it takes a long time to sew between the final hook and the hook during positioning, which reduces sewing efficiency. There is a limit to increasing the position speed as described above in terms of the 4'n degrees at which the needle position stops, and countermeasures for these two contradictory problems are extremely difficult, and no solution has been proposed. The current situation was that there was no such thing.

SUMMARY OF THE INVENTION It is an object of the invention to provide a sewing machine and a drive device that eliminates these two drawbacks, improves sewing efficiency, and has high accuracy in stopping at fixed positions.

Structure of the Invention The non-invention is that in the process of stopping the needle hole position, a plurality of Step 9 is configured to set one of the conversion elements to the actual measured speed and to select data included in the conversion element that instructs the setting of n speed 1W to the actual measured rotation angle position. And, by arranging each of the conversion elements so that the speed setting value data reaches a maximum at a passing position of the target stop position and a minimum immediately before the target stop position, the rotation angle position and speed can be actually measured. According to the result, the sewing machine is stopped at a target position using a predetermined braking curve, and in particular, the braking curve can be freely selected by selecting the speed setting value data by the selection means. Therefore, it is possible to make the final needle sewing time sufficiently short and constant, improving sewing efficiency, and furthermore, the speed just before the target stop position can be kept the same as before or lower than before. This makes it possible to achieve needle position stopping accuracy with less variation than ever before, and especially when a digital speed control system is configured, for example, the knob microcomputer (hereinafter referred to as the knob microcomputer) commonly used in recent years can be used. It has many advantages, such as being able to be constructed at a very low cost by making full use of microcomputers (also called microcomputers).

Various other features and advantages will become clear from the description below.

DESCRIPTION OF EMBODIMENTS A non-inventive embodiment will be described below with reference to the block diagram of FIG.

In the figure, 1 is a frequency generator, which is attached to the shaft end of the sewing machine and outputs a plurality of pulse signals "= v p 11 per rotation with a period proportional to the rotational speed of the sewing machine. The needle position detector, which is attached to the shaft end of the sewing machine in the same way as the frequency generator 1, generates a needle position signal "ND" in response to the -1- position or down position of the hook of the sewing machine. It is something. 3 is the speed setting device, and the sewing machine pedal (
(not shown), outputs the signal tt P N 11 at the neutral position of the pedal, and outputs a value that changes depending on the pedal distance at the pedal depression position as a 4-pinto speed command signal "sv'". and output it. Reference numerals 4 and 5 denote a clutch coil and a brake coil, which are built into the output section of the motor 6. When the clutch coil 4 is energized, the entire rotational force of the motor 6, which is constantly rotating, is generated through its magnetic circuit. Clutch lining, output part 1 (not shown) is fully connected and further transmitted to the sewing machine via the booley label plate, and on the other hand, the brake lining (not shown) is stopped through its magnetic circuit to excite the brake coil 6. The operation of press-fitting the sewing machine and transmitting the entire static force to the sewing machine described in 2'L is performed. Normally, variable speed control is performed by controlling the excitation current to the clutch coil 4, controlling the pressure contact force on the clutch lining surface, and causing appropriate slippage.

The other parts are blocks of electronic circuits, and can be replaced with discrete ICs, etc.! Regarding the shira, two explanations will be given one after another according to the operation explanation below.

When the depressing of the pedal is detected by the speed setting device 3 and the depressing signal "P N " changes from H" to + + L !+, the stop side (goods) means 7 outputs the signal "OLD""Total short time IIL"
→ Set to “H” and connect the flip-flop (
9 (hereinafter referred to as F/F), the clutch coil 4 is energized via the driver 10, and the sewing machine is started as described above.

The speed of the sewing machine mentioned above, which started rotating at l:9, is all controlled digitally as shown below.
Such a method has already been clearly disclosed in Japanese Patent Application No. 139071/1982 or 139073/1983.

Figures 3 to 5 show the above-mentioned speed open side.
The same figure will also be explained below.

While the sewing machine starts rotating as described above, the speed setting device 3 outputs the speed command signal "sv'" as 4-bit data nS7μ speed command signal ++ S V 14
→The data is given as address data in the ROM 11, and by selecting the content of the corresponding ROM address, it is converted into a speed setting value indicating the number of divisions for speed setting, which will be described later, and then output to the data selector 12. The data selector 12 outputs the input on the ++ B jl side because the input of its select terminal +l 811 is L'', and therefore the speed setting value based on the speed command signal "sv" from the speed setting device 3 is set. +j n v” is output and set in the n1 frequency divider 13.

The frequency divider 13 divides the pulse signal tTFPn output from the frequency generator 1 by the number of times the speed setting value +=nv+" has been set, and then divides the pulse signal tTFPn output from the frequency generator 1 by the number of times the set speed value +=nv+" is set.ゞPD” is output. The period counter 14 counts the clock pulse signal from the clock oscillator 15 over the period of the frequency-divided signal "PD", holds the counting result in the launch circuit 16, and stores the 8-bit period data "'TP".
The above clock pulse signal is outputted to the arithmetic unit 17 as ``. It is necessary to select a pulse signal with a sufficiently short resolution '(zl'H) so that the speed control system is not affected too much by variations in the period of

After the arithmetic unit 17 performs the arithmetic operation to be described later, the arithmetic unit 17 applies an error to the result of the arithmetic operation, and if the periodic data "TP" is large, (
(at low speed/if applicable), or gate 8°F/F9. The clutch coil 4 is excited through the driver 1Qf, and if the periodic data "'TP" is small (high speed), the OR gate 18°F/F191 acts to excite the brake coil 5 through the driver 20, The operation time is determined by inputting the calculation result data by the calculator 17 into the digital counter 21 as 8-bit data and counting the clock pulse signal by the number of times of the data. After the elapsed time, the F/F 9 or F/F 19 is reset, and the clutch coil 4 or brake coil 5 is turned off.
Ru.

In this process, after actually measuring the frequency-divided data ゛=TP11 of the pulse signal "FP" output from the frequency generator 1 and performing calculations, the data is calculated between the next frequency-divided period. Control aI of clutch coil 4 or brake coil 5
As in I, the actual measurement and control (goods) are repeated one after another, and the speed side (goods) is not achieved.The details are shown in Figures 3 to 6, and the following will be described according to the same figures. .

FIG. 3 is a graph showing an example of the calculation formula by the calculation unit 17, where TcB==AT, -B=--
・(1) (World A, Bi constant + Tpi actual measurement period 1'
raB: indicates clutch size or brake application time).

In the above equation (1), the constant A determines the rate of change in the clutch/brake application time TCB with respect to the actually measured cycle T, and is therefore considered to be a constant that determines the gain of the speed control system. It is determined in consideration of stability or responsiveness. On the other hand, the constant B determines the rotational speed of the sewing machine, and is used to determine the speed (hereinafter referred to as the reference speed) when the load on the sewing machine is constant"!υ and the frequency division number is 0. is uniquely determined.

If the sewing machine is operating stably at the 0 point shown in the figure, T(t
Clutch current I according to the duty cycle Blfi
c will be in balance with the load on the sewing machine.

Figure 4 shows the state of acceleration, and as the sewing machine accelerates, the actual measurement period TP becomes shorter, and therefore the calculation result from the above calculation formula also gradually decreases to TC1 + Te3 + T (+3).Q, clutch current IC decreases and the operation described in - is repeated until it reaches a stable state in which it is balanced with the sewing machine load.

On the other hand, Figure C shows the process in which the sewing machine gradually decelerates, and as the measured period tt Tp I+ increases, the brake-on time decreases to TBj + TB2, and the clutch-on time further increases to TI + T02 r Te3. , so the clutch current 1 is lower than the brake current.
This represents the process of switching to an increase in G.

Here, we have described the operation at the substrate velocity, but
By substituting the data after frequency division by the number of frequency divisions n as the actual measurement period "T P ", the gain of the speed side (goods) system is sufficiently high against the change due to the rotational speed of the load of the eli sewing machine. In this case, a stepwise sewing machine speed as shown in equation (2) below can be obtained. The speed command signal "s"
It is clear that the sewing machine speed can be set for the pedal depression position by appropriately dividing the frequency dividing number to each address in the ROM 11 indicated by the 4 focus data of "v". , an example is shown in FIG. Note that the number n of frequency division is shown in parentheses ( ).

As described above, the variable speed control is performed when the pedal is depressed.Next, the operation when the pedal is depressed to the neutral position will be described.

Here, 22 indicates a position counter, which is reset at the front edge of the needle position signal "ND" every - rotation while the sewing machine is running, and is reset by the pulse signal ++F from the frequency generator 1. The counting of P11 is repeated, and therefore, the output "P" indicates the rotation angle position data with respect to the front edge of the button device signal "ND". For example, if a 160-pole frequency generator 1 is used, the position data llp'' will have 8-bit rotational angle position data from 0 to 160 as an 8-bit binary value. The ROM 23 is simplified so that only the second three bits of the bit position data are used and the value is between ``0'' and ``6''. ROM24
．． 86M26(7) At17 S”Q”～”2
'', and speed setting value data corresponding to the number of divisions n is assigned to each ROM in correspondence with each address.Furthermore, the upper address of the %ROM is
3'' is connected to a switch 26, through which one of the two speed setting value data groups can be selected.

Examples of data allocation to each of the above ROMs are shown in the table below and FIG. 6. As shown in the figure, the above-mentioned position data ゛P
There are six types of data for ″, and for each address (
The data shown in (v) is divided into 1 digit, and the switch 22 is configured to select either area a or area b. , that is, the ROM 23 is 6-2 (6-2), R
OM24 is 9-5 (7-4), ROM25 is 4-0 (3
~o) are assigned to the position data in six stages such that the position through which the front edge of the button device signal passes is the maximum, and the position immediately before that is the minimum.

As mentioned above, the pedal is depressed '1. If the fL1 sewing machine is operating at high speed and the pedal is set to neutral,
The neutral speed setting device 3 detects that the pedal is in neutral.
5. Output signal It P N ++ L″→11 H++
and this output signal "PN" causes the data selector 12 to
“At the same time as switching to the input selection state, a full command is given to the stop braking means 7 to start the stop braking system.

Here, the stop/open side 1 means 7 is usually constituted by a microcomputer, and an example of its control operation is shown in a flowchart in FIG. 7, and its operation will be described according to the lower opening.

In the main routine, if the pedal is fully depressed, all flags and outputs 01 to C3 are set to the initial state at 27. Next, when the pedal is in the neutral position and the signal T+ P N 11 changes from "L" to "H", T
The processing of P interrupt is as shown in 28.
+1 and selects the ROM 23'i.

The data in the ROM 23 selected as described above is sent to the frequency divider 13 via the data selector 12i.
1 The pulse signal +t y p ++ is divided by the set frequency division number "DV", and then its period is actually measured f
In the next cycle as 'L"TP"2, the stopped side (
property) to be given to means 7. It is determined by a total of 29 whether the period "TP" measured in this manner is greater than or equal to the set value 721. That is, this judgment is a judgment as to whether the speed is higher than the speed shown by the two-dot chain line in FIG.

The selected ROM 24 outputs the speed setting values 9 to 6 (7 to 4) according to the position data ``P'', and checks whether the actually measured period ``TP'' at 31 is greater than or equal to the setting value +t Tp1!1. The actual measurement period II T P T1 is repeated.
FLNl is set when TPl is equal to or higher than the set value of 2.

Thereafter, when the front edge of the needle position signal ``ND'' is confirmed at step 32, FLN2 is set and C3 is set to L'', the ROM 26 is selected, and the speed setting is successively lowered, so that a sequential side slope is performed. Nasa 1.Ru.

1- As shown in FIG. 6, ○"2 of the speed setting value of the ROM 25 is selected. n- After the sewing machine is set to the reference speed, which is the lowest speed, as shown in 33. When the front edge of the needle position signal "ND" is detected, the "BRD" signal is output for the time required for stopping, and the brake coil 5 is energized to stop the sewing machine at a predetermined needle position. , completes a series of hook position stop control 'i11.

The above operation describes the case where the sewing machine stops from a high speed. In this case, the speed is actually measured while repeating the speed setting according to the ROM 24, and the actual value becomes less than the set speed. After that point, switch to full 7-dimensional bactericidal control, sequentially reduce the set speed, select the ROM 25 at the time when the front edge of the needle position signal "ND" is detected, and further reduce the set speed according to the rotation angle position, After setting the reference speed to the set speed before the front hook position signal "ND", set the sewing machine's hook to the local position J1 at the front edge, and it will be done in a timely manner. In addition, RO in Figure 6
The above-mentioned external position accompaniment control from a speed below the setting based on M23 is performed by suddenly braking according to the set speed in the ROM25.

” 8th in the entire time chart of the process of stopping from two consecutive high speeds.
As shown in the figure. The figure shows a case where the sewing machine performs the external position accompaniment control from a high speed; in such a case, the settings based on the ROM 24 are repeated 12 times according to the actually measured rotational angle position, and during this time The brake coil is fully energized and the sewing machine is decelerated with the maximum slope (negative acceleration). At point Ip11T, when the set speed based on the ROM 24 is reached, the sewing machine enters the sequential braking 1. Transition heel ROM24 and RO
The speed of the sewing machine decreases according to the precise braking curve set by M26, and finally comes to a stop at the predetermined needle position.

Here, the above-mentioned stopping side slope to the target position is performed according to RσM24 and 25, but it is also possible to increase the number of forces by 11 to perform the full side slope at higher speed (1111), but the purpose of the present invention is not achieved. If you stop at the old position of the marker, it is not a good idea to control the high speed side too much and make the slope gentler. The period one to two stitches before the stop position is marked as an sequential braking sub-section, and fl- is the most effective way to reach the target.

The time TE required to sew one piece before stopping in FIG. 8 can be determined by selecting the speed setting value in the ROM 25 using the switch 22 and setting the entire slope of the braking curve for one revolution. That is, in the braking curve as shown in FIG.
As shown in a of the same figure, the speed setting value data group in the ROM is prepared in a larger number than the one shown in the embodiment, and one of them is selected by using several switches. In this case, the braking curve can be freely selected. However, the maximum slope is limited by the slope when the brake coil is fully excited.

1. When stopping the hook at a predetermined position, the stopping position will vary due to variations in braking force due to variations in power supply voltage, variations in frictional force on the surface of the brake lining, etc., but the reference speed before stopping shown in the figure ! It is generally clear that the above fluctuation range of l: can be made smaller by lowering N and l, and by configuring this method, the invention can further bring out its full effect. In other words, the above-mentioned This can be easily achieved by increasing the constant B in equation (1) after the pedal is in the neutral position, thereby decreasing the reference speed NL.

The configuration of this embodiment described above is entirely digital, and most of it can be configured with a one-chip microcomputer.

Effects of the Invention As is clear from the above explanation, the invention is to actually measure the rotational angular position and rotational speed in the process of stopping the needle of the sewing machine at the target position, and to store braking curve data in advance based on the measurement results. This is based on the idea of stopping the sewing machine at a predetermined target position according to the braking curve while selecting the data of the conversion element and setting the speed, and further selecting the braking curve with a simple switch operation. According to the present invention, the sewing time between stitches before the final stop, which conventionally took a long time, can be shortened and made constant, thus improving sewing efficiency. In addition, the operability has been improved, and the accuracy of the stopping position can be further improved, and the load and load caused by the sewing machine can be improved.
It has various features such as being able to select the best braking curve in response to differences in inertia, etc., and can be constructed at a low cost, and its effects are extremely impressive.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the operation of the conventional example, Fig. 2 is an explanatory diagram showing an example of the configuration of speed setting data, Fig. 7 is an explanatory diagram showing the uninvented operation, and Fig. 8 is an explanatory diagram showing the operation of the sewing machine of the present invention. FIG. 3 is an explanatory diagram showing the relationship between speed and time. 1... Frequency generator, 2... Needle position detector, 3... Speed setter, 4... Clutch coil, 5... Brake Coil, 6...
・Motor, 7... Stop side diagonal means, 111.23
~25... ROM112... Data selector, 13... Frequency divider, 14... Period counter, 17... Arithmetic unit, 21・・・・・・
・Preset counter, 22...Position counter, 26...Switch.

Claims (1)

[Claims] (1) A sewing machine, a motor that drives the sewing machine,
a frequency generator that generates a pulse signal with a period that changes in proportion to the rotational speed of the sewing machine; a needle position detector that detects a predetermined needle position of the sewing machine and outputs a needle position signal; and a pedal regulation. a speed setting device that outputs a stop command signal at a position and outputs a speed command signal according to a separation distance from the specified position; and a position that outputs a rotation angle signal according to a rotation angle position based on the needle position signal. Selecting a measuring means, a speed detecting means for detecting the rotational speed of the sewing machine and outputting an actual speed signal, a converting means for converting the rotation angle signal into a speed setting value, and the speed setting value data of the converting means. It consists of a selection means and a speed control means for controlling the speed of the motor, and the speed control means operates according to the speed command signal when the pedal is moved to a position other than the specified position. In the fixed position stopping process when the needle is activated and the stop command signal is output, the needle position signal is detected after the operation is performed according to the speed setting value selected by the selection means from the conversion means. A sewing machine driving device configured to position and stop the sewing machine at a position. (2) The conversion means is configured to include a plurality of conversion elements that convert the rotation angle signal into a speed setting value that reaches a maximum at the time when the needle position signal passes and becomes a minimum just before that,
In the fixed position stopping process, one of the conversion elements is selected in accordance with the actual speed signal, and after successively switching to the conversion element having the smaller speed setting value, the needle is stopped at a predetermined position. A sewing machine driving device according to claim 1. (3) The speed detection means includes a clock oscillator that generates a clock pulse signal and a counter, counts the number of clock pulse signals during one cycle of the pulse signal of the frequency generator, and outputs the counting result as the actual speed signal. A sewing machine drive device according to claim 1, which is configured to do so. (4) The position measuring means includes a counter I means, and after setting the counting means to an initial state by a needle position signal generated every revolution of the sewing machine, counts the pulse signals from the frequency generator, and counts the pulse signals from the frequency generator. The sewing machine drive device according to claim 1, wherein the sewing machine drive device is configured to output a chanting value as the position signal. (6) Construct one conversion element included in the conversion means with ROM (
~, the address of the ROM is specified according to a position signal, and a plurality of ROMs are provided, and one of the plurality of ROMs is selected according to an actual speed signal. The sewing machine drive device according to item 2. (6) The sewing machine driving device according to claim 1, wherein the selection means includes a switch, and the speed setting value data of the conversion means is selected by the switch. (7) a speed detection means, a position measurement means, a conversion means,
Claim 1, 2 or 3 in which the speed side (goods) means is constituted by a chip microcomputer.
The sewing machine drive device according to item 4, item 5, or item 6.