JPS62213793A - Tape feeder in 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] [Industrial application field]

The present invention relates to a tape feeding device for a sewing machine having a tape sewing function.

[Prior art]

Conventionally, tape feeding devices in sewing machines include a device that controls the feeding of the tape at a speed synchronized with the feeding speed of the work cloth (Japanese Patent Application Laid-Open No. 175586/1986), and a device that measures the tension on the tape with a strain gauge. A device that controls the tape tension so that the value is equal to a set target value (
British Patent Publication GBA2152016) is known. The former device has the characteristic that the ratio of the tape feed speed to the work cloth feed speed remains constant even if the work cloth feed speed changes. Therefore, when the tape elongation is set to the desired state from the beginning of sewing, tape slack due to changes in the feed speed of the workpiece fabric during sewing,
Overextension can be prevented. In particular, even if there are speed fluctuations due to acceleration and deceleration at the start and end of sewing, the elongated state of the tape can be maintained constant. Furthermore, the latter attempts to directly control the tension applied to the tape independently of the sewing speed. Therefore, there is a characteristic that the tape can always be attached to the work cloth with a set tension.

[Problems to be solved by the invention]

However, in devices that control the tape feed speed, the elongation rate of the tape is controlled by adjusting the ratio of the tape feed speed to the workpiece fabric feed speed. It is difficult to set a growth rate of That is, a time delay occurs until the tape reaches a set elongation rate. For this reason, when sewing the tape at a set elongation rate from the beginning of sewing, or partially stretching the tape in a predetermined section and joining to create gathers,
It is difficult to selectively add gathers to desired sections. Additionally, if the feed pitch of the work cloth changes, it is necessary to change the feed speed of the tape accordingly, and when the tape is attached without stretching, the feed speed of the work cloth and the tape feed speed must be changed. They must match perfectly, and if there are some errors, the errors will accumulate during long sewing, resulting in the tape being attached in a stretched state or becoming loose. Furthermore, the finished dimensions of the gathered product are determined by the elongation rate of the tape to be applied. Devices that directly control the tension of the tape do not directly control the elongation rate of the tape, and therefore cannot directly control the finished dimensions of the product.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to improve responsiveness in tape feed control and to directly control finished dimensions. That's a thing.

[Means to solve the problem]

The structure of the invention for solving the above problems is as follows. The present invention provides a tension applying means that variably applies tension to a tape that is supplied between a presser foot and a feed dog to be sewn onto a workpiece cloth, a tension detector that detects the tension of the tape, and an elongation of the tape. an elongation rate data input means for variably inputting a value related to the elongation rate; a conversion means for converting in the opposite direction, a growth rate of the control target set by the data input means,
a control device that outputs a signal for controlling the tension of the tape to the tension applying means so that the tension detected by the tension detector becomes equivalently equal to the tension detected by the tension detector; It is characterized by: The data input means can be configured by directly inputting the elongation rate of the tape numerically, setting it with a dial gauge, or inputting the sewing length and the elongation rate of the tape in that section numerically for each sewing section. . In particular, if the data input means is configured to input and set the elongation rate of the tape by inputting the sewing length of the work cloth to be sewn and the tape length, the part of the work cloth of the specified length will be The length can be directly controlled. Note that one or both of these values may be given by counting.

[Effect]

Values related to the control target elongation rate of the tape to be sewn are input and set, the actual tension of the tape is detected by the tension detector, and these values are converted into one of the physical quantities by the conversion means. and the tape tension is adjusted so that the converted values are equal. As a result, the tape is controlled to have the commanded elongation rate regardless of the feed rate of the work cloth. Therefore, the responsiveness of controlling the elongation rate is high, and a predetermined elongation rate can be obtained from the beginning of sewing, and the elongation rate can be easily changed at a desired location. Furthermore, since it is controlled by the elongation rate of the tape, the finished dimensions of the product can be directly controlled.

【Example】

The present invention will be described below based on specific examples. FIG. 1 is a perspective view showing the overall configuration of a sewing machine equipped with the apparatus of this embodiment. An arm 3 is protruded from the sewing machine frame 1, and a needle 6 is attached to the table 2.
It is arranged so that it can move up and down. A support arm 4 is pivotally supported on the lower side of the arm 3, and a presser foot 5 is fixed to the tip of the support arm 4. The presser foot 5 controls the feed of the workpiece cloth 8 by acting together with a feed dog (path shown) disposed below. The motor fixing base 9 is fixed to the upper part of the sewing machine frame 1, and a motor 20 is disposed thereon. The tension applying means mainly includes a motor 20, a driving roller 21, a driven roller 22, a tension lever 32, and a coil spring 33. Drive roller 21 is operatively coupled to motor 20 via a drive shaft 25 and gears. The driven roller 22 is in contact with the drive roller 21 and is supported by a bearing 23 so as to rotate in the opposite direction as the drive roller 21 rotates. The tension lever 32 is rotatably supported by a support member 34 provided on the arm 3. A coil spring 3 is attached to one end of the tension lever 32.
3 is engaged, which biases the tension lever 32 to rotate in six directions. The tape 7 is wound around a bobbin 12, which is supported by a support 11 fixed to a motor fixing base 9. The tape 7 is unwound from the bobbin 12, is sandwiched between the driven roller 22 and the driving roller 21, and is wound half a turn around each of them, descending along the front surface of the arm 3, and passing through the tension roller 31. and reaches the presser foot 5. Tension is applied to the tape 7 by a tension roller 31. The tension lever 32 stops at a position where it generates a rotating force that balances the tension of the tape 7. The more it rotates in the anti-A direction, the greater the tension applied to the tape 7. The tape 7 moves forward and backward as the drive roller 21 rotates forward and backward.
being moved backwards. An angle detector 40 consisting of a potentiometer is provided to detect the rotation angle θ of the tension lever 320, and its output signal is input to the control device 50 via an A/D converter 58. Since the rotation angle θ of the tension lever 32 is proportional to the tension of the tape,
The current tension of the tape 7 can be measured from this signal, and the desired tension can be obtained by controlling the rotation of the motor 20 so that the tension lever 32 stops at the commanded angle. FIG. 2 is a block diagram showing the electrical configuration of the tape feeding device according to the embodiment. The data input means includes a dial gauge 57 for manually setting the elongation rate;
It consists of a keyboard 56 for inputting programmed data regarding the elongation rate of the tape together with the sewing length, and a CRT display 59 for displaying the input data. Moreover, the control device 50
is composed of a computer system, which includes a central processing unit (CPU) 51, a ROM 52 that stores a control program, and a proportional constant for the tape elongation rate of the rotation angle of the tension lever 320 for each type of tape. , a RAM 53 for storing programmed data regarding tape feeding, an input/output board 54, and a motor drive circuit 55. RAM53 is a battery (
It is backed up by the route shown in the diagram). motor 20
is a pulse motor, and the motor drive circuit 55 is C
This is a pulse generator that receives rotation command pulses from the PU 51 and generates multiphase excitation pulses. Reference numeral 60 denotes a stitch number detector, which is comprised of an encoder that detects the number of rotations of a main shaft that controls the vertical movement of the sewing machine needle, and a counter that counts the signal thereof. Next, the operation of the device of this embodiment will be explained based on a flowchart showing the processing procedure of the CPU 51. (a) Measurement of elongation characteristics of the tape with respect to the rotation angle of the tension lever. First, as shown in FIG. 3, a signal is input from the angle detector 40, and the rotation angle θ of the tension lever 32 is determined to be the angle θ at which the tension applied to the tape 7 is zero. The motor 20 is controlled so that (100 to 108
). Here, the rotation angle θ is an angle taken in the direction from the vertical direction. Next, the drive roller 21 is rotated by a predetermined angle α, and the tape is wound up by Rα (a value converted to an elongation rate of 0, where R is the radius of the roller). At that time, the tension lever 320 [I angle β is the angle detected input from the device 40 (1
1o-112). Next, the proportionality constant of the rotation angle θ to the elongation rate X of the tape is calculated using the following equation. However, f(θ) is the path length from the drive roller 21 to the presser foot 5 at the rotation angle θ. Once the proportionality constant is determined in this way, the relationship between the rotation angle θ and the elongation rate X can be determined using the following equation. θ=θ. -A-x -・・-(
2) (b) In manual setting mode, the elongation rate of the tape 7 is set at any time by the dial gauge 57, and the manual setting controls the rotation of the motor 2o so that the actual elongation rate of the tape 7 is equal to the set value. In the mode, processing is performed as shown in FIG. First of all,
R is the proportionality constant A corresponding to the tape attached to the device.
Data for selection from the AM 53 is input from the keyboard 56 (202). Next, the control target value Xs of the elongation rate is inputted from the dial gauge 57, and the control target angle θ3 of the tension lever 32 for realizing the elongation rate is calculated using the following equation (204 to 206). σs = −A−x 3+θ.・・・・・・
(3) After that, the output data of the angle detector 40 is input as θ (20g>. The measured value θ of the rotation angle is compared with the control target angle θ, and the control target angle θS is smaller than the measured value θ by Δ. When it is large, the actual tape elongation rate is too large compared to the target value, so the motor 20 is rotated forward by a predetermined amount and the tape elongation rate is controlled to be small (210 to 214
). On the other hand, when the measured value θ is larger than the control target angle θ by Δ, the actual elongation rate of the tape is too small relative to the target value, so the motor 20 is reversed by a predetermined amount, and the elongation rate of the tape increases. (212-216)
. The above series of processes is repeatedly executed in real time, and eventually the rotation angle θ of the tension lever 320 is controlled within a range of ±Δ with respect to the control target angle θ5. As a result, the elongation rate of the tape is also controlled within a predetermined range with respect to the control target value Xs. In this way, the elongation rate of the tape is accurately controlled to the target value set by the dial gauge, both during sewing and when the sewing machine is stopped. Therefore, the tape can be sewn onto the workpiece cloth at the set elongation rate from the first stitch at a desired position. (C) When in program setting mode The device of this embodiment programs the sewing length and tape elongation rate of each divided section on the sewing path as data in the RAM 53 in advance, and stores the sewing length and tape elongation rate of that section as data. The sewing machine has an operation mode in which sewing is performed while sequentially controlling the elongation rate of the tape according to the data obtained. First, in step 304 of FIG.
6 and the CRT display 59, the sewing length 1) to L (m) and the corresponding tape length 1 (1) are displayed for each sewing section.
~1(m) is input (304). Such data is
Number of stitches K (1) ~ K (m) and elongation rate xs (1) ~ xs
(m), and further converted into the corresponding control target angle θ3(1) to θ,(m) using equation (3), and R
It is stored in AM53 (306). In addition, the count is the value obtained by dividing the sewing length by the feed pitch, and the elongation rate X is the value obtained by subtracting the tape length l from the sewing length. This is the value divided by . When the sewing machine start switch 565 is on, the sewing machine motor 64 is driven. The elongation rate of the tape in each sewing section j is controlled as detailed in section (b) (310 to 318). Then, the current stitch count data is input from the stitch count detector 60, and it is determined whether sewing of the j-th section is completed (320-322). When the rotation angle θ of the tension lever 32 is not completed, the rotation angle θ of the tension lever 32 is controlled to the control target angle θ3 (j), and therefore, the elongation rate of the tape is controlled to the target value S (j) of the elongation rate of the j-th section. , sewing progresses. When the rotation angle of the tension lever 32 is completed, the rotation angle of the tension lever 32 is controlled to the control target angle θs (j+1) of the next section, that is, the elongation rate of the tape is controlled to the target value of the elongation rate of the next section. Sewing of the section proceeds (309 to 324
．． 326). In this way, sewing progresses up to the final section. [Modification] In addition to the tension applying means of the above configuration and a tension detector configured with an angle detector, tension is applied directly by a drive roller and a driven roller without using a tension lever, and the tension from the tape applied to the axis of the roller is applied. The force may be detected by a piezoelectric transducer.

【Effect of the invention】

In the tape feeding device of a sewing machine, the present invention provides a value related to the elongation rate of the tape as a control target value, measures the actual tension of the tape, converts one of them into the same physical quantity, and then makes the two values equal. It is characterized by controlling the tension of the tape. Therefore, since the elongation state of the tape is directly controlled to the target value, the finished dimensions of the product can be easily determined. Furthermore, since the elongation state of the tape is controlled independently of the feed control of the work cloth, the responsiveness to changes in the elongation rate is high, and desired gathers can be easily created at desired locations.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a sewing machine equipped with a tape feeding device according to a specific embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of the tape feeding device, and FIG.
4 and 5 are flowcharts showing the processing procedure of the computer system used in the same apparatus.

Claims (2)

[Claims] (1) Tension applying means that variably applies tension to the tape supplied between the presser foot and the feed dog to be sewn onto the work cloth, a tension detector that detects the tension of the tape, and an elongation rate of the tape. an elongation data input means for variably inputting a value related to the elongation; and a value related to the elongation entered by the elongation data input means to a corresponding value related to the tape tension, or vice versa. a conversion means for converting the direction; a growth rate of the control target set by the data input means;
a control device that outputs a signal for controlling the tension of the tape to the tension applying means so that the tension detected by the tension detector becomes equivalently equal to the tension detected by the tension detector; A tape feeding device in a sewing machine. (2) The elongation rate data input means is a data input means for inputting a value related to the sewing length of the work cloth and a tape length corresponding thereto.
Tape feeding device in the sewing machine described in Section 2.