JPH0667431B2 - Sizing device for sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention corrects the actual cloth feed amount by the feed dog for each stitch to match the set cloth feed pitch, and at the same time, sew the set number of stitches. The present invention relates to a constant-dimension sewing device for a sewing machine configured to stop the main shaft of the sewing machine and perform constant-dimension sewing when the above-mentioned steps are completed.

(Prior Art) Conventionally, this type of constant-dimension sewing device detects the number of stitches from the start of sewing to the end of sewing, and when the number of stitches matches the number of stitches corresponding to a predetermined sewing length, the sewing machine It is known that the main shaft is stopped.

(Problems to be solved by the invention) However, in general, when the sewing machine is operated at a high speed, the responsiveness between the respective parts in the feed mechanism is lowered by inertia, and the stitch pitch is lower than that at the low speed operation. Grows by about 10 to 15%. Therefore, according to the conventional constant-dimension sewing device, there is a problem that the actual sewing length does not exactly match the required sewing length even if the sewing is performed according to the set number of stitches.

Structure of the Invention (Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and the means for solving the problems is as shown in FIG. Forming mechanism including a needle 5 which is moved up and down, a feed dog 10 for intermittently transferring a work cloth in accordance with a four-feed motion, and a swing of a horizontal feed shaft 6 including a feed base 8 and a horizontal feed shaft 6. A horizontal feed mechanism for imparting a horizontal movement to the feed dog 10 in response to the movement, and a signal generation for generating a signal in synchronization with the horizontal movement of the feed dog 10 provided on the horizontal feed shaft 6 or the feed base 8. Device 44, pitch setting means 30, 31 for setting the cloth feed pitch per needle, pitch changing means 38 for changing the cloth feed pitch by changing the swing amount of the horizontal feed shaft 6, and the number of stitches setting The means 49, the number of stitches detecting means 50, and the above-mentioned signal according to one swing of the horizontal feed shaft 6. With the signal output from the raw device 44 controls the operation of the pitch changing means 38 so as to match the signal corresponding to the set cloth feed pitch,
The sewing machine main shaft 2 is controlled to stop when the number of detected stitches matches the set number of stitches.

(Operation) Therefore, in the constant-dimension sewing device of the present invention, the signal generator 44 outputs a signal corresponding to the actual cloth feed amount extremely accurately, and the signal and the signal corresponding to the set cloth feed pitch. Are compared, and the pitch changing means 38 is operated based on the comparison value to correct the cloth feed pitch for each stitch to match the set value, and at the same time, to sew the stitch number that matches the set number of stitches. When the sewing is completed, the rotation of the sewing machine main shaft 2 is stopped, and thereby the fixed length sewing with the sewing length that exactly matches the required sewing length is performed.

(Embodiment) An embodiment embodying the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a sewing machine main shaft 2 is rotatably supported in an arm portion 1a of a sewing machine frame 1, and a pulley 3 is attached to the right end thereof. A needle bar 4 is vertically movably supported on an arm portion 1a of the sewing machine frame 1, and a needle 5 is attached to a lower end of the needle bar 4. Further, a motor 13 is installed below the bed portion 1b of the sewing machine frame 1 constituting the work cloth supporting surface,
It is connected to the pulley 3 via 15. Then, with the rotation of the sewing machine main shaft 2 driven by the motor 15, the needle 5 moves up and down through a work cloth (not shown) on the bed portion 1b, and a thread wheel (not shown) provided in the bed portion 1b. A lock stitch is formed on the work cloth in cooperation with the catcher. Accordingly, the stitch forming mechanism is constituted by the needle 5 and the thread catcher.

As shown in FIG. 2, a horizontal feed shaft 6 and a vertical feed shaft 7 extending in parallel to each other in the left-right direction are rotatably supported in the bed portion 1b of the sewing machine frame 1. A feed base 8 is rotatably supported on a left end of the horizontal feed shaft 6 via a support arm 9, and a feed dog 10 which is capable of projecting and retracting from the upper surface of the bed portion 1b is attached to the upper surface thereof. The vertical feed shaft 7
A bifurcated arm 11 is attached to the left end of and is engaged with an engaging portion 8a at the front end of the feed base 8. And the sewing machine spindle 2
When the horizontal feed shaft 6 and the vertical feed shaft 7 are reciprocally rotated in accordance with the rotation, the feed dog 10 is moved by four feeds, and the work cloth on the bed portion 1b is horizontally fed intermittently. It has become so.

That is, a horizontal feed eccentric cam 12 is mounted on the sewing machine main shaft 2 as shown in FIG. 3, and a crank rod 14 is fitted to the eccentric cam 12 at its upper end. A feed selector 16 is rotatably supported by a support shaft 17 in the bed portion 1b of the sewing machine frame 1 so as to correspond to the lower end of the crank rod 14. A rotation lever 18 is rotatably supported by a support pin 19 between the rear end portions of the feed switching device 16, and a front end thereof is rotatably connected to a lower end of the crank rod 14 by a connection pin 20. . A connecting arm 21 is fixed on the horizontal feed shaft 6 behind the feed changer 16, and a connecting rod 22 is provided between the upper end of the horizontal feed shaft 6 and the front end of the rotating lever 18 by a shaft 23 and the connecting pin 20. It is installed. Then, when the horizontal feed eccentric cam 12 is rotated in a state where the support pin 19 is set and arranged at a predetermined position by the rotation adjustment of the feed changer 16, the rotation lever 18 is moved via the crank rod 14. The support pin 19 is reciprocally rotated up and down in the vertical direction, and in accordance with the setting position of the support pin 19, the connecting arm 21 is given a turning force in the front-rear direction via the connecting rod 22, and the horizontal feed shaft 6 is moved to a predetermined position. It is swung in the range. Therefore, the horizontal feed shaft 6, the feed base 8, the crank rod 14, the feed changer 16 and the like constitute the horizontal feed mechanism of this embodiment, and the horizontal movement of the horizontal feed shaft 6 causes the feed dog 10 to move horizontally. The exercise of is given.

An eccentric cam for vertical feed (not shown) is attached to the sewing machine main shaft 2, and a crank rod for vertical feed is connected between the eccentric cam and the vertical feed shaft 7. Then, as the eccentric cam for vertical feed rotates, the vertical feed shaft 7 is reciprocally rotated within a predetermined range via the crank rod, so that the feed dog 10 is vertically moved via the feed base 8. It is supposed to be granted.

As shown in FIG. 4, a feed adjusting member 25 is rotatably supported by a support shaft 26 in the arm portion 1a of the sewing machine frame 1, and is rotated clockwise by the action of a spring (not shown). The V-shaped feed control cam 27 is urged on its front side.
Are formed. A connecting rod is provided on the rear side of the feed adjusting member 25.
An upper end 28 is rotatably attached by a screw 29, and a lower end thereof is rotatably connected to a support pin 19 on the feed changer 16 as shown in FIGS. Further, as shown in FIG. 4, a manual operation member 30 is screwed onto the arm portion 1a of the sewing machine frame 1 in front of the feed adjusting member 25, and the feed control cam of the feed adjusting member 25 is attached to the inner end thereof. A holding portion 32 is provided which engages with the member 27 and regulates and holds the feed adjusting member 25 at a predetermined position against the action of the spring.

Then, the feed adjusting member 25 is always arranged at the position shown by the solid line in FIG. 4 by the action of the spring, and the connecting rod 28 is pushed down, so that the feed changer as shown in FIG. 3 (a).
16 is arranged at the lower rotation position where the cloth feed pitch is large. Therefore, in this state, when the feed adjusting member 25 is rotated counterclockwise as shown by a chain line in FIG. 4 against the action of the spring by the rotation operation of the manual operation member 30, the connecting rod 28 The feed changer 16 is rotated in the clockwise direction in FIG. 3 (a) via the ascent of the connecting pin 20 and the axis of the support pin 19 on the feed changer 16 is the connecting pin 20 as shown in FIG. 3 (b). And axis
The cloth feed pitch becomes smaller as it gets closer to the straight line LL connecting with the axis of 23, and the axis of the support pin 19 moves upward beyond LL as shown in FIG. 3 (c). The cloth feed direction is reversed.

On the other hand, as shown in FIG. 4, the operating portion of the manual operating member 30.
An annular magnet body 24 is attached to the back surface of 30a. The arm portion 1a of the machine frame 1 of the sewing machine faces the magnet body 24.
A pitch detector 31 composed of a Hall element is embedded in the front surface, and when the manual operation member 30 is rotated, a signal corresponding to the amount of the rotation operation is output from the pitch detector 31. The cloth feed pitch per needle is detected. Therefore, the manual operation member 30 and the pitch detector 31 constitute pitch setting means.

As shown in FIG. 2, an operating shaft 34 is provided in the arm portion 1a of the sewing machine frame 1 so as to extend leftward and rightward above the feed switching device 16.
Is rotatably supported, and an operation lever 37 exposed to the outside of the arm portion 1a is attached to the right end thereof. Also, the operating axis
The actuating arm 35 is fixed to the left end of 34, and its rear end is screwed.
It is rotatably connected to the intermediate portion of the connecting rod 28 by 36. Then, the operating shaft 34 is pushed by pressing the operating lever 37.
When the arm is rotated clockwise in FIG.
The feed changer 16 is rotated through the 35 and the connecting rod 28 to the reversing position as shown in FIG. 3 (c) so that the cloth feeding direction is reversed.

Further, a servo solenoid 38 is disposed in the arm portion 1a of the sewing machine frame 1 behind the operating shaft 34, and a front end of the armature 39 is operatively connected to the operating shaft 34 via a connecting body 40. The servo solenoid 38 constitutes the pitch changing means in this embodiment, and the armature
When the operating shaft 34 is rotated by a predetermined amount in the clockwise direction in FIG. 2 in accordance with the forward movement of 39, the feed switch 16 is moved to the state shown in FIG. 3 (b) via the operating arm 35 and the connecting rod 28. As shown, the cloth feed amount is rotated in the decreasing direction so that the cloth feed pitch is reduced and corrected.

On the other hand, a detected piece 42 having a large number of slits 41 is fixed on the horizontal feed shaft 6 between the feed base 8 and the feed changer 16, and the sewing machine corresponds to the detected piece 42. A photo interrupter 43 is provided in the bed portion 1b of the frame 1. The detected piece 42 and the photo interrupter 43 constitute a signal generator 44, which outputs a signal of the number of pulses corresponding to the swing amount of the horizontal feed shaft 6.

Further, as shown in FIG. 1, the arm position la is provided with a needle position detector 50 composed of a light emitting element and a light receiving element facing the pulley 3, and a reflector 33 is attached to the pulley 3. . On the reflector 33, there are light reflection portions for timing signals, needle up position detection signals, and needle down position detection signals for reflecting the light from the light projecting element and entering the light receiving element at predetermined angles. Formed at intervals. Then, the needle position detector 50, when detecting the reflected light from each light reflecting portion for the needle up and needle down position detection signals, directs the needle up signal and the needle down signal to the CPU 46 described later at different timings. The CPU 46 outputs the needle 5 based on these signals.
The number of up and down movements of is detected. Therefore, the needle position detector 50 and the CPU 46 form a needle number detecting means.

Next, the control circuit of the sewing machine in this embodiment will be described with reference to FIG. A start switch 48, a stitch number setting key 49, the signal generator 44, the pitch detector 31 and the needle position detector 50 are connected to a central processing unit (CPU) 46 as a control means through an input interface 47. There is. The stitch number setting key 49 is composed of a numeric keypad on the operation panel 45 (see FIG. 1) provided on the front surface of the arm portion 1a of the sewing machine frame 1. Also, output interface 52
A drive solenoid 55 for connecting / disconnecting a clutch mechanism provided in the drive transmission system between the motor 13 and the sewing machine main shaft 2 is connected to the servomotor for changing the cloth feed pitch. The solenoid 38 is connected.

Further, a random access memory (RAM) 53 and a read only memory (ROM) 54 are connected to the CPU 46. R
The OM54 is equipped with a program to control the entire sewing machine. The RAM 53 stores set cloth feed pitch data set by the operation of the manual operation member 30 and detected by the pitch detector 31, and predetermined stitch number data set by the operation of the stitch number setting key 49. It And
The CPU 46 compares the signal corresponding to the cloth feed amount per one stitch output by the signal generator 44 with one swing of the horizontal feed shaft 6 with the set cloth feed pitch data output by the pitch detector 31. Calculate and output a signal based on the difference to drive the servo solenoid 38, and add the number of vertical movements of the needle 5 based on the needle up and needle down signals output from the needle position detector 50 from the start of sewing. When the added value and the set number of stitches data match, a drive signal is output to the drive solenoid 55 to stop the rotation of the sewing machine main shaft 2.

Next, the operation of the sewing machine configured as described above will be described with reference to FIG.

Now, at the time of starting sewing, a desired cloth feed pitch is set by the operation of the manual operation member 30, and a predetermined number of stitches is input and set by the operation of the stitch number setting key 49, and at the step S1, The 1 set cloth feed pitch data detected by the pitch detector 31 and the set stitch number data are stored in the RAM 53. Next, in step S2, the operation of the start switch 48 is confirmed, sewing is performed by the needle 5 as the sewing machine spindle 2 rotates, and cloth feed by the feed dog 10 is performed as the horizontal feed shaft 6 swings. Then, in step S3, the number of pulses corresponding to the swing amount of the horizontal feed shaft 6 output from the signal generator 44 is added. Then, in step S4, when one up / down movement of the needle 5 is confirmed by the needle up signal output from the needle position detector 50 and the next needle up signal, the process proceeds to step S5, and the addition value is stored. It is determined whether or not it matches the cloth feed pitch data. If they match, the process returns to step S3, and the sewing of the next needle is executed at the same cloth feed pitch as the preceding needle.

By the way, when the responsiveness of the feed mechanism section is lowered due to inertia and the cloth feed pitch is extended due to the high-speed operation of the sewing machine, and the cloth feed amount of the preceding needle does not match the set cloth feed pitch data, From step S5 to step S6, the servo solenoid 38 is driven by the pulse number signal based on the difference between the two data. And the armature in FIG.
With the projecting movement of 39, the operating shaft 34, the operating arm 35, and the connecting rod 28
Also, the horizontal feed shaft 6 is rotated in the direction of decreasing the cloth feed amount through the feed changer 16, and the cloth feed pitch by the feed dog 10 is reduced and corrected. In step S7, the reduced pulse number output from the signal generator 44 in accordance with the rotation of the horizontal feed shaft 6 during the reduction correction is subtracted from the pulse number corresponding to the cloth feed amount of the preceding needle. Subsequently, in step S8, it is determined whether or not the subtracted value matches the set cloth feed pitch data, and the above-described correction operation is executed until they match.

When the cloth feed pitch is corrected according to the set value by the operation of the servo solenoid 38, the process proceeds to step S9, where it is determined whether the number of stitches from the start of sewing matches the set number of stitches. The process returns to S3 and the sewing of the next needle and the above-mentioned correction process are repeated. On the other hand, when the sewing that matches the set number of stitches is completed, the process proceeds to step S10, and after the needle down position of the needle 5 is confirmed based on the needle down signal from the needle position detector 50,
In step S11, the drive solenoid 55 is operated, the clutch mechanism is disengaged, and the rotation of the sewing machine main shaft 2 is stopped.

The present invention is not limited to the configuration of the above-described embodiment. For example, as shown in FIG. 7, one side surface of the feed base 8 is provided with an inclined surface 58 inclined with respect to the horizontal movement direction of the feed dog 10. While fixing the detected piece 59 provided with, the Hall element 60 is arranged in the bed portion 1b so as to face the detected piece 59, the signal generator 44 is constituted by both 59, 50, As shown in FIG. 8, a plate 62 to be detected having a large number of slits 61 is fixed to one side surface of the feed base 8 so as to extend along the longitudinal direction of the feed plate 8, and the plate 62 to be detected is attached.
The light emitting and receiving elements 63 and 64 are arranged so as to sandwich the
The signal generator 44 is configured by 4 or the signal generator 44 is configured by a linear encoder or the like, and the configuration of each unit is arbitrarily changed and embodied without departing from the scope of the present invention. It is also possible.

As described in detail above, according to the present invention, the signal generator is provided on the horizontal feed shaft or the feed base, and even when the sewing machine is operated at high speed, the signal generator actually uses the feed dog. Since a signal corresponding to the cloth feed amount of is output very accurately, the pitch changing means is operated to change the cloth feed pitch for each stitch so that the signal matches the set cloth feed pitch data. It is said that the stitch pitch can be obtained according to the set value, good stitches can be formed without pitch unevenness and irregularity of thread tightening, and fixed-dimension stitching with a stitch length that exactly matches the required stitch length can be performed. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the configuration of the present invention. 2 to 6 show an embodiment of the present invention, FIG. 2 is a perspective view showing a horizontal feed mechanism, and FIGS. 3 (a), (b), and (c) are adjustments of the cloth feed amount. FIG. 4 is a partial longitudinal sectional view showing the structure, FIG. 4 is a partial side sectional view of the sewing machine, FIG. 5 is a control circuit diagram, and FIG. 6 is a flow chart diagram. 7 and 8 show another example of the signal generator according to the present invention. FIG. 7 is a plan view and FIG. 8 is a longitudinal sectional view. In the figure, 1 is a machine frame, 1b is a bed constituting a work cloth supporting surface, 2 is a sewing machine spindle, 5 is a needle, 6 is a horizontal feed axis, 7 is a vertical feed axis, 8 is a feed table, and 10 is a feed. Tooth, 13 is a motor, 16 is a feed changer, 25 is a feed adjusting member, 30 is a manual operating member, 31 is a pitch detector, 38 is a servo solenoid that constitutes pitch changing means, 44 is a signal generator, and 46 is a control CPU as means, 49 is a stitch number setting key, 53 is RAM, and 54 is ROM.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Katsuhiko Sato 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Brother Industries, Ltd. (72) Inventor Tetsuo Ozawa 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Brother Industries, Ltd.

Claims (1)

[Claims] 1. A stitch is provided on a work cloth on the work cloth support surface (1b), including a needle (5) which is moved up and down across the work cloth support surface (1b) as the sewing machine spindle (2) rotates. The stitch forming mechanism to be formed and the feed dog (1
0), a feed table (8) for supporting the feed dog (10), and a horizontal feed shaft (6) for supporting the feed table (8) and swinging with the rotation of the sewing machine main shaft (2). ), Which is provided on the horizontal feed shaft (6) or the feed table (8), and a horizontal feed mechanism that imparts a horizontal motion to the feed dog (10) with the swing of the horizontal feed shaft (6). , A signal generator (44) for generating a signal synchronized with the horizontal movement of the feed dog (10), and a pitch setting means (3) for setting the cloth feed pitch per needle.
0, 31) and the horizontal feed mechanism are operatively connected, and by changing the swing amount of the horizontal feed shaft (6) during sewing,
Pitch changing means (38) capable of changing the cloth feed pitch
A needle number setting means (49) for setting a predetermined number of stitches; a needle number detecting means (50) for detecting the number of vertical movements of the needle (5) associated with sewing work; and the horizontal feed shaft (6). The pitch changing means (38) is operated and controlled so that the signal output from the signal generator (44) with one swing of No. 1 coincides with the signal corresponding to the set cloth feed pitch. Number of stitches detection means (5
0) the control means (46) for controlling the sewing machine spindle (2) to stop when the number of stitches detected by the sewing machine matches the set number of stitches. Sewing equipment.