JP2007181551A - Sewing machine cloth feeder - Google Patents

Abstract

The sewing pitch is made substantially the same.
A cloth feed device 1 for a sewing machine includes a cloth feed mechanism S for feeding a cloth placed on a needle plate 2 by a feed dog in synchronism with the vertical movement of a needle bar 4 that moves up and down by driving a sewing machine motor. Cloth feed amount input means for inputting the data of the cloth feed amount by the cloth feed mechanism S, drive control means for driving the cloth feed mechanism S based on the data of the cloth feed amount input by the cloth feed amount input means, A storage for storing a cloth thickness detecting means 70 for detecting the thickness of the cloth fed by the cloth feeding mechanism S and a cloth feed amount conversion table in which the thickness of the cloth and the cloth feed amount suitable for the thickness of the cloth are associated with each other. And a cloth feed amount corresponding to the thickness of the cloth detected by the cloth thickness detecting means 70 are extracted from the cloth feed amount conversion table and inputted by the cloth feed amount input means so as to be the extracted fabric feed amount. Cloth feed amount correction means for correcting the data of the cloth feed amount , Comprising a.
[Selection] Figure 3

Description

  The present invention relates to a cloth feed device for a sewing machine.

  The sewing machine is provided with a cloth feeding device (see, for example, Patent Document 1). As shown in FIG. 6, the cloth feeding device 100 for a sewing machine includes a main shaft 101 connected to a sewing machine motor that is a driving source for sewing. The main shaft 101 rotates around the axis as the sewing machine motor is driven. The main shaft 101 is provided with a feed cam 102 composed of an eccentric cam. A rod 103 is connected to the feed cam 102, and a rod 104 is connected to the rod 103. A connecting arm 105 is connected to one end of the rod 104, and an upper feed shaft 106 is connected to the connecting arm 105. A swing arm 107 is connected to the upper feed shaft 106, and a needle bar swing base 108 is connected to the swing arm 107. On the other hand, an adjustment body 109 is provided at the other end of the rod 104 so that the swinging width of the upper feed shaft 106 can be changed according to the inclination angle of the adjustment body 109.

The main shaft 101 is provided with a counterweight 110. A crank rod 111 is connected to the counterweight 110, and a needle bar 112 is connected to the crank rod 111.
When the main shaft 101 is rotated by driving the sewing machine motor, the needle bar swinging base 108 swings about the fulcrum shaft 108a, and the counterweight 110 swings to move the needle bar 112 up and down.
Note that one end of a link 115 is rotatably connected to the adjustment body 109 by a step screw 116, and an adjustment stand 117 is rotatably connected to the other end of the link 115. The adjusting table 117 is fixed to a shaft 118 that is rotatably supported by the frame. An adjustment dial 119 and a dial shaft 120 are supported on the frame, and the dial shaft 120 is formed with a screw that moves in the axial direction by rotation. The adjustment base 117 is always in contact with the tip of the dial shaft 120 by the force of the spring 121. When the adjustment dial 119 is turned to move the dial shaft 120 in the axial direction, the inclination of the adjustment base 117 changes. .
JP-A-7-136363

FIG. 7 shows the locus of the needle tip of the sewing needle 125 when the feed cam 102 is an eccentric cam. When the feed cam 102 is formed of an eccentric cam, the needle tip draws an elliptical locus R. In such an elliptical locus R, the position where the sewing needle 125 pierces the cloth is at a position a when the cloth is thin (cloth thickness t1) and a position b when the cloth is thick (cloth thickness t2). , The difference c is different. This appears as a difference in the cloth feed amount set by the dial 119. In particular, when the thickness of the fabric is remarkably different during a series of sewing operations (for example, putting on a wide pad), the sewing pitch is different in one process, which is a factor of deteriorating the quality of the sewn product.
As a means for solving such a problem, there is a method in which the feed cam 102 is constituted by a triangular cam and the locus of the needle tip is made close to a rectangle to prevent the sewing pitch from being disturbed due to the thickness of the cloth. There was a problem that acceleration / deceleration was large, speed could not be increased, and noise and vibration were large.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cloth feeding device for a sewing machine that can make the sewing pitch substantially the same.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a sewing machine cloth feeding device, wherein a sewing needle is provided at the lower end, and the needle bar moves up and down by driving a sewing machine motor as a driving source at the time of sewing. A cloth feed mechanism that feeds the cloth placed on the needle plate by the feed dog in synchronization with the vertical movement of the cloth, a cloth feed amount input means for inputting data of the cloth feed amount by the cloth feed mechanism, and the cloth feed amount. Drive control means for driving the cloth feed mechanism based on the cloth feed amount data input by the input means, cloth thickness detection means for detecting the thickness of the cloth fed by the cloth feed mechanism, Storage means for storing a cloth feed amount conversion table in association with a cloth feed amount suitable for the thickness of the cloth, and a cloth feed amount corresponding to the cloth thickness detected by the cloth thickness detecting means. Extracted from feed amount conversion table, before extracted Characterized in that it comprises a cloth feed quantity correcting means for correcting the inputted cloth feed amount of data was by the cloth feed amount input means such that the cloth feed quantity.

According to the first aspect of the invention, when the cloth feed amount data by the cloth feed mechanism is input by the cloth feed amount input means and sewing is started, the drive control means is input by the cloth feed amount input means. The cloth feed mechanism is driven based on the cloth feed amount data. Here, the cloth thickness detecting means detects the thickness of the cloth fed by the cloth feeding mechanism. Then, the cloth feed amount correcting means extracts the cloth feed amount corresponding to the cloth thickness detected by the cloth thickness detecting means from the cloth feed amount conversion table, and the cloth feed amount is set so as to be the extracted cloth feed amount. The cloth feed amount data input by the input means is corrected. After correction of the cloth feed amount data, the drive control means controls the driving of the cloth feed mechanism so as to feed the cloth according to the corrected cloth feed amount data.
Thereby, even if the thickness of the fed fabric changes, the fabric feed amount by the fabric feed mechanism can be corrected according to the thickness of the fabric, so that the sewing pitch can be made substantially the same.

  According to the present invention, even if the thickness of the cloth to be fed changes, the cloth feed amount by the cloth feed mechanism can be corrected according to the thickness of the cloth. Therefore, the sewing can be performed regardless of the thickness of the cloth to be fed. The pitch can be made substantially the same.

Hereinafter, the best mode of a cloth feeding device for a sewing machine will be described in detail with reference to the drawings.
<Configuration of sewing machine>
As shown in FIGS. 1 to 4, the cloth feeding device 1 of the sewing machine moves in the cloth feeding direction and feeds the cloth while being in contact with the cloth, which is the sewing material on the needle plate 2, from above. 20, a presser 30 that presses the cloth toward the needle plate 2 from above, a first operating mechanism 40 that alternately applies a reciprocating motion in the vertical direction to the upper feed 20 and the presser 30, and the upper feed 20 When the upper movement 20 and the presser 30 are each lowered, the second movement mechanism 50 (see FIG. 3) that provides the reciprocating movement in the cloth feeding direction and the lower limit position are determined by contacting the upper movement 20 and the presser 30 from below. An adjustment mechanism (not shown) that can adjust the lower limit position, and a cloth thickness sensor 70 (FIG. 3) as a cloth thickness detecting means for detecting the thickness of the cloth that is placed on the throat plate 2 and is fed with the cloth. Reference) and the cloth feed amount according to the cloth thickness detected by the cloth thickness sensor 70. And a control device 80 (see FIG. 4) as a cloth feed amount correcting means for correcting the data, and an operation panel 90 (see FIG. 4) as a cloth feed amount input means for inputting cloth feed amount data. Yes. Here, the cloth feed mechanism S that feeds the cloth placed on the needle plate by the feed dog in synchronization with the vertical movement of the needle bar (described later) includes an upper feed 20, a presser 30, and a first operating mechanism. 40 and a second operating mechanism 50.

  The upper feed 20 includes an upper feed bar 21 formed so as to extend in the vertical direction along the longitudinal direction of the needle bar 4 provided with the sewing needle 3 at the lower end, and an upper feed leg supported by the lower end portion of the upper feed bar 21. 22 (see FIG. 1). A square piece 24 is rotatably connected to the upper end of the upper feed bar 21 via an upper feed bar holder that holds and fixes the upper feed bar 21. The square piece 24 is slidably engaged with an elongated hole of a guide member 63 extending in the vertical direction. The guide member 63 is fixed to a needle bar swinging table 6 that supports the needle bar 4 and the upper feed bar 21 so as to be swingable with respect to a sewing machine frame (not shown). For this reason, the moving direction of the upper feed 20 is regulated so as to move along the long direction of the long hole of the guide member 63.

At the lower end of the upper feed bar 21 is a feed dog (not shown) that presses the cloth placed on the needle plate 2 from above and projects on the needle plate 2 from below the needle plate 2 at a predetermined timing. An upper feed leg 22 for attaching the cloth and feeding the cloth in the feed direction is attached. The tip of the upper feed leg 22, that is, the lower end portion of the upper feed 20, is curved so as to extend in the surface direction of the needle plate 2 from the vertical direction. Is formed in a sawtooth shape. The upper feed leg 22 is formed with an insertion hole 22a for allowing the sewing needle 3 to pass therethrough.
Further, the upper feed 20 is connected to a second operating mechanism 50 described later, so that it swings together with the needle bar 4, and its lower end portion can reciprocate in the cloth feed direction.

Here, the sewing needle 3 and the needle bar 4 will be described. The needle bar 4 is connected to an eccentric cam 10 provided at the tip of the main shaft 5 via a link 11, and with the rotation of the main shaft 5 around the axis, It operates in the vertical direction (see FIG. 1). The needle bar 4 is attached such that its longitudinal direction is along the vertical direction, and is arranged substantially parallel to the upper feed 20. A sewing needle 3 through which a thread is passed is attached to the lower end of the needle bar 4, and the needle bar 4 moves in the vertical direction so that the tip of the sewing needle 3 is formed in the upper feed leg 22. The cloth is pierced through the cloth 22a.
The vertical movement of the needle bar 4 is synchronized with the vertical movement of the upper feed 20 by the first operating mechanism 40, so that both the sewing needle 3 and the upper feed leg 22 move up and down.

The presser 30 is provided side by side in the cloth feeding direction with respect to the upper feed 20 and includes a presser bar 31 disposed along the vertical direction.
A square piece 34 is rotatably connected to a substantially central portion of the presser bar 31 via a presser bar holder (not shown) that holds and holds the presser bar 31. As in the case of the above-described upper feed 20, the square piece 34 extends in the vertical direction and is slidable and freely slidable in an elongated hole of a guide member 64 fixed to a sewing machine frame (not shown). Are combined.
A presser foot 32 is attached to the lower end of the presser bar 31 to press the cloth placed on the needle plate 2 from above. The tip of the presser foot 32, that is, the lower end portion of the presser 30 is curved so as to extend in the surface direction of the needle plate 2 from the vertical direction, and the inner side of the portion pressing the cloth against the needle plate 2 is vertically penetrated. It is formed in a rectangular frame shape. The inside of the frame is formed long enough to allow reciprocation along the feed direction of the above-described upper feed 20.

The first operation mechanism 40 obtains the driving force of the sewing machine motor and alternately applies a reciprocating operation in the vertical direction to the upper feed 20 and the presser 30.
The first operation mechanism 40 includes a swing shaft 41 disposed substantially parallel to the main shaft 5 that outputs the drive of the sewing machine motor.
The swinging shaft 41 is connected to the main shaft 5 via an eccentric cam 45 and a rod 46 at one end thereof, and reciprocally rotates around the shaft as the main shaft 5 rotates. Further, the base end of the swing arm 42 is fixed to the other end of the swing shaft 41.
The swing arm 42 is rotatably connected to a first connection position of the triangular link 44 via a transmission link (not shown).

  The triangular link 44 is a link body formed in a substantially triangular shape, and is pivotally connected to the transmission link at one vertex that is the first connecting position, and drives the upper feed 20 and the presser 30 up and down. The driving force is obtained. The triangular link 44 is rotatably connected to the upper feed 20 at a second connecting position including one of the other two vertices, and includes a third vertex including the other of the other two vertices. Is connected to the presser 30 at the connecting position. Note that the upper feed 20 and the presser 30 are urged downward via a biasing member (not shown) such as a spring directly or indirectly via the triangular link 44.

The second operation mechanism 50 is for imparting a reciprocating operation in the cloth feeding direction to the upper feed 20 and the needle bar 4.
As shown in FIGS. 1 to 3, the second operating mechanism 50 includes a rod 52 having one end rotatably connected to the main shaft 5 via an eccentric cam 51. A rod 53 that intersects the other end of the rod 52 substantially perpendicularly to the other end of the rod 52 is rotatably connected at a substantially central portion thereof. A square piece 54 is rotatably attached to the upper end of the rod 53, and the square piece 54 is engaged with an adjusting body 55 having a guide groove 55 a for guiding the square piece 54. That is, the square piece 54 is engaged inside the guide groove 55a so as to be slidable, that is, slidable.

The adjusting body 55 is configured to be tiltable. Specifically, as shown in FIG. 3, one end of a link 55b is rotatably connected to the adjustment body 55 by a step screw 55c. One end of a connecting arm 55d is connected to the other end of the link 55b by a step screw 55e, and the other end of the connecting arm 55d is connected to the output shaft of the pulse motor 55f by a set screw 55g.
Thereby, when the pulse motor 55f is driven and the output shaft rotates, the drive is transmitted to the adjusting body 55 via the connecting arm 55d and the link 55b, and the adjusting body 55 can be swung. By swinging the adjusting body 55, the inclination of the guide groove 55a also changes, so that the amount of movement of the square piece 54 can be changed.

Further, one end of an upper feed shaft swing arm 56 is rotatably connected to the lower end of the rod 53. One end of the upper feed shaft 57 is fixed to the other end of the upper feed shaft swing arm 56. The upper feed shaft 57 is disposed substantially parallel to the main shaft 5 described above, and the base end portion of the upper feed arm 58 is fixed to the other end of the upper feed shaft 57.
The upper feed arm 58 is connected to the needle bar rocking base 6 described above via a square piece 54 that is rotatably connected at the tip (lower end) thereof. Thereby, the second operation mechanism 50 can reciprocate the upper feed 20 and the needle bar 4 in the cloth feed direction, and can change and adjust the feed amount.

(Cloth thickness sensor)
The cloth thickness sensor 70 includes a detection arm 71 whose tip is in contact with the cloth on the needle plate 2 from above in the vicinity of the presser 30 and a potentiometer 72 that detects the swing angle of the detection arm 71. The potentiometer 72 is disposed at the lower end of the tip of the sewing machine arm.

The potentiometer 72 includes a rotatable detection shaft (not shown), and has a function of outputting a signal corresponding to the rotation angle generated on the detection shaft to the control device 80 (see FIG. 4). The base end portion of the detection arm 71 is pivotally supported.
The detection arm 71 has a base end portion supported by the detection shaft of the potentiometer 72, and a distal end portion that is perpendicular to the detection axis and hangs obliquely downward. The tip of the detection arm 71 is landed on the upper surface of the needle plate 2 adjacent to the presser 30 in the vertical direction, and is arranged so as to contact the cloth set on the upper surface of the needle plate 2 during sewing. Yes. Accordingly, at the time of sewing, the detection arm 71 is rotated according to the thickness of the cloth, and the detection shaft of the potentiometer 72 on the base end side outputs a signal to the control device 80 described later by the rotation angle corresponding to the thickness. The control device 80 calculates the thickness of the cloth from the detected rotation angle and the known length of the detection arm 71.

The operation panel 90 (see FIG. 4) is used by an operator to perform various setting operations on the sewing machine and input operations for various data. The operation panel 90 and the sewing machine 1 are connected by a wired or wireless line (not shown).
The operation panel 90 includes a plurality of operation key groups (not shown) that can perform various settings of the sewing machine 1 and various data input operations, a data display unit (not shown) that displays various setting states, and the like. .
Note that data set and input via the various keys on the operation panel 90 is output to the control device 80 described later.

(Control device)
As shown in FIG. 4, the control device 80 includes a CPU 81 that executes each process in accordance with a processing program related to sewing, a RAM 82 that expands the process program and serves as a work area for the CPU 81, a processing program for executing each process, ROM 83 for storing processing data and the like.
The RAM 82 temporarily stores cloth feed amount data 82 a that is data of the cloth feed amount input from the operation panel 90.
The ROM 83 stores a drive control program 83a for realizing the function of driving the above-described cloth feed mechanism S (specifically, the pulse motor 55f) based on the cloth feed amount data 82a input from the operation panel 90. Yes. That is, when the CPU 81 executes the drive control program 83a, the control device 80 functions as a drive control unit.
The ROM 83 stores a cloth feed amount conversion table 83b in which the cloth thickness and the cloth feed amount suitable for the cloth thickness are associated with each other. That is, the ROM 83 functions as a storage unit.
In the ROM 83, the cloth feed amount corresponding to the thickness of the cloth detected by the potentiometer 72 is extracted from the cloth feed amount conversion table 83b, and the cloth feed input by the operation panel 90 so as to become the extracted cloth feed amount. A cloth feed amount correction program 83c that realizes a function of correcting the amount data 82a is stored. That is, when the CPU 81 executes the cloth feed amount correction program 83c, the control device 80 functions as a cloth feed amount correction means.

<Sewing method using cloth feeding device>
Next, a sewing method using the cloth feeding device will be described.
As shown in FIG. 5, when the user inputs a cloth feed amount from the operation panel 90 before sewing (step S1), the input cloth feed amount is temporarily stored in the RAM 82 as the cloth feed data 82a. Then, when a sewing start instruction is input by the user depressing the pedal, the CPU 81 performs sewing while controlling the driving of the pulse motor 55f so that the cloth feed amount stored in the RAM 82 is obtained (step S2). During sewing, the thickness of the cloth is detected by the potentiometer 72 (step S3). When the thickness of the cloth is detected, the CPU 81 executes the cloth feed amount correction program 83c, thereby causing the cloth feed amount conversion table 83b. The cloth feed amount corresponding to the cloth thickness detected by accessing is extracted (step S4). At this time, the CPU 81 updates the cloth feed amount data 82a stored in the RAM 82 to the extracted cloth feed amount.

Then, the CPU 81 executes the drive control program 83a to drive the pulse motor 55f so that the RAM 82 has the updated cloth feed amount (step S5).
Next, the CPU 81 determines whether or not a series of sewing has been completed (step S6). Here, when the CPU 81 determines that a series of sewing has been completed (step S6: YES), the CPU 81 ends the present process. On the other hand, when the CPU 81 determines that the series of sewing is not finished (step S6: NO), the CPU 81 returns to the process of step S3.

<Effect>
According to the sewing machine feeding device 1, when the cloth feed amount data 82a is input from the operation panel 90 and sewing is started, the CPU 81 executes the drive control program 83a, thereby causing the cloth feed input by the operation panel 90 to be performed. The pulse motor 55f is driven based on the quantity data 82a. Here, the potentiometer 72 detects the thickness of the cloth fed by the cloth feeding mechanism S. Then, the CPU 81 executes the cloth feed amount correction program 83c to extract the cloth feed amount corresponding to the detected cloth thickness from the cloth feed amount conversion table 83b, so that the extracted cloth feed amount is obtained. The cloth feed amount data 82a input to is corrected. After correcting the cloth feed amount data 82a, the CPU 81 controls the driving of the pulse motor 55f so as to feed the cloth according to the corrected cloth feed amount data 82a.
Thereby, even if the thickness of the cloth to be fed changes, the drive of the pulse motor 55f can be controlled in accordance with the thickness of the cloth to correct the cloth feed amount by the cloth feed mechanism S. Can be almost the same.
Further, since an eccentric cam can be used as the feed drive mechanism, noise and vibration as in the case of using a triangular cam are reduced, and the burden on the operator is reduced. Furthermore, since the rotational speed of the main shaft can be increased as compared with the case where a triangular cam is used, the productivity of the sewing product can be improved.

<Others>
The scope of the present invention is not limited to the above embodiment. For example, each program stored in the ROM may be a single program or may be further subdivided. Moreover, in the said embodiment, you may make it process not only what processes by software like a program but by hardware. The cloth thickness detecting means for detecting the cloth thickness is not limited to a potentiometer, and may be an encoder. Further, although the upper feed mechanism has been described as the cloth feed mechanism, a lower feed mechanism provided with a feed dog that feeds the cloth in contact with the lower surface of the cloth may be used.
In addition, the design can be freely changed within the scope of the invention.

The perspective view which shows the cloth feeder of a sewing machine. The front view which shows a 2nd operation | movement mechanism. The disassembled perspective view explaining the drive mechanism of an adjustment body. The block diagram which shows the structure of a control apparatus. The flowchart which shows a sewing process. The perspective view which shows the feeding apparatus of the sewing machine in a prior art. The figure explaining the problem in a prior art.

Explanation of symbols

1 Sewing machine cloth feed device 2 Needle plate 4 Needle bar 70 Cloth thickness sensor (cloth thickness detection means)
80 Control device (drive control means, cloth feed amount correction means)
82a Cloth feed amount data (cloth feed amount data)
83 ROM (storage means)
90 Operation panel (cloth feed amount input means)
S Cloth feed mechanism

Claims (1)

A cloth feed mechanism that has a sewing needle at the lower end and feeds the cloth placed on the needle plate by the feed dog in synchronization with the vertical movement of the needle bar that moves up and down by the drive of the sewing machine motor that is the drive source during sewing. When,
A cloth feed amount input means for inputting data of a cloth feed amount by the cloth feed mechanism;
Drive control means for driving the cloth feed mechanism based on the cloth feed amount data input by the cloth feed amount input means;
Cloth thickness detecting means for detecting the thickness of the cloth fed by the cloth feeding mechanism;
Storage means for storing a cloth feed amount conversion table in which a cloth thickness and a cloth feed amount suitable for the thickness of the cloth are associated with each other;
A cloth feed amount corresponding to the thickness of the cloth detected by the cloth thickness detection means is extracted from the cloth feed amount conversion table and is input by the cloth feed amount input means so as to be the extracted cloth feed amount. Cloth feed amount correcting means for correcting the data of the cloth feed amount,
A sewing machine cloth feed device comprising:

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