JP4486773B2 - sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine.
[0002]
[Prior art]
A cloth feed device that conveys the sewing product at a predetermined feed pitch in the conveyance direction for each stitch, and a needle swing device that can move the sewing needle in an arbitrary amount of movement in a direction orthogonal to the conveyance direction of the sewing product, 2. Description of the Related Art A sewing machine that forms a stitch pattern by repeating a unit pattern on a workpiece by changing a movement amount of a sewing needle by a needle swing device has been conventionally known. In such a sewing machine, storage means for determining the amount of movement of the sewing needle required to form the stitch pattern is stored for each needle based on the stitch data and storage means for storing the stitch data corresponding to the number of stitches. Pattern sewing control means for changing the amount of movement of the sewing needle by the needle swing device to form a stitch pattern is provided. In addition, it is also well known in the art to perform back stitching in order to prevent fraying of the thread end at the start or end of sewing in a sewing machine.
[0003]
As a stitch pattern formed in the sewing machine that moves the sewing needle in a direction orthogonal to the conveyance direction of the workpiece, a zigzag with a constant sewing width W from the pattern start point to the pattern end point as shown in FIG. There is a (staggered) pattern 50 and a stitch pattern 56 that repeatedly forms a unit pattern 56A whose sewing width continuously changes as shown in FIG. The workpiece is conveyed in the C direction by the cloth feeding device, and the sewing needle is moved in the AB direction by the needle swing device. FIG. 10B illustrates a circular pattern, but FIG. 11 illustrates a scalloped pattern formed by 24 needles as another example of the unit pattern 56A in which the sewing width changes. FIG. 11A shows a scalloped pattern with the arc portion facing right, and FIG. 11B shows a scalloped pattern with the arc portion facing left. The scalloped pattern is a crescent-shaped shell-shaped pattern, and is used, for example, to sew the front part of a sewing object such as a girdle or a body suit, and gives a high-quality feeling to the sewing object.
[0004]
FIG. 12A shows an example of staggered stitches 52 and 54 at the start and end of sewing of the staggered pattern 50. The amount of movement of the sewing needle when performing the back stitches 52 and 54 is performed by using the amount of movement of the sewing needle required for forming the staggered pattern 50 as it is and reducing the feed pitch of the sewing product by the cloth feeding device. ing. FIG. 12B shows a seam pattern when the back stitches 52 and 54 in FIG. 12A are performed without changing the feed pitch.
[0005]
[Problems to be solved by the invention]
However, in the case of the stitch pattern 56 in which the stitch width changes continuously, the amount of movement determined based on the stitch data for forming the stitch pattern is used as it is as the amount of movement of the sewing needle in order to perform stop stitching. If the method of using and making the conveyance pitch of a to-be-sewn product small is adopted, it looks bad. The case of the scalloped pattern shown in FIG. 13 will be described as an example. As shown in FIG. 13A, as shown in (a), the start stitch 58 and the end stitch 60 at the end of the stitch pattern 56 are the start of sewing of the stitch pattern 56 in (b). Since the portion 57 and the sewing end portion 59 are simply contracted in the feed direction, in the case of the illustrated example, part of the back stitches 58 and 60 protrudes extremely to the left, and looks good. bad.
[0006]
Japanese Patent Laid-Open No. 2000-157766 discloses an example of a device for creating backstitch data used in a sewing machine that repeatedly forms a predetermined stitch pattern on such a workpiece. This device determines the movement amount of the sewing needle based on the stop stitch data corresponding to the arbitrary number of stitches of the stitch data, and includes at least two stitches composed of the stitch data corresponding to the arbitrary stitch number and the stitch data adjacent to the stitch data. This is derived so as to be close to the average value of the movement amount of the seam based on the data. In this method, it is necessary to perform the calculation as described above for all the set number of stitches for back stitching. Further, since this apparatus is provided with a stop table stored corresponding to the conveyance of the sewing object for each step, a large storage area in the pattern memory is required, resulting in an increase in cost.
[0007]
It is an object of the present invention to provide a sewing machine that can perform stitch sewing of a stitch pattern whose stitch width continuously changes with a small storage area in a pattern memory and simple and good-looking.
Another object of the present invention is to provide a sewing machine that can reliably prevent fraying of the thread end at the start or end of sewing in a simple manner.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1
A sewing needle that can move up and down;
A cloth feeding device that conveys the sewing product at a predetermined feeding pitch in the conveying direction for each stitch;
A feed pitch changing device capable of changing the feed pitch;
A needle swing device capable of moving the sewing needle to an arbitrary needle swing position in a direction orthogonal to the transport direction;
A seam pattern selecting means for selecting a shell-shaped scalloped pattern having a stitch width which is formed at a predetermined number of stitches and continuously changes in a plurality of different stitch widths and has the widest center width.
Storage means for storing stitch data for determining the needle swing position for forming the scalloped pattern on the sewing product in correspondence with the number of stitches;
The number of backtack stitches setting means for setting the number of backtack stitches,
Based on the stitch data of the scalloped pattern, the scalloped pattern selected by the stitched pattern selecting means is repeated on the workpiece by changing the stitching position by the stitching device for each needle. Pattern sewing control means for forming a pattern;
A pattern sewing needle number setting switch for setting the number of stitches of the scallop pattern to be formed on the sewing product;
A stop sewing data of sewing end, said a scalloped pattern sewing of the last stitch of the stitch data, the scallop pattern sewing of whether to create a stitch data of the last stitch and the next stitch data as repeated data alternately, or, the and stitch data of the last stitch scallop pattern stitch, a stitch data creating apparatus for creating a repetitive data one stitch before the stitch data in alternating stitch data of the last needle of the scalloped pattern sewing,
After the scallop pattern sewing for the number of stitches set by the pattern sewing needle number setting switch is finished, when the back stitch at the end of sewing is selected, the number of stitches set by the back stitch needle number setting means is In addition, the sewing machine includes a backtack control means for forming a backtack on the workpiece by changing the needle swinging position by the needle swinging device for each needle based on the backtack data at the end of sewing,
A sewing machine is provided in which the feed pitch of the workpiece is made smaller than the predetermined feed pitch by the feed pitch changing device at the time of back stitching.
The invention according to claim 2 is the sewing machine according to claim 1,
The backtack data creation device
The back stitch data at the start of sewing is created as data in which the stitch data at the 0th needle of the scalloped stitch and the stitch data at the 1st needle are alternately repeated ,
A sewing machine is provided in which the backstitch control means forms a backstitch on the workpiece when the backstitch at the start of sewing is selected.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the sewing machine according to the present invention will be described. As shown in FIGS. 1 and 2, the sewing machine according to the present embodiment includes a sewing machine frame 1, a sewing machine main shaft 2 that is rotatably supported in the sewing machine frame 1, and a needle bar that can move up and down in conjunction with the main shaft 2. 3, and a feed dog (cloth feed device) 4 that performs a feed motion for transporting the workpiece in the transport direction (direction C in FIG. 2) in conjunction with the main shaft 2, and the needle bar 3 to be sewn 6 1 is provided with a needle swinging device 100 that can be moved by an arbitrary amount of movement in a direction (AB direction in FIG. 1) perpendicular to the conveying direction. A sewing needle 5 is fixed to the lower end of the needle bar 3.
[0013]
A presser foot 8 is disposed above the sewing machine bed 7 that supports the workpiece 6 so as to face the feed dog 4. The presser foot 8 is lowered during sewing to press the workpiece 6 to be sewn. The feed dog 4 draws an elliptical movement trajectory D vertically and horizontally in conjunction with the main shaft 2 and is sewn between the feed dog 4 while floating from the lower side of the sewing machine bed 7 to the upper side. 6 is conveyed in the conveyance direction C. The sewing machine frame 1 is further provided with a feed pitch adjustment dial 9, a back stitch feed pitch adjustment dial 40, and an operation panel 10. The feed pitch adjustment dial 9 sets the transport amount (feed pitch) for each stitch. Further, the feed stitch adjustment dial 40 for back stitching sets the feed pitch at the time of back stitching. The feed pitch set by the feed pitch adjustment dial 9 and the feed stitch adjustment dial 40 for back stitching is selected by the movement of the feed adjustment body (not shown) constituting the feed mechanism. Is done.
Usually, the feed adjusting body is biased in one direction by a spring. Then, the workpiece is fed by the set amount of the feed pitch adjustment dial 9. Further, at the time of backtacking, a backtack solenoid 41 shown in FIG. 3 is driven to move the feed adjusting body against the urging force of the spring. The workpiece is fed at the feed pitch of the back-sewing feed pitch adjustment dial 40. The back stitch solenoid 41, the back feed feed pitch adjusting dial 40 and the feed adjuster constitute a feed pitch changing device.
[0014]
The operation panel 10 has a stitch pattern selection switch 10a for selecting a unit pattern formed by a predetermined number of stitches, a back stitching method selection switch 10b, a back stitch number setting switch 10c for setting the number of back stitches, and a pattern start position. A selection switch 10d, a pattern sewing needle number setting switch 10e for setting the number of stitches of the seam, and the like are provided. The backtacking method selection switch 10b is a switch for selecting which of various backtacking methods is to be used. Hereinafter, only the case where the backsewing method according to the present invention is selected will be described. In addition to this, on the operation panel 10, it is possible to make various selections or settings, such as whether or not there is back stitching at the start of sewing, whether or not back sewing is performed at the end of sewing.
[0015]
The needle swing device 100 includes a needle bar support base 11, a stepping motor 12, a needle swing link 13, and a needle bar support base shaft 14. The needle bar support 11 supports the needle bar 3 so that it can move up and down. The stepping motor 12 can rotate its output shaft 12a intermittently in either the forward or reverse direction.
[0016]
A needle swing drive arm 15 is fixed to the output shaft 12a of the stepping motor 12, and one end of the needle swing link 13 is rotatably connected to the needle swing drive arm 15 via a needle swing link pin 13a. One end of the needle bar support base shaft 14 is connected to the other end of the needle swing link 13 by a needle swing link pin 13 b via a needle bar support base shaft holder 16, and the other end is fixed to the needle bar support base 11. ing. The needle bar support base shaft 14 is supported by first and second needle bar support base bearings 17a and 17b attached to the sewing machine frame 1 so as to be slidable in the axial direction.
[0017]
When the output shaft 12 a of the stepping motor 12 rotates, the needle bar support base shaft 14 reciprocates via the needle swing driving arm 15 and the needle swing link 13. Various pattern sewing is performed by combining the reciprocating motion of the needle bar 3 by the reciprocating motion of the needle bar support base shaft 14 and the cloth feed orthogonal thereto.
[0018]
Next, the control system of the sewing machine according to the present embodiment will be described based on the block diagram shown in FIG. The control device 20 includes a ROM 22 that stores programs and data necessary for controlling the sewing machine such as a sewing work program, a CPU 24 that performs various calculations and processes, and a RAM (storage means) 26. In the RAM 26, stitch data for determining the amount of movement of the sewing needle 5 required to form the unit pattern 56A having a predetermined number of stitches on the workpiece 6 is stored in association with each stitch and calculated by the CPU 24. Stored data and the like are stored. The CPU 24 is connected to the input / output interface 28.
[0019]
The input section of the input / output interface 28 includes a pedal switch 30, a stitch pattern selection switch 10a, a back stitching method selection switch 10b, a back stitch number setting switch 10c, a pattern start position selection switch 10d, and a pattern stitch number setting. A switch 10e is connected. The pedal switch 30 is a foot-operated type, and outputs a pattern sewing start signal by a forward stepping and a pattern sewing end signal by a stepping back.
[0020]
The sewing machine motor 32 for rotationally driving the main shaft 2 of the sewing machine and the stepping motor 12 for moving the needle bar 3 are connected to the output section of the input / output interface 28 via motor drivers 33 and 34, respectively.
[0021]
4A is a diagram for explaining stitch data of the unit pattern 56A stored in the RAM 26, and FIG. 4B is a unit pattern 56A of a scallop pattern formed by 24 needles. In (a), M0, M1, M2,... Indicate each needle drop point, and the suffix indicates the number of stitches. O indicates a reference position of the sewing needle 5. A distance Dx from the reference position to each needle drop point is stitch data, and the stitch data is stored in the RAM 26 in correspondence with the number of stitches. That is, D0, D1, D2... Indicate stitch data, and the subscripts indicate the corresponding number of stitches. Since this unit pattern 56A is repeatedly formed on the sewing product, the stitch data D1 of the needle drop of the first stitch is the next of the stitch data D24 of the needle drop of the 24th stitch.
[0022]
In the case of the pattern start position selection switch 10d, for example, in the case of the scalloped pattern 56A, the sewing starts from the “start of mountain” starting from the position where the center of the scalloped pattern 56A has the widest sewing width, and from the position where the first sewing width is the narrowest. You can select the “beginning of the valley” to begin. FIG. 4 shows the stitch pattern 56 and stitch data in the case of “start of valley”. In the case of “start of peak”, the stitch pattern is started with the needle drop point M12 in FIG. 4 as the zeroth stitch.
[0023]
Next, the control operation by the control device 20 of the present embodiment will be described based on the flowcharts of FIGS. 5 and 6. In addition, this flowchart shows only the control operation by the control device 20, and the operation by the operator is not shown. For example, it is assumed that the stitch pattern and back stitching method are selected by operating the switch group of the operation panel 10 and the number of back stitch needles and the pattern start position are set before the operation according to this flowchart.
[0024]
In the figure, S1, S2,... Indicate processing order (step) numbers. First, in S1, it is determined whether or not there is a sewing start request by stepping on the pedal switch 30, and if there is a request, the process proceeds to S2 and it is determined whether or not the back stitching at the start of sewing is selected. If it is selected, the backtack solenoid 41 is driven at S2a to switch to the feed pitch set by the backsew feed pitch adjustment dial 40. Next, backtack data is created in S3. As shown in FIG. 7, the method for creating the backstitch data is that the seam data D0 of the 0th stitch and the seam data D1 of the 1st stitch of the stitch pattern 56 are equal to the number of stitches set by the backstitch stitch number setting switch 10c. Repeat alternately and use as backtack data. FIG. 7 shows an example in which the number of stitches set for backtacking is five. Also, for convenience of explanation, the number of stitches Mx constituting the unit pattern 56A is shown as the number of pattern sewing needles. Therefore, the number of stitches set by the pattern sewing needle number setting switch 10e is one after the 24 stitches. Is the total number of stitches in each unit pattern 56A. Therefore, the next of 24 stitches is calculated as 25 stitches.
[0025]
After the backtack data is created in S3, the process proceeds to S4 and a sewing operation is performed. That is, the stepping motor 12 is driven for a predetermined step based on the created backtack data, and the sewing needle 5 is moved in the direction orthogonal to the conveying direction by the needle swinging device 100 to move the sewing needle 5 up and down. Further, the workpiece 6 is conveyed by the feed dog 4 in the conveyance direction by one stitch at the feed pitch set by the back stitch feed pitch adjustment dial 40. In S5, it is determined whether or not the number of backtack stitches set by the backtack stitch number setting switch 10c has been reached. If it has not been reached, S4 is repeated to repeat backtack 58 for the set number of stitches as shown in FIG. Is executed.
[0026]
When the number of backtack stitches reaches the set number of stitches in S5, the process proceeds to S5a. In S5a, the energization of the backtack solenoid 41 is stopped, and the normal feed pitch set by the feed pitch adjustment dial 9 is switched. If the end of S5a and the stop stitching at the start of sewing are not selected in S2, the process proceeds to S6 and the stitch data for pattern sewing is read from the RAM 26. Subsequently, the process proceeds to S7, and the stepping motor 12 is driven by a predetermined step according to the stitch data read in S6, and the sewing needle 5 is moved in the direction orthogonal to the conveying direction by the needle swinging device 100, and the sewing needle 5 is moved up and down. The workpiece 6 is conveyed by the feed dog 4 in the conveying direction for one stitch. In S8, it is determined whether or not there is a sewing end request by depressing the pedal switch 30, or whether or not the number of pattern sewing needles set by the pattern sewing needle number setting switch 10e has been reached. If the number of stitches has not been reached, the required pattern sewing is executed by repeating S7.
[0027]
When the pattern sewing is completed, the process proceeds to S9, where it is determined whether or not the backtacking at the end of sewing is selected. If it is selected, the backtack solenoid 41 is driven in S9a to The feed pitch is adjusted to the feed pitch set by the feed pitch adjustment dial 40. Next, backtack data is created in S10. As shown in FIG. 8, the method for creating this backstitch data is to stop the seam data D15 of the last stitch (M15 in the illustrated example) of the stitch pattern 56 and the seam data D16 of the next needle drop point M16 at the end of pattern sewing. The stitching data is repeated alternately for the number of stitches set by the stitching number setting switch 10c. FIG. 8 shows an example in which the number of stitches set for backtacking is four.
[0028]
Subsequently, the process proceeds to S11 where a sewing operation for one stitch is performed. In S12, it is determined whether or not the number of backtack stitches set by the backtack stitching number setting switch 10c has been reached. If not, S11 is repeated to repeat backtack 60 with the set number of stitches as shown in FIG. Is executed. When the set number of stitches is finished, the process proceeds to S12a. In S12a, the energization of the backtack solenoid 41 is stopped, and the normal feed pitch set by the feed pitch adjustment dial 9 is switched. Next, the process proceeds to S13, where thread trimming is performed, and the sewing operation is completed.
[0029]
7 and 8 both show an example in which “start of valley” is selected by the pattern start position selection switch 10d, but the back stitch 58 at the start of sewing when “start of mountain” is selected. An example of this is shown in FIG.
[0030]
As mentioned above, although the sewing machine by this invention was demonstrated based on embodiment shown in drawing, this invention is not limited to this embodiment, A various change is possible.
For example, in the above embodiment, as shown in FIG. 4A, the movement amount of the sewing needle is determined by the distance Dx (stitch data) from the reference position O (base line) of the sewing needle 5 to each needle drop point. The needle swing position has been changed. Instead of this, it is also conceivable that stitch data is prepared as position data (absolute position) from the reference position O, and the scallop pattern or the like is created by changing the needle swing position.
[0031]
For example, in the case of stop stitching at the start of sewing, an example in which the stitch data is generated by alternately repeating the stitch data D0 of the zeroth stitch and the stitch data D1 of the first stitch of the stitch pattern 56 has been shown. Instead of the data D1, the stitch data D2 of the second needle or the stitch data D3 of the third needle can be used. Similarly, in the case of backtacking at the end of sewing, an example in which backtack data is generated by alternately repeating the seam data D15 of the last needle M15 and the seam data D16 of the next needle drop point M16 of the seam pattern 56 at the end of pattern sewing. However, instead of the stitch data D16 of the next needle drop point M16, the stitch data D14 of the needle drop point M14 just before that stitch, or the stitch data D13 of the needle drop point M13 just before that can be used. .
[0032]
In addition, the backstitch data can be created so as to obtain a stitch width obtained by multiplying the stitch width derived from the two stitch data by a predetermined coefficient. It is preferable that the coefficient in this case can be set to an arbitrary value (for example, 0.1 to 1.0) on the operation panel 10. Further, at this time, if the stitches are formed on the basis of the left needle drop point at the start of sewing and the last needle drop position is used as the reference for the final needle drop at the end of sewing, the appearance after sewing is good.
[0033]
【The invention's effect】
According to the present invention, the backtack data creation device is based on only two data, that is, the seam data of the seam pattern at the position closest to the position where the backsew is performed on the sewing product and the seam data at the vicinity thereof. Backtack control that creates backtack on the sewing product by creating data and changing the needle swing position by the needle swing device for each stitch based on backsew data over the set number of backstitch needles Means, and in the case of backstitching, the feed pitch of the workpiece is made smaller than the predetermined feed pitch, so it is possible to easily create backstitch data for a stitch pattern in which the sewing width changes continuously, In addition, the back stitch can be performed with good appearance.
[Brief description of the drawings]
FIG. 1 is a diagram showing a main part of an embodiment of a sewing machine according to the present invention.
FIG. 2 is a diagram showing a main part of the present embodiment.
FIG. 3 is a block diagram of the present embodiment.
4A is a diagram for explaining stitch unit data of a scallop pattern formed by 24 needles, and FIG. 4B is a diagram for explaining stitch data of a unit pattern stored in a RAM.
FIG. 5 is a flowchart showing the operation of the present embodiment.
FIG. 6 is a flowchart showing the operation of the present embodiment.
7A is a diagram showing pattern stitching and backstitching according to the present embodiment, and FIG. 7B is a diagram showing stitch data and backstitch data.
FIG. 8A is a diagram showing pattern stitching and backstitching according to the present embodiment, and FIG. 8B is a diagram showing stitch data and backstitch data.
FIG. 9 is a diagram illustrating an example of pattern sewing and back stitching at the start of sewing when “mountain start” of the scalloped pattern is selected.
FIGS. 10A and 10B are diagrams showing patterns that can be sewn with a sewing machine having a needle swing device, wherein FIG. 10A shows a staggered pattern, and FIG. 10B shows a pattern that repeats a circular unit pattern.
11A and 11B are diagrams showing a scalloped pattern, in which FIG. 11A shows a scalloped pattern with an arc portion facing right, and FIG. 11B shows a scalloped pattern with an arc portion facing left.
12A shows an example of staggered stitches at the start and end of a staggered pattern, and FIG. 12B shows a stitch pattern when the staggered pattern of FIG.
FIG. 13A shows an example of a scallop stitch at the start and end of sewing, and FIG. 13B shows a stitch pattern when the scallop pattern of FIG.
[Explanation of symbols]
4 Feed dog (cloth feed device)
5 Sewing needle 6 Workpiece 9 Feed pitch adjusting dial 10 Operation panel 10a Stitch pattern selection switch 10c Stop stitch number setting switch 12 Stepping motor 20 Controller 26 RAM
40 Back feed stitch adjustment dial (feed pitch changing device)
41 Backtack solenoid (feed pitch changing device)
56 stitch pattern 56A unit pattern 58, 60 back stitch 100 needle swing device

Claims (2)

A sewing needle that can move up and down;
A cloth feeding device that conveys the sewing product at a predetermined feeding pitch in the conveying direction for each stitch;
A feed pitch changing device capable of changing the feed pitch;
A needle swing device capable of moving the sewing needle to an arbitrary needle swing position in a direction orthogonal to the transport direction;
A seam pattern selecting means for selecting a shell-shaped scalloped pattern having a stitch width which is formed at a predetermined number of stitches and continuously changes in a plurality of different stitch widths and has the widest center width.
Storage means for storing stitch data for determining a needle swing position for forming the scalloped pattern on the workpiece to be sewn corresponding to the number of stitches;
The number of backtack stitches setting means for setting the number of backtack stitches,
Based on the stitch data of the scalloped pattern, the scalloped pattern selected by the stitched pattern selecting means is repeated on the workpiece by changing the stitching position by the stitching device for each needle. Pattern sewing control means for forming a pattern;
A pattern sewing needle number setting switch for setting the number of stitches of the scallop pattern to be formed on the sewing product;
A stop sewing data of sewing end, said a scalloped pattern sewing of the last stitch of the stitch data, the scallop pattern sewing of whether to create a stitch data of the last stitch and the next stitch data as repeated data alternately, or, the A backtack data creation device for creating stitch data of the last stitch of scalloped pattern sewing and stitch data of one stitch before the stitch data of the last stitch of scalloped pattern stitching as alternately repeated data ;
After the scalloped pattern sewing for the number of stitches set by the pattern stitching needle number setting switch is finished, when the back stitching at the end of sewing is selected, over the number of stitches set by the backsew stitch number setting means, In addition, it comprises a backtack control means for forming a backtack on the sewing product by changing the needle swing position by the needle swinging device for each needle based on the backtack data at the end of sewing,
A sewing machine characterized in that the feed pitch of the sewing product is made smaller than the predetermined feed pitch by the feed pitch changing device at the time of back stitching. The backtack data creation device
The back stitch data at the start of sewing is created as data in which the stitch data at the 0th needle of the scalloped stitch and the stitch data at the 1st needle are alternately repeated ,
The sewing machine according to claim 1, wherein the backtack control means forms a backtack on the sewing product when backtacking at the start of sewing is selected.

Images