JP2010201013A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent problems including the interference of a sewing needle with a needle plate by permitting a decision to be reliably made about whether or not a plurality of sewing needles are mounted on a needle bar. <P>SOLUTION: The sewing machine is provided with an image sensor 23 photographing a twin needle 7 and pinholes 11 from the front diagonal upper right in the lower end of a head portion 4. The sewing machine performs image processing such as binarization and outline (edge) extraction for an image photographed by the image sensor 23 to extract an outline image of the twin needle 7 and the pinholes 11. On the basis of the outline image, the sewing machine computes the width between the sewing needles of the twin needle 7. On the basis of the computed width, the sewing machine carries out control to regulate the needle swing width of the needle bar 5 on which the twin needle 7 is mounted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine including a needle bar swinging mechanism that swings a needle bar on which a plurality of sewing needles can be mounted.

  For example, a household sewing machine is generally equipped with a needle bar swing mechanism that swings the needle bar left and right using a stepping motor as a drive source, and zigzag stitching (zigzag stitching) on the work cloth while swinging the needle bar left and right. ) The pattern can be sewn. In this case, the needle hole formed in the needle plate has a horizontally long shape corresponding to the swinging of the needle bar (sewing needle). In addition to the above-described staggered stitching, the left base line position where the needle bar (sewing needle) is moved to the left by a predetermined amount from the reference position (medium base line position), or the right side, depending on the type of stitch pattern In some cases, the sewing is performed at the right base line position moved by a predetermined amount. The left base line position and the right base line position are of course set in advance so that the needle drop position of the sewing needle has a predetermined interval with respect to the left and right ends of the needle hole (does not interfere with the needle plate). It is.

  By the way, in some sewing machines, two needles are prepared as accessories, and a sewing operation with two needles (double needle mode) is possible (for example, see Patent Document 1). The two needles are configured to include two sewing needles arranged side by side at a predetermined interval (for example, 3 mm) on the left and right at the lower portion of the mounting base portion attached to the needle bar. By attaching these two needles to the needle bar instead of the normal sewing needles, and setting the upper thread (for example, upper threads of different colors) to the two sewing needles and executing the sewing operation, A stitch pattern in which two upper threads are arranged in parallel is formed.

  When the zigzag sewing operation is executed in the two-needle mode as described above, if the needle swing width becomes too large, the sewing needle may interfere with the needle plate. Therefore, in the sewing machine disclosed in Patent Document 1, whether or not the two needles are attached is determined by the user's switch input operation or the movable spool pin being rotated to rotate the second upper thread supply source thread spool It is determined by a switch that detects that it is in a state where it can be mounted. Based on this determination, the needle swing width of the needle bar is limited in the two-needle mode.

JP 54-127753 A

  In the sewing machine disclosed in Patent Document 1, whether or not the two needles are attached to the needle bar is determined based on the user's switch operation or the rotation operation of the movable thread stand bar. For this reason, the user may erroneously or forget to perform the switch operation and the rotation operation of the movable spool pin. In this case, there is a possibility that the sewing machine does not limit the swing width of the needle by determining that the normal mode is not the two-needle mode although the two needles are attached to the needle bar. Or, conversely, there is a possibility that the needle swing width may be limited more than necessary by determining the two-needle mode even though a normal sewing needle is attached.

  In addition, the above-mentioned two needles have a plurality of types in which the thickness of the needle and the width dimension between the two sewing needles are different. Particularly, when the two needles having a large width dimension (for example, 5 mm) are used, the above-described needles are used. Even if the swing width is limited, the possibility that the sewing needle interferes with the needle plate still remains, and safety cannot be said to be sufficient.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to execute a sewing operation with a plurality of sewing needles and to ensure that the plurality of sewing needles are attached to a needle bar. It is to provide a sewing machine that can prevent a problem such as interference between a sewing needle and a needle plate.

  In order to achieve the above object, a sewing machine according to claim 1 of the present invention is a needle bar on which a plurality of sewing needles can be mounted, a needle bar swinging mechanism for swinging the needle bar, and the sewing needle inserted therethrough. In a sewing machine comprising a needle plate having a possible needle hole, a photographing means for photographing the needle hole and the sewing needle, and a needle hole and the sewing needle based on an image photographed by the photographing means. Extraction means for extracting a contour image, width calculation means for calculating a width dimension between left and right sewing needles of the plurality of sewing needles based on the contour image extracted by the extraction means, and the width calculation means And a swinging range control means for controlling a swingable range of the needle bar by the needle bar swinging mechanism according to the result.

  According to the above configuration, the needle hole and the sewing needle are photographed by the photographing means, and the contour image of the needle hole and the sewing needle is extracted by the extracting means based on the image. Then, the width calculating means calculates the relative positional relationship between the needle hole and the sewing needle and the width dimension between the left and right sewing needles among the plurality of sewing needles. Thereby, it is possible to directly detect whether or not a plurality of sewing needles are mounted on the needle bar, and it is possible to accurately detect the width dimension between actual sewing needles. Therefore, no matter what width of the sewing needle is mounted, the swing range control means causes the needle bar to swing so that the sewing needle does not interfere with the needle plate. The possible range is appropriately controlled.

  By the way, with this type of sewing machine, if a large impact (dropping, etc.) is applied to the machine body or the mechanism part is loosened, the needle bar position (and thus the needle drop position of the sewing needle) ) May deviate from the normal position. If such needle bar misalignment occurs, it will not be possible to perform good sewing work. If it is severe, the needle swing width will be limited as described above. There is also a possibility that the sewing needle may interfere with the needle plate.

  Therefore, the sewing machine according to claim 2 is the invention according to claim 1, wherein, based on the contour image extracted by the extracting means, the position of the needle bar with respect to the needle hole is at a preset normal position. And a correction control means for driving and controlling the needle bar swing mechanism to correct the needle bar to the normal position in accordance with the determination result of the determination means. It is characterized by.

  According to a third aspect of the present invention, in the invention of the second aspect, when the position of the needle bar is a position corresponding to a left base line or a right base line, the determination unit is based on the contour image extracted by the extraction unit. The left and right intervals between the sewing needle located at the left end or the right end of the plurality of sewing needles and the left end portion or the right end portion of the needle hole, and the thickness dimension of the sewing needle are calculated, and the calculated Based on the interval and the thickness dimension of the sewing needle, it is determined whether or not the position of the needle bar is in a normal position.

  The sewing machine according to a fourth aspect is the sewing machine according to the second aspect, wherein the judging means is configured to determine the sewing needle when the position of the needle bar is a position corresponding to the left base line based on the contour image extracted by the extracting means. A left side distance between the left end portion of the needle hole and a right side distance between the sewing needle and the right end portion of the needle hole when the position of the needle bar is a position corresponding to a right base line; It is characterized in that it is determined whether the position of the needle bar is in a normal position based on the calculated left interval and right interval.

  The sewing machine according to claim 5 is provided with a notifying means in the invention according to any one of claims 2 to 4, and when the judging means judges that the position of the needle bar is abnormal, a warning is given by the notifying means. It is characterized by that.

  A sewing machine according to a sixth aspect of the present invention includes the storage unit according to any one of the second to fifth aspects, and stores the corrected position data of the needle bar based on the determination of the determination unit in the storage unit. It is characterized by that.

  According to the sewing machine of claim 1, it is possible to execute a sewing operation with a plurality of sewing needles, and it is possible to reliably determine whether or not a plurality of sewing needles are attached to the needle bar. The needle swing width can be controlled according to the actual width dimension of the plurality of sewing needles. Therefore, it is possible to obtain an excellent effect that problems such as interference between the sewing needle and the needle bar can be prevented in advance.

  According to the sewing machine of the second aspect, in addition to the effect of the invention of the first aspect, based on the photographed image of the needle hole and the sewing needle, the actual positional relationship between the needle hole and the sewing needle is directly determined. It can be detected, and it can be accurately determined whether or not the position of the needle bar is the normal position, and correction can be made when there is a deviation. Accordingly, it is possible to prevent problems such as interference between the needle plate and the sewing needle due to the deviation of the needle bar from the normal position. Further, since the photographing means and the extracting means can be used (shared) for judging the deviation from the normal position of the needle bar, it is not necessary to add a dedicated configuration separately, and a simple configuration can be achieved. Can do.

  According to the sewing machine of claim 3, in addition to the effect of the invention of claim 2, when the needle bar is the left base line or the right base line, the sewing needle located at the left end or the right end of the plurality of sewing needles and the needle Whether or not the needle bar is in the normal position can be reliably determined based on the calculation of the distance in the left-right direction between the left end portion or the right end portion of the hole and the thickness dimension of the sewing needle. .

According to the sewing machine of the fourth aspect, in addition to the effect of the invention of the second aspect, based on the calculation of the left interval and the right interval, whether or not the needle bar is in the normal position is reliably determined. Judgment can be made.
According to the sewing machine of claim 5, in addition to the effect of the invention of any one of claims 2 to 4, when the position of the needle bar of the sewing needle is abnormal, the user is notified of the abnormality by the notification of the notification means. You can notice and take appropriate measures.

  According to the sewing machine of the sixth aspect, in addition to the effect of the invention according to any one of the second to fifth aspects, since the corrected position data of the needle bar is stored, the needle bar is corrected to the normal position. The sewing operation can be performed while always maintaining the state.

1 is a perspective view of a sewing machine according to a first embodiment of the present invention. The perspective view which expands and shows a sewing needle part Front view showing the configuration of the needle bar swing mechanism Enlarged front view showing a needle bar with two needles Top view of needle plate Block diagram schematically showing the electrical configuration of the sewing machine Diagram showing the relationship between needle hole and needle bar position Flowchart showing the overall procedure when using the sewing machine executed by the control device The flowchart which shows the detail of the two-needle recognition process of FIG. The flowchart which shows the detail of the right-and-left sewing needle position coordinate calculation process of the two needles of FIG. The flowchart which shows the detail of the needle swing width limit value calculation process of FIG. The figure which shows the relationship between the needle bar which concerns on the 2nd Embodiment of this invention, and three base line positions. FIG. 8 equivalent diagram according to the second embodiment The flowchart which shows the detail of the position correction judgment process of the needle bar of FIG. The figure which shows the relationship between the needle bar which concerns on the 3rd Embodiment of this invention, and three base line positions. FIG. 8 equivalent diagram according to the third embodiment The flowchart which shows the detail of the position correction judgment process of the needle bar of FIG.

(1) First Embodiment Hereinafter, a first embodiment in which the present invention is applied to, for example, a household sewing machine will be described with reference to FIGS. 1 to 11. This embodiment corresponds to claim 1.
FIG. 1 shows the overall appearance of the sewing machine M according to this embodiment. Here, the main body of the sewing machine M includes a sewing machine bed 1 extending in the left-right direction (X direction), a leg column 2 extending upward from the right end of the sewing bed 1, and an upper end of the leg column 2 from the top. The arm portion 3 extending leftward is integrally formed. A tip portion of the arm portion 3 is a head portion 4. Further, a cover 3a is provided on the upper portion of the arm portion 3 so as to open and close a yarn spool storage portion (not shown) that stores an upper thread spool (not shown). The side where the user who operates the sewing machine M is located is the front, and the opposite direction is the rear. The side on which the pedestal 2 is located is the right side, and the opposite side is the left side.

  As shown in FIG. 2, a needle bar 5 is provided on the head 4 at the tip of the arm portion 3 so as to be movable up and down and swingable in the left and right direction (X direction). As shown in FIG. 3, the needle bar 5 is supported by a needle bar base 45. The needle bar 5 is attached to the lower end 51 of the needle bar 5 via the needle stopper member 8.

  Here, the sewing needle will be described. As sewing needles that can be attached to the needle bar 5 (that can be used in the sewing machine M), for example, a plurality of types of normal sewing needles (not shown) having different thickness dimensions are prepared. As shown in FIGS. 2 to 4 and 7, two needles 7 as a plurality of sewing needles are attached as standard products. The two needles 7 are integrally formed with two sewing needles 7a and 7b that are arranged in parallel at a predetermined interval in the left-right direction and extend downward at a lower portion of the mounting base portion 7c attached to the needle bar 5. It is configured. However, the vertical positions of the respective needle holes 7f and 7g (and the respective needle tips) of the sewing needles 7a and 7b are slightly different depending on the so-called encounter timing relationship with a horizontal hook (not shown) described later. . The attachment base portion 7c is provided on the needle bar 5 by a needle support portion 7d for fixing and supporting the two sewing needles 7a and 7b, and extending upward from the needle support portion 7d. A shaft-shaped mounting portion 7e is integrally provided. The sewing needle 7a and the sewing needle 7b are supported at a position that is symmetric with respect to the central axis of the mounting portion 7e, that is, a position that is symmetric with respect to the central axis of the needle bar 5. However, depending on the type of the two needles, although not shown, there are also two sewing needles that are supported at positions that are not symmetrical with respect to the central axis of the mounting portion 7e. As shown in FIG. 2, the two needles 7 are mounted on the needle bar 5, and the sewing threads are executed by setting the upper threads Ta and Tb (for example, upper threads of different colors) to the two sewing needles 7a and 7b, respectively. As a result, a seam in which two upper threads are arranged in parallel at a predetermined interval is formed on the work cloth.

  Here, in the two needles 7 shown in the present embodiment, the width dimension between the sewing needles 7a and 7b is set to 3 mm, for example, and the thickness dimension of each of the sewing needles 7a and 7b is set to 0.9 mm, for example. The needle 7 is attached as a standard product of the sewing machine M. However, as the above-described double needle 7, two kinds of needles having different width dimensions and different thickness dimensions of the sewing needles are also sold, and the user may use two needles other than the standard ones. As will be described later, in the present embodiment, even a double needle different from the double needle 7 which is a standard product in such a width dimension and thickness dimension can be handled (can be used without any trouble).

  As shown in FIG. 2, a needle set screw 9 is provided at the right end portion of the needle set member 8, and the user rotates the needle set screw 9 to attach / detach (replace) the sewing needle. Can be done. The head 4 is provided with a presser foot 6 positioned below the needle bar 5 (two needles 7).

  Although not shown in detail, a sewing machine main shaft that is rotationally driven by a sewing machine motor 12 (see FIG. 6) is provided in the arm portion 3. Furthermore, in the arm portion 3, the needle bar 5 is moved in the left-right direction using a needle bar drive mechanism for moving the needle bar 5 up and down by the driving force of the sewing machine spindle, and a stepping motor 13 (see FIGS. 3 and 6) A needle bar swing mechanism 14 (see FIG. 3) that swings in the X direction), a balance drive mechanism that moves the balance (not shown) up and down in synchronization with the vertical movement of the needle bar 5, and the tension of the upper thread is adjusted. A thread tension device and the like are provided. The needle bar swing mechanism 14 will be described later.

  Although not shown in detail, the sewing machine main shaft is provided with a fan-shaped shutter (shielding plate) that rotates integrally with the main shaft. A photo interrupter for optically detecting the rotation state of the shutter is provided in a sewing machine frame (not shown). A spindle angle detector 15 (see FIG. 6) is constituted by the shutter and the photo interrupter. By detecting the angle of the main shaft by the main shaft angle detector 15, the vertical position of the needle bar 5 driven up and down by the main shaft can be determined. When a start / stop key 16a described later is operated to stop the sewing operation, the needle bar 5 is set to stop at the needle up position (substantially the highest position in the vertical movement).

  As shown in FIG. 1, a plurality of key switches 16 are operably provided on the front side of the arm portion 3. Although not described in detail, the key switch 16 includes a start / stop key 16a for instructing start and stop of a sewing operation, a reverse stitching key, a needle up / down key, a thread trimming key, a speed adjustment knob, and the like. On the front surface of the pedestal 3, there is provided a liquid crystal display 17 that is large and has a vertically long shape and capable of full color display.

  The liquid crystal display 17 displays a number of stitch patterns such as a practical pattern and an embroidery pattern, function names for executing various functions necessary for the sewing work, various message information, and the like. In addition, a touch panel 18 (see FIG. 6) is provided on the surface of the liquid crystal display 17, and the touch panel 18 allows a desired stitch pattern to be selected and a necessary function to be executed. At this time, as will be described later, an error message (warning) is displayed on the liquid crystal display 17 when it is determined that there is an abnormality in the two needles 7. It is configured.

  On the other hand, a needle plate 10 (see FIGS. 1 and 5) is provided on the upper surface of the sewing machine bed 1. Although not shown, the sewing machine bed 1 contains a feed dog driving mechanism and a lower thread bobbin that are located below the needle plate 10 and that drive the feed dog in synchronization with the vertical movement of the needle bar 5. A horizontal hook that forms seams in cooperation with the two needles 7, a thread trimming mechanism that cuts the upper thread and the lower thread, and the like are provided. As shown in FIG. 1, a practical sewing table 19 used for sewing a practical pattern by transferring a work cloth (not shown) with the feed dog as shown in FIG. Removably mounted.

  A known embroidery machine (embroidery frame moving device) 20 (see FIG. 6) is detachably attached to the left side portion of the sewing machine bed 1 with the practical sewing table 19 removed. Although not shown in detail, the embroidery machine 20 places the embroidery frame holding the work cloth in the X direction (left-right direction) and the Y direction (front-rear direction) perpendicular to it on the sewing machine bed 1 (needle plate 10). It is configured to be freely transferred. The embroidery machine 20 is electrically connected to a control device 22 (control unit) of a sewing machine, which will be described later, via a connector 21 (shown only in FIG. 6) provided on the sewing machine bed 1 while being mounted on the sewing machine bed 1. Connected to.

  FIG. 5 shows a plan view of the needle plate 10. The needle plate 10 has a substantially rectangular plate shape as a whole, and is made of a metal first needle plate 35 fixed to the sewing machine bed 1 and a synthetic resin that is detachably attached to the first needle plate 35. The second throat plate 36 is provided.

  The first needle plate 35 is formed with a needle hole 11 through which the two needles 7 can pass, and a plurality of (for example, seven) square holes 37 into which the feed dogs for feeding the work cloth can be projected and retracted. The needle hole 11 has a horizontally long shape corresponding to the swinging of the needle bar 5 (double needle 7). Each of the square holes 37 is provided so as to surround the needle hole 11 in an elongated linear shape in the front-rear direction.

  On the other hand, a transparent synthetic resin needle plate cover 39 is removably attached to the second needle plate 36 so as to cover the bobbin insertion port for introducing the lower thread bobbin into the horizontal shuttle mechanism from above. A guide groove 42 for guiding the lower thread and a cutting blade 43 for cutting the lower thread are provided on the upper surface of the second needle plate 36 on the left side of the needle plate cover 39.

  Next, the needle bar swing mechanism 14 that swings the needle bar 5 in the left-right direction (X direction) will be described. As shown in FIG. 3, an upper end portion of a needle bar base 45 that supports the needle bar 5 is pivotally supported by a sewing machine frame (not shown) in the head 4 and can swing in the left-right direction. It has become. The needle bar 5 is supported so as to be movable up and down by support parts 48 and 49 provided at two locations on the right and left sides of the needle bar base 45, and the needle bar 5 is provided at a substantially intermediate part between the support parts 48 and 49. It is connected to the needle bar swing mechanism 14 by a hug 25.

  The needle bar swing mechanism 14 includes a needle bar base 45, a swing lever 46, the stepping motor 13, a swing cam 47 rotated by the stepping motor 13, and the like provided on a sewing machine frame (not shown). Have.

  The swing lever 46 has a shape that extends in the vertical direction substantially parallel to the needle bar base 45, and a substantially central portion in the vertical direction is pivotally supported on a sewing machine frame (not shown) by a pivot pin 50. The lower end 51 is in contact with a cam body 52 fixed to the lower end 51 of the needle bar base 45. A pin 54 is fixed to the upper end of the swing lever 46 and abuts against a cam surface 55 of a swing cam 47 that swings the needle bar base 45 in the left-right direction. The needle bar base 45 is configured such that a lower end portion 51 thereof is urged leftward by a coil spring (not shown) and the respective contact states are maintained.

  A drive gear 56 is attached to the output shaft of the stepping motor 13 fixed to the sewing machine frame (not shown) and meshes with the gear portion 53 on the outer peripheral portion of the swing cam 47. The cam surface 55 of the oscillating cam 47 continuously has a radius expanding cam surface having a large distance from the rotation axis and a radius reducing cam surface having a small distance from the rotation axis. Thus, at the reference position (origin position) of the stepping motor 13, the central axis of the needle bar 5 (two needles 7) is in a state perpendicular to the upper surface of the needle plate 35. In this state, the needle bar 5 As shown in FIG. 7, the two needles 7 move up and down while penetrating through the central portion of the needle hole 11 of the needle plate 10. This position is referred to as a middle baseline position C.

  On the other hand, when the stepping motor 13 is driven by, for example, a pulse in the plus direction, the upper end portion of the swing lever 46 moves to the left by the rotation of the swing cam 47. Therefore, the lower end portion of the swing lever 46 moves in the right direction, and the needle bar base 45 moves in the right direction together with the needle bar 5. On the other hand, when the stepping motor 13 is driven by a pulse in the minus direction, the upper end portion of the swing lever 46 moves to the right by the rotation of the swing cam 47. Therefore, the lower end portion of the swing lever 46 moves leftward, and the needle bar base 45 moves leftward together with the needle bar 5. Needless to say, the amount of swing of the needle bar 5 in the left-right direction depends on the number of pulses applied.

  As described above, the sewing machine M can be sewn in a zigzag pattern by swinging the needle bar 5 (two needles 7) left and right with a predetermined needle swing width by the needle bar swing mechanism 14. At this time, when the user selects a zigzag stitch pattern with the touch panel 18, the needle swing width at that time can be further set. Specifically, when the user selects a zigzag stitch pattern, a standard needle swing width is automatically set. When the user wants to change the needle swing width, the user increases or decreases the standard swing width. Do the following.

  Now, as shown in FIG. 2, at the lower front end of the head 4, photographing is performed to take images of the two needles 7 and the needle holes 11 at a position diagonally forward and upward with respect to the two needles 7. An image sensor 23 is provided as a means. In the present embodiment, the image sensor 23 is formed of, for example, a small CMOS image sensor.

  Since the two needles 7 (needle bar 5) stop at the needle upper position raised from the needle plate 10 when the sewing operation is stopped, the sewing machine motor 12 pulls the two needles 7 (needle bar 5) as described later. The image sensor 23 captures an image of the two needles 7 and the needle hole 11 stopped at the needle lower position in a state where the needle sensor is moved to the needle lower position (needle drop position, approximately the lowest position of the vertical movement). ing.

  FIG. 6 schematically shows the electrical configuration of the sewing machine according to the present embodiment. Here, the control device 22 is mainly composed of a microcomputer, and includes a CPU 26, a ROM 27, a RAM 28, an EEPROM 29, and the like. The ROM 27 stores a control program for controlling the sewing operation, stitch data necessary for the sewing operation, a program for determining the displacement of the needle bar 5 described later, and data therefor, such as the left base line position and the middle base line position. The data of the normal position of each needle bar 5 at the right base line position (for example, the interval from the left end of the needle hole 11, hereinafter referred to as normal position data) is stored.

  Various key switches 16 including the start / stop key 16a and the touch panel 18 are connected to the control device 22, and operation signals thereof are input, and the spindle angle detector 15 is also connected. The detection signal is input. As described above, the image processing circuit 24 is connected to the control device 22, and the control device 22 controls the image sensor 23, and the contour images of the double needle 7 and the needle hole 11 are output from the image processing circuit 24. It is designed to be entered.

  Further, the liquid crystal display 17 is connected to the control device 22 via a drive circuit 30, and the sewing machine motor 12 and the stepping motor 13 are connected via drive circuits 31 and 32, respectively. The sewing operation is executed by controlling them. Further, an alarm buzzer 34 is connected to the control device 22 via a drive circuit 33. The connector 21 is also connected to the control device 22.

  In this embodiment, as will be described later in the description of the operation (flowchart description), the control device 22, when sewing the zigzag stitch pattern, identifies its software configuration (sewing needle identification and needle swing). Execution of the width control program), it is determined whether or not the two needles 7 are attached to the needle bar 5. When the two needles 7 are attached to the needle bar 5, the width of the two needles 7 is determined. Depending on the dimensions, the needle swing width is limited.

  At this time, the control device 22 (and the image processing device 24) extracts contour images of the needle hole 11 and the sewing needles 7a and 7b based on the image taken by the image sensor 23. Based on the extracted contour image, the width dimension between the left and right sewing needles 7a and 7b is calculated. Then, the swingable range of the needle bar 5 by the needle bar swing mechanism 14 is controlled according to the width dimension. Therefore, the control device 22 (and the image processing device 24) functions as an extraction unit, a width calculation unit, and a swing range control unit.

  More specifically, the control device 22 takes in images of the two needles 7 and the needle holes 11 by the image sensor 23 before the sewing machine M actually starts the sewing operation, and an image processing circuit based on the image data. 24, the contour images of the two needles 7 and the needle hole 11 are extracted. Then, the control device 22 calculates the width dimension of the two needles 7 based on the contour images of the two needles 7 and the needle hole 11, and sets the upper limit value of the needle swing width according to the width dimension. Then, the currently set needle swing width is compared with the upper limit value, and if the needle swing width is too large, the needle swing width of the two needles 7 is corrected to be reduced. When the set needle swing width is larger than the upper limit value, an error notification to the effect that the needle swing width exceeds the upper limit value is given to the user, and the user changes the needle swing width operation (or two). You may make it wait for replacement | exchange of this needle | hook etc.).

  FIG. 7 is a diagram schematically showing the relationship between the two needles 7 and the needle holes 11 expressed in the X-axis coordinate system. The X axis is drawn with the right direction on the left and right as the positive direction, and the center in the left and right direction (medium baseline position) of the needle hole 11 is the X axis coordinate 0 point (origin). A position set to the right by leaving a gap of a predetermined distance (for example, 0.5 mm) from the left end of the needle hole 11 is defined as a coordinate XL (<0), and a gap of a predetermined distance (for example, 0.5 mm) from the right end. The position set to the left is set as the coordinate XR (> 0). Here, the gap is provided so that the sewing needles 7a and 7b and the needle hole 11 do not interfere with each other. The point reached by the sewing needle 7a when the sewing needle 7a is swung to the left by the distance of the needle swing width A is defined as a point XL (A), and the needle bar 7b is swung to the right by the distance of the needle swing width A. The arrival point of the sewing needle 7b at this time is defined as a point XR (A). The swingable range refers to the distance from the point XL (A) to the point XR (A).

  In the present embodiment, as shown in FIG. 7, the width dimension B on the outer side of each of the sewing needles 7 a and 7 b of the double needle 7 is obtained from the contour image, and the needle of the double needle 7 is based on the width dimension B. The left swing width limit value AL and the right swing width limit value AR of the swing width are calculated. Then, the swingable range of the needle bar 5 is limited by the left swing width limit value AL and the right swing width limit value AR. As a result, it is possible to prevent the sewing needle 7a or 7b from interfering with the needle plate 10 regardless of the width B of the two needles 7 attached to the needle bar 5. In this embodiment, immediately after the sewing machine M is turned on, that is, the initial position of the needle bar 5 is always located at the X-axis coordinate 0 point (origin) regardless of the selected stitch pattern, and the middle baseline position. It shall be in

  Next, the operation of the above configuration (the control content of the control device 22) will be described with reference to FIGS. The flowchart of FIG. 8 shows an overall procedure at the time of sewing the zigzag stitch pattern of the sewing machine M executed by the control device 22. Further, the flowchart of FIG. 9 specifically shows the processing contents of the two-needle recognition process (S1) by the image sensor 23 in the flowchart of FIG. Note that this two-needle recognition process may be executed every time, for example, immediately after the sewing machine M is turned on, or may be executed when the user performs a key operation.

  The flowchart of FIG. 10 specifically shows the processing contents of the sewing needles 7a and 7b position coordinate calculation processing (S4) of the two needles 7 in the flowchart of FIG. The flowchart of FIG. 11 specifically shows the processing contents of the needle swing width limit value calculation process (S5) in the flowchart of FIG.

  In the flowchart of FIG. 8, when the control device 22 is activated by turning on the sewing machine M, the two-needle recognition process in step S <b> 1 is executed. In step S1, two-needle recognition processing is performed based on image data acquired by the image sensor 23 (see FIG. 2) as shown in FIG. 9, and the sewing needles mounted on the needle bar 5 are two needles. Whether or not it is a double needle, the width B (see FIG. 7) of the double needle 7 is calculated.

  Specifically, as shown in FIG. 9, in step S <b> 21, image data of the sewing needle attached to the needle bar 5 is acquired by the image sensor 23. This image data is converted into a contour image of the sewing needle by an image processing circuit 24 (see FIG. 6).

  In step S22, based on the contour image of the sewing needle, it is determined whether or not the sewing needle is at the origin position of the X-axis coordinates. As described above, the needle bar 5 is positioned at the origin of the X-axis coordinates immediately after the sewing machine M is turned on, and the needle attached to the needle bar 5 is also positioned at the origin (S22: YES). The sewing needle mounted on the bar 5 can be determined as a single needle. In this case, the single needle mode is set in step S23, and the process proceeds to step S2 in FIG. In step S2, it is determined NO, and the process proceeds to step S11. In step S11, sewing is started by the user's operation of the start / stop key 16a. In step S12, a staggered (zigzag) pattern with one needle is sewn. Then, when the user finishes the sewing, the sewing machine M stops the sewing by the user's operation of the start / stop key 16a (S13).

  Returning to FIG. 9, when the sewing needle is not at the origin position of the X-axis coordinate in step S22 (S22: NO), the process proceeds to step S24 and the sewing needle is located on both the left and right sides of the origin position of the X-axis coordinate from the contour image. Determine whether or not. If the sewing needle is not on both the left and right sides of the origin position of the X-axis coordinate (S24: NO), the process proceeds to step S23 to set the single-needle mode, and the process proceeds to step S2 as described above, and the subsequent processing is performed. Done.

  In step S24, when the sewing needles are on both the left and right sides of the origin position of the X-axis coordinate (S24: YES), the process proceeds to step S25, the two-needle mode is set, and the process proceeds to step S26, where the two-needle 7 is determined from the contour image. The width dimension B (see FIG. 7) is calculated. Thereafter, the process proceeds to step S2 (see FIG. 8), and since the two-needle mode is set (step S2: YES), the process proceeds to step S3.

  Returning to FIG. 8, in step S3, the width dimension B of the two needles 7 measured in step S26 (see FIG. 9) is acquired, and the process proceeds to step S4 where X of the left and right sewing needles 7a, 7b of the two needles 7 is acquired. Axis coordinate calculation processing is performed. As shown in FIG. 10, the width dimension B of the two needles 7 is read in step S31. Next, in step S32, the X-axis coordinate of the sewing needle 7a on the left side of the two needles 7 is calculated. The X-axis coordinate X1 of the sewing needle 7a is X1 = −B / 2 (<0). In step S33, the X-axis coordinate of the sewing needle 7b on the right side of the two needles 7 is calculated. The X-axis coordinate X2 of the sewing needle 7b is X2 = B / 2 (> 0).

  In step S5 (see FIG. 8), the needle swing width limit value calculation process of the two needles 7 is performed, and the movable range of the two needles 7 in the left-right direction is calculated. As shown in FIG. 11, the limit value of the left swing width of the two needles 7 is calculated as left swing width limit value AL (see FIG. 7) = | XL−X1 | in step S41. The limit value of the right hand swing width of the two needles 7 is calculated as the right swing width limit value AR = | XR−X2 | in step S42.

  In step S6, the needle swing width A of the stitch pattern to be sewn is acquired. In step S7, it is determined whether or not the needle swing width A> the left swing width limit value AL. When the needle swing width A is equal to or smaller than the left swing width limit value AL (S7: NO), even if the two needles 7 are swung with the needle swing width A, the sewing needle 7a does not interfere with the needle plate 10. The process proceeds to step S9. In step S9, it is determined whether or not the needle swing width A> the right swing width limit value AR. When the needle swing width A is equal to or smaller than the right swing width limit value AR (S9: NO), the sewing needle 7b does not interfere with the needle plate 10 even if the two needles 7 are swung with the needle swing width A. . Then, the process proceeds to S11 where sewing is started by the user's operation of the start / stop key 16a. In step S12, a zigzag (zigzag) pattern is sewn with the two needles 7 having the needle swing width A. Then, as the user finishes the sewing, the sewing machine M stops the sewing by operating the user's start / stop key 16a (S13).

  On the other hand, if the needle swing width A> the left swing width limit value AL (S7: YES), the process proceeds to step S8 to reduce the stitch swing width A of the stitch pattern to the left swing width limit value AL. That is, the sewing machine M restricts the needle swing width of the needle bar 5 to the left swing width limit value AL, and proceeds to step S9. In step S9, if the needle swing width A> the right swing width limit value AR (S9: YES), the process proceeds to step S10 and the stitch swing width A of the stitch pattern is reduced to the right swing width limit value AR. To do. That is, the sewing machine M limits the needle swing width of the needle bar 5 to the right swing width limit value AR. Thereafter, the process proceeds to step S11, where sewing is started by the user's operation of the start / stop key 16a. In step S12, a zigzag stitch (zigzag stitch) pattern is sewn with a single needle. At this time, since the needle swing width A is limited to the left swing width limit value AL and the right swing width limit value AR as described above, even if the two needles 7 are swung with the needle swing width A, the sewing needle 7b does not interfere with the needle plate 10. Then, when the user finishes the sewing, the sewing machine M stops the sewing by the user's operation of the start / stop key 16a (S13).

  In the present embodiment described above, it is possible to execute a sewing operation with a plurality of sewing needles, and in this embodiment with the two needles 7, and an image processing circuit 24 uses an image photographed by the image sensor 23. Based on the extracted contour image of the two needles 7 and the needle hole 11, it is reliably and automatically identified whether the sewing needle attached to the needle bar 5 is a single needle or a double needle. be able to. Further, based on the above image, the actual positional relationship between the needle hole 11 and the two needles 7 and the width B of the sewing needles 7a and 7b can be directly detected, and a zigzag stitch pattern is formed. The needle swing width A in sewing can be limited so that the two needles 7 and the needle plate 10 do not interfere with each other. For this reason, the sewing machine M has a sewing plate 7a, 7b and a needle plate that constitute the two needles during sewing no matter what two needles are used when sewing a zigzag stitch pattern. 10 can be reliably prevented.

(2) Second Embodiment Hereinafter, a second embodiment of the present invention will be described mainly with reference to FIGS. This embodiment corresponds to claims 1, 2, 3, 5, and 6. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment, the hardware configuration of the sewing machine M is the same as the configuration according to the first embodiment, but the software configuration (the control content of the control device 22) is the same as that of the first embodiment. And different.

  In the present embodiment, as shown in FIG. 12, even in a linear pattern or the like, in addition to the above-mentioned middle base line position C, the needle bar 5 is swung to the left by a predetermined amount and is closer to the left end in the needle hole 11. Left baseline position L through which the two needles 7 pass, or right baseline position R through which the two needles 7 penetrate the right end portion of the needle hole 11 while the needle bar 5 is swung to the right by a predetermined amount. It is also possible to sew with. At this time, when the sewing machine M is turned on, the needle bar 5 moves to a position corresponding to one of the middle baseline position C, the left baseline position L, and the right baseline position R according to the selection of the stitch pattern by the user. ing. In the standard two-needle 7, the left base line position L is set so that the distance between the left end of the needle hole 11 and the sewing needle 7 a is 0.5 mm (normal position), and the right base line position R In this case, the distance between the right end of the needle hole 11 and the sewing needle 7b is set to 0.5 mm (normal position).

  Here, in this type of sewing machine M, when a large impact (dropping, etc.) is given to the sewing machine body or the screw of the mechanism part is loosened, the position of the needle bar 5 (and eventually the sewing needle) There is a risk that the needle entry position) will deviate from the normal position. If such a deviation of the needle bar 5 occurs, a good work cannot be performed, or if the needle bar 5 is severe, the needle bar 5 does not move even though the needle swing width A is limited as described above. There is a possibility that the sewing needles 7a and 7b may interfere with the needle plate 10 during the movement.

  Therefore, in this embodiment, immediately after the sewing machine M is turned on, the control device 22 identifies whether or not the two needles 7 are attached to the needle bar 5 as described in the first embodiment, The upper limit of the swingable range of the needle bar 5 when the two needles 7 are mounted on the needle bar 5 is set. At the same time, the control device 22 extracts the contour image extracted from the image of the needle hole 11 and the two needles 7 (sewing needles 7a and 7b) photographed by the image sensor 23 and the inner width dimension B1 of each of the sewing needles 7a and 7b (see FIG. 12), it is determined whether or not the needle bar 5 is in the normal position. When the position of the needle bar 5 is deviated from the normal position, the position of the needle bar 5 is changed from the normal position. Correct so that Therefore, the control device 22 also functions as a determination unit and a correction control unit. Thereafter, sewing is performed according to a stitch pattern preset in the sewing machine M.

  Specifically, when the position of the needle bar 5 is a position corresponding to the left base line or the right base line, the control device 22 uses the double needle based on the contour image of the sewing needle 7a or 7b extracted by the image processing circuit 24. 7, the horizontal distance E between the sewing needle 7 a or 7 b and the left end or right end of the needle hole 11 and the thickness D of the sewing needles 7 a and 7 b are calculated, and the calculated distance E Based on the thickness D of the sewing needles 7a and 7b, it is determined whether or not the position of the needle bar 5 is in the normal position.

The control device 22 includes a liquid crystal display 17 and a buzzer 34 as notification means. When the control device 22 determines that the position of the needle bar 5 deviates from a normal position to a predetermined value or more and is abnormal, the notification means notifies the user. Announce a warning.
The control device 22 includes a RAM 28 as storage means, and the control device 22 stores the corrected position data of the needle bar 5 based on the above determination and the movement amount (number of pulses) of the needle bar 5 at the time of correction in the RAM 28. To do.

  The operation of the above configuration according to the present embodiment (the control content of the control device 22) will be described in detail below. FIG. 12 schematically shows the relative positional relationship between the needle bar 5 and the three baseline positions. The flowchart of FIG. 13 shows an overall procedure at the time of sewing the stitch pattern of the sewing machine M executed by the control device 22 according to the present embodiment. The flowchart of FIG. 14 specifically shows the processing contents of the needle bar position correction determination process (S52) in the flowchart of FIG.

  In the flowchart of FIG. 13, when the control device 22 is activated by turning on the sewing machine M, the process of step S50 is executed. In step S50, processing similar to that in steps S1 to S8 (see FIGS. 8 to 11) in the first embodiment is performed, and thus description thereof is omitted. However, in the first embodiment, the processing from step S1 to step S8 is performed in a state where the needle bar 5 is positioned at the X-axis coordinate 0 point (origin), but in the present embodiment, the needle bar 5 This is performed in the same manner even when the positions of the positions corresponding to the left baseline position L and the right baseline position R are.

Next, the process proceeds to step S51, and the inner width dimension B1 of the two needles and the thickness dimension D of the sewing needles 7a and 7b are measured.
The process proceeds to step S52, and an interval E (see FIG. 12) between the left end portion of the needle hole 11 and the sewing needle 7a is calculated based on the already extracted contour images of the two needles 7 and the needle hole 11.
In step S53, a needle bar position correction determination process for the needle bar 5 is performed. The needle bar position correction determination process will be described with reference to FIG.

  In step S60 (see FIG. 14), it is determined whether the position of the needle bar 5 is the left base line position L or not. In the case of the left base line position L (S60: YES), the process proceeds to step S61 and is calculated from the inner width dimension B1 of the two needles 7 measured in step S1, the left interval E, and the thickness dimension D (E + D + B1). Whether the value of / 2) is equal to the normal position data of the left base line position L is determined. When the value of (E + D + B1 / 2) and the normal position data of the left base line position L are equal (S61: YES), it is determined that the position of the needle bar 5 is normal. Thereafter, the process proceeds to step S11. Then, sewing is started by the user's operation of the start / stop key 16a. The value of (E + D + B1 / 2) means the distance between the left end of the needle hole 11 and the center of the needle bar 5.

  When the value of (E + D + B1 / 2) and the normal position data of the left base line position L are different (S61: NO), the process proceeds to step S62, and the value of (E + D + B1 / 2) and the left base line position L It is determined whether or not the difference from the normal position data is 2 mm or more, for example. If the difference between the value of (E + D + B1 / 2) and the normal position data of the left base line position L is 2 mm or more (step S62: YES), it is determined that the needle bar position correction process is beyond the possible range and that it is abnormal. Is done. At this time, the process proceeds to step S63, a warning indicating that there is an abnormality is displayed on the liquid crystal display 17, and the buzzer 34 is sounded to notify the user to repair the sewing machine M. The sewing machine M stands by in step S63.

  When the difference between the value of (E + D + B1 / 2) and the normal position data of the left baseline position L is less than 2 mm (step S62: NO), the process proceeds to step S64, and the normal position data of the left baseline position L is It is determined whether or not the value is greater than (E + D + B1 / 2). When the normal position data of the left baseline position L is larger than the value of (E + D + B1 / 2) (step S64: YES), the process proceeds to step S65, and the value of (E + D + B1 / 2) becomes equal to the normal data. Until then, the stepping motor 13 is driven through the drive circuit 32 (see FIG. 6) (plus pulse is applied), and the needle bar 5 is moved rightward.

  In step S66, the movement amount (correction pulse number) of the needle bar 5 moved by driving the stepping motor 13 is stored in the RAM 28 (see FIG. 6). Next, the process proceeds to step S11, where sewing is started by the user's operation of the start / stop key 16a. Since the movement amount is stored in the RAM 28, the position of the needle bar 5 is maintained at the normal position of the left base line position L during sewing of the sewing machine M.

  In step S64, when it is determined that the normal position data of the left baseline position L is smaller than the value of (E + D + 1/2) (S64: NO), the process proceeds to step S67 and the value of (E + D + B1 / 2) is obtained. Until the value becomes equal to the normal position data, the stepping motor 13 is driven through the drive circuit 32 (a pulse in the minus direction is applied), and the needle bar 5 is moved in the left direction.

  In step S68, the movement amount of the needle bar 5 moved by driving the stepping motor 13 is stored in the RAM 28. Next, the process proceeds to step S11, and when sewing is started by the user's operation of the start / stop key 16a, the movement amount is stored in the RAM 28. Therefore, during sewing of the sewing machine M, the needle bar 5 is moved to the normal position. Maintained. The user performs a predetermined sewing operation (S12). When the user finishes using the sewing machine M, the sewing machine M stops sewing by operating the user's start / stop key 16a (S13).

  On the other hand, when the needle bar 5 is not at the left base line position L in step S60 (S60: NO), the process proceeds to step S69 to determine whether or not the position of the needle bar 5 is at the middle base line position C. When the position of the needle bar 5 is at the middle baseline position C (S69: YES), the same processing as when the position of the needle bar 5 is at the left baseline position L is performed. In steps S70 to S77, only the normal position data is different, and the same processing as in steps S61 to S68 is performed. Therefore, detailed description is omitted.

  Furthermore, when the position of the sewing needle 7 is not at the middle baseline position C (S69: NO), that is, when the position of the needle bar 5 is at the right baseline position R, the position of the needle bar 5 is also at the left baseline position L. The same processing as in the case is performed. In steps S78 to S95, only the normal position data is different, and the same processing as in steps S61 to S68 is performed, and detailed description thereof is omitted.

  In the present embodiment described above, based on the contour image of the two needles 7 and the needle holes 11 extracted by the image processing circuit 24 from the images of the needle holes 11 and the two needles 7 photographed by the image sensor 23. Thus, the actual positional relationship between the needle hole 11 and the two needles 7 can be directly detected, and the needle bar 5 is located at any one of the left baseline position L, the middle baseline position C, and the right baseline position R. Even at this time, it is possible to accurately determine and correct whether the position is a normal position. Accordingly, it is possible to prevent problems such as interference between the needle plate 10 and the two needles 7 due to the deviation of the position of the needle bar 5 from the normal position.

  Since the image sensor 23 and the image processing circuit 24 used for controlling the needle swing width A can be used (shared), it is possible to correct the determination of the deviation of the position of the needle bar 5 from the normal position. It is not necessary to add a separate configuration separately, and a simple configuration can be achieved.

  Based on the contour image of the two needles 7 and the needle hole 11 obtained by the image sensor 23 and the image processing circuit 24, the distance E between the sewing needle 7a and the left end of the needle hole 11, the width dimension B1, and the thickness of the sewing needle 7a. The dimension D is calculated, and based on these, the needle swing width of the needle bar 5 corresponding to the two needles 7 can be determined accurately. Can be used for

When the needle bar 5 is displaced by 2 mm or more from the normal position, the notification means of the liquid crystal display 17 and the buzzer 34 can promptly notify the user of the abnormality, and the user can appropriately deal with such an abnormality. Treatment can be performed.
Since the corrected position data of the needle bar 5, that is, the movement amount of the needle bar 5 at the time of the correction, is stored in the RAM 28, a predetermined sewing operation is always performed with the position of the needle bar 5 corrected to the normal position. be able to.

(3) Third Embodiment Hereinafter, a third embodiment of the present invention will be described mainly with reference to FIGS. This embodiment corresponds to claims 1, 2, 4, 5, and 6. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the third embodiment, the hardware configuration of the sewing machine M is the same as the configuration according to the first and second embodiments. However, the software configuration (the control contents of the control device 22) is the same as the second configuration. Different from the embodiment.

  In the present embodiment, based on the contour image of the two needles 7 and the needle hole 11 extracted by the image processing circuit 24, the sewing needle 7a and the needle hole 11 when the position of the needle bar 5 is a position corresponding to the left base line. The left-side distance E between the left end and the right-side distance H between the sewing needle 7b and the right end of the needle hole 11 when the position of the needle bar 5 corresponds to the right base line is calculated. Based on the left interval E and the right interval H, it is determined whether or not the position of the needle bar 5 is in the normal position. If the position of the needle bar 5 is not in the normal position, correction or the like is performed.

  FIG. 15 schematically shows the positional relationship between the needle bar 5 and the three baseline positions. The flowchart of FIG. 16 shows an overall procedure at the time of sewing the stitch pattern of the sewing machine M executed by the control device 22 according to the present embodiment. The flowchart of FIG. 17 specifically shows the processing contents of the needle bar position correction determination process (S105) in the flowchart of FIG.

Hereinafter, the flowchart shown in FIG. 16 will be described in detail.
In step S101, the needle bar swing mechanism 14 is driven via the drive circuit 32 to move the needle bar 5 to the left base line position L, and the sewing machine motor 12 is driven via the drive circuit 31 to lower the needle bar 5.

In step S102, the image sensor 23 (see FIG. 2) converts an image obtained by photographing the sewing needle 7 and the needle hole 11 into an image of a substantially front view, and then performs arithmetic processing based on data obtained from the contour (edge) extraction processing. Then, the contour images of the double needle 7 and the needle hole 11 at the left base line position L are obtained.
In step S103, the needle bar swing mechanism 14 is driven via the drive circuit 32 to move the needle bar 5 to the right baseline position R, and the sewing machine motor 12 is driven via the drive circuit 31 to lower the needle bar 5.

In step S104, the image sensor 23 converts the image obtained by photographing the sewing needle 7 and the needle hole 11 into a substantially front view image, and then performs arithmetic processing based on the data obtained from the contour (edge) extraction processing to obtain the right baseline position. Contour images of the double needle 7 and the needle hole 11 in R are obtained.
In step S105, the above-described two-needle recognition process and the needle swing width restriction process are performed.

  In step S106, a needle bar position correction determination process is performed. The needle bar position correction determination process will be described with reference to FIG. In step S111, based on the contour image of the two needles 7 and the needle hole 11 at the left base line position L obtained in step S102, the left interval E from the left end of the needle hole 11 to the sewing needle 7a (see FIG. 15). Is calculated. In step S112, the right distance H from the right end of the needle hole 11 to the sewing needle 7b based on the contour image of the two needles 7 and the needle hole 11 at the right base line position R obtained in step S104 (see FIG. 15). Is calculated.

  Subsequently, the left interval E and the right interval H are compared, and a process corresponding to the comparison result is performed. In step S113, it is determined whether the left interval E and the right interval H are equal. When it is determined that the left interval E and the right interval H are equal (S113: YES), the position of the needle bar 5 is assumed to be normal (normal position) and the process proceeds to step S1 (see FIG. 16), and step S1 described later is performed. After that, it is identified whether or not the two needles 7 are attached to the needle bar 5 and a process for controlling the swingable range of the needle bar 5 when the two needles 7 are attached to the needle bar 5 is performed. . When the left interval E and the right interval H are different (S113: NO), the process proceeds to step S114.

  In step S114, it is determined whether or not the difference between the left interval E and the right interval H is 2 mm or more. When the difference between the left interval E and the right interval H is 2 mm or more (S114: YES), it is determined that the sewing machine M exceeds the possible range of the needle bar position correction determination process and is abnormal. At this time, the process proceeds to step S115, a warning that the abnormality is present is displayed on the liquid crystal display 17, and the buzzer 34 is sounded to notify the user to repair the sewing machine M. The sewing machine M stands by in step S115. . When the difference between the left interval E and the right interval H is less than 2 mm (S114: YES), the process proceeds to step S116.

  In step S116, it is determined whether the left interval E is greater than the right interval H. When the left interval E is larger than the right interval H (S116: YES), the needle bar 5 is located on the right side of the normal position, and therefore the drive circuit 32 (see FIG. 6) until the left interval E becomes equal to the right interval H. Then, the stepping motor 13 is driven (a negative pulse is applied), and the needle bar 5 is moved to the left (S117).

  In step S118, the movement amount of the needle bar 5 moved by driving the stepping motor 13 is stored in the RAM 28. Next, the process proceeds to step S1, where it is identified whether or not the double needle 7 is attached to the needle bar 5 after step S1, which will be described later, and the needle when the double needle 7 is attached to the needle bar 5. Processing for controlling the swingable range of the rod 5 is performed.

  When the left interval E is smaller than the right interval H (S116: NO), since the needle bar 5 is located on the left side from the normal position, stepping is performed via the drive circuit 32 until the left interval E becomes equal to the right interval H. The motor 13 is driven (a pulse in the plus direction is applied), and the needle bar 5 is moved to the right (S119).

  In step S120, the movement amount of the needle bar 5 moved by driving the stepping motor 13 is stored in the RAM 28. Next, the process proceeds to step S1 (see FIG. 16), and identification of whether or not the double needle 7 is attached to the needle bar 5 after step S1 described later, and the double needle 7 is attached to the needle bar 5. In this case, a process for controlling the swingable range of the needle bar 5 is performed.

  In steps S1 to S8 (see FIG. 16), the same processing as in steps S1 to S8 (see FIGS. 8 to 11) according to the first embodiment is performed. In the second embodiment, the needle bar 5 is corrected so as to be positioned at the normal position (X-axis coordinate 0 point (origin)) of the middle baseline position C by the needle bar position correction determination process (S105), and then the step. It differs from the first embodiment in that the processing from S1 to step S8 is performed.

  Next, the process proceeds to step S11, where sewing is started by the user's operation of the start / stop key 16a. In step S12, a zigzag stitch (zigzag) pattern is sewn with the two needles 7. Then, when the user finishes the sewing, the sewing machine M stops the sewing by the user's operation of the start / stop key 16a (S13).

  In the present embodiment described above, the left interval E between the needle bar 5 and the left end of the needle hole 11 at the left baseline position L, and the right interval H between the needle bar 5 and the needle hole 11 right end at the right baseline position R, In order to reliably determine whether the position of the needle bar 5 is the normal position based on the coincidence and magnitude relationship between the left interval E and the right interval H, the needle bar 5 is moved to the normal position (medium The base line position C and the X-axis coordinate 0 point (origin) can be reliably positioned. Furthermore, when the needle swing width in the sewing of the zigzag stitch pattern is too large, the needle swing width can be automatically reduced so that the two needles 7 and the needle plate 10 do not interfere with each other. Thus, it is possible to reliably prevent problems such as interference between the sewing needles 7a and 7b constituting the two needles 7 and the needle plate 10 during sewing.

(4) Other Embodiments The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications or expansions are possible.
In the first to third embodiments described above, an example in which the present invention is applied to a household sewing machine has been described. However, the present invention is not limited thereto, and the present invention can be applied to an industrial sewing machine.

In the first to third embodiments described above, the two needles 7 are shown as an example as a plurality of sewing needles. However, the present invention is not limited to this, and the present invention is also applied to, for example, a sewing needle that includes three or more sewing needles arranged at predetermined intervals on the left and right at the lower portion of the mounting base portion 7c attached to the needle bar 5. Can do.
In the first to third embodiments described above, the example in which the stepping motor 13 is used as the drive source of the needle bar swinging mechanism 14 is shown. However, the present invention is not limited to this. For example, a solenoid is used to drive the needle bar swinging mechanism 14. It may be used as a source.

In the first to third embodiments described above, an example in which a small CMOS image sensor is used for the image sensor 23 is shown. However, the present invention is not limited to this, and a small CCD image sensor may be used.
In the first to third embodiments described above, an example in which the movement amount of the needle bar 5 is stored in the RAM 28 (see FIG. 6) is shown, but the present invention is not limited to this, and the movement amount of the needle bar 5 may be stored in the EEPROM 29.

  In the second and third embodiments described above, the thickness dimension (0.9 mm) of the sewing needles 7a, 7b and the needle bar position abnormality determination (S62, S71, S79) in the needle bar position correction determination process (S52, S105). The specific numerical values such as the threshold value (2 mm) of S114) are merely examples, and various threshold values can be set depending on, for example, the type of sewing machine.

M sewing machine 5 needle bar 7 double needle 7a sewing needle 7b sewing needle 10 needle plate 11 needle hole 14 needle bar swinging mechanism 17 liquid crystal display (notification means)
22 Control device (correction control means)
23 Image sensor (photographing means)
24 Image processing circuit (extraction means)
26 CPU (determination means)
28 RAM (storage means)
29 EEPROM (storage means)
34 Buzzer (notification means)

Claims (6)

A needle bar capable of mounting multiple sewing needles;
A needle bar swing mechanism for swinging the needle bar;
In a sewing machine comprising a needle plate having a needle hole through which the sewing needle can be inserted,
Photographing means for photographing the needle hole and the sewing needle;
Extraction means for extracting a contour image of the needle hole and the sewing needle based on the image photographed by the photographing means;
Based on the contour image extracted by the extraction means, a width calculation means for calculating a width dimension between the left and right sewing needles of the plurality of sewing needles;
And a swing range control means for controlling a swingable range of the needle bar by the needle bar swing mechanism according to a result of the width calculation means. Determining means for determining whether the position of the needle bar with respect to the needle hole is at a preset normal position based on the contour image extracted by the extracting means;
2. A correction control unit that drives and controls the needle bar swinging mechanism to move the needle bar to the normal position in accordance with a determination result of the determination unit. The sewing machine according to 1. When the position of the needle bar is a position corresponding to the left base line or the right base line,
Based on the contour image extracted by the extraction means, a left-right distance between a sewing needle located at the left end or the right end of the plurality of sewing needles and a left end portion or a right end portion of the needle hole, and the sewing needle Calculate the thickness dimension,
The sewing machine according to claim 2, wherein it is determined whether or not the position of the needle bar is in a normal position based on the calculated interval and the thickness dimension of the sewing needle. The determination means is based on the contour image extracted by the extraction means,
A left-side interval between the sewing needle and the left end of the needle hole when the position of the needle bar is a position corresponding to the left base line; and the sewing needle when the position of the needle bar is a position corresponding to the right base line; Calculating the right-side distance between the right end of the needle hole and
The sewing machine according to claim 2, wherein it is determined whether or not the position of the needle bar is in a normal position based on the calculated left interval and right interval.   5. The sewing machine according to claim 2, further comprising a notification unit, wherein when the determination unit determines that the position of the needle bar is abnormal, the notification unit notifies a warning.   The sewing machine according to any one of claims 2 to 5, further comprising a storage unit, wherein the position data of the needle bar after correction based on the determination of the determination unit is stored in the storage unit.

Images