JP7441646B2 - zigzag sewing machine - Google Patents

Description

The present invention relates to a zigzag stitch sewing machine that performs sewing to join two objects to be sewn together.

In order to join the edge parts of the workpiece to the end edge of the workpiece, sewing is performed using a zigzag sewing machine that swings the needle left and right in the direction of sewing progress.
In conventional sewing, for example, if the shapes of the edge of one workpiece and the edge of the other workpiece do not match, the operator manually adjusts the edges. Each sewing workpiece is sent to the needle drop position by matching the needles with each other (see, for example, Patent Documents 1 and 2).

Special Publication No. 55-48838 Japanese Patent Application Publication No. 2003-38877

However, since the work of butting the edges of each workpiece against each other and sending the workpieces to the needle drop position requires skill, there is a risk that the quality of sewing may vary greatly depending on the operator.

An object of the present invention is to maintain stably high stitching quality.

The invention according to claim 1 is
In a zigzag sewing machine that performs seam sewing by butting the edges of two objects to be sewn,
a lateral feed mechanism that individually moves the two objects to be sewn along the needle swing direction of the sewing needles upstream of the needle drop position in the feeding direction of the objects to be sewn;
On a conveying surface that is upstream of the cross-feeding mechanism in the feed direction of the workpieces, the two workpieces respectively arranged in one direction and the other direction in the needle swing direction are joined together. a position detection unit that detects the position of the end edge in the needle swing direction;
a control device that controls the horizontal feed mechanism so that the end edges of the two objects to be sewn approach or come into contact with each other based on detection by the position detection section;
The position detection unit includes a light source that irradiates a line-shaped detection light along the needle swing direction so as to straddle the edge portions of each of the two objects to be sewn, and the irradiation direction of the light source is different. an imaging unit that captures images of the detection light irradiated onto the two objects to be sewn from the direction;
comprising a height difference forming portion that forms a height difference between the edge portion of one of the objects to be sewn and the edge portion of the other object to be sewn at a position where the detection light is irradiated on the conveyance surface;
The control device determines the position of the end edge portions of the two objects to be sewn in the needle swing direction, which is determined from the position in the needle swing direction of each divided end of the two divided lights obtained by dividing the detection light. The present invention is characterized in that the lateral feed mechanism is controlled so that the positions approach or come into contact with each other .

Furthermore, the invention according to claim 1 is as follows:
The irradiation direction of the detection light of the light source and the direction of the line of sight of the imaging unit are both directions on a plane that is perpendicular to the conveying surface and parallel to the feeding direction of the workpiece. It is characterized by

The invention according to claim 2 provides a zigzag stitch sewing machine according to claim 1 , comprising:
The direction of irradiation of the detection light from the light source is a direction normal to the conveyance surface.

The invention according to claim 3 provides a zigzag stitch sewing machine according to claim 1 or claim 2 ,
The light source is a laser light source.

The invention according to claim 4 is a zigzag stitch sewing machine according to any one of claims 1 to 3 , which includes:
The control device determines whether a gap exists between the edge portion of one of the objects to be sewn and the edge portion of the other object to be sewn, and if there is no gap, the control device The present invention is characterized in that the lateral feed mechanism is controlled such that the two objects to be sewn are moved so that the end edges of the objects to be sewn approach or come into contact with each other.

As described above, according to the present invention, since the lateral feed mechanism is provided which is controlled according to the detection result of the position detection section, it is possible to stably maintain high sewing quality regardless of the skill level of the operator. It becomes possible.
Further, in the present invention, the edge portion of each workpiece is irradiated with line-shaped detection light in a divided state in the conveyance direction of the workpiece by the height difference forming section. Even if there is no gap between the edges, the position of each edge in the needle swing direction can be properly detected, and the needle swing direction of the edge of each workpiece can be more accurately detected. It becomes possible to adjust the position of the sewing machine, and it becomes possible to improve the sewing quality.

FIG. 1 is a side view showing the configuration of main parts of the zigzag sewing machine according to the present embodiment. FIG. 1 is a plan view showing the configuration of main parts of a zigzag sewing machine. FIG. 2 is a block diagram showing a control system of the zigzag sewing machine. FIG. 3 is a plan view showing an example of two objects to be sewn. FIG. 3 is a plan view showing an example of zigzag stitches. FIG. 3 is a cross-sectional view illustrating the configurations of first and second lateral feed mechanisms. FIG. 3 is an explanatory diagram showing an example of an image captured by a camera of detection light irradiated to each sewing object having a height difference formed by a height difference forming section so as to straddle the edge portions of each other; It is a flowchart which shows edge part position adjustment control. It is a flowchart which shows another example of edge part position adjustment control. FIG. 10(A) is a plan view showing another example of the height difference forming portion, and FIG. 10(B) is a side view. It is a side view which shows still another example of a height difference formation part.

[Embodiment of the invention]
Embodiments of the present invention will be described. 1 is a side view showing the configuration of the main parts of a zigzag stitch sewing machine 10 according to the present embodiment, FIG. 2 is a plan view of the zigzag stitch sewing machine 10, and FIG. 3 is a block diagram showing a control system of the zigzag stitch sewing machine 10.
Note that when the zigzag stitch sewing machine 10 (hereinafter simply referred to as the sewing machine 10) is placed on a horizontal surface, the feed direction of the sewing objects C1 and C2 is horizontal. In the following description, the feeding direction of the objects C1 and C2 to be sewn is the X-axis direction, the horizontal direction perpendicular to the X-axis direction is the Y-axis direction, and the vertical vertical direction is the Z-axis direction.
Further, in the X-axis direction, the downstream side in the feeding direction of the objects to be sewn C1 and C2 is referred to as "front", the upstream side is referred to as "rear", and in the Y-axis direction, the left hand side when facing forward is referred to as "left". , the right hand side is "right", one side in the Z-axis direction is "top", and the other is "bottom".

The sewing machine 10 is a sewing machine suitable for joining and sewing the end edges C11 and C21 of two objects to be sewn C1 and C2 against each other.
FIG. 4 is a plan view showing an example of the object to be sewn C1 and the object to be sewn C2. Here, the objects to be sewn C1 and C2 are both made of a sheet material that is thicker than the height difference between the objects to be sewn C1 and C2 formed by the height difference forming portion H1, which will be described later, and has elastic flexibility. Illustrate. Note that this is just an example, and it is also possible to join and sew thin sheet materials made of other materials.

The shape of the edge C11 located at one end in the Y-axis direction of the workpiece C1 to be joined is different from the shape of the end edge C21 located at the other end in the Y-axis direction of the workpiece C2. By joining these together by joining and sewing, each of the objects to be sewn C1 and C2 has a curved shape, and the finished product after sewing has a three-dimensional shape.
The sewing machine 10 abuts the edges C11 and C21 of the objects to be sewn C1 and C2 to the needle drop position so that there are no gaps, and feeds the objects to be sewn to the needle drop position so that the stitches cross over both edge portions C11 and C21. Use zigzag stitches to join and sew.

FIG. 5 is a plan view showing an example of a zigzag stitch. As shown in the diagram, the zigzag stitches have stitches that run diagonally alternately on the left and right, forming a continuous sawtooth pattern along the By straddling the edge portions C11 and C21, the edge portions C11 and C21 are connected in close contact with each other.
In addition, although FIG. 5 shows an example of a so-called four-point zigzag stitch in which three stitches are dropped alternately on the edge portions C11 and C21, one stitch is dropped on the edge portions C11 and C21. It is also possible to form a so-called two-point zigzag stitch in which the needle drops alternately.

[Schematic configuration of zigzag sewing machine]
As shown in FIGS. 1 to 3, the zigzag stitch sewing machine 10 includes a needle vertical movement mechanism that moves the sewing needle 11 up and down at the needle drop position F, and a needle oscillation mechanism that oscillates the sewing needle 11 along the Y-axis direction. A feeding mechanism that feeds the sewing objects C1 and C2 at a predetermined feeding pitch by the feed dog 21 at the needle drop position of the sewing needle 11, and an upper thread threaded through the sewing needle 11 below the feed dog 21. A hook mechanism that entangles the bobbin thread in the thread, and a moving motion in the Y-axis direction are applied to each of the sewing objects C1 and C2, which are arranged side by side along the Y-axis direction behind the needle drop position F (upstream side in the feeding direction). and edge portions C11 and C21 of two workpieces C1 and C2 respectively arranged on one side and the other side in the needle swing direction behind the cross feed mechanism 30 (on the upstream side in the feeding direction). The sewing machine includes a position detection unit 40 that detects the position of the machine in the Y-axis direction, a sewing machine frame that houses or supports each of the above components, and a control device 90 that controls each of the above components.

The needle vertical movement mechanism is a well-known structure that uses the sewing machine motor 12 as a driving source and uses a crank mechanism to vertically move the needle bar that holds the sewing needle 11.
The needle swing mechanism is a well-known structure that uses the needle swing motor 13 as a drive source to arbitrarily move a needle bar stand that supports a needle bar so as to be movable up and down along the Y-axis direction.
The feed mechanism receives power from a feed dog 21 that can be retracted from left and right openings formed in a needle plate (not shown) provided on the upper surface of the sewing machine bed of the sewing machine frame, and a sewing machine motor 12, and is moved in the X-Z plane. This is a well-known configuration including a power transmission mechanism that provides the feed dog 21 with an elliptical motion along the same direction. When moving along the upper part of the locus of the elliptical motion, the feed dog 21 protrudes upward from the opening of the throat plate and can feed the objects C1, C2 to be sewn in the moving direction. In addition, in this feeding mechanism, the amount of one feeding (feeding pitch) can be arbitrarily adjusted by the feeding adjustment motor 14.
Further, a presser foot 23 is provided above the protruding and retracting position of the feed dog 21 on the throat plate to press down each of the sewing objects C1 and C2 with a constant spring pressure.
The hook mechanism includes an outer hook that captures a loop of upper thread by rotation, an inner hook that stores a bobbin wound with a bobbin thread, and a power transmission mechanism that receives power from the sewing machine motor 12 and applies rotational force to the outer hook. This is a well-known configuration.

In the zigzag stitch sewing machine 10, the upper surface of a sewing machine bed portion of a sewing machine frame (not shown) serves as a conveying surface H for each of the objects to be sewn C1 and C2. This conveyance surface H is parallel to the XY plane and is flush with the upper surface of the throat plate (not shown). In the following description, the transport surface H includes the upper surface of the throat plate.
An oblong needle hole corresponding to the maximum permissible needle swing width is formed as a needle drop position F at a position directly below the needle bar on the conveying surface H. The longitudinal direction of this needle hole is parallel to the Y-axis direction.
Note that the needle swinging mechanism swings the needle with the same width in the left-right direction around the intermediate point in the Y-axis direction of the needle hole, which is the needle drop position F. A straight line along the X-axis direction passing through the midpoint of this needle hole is defined as the base line K of the needle swing.
During sewing, on the conveyance surface H, one workpiece C1 is placed on the left side of the base line K, and the other workpiece C2 is placed on the right side of the base line K.

[Horizontal feed mechanism]
The cross-feeding mechanism 30 moves the objects C1 and C2 along the Y-axis direction so that the edge C11 of the object C1 and the edge C21 of the object C2 approach or come into contact with each other on the base line K. to add movement motion.
The cross-feeding mechanism 30 includes a first cross-feeding mechanism 30A that is disposed on the left side of the base line K and provides a movement motion along the Y-axis direction from above to the workpiece C1, and a first cross feed mechanism 30A that is disposed on the right side of the base line K. , and a second lateral feed mechanism 30B that applies a movement motion along the Y-axis direction from above to the sewing object C2.

FIG. 6 is a sectional view illustrating the configuration of the first and second lateral feed mechanisms 30A and 30B. Note that since these first and second lateral feed mechanisms 30A and 30B have the same structure and configuration, the same reference numerals are given to the configurations, and redundant explanation will be omitted.

The first and second horizontal feed mechanisms 30A and 30B include a roller 31 that feeds the workpiece C1 or C2 in the tangential direction of the outer circumference, and a plurality of wheels 32 arranged at uniform intervals along the outer circumference of the roller 31. A rotating shaft 33 to which a roller 31 is fixedly mounted, a support frame 34 that rotatably supports the rotating shaft 33, a pair of sprockets 35 and 36 and a timing belt 37 that transmit torque from a drive source to the rotating shaft 33, It is equipped with a lateral feed motor 38 as a driving source.

Each wheel 32 is provided on the outer periphery of the roller 31 at uniform intervals, and is rotatable around an axis along the tangential direction at each attachment position. Alternatively, C2 allows the roller 31 to move in a direction along the rotation axis 33 or in a direction somewhat inclined with respect to the rotation axis 33.
Strictly speaking, the roller 31 comes into contact with the workpiece C1 or C2 through each wheel 32, but in this specification, for the sake of simplicity, the workpiece C1 or C2 is referred to as the "roller 31". "contacts the outer periphery of the roller 31" or "contacts the roller 31".

[Position detection unit]
As shown in FIG. 1, the position detection unit 40 generates a line-shaped detection light L along the Y-axis direction across the base line K on the conveyance surface H that is behind the lateral feed mechanism 30 (upstream side in the feed direction). It has a light source 41 that emits light, and a camera 42 as an imaging unit that captures an image of the detection light L from a direction different from the direction of irradiation of the light source 41.

Specifically, the light source 41 is composed of a laser light source of single wavelength light, and the camera 42 has a filter suitable for imaging the single wavelength light of the light source 41.
The light source 41 irradiates detection light L downward in the Z-axis direction. On the other hand, the camera 42 captures an image with the detection light irradiation position on the conveyance surface H as the center of the imaging range with a line of sight parallel to the XZ plane and tilted diagonally downward. It is attached to the sewing machine 10 as shown in FIG.

On the other hand, as shown in FIG. 2, on the conveyance surface H, there is a height difference forming part that forms a height difference between one workpiece C1 and the other workpiece C2 in the vicinity of the irradiation position of the detection light L. H1 is provided.
The height difference forming portion H1 is a rectangular protrusion provided on one side (right side) in the Y-axis direction of the conveyance surface H with the base line K as a boundary, so as to be higher than the conveyance surface H. The height difference forming portion H1 has a smooth upper surface along the XY plane, and its width in the X-axis direction is set to be sufficiently wider than the detection light L. As a result, the right half of the detection light L is irradiated onto the upper surface of the height difference forming portion H1 in a state where there are no objects to be sewn C1 and C2.
Note that the height difference forming portion H1 may be separated from the base line K to some extent because it is sufficient to provide a height difference between one workpiece C1 and the other workpiece C2, and the shape is not rectangular. Good too.

In FIG. 7, a camera 42 detects detection light L that is irradiated onto a sewing object C1 and a sewing object C2, which have a height difference formed by a height difference forming portion H1, so as to straddle the mutual edge portions C11 and C21. This is a captured image.
The camera 42 is equipped with an image sensor such as a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and can convert a captured image into image data, and the image data is transferred to an image processing device 43 (see FIG. 3). is input.
Then, the processing results of the image processing device 43 are input to the control device 90, and the amount of deviation in the Y-axis direction of the edge portions C11 and C21 with respect to the base line K is determined from the position of each part of the detection light L within the imaging range. The amount of position adjustment of the sewing objects C1 and C2 in the Y-axis direction by the first and second lateral feed mechanisms 30A and 30B is determined.

The respective edge portions C11 and C21 of the objects to be sewn C1 and C2 must be conveyed to the needle drop position F at a position that coincides with the base line K in the Y-axis direction. It is necessary to accurately detect the position in the Y-axis direction.
Therefore, if the part of the detection light L on the side of the workpiece C1 is the divided light L1, and the part on the side of the workpiece C2 is the divided light L2, the position of the right end of the divided light L1 in the Y-axis direction is determined from the captured image. This makes it possible to detect the amount of deviation of the edge portion C11 of the object to be sewn C1 with respect to the base line K. Similarly, by determining the position of the left end of the divided light L2 in the Y-axis direction from the captured image, it is possible to detect the amount of deviation of the edge C21 of the sewing object C2 with respect to the base line K.

Note that when there is a gap N in the Y-axis direction between the object to be sewn C1 and the object to be sewn C2, reflected light due to the detection light L being directly irradiated onto the upper surface of the conveying surface H in the gap N is However, for example, by applying a low-reflectivity coating to the upper surface of the conveying surface H, it becomes possible to easily distinguish between the split lights L1 and L2 and the direct reflected light from the upper surface of the conveying surface H. .

By the way, when the conveyance surface H is assumed to have no height difference forming portion H1, if a gap N is created between the edge portions C11 and C21 of the objects to be sewn C1 and C2 on the conveyor surface H, the objects to be sewn are Since the divided light L1 on the C1 side and the divided light L2 on the sewing object C2 side are separated in the Y-axis direction, the right end of the divided light L1 and the left end of the divided light L2 can be clearly extracted from the captured image. It is possible to accurately detect each position in the Y-axis direction.
However, if the gap N is not generated between the edge portions C11 and C21, the right end of the divided light L1 and the left end of the divided light L2 are combined to form a line light on a straight line, so the divided light L1 It becomes difficult to extract the right end of the divided light L2 and the left end of the divided light L2, and it becomes difficult to accurately detect the positions of the right end of the divided light L1 and the left end of the divided light L2 in the Y-axis direction.

In order to deal with such a problem, a height difference forming portion H1 is provided to form a height difference between the workpiece C1 and the workpiece C2 at the irradiation position of the detection light L on the conveyance surface H. When the camera 42 captures an image from an oblique direction, a shift S in the X-axis direction always occurs between the divided light L1 and the divided light L2, regardless of the presence or absence of the gap N between the edge portions C11 and C21. Therefore, the right end of the divided light L1 and the left end of the divided light L2 can be clearly extracted from the captured image, and their respective positions in the Y-axis direction can be detected more reliably and more accurately.

[Control device]
As shown in FIG. 3, the sewing machine 10 includes a control device 90 that controls the entire sewing machine during sewing.
The control device 90 includes the sewing machine motor 12 of the needle vertical movement mechanism, the needle oscillation motor 13 of the needle oscillation mechanism, the feed adjustment motor 14 of the feed mechanism, and the lateral feed motors of the first and second lateral feed mechanisms 30A and 30B. 38 are connected via drive circuits 12a, 13a, 14a, and 38a, respectively.
Further, an encoder 15 for detecting the shaft angle is provided on a sewing machine main shaft (not shown) that is rotationally driven by the sewing machine motor 12, and outputs the detected shaft angle to the control device 90 via an interface 15a. . From the output of this encoder 15, the rotation speed and rotation angle of the main shaft can be detected.

Further, the light source 41 of the position detection section 40 is connected to the control device 90 via a power supply circuit 41a.
Further, a camera 42 of the position detection section 40 is connected via a drive circuit 42a, and an image processing device 43 is connected via an interface 43a.

The control device 90 includes a CPU 91 that performs various calculation processes, a ROM 92 that stores programs related to the operation control of each of the components described above, a RAM 93 that stores various data related to the processing of the CPU 91 in a work area, and various settings. It is equipped with an EEPROM 94 as a storage section for recording data, sewing data, etc.
Note that as a recording medium for various setting data, sewing data, etc., any non-volatile recording medium can be used instead of the EEPROM 94.
Further, the sewing machine 10 includes an operation panel 95 for inputting various settings and displaying various information, and the operation panel 95 is also connected to the control device 90 via an interface 95a.

[Sewing operation control]
When performing a four-point zigzag stitch, the CPU 91 of the control device 90 controls the needle oscillation motor 13 when a specified main shaft angle is detected by the encoder 15 when the sewing machine motor 12 is driven. Move the sewing needle to the left or right at a predetermined needle swing width.
In the case of four-point zigzag stitch, the left and right needle oscillation directions are switched every three stitches, so the needle oscillation motor 13 counts the number of stitches from the output of the encoder 15 and changes the needle oscillation direction every three stitches. control.
If the number of stitches to be sewn is set in advance, the number of stitches is counted during sewing, and when the target number of stitches is reached, the sewing is finished.
Further, if the number of stitches is not set in advance, the sewing machine terminates the sewing upon receiving an input of a command to terminate the sewing.

[Edge position adjustment control]
Next, the edge position adjustment control executed by the CPU 91 of the control device 90 during the sewing will be described based on the flowchart of FIG. 8. This edge position adjustment control is repeatedly executed in short cycles during sewing. This edge position adjustment control may be performed in synchronization with the needle drop cycle, or may be performed at a shorter cycle.

According to the control program stored in the ROM 92, the CPU 91 of the control device 90 receives the detection light L from the light source 41 of the position detection unit 40 at the rear of the needle drop position F (upstream side in the feeding direction) during the zigzag sewing operation. The upper surfaces of the sewing objects C1 and C2 are irradiated (step S1).
Since the objects to be sewn C1 and C2 are provided with a height difference by the height difference forming portion H1, the detection light L is divided in the X-axis direction at the boundary between the objects to be sewn C1 and C2, and the divided lights L1 and L2 are An image is taken by the camera 42 (step S3).

The captured image is converted into image data, and the end positions of the divided lights L1 and L2 are detected by image processing by the image processing device 43 (step S5).
The CPU 91 determines the amount of deviation in the Y-axis direction from the position of the right end of the detected divided light L1 with respect to the base line K, and determines the amount of position adjustment of the workpiece C1 in the Y-axis direction by the first lateral feed mechanism 30A. . Similarly, the amount of deviation in the Y-axis direction from the position of the left end of the detected divided light L2 with respect to the base line K is determined, and the amount of position adjustment of the workpiece C2 in the Y-axis direction by the second lateral feed mechanism 30B is determined. decide.

Then, the CPU 91 controls the respective lateral feed motors 38 of the first and second lateral feed mechanisms 30A and 30B to adjust the positions of the sewing objects C1 and C2 in the Y-axis direction (step S7).
As a result, the end edge C11 of the workpiece C1 and the end edge C21 of the workpiece C2 are positioned at the base line K immediately before the needle drop position F, and the feed mechanism moves the end edge C11 of the workpiece C1 and the end edge C21 of the workpiece C2 to the base line K, and Then, seaming sewing is performed with the end edge C11 of the workpiece C1 and the end edge C21 of the workpiece C2 in close contact with each other.

[Technical effects of embodiments of the invention]
As described above, since the sewing machine 10 includes the cross-feeding mechanism 30 that is controlled according to the detection result of the position detection section 40, it is possible to stably maintain high sewing quality regardless of the skill level of the operator. It becomes possible.
Further, in the sewing machine 10, the light source 41 of the position detection unit 40 irradiates a line-shaped detection light L along the Y-axis direction so as to straddle the respective edge portions C11 and C21 of the two objects to be sewn C1 and C2. However, the camera 42 images the detection light L irradiated onto the two sewing objects C1 and C2 from a direction different from the irradiation direction of the light source 41.
Then, at the irradiation position of the detection light L on the conveying surface H in a state where there are no objects to be sewn C1 and C2, a height difference forming portion H1 that forms a height difference between one object to be sewn C1 and the other object to be sewn C2. Since the split light L1 and the split light L2, which are obtained by splitting the detection light L into the workpiece C1 side and the workpiece C2 side, are imaged in a state shifted in the X-axis direction, Even when there is no gap between the sewing objects C1 and C2, the positions of the right end of the divided light L1 and the left end of the divided light L2 in the Y-axis direction can be detected well, and the positions of the right end of the divided light L1 and the left end of the divided light L2 can be detected well, The end edge portions C11 and C21 can be adjusted to appropriate positions on the base line K in the Y-axis direction, respectively, and it is possible to perform seam-sewing without creating any gaps. In addition, zigzag stitch sewing can be performed so that the boundary between the workpiece C1 and the workpiece C2 is located at the center of the seam in the Y-axis direction, thereby making it possible to improve the quality of the sewing.

Further, the irradiation direction of the detection light L of the light source 41 of the position detection unit 40 and the direction of the line of sight of the camera 42 are both set to - Any direction on the Z plane. Therefore, if the edge of the divided light L1 and the edge of the divided light L2 match in the Y-axis direction, the edge parts of the workpiece C1 and workpiece C2 are close to each other or It can be determined that they are in contact, and even if they do not match and are separated, it is possible to eliminate the need for computation to correct the separation distance on the screen by taking into account the inclination of the optical axis or line of sight. This makes it easier to simplify processing and ensure accuracy. On the other hand, when irradiation or imaging is performed from a direction inclined with respect to the A separation occurs on the imaging screen, and if a separation occurs, a computation is required to correct the separation distance on the screen by taking into account the inclination of the optical axis or line of sight, which complicates the processing. .

Furthermore, since the irradiation direction of the detection light L from the light source 41 is perpendicular to the conveying surface H, the divided light L1 and the divided light L2 can be detected with high brightness, and the right end of the divided light L1 and the divided light L2 The position of the left end in the Y-axis direction can be detected more accurately, and the sewing quality can be further improved.

In particular, by using the light source 41 as a laser light source, it is possible to irradiate the detection light L consisting of a single wavelength light, and the influence of disturbance light can be easily suppressed, so that the divided light L1 and the divided light L2 can be It is possible to accurately detect the positions of the right end of the divided light L1 and the left end of the divided light L2 in the Y-axis direction, thereby further improving the sewing quality.

[others]
The details shown in each of the above embodiments can be changed as appropriate without departing from the spirit of the invention.
For example, in the above embodiment, the case where the thickness of the objects to be sewn C1 and C2 is thicker than the height difference formed by the height difference forming portion H1 has been exemplified. The object to be sewn C1, which is located at a lower position than the object to be sewn C2, rarely sinks into the object to be sewn C2, and therefore there is little need to consider the sinking.
On the other hand, when the thickness of the sewing objects C1 and C2 is thinner than the height difference formed by the height difference forming part H1, the thickness of the sewing object C1 with respect to the sewing object C2 is It is preferable to consider sneaking.

FIG. 9 shows a flowchart of edge position adjustment control that takes into account the above-mentioned intrusion.
This edge position adjustment control may also be performed in synchronization with the needle drop cycle, or may be performed at a shorter cycle.
In the case of this edge position adjustment control, the CPU 91 of the control device 90 detects a position detecting point behind the needle drop position F (upstream side in the feeding direction) during the zigzag stitch sewing operation according to the control program stored in the ROM 92. Detection light L is emitted from the light source 41 of 40 onto the upper surfaces of the objects to be sewn C1 and C2 (step S11).
Then, the divided light L1 of the workpiece C1 and the divided light L2 of the workpiece C2 obtained by the height difference of the height difference forming portion H1 are imaged (step S13), and the right end of the divided light L1 and the divided light L2 are captured. It is determined whether or not a gap N exists between the left end portion of (step S15).

At this time, if there is no gap N between the right end of the split light L1 and the left end of the split light L2, the CPU 91 controls the lateral feed motors 38 of the first and second lateral feed mechanisms 30A and 30B. The objects to be sewn C1 and C2 are moved in the direction of separation from each other so as to create a gap between the edge C11 of the object C1 and the edge C21 of the object C2 (step S17). ).
Then, imaging is performed again (step S13), and the presence or absence of the gap N is determined (step S15).

In determining the presence or absence of the gap N, if the gap N exists, the end positions of the divided beams L1 and L2 are detected (step S19).
Then, the CPU 91 determines the amount of deviation in the Y-axis direction from the end positions of the divided beams L1 and L2 with respect to the base line K, and controls each lateral feed motor 38 of the first and second lateral feed mechanisms 30A and 30B, The positions of the objects to be sewn C1 and C2 in the Y-axis direction are adjusted (step S21).
As a result, the state in which the end edge C11 of the workpiece C1 sinks into the workpiece C2 is eliminated, and the end edge C11 of the workpiece C1 and the end edge C21 of the workpiece C2 are aligned with the base line K. It becomes possible to perform splicing sewing while positioning the sewing machine at the position shown in FIG.

Moreover, although the height difference forming part H1 mentioned above was illustrated as the protrusion which protrudes upward on the conveyance surface H, it is not limited to this.
For example, as shown in FIGS. 10(A) and 10(B), a height difference forming portion H1 formed of a substantially hemispherical protrusion may be provided on the conveying surface H on the right side near the base line K.
Alternatively, as shown in FIG. 11, an inclined portion H11 that gradually increases the change in height difference may be provided at the upstream end in the conveying direction of the height difference forming portion H1 shown in FIG. Alternatively, an inclined portion H12 that gradually reduces the change in height difference may be provided at the downstream end of the height difference forming portion H1 in the conveying direction. Either or both of these inclined portions H11 and H12 may be provided.

Although the height difference forming portion H1 is provided on the right side of the base line K, it goes without saying that it may be provided on the left side to make the object C1 higher than the object C2.
In addition, in the example of edge position adjustment control shown in FIGS. 8 and 9, the first and second Although the case where each cross-feed motor 38 of the second cross-feed mechanisms 30A, 30B is controlled is illustrated, the position may be adjusted so that a minute gap N is generated within an acceptable range of stitching quality.

10 Staggered stitch sewing machine 11 Sewing needle 12 Sewing machine motor 13 Needle swing motor 30 Cross feed mechanism 30A First cross feed mechanism 30B Second cross feed mechanism 38 Cross feed motor 40 Position detection section 41 Light source 42 Camera (imaging section)
43 Image processing device 90 Control device 91 CPU
C1, C2 Sewn object C11, C21 Edge portion F Needle drop position H Conveying surface H1 Height difference forming portion H11, H12 Inclined portion K Base line L Detection light L1, L2 Separated light N Gap S Displacement

Claims (4)

In a zigzag sewing machine that performs seam sewing by butting the edges of two objects to be sewn,
a lateral feed mechanism that individually moves the two objects to be sewn along the needle swing direction of the sewing needles upstream of the needle drop position in the feeding direction of the objects to be sewn;
On a conveying surface that is upstream of the cross-feeding mechanism in the feed direction of the workpieces, the two workpieces respectively arranged in one direction and the other direction in the needle swing direction are joined together. a position detection unit that detects the position of the end edge in the needle swing direction;
a control device that controls the horizontal feed mechanism so that the end edges of the two objects to be sewn approach or come into contact with each other based on detection by the position detection section;
The position detection unit includes a light source that irradiates a line-shaped detection light along the needle swing direction so as to straddle the edge portions of each of the two objects to be sewn, and the irradiation direction of the light source is different. an imaging unit that captures images of the detection light irradiated onto the two objects to be sewn from the direction;
The irradiation direction of the detection light of the light source and the direction of the line of sight of the imaging unit are both directions on a plane perpendicular to the conveying surface and parallel to the feeding direction of the workpiece. ,
comprising a height difference forming portion that forms a height difference between the edge portion of one of the objects to be sewn and the edge portion of the other object to be sewn at a position where the detection light is irradiated on the conveyance surface;
The control device determines the position of the end edge portions of the two objects to be sewn in the needle swing direction, which is determined from the position in the needle swing direction of each divided end of the two divided lights obtained by dividing the detection light. A zigzag stitch sewing machine, characterized in that the horizontal feed mechanism is controlled so that positions approach or abut each other . 2. The zigzag stitch sewing machine according to claim 1 , wherein an irradiation direction of the detection light from the light source is a direction normal to the conveyance surface. 3. The zigzag stitch sewing machine according to claim 1 , wherein the light source is a laser light source. The control device determines whether a gap exists between the edge portion of one of the objects to be sewn and the edge portion of the other object to be sewn, and if there is no gap, the control device Claims 1 to 3 are characterized in that the horizontal feed mechanism is controlled so that the two objects to be sewn are moved so that the end edges of the objects to be sewn approach or come into contact with each other. The zigzag stitch sewing machine described in any one of the above.

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