Cloth movement detection device and sewing machine

Abstract

To provide a cloth movement detection device and a sewing machine, which can accurately detect the movement of cloth.SOLUTION: A cloth movement detection device 10 includes: a light detection section 2 which detects light and detects the movement of cloth; a body section 1 which incorporates the light detection section 2 and is attachable / detachable to / from a presser bar of a sewing machine; and a presser support section 20 which is formed with a cloth presser section 21 which can come into contact with cloth and is attachable / detachable to / from the body section 1. A window section 4 through which light can pass is provided on a bottom surface of the body section 1. The cloth presser section 21 is positioned below the bottom surface of the body section 1 in a state that the presser support section 20 is mounted in the body section 1.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a cloth movement detection device and a sewing machine. [Background technology]

[0002] In the sewing operation of a sewing machine, stitches are formed on the fabric by moving the needle up and down while feeding the fabric. Usually, sewing machines are provided with a fabric feed mechanism that automatically feeds the fabric. On the other hand, in the case of quilting, stitches are sometimes formed by manually feeding the fabric in any direction without using a feed mechanism.

[0003] When stitching by hand, the fabric must be fed at a constant speed in accordance with the vertical movement speed of the needle in order to achieve the desired stitch pitch. In quilting, where multiple pieces of fabric are layered and stuffed with cotton between them, feeding the fabric is difficult, and it takes time to master how to achieve the desired stitch pitch.

[0004] To solve this problem, there is a technique for adjusting the needle movement speed by detecting the movement of the cloth and changing the motor rotation speed in response to the detection result, as disclosed in the following Patent Documents 1 to 3. This makes it relatively easy to obtain a desired stitch pitch by adjusting the needle movement speed, even if the movement speed of the cloth being fed by hand is not constant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4724938 [Patent Document 2] U.S. Patent No. 6,883,446 [Patent Document 3] U.S. Patent No. 7,325,502 Summary of the Invention [Problem to be solved by the invention]

[0006] The light detector (sensor) that detects the movement of the fabric as described above is installed near the sewing needle. The light detector is, for example, an image sensor, and detects light reflected by the fabric.

[0007] When the light detector is provided in a position close to the fabric so as to be in contact with the fabric, the detection range of the light detector is narrower than when the light detector is located away from the fabric. The inventors have found that, depending on the type and pattern of the fabric, the light detector cannot detect the movement of the fabric and judges the amount of movement of the fabric to be zero. As a result, even though the fabric is actually being moved by hand, the needle operation slows down or stops, causing a problem in which the desired predetermined stitch pitch cannot be obtained.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a cloth movement detection device and a sewing machine that are capable of detecting the movement of the cloth with high accuracy. [Means for solving the problem]

[0009] In order to solve the above problems, the cloth movement detection device and sewing machine of the present invention employ the following means. In other words, the cloth movement detection device of the present invention comprises a light detection unit that detects movement of the cloth by detecting light, a main body in which the light detection unit is built in and which is detachable from the presser bar of a sewing machine, and a presser support unit which is detachable from the main body and has a cloth presser part that can contact the cloth and is formed therein, and a window part through which the light can pass is provided on the bottom surface of the main body, and when the presser support unit is attached to the main body, the cloth presser part is located below the bottom surface of the main body.

[0010] According to this configuration, the light detection unit detects light and detects the movement of the cloth. The main body unit having the light detection unit is detachable from the presser bar of the sewing machine, so that the main body unit is installed on the presser bar when it is necessary to detect the movement of the cloth. The presser support unit is detachable from the main body unit, so that presser support units of various shapes can be replaced and attached to the main body unit. The presser support unit is formed with a cloth presser unit, which can contact the cloth and prevent the cloth from floating up. When the presser support unit is attached to the main body unit, the cloth presser unit is located below the bottom surface of the main body unit, so that the window unit provided on the bottom surface of the main body unit is located above the cloth presser unit of the presser support unit. As a result, unlike when the light detection unit is provided in a position close to the cloth so as to contact the cloth, the light detection unit is separated from the cloth, so that the detection range of the light detection unit is wide. As a result, it is possible to detect the amount of movement of the cloth with high accuracy.

[0011] In the above invention, the main body may include a light irradiating unit that is built in and irradiates the cloth with infrared rays, and the light detecting unit may be capable of detecting infrared rays reflected by the cloth.

[0012] According to this configuration, the light irradiation unit is built into the main body and irradiates the cloth with infrared rays, so that the infrared rays emitted by the light irradiation unit create shadows on the surface of the cloth, making it easier for the light detection unit to detect the movement of the cloth.

[0013] In the above-mentioned invention, a visible light cut filter that blocks visible light and transmits infrared light may be provided in the window portion.

[0014] This configuration reduces the incidence of external light in the visible light range at the light detection unit. When detecting visible light, differences in the color of the fabric may cause differences in the amount of movement detected. In contrast, when detecting infrared light, the color of the fabric due to visible light is ignored, so the difference in the amount of movement detected due to differences in the color of the fabric is reduced, improving detection accuracy.

[0015] In the above invention, the light irradiation unit and the light detection unit may be disposed in the main body so that when a ruler is inserted between the presser support unit and the needle plate of the sewing machine, light irradiated by the light irradiation unit and reflected by the surface of the ruler does not enter the light detection unit.

[0016] With this configuration, even when a ruler, such as a quilting ruler, is inserted between the presser support part and the needle plate of the sewing machine, the light reflected from the surface of the ruler does not cause whiteout in the detection results of the light detection unit, and the light detection unit can reliably detect light reflected from the fabric.

[0017] In the above invention, the presser support portion has an attachment portion configured to be detachably attached to the side of the main body portion, the bottom of the attachment portion is provided at a position spaced apart from the needle plate of the sewing machine, and the cloth pressing portion is provided below the bottom of the attachment portion.

[0018] According to this configuration, since the bottom of the attachment part is provided at a position separated from the needle plate of the sewing machine, a space is formed between the bottom of the attachment part and the needle plate of the sewing machine. Also, since the presser foot is provided below the bottom of the attachment part, a space is formed around the side of the presser foot.

[0019] In the above invention, the pressing support portion has an attachment portion configured to be attached and detached to the side of the main body portion, and the attachment portion is provided with a wall portion extending to a height position of the cloth pressing portion, and the wall portion may have a shape that surrounds the window portion.

[0020] With this configuration, since the wall of the attachment part extends up to the height of the cloth presser part, it is possible to prevent the cloth from becoming loose between the bottom surface of the main body and the needle plate. Since the wall of the attachment part has a shape that surrounds the window part, it is difficult for light that is a disturbance unrelated to the movement of the cloth to be incident on the light detection part.

[0021] In the above invention, the main body may be provided with a display unit that can be turned on and off, and the display unit may be turned on or off depending on an operating state of the sewing machine.

[0022] According to this configuration, the display unit turns on or off depending on the operating state of the sewing machine, so that the operator can easily recognize the operating state of the sewing machine. The operating state of the sewing machine is, for example, the start or end of a mode in which the needle starts to move up and down when the fabric moves, and, for example, when this mode is started, the needle starts to move up and down when the fabric moves, even if the sewing machine motor has stopped and the needle has stopped moving up and down. The operator can recognize whether the mode in which the needle starts to move up and down when the fabric moves has started or ended by the display unit turning on or off.

[0023] In the above invention, the pressing support portion may have a rotation fulcrum portion provided on both side surfaces and protruding toward the rear side, and the main body portion may have a rotation fulcrum receiving portion in a recess formed on both side surfaces corresponding to the rotation fulcrum portion.

[0024] According to this configuration, the rotation fulcrum part of the presser support part is inserted into the rotation fulcrum receiving part of the main body part. The presser support part is then pushed upward around the rotation fulcrum part as an axis. The presser support part and the main body part can operate around the rotation fulcrum part as an axis, and the operator can easily and reliably attach the presser support part to the main body part.

[0025] In the above invention, the main body portion has a button provided on the rear side and a fixed pin protruding from the side and arranged to be linked to the button, the pressing support portion has a pin hole formed on the side and capable of engaging with the fixed pin, and the engagement of the fixed pin with the pin hole may be released by pressing the button.

[0026] According to this configuration, the fixing pin of the main body and the pin hole of the pressing support part are engaged with each other, so that the pressing support part is fixed to the main body part. When the button is pressed, the fixing pin is disengaged from the pin hole, and the pressing support part is removed downward from the main body part.

[0027] The sewing machine of the present invention includes the cloth movement detection device described above, and a control unit that controls the operation of a motor that moves the needle of the sewing machine based on the movement of the cloth detected by the cloth movement detection device.

[0028] According to this configuration, the operation of the motor that operates the needle of the sewing machine is controlled based on the movement of the cloth detected by the cloth movement detection device, so that the needle can be operated to achieve a constant finished stitch pitch, for example, by increasing the rotational speed when the cloth movement speed increases and decreasing the rotational speed when the cloth movement speed decreases.

[0029] In the above invention, the control unit may have an input receiving unit that receives input regarding adjustment of the sensitivity of the light detection unit, and a speed adjustment unit that adjusts the rotational speed of the motor based on information input by the input receiving unit.

[0030] According to this configuration, the rotation speed of the motor is adjusted based on the information inputted in the input receiving unit, so that, for example, if there is a discrepancy between the set stitching pitch and the actual stitching pitch, it is possible to bring the stitching pitch closer to the desired stitching pitch. Effect of the Invention

[0031] According to the present invention, the movement of the cloth can be detected with high accuracy. [Brief description of the drawings]

[0032] [Figure 1] 1 is a side view showing a sewing machine and a cloth movement detection device according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view showing a cloth movement detection device according to an embodiment of the present invention, in a state where it is attached to a presser bar. [Diagram 3] FIG. 2 is a bottom view showing the cloth movement detection device according to the embodiment of the present invention. [Figure 4] 1 is a side view showing a cloth movement detection device according to an embodiment of the present invention; [Diagram 5] 1 is a vertical cross-sectional view showing a cloth movement detection device according to an embodiment of the present invention, illustrating a state where the cloth movement detection device is attached to a presser bar. [Figure 6] 1 is a block diagram showing a sewing machine and a cloth movement detection device according to an embodiment of the present invention; [Figure 7] 4 is a flowchart showing the operation of the sewing machine and the cloth movement detection device according to the embodiment of the present invention. [Figure 8] 1 is a perspective view showing a cloth movement detection device according to an embodiment of the present invention; [Figure 9] 1 is a vertical cross-sectional view showing a cloth movement detection device according to an embodiment of the present invention, illustrating a state where the cloth movement detection device is attached to a presser bar. [Figure 10] 1 is a perspective view showing a cloth movement detection device according to an embodiment of the present invention; [Figure 11] FIG. 1 is a perspective view of a sewing machine according to an embodiment of the present invention, showing a state in which a quilting ruler is being used. [Figure 12] 1 is a vertical cross-sectional view showing a cloth movement detection device according to an embodiment of the present invention, illustrating a state where the cloth movement detection device is attached to a presser bar. [Figure 13] 1 is a perspective view showing a cloth movement detection device according to an embodiment of the present invention; [Figure 14] 1 is a vertical cross-sectional view showing a cloth movement detection device according to an embodiment of the present invention, illustrating a state where the cloth movement detection device is attached to a presser bar. [Figure 15] FIG. 1A is a schematic diagram showing a light detection unit and a light irradiation unit of a cloth movement detection device according to an embodiment of the present invention, and FIG. [Figure 16] FIG. 4A is a schematic diagram showing a light detection section and a light irradiation section according to a comparative example, and FIG. 4B is a plan view showing the detection range of the light detection section. [Figure 17] 1 is a perspective view showing the inside of a cloth movement detection device according to an embodiment of the present invention; [Figure 18] 1 is a side view showing a cloth movement detection device according to an embodiment of the present invention, illustrating a state in which a presser support part is attached to or detached from a main body part. FIG. [Figure 19] 1 is a schematic diagram showing a positional relationship between a light detection unit and a cloth in a cloth movement detection device according to an embodiment of the present invention; [Figure 20] FIG. 13 is a schematic diagram showing the positional relationship between a light detection unit and a cloth according to a comparative example. [Figure 21] 11 is a graph showing the relationship between the moving speed of the cloth and the rotation speed of the motor. [Figure 22] FIG. 11 is an explanatory diagram showing a stitching pitch caused by sensitivity adjustment. [Diagram 23] 4 is a schematic diagram showing a sensitivity adjustment section displayed on a display of the sewing machine according to one embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A cloth movement detection device 10 according to the present embodiment, which will be described later, can be detachably attached to a sewing machine 50 according to one embodiment of the present invention. Figs. 1 and 2 show a state in which the cloth movement detection device 10 is installed on the sewing machine 50. The sewing machine 50 according to the present embodiment can receive data relating to the amount of movement of the cloth 70 detected by the cloth movement detection device 10, and can control, for example, the vertical drive of the needle 53 based on the received data. That is, the sewing machine 50 according to the present embodiment has a control unit 5 compatible with the cloth movement detection device 10.

[0034] The cloth movement detection device 10 is a component that is detachable from the presser bar 51 of the sewing machine 50, and includes a main body 1 and a presser support 20. In the cloth movement detection device 10, the presser support 20 is detachable from the main body 1.

[0035] The main body 1 has a casing formed in a shape that can be attached to the presser bar 51, for example, at the upper part of the front side of the outer periphery. The main body 1 is fixed to the presser bar 51 by being sandwiched between the presser bar 51 and a set screw 52. The presser support part 20 is detachably attached to the main body 1 at the lower part of the outer periphery. Since the main body 1 is detachable from the presser bar 51 of the sewing machine 50, the main body 1 is installed on the presser bar 51 when it is necessary to detect the movement of the fabric 70.

[0036] As shown in FIG. 5, the main body 1 includes a light detection unit 2, a light irradiation unit 3, a window unit 4, and the like. The light detection unit 2 detects light to detect the movement of the cloth 70, i.e., the change in position of the cloth 70. The light detection unit 2 is an imaging element that captures an image of an object and converts the image capture result into an electrical signal. The light detection unit 2 is, for example, an infrared imaging element that can detect infrared wavelengths in the object. The light detection unit 2 detects the amount of movement of the object per unit time based on the image capture result, and sends the detection result to the control unit 5.

[0037] The light irradiation unit 3 irradiates light onto the cloth 70 placed on the sewing machine 50. The light irradiation unit 3 is, for example, a light emitting diode (LED), and in the case of irradiating infrared rays, is an infrared LED.

[0038] The window 4 is made of a material such as plastic, and is a member that can transmit light. As shown in Fig. 3, the window 4 is provided on the bottom surface of the main body 1. When the light detection unit 2 detects infrared rays, the window 4 is a visible light cut filter that blocks visible light and transmits infrared rays. This reduces the incidence of light in the visible light range from the outside at the light detection unit 2, and also reduces the difference in the amount of movement detected due to differences in the color of the cloth 70, thereby improving the detection accuracy.

[0039] When the surface of the cloth 70 is hit by light from multiple directions, such as natural light, indoor lighting, and light from lighting mounted on the sewing machine 50, in addition to the light from the light irradiation unit 3, the shadows of the cloth 70 disappear. In addition, when the light from outside changes or the shadow of a person or object reflected on the cloth 70 moves, the light detection unit 2 may erroneously detect the movement of the cloth 70. In response to this, by using an infrared LED as the light irradiation unit 3 and a visible light cut filter for the window unit 4, the influence of light from outside can be reduced and the shadows created by the light irradiation unit 3 can be maintained.

[0040] 6, the control unit 5 includes a cloth movement speed calculation unit 31 and a motor drive control unit 32. The control unit 5 includes a CPU, a memory, a storage unit, and the like, and various operations are realized by programs.

[0041] The cloth movement speed calculation unit 31 calculates the movement speed of the object, i.e., the cloth 70, based on the movement amount of the object detected by the light detection unit 2. The motor drive control unit 32 calculates the rotation speed of the motor 54, which moves the needle 53 in the up and down direction, based on the calculated movement speed of the cloth 70 and the sewing pitch set by the operator. The motor drive control unit 32 controls the operation of the motor 54 based on the calculated rotation speed of the motor 54. In this way, the operation of the motor 54 is controlled so that the sewing pitch is constant (the set sewing pitch) regardless of the movement speed of the cloth 70.

[0042] The main body 1 is attached to the presser bar 51 so that the bottom surface of the main body 1 is not in contact with the cloth 70 and is located away from the surface of the cloth 70. The light detection unit 2 captures feature points such as a pattern on the surface of the cloth 70 and detects the amount of movement of the feature points. Conventionally, as shown in FIG. 20, when the light detection unit is provided in a position close to the cloth 70 so as to be in contact with the cloth 70, the detectable range is narrower than when the light detection unit 2 is located away from the cloth 70 as in this embodiment. In this case, since the object that can be captured by imaging is limited, depending on the type and color of the cloth 70, even if the cloth 70 actually moves, the feature points may not be recognized in the captured image, and there may be no change in the object over time, or the feature points 72 may not be tracked.

[0043] In contrast, in this embodiment, as shown in FIG. 19, the bottom surface of the main body 1 is located away from the cloth 70, so the detection range of the light detection unit 2 is widened. As a result, more objects are captured by imaging, and the feature points 72, whose positions change according to the actual movement of the cloth 70, are easily recognized. Then, the object changes reliably in the captured image, and the feature points 72 are easily tracked, so that the movement amount of the cloth 70 can be accurately detected. More specifically, when a cloth such as a laminate with few surface irregularities or a dense and glossy velvet is used, it is difficult for the light detection unit installed in a position close to the cloth so as to contact it as in the conventional method to detect the movement amount of the cloth. On the other hand, in this embodiment, the detection range of the light detection unit 2 is widened, and the pattern on the surface of the cloth 70, the sewn thread, and the dust on the surface can be imaged and recognized as the feature points 72, so that the movement amount of the cloth 70 can be detected even for a cloth such as a laminate or velvet.

[0044] The sewing machine 50 to which this embodiment is applied can be switched between a cloth movement detection mode, in which the cloth 70 is moved manually using the cloth movement detection device 10 and the needle 53 starts to move up and down, and a normal sewing mode, in which the cloth 70 is moved mechanically using a normal feed mechanism. The cloth movement detection mode can be selected by a dedicated switching button displayed on the display 55 of the sewing machine 50. In addition, when the cloth movement detection device 10 is installed and the cable 11 is connected so that transmission and reception of electrical signals is possible, the dedicated switching button may be displayed on the display 55.

[0045] In addition, when the cloth 70 is being fed by hand, if it is determined based on the detected amount of movement that the movement speed of the cloth 70 is equal to or greater than a predetermined threshold, the rotation of the motor 54 may be stopped and a warning may be displayed or a warning sound may be emitted.

[0046] Next, the pressing support part 20 that is detachable from the main body part 1 will be described. In this embodiment, a plurality of types of presser support parts 20 having shapes according to sewing work and ease of use are prepared in advance and are replaceable. That is, presser support parts 20 are detachable from main body part 1, and presser support parts 20 of various shapes can be attached to main body part 1 by replacing them.

[0047] 2 to 5, the presser support section 20 has a cloth presser section 21 that can come into contact with the cloth 70. The cloth presser section 21 has a shape that prevents the cloth 70 from lifting up in the vicinity of the needle drop position. Between the bottom surface of the cloth presser section 21 and the needle plate, there is only a gap large enough for the cloth 70 to pass through.

[0048] When the presser support part 20 is attached to the main body part 1, the cloth pressing part 21 is located below the bottom surface of the main body part 1, and therefore the window part 4 provided on the bottom surface of the main body part 1 is located above the cloth pressing part 21 of the presser support part 20. As a result, unlike the case where the light detection part 2 is provided in a position close to the cloth 70 so as to be in contact with it as shown in Fig. 19, the light detection part 2 is separated from the cloth 70 as shown in Fig. 20, and the detection range of the light detection part 2 is widened. As a result, it is possible to accurately detect the amount of movement of the cloth 70.

[0049] 12 and 13, the presser support 20 used with the quilting ruler 80 will now be described. In this case, the cloth presser portion 21 of the presser support portion 20 has an annular shape surrounding the needle drop position. The presser support portion 20 has an attachment portion 22 configured to be fixed to the side surface of the main body portion 1. The attachment portion 22 is a plate-like member formed to fit along the side surface of the main body portion 1, and a pin hole 23 is formed in the upper portion. The bottom of the attachment portion 22 is provided at a position separated from the needle plate so that a space is formed between the bottom of the attachment portion 22 and the needle plate of the sewing machine 50. When the presser support portion 20 is attached to the main body portion 1, the bottom of the attachment portion 22 is separated from the needle plate by, for example, about 5 mm.

[0050] Furthermore, the cloth pressing portion 21 is provided below the bottom of the attachment portion 22 so that a space is formed around the side surface of the cloth pressing portion 21 when the presser support portion 20 is attached to the main body portion 1 .

[0051] Since the cloth presser 21 is located below the attachment part 22 and a space is formed between the bottom surface of the main body 1 and the needle plate, and around the cloth presser 21, a quilting ruler 80 other than the cloth 70 can be inserted into this space. As a result, as shown in Fig. 11, by pressing the quilting ruler 80 against the periphery of the annular cloth presser 21 and moving the quilting ruler 80 and the cloth 70 simultaneously while guiding them around the periphery of the cloth presser 21, a pattern corresponding to the shape formed on the quilting ruler 80 can be sewn onto the cloth 70.

[0052] 2 to 5, the presser support portion 20 will be described when sewing is performed without using the quilting ruler 80. FIG. In this case, the presser support part 20 has a wall part of the attachment part 22 extending up to the height position of the cloth presser part 21 , and the wall part has a shape surrounding the window part 4 .

[0053] When the presser support part 20 used together with the above-mentioned quilting ruler 80 is attached, if sewing is performed without using the quilting ruler 80, as shown in FIG. 14, the fabric 70 will become loose between the bottom surface of the main body 1 and the needle plate, causing unevenness, and the movement of the fabric 70 will not be accurately detected by the light detection part 2.

[0054] Unlike the case where a space is formed around the side surface of the cloth pressing part 21, by extending the wall part of the attachment part 22 up to the height position of the cloth pressing part 21, it is possible to prevent the cloth 70 from loosening between the bottom surface of the main body 1 and the needle plate, as shown in Fig. 5. As a result, the distance between the light detection part 2 and the cloth 70 is kept constant, so that the amount of movement of the cloth 70 can be accurately detected.

[0055] Furthermore, by having the wall of the mounting part 22 surround the window 4, not only is the distance between the light detection part 2 and the fabric 70 kept constant, but also light that is an external disturbance unrelated to the movement of the fabric 70 is less likely to be incident on the light detection part 2. Instead of the wall surrounding the window 4, as shown in Fig. 9, a transparent plate-like member 25 that is approximately parallel to the needle plate may be provided on the presser support part 20. The plate-like member 25 prevents the fabric 70 from loosening between the bottom surface of the main body 1 and the needle plate.

[0056] Furthermore, the shape of the cloth pressing portion 21 is not limited to the above-mentioned example, and may be substantially U-shaped when viewed in a plan view with the front side of the cloth pressing portion 21 open as shown in FIG. 8, or may be disk-shaped as shown in FIG. 10.

[0057] Next, the display unit 7 provided on the main body 1 will be described. The display unit 7 can be turned on and off, and is provided on the front side of the main body 1 as shown in FIG. 2 and other figures. The display unit 7 is composed of, for example, an LED. The display unit 7 turns on or off depending on whether a cloth movement detection mode, in which the needle 53 starts to move up and down when the cloth 70 moves, is on or off. The cloth movement detection mode is a state in which operation is performed using the cloth movement detection device 10. When the display unit 7 is on, it indicates that the cloth movement detection mode is on, and when the display unit 7 is off, it indicates that the cloth movement detection mode is off.

[0058] According to this embodiment, first, when an operator starts operation using the cloth movement detection device 10, the display unit 7 lights up. This allows the operator to recognize that the cloth movement detection mode has started even if the needle 53 is stopped. If the display unit 7 is not provided, the operator needs to check the start or end of the cloth movement detection mode described above on a display provided on the main body of the sewing machine. On the other hand, according to the display unit 7 according to this embodiment, the operator can check the start and end of the cloth movement detection mode at hand without checking the display, allowing the operator to work safely.

[0059] Next, with reference to FIG. 7, an operation when the cloth movement detection device 10 is installed and sewing work is performed in the cloth movement detection mode will be described.

[0060] When the cloth movement detection mode is started, the up and down movement of the needle 53 stops while the movement of the cloth 70 is stopped, and when the cloth 70 is moved, the motor 54 is driven to start the up and down movement of the needle 53. Then, when the cloth 70 is moved, the movement speed of the cloth 70 is calculated, and the rotation speed of the motor 54 is changed according to the movement speed of the cloth 70. Then, by changing the movement speed of the needle 53 in the up and down direction, sewing is performed so as to achieve a predetermined stitch pitch.

[0061] The cloth movement detection mode is started when the operator presses a start / stop key provided on the sewing machine 50 or steps on the foot controller. First, it is determined whether the start / stop key has been pressed or the foot controller has been stepped on (step S1). If the start / stop key has not been pressed or the foot controller has not been stepped on, the cloth movement detection mode is not started.

[0062] When it is determined that the start / stop key has been pressed or the foot controller has been stepped on, the light detection unit 2 starts detecting the amount of movement of the cloth 70 moved within a unit time (step S2), and determines whether the cloth 70 is moving (step S3). When it is determined that the cloth 70 is moving, the cloth movement speed calculation unit 31 of the control unit 5 calculates the movement speed of the cloth 70 based on the amount of movement detected by the light detection unit 2 (step S4). On the other hand, when it is determined that the cloth 70 is not moving, that is, when the movement speed of the cloth 70 is zero, the motor 54 is stopped (step S7).

[0063] When it is determined that the cloth 70 is moving and the moving speed is calculated, the motor drive control unit 32 sets the rotation speed of the motor 54 of the sewing machine 50 based on the moving speed of the cloth 70 calculated by the cloth moving speed calculation unit 31 and the set sewing pitch (step S5). Specifically, when it is determined that the moving speed of the cloth 70 has increased, the rotation speed of the motor 54 is increased, and the vertical movement of the needle 53 is made faster. When it is determined that the cloth moving speed has decreased, the rotation speed of the motor 54 is decreased, and the vertical movement speed of the needle 53 is made slower. Then, the motor 54 is driven based on the set rotation speed, and the needle 53 moves in the vertical direction (step S6). As a result, sewing is performed to achieve a predetermined sewing pitch.

[0064] With the cloth movement detection mode started, it is determined whether the start / stop key has been pressed or the foot controller has been released (step S8). If the start / stop key has not been pressed or the foot controller has not been released, the cloth movement detection mode continues. When the operator presses the start / stop key provided on the sewing machine 50 or releases the foot controller, the motor 54 is stopped (step S9) and the cloth movement detection mode is terminated.

[0065] There is no problem when the operator is aware that the cloth movement detection mode has started, but it may happen that the operator does not recognize that the cloth movement detection mode has started, for example, if the movement of the cloth 70 is stopped for a long time after the cloth movement detection mode has started. If the operator suddenly moves the cloth 70 or tries to pull out the cloth 70 without being aware that the cloth movement detection mode has started, the motor 54 of the sewing machine 50 may be driven without the operator's intention, causing the needle 53 to move up and down at high speed. In contrast, in this embodiment, the display unit 7 allows the operator to check the start and end of the cloth movement detection mode at his or her fingertips. If the cloth movement detection mode has started and the display unit 7 is lit, the operator will not accidentally move or pull out the cloth 70, and the sewing machine 50 will not operate without the operator's intention, allowing the operator to safely operate the sewing machine 50.

[0066] Next, the attachment mechanism of the presser support portion 20 will be described with reference to FIGS. As shown in FIG. 17, the main body 1 is provided with a button 6 on the back side. When the button 6 is pressed, the fixing pin 8 moves towards the front side of the main body 1. The fixing pin 8 protrudes from the side of the main body 1 and is provided so as to be interlocked with the button 6 via a connecting part 12. As shown in FIG. 4, the fixing pin 8 can be engaged with a pin hole 23 formed in the side of the pressing support part 20, and the pressing support part 20 is fixed to the main body 1 by the fixing pin 8 and the pin hole 23 engaging with each other. When the button 6 is pressed, the fixing pin 8 moves, and the engagement of the fixing pin 8 with the pin hole 23 is released, and the pressing support part 20 is removed downward from the main body 1.

[0067] 18, the pressing support part 20 has a rotation fulcrum part 26 on the back side. The rotation fulcrum part 26 is formed on both side surfaces of the pressing support part 20, protrudes toward the back side, and has a circumferential surface on the outer periphery. Also, as shown in FIG. 18, the main body part 1 has a rotation fulcrum receiving part 14 corresponding to the rotation fulcrum part 26. The rotation fulcrum receiving part 14 is a recessed part formed on both side surfaces of the main body part 1.

[0068] The operation of attaching the pressing support portion 20 will now be described. First, from the state in which the pressing support part 20 is removed as shown in FIG. 18(a), the rotation fulcrum part 26 of the pressing support part 20 is inserted into the rotation fulcrum receiving part 14 of the main body part 1 as shown in FIG. 18(b). Then, as shown in FIG. 18(c), the pressing support part 20 is pushed upward with the rotation fulcrum part 26 as an axis. As a result, the fixing pin 8 biased by the spring 13 is guided by the edge of the pressing support part 20 and retreats to the front side. Then, as shown in FIG. 18(d), the pressing support part 20 is further pushed upward, so that the fixing pin 8 is guided by the hook part 24 formed on the inner surface of the pressing support part 20, and the fixing pin 8 moves to the pin hole 23, and the fixing pin 8 engages with the pin hole 23 of the pressing support part 20. The fixing pin 8 and the pin hole 23 engage with each other, and the pressing support part 20 is fixed to the main body part 1.

[0069] The rotation fulcrum part 26 of the pressing support part 20 can be inserted into the rotation fulcrum receiving part 14 of the main body part 1, and the pressing support part 20 and the main body part 1 are shaped to realize operation with the rotation fulcrum part 26 as an axis, so that the worker can easily and reliably attach the pressing support part 20. Also, since the fixing pin 8 is guided by the edge of the pressing support part 20 and the hook part 24, and the fixing pin 8 and the pin hole 23 are configured to engage with each other, the worker only needs to push the pressing support part 20 upward during attachment, making the work easy.

[0070] Next, the operation of removing the pressing support part 20 will be described. First, from a state in which the pressing support part 20 is attached as shown in Fig. 18(d), the button 6 is pressed and the fixing pin 8 is moved to the front side of the main body part 1 as shown in Fig. 18(c). This causes the fixing pin 8 to be disengaged from the pin hole 23 as shown in Fig. 18(b), and the fixing pin 8 also comes off from the hook part 24 formed on the inner surface of the pressing support part 20. As a result, the pressing support part 20 comes off downward from the main body part 1 due to its own weight as shown in Fig. 18(a).

[0071] Since the fixing pin 8 is disengaged from the pin hole 23 simply by the worker pressing the button 6 on the back side of the main body 1, the worker need only press the button 6 without directly pressing the fixing pin 8, making removal easy.

[0072] Next, the adjustment of the sensitivity of the light detection section 2 will be described. Due to the influence of the material and color of the cloth, and the sensitivity of the light detection unit 2, the calculated movement amount may differ from the actual movement amount of the cloth, and the vertical movement speed of the needle 53 may differ from the desired movement speed.

[0073] Therefore, in this embodiment, the control unit 5 has a function that allows an operator to adjust the sensitivity of the light detection unit 2. As shown in Fig. 6, the control unit 5 has an input receiving unit 33 that receives input related to the adjustment of the sensitivity of the light detection unit 2, and a speed adjustment unit 34 that adjusts the rotation speed of the motor 54 based on the input information. The speed adjustment unit 34 changes and calculates the rotation speed of the motor based on the input information related to the sensitivity adjustment. The motor drive control unit 32 drives the motor based on the rotation speed calculated by the speed adjustment unit 34, and changes the movement speed of the needle 53 in the up and down direction.

[0074] 23, a sensitivity adjustment section 60 having a sensitivity adjustment slide bar 61 and buttons 62, 63 is displayed on a display 55 provided on the sewing machine 50. When an input is made using button 62 displaying +, the sensitivity of the light detection section 2 is increased, and when an input is made using button 63 displaying -, the sensitivity of the light detection section 2 is decreased. Note that the present invention is not limited to being displayed on the display 55, and a slidable knob and bar may actually be provided on the main body of the sewing machine 50.

[0075] As shown in Fig. 21, when an input is made in the direction to increase the sensitivity, the rotation speed of the motor 54 relative to the amount of movement of the cloth, i.e., the vertical movement speed of the needle 53, is made faster than when the sensitivity adjustment is not made. As a result, as shown in Fig. 22, for the same amount of movement of the cloth, the finished stitch pitch of the stitch 74 becomes shorter than when the sensitivity adjustment is not made. It is advisable to make an input in the direction to increase the sensitivity when the actual finished stitch pitch is longer than the set finished stitch pitch during sewing.

[0076] As shown in Fig. 21, when an input is made in the direction to decrease the sensitivity, the rotation speed of the motor 54 relative to the amount of movement of the cloth, i.e., the vertical movement speed of the needle 53, is made slower than when the sensitivity adjustment is not made. As a result, as shown in Fig. 22, for the same amount of movement of the cloth, the finished stitch pitch of the stitch 74 becomes longer than when the sensitivity adjustment is not made. It is advisable to make an input in the direction to decrease the sensitivity when the actual finished stitch pitch is shorter than the set finished stitch pitch during sewing.

[0077] As described above, since the sensitivity adjustment function is provided, when there is a discrepancy between the set stitch pitch and the actual stitch pitch, the worker can use the sensitivity adjustment function to bring the stitch pitch closer to the desired stitch pitch. When the actual stitch pitch differs due to factors such as the fabric 70 that is difficult for the light detection unit 2 to detect or the variation in sensitivity of the light detection unit 2, the worker can deal with this by adjusting the sensitivity instead of changing the stitch pitch setting. As a result, the worker can sew with confidence without feeling uncomfortable because the set stitch pitch differs from the actual stitch pitch.

[0078] Next, the positional relationship between the light detection unit 2 and the light irradiation unit 3 will be described with reference to FIGS. In the case of using the quilting ruler 80, as shown in FIG. 16(a), when the distance between the light detection unit 2 and the light irradiation unit 3 is short, the light irradiated from the light irradiation unit 3 is reflected not only by the cloth 70 but also by the surface of the quilting ruler 80, and as shown in FIG. 16(b), a blown-out part 82 occurs in the detection result of the light detection unit 2. Therefore, as shown in FIG. 15(a), the installation positions of the light detection unit 2 and the light irradiation unit 3 are determined so that the light irradiated from the light irradiation unit 3 and reflected by the surface of the quilting ruler 80 does not enter the light detection unit 2, and the light detection unit 2 and the light irradiation unit 3 are installed inside the main body unit 1 at the determined positions. For example, the positional relationship between the light detection unit 2 and the light irradiation unit 3 is determined based on the detection range of the light detection unit 2, the distance between the light detection unit 2 and the cloth 70, and the irradiation angle of the light irradiation unit 3.

[0079] As a result, as shown in FIG. 15(b), no whiteout areas occur in the detection results of the light detection unit 2, and even when a quilting ruler 80 is used, the light detection unit 2 can reliably detect light reflected by the fabric 70.

[0080] Next, another application example of cloth movement detection according to this embodiment will be described. In the above embodiment, an example has been described in which, when cloth 70 is fed by hand, the rotation of motor 54 of the sewing machine, i.e., the vertical movement speed of needle 53 is controlled based on the detected amount of movement to obtain a predetermined stitch pitch. The present invention is not limited to this example, and the detected amount of movement can be applied to, for example, the operation of sewing machine 50, which will be described later.

[0081] For example, when an embroidery carriage is attached to the sewing machine 50 and the embroidery frame is moved in two perpendicular directions by the transport mechanism of the embroidery carriage, the movement amount of the fabric 70 is detected. The motor 54 may step out due to an overload or other cause, causing the embroidery frame to move a distance different from the planned movement distance. Therefore, when the detected movement amount of the fabric 70 is compared with the planned movement distance of the embroidery stitching and it is determined that the actual movement distance is longer or shorter than the planned movement distance, the sewing operation of the sewing machine 50 is automatically stopped or the movement of the embroidery carriage is adjusted to an appropriate movement distance. This makes it possible to correct the sewing misalignment in the embroidery stitching.

[0082] Also, for example, when a feed mechanism for the cloth 70, such as a feed dog, is operated to feed the cloth 70, the amount of movement of the cloth 70 is detected. The cloth 70 may move an amount different from the planned amount or may stop due to factors such as the cloth 70 getting caught. Therefore, based on the detected amount of movement of the cloth 70, when it is determined that the cloth 70 has not moved compared to the planned amount or that the cloth 70 has stopped, the sewing operation of the sewing machine 50 is stopped. This makes it possible to prevent poor sewing caused by tangled threads due to continued sewing in the same place.

[0083] In both application examples, the bottom surface of the main body 1 is located farther away from the cloth 70 than in the past, and the detection range of the light detection unit 2 is wider. As a result, more objects are captured within the detection range, and it becomes easier to capture feature points whose positions change in accordance with the actual movement of the cloth 70. Furthermore, because changes are reliably generated in the captured image and feature points are easier to track, the amount of movement of the cloth 70 can be accurately calculated. [Explanation of symbols]

[0084] 1: Main body 2: Light detection section 3: Light irradiation unit 4: Window section 5: Control section 6: Button 7: Display section 8: Fixed pin 10: Cloth movement detection device 11: Cable 12:Connection part 13: Spring 14: Rotational support part 20: Presser support part 21: Cloth presser 22: Mounting part 23: Pin hole 24: Hook part 25: Plate-shaped member 26: Rotational fulcrum 31: Cloth movement speed calculation section 32: Motor drive control unit 33: Input reception section 34: Speed ​​adjustment section 50: Sewing machine 51: Pressing rod 52: Setscrew 53: Needle 54: Motor 55: Display 60: Sensitivity adjustment section 61: Sensitivity adjustment slider 62: Button 63: Button 70: Cloth 72: feature points 74:Stitches 80: Quilting ruler 82: Whiteout area

Claims

1. a light detection unit that detects movement of the cloth by detecting light; a main body portion in which the light detection unit is built-in and which is detachable from a presser bar of a sewing machine; a presser support part having a cloth pressing part capable of contacting the cloth and being detachable from the main body part; Equipped with a window portion through which the light can pass is provided on a bottom surface of the main body portion; A cloth movement detection device in which, when the presser support portion is attached to the main body portion, the cloth presser portion is located below a bottom surface of the main body portion.

2. A light irradiation unit is built into the main body and irradiates the cloth with infrared rays, The cloth movement detection device according to claim 1 , wherein the light detection unit is capable of detecting infrared rays reflected by the cloth.

3. 3. The cloth movement detection device according to claim 2, wherein a visible light cut filter that blocks visible light and transmits infrared light is provided in the window.

4. 4. The cloth movement detection device according to claim 2, wherein the light irradiating unit and the light detecting unit are disposed in the main body so that, when a ruler is inserted between the presser support unit and the needle plate of the sewing machine, light irradiated by the light irradiating unit and reflected by the surface of the ruler does not enter the light detecting unit.

5. The pressing support portion has an attachment portion configured to be detachable from a side surface of the main body portion, a bottom portion of the attachment portion is provided at a position spaced apart from a needle plate of the sewing machine; The cloth movement detection device according to claim 1 , wherein the cloth pressing portion is provided below a bottom portion of the attachment portion.

6. The pressing support portion has an attachment portion configured to be detachable from a side surface of the main body portion, The mounting portion is provided with a wall portion extending to a height position of the presser foot, The cloth movement detection device according to claim 1 , wherein the wall portion has a shape surrounding the window portion.

7. The main body is provided with a display unit that can be turned on and off, The cloth movement detection device according to claim 1 , wherein the display unit is turned on or off depending on an operating state of the sewing machine.

8. The pressing support portion has a rotation fulcrum portion provided on both side surfaces and protruding toward the rear side, The cloth movement detection device according to claim 1 , wherein the main body has rotation fulcrum receiving portions that are recesses formed on both side surfaces and correspond to the rotation fulcrum portion.

9. The main body has a button provided on a rear side and a fixing pin protruding from a side surface and interlocking with the button, the pressing support portion has a pin hole formed on a side surface thereof and capable of engaging with the fixing pin; 9. The cloth movement detection device according to claim 1, wherein the fixing pin is released from the pin hole by pressing the button.

10. A cloth movement detection device according to any one of claims 1 to 9, a control unit that controls operation of a motor that operates a needle of the sewing machine based on the movement of the cloth detected by the cloth movement detection device; A sewing machine equipped with:

11. The control unit is an input receiving unit that receives an input regarding adjustment of the sensitivity of the light detection unit; a speed adjusting unit that adjusts a rotation speed of the motor based on information inputted by the input receiving unit; 11. The sewing machine of claim 10, further comprising:

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