JP2024071028A - Error detection device for bobbin case replacement device - Google Patents

Abstract

[Problem] To not only detect multiple types of errors that occur in a bobbin case replacement device, but also to communicate which error has occurred to a sewing machine user so that the user can know without having to check the bobbin case replacement device, and to efficiently take measures to resolve the error. [Solution] An error detection device 40 for a bobbin case replacement device includes a dog 41 having multiple detectable parts at rotational positions corresponding to the type of error, a sensor 51 that detects the detectable parts reached by the rotation of the dog 41, a control device 70 that identifies and outputs the type of error based on the difference in the arrival timing of the detectable parts detected by the sensor 51, and a transmission device 80 that transmits the type of error output by the control device to the sewing machine user. [Selected Figure] Figure 7

Description

The present invention relates to an error detection device for a bobbin case replacement device of a sewing machine.

The bobbin case replacement device removes a bobbin case that contains a bobbin that has run out of lower thread or is nearly out of thread (hereinafter referred to as an "empty bobbin case") from the sewing machine's hook, and replaces it with a bobbin case that contains a bobbin that is fully wound with lower thread (hereinafter referred to as a "refill bobbin case"), which is attached to the hook.

The applicant previously disclosed in Patent Document 1 a bobbin case replacement device including a refill bobbin case receiver for setting a refill bobbin case, a fixed base, a swivel base rotatable relative to the fixed base, a claw device having openable and closable claws for gripping an empty bobbin case or a refill bobbin case, a swivel mechanism for enabling the swivel base to swivel between a direction facing the refill bobbin case receiver and a direction facing the shuttle, a front-to-rear slide mechanism for enabling the claw device to slide forward and backward relative to the swivel base, a claw opening/closing mechanism for opening and closing the claws, and a single drive shaft for driving all of the swivel mechanism, the front-to-rear slide mechanism, and the claw opening/closing mechanism. This bobbin case replacement device has the excellent effect of reducing the failure rate by using only one drive shaft, reducing downtime due to repairs, and increasing the operating rate of the sewing machine.

The bobbin case changing device is also provided with an error detection device that detects, with a single sensor, (a) an error of forgetting to put a refill bobbin case into the refill bobbin case receiver, (b) an error of removing an empty bobbin case from the shuttle, and (c) an error of removing a refill bobbin case from the refill bobbin case receiver. This error detection device is equipped with a disk-shaped dog that rotates in synchronization with the drive shaft and the turning cam and has multiple open slits formed at rotation positions corresponding to the errors (a) to (c) above, a bar-shaped dog with open slits that slides back and forth together with the claw device, and a sensor that is installed near the disk-shaped dog at a position where the disk-shaped dog and the bar-shaped dog are lined up and detects the open slits reached by the rotation of the plate-shaped dog. This error detection device has the excellent effect of reducing the failure rate by using only one sensor for error detection, reducing downtime due to repairs, and increasing the operating rate of the sewing machine.

Patent No. 6945206

However, the error detection device simply stops the bobbin case changing device when it detects any of the above errors (a) to (c). This causes a problem in that the sewing machine user cannot know which error has occurred unless he or she goes to the sewing machine head and checks the bobbin case changing device.

This problem also resulted in the problem that it was not possible to efficiently resolve the errors. In other words, the measures to resolve the above errors (A) to (C) are different, as follows:
(a) When an error occurs due to a refill bobbin case not being inserted, it is necessary to take measures to set the bobbin case with the lower thread wound in the refill bobbin case receiver.
(a) When an empty bobbin case removal error occurs, it is necessary to take steps to remove the empty bobbin case from the hook.
(c) When an error occurs in removing the refill bobbin case, it is necessary to check the cause of the error and take appropriate action, such as correctly resetting the refill bobbin case in the refill bobbin case receiver.

In the above (a), the sewing machine user needs to prepare and take a replacement bobbin case, but in the above (b) and (c), this is not necessary. If such things can only be determined after checking the bobbin case replacement device, it will be inefficient when taking action.

The object of the present invention is not only to detect multiple types of errors that occur in the bobbin case changing device, but also to communicate to the sewing machine user which error has occurred so that the user can know without having to check the bobbin case changing device, and to enable efficient action to resolve the error.

The present invention provides an error detection device for detecting multiple types of errors in a bobbin case replacement device of a sewing machine,
a dog that rotates in synchronization with a drive shaft of the bobbin case changing device and has a plurality of detection targets at rotation positions corresponding to the type of error;
a sensor provided near the dog and configured to detect a detection target portion reached by rotation of the dog;
a control device that identifies the type of error based on the difference in arrival timing of the detected part detected by the sensor and outputs the type of error;
and a transmission device that transmits the type of error output by the control device to a user of the sewing machine.

Examples of multiple types of errors include, but are not limited to, an error in forgetting to place a refill bobbin case in the refill bobbin case receiver, an error in removing an empty bobbin case from the hook, and an error in removing a refill bobbin case from the refill bobbin case receiver.

The detected part and the sensor are not particularly limited, but an example of the detected part is an open slit, and the sensor is a photosensor that detects light that passes through the open slit. The shape of the main body of the dog other than the detected part is not particularly limited, and examples of the shape include a disk shape, a square plate shape, a cylinder shape, etc.

The control device is not particularly limited, but may include a pulse generating unit that generates pulses, a motor driver that operates a drive motor for rotating a drive shaft based on the pulses, a pulse counting unit that counts the pulses, and a determination unit based on the pulse count number and a photosensor signal. The following two examples are given as examples of this aspect.
(1) An example in which the pulse generating unit, the pulse counting unit, and the determination unit are implemented by a CPU (Central Processing Unit). The CPU may be an MCU (Micro Controller Unit) or an MPU (Micro Processor Unit).
(2) An example in which the pulse generating unit is implemented by a circuit that generates a clock signal and a circuit that outputs a pulse based on the clock signal, the pulse counting unit is implemented by a counter circuit that counts pulses by counting the clock signal, and the judgment unit is implemented by a judgment circuit.

The transmission device is not particularly limited, but the following three examples are given.
(a) A light-emitting device that emits light in a color corresponding to the type of error.
(b) a display device that displays a character or graphic according to the type of error.
(c) a sound device that produces a sound or voice corresponding to the type of error;

It is preferable that the error detection device also detects the origin of the drive shaft.

In order to distinguish between error detection and origin detection, it is preferable that the detected part for error detection be an open slit with a relatively narrow slit width, and the detected part for origin detection be an open slit with a relatively wide slit width, and that the sensor detects the difference between the two slit widths.
is preferred.

The present invention not only detects multiple types of errors that occur in the bobbin case changing device, but also communicates to the sewing machine user which error has occurred so that the user can know without having to check the bobbin case changing device, allowing efficient action to be taken to resolve the error.

FIG. 1 is a perspective view of a bobbin case changing device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the device. FIG. 3 is a perspective view of the rotating base, the forward/backward slide mechanism, the error detection device, etc. of the device. FIG. 4 is an exploded perspective view of the three cams and the like of the device. FIG. 5 is an exploded perspective view of the claw device and other parts of the device. FIG. 6 is a side view of the disk-shaped dog and the bar-shaped dog of the error detection device. FIG. 7 is a block diagram of the error detection device. FIG. 8 is a timing chart of the bobbin case exchanging device. FIG. 9 shows the detection of an error in which a replenishment bobbin case is not inserted in the device, where (a) is a side view in a normal state, and (b) is a side view in an error state. FIG. 10 shows the detection of an error in removing an empty bobbin case in the device, where (a) is a side view in a normal state and (b) is a side view in an error state. FIG. 11 shows the detection of an error in removing a replenishment bobbin case in the device, where (a) is a side view in a normal state and (b) is a side view in an error state. FIG. 12 is a flow chart of error detection by the error detection device. FIG. 13 is a timing chart of error detection by the error detection device.

An error detection device for detecting multiple types of errors in a bobbin case replacement device of a sewing machine,
a dog that rotates in synchronization with a drive shaft of the bobbin case changing device and has a plurality of detection targets at rotation positions corresponding to the type of error;
a sensor provided near the dog and configured to detect a detection target portion reached by rotation of the dog;
a control device that identifies the type of error based on the difference in arrival timing of the detected part detected by the sensor and outputs the type of error;
and a transmission device that transmits the type of error output by the control device to a user of the sewing machine.
The type of sewing machine is not particularly limited, and examples include a straight stitch machine, a pattern stitch machine, an embroidery machine, and the like.

Next, an embodiment of the present invention will be described with reference to Figs. 1 to 13. Note that the structure, material, shape, and dimensions of each part in the embodiment are examples and can be modified as appropriate without departing from the spirit of the invention.

The sewing machine 60 comprises a sewing machine head (not shown) and a bed 61 below it. The bed 61 is attached to the top of a machine frame 62, and a drive shaft 63 passes through the bed 61. The bed comprises a shuttle 64 driven by the drive shaft 63, and a needle plate 65 covering the shuttle 64.

The bobbin case changing device 1 is provided in front of the shuttle 64. In the following, when viewed from the bobbin case changing device 1, the side of the shuttle 64 is referred to as the "front", moving towards the shuttle 64 is referred to as "forward", the opposite side is referred to as the "rear", and moving away from the shuttle 64 in the opposite direction is referred to as "rear".

As shown in FIGS. 1 to 7, the bobbin case changing device 1 includes:
A refill bobbin case receiver 2 for setting a refill bobbin case B;
A fixed base 3;
A swivel base 4 swivelable relative to a fixed base 3;
a claw device 6 having an openable and closable claw 10 for gripping an empty bobbin case A or a refill bobbin case B;
a turning mechanism 17 for turning the turning base 4 between a direction facing the replenishment bobbin case receiver 2 and a direction facing the shuttle 64;
a front-rear slide mechanism 22 that allows the claw device 6 to slide forward and backward relative to the swivel base 4;
a claw opening/closing mechanism 34 that enables the claw 10 to be opened and closed;
a single drive shaft 16 for driving the swivel mechanism 17, the front-rear slide mechanism 22, and the claw opening/closing mechanism 34;
One drive motor 14 for rotating a drive shaft 16;
The system includes an error detection device 40 which detects, by one sensor, an error of forgetting to put a refill bobbin case into the refill bobbin case receiver 2, an error of removing an empty bobbin case from a hook 64, an error of removing a refill bobbin case from the refill bobbin case receiver 2, and the origin of a drive shaft 16.

[Refill bobbin case holder 2]
The replenishment bobbin case receiver 2 is a receiving plate that is tilted obliquely forward so that its rear surface faces obliquely upward and rearward, and has a recess formed in it for setting the replenishment bobbin case B. The replenishment bobbin case receiver 2 is attached to the machine frame directly below the shuttle 64 via a bracket.

[Fixed base 3]
The fixed base 3 is a plate-like body extending in the vertical direction and the front-rear direction, and is fixed to the side of the replenishment bobbin case receiver 2. The base is formed with an escape hole for escaping the rotation of the motor, which will be described later.

[Rotating base 4]
The swivel base 4 is a plate-like body extending vertically and in the front-to-rear direction, and its upper rear part is pivotally attached to the upper part of the fixed base 3 by a swivel support shaft 5, so that its front part can swivel around the swivel support shaft 5.

[Claw device 6]
The claw device 6 comprises a slide base 7, a lower pressure plate 9 attached onto the slide base 7 via a pin receiver 8, a claw 10 rotatably attached onto the lower pressure plate 9 by a fulcrum shaft 11 that engages with the pin receiver 8, a claw receiver 12 fixed onto the lower pressure plate 9, and an upper pressure plate 13 that covers the claw 10 and the claw receiver 12.
Together with a rear slide block 28 (described later), the slide base 7, the lower pressing plate 9, the claws 10, the claw receivers 12 and the upper pressing plate 13 can all slide back and forth.
When the claw 10 rotates toward the claw receiver 12, it grips the knob of the bobbin case together with the claw receiver 12 and is in a "closed" state, and when it rotates away from the claw receiver 12, it releases the knobs of the bobbin cases A and B and is in an "open" state.

[Drive motor 14]
The drive motor 14 is attached sideways to the rear of the swivel base 4. The motor body 15 is on the left side of the swivel base 4 and passes through a relief hole in the fixed base 3, and the drive shaft 16 rotated by the motor body 15 protrudes to the right side of the swivel base 4. A DC motor with a reducer is used for the drive motor 14, and the time required for one rotation of the motor (output shaft) is 5 seconds.

[Turning mechanism 17]
The turning mechanism 17 includes a turning cam 18 attached to the drive shaft 16 and rotating therewith, and a cam follower 19 attached to the fixed base 3 via a base 20 and a turning phase adjustment plate 21 .
The turning cam 18 is a plate cam with a cam edge of a specific cam profile, and as the cam edge rotates, each phase presses the cam follower 19, causing the turning base 4 to turn together with the turning cam 18. The turning phase can be adjusted by adjusting the position of the turning phase adjustment plate 21 relative to the base 20 and stopping it. A spring mechanism (not shown) is provided to bias the turning mechanism 17 in the direction in which the cam follower 19 abuts against the turning cam 18.
The rotation angle of the rotating base 4 caused by the rotating cam 18 or the like (the angle between the direction facing the refill bobbin case receiver 2 and the direction facing the shuttle 64) is, for example, 20 to 40° (30° in the illustrated example), which makes it easy to incorporate the mechanism and shortens the rotation time.

[Front-rear slide mechanism 22]
The front-rear slide mechanism 22 includes a front-rear slide cam 23 that rotates in synchronization with the drive shaft 16 and the swivel cam 18, a four-joint link 25 with a cam follower 24, a front-rear slide lever 26 attached to one lever of the four-joint link 25, a front-rear slide shaft 27 attached to the swivel base 4, a rear slide block 28 and a front slide block 29 slidably engaged with the front-rear slide shaft 27, a spring 31 interposed in a gap 30 between the slide blocks 28, 29 with a front-rear length of approximately 8 mm, and a lever drive pin 32 that protrudes from the rear slide block 28 and engages with the front-rear slide lever 26, and the slide base 7 of the claw device 6 is attached to the front slide block 29.

The forward/backward sliding cam 23 rotates in synchronization with the turning cam 18 by inserting a number of connecting screws 33 into the holes of the forward/backward sliding cam 23, which are also inserted into the holes of the turning cam 18. The forward/backward sliding cam 23 is a plate cam with a cam edge of a specific cam profile, and as it rotates, each phase of the cam edge pushes the cam follower 24, causing the four-bar link 25 to swing forward and backward. With this swing, the forward/backward sliding lever 26 swings and pushes the lever drive pin 32, causing the rear slide block 28 to push the front slide block 29 via the spring 31, so that the rear slide block 28 and the front slide block 29 slide by the same amount, and the claw device 6 attached to the front slide block 29 at the slide base 7 slides forward and backward. In addition, a spring mechanism (not shown) is provided to bias the forward/backward sliding mechanism 22 in the direction in which the cam follower 24 abuts against the forward/backward sliding cam 23.

More specifically, when the forward and backward sliding distance of the rear slide block 28 and the front slide block 29 reaches 44 mm, the lower presser plate 9 and the upper presser plate 13 press down on the bobbin cases A and B as described below, so the front slide block 29 (and the slide base 7 and bar-shaped dog 46 attached thereto) will no longer slide. After that, only the rear slide block 28 slides 2 mm while compressing the spring 31, reaching a stroke of 46 mm, and the gap 30 shrinks from 8 mm to 6 mm.

However, if there are no bobbin cases A and B to be pressed, when the rear slide block 28 and the front slide block 29 have slid back and forth to 44 mm, the lower presser plate 9 and the upper presser plate 13 do not press the bobbin cases A and B, and the front slide block 29 can slide further. After that, the rear slide block 28 slides 2 mm together with the front slide block 29 (and the slide base 7 and bar-shaped dog 46 attached thereto) to reach a stroke of 46 mm.

[Claw opening/closing mechanism 34]
The claw opening/closing mechanism 34 includes a claw opening/closing cam 35 that rotates in sync with the drive shaft 16 and the swivel cam 18, a claw opening/closing lever 37 with a cam follower 36, a four-bar link 38, and a claw drive pin 39 that extends downward from behind the fulcrum shaft 11 of the claw 10, passes through a slit in the lower pressure plate 9, and abuts against the side edge of the four-bar link 38.

The claw opening/closing cam 35 rotates in synchronization with the swivel cam 18 by inserting multiple connecting screws 33 into its holes, which are also inserted into the holes of the swivel cam 18. The claw opening/closing cam 35 is a plate cam with a cam edge of a specific cam profile, and as it rotates, each phase of the cam edge pushes the cam follower 36 to swing the claw opening/closing lever 37 back and forth, which swings the four-section link 38 back and forth via the engagement pin and displaces the side edge of the four-section link 38 laterally, which pushes the claw drive pin 39, causing the claw 10 to rotate and open/close. In addition, a spring mechanism (not shown) is provided to bias the claw opening/closing mechanism 34 in the direction that causes the cam follower 36 to abut against the claw opening/closing cam 35.

[Error detection device 40]
The error detection device 40 includes a disk-shaped dog 41 that rotates in synchronization with the drive shaft 16 and the turning cam 18 and has a number of open slits at rotational positions according to the type of error, a bar-shaped dog 46 that is attached to the slide base 7 and slides back and forth together with the disk-shaped dog 41, and one photosensor 51 that is attached to the sensor base 50 and is provided near the disk-shaped dog 41, and detects the open slit reached by the rotation of the disk-shaped dog 41. (Furthermore, a control device 70 and a transmission device 80 are newly included, but this will be described later.)

The disk-shaped dog 41 rotates in synchronization with the drive shaft 16 and the turning cam 18 by inserting a plurality of connecting screws 33 into the holes of the disk-shaped dog 41, which are also inserted into the turning cam 18. The disk-shaped dog 41 is a disk in which an open slit is formed that matches the phase with the cam angle. As shown in FIG. 6 in detail,
A disk-side origin detection slit 42 aligned with the phase of the drive shaft 16 at 0° (origin),
- A slit 43 for preventing a replenishment bobbin case from being forgotten on the disk side, which is aligned with the phase of 160°;
- A slit 44 for an empty bobbin case on the disk side aligned with a phase of 270°;
A disk-side slit 45 for a replenishment bobbin case is formed in accordance with a phase of 290°. The slit width of the disk-side origin detection slit 42 is 7.5° in terms of rotation angle. The slit width of the error detection open slits 43, 44, 45 is 2.5° in terms of rotation angle.

The bar-shaped dog 46 is a strip plate extending in the front-rear direction and having an open slit formed therein that is in phase with the cam angle. In detail,
- Bar side origin detection slit 47;
A slit 48 for a bar-side empty bobbin case is formed.

The disk-shaped dog 41 and the bar-shaped dog 46 are arranged close to each other in the horizontal direction, in a positional relationship in which their slits can overlap.

The sensor base 50 is attached to the upper part of the swivel base 4 so as to be located above the disk-shaped dog 41 and the bar-shaped dog 46 .
One photosensor 51 is made up of a light emitter and a light receiver attached to a sensor base 50, and detects that the open slit of the disk-shaped dog 41 and the open slit of the bar-shaped dog 46 are aligned (by detecting light that has passed through the open slit), and detects an error in forgetting to put a replenishment bobbin case into the replenishment bobbin case receiver 2, an error in removing an empty bobbin case from the shuttle 64, an error in removing a replenishment bobbin case from the replenishment bobbin case receiver 2, and the origin of the drive shaft 16. Details of this will be described later.

The mechanical configuration of the bobbin case changing device 1 described so far is basically the same as the configuration of the bobbin case changing device disclosed in Patent Document 1 (except for the slight difference in the phase angle of the open slits 43-45). However, in this embodiment, the error detection device 40 further includes a control device 70 that identifies and outputs the type of error based on the difference in the arrival timing of the open slits detected by the photosensor 51, and a transmission device 80 that transmits the type of error output by the control device 70 to the sewing machine user, which is different from the error detection device in Patent Document 1.

As shown in FIG. 7, the control device 70 includes a start switch 71 for the drive motor 14, a pulse generating unit that generates pulses, a motor driver 72 that operates the drive motor 14 based on the pulses, a pulse counting unit that counts the pulses, and a determination unit that uses the pulse count number and a photosensor signal. The following two examples are given as examples.
(1) As shown in FIG. 7A, the pulse generating unit, the pulse counting unit, and the determination unit are implemented by an MCU 73.
(2) As shown in FIG. 7( b ), the pulse generating unit is made up of a clock signal generating circuit 74 that generates a clock signal and a pulse output circuit 75 that outputs a pulse based on the clock signal, the pulse counting unit is made up of a counter circuit 76 that counts pulses by counting the clock signals, and the judgment unit is made up of a judgment circuit 77.

The frequency of the pulses generated by the pulse generating unit is 2,000 Hz (=pls/sec), and as mentioned above, it takes 5 seconds for the motor (output shaft) to complete one revolution, so the number of pulses per revolution is 10,000 pls.

The transmission device 80 is a light-emitting device that uses a full-color LED to emit four colors (e.g., yellow, red, green, and blue) or three colors (e.g., yellow, red, and blue).

The configuration of the control device 70 will be described in more detail after explaining the following [Basic operation] and [Error detection and origin detection].

[basic action]
The basic operation of the bobbin case exchanging device 1 of this embodiment configured as above will be described with reference to the timing chart of Fig. 8. Note that, since the mechanical configuration is the same as that of the above-mentioned Patent Document 1, the drawings for the basic operation are basically the same as Figs. 8 to 21 of Patent Document 1, and therefore will be omitted.

(1) When the phase of the drive shaft 16 is 0° (origin), the claw device 6, together with the swivel base 4, is in an intermediate position between the direction facing the replenishment bobbin case receiver 2 and the direction facing the shuttle 64. At this time, an empty bobbin case A is present in the shuttle 64, and a replenishment bobbin case B is set in the replenishment bobbin case receiver 2.
Then, when the drive shaft 16 starts to rotate in one direction, as shown in the timing chart, the claw device 6 starts to rotate together with the swivel base 4 toward the side facing the shuttle 64, and the claw device 6 starts to move forward.

(2) When the drive shaft 16 rotates to a phase of 30°, the claw device 6, together with the swivel base 4, faces the shuttle 64, and the claw device 6 advances to just before the empty bobbin A. At this time, the claws 10 start to close from the "open" position.

(3) When the drive shaft 16 rotates to a phase of 35°, the claw device 6 has finished moving forward, the front ends of the lower pressure plate 9 and the upper pressure plate 13 are pressing the empty bobbin case A, and the claws 10 have rotated slightly from "open" to "closed", but have not yet grasped the knob of the empty bobbin case A. The reason for pressing the empty bobbin case A before grasping the knob in this way is to prevent the entire empty bobbin case A from moving and tilting when the knob is grasped (stabilization of the empty bobbin case A).

(4) When the drive shaft 16 rotates to a phase of 60°, the claw 10 is "closed" and grips the knob of the empty bobbin case A, and the claw device 6 begins to move backward. After that, the claw device 6 begins to rotate together with the rotating base 4 in the direction facing the refill bobbin case receiver 2.

(5) When the drive shaft 16 rotates to a phase of 105°, the claw device 6, together with the swivel base 4, is in a position halfway between the direction facing the refill bobbin case receiver 2 and the direction facing the shuttle 64, and the claw device 6 has finished retracting. After that, the claw 10 starts to open from "closed," and the knob is released to drop the empty bobbin case A.

(6) When the drive shaft 16 rotates to a phase of 130°, the claw device 6, together with the swivel base 4, faces the refill bobbin case receiver 2, and the claw device 6 begins to move forward (strictly speaking, from 125°).

(7) When the drive shaft 16 rotates to a phase of 145°, the claw device 6 advances to just before the refill bobbin case B.

(8) When the drive shaft 16 rotates to a phase of 155°, the claw device 6 has finished moving forward, the front ends of the lower pressure plate 9 and the upper pressure plate 13 are pressing the refill bobbin case B, and the claws 10 have rotated slightly from "open" to "closed", but have not yet grasped the knob of the refill bobbin case B. The reason for pressing the refill bobbin case B before grasping the knob in this way is to prevent the entire refill bobbin case B from moving and tilting when the knob is grasped (stabilization of the refill bobbin case B).

(9) When the drive shaft 16 rotates to a phase of 180°, the claw 10 is "closed" and grips the knob of the refill bobbin case B, and the claw device 6 begins to move backward. After that, the claw device 6 begins to rotate together with the swivel base 4 in the direction facing the shuttle 64.

(10) When the drive shaft 16 rotates to a phase of 210°, the claw device 6 finishes retreating and (more precisely, from 205°) the claw device 6 starts rotating together with the swivel base 4 in the direction facing the shuttle 64.

(11) When the drive shaft 16 rotates to a phase of 260°, the claw device 6, together with the swivel base 4, faces the shuttle 64, and the claw device 6 advances to just before the shuttle 64.

(12) When the drive shaft 16 rotates to a phase of 280°, the claw device 6 has finished moving forward and has inserted the refill bobbin case B into the shuttle 64, and the claw 10 begins to rotate from the "closed" position.

(13) When the drive shaft 16 rotates to a phase of 310°, the claws are "open" and the refill bobbin case B has been attached to the shuttle 64. The claw device 6 starts to rotate together with the swivel base 4 in the direction facing the refill bobbin case receiver 2, and the claw device 6 starts to move backwards (strictly speaking, from 305°).

(14) When the drive shaft 16 rotates to a phase of 340°, the claw device 6, together with the swivel base 4, reaches a position halfway between the direction facing the replenishment bobbin case receiver 2 and the direction facing the shuttle 64, and the claw device 6 finishes retreating. After that, the drive shaft 16 rotates to a phase of 0° (origin).

As described above, the bobbin case replacement is completed with one rotation of the drive shaft 16 in one direction. The next bobbin case replacement is also completed with one rotation of the drive shaft 16 in the same direction.

[Error detection and origin detection]
Next, in the bobbin case changing device 1 of this embodiment, the detection of three types of errors that must be detected because they can cause operational problems, and the detection of the origin of the drive shaft 16 will be described with reference to the timing chart of FIG. 8 and the operation diagrams of FIG. 9 to FIG. 11.

(a) Refill bobbin case not inserted error detection FIG. 9 is an operation diagram when the drive shaft 16 rotates to a phase of 160° (immediately after [Basic operation] (8)), and the refill bobbin case B is about to be removed from the refill bobbin case receiver 2.

13A shows a normal state, that is, when a replenishment bobbin case B is set in the replenishment bobbin case receiver 2. As explained in the above [Front-rear slide mechanism 22] and [Basic operation] (8), when the front-rear slide amount of the rear slide block 28 and the front slide block 29 reaches 44 mm, the lower presser plate 9 and the upper presser plate 13 (not shown in the figure) press the replenishment bobbin case B, the front slide block 29 and the bar-shaped dog 46 do not slide any further, and then only the rear slide block 28 slides 2 mm while compressing the spring 31 (see FIG. 3) in the gap 30, and the gap 30 is reduced from 8 mm to 6 mm. At this time, the disk-side replenishment bobbin case missing slit 43 passes over the photosensor 51, but the rear end of the bar-shaped dog 46 blocks the slit 43, so that the photosensor 51 does not detect an error.
The distance from the front end of the front slide block 29 to the photosensor 51 is 103 mm.

Figure (b) shows an error, i.e., the case where the refill bobbin case B has been forgotten to be set in the refill bobbin case receiver 2. As explained in the [front-rear slide mechanism 22] above, the lower presser plate 9 and the upper presser plate 13 do not press the refill bobbin case, so the rear slide block 28 slides together with the front slide block 29 and the bar-shaped dog 46 to the stroke of 46 mm, the spring 31 in the gap 30 is not compressed, and the gap 30 is 8 mm. In other words, the bar-shaped dog 46 is 2 mm forward from the normal state in (a) above. At this time, the disk-side refill bobbin case forgotten slit 43 passes over the photosensor 51, and since the rear end of the bar-shaped dog 46 does not block the slit 43, the photosensor 51 detects an error and the bobbin case exchange device 1 stops.

(a) Detection of an Empty Bobbin Case Removal Error FIG. 10 is an operation diagram when the drive shaft 16 rotates to a phase of 270° (immediately after [Basic Operation] (11)), and a replenishment bobbin case B is about to be attached to the shuttle 64.

13A shows a normal state, that is, a case where a refill bobbin case B is attached to the shuttle 64 from which the empty bobbin case A was removed in the previous [basic operation] (4). The rear slide block 28 and the front slide block 29 are in the middle of their strokes, and the refill bobbin case B is not hitting anything, so the spring 31 (see FIG. 3) in the gap 30 is not compressed, and the gap 30 is 8 mm. At this time, the disk-side empty bobbin case slit 44 passes over the photosensor 51, but the rear part of the bar-shaped dog 46 blocks the slit 44, so the photosensor 51 does not detect an error.
The distance from the front end of the front slide block 29 to the photosensor 51 is 91 mm.

Figure (b) shows the case where an error occurs, that is, a replacement bobbin case B is attached to the shuttle 64 where an empty bobbin case A remains due to a removal error in the previous [basic operation] (4). The rear slide block 28 and the front slide block 29 are in the middle of their strokes, but because the replacement bobbin case B hits the empty bobbin case A, the front slide block 29 and the bar-shaped dog 46 have already stopped sliding, and only the rear slide block 28 slides 4 mm while compressing the spring 31 in the gap 30, and the gap 30 is reduced from 8 mm to 4 mm. In other words, the bar-shaped dog 46 is 4 mm behind the normal state in (a) above. At this time, the disk-side empty bobbin case slit 44 passes over the photosensor 51, and the bar-side empty bobbin case slit 48 matches the slit 44, so the photosensor 51 detects an error and the bobbin case exchange device 1 stops.

(c) Refill bobbin case removal error detection FIG. 11 is an operation diagram when the drive shaft 16 rotates to a phase of 290° (immediately after [basic operation] (12)), and the attachment of the refill bobbin case B to the shuttle 64 is about to be completed.

Figure (a) shows the normal operation, that is, when the refill bobbin case B that was removed from the refill bobbin case holder 2 and gripped in the previous [basic operation] (9) is attached to the shuttle 64. As in (a) above (although in a different location), the lower pressure plate 9 and upper pressure plate 13 hold down the refill bobbin case B, so the gap 30 is reduced from 8 mm to 6 mm. At this time, the slit 45 for the disk-side refill bobbin case passes over the photosensor 51, but the rear end of the bar-shaped dog 46 blocks the slit 45, so the photosensor 51 does not detect an error.

Figure (b) shows the case where an error occurs, that is, when attempting to attach to the shuttle 64 a replenishment bobbin case that was not gripped due to an error in removal from the replenishment bobbin case receiver 2 in the previous [basic operation] (9). As with (a) and (b) above (although in a different location), the lower pressure plate 9 and upper pressure plate 13 do not hold down the replenishment bobbin case, so the gap 30 is 8 mm. In other words, the bar-shaped dog 46 is 2 mm forward of the normal state in (a) above. At this time, the slit 45 for the disk-side replenishment bobbin case passes over the photosensor 51, and because the rear end of the bar-shaped dog 46 does not block the slit 45, the photosensor 51 detects an error and the bobbin case changing device 1 stops.

(e) Detection of the origin of the drive shaft 16 When the drive shaft 16 rotates once and correctly reaches the phase of 0° (origin), the disc side origin detection slit 42 and the bar side origin detection slit 47 coincide on the photosensor 51, so that the photosensor 51 detects the origin and the bobbin case changing device 1 stops.

To detect the above three types of errors and to detect the origin of the drive shaft 16, the control device 70 of the error detection device 40 is configured to operate as shown in the flowchart of FIG. 12, the time chart of FIG. 13, and as described below.

(1) When the sewing machine operator turns on the start switch 71 (S1 in FIG. 12), the drive motor 14, which is energized by the motor driver 72 based on the pulse generated by the pulse generating unit, starts to rotate (S2), and the pulse counting unit starts to count pulses (S3).

(2) Under normal circumstances when the photosensor 51 does not detect any of the open slits 42-45, the pulse counting unit continues to count pulses (S4-S6-S3).

(3) When the photosensor 51 detects any of the slits 42-45 (S4), a slit detection flag is set (S5), and the pulse counting unit continues to count the number of pulses for slit width detection up to 120 (S6-S7-S8) in addition to the one-round count, and checks the sensor state (S9).

(4) Here, the slit width of the disk-side origin detection slit 42 is 7.5° in terms of rotation angle, which translates to approximately 210 (≈10,000/360 x 7.5) in terms of pulse count (Figure 13(a)). If the sensor state is "H" at the 120th pulse point, it is determined that the disk-side origin detection slit 42 has been detected, which indicates the completion of normal operation and not an error, and the motor is stopped and operation is completed at the origin position (S9-S14-S15).

(5) On the other hand, the slit width of the error detection slits 43, 44, and 45 is 2.5° in rotation angle, which translates to approximately 70 pulse counts (≈10,000/360 x 2.5) (Figure 13(b)). If the sensor state is "L" at the 120th pulse point, that is, if an error has been detected, the motor is stopped (S9-S10).

(6) The pulse counting unit that detects the error then identifies the type of error, as shown in FIG. 13(c).
As shown in (A) above (FIG. 9), when the disk-side slit 43 for detecting a forgotten replenishment bobbin case reaches the photosensor 51 at a phase of 160° and an error is detected in the slit 43, the number of counted pulses is approximately 4560 (≈10000/360×160+120).
As shown in (a) above (FIG. 10), when the disk-side empty bobbin case slit 44 reaches the photosensor 51 at a phase of 270° and an error of the slit 44 is detected, the number of counted pulses is approximately 7620 (≈10000/360×270+120).
As shown in (c) above (FIG. 11), when the disk-side replenishment bobbin case slit 45 reaches the photosensor 51 at a phase of 290° and an error of the slit 45 is detected, the number of counted pulses is approximately 8180 (≒10000/360×290+120).
When the origin is detected, the number of counted pulses becomes 10,000.

The pulse counting unit therefore identifies whether the detected error is (a) a refill bobbin case not being inserted error, (b) an empty bobbin case removal error, (c) a refill bobbin case removal error, or (d) an origin detection error, based on the number of counted pulses, and outputs the identified error, causing the LED of the transmission device 80 to light up. Here, the following two examples are given as examples of how to identify and light up the LED.

[a] A full-color LED is used for the transmission device 80, and for example, when (a) is identified, a yellow LED is turned on, when (b) is identified, a red LED is turned on, when (c) is identified, a green LED is turned on, and when (d) the origin is detected, a blue LED is turned on. The lighting may be flashing.

As mentioned in the section [b] [Problems to be Solved by the Invention], in the case of (A), the sewing machine user needs to prepare and carry a replacement bobbin case, but this is not necessary for (B) and (C). From the viewpoint of the sewing machine user, (B) and (C) may be treated as the same without distinction. Therefore, as added in FIG. 13(c), an error judgment standard of 6500 is set, and (B) and (C) detected after this 6500 are not distinguished and are treated as one type of error detection. A full-color LED is used for the transmission device 80, and for example, when (A) is identified, a yellow light is turned on, when (B) and (C) are identified, a red light is turned on, and when (D) the origin is detected, a blue light is turned on. The light may be flashing.

As described above, according to this embodiment, not only are multiple types of errors that occur in the bobbin case changing device detected, but also which error has occurred is communicated to the sewing machine user so that the user can know without having to check the bobbin case changing device, allowing efficient measures to resolve the error. The transmission device 80 may be installed in or near the bobbin case changing device, or may be installed away from the bobbin case changing device.

The present invention is not limited to the above-described embodiment, and can be embodied by making appropriate modifications without departing from the spirit of the invention.
(1) The transmission device may be the display device or sound device described above, and may transmit the type of error using letters, figures, sounds, voice, etc.
(2) The present invention can be embodied in a multi-head sewing machine, and the transmission device can be used as a screen for the operation unit of the multi-head sewing machine, so that it is possible to centrally display which of the bobbin case exchange devices for which sewing machine heads an error has occurred.

A Empty bobbin case B Refill bobbin case 1 Bobbin case exchange device 2 Refill bobbin case receiver 14 Drive motor 16 Drive shaft 40 Error detection device 41 Disc-shaped dog 42 Disc-side origin detection slit 43 Disc-side slit for forgotten refill bobbin case 44 Disc-side slit for empty bobbin case 45 Disc-side slit for refill bobbin case 46 Bar-shaped dog 47 Bar-side origin detection slit 48 Bar-side slit for empty bobbin case 51 Photo sensor 60 Sewing machine 61 Bed 64 Hook 70 Control device 71 Start switch 72 Motor driver 73 MCU
74 Clock signal generating circuit 75 Pulse output circuit 76 Counter circuit 77 Determination circuit 80 Transmission device

Claims (11)

An error detection device (40) for detecting multiple types of errors in a bobbin case replacement device of a sewing machine, comprising:
a dog (41) that rotates in synchronization with a drive shaft (16) of the bobbin case changing device and has a plurality of detectable portions (43-45) at rotational positions corresponding to the type of error;
a sensor (51) provided near the dog (41) and detecting a detection target portion (43-45) reached by rotation of the dog (41);
a control device (70) that identifies and outputs a type of error based on a difference in arrival timing of the detected parts (43-45) detected by the sensor (51);
A control device (70) for controlling a sewing machine to detect an error in a bobbin case replacement device, comprising: a transmission device (80) for transmitting the type of error output by the control device (70) to a sewing machine user. An error detection device for a bobbin case replacement device as described in claim 1, in which the multiple types of errors include an error of forgetting to place a refill bobbin case in the refill bobbin case receiver (2), an error of removing an empty bobbin case from the hook (64), and an error of removing a refill bobbin case from the refill bobbin case receiver (2). An error detection device for a bobbin case replacement device as described in claim 1, in which the detected portion (43-45) is an open slit, and the sensor (51) is a photosensor that detects light that passes through the open slit. The control device (70) is an error detection device for a bobbin case replacement device according to claim 3, which includes a pulse generating unit that generates pulses, a motor driver unit that operates a drive motor (14) for rotating a drive shaft based on the pulses, a pulse counting unit that counts the pulses, and a determination unit based on the pulse count number and a photosensor signal. An error detection device for a bobbin case replacement device according to claim 4, in which the pulse generating unit, pulse counting unit and judgment unit are handled by a CPU (73). An error detection device for a bobbin case replacement device according to claim 4, in which the pulse generating section is made up of a circuit (74) that generates a clock signal and a circuit (75) that outputs a pulse based on the clock signal, the pulse counting section is made up of a counter circuit (76) that counts the clock signal to count pulses, and the judgment section is made up of a judgment circuit (77). An error detection device for a bobbin case replacement device according to any one of claims 1 to 6, wherein the transmission device (80) is a light-emitting device that emits light in a color corresponding to the type of error. An error detection device for a bobbin case replacement device according to any one of claims 1 to 6, wherein the transmission device (80) is a display device that displays characters or graphics according to the type of error. The error detection device for the bobbin case replacement device according to any one of claims 1 to 6, wherein the transmission device (80) is a sound device that produces a sound or voice according to the type of error. An error detection device for a bobbin case replacement device according to any one of claims 1 to 6, wherein the error detection device (40) is also configured to detect the origin of the drive shaft (16). An error detection device for a bobbin case replacement device according to claim 10, in which the detectable part (43-45) for error detection is an open slit with a relatively narrow slit width, the detectable part (42) for origin detection is an open slit with a relatively wide slit width, and the sensor (51) detects the difference between the two slit widths in order to distinguish between error detection and origin detection.

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