JPS621751B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] [Industrial Application Field] The present invention is applicable to industrial sewing machines, which operate virtually continuously for long periods of time and require frequent replacement of the bobbin thread. This invention relates to an automatic bobbin thread supply device used in sewing machines.

[Conventional technology]

In sewing machines, the bobbin thread is wound around a small bobbin. When using a sewing machine, a bobbin is attached to a bobbin case, and the bobbin case is attached to an inner hook. Since the amount of thread wound around one bobbin is small, when operating continuously like an industrial sewing machine, the lower thread is consumed quickly and the lower thread needs to be replaced frequently. This type of bobbin thread replacement work is extremely troublesome and time consuming.

Therefore, in the technique disclosed in Japanese Patent Publication No. 15145/1983, for example, the inner hook and the outer hook are formed into cylindrical shapes, and the bobbin case is inserted from one end of the hook and discharged from the other end. Moreover, the structure is such that a large number of bobbin cases are stored, and each bobbin case is pushed out one by one and inserted into the hook. Therefore, the bobbin case can be replaced by a simple lever operation.

[Problem that the invention seeks to solve]

However, in the conventional technology, a person has no choice but to determine the presence or absence of the bobbin thread and replace it, so in any case, an operator is required to monitor the sewing machine, and when many sewing machines are operated at the same time, However, the operator's work of monitoring and replacing the bobbin thread is difficult. In addition, in order to accurately position the bobbin cases to be replenished in the inner hook using a mechanism with a simple structure, a plurality of bobbin cases to be replenished are held side by side in a cylindrical object placed on an extension of the hook shaft.
It is preferable to push the bobbin cases from the rear side of the cylinder, and push out the bobbin cases one by one from the front side of the cylinder. It is not possible to store many bobbin cases at once, and continuous operation for long periods of time is not possible.

SUMMARY OF THE INVENTION An object of the present invention is to store a large number of bobbin cases at one time and enable long-term unattended operation of a sewing machine.

[Structure of the invention]

[Means for solving the problem] In order to achieve the above object, in the present invention,
The inner hook and the outer hook are formed in a cylindrical shape so that the bobbin case can pass through the tube in the axial direction, and a conveying device that supplies the bobbin cases to the hook, and a conveying device that holds a large number of bobbin cases. A bobbin case holding means is provided for feeding the bobbin cases one by one.
The conveying device includes a gripping member that grips the bobbin case, a pressing member that moves the bobbin case in the axial direction of the hook, a first driving means that drives the pressing member, and a gripping member that moves the gripping member and the pressing member in a direction perpendicular to the axis of the hook. A second driving means for moving the device to a predetermined position and positioning it at a predetermined position, and an electronic control means for controlling these are provided.

[Effect]

For example, when the remaining amount of bobbin thread becomes low and it becomes necessary to replace the bobbin case, one bobbin case is supplied from the bobbin case holding means to the gripping member, the gripping member is positioned at a predetermined position facing the shuttle mechanism,
When the pressing member pushes out the bobbin case held by the gripping member, it pushes out the old bobbin case attached to the inner pot from one end of the inner pot, and a new bobbin case is inserted from the other end of the inner pot. In this case, since the bobbin case holding means can be arranged at a position offset from the rotation axis of the hook mechanism, there is less restriction on the arrangement space, and therefore a large number of bobbin cases can be stored in the bobbin case holding means.

By the way, in order to ensure reliable operation of this type of device, it is necessary to arrange a large number of sensors in each part and accurately position each part. However, it is preferable to have fewer sensors. Therefore, in a preferred embodiment of the present invention, a detection means for detecting whether the pressing member is in a predetermined position is provided, and the output of the sensing means determines whether or not the gripping member is gripped, and the reference position of the pressing member. Make a judgment. Also,
A stepping motor is used as the first driving means, and the position of the pressing member is determined by the number of driving steps. This reduces the number of sensors.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1, 2, 3, 4, 5, 6a, 6b, 7, 8, 9 and 10, the present invention is implemented. The mechanical section of the automatic bobbin thread supply device is shown. Fig. 1 is a longitudinal sectional view seen from the front, Fig. 2 is an enlarged sectional view showing the inside of the sewing machine bed 1, Fig. 3 is a longitudinal sectional view seen from the left side, and Fig. 4 is a scaled-down plan view. 5 is a partially enlarged view of FIG. 3, FIG. 6a is a front view of the bobbin case 15, FIG. 6b is a right side view of the bobbin case 15, and FIG. 7 is a bobbin case magazine ₂₉₁ with the bobbin case 15 attached. FIG. 8 is a partially enlarged view of FIG. 1, FIG. 9 is a side view taken from the - line in FIG. 1, and FIG. 10 is a sectional view taken from the - line in FIG. 1. be.

This will be explained with reference to each drawing. Figures 2 and 3
As shown in the figure, inside the sewing machine bed 1,
A lower shaft sewing mechanism 100 is provided. A shuttle mechanism is provided below the needle 18. 2 is the inner pot, and 3 is the outer pot. The inner hook 2 and the outer hook 3 are each formed into a cylindrical shape, and one bobbin case 1 used for sewing is placed inside the inner hook 2, that is, in a through hole.
5 is loaded.

In this example, three elastic protrusions 16 are formed on the outer circumferential surface of the bobbin case 15, and these protrusions engage with annular grooves 2a formed on the inner circumferential wall of the inner hook 2. Bobbin case 15
is positioned in the axial direction of the inner pot 2. In addition, two protrusions 2b provided on a part of the inner peripheral wall of the inner pot 2,
By engaging with the recess 15a of the bobbin case 15, the bobbin case 15 is positioned relative to the inner hook 2 so as not to move in the circumferential direction (see FIG. 5).

The inner hook 2 is rotatably supported within a through hole of the outer hook 3. The outer hook 3 is fixed to a tubular hook shaft 6 by a screw 5, and the hook shaft 6 is rotatably supported on the sewing machine bed 1 by two needle bearings 9 located on the outer periphery of the hook shaft 6. ing. 7 and 8 are washers for thrust stopping the hook shaft 6. The inner diameter of the hook shaft 6 matches the inner diameter of the inner hook 2, and the bobbin case 15 can pass through the through hole thereof.

A gear 6a is formed on a part of the outer periphery of the hook shaft 6, and a lower shaft gear 11 fixed to a lower shaft 10 meshes with this gear 6a. Therefore, when the lower shaft 10 is driven, its driving force is transmitted to the hook shaft 6, and the outer hook 3 rotates. Since the inner hook 2 is prevented from rotating by the hook stopper 4 that engages with it, the outer hook 3
It doesn't move even if it rotates.

In FIG. 2, the left side of the hook mechanism is provided with a solenoid SL3 for detecting the remaining amount of bobbin thread and a proximity sensor S5 for detecting the position of its rear flange. Although not shown, the solenoid
A conventionally known thread trimming mechanism is provided between the SL3 and the shuttle mechanism. 17 is a needle bar that supports the needle 18, 19 is a presser foot, 20 is a needle plate, and 21 is a lint cover.

A conveyance mechanism, which will be described later, is positioned on the right side of the hook shaft 6 in FIG. 2, as shown by an imaginary line. This transport mechanism loads the bobbin case 15 into the inner hook 2.

The bobbin case 15 will be explained with reference to FIGS. 6a and 6b. The inside of the bobbin case 15 is provided with a space for mounting the bobbin 13 and a guide shaft 15b formed in the center thereof. A bobbin stopper knob 14 for preventing the bobbin 13 from falling off is provided on the head of the guide shaft 15b.
The bobbin stopper knob 14 is supported by a pin 22 on the head of the guide shaft 15b, and is rotatable in the direction of arrow AR5.

The guide shaft 15b has a cylindrical shape, and is provided with a push rod 24 and a compression coil spring 23 disposed around its outer periphery. push rod 24
Due to the force of the coil spring 23, its head presses against the cam surface 14a of the bobbin stopper knob 14. Depending on the shape of its cam surface, the bobbin locking knob 14 positions itself in either the solid line position or the phantom line position shown in FIG. 6b.

Reference numeral 25 designates an idling prevention spring for preventing the bobbin 13 from idling during sewing, and is held between the head of the push rod 24 and the coil spring 23. Plate spring 2 shown in FIG. 6a
6 is fixed to the bobbin case 15 by a screw 27, and the part of the thread 12 pulled out from the bobbin 13 is held between the bobbin case 15 and the thread 1
Apply tension to 2. The amount of tension is determined by adjusting screw 2.
8.

The bobbin 13 is composed of two cylindrical members 13A and 13B each provided with a flange, and the cylindrical portion 13Ba of the member 13B is connected to the member 13A.
It is fitted on the outside of the cylindrical part. Member 13B
The movement of the member 13A is restricted by the head of the cylindrical part and the protrusion 13Aa formed on the cylindrical part, but it is allowed to slide slightly in the axial direction of the cylinder.
Therefore, the flange 13C of the bobbin 13 can be slightly expanded and contracted in its axial direction.

The thread 12 is wound with the flange 13C of the bobbin 13 stretched. When the thread 12 is wound,
A portion of the thread is caught between the cylindrical portion 13Ba and the protrusion 13Aa, and this thread prevents the movement of the cylindrical portion 13Ba, so that the bobbin 13 normally maintains its stretched state. However, when the yarn wound around the bobbin 13 is consumed and the remaining amount of yarn decreases, the cylindrical portion 13Ba becomes movable. In this embodiment, at a predetermined time, the solenoid SL3 shown in FIG. Detects the remaining amount of thread.

Next, the bobbin case payout mechanism 210 provided below the sewing machine bed 1 will be explained. In this example, the bobbin case 15 attached to the inner pot 2 has three bobbin case magazines 29 ₁ , 19 ₂ and 2
9 _{and 3} are loaded in large numbers and stored so that they can be automatically drawn out one after another. As shown in FIGS. 4 and 7, each bobbin case magazine has a generally cylindrical shape, and includes a cylindrical portion 29a having a space therein for loading a large number of bobbin cases 15, and a bobbin case magazine. A base 29b for supporting the magazine, a long groove 29c formed throughout the axial direction to guide the protrusion 16 of the bobbin case, and an opening 29d formed throughout the axial direction in the head of the cylindrical portion. We are prepared.

Plate-shaped magazine attachment fittings 30 and 31 made of a magnetic material are fixed to the base 29b of each bobbin case magazine by press-fitting and caulking. Each bobbin case magazine has a magazine base 42
It is placed at a predetermined position above (see FIG. 4). Permanent magnets 44 are fixed to the magazine base 42 at positions facing the magazine mounting fittings 30 and 31 of each bobbin case magazine. Therefore, each bobbin case magazine 29 ₁ , 29 ₂ and 29 ₃ is held in a predetermined position on the magazine base 42 by the attractive force of the magnet.

The magazine attachment fittings 30 fixed to each bobbin case magazine are each bent at one end to form an engaging portion 30a. A push rod 46 is arranged on the magazine base 42 at a position facing each engaging portion 30a. The push rod 46 is movably supported by the bush 45, and receives a force from a compression coil spring 47 that pushes the magazine mounting bracket 30 toward the left in FIG.

A circular slide head 65 is arranged at a position facing each push rod 46 with each engaging portion 30a in between. The slide head 65 is connected to the air cylinder 6
It is fixed to the tip of the cylinder shaft 63a of No. 3. 6
6 is a rock nut. When the air cylinder 63 is driven to push out the slide head 65, the slide head 65 pushes the engaging portion 30a against the force of the spring 47.

Each bobbin case magazine is engaged on the magazine base 42 by magnetic force, so when a force is applied, it slides and moves on the magazine base 42, and the engaging part 30a comes into contact with the end of the magazine base 42. The bobbin case magazine is advanced to the contact position, that is, the position shown in solid lines in FIGS. 1 and 8. When the slide head 65 returns to its original position, the force of the spring 47 causes the bobbin case magazine that has moved forward to return to its original retracted position.

The magazine base 42 has a guide rod 4 oriented in a direction perpendicular to the axial direction of the bobbin case magazine.
A guide rod 41 is supported movably in the axial direction by the magazine base 1 and is screwed into a magazine base shaft nut 50 fixed to the magazine base 42.
It is moved by rotating a threaded rod 39 parallel to . One end of the threaded rod 39 is supported by the feeder base 34 via a bearing 38, and the other end is supported by the joint 3.
6, it is coupled to the drive shaft of the stepping motor M2. 37 is a set screw.

A thin plate is attached to the end of the magazine base 42 (the left end in FIG. 4), and the thin plate has magazine base positioning holes at positions that coincide with the shaft centers of the respective bobbin case magazines 29 ₁ , 29 ₂ and 29 ₃ . 49 ₁ , 49 ₂ and 49 ₃ are open. Two transmissive optical sensors S4 and S6 are fixed on the feeder base 34. The optical sensor S4 is located in the magazine base positioning hole 49.
₁ , 49 ₂ and 49 ₃ , and the optical sensor S6 is located at a position where it can detect the magazine base 4.
2 is located at a home position (retracted position), one end of the thin plate is detected.

In this example, when the optical sensor S4 detects each magazine base positioning hole 49 ₁ , 49 ₂ and 49 ₃ , the bobbin case magazine 29
The centers of the cylindrical portions of the bobbin case magazines 29 1 , ₂ and 29 ₃ coincide with the pressing portion 51a of the bobbin case feeding body _{51 ,} which will be described later.
The engaging portions 30a of ₉₂ and ₂₉₃ are aligned with the aforementioned slide head 65.

In the illustrated state, the optical sensor S4 detects the magazine base positioning hole ₄₉₁ , and the center of the cylindrical part of the bobbin case magazine ₂₉₁ is aligned with the pressing part 51a of the bobbin case feeding body, so the bobbin case magazine ₂₉₁ is selected.

The bobbin case feeding body 51 includes a threaded rod 58 arranged toward the axial direction of each bobbin case magazine.
and a guide rod 59, and when the threaded rod 58 rotates, it moves in its axial direction. The threaded rod 58 has one end connected to the caulking metal 57,
It is rotatably supported by a bracket 56, and the other end is
It is coupled via a joint 54 to the drive shaft of the stepping motor M1. A part of the bobbin case feeding body 51 is arranged as the pressing portion 51a at a position that coincides with the central axis of the bobbin case magazine being selected, as described above.

Therefore, by driving the stepping motor M1, if the bobbin case payout body 51 moves to the right in FIG. 1, the rearmost bobbin case in the selected bobbin case magazine will be pushed in that direction. The bobbin case is then unwound in the axial direction. In this example, the position shown by the imaginary line in FIGS. 1 and 8 is the home position of the bobbin case payout body 51, and the proximity sensor S2 for detecting the bobbin case payout body 51 is located at that position. It has been placed.

Note that the pressing portion 51a of the bobbin case feeding body
A distance sensor S3 for detecting the distance between the bobbin case and the rearmost bobbin case in the bobbin case magazine is mounted in the center of the bobbin case magazine with its detection surface facing the bobbin case side.

Next, the bobbin case transport mechanism 220 that transports the bobbin case in the bobbin case payout mechanism 210 and loads it into the inner hook 2 will be described. Transport box 6
A gripping tube 69 for gripping one bobbin case inside is fixed to one end of the bobbin case 8. A through hole is provided in a portion of the transport box 68 that coincides with the central axis of the grip tube 69, and a push rod 70 is provided in the through hole. A grip cylinder 69 is attached to the head of the extrusion rod 70.
A circular washer 72 and an elastic body 71, which are slightly smaller than the inner diameter of the inner diameter, are fixed.

A guide pin 76 is provided slightly below the push rod 70 and has one end fixed to the transport box 68. The detection plate 75 has a dogleg shape, is engaged with a guide pin 76 through a hole formed in its center, and is moved to the left side in FIG. 1 by a compression coil spring 77 attached to the guide pin 76. I am receiving a force to move towards it. One arm of the detection plate 75 is arranged in the inner space of the grip tube 69. A proximity sensor S1 is arranged at a position facing the other arm of the detection plate 75 (see FIG. 4). The proximity sensor S1 is
They are individually placed in the transport box 68.

In this embodiment, the proximity sensor S1 is a grip cylinder 69.
It is detected whether the bobbin case 15 is gripped and whether the push rod 70 is at a predetermined reference position. That is, when the pushing rod 70 is moved to the right in FIG. 1, the washer 72 pushes the detection plate 75 to the right, and the detection state of the proximity sensor S1 changes. When the push rod 70 is positioned at this reference position, the proximity sensor S1 is always in the detection state, so the push rod 70 is moved back a little from that position, and the position where the proximity sensor S1 is in the non-detection state is set as the home position. In this state, when the bobbin case 15 is inserted into the grip tube 69, the bobbin case 15 pushes the detection plate 75 via the elastic body 71 and washer 72, thereby changing the state of the proximity sensor S1, and the grip tube 69 is detected to have gripped the bobbin case.

Air piping 78 is installed slightly above the proximity sensor S1.
is formed. One end of the air pipe 78 is connected to a high-pressure air source (not shown), and a nozzle 79 is formed at the other end. nozzle 79
is arranged with its opening directed toward the inner space of the grip cylinder 69 and slightly inclined with respect to the axial direction.

The pushing rod 70 is formed with teeth, and a gear 73 meshes with the teeth. Gear 73 is coupled to a drive shaft of stepping motor M3. The transport box 68 is supported by a cylinder shaft 80a of an air cylinder 80 provided below and a guide rod 82 so as to be movable up and down with respect to the supply device base 34. 83 is a bearing of the guide rod 82.

FIG. 11 shows an outline of the electric circuit of the sewing machine and the automatic bobbin thread supply device. In addition, the sewing machine body 300
has the same configuration as a conventionally known industrial sewing machine. The operation of the device is controlled by a microcomputer.
Controlled by CPU. The microcomputer CPU is, in this example, a microprocessor.
It consists of an MPU, read-only memory ROM, read/write memory RAM, address decoder, timing controller, I/O port, etc.

Proximity sensors S1, S2, S5 and transmission optical sensors S4, S6 have their output terminals directly connected to the I/O ports, respectively, and the output terminal of distance sensor S3 is connected to one end of analog comparator CMP, and the output terminal of CPM is connected to one end of analog comparator CMP. The output terminal is connected to the I/O port. A predetermined comparison voltage Vref is applied to the other input terminal of the analog comparator CMP.

A switch SW1 connected to the I/O port is a mode switch for instructing the operating mode. In other words, in this example, three bobbin case magazines 29 ₁ , 29 ₂ and 29 ₃ can be loaded at once and any one of them can be selected, so either the threads of the same color can be loaded on them, or the threads of different colors can be loaded on them. Depending on how you wear it, you can choose between two operating modes.

Specifically, if switch SW1 is off, it is determined to be the first operation mode in which no thread color is specified, and when each bobbin case magazine becomes empty, the next bobbin case magazine is selected, and all bobbin case magazines are The bobbin cases are automatically replenished one after another until the bobbin cases run out. If switch SW2 is on, the second operation mode with thread color specification is selected, the bobbin case magazine is automatically selected according to the thread color information included in the sewing information, and the bobbin thread color is automatically changed. .

In the stepping motor M1, one end of each phase is connected to each output terminal of the driver DV1, and the other end of each phase is commonly connected and connected to the output terminal of the driver DV5. A predetermined DC voltage VD is applied to the driver DV5. Similarly, the stepping motor M2 has a driver DV2 and
DV6 is connected to the stepping motor M3, and drivers DV3 and DV7 are connected to the stepping motor M3. Each of the drivers DV1, DV2, and DV3 sets the output terminal to an on level (ground) or an off level depending on the signal level applied to the control input terminal. Drivers DV5, DV6, and DV7 turn on/off the application of DC voltage VD to the output terminals according to the signal level applied to the control input terminals.

The input terminals of drivers DV1, DV2 and DV3 are connected to each other and connected to the motor controller MCU.
are commonly connected to the output terminals of the The motor controller MCU is an excitation signal generator, and in this example, generates four-phase pulse signals in response to drive direction control signals CW/CCW and clock pulse CLK applied to its input terminal. If the drive direction control signal is at CW level, a pulse signal for forward rotation is output, and when the drive direction control signal is at CCW level, a pulse signal for reverse rotation is output. The period of the pulse signal, that is, the driving speed of each stepping motor, is determined by the clock pulse.
Determined by the CLK period.

The output terminal of the multiplexer MPX is connected to the clock pulse input terminal of the motor controller MCU. The three signal input terminals of the multiplexer MPX are one connected to the output terminal of the oscillator OSC, and the other whose input terminal is connected to the output terminal of the oscillator OSC.
The output terminal of the frequency divider DVD is connected to the output terminal of the frequency divider DVD, and the remaining one is grounded. The two control terminals of multiplexer MPX are connected to the I/O ports of the microcomputer. Therefore, by controlling the state of this control terminal, the microcomputer CPU can control the driving speed of each stepping motor.

The control terminals of each driver DV5, DV6 and DV7 are connected to the I/O port of the microcomputer CPU, respectively.

SL1, SL2, SL3 and SL4 are solenoids. Solenoid SL1 is a control solenoid for a solenoid valve that controls the air cylinder 80, solenoid SL2 is a control solenoid for a solenoid valve that controls the air cylinder 63, and SL4 is a control solenoid for a solenoid valve that controls the air cylinder 63.
This is a control solenoid for a solenoid valve that controls on/off the air blowing from the high pressure air source connected to 8.

Each solenoid SL1, SL2, SL3 and SL4
are connected to each output terminal of driver DV4. Each input terminal of the driver DV4 is connected to an I/O port of the microcomputer CPU.

Figures 12a, 12b, 12c and 12d schematically show the operation of the microcomputer CPU. Note that FIG. 12a shows the main routine, and the others show each subroutine. The operation of the CPU will be explained with reference to each drawing.

When the power is turned on, initial settings are performed first. In this initial setting, first the microcomputer
Initialize the output port level of the CPU itself, clear the memory, set the mode, etc., and then configure each mechanical section. In the initial state, air blowing is prohibited, the sewing machine is set to a stopped state, and the bobbin case magazine is set to the retracted position (air cylinder 6
(Return the plunger from step 3), and then remove the magazine base 42.
is set to the home position, and the push rod 70 is set to the home position (7 after S1 is no longer turned on).
0), the transport box 68 is set to the lower limit position (the position where the grip cylinder 69 matches the magazine), and the bobbin case feeding body 5
1 is set to the home position (position where S2 is turned on).

Next, the state of mode switch SW1 is determined.

If it is on, the flag F1 is set to "1", and if it is off, F1 is set to "0".

Next, the motor M2 is set to normal rotation drive, and the magazine base 42 is moved until the optical sensor S4 turns on for the first time. Since the magazine base 42 starts from the home position, the bobbin case magazine ₂₉₁ is thereby positioned to match the pressing portion 51a of the bobbin case feeding body. That is, this selects the bobbin case magazine ₂₉₁ . Also at this time,
In order to know the type of magazine being selected, register R1 is set to 1.

Once the above processing is complete, wait until you receive an instruction to start operation. When the instruction is received, the state of the flag F1 is determined, and if it is "1" (thread color specified), the "magazine exchange process" is executed, and then the process proceeds to the "bobbin thread replenishment process", and the flag F1 is set to "0". (If no thread color is specified), immediately proceed to the "bobbin thread replenishment process". Briefly speaking, in this "magazine exchange process", a bobbin case magazine to be positioned at the bobbin case payout position is selected and positioned according to the specified thread color. Roughly speaking, in the "bobbin thread replenishment process", one bobbin case is paid out from the selected bobbin case magazine, and the bobbin case is transferred to the transport mechanism 220.
The work of loading the inner pot 2 is carried out via the . That is, in the initial state, it is determined that the bobbin case is not attached to the inner pot 2, and the bobbin case replenishment operation is performed without any special instruction.

Checks whether there is an operation signal and operates the sewing machine according to the instruction. Operating the sewing machine is
This continues until the specified sewing operation is completed.
When the predetermined operation is completed, the sewing machine is stopped, a thread cutting operation (cutting the bobbin thread pulled out from the bobbin case loaded in the inner hook 2) is performed, and then a lower thread remaining amount detection operation is performed.

The lower thread remaining amount detection operation is performed by energizing the solenoid SL3 and bringing its plunger into contact with the flange of the bobbin 13 inside the bobbin case in the inner hook. As described above, the bobbin 13 maintains a stretched state in the axial direction depending on the remaining amount of yarn wound on it. The bobbin is allowed to shrink in the axial direction. Therefore, when the remaining amount of yarn is small, when the plunger of the solenoid SL3 hits the flange of the bobbin 13, the bobbin 13 contracts in the axial direction. In other words, the stroke of the plunger when energizing the solenoid SL3 changes depending on the remaining amount of yarn. The proximity sensor S5 is
The rear flange connected to the plunger of solenoid SL3 is detected, and if the remaining amount of thread is sufficient, the flange does not approach S5, so S5 remains off, but when the remaining amount of thread decreases, the flange approaches S5, At that time, S5 is turned on. Therefore, the remaining amount of yarn can be determined by monitoring the state of the proximity sensor S5 when the solenoid SL3 is energized.

If the thread remaining amount is low, a "bobbin thread replenishment process" is executed. In addition, even if the remaining amount of thread is sufficient, the flag F1
If the status is "1", that is, the mode with thread color specification, it is checked whether there is a thread replacement instruction from the sewing program, and if there is such an instruction, the "magazine replacement process" is performed, and then Execute "bobbin thread replenishment process". Then, the process returns to the operation signal check process and the above operation is repeated.

Referring to Figure 12b, "Magazine replacement process"
Explain. In this process, the state of the flag F1 is first checked, and processing is performed according to the result. First, the case where the flag F1 is "1", that is, the case where the thread color is specified will be explained. In addition, if the thread color is specified, each bobbin case magazine 29 ₁ ,
29 ₂ and 29 ₃ must be loaded with a bobbin case in which a bobbin with a thread of a predetermined color is wound thereon according to the position where the bobbin case is placed.

The thread color designation information is input, and the magazine value corresponding to the thread color is loaded into the register R2. The contents of registers R1 and R2 are compared, and if they match, nothing is done and the process returns to the main routine. R1<
If R2, the motor M2 is set to forward rotation drive; otherwise, the motor M2 is set to reverse rotation drive (signal CW/CCW is set).

Before starting the drive, the optical sensor S4 detects the positioning holes 49 ₁ , 49 ₂ and 4 of the magazine base.
9 or ₃ is detected and is in the on state, but when driving starts, it becomes the off state. Therefore, the next time the optical sensor S4 is turned on, the bobbin case magazine located next to the previously selected bobbin case magazine has reached the selected position. When optical sensor S4 turns on, the number of times it turns on is stored in register N.
and compares the contents of N with the difference between registers R1 and R2. If they do not match, the motor M2 continues to be driven, and if they match, the motor M2 is stopped, the contents of the register R2 are set in the register R1, and the process returns to the main routine.

The case where the flag F1 is "0", that is, the case where there is no thread color specification, will be explained. Set the motor M2 to normal rotation drive and wait for the optical sensor S4 to turn on.
When the optical sensor S4 is turned on, the motor M2 is stopped, the contents of the register R1 are incremented by 1, and the process returns to the main routine.

The "bobbin thread replenishment process" will be explained with reference to FIG. 12c. In addition, the following bobbin case magazine 29 ₁
The following explanation assumes that is selected. First, the solenoid SL2 is turned on and the cylinder shaft 63a of the air cylinder 63 is let out. As a result, the slide head 65 coupled to the cylinder shaft 63a
moves to the right in FIG. 1 and presses the engaging portion 30a of the magazine attachment fitting fixed to the selected bobbin case magazine ₂₉₁ . Therefore, the bobbin case magazine slides on the magazine base 42 and is positioned at a transport position close to the bobbin case transport device 220.

Next, the stepping motor M1 is set to normal rotation drive. When the motor M1 rotates forward, the threaded rod 58 connected to its drive shaft rotates, and the bobbin case drawing body 51 screwed therewith moves toward the right in FIG. 1. After setting the motor M1 to normal rotation drive, the microcomputer CPU monitors the state of the distance signal, that is, the output signal of the analog comparator CMP connected to the distance sensor S3.

If the distance is greater than a predetermined value, the speed signal is set to high speed. That is, the multiplexer MPX is controlled to apply the direct output pulses of the oscillator OSC to the motor controller MCU as clock pulses. Incidentally, at the same time as driving of the motor M1 is started, counting of the number of clock pulses applied to the motor controller MCU is started. That is, by counting the number of clock pulses, the step value, that is, the distance that the bobbin case payout body 51 has moved since the start of driving can be determined.

While the distance sensor S3 detects that the distance is not a predetermined short distance, the number of driving steps is checked. N1 is the first bobbin case magazine ₂₉₁
It can be determined that the bobbin case feeding body 51 has reached a position that is a distance corresponding to the short distance from the rear end of the bobbin case (the left end in FIG. 1) at the rightmost bobbin case position in the figure. This value corresponds to the drive step.

Normally, since the bobbin case magazine is not empty, the distance sensor S3 detects a short distance before the number of drive steps reaches N1. When S1 detects a short distance, it sets the speed signal to low speed. That is, by controlling the multiplexer MPX, the frequency divider
A pulse signal with a relatively long period obtained at the output terminal of the DVD is applied as a clock pulse to the motor controller MCU.

Next, the output state of the proximity sensor S1 is checked. In this case, the proximity sensor S1 is initially off, but the bobbin case located at the rightmost end in _FIG . When the detection plate 75 is pressed through the washer 72, the proximity sensor S1 detects the detection plate 75 and turns on.

When the proximity sensor S1 is turned on, it is determined that the grip cylinder 69 has completely gripped the bobbin case 15, and the stepping motor M1 is stopped. Next, the speed signal is set to high speed again, and the stepping motor M1
Set to reverse drive. Therefore, the bobbin case payout body 51 is driven back toward the home position. Also, the solenoid SL2 is turned off and the plunger 63a of the air cylinder 63 is returned. Therefore, the engaging portion 30a of the magazine attachment fitting fixed to the bobbin case magazine ₂₉₁ is returned to the retracted position by the push rod 46, and the bobbin case magazine 2
9 ₁ (right end in FIG. 1) leaves the bobbin case transport mechanism 220.

When the bobbin case magazine ₂₉₁ is separated from the bobbin case transport mechanism 220, the solenoid SL1 of the solenoid valve that controls the air cylinder 80 is set to ON, and the cylinder 80a is pushed upward. As a result, the transport box 68, the grip tube 69, etc. are lifted upward. In this example, the grip cylinder 69 is positioned so as to coincide with the hook shaft 6 just at the upper limit position. Thereafter, when the proximity sensor S2 detects the bobbin case feeding body 51, that is, when the bobbin case feeding body 51 reaches the home position, the stepping motor M1 is stopped.

Next, the solenoid SL4 of the solenoid valve that controls air blowing from the nozzle 79 is turned on, and the nozzle 79
Start blowing air from.

As shown in FIG. 5, each bobbin case 15 has one end of the thread pulled out from its front surface, but the thread may get caught in the surrounding mechanism. However, in this embodiment, since the air is blown out from inside the gripping cylinder, the air flows through the circumferential surface of the bobbin case 15, so that the end of the thread pulled out from the bobbin case is flown in the direction of the air flow. ,
Since it does not touch the surrounding mechanism, it will not get caught in the mechanism part. In addition, since the hook rotates at high speed in the hook mechanism, the generation of lint is unavoidable.
The air flow blown out from the nozzle 79 blows away lint and the like adhering to various parts of the hook mechanism toward the tip, and the hook mechanism is therefore automatically cleaned.

Subsequently, the stepping motor M3 is set to normal rotation drive, and the pushing rod 70 is driven toward the left side in FIGS. 1 and 2. At the same time, counting of clock pulses applied to the motor controller MCU is started, and the amount of drive of the push rod 70 is ascertained. The number of driving steps is checked and waits until it reaches a predetermined value N3. This predetermined value N3 is
Bobbin case 15 located at the tip of push rod 70
The push rod 7 is completely loaded into the inner pot 2.
0 corresponds to the distance (number of steps) from the home position to be driven.

When the push rod 70 is driven, the bobbin case held in the grip tube 69 is pushed out from the grip tube 69, pushed into the hook shaft 6 as shown by the imaginary line in FIG. 2, and further advanced. Then, it is set at a predetermined position inside the inner pot 2. When the bobbin case is attached to the inner hook 2, the stepping motor M3 is set to a stopped state, and then set to reverse drive.

Then, the state of the proximity sensor S1 is checked.
In the proximity sensor S1, the grip tube 69 is attached to the bobbin case 1.
When the bobbin case 5 is gripped, it is turned on, but when the push rod 70 is driven and it pushes the bobbin case out of the grip tube 69, it is turned off again. And extrusion rod 7
0 enters the grip tube 69 and returns further, the washer 72 coupled thereto pushes the detection plate 75, thereby turning on the proximity sensor S1 again.

When the proximity sensor S1 is turned on, the stepping motor M3 is stopped, and then the solenoid SL4 is turned off to stop blowing air from the nozzle 79.
Next, the solenoid SL1 is turned off, the cylinder shaft 80a of the air cylinder 80 is moved backward, and the transport box 68 is lowered to the lower limit position.

Finally, the stepping motor M3 is driven in normal rotation while monitoring the state of the distance sensor S1, and when S1 is turned off, the motor M3 is stopped. This enables the next bobbin case supply operation.

When driving the bobbin case payout body 51 to pay out the bobbin case in the bobbin case magazine 29 ₁ , the operation is normally as described above.
The bobbin case magazine may be empty. In that case, after setting the speed signal to high speed, the number of driving steps of stepping motor M1 exceeds N1.
When this is detected, the stepping motor M1 is immediately set to reverse drive, and the bobbin case payout body 51 is driven in the return direction to return it to the home position. Bobbin case feeding body 51
When the motor reaches the home position, the stepping motor M1 is stopped and the solenoid SL2 is set to OFF.

Here, the state of flag F1 is checked. If the flag F1 is "0", that is, no thread color is specified, the "magazine exchange process" is executed and another bobbin case magazine is selected. However, if the content of register R1 is 3, all bobbin case magazines are empty, so "magazine empty processing" is executed. If flag F1 is "1", that is, thread color is specified, "magazine empty processing" is performed regardless of the state of register R1.
Execute.

"Magazine empty processing" will be explained with reference to FIG. 12d. First, the stepping motor M2 is set to reverse drive, and the motor M2 is driven until the optical sensor S6 is turned off. Thereby, the magazine base 42 is positioned at a predetermined home position where it is easy to attach and detach the bobbin case magazine. It then displays that the magazine is empty and waits for the replenishment process to be completed.

When the replenishment work is completed, clear the magazine empty display, set the stepping motor M2 to normal rotation drive, position the magazine base 42 so that the bobbin case magazine ₂₉₁ is selected, and set 1 in the register R1. and return to the main routine.

Figures 13a and 13b show modified examples of the bobbin case. In this bobbin case 90, one side 91a and 92a of two "L" shaped fittings are arranged on the outer peripheral surface of the bobbin case 90 in order to stop movement in the circumferential direction. The other sides of these metal fittings 91 and 92 are each supported by the bobbin case 90 so as to be slidable in the radial direction, and the sliding range thereof is restricted by a protrusion (91b) or the like. Also,
One end of the metal fittings 91 and 92 is connected to a compression coil spring 93 whose center portion is fixed to the bobbin case 90.
is connected at both ends.

Therefore, the metal fittings 91 and 92 are always subjected to a force directed toward the outside of the bobbin case 90 by the spring 93, and normally each side 91a, 92a protrudes to the outer periphery of the bobbin case 90. However, when each of the metal fittings 91 and 92 receives a force directed toward the center of the bobbin case 90 from the outside, the bobbin case 90
Retract to a position inside the outer periphery of.

In addition, when using the bobbin case 90 of this modification, the shape and shape of the groove (for example, 29c) formed in the inner circumferential wall of the inner pot 2 etc. to which it is attached depends on the shape and position of the metal fittings 91 and 92. Need to change position.

In the above embodiment, for example, the bobbin case payout body 51 of the bobbin case payout mechanism 210 is driven by a mechanism using a threaded rod 58, but the driving force may be transmitted using a timing belt, for example. Good too.

In addition, in the above embodiment, the transport box 6
8 etc. are driven in the vertical direction using an air cylinder 80, but they may be driven using an electric motor such as a stepping motor. Also, the driving direction is
The direction is not limited to the vertical direction, but may be the lateral direction (horizontal direction). However, in the case of a general sewing machine, it is preferable to set it in the vertical direction so as not to interfere with the operation of each mechanical part.

〔Effect of the invention〕

As described above, according to the present invention, the bobbin case is automatically replaced when a predetermined instruction is given.
This eliminates the need for human work and enables unmanned operation of the sewing machine. In particular, since the bobbin case holding means can be placed at a position offset from the drive shaft of the hook mechanism, the number of bobbin cases that can be stored at one time in the holding means increases, and operation is required for a long time to replace the bobbin cases. The sewing machine can be operated continuously without interruption.

[Brief explanation of the drawing]

1 is a longitudinal sectional view showing the automatic bobbin thread supply mechanism 200, FIG. 2 is an enlarged longitudinal sectional view showing the lower shaft sewing mechanism 100, FIG. 3 is a longitudinal sectional view seen from the left side of FIG. 4 is a reduced plan view showing the automatic bobbin thread supply mechanism 200, FIG. 5 is a partially enlarged view of FIG. 3, FIG. 6a is a front view of the bobbin case 15, and FIG. 6b is a partially cutaway right side of the bobbin case 15. 7 is a vertical cross-sectional view of the bobbin case magazine loaded with bobbin cases, FIG. 8 is an enlarged vertical cross-sectional view of the bobbin case feeding mechanism 210, and FIG. 9 is a vertical cross-sectional view of the bobbin case feeding mechanism 210.
20 is a left side view (--line in FIG. 1), and FIG. 10 is a sectional view taken along the --- line in FIG. Fig. 11 is a block diagram showing the electrical circuit of the sewing machine, Fig. 12a is a flowchart showing the general operation of the microcomputer CPU shown in Fig. 11, Fig. 12b,
2c and 12d are flowcharts showing the operation of each subroutine of the CPU. Chapter 13a
Figure 13b is a front view and a partially cutaway right side view showing a modified example of the bobbin case. 1... Sewing machine bed, 2... Inner hook, 2a... Groove of inner hook, 2b... Protrusion of inner hook, 3... Outer hook, 4... Hook stopper,
5... Screw, 6... Hook shaft, 6a... Gear, 7, 8... Washer, 9... Needle bearing, 10... Lower shaft, 1
1... Lower shaft gear, 12... Lower thread, 13... Bobbin, 13
A, 13B... Member constituting the bobbin, 13Aa...
Projection, 13Ba...Cylindrical part, 14...Bobbin stop knob, 14a...Cam surface, 15...Bobbin case, 16
... protrusion, 17 ... needle bar, 18 ... needle, 19 ... presser foot,
20...throat plate, 21...lint cover, 22...pin,
23...Coil spring, 24...Push rod, 25...
Idling prevention spring, 26...Plate spring, 27...Screw, 28...Adjustment screw, 29 ₁ , 29 ₂ , 29 ₃ ...
Bobbin case magazine, 29a...cylindrical part, 29b
...base, 29c...long groove, 29d...opening, 30,
31... Magazine mounting bracket, 30a... Engagement part, 32
...Stopper, 33...Countersunk screw, 34...Sewing machine base, 36...Coupling, 37...Set screw, 38...Bearing,
39... Threaded rod, 40... Set screw, 41... Guide rod, 42... Magazine base, 42a... Detection plate,
43...Magazine positioning groove, 44...Permanent magnet, 4
5... Bush, 46... Push rod, 47... Coil spring, 49 ₁ , 49 ₂ , 49 ₃ ... Magazine base positioning hole, 50... Magazine base shaft nut,
51...Bobbin case feeding body, 52...Bracket, 54...Joint, 55...Set screw, 56...Bracket, 57...Caulking metal, 58...Threaded rod, 59
...Guide rod, 60...Nut, 63...Air cylinder, 63a...Cylinder shaft, 65...Slide head, 66...Lock nut, 68...Transportation box,
69...Gripping tube (gripping member), 70...Extruding rod (pressing member), 71...Elastic body, 72...Washer, 73...Gear, 75...Detection plate, 76...Guide pin, 77...Coil spring, 78...For air Piping, 79...nozzle, 80 air cylinder (second driving means) 80a
...Cylinder shaft, 82...Guide rod, 83...Bearing, 84...Bobbin case receiver, 85...Bobbin case collection box, 100...Lower shaft system sewing mechanism, 200...Bobbin thread automatic supply mechanism, 210...Bobbin case feeding mechanism (bobbin case) Holding means) 220...Bobbin case transport mechanism, AR1 to AR6...Arrow, M1, M
2, M3...Stepping motor (first drive means), SL1, SL2, SL3, SL4...Solenoid,
S1, S2, S5... Proximity sensor, S3... Distance sensor, S4, S6... Transmissive optical sensor, SW1... Mode switch, CPU... Microcomputer (electronic control means) CMP... Analog comparator.

Claims (1)

[Claims] 1. A hook mechanism having a cylindrical inner hook and an outer hook; A gripping member that grips one bobbin case; A bobbin that holds a plurality of bobbin cases and sequentially supplies the bobbin cases to the gripping member. case holding means; a pressing member that passes through the gripping member and moves in the direction of an axis parallel to the rotating axis of the hook mechanism; first driving means that drives the pressing member; a second driving means that moves in a direction perpendicular to the rotational axis of the hook mechanism and positions it at a position facing the hook mechanism and a position facing the bobbin case holding means; and the first driving means and the second driving means. control, and upon receiving a predetermined instruction, positions the gripping member at a position facing the bobbin case holding means, supplies the bobbin case to the gripping member, and positions the gripping member at a position substantially coinciding with the rotation axis of the shuttle mechanism. An automatic bobbin thread supply device for a sewing machine, comprising: electronic control means for driving a pressing member to mount the bobbin case gripped by the gripping member on the shuttle mechanism; 2. The automatic bobbin thread supply device for a sewing machine according to claim 1, wherein the gripping member includes a gripping detection means for detecting whether or not the bobbin case is gripped. 3. The grip detection means detects whether the pressing member is in a predetermined position, and the electronic control means monitors the detection output of the grip detection means, positions the pressing member at a predetermined reference position, and in that state. When the gripping member grips the bobbin case, the gripping member is positioned to face the hook mechanism, and the pressing member is moved by a predetermined amount to attach the bobbin case to the hook mechanism. Automatic bobbin thread feeding device for sewing machine. 4. The automatic bobbin thread supply device for a sewing machine according to claim 1, wherein the first driving means is a stepping motor. 5. The automatic bobbin thread supply device for a sewing machine according to claim 1, 2, 3, or 4, wherein the second driving means includes an air cylinder and a solenoid valve for controlling the air cylinder.