JP4509805B2 - 2-needle sewing machine - Google Patents

Description

  The present invention relates to a two-needle sewing machine.

2. Description of the Related Art Conventionally, in order to align a needle drop point on a sewing machine, a technique is known in which the sewing needle is lowered by an operation of a switch or the like, and stopped at a set position immediately before the sewing needle pierces a workpiece (for example, , See Patent Document 1).
Then, the sewing needle can be more accurately aligned with the needle drop point by adjusting the position of the sewing product in a state where the tip of the sewing needle and the sewing product are brought close to each other.

In particular, in the case of a two-needle sewing machine in which two needles are attached to one needle bar, the direction of the sewing product (the direction of the seam formed on the sewing product, the cloth feed direction) is changed during sewing. In this case, the direction of the sewing machine cannot be changed unless the sewing needle is removed from the sewing product so that the sewing needle is retracted to the upper needle position above the sewing product. Therefore, in order to improve the appearance of the stitch shape, for example, at the first needle drop position after the direction of the sewing product is changed, the needle drop point of the outer sewing needle before the direction of the sewing product is changed, for example. It is necessary to align so that it is the same as the needle entry point of the last needle entry position.
When aligning the needle drop point, it is possible to utilize the technology that stops the sewing needle just before the needle pierces the sewing product as described above. Can be aligned.

In addition, adjustment of the position at which the sewing needle stops as the sewing machine stops is not performed by mechanical alignment with the detection plate of the needle position detector provided on the sewing machine, but the needle position is set by an operation switch, etc. Thus, a technique for stopping the sewing needle at a desired stop position is known (see, for example, Patent Document 2 and Patent Document 3).
Japanese Patent Publication No. 6-77638 Japanese Patent Publication No. 1-333199 Japanese Patent No. 2866014

  However, in the case of the above-mentioned patent document 1, when the operator performs alignment of the needle drop point, an operation of depressing a switch for lowering the sewing needle has to be performed each time, which is troublesome. .

Further, in the case of the above-mentioned Patent Documents 2 and 3, by setting the position where the sewing needle stops to the position just before the sewing needle pierces the workpiece, the needle drop point is automatically set when the sewing machine stops. Since the sewing needle can be stopped at a position where alignment can be easily performed, troublesome operations such as those described in Patent Document 1 can be eliminated.
However, when the sewing machine stops and the sewing needle is stopped at a position just before it pierces the sewing product, the sewing product may be taken out from under the sewing needle or placed under the sewing needle. This causes a problem that the sewing product may be caught by the sewing needle and damaged. For this reason, the needle tip of the sewing needle could not be stopped very close to the workpiece.

  An object of the present invention is to provide a two-needle sewing machine capable of easily aligning a needle drop point during sewing.

  In order to solve the above-described problems, the invention according to claim 1 is configured to rotate the sewing machine main shaft and move the two sewing needles supported by the needle bar connected to the sewing machine main shaft up and down with respect to the sewing product. And a spindle position detecting means for detecting the rotation angle position of the sewing machine spindle rotated by the sewing machine motor, and is always located at the neutral position, and is operated to swing between the front stepping position and the stepping back position by the operation. The sewing machine main shaft is rotated by a swinging operation from the neutral position of the sewing pedal to the front stepping position, and the swinging operation to the neutral position after the swinging operation of the sewing pedal to the front stepping position and to the stepping back position are performed. The motor drive that controls the sewing machine motor to stop the tips of the two sewing needles above the sewing product based on the rotational angle position detected by the spindle position detecting means by the swinging operation of the sewing machine. In the two-needle sewing machine comprising the control means, the motor drive control means is configured such that when the sewing pedal is swung to the neutral position after the swinging operation of the sewing pedal to the front stepping position, the two sewing needles When the tip is stopped at the position just above the needle just before the workpiece, and the sewing pedal is swung back to the return position, the tip of the two sewing needles is a predetermined needle position above the position just above the previous needle. The sewing machine motor is controlled so as to be stopped immediately.

According to the first aspect of the present invention, the two-needle sewing machine moves the sewing machine needle up and down together with the needle bar by driving the sewing machine motor and rotating the sewing machine main shaft based on the swing operation of the sewing machine pedal. To sew the workpiece. In particular, based on the fact that the sewing pedal has been swung to the forward stepping position, the sewing machine spindle is rotated by driving the sewing machine motor to perform the sewing operation.
Then, based on the swing operation of the sewing pedal to the return position, the driving of the sewing machine motor is stopped so that the rotational angle position of the sewing machine main shaft detected by the main shaft position detecting means corresponds to a predetermined needle up position, The sewing needle is stopped at a needle upper position above the previous needle upper position so that the sewing needle is retracted above the workpiece.
Further, based on the swinging operation of the sewing pedal to the neutral position, the driving of the sewing machine motor is stopped so that the rotation angle position of the sewing machine main shaft detected by the main shaft position detecting means corresponds to the immediately preceding needle upper position, and the sewing needle The sewing needle is stopped at the immediately preceding needle upper position so that is closer to the sewing product than the predetermined needle upper position.

  According to a second aspect of the present invention, there is provided a sewing machine motor that rotates a sewing machine main shaft and moves two sewing needles supported by a needle bar connected to the sewing machine main shaft up and down with respect to an article to be sewn. Main shaft position detecting means for detecting the rotational angle position of the main shaft to be rotated, a sewing machine pedal that is always positioned at the neutral position and is swung to the front stepping position and the stepping back position by the operation, and a plurality of stitches Sewing pattern storage means for storing a plurality of sewing patterns formed by combining a plurality of sewing processes, sewing pattern selection means for selecting a desired sewing pattern from a plurality of sewing patterns stored in the sewing pattern storage means, and sewing For each sewing process of the sewing pattern selected by the pattern selection means, the sewing machine spindle is rotated by swinging the sewing pedal from the neutral position to the forward position. Motor control for controlling the sewing machine motor to automatically stop the tips of the two sewing needles above the workpiece based on the rotational angle position detected by the spindle position detecting means at the end of the sewing process. A final step of determining whether or not the sewing step that is sewn by the rotation of the main spindle of the sewing machine by swinging the sewing pedal to the front step position is the final sewing step. The motor drive control means includes a judging means, and when the tip of the sewing needle is automatically stopped above the workpiece for each sewing process, the final process judging means judges that the sewing process is not the final sewing process. In this case, the tips of the two sewing needles are stopped at the position immediately above the needle just before the workpiece, and the final process determining means determines that the sewing process is the final sewing process. If it is characterized by controlling the sewing machine motor to stop at a predetermined needle upper position above than immediately before the needle on position the tips of the two sewing needles.

According to the second aspect of the invention, the two-needle sewing machine moves the sewing machine needle up and down together with the needle bar by driving the sewing machine motor and rotating the sewing machine main shaft based on the swing operation of the sewing machine pedal. To sew the workpiece. In particular, for each sewing process in the sewing pattern selected by the sewing pattern selection means among a plurality of sewing patterns that are stored in the sewing pattern storage means and are combined with a plurality of sewing processes having a plurality of stitch numbers, the sewing machine The sewing operation is performed so that the motor is temporarily stopped.
Then, after the final sewing process in the selected sewing pattern, the driving of the sewing machine motor is stopped so that the rotational angle position of the sewing machine main shaft detected by the main shaft position detecting means corresponds to the predetermined upper needle position. The sewing machine needle is stopped at the upper needle position above the previous needle upper position so as to retreat above the workpiece.
Further, after the sewing process other than the last in the selected sewing pattern, the driving of the sewing machine motor is stopped so that the rotational angle position of the sewing machine main shaft detected by the main shaft position detecting means corresponds to the immediately preceding needle upper position, and the sewing needle is The sewing needle is stopped at the previous needle upper position so that it is closer to the sewing product than the predetermined needle upper position.

  According to a third aspect of the present invention, in the two-needle sewing machine according to the first or second aspect, the second needle sewing machine further comprises setting means for setting the position immediately above the needle.

  According to the invention described in claim 3, the same effect as that of the invention described in claim 1 or 2 can be obtained, and in the two-needle sewing machine, the immediately preceding needle upper position can be set by the setting means. It is possible to set the rotation angle position at which the needle stops at the position just above the previous needle.

  According to a fourth aspect of the present invention, in the two-needle sewing machine according to the second aspect, the front needle upper position individual setting unit for individually setting the front needle upper position for each sewing pattern is provided, and the sewing pattern storage unit includes: The immediately preceding needle upper position set by the immediately preceding needle upper position individual setting means is stored individually for each sewing pattern.

  According to the invention described in claim 4, the same effect as that of the invention described in claim 2 is achieved, and in the two-needle sewing machine, the immediately preceding needle upper position is set for each sewing pattern by the immediately preceding needle upper position individual setting means. The rotation angle position at which the sewing needle stops at the position immediately above the previous needle can be set. Then, the set immediately preceding needle up position and the rotational angle position corresponding to the immediately preceding needle up position can be individually stored in the sewing pattern storage means for each sewing pattern.

  According to the first aspect of the present invention, in the two-needle sewing machine, the sewing machine pedal is moved up and down by driving the sewing machine motor by swinging the sewing pedal to the front stepping position and rotating the sewing machine main shaft. The sewing operation for forming the seam can be performed.

Based on the swing operation of the two-needle sewing machine pedal to the return position, the sewing needle can be stopped at a predetermined upper needle position above the workpiece.
Therefore, after completing a series of sewing operations, such as completing the formation of the desired seam, the sewing machine pedal is operated to swing back so as to return to the stepping-back position, and the sewing needle is moved to a position higher than the previous needle upper position. By stopping at the upper needle upper position, the sewing product is hooked on the sewing needle when the sewing product is taken out from under the sewing needle or the sewing product is placed under the sewing needle. It is possible to reduce troubles that cause contact and damage.

Further, based on the swinging operation of the sewing pedal of the two-needle sewing machine to the neutral position, the tip end of the sewing machine needle can be stopped at the immediately preceding needle upper position where it is close to the article to be sewn.
Therefore, when the operator suspends the sewing operation of the sewing machine during sewing and changes the sewing direction by rotating the direction of the sewing object, the sewing needle is stopped at the position immediately above the previous needle. As a result, the tip of the sewing needle can be easily aligned with the needle drop position of the sewing product.
Therefore, the sewing needle can be easily aligned with the needle drop point before the temporary stop even after the direction of the sewing object is changed during the sewing. By forming the seam so that the sewing needle drops at a predetermined needle drop point before and after changing the direction of the workpiece, the appearance of the seam shape can be improved.

  According to the second aspect of the present invention, in the two-needle sewing machine, the sewing machine pedal is moved up and down by rotating the sewing machine pedal to the front step position to drive the sewing machine motor and rotationally drive the sewing machine main shaft. The sewing operation for forming the seam based on the selected sewing pattern can be performed.

Then, based on the completion of the sewing in the final sewing step, the sewing needle is stopped at a predetermined upper needle position above the sewing product so that the sewing according to all the sewing steps in the sewing pattern is completed. it can.
Therefore, the sewing needle automatically stops at a predetermined needle upper position above the immediately preceding needle upper position in accordance with the completion of a series of sewing operations such as finishing forming the stitches of a desired sewing pattern, When taking out the sewing product from under the sewing needle or placing the sewing product under the sewing needle, there is a problem that the sewing product may get in contact with the sewing needle and be damaged. Can be reduced.

Also, based on the completion of sewing for a predetermined number of stitches in each sewing process so that the sewing of each sewing process other than the final sewing process in the sewing pattern is completed, the tip of the sewing needle is immediately before the sewing product. The needle can be stopped at the position immediately above the needle close to.
Therefore, when the previous sewing process is finished and the process proceeds to the next sewing process, the sewing needle automatically stops at the position immediately above the previous needle, so that the operator can sew the sewing machine during the sewing process that is in the middle of sewing. When changing the sewing direction by rotating the direction of the object, the sewing needle is located at the upper position of the previous needle, making it easy to smoothly align the tip of the sewing needle with the needle drop position of the sewing object. Become.
Therefore, the sewing needle can be easily aligned with the last needle drop point in the previous sewing process when the next sewing process is advanced after changing the direction of the workpiece during sewing. By forming the seam so that the sewing needle drops at a predetermined needle drop point before and after changing the direction of the workpiece, the appearance of the seam shape can be improved.

  According to the third aspect of the present invention, in the two-needle sewing machine, it is possible to set the immediately preceding needle upper position by the setting means, and it is possible to set the rotation angle position at which the sewing needle stops at the immediately preceding needle upper position. .

  In other words, by adjusting the rotation angle position corresponding to the upper position of the previous needle, the height from the sewing object when the sewing needle stops at the upper position of the previous needle, and the distance between the sewing object and the tip of the sewing needle. Can be adjusted. And according to the thickness of a to-be-sewn material, an operator's ease of sewing work, etc., the needle upper position just before a sewing needle stops can be adjusted.

  According to the fourth aspect of the present invention, in the two-needle sewing machine, the front needle upper position can be individually set for each sewing pattern by the front needle upper position individual setting means, and the sewing needle can be set to the front needle upper position. It is possible to set the rotation angle position at which the rotation stops. Then, the set immediately preceding needle up position and the rotational angle position corresponding to the immediately preceding needle up position can be individually stored in the sewing pattern storage means for each sewing pattern.

In other words, by adjusting the rotation angle position corresponding to the upper position of the previous needle, the height from the sewing object when the sewing needle stops at the upper position of the previous needle, and the distance between the sewing object and the tip of the sewing needle. Can be adjusted. And according to the thickness of a to-be-sewn material, an operator's ease of sewing work, etc., the needle upper position just before a sewing needle stops can be adjusted.
In particular, since the position immediately above the previous needle can be set and stored individually for each sewing pattern, if the thickness of the material to be sewn is different according to each sewing pattern, just selecting the sewing pattern The needle up position can be automatically changed, and the troublesomeness of setting the needle up position immediately before each sewing pattern selection can be eliminated, and the sewing efficiency can be improved.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
The sewing machine 100 in this embodiment is a two-needle sewing machine that forms two stitches by two sewing needles supported by one needle bar.
And the sewing machine 100 is used for the sewing etc. which sew the tag T etc. to the fabric C, for example, as shown to Fig.7 (a). In this case, the tag T is sewn to the fabric C by performing sewing corresponding to the sewing steps S1, S2, S3, and S4 on the four sides of the tag T, and between each sewing step. When the sewing needle (3L, 3R) is positioned at the corner of the tag T, the sewing operation is temporarily stopped and the sewing machine is started after the operator changes the direction of the fabric C or the tag T. Steps are to be executed.

(Embodiment 1)
As shown in FIG. 1, the sewing machine 100 can be replaced with a sewing machine motor 1, a sewing machine main shaft 2 that is rotationally driven by the sewing machine motor 1, a needle bar 3 that moves up and down by the rotational driving of the sewing machine main shaft 2, and a needle bar 3. Are provided with two sewing needles 3L and 3R, an operation panel 5 for performing operation input to the sewing machine 100, a pulley 6 for moving the needle bar 3 up and down by manual operation, and the like.

  Further, as shown in FIG. 2, the sewing machine 100 includes a sewing machine motor 1 that rotationally drives the sewing machine main shaft 2, an encoder 1 a that is provided in the sewing machine motor 1 and detects the rotation speed of the sewing machine motor, and is driven by the sewing machine motor 1. A needle position detector 7 for detecting the position of the sewing needles 3L, 3R that move up and down, a sewing pedal 8 for operating the sewing machine 100, a thread trimming device 9 for cutting a sewing thread such as an upper thread and a lower thread, An operation panel 5 for performing operation input to the sewing machine 100, a control unit 10 for controlling the operation of each of the above parts, and the like are provided.

A sewing machine motor 1 that is a power transmission mechanism, a sewing machine main shaft 2, a lower shaft (not shown), and the like are disposed in a sewing machine frame 100 a of the sewing machine 100. The sewing machine main shaft 2 is arranged inside the sewing machine arm portion, and the lower shaft (not shown) is arranged inside the sewing machine bed portion.
The sewing machine main shaft 2 is connected to a sewing machine motor 1, and rotational power is applied by the sewing machine motor 1. Further, the lower shaft (not shown) is connected to the sewing machine main shaft 2 via a vertical axis (not shown). When the sewing machine main shaft 2 rotates, the power of the sewing machine main shaft 2 passes through the vertical axis (not shown). It is transmitted to the lower shaft side so that the lower shaft rotates.
A needle bar 3 that moves up and down by the rotation of the sewing machine main shaft 2 is connected to the front end of the sewing machine main shaft 2 via a needle bar drive mechanism 4, and sewing needles 3 </ b> L and 3 </ b> R are provided at the lower end of the needle bar 3. It has been. A hook (not shown) is provided at the front end of the lower shaft (not shown).
When the lower shaft rotates together with the sewing machine main shaft 2, an upper thread that is supplied from a thread supply source and inserted through the sewing needles 3L and 3R in cooperation with the sewing needles 3L and 3R and a shuttle (not shown); A seam is formed on the workpiece by lower thread supplied through a hook (not shown).
The connection configuration of the sewing machine motor 1, the sewing machine main shaft 2, the needle bar 3, the sewing machine needles 3L and 3R, the lower shaft (not shown), the shuttle (not shown), and the like are the same as those conventionally known. Do not mention.

The sewing machine motor 1 rotates the sewing machine spindle 2 based on a drive control signal sent from a control unit 10 (CPU 10a), which will be described later, via a drive circuit, based on an operation of the sewing pedal 8.
The sewing machine main shaft 2 is connected to a needle bar 3 via a needle bar drive mechanism 4. When the sewing machine main shaft 2 is rotated by the sewing machine motor 1, the needle bar 3 reciprocates up and down with respect to the mounting surface 100 b of the sewing machine, and the needle bar 3 is provided at the tip of the needle bar 3 as the needle bar 3 moves. The sewing needles 3L and 3R are reciprocated to drive the needle so as to sew the workpieces placed on the placement surface 100b.

  The pulley 6 can be rotated manually, and by rotating the pulley 6 manually, the sewing machine main shaft 2 can be rotated and the needle bar 3 can be moved up and down. The position and height of 3R can be adjusted.

The encoder 1a is configured to detect the rotation angle of the sewing machine main shaft 2 that rotates 360 ° around the circumference. For example, each time the sewing machine main shaft 2 rotates 1 °, the encoder 1a outputs a pulse signal to the control unit 10 (CPU 10a).
The needle position detector 7 detects a predetermined rotation angle of the sewing machine main shaft 2 that rotates 360 ° around the circumference. For example, the needle position detector 7 detects that the sewing machine main shaft 2 is at a position of 0 °. Sewing needles 3L and 3R (needle bar 3) are detected by detecting that needles 3L and 3R (needle bar 3) are located at the top dead center, and detecting that the main spindle 2 is at a position rotated by 180 °. 3) is detected to be located at the bottom dead center. Then, the needle position detector 7 outputs the positions of the sewing needles 3L, 3R detected when the predetermined rotational angle position of the sewing machine spindle 2 is detected to the control unit 10 (CPU 10a).

The encoder 1a and the needle position detector 7 cooperate to function as a spindle position detecting means for detecting the rotational angle position of the sewing machine spindle 2 rotated by the sewing machine motor 1.
For example, as shown in FIG. 3, the control unit 10 to be described later rotates the main spindle 2 of the sewing machine 180 at a timing when the needle position detector 7 is positioned at the bottom dead center of the sewing needles 3L and 3R (needle bar 3). After the needle position detection signal is output to the control unit 10 in response to the detection of being in the position, the control unit 10 rotates the sewing machine spindle 2 based on the number of pulse signals output to the control unit 10 by the encoder 1a. The angular position is recognized.
That is, in the sewing machine 100, a rotational angle position of the sewing machine main shaft 2 corresponding to a later-described retracted position or a proximity position, which is a predetermined position where the sewing needles 3L and 3R stop, is detected, and the sewing machine main shaft 2 is rotated at that position. The drive of the sewing machine motor 1 is stopped so as to be stopped.

The sewing machine pedal 8 is an operation switch for an operator to operate the sewing machine 100. This sewing pedal 8 is a command to start, drive speed, stop, etc. according to the operation of the operator's pedal depression and the amount of depression through an input circuit that converts the operation of the sewing pedal 8 into an electrical signal. Is output as a drive input signal to a control unit 10 (CPU 10a), which will be described later, to drive the sewing machine 100.
In particular, the sewing machine pedal 8 is provided so as to be swingable so that a predetermined axis is an axis, and the sewing pedal 8 is provided with a spring member (not shown) and the like, and a force such as depressing the sewing pedal 8 is provided. When does not act, the sewing pedal 8 can be returned to the neutral position which is the reference position by the elastic force of the spring member.
When the sewing pedal 8 is stepped forward and is swung to the forward position, the sewing machine motor 1 is driven to rotate the sewing machine main shaft 2 to thereby rotate the needle bar 3 (sewing needles 3L, 3R). ) To the control unit 10.
On the other hand, based on the fact that the sewing pedal 8 is stepped back and is swung to the return position, the sewing needles 3L and 3R are at a predetermined upper needle position above the placement surface 100b (sewing object). A sewing end stop signal for stopping the rotation of the sewing machine spindle 2 is output to the control unit 10 so as to stop at a certain retracted position.
Further, based on the fact that the sewing pedal 8 is swung to the neutral position that is the reference position, the sewing needles 3L and 3R stop at the close position that is the position immediately above the needle that is closer to the sewing product than the retracted position, A sewing midway stop signal for stopping the rotation of the sewing machine main shaft 2 is output to the control unit 10 so that the tip ends of the two sewing needles 3L and 3R are positioned immediately before the workpiece.

  The thread trimming device 9 is a device that cuts the upper thread and the lower thread with a knife (not shown) when a series of sewing operations in the sewing machine 100 is finished. In particular, the sewing machine needles 3L and 3R are finished after predetermined sewing is finished. When the sewing machine stops at the retracted position or after the end of the sewing of the final sewing step (final sewing process) in each sewing pattern, the upper thread and the lower thread are cut.

  As shown in FIG. 2, the operation panel 5 includes a liquid crystal panel 5a including a display device such as an LCD and a touch panel provided on the surface of the display device, and an operation switch 5b for performing predetermined operation input. A CPU 50a that performs overall control of the operation panel 5, a ROM 50b that stores various data related to the operation panel 5, a RAM 50c that is used as a work area related to the operation panel 5 and temporarily stores various processing data, and the like. Act as part of the means.

The display device of the liquid crystal panel 5a has various sewing information output via the CPU 50a (for example, the height from the placement surface 100b (sewing object) when the sewing needles 3L and 3R stop at the retracted position, Corresponding to the angle and rotation angle position of the sewing machine main shaft 2 corresponding to the retracted position, the height from the placement surface 100b (sewing object) when the sewing needles 3L, 3R stop at the close position, and the close position. The angle and rotation angle position of the sewing machine spindle 2), various switches (setting switch, input switch), and the like are displayed.
The touch panel of the liquid crystal panel 5a detects coordinates instructed by a touch reading principle such as an electromagnetic induction type, a magnetostriction type, and a pressure sensitive type, and outputs the detected coordinates to the CPU 50a as a position signal.

  The operation switch 5b includes various switches for operating the operation panel 5. The operation switch 5b includes a switch for switching a display screen on the liquid crystal panel 5a, a switch for transmitting / receiving various data to / from the control unit 10 of the sewing machine 100, and the like. is doing.

The CPU 50a performs overall control of the operation panel 5 and also sets various data relating to sewing set on the operation panel 5 (for example, the placement surface 100b (sewing object to be sewn when the sewing needles 3L and 3R stop at the retracted position or the close position). ) And the angle and rotation angle position of the sewing machine spindle 2 corresponding to these positions are output to the control unit 10 of the sewing machine 100.
The ROM 50b stores various data related to the operation panel 5, in particular, a program for setting the height when the sewing needles 3L and 3R are stopped, the angle of the sewing machine spindle 2 according to the height and the rotational angle position, and data related to sewing. Remember.
For example, when setting new sewing data, the RAM 50c temporarily stores various data related to the sewing.

Then, on the operation panel 5 as setting means, data relating to the sewing that has been input and set (data relating to the height at which the sewing needles 3L, 3R are stopped and the angle or rotational angle position of the sewing machine spindle 2 corresponding to the height) ) Is output to the control unit 10 of the sewing machine 100 via the CPU 50a and stored in the EEPROM 10d described later.
For example, the rotation angle of the sewing machine main shaft 2 when the sewing needles 3L and 3R stop at the retracted position is set to “50 °”, and the rotation angle of the sewing machine main shaft 2 when the sewing needles 3L and 3R stop at the close position. Since it is set to “80 °” and stored in the EEPROM 10d, the sewing needles 3L and 3R stop at the retracted position where the sewing needles 3L and 3R are retracted above the workpiece, and the tip ends of the sewing needles 3L and 3R are retracted. It is possible to stop at a close position closer to the sewing object than the position.
Note that the proximity position is preferably set to a rotation angle so that the sewing needles 3L and 3R are positioned immediately before the sewing needles 3L and 3R pierce the sewing product according to the cloth thickness of the sewing product.

  The control unit 10 includes a CPU 10a, a ROM 10b, a RAM 10c, and an EEPROM 10d.

  The CPU 10a controls various control programs for the two-needle sewing machine stored in the ROM 10b, the ROM 10b, and the EEPROM 10d in accordance with the drive input signal input from the sewing pedal 8 and various signals and data input from the operation panel 5. The operation of each part is centrally controlled according to the data relating to sewing stored in, and the processing result is stored in the work area in the RAM 10c. Then, the processing result stored in the RAM 10c is stored in the EEPROM 10d.

In the ROM 10b, a control program and control data of the sewing machine 100 and data relating to various types of sewing are written and stored.
The RAM 10c is provided with various work memories and counters, and is used as a work area during the sewing operation.
The EEPROM 10d is set on the operation panel 5 and input via the CPU 50a or the like, and the rotation angle position (for example, rotation angle 50 °) of the sewing machine spindle 2 when the sewing needles 3L and 3R stop at the retracted position, The rotation angle position (for example, rotation angle 80 °) of the sewing machine main shaft 2 when the sewing needles 3L and 3R stop at the close position is stored.

  The control unit 10 detects the number of rotations of the sewing machine motor 1 based on the pulse signal output from the encoder 1a, and the number of times the needle bar 3 has moved up and down (one reciprocation up and down) from the detected number of rotations of the sewing machine motor 1. Detect the number of stitches.

  In addition, the control unit 10 determines that the needle position detector 7 has a rotational angle position (for example, a rotational angle) of the sewing machine spindle 2 at which the sewing needles 3L and 3R (needle bar 3) are positioned at the bottom dead center or the top dead center. 180 ° (bottom dead center), 0 ° (top dead center)) after detection signal is input, based on detecting a predetermined number of pulse signals output from the encoder 1a, it is moved to the retracted position or the proximity position. Control for recognizing the rotation angle position (for example, rotation angle 50 ° (retraction position), 80 ° (proximity position)) of the corresponding sewing machine main shaft 2 is performed.

Further, the control unit 10 rotates the sewing machine spindle 2 by driving the sewing machine motor 1 based on the swinging operation of the sewing pedal 8 to the front stepping position, and the sewing pedal 8 swings to the front stepping position. After the sewing operation, the sewing machine pedal 8 is swung to the return position and the sewing pedal 8 is swung to the neutral position. It functions as a motor drive control means for stopping the rotation of the main shaft 2.
In particular, the control unit 10 as the motor drive control means is configured so that the sewing needles 3L and 3R are placed on the placement surface 100b based on a sewing end stop signal that is output when the sewing pedal 8 is swung to the return position. The rotational angle position of the sewing machine spindle 2 detected by the encoder 1a as the spindle position detecting means and the needle position detector 7 so as to stop at the retracted position retracted above the workpiece to be placed is the retracted position. The driving of the sewing machine motor 1 is stopped so as to reach a sewing end position (for example, a rotation angle of 50 °) corresponding to.
Further, the control unit 10 as the motor drive control means is based on a sewing midway stop signal output when the sewing pedal 8 is swung to the neutral position, and the sewing needles 3L and 3R are more sewn than the retracted position. So that the rotation angle position of the sewing machine main shaft 2 detected by the encoder 1a as the main shaft position detecting means and the needle position detector 7 corresponds to the close position (for example, rotation) The driving of the sewing machine motor 1 is stopped so that the angle becomes 80 °.

The retreat position where the sewing needles 3L and 3R stop is a position where the tip ends of the sewing needles 3L and 3R are separated from the placement surface 100b, and when handling the workpiece on the placement surface 100b, This is a position where it is difficult to make contact with the sewing object by hooking it on the tip of the sewing needles 3L, 3R.
The proximity position where the sewing needles 3L, 3R stop is a position where the tip end of the sewing needles 3L, 3R comes closer to the placement surface 100b than the retracted position, and the tip ends of the sewing needles 3L, 3R are to be sewn. The sewing needles 3L and 3R are easily positioned at a predetermined needle drop point (needle drop position) on the sewing product.

  The control unit 10 functions as a setting unit that sets a rotation angle position corresponding to the height so as to adjust the height from the placement surface 100b when the sewing needles 3L and 3R stop. The sewing needles 3L and 3R function as a part of setting means for setting the rotation angle position corresponding to the sewing middle position when stopping at the close position.

  Next, the sewing operation in the sewing machine 100 will be described based on the flowchart shown in FIG.

  First, based on the main power supply of the sewing machine 100 being turned on, the control unit 10 of the sewing machine 100 stores the rotation angle of the sewing machine main shaft 2 corresponding to the retracted position stored in the EEPROM 10d where the sewing needles 3L and 3R stop. The sewing intermediate position corresponding to the rotation angle position of the sewing machine main shaft 2 corresponding to the rotation angle (for example, rotation angle 50 °) of the sewing end position, which is the position, or the proximity position where the sewing needles 3L, 3R stop (upward position immediately before the needle) Is read and stored temporarily in the RAM 10c (step S101).

Next, the control unit 10 determines whether or not the sewing pedal 8 has been stepped forward (a swinging operation to the front step position) (step S102).
If the control unit 10 determines that the sewing pedal 8 has been stepped forward (step S102; Yes), it outputs a drive control signal to the sewing machine motor 1 to drive the sewing machine motor 1 to drive the sewing machine main shaft 2 to rotate (step). S103). The sewing machine spindle 2 rotates at a rotational speed corresponding to the depression amount of the sewing pedal 8, and the sewing needles 3L and 3R (needle bar 3) move up and down at a sewing speed corresponding to the rotational speed to form a seam. Perform sewing operation.

Next, the control unit 10 determines whether or not the sewing pedal 8 has been stepped back (swing operation to the return position) based on whether or not a sewing end stop signal has been output from the sewing pedal 8 (step S104). .
When the control unit 10 determines that the sewing machine pedal 8 has been stepped back (step S104; Yes), the process proceeds to step S111, and the sewing operation 100 is finished.

On the other hand, if the control unit 10 determines that the sewing pedal 8 has not been stepped on (step S104; No), the control unit 10 determines whether or not the sewing pedal 8 is swing-operated and positioned at the neutral position. Then, it is determined whether or not a sewing midway stop signal is output from the sewing pedal 8 (step S105).
When the control unit 10 determines that the sewing pedal 8 is not in the neutral position (step S105; No), the process returns to step S103.

  On the other hand, when the control unit 10 determines that the sewing pedal 8 is in the neutral position (step S105; Yes), the control unit 10 outputs a sewing machine motor deceleration signal for stopping the driving of the sewing machine motor 1 (step S106). ). Then, the control unit 10 determines whether or not the sewing machine motor 1 has been reduced to a predetermined low speed rotation that can be stopped immediately (step S107).

When the control unit 10 determines that the sewing motor 1 has decreased to a predetermined low speed rotation that can be stopped immediately (step S107; Yes), the control unit 10 determines that the rotational angle position of the sewing machine spindle 2 is a sewing intermediate position (proximity position). It is determined whether or not a rotation angle corresponding to (for example, a rotation angle of 80 °) has been reached (step S108).
When the control unit 10 determines that the rotation angle position of the sewing machine spindle 2 has reached the rotation angle (for example, rotation angle 80 °) of the sewing intermediate position (proximity position) (step S108; Yes), the control unit 10 The drive of the sewing machine motor 1 is stopped so that the needles 3L and 3R stop at the close positions (step S109).

Then, the operator changes the sewing direction by rotating the direction of the sewing object while the sewing operation of the sewing machine 100 is temporarily stopped. At this time, since the sewing needles 3L and 3R are stopped at the close positions, the tip of the sewing needle is located immediately before the sewing product, and the needle tip (tip) of the sewing needle is positioned at the needle drop position of the sewing product. It is easy to align with. Therefore, even after changing the direction of the workpiece, the sewing needle can be easily aligned with the needle drop point before the temporary stop.
Specifically, for example, as shown in FIG. 7B, sewing is performed from the upper side to the lower side in the drawing, and when the sewing needle 3R is located at the needle drop point P, the sewing operation of the sewing machine 100 is performed. The machine is temporarily stopped so that the sewing needles 3L and 3R stop at the close positions. Then, in the drawing, the position of the sewing machine needle 3R so that the sewing needle 3R drops to the needle drop position P after the operator changes the direction of the sewing product to rotate in order to perform sewing from the right side to the left side. Combine. At this time, since the needle tips (tip portions) of the sewing needles 3L and 3R are close to the workpiece, it is easy to align them.
Thus, by forming the seam so that the sewing needle 3R drops at the needle drop point P before and after changing the direction of the sewing object, the appearance of the seam shape can be improved.

  Next, the control unit 10 determines whether or not the sewing pedal 8 has been swung to the front step position (step S110), and if the control unit 10 determines that the sewing pedal 8 has been stepped forward (step S110; Yes). ), The process returns to step S103.

  In step S111, the control unit 10 outputs a sewing machine motor deceleration signal for stopping the driving of the sewing machine motor 1 (step S111). And the control part 10 judges whether the sewing machine motor 1 fell to the predetermined | prescribed low speed rotation which can be stopped immediately (step S112).

If the control unit 10 determines that the sewing motor 1 has decreased to a predetermined low speed rotation that can be stopped immediately (step S112; Yes), the control unit 10 determines that the rotational angle position of the sewing machine spindle 2 is the sewing end position (retracted position). It is determined whether or not a rotation angle corresponding to (for example, a rotation angle of 50 °) has been reached (step S113).
When the control unit 10 determines that the rotation angle position of the sewing machine spindle 2 has reached the rotation angle (for example, rotation angle 50 °) of the sewing end position (retraction position) (step S113; Yes), the control unit 10 The drive of the sewing machine motor 1 is stopped so that the needles 3L and 3R stop at a retracted position that is a predetermined needle upper position above the close position (the position immediately above the needle) (step S114).
At this time, since the sewing needles 3L and 3R are stopped at the retracted position so that the distal ends of the sewing needles 3L and 3R are separated from the sewing product, the sewing products are hooked on the distal ends of the sewing needles. Can be removed from the mounting surface 100b without being damaged.

  Then, the control unit 10 causes the thread trimming device 9 to perform a thread trimming operation (step S115), and ends the sewing operation of the sewing machine 100.

  As described above, in the sewing machine 100 according to the present invention, the sewing machine needle 1 is driven to swing to the front stepping position, the sewing machine motor 1 is driven, and the sewing machine spindle 2 is rotationally driven, whereby the sewing needles 3L, 3R. The sewing operation for forming the seam can be performed by moving the (needle bar 3) up and down.

Then, based on the sewing end stop signal output by swinging the sewing machine pedal 8 of the sewing machine 100 to the return position, the sewing needles 3L and 3R are located above the workpiece to be placed on the placement surface 100b. Can be stopped at the retracted position.
Therefore, when a series of sewing operations, such as the formation of a desired seam, is completed, the sewing pedal 8 is stepped back and swinged to the return position to stop the sewing needles 3L and 3R at the retracted position. When the workpiece to be sewn on the placing surface 100b is taken out from under the sewing needle or the workpiece to be placed is placed on the placing surface 100b under the sewing needle, the workpiece to be sewn is the sewing needle 3L, Troubles such as being caught by 3R and being damaged can be reduced.

Further, the sewing needles 3L and 3R come close to the workpiece to be sewn based on a sewing intermediate stop signal outputted by swinging the sewing pedal 8 of the sewing machine 100 to the neutral position and positioning the sewing pedal 8 to the neutral position. It can be stopped at a close position.
Therefore, when the operator temporarily stops the sewing operation of the sewing machine 100 during sewing and changes the sewing direction by rotating the direction of the sewing object, the sewing needles 3L and 3R are stopped at the close positions. By doing so, it becomes easy to align the tip portions of the sewing needles 3L, 3R smoothly with the needle drop position of the sewing product.
Therefore, even after the direction of the sewing product is changed, the sewing needle can be easily aligned with the needle drop point before the temporary stop. By forming the seam so that the sewing needle drops at a predetermined needle drop point before and after changing the direction of the workpiece, the appearance of the seam shape can be improved.

(Embodiment 2)
Next, a second embodiment of the sewing machine 100 according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

  The sewing machine 100 according to the second embodiment is a sewing machine that stores a plurality of sewing patterns in which a plurality of sewing steps defined by the number of stitches are combined, and executes a sewing process for the selected sewing pattern. Each time the sewing is executed, the sewing operation is stopped and the next sewing step is executed based on the starting operation of the sewing machine.

The operation panel 5 functions as a part of the sewing pattern selection means and the immediately preceding needle upper position individual setting means.
The display device of the liquid crystal panel 5a of the operation panel 5 has various sewing information output from the CPU 50a (for example, the number of the selected sewing pattern, the sewing step (sewing process) number in the sewing pattern), the type of the stitch shape, The number of stitches at the sewing step (sewing process), the sewing needle stop height at each sewing step (sewing process), etc.) and various switches (setting switch, input switch) are displayed. In addition, the touch panel of the liquid crystal panel 5a detects coordinates instructed by a touch reading principle such as an electromagnetic induction type, a magnetostriction type, and a pressure sensitive type, and outputs the detected coordinates to the CPU 50a as a position signal.

  The operation switch 5b of the operation panel 5 includes various switches for operating the operation panel 5, and switches a sewing pattern setting screen on the liquid crystal panel 5a, a sewing information display screen related to the sewing pattern, and the like. The control unit 10 includes a switch for transmitting / receiving various data.

The CPU 50 a performs overall control of the operation panel 5 and outputs various data related to the sewing pattern set on the operation panel 5 to the control unit 10 of the sewing machine 100.
The ROM 50b stores various data relating to the operation panel 5, in particular, a program for setting a sewing pattern and data relating to the sewing pattern.
For example, when a new sewing pattern is set, the RAM 50c temporarily stores various data related to the sewing pattern.

  In the operation panel 5, the number of the sewing pattern, the number of sewing steps (sewing process) in each sewing pattern, the type of stitch shape, the number of stitches in each sewing step (sewing process), and the end of each sewing step (sewing process) The sewing needle stop height or the like is input, and data relating to the set sewing pattern is output to the control unit 10 of the sewing machine 100 via the CPU 50a and stored in an EEPROM 10d described later.

Here, a sewing pattern is demonstrated based on an example of the operation panel 5 shown in FIG.
The liquid crystal panel 5a of the operation panel 5 includes a sewing pattern number 51 (sewing pattern No. 7 in the figure) for specifying a sewing pattern, and a sewing step (sewing process) number 52 (sewing step “ 1 ”), stitch shape number 53 (No. 3 (ordinary stitch) in the figure) for specifying the type of stitch shape (for example, ordinary stitching, staggered stitching, scalloping, etc.), and the needle in the sewing step (sewing process) 54 (number of stitches “500” in the figure), the rotation angle 55 (“80 °” in the figure) of the sewing machine spindle 2 that specifies the stop height of the sewing needle at the end of the sewing step (sewing process), and the like. It is displayed.
For example, the sewing pattern “No. 7” indicates a sewing pattern related to normal sewing including four steps (four steps) from the sewing steps S1 to S4. At the end of sewing from the sewing steps S1 to S3, the sewing machine When the rotation angle of the main shaft 2 is “80 °”, the sewing needle stops at the position where the tip ends of the sewing needles 3L, 3R are close to the workpiece, and when the sewing step S4 is finished, the main shaft No. 2 is a position where the rotation angle is “50 °”, and the sewing needles 3L and 3R are stopped at the retracted position where the sewing needles 3L and 3R are retracted above the workpiece.

  The CPU 10a of the control unit 10 includes various control programs for the two-needle sewing machine stored in the ROM 10b according to the drive input signal input from the sewing pedal 8, the various signals and data input from the operation panel 5, and the like. The operation of each part is centrally controlled according to the sewing pattern data stored in the ROM 10b and the EEPROM 10d, and the processing results are stored in the work area in the RAM 10c. Then, the processing result stored in the RAM 10c is stored in the EEPROM 10d.

In the ROM 10b of the control unit 10, the control program and control data of the sewing machine 100 and data related to various sewing are written and stored. In particular, the ROM 10b stores a plurality of sewing patterns which are a combination of a plurality of sewing steps (sewing steps) having a plurality of stitch numbers set in advance as sewing pattern storage means.
The RAM 10c is provided with various work memories and counters, and is used as a work area during the sewing operation. Further, various data in the data selection processing regarding the sewing pattern is also temporarily stored in the RAM 10c.
The EEPROM 10d stores a plurality of sewing patterns, which are set on the operation panel 5 and input through the CPU 50a or the like as a sewing pattern storage means, and are a combination of a plurality of sewing steps (sewing steps) having a plurality of stitches. . Further, the EEPROM 10d individually stores data such as a rotation angle position related to the proximity position which is the immediately preceding needle upper position set by the immediately preceding needle upper position individual setting unit for each sewing pattern.

  Then, the control unit 10 specifies and selects the sewing pattern stored in the ROM 10b or the EEPROM 10d based on the input of the sewing pattern number for specifying the sewing pattern via the operation panel 5, and selects the sewing pattern as the sewing pattern. It functions as a part of the sewing pattern selection means for executing the sewing based on.

Further, when the control unit 10 executes the sewing based on the sewing pattern selected by the control unit 10 as the sewing pattern selection means, the sewing step (sewing process) of the currently executed sewing pattern is the final sewing step. It functions as a final process determination means for determining whether or not (sewing process).
When the control unit 10 as the final process determining means determines that the sewing step (sewing process) in the sewing pattern currently being sewn is the final sewing step (sewing process), the motor is driven. The two sewing needles 3L and 3R are stopped at a retracted position, which is a predetermined needle upper position above the proximity position (previous needle upper position), by the control unit 10 serving as a control means.
If the control unit 10 as the final process determining means determines that the sewing step (sewing process) in the sewing pattern currently being sewn is not the final sewing step (sewing process), motor drive control is performed. The control unit 10 as a means is stopped at a close position so that the tip ends of the two sewing needles 3L and 3R are positioned immediately before the sewing product.

Further, the control unit 10 drives the sewing machine motor 1 according to the sewing step (sewing process) of the sewing pattern selected by the sewing pattern selection means based on the swinging operation of the sewing pedal 8 to the forward stepping position. Thus, the sewing machine spindle 2 is rotated by stopping the driving of the sewing machine motor 1 at the end of the sewing step (sewing process) for each sewing step (sewing process) in the sewing pattern. It functions as motor drive control means that automatically stops rotation.
In particular, the control unit 10 as the motor drive control means is configured so that the sewing pedal 8 is in the forward-depressed position when performing sewing based on a sewing pattern in which a plurality of sewing steps (sewing steps) having a plurality of stitches are combined. As the swing operation is performed, sewing is performed for the number of stitches set in each sewing step.
Based on the determination of the control unit 10 as the final process determination means, the control unit 10 as the motor drive control means places the sewing needles 3L and 3R after the final sewing step (sewing process) in the sewing pattern. The rotational angle position of the sewing machine main shaft 2 detected by the encoder 1a as the main shaft position detecting means and the needle position detector 7 so as to stop at the retracted position retracted above the sewing product placed on the surface 100b. Is stopped at a sewing end position (for example, a rotation angle of 50 °) corresponding to the retracted position.
Further, based on the determination of the control unit 10 as the final process determination unit, the control unit 10 as the motor drive control unit retracts the sewing needles 3L and 3R after a sewing step (sewing process) other than the final in the sewing pattern. Sewing in which the rotational angle position of the sewing machine main shaft 2 detected by the encoder 1a as the main shaft position detecting means and the needle position detector 7 corresponds to the close position so as to stop at a close position closer to the workpiece than the position. The driving of the sewing machine motor 1 is stopped so as to reach a midway position (for example, a rotation angle of 80 °).

That is, in the second embodiment, the control unit 10 as the motor drive control unit performs each sewing step when performing sewing based on a sewing pattern in which a plurality of sewing steps (sewing steps) having a plurality of stitches are combined. After sewing is performed for the number of stitches set in step S1, the sewing machine motor 1 is stopped, so that the sewing needles 3L and 3R are stopped at predetermined positions. Then, after the final sewing step (sewing process) in the sewing pattern, the sewing needles 3L and 3R stop at the retracted position, and after the sewing step (sewing process) other than the final in the sewing pattern, the sewing needle 3L. 3R stops at a close position closer to the sewing product than the retracted position.
In addition, like the control unit 10 as the motor drive control means of the first embodiment, the sewing needles 3L and 3R are moved by swinging the sewing pedal 8 to the return position or swinging to the neutral position. You may use together stopping to a predetermined position. As a result, the sewing operation can be temporarily stopped when any trouble or trouble occurs during sewing, such as thread breakage.

  Further, the control unit 10 adjusts the rotation angle position corresponding to the height so as to adjust the height from the placement surface 100b when the sewing needles 3L and 3R are stopped. In particular, it functions as a part of setting means for individually setting data such as the rotation angle position corresponding to the sewing intermediate position when the sewing needles 3L and 3R stop at the close position for each sewing pattern.

  Next, the sewing operation of the sewing machine 100 in the second embodiment will be described based on the flowchart shown in FIG.

  First, based on the main power supply of the sewing machine 100 being turned on, the control unit 10 of the sewing machine 100 initially sets the sewing step number S for counting the sewing steps (sewing process) to “S = 1”, Further, the number N of process stitches for counting the number of stitches in each sewing step (sewing process) is initially set to “N = 0” (step S201).

  Next, the control unit 10 stops the total number of steps (total number of sewing steps) T and the sewing needles 3L and 3R in the sewing pattern stored in the EEPROM 10d as the sewing pattern selected by the sewing pattern selection means. Sewing machine corresponding to the rotation angle of the sewing end position (for example, the rotation angle of 50 °), which is the rotation angle position of the sewing machine spindle 2 corresponding to the retracted position, and the close position (position immediately above the needle) where the sewing needles 3L and 3R stop. A rotation angle (for example, a rotation angle of 80 °) at the sewing intermediate position that is the rotation angle position of the main shaft 2 is read and temporarily stored in the RAM 10c (step S202).

  Next, the control unit 10 reads the number of stitches M set as the S-th sewing step in the sewing pattern selected by the sewing pattern selection means from the EEPROM 10d and temporarily stores it in the RAM 10c (step S203).

Next, the control unit 10 determines whether or not the sewing pedal 8 has been stepped forward (a swinging operation to the front step position) (step S204).
If the control unit 10 determines that the sewing pedal 8 has been stepped forward (step S204; Yes), it outputs a drive control signal to the sewing machine motor 1 to drive the sewing machine motor 1 to drive the sewing machine spindle 2 to rotate (step). S205). The sewing machine spindle 2 rotates at a rotational speed corresponding to the depression amount of the sewing pedal 8, and the sewing needles 3L and 3R (needle bar 3) move up and down at a sewing speed corresponding to the rotational speed to form a seam. Perform sewing operation.

Next, the control unit 10 determines whether or not the sewing pedal 8 has been stepped on backward (oscillation operation to the stepping-back position) (step S206).
When the control unit 10 determines that the sewing pedal 8 has been stepped back (step S206; Yes), the process proceeds to step S216, and the sewing operation 100 is finished.

  On the other hand, when the control unit 10 determines that the sewing machine pedal 8 is not stepped back (step S206; No), the control unit 10 determines that the stitches are formed by one stitch and the number of stitches is increased, and the process needle. The number N is counted up as “N = N + 1” (step S207).

Next, the control unit 10 determines whether or not the number of process stitches N in the Sth sewing step matches the number of stitches M set as the Sth sewing step (step S208).
When the control unit 10 determines that the number of process stitches N in the S-th sewing step does not match the set number of stitches M (step S208; No), the process returns to step S205.

  On the other hand, when the control unit 10 determines that the number of process stitches N in the S-th sewing step matches the set number of stitches M (step S208; Yes), the sewing for the number of stitches in the S-th sewing step is performed. When finished, the control unit 10 determines that the sewing process in the S-th sewing step is completed, and the process proceeds to step S209.

In step S209, the control unit 10 determines whether or not the S-th sewing step for which the sewing process has been completed is the T-th sewing step that is the final sewing step (step S209).
When the control unit 10 determines that the Sth sewing step is the Tth sewing step which is the final step (step S209; Yes), the process proceeds to step S216.
On the other hand, when the control unit 10 determines that the S-th sewing step is not the T-th sewing step, which is the final step (step S209; No), the control unit 10 performs a sewing machine for stopping the driving of the sewing machine motor 1. A motor deceleration signal is output (step S210). And the control part 10 judges whether the sewing machine motor 1 fell to the predetermined | prescribed low speed rotation which can be stopped immediately (step S211).

If the control unit 10 determines that the sewing motor 1 has decreased to a predetermined low-speed rotation that can be stopped immediately (step S211; Yes), the control unit 10 determines that the rotational angle position of the sewing machine spindle 2 is a sewing intermediate position (proximity position). It is determined whether or not a rotation angle corresponding to (for example, a rotation angle of 80 °) has been reached (step S212).
When the control unit 10 determines that the rotation angle position of the sewing machine spindle 2 has reached the rotation angle (for example, rotation angle 80 °) at the sewing intermediate position (proximity position) (step S212; Yes), the control unit 10 The drive of the sewing machine motor 1 is stopped so that the needles 3L and 3R stop at the close positions (step S213).

Then, the operator changes the sewing direction by rotating the direction of the sewing object while the sewing operation of the sewing machine 100 is temporarily stopped. At this time, since the sewing needles 3L and 3R are stopped at the close positions, the tip end of the sewing needle is positioned immediately before the sewing product, and the needle tip (tip portion) of the sewing needle is positioned at the needle drop position of the sewing product. It is easy to align with. Therefore, even after changing the direction of the workpiece, the sewing needle can be easily aligned with the needle drop point before the temporary stop.
Specifically, for example, as shown in FIG. 7B, sewing corresponding to the sewing step (for example, S1, S2, S3) from the upper side to the lower side in the figure is performed, and the needle drop point P is set at the sewing machine. The sewing for a predetermined number of stitches is completed at the timing when the needle 3R is positioned, the sewing operation of the sewing machine 100 is temporarily stopped, and the sewing needles 3L and 3R are stopped at the close positions. Then, in the drawing, after the operator changes the direction of the sewing object to rotate in order to perform the next sewing step from the right side to the left side, the sewing needle 3R is moved to the needle drop position P. Align so that it falls. At this time, since the needle tips (tip portions) of the sewing needles 3L and 3R are close to the workpiece, it is easy to align them.
In this way, by forming the seam so that the sewing needle 3R drops at the needle drop point P before and after changing the direction of the workpiece by switching the sewing step, the appearance of the seam shape can be improved. it can.

  Then, the control unit 10 counts up the number S of sewing steps to “S = S + 1” in order to shift to the next sewing step when one sewing step is completed, and the needle in the next sewing step. The number of process stitches N for counting the number is reset to “N = 0” (step S214).

  Next, the control unit 10 determines whether or not the sewing pedal 8 has been operated to swing forward (step S215), and when the control unit 10 determines that the sewing pedal 8 has been pressed forward (step S215; Yes). ), The process returns to step S203.

  In step S216, the control unit 10 outputs a sewing machine motor deceleration signal for stopping the driving of the sewing machine motor 1 (step S216). And the control part 10 judges whether the sewing machine motor 1 fell to the predetermined | prescribed low speed rotation which can be stopped immediately (step S217).

When the control unit 10 determines that the sewing motor 1 has decreased to a predetermined low-speed rotation that can be stopped immediately (step S217; Yes), the control unit 10 determines that the rotational angle position of the sewing machine spindle 2 is the sewing end position (retracted position). It is determined whether or not a rotation angle corresponding to (for example, a rotation angle of 50 °) has been reached (step S218).
When the control unit 10 determines that the rotation angle position of the sewing machine spindle 2 has reached the rotation angle (for example, rotation angle 50 °) of the sewing end position (retraction position) (step S217; Yes), the control unit 10 The drive of the sewing machine motor 1 is stopped so that the needles 3L, 3R stop at the retracted position (step S219).
At this time, the sewing needles 3L and 3R are stopped so that the tip portions of the sewing needles 3L and 3R are away from the sewing product, so that the placing surface 100b is not caught by being hooked on the tip portion of the sewing needle and being damaged. Can be taken out from.

  Then, the control unit 10 causes the thread trimming device 9 to perform a thread trimming operation (step S220), and ends the sewing operation of the sewing machine 100.

  As described above, in the sewing machine 100 according to the present invention, the sewing machine needle 1 is driven to swing to the front stepping position, the sewing machine motor 1 is driven, and the sewing machine spindle 2 is rotationally driven, whereby the sewing needles 3L, 3R. The sewing operation for forming the seam based on the sewing pattern can be performed by moving the (needle bar 3) up and down.

Then, the sewing needles 3L and 3R are placed on the mounting surface 100b based on the sewing end stop signal output after finishing the sewing of the final sewing step so that the sewing according to all the sewing steps in the sewing pattern is finished. It can be stopped at the retracted position above the workpiece to be placed.
Therefore, the sewing needles 3L and 3R automatically stop at the retracted position in accordance with the completion of a series of sewing operations, such as the formation of the stitches of the desired sewing pattern, and the sewing on the placement surface 100b. When the article is taken out from under the sewing needle or the article to be sewn is placed on the mounting surface 100b under the sewing needle, the article to be sewn is brought into contact with the sewing needle 3L, 3R, etc. Troubles that can be hurt can be reduced.

In addition, the sewing needles 3L and 3R are attached to the sewing product based on a sewing intermediate stop signal output after the completion of sewing for a predetermined number of stitches in each sewing step so as to finish the sewing in each sewing step in the sewing pattern. It can be stopped at a close position.
Therefore, when the previous sewing step is finished and the next sewing step is started, the sewing needles 3L and 3R are automatically stopped at the close position, so that the operator can perform the sewing between the sewing steps during the sewing. When changing the sewing direction by rotating the direction of the sewing product, the sewing needles 3L, 3R are positioned in the proximity positions, so that the tip of the sewing needles 3L, 3R is smoothly at the needle drop position of the sewing product. It becomes easy to align with.
Therefore, when the next sewing step is advanced after changing the direction of the workpiece, the sewing needle can be easily aligned with the last needle drop point in the previous sewing step. By forming the seam so that the sewing needle drops at a predetermined needle drop point before and after changing the direction of the workpiece, the appearance of the seam shape can be improved.

  In the above embodiment, the rotational angle position of the sewing machine main shaft 2 corresponding to the retracted position is set to 50 °, and the rotational angle position of the sewing machine main shaft 2 corresponding to the proximity position is set to 80 °. The rotation angle position (rotation angle) of the sewing machine main shaft 2 corresponding to the retraction position or the proximity position may be any rotation angle, and the cloth thickness of the sewing product or the operator's It can be adjusted according to work efficiency.

  Further, in the final sewing step (sewing process) in the sewing pattern, the sewing needles 3L and 3R are stopped at the retracted position, and in the other sewing steps (sewing process), the sewing needles 3L and 3R are stopped at the close position. Not only, but the height position of the sewing needles 3L, 3R is set for each sewing step, for example, the stop position according to the thickness of the sewing location in the sewing step is determined, and the retracted position or the proximity position May be set.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

1 is a schematic external view showing a two-needle sewing machine according to the present invention. It is a block diagram which shows the principal part structure of the 2 needle | hook sewing machine which concerns on this invention. It is explanatory drawing which shows an example of the signal which an encoder and a needle position detector output. It is a flowchart which shows the sewing operation | movement of the sewing machine in Embodiment 1 of this invention. It is explanatory drawing which shows the example of a display of the liquid crystal panel in an operation panel. It is a flowchart which shows the sewing operation | movement of the sewing machine in Embodiment 2 of this invention. It is explanatory drawing regarding sewing of a 2 needle | hook sewing machine, and is the external appearance perspective view (a) at the time of a series of seam formation, and the enlarged view (b) of the corner | angular part of the seam.

Explanation of symbols

1 sewing machine motor 1a encoder (spindle position detection means)
2 Sewing machine spindle 3 Needle bar 3L, 3R Sewing needle 5 Operation panel (sewing pattern selection means, setting means, previous needle upper position individual setting means)
5a Liquid crystal panel 5b Operation switch 7 Needle position detector (spindle position detection means)
8 Sewing pedal 10 Control unit (motor drive control means, setting means, individual needle upper position individual setting means, sewing pattern selection means, final process determination means)
10a CPU
10b ROM (sewing pattern storage means)
10c RAM
10d EEPROM (sewing pattern storage means)
100 sewing machines (2 needle sewing machines)
C Fabric (Sewing product)
T tag (workpiece)
P Needle entry point

Claims (4)

A sewing machine motor that rotates the sewing machine main shaft and moves two sewing needles supported by a needle bar connected to the sewing machine main shaft up and down with respect to the sewing product;
Spindle position detecting means for detecting a rotational angle position of the sewing machine spindle rotated by the sewing machine motor;
A sewing pedal that is always in a neutral position and is swung between a forward and a return position by an operation;
The sewing machine main shaft is rotated by a swinging operation of the sewing pedal from the neutral position to the front stepping position, and the swinging operation to the neutral position after the swinging operation of the sewing pedal to the front stepping position is performed. The sewing machine motor is controlled so that the tip ends of the two sewing needles are stopped above the sewing product based on the rotational angle position detected by the spindle position detecting means by the swinging operation to the return position. A two-needle sewing machine comprising:
The motor drive control means is configured to push the tip ends of the two sewing needles when the sewing pedal is swung to the neutral position after the sewing pedal is swung to the front position. When the sewing machine pedal is swung to the stepping-back position after stopping immediately before the previous needle up position, the tips of the two sewing needles are set to a predetermined needle up position above the previous needle up position. A two-needle sewing machine that controls the sewing machine motor to stop. A sewing machine motor that rotates the sewing machine main shaft and moves two sewing needles supported by a needle bar connected to the sewing machine main shaft up and down with respect to the sewing product;
Spindle position detecting means for detecting a rotational angle position of the sewing machine spindle rotated by the sewing machine motor;
A sewing pedal that is always in a neutral position and is swung between a forward and a return position by an operation;
Sewing pattern storage means for storing a plurality of sewing patterns formed by combining a plurality of sewing steps having a plurality of stitch numbers;
Sewing pattern selection means for selecting a desired sewing pattern from a plurality of sewing patterns stored in the sewing pattern storage means;
For each sewing process of the sewing pattern selected by the sewing pattern selection means, the sewing machine main shaft is rotated by a swinging operation of the sewing pedal from the neutral position to the front stepping position, and when the sewing process ends, Motor drive control means for controlling the sewing machine motor so as to automatically stop the tips of the two sewing needles above the sewing product based on the rotational angle position detected by the spindle position detection means; In this needle sewing machine,
A final process determining means for determining whether or not the sewing process that is sewn by the rotation of the sewing machine main shaft by the swinging operation of the sewing pedal to the front stepping position is the final sewing process;
The motor drive control means determines that the sewing process is not the final sewing process by the final process determining means when the tip of the sewing needle is automatically stopped above the workpiece for each sewing process. In this case, the tip ends of the two sewing needles are stopped at the position immediately above the sewing needle immediately before the workpiece, and the final process determining means determines that the sewing process is the final sewing process. A two-needle sewing machine that controls the sewing machine motor to stop the tips of two sewing needles at a predetermined upper needle position above the previous upper needle upper position.   The two-needle sewing machine according to claim 1 or 2, further comprising setting means for setting the position immediately above the previous needle. An immediately preceding needle upper position individual setting means for individually setting the immediately preceding needle upper position for each sewing pattern;
The two-needle sewing machine according to claim 2, wherein the sewing pattern storage means individually stores the immediately preceding needle upper position set by the immediately preceding needle upper position individual setting means for each sewing pattern.

Images