JP3439495B2 - Automatic reverse feed stitch control device of sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic reverse stitch control device for a sewing machine. 2. Description of the Related Art In sewing with a sewing machine, an object to be sewn,
For example, it is known that reverse stitching is often performed at the beginning of sewing where a force is applied such as a pocket of work clothes. This reverse sewing at the start of sewing means that when the sewing machine is started by stepping on the pedal, only the forward stitch and the reverse stitch having a predetermined number of stitches set in advance, or only the reverse stitch are formed. The formation of the reverse stitches having the predetermined number of stitches will be briefly described below. When the motor is driven, the main shaft of the sewing machine rotates, and the rotation of the main shaft is used as a drive source to perform vertical movement of the needle and feed movement of the feed dog. A feed amount adjusting mechanism is provided between the feed dog and the main shaft, and normally feeds a predetermined amount of feed motion in the forward direction to the feed dog, but the reverse feed solenoid is biased. Then, the same mechanism operates to give the feed dog a predetermined amount of movement in the opposite direction. Therefore, at the time of reverse stitching, the reverse feed solenoid is urged for a predetermined number of stitches to form a reverse stitch. If the pedal is in the front stepping state at the end of the reverse stitching, a forward stitch is formed without stopping continuously, and a normal seam is formed until the pedal is released. . [0003] However, the above sewing machine has the following problems. That is, in a case where normal sewing is performed after the reverse stitching in a direction having a certain angle with respect to the direction of the reverse stitching as shown in FIG. 6, it is desirable to start sewing from the end D of the reverse stitching. However, a considerable amount of skill is required to release the pedal and stop the formation of the seam at the position D before the reverse stitching is completed. Therefore, it is difficult to stop the seam at the end D of the reverse stitch except for a skilled worker. As a result, the stitches C in the forward direction are excessively formed, and a desired stitch row, for example, E, cannot be continuously formed from the end D of the reverse stitching, resulting in a problem that the quality of a sewn product deteriorates. In FIG. 6, the reverse stitch row B at the time of reverse stitching is separated from the forward stitch row A in order to complicate the drawing, but the stitch rows actually overlap in the order of A, B, and C from below. ing. Accordingly, an object of the present invention is to provide an automatic reverse stitch control device for a sewing machine which can improve the quality of sewing products and does not require skill. In order to achieve the above-mentioned object, an automatic reverse sewing machine control device for a sewing machine according to the present invention, as shown in FIG. 1, rotates or stops a sewing machine main shaft 1 at a set speed. And a pedal 2 for setting the rotation speed of the sewing machine spindle 1 in accordance with the amount of stepping operation from a release position where the sewing machine spindle 1 is stopped, and the pedal 3 being depressed. Pedal depression amount detection means 4 for detecting the operation amount, speed control means 5 for driving the sewing machine in connection with the front depression operation of the pedal 3, and sending out a stop signal in relation to release, A motor driving means 6 for driving and stopping the motor 2 in response to a signal from a control means 5; 7, reverse feed means 9 for setting the feed of the feed dog 8 in the reverse direction by an electric action, and needle vertical position detecting means 10 for detecting a predetermined rotation angle of the main shaft 1 of the sewing machine and generating a detection signal. Counter 11 for counting the detection signal
And reverse stitching needle number setting means 1 for setting the number of reverse stitching stitches
2 and a sewing start reverse sewing control means 13 for operating the reverse feed means 9 while the counter 11 counts a predetermined number of detection signals after the sewing machine is started by the pedal operation of the pedal 3. In a sewing machine which performs a normal stitch formation by a pedal operation after a predetermined number of stitches are stitched at the start of sewing, a manually operable switching operation means 14 for generating a switching signal; Then, when the counter 11 counts the predetermined number of detection signals, the sewing machine is stopped irrespective of the front stepping operation of the pedal 3, and thereafter, the pedal 3 is restarted.
And control means 15 acting on the motor drive means 6 so as to end the reverse stitching control by an operation . According to the automatic reverse sewing controller of the sewing machine in such a means, when the switching operation means 14 is turned on, the control means 15 controls the sewing machine at the end of the reverse sewing regardless of the front stepping operation of the pedal 3. Motor drive means 6 to stop
And the end stitch position in the automatic reverse stitching is stopped at the position of the set value at which the initial reverse stitching ends. An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram of an automatic reverse stitch control device for a sewing machine according to an embodiment of the present invention. As shown in FIG. 1, the automatic reverse sewing controller for the sewing machine includes a sewing machine head 22, a rotatable sewing machine main shaft 1 inserted into the sewing machine head 22, and pulleys 30a, 30
b, by detecting a predetermined rotation angle of the main shaft 1 and the main shaft motor 2 rotating or stopping at a set speed via the belt 31, it is determined whether the needle 30 is located above or below the needle plate 32 as a boundary. A needle vertical position detecting means 10 for detecting whether or not the needle 30 is stuck in the workpiece and counting how many needles have been sewn; a sewing machine speed detecting means 16 for detecting a rotation speed of the main shaft 1; Feed means 7 which, in conjunction with the main shaft 1, feeds the feed dog 8 in a forward or reverse direction with a predetermined feed amount and can adjust the feed amount.
Reverse feed means 9 comprising a reverse feed solenoid 9b for setting the feed of the feed dog 8 in the reverse direction and a solenoid biasing means 9a for electrically operating the reverse feed solenoid 9b.
A pedal 3 for setting the rotation speed of the spindle 1 in accordance with a stepping operation amount from a release position where the sewing machine spindle 1 stops, and a pedal depression amount detecting means 4 for detecting the stepping amount of the pedal 3 And reverse stitching operation setting means 17 for setting whether or not to perform reverse stitching, reverse stitching needle number setting means 12 for setting the number of stitches for reverse stitching, and automatic reverse stitching without being restricted by whether or not the pedal 3 is depressed forward. Switching operation means 14 for generating a switching signal for stopping the sewing at the end stitch position, this switching operation means 14, the pedal depression amount detecting means 4, the needle vertical position detecting means 10, the sewing machine speed detecting means 16, a controller for sending signals to the motor 2 and the reverse feed means 9 in response to signals from the reverse stitching operation setting means 17 and the reverse stitching needle number setting means 12. It has an over 20. The pedal depression amount detecting means 4, the needle up / down position detecting means 10, the sewing machine speed detecting means 16, the reverse stitching operation setting means 17 and the reverse stitching needle number setting means 12 are of a known structure, and have a switching operation. The means 14 also has a well-known structure in which the power is simply supplied when the switch is turned on, and the power is released when the switch is turned off. Also, spindle 1
The mechanism for converting the rotational movement of the needle 30 into the vertical movement (linear movement) of the needle 30 and the reverse feed means 9 including the feed means 7, the reverse feed solenoid 9b and the solenoid urging means 9a are also known structures. The description in is omitted. The controller 20 for sending a signal to the motor 2 and the reverse feed means 9 includes a counter 11 for counting the number of stitches based on a signal from the needle up / down position detecting means 10 in FIG. If the reverse sewing is set in advance in the reverse sewing operation setting means 17 after the sewing machine is activated by the previous stepping operation, the detection signal from the counter 11 and a predetermined number of signals preset in the reverse sewing number setting means 12 are used. First comparing means 13
a stitch control means 13 for sending a reverse feed signal to the reverse feed means 9 by the reverse feed solenoid control means 13b during the number of stitches set as reverse feed by the signal from the first comparing means 13a; The detection signal from the counter 11 and a predetermined number of signals set in advance in the reverse stitching stitch number setting means 12 are compared by a second comparing means 15a, and the detection signal from the counter 11 and the stitch number setting means 12 are compared.
When the number of stitches corresponding to the predetermined number of stitches coincides with each other, a coincidence signal is generated, and in response to the coincidence signal, the control means 15 sends a stop signal from the predetermined number control means 15b.
A speed control signal to the motor driving means 6 in response to signals from the pedal depression amount detecting means 4 and the sewing machine speed detecting means 16;
When the ON signal is received from the controller, a signal for rotating the spindle 1 at a constant speed lower than the speed at the time of the normal sewing is transmitted during the reverse stitching operation. The stop signal from the control means 15 is sent preferentially without being constrained by the signal from the depression amount detecting means 4, and the signal which has reached the end stitch number of the reverse stitch set after receiving the stop signal is compared with the first comparison signal. Mean 13
a, a brake signal is sent to the motor driving means 6 by a needle down signal from the needle up / down position detecting means 10 and the spindle 1 is moved to the initially set seam position and the needle 30 is stuck in the cloth. This is a microcomputer configured to achieve the same function as the speed control means 5 for sending a signal to stop the operation. In FIG. 1, solid arrows indicate electric signal lines, and dotted arrows indicate lines that propagate an operation by mechanical connection. In the ROM in the controller 20, a program capable of achieving the above function is written, and each set value and a data table are stored and processed. FIG. 3 is a flowchart showing the program written in the ROM. The operation of the apparatus will be described below according to a program. When the program starts, first, in step 1, it is determined whether or not the reverse stitching operation setting means 17 is on. If it is off, the automatic reverse stitching is not performed. And proceeds to step 2, and in step 2,
It is determined whether or not the switching operation means 14 is ON. If the switching operation means 14 is ON, the process proceeds to step 4; Here, the normal automatic reverse sewing control means that a set value of the number of stitches to be automatically reversely sewn is input in advance in the number of reverse stitch stitches setting means 12 before the sewing machine is started. While the main shaft 1 is rotated at a constant speed lower than the speed at the time of normal sewing, the vertical position of the needle is detected by the needle vertical position detecting means 10,
The number of stitches is added as a counter value, and when this counter value is compared with a preset value for reversing the sewing direction at the time of reverse stitching by the first comparing means 13a shown in FIG. Is reversed by the reverse feed means 9 and the feed means 7, and the counter value and the preset set value for ending the reverse stitching are compared by the first comparing means 13a. If not, it is determined that the automatic reverse stitching has been completed, and the spindle motor 2 is stopped.
In conjunction with this, the feed means 7 is also stopped. On the other hand, when the sewer is stepping on the pedal 3, even if the counter value is equal to the preset value for ending the reverse stitching,
Subsequently, assuming that the sewing will be performed, the constant speed is released, and normal sewing in the forward direction is performed at a speed corresponding to the stepping amount detected by the pedal stepping amount detecting means 4. Then, in step 3 , when the normal automatic reverse sewing control ends, the flow ends to perform the next sewing. On the other hand, if it is determined in step 2 that it is on, the process proceeds to step 4. In step 4, it is determined whether or not the pedal 3 is on. If it is off, automatic reverse stitching has not started. This determination is repeated until it is turned on. If it is on, automatic reverse sewing is started, and the process proceeds to step 5. In step 5, the speed of the spindle 1 (of course, the number of rotations is also possible) is detected by the sewing machine speed detecting means 16, and reverse sewing is performed. During operation, the main shaft 1 is controlled to rotate at a constant speed lower than the speed at the time of normal sewing. Here, in the same manner as the normal automatic reverse sewing described above, the vertical position of the needle is detected by the needle vertical position detecting means 10, the number of stitches is added as a counter value, and the counter value and the preset reverse sewing are performed. When the set values for reversing the directions are compared and become equal, the feed direction of the feed dog 8 is changed to the reverse feed means 9 and the feed means 7.
Is reversed by Then, the process proceeds to step 6, where the set value for terminating the reverse stitch is changed. The relationship between the speed or the number of rotations of the main shaft 1 and the number of stitches is, for example, as shown in FIG. 4. When the set value for ending the reverse stitching is, for example, 8 stitches, 1 < deceleration mode will be indicated by br /> point chain line, in advance, for example, 6
If a stop signal is sent to the spindle motor 2 at the stitch, it is understood that the rotation speed is reduced as indicated by the dashed line, and the automatic reverse stitching is completed around the desired eighth stitch. That is, since the main spindle 1 is rotating at a constant speed during the reverse stitching, if the set number of stitches for the reverse stitching is known in advance, the end point of the stitch in accordance with the deceleration mode indicated by the dashed line can be known. Therefore, in this step 6, the number of stitches at the start of deceleration of the deceleration line (dash-dot line shown in FIG. 4) in which the set value for ending the reverse stitching is set to the end point of the automatic reverse stitching as the set value for ending the initial reverse stitching. (6th stitch in FIG. 4). Then, the process proceeds to a step 7, and in the step 7, the second setter 15a shown in FIG. 1 compares the changed set value for terminating the reverse feed stitching with the actually counted counter value. If they do not match, even if the spindle motor 2 is stopped here, it is determined that the end of the stop sewing does not reach the desired position, and this determination is repeated until they match. If the motor 2 is stopped, it is determined that the end of the lock stitch stops at a desired position, and the process proceeds to step 8. In step 8, a deceleration mode for stopping the spindle motor 2 is entered. In step (1), it is determined whether or not the number of stitches has reached the number of stitches at which the reverse stitching is completed, based on a signal from the first comparing means 13a shown in FIG. If the number of stitches is not reached, the determination is repeated until the set number of stitches is reached. When the number of stitches has been reached, the process proceeds to step 10, and in step 10, it is determined whether or not the needle 30 is at the lower position. That is, it is determined whether or not the needle 30 is stuck in the cloth. If the needle 30 is not at the lower position, the main shaft 1 is rotated by inertia as it is, and if the needle 30 is at the lower position, the process proceeds to step 11, Step 11
, The brake is applied to the motor 2 to stop the needle 30 at the needle position. Then, the feed operation of the feed dog 8 interlocked with the spindle motor 2 also stops at the same time. Thereafter, the process proceeds to Step 12, and Step 1
In step 2, it is determined whether or not the pedal 3 is off. If the pedal 3 is on, this determination is repeated until the pedal 3 is off because the next sewing cannot be performed. If the pedal 3 is off, the process proceeds to step 13.
In step 13, it is determined again whether or not the pedal 3 is on. If the pedal 3 is off, this determination is repeated until it is turned on because there is no intention to perform the next sewing. This flow is terminated assuming that there is. As described above, in this embodiment, if the switching operation means 14 is turned on, the automatic reverse sewing can be stopped at the position of the initial set value regardless of the depression of the pedal 3, and at the time of termination. The needle 30 is stopped at the lower position, so that if the normal sewing is continuously performed at a certain angle with respect to the stitch direction in which the automatic reverse sewing is performed, the needle 30 will hold down the cloth. ,
Sewing can be reliably started from the end of the lock stitch. FIG. 5 is a diagram showing the overall construction of an automatic reverse sewing controller for a sewing machine according to another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that the speed control in the controller 20 is different. A part of the function provided to the means 5 is provided to the pedal control means 5a and the predetermined number of stop control means 15c. Here, the pedal control unit 5a and the predetermined number of stop control units 15c are respectively a pedal depression amount detection unit 4, a sewing machine speed detection unit 16, and a needle vertical position detection unit 1.
In response to the signal from the switching operation means 14 and 0, the pedal control means 5a gives priority to the signal from the predetermined number of stop control means 15c when the ON signal is not received from the switching operation means 14 in the speed control means. 5b, an acceleration / deceleration signal and a stop signal are sent out.
In 5c, when an ON signal is received from the switching operation means 14, a constant speed signal and a stop signal are sent to the speed control means 5b prior to the signal from the pedal control means 5a. As described above, in the present embodiment, a part of the function provided to the speed control means 5 in the controller 20 is partially replaced by the pedal control means 5a and the predetermined number of stop control means 15.
It is needless to say that the same effect as in the previous embodiment can be expected because c is provided. Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. Needless to say. As described above, according to the automatic reverse feed stitching control device of the sewing machine of the present invention, the position of the end stitch in the automatic reverse feed stitch is initially set by the switching operation means regardless of the pedal stepping operation. Since it is possible to stop at the position of the value, the quality of the sewn product can be improved without requiring skill.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is a schematic configuration diagram of an automatic reverse feed stitching control device showing one embodiment of the present invention. FIG. 3 is a flowchart of a program stored in a controller in FIG. 2; FIG. 4 is a diagram showing the relationship between the number of rotations and the number of stitches. FIG. 5 is an overall configuration diagram showing another embodiment of the present invention. FIG. 6 is a view illustrating a stitch of automatic reverse stitching according to the related art. [Description of Signs] 1 sewing machine spindle 2 motor 3 pedal 4 pedal depression amount detection means 5 speed control means 6 motor drive means 7 feed means 8 feed dog 9 reverse feed means 10 needle vertical position detection means 11 counter 12 reverse stitch number setting Means 13 Reverse sewing control means at the start of sewing 14 Switching operation means 15 Control means 17 Reverse sewing operation setting means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-52794 (JP, A) JP-A-57-192591 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D05B 1/00-97/12

Claims (1)

(57) [Claim 1] A motor connected to rotate or stop a sewing machine spindle at a set speed, and a stepping operation amount from a release position for stopping the sewing machine spindle. A pedal for setting the rotation speed of the sewing machine spindle; a pedal depression amount detecting means for detecting the pedal depression operation amount; and driving and releasing the sewing machine in association with the front pedal operation of the pedal. Speed control means for sending a signal to stop in relation to, driving of the motor by a signal from the speed control means,
Motor drive means for stopping, feed means for providing a feed motion of a predetermined feed amount in a forward or reverse direction to the feed dog in conjunction with the main shaft of the sewing machine, and feeding of the feed dog in a reverse direction by electric action Reverse feed means for setting; needle vertical position detecting means for detecting a predetermined rotation angle of the sewing machine spindle to generate a detection signal; a counter for counting the detection signal; and setting of the number of reverse stitches for setting the number of reverse stitches Means, and a sewing start reverse sewing means for operating the reverse feed means while the counter counts a predetermined number of detection signals set after the sewing machine is started by the pedal stepping operation at the start of sewing. Switching operation means that can be manually operated to generate a switching signal in a sewing machine that performs normal stitch formation by pedal operation after the reverse stitching of a predetermined number of stitches , In connection with the generation of the switching signal, the counter stops regardless sewing machine pedal front step operation at the time of counting the detection signal of the predetermined number, then again the pedal
An automatic reverse feed stitching control device for a sewing machine, further comprising control means for acting on the motor drive means so as to end the reverse feed stitch control by an operation .