JP2006158650A - sewing machine - Google Patents

Abstract

An object of the present invention is to provide a sewing machine that can freely loosen a yarn.
A sewing machine 10 is placed on the upper surface of a table 1 and supports a main body frame 20 that supports and stores almost the entire structure thereof, and a needle that holds a sewing needle 11 and is supported by the main body frame 20 so as to be movable up and down. A bar, a vertical movement mechanism that moves the needle bar up and down by driving the sewing machine motor 3, a feed mechanism that feeds a workpiece placed on the needle plate 13 along the X-axis direction, and sewing on the needle plate 13 A cloth presser 12 that presses and presses an object from above, a cloth thickness detection means 30 that detects the thickness of the sewing object on the needle plate 13, and a sewing thread according to the detected thickness detected by the cloth thickness detection means 30 A yarn loosening mechanism 40 as working means for performing the yarn loosening, and an operation control means 80 for performing operation control on each of the above-described components.
[Selection] Figure 1

Description

  The present invention relates to a sewing machine, and more particularly, to a sewing machine that can draw out excess thread during sewing.

  When sewing a sewing machine in which a plurality of items to be sewn are sewed together, in order to form a uniform seam, a substantially flat plate-like shape is formed near the sewing position of the item to be sewn conveyed by the feed mechanism, i.e., the needle drop position. A pressing force is applied by the cloth presser. For this reason, the sewing position of the workpiece is compressed by receiving the pressing force. And the compression part moved to the conveyance direction from the cloth pressing position with conveyance is released from the pressing force of the cloth pressing, and is restored to the original thickness by a repulsive force (restoring force).

  Further, a needle through which the upper thread is passed from the upper surface side is passed through the compression portion described above, and on the lower side of the needle plate, the lower thread is stretched over the upper thread passed through the needle tip, When the workpiece is pulled out from the lower side to the upper side, the upper thread and the lower thread are tightened to perform sewing (a seam is formed).

  Here, for example, when sewing the sleeve and body of the suit, the thickness of the original shoulder pad is maintained even after sewing at the seam portion formed on the shoulder pad, due to the requirement for finished quality. It is desirable. In general, since the seam is formed in the compressed part of the cloth presser in the sewing machine, it has flexibility such as a shoulder pad, and the original thickness and the thickness when pressed by the cloth presser are greatly different. When sewing a sewn product, there has been a problem that the thickness of the stitched portion after sewing is significantly thinner than the original thickness of the sewn product and becomes recessed.

In view of the above problems, the needle thread that is driven up and down on the upper side of the needle plate traverses the lever that swings left and right, so that the upper thread is entangled in advance and the thread length after sewing is given a margin. There is known a sewing machine that makes it possible (see Non-Patent Document 1, for example). In such a conventional sewing machine, the lever is configured to have a cloth thickness detecting means capable of moving up and down according to the cloth thickness via a link mechanism. As a result, a certain amount of excess needle thread can be secured during sewing according to changes in the thickness of the fabric, and the difference between the thickness of the seam portion after sewing and the original thickness of the workpiece can be reduced. It can be done.
D697 parts book, made by Dulkop

  However, in the conventional sewing machine shown in Non-Patent Document 1, the cloth thickness detecting means for detecting the original cloth thickness has a rod connected by a long hole and a pin engaged with the long hole. Therefore, the amount of up and down movement of the lever relative to the amount of change in fabric thickness can only be adjusted to a certain ratio. That is, it can only change linearly (primary) with respect to the change in the thickness of the cloth, and the response to the change in the thickness of the cloth is an approximation based only on the original thickness of the cloth. . Further, since the ratio adjustment is a manual operation, it cannot be performed during sewing, and there is a problem that sewing must be performed at a constant ratio.

  Furthermore, the length of the excess yarn is determined based solely on the original thickness of the cloth detected by the cloth thickness detecting means, and when sewing a sewing product having different elasticity and restoring force, the connecting portion I had to readjust the slot and pin again. The adjustment of the pin that engages with the elongated hole portion is manually performed by the operator, so it takes time and is difficult to make fine adjustment, and there is a problem that reproducibility is low when sewing the same material to be sewn. .

  Further, the swinging motion of the lever in the left-right direction can only be switched between operation and stop, and the swing width in the left-right direction cannot be adjusted according to the thickness of the fabric and the amount of restoration. That is, there is a problem that the amount of the upper thread secured according to the fabric thickness cannot be adjusted by the operation in the left-right direction.

  Further, the swinging motion of the lever in the left-right direction is configured such that the rotation of the sewing machine main shaft is transmitted through a gear, and the number of rotations is transmitted by half. Therefore, every time the needle driven up and down in synchronization with the main spindle of the sewing machine makes two reciprocations up and down, the lever makes one reciprocation left and right. For this reason, the lever drive pattern with respect to the left-right direction has a problem that the operation pattern cannot be changed because the lever only crosses the lower side of the needle every time the needle is raised.

  An object of the present invention is to provide a sewing machine that can freely loosen a yarn.

In order to solve the above-described problem, the invention according to claim 1 includes a needle drive mechanism that drives a needle up and down, a feed mechanism that conveys a sewing product on a needle plate in synchronization with the needle drive mechanism, A pressing mechanism that presses the sewing product onto the needle plate, and a needle thread passed between the needle and the sewing product by traversing the vertical movement path of the needle in a direction intersecting the feeding direction. In a sewing machine comprising: a thread loosening mechanism having a lever arranged along a feeding direction so as to draw out an extra thread length by entanglement,
The thread loosening mechanism has cross direction driving means for driving the lever so as to cross the vertical movement path of the needle in a direction crossing the feed direction for each stitch.
The sewing machine includes a control unit having a function of controlling a driving frequency or a driving amount of the cross direction driving unit.

  According to the first aspect of the present invention, the lever of the yarn slackening mechanism is driven by the cross direction driving means, and the driving frequency, drive amount or driving speed of the cross direction driving means is controlled by the control means. In other words, the lever of the thread loosening mechanism can freely set or change the driving frequency, driving amount or driving speed in the direction crossing the vertical movement of the needle in the control means, and can drive in the cross direction according to the setting in the control means. Driven in the left-right direction by the means.

  According to a second aspect of the present invention, in the sewing machine according to the first aspect, the thread loosening mechanism includes a vertical driving means capable of driving the lever in the vertical direction and the sewing product conveyed by the feeding mechanism. Thickness detecting means for detecting the thickness of the upper and lower drive means, and the control means has a function of controlling the vertical drive means based on the detected thickness of the thickness detecting means.

  In the invention described in claim 2, the thickness detecting means detects the thickness of the workpiece to be conveyed to the sewing position by the feed mechanism. Further, the lever of the yarn loosening mechanism is moved up and down by the vertical drive means. The vertical driving means is driven and controlled by the control means based on the detection value detected by the thickness detecting means, that is, the original thickness of the sewing product. That is, the original thickness of the sewing product detected by the thickness detection means is output to the control means and stored in the control means, or the lift amount of the lever is calculated according to the setting in the control means and By performing feedback in real time to the driving means, sewing is performed to accurately extract the length of the thread to be secured for each stitch.

  According to a third aspect of the present invention, in the sewing machine according to the second aspect, the control means has a function of controlling the cross direction driving means based on a detection value of the thickness detection means. .

  In the invention according to claim 3, the cross direction driving means of the yarn slackening mechanism is controlled by a control means for controlling the cross direction driving means based on the original thickness of the sewing product detected by the thickness detecting means. Its drive is controlled. That is, the original thickness of the sewing product conveyed by the feed mechanism is detected by the thickness detection means, and the detected value is output to the control means. The control means controls not only the vertical drive means but also the driving of the cross direction drive means based on the detected value.

  According to the first aspect of the present invention, the lever of the yarn slackening mechanism can be driven by the cross direction driving means, and the cross direction driving means is controlled by the control means in the lateral driving frequency, the driving amount, the driving speed, and the like. It can be set or changed freely. Therefore, compared with a conventional sewing machine having a lever that is driven by obtaining a driving force divided from the sewing machine motor, it is possible to freely set the driving frequency or driving amount of the lever in the left-right direction. Can also perform control to change the driving frequency and driving amount during sewing. As a result, the length of the thread that can be pulled out excessively in the sewing operation per stitch (one pitch) can be set to a desired value or a desired change can be caused. Accordingly, various sewing operations are possible depending on the thickness and material of various sewing objects.

  According to the second aspect of the present invention, the same effect as that of the first aspect of the invention can be obtained, and in particular, the lever of the thread loosening mechanism is the sewing product detected by the thickness detecting means. The drive can be controlled by the control means based on the original thickness. Therefore, as compared with the conventional sewing machine in which the raising / lowering amount can be changed at a constant ratio by having the detection arm connected through the long hole and the pin, the raising / lowering amount in the vertical direction can be freely set or changed. It becomes possible. This makes it possible to finely set the length of the extra thread to be secured in the sewing operation per stitch (one pitch), and to perform sewing to maintain the original thickness of the sewing product even after sewing. It becomes possible. Further, the vertical drive means is controlled by a control means for controlling the vertical drive means based on the detected thickness detected by the thickness detection means. The original thickness is fed back in real time, and an extra length of yarn that accurately corresponds to the original thickness of the workpiece can be pulled out for each stitch.

  According to the invention described in claim 3, the same effect as that of the invention described in claim 2 can be obtained, and in particular, the control means can control the thickness of the sewing product detected by the thickness detection means. By providing the function to control the driving of the cross direction drive means based on the original thickness of the sewing material conveyed by the feeding mechanism can be fed back in real time and should be pulled out for each stitch. The length of the yarn can be ensured accurately. In addition to the vertical drive means, the operation of the cross direction drive means can also be controlled based on the original thickness of the sewing product detected by the thickness detection means, so that the sewing material conveyed to the sewing position can be controlled. The driving frequency, driving amount and driving speed of the vertical driving means and the cross direction driving means can be arbitrarily combined in accordance with the original thickness of the object, and various sewing conditions and sewing patterns can be used. Accordingly, a seam can be formed.

(Overall configuration of the embodiment)
Embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a main configuration of the sewing machine 10.
Here, a direction in which a sewing needle 11 to be described later moves up and down is defined as a Z-axis direction (vertical direction), and a direction perpendicular to the Z-axis direction (feeding direction of the workpiece) is defined as an X-axis direction (front-rear direction). A direction perpendicular to both the axial direction and the Z-axis direction is defined as a Y-axis direction (left-right direction). In the sewing machine 10, the needle plate 13 provided on the upper side of the sewing machine bed portion 21 is arranged in parallel to the XY plane.

The sewing machine 10 according to the present embodiment is a sewing machine that sews a thick material, such as a pad, to a cloth that is a sewing object, and has a configuration that is more suitable for sewing thicker than usual. In the following description, when “sewed product” is simply referred to, the fabric and the pad are overlapped.
The sewing machine 10 is placed on the upper surface of the table 1, and supports a main body frame 20 that supports and stores almost the entire configuration thereof, a needle bar that holds the sewing needle 11 and is supported by the main body frame 20 so as to be movable up and down, and a sewing machine. A vertical movement mechanism as a needle drive mechanism that moves the needle bar up and down by driving the motor 3, a feed mechanism that feeds the workpieces placed on the needle plate 13 along the X-axis direction, A cloth presser 12 that constitutes a presser mechanism that presses and holds the sewing product from above, a cloth thickness detection means 30 that detects the thickness of the sewing product on the needle plate 13, and a detection detected by the cloth thickness detection means 30 A thread loosening mechanism 40 is provided as working means for loosening the sewing thread according to the thickness, and an operation control means 80 for controlling the operation of each of the above-described components.

(Body frame)
The main body frame 20 includes a sewing machine bed portion 21 provided with a needle plate 13 on the upper surface of one end thereof, a vertical body portion 22 erected from the other end side of the sewing machine bed portion 21, and an upper end of the vertical body portion 22. A sewing machine arm portion 23 extending in the same direction as the sewing bed portion 21 is provided, and is formed in a substantially U shape as a whole.

(Sewing needle)
The sewing needle 11 is driven to reciprocate along the Z-axis direction by a vertical movement mechanism via a needle bar (not shown) supported by the main body frame. An upper thread (not shown) is passed in the vicinity of the tip of the sewing needle 11, and the upper thread is fed to the lower side of the needle plate 13 through the workpiece on the upper surface of the needle plate 13 by the reciprocating operation in the Z-axis direction. Sewing is performed by tying around the lower thread of a hook (not shown).

(Vertical movement mechanism)
A vertical movement mechanism (not shown) is fixed to the main body frame, and is arranged so as to be able to rotate along the Y-axis direction within the sewing machine arm portion 23 and upper and lower metal bearings that slidably support the upper and lower ends of the needle bar. An upper shaft, a sewing machine motor 3 that rotationally drives the upper shaft, a rotary weight fixedly provided at an end of the upper shaft, a crank rod that connects a portion eccentric from the rotation center of the rotary weight and the needle bar; It has.
When the upper shaft and the rotary weight are rotationally driven by the sewing machine motor 3, the crank rod can convert the rotational driving force into the vertical driving force and transmit it to the needle bar, and can be driven to reciprocate in the vertical direction. It has become.

(Cloth presser)
FIG. 2 is an enlarged perspective view showing a configuration around the cloth presser 12. The cloth presser 12 has a rectangular frame shape, and the inside penetrates vertically. The sewing needle performs needle dropping inside the cloth presser 12 and performs sewing inside the cloth presser 12. Further, the yarn loosening member 41 also moves in the Y-axis direction within the frame of the cloth presser 12.
The cloth presser 12 is held at the lower end of a cloth presser support bar 14 that is supported so as to be movable along the Z-axis direction at the lower part of the tip of the sewing machine arm part 23. This cloth presser support bar 14 is not shown. It moves up and down by a pressing stepping motor.
That is, the operation control means 80 controls the pressing stepping motor in accordance with the cloth thickness detected by the cloth thickness detection means 30 during sewing and adjusts the height of the cloth presser 12 so that the cloth presser is controlled from an appropriate height. Is to be done.

(Feeding mechanism)
A feed mechanism (not shown) includes a feed dog that is below the needle plate 13 and protrudes and appears on the upper surface of the needle plate, and a transmission mechanism that moves the feed dog in the feed direction along the X-axis direction. Such a transmission mechanism is driven by the sewing pitch in a constant direction (forward feed direction) in the X-axis direction while causing the feed dog to appear on the upper surface of the needle plate 13 by driving the sewing machine motor. Further, the feeding operation of the transmission mechanism is periodically performed in synchronization with the vertical movement of the sewing needle 11. As a result, the feed mechanism feeds the workpieces on the needle plate 13 in units of sewing pitches.

(Cloth thickness detection means)
The cloth thickness detection means 30 is a potentiometer which is a detection arm 31 whose tip is in contact with the workpiece on the needle plate 13 from above in the vicinity of the cloth presser 12 and an angle detection means for detecting the swing angle of the detection arm 31. 32. The potentiometer 32 is disposed at the lower end of the tip end of the sewing machine arm portion 23.

The potentiometer 32 includes a rotatable detection shaft, and the detection shaft is supported inside the main body frame 20. The potentiometer 32 has a function of outputting a signal corresponding to the rotation angle generated on the detection shaft to the operation control means 80 and supports the base end portion of the detection arm 31 by the detection shaft.
The detection arm 31 has a base end portion supported by the detection shaft of the potentiometer 32 and a tip end portion which is perpendicular to the detection axis and hangs obliquely downward. The tip end of the detection arm 31 lands at a position adjacent to the cloth presser 12 in the Y-axis direction on the upper surface of the needle plate 13, and abuts on the workpiece to be sewn set on the upper surface of the needle plate 13 during sewing. It is an arrangement. Therefore, at the time of sewing, the detection arm 31 is rotated according to the thickness of the workpiece, and the detection shaft of the potentiometer 32 on the base end side outputs a signal to the operation control means 80 by the rotation angle corresponding to the thickness. Do. In the operation control means 80, the thickness of the workpiece is calculated from the detected rotation angle and the known length of the detection arm 31.

(Thread loosening mechanism)
The thread loosening mechanism 40 is temporarily entangled with the sewing thread to be sewn into the sewing product by traversing the vertical movement path of the sewing needle 11 in the direction (Y-axis direction) intersecting the feed direction (X-axis direction). A thread loosening member 41 that performs loosening, a holding body 42 of a thread loosening member 41 supported so as to be able to rotate and move up and down with respect to the cloth presser support bar 14, and a Z axis via the holding body 42 Left and right drive mechanism 44 as a cross direction drive means for rotating the yarn loosening member 41 about the direction, and a vertical drive means for moving the yarn loosening member 41 along the Z-axis direction via the holding body 42 And a vertical drive mechanism 51.

  The holding body 42 is disposed in the vicinity of the lower end portion of the cloth presser support bar 14 and somewhat above the cloth presser 12. The holding body 42 is formed with a through hole, and can be moved along the cloth presser support bar 14 by inserting the cloth presser support bar 14 through the through hole. Is possible.

The yarn loosening member 41 has a base end portion fixed to the holding body 42 and extends from the base end portion in a direction orthogonal to the cloth presser support bar 14 (along the X-axis direction). At the same time, the front end of the U-turn extends in the opposite direction. Further, the thread loosening member 41 is arranged so that the distal end side portion 41b and the proximal end portion side portion 41a are parallel to each other with the folded-back portion as a boundary, but are shifted from each other in the Y-axis direction and the Z-axis direction. Yes.
As described above, since the holding body 42 is supported so as to be rotatable about the cloth presser support bar 14, the thread loosening member 41 similarly rotates about the support bar 14. The thread loosening member 41 is disposed so as to pass through the vertical movement path of the sewing needle 11 by its rotation.
The thread loosening member 41 is reciprocally rotated by a left and right drive mechanism 44 within a certain angular range across the vertical movement path of the sewing needle 11, but the thread loosening member 41 is generally along the X-axis direction. The reciprocating rotation is performed in an angle range that maintains the state (a range that is at least along the X axis direction rather than the Y axis direction).

  The left / right movement mechanism 44 is a cross direction driving means for driving the thread loosening member 41 so as to cross the vertical movement path of the sewing needle 11 driven up and down through the needle thread in a direction crossing the feeding direction. A left and right drive motor 45 serving as a drive source for turning the member 41, a drive arm 46 to which a base end portion of an output shaft of the left and right drive motor 45 is connected, and a support member (not shown) are rotatably supported on the main body frame 2. The support shaft 47, the input arm 48 fixedly provided at the upper end portion of the support shaft 47, the output arm 49 fixedly provided at the lower end portion of the support shaft 47, the rotating end portion of the input arm 48, and the drive arm And a connecting link body 50 that connects the rotating end portions of 46.

The left and right drive motor 45 is a pulse motor (stepping motor) whose drive frequency and drive amount (rotation amount) can be controlled according to a pulse signal from an operation control means 80 described later, and its output shaft is along the Z-axis direction. As shown in FIG. The drive arm 46 extends in a direction perpendicular to the output shaft of the drive motor 45.
The support shaft 47 is supported by the main body frame 20 so as to be parallel to the Z-axis direction. The input arm 48 and the output arm 49 are extended in the direction perpendicular to the support shaft 47 at the upper end portion and the lower end portion of the support shaft 47, respectively. Further, since the rotation end portions of the drive arm 46 and the input arm 48 are connected by the connection link body 50, the drive arm 46 and the input arm 48 are supported via the arms 46, 48 and the link body 50 by driving the left and right drive motor 45. The shaft 47 and the output arm 49 can be rotated. The thread loosening member 41 is driven in the left-right direction by the left / right drive mechanism 40 when the sewing needle 11 that is reciprocated up and down by the vertical movement mechanism is positioned above the thread loosening member 41. It goes without saying that it is controlled to be done.

  The output arm 49 is formed in a shape in which the extended rotation end portion is bifurcated and engaged with the engagement protrusion 43 protruding upward from the holding body 42 entering the inside. It is like that. The engagement protrusion 43 protrudes from the holding body 42 so as to be parallel to the cloth presser support rod 14 inserted into the through hole of the holding body 42. What is the thread loosening member 41 across the through hole? It is provided at the opposite end. With this arrangement, when the output arm 49 swings by driving the left and right drive motor 45, the holding body 42 and the thread loosening member 41 rotate about the cloth presser support rod 14 via the engagement protrusion 43, Furthermore, it is possible to move the tip end portion 41b of the yarn loosening member 41 along the Y-axis direction.

  The vertical movement mechanism 51 includes a vertical drive motor 52 that is a drive source for the vertical movement of the yarn loosening member 41, a drive arm 53 to which a base end portion of an output shaft of the vertical drive motor 52 is connected, and a support member (not shown). An action link body 54 whose one end is rotatably supported by the main body frame 2, and a connecting link body 55 that connects an intermediate position in the longitudinal direction of the action link body 54 and a rotation end of the drive arm 53 are provided. Yes.

  The vertical drive motor 52 is a pulse motor (stepping motor) whose drive frequency and drive amount (rotation amount) can be controlled in accordance with a pulse signal from an operation control means 80 described later, like the left and right drive motor 45 described above. The main body frame 20 is fixedly equipped so that its output shaft is along the Y-axis direction. The drive arm 53 extends in a direction orthogonal to the output shaft of the drive motor 52. Further, since one end portion of the connection link body 55 is connected to the rotation end portion of the drive arm 53, when the drive arm 53 is rotated by driving the vertical drive motor 52, the connection link body 55 is substantially omitted. It can be moved forward along the longitudinal direction.

  As described above, one end of the action link body 54 is pivotally supported on the main body frame 20 by a support member (not shown). A boss-like protrusion 56 protruding in a direction perpendicular to the longitudinal direction is provided at the other end of the action link body 54. A groove 57 is formed on the side surface of the holding body 42 in parallel with the direction in which the yarn loosening member 41 extends (substantially the X-axis direction), and the protrusion 56 is inserted inside the groove 57. Thus, the action link body 54 and the holding body 42 are engaged with each other. Furthermore, since the connecting link body 55 is connected to the longitudinal intermediate position of the action link body 54, when the vertical drive motor 52 is driven, the action link body 54 is connected via the drive arm 53 and the connection link body 55. As a result, the support 42 and the thread loosening member 41 are moved up and down along the cloth holding support rod 14 via the projection 56 at the other end of the action link body 55. Can be moved.

(Operation control means)
The operation control means 80 is a control means for controlling the entire operation of the sewing machine 10, and includes a CPU 81, a RAM 82, a ROM 83, an EEPROM 84, etc., as shown in the block diagram of FIG. In addition to the operation panel 90 (input means), the operation control means 80 is connected to a spindle drive circuit, a pedal device, a rotation speed detection circuit, a head rotation angle detection circuit, a comparison / determination unit and the like (not shown). .
Specifically, the CPU 81 sends the spindle drive circuit to the sewing machine motor 3 based on signals output from the operation panel 90 (input means), a pedal device (not shown), a rotation speed detection circuit, a head rotation angle detection circuit, and the like. By performing this drive control command, the amount of current flowing through the sewing machine motor 3 is optimally controlled, and the rotational speed of the sewing machine motor 3 is controlled. The RAM 82 serving as storage means becomes a work area for temporarily storing data in the processing of the CPU 81, and the ROM 83 stores a control program for the CPU 81 to perform each processing. The EEPROM 84 is a non-volatile memory that can be stored without erasing the stored contents even when the power of the sewing machine 10 is turned off. The EEPROM 84 stores each operation control program and sewing data in a rewritable manner. Yes.
An operation panel 90 is connected to the operation control means 80 in the present embodiment, and an operation pattern of the sewing machine 10 can be set or changed by an input operation of the operator. In the present embodiment, the left and right drive motor 45 and the vertical drive motor 52 of the yarn loosening mechanism 40 are connected, and the drive frequency and drive of the left and right drive motor 45 and the vertical drive motor 52 are controlled from the operation panel 90 described above. Each set value for controlling the amount and the like can be input.

  Although not shown in FIG. 1, the operation panel 90 is disposed on the upper portion of the main body frame 20, and transmits each set value input by the operator's operation to the operation control means 80 as an output signal.

The operation control means 80 in this embodiment has a function of controlling the drive frequency and drive amount of the left and right drive motors 45 and 52 based on the detection value of the cloth thickness detection means 30 described above. Specifically, the operation control means 80 determines the drive amount of the left and right drive motor 45 or the vertical drive motor 52 with respect to the value (cloth thickness) detected by the cloth thickness detection means 30 in accordance with the input operation from the operation panel 90 described above. It has a function to perform control to determine. That is, for example, when the original thickness of the cloth detected by the cloth thickness detecting means 30 is h, the amplitude in the left / right direction by the left / right drive motor 45 is a * h, and the up / down direction by the up / down drive motor 52 is It has a function of controlling the movement amount to b * h (a and b can be set and input from the operation panel 90). Each set value (for example, a, b, etc.) input from the operation panel 90 is stored by being stored in the EEPROM 84 of the operation control means 80. That is, it is possible to oscillate at an arbitrary amplitude by arbitrarily changing the values of a and b. Alternatively, control may be performed by adding a predetermined set value to the detected thickness to obtain the amplitude in the horizontal direction or the amount of movement in the vertical direction.
Further, the operation control means 80 has a function of accepting an input (setting or change) from the operation panel 90 even during the sewing operation.
Further, the operation control means 80 can set the left and right vibration frequency (driving frequency) of the yarn slackening member 41, that is, the thinning-out rate and the like by the input operation from the operation panel 90. Specifically, for example, when control (thinning out) is performed to drive (swing) the thread loosening member 41 once every time the needle drop number becomes n times, the set value n can be set from the operation panel 90. Is. More specifically, it has a function of controlling the left and right drive motor 45 to be driven when the rotation number of the output shaft of the sewing machine motor 3 is counted and the approximate count value becomes n.
Further, the operation control means 80 has a function of performing control to change the drive amount of the yarn loosening member 41 when the cloth thickness detected by the cloth thickness detection means 80 becomes a certain value (for example, ds) or more. ing. Specifically, when the thickness is less than the detected thickness ds, the operation control means 80 sets the amplitude in the horizontal direction by the left and right drive motor 45 as a * h and the amount of movement in the vertical direction by the vertical drive motor 52 as described above. When the detected thickness is equal to or greater than ds, the amplitude in the left-right direction by the left-right drive motor 45 remains a * h as described above, but the amount of movement in the up-down direction by the vertical drive motor 52 is b ′ *. Control h is performed. At this time, the constant values ds and b ′ can be set by performing an input operation from the operation panel 90. When there is a setting, the operation control means 80 performs a process of storing each setting value in the above-described EEPROM 84. .

Next, the operation of the sewing machine 10 according to the present embodiment will be described in detail with reference to the drawings.
First, when the cloth that is to be sewn is conveyed between the needle plate 13 and the front end (lower end) of the detection arm 31 by the feed operation of the feed mechanism, the front end of the detection arm 31 rises according to the thickness of the cloth. The detection arm 31 is rotated around the detection axis of the potentiometer 32. Then, the rotation angle of the detection shaft rotated with the rotation of the detection arm 31 is detected by the potentiometer 32. The angle detected here is output to the operation control means 80 as an electrical signal corresponding to the rotation angle.
A detection signal from the cloth thickness detection means 30 is recognized by the CPU 81. Based on the cloth thickness calculated from the detection signal, the CPU 81 follows the operation control program stored in the RAM 82, the ROM 83, the EEPROM 84, etc., which are storage means, while the sewing needle 11 is raised to the upper position. 11 outputs a signal indicating a driving amount for driving the thread loosening member 41 in a direction (left-right direction) intersecting the vertical movement path 11 to the left-right driving motor 45 and the vertical driving motor 52. A drive amount signal is intermittently output to the left and right drive motor 45 according to the set drive frequency. Based on the output signal, the left and right drive motor 45 and the vertical drive motor 52 are driven, and the yarn loosening member 41 is driven in the vertical direction and the horizontal direction. Further, as the thread loosening member 41 is driven, a needle thread is temporarily entangled with the tip end side portion 41b of the thread loosening member 41, and the cloth thickness is increased every sewing operation for one stitch (1 pitch). A sewing thread having a length corresponding to the length is secured.

Next, an operation for securing an excess thread during sewing by the thread loosening mechanism 40 will be described in detail with reference to an operation explanatory diagram shown in FIG. FIG. 4 is a schematic view when the vicinity of the needle plate 13 to be sewn is viewed from the upper side (Z-axis direction).
First, the cloth is conveyed from the lower side along the XY plane in FIG. a1 is a needle drop position, and the tip end portion 41b of the thread loosening member 41 is initially waiting in a state of being moved to the left side in FIG. 4 with respect to the needle drop position a1 (see FIG. 4A). .
Next, when the cloth is conveyed upward (in the X-axis direction) in FIG. 4 in accordance with the feeding operation of the feeding mechanism, the tip of the sewing needle 11 that has been pulled out of the cloth and raised at the first needle drop position a1 is moved. The left and right drive motor 45 is driven while being positioned on the upper position side with respect to the distal end side portion 41b, and the yarn loosening member 41 is moved to the right side of the needle drop position a1. At this time, the upper thread hung between the needle drop position a1 and the tip of the sewing needle 11 is moved to the right side of the needle drop position by the tip end portion 41b. The upper thread enters the next needle drop position a2 as well as the front end of the sewing needle 11, whereby the upper thread is passed over the front end portion 41 (see FIG. 4B). When the sewing needle 11 is pulled out and raised from the needle drop position a2, the tip end portion 41b is moved to the left side. Then, when the sewing needle 11 enters the third needle drop position a3, the upper thread is passed over the tip end portion 41b (FIG. 4C). Thus, every time the needle is reciprocated up and down twice by the vertical movement mechanism, the thread loosening member 41 is reciprocated once in the left and right (Y-axis) direction, and guides the upper thread to the right and to the left while guiding the upper thread. A thread is stretched around the side portion 41b. The upper thread hung around the tip end portion 41b is moved in the transport direction (X-axis direction), that is, upward in FIG. 4 in accordance with the feeding operation, and the needle drop is repeated (FIG. 4D). To (f)), when the open end of the tip end portion 41b is interrupted, the tip end portion 41 is detached from the tip end portion 41 and a surplus yarn is secured (see FIG. 4G). The extra yarn length in this case is determined for each pitch based on the cloth thickness detected by the cloth thickness detection means 30 described above, and the driving amount of the left and right driving motor 45 and the driving amount of the vertical driving motor 51 are determined. Control for ensuring an optimum length is performed by controlling.

Further, the operation control means 80 determines the drive amount of the left and right drive motor 45 or the vertical drive motor 52 with respect to the value (cloth thickness) detected by the cloth thickness detecting means 30 in accordance with the input operation from the operation panel 90 described above. Take control. That is, for example, when the original thickness of the cloth detected by the cloth thickness detecting means 30 is h, the amplitude in the left and right direction by the left and right drive motor 45 is h * a, and the up and down direction by the vertical drive motor 52 is Control is performed so that the movement amount is h * b (a and b can be set and input from the operation panel 90). Note that the values a, b, etc. input from the operation panel 90 are stored by being stored in the EEPROM 84. That is, it is possible to oscillate with an arbitrary amplitude by arbitrarily changing the values of a and b.
Further, the operation control means 80 accepts input (setting or change) from the operation panel 90 even during the sewing operation.
Further, the operation control means 80 can set the left and right vibration frequency (driving frequency), the thinning rate, and the like of the yarn loosening member 41 by an input operation from the operation panel 90. Specifically, for example, when control (thinning out) is performed to drive (swing) the thread loosening member 41 once every time the needle drop number becomes n times, the set value n can be set from the operation panel 90. Is. More specifically, the left and right drive motor 45 is controlled to be driven when the rotational speed of the output shaft of the sewing machine motor 3 is counted and the approximate count value becomes n.
Further, when the fabric thickness value is equal to or greater than a certain value ds, the control is performed to change the ratio of the yarn loosening amount determined based on the fabric thickness value. , You can perform a variety of sewing.

Next, the control operation of the operation control means 80 will be described in detail based on the flowchart shown in FIG.
First, when the start switch is turned on, the sewing machine motor 3 which is the main motor is driven (step S1). As the sewing machine motor 3 is driven, the CPU 81 determines whether or not the output shaft of the sewing machine motor 3 is the yarn loosening start angle (step S2). That is, the sewing needle 11 that is driven up and down by the vertical movement mechanism by the rotation of the output shaft of the sewing machine motor 3 is in the range above the thread loosening member 41, and the thread loosening member 41 is connected to the sewing needle 11. The CPU 81 determines whether or not it is time to cross the vertical movement path.
When the output shaft of the sewing machine motor 3 is at the thread loosening operation start angle (step S2; Yes), that is, when the sewing needle 11 is in the upper position, the thinning counter provided in the operation control means 80 Is counted as one count, and the count is sequentially added according to the number of rotations of the sewing machine motor 3 (step S3), and the number is recorded in the operation control means 80. When the CPU 81 recognizes that the count number has reached the set value M stored in the storage means, that is, the number of movements (thinning rate) in the left-right direction with respect to the number of times the sewing needle 11 moves up and down (step S4). ), The accumulated number of counts is returned to 0 again (step S5), and the cloth thickness d detected by the cloth thickness detection means 30 is stored in the storage means, or input or changed from the operation panel 90. It is determined whether or not the cloth thickness ds has been exceeded (step S6). That is, the CPU 81 determines whether or not the cloth thickness d detected by the cloth thickness detecting means 30 has exceeded the threshold value ds for starting the thinning operation. When the cloth thickness does not exceed the above-described threshold value (step S6; No), for example, the left and right drive motor 45 is changed to d * a and the upper and lower drive motor 52 is changed to d * b (a and b are changed) with respect to the cloth thickness d. A signal for driving in the left and right directions and the up and down directions with a drive amount of possible setting values) is output (step S7). And it returns to the process of step S2.
If the cloth thickness exceeds the above-described threshold (step S6; Yes), for example, the left and right drive motor 45 is d * a and the up and down drive motor 52 is d * b ′ (b ′) with respect to the cloth thickness d. Is a set value that can be changed) and outputs signals for driving in the left and right directions and the up and down directions (step S12). And it returns to the process of step S2.
When the count number does not reach the thinning set value M in step S4 (step S4; No), only the vertical drive motor 52 is d * according to the cloth thickness d (step S8) detected by the cloth thickness detection means 30. Control for driving with the driving amount b is performed (step S9). In other words, when the count number, that is, the number of needle drops is less than the set number of thinnings, the control is performed not to drive in the left-right direction (thinning) but only to move up and down following the thickness of the cloth. Is done. Thereafter, it is determined again whether or not the output shaft of the sewing machine motor 3 is at the yarn loosening start angle (step S2).
Further, when the output shaft of the sewing machine motor 3 is not the yarn loosening start angle in step S2 (step S2; No), a coefficient a that determines the left and right driving amount corresponding to the fabric thickness d from the operation panel 90 during the sewing operation. And control which judges whether the input operation which changes the coefficient b which determines the drive amount to the up-down direction corresponding to the fabric thickness d was performed is performed (step S10). And when input operation which changes setting value a and b is performed (step S10; Yes), after the control which memorize | stores the changed value as a new drive amount with respect to the left-right direction and an up-down direction, respectively was performed ( In step S11), it is determined whether or not the output shaft of the sewing machine motor 3 is at the yarn loosening start angle (step S2). When the input operation for changing the set values a and b is not performed (step S10; No), the process proceeds to step S2 again to determine whether or not the output shaft of the sewing machine motor 3 is at the yarn loosening start angle. (Step S2).

  As described above, according to the sewing machine 1 according to the present embodiment, the yarn loosening member 41 of the yarn loosening mechanism 40 is a motor capable of controlling the rotation amount independent of the sewing machine motor 3 as the drive source of the left and right drive mechanism 44. Therefore, the left and right drive mechanism 44 can freely set or change the drive frequency, drive amount, drive speed, and the like in the left and right directions by the operation control means 80. Therefore, compared with a conventional sewing machine having a thread loosening member 41 driven by obtaining a driving force divided from the sewing machine motor 3, the frequency of driving the thread loosening member 41 in the left-right direction, the drive amount, and It is possible to perform control for driving by freely setting or changing the driving speed or the like. As a result, it is possible to loosen the thread excessively or with less in the sewing operation per stitch (one pitch). Therefore, according to the thickness and material of various sewing products, it is possible to perform sewing to maintain the original thickness of the sewing product even after sewing, and the desired thickness can be obtained without impairing the original thickness of the sewing product. Finished quality can be obtained.

  Further, the thread loosening member 41 of the thread loosening mechanism 40 can be controlled by the control program of the operation control means 80 based on the original thickness of the sewing product detected by the cloth thickness detection means 30. Therefore, it is possible to freely set or change the vertical movement amount as compared with the case of performing manual adjustment. This makes it possible to finely set the length of the thread to be secured (loosened) excessively in the sewing operation per stitch (one pitch), and to perform sewing to maintain the original thickness of the sewing object even after sewing. be able to. Further, since the drive of the vertical drive mechanism 51 is controlled by the operation control means 80 that controls the vertical drive mechanism 51 based on the detected thickness detected by the cloth thickness detection means 30, the vertical drive mechanism 51 is conveyed to the sewing position. The original thickness of the sewing product to be sewn is fed back in real time, and a thread having a length that accurately corresponds to the original thickness of the sewing product can be secured for each stitch.

Further, the operation control means 80 has a function of controlling the driving of the left and right drive mechanism 44 based on the thickness of the sewing product detected by the cloth thickness detection means 30, thereby enabling the movement control means 80 to be conveyed by the feed mechanism. The original thickness of the sewn product can be fed back in real time to the driving in the left-right direction, and an extra length of yarn to be secured for each stitch can be accurately secured. Further, since the operation of the left and right drive mechanism 44 in addition to the vertical drive mechanism 51 can also be controlled based on the original thickness of the sewing product detected by the cloth thickness detection means 30, it is conveyed to the sewing position. Corresponding to various sewing conditions and sewing patterns by arbitrarily combining the driving frequency, driving amount, driving speed and the like of the vertical driving mechanism 44 and the left / right driving mechanism 51 in accordance with the original thickness of the workpiece. Seams can be formed.
Since the left and right drive motor 45 that drives the yarn loosening member 41 and the vertical drive motor 52 that drives up and down are both configured to apply pulse motors, the storage means (RAM 82 and ROM 83) provided in the operation control means 80 are used. , EEPROM 84, etc.) can store settings such as the drive amount and drive frequency, and the reproducibility when sewing a similar sewing product can be improved. Therefore, the time required for setting the sewing conditions can be greatly shortened, and the work efficiency can be greatly improved.
Further, since the driving frequency and driving amount of the yarn loosening member 41 can be set and changed only by an input operation from the operation panel connected to the operation control means 80, compared with a case where adjustment is performed manually. No complicated operation is required. Therefore, the time required for setting and changing can be greatly shortened.
Further, since numerical control by setting input from the operation panel 90 is made possible, the reproducibility of the same sewing operation is high, the sewing product quality is smoothly switched, and the productivity can be improved.
The left and right drive motors 45 and the up and down drive motors 52 need only be controllable by the operation control means 80, and may be servo motors or the like, not limited to pulse motors, for example.

1 is a perspective view showing a main part configuration of a sewing machine 10 according to the present embodiment. It is an expansion perspective view which shows the surrounding structure of the cloth presser 12 in this embodiment. It is a block diagram which shows the structure of the operation control means 80 in this embodiment. It is operation | movement explanatory drawing explaining the sewing operation | movement in this embodiment. It is a flowchart which shows the control operation | movement by the operation control means 80 in this embodiment.

Explanation of symbols

3 sewing machine motor 10 sewing machine 11 sewing needle 12 cloth presser 13 needle plate 20 main body frame 30 cloth thickness detection means 31 detection arm 32 potentiometer 40 thread loosening mechanism 41 thread loosening member 45 left and right drive motor (left and right drive means)
52 Vertical drive motor (vertical drive means)
80 Operation control means (control means)
90 Operation panel (input means)

Claims (3)

A needle drive mechanism for driving the needle up and down;
A feed mechanism that conveys the workpiece on the needle plate in synchronization with the needle drive mechanism;
A pressing mechanism for pressing the sewing product onto the needle plate;
Arranged along the feed direction so that the needle thread passed between the needle and the workpiece is entangled by crossing the vertical movement path of the needle in the direction crossing the feed direction, and the thread length is pulled out excessively. In a sewing machine comprising a thread loosening mechanism having a lever that is made,
The thread loosening mechanism has cross direction driving means for driving the lever so as to cross the vertical movement path of the needle in a direction crossing the feed direction for each stitch.
A sewing machine comprising a control unit having a function of controlling a driving frequency or a driving amount of the cross direction driving unit. The thread loosening mechanism is
Vertical drive means capable of driving the lever in the vertical direction;
Thickness detecting means for detecting the thickness of the sewing product conveyed by the feeding mechanism,
The control means includes
Having a function of controlling the vertical drive means based on the thickness detected by the thickness detection means;
The sewing machine according to claim 1, wherein:   The sewing machine according to claim 2, wherein the control means has a function of controlling the cross direction driving means based on a detection value of the thickness detection means.

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