JP2017184983A - sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a feed locus so that feed dog height increases according to the speed of a main shaft.SOLUTION: A horizontal feed mechanism 40 for transmitting a reciprocation operation in the horizontal direction with respect to a feed bar 32 includes a feed adjusting motor 57 for changing and adjusting a pitch of the reciprocation operation in the horizontal direction with respect to the feed bar 32. A vertical feed mechanism 60B for imparting a reciprocation operation in the vertical direction with respect to the feed bar 32 has a vertical feed motor 66 which serves as a driving source of the reciprocation operation in the vertical direction with respect to the feed bar 32. A control device 90 which controls these feed adjusting motor 57 and the vertical feed motor 60B and which performs a feed operation of a workpiece by a feed dog 31 controls the vertical feed motor 66 so that the feed dog 31 circulates with a predetermined locus in synchronization with a rotation angle of a main shaft which is rotationally driven by a sewing machine motor 16, and controls the vertical feed motor 66 so as to make the height of the feed dog 31 in a feed section during high-speed rotation of the main shaft higher than that during low-speed rotation.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a sewing machine that performs feed adjustment.

  2. Description of the Related Art Conventionally, in a sewing machine that performs cloth feeding by holding a cloth between a presser and a feed dog, a feed mechanism using a feed dog that moves mechanically linked to a spindle has been employed (see Patent Document 1).

JP2013-146326A

However, with a sewing machine that feeds the fabric with the presser and feed dog sandwiched, if the sewing speed is increased, the feed dog's revolving motion will also be faster. (Jumping), there was a problem that the holding pressure drops.
At this time, if the height of the feed dog is made higher, the gap between the presser and the presser will be reduced, so that the decrease in the presser pressure can be compensated for, but this time the presser pressure at the low speed will be increased.
In conventional feed mechanisms that use a feed dog that moves mechanically linked to the spindle, it is difficult to change the feed dog height during spindle rotation. It was not possible to achieve both.

  The subject of this invention is changing a feed locus so that feed dog height may become high according to a spindle speed.

In order to solve the above problems, the invention described in claim 1
A needle up-and-down movement mechanism that moves the needle bar up and down;
A sewing machine motor as a drive source of the needle up-and-down movement mechanism;
A feed base for supporting a feed dog that feeds the workpiece on the needle plate;
A horizontal feed mechanism that obtains power from the sewing machine motor and transmits a horizontal reciprocating motion to the feed base;
In a sewing machine provided with a vertical feed mechanism that gives a reciprocating motion in the vertical direction to the feed base,
The horizontal feed mechanism has a feed adjustment motor that changes and adjusts the pitch of a horizontal reciprocating operation with respect to the feed base by the sewing machine motor,
The vertical feed mechanism has a vertical feed motor serving as a drive source for a reciprocating motion in the vertical direction with respect to the feed base,
A controller for controlling the feed adjustment motor and the vertical feed motor to perform the feed operation of the sewing product by the feed dog;
The control device controls the vertical feed motor so as to circulate the feed dog in a predetermined locus in synchronization with a rotation angle of the main shaft that is rotationally driven by the sewing machine motor, and according to a rotation speed of the main shaft. The vertical feed motor is controlled so as to correct the locus of the feed dog in the feed section.

The invention described in claim 2
The sewing machine according to claim 1,
The control device controls the vertical feed motor so that when the spindle rotates at a high speed, the locus of the feed dog in the feed section becomes higher than that during low-speed rotation.

  According to the present invention, even if the spindle is rotating, the feed dog height and feed locus can be arbitrarily changed by software, so that the feed dog height in the feed section is increased according to the spindle speed. The feed locus can be changed.

It is a perspective view which shows the main structures in the sewing machine bed part of a sewing machine. It is a perspective view of a feed adjustment mechanism. It is a perspective view of a vertical feed mechanism. It is operation | movement explanatory drawing of the vertical feed mechanism at the time of the axis angle of a vertical feed motor 0 degree. It is operation | movement explanatory drawing of the vertical feed mechanism at the time of the shaft angle of -5 degrees of a vertical feed motor. It is operation | movement explanatory drawing of the vertical feed mechanism at the time of the shaft angle +5 degree of a vertical feed motor. It is a block diagram which shows the control system of a sewing machine. It is a diagram which shows the locus | trajectory of the reference | standard shape in the case of performing normal feeding. It is a diagram showing the relationship between the shaft angle of the vertical feed motor and the main shaft angle of the reference trajectory pattern data obtained by clockwise rotation and counterclockwise rotation. FIG. 5 is a diagram showing an example of changing the feed dog height when the rotation speed of the main shaft is 3000 rpm, showing the rotation trajectory of the feed dog. It is a diagram showing the relationship between the shaft angle of the vertical feed motor and the main shaft angle of the trajectory pattern data when the main shaft rotation speed obtained by the clockwise rotation and the counterclockwise rotation is 3000 rpm. FIG. 9 is a diagram showing an example of changing the feed dog height when the rotation speed of the spindle is 4000 rpm, showing the rotation trajectory of the feed dog. It is a diagram showing the relationship between the shaft angle of the vertical feed motor and the main shaft angle of the trajectory pattern data when the main shaft rotation speed obtained by the clockwise rotation and the counterclockwise rotation is 4000 rpm.

[Schematic Configuration of Embodiment]
Hereinafter, a sewing machine which is an embodiment of the present invention will be described in detail.
FIG. 1 is a perspective view showing a main configuration in the sewing machine bed portion of the sewing machine 100.

As shown in the figure, the sewing machine 100 includes a needle vertical movement mechanism (not shown) that moves the sewing needle up and down, a sewing machine motor 16 (see FIG. 7) that is a driving source thereof, and a spindle (not shown) that is rotated by the sewing machine motor 16. And a shuttle 12 that entangles the upper thread with the lower thread, a feeding device 30 that feeds the cloth as the sewing material on the needle plate 11 in accordance with the vertical movement of the sewing needle, and a rotational force from the main shaft to the lower shaft 33 of the feeding device 30. A belt mechanism 20 for transmitting the above, a thread trimming device 14 for cutting the upper thread and the lower thread (see FIG. 7), a sewing machine frame (not shown) for supporting each of the above components, and a control device 90 for controlling each of the above components (see FIG. 7).
The sewing machine 100 is a so-called lockstitch sewing machine, and includes various components such as a balance mechanism, a thread tension, and a cloth presser that are included in a general lockstitch sewing machine.

The sewing machine frame includes a bed portion positioned at a lower portion of the entire sewing machine, a standing body portion that is erected upward at one end portion in the longitudinal direction of the sewing machine bed portion, and the same direction as the bed portion from the upper end portion of the standing body portion. And an arm portion (not shown) extending in the direction.
In the following description, the horizontal direction parallel to the longitudinal direction of the sewing machine bed is defined as the Y-axis direction, the horizontal direction orthogonal to the Y-axis direction is defined as the X-axis direction, and is orthogonal to the X-axis and Y-axis directions. Let the direction be the Z-axis direction.

[Needle vertical movement mechanism and belt mechanism]
The needle up-and-down movement mechanism is disposed on the inner side of the arm portion, is rotationally driven by the sewing machine motor 16 and is disposed along the Y-axis direction, a needle bar that holds the sewing needle at the lower end, and a main shaft. And a crank mechanism (not shown) for converting the rotational force into a reciprocating drive force for vertical movement and transmitting it to the needle bar.
The belt mechanism 20 includes a main driving pulley fixedly mounted on the main shaft, a driven pulley 21 fixedly mounted on the lower shaft 33 of the feeding device 30, and a timing belt 22 spanned between the main driving pulley and the driven pulley 21. It has. The lower shaft 33 rotates at the same speed as the main shaft by the belt mechanism 20.
Instead of the belt mechanism, a rotational force may be transmitted from the main shaft to the lower shaft 33 by a gear transmission mechanism including a vertical axis and a bevel gear.

[Feeding device]
As shown in FIG. 1, the feeding device 30 obtains power from a feed dog 31 that appears and disappears from the opening of the needle plate 11 and feeds the fabric in a predetermined direction, a feed base 32 that holds the feed dog 31, and the sewing machine motor 16. The horizontal feed mechanism 40 that transmits the reciprocating motion in the X-axis direction (horizontal direction) to the feed base 32 and the vertical feed mechanism 60B that imparts the reciprocating motion in the vertical direction to the feed base 32 are provided.

[Horizontal feed mechanism]
The horizontal feed mechanism 40 includes a feed adjusting mechanism 50 that adjusts the stroke of the reciprocating operation in the X-axis direction with respect to the feed base 32, a crank rod 41 that takes out the reciprocating operation along the X-axis direction from the lower shaft 33, and the feed adjusting mechanism 50. A horizontal feed shaft 42 to which reciprocating rotation is applied from the crank rod 41, and a horizontal feed arm for converting the reciprocating rotational driving force of the horizontal feed shaft 42 into a reciprocating driving force in the feeding direction and transmitting it to the feed base 32. 43.

  One end of the crank rod 41 rotatably holds an eccentric cam (not shown) fixed to the lower shaft 33, and the other end is connected to the feed adjusting mechanism 50. The crank rod 41 is arranged so that its longitudinal direction is generally along the X-axis direction. When the lower shaft 33 is driven at full rotation, the other end of the crank rod 41 is doubled by the eccentric cam. The reciprocating motion is performed along the longitudinal direction with a stroke of. The reciprocating motion of the crank rod 41 is transmitted as reciprocating power to the horizontal feed shaft 42 via the feed adjusting mechanism 50.

  As shown in FIG. 2, the feed adjusting mechanism 50 is fixedly mounted on the horizontal feed shaft 42 and extends outward in the radial direction with the horizontal feed shaft 42 as the center. A pair of first link bodies 53 that connect the end portion and the swing arm 51, a pair of second link bodies 54 that guide the reciprocating motion direction of the other end portion of the crank rod 41 in either direction, A feed adjustment body 55 that determines the guiding direction by the second link body 54, a support shaft 52 that rotates integrally with the feed adjustment body 55, a fixed attachment to the support shaft 52, and the support shaft 52 as a center. An input arm 56 extended outward in the radial direction and a feed adjustment motor that rotates the feed adjustment body 55 to adjust the amount of reciprocation in the X-axis direction (horizontal direction) transmitted from the lower shaft 33 to the feed base 32. 57 and the output of the feed adjustment motor 57 And a two transmission links 58 and 59 for transmitting the input arm 56 twice power from.

The first link body 53 has one end connected to the other end of the crank rod 41 and the other end connected to the swing end of the swing arm 51, both of which rotate around the Y axis. It is linked movably.
One end of the second link body 54 is connected to the other end of the crank rod 41 together with one end of the first link 53, and the other end is connected to the rotating end of the feed adjusting body 55. Both end portions are connected so as to be rotatable about the Y axis.
The feed adjusting body 55 is fixedly equipped with a support shaft 52 along the Y-axis direction at the base end portion, and the support shaft 52 is supported so as to be rotatable around the Y-axis in the sewing machine frame.
Further, the rotation end portion of the feed adjusting body 55 is connected to the other end portion of the second link body 54 so as to be rotatable around the Y axis.

  In the feed adjusting mechanism 50, the feed adjusting body 55 is rotated so that the longitudinal directions of the first link body 53 and the second link body 54 coincide with each other, that is, the link bodies 53, 54 are just overlapped. When moved, the driving force of the crank rod 41 is not transmitted to the swing arm 51. At this time, since the reciprocating rotation is not transmitted to the horizontal feed shaft 42, the reciprocating stroke of the feed base 32 in the X-axis direction is 0, that is, the sewing pitch is 0. In this way, the rotation angle of the feed adjusting body 55 in which the link bodies 53 and 54 overlap each other is referred to as a “neutral angle of the feed adjusting body 55”.

When the feed adjusting body 55 is rotated from the neutral angle to one side, a reciprocating swinging motion is applied to the swinging arm 51 in accordance with the amount of the pivoting angle, thereby increasing the sewing pitch in the forward feed direction. Can be bigger.
Further, when the feed adjusting body 55 is rotated in the reverse direction from the neutral angle, a reciprocating swinging operation can be imparted to the swinging arm 51 side according to the rotational angle amount. Is transmitted with the phase reversed, and thereby the sewing pitch in the reverse feed direction can be increased.

The feed adjusting motor 57 is arranged with the output shaft directed in the Y-axis direction on one end side in the Y-axis direction inside the sewing machine bed portion. One end of the transmission link 58 is fixed to the output shaft of the feed adjustment motor 57 with its longitudinal direction being substantially in the X-axis direction. Accordingly, the other end portion of the transmission link 58 rotates up and down by driving the feed adjusting motor 57.
The transmission link 59 has a lower end connected to the other end of the transmission link 58 so as to be rotatable about the Y axis in a state where the longitudinal direction thereof is substantially along the Z-axis direction. Accordingly, the transmission link 59 moves up and down as a whole by driving the feed adjusting motor 57.
The input arm 56 is fixedly mounted on the support shaft 52 and extends substantially along the X-axis direction from the support shaft 52, and its extended end rotates around the Y axis at the upper end of the transmission link 59. Connected as possible.
Accordingly, when the feed adjusting motor 57 is driven, the feed adjusting body 55 can be rotated via the transmission links 58 and 59 and the input arm 56.

  The horizontal feed shaft 42 is supported so as to be rotatable along the Y-axis direction in the sewing machine bed portion, and is disposed downstream of the lower shaft 33 in the cloth feed direction (left side in FIG. 1). A reciprocating power is applied from the lower shaft 33 to the one end of the horizontal feed shaft 42 on the vertical barrel side via the feed adjusting mechanism 50 described above, and from the other end of the horizontal feed shaft 42 via the horizontal feed arm 43. The reciprocating motion along the X-axis direction is transmitted to the feed base 32.

The base end of the horizontal feed arm 43 is fixedly connected to the end of the horizontal feed shaft 42 on the needle plate 11 side, and the swinging end thereof is connected to the feed base 32 in a state of being directed substantially upward. .
Accordingly, the horizontal feed arm 43 can reciprocate the feed base 32 along the X-axis direction by driving the sewing machine motor 16. Further, the stroke of the reciprocating operation along the X-axis direction of the feed base 32 can be arbitrarily adjusted by controlling the feed adjustment motor 57 of the feed adjustment mechanism 50.

The feed base 32 is disposed below the needle plate 11, one end in the cloth feed direction (X-axis direction) is connected to the vertical feed mechanism 60 </ b> B, and the other end is connected to the horizontal feed arm 43. Further, a feed dog 31 is fixedly installed at the upper part of the intermediate position in the longitudinal direction of the feed base 32.
Thus, the feed base 32 is given a reciprocating drive force in the vertical direction from one end thereof, and a reciprocating drive force in the feed direction is given from the other end in the same cycle. Then, by combining these reciprocating driving forces, an ellipse motion is performed along the XZ plane. The feed dog 31 also performs an ellipse motion along with the feed base 32, and the tip of the feed dog 31 protrudes upward from the opening of the needle plate 11 when moving along the upper region of the ellipse motion trajectory. It is possible to send.

[Vertical feed mechanism]
FIG. 3 is a perspective view of the vertical feed mechanism 60B, and FIGS. 4 to 6 are operation explanatory views of the vertical feed mechanism 60B.
The vertical feed mechanism 60B is connected to the vertical feed motor 66 serving as a drive source for the reciprocating operation in the vertical direction (Z-axis direction) with respect to the feed base 32, and is connected to the output shaft of the vertical feed motor 66 to perform a rotation operation. One link 61B, a second link 62B having one end connected to the rotating end of the first link 61B, a third link 63B having one end connected to the other end of the second link 62B, and a third A rotation shaft 67 coupled to the other end of the link 63B and fixed in position within the sewing machine frame; a fourth link 64 coupled to the third link 63B via the rotation shaft 67; A fifth link 65 having one end connected to the rotating end of the four links 64 and the other end connected to one end of the feed base 32 is provided.
In addition, it can be easily considered to change to a configuration using a motor, an eccentric cam, and a link, or a configuration using a motor, a rack, and a pinion instead of the vertical feed mechanism 60B.

The vertical feed motor 66 is disposed at the end on the needle plate 11 side in the Y-axis direction in the sewing machine bed portion, and is spaced apart from the feed adjustment motor 57 of the feed adjustment mechanism 50 described above in the Y-axis direction. These motors 57 and 66 both require a large installation space, but are arranged in the sewing machine bed portion so as to be separated from each other in the longitudinal direction, so that the space between them can be changed to other configurations of the sewing machine, for example, As with the motor, it is possible to secure an installation space for a solenoid that is a drive source of the yarn trimming device 14 that requires a large installation space.
The vertical feed motor 66 is arranged with its output shaft along the Y-axis direction.

Further, the vertical feed motor 66 uses a motor having the same specification and the same performance as the feed adjustment motor 57 described above, but having the same model and type.
Thereby, it is possible to share the motor and its peripheral members, and it is possible to reduce costs and improve maintainability.

The first link 61 </ b> B is fixedly supported by the output shaft of the vertical feed motor 66 at the base end that is the center of rotation.
On the other hand, the other end of the third link 63B is fixedly supported by a rotating shaft 67 that is rotatably supported by a frame of the sewing machine bed portion.
The pivot end of the first link 61B and the pivot end of the third link 63B are connected to one end and the other end of the second link 62B so as to be rotatable about the Y axis.
And these 1st-3rd links 61B-63B are the states in which the 1st link 61B is substantially parallel to the Z-axis direction, and the rotation edge part has faced upwards, as shown in FIG. When the link 63B is substantially parallel to the Z-axis direction and the rotation end thereof is directed downward, the second link 62B has a respective length so that the second link 62B is in a horizontal state substantially parallel to the X-axis direction. Is set.

Accordingly, when the output shaft of the vertical feed motor 66 is the shaft angle (0 °) shown in FIG. 4, the first link 61B and the second link 62B are 90 degrees (right angle). This state is the “origin” in the link row composed of the first to third links 61B to 63B.
At the shaft angle that is the “origin”, the height of the feed dog 31 coincides with the height of the upper surface of the needle plate 11.
Further, when the vertical feed motor 66 is rotationally driven in the reverse direction (counterclockwise) as shown in FIG. 5 with respect to the axis angle serving as the “origin”, the feed dog 31 rises from the upper surface of the needle plate 11, 6, when the vertical feed motor 66 is rotationally driven in the forward direction (clockwise), the feed dog 31 is lowered from the upper surface of the needle plate 11.
In the sewing machine 100, the control device 90 has a maximum of the first link 61B and the second link 62B arranged on the same straight line with respect to the vertical feed motor 66 for a feed operation by the feed dog 31. Operation control is performed in which the reciprocating rotation in the forward and reverse directions is performed once within an angle range that does not reach the output shaft angle in the extended state (for example, the origin ± 10 °).

  Thus, the link row composed of the first to third links 61B to 63B maintains the rotation operation of the vertical feed motor 66 and the application of the vertical motion to the feed base 32 at the same frequency, so that the horizontal direction Compared with the case where the reciprocating motion of feeding is applied by a motor independent of the sewing machine motor 16, the reciprocating stroke is small, and the followability to high-speed rotation sewing is excellent. In particular, when the vertical feed motor 66 is driven within a range including an axial angle at which the first link 61B and the second link 62B form a right angle, the reciprocating stroke can be further reduced, and high-speed rotation sewing can be achieved. Can be further improved.

Further, the fourth link 64 is pivoted integrally with the third link 63B because the base end is fixed to the pivot shaft 67 in a state substantially along the X-axis direction.
The fifth link 65 has one end connected to the rotating end of the fourth link 64 and the other end connected to one end of the feed base 32 in a state substantially along the Z-axis direction. The vertical movement can be transmitted to the feed base 32 via the fifth link 65 by the rotation of the fourth link 64.

[Thread trimming device]
The thread trimming device 14 is provided with a fixed knife and a moving knife arranged between the feed dog 31 and the shuttle 12, a cam provided on the lower shaft 33, and engages with the cam to give a cutting operation to the moving knife. A cam roller and a solenoid for engaging the cam roller with the cam are provided. The solenoid is operated by the control of the control device 90, and the cam roller is engaged with the cam by the operation of the solenoid to transmit the reciprocating cutting operation to the moving knife, and the upper thread and lower thread are cooperated by the moving knife and the fixed knife. Cut the yarn.

[Sewing machine control system]
A control system of the sewing machine 100 is shown in a block diagram of FIG. As shown in FIG. 7, the sewing machine 100 includes a control device 90 that controls the operation of each component. The control device 90 is connected to a sewing machine motor 16, a feed adjustment motor 57, and a vertical feed motor 66 via respective motor drive circuits 16a, 57a, 66a.
Further, the sewing machine motor 16 is provided with an encoder 161 for detecting the number of rotations thereof, and this encoder 161 is also connected to the control device 90 via a motor drive circuit 16a.
The control device 90 is connected to the thread trimming device 14, and the control device 90 controls a solenoid that is driven when the thread trimming is executed.

The control device 90 includes a CPU 91, a ROM 92, a RAM 93, and an EEPROM 94 (EEPROM is a registered trademark), and executes various operation controls to be described later.
Further, an operation input unit 96 for inputting selection, execution, and setting of various operation controls for the feeding device 30 to be described later is connected to the control device 90 via an interface 97.

[Feeder operation control (standard trajectory pattern)]
In the sewing machine 100, since the vertical feed motor 66 performs the vertical reciprocation of the feed dog 31 independently of the sewing machine motor 16, by controlling the vertical feed motor 66, the trajectory of the circular movement of the feed dog 31 is arbitrary. It is possible to change to
FIG. 8 shows a trajectory of a reference shape when normal feeding is performed. In FIG. 8, the horizontal axis indicates the position of the feed dog 31 in the X-axis direction, and the vertical axis indicates the position of the feed dog 31 in the Z-axis direction. The left side of the horizontal axis is the downstream side in the feed direction, and the position where the horizontal axis is 0 is the needle drop position. Further, the position where the vertical axis is 0 is the height of the upper surface of the needle plate 11 (the same applies to FIGS. 10 and 12 described later).
In this reference-form trajectory, the ellipse is substantially symmetrical vertically with respect to the upper surface of the needle plate 11. In addition, the range of the spindle angle in which the tooth tip (upper end) of the feed dog 31 is located at a position higher than the upper surface of the needle plate 11 is defined as a “feed section”.

The control device 90 holds in the EEPROM 94 locus pattern data in which the axis angle of the vertical feed motor 66 for positioning the feed dog 31 at each position of the dots arranged on the oval locus is associated with the main shaft angle. doing.
The shaft angle of the feed adjustment motor 57 determines the width (sewing pitch) of the horizontal axis of the oval locus. Therefore, when the sewing pitch is set from the operation input unit 96, the feed dog is rotating around. Maintains the shaft angle of the feed adjusting motor 57 at which the sewing pitch becomes the set value.

  Then, the control device 90 reads the locus pattern data into the RAM 93 at the time of sewing, monitors the output of the encoder 161, and sets the vertical feed motor 66 as the locus pattern data every time a predetermined spindle angle is reached. The feed dog 31 is moved around in accordance with the locus of FIG.

FIG. 9 shows the relationship between the shaft angle (vertical axis) and the main shaft angle (horizontal axis) of the vertical feed motor 66 obtained from the reference-form trajectory.
The change in the shaft angle of the vertical feed motor 66 in the reference trace pattern of FIG. 8 is a sine curve of approximately 2π as shown in FIG.
Since the feed dog reciprocates up and down once in one reciprocal rotation in the forward and reverse directions, there are two patterns of trajectory pattern data obtained by clockwise rotation and trajectory pattern data obtained by counterclockwise rotation. There is no need to prepare a type, and only one type of trajectory pattern data is stored.

[Change feed dog height]
As described above, the power for raising and lowering the feed dog 31 of the sewing machine 100 is not obtained by mechanically linking the spindle to the spindle as in the prior art, but the actuator prepared for the vertical movement of the feed dog 31 in the embodiment, It is obtained from a vertical feed motor 66 by a pulse motor.
The spindle rotating sewing machine motor 16 and the vertical feed motor 66 are collectively controlled by the CPU 91 so that the spindle rotational speed information can be used for the feed dog vertical actuator control.
With this configuration, the height of the feed dog 31 can be changed independently even while the main shaft is rotating.

  Here, the sewing speed, that is, the spindle rotation speed is detected based on the amount of depression of the sewing machine pedal 101 or the rotation speed of the sewing machine motor 16 by the encoder 161 as shown in FIG.

[Operation control of feeder]
The trajectory of the feed dog when the spindle rotation speed is 2000 rpm is the same as the trajectory of the reference shape in the case of performing normal feed shown in FIG.
At low speeds, the feed dog strikes the presser vigorously, and jumping that raises the presser does not occur. Therefore, it is not necessary to correct the reference-form trajectory.
The control device 90 holds in the EEPROM 94 locus pattern data in which the axis angle of the vertical feed motor 66 for positioning the feed dog 31 at each position of the dots arranged on the oval locus is associated with the main shaft angle. doing.

  Then, when it is determined that the main shaft rotation is low speed (for example, 0 to 2500 rpm), the control device 90 performs control so that the vertical feed motor 66 is positioned at the shaft angle determined in the trajectory pattern data every time a predetermined main shaft angle is reached. .

  Further, since the relationship between the axis angle (vertical axis) and the upper axis angle (horizontal axis) of the vertical feed motor 66 is the same as that of the reference form, it is as shown in FIG.

FIG. 10 is a deformation locus of the feed dog when the spindle rotation speed is 3000 rpm. This trajectory is a trajectory in which the height of the feed dog 31 cutting edge in the feed section is higher than that of the reference trajectory. When the feed dog 31 circulates along this locus, the height of the cutting edge of the feed dog 31 passes through a position higher than that of the reference locus, so that, for example, presser jumping occurs as the rotational speed of the spindle increases. However, the gap between the presser and the feed dog can be reduced, and the sewing operation can be performed satisfactorily while maintaining an appropriate presser pressure.
The control device 90 holds in the EEPROM 94 locus pattern data in which the axis angle of the vertical feed motor 66 for positioning the feed dog 31 at each position of the dots arranged on the oval locus is associated with the main shaft angle. doing.

  Then, when it is determined that the spindle rotation speed is 3000 rpm, the control device 90 performs correction control so that the vertical feed motor 66 is positioned at the axis angle defined in the locus pattern data for 3000 rpm every time a predetermined spindle angle is reached.

  FIG. 11 shows the relationship between the axis angle (vertical axis) of the vertical feed motor 66 and the upper axis angle (horizontal axis) of the trajectory pattern data obtained by the rotation of the deformation trajectory of FIG. It drives so that the height of the blade edge of the feed dog 31 may become high with respect to a reference-form locus pattern.

FIG. 12 shows the deformation trajectory of the feed dog when the spindle rotation speed is 4000 rpm. This trajectory is a trajectory in which the height of the feed dog 31 cutting edge in the feed section is further higher than the trajectory at 3000 rpm shown in FIG. If the feed dog 31 circulates along this trajectory, the height of the blade tip of the feed dog 31 passes through a position higher than that at 3000 rpm. The gap between the feed dog and the feed dog can be reduced, and the sewing operation can be performed satisfactorily while maintaining an appropriate pressing pressure.
The control device 90 holds in the EEPROM 94 locus pattern data in which the axis angle of the vertical feed motor 66 for positioning the feed dog 31 at each position of the dots arranged on the oval locus is associated with the main shaft angle. doing.

  When it is determined that the main shaft rotation is 4000 rpm, the control device 90 controls the vertical feed motor 66 to be positioned at the shaft angle defined in the trajectory pattern data for 4000 rpm every time a predetermined main shaft angle is reached.

  FIG. 13 shows the relationship between the axis angle (vertical axis) of the vertical feed motor 66 and the upper axis angle (horizontal axis) of the trajectory pattern data obtained by the rotation of the deformation trajectory of FIG. It drives so that the height of the blade edge of the feed dog 31 may become still higher with respect to the locus pattern at 3000 rpm.

As described above, the control device 90 holds, in the EEPROM 94, the locus pattern data in which the shaft angle of the vertical feed motor 66 for positioning the feed dog 31 is recorded in association with the spindle angle in accordance with the spindle rotational speed. .
When the spindle rotates at high speed, the height of the feed dog 31 in the feed section is corrected according to the speed so that the jumping of the presser occurs when the rotation speed of the spindle increases. However, the optimum pressure can be maintained.
Further, since it is not necessary to correct the height of the feed dog 13 in the feed section when the spindle speed is low, the pressing pressure can be kept optimal even when the spindle low speed operation and the high speed operation are mixed in one sewing. it can.

[Effects of the embodiment]
As described above, according to the sewing machine 100 of the embodiment, the horizontal feed mechanism 40 includes the feed adjustment motor 57 that changes and adjusts the pitch of the horizontal reciprocating operation with respect to the feed base 32 by the sewing machine motor 16. A control device 90 has a vertical feed motor 66 as a driving source for a reciprocating operation in the vertical direction with respect to the feed base 32, and controls the feed adjusting motor 57 and the vertical feed motor 66 to feed the sewing product by the feed dog 31. It has.
Therefore, the reciprocating motion of the feed dog 31 up and down can be arbitrarily operated without being restricted by the sewing machine motor 16, and as described above, the feed dog 31 can be moved around in a variety of trajectory patterns. It becomes possible.

Further, the reciprocating operation of the feed dog 31 in the horizontal direction can be executed for some of the various trajectory patterns described above by using another motor independent from the sewing machine motor 16 as a drive source. However, since the horizontal reciprocating stroke is much larger than the vertical reciprocating stroke, a motor having a lower inertia and a larger output is required. In addition, since the motor tends to increase the inertia when the output increases, it is difficult to obtain such a motor in practice. Therefore, it is necessary to reduce the sewing speed and feed the motor.
On the other hand, in the sewing machine 100 of the embodiment, the driving source for the reciprocating operation in the horizontal direction of the feed dog 31 is the sewing motor 16, and the driving source for the reciprocating operation in the vertical direction of the feed dog 31 is the vertical feeding motor 66. The vertical movement of the feed dog 31 may be reciprocated within a narrow range of reciprocating strokes, and a small and low-output one that is easily available can be used as the vertical feed motor 66. And it can feed with more various locus patterns.
In addition, since the adjustment of the sewing pitch uses the conventional configuration of the feed adjusting body 55 and the feed adjusting motor 57, the reliability and stability are high and the accuracy is high.

In particular, the control device 90 controls the vertical feed motor 66 so that the height of the feed dog 31 in the feed section is higher than that during low speed rotation when the spindle rotates at high speed. The height / feed locus of 31 can be arbitrarily changed by software, and the feed locus can be changed so that the height of the feed dog 31 is increased according to the spindle speed.
Therefore, even if pressing jumping occurs during high-speed rotation of the spindle, the optimal pressing pressure can be maintained.
Further, since it is not necessary to change the height of the feed dog 13 in the feed section when the spindle speed is low, the pressing pressure can be kept optimal even when the spindle low speed operation and high speed operation are mixed in one sewing. Can do.

[Others]
Further, in the embodiment of the present invention, the lock stitch sewing machine is illustrated, but the feeding device 30 can be applied to any type of sewing machine that feeds a sewing object with a feed dog.
Moreover, although the case where the first link 61B was directly attached to and connected to the output shaft of the vertical feed motor 66 was illustrated in the embodiment of the above invention, the output shaft of the vertical feed motor 66 and the first link 61B are exemplified. You may connect indirectly by interposing a transmission member or a transmission mechanism in between.
In addition, it is needless to say that other specific detailed structures can be appropriately changed.

The feed dog height change control during high-speed rotation described above is detected by preparing a plurality of trajectory patterns in which the height of the feed dog in the upper half of the feed turning trajectory is increased step by step. An appropriate one may be selected from a plurality of trajectory patterns prepared in advance according to the main shaft rotation speed, and the operation control may be performed so that the feed dog 31 goes around the selected trajectory pattern.
Alternatively, a reference-form trajectory pattern as shown in FIG. 8 is prepared in advance, a reference speed corresponding thereto is determined, and based on a correction value calculated from a speed difference between the reference speed and the detected spindle rotation speed. The height of the feed dog at each point in the upper half of the feed turning trajectory in the reference trajectory pattern is corrected, and the operation control is performed so that the feed dog 31 circulates the corrected trajectory pattern. good.

11 Needle plate 14 Thread trimmer 16 Sewing machine motor 30 Feeder 31 Feed dog 32 Feed base 40 Horizontal feed mechanism 50 Feed adjustment mechanism 55 Feed adjustment body 57 Feed adjustment motor 60B Vertical feed mechanism 61B First link 61C Groove cams 62B and 62C First Two links 63A, 63B Third link 64 Fourth link 65 Fifth link 66 Vertical feed motor 67 Rotating shaft 90 Controller 100 Sewing machine 101 Sewing pedal 161 Encoder

Claims (2)

A needle up-and-down movement mechanism that moves the needle bar up and down;
A sewing machine motor as a drive source of the needle up-and-down movement mechanism;
A feed base for supporting a feed dog that feeds the workpiece on the needle plate;
A horizontal feed mechanism that obtains power from the sewing machine motor and transmits a horizontal reciprocating motion to the feed base;
In a sewing machine provided with a vertical feed mechanism that gives a reciprocating motion in the vertical direction to the feed base,
The horizontal feed mechanism has a feed adjustment motor that changes and adjusts the pitch of a horizontal reciprocating operation with respect to the feed base by the sewing machine motor,
The vertical feed mechanism has a vertical feed motor serving as a drive source for a reciprocating motion in the vertical direction with respect to the feed base,
A controller for controlling the feed adjustment motor and the vertical feed motor to perform the feed operation of the sewing product by the feed dog;
The control device controls the vertical feed motor so as to circulate the feed dog in a predetermined locus in synchronization with a rotation angle of the main shaft that is rotationally driven by the sewing machine motor, and according to a rotation speed of the main shaft. A sewing machine that controls the vertical feed motor so as to correct the trajectory of the feed dog in the feed section.   The said control apparatus controls the said up-and-down feed motor so that the locus | trajectory of the said feed dog in a feed area may become a locus higher than at the time of low speed rotation at the time of the high speed rotation of the said spindle. sewing machine.

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