JPH0310938Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention changes the feed amount of either the upper or lower feed dog or a pair of front and rear feed dogs to change the feed amount of both feed dogs. The present invention relates to a feed amount adjusting device for a sewing machine used for sewing using a difference.

[Prior art and its problems]

In order to obtain a predetermined sewn product, it is necessary to appropriately change and adjust the feed amount of the feed dog that feeds the fabric in the sewing machine. For example, when correcting sagging or performing shirring stitches, it is necessary to perform sewing while changing the feed amount of one of the pair of feed teeth as needed. In this case, it is essential that the feed amount be adjusted with high accuracy in order to obtain high sewing quality.

For this reason, the feed amount has conventionally been adjusted and changed as follows. That is, a back lever shaft in the sewing machine is driven by a motor, and the amount of feed of the feed dog is adjusted by the rotation angle of the motor. This is employed in so-called serging machines and the like.

Also, means is employed in which the stop position of the buckle lever stopper is regulated by a motor and the buckle lever is moved to a predetermined position using a solenoid or the like to adjust the feed amount. In either case, a well-known back lever or back lever shaft for changing the feed amount or feed direction of the feed dog is operated by an actuator such as a motor to change and adjust the feed amount.

However, in any of the above cases, the feed rate is controlled by regulating the swinging movement of the feed dog through a complicated mechanism consisting of a so-called square piece, a swing, etc. There is a problem in that the relationship between the amount controlled by the actuator and the amount of displacement of the feed amount in the feed dog, which is the output, is not linear, making it difficult to control the feed amount with high precision.

For example, if you compare the feed amount of the feed dog when the motor, which is the driving source for the displacement of the back lever, is rotated 10 degrees and when it is rotated 20 degrees, you will find that even if the rotation angle of the motor changes by twice, the feed amount is not necessarily doubled. unchanged,
It becomes extremely difficult to control the motor to control the feed amount with high precision.

Furthermore, since the feed amount adjustment/change mechanism described above has a complicated structure, various plays occur, making it even more difficult to adjust and change the feed amount with high precision as required.

In this way, with the above-mentioned conventional technology, it is difficult to change the feed amount with high precision at any time to perform advanced shirring stitches or to correct for unevenness, making it difficult to obtain high-quality sewn products. It was difficult.

[Summary of the idea]

This invention makes it possible to adjust the center position of the reciprocating rotation of the frame for swinging the horizontal feed arm, which is directly connected to the feed dog and swings in the fabric feed direction, thereby adjusting the rotational angular displacement of the motor. This is intended to solve the above-mentioned conventional problems by obtaining a relationship in which the change in the feed amount of the changing feed dog is almost proportional.

That is, a feed control motor fixed to the sewing machine drives a ball screw via a coupling. As a result, the rotation base fixed to the ball screw and the slider rotatably supported by the rotation base and fitted to the movement shaft provided on the frame are moved in the direction of the movement axis by the rotation of the feed control motor. . Due to this movement, the rotating base, which is the center of reciprocating rotation of the frame, and the pivot point of the slider move, and the swinging of the link that swings the feed dog, the horizontal feed arm, the horizontal feed shaft, etc. is controlled by the feed control motor. It changes in proportion to the rotation angle, that is, the amount of movement of the rotation base and slider.

[Example of idea]

An embodiment of this invention will be described based on the drawings.

Figures 1 and 2 are views showing one embodiment of this invention, with Figure 1 being a perspective view of the main parts, and Figure 2 being a partially omitted perspective view seen from the direction of arrow A in Figure 1. .

In the figure, reference numeral 1 denotes a feed control motor fixed to a sewing machine frame (not shown), which drives a ball screw 3 via a coupling ring 2. Reference numeral 4 denotes a ball screw that is screwed into the ball screw 3, and one end of a rotating base 5, which is a member having a substantially L-shaped cross section and moves along the ball screw 3 and with the ball screw 4, is fixed.

The other end of the rotating base 5 is rotatably connected to the slider 6 at a pivot point 5a.

The slider 6 is a box-shaped member that fits into a moving shaft 7 provided on the frame 8 and is movable along this moving shaft 7. The frame 8 includes a pair of side plates 8
a, 8a, a substrate 8b, and the moving shaft 7 installed between the side plates 8a, 8a.

A link 9 is provided at the center of the board 8b of the frame 8.
The upper end of is rotatably supported. Further, the lower end of the feed rod 11 is pivotally supported at one end of the base plate 8b of the frame 8.

The upper end of the feed rod 11 is connected to the upper shaft of the sewing machine via an eccentric cam and swings up and down, causing the frame 8 to reciprocate about the pivot point 5a between the rotating base 5 and the slider 6.

The lower end of the link 9 is pivotally supported by one end of the horizontal feed arm 10, transmits the reciprocating rotation of the frame 8 to the horizontal feed arm 10, and swings this in the fabric feeding direction.

Reference numeral 12 denotes a horizontal feed shaft whose one end is fixed to the horizontal feed arm 10 and swings in the same direction as this, and has a feed table arm 13 at the other end. 14, one end is rotatably supported by the feed arm 13, and the other end 14a
is a feed table supported by a vertical feed shaft (not shown).

This feed base 14 has a feed dog 1 fixed thereto.
5 in the horizontal direction by swinging the horizontal feed shaft 12,
The fabric is fed in a predetermined direction by swinging in the vertical direction by the swinging of a vertical feed shaft (not shown).

The operation of this embodiment will be explained based on the above-described configuration.

When the sewing machine is started and the upper shaft rotates, the feed rod 11 starts moving up and down via an eccentric cam (not shown). This swinging of the feed rod 11 causes the frame 8 to move around the pivot point 5 of the rotating base 5 and the slider 6.
It rotates back and forth around a.

The reciprocating rotation of the frame 8 causes the link 9 to swing in the vertical direction. Therefore, the horizontal feed arm 10 swings about the axis of the horizontal feed shaft 12 in the fabric feeding direction. Due to this swinging of the horizontal feed shaft 12, the feed dog 15 swings in the horizontal direction via the feed bar arm 13 and the feed bar 14 to feed the fabric in a predetermined direction.

The amount of horizontal movement of the feed dog 15, that is, the feed amount, is adjusted by adjusting the position of the slider 6 on the movement axis 7 driven by the feed control motor 1.

That is, when the feed control motor 1 rotates, the ball screw 3, the ball screw 4, and the rotation base 5
The slider 6 moves in either direction of the arrow B on the movement axis 7 in the frame 8.

On the other hand, the frame 8 is rotated by the swinging of the feed rod 11, so that the shaft fulcrum 5 of the slider 6 and the rotating base 5 is
Since it swings around point a, the amplitude and phase of the swing of the frame 8 at the pivot point between the link 9 and the substrate 8b of the frame 8 change depending on the movement position of the slider 6.

That is, when the pivot point 5a of the slider 6 and the rotating base 5 is located at a position overlapping the pivot point of the link 9 and the board 8b, the frame 8
The link 9 does not swing because it swings about the pivot between the base plate 8b and the base plate 8b.

Therefore, in this position, the feed dog 15 also does not swing in the horizontal direction, so the cloth is not fed. The slider 6 moves to the pivot point 5a with the rotation base 5.
When the link 9 and the substrate 8b move from the pivot point between the link 9 and the substrate 8b, the pivot point between the link 9 and the substrate 8b starts to vibrate due to the swinging of the frame 8, and therefore the feed dog 15 also starts swinging and the cloth The sending is done.

Then, as the slider 6 moves in either direction of the arrow B and approaches one of the pair of side plates 8a, 8a of the frame 8, that is, as the pivot point 5a of the slider 6 and the rotating base 5 becomes closer to the link 9 and the base plate 8b. The amount of swing of the link 9 increases as the distance from the pivot point increases, and therefore the amount of swing of the feed dog 15, that is, the amount of feed increases.

In this way, the slider 6 and the rotating base 5
Since the distance between the pivot point 5a and the pivot points of the link 9 and the board 8b is the rotation radius of the pivot point of the link 9 and the board 8b around the pivot point 5a, the amount of movement of the slider 6, that is, the feed The amount of rotation of the control motor 1 is proportional to the amount of swing of the feed dog 15 via the link 9, the horizontal feed arm 10, the horizontal feed shaft 12, etc., that is, the amount of feed.

Therefore, by controlling the rotation angle of the feed control motor 1, the amount of swing of the feed dog, that is, the amount of cloth feed can be adjusted with high precision.

[Effect of idea]

As explained above, in this invention, since the amount of swing in the feed dog, that is, the amount of cloth feed can be changed at any time with high precision, it is possible to obtain a high-quality sewn product in crisscross stitching or the like.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part showing an embodiment of this invention, and FIG. 2 is a partially omitted perspective view as seen from direction A in FIG. 1. 1...Feed control motor, 3...Ball screw, 4...Screw screw, 5...Rotation base,
6...Slider, 7...Movement axis, 8...Frame, 9...Link, 10...Horizontal feed arm, 1
1...Feed rod, 12...Horizontal feed axis.

Claims (1)

[Scope of Claim for Utility Model Registration] A feed rod that moves up and down in conjunction with the upper shaft via a cam mechanism, a frame that pivotally supports the lower end of the feed rod at one end, one end that is pivotally supported in the center of the frame, and the other end that is pivotally supported at one end. A link that is pivotally supported by a horizontal feed arm that fits a horizontal feed shaft that drives the feed dog in a predetermined direction, a slider that is movably fitted to a moving shaft provided on the frame, and one end of which is connected to the slider. The feed rod is supported by a rotary base, and the other end is fixed to a ball screw that moves on a ball screw by the rotation of a motor. A feed rate adjusting device for a sewing machine, characterized in that a pivot point between a slider and a rotating base, which is a center of rotation of a frame that rotates reciprocatingly, is variable in the direction of the moving axis.