JPS62176485A - Walking pressure of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Purpose of the Invention (Industrial Application Field) This invention provides an upper feed dog that faces the work cloth on the work cloth support surface from above, and the upper feed dog faces the work cloth below the work cloth. This invention relates to an upper feed device for a sewing machine that performs four-movement feed together with a lower feed dog to apply feed to a work cloth.

(Prior art) Generally, when sewing work cloth with a sewing machine equipped with this type of top feed device, if the work cloth is thick, the top feed dog separates from the work cloth at the raised position of the four-motion feed. First, there is a problem in that the work cloth is fed in a direction opposite to the feed direction.

In order to solve this problem, conventionally, as shown in Japanese Utility Model Application Publication No. 58-169862, a vertical motion amount adjusting means is provided in a vertical motion imparting mechanism for imparting vertical motion to the upper feed dog. The vertical motion given to the upper feed dog can be changed by changing the connection position of the connecting link on the setting lever constituting the adjustment means according to the thickness of the work cloth. It has been proposed that the

(Problems to be Solved by the Invention) However, in this conventional device, since the vertical movement of the upper feed dog is mechanically changed,
There were problems in that the structure was complicated and the number of parts increased, and the operation to change the setting of the vertical momentum was extremely troublesome.

In addition, in the conventional device, the lowering position of the upper feed dog in the four-movement feed is kept constant, and the raising position is changed based on the lowering position, so that the vertical motion is substantially changed. When the thickness of the work cloth is large, there is a problem that the vertical movement of the four-movement feed of the upper feed dog becomes large, making it impossible to follow high-speed operation.

Structure of the Invention (Problems to be Solved by the Invention) The present invention has been made by paying attention to the above-mentioned problems.
an upper feed dog 16 to which a four-movement feed is applied as the sewing machine main shaft 2 rotates in order to apply feed to the upper work cloth W;
Cloth thickness detecting means 25 outputs a detection signal corresponding to the thickness of the work cloth W;
A vertical position changing means 26 for changing the vertical position of 6 is provided.

(Function) Therefore, in the upper feed device of the sewing machine of the present invention, the thickness of the workpiece cloth is detected by the cloth thickness detection means, and the vertical position of the upper feed dog is automatically adjusted by the vertical position changing means based on the detection signal. The structure is simple and the number of parts can be reduced, and there is no need to manually change the upper and lower positions of the upper feed dog according to the thickness of the fabric, making it easier to handle. Furthermore, there is no change in the vertical movement of the four-motion feed of the upper feed dog, and it is possible to sufficiently follow high-speed operation.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Now, in the sewing machine of this embodiment, the sewing machine frame 1
A sewing machine main shaft 2 is rotatably supported inside and is rotationally driven by a motor (not shown). A support shaft 3 is rotatably supported within the sewing machine frame 1 so as to extend parallel to the main shaft 2 of the sewing machine. A presser arm 4 is fixed at its base end to the support shaft 3 so as to be able to rotate integrally with the support shaft 3, and a presser arm 4 is provided at its tip for pressing the work cloth W toward the work cloth support surface 5 on the sewing machine frame. A presser foot 6 is attached. At the center of the upper part of the presser foot 4, a presser foot 6 is attached by applying a pressing force to rotate the presser foot 4 in the clockwise direction in FIG.
A predetermined presser foot pressure is applied to the presser foot.

A vertical feed shaft 9 and a horizontal feed shaft 10 are each rotatably supported within the sewing machine frame 1 so as to extend parallel to the sewing machine main shaft 2. Due to the action of the vertical feed eccentric wheel and the horizontal feed eccentric wheel (not shown), they are rotated reciprocally through respective eccentric wheel holders that engage with them. A vertical feed arm 11 is fixed to the vertical feed shaft 9, and a connecting link 12 is rotatably attached to the tip of the arm 11 by a pin 13.

At the upper end of the connecting link 12, an upper feed bar 14 is rotatably supported by a bin 15 at approximately the center thereof, and an upper feed dog 16 having teeth on the lower surface is attached to one end thereof, and an upper feed dog 16 having teeth on the lower surface is attached to the other end. An actuation piece 14a is formed. A press rod 17 is engaged with the upper end of the upper feed table 14 through the engagement opening 11a at its lower end, and the spring force of the press spring 18 provided on the press rod 17 moves the upper feed table 14 to the first position.
The upper feed dog 16 is urged toward the workpiece cloth W on the workpiece cloth support surface 5 by being rotationally biased in the clockwise direction in FIG.

A horizontal feed arm 20 is fixed to the horizontal feed shaft 10 so as to be rotatable together with the horizontal feed shaft 10. At the tip of the horizontal feed arm 20, a connecting link 21 has a pin 22 at one end.
The other end is rotatably connected to the upper feed table 14 via the pin 15. or,
Figure 1(a).

As shown in (b), there is a collar 1 on the upper edge of this connecting link 21.
9 are arranged. With the reciprocating rotation of the vertical feed shaft 9, a vertical movement is applied to the upper feed table 14 via the vertical feed arm 11 and the connecting link 12, and with the reciprocating rotation of the horizontal feed shaft 10, a horizontal A horizontal movement is applied to the upper feed table 14 via the feed arm 20 and the connecting link 21, so that the upper feed m16 is fed by four movements.

The sewing machine frame 1 is arranged so as to correspond to the upper feed dog 16.
Inside, a lower feed dog 23 having teeth on its upper surface is disposed so as to be retractable above the work cloth support surface 5.

Based on the rotation of the sewing machine main shaft 2, the lower feed dog 23 is moved to the upper feed dog 16 by a lower feed device (not shown).
The workpiece cloth W on the workpiece cloth support surface 5 is fed by four motions in synchronization with the workpiece cloth support surface 5 by the cooperation of both the upper and lower feed teeth 16 and 23.

A permanent magnet 24 is attached to the lower part of one end of the presser arm 4,
A Hall element 25 is disposed within the sewing machine frame 1 so as to be able to come into contact with and separate from the permanent magnet 24.
．． 25 constitutes a heavy thickness detector 37 as cloth thickness detection means. As shown by the chain line in FIG. 2, a work cloth W is interposed between the work cloth support surface 5 and the presser foot 6, and the presser arm 4 is moved up and down depending on the thickness of the work cloth W. When the cloth is moved, the heavy thickness detector 37 outputs a detection signal corresponding to the cloth thickness. A servo solenoid 26 constituting a vertical position changing means is disposed within the sewing machine frame 1, and the lower end of the armature 27 engages with the actuating piece 14a of the upper feed table 14 from above through an engagement opening 27a. There is. Then, this servo solenoid 26 is activated based on the detection signal from the heavy-duty detector 37, and the upper feed table 14 is rotated about the pin 15 as shown in FIG. The position is about to change.

Next, in the sewing machine configured as described above, the configuration of the control circuit specifically for controlling the operation of the servo solenoid 26 will be explained with reference to FIG.
PLI) 31 has a read-only memory (ROM) 3
2 and random access memory (RAM) 33 are connected. The ROM 32 stores a program for controlling the entire sewing machine, and the RAM 33 stores the operating amount of the servo solenoid 26 corresponding to the weight detection data from the weight detector 37.

Further, a heavy-weight detector 37 is connected to the CPU 31 via an input interface 34, and a detection signal from the heavy-weight detector 37 is input to the CPU 31. Further, a servo solenoid 26 is connected to the CPU 31 via an output interface 35 and a drive circuit 36, so that an operating signal is output from the CPU 31 to the servo solenoid 26.

Next, the operation of the sewing machine configured as described above will be explained.

Now, in this sewing machine, the work cloth support surface 5 and the presser foot 6
When the work cloth W is interposed between the work cloth W, the presser arm 4 is moved up and down according to the thickness of the work cloth W, and this movement is detected and a detection signal corresponding to the cloth thickness is sent from the heavy thickness detector 37 to the CPU 31. is output. Based on the detection signal, an activation signal is output from the CPLI 31 to the servo solenoid 26, and the armature t2
7 is protruded downward and the upper feed table 14 is rotated counterclockwise around the bin 15 as shown by the chain line in FIG. Can be placed in any vertical position.

In this state, when the vertical feed shaft 9 and the horizontal feed shaft 10 are reciprocated as the sewing machine main shaft 2 rotates, the vertical feed arm 11
A vertical movement is applied to the upper feed table 14 via the connecting link 12 and the horizontal feeding arm 20 and the connecting link 2.
Horizontal movement is applied to the upper feed table 14 via the upper feed dog 1, the upper feed dog 16 is fed four movements, and the feed is applied to the workpiece cloth W by the cooperation of the upper feed dog 16 and the lower feed dog 23. .

At this time, if the thickness of the work cloth W is thin, as shown in FIG.
), the upper feed dog 16 is fed in four movements at a lower position, but as the thickness of the workpiece cloth W becomes thicker, as shown in FIG. 3(b)
As shown in the figure, since the upper feed dog 16 is fed in four movements at a high position, the upper feed dog 16 is reliably separated from the work cloth at the raised position of the four movement feed, and is moved in the opposite direction to the feed direction with respect to the work cloth W. This ensures that the risk of being sent to is prevented. In addition, in this sewing machine, the vertical motion of the upper feed dog 16 during the four-movement feed is not changed, and only the vertical position of the upper feed dog 16 is changed according to the thickness of the work cloth W. Even if the weight becomes thicker, the luck of four movements is a.
m does not become large, and the cloth can be fed reliably following high-speed operation.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiment. For example, a presser foot can be used as the cloth thickness detection means. It is also possible to arbitrarily change and embody the configuration of each part without departing from the spirit of the invention, such as by providing a potentiometer operably connected to the support shaft of l14.

Effects of the Invention As detailed above, in the present invention, the thickness of the work cloth is detected by the cloth thickness detection means, and the vertical position of the upper feed dog is automatically changed by the vertical position changing means based on the detected signal. , the structure is simple and the number of parts can be reduced, and there is no need to manually change the vertical position of the upper feed dog depending on the thickness of the fabric to be processed, making handling easier. There is no change in the vertical motion of the four-movement feed of the teeth, and it has the excellent effect of being able to sufficiently follow high-speed operation.

[Brief explanation of drawings]

FIG. 1(a) is a side sectional view of the main part of a sewing machine embodying the present invention, and FIG. 1(b) is a B--B in FIG. 1(a).
Figure 2 is a partial side sectional view showing the operating state of Figure 1. Figures 3 (a) and (b) are views of the upper feed dog when the thickness of the work cloth is thin and when it is thick. FIG. 4 is a partial side cross-sectional view showing the four-movement feeding state, and is a block diagram of a control circuit for controlling the operation of the servo solenoid. ”2
...Sewing machine main shaft, 5...Working cloth support surface, 16...
Upper feed dog, 23...Lower feed dog, 26...Servo solenoid constituting vertical position changing means, 37... Heavy thickness detector as cloth thickness detection means.

Claims (1)

[Claims] 1. In cooperation with the lower feed dog (23), the work cloth support surface (5)
In order to give feed to the upper workpiece cloth (W), there is an upper feed dog (16) that gives four-movement feed according to the rotation of the sewing machine main shaft (2), and an upper feed dog (16) that gives a four-movement feed according to the thickness of the workpiece cloth (W). cloth thickness detecting means (25) for outputting a detection signal from the cloth thickness detecting means (25);
6) A top feed device for a sewing machine, comprising a top and bottom position changing means (26) for changing the top and bottom positions of the sewing machine.