JPS5845672Y2 - cloth feeding device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a sewing machine.

Generally, sewing machines are equipped with a cloth feed device consisting of a feed dog that feeds the cloth in synchronization with the vertical movement of the needle, and this cloth feed device is an essential element for both industrial sewing machines and general household sewing machines. It has become.

By the way, the cloth feed device in general home sewing machines has a small vertical movement speed of the sewing machine needle, so the cloth feed speed of the cloth feed device can be slow, but in industrial sewing machines, the vertical movement speed of the sewing machine needle is generally low. Because it is extremely fast compared to home sewing machines, a special cloth feeding device may be required in addition to this cloth feeding device.

However, in conventional special cloth feeding devices of this kind, the rotation of the main shaft for driving the sewing machine needle is decelerated by a reduction gear, and then converted into rocking motion by a crank mechanism, and the rocking motion is converted into rocking motion by a one-way clutch. A so-called mechanical cloth feeding device was used, which converts the sewing machine needle into intermittent rotational motion again, and rotates the double-feed reroller during the intermittent rotational motion. (a) When the vertical movement of the sewing machine needle becomes extremely high Due to the inertia of the one-way clutch and the cloth feed roller itself, the double feed reroller stops rotating intermittently and rotates continuously.As a result, the sewing machine needle feeds the fabric while it is stabbing the fabric, causing the sewing machine needle to (b) The durability of the cloth feeding device itself at high speed rotation depends on the high speed durability of the one-way clutch, so if the spring is damaged, the service life may be less than one month at an operating speed of 3.5Q□ rpm. (c) It is large and heavy.

(d) Since the distance between the needle and the cloth feed roller is large, there are problems such as curve sewing cannot be performed.

In response to this, the applicant has developed a so-called electronic cloth feeding device in place of this mechanical cloth feeding device.

The electronic cloth feeding device developed by the present applicant uses a step motor, which is actuated by pulses output in synchronization with the rotation of the main shaft of the sewing machine, and this operation causes the rotation of the output shaft of the step motor. The transmission is transmitted via an endless belt or the like to a roller provided on the downstream side of a cloth feeding device consisting of a feed dog, etc., and the roller is rotated in synchronization with the cloth feed operation of the feed dog and the up and down movement of the needle. It is configured to transport the cloth through rotation in cooperation with the cloth feeding operation by the feed dog.

By the way, in such an electronic cloth feeding device, the setting of the cloth feeding amount corresponding to various cloth feeding amounts using the feeding teeth is as follows.
Generally, this is done by replacing the pulley provided on the output shaft of the step motor with a pulley having a different outer diameter, or by changing the number and pulse interval of pulses supplied to the step motor.

By the way, when simply replacing the pulley, it is necessary to replace it with a bell I having a predetermined length.On the other hand, when the belt is not replaced, an idler applies a predetermined tension to the bell I. Therefore, the workability is poor and the configuration is complicated.

On the other hand, when changing the number of pulses and pulse interval, increase the resolution of rotation angle detection of the main shaft of the sewing machine, make it possible to set the number of pulses and pulse interval arbitrarily, and use a step motor with good response characteristics. However, it is difficult to say that either method is preferable since the configuration becomes complicated and expensive.

The present invention has been devised in view of the above points, and its purpose is to provide a cloth feeding device that can set the cloth feeding amount corresponding to various cloth feeding amounts by the feed dog with a simple configuration and operation. It is about providing.

Next, a preferred specific example of the present invention will be explained based on the drawings.

In FIGS. 1 to 3, a base 4 having an L-shaped planar shape is fixed near the head portion 3 of the sewing machine main body 2 mounted and fixed on the base 1, and the protruding piece 5 of this base 4 A guide block 6 is fixed to the base end on the opposite side, and a guide block 7 is fixed to the end of the protruding piece 5.

A through hole 8 extending vertically is formed in the guide block 6, and a through hole 9 similarly extending vertically and a screw hole 10 are formed in the other guide block 7. Slide rods 12 and 13 are provided in both page through holes 8 and 9 to protrude upward from a bracket 11 as a support.
is slidably inserted.

A threaded part 14 is formed at the upper end of the slide rod 13, and a nut 15 is threaded into this threaded part 14, thereby fixing the slide rod 13 and therefore the slide rod 13. The descending distance of the racket 11 can be adjusted.

In this way, the nut 15 has a stopper function and a position adjustment function, and by raising and lowering the screwing position of the nut 15, it is possible to adjust the height of the double feed reroller, which will be described later, from the base 1. If there is no reroller, it is possible to provide a slight gap between the double feed reroller and the base so that they do not come into contact with each other.

A male thread of a cylindrical member 17 having a boring portion 16 and a male thread on the outer circumferential surface is screwed into the screw hole 10,
A spring 18 is located within the boring portion 16, and the compression of the spring 18 is adjusted.
8 presses the bracket 11 downward.

Reference numeral 19 denotes a guide rod, which is inserted into the inner hollow part of the spring 18 to prevent the spring 18 from wobbling.

The bracket 11 has a horizontal plate 20 and a vertical plate 21 attached downwardly and at right angles to the horizontal plate 20. The lower ends of each are inserted and fixed with nuts 22, and the vertical plate 21 has a long hole 23, and a screw 24 inserted into the long hole 23 connects the step motor 25.
is fixed to the vertical plate 21 so that its position can be adjusted in the vertical direction.

That is, by loosening the screw 24, the step motor 25 can be set at any position in the vertical direction with respect to the vertical plate 21.

A rotating shaft 26 of the step motor 25 projects from the vertical plate 21 through a long hole 26a provided in the vertical plate 21, and a pulley 27 as a first rotating body is attached to the rotating shaft 26 in a replaceable manner. It is being

An arm 28 is integrally extended 45 degrees downward from the vertical plate 21, and a rotary shaft 29 is rotatably attached to the tip of the arm 28.
A pulley 3 serving as a second rotating body is located in the middle of the rotating shaft 29.
0 is fixedly attached, and this rotating shaft 2
A double feed reroller 31 is fixedly attached to the tip of the roller 9 by a set screw 31 a that is screwed onto the roller 31 and abuts against the shaft 29 .

An endless belt, preferably a timing belt 32, is stretched between both pulleys 27 and 30, and the rotational force of the rotating shaft 26 of the step motor 25 is transferred from the pulley 27 to the pulley 30-\ via the timing belt 32. is transmitted, causing the roller 31 to rotate.

A belt 33 that transmits rotational force from another drive device is hung around a pulley 34, and when the pulley 34 is rotated by the movement of the belt 33, the main shaft of the sewing machine fixed to the pulley 34 is rotated, and this rotation This causes the cloth feed operation by the feed dog 35 and the vertical movement of the needle 36.

A presser plate 36 is provided on the feed dog 35 and is supported by a rod 37 that moves up and down by the operation of a hand lifter, and the fabric is held between the presser plate 38 and the feed dog 35 and transferred.

39 is a pulse generator that optically or magnetically detects the rotation angle of the main shaft of the sewing machine and outputs a series of pulses.Based on the pulses from this generator 39, a pulse controller 40
outputs a predetermined number of pulses to the step motor drive circuit 41, and the drive circuit 41 uses these pulses to drive the step motor 2.
Activate 5.

When the step motor 25 is operated, its output shaft 26 is rotated, which rotates the roller 31, and the cloth held between the roller 31 and the base 1 and conveyed by the feed teeth 35 is rotated. further transported.

In a cloth feeding device including such a step motor 25 or the like, when changing the cloth feeding amount in response to a change in the cloth feeding amount of the feed dog 35, a pulley 27 a or 27b is used.

For example, the pitch cloth feed amount by the feed dog 35 is 1.2~
If it is within the range of 2.0 mm, pulley 27a is used, and if it is within the range of 1.8 to 2.6 mm or 2.2 to 3.2 mm, pulley 27 or 27b is used, respectively.

When replacing the pulley, loosen the screw 24,
The pulley is removed from the output shaft 26, a pulley of a different diameter is attached and fixed to the output shaft 26, and the step motor 25 is moved upward or upward along the elongated holes 23, 26a so that the belt 32 is stretched to a predetermined tension. The step motor 25 is moved downward to adjust and set the distance between the attached pulley and the pulley 30, and then the screw 24 is tightened to fix the step motor 25 in that position.

In addition, in such a cloth feeding device, the cloth feeding amount of the roller 31 and the cloth feeding amount of the feeding dog 35 are adjusted so that the cloth is slightly pulled toward the roller 31 side between the roller 31 and the feeding dog 35. By setting the relationship between the cloth feeding period of the roller 31 and the cloth insertion period of the needle 36, it is possible to reduce the occurrence of sagging, sticking, etc. A more favorable effect can be obtained by pulling the .

Further, the roller 31. If the linearity of sewing is impaired due to a slight difference in the cloth feeding direction and cloth feeding phase between both feed dogs 35, loosen the set screw 31a and move the roller 31 in either of the axial directions to adjust the relationship with the feed dog 35. Improving linearity can be achieved by fixing at an optimal position.

In the above specific example, the position of the step motor can be adjusted in the vertical direction, but the present invention is not limited to this.
The position may be adjustable diagonally or laterally, and in this case, the elongated hole is provided diagonally or laterally.

Furthermore, although the cloth is conveyed while being held between the rollers and the base, for example, the rollers may be omitted and the cloth may be conveyed while being held between the belt 32 and the base.

As described above, according to the present invention, the conventional cloth feeding device can be replaced without increasing the resolution of the pulse generator, without complicating the configuration of the pulse controller, and without replacing the Peru-F. The amount of cloth feed can be variably set in accordance with the amount of feed, and the position of the roller can be adjusted along the axial direction, thereby increasing the stability of straight sewing and improving the efficiency of sewing work.

That is, in the fabric feeding device of the present invention, the step motor is provided in a position-adjustable manner on a support supported by the sewing machine body, and the step motor is provided with a first motor with an endless belt stretched between it and a second rotary member. Since the rotating body is replaceably fixed to the output shaft of the step motor, it is possible to simply replace the first rotating body without changing the intermittent rotational speed of the step motor, or without replacing the endless belt. By adjusting the mounting position of the step motor to the support body, not only can the intermittent rotational speed of the second rotary body be changed, but also the second rotary body can be attached to an arm integrally extending from the support body. Since it is rotatably provided, even if the mounting position of the step motor to the support body is changed as mentioned above,
The second rotating body is maintained in the vicinity of the feed dog without any change in its position relative to the support body.

Therefore, the cloth is fed by a cloth feeding member consisting of an outer surface of an endless belt hung on a second rotary body that may be located near the feed dog, or a roller provided coaxially with the second rotary body. As a result, regardless of the cloth feed speed, the cloth feed member is always kept at the same position or distance (with respect to the cloth feed direction) near the feed dog from the sewing machine body, in other words, the needle, presser plate, or feed dog. Can be kept.

By the way, in order to perform curved stitches, etc., it is preferable to provide the cloth feed member near the feed dog. If the distance between the cloth feeding member that applies a feeding force and the feed dog that frictionally engages with the bottom surface of the work cloth and applies a cloth feeding force to the bottom surface becomes too small, the instantaneous cloth feeding by the cloth feeding member Due to the difference between the feed speed and the instantaneous cloth feed speed by the feed dog, the part of the workpiece fabric between the cloth feed member and the feed dog is likely to be significantly displaced and deformed in the cloth feeding direction, and the workpiece cloth part that does not suffer from the deformation of the workpiece. If the sewing thread is pulled strongly, the sewing thread may break at the processed fabric part, or it may bite into the processed fabric and damage the processed fabric, or new sewing thread may be pulled out from the bobbin winding, causing slack in the thread after sewing. There is a risk that this may occur.

However, when the fabric feeding device of the present invention is used, this risk is reduced because the distance between the fabric feeding member and the feeding dog is kept constant.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a preferred embodiment of the present invention, FIG. 2 is an explanatory side view of the bracket etc. shown in FIG. 1, and FIG. 3 is an explanatory view of the roller etc. shown in FIG. 1. 2... Sewing machine body, 11... Bracket, 25... Step motor, 26...
・Output shaft, 27...Pulley, 29...
Shaft, 30...Pulley, 31...Roller, 32...Timing belt.

Claims (1)

[Scope of utility model registration request] A sewing machine main body, a support supported by the sewing machine main body, a Stellaf 0 motor provided on the support so that its position can be adjusted, and a first rotating body replaceably fixed to the output shaft of the Stellaf 0 motor. , comprising a second rotating body rotatably provided on an arm extending integrally from the support body, and an endless belt suspended between the first and second rotating bodies. Cloth feeding device.