JP2003062372A - Frame driving mechanism for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease error of movement of a driving frame. SOLUTION: The Y-direction driving mechanism 8 of the driving frame 7 of a sewing machine is freely slidably supported in the Y-direction and is provided with a movable part 20 connected with the driving frame 7, a pair of pulleys 21 and 22 freely rotatably supported at an interval in the Y-direction and a belt part 23 wound and hung on both pulleys 21 and 22 and connected with the movable part 20. The belt part 23 whose wound and hung parts on both pulleys 21 and 22 when both pulleys 21 and 22 are rotated are constituted of timing belts 27 as highly flexible members, and parts which are not wound and hung on both pulleys 21 and 22 are constituted of plate-like bodies 28 (e.g. a steel material, an aluminum material) as highly rigid members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame drive mechanism for driving a drive frame of a sewing machine. In the sewing machine, the left-right direction is conventionally referred to as the X direction (or the V direction), and the front-rear direction is referred to as the Y direction (or the H direction).

[0002]

2. Description of the Related Art An example of a conventional frame driving mechanism for a sewing machine is a Y-direction driving mechanism in a multi-head sewing machine that drives a rectangular frame-shaped driving frame placed on a table in the Y direction.
As shown in FIG. 5, the Y-direction drive mechanism 80 includes a front base 81 and a rear base 81 arranged in a row in the front-rear direction in the Y direction with a lower shaft 96 for driving a shuttle (not shown) built in the bed 95 interposed therebetween. A side base 82, a front movable part 83 and a rear movable part 84 slidably supported in the Y direction on the bases 81, 82, respectively, and a connecting member 85 for connecting the movable parts 83, 84.
And a driven pulley 86 and a drive pulley 87 that are rotatably supported in the front and rear of the rear movable portion 84, and are wound around both pulleys 86 and 87, and the rear movable portion 84
And a timing belt 88 connected to the front and rear of the. The front movable portion 83 and the rear movable portion 84 are engaged with the front frame piece 90 and the rear frame side 91 of the drive frame via the engagement rollers 89, respectively. A drive motor 92 is connected to the drive pulley 87. Then, the driving force of the driving motor 92 is transmitted to the rear movable portion 84 via the driving pulley 87, the driven pulley 86, and the timing belt 88. Further, the driving force transmitted to the rear movable portion 84 is transmitted to the front movable portion 83 via the connecting member 85.

[0003]

However, the front movable portion 83 is connected to the rear movable portion 8 via the connecting member 85.
Since it is configured to be driven following 4, the deformation of the connecting member 85 or the like causes a relative movement error between the front movable portion 83 and the rear movable portion 84.

It is assumed that the driven pulley 86 is arranged on the front side of the front base 81, the drive pulley 87 is arranged on the rear side of the rear base 82, and the front end side and the rear end side of the timing belt 88 are respectively moved to the front movable parts. By connecting to 83 and the rear movable portion 84, the relative movement error can be eliminated. However, the timing belt 88
Is mainly composed of rubber or soft resin and has the drawback of expanding and contracting. In some cases, wires extending in the belt length direction are embedded to reduce the amount of expansion and contraction.
It still expands and contracts. In particular, when the distance between the driven pulley 86 and the drive pulley 87 becomes wider, the amount of expansion and contraction of the timing belt 88 increases accordingly, and the driven pulley 86 rotates relative to the rotation of the drive pulley 87 and the front movable portion 83 and the rear movable portion 84. There is a problem in that the error in the movement of is increased.

An object of the present invention is to solve the above problems and to provide a frame driving mechanism for a sewing machine which can reduce the movement error of the driving frame.

[0006]

In order to achieve the above object, a frame driving mechanism of a sewing machine according to the present invention includes a movable portion slidably supported in the driving direction and connected to the driving frame, and the driving direction. In a frame drive mechanism of a sewing machine, which is provided with a pair of pulleys rotatably supported at a distance from each other, and a belt portion wound around the pulleys and connected to the movable portion, the belt portion is The portion that does not wind around the pulley when the pulley rotates is composed of a member having high rigidity.

Further, the frame driving mechanism of the sewing machine of the present invention is slidably supported in the driving direction, and is also rotatably supported with a movable portion connected to the driving frame and spaced from each other in the driving direction. In a frame drive mechanism of a sewing machine including a pair of pulleys and a belt portion that is wound around the pulleys and that is connected to the movable portion, the belt portion is wound around the pulleys when the pulleys rotate. The part without is reinforced by a member having high rigidity.

The drive frame is formed in a rectangular frame shape,
An example is shown in which the movable portion is engaged with frame pieces on both sides in the driving direction of the drive frame, and the belt portion is connected to both end sides of the movable portion in the driving direction.

[0009]

1 to 3 show a frame driving mechanism of a multi-head sewing machine according to an embodiment of the present invention.
The sewing machine 1 includes a table 3 supported on a machine frame 2 substantially horizontally, a plurality of beds 4 arranged in a row in the X direction of the machine frame 2,
The sewing machine heads 5 arranged in the X direction above the table 3 corresponding to the bed 4, the drive frame 7 placed on the table 3, and the drive frame 7 supported by the machine frame 2 from below. A Y-direction drive mechanism 8 as a frame drive mechanism of the present invention that drives in the Y-direction and an X-direction drive mechanism 9 that is supported by the machine frame 2 and that drives the drive frame 7 in the X-direction from below are provided. . As is well known, by the cooperation of the needle 10 that is vertically reciprocally driven by the sewing machine head 5 and the shuttle (not shown) that is rotationally driven by the bed 4,
The work cloth stretched and held by the drive frame 7 is sewn.

The drive frame 7 includes a pair of front and rear frame sides 7a and 7b extending in the X direction, and a pair of left and right frame sides 7c extending in the Y direction.
7d is formed in a rectangular frame shape. Frame piece 7a,
7b is driven by the Y-direction drive mechanism 8, and the frame piece 7d is driven by the X-direction drive mechanism 9.

The Y-direction drive mechanism 8 sandwiches a cylindrical rail base 15 supported by the machine frame 2 and extending in the Y-direction, and a lower shaft 16 for driving a shuttle (not shown) built in the bed 4 between the rails. A front rail 17 and a rear rail 18 arranged in a row in the front-rear direction in the Y direction on the upper surface of the base 15, and a front rail 17 and a rear rail 18 each having a front end and a rear end slidably supported respectively. The part 20, the driven pulley 21 and the drive pulley 22 that are rotatably supported in the front and rear of the rail base 15 at intervals in the Y direction, and the rail base 15.
It is wound around the pulleys 21 and 22 via the inside of the rail, and both ends of the movable portion 2 are above the rail base 15.
The belt portion 23 has a loop shape by being connected to the front and rear sides of 0. A pair of engagement rollers 25 are provided at the front end and the rear end of the movable part 20, respectively, and the front frame piece 7a and the rear frame piece 7b of the drive frame 7 are arranged in the X direction relative to the engagement rollers 25, respectively. It is movably engaged. A drive motor 30 is connected to the drive pulley 22. Then, the driving force of the drive motor 30 is transmitted to the movable portion 20 via the drive pulley 22, the driven pulley 21, and the belt portion 23.

The belt portion 23 is constructed by a timing belt 27, which is a member having high flexibility, around which the pulleys 21 and 22 are wound when the pulleys 21 and 22 are rotated, and is wound around the pulleys 21 and 22. The non-existing portion is constituted by a plate-like body 28 (for example, a steel material or an aluminum material) as a member having high rigidity. In this example, the timing belt 27 is mainly made of rubber or resin, and a wire extending in the belt length direction for preventing expansion and contraction is embedded therein. The plate-like body 28 is the rail base 15
It is movably supported in the Y direction by a guide roller 29 that is rotatably supported inside and extends in the X direction.

According to the Y-direction drive mechanism 8 of the sewing machine configured as described above, the front and rear end portions are connected to the belt portion 23 so that the drive force is directly transmitted to the front and rear end portions. Since the one movable portion 20 configured to drive the frame pieces 7a and 7b on both sides of the drive frame 7,
Unlike the prior art, both frame pieces 7a and 7b can be stably driven without relative error, and the number of parts can be reduced.

Further, the driven pulley 21 or the drive pulley 22
The portion that needs flexibility to wrap around is formed by the timing belt 27 as in the conventional case, and the portion that does not need flexibility because it does not wrap around the pulleys 21 and 22 is a highly rigid plate that does not worry about expansion and contraction. Since the belt-shaped member 28 is formed of the strip 28, it is possible to reduce the movement error due to the expansion and contraction of the belt portion 23. According to the conventional frame drive mechanism, the wider the gap between the pulleys, the longer the timing belt mainly made of rubber or soft resin and the movement error due to its expansion and contraction increases. The length of the timing belt 27, which is a highly flexible member, can be kept unchanged, so that the movement error can be prevented from increasing.

Further, for example, in comparison with a frame drive mechanism of a type in which the drive frame 7 is driven by a female screw member screwed into a ball screw or a rack meshed with a pinion, which has not been put into practical use. A frame drive mechanism of a type in which a drive frame is driven by a belt wound around a pair of pulleys, which is a target of the present invention, is generally well used. Therefore, the present invention can be easily put to practical use and can be constructed at low cost.

The present invention is not limited to the above-described embodiment, but may be embodied with various modifications as appropriate without departing from the spirit of the invention, for example, as follows. (1) As shown in FIG. 4, both pulleys 21 of the belt portion 23,
Instead of forming the portion that does not wind around 22 with the plate-like body 28, the entire length of the belt portion 23 is formed with the timing belt 27 as a highly flexible member, and the pulleys 21 and 22 of the belt portion are The reinforcing member 40 (for example, a steel material, an aluminum material, etc.) having a high rigidity is used to reinforce the portion that does not wind around. (2) To configure the Y-direction drive mechanism so as to drive the drive frame 7 from the upper side.

[0017]

As described above in detail, according to the frame driving mechanism for a sewing machine according to the inventions of claims 1 to 3, there is an excellent effect that the movement error of the drive frame can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a sewing machine including a frame drive mechanism according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a view similar to FIG. 2, showing a modification of the present invention.

FIG. 5 is a side sectional view showing a frame driving mechanism of a conventional sewing machine.

[Explanation of symbols]

1 sewing machine 7 drive frame 7a Front frame piece 7b Rear frame piece 8 Y-direction drive mechanism 17 front rail 18 Rear rail 20 Moving part 21 Driven pulley 22 Drive pulley 23 Belt 27 Timing belt 28 Plate 29 Guide roller 30 drive motor 40 Reinforcement member

Claims (3)

[Claims] 1. A movable portion slidably supported in a driving direction and coupled to a driving frame, and a pair of pulleys rotatably supported at intervals in the driving direction.
In a frame driving mechanism of a sewing machine, which is wound around both pulleys and includes a belt portion connected to the movable portion, the belt portion is rigid at a portion that does not wind around the pulley when the pulley rotates. The frame drive mechanism of the sewing machine composed of high-quality members. 2. A movable portion slidably supported in the driving direction and coupled to the driving frame, and a pair of pulleys rotatably supported at intervals in the driving direction.
In a frame driving mechanism of a sewing machine, which is wound around both pulleys and includes a belt portion connected to the movable portion, the belt portion is rigid at a portion that does not wind around the pulley when the pulley rotates. Frame drive mechanism of the sewing machine reinforced by high-quality members. 3. The drive frame is formed in a rectangular frame shape, the movable portion is engaged with frame pieces on both sides in the drive direction of the drive frame, and the belt portion is movable in the drive direction. The frame drive mechanism for a sewing machine according to claim 1, wherein the frame drive mechanism is connected to both ends of the section.