JP2722774B2 - Drive power transmission structure of sewing machine - Google Patents

Description

The present invention relates to a driving force transmission mechanism structure of a sewing machine, and more particularly, to a structure for transmitting a driving force of a motor or the like to an upper shaft, a lower shaft, or the like.

2. Description of the Related Art Conventionally, an AC motor or the like has been used as a device for driving a sewing machine, and this motor is usually mounted below a table of the sewing machine.

The driving force of the motor is transmitted by a belt to a pulley provided outside the arm, and transmitted to an upper shaft connected to the pulley to drive the needle bar and the like. The driving force transmitted to the upper shaft is transmitted to the lower shaft using a cam, a vertical axis, and the like, and the feed dog and the like are driven.

However, in recent years, in order to simplify and reduce the weight of the sewing machine and to reduce the loss of driving force transmission,
There has been proposed a configuration in which a motor is built in an arm of a sewing machine and a drive shaft and an upper shaft of the motor are coaxially connected.

As shown in FIG. 4, the connection between the drive shaft and the upper shaft of this motor includes a cylindrical coupling P4 that fixes the ends of the drive shaft P1 and the upper shaft P2 in its own through hole P3. used. Also,
A timing pulley P5 is externally fitted to and fixed to the drive shaft P1 of the motor adjacent to the coupling P4, and a timing belt P6 is attached to the timing pulley P5, so that the driving force of the motor is transmitted to the lower shaft.

[Problems to be Solved by the Invention] However, if the coupling P4 and the timing pulley P5 are arranged and fixed as described above, the following problems occur, which is not always preferable.

That is, for example, when removing the motor for repair or the like, the drive shaft P1 must be removed from the coupling P4. However, since the timing pulley P5 is fixed to the drive shaft P1, when removing the drive shaft P1, the timing pulley P1 and the timing belt P6 must also be removed. Therefore, when the motor is to be mounted again after the repair, the timing of the upper shaft and the lower shaft must be adjusted, and the operation is troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driving force transmission structure of a sewing machine that facilitates a work for attaching and detaching a motor to and from the sewing machine.

[Means for Solving the Problems] According to the present invention for solving the problems, a drive shaft penetrating a timing pulley and an upper shaft arranged coaxially with the drive shaft are provided in a through hole of the coupling. A driving force transmission structure of the sewing machine that transmits the driving force of the drive shaft to the lower shaft via the timing pulley and the timing belt while being fixedly connected, wherein the coupling is provided on the outer peripheral surface of the drive shaft. The gist of the present invention is a driving force transmission structure for a sewing machine, wherein the driving force transmission structure extends between the timing pulley and the inner peripheral surface of the through hole and includes a fixing portion for fixing the timing pulley to the coupling.

[Operation] In the present invention, the drive shaft and the upper shaft are coaxially connected by the coupling, and the driving force is transmitted to the upper shaft. The driving force of the drive shaft is transmitted to the lower shaft by the timing belt wrapped around the timing pulley.

Then, the coupling extends between the outer peripheral surface of the drive shaft and the inner peripheral surface of the through hole of the timing pulley, and the timing pulley is fixed to the coupling by a fixing portion. That is, the drive shaft and the timing pulley are not directly connected and fixed, but the timing pulley and the coupling are directly connected and fixed.

Therefore, when the drive shaft of the motor rotates during the normal operation of the sewing machine, the driving force of the drive shaft is transmitted to the timing pulley via the coupling, and the drive shaft, the coupling and the timing pulley rotate integrally. On the other hand, when the drive shaft is separated from the coupling for repair or the like, since the drive shaft and the timing pulley are not fixed, only the drive shaft can be pulled out. Therefore, since the work can be performed without removing the timing pulley, it is not necessary to adjust the operation timing of the sewing machine.

Example Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show an industrial sewing machine 3 in which a motor 1 is built in an arm 2.

As shown in FIG. 1, the arm 2 of the sewing machine 3 of this embodiment
Is manufactured by aluminum die-casting and has an outer wall surrounding the internal structure of the sewing machine 3.

The arm 2 can be separated into three parts like an arm lower part 4, a lid 5 and a cover 6, and the motor 1 is disposed at the end of the arm 2 on the pillar 7 side, and the other end, that is, A needle bar 30 (FIG. 2) and the like are housed on the head 8 side, and electrical components such as a thread scraper solenoid 9 are mounted outside the needle bar 30.

A cylindrical wall (sleeve) 10 is formed on the upper part of the pillar 7 so as to cover the periphery of the motor 1, and a number of inner grooves 11 are formed on the outer peripheral surface of the sleeve 10 along the longitudinal direction. Is formed. Except for the periphery of the sleeve 10, the upper portion of the arm 2 is covered with the detachable lid 5, and when the lid 5 is removed, the internal structure such as the upper shaft 12 is exposed.

A cover 6 is attached to the outside of the sleeve 10, and an outer groove 14 is provided on the outer surface of the cover 6.

Of the outer wall of the arm 2, a wall portion 15 located on the back side of the sleeve 10 slightly protrudes outward to form a slight space 16 between itself and the sleeve 10. Further, from the front side wall portion 17 of the horizontal portion of the arm 2 to the back side wall portion 18,
Support walls 20 and 21 are formed at the locations, and the support walls 20 and 21 are formed.
Notches 22, 23 between the tip of the
Are formed.

As shown in FIG. 2 (A), a timing pulley externally fitted to a drive shaft 25 is provided on the inner end 24 side of the motor 1.
The timing pulley 26 is provided with a fan 27 for introducing cooling air.

The drive shaft 25 and the upper shaft 12 are coaxially connected by a coupling 29 disposed adjacent to the timing pulley 26, and the upper shaft 12 passes through the two support walls 20, 21. It extends to the head 8 and transmits driving force to the needle bar 30 and the like.

Further, a timing belt 33 is wound around the timing pulley 26 and the timing pulley 32 of the lower shaft 31, and the driving force is transmitted to the lower shaft 31. Further, as shown in FIG. The driving force is applied to the horizontal feed shaft from the
It is transmitted to 35 and the hook shaft 36.

The coupling 29 is, as shown in FIG.
a and a thin portion 29b. The thick portion 29a has two screw holes 40 and 41 formed in the thick portion 29a.
By tightening the screws 42, 43 put in 40, 41,
The drive shaft 25 and the upper shaft 12 are connected and fixed coaxially. on the other hand,
The thin portion 29b is supported by the support wall 20 via a bearing 45, further penetrates the support wall 20, and the outer peripheral surface of the drive shaft 25 and the upper shaft 12
And the inner peripheral surface of the timing pulley 26.

The timing pulley 26 includes a main body portion 26a and a main body portion 2 of the timing pulley 26 on which the timing belt 33 is hung.
A fixing portion 26b that protrudes from 6a toward the support wall 20 side.The timing pulley 26 and the coupling 29 are connected and fixed by inserting and tightening a screw 47 into a fixing hole 46 formed in the fixing portion 26b. . That is, the timing pulley 26
Is fixed to the coupling 29, but is not directly connected to the drive shaft 25.

 With such a configuration, the following operation and effect can be obtained.

First, when the motor 1 is turned on, the drive shaft 25 rotates. Since the drive shaft 25 and the upper shaft 12 are connected by a coupling 29, and furthermore, the coupling 29 and the timing pulley 26 are connected, the drive shaft 25, the upper shaft 12, the coupling 29 and the timing pulley 26 are It rotates integrally with the rotation of the drive shaft 25. As a result, the driving force is
And transmitted to the lower shaft 31 via the timing belt 33.

When the motor 1 is taken out of the sewing machine 3 for maintenance or the like, the screw 43 on the drive shaft 25 side attached to the coupling 29 is loosened, and the drive shaft 25 is moved in the direction indicated by the arrow C.
(Fig. 3). Thereby, the motor 1
Is separated from the coupling 29, but the timing pulley 26 remains fixed to the coupling 29. When the motor 1 is mounted, the reverse operation is performed.

As described above, in the present embodiment, when the drive shaft 25 of the motor 1 is separated from the coupling 29 at the time of maintenance or the like, the timing pulley 26 does not need to be removed, so that the timing belt 33 may be left on. Therefore, the upper shaft 12 and the lower shaft
Adjustment of the timing with 31, that is, the operation of the needle bar 30 and the feed dog
There is no need to adjust the timing of the operation such as 49 (FIG. 2) again, which has the effect of significantly improving the work efficiency of disassembly and assembly.

[Effect of the Invention] In the present invention, the timing pulley is fixed to the coupling, and the timing pulley and the drive shaft are not directly connected. Therefore, when disassembling or assembling the motor, the timing belt is not loosened even if the drive shaft is taken out of the coupling. Therefore, there is no need to adjust the timing of the sewing operation of the sewing machine again, and there is an advantage that work efficiency at the time of manufacturing and maintenance is improved.

[Brief description of the drawings]

1 is an exploded perspective view showing a sewing machine according to an embodiment of the present invention,
2 (A) is an explanatory view showing the internal structure of the sewing machine from the front, FIG. 2 (B) is an explanatory view showing the internal structure of the sewing machine from the side, and FIG. 3 is an enlarged view showing the vicinity of the coupling. FIG. 4 is a sectional view showing an enlarged view of the vicinity of a conventional coupling. 1 Motor 25 Drive shaft 26, 32 Timing pulley 29 Coupling 31 Lower shaft 33 Timing belt

Claims (1)

(57) [Claims] 1. A drive shaft passing through a timing pulley and an upper shaft disposed coaxially with the drive shaft are fixedly connected in a through hole of a coupling, and are connected via the timing pulley and a timing belt. A driving force transmitting structure of the sewing machine that transmits a driving force of the driving shaft to a lower shaft, wherein the coupling extends between the outer peripheral surface of the driving shaft and the inner peripheral surface of the through hole of the timing pulley; A driving force transmission structure for a sewing machine, comprising: a fixing portion for fixing the timing pulley to the coupling.