JPH0121996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an industrial sewing machine in which a drive motor can be manufactured and assembled in advance and then easily and reliably attached to a sewing machine arm.

[Prior art]

Conventionally, this type of device has a drive motor that is separately attached to the bottom of the sewing machine table and is transmitted and driven by a belt pulley, built into the sewing machine body, and the motor output shaft and sewing machine shaft are integrated and directly driven.
So-called industrial sewing machines with built-in drive motors have been proposed, but none of the previous proposals have been concrete or practical (feasible).
In fact, it has been difficult to put into practical use a small, high-performance electric motor that satisfies these requirements, and there have been no actual products.

Further, the stator of the drive motor that drives sewing functional elements such as the needle bar mechanism is directly fixed to the sewing machine arm, and the rotor is fitted to the upper shaft of the sewing machine. Therefore, there are drawbacks such as the heat generated by the rotation being transmitted through the stator and heating the surface of the sewing machine arm, the assembly work requiring a great deal of labor and time, and the unbalanced rotation being difficult to correct.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is possible to easily and accurately assemble the drive motor into the sewing machine arm after manufacturing and assembling the drive motor as an individual unit. It is an object of the present invention to provide a sewing machine that can be easily assembled and thereby dramatically improve assembly efficiency during manufacturing of the sewing machine.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front (cross-sectional) view showing the structure of the embodiment, and FIG. 2 is a right side view with the hand pulley cover of FIG. 1 removed. In the figure, 100 is a drive motor (hereinafter referred to as motor), 200 is a sewing machine arm (hereinafter referred to as arm), and 300 is a sewing machine bed.

The motor 100 includes a stator magnet 101, a rotor 102, a motor shaft 103 to which the rotor 102 is fixed, and which also serves as the upper shaft of a conventional sewing machine.
Yoke 104 holding the stator magnet 101
A left bracket 10 is fixed to both sides of this yoke 104 with bolts or the like (not shown) and supports the motor shaft 103 via ball bearings 106 and 107.
8 and a right side bracket 109.

The left shaft end 103a of the motor shaft 103 has a ball bearing 11 fitted in the shaft box 201 of the arm 200.
0, and a balance ring 110a is fitted thereon. This balance ring 110a is connected to the motor 100 with respect to sewing functional element members including a sewing machine needle bar mechanism A to be described later.
The rotor 102 functions to correct the rotational balance of the rotor 102. On the other hand, the right shaft end 10
An electromagnetic brake 111 that suddenly stops the motor 100, and a drive side timing pulley 112 that drives a sewing machine lower shaft 301 via a belt 211, which will be described later, are installed near 3b. Here, the brake magnet 111a and the movable plate 111b of the electromagnetic brake 111 are respectively attached to the right side bracket 1.
09, it is attached to the drive side timing pulley 112.

The motor 100 has a left shaft end 103a of a motor shaft that is manufactured and assembled individually in advance before assembly, and is fitted and supported via a ball bearing 110 in an shaft box 201 provided on an arm 200, which will be described later. , the left side bracket 108 fitted into the flange hole 202
It is assembled and supported on the arm 200 by the flange portion 108a of the arm 200, and the right side bracket 109 which is fixed to the plurality of mounting seats 203 of the arm 200 with bolts 113 passing through the mounting ears 109a. Therefore, as shown in FIG. 2, the mounting ears 109a and the mounting seats 203 constitute a motor support portion that partially supports the outer circumferential surface of the motor 100 in its radial direction. The motor 100 is supported such that a heat insulating space is formed between its outer peripheral surface and the inner wall surface of the sewing machine arm 200.

Next, the motor 100 is attached to the arm 200.
An axle box 201 for assembling and supporting the flange hole 202, a mounting seat 203, and an assembly hole 204 are integrally formed, and a face plate 205 is attached to the left end. Then, the left shaft end 103 of the motor shaft 103
A needle bar mechanism A is arranged at a. This needle bar mechanism A includes a needle bar 206 to which a sewing machine needle 207 is attached.
A needle bar crank 208 that moves this needle bar 206 up and down, a thread take-up crank 209 that moves a balance (not shown), and a crank 21 that drives this needle bar crank 208 and thread take-up crank 209.
It consists of 0. On the other hand, the motor shaft 103
A detector 212 for detecting the rotation speed and stop angle of the motor 100 (that is, the rotation speed of the sewing machine and the stop position of the sewing machine needle) and a hand pulley 213 are fitted to the right shaft end 104b. A cover 214 that covers the assembly hole 204 and covers the motor 100 and timing belt 211 is attached to the arm 200 on the right side. Here, the cover 214 is located between the driving timing pulley 112 and the detector 212 on the sewing machine arm 20.
It is removably attached to the right side of 0. Therefore, in this attached state, the cover 214 covers the driving timing pulley 112, the timing belt 211, the electromagnetic brake 111, and the right end of the motor 100 on the inside, and covers the right end of the motor 100 between the cover 214 and the hand pulley 213 on the outside. The detector 212 is covered. In this case, the cover 21
A projecting frame portion 214a is previously integrally formed on the outer side surface of the sensor 4, and the projecting frame portion 214a surrounds the detector 212 between the hand pulley 213 and the detector 212. Although not shown, the arm 200 is further assembled with a presser mechanism element and an upper thread adjuster similar to those of the conventional art.

Next, in the bed 300, a lower shaft 301 that is rotated at the same speed as the motor shaft 103 via the timing belt 211 that engages with the driving side timing pulley 112 and transmits rotation is attached to two ball bearings 302. is supported through. This lower shaft 30
1 includes a driven timing pulley 303 that engages with the timing belt 211, a feed actuating cam 304 that drives horizontal and vertical feed shafts 307, 308 similar to the conventional one, and a thread cutting mechanism (not shown) similar to the conventional one. Thread trimming operation cam 305 that operates
A drive gear 306 that drives a hook rotating shaft 309, which will be described later, is fitted therein. Kama rotation shaft 309
is supported by the bed 300 via bearings 310 and 311, and a hook 312 and a driven gear 313 are fitted at both left and right ends, respectively. This driven gear 313 engages with the drive gear 306 and is connected to the motor shaft 1.
03 and rotates the hook 312 at the needle bar 2.
Rotationally driven in synchronization with the vertical movement of 06. Sewing elements of a conventional sewing machine such as a throat plate 314, a feed dog table 315, and a feed arm 316 are assembled.

Next, the operation will be explained.

To explain the operation using the above-mentioned components, an electric signal corresponding to a foot operation by a worker is input to a control device (not shown) of the motor 100, and a predetermined voltage is applied to the motor 100 from the control device. The rotation of the motor 100 causes the needle bar 206 to move up and down via a crank 210 directly connected to the motor shaft 103, thereby moving a balance (not shown). At the same time, the lower shaft 301 rotates at the same speed via the timing pulleys 112, 303 and the timing belt 211, and the rotary shaft 309 rotates at double speed via the gears 306, 313. By this Kama 31
The needle bar 206 and the feed mechanism rotate and move in synchronization with the needle bar 206, and sewing operation similar to the conventional sewing operation is performed. Then, when the required sewing is completed, the motor 100 performs rapid deceleration and low-speed positioning operation based on commands from the control device in the same manner as described above, the detector 212 detects a predetermined stop position, and the electromagnetic brake 111 is activated to perform a steady positioning operation. It stops at a certain position, and at a predetermined time, thread cutting operations similar to conventional ones can be performed.

According to the above configuration, like the conventional industrial sewing machine with a built-in drive motor, the entire sewing machine including the drive device is compact and easy to install and handle. It is safe because the transmission mechanism (pulley and belt) to the drive device is built-in and not exposed. Since the drive device and main body are integrated, the sewing machine main body can be arranged and moved (up and down, rotation, etc.)
This has the effect of increasing the degree of freedom in the process and making it easier to adapt to automated machinery.

Furthermore, in conventional devices, the stator of the motor, which is a component of the built-in motor, is directly fixed to the sewing machine arm, and the rotor of the motor is mounted on the sewing machine supported by the sewing machine arm, similar to the conventional sewing machine. It is fitted onto the shaft. However, in the present invention, as described above, the components of the motor 100 are assembled in advance as an individual unit and then assembled into the arm 200, so that the following unique effects can be obtained.

In the manufacturing process of conventional sewing machines, there is usually an oil cleaning process for the purpose of removing foreign substances such as metal powder inside and smoothing out bearings and other sliding parts. I hate it. Also, in the motor manufacturing process, there is a balancing process to achieve the rotational balance (good balance) of the rotor, and the performance of the motor itself (operating characteristics,
There is a testing process to confirm (voltage-proof insulation properties, etc.). For this reason, it was extremely difficult to manufacture the conventional device, but with the present invention, each of the above operations is extremely easy.

Motors naturally generate heat due to operating losses.
For this reason, in conventional machines, the stator that generates heat (including heat transferred from the rotor) is fixedly supported directly on the sewing machine arm, which is close to the worker, which increases the temperature of the arm surface, which is dangerous and at least uncomfortable. . In contrast, in the present invention, the heat-generating motor 100 is attached to a mounting seat 203 that partially protrudes from the outer sheath of the arm 200, and an appropriate space is generally provided between the outer sheath of the motor 100 and the arm 200. Arm 2
There is less heat transfer to the 00 surface (high temperature gradient), which eliminates or at least alleviates the problems of conventional devices.

In this invention, in the balancing process of the rotor 102 in the manufacturing process of the drive motor 100 alone, the needle bar 207 balance and its operating crank 20, which are later attached to the motor shaft 103, are
Since components such as 8 to 210 that rotate integrally with the motor shaft 103 or their equivalent dummies can be assembled together and the overall balance can be easily corrected at the same time, unbalanced rotation of the upper shaft of conventional sewing machines can be reliably prevented. , low-vibration, low-noise driving performance can be obtained.

Furthermore, although none of these have been made clear in the conventional sewing machine, in this invention, the only elements that are directly driven by the motor shaft 103, which also serves as the upper shaft of the conventional sewing machine, are the needle bar mechanism A and the thread take-up mechanism, and the motor shaft 1
A lower shaft 301 that rotates at the same time as 03 is transmitted to the bed 300 by a timing belt 211, etc., and the lower shaft 301 operates the feed mechanism and thread trimming mechanism, and a gear 306 etc. is used to connect the lower shaft of the conventional sewing machine. Since the corresponding rotary shaft 309 is driven to rotate at double speed, the sewing functional elements of the conventional sewing machine in the arm 200 are minimized.

(4) Therefore, in this invention, in order to assemble the motor 100 inside the arm 200,
There is no need to increase the volume of the cylindrical portion of 0 so much compared to the conventional case.

In addition, since the joint part of the arm 200 with the bed 300 is limited to members such as the timing belt 211 and the presser foot lifting connecting rod, there is free space, and this part is used to operate the setting switch of the control device such as automatic tacking. The parts can be stored, and the design and operability can be improved by hand operation.

(5) Also prevents oil leakage, which is a drawback of conventional sewing machines.
According to this invention, the functional elements configured in the arm 200 are limited to the needle bar 207 and the balance mechanism, so it is easy to lubricate the bearings of these sliding parts with oil-impregnated metal grease, etc., and the arm 200 This can solve oil leaks from the parts.

(6) Similarly, conventional sewing machines require lubricating and lubricating the bearings that support the upper shaft, the vertical shaft gear that transmits data from the upper shaft to the lower shaft, the sliding parts of the feed operation cam, the sliding parts of the needle bar and thread take-up mechanism, etc. Since the oil supply pump for this purpose is omitted, the load torque on the motor 100 is reduced accordingly, and electric energy can be saved.

Incidentally, the motor 10 of the present invention is assembled in advance.
0 within the arm 200, the motor shaft 106 is quite long, as is clear from FIG. rod 206,
Inertial loads such as the balance crank 209 balance (not shown), inertial loads such as the brake movable plate 111b, drive side timing pulley 112, and hand pulley 213 on the right shaft end 103b, the tension of the timing belt 211, and the motor shaft. Naturally, the inertial load of its own rotor 102 is applied to the center of each rotor 106 . Therefore, the motor shaft 106
Considerable support points are required to ensure a given rotational stiffness. However, in general, supporting systems with three or more points are extremely difficult because, as is well known, if the axial center accuracy is not achieved, twisting will occur, and strict machining and assembly accuracy is required.

The present invention solves this problem by implementing the following measures. That is, the motor shaft 103 is supported at two points relative to the motor 100 by two ball bearings 106 and 107, and the entire motor 100 is supported by the arm 200.
On the other hand, two points, the axle box 201 and the flange hole 202, which are formed therein, are dimensioned and fit onto the shaft center for fixed support. Therefore, the machining and assembly accuracy can be performed at the conventional normal level, and it is clear that the left shaft end 103a has sufficient shaft rigidity, and the right shaft end 103b has relatively high rigidity.
It is expected that this will be sufficient since it is supported by the 0 yoke (frame) 104 and the right side bracket 109.
Furthermore, the arm 200 of the motor 100 is fastened to the fixed support portion by the right side bracket 109.
mounting ears 109a and mounting seats 203 of the arm 200
are fixed with bolts 113, and the mounting ear 109a and mounting seat 203 generated by the fastening force are
The support rigidity of the right shaft end portion 103b is reinforced by the frictional force of the joint end surface.

〔Effect of the invention〕

As described above, according to the present invention, the inner wall of the sewing machine arm in which the drive motor is built-in and supported has a flange hole that fits and supports the outer wall on one end of the drive motor, and a flange hole that fits and supports the drive motor at a position spaced from the flange hole. An axle box into which one end side of the motor shaft of the motor is rotatably inserted and supported is provided, and the drive motor is supported at two points in a centered state within the sewing machine arm by these flange holes and the axle box. Therefore, when assembling the drive motor into the sewing machine arm, all one has to do is insert and support one end of the motor shaft into the shaft box, and fit the outer wall of one end of the drive motor into the flange hole. Then, the axis of the drive motor is inevitably aligned within the sewing machine arm, and the drive motor is reliably assembled at a predetermined position within the sewing machine arm. Therefore, the work of assembling the drive motor can be carried out very simply, efficiently, and with high precision, and there is an effect that the efficiency of assembling the sewing machine is greatly improved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of one embodiment of the present invention;
The figure is a right side view with the hand pulley cover of FIG. 1 removed. 100... Drive motor, 102... Rotor, 1
03...Motor shaft, 200...Sewing machine arm, 2
06...Needle bar, 300...Sewing machine bed, 302
...Kama.

Claims (1)

[Scope of Claims] 1. In a sewing machine in which a drive motor that independently supports a motor shaft that also serves as an upper shaft of the sewing machine is manufactured and assembled as an individual unit in advance, and then the drive motor is incorporated and supported within a sewing machine arm, the inner wall of the sewing machine arm a flange hole provided in the flange hole for fitting and supporting the outer wall portion of the one end side of the drive motor; and a flange hole provided in the inner wall portion of the sewing machine arm spaced apart from the flange hole to rotatably insert and support the one end side of the motor shaft. 1. A sewing machine comprising: an axle box that allows the drive motor to be supported at two points within the sewing machine arm in a centered manner by the flange hole and the axle box. 2 The drive motor has a pair of left and right support brackets at both ends, the left side support bracket is fitted and supported in the flange hole, and the right side support bracket is fitted with a bolt or the like to a mounting ear provided inside the sewing machine arm. 2. The sewing machine according to claim 1, wherein the sewing machine is fixed with a.