JPS6366557B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a sewing machine that reduces vibration and noise by correcting the rotational balance of a motor rotor including a sewing machine element that rotates integrally with the motor rotor. It is something.

[Prior art]

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

Furthermore, 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, the heat generated by rotation is transmitted through the stator and heats the surface of the sewing machine arm, and assembly work requires a lot of labor and time. It is difficult to correct unbalanced rotation, which causes vibration and noise. It was hot.

[Summary of the invention]

This invention was made to eliminate the drawbacks of the conventional sewing machine as described above, and although the drive motor is built-in and supported within the sewing machine arm, the rotational balance of the motor rotor can be corrected. In addition to being able to reduce vibration and noise, the transmission of heat from the drive motor to the sewing machine arm can be suppressed as much as possible, and the configuration can be simplified even though it is equipped with an electromagnetic brake. The purpose is to provide a sewing machine with

[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.
FIG. 2 is a right side view of FIG. 1 with the hand pulley cover 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 rotor magnet 101
A left bracket 10 is fixed to both sides of the 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 is
Ball bearing 1 fitted into axle box 201 of arm 200
10, and a balance ring 110a is fitted therein. This balance ring 110a is connected to a sewing machine needle bar mechanism A to be described later.
The motor 10 for sewing functional element members including
The rotor 102 functions to correct the rotational balance of the rotor 102. On the other hand, the right shaft end 1
An electromagnetic brake 111 for suddenly stopping the motor 100 and a driving timing pulley 112 that drives a lower shaft 301 of the sewing machine via a belt 211, which will be described later, are installed near 03b. Here, the brake magnet 111a of the electromagnetic brake 111
The movable plate 111b is attached to the right side bracket 109 and the drive side timing pulley 112, respectively.

The motor 100 has a left shaft end 103a of a motor shaft that is manufactured and assembled individually in advance 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 axle, a flange hole 202, a mounting seat 203, and an assembling hole 204 are integrally formed, and a face plate 205 is attached to the left end. Then, the left shaft end 1 of the motor shaft 103
A sewing machine needle bar mechanism (A) is arranged at 03a. This sewing machine 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 thread take-up (not shown), and a thread take-up crank 209 that moves a thread take-up (not shown). It is composed of a crank 210 that drives a needle bar crank 208 and a thread take-up crank 209. On the other hand, a hand pulley 213 and a detector 212 for detecting the rotational speed and stop angle of the motor 100 (that is, the rotational speed and sewing machine needle stop position) of the motor 100 are fitted onto the right shaft end 104b of the motor shaft 103. On the right side, the assembly hole 204 is covered and the motor 100 and timing belt 21 are mounted.
A cover 214 covering the arm 200 is attached to the arm 200. 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 engages with the driving side timing pulley 112 and is driven to rotate at the same speed as the motor shaft 103 via the timing belt 211 that transmits rotation is attached to two ball bearings 302. 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
is engaged with the drive gear 306 and rotates at twice the speed of the motor shaft 103, rotating the hook 312 in synchronization with the vertical movement of the needle bar 206. 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
2 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. When the required sewing is completed, the motor 100 performs rapid deceleration and low-speed positioning operation based on the command from the control device in the same manner as above, the detector 212 detects a predetermined stop position, and the electromagnetic brake 111 is activated. It stops at a predetermined 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, belt) to the drive device is built-in and not exposed. Since the drive device and the main body are integrated, the sewing machine main body can be arranged and moved (up and down, rotated, etc.) with greater freedom, making it easier to adapt to automated machinery. Furthermore, as mentioned above, 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 the upper shaft of the sewing machine, which is supported by the sewing machine arm, similar to conventional sewing machines. is attached to. However, in this invention, as described above, the motor 1
Since the components of 00 are assembled and configured in advance as a single unit and then assembled into the arm 200, the following unique effects can be obtained.

(1) 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. Avoid adhesion of oil. In addition, in the motor manufacturing process, there is a balancing process to achieve the rotational balance (good balance) of the rotor, as well as 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.

(2) 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. Therefore, there is less heat transfer to the surface of the arm 200 (high temperature gradient), and the problems of the conventional device can be eliminated or at least alleviated.

(3) In the present invention, the drive motor 100 is assembled to the motor shaft 103 later in the balancing process of the rotor 102 in the manufacturing process of the drive motor 100 alone. Therefore, the needle bar 207, the balance and its operating crank 2
Since components that rotate integrally with the motor shaft 103 such as 08 to 210 or their equivalent dummies can be assembled together and the overall balance adjustment can be easily carried out at the same time, unbalanced rotation of the upper shaft of conventional sewing machines can be reliably prevented. This enables low-vibration, low-noise driving performance. Furthermore, although this is not clarified in the conventional sewing machine, in this invention, the element directly driven by the motor shaft 103, which also serves as the upper shaft of the conventional sewing machine, is the needle bar mechanism (A).
A lower shaft 301 that rotates at the same time as the motor shaft 103 is transmitted to the bed 300 by a timing belt 211 or the like, and this lower shaft 3 is connected only by a balance mechanism.
Activate the feed mechanism and thread trimming mechanism with 01,
Further, since the rotary shaft 309, which corresponds to the lower shaft of the conventional sewing machine, is driven to rotate at double speed by the gear 306, etc., 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. Also, the bed 30 of the arm 200
The joint with 0 is the timing belt 211 mentioned above.
Since it is limited to parts such as the presser foot lifting and connecting machine, it frees up space, and the operating parts such as the setting switch of the control device for automatic fastening sewing can be stored in this area.The design and operability are improved by the hand-held operation. can do.

(5) Also prevents oil leakage, which is a drawback of conventional sewing machines.
In this case, the functional elements configured in the arm 200 section are limited to the needle bar 207 and the thread take-up mechanism, so it is easy to lubricate these sliding bearings with oil-impregnated metal grease, etc., and the arm 200 section is Can solve oil leaks from.

(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 heavenly crank 209 and a balance (not shown); inertial loads such as the brake movable plate 111b, the driving side timing pulley 112, and the hand pulley 213 on the right shaft end 103b; and the tension of the timing belt 211; Naturally, the inertia load of its own rotor 102 is applied to the center of the motor shaft 106. Therefore, the motor shaft 10
Significant support points are required to ensure a given rotational stiffness of 6. However, in general, supporting systems with three or more points are extremely difficult because, as is well known, if the axial center accuracy cannot be obtained, twisting will occur, and strict machining accuracy and assembly accuracy are 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 in this, are fitted to the shaft center according to the dimensions and are fixedly supported. Therefore, 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.
Yoke (frame) 104 and right side bracket 1
09 is expected to be sufficient, but in addition, the motor 100 is fastened to the fixed support portion for the arm 200 by attaching the mounting lug 109a of the right side bracket 109 to the mounting seat 203 of the arm 200 with a bolt 113. The support rigidity of the right shaft end 103b is reinforced by the frictional force between the joint end surfaces of the mounting lug 109a and the mounting seat 203 generated by the fastening force.

〔Effect of the invention〕

As described above, according to the present invention, with the drive motor built in the sewing machine arm, the outer circumferential surface of the drive motor is partially supported, and the inner wall surface between the outer circumferential surface of the drive motor and the sewing machine arm is Since a heat insulating space is formed between the two, this space can prevent the heat generated by the drive motor from being transmitted to the sewing machine arm. This has the effect of being able to eliminate inconveniences caused by heating of the sewing machine arm. In addition, a balance ring is provided on one end of the motor shaft of the drive motor to balance the rotation of the motor rotor with respect to sewing functional elements such as a needle bar and a thread take-up that are linked to the motor shaft. The ring inevitably corrects the rotational balance of the motor rotor, and for this reason, it is necessary to correct the rotational balance of the motor rotor during assembly and manufacturing of the sewing machine and during the performance confirmation test process of the motor itself. Each operation can be performed extremely easily, and the sewing machine assembly manufacturing efficiency can be improved. Furthermore, the movable plate of the electromagnetic brake disposed at the other end of the motor shaft is provided on a timing pulley that is connected to the other end of the motor shaft and transmits power to the lower shaft of the sewing machine. There is also the effect that other members for attachment are not required, and the attachment configuration is simplified.

[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)

[Claims] 1. In a sewing machine configured such that a drive motor that independently supports a motor shaft that also serves as the upper shaft of the sewing machine is manufactured and assembled as an individual unit in advance, and then the drive motor is internally supported within the sewing machine arm, the outer circumferential surface of the drive motor and the sewing machine A motor support part that partially supports the drive motor within the sewing machine arm so that a heat insulating space is formed between the arm and the inner wall surface of the arm, and the motor support part is assembled and interlocked with one end of the motor shaft. A sewing function element such as a needle bar and a thread take-up; a balance ring provided at one end of the motor shaft to balance the rotation of the motor rotor of the drive motor with respect to the sewing function element; A sewing machine comprising: a timing pulley provided at the other end for transmitting power to the lower shaft of the sewing machine; and an electromagnetic brake provided near the movable plate provided on the timing pulley. .