JPS60182995A - Sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sewing machine in which the rotational balance of a motor rotor is corrected to completely reduce vibration and noise.

[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/boot, 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 drive motors have been proposed, but Kotobuki has found that none of the previous proposals have any concreteness or practicality (feasibility), and there is no need for a small, high-performance electric motor that satisfies these requirements. It was difficult to put it into practical use, and there were no actual products.

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 not completely 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 the assembly work requires a lot of labor and time. It is difficult to correct unbalanced rotation, which causes vibration and noise. was there.

[Summary of the invention]

This invention has been developed to eliminate the drawbacks of the conventional ones as described above, and by assembling a sewing function element such as a needle bar or an equivalent dummy near one end of the motor shaft, the motor rotor can be easily fixed. The purpose of the present invention is to provide a sewing machine whose rotational balance can be corrected and whose vibration and noise are completely reduced.

[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 a motor);
200 is a sewing machine arm (hereinafter referred to as arm), 300
Chills on the sewing machine bed.

The motor 100 has a stator magnet 101 and a rotor 10.
2, a motor shaft 103 to which the rotor 102 is fixed and also serves as the upper shaft of a conventional sewing machine, and the rotor magnet 101.
A yoke 104 that holds the
Left side bracket 1 supporting motor shaft 103 via 7
08, and a right side bracket 109.

The left shaft end 103a of the motor shaft 103 is as follows.

It is rotatably supported by a ball bearing 110 fitted in an axle box 201 of the arm 200, and a ring 110a is fitted therein. On the other hand, near the right shaft end 103b, an electromagnetic brake 111 for suddenly stopping the motor 100, and a driving side timing pulley 112 that drives the sewing machine lower shaft 301 via a bell 211', which will be described later, are installed. Here, the brake magnet 11 of the electromagnetic brake 111 is
1a and the movable plate 111b are respectively attached to the right side bracket 1.
09, it is attached to the drive side timing pulley 112.

The motor 100 is manufactured and assembled individually in advance before being assembled into an axle box 20 provided on an arm 200, which will be described later.
The left shaft end 103a of the motor shaft is fitted and supported by the arm 2 via the ball bearing 110, the flange part 108a of the left bracket 108 fitted into the flange hole 202, and the arm 2.
It is assembled and supported by the arm 200 with the right side bracket 109 which is fixed to the plurality of mounting seats 203 of 00 with bolts 113 passing through the mounting ears 109at.

Next, the arm 200 is integrally formed with an axle box 201 for assembling and supporting the motor 100, a flange hole 202, a mounting seat 203, and an assembly hole 204, and a face plate 205 is provided at the left end. is installed. And motor shaft 1
The left shaft end 103aVI- of 03 is connected to the sewing machine needle bar mechanism (
5) is located. Inside this sewing machine needle bar mechanism, there is a needle bar 206 to which a sewing machine needle 207 is attached, a needle bar crank 208 that moves the needle bar 206 up and down, and a personal crank 209 that moves the celestial position (not shown). It is composed of a crank 210 that drives the needle bar crank 208 and the personal crank 209. On the other hand.

Right shaft end 104bK motor 10 of the motor shaft 103
A hand pulley 213 and a detector 212 for detecting the zero rotation speed and stop angle (that is, the rotation speed of the sewing machine and the stop position of the sewing machine needle) are fitted. A cover 214 is attached to the arm 200 on the right side, which covers the assembly hole 204 and also covers the motor 100 and the timing bell (211'z).

Although not shown in the drawings, the arm 200 is further assembled with a presser mechanism element and an upper thread adjuster, which are similar to those of the prior art.

Next, the drive side timing pulley 1 is mounted on the bed 300.
12 and transmits the rotation) 2
A lower shaft 301 that is rotated at the same speed as the motor shaft 103 is supported through two ball bearings 302. The timing belt 211 is attached to this lower shaft 301.
The driven side timing pulley 303 that engages with the conventional horizontal and vertical feed shafts 307, 308'! The r drive feed operating cam 304, the thread trimming operating cam 305 (shown in the figure) that operates a thread trimming mechanism similar to the conventional one, and the drive gear 306 that drives the hook rotating shaft 309 (described later) are completely fitted. There is. The rotary shaft 309 has a bearing 310. '311
'fi: supported by the bed 300 through hooks 312. A driven gear 313 is fitted. This driven gear 313 engages with the drive gear 306,
It rotates at twice the speed of the motor shaft 103, and the hook 312 is driven to rotate 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 tooth table 315, and a feed arm 316 are assembled.

Next, the operation will be explained.

To explain the operation using the above components, the electric signal corresponding to the operator's foot operation is the control device for the motor 100! (not shown), and a predetermined voltage is applied to the motor 10 from the control device.
Applied to 0. 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, causing the person (not shown) to move.

At the same time, the timing pulleys 112, 303. The lower shaft 301 rotates at the same speed via the timing belt 211,
A rotary shaft 309 rotates at double speed through gears 306 and 313. As a result, the hook 312 and the feed mechanism completely rotate and move in synchronization with the needle bar 20G, and the 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, (1) the entire sewing machine including its 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 main body are integrated, the degree of freedom in arrangement and movement (up and down, rotation, etc.) of the sewing machine main body is increased, and it has the advantage of being easily adapted to automated machinery. As mentioned above, in conventional sewing machines, 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 supported by the sewing machine arm, similar to conventional sewing machines. It is fitted on the upper shaft.

However, in the present invention, as described above, the components of the motor 100 are assembled in advance as a single unit and then assembled into the arm 200, so that the following unique effects can be obtained.

(1) In the manufacturing process of conventional sewing machines, there is usually a process of cleaning with hot oil for the purpose of removing foreign substances such as metal powder inside and cleaning the bearings and other sliding parts. Avoid adhesion of oil. Also, in the motor manufacturing process, there is a balancing process to achieve the perfect rotational balance (balance) of the rotor.

Also, the performance of the motor itself (operating characteristics, voltage-proof insulation characteristics, etc.)
There is a testing process for confirmation. 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 operator, which increases the temperature of the arm surface.
Dangerous or at least unpleasant. In contrast, in the present invention, the heat generating motor 100 is attached to a mounting seat 203 that partially protrudes from the arm 200 outer sheath, and an appropriate space is generally provided between the motor 100 outer sheath and the arm 200 outer sheath. 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, in the process of balancing the rotor 102 in the manufacturing process of the drive motor 100 alone.

It will be assembled to the motor shaft 103 later. Therefore, the needle bar 20
7. The unbalanced rotation of the upper shaft of conventional sewing machines can be done easily by assembling parts that rotate integrally with the motor shaft 103, such as the person and its operating cranks 208 to 210, or their equivalent dummies, and at the same time making overall balance corrections. is reliably prevented, and low-vibration and low-noise driving performance can be achieved. Furthermore, although none of these are clearly defined in conventional sewing machines, in this invention, the only elements that are directly driven by the motor shaft 103, which also serves as the upper shaft of conventional sewing machines, are the needle bar mechanism and the thread take-up mechanism, which are the same as the motor shaft 103. The rotating lower shaft 301 is transmitted through a timing belt 211, etc., and the lower shaft 301 operates the feeding mechanism and thread trimming mechanism, and the gear 306 etc. is used to operate the lower shaft of a conventional sewing machine. Since the rotary shaft 309'i can be driven to rotate at double speed, the sewing functional elements of the conventional sewing machine in the arm 200 are minimized.

(4) Therefore, in the present invention, in order to assemble the motor 100 into the arm 200, it is not necessary to make the volume of the cylindrical portion of the arm 2000 so large compared to the conventional art. 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 11-up coupling machine, there is free space, and this part can be used for setting switches for control devices such as automatic fastening sewing. The design and operability can be improved by storing the operating parts at hand.

(5) Also prevents oil leakage, which is a drawback of conventional sewing machines.

In this case, the functional elements configured within the arm 200 are limited to the needle bar 207 and the thread take-up mechanism.

The lubrication of these sliding bearings can be done entirely with oil-impregnated metal grease, etc., making it easy to eliminate oil lubrication and solving the problem of oil leakage from the arm 200 section.

(6) Similarly, lubricating the bearings that support the upper shaft of conventional sewing machines, 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. Because the oil supply pump is an oil line.

The load torque on the motor 100 is reduced by that amount, and electric energy can be saved.

Incidentally, the pre-assembled motor 100 of this invention? When assembled and supported within the arm 200, the motor shaft 106 is quite long, as is clear from FIG.
8, needle bar 206, personal crank 209. Inertia loads such as a balance (not shown), a brake movable plate 111b, a drive side timing pulley 112, and
Naturally, the inertial load of the motor pulley 213, the tension of the timing belt 211, and the inertial load of its own rotor 102 are applied to the center of the motor shaft 106, respectively. Therefore, in order to fully ensure the predetermined rotational rigidity of the motor shaft 106, a reasonable support point is required. However, in general, supporting systems with three or more points are extremely difficult as they require strict machining accuracy and assembly accuracy because, as is well known, if the meticulous precision is not achieved, twisting will occur.

This problem has been solved by the present invention 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 at two points relative to the arm 200: the axle box 201 and the flange hole 202 formed therein. It is dimensionally fitted onto the shaft center and 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 103a has sufficient shaft rigidity.
3b is supported by the yoke (frame) 104 of the motor 100, which has relatively high rigidity, and the right side bracket 109, so it is expected to be sufficient.

Furthermore, the arm 200 of the motor 100 is fastened to the above-mentioned fixed support part by the mounting ear 109 of the right side bracket 109.
a is attached to the mounting seat 203 of the arm 200 using a bolt 113, and the friction force generated by the fastening force between the joint end surface of the mounting ear 109a and the mounting seat 203 reinforces the support rigidity of the right shaft end portion 103b.

〔Effect of the invention〕

As described above, according to the present invention, since the sewing element such as a needle bar or an equivalent dummy is assembled near one end of the motor shaft, the rotational balance of the morph rotor can be corrected.
It has the effect of completely reducing vibration and noise.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG.
It is a right side view with the hand pulley cover completely removed. 100... Drive motor, 102... Rotor, 103
...Motor shaft, 200...Sewing machine arm, 206.
...Needle bar, 300...Sewing machine bed. 302... Kama. Patent Applicant: Mitsubishi Electric Co., Ltd. Figure 2 Procedural Amendment (Voluntary) February 8, 1939 1. Indication of Case: Japanese Patent Application No. 59-38392 2. Title of Invention: Misi. 3. Person who makes [de+ti, +]i 5. Subject of amendment (1) Claims column of the specification (2) Detailed description of the invention column of the specification (3) Drawing 6, Contents of amendment (1) Amend the entire claims as per the attached sheet. (2) In the 1st page of the specification, lines 13 to 14, the phrase “rotational balance correction is performed” should be replaced with “rotational balance correction (4) Amend as shown in the attached sheet in Figure 1. (2) List of attached documents (1) Patent after amendment One document stating the scope of claims (
2) One or more documents stating the amended Figure 1. Is the scope of the amended claim a motor shaft that also serves as the upper shaft of a sewing machine? Completely equipped with a drive motor that is supported independently and a sewing machine arm that houses this drive motor, sewing functional elements such as a needle bar and thread take-up or an equivalent dummy are installed near one end of the motor shaft, and the rotation balance of the motor rotor is installed. This sewing machine is characterized by the ability to make corrections.

Claims (1)

[Claims] Completely equipped with a drive motor that independently supports a motor shaft that also serves as the upper shaft of the sewing machine, and a sewing machine arm that houses this drive motor, and a sewing functional element such as a needle bar, thread take-up lever, or equivalent dummy located near one end of the motor shaft. The sewing machine is characterized in that the rotational balance of the motor rotor can be corrected.