JPS59185154A - Noise preventing mechanism of linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce noise upon vibration of a supporting bearing in incrementing operation by providing a prepressure generator having a permanent magnet and a magnetic member at both ends of the primary side magnetic flux generator of a linear pulse motor. CONSTITUTION:The primary side magnetic flux generator 21 of a linear pulse motor is formed of a core, a permanent magnet, poles 29, 30 having coils 31, 32 and toothed parts 29, 30, and prepressure generators 34, 35 formed of magnetic circuits having permanent magnets 34a, 35a, magnetic members 34b, 35b are mounted at both ends, and moved on the secondary side scale 33 having a toothed part 33a via wheels 23, 24. Accordingly, suction gas attracting force is generated in a gap G between the members 34b, 35b and the scale 33, the vibration generated at a bearing K' part can be absorbed by the vibrating force at the excitation switching time in incrementing operation, thereby reducing the noise.

Description

[Detailed description of the invention] This release F! A relates to a noise prevention mechanism caused by vertical vibration of the bearing that supports the primary magnetic flux generator of the linear pulse motor. In general, a linear pulse motor has a fixed displacement amount ( Usually a 4-ball type.

1/4 pitch) each - next side? Operates in steps. Along with this, pulse motors are being applied to various devices that require accurate positioning control.

For example, as an example of this application, head feeding of various printers,
There are office automation equipment such as a head feeder for a rechargeable reader. The basic configuration of this linear pulse motor is shown in the front view 9 in FIG. In other words, in Figure 1,
1 is the primary side responsible for generating the magnetic flux of the linear pulse motor, and there are two iron cores 2 and 3 that are magnetically cut off at the center of the front.
1 The relevant iron, 2, 3 Side plates 4, 5 fixed on both sides.
．． Permanent magnets 6 and 7 are magnetized with the polarities shown on the back of each of the above-mentioned irons 2.3, and a magnetic plate 8 is bonded to the back of the permanent magnets 6 and 7. The magnetic poles 2. formed on each of the above iron cores 2.3. a, 2b, 3a, 3b Coil 9a with Ic attached.

9b, 9c, 9d, shafts 10, 11 supported on both sides of the side plates 4, 50; wheels 12-15 rotatably supported on K-bearings K; and,
Tooth portions 2a, l of magnetic pole 2a, tooth portion 2bl of magnetic pole 2b
are arranged at a 1/2 pitch, the teeth 3al of the magnetic pole 3a are arranged at a 1/4 pitch, and the teeth 3bl of the magnetic pole 3b are arranged at a 5/4 pitch. On the other hand, the coils 9a and 9b and the coils 90 and 1d form a pair, and each pair of coil groups is connected in series by 7'L so as to generate magnetic flux in opposite directions. 16 is a scale forming the secondary side of the linear pulse motor, and tooth portions 16a having the same pitch as each of the magnetic pole tooth portions 2al, 2bl, 3al, 3bl, etc. are formed on a flat surface.

In the linear pulse motor shown in FIG. 1 above, first, when a current is supplied to the coils 9a, 9b, the magnetic pole 2a
The magnetic flux becomes a magnetic flux in the same direction as the permanent magnet 6, and the magnetic flux flowing in the magnetic pole 2b goes in the opposite direction and is canceled out.A magnetic attraction force acts only on the magnetic pole 2a, and the teeth 2al of the magnetic pole 2a face the scale teeth 16a. It will come to a stable stop at the specified position.

Next, coil 9a! Cut off the current to the magnetic pole 3a
, 3b, when current is supplied to the coils 9c, 9d wound in series, the magnetic flux from the toothed portion 3al of the magnetic pole 3a is strengthened.

The magnetic flux from the toothed portion 3b1 of the magnetic pole 3b is canceled out by the magnetic flux from the permanent magnet 7. At this time, the tooth portions 3a, 1 of the magnetic pole 3a are stepped (1
/4 pitches). Next, cut off the excitation coils 9c and 9d 47) 'fJL flow, and this time coil Qa,
By supplying an excitation current to the series circuit 9b in the opposite direction to the previous excitation, the magnetic flux from the magnetic pole 2b is added to the magnetic flux of the permanent magnet 6, and eventually the tooth portion 2bl of the magnetic pole 2b and the scale tooth portion 16a are opposed to each other. Move 1/4 pitch to the desired position. Thereafter, by performing similar operations one after another, the primary side l responsible for generating magnetic flux moves in steps of up/4 pitches with respect to the fixed school 16.

By the way, the linear pulse motor shown in FIG. 1 above changes the magnetic attraction force (excitation) J)'ft and Lq between the primary side magnetic flux generating part l and the scale 16 for each stepwise movement. , l) Vertical and longitudinal vibrations using the bearing K, which has the lowest rigidity among the components of the near-pulse motor, as a fulcrum? generates noise. This noise is compared to the above-mentioned bearing K (rl), and the higher the spring constant of this bearing, the lower it is.
If the weight of the primary magnetic flux generating section 10 of the linear pulse motor is the main factor, it is not possible to obtain a significant repulsion constant.

Generally speaking, the spring constant of a bearing I is as shown in Figure 2.The amount of deformation y with respect to the load G is the amount of deformation per unit load in the low load region, and the amount of deformation per unit load in the high load region. It has characteristic 7 that the amount of displacement is small. Therefore, if the bearing is considered as a spring as an elastically deformable body, the more preload is applied, the smaller the amount of deformation per unit load will be.

However, with the preload mainly based on gravity on the primary side of a conventional linear pulse motor, sufficient preload (preload sufficient to sufficiently reduce the vibration amplitude during excitation during stepping of the linear motor) cannot be obtained, and the noise level has increased. He was in a high state.

An object of the present invention is to increase the preload by increasing the actual load exerted on the secondary side of the primary side by magnetic attraction, thereby reducing the noise level during operation.

Hereinafter, the configuration according to the present invention will be specifically explained.

First, the gist of this invention is to constantly apply magnetic attraction force between the primary and secondary of a linear pulse motor to increase the preload force of both, and will be explained based on an example of the tool body shown in FIG. 3.

In Fig. 3, 21 is the linear pulse motor on the next side?
This is a magnetic flux generating part. Reference numeral 22 denotes the primary main body, which includes the parts (permanent magnets 6, 7, magnetic plates 8, side plates 4, 5
etc.). Reference numerals 23 and 24 denote shafts, which are attached to the lower portions of both longitudinal ends of the downstream main body 22, and inner races '' are fixed to bearings at both ends of these shafts. The outer race of each bearing is provided with 25 to 2 wheels.

29a, 29b, 30a, 30b td magnetic pole,
Teeth 2.9a, l, 29bl, respectively on the magnetic pole generation surface.
30a-1 and 30bl are formed and supported by the next main body 22. 31a, 31b, 32a, and 32b are excitation coils, each of which corresponds to the magnetic pole 29 aI 29
b, 3o a, 30 b K.

It is installed+. Each pair of coils 31a, 31b- and coil 32-32b are excited at the same time, and are wound in different directions. 33 is a scale, on the surface facing the magnetic flux generation center 21, the magnetic pole tooth portion 29al, 2
9b engineering.

Teeth portions 33a having an equal pitch of 30a4.30bl are formed, and the primary side wheels 25-2 are guided along this scale 33. 34.35 are preload generators, each -
It is attached to both longitudinal ends of the next magnetic flux generating section 21 .

The preload generators 34 and 35 each have nine permanent magnets 34a1, 34b+ and 35a.
, magnetism=tt U35b, each of which is a permanent magnet 34a.

The magnetic flux from 35a is applied to each magnetic member 34b, 35
b.

A closed magnetic circuit is formed through the air gap G and the scale leaf 1, -
1/). At this time, if the gap Of between the magnetic members 34b, 35b and the scale surface is made small, the magnetic attraction force, that is, the preload force can be increased accordingly.

In the configuration shown in FIG. 3 above, each pair of coils 31a
, 31b, 32a, and 32b are excited based on a rectangular wave voltage by alternately changing the direction of the current, and stepwise operation is performed by 3 pitches as described in the operation explanation for FIG. 1. obtain. At this time, each time the excitation is switched, an excitation force is applied, and a vibration is generated due to the spring action based on the elastic deformation of the bearing portion.

Although this vibration causes noise, the spring constant of the bearing is kept low based on the magnetic attraction force of the preload generator 34, 35, and as is clear from the characteristics shown in Fig. 2, the step of the linear pulse motor increases. The vibration amplitude for each decreases significantly.

On the other hand, the preload generators 34 and 35 act as a braking force on the thrust of the stepping motion of the linear pulse motor by this magnetic attraction force. Since it moves with the help of the brake, it does not exert much braking action.

In addition, the preload generating device 34, 35 shown in FIG. 3 1/i:
1 shows a configuration using a permanent magnet as a magnetic flux generation source, but the electromagnet 1c can be replaced as the magnetic flux generation source.

FIG. 4 is a partially cutaway front view showing another embodiment of the present invention, and portions equivalent to those in FIG. 3 are designated by the same reference numerals.

The explanation will be omitted. In Fig. 4, 22M is a permanent magnet included in the main body of the primary side magnetic flux generation part, and the magnetic flux generated from this is attracted to the scale 33ft at the scale facing surface 22N in the support part. It is responsible for the preload.

As described above, the linear pulse mode according to the present invention
The noise prevention mechanism uses a linear pulse motor.

6 Stenop drive i] V to reduce the excitation force generated at the time of
It is strained. Based on this configuration, it is possible to reduce noise when driving a linear pulse motor, and it is also possible to easily comply with the noise level limit ν of the specifications of products to which the linear pulse motor is applied (printers, etc.). .

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view of Linear Pulse Tanabata, Figure 2
The figure is a graph showing the relationship between bearing load and displacement, and Figures 3 and 4 are examples of the present invention. FIG. 21＠...Primary side magnetic flux generation section of linear pulse motor 33...S) 1-35...Preload generator 35a
・・Permanent magnet 22M・・Water-immersed magnet Applicant Shinko Electric Co., Ltd. Agent Patent attorney Haruya Saito l Figure 0 → Load G Figure 3 Figure 4 Procedural amendment (voluntary) May 19, 1980 Retention date Mr. Hsu, Director-General of the Agency, Incident Display Patent Application No. 604fli4 of 1982
No. 2, Name of invention Noise prevention mechanism for linear pulse motor 3
, Relationship with the case of the person making the amendment Patent applicant 4, agent Correct the statement "Bearing K deformed." 2, page 8, 9~] In line 0, the statement ``The spring constant is kept low'' is corrected to ``The spring constant is made high.'' 5, page 9, line ``Excitation method'' is 1 vibration amplitude.''
I am corrected.

Claims (1)

[Claims] ■ In the primary side magnetic flux generation part of the linear pulse motor,
At least when driving a linear pulse motor. Preload force between secondary scale? Equipped with magnetic circuit means to give? Features of linear pulse smoke noise prevention mechanism 1゜2 A preload generating device consisting of a permanent magnet and a magnetic member at both ends in the longitudinal force direction V of the primary side magnetic flux generating part of a linear pulse motor. I did 4! f21'N
l'J Required range @ of the linear pulse motor described in item 1
Sound prevention mechanism. 3. Noise of the linear pulse motor as set forth in claim 1, which is equipped with a preload generating device consisting of an electromagnet and a magnetic section at both ends in the longitudinal direction of the primary side magnetic flux generating part of the linear pulse motor, and is used as a magnetic circuit means. Prevention mechanism. 4. The linear pulse motor according to claim 1, characterized in that the permanent magnets in the magnetic circuit means, which serve as magnetic flux generation sources and which carry thrust, are extended to both ends of the primary magnetic flux generation length in the longitudinal direction of the linear pulse motor. Noise prevention mechanism.