JPS59136063A - Noise reducing mechanism of linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce a noise due to a resonance phenomenon of a linear pulse motor by engaging any number of spacers of arbitrary shape with an axle supporting shaft between the primary side core and the axle and movably fastening the axle along the shaft. CONSTITUTION:Wheels 12-15 are rotatably provided at shafts 10, 11 at cores 2, 3 on the back surfaces of which permanent magnets 6, 7 are respectively arranged, coils 9a-9d are respectively wound on poles 2a, 2b, 3a, 3b formed with toothed parts which are displaced by 1/4 from each other to form the primary side, and moved on the secondary side made of a scale 10 having toothed parts 16a of constant pitch. Any number of spacers 17 of arbitary shape are engaged with the shafts 10, 11 between the cores 2, 3 and the wheels 12-15 and the wheels 12-15 are movably fastened along the shaft 10. Accordingly, a noise can be reduced by not bringing the drive frequency of a motor to its intrinsic frequency by controlling the spacers 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to linear pulse smoke noise reduction.

-General+,: Linear pulse smoke steps the -next or secondary scale by a certain distance (usually 1./4 pitch for a 4-ball type) for each input pulse supplied to the primary coil. Operate in steps.

Along with this operation, linear pulse motors are being applied to OA equipment, such as head feeding of various printers and photoelectric reading devices, which require accurate positioning control.

The conventional configuration of this linear pulse motor is shown in FIGS. 1 and 2. That is, Fig. 1 is a partially cutaway front view, and Fig. 2 is a partially cutaway side view. In each figure, 1 is the primary side where the magnetic flux of the linear pulse smoke is generated, and the magnetic flux is generated at the center of the front. Two iron cores 2 and 3 that are in a cut-off state, and a side plate 4 that fixes the iron cores 2 and 3 on both sides.
, 5, permanent magnets 6, 7 magnetized with the polarities shown on the back m1 of each of the above-mentioned iron cores 2, 3, a magnetic plate 8 joined to the back side of the permanent magnets 6, 7, each of the above-mentioned iron cores 2, Coils 9a, 9b, 9c, 9d attached to magnetic poles 2a, 2b, 3a, 3b formed in 3 are rotatably supported on shafts 10, 11 supported under both sides of each side plate 4, 5. It consists of wheels 12-15. Each of the magnetic poles 2a, 2b, 3a+3b is provided with a toothed portion 2al, 2b1.3a1.3bl having a pitch of 1/4 inch and 1/4 inch. Reference numeral 16 denotes a scale forming the secondary side of the linear pulse smoke, and tooth portions 16a having the same pitch as each of the magnetic pole tooth portions 2a1 and the like are formed on a flat surface.

In the linear pulse mode shown in FIGS. 1 and 2, when driving, for example, by the -phase excitation method, in the process of sequentially exciting each coil 9a to 9d, each magnetic pole 2a
+ Teeth 2a1゜2b formed on 2b, 3a, 3'b
1, 3al, and 3bl sequentially face the teeth of the secondary scale. /4 pitches (it looks continuous, but in principle it's just a step-like position). At this time, one of the primary magnetic flux generating device 1 and the secondary scale 16 is fixed (normal scale), and the other is engaged with the positioning load and made movable to achieve practical use.

However, in the conventional configuration described above, the rigidity of the primary side 1 of the linear pulse smoke is constant, that is, the natural frequency is constant, so at a specific linear pulse smoke drive frequency, the vibration of the linear pulse motor and the noise generated due to it are It had the disadvantage of causing a resonance phenomenon in which the

The present invention has been made to eliminate the above-mentioned drawbacks.
By varying the rigidity of the primary side of the linear pulse motor, the purpose is to run the linear pulse smoke with low vibration and low noise at any linear pulse smoke drive frequency.

Next, an embodiment of the present invention will be described based on FIGS. 3 and 4.

FIG. 3 is a side view of a linear pulse motor according to the present invention.
The numbers in the inner cylinder 2 in the figure correspond to each other. In Fig. 3, 4/ and 5/ are side plates that fix the iron core 2 on both sides, and provide space between the side plates 4'+5' and the scale 16 for the wheels 1, 2, and 13 to fit. It is. 17 is a spacer which connects the iron core 2 and the wheel 12.
The wheel 1.2.13 fits into the part of the shaft 10 between 13.
It is attached to the outer shaft 100 of the wheel 12, 13 so that it can be fixed at any position. FIG. 4 is a diagram when all the spacers 17 in FIG. 3 are removed to eliminate the space between the iron core 2 and the wheels 12, 1.3.

Hereinafter, the wheel arrangement shown in FIG. 3 will be referred to as span A1, and the wheel arrangement shown in FIG. 4 will be referred to as span B. FIG. 5 is a graph of the relationship between the motor drive frequency and the noise level when the linear pulse motor is operated with span A and span B, where A is the graph for the span A and B is the graph for the span B.

” - When operating a linear pulse motor with a span of 8 in the above configuration, the natural frequency of the motor is ]000]1
z, when this motor is operated at a drive frequency of 1000 Hz, a sound exceeding 80 dEA is generated as shown in FIG. If the spacer 17 is removed and the span is set to B, the rigidity of the motor increases and the natural frequency of this motor becomes 1500.Hz.

When this motor is operated in this way at a drive frequency of 1.000 Hz, the output power is 70 dBA (as shown in Figure 5);
It fits within ffi degree of noise. In other words, the above motor is 100
When operating at a drive frequency of 0Hz, 80d at span 8
A noise of 70 dBA is generated in the span B.

Therefore, by changing span A to span B, 10 dBA
Noise can be reduced.

In this way, by changing the position of the wheels 12, 13, the number of spacers 17, and the dimensions, the drive frequency of the motor and the natural frequency do not match, thereby reducing noise.

In the above embodiment, the side plate on the primary side of the linear pulse smoke is cut to create a space so that the wheels can be moved, but if the wheels are movable due to the structure of the side plate or other reasons, it is necessary to cut out the side plate. There isn't.

As described above, according to the present invention, the rigidity of the motor can be varied by adjusting the position of the linear pulse smoke wheel by the number and dimensions of the spacers, and the driving frequency of the motor can be adjusted. It is possible to make the natural frequencies not coincide with each other, thereby preventing the resonance phenomenon of the motor described above, and making it possible to run the linear pulse motor with low noise over the entire frequency range.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of a conventional linear pulse motor, Fig. 2 is a partially cutaway side view of a conventional linear pulse motor, and Figs. 3 and 4 are side views of a linear pulse motor according to the present invention. , FIG. 5 is a graph showing the relationship between the drive frequency of the motor and the noise level when the linear pulse smoke shown in FIGS. 3 and 4 is operated. 1・・・・・・・・・・・・Linear pulse smoke primary side 2
... Iron core 4'+5' ... Side plate 10 ... Axis 12.1.3 ... Wheel] 6 ... Secondary side school 17 ...Repacer 1 18 ...... Fastener Applicant Shinko Electric Co., Ltd. Agent Patent Attorney Haruya Saito 1 Figure 2 Figure 5

Claims (1)

[Claims] A linear pulse smoke noise reduction m structure in which an arbitrary number of spacers are inserted in a removable manner, and the wheel is fixed to the outside of the spacer so as to be movable along the axis according to the number and dimensions of the spacer.