JPS59117399A - Electromagnetic vibrator - Google Patents

Abstract

PURPOSE:To increase the output of vibration by fitting >=2 electromagnetic in the circumferential direction of inner wall of a casing so that the magnetic flux is directed in the axial direction of the casing and supporting a vibrator having a permanent magnet by a plate spring so as to vibrate the oscillator in the thrust direction. CONSTITUTION:In the circumferential direction of the inner wall of the casing 21, >=2 electromagnets are fitted. An opening section of a yoke 22 having a channel shaped cross section of the electromagnets is directed in the direction of a shaft 24 of the casing 21, a coil 23 is inserted to the inside, so as to make the magnetic flux in parallel with the shaft 24 between magnetic poles 22a, 22b. Both ends of the shaft 24 of the vibrator having a moving mass 28 are supported freely vibratorily by disc springs 25, 25 fixed to the casing 21. Plural permanent magnets 26 are fitted among magnetic path forming yokes 27a-27c at a nearly center part of the shaft 24 and at a position corresponding to the magnetic poles 22a, 22b of the electromagnets so that the opposite poles of the permanent magnets 26 are in contact with each other. In energizing the electromagnets by an AC power, the magnetic poles 22a, 22b produce N and S poles alternately and repeat adsorption and repulsion with the permanent magnets 26. Moreover, the center of vibration of the springs 25 and the center of gravity of the shaft 24 are made coincident with each other and efficient vibration is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic vibrator used in a vibration transport device for materials, products, etc.

[Background technology]

2. Description of the Related Art Some transportation devices for materials, products, etc. include an electromagnetic vibrator attached to a horizontal or inclined gutter-shaped tray, and the tray is vibrated for transportation.

Most general electromagnetic vibrators are single-phase AC powered by a commercial frequency power source, and their structure generally uses a two-mass resonance system. These general structures are shown in FIG. 1 ((a) is a front view, (b) is a side view) and FIG. 2. In this figure, the electromagnetic vibrator includes a yoke (]), a coil (2) attached to it that generates magnetic flux, a movable iron core (3) and a resonant spring (41) placed across an air gap. ,(41'
It is composed of. In the figure, (5) is the tray mass, (6
) is the opposing mass, and (7) is the support spring.

When an AC voltage is applied to the coil (2), a current flows, and an attractive force is generated between the yoke (1) and the movable core (3), and the repulsive force of the movable core (3) springs (41, (41) Overcoming York (approximately 11).

When the instantaneous value of the voltage decreases and the attraction force decreases, the spring (4
) increases and the movable iron core (3) moves in the opposite direction. The tray mass (5) with this movable iron core (3) is:
It has a structure in which it is vibrated with a counter mass (6) via resonance springs (41, (41')).

The natural frequency of the resonance spring (4), (41') connecting this tray mass (5) and counter mass (6) is set close to the power supply frequency, so a slight vibration force can be applied to the tray mass (5).
) can be made to vibrate greatly.

FIG. 3 is a time chart of voltage when commercial single-phase AC is used, FIG. 4 is a time chart of attraction force, and FIG. 5 is a time chart of vibration amplitude.

If a commercial single-phase AC power source is used as is to excite the coil, the attractive force will change as shown in Figure 4, and it will reach the O level twice per cycle, so the movable iron core (3) The vibration frequency is twice the commercial frequency.

The vibration in this state is caused by the movement of the movable iron core (3) as shown in Figure 5.
will not return to its resting position and will vibrate.

However, vibrations with a frequency twice the commercial frequency cannot provide sufficient amplitude to the tray mass (5),
゛No practical effect can be expected.

In order to improve these problems, it is possible to control the waveform of the commercial power supply, for example, by controlling the conduction angle of the single-phase half-wave power supply using a rectifier or by using a combination of Cyrisk, etc. Efforts have been made to generate the same vibration frequency and control the amplitude.

Figures 6, 7 and 8 show attraction force and amplitude curves at half-wave voltage.

In addition to the half-wave voltage control mentioned above, the
There is a device that uses a permanent magnet and is devised to generate a vibration frequency equivalent to the frequency of the power supply used, as described in Japanese Patent No. 3. FIGS. 9 and 10 (FIG. 10 is a principle diagram of the configuration shown in FIG. 9) are one example thereof. This has one E-shaped yoke (11) on the fixed side,
The movable iron core has U-shaped permanent magnets (12) facing each other so that their salient poles intertwine alternately, and a power source is generated by passing alternating current to the excitation coil (13) of the E-shaped yoke (11). It generates vibrations equal to the frequency.

That is, in FIG. 10, when the left pole of the permanent magnet (12) sandwiching the center rod of the E-shaped yoke (11) is S, and the right pole is N, when the power supply voltage is in a positive half wave, the As shown in the figure, an S pole is generated at the center rod of the yoke (11), and N poles are generated on both sides of the S pole. As a result, the permanent magnet (12) moves to the left in the drawing due to magnetic attraction and repulsion. Next, at the negative half-wave of the power supply voltage, the center rod of the yoke (11) is N+
Since the permanent magnet (12) is excited by i, the permanent magnet (12) moves to the right. In this way, the permanent magnet (I2) vibrates from side to side at the same frequency as the frequency of the power supply voltage.

However, this method also has the following problems.

■In order to strengthen the magnetic action between the permanent magnet (I2) and the yoke (II), it is necessary to shorten the air gap, but this will prevent the permanent magnet from taking a large movement stroke, and will cause resonance during startup. When passing through the resonance point of low eL number, the vibration stroke becomes very large and the yoke (11) and permanent During that time, the magnet (12) repeatedly collides with the magnet (12), so-called "
A "knocking" phenomenon occurs, leading to damage to moving parts and deterioration of springs.

■The center of the point where magnetic repulsion is generated and the driven body (I2
) may not necessarily be aligned with the center of the spring that transmits vibrations to the outside, and as a result, part of the magnetic attraction and repulsion forces act on the resonant spring as unnecessary torsional force. , making its design difficult.

[Purpose of the invention]

The present invention solves these conventional problems and allows a relatively large vibration stroke, and also allows the center of the magnetic attraction/repulsion force to be generated and the center of gravity of the vibrating body to coincide with the center of the resonant spring. Therefore, it is an object of the present invention to provide an electromagnetic vibrator that can improve vibration force transmission to a tray mass.

[Structure of the invention]

The present invention has a cylindrical casing attached to a vibrated body, an inner wall of the casing, and at least two salient pole parts, and an opening formed between the salient pole parts is oriented toward the center of the casing. A ring-shaped coil is installed in the opening of the U-shaped yoke so that the center axis of the casing coincides with the center axis of the casing. At the top, there is a vibration shaft that is supported so as to be able to vibrate in the longitudinal direction with respect to the casing, and on this vibration shaft,
A permanent magnet is attached such that an outer magnetic pole is close to a salient pole portion of the yoke, and magnetic poles located between the salient pole portions of the yoke and outside both salient pole portions have different polarities. This relates to an electromagnetic vibrator.

〔Example〕

The present invention will be described below in Figure 1I (longitudinal side view) and Figure 12 (
A description will be given based on the embodiment shown in FIG. 11 (a sectional view taken along the line 1-1).

In this figure, (21) is the casing, (22) is a U-shaped yoke (fixed core) placed at the location where the circumference is divided into four parts, and (23) is attached to fit into this yoke (22). (24) is a vibration shaft made of a non-magnetic material, (25) is a disc-shaped spring that supports this vibration shaft (24) on the casing (2I) so as to be able to freely vibrate in the longitudinal direction. 26) is a ring-shaped permanent magnet (vibrator) mounted on the vibration shaft (24), and (27a) to (27c) are yokes for forming a magnetic circuit.

(28) is the moving mass.

The ring-shaped permanent magnet that is the vibrator is located at the center of the T-shaped cross section.
．． The land rail (27a) is arranged so that the inside is the north pole (or south pole) and the outside is the south pole (or north pole), and the area around the center yoke (27a) is the north pole (or south pole). , outer yoke (2
7b) and (27c) (7) Surroundings are S pole (or N pole)
It is configured so that Note that when a plurality of permanent magnets are used between the yokes, a vibrator with a large output capacity can be obtained by stacking them in the axial direction so that each magnet becomes a salient pole.

In order to prevent eddy current loss caused by the AC power source, the U-shaped yoke (22) is arranged as a silicon steel laminated core so that the magnetic flux of the ring-shaped permanent magnet (26), which is the vibration generating part, can be fully utilized. .

The disc spring (25) can be made of a metal leaf spring material, but generally the peaks at the resonance point are flat. It is constructed in the form of a shear type rubber spring made of P material or a metal inner cylinder and outer cylinder glued together with rubber.

The U-shaped yoke (22) and each yoke (27a) to (27
C) is the pole (of the yoke (22)) as shown in FIG.
Center yoke (27a) between 22a) and (22b)
The pole (22a) of the yoke (22) and (
22b) on both sides (27b) and (27c)
Place them so that they are located.

The movable mass (2B) is attached so as to be removable or replaceable, and is configured so that an appropriate mass can be attached depending on the setting of the constant of the two-mass resonance system.

Now, when alternating current is applied to the coil (23), a positive half wave causes one pole (22a) of the yoke (22) to become the N pole and the other pole (22b) to the S pole, as shown in Figure 11. As shown in , the electromagnetic attractive force and the anti-force act on the permanent magnet (26), and the vibration shaft (24) moves to the right in the drawing against the supporting force of the disc spring (25). do.

Next, one pole (2
2a) is reversed to the S pole, and the other pole (22b) is reversed to the N pole, and the vibration axis (24) swings to the left in the drawing and receives the J force. They will vibrate at the same frequency. If the casing (21) of the electromagnetic vibrator with such a configuration is attached to the vibrated body,
The resonance effect with the vibration shaft (24) causes the vibrated body to vibrate.

[Su J Ka]

As described above, the present invention has the following effects.

(1) It is possible to provide a resonant electromagnetic oscillator in which the vibration shaft has a relatively thick one-stroke stroke, and the "knocking" phenomenon between two masses does not occur.

■Since the arrangement is such that the electromagnetic force acting on the ring-shaped permanent magnet is concentrated on the vibration axis, the generated electromagnetic force coincides with the vibration transmission direction, and therefore vibration transmission efficiency is high.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the outline of the configuration of a conventional electromagnetic vibrator.
Fig. 2 is an explanatory diagram showing its operating principle, Figs. 3 to 5 are waveform diagrams to explain temporal changes in vibration generation when AC power is directly applied as excitation voltage, and Figs. 6 to 8 is a waveform diagram explaining the temporal change in vibration generation when a half-wave rectified voltage is applied as the excitation voltage, Figure 9 is a sectional view showing the configuration of another conventional electromagnetic oscillator, and Figure 10 is its operating principle. FIG. 11 is a vertical sectional side view showing the configuration of an embodiment of the present invention, and FIG. 12 is a sectional view taken along the line I-1 in FIG. 11. (21) : Casing (22) : U-shaped yoke (fixed core) (23)
: Coil (24) : i-linear Φ mountain (25) : Disk-shaped spring (26) : Ring-shaped permanent magnet (27a) to (27c) : Yoke for forming magnetic circuit (28)
: Movable mass lifting license applicant Murakami Seiki Co., Ltd. Agent
Handmade profit (2 people) Figure 11 Figure 12

Claims (1)

[Claims] 1. A cylindrical casing attached to a vibrated body; an inner wall of the casing having at least two salient pole parts, and an opening formed between the salient pole parts of the casing; a U-shaped yoke attached to point toward the center; a ring-shaped coil attached to the opening of the U-shaped yoke so that its axis coincides with the center axis of the casing; and an axis of the casing. a vibration shaft supported on the center so as to be able to vibrate in the longitudinal direction with respect to the casing, and a salient pole of the yoke with an outer magnetic pole in close proximity to the salient pole portion of the yoke on the vibration shaft; An electromagnetic vibrator consisting of permanent magnets with magnetic poles located between the parts and outside both salient pole parts having different polarities.