JPH0510379A - Vibration-proof device and applied voltage control method for electromagnet - Google Patents

Abstract

PURPOSE:To effectively absorb the vibration over wide frequencies. CONSTITUTION:A pressure receiving liquid chamber 38 and an auxiliary liquid chamber 40 are provided, and they are connected by a limit passage 44. A large diaphragm 28 is provided for the auxiliary liquid chamber 40, and a small diaphragm 26 is provided for the pressure receiving liquid chamber 38. A steel plate 30 is fixed on the surface of the small diaphragm 26. An electromagnet 50 is provided on the outer periphery of a circular section 14, and a magnetic core 52 is faced to the steel plate 30. At the time of low-frequency vibration, the steel plate 30 is attracted, and the movement of the small diaphragm 26 is prevented. A liquid is reciprocated in the limit passage 44 by the pressure change of the vibration of the pressure receiving liquid chamber 38 to receive passing resistance, and the low-frequency vibration is absorbed. At the time of high-frequency vibration, the limit passage 44 is clogged, the attraction of the steel plate 30 is released, and the small diaphragm 26 is vibrated. The rise of the dynamic spring constant of a vibration-proof device 10 is suppressed, and the high-frequency vibration is absorbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device which is used in a vehicle, an engine mount of an automobile or the like, and which absorbs and attenuates vibrations from a vibration generator, and a method for controlling an applied voltage of an electromagnet thereof.

[0002]

2. Description of the Related Art As an anti-vibration device used for automobile engine mounts, car mounts, body mounts, etc.
A vibration isolator of a liquid chamber type is known (JP-A-60-1).
13835 publication). As shown in FIG. 9, the liquid chamber of the vibration isolator 100 is divided into a main liquid chamber 104 and a sub liquid chamber 106 by a partition wall 102, and the main liquid chamber 104 and the sub liquid chamber 106 have a restricted passage 108. Is communicated with. Therefore, when the vibration is transmitted to the vibration isolator 100, the vibration occurs due to the passage resistance and the liquid column resonance when moving through the restriction passage for the liquid filled in the main liquid chamber 104 and the sub liquid chamber 106. Is absorbed. In addition, in the vibration isolator 100, the movable body 112, which is attached to the hole 110 formed in the partition wall 102 so as to be movable within a predetermined range, expands or contracts the liquid chamber during high frequency vibration in which the restricted passage 108 is clogged. By making a minute movement in the direction of movement, the rise in pressure in the liquid chamber is limited and high frequency vibrations are absorbed.

In this vibration isolator 100, however, the liquid can pass not only through the restricted passage 108 but also through the gap between the movable body 112 and the hole 110, and the movement of the movable body 112 causes vibration at low frequencies. In some cases, the amount of liquid passing through the restriction passage 108 decreases, and the damping action due to the passage resistance in the restriction passage 108 cannot be sufficiently obtained.

[0004]

SUMMARY OF THE INVENTION In consideration of the above facts, it is an object of the present invention to provide an anti-vibration device capable of surely absorbing vibrations over a wide range of frequencies and a method for controlling an applied voltage of an electromagnet thereof. Is.

[0005]

The invention according to claim 1 is
A first mounting member connected to one of the vibration generating portion or the vibration receiving portion, a second mounting member connected to the other of the vibration generating portion or the vibration receiving portion, the first mounting member and the second An elastic body provided between the mounting member and the mounting member and deformable when vibration occurs, a pressure receiving liquid chamber capable of expanding and contracting with the elastic body as a part of a partition wall, and an elastic film forming a partition wall of a part of the pressure receiving liquid chamber. An attracted means attached to the elastic film and attracted by a magnetic force; an electromagnet that attracts the attracted means; a sub liquid chamber separated from the pressure receiving liquid chamber; the pressure receiving liquid chamber and the sub liquid chamber. And a restricted passage that communicates with.

According to a second aspect of the present invention, a DC voltage is applied to the electromagnet when the attracted means is attracted, and a polarity of a voltage applied to the electromagnet when the attracted means is released. Is applied and then the applied voltage is set to zero.

According to a third aspect of the present invention, when the adsorbed means whose adsorption has been released is next adsorbed, a voltage having a polarity opposite to the polarity when the adsorbed means was previously adsorbed is applied to the electromagnet. It is characterized in that it is applied to.

[0008]

According to the invention described in claim 1, for example, when the first mounting member is connected to the vibration generating portion and the second mounting member is connected to the vibration receiving portion, the vibration transmitted from the vibration generating portion The first mounting member, the elastic body, and the second mounting member are sequentially supported by the vibration receiving portion, and the vibration is absorbed by the resistance based on the internal friction of the elastic body. Further, when the vibration has a low frequency, the elastic membrane of the pressure receiving liquid chamber is made immovable by adsorbing the adsorbing means by the electromagnet. As a result, the liquid passes between the pressure receiving liquid chamber and the sub liquid chamber through the restriction passage,
It is possible to effectively absorb low-frequency vibration by causing liquid column resonance or passage resistance in the restricted passage.

When the vibration has a high frequency, the restriction passage becomes clogged. In this case, therefore, the operation of the suction means is released to bring the elastic film into a free state. As a result, the elastic film vibrates due to the pressure change due to the vibration in the pressure receiving liquid chamber, and the pressure rise in the pressure receiving liquid chamber is suppressed, so that a low dynamic spring constant of the vibration isolator can be obtained. Therefore, high frequency vibration can be effectively absorbed.

According to the method of claim 2, a DC voltage is applied to the electromagnet when the attracted means is attracted, and a polarity of the voltage applied to the electromagnet is predetermined when the attracted means is released. The applied voltage is set to zero after being inverted for a minute time. That is, when the attracted means releases the attraction, the magnetic force of the electromagnet becomes zero after the polarity is reversed for a predetermined minute time. Therefore, since the electromagnet is made to have the same polarity as the residual magnetism of the attracted means magnetized at the time of attraction for a minute time and then the magnetic force is made zero, the attracted means is repulsed by the electromagnet and can be separated away instantly.

According to the third aspect of the present invention, when the adsorbed means whose adsorption has been released is next adsorbed, a voltage having a polarity opposite to the polarity when the adsorbed means is previously adsorbed is applied to the electromagnet. It is designed to be applied. Therefore, when the attracted means that has been released from attraction is next attracted, the electromagnet has a polarity opposite to the polarity when the attracted means was previously attracted. That is, since the electromagnet and the attracted means are magnetized to alternate poles for each attraction, the electromagnet and the attracted means are less likely to be magnetized as compared with the method of attracting with a specific polarity. Further, there is little risk that a member such as iron arranged around the electromagnet will be magnetized.

[0012]

【Example】

[First Embodiment] A vibration isolation device 10 according to a first embodiment of the present invention.
Will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the anti-vibration device 10 is provided with a mounting frame 12 for mounting on a vehicle body (not shown), and an annular portion 14 of the mounting frame 12 has an outer cylinder. 16 is inserted. A thin rubber layer 18 is vulcanized and adhered to the inside of the outer cylinder 16. The thin rubber layer 18 is separated from the outer cylinder 16 at a circular hole 22 portion formed in the upper portion of the outer cylinder 16 to form a small diaphragm 26, and a rectangular hole 24 portion formed in the lower portion of the outer cylinder 16 is formed. A large diaphragm 28 is formed apart from the outer cylinder 16.

An intermediate block 25, which is formed in a substantially cylindrical shape, is inserted into the outer cylinder 16, and the outer peripheral surface in the radial direction is attached in close contact with the inner peripheral surface of the thin rubber layer 18. The intermediate block 25 includes the intermediate cylinder 32, the inner cylinder 34, and the elastic body 3.
6 is integrally molded, and the intermediate cylinder 32 and the inner cylinder 3
4 is arranged coaxially with the outer cylinder 16.

In the elastic body 36 of the intermediate block 25, a notch 23 is formed in the upper axial middle portion and a lower portion 27 is formed in the lower axial middle portion. A cavity 70 is formed below the inner cylinder 34 between the intermediate cylinder 32 and the elastic body 36, and the cavity 70 penetrates the intermediate block 25 in the axial direction.

The notch 23 is surrounded by the thin rubber layer 18 and the small diaphragm 26 to form a pressure receiving liquid chamber 38, and the notch 27 is thin rubber layer 18 and the large diaphragm 28.
The sub liquid chamber 40 is surrounded by.

On the other hand, a groove 42 is formed on the outer peripheral surface of the intermediate block 25 along the outer peripheral direction. One of the grooves 42 is connected to the cutout 27 and the other is connected to the cutout 23. By being surrounded by the outer cylinder 16, the limiting passage 44 is formed.
Are configured.

The pressure receiving liquid chamber 38, the sub liquid chamber 40 and the restriction passage 44 are filled with a liquid such as water or oil. The side of the large diaphragm 28 opposite to the side of the sub liquid chamber 40 is an air chamber 46, which is communicated with the outside if necessary.

As shown in FIG. 2, this small diaphragm 2
A steel plate 30 is fixed to the outer surface of the roller 6 in the radial direction. This steel plate 30 is formed in a disc shape, and further,
It is curved in an arc shape along the inner peripheral shape of the annular portion 14.
In the free state of the small diaphragm 26, the steel plate 30 is separated from the inner peripheral surface of the annular portion 14 by a predetermined dimension (see FIG. 2). The space formed between the annular portion 14 and the small diaphragm 26 is an air chamber 45.

On the other hand, a hole 48 is formed in the annular portion 14 of the mounting frame 12 coaxially with the circular hole 22 of the outer cylinder 16, and an electromagnet 50 is formed on the outer periphery of the annular portion 14 corresponding to the hole 48. Are arranged. The electromagnet 50 includes a case 51, a magnetic core 52, and a coil 54 wound around the magnetic core 52, and the case 51 is fixed to the annular portion 14. Further, the magnetic core 52 is positioned such that the front end surface 52A on the hole 48 side is in contact with the tangent line of the inner circumference of the annular portion 14. The coil 54 of the electromagnet 50 is connected to a DC power source 56 such as a battery and the control means 58, and when one of the lead wires 54A drawn from the coil 54 is made positive and the other lead wire 54B is made negative. The tip surface 52A side of the magnetic core 52 becomes the N pole. Further, when one of the conducting wires 54A drawn out from the coil 54 is made negative and the other of the conducting wires 54B is made positive, the end face 52A side of the magnetic core 52 becomes the S pole.
At least a vehicle speed sensor 60 and an engine speed sensor 62 are connected to the control means 58, and the voltage applied to the coil 54 is turned on / off and the polarity is switched based on the vehicle speed and the engine speed.

Next, the operation of this embodiment will be described. In this vibration isolator 10, when the mounting frame 12 is connected to an engine (not shown) that is a vibration source and the inner cylinder 34 is fixed to a vehicle body (not shown) such as an automobile, the vibration generated in the engine is elastic body 36 through the mounting frame 12. The vibration can be absorbed by the damping function based on the internal friction of the elastic body 36.

At this time, the control means 58 controls the vehicle speed sensor 60.
When it is determined that the vibration is low frequency vibration based on the detection signal from the engine speed sensor 62, the control unit 58 energizes the coil 54 of the electromagnet 50. At this time, one side 54A of the conductive wire is made positive, and the other side 54B of the conductive wire is made negative so that the tip surface 52A side of the magnetic core 52 becomes the N pole. As a result, the magnetic core 52 side of the steel plate 30 is made an S pole, the steel plate 30 is attracted to the magnetic core 52, the steel plate 30 and the small diaphragm 26 are brought into close contact with the inner peripheral surface of the annular portion 14, and the pressure receiving liquid chamber 38
Movement due to pressure changes inside is blocked. Therefore, the liquid moves back and forth between the pressure receiving liquid chamber 38 and the sub liquid chamber 40 via the restriction passage 44 to vibrate the large diaphragm 28, resonates in the liquid column in the restriction passage 44, and receives the passage resistance and receives a low frequency. Absorbs vibration.

On the other hand, when the frequency of the vibration input to the vibration isolator 10 increases, the restriction passage 44 becomes clogged. When the control means 58 determines that the vibration is high frequency vibration based on the detection signals from the vehicle speed sensor 60 and the engine speed sensor 62, the applied voltage is turned off after the polarity of the applied voltage is inverted for a predetermined time as shown in FIG. To do. Steel plate 30
Is because the magnetic core 52 side is opposite to the magnetic core 52 due to the residual magnetism not only while the current is flowing through the coil 54 but also after the current flowing through the coil 54 is turned off. Turns off after reversing the polarity of the applied voltage for a predetermined time,
That is, by making the front end surface 52A side of the magnetic core 52 the S pole and then turning off the applied voltage, the steel plate 30 repels and can be instantly separated from the magnetic core 52. The time when the polarity of the applied voltage is reversed is set to the time when the repulsed steel plate 30 is not attracted to the magnetic core 52 again. As a result, the small diaphragm 26 is separated from the inner peripheral surface of the annular portion 14 and is in a free state, as shown in FIG. The small diaphragm 26 vibrates due to the pressure change due to the vibration in the pressure receiving liquid chamber 38, and the pressure increase in the pressure receiving liquid chamber 38 is suppressed, and the low dynamic spring constant of the vibration isolator 10 is obtained.

[Second Embodiment] A second embodiment of the present invention is shown in FIG.
Follow the instructions below. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, an air hole 64 communicating with the atmosphere is formed in the annular portion 14 corresponding to the air chamber 45,
The air in the air chamber 45 can freely move to and from the atmosphere side. Therefore, the movement of the small diaphragm 26 due to the pressure change of the liquid in the pressure receiving liquid chamber 38 is improved, and the small diaphragm 26 can vibrate to a higher frequency range.
It is possible to absorb vibrations in a wider frequency range as compared with a closed air chamber 45.

[Third Embodiment] FIG. 6 shows a third embodiment of the present invention.
Follow the instructions below. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 6, in this embodiment, the steel plate 30 is used.
A small protrusion 66 formed of an elastic body is provided on the surface of the. Therefore, the contact noise when the steel plate 30 is attracted by the magnetic core 52 of the electromagnet 50 and comes into contact with the inner peripheral surface of the annular portion 14 and the magnetic core 52 is reduced.

[Fourth Embodiment] FIG. 7 shows a fourth embodiment of the present invention.
Follow the instructions below. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, a gap (dimension t in FIG. 7) is provided between the tip surface 52A of the magnetic core 52 of the electromagnet 50 and the inner peripheral surface of the annular portion 14, and the tip surface 52A of the magnetic core 52 is provided. A ring-shaped elastic body 68 is fixed, and this elastic body projects by a predetermined dimension toward the steel plate 30 side from the front end surface 52A of the magnetic core 52. Therefore, also in this case, the contact noise when the steel plate 30 is attracted by the magnetic core 52 of the electromagnet 50 and abuts on the inner peripheral surface of the shaped portion 14 and the magnetic core 52 as in the second embodiment is prevented. .

[Fifth Embodiment] FIG. 8 shows a fifth embodiment of the present invention.
Follow the instructions below. The configuration of the present embodiment is the same as that of the first embodiment, so the illustration is omitted.

In this embodiment, as shown in FIG. 8, when the steel plate 30 is attracted again after the applied voltage is turned off, the tip surface 52A side of the magnetic core 52 is placed on the opposite pole to that of the previous attraction. Therefore, the control means 58 applies a voltage to the coil 54. In this way, the magnetic core 52 and the steel plate 30 are magnetized to alternate poles for each adsorption, so that the magnetic core 52 and the steel plate 30 are hard to be magnetized. Further, the risk of magnetizing the iron members arranged around the magnetic core 52 and the steel plate 30 is reduced.

In this embodiment, the electromagnet 50 is driven by direct current. However, the present invention is not limited to this, and it is sufficient that the electromagnet 50 can adsorb the steel plate 30, and the electromagnet 50 is driven by alternating current. It may be configured.

In the present embodiment, the steel plate 30 is used as the attracted means, but the invention is not limited to this, and the attracted means may be other materials such as stainless steel, iron alloys, and resins. The material is not limited as long as it is attracted by magnetic force.

Further, in this embodiment, the small diaphragm 26 is used.
Although the steel plate 30 is fixed to the small diaphragm 26 in the present invention, the present invention is not limited to this, and the attracting means such as a steel plate may be embedded in the small diaphragm 26. The metal powder such as iron is embedded in the small diaphragm 26. May be Further, the small diaphragm 26 may be formed of an elastic body mixed with metal powder such as iron.

In order to reduce the contact noise between the steel plate 30 and the magnetic core 52 of the electromagnet 50, the steel plate 30 or the magnetic core 52
A thin cushioning material such as resin may be attached to the abutting portion of.

In each of the embodiments, the invention is applied to the bush type vibration isolator, but the invention may be applied to the vibration isolator having a structure other than the bush type. is there.

[0037]

As described above, since the vibration isolator of the present invention has the above-described structure, it has an excellent effect that vibrations over a wide range of frequencies can be reliably absorbed.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a vibration isolator according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the vibration damping device according to the first embodiment of the present invention, showing a state in which a small diaphragm is in close contact with the inner circumference of the annular portion.

FIG. 4 is a graph showing a waveform of a voltage applied to a coil.

FIG. 5 is a sectional view showing an annular portion of a vibration damping device according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a vibration damping device according to a third embodiment of the present invention and showing a small diaphragm.

FIG. 7 is a sectional view showing a vibration damping device according to a fourth embodiment of the present invention and showing a small diaphragm.

FIG. 8 is a graph showing a waveform of a voltage applied to a coil according to a fifth embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a conventional vibration damping device.

[Explanation of symbols]

10 Anti-vibration device 16 Outer cylinder (first mounting member) 26 Small diaphragm (elastic membrane) 30 Steel plate (adsorbed means) 34 Inner cylinder (second mounting member) 36 Elastic body 38 Pressure receiving chamber 40 Sub liquid chamber 44 restricted passage 50 electromagnets

Claims (3)

[Claims] 1. A first mounting member connected to one of the vibration generating portion and the vibration receiving portion, a second mounting member connected to the other of the vibration generating portion and the vibration receiving portion, and the first mounting member. An elastic body that is provided between the member and the second mounting member and deforms when vibration occurs, a pressure receiving liquid chamber that can be expanded and contracted by using the elastic body as a part of a partition wall, and a partition wall of a part of the pressure receiving liquid chamber. An elastic film, an attracted device attached to the elastic film and attracted by a magnetic force, an electromagnet that attracts the attracted device, a sub liquid chamber separated from the pressure receiving liquid chamber, and the pressure receiving liquid chamber. An anti-vibration device, comprising: a limiting passage that communicates with the sub liquid chamber. 2. A DC voltage is applied to the electromagnet when the attracted means is attracted, and a polarity of the voltage applied to the electromagnet is reversed for a predetermined minute time when the attracted means is released. Then, the applied voltage control method for the electromagnet is characterized by setting the applied voltage to zero. 3. When the adsorbed means whose adsorption has been released is next adsorbed, a voltage having a polarity opposite to the polarity when the adsorbed means was previously adsorbed is applied to the electromagnet. And a method for controlling the applied voltage of the electromagnet.