JPH06280938A - Damping device for printed circuit board - Google Patents

Abstract

PURPOSE:To generate a desired damping force easily by installing protrusively a permanent magnet on each side of a printed circuit board, and furnishing a pair of electric magnets having magnetic poles opposite the permanent magnet in such a way pinching the printed circuit board, and thereby adjusting the energization current for the electric magnets. CONSTITUTION:In a printed circuit board 1 a permanent magnet 5 is embedded in such a way that the upper and lower magnetic poles protrude at the sides of the board 1, and on a spacer 6 installed upright on a mounting board 4, electric magnets 7a, 7b are mounted as confronting the permanent magnet 5 while positioning over and under the same 5. The electric magnets 7a, 7b consist of respective energization coils 8, 9 and iron cores 13a, 13b, and one end of the coil 8 is connected with one end of the other coil 9, while the other ends of the coils 8, 9 are connected with a current adjuster 10. This current adjuster 10 adjusts the energization currents to be fed to the coils 8, 9 so that the spring constant set by a spring constant adjuster 11 is accomplished, and thereby the printed circuit board 1 is supported with a proper damping force.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board vibration damping device, and more particularly, to a printed circuit board vibration damping device that absorbs and attenuates vibrations and shocks transmitted to the printed circuit board by the repulsive force of magnetic force.

[0002]

2. Description of the Related Art As a conventional vibration damping device for a printed circuit board, there is known one in which the printed circuit board is supported by a rubber cushion and the vibration and shock transmitted to the printed circuit board are absorbed and attenuated by the elastic force of the rubber cushion. There is. FIG. 7 is a cross-sectional view of a printed circuit board vibration damping device using such a rubber buffer. 1 is a printed circuit board, 2 is a rubber shock absorber, 3 is a mounting member fixed to the rubber shock absorber 2 by baking or adhesion,
Reference numeral 4 is a mounting board for fixing the printed circuit board.

Although not a vibration damping device for printed circuit boards, a bearing device utilizing magnetic force is disclosed in, for example, Japanese Patent Laid-Open No. 2-23.
It is disclosed in Japanese Patent No. 6019 and Japanese Patent Laid-Open No. 3-69819.

[0004]

The conventional vibration damping device for a printed circuit board using the rubber shock absorber has a problem that the vibration damping force of the rubber shock absorber is fixed and cannot be flexibly dealt with different printed circuit boards. . The present invention has been made to solve such a problem, and an object of the present invention is to obtain a printed circuit board vibration damping device capable of flexibly adjusting the vibration damping force according to the printed circuit board.

[0005]

First, a vibration damping device for a printed circuit board according to the present invention is provided with a permanent magnet projecting on both sides of the printed circuit board and a permanent magnet provided so as to sandwich the printed circuit board and opposed to the permanent magnet. A pair of electromagnets having magnetic poles, power supply means for supplying an exciting current to the exciting coil of the electromagnet so that the magnetic poles of the electromagnets have the same polarity as the opposing magnetic poles of the permanent magnet, and the exciting current adjustment for adjusting the exciting current. Means and means are provided.

Secondly, the vibration damping device for a printed circuit board of the present invention is characterized in that, in addition to the above-mentioned first structure, at least one opposing surface of the permanent magnet or the electromagnet is covered with a cushioning material. is there.

Thirdly, in the vibration damping device for a printed circuit board of the present invention, in addition to the above-mentioned first structure, at least one of the cores of the permanent magnets or the electromagnets is formed by mixing the magnetic powder with the buffer material. It is characterized by consisting of things.

Fourthly, the vibration damping device for a printed circuit board according to the present invention is, in addition to the first to third configurations, a vibration detection means for detecting a vibration transmitted to or likely to be transmitted to the printed circuit board. It is characterized by further comprising a damping force adjusting means for changing the damping force according to the detected vibration.

[0009]

In the vibration damping device for a printed circuit board having the above-described first structure, the repulsive force of the magnetic force between the permanent magnet and the electromagnet becomes the vibration damping force. Therefore, the exciting current flowing in the exciting coil of the electromagnet is adjusted by the exciting current adjusting means. A desired damping force can be easily obtained by adjusting.

In the vibration damping device for a printed circuit board having the above-mentioned second structure, since at least one of the opposing surfaces of the permanent magnet or the electromagnet is covered with the cushioning material, the absorption / attenuation of the vibration / shock is insufficient and the permanent magnet and the electromagnet. Even when and are in contact with each other, the vibration / impact due to the contact can be alleviated by the buffer force of the buffer material.

In the vibration damping device for a printed circuit board having the third structure, at least one of the cores of the permanent magnets and the electromagnets is formed by mixing the magnetic powder with the cushioning material, so that the vibration
Even if the permanent magnet and electromagnet come into contact with each other due to insufficient shock absorption / damping, the vibration / shock caused by the contact is absorbed by the cushioning force of the cushioning material (specifically, the deformation of at least one of the permanent magnet and the electromagnet core). Can be relaxed.

In the printed circuit board vibration damping device having the above-mentioned fourth structure, the vibration / impact transmitted to the printed circuit board or the vibration / impact that may be transmitted is detected by the vibration detecting means, and the detected vibration / impact is detected. Since the damping force is changed by the damping force adjusting means, it is possible to positively cancel the vibrations / impacts transmitted to the printed circuit board or the vibrations / impacts likely to be transmitted.

[0013]

EXAMPLES Example 1. FIG. 1 is a sectional configuration diagram of a printed circuit board vibration damping device according to a first embodiment. Permanent magnets 5 are embedded in the printed board 1 and project on both sides of the printed board 1. The permanent magnet 5 is a ferrite magnet, and the magnetic pole protruding above the printed circuit board 1 is an S pole, and the magnetic pole protruding below the printed circuit board 1 is an N pole. On the mounting board 4,
Spacers 6 are provided so as to sandwich the printed board 1. Electromagnets 7a and 7b are inserted in the spacer 6, respectively. The electromagnet 7a includes an exciting coil 8 and an iron core 13a.
It consists of The electromagnet 7b is composed of an exciting coil 9 and an iron core 13b. One end of the exciting coil 8 is connected to one end of the exciting coil 9. The other ends of the exciting coils 8 and 9 are connected to the current regulator 10. The current regulator 10 is connected to the spring constant regulator 11. Further, the spring constant adjuster 11 is connected to the main power supply device 12.

From the main power unit 12, the spring constant adjuster 11
And through the current regulator 10 to the exciting coils 8 and 9,
An exciting current is supplied, the lower magnetic pole of the electromagnet 7a becomes the S pole, and the upper magnetic pole of the electromagnet 7b becomes the N pole. Therefore,
A repulsive force due to magnetic force acts between the permanent magnet 5 and the electromagnets 7a and 7b, so that the printed circuit board 1 floats in the air and is supported by an invisible spring. The operator can arbitrarily set the spring constant by the spring constant adjuster 11. The current adjuster 10 adjusts the exciting current so as to achieve the set spring constant.

According to the printed circuit board vibration damping device of the first embodiment, if the spring constant adjuster 11 is provided with an appropriate spring constant according to the mass of the printed circuit board and the vibration / impact environment, printing is performed with an appropriate vibration damping force. The substrate 1 can be supported, and vibrations and shocks can be absorbed and damped appropriately.

Example 2. FIG. 2 is a cross-sectional view of a printed circuit board vibration damping device according to a second embodiment. This printed circuit board vibration damping device has substantially the same structure as the printed circuit board vibration damping device shown in FIG. 1, except that the opposing surfaces of the permanent magnet 5 and the electromagnets 7a and 7b are covered with rubber 14. . Example 2
According to the printed circuit board vibration damping device of FIG.
Permanent magnet 5 and electromagnet 7 without being able to absorb and damp shock
When the a and 7b come into contact with each other, the rubber 14 can alleviate vibration and impact.

Embodiment 3. FIG. 3 is a sectional view of a printed circuit board vibration damping device according to a third embodiment. This printed circuit board vibration damping device has substantially the same structure as the printed circuit board vibration damping device shown in FIG. 1, but instead of the permanent magnet 5, rubber is mixed with hard magnetic powder and molded and magnetized. The difference is that the rubber magnet 15 is used. Further, instead of the electromagnets 7a and 7b, a rubber core 2 formed by mixing soft magnetic powder with rubber and molding the mixture.
The difference is that electromagnets 17a and 17b having 3a and 23b are used. According to the printed circuit board vibration damping device of the third embodiment, when the rubber magnet 15 and the electromagnets 17a and 17b come into contact with each other without being able to absorb and damp the vibrations and shocks of the mounting board 4, the rubber magnet 15 and the rubber magnets. The cores 23a and 23b are deformed, so that vibration and impact can be mitigated.

Example 4. FIG. 4 is a sectional view of a printed circuit board vibration damping device according to a fourth embodiment. Permanent magnets 5 are embedded in the printed board 1 and project on both sides of the printed board 1. The permanent magnet 5 is a ferrite magnet, and the magnetic pole protruding above the printed circuit board 1 is an S pole, and the magnetic pole protruding below the printed circuit board 1 is an N pole. A spacer 6 is provided on the mounting board 4 so as to sandwich the printed circuit board 1. The spacer 6 includes electromagnets 27a and 27b.
Are inserted respectively. The electromagnet 27a includes an exciting coil 28 and an iron core 13a. Also, the electromagnet 27
b is composed of an exciting coil 29 and an iron core 13b. The exciting coils 28 and 29 are independent of the current regulator 30.
It is connected to the. The current regulator 30 is connected to the spring constant regulator 31. Further, the spring constant adjuster 31 is
It is connected to the waveform processing device 40. Further, the waveform processing device 40 is connected to the main power supply device 42. on the other hand,
A vibration sensor 18 (for example, a piezoelectric acceleration sensor) for detecting a vibration / impact applied to the printed board 1 is attached to the printed board 1. The detection signal output from the vibration sensor 18 is input to the waveform processing device 40 via the vibration meter 19.

From the main power supply unit 42 to the waveform processing unit 40,
Exciting currents are independently supplied to the exciting coils 28 and 29 via the spring constant adjuster 31 and the current adjuster 30, so that the lower magnetic pole of the electromagnet 27a becomes the S pole and the upper magnetic pole of the electromagnet 27b becomes Become the N pole. Therefore, the permanent magnet 1
A repulsive force due to a magnetic force acts between the electromagnet 5 and the electromagnets 27a and 27b, and the printed circuit board 1 floats in the air and is supported by an invisible spring. The operator can arbitrarily set the spring constant by the spring constant adjuster 31. The current adjuster 30 adjusts the exciting current so as to realize the set spring constant.

When the printed circuit board 1 is vibrated / impacted, the vibration / impact is quantified by the vibration sensor 18 and the vibrometer 19 and input to the waveform processing device 40 as a detection voltage. The waveform processing device 40 is shown in FIG.
When a detection voltage as shown in (a) is input, the phase is inverted as shown in (b) of FIG. 5 and the next voltage waveform is predicted as shown in (c) of FIG. After correcting the time delay due to the calculation of and the delay time of the repulsive force due to the magnetic force,
As shown in (d) and (e) of FIG.
And a voltage waveform to be applied to the exciting coil 29, which are respectively decomposed and input to the spring constant adjuster 31. The spring constant adjuster 31 adjusts the spring constant according to the calculated voltage waveform. Therefore, the vibration / impact transmitted to the printed circuit board 1 can be positively canceled. FIG. 6 is a vibration damping control system diagram of the printed circuit board vibration damping device.

According to the printed circuit board vibration damping apparatus of the fourth embodiment, the vibration damping force is adjusted in accordance with the vibrations / impacts transmitted to the printed circuit board 1, so that the vibrations / impacts can be positively canceled.

[0022]

According to the vibration damping device for a printed circuit board of the present invention, since the repulsive force of the magnetic force between the permanent magnet and the electromagnet becomes the vibration damping force, the exciting current flowing in the exciting coil of the electromagnet is changed to the exciting current adjusting means. The desired damping force can be easily obtained by adjusting the.

Further, if at least one of the opposing surfaces of the permanent magnet or the electromagnet is covered with the cushioning material, even if the permanent magnet and the electromagnet come into contact with each other due to insufficient absorption / damping of vibration / shock, the contact is made. Vibration and shock caused by can be alleviated by the cushioning force of the cushioning material.

Further, if at least one of the permanent magnet or the core of the electromagnet is formed by mixing the magnetic powder with the buffer material, the absorption / damping of vibration / shock is insufficient and the permanent magnet and electromagnet are separated. Even in the case of contact, vibration / impact due to the contact can be alleviated by the buffering force of the buffer material (specifically, deformation of at least one of the core of the permanent magnet or the electromagnet).

Further, the vibration / impact transmitted to the printed circuit board or the vibration / impact that may be transmitted is detected by the vibration detecting means, and the vibration damping force adjusting means changes the damping force according to the detected vibration / impact. With the configuration, it is possible to positively cancel the vibration / impact transmitted to the printed circuit board or the vibration / impact that may be transmitted.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a printed circuit board vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional configuration diagram of a printed circuit board vibration damping device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional configuration diagram of a printed circuit board vibration damping device according to a third embodiment of the present invention.

FIG. 4 is a sectional configuration diagram of a vibration damping device for a printed circuit board according to a fourth embodiment of the present invention.

5 is a conceptual diagram of waveform processing in the printed circuit board vibration damping device of FIG. 4;

6 is a control system diagram of the printed circuit board vibration damping device of FIG. 4;

FIG. 7 is a cross-sectional configuration diagram of an example of a conventional printed circuit board vibration damping device.

[Explanation of symbols]

1 Printed circuit board 4 Mounting board 5 Permanent magnet 6 Spacer 7a, 7b, 17a, 17b, 27a, 27b Electromagnet 8, 9, 28, 29 Excitation coil 10, 30 Current regulator 11, 31 Spring constant regulator 12, 42 Main power supply Device 13a, 13b Iron core 14 Rubber 15 Rubber magnet 18 Vibration sensor 19 Vibrometer 23a, 23b Magnetic rubber core 40 Waveform processing device

Claims (4)

[Claims] 1. A permanent magnet protruding on both sides of a printed circuit board, a pair of electromagnets provided so as to sandwich the printed circuit board and having magnetic poles facing the permanent magnet, and magnetic poles of the electromagnets opposed to the permanent magnet. A vibration damping device for a printed circuit board, comprising: power supply means for supplying an exciting current to the exciting coil of the electromagnet so as to have the same polarity as that of, and exciting current adjusting means for adjusting the exciting current. 2. The vibration damping device for a printed circuit board according to claim 1, wherein at least one facing surface of the permanent magnet or the electromagnet is covered with a cushioning material. 3. The vibration damping device for a printed circuit board according to claim 1, wherein at least one of the cores of the permanent magnets or the electromagnets is formed by mixing magnetic powder with a buffer material and molding the mixture. Vibration control device for printed circuit boards. 4. The vibration damping device for a printed circuit board according to any one of claims 1 to 3, further comprising: vibration detection means for detecting a vibration / impact transmitted to the printed circuit board or a vibration / impact that is likely to be transmitted. A vibration damping device for a printed circuit board, further comprising vibration damping force adjusting means for changing the vibration damping force according to the detected vibration / shock. [0001]