WO2018092833A1

WO2018092833A1 - Vibration actuator mounting structure, electronic equipment provided with said vibration actuator mounting structure, and method for manufacturing vibration actuator mounting structure

Info

Publication number: WO2018092833A1
Application number: PCT/JP2017/041218
Authority: WO
Inventors: 慎介岡安; 宗一郎関田
Original assignee: 日本電産コパル株式会社
Priority date: 2016-11-17
Filing date: 2017-11-16
Publication date: 2018-05-24
Also published as: JP6715748B2; CN109963659B; CN109963659A; JP2018079434A

Abstract

The present invention makes it possible to suppress generation of sound and sufficiently generate vibration while saving space and with a simple structure. The present invention is provided with: a vibration actuator 10 having an outside surface on one end in a direction crossing the direction of vibration of an oscillator 12 as a vibration transmitting surface 11A; a first elastic sheet 20 affixed in contact with the vibration transmitting surface 11A; and a high specific gravity sheet 40 having specific gravity larger than the first elastic sheet 20 and affixed in contact with a surface on a side of the first elastic sheet 20 opposite to the vibration source. The surface of the high specific gravity sheet 40 opposite to the vibration source is in contact with a housing 50, which is the object to be vibrated.

Description

Vibration actuator mounting structure, electronic device including the vibration actuator mounting structure, and manufacturing method of the vibration actuator mounting structure

The present invention relates to a vibration actuator mounting structure in which a vibration actuator is fixed to a vibration object, an electronic device including the vibration actuator mounting structure, and a method for manufacturing the vibration actuator mounting structure.

Vibration actuators (or vibration motors) are widely used as devices that are built into portable electronic devices and transmit signal generation such as incoming calls and alarms to the wearer by vibrations. Has become an indispensable device. In recent years, vibration actuators have attracted attention as devices for realizing haptics (skin sensation feedback) in human interfaces such as touch panels.
Various types of such vibration actuators have been developed. In particular, there is a linear vibration actuator that can generate a relatively large vibration by linear reciprocating vibration of the mover. The linear vibration actuator has a weight and a magnet on the mover side, and the Lorentz force acting on the magnet becomes a driving force by energizing the coil provided on the stator side, and the mover that is elastically supported along the vibration direction. This is to reciprocate in one axis direction (see, for example, Patent Document 1).

JP 2016-34172 A

By the way, the purpose of such a vibration actuator is to make the user perceive various signals by vibration without generating sound. However, in the actual use state, the vibration of the vibration actuator is transmitted to the case and the like. Sound may be generated.
Therefore, there is a need for a structure that generates sufficient vibrations by suppressing the generation of noise such as vibration noise.In particular, in small electronic equipment, the installation space for vibration actuators is severely limited, and the structure is space-saving and simple. Therefore, it is necessary to devise such a structure.

In order to solve such a problem, the present invention has the following configuration.
A vibration actuator having an outer surface at one end intersecting the vibration direction of the vibrator as a vibration transmission surface, an elastic member in contact with and fixed to the vibration transmission surface, and a specific gravity greater than the elastic member and anti-vibration of the elastic member A vibration actuator mounting structure comprising: a high specific gravity member fixed in contact with a surface on the source side, wherein the surface on the anti-vibration source side of the high specific gravity member is in contact with a vibration object.

(A) is a perspective view which shows an example of the vibration actuator attachment structure which concerns on this invention, (b) is the longitudinal cross-sectional view which cut | disconnected (a) in the center of the transversal direction, and is a model of the internal structure of a vibration actuator Is shown. It is a top view of the electronic device provided with the same vibration actuator attachment structure, and shows the state which removed the front side panel. It is a principal part longitudinal cross-sectional view which shows the state which is performing the vibration sound pressure measurement about the electronic device provided with the vibration actuator attachment structure. It is a longitudinal cross-sectional view which shows the Example of the vibration actuator attachment structure which concerns on this invention, the comparative example 1, and the comparative example 2, respectively. It is a wave form diagram which shows a measurement result by setting a horizontal axis to a frequency and a vertical axis | shaft to a vibration level about the Example and comparative example 1 of a vibration actuator attachment structure in this invention. It is a wave form diagram which shows a measurement result by making a horizontal axis into a frequency and making a vertical axis into a sound pressure level about the Example and comparative example 1 of a vibration actuator attachment structure in this invention. FIG. 5 is a graph comparing the vibration levels (upper side) and a graph comparing the sound pressure levels (lower side) for the examples of the vibration actuator mounting structure according to the present invention, Comparative Example 1 and Comparative Example 2. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts having the same function, and repeated description in each drawing will be omitted as appropriate.

As shown in FIG. 1, the vibration actuator mounting structure 1 is fixed in contact with the vibration transmission surface 11 </ b> A having a vibration transmission surface 11 </ b> A whose outer surface at one end crossing the vibration direction of the vibrator 12 is in contact with the vibration transmission surface 11 </ b> A. Than the first elastic sheet 20 (elastic member), the second elastic sheet 30 (elastic member) fixed in contact with the outer surface of the other end portion of the vibration actuator 10 in the crossing direction, and the first elastic sheet 20 And a high specific gravity sheet 40 that is in contact with and fixed to the surface of the first elastic sheet 20 on the side of the anti-vibration source, and the surface of the high specific gravity sheet 40 on the side of the anti-vibration source is the housing 50 ( It is in contact with the vibration object.

As shown in FIG. 1B, the vibration actuator 10 includes a vibrator 12 having a magnet 12A and a weight 12B integrally in a hollow long cubic case 11, and a case close to the magnet 12A. 11 includes a drive coil 13 fixed to the inner surface and an elastic member 14 that repels the vibrator 12, and the vibrator 12 reciprocates in the longitudinal direction of the case 11 by a magnetic action when the drive coil 13 is energized.
The case 11 is a vibration for transmitting a vibration of the vibrator 12 to the outside by a surface parallel to the vibration direction of the vibrator 12 that is one end face in a direction orthogonal to the longitudinal direction (Z direction in the drawing). It is a transmission surface 11A.
According to an example of the present embodiment, the vibration actuator 10 has dimensions of 25 mm in the longitudinal direction (X direction), 6.0 mm in the short direction (Y direction), and 2.5 mm in the thickness direction (Z direction). is there.
As another example of the vibration actuator 10, the vibrator may be vibrated in the short direction of the case 11.

The first elastic sheet 20 is a polyurethane sheet having a semi-open cell structure as internal bubbles and a PET film having a thickness of 50 μm laminated and integrally formed, and the entire thickness is about 0.2 mm.
General physical properties of the first elastic sheet 20 are as follows: density 320 kg / m ³ (test method: JIS K6401), 25% compression load 0.011 MPa (test method: JIS K6254), compressive residual strain 2.2% (test method: JIS K6401).
The first elastic sheet 20 has an effect of suppressing vibration and transmission of sound pressure due to its elasticity and semi-open cell structure.
For the first elastic sheet 20, for example, a product number SR-S-32P manufactured by Roger Sinoac Co., Ltd. can be used.
The first elastic sheet 20 is formed in a rectangular sheet shape having substantially the same shape as the vibration transmission surface 11A of the vibration actuator 10 (25 mm × 2.5 mm in the illustrated example), and is bonded to the vibration transmission surface 11A. It is bonded and fixed via an agent.

The second elastic sheet 30 is an elastic sheet having a thickness greater than that of the first elastic sheet 20. In the example of the present embodiment, the second elastic sheet 30 is made of the same material as the first elastic sheet 20 and has a thickness of about 0.6 mm. The sheet material is used.
The second elastic sheet 30 is formed in a rectangular sheet shape having substantially the same shape (25 mm × 2.5 mm in the illustrated example) as the surface opposite to the vibration transmitting surface 11A of the vibration actuator 10, It is bonded and fixed to the surface via an adhesive.
The back surface of the touch operation panel A1 (including a touch display) of the electronic device A described later is in contact with the surface of the second elastic sheet 30.

The high specific gravity sheet 40 is a sheet material made of a composite material including a metal powder and a synthetic resin material, and has a specific gravity and thickness larger than those of the first elastic sheet 20.
The high specific gravity sheet 40 in the illustrated example has a specific gravity of about 11.5, a thickness of about 1 mm, a hardness of 95.6 durometer A (test method: JIS K6253), a tensile strength of 4.4 MP (test method: JIS K6251), at the time of cutting. The elongation is 25% (test method: JIS K6251). As a preferred example of the metal powder, tungsten powder is used. In addition, an elastic synthetic resin material (for example, urethane) such as an elastomer resin is used as the synthetic resin material.
The high specific gravity sheet 40 has an effect of attenuating vibration and sound pressure.
In addition, as this high specific gravity sheet | seat 40, the product name: Nippon Tungsten Co., Ltd. product name: Resin tungsten sheet | seat, the thing of specific gravity 11.5 or more can be used, for example.
The high specific gravity sheet 40 is formed in a rectangular sheet shape having substantially the same shape as the first elastic sheet 20 (25 mm × 2.5 mm in the illustrated example), and is on the anti-vibration source side of the first elastic sheet 20. It is bonded and fixed to the surface of this through an adhesive.
Further, the surface on the anti-vibration side of the high specific gravity sheet 40 is bonded and fixed to the inner surface of a casing 50 (vibration object) in the electronic device A described later via an adhesive.

The electronic device A is a smartphone according to the illustrated example, and is equipped with a battery pack, a CPU, a storage device, a communication unit, and the like in the housing 50, and the front panel of the housing 50 is touched. The operation panel A1 (see FIG. 3) passes through, and the touch operation panel A1 is exposed to the outside.
FIG. 2 shows a state in which the front panel and the touch operation panel A1 are removed.

The casing 50 is made of a 7000 series aluminum alloy and is formed in a rectangular box shape having an X direction of about 67 mm, a Y direction of about 138 mm, and a Z direction of about 7 mm. The thickness of each part is 0.9 mm. .

The vibration actuator 10, the first elastic sheet 20, the second elastic sheet 30, and the high specific gravity sheet 40 described above are arranged so as to be sandwiched between the bottom surface in the housing 50 and the back surface of the touch operation panel A1 ( (See FIG. 3).

In addition, the manufacturing method of the vibration actuator mounting structure 1 having the above-described configuration includes a step of bonding the first elastic sheet 20 to the vibration transmission surface 11A of the vibration actuator 10 and a side opposite to the vibration transmission surface 11A of the vibration actuator 10. A step of adhering the second elastic sheet 30 to the surface, a step of adhering the high specific gravity sheet 40 to the surface of the first elastic sheet 20 on the anti-vibration source side, and an anti-vibration source side surface of the high specific gravity sheet 40. And the process of adhering to the casing 50 (vibration object), and the order in which these processes are performed can be appropriately set.

Next, the results of comparative tests on the vibration actuator mounting structure 1 configured as described above will be described.
In this embodiment, the electronic device A having the vibration actuator mounting structure 1 is opened by removing the front panel and the touch operation panel A1 (see FIG. 3).
Further, the comparative example 1 omits the high specific gravity sheet 40, and the first elastic sheet 20 has the same thickness as the second elastic sheet 30 (about 0.6 mm) and is made of the same material. The surface of the elastic sheet 20 ′ on the side opposite to the vibration source is bonded and fixed to the housing 50 (vibration object) (see the center of FIG. 4).
Further, in Comparative Example 2, only the first elastic sheet 20 is omitted, and the vibration transmission surface 11A of the vibration actuator 10 is directly bonded to the high specific gravity sheet 40 (see the lower side in FIG. 4). .

In this comparative test, the vibration pickup B1 was bonded and fixed to the outer surface of the casing 50, and the microphone B2 was installed 10 cm above the casing 50.
Then, AC power having a predetermined waveform was applied to the vibration actuator 10 to vibrate the vibrator 12 in the vibration actuator 10 at about 150 Hz, and measurement of the vibration level and sound pressure level and frequency analysis were performed.

FIG. 5 is a graph showing measurement results with the horizontal axis representing the frequency and the vertical axis representing the vibration level. In the upper comparative example 1, the average level L (in the dense part in the range a of 1000 to 3000 (Hz) (L The level L is approximately −100 (dB) in the range a of 1000 to 3000 (Hz) in the lower embodiment, which is sometimes referred to as a floor level). That is, the vibration level of the example is approximately 10 (dB) lower than that of the comparative example 1.

FIG. 6 is a graph showing measurement results with the horizontal axis representing frequency and the vertical axis representing sound pressure level. In the upper comparative example 1, the level L is approximately −15 (dB) in the range a of 1000 to 3000 (Hz). In the lower embodiment, the level L is approximately −20 (dB) in the range a of 1000 to 3000 (Hz). That is, the sound pressure level of the example is about 5 (dB) lower than that of the comparative example 1.

Also, from these graphs, it can be seen that both the vibration and the sound pressure tend to be lower in the example than in Comparative Example 1 in a high frequency region of about 700 Hz or more.

The bar graph on the upper side of FIG. 7 is a comparison of vibration levels for the example, comparative example 1, and comparative example 2.
The bar graph on the lower side of FIG. 7 compares the sound pressure level (A characteristic sound pressure level) for Example, Comparative Example 1, and Comparative Example 2.
From these graphs, the vibration level is not significantly different between Example, Comparative Example 1 and Comparative Example 2, but the sound pressure level is lower in Comparative Example 2 than in Comparative Example 1, and further in Example than in Comparative Example 2. Was low. The sound pressure level of the example was 1.6 db smaller than that of the comparative example 1.

Therefore, according to the vibration actuator mounting structure 1, the sound pressure level can be remarkably reduced without substantially reducing the vibration level by the space-saving, thin and light simple structure.
That is, in this embodiment, vibration and sound pressure in a high frequency region of 700 Hz or higher are reduced, but generally, vibration of 500 Hz or higher is hardly perceived, and therefore only the sound pressure level is significant for the entire frequency. It is inferred that it has declined.

In the vibration actuator mounting structure 1 of the present embodiment, the second elastic sheet 30 opposite to the vibration transmission surface 11A is brought into contact with the back surface of the touch operation panel A1, so that the vibration actuator 10 and the touch operation panel are in contact with each other. The contact state of A1 is stabilized. For this reason, generation | occurrence | production of noises, such as a chatter sound, can be prevented.

In addition, according to the said embodiment, although the electronic device A which comprises the vibration actuator attachment structure 1 was used as the smart phone, as another example of this electronic device A, it does not have a wristwatch type wearable computer or touch operation panel A1. It can be used for electronic devices.

As described above, the embodiments of the present invention have been described in detail. However, the specific configuration is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: Vibration actuator mounting structure
10: Vibration actuator 11: Case
11A: Vibration transmission surface 20: First elastic sheet (elastic member)
30: Second elastic sheet (elastic member)
40: High specific gravity sheet (high specific gravity member)
50: Housing (vibration object)
A: Electronic equipment
A1: Touch operation panel B1: Vibration pickup
B2: Microphone

Claims

A vibration actuator having an outer surface at one end intersecting the vibration direction of the vibrator as a vibration transmission surface, an elastic member in contact with and fixed to the vibration transmission surface, and a specific gravity greater than the elastic member and anti-vibration of the elastic member A vibration actuator mounting structure comprising: a high specific gravity member fixed in contact with a surface on the source side, wherein the surface on the anti-vibration source side of the high specific gravity member is in contact with a vibration object.
2. The vibration actuator mounting structure according to claim 1, wherein the elastic member has internal bubbles.
3. The vibration actuator mounting structure according to claim 1, wherein the high specific gravity member includes a synthetic resin material and a metal powder.
The vibration actuator mounting structure according to any one of claims 1 to 3, wherein a thickness of the high specific gravity member in the intersecting direction is larger than a thickness of the elastic member in the same direction.
The elastic member is a first elastic member,
5. The vibration actuator mounting structure according to claim 1, wherein a second elastic member is in contact with and fixed to the outer surface of the vibration actuator at the other end in the intersecting direction.
An electronic device comprising the vibration actuator mounting structure according to any one of claims 1 to 5.
Adhering the elastic member to the vibration transmitting surface of the vibration actuator, adhering the high specific gravity member to the anti vibration source side surface of the elastic member, and the anti vibration source side surface of the high specific gravity member A method for manufacturing a vibration actuator mounting structure according to any one of claims 1 to 6, further comprising a step of adhering to the vibration object.