KR100675041B1 - Plat spring rigity controling method of actuator - Google Patents

Abstract

A method for adjusting rigidity of a leaf spring of an actuator is provided to obtain a stable resonant frequency by adjusting the resonant frequency without forming a hole on the leaf spring. A leaf spring of an actuator includes a main body(53), a supporting part(51) formed at an end of the main body in order to be coupled with a housing, and a fixing part(52) formed at a part of the main body. A method for adjusting the rigidity of the leaf spring includes a process for coupling a mass with a position of the fixing part, a process for generating a measured value by measuring a resonant frequency of a leaf spring(50) coupled with the mass, and a process for determining the position of the fixing part by comparing the measured value with the predetermined reference value.

Description

Plate spring rigity controling method of actuator

1 is a longitudinal sectional view of an actuator according to the prior art;

Figure 2 is a bottom view of a leaf spring according to the prior art.

3 is a bottom view of a leaf spring according to a preferred embodiment of the present invention.

Figure 4a is an exemplary view showing a method of changing the position of the fixing portion of the leaf spring in accordance with a preferred embodiment of the present invention.

Figure 4b is an exemplary view showing a method of modifying the size of the fixing portion of the leaf spring in accordance with a preferred embodiment of the present invention.

5 is a flow chart of a method of adjusting the stiffness of the leaf spring according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

50: leaf spring 51: support

51a: Supporting force point 52: Fixed part

52a: fixed part strength point 54: leg part

The present invention relates to an actuator, and more particularly, to easily adjust the stiffness of a leaf spring elastically supported in a housing so as to vibrate up and down a magnetic field part and a mass body during operation of a vibration generating coil in accordance with a resonance frequency. The present invention relates to a method for adjusting the stiffness of the leaf spring of the actuator which is improved to reduce vibration defects and to reduce manufacturing costs.

In general, a mobile communication device such as a mobile phone or a pager includes an actuator capable of outputting sound and vibration, and such an actuator outputs an electric and electronically received voice signal or a pre-input bell or melody as a human readable sound. Or to output a vibration signal as an incoming signal.

1 is a longitudinal cross-sectional view showing an actuator according to the prior art, in which the conventional actuator 1 has an open lower portion of a housing 1a made of a hollow cylinder blocked by a shield plate 2, and the housing 1a. The diaphragm 3, which is a vibration plate for sound generation, is fixedly disposed on the open upper portion of the support ring 13, and the circumferential edge is inserted into and fixed to the inner wall of the housing 1a. A voice coil 4 is fixed to the center of the lower surface of the diaphragm 3.

In addition, an opening is formed in the center between the shield plate 2 and the diaphragm 3 and a leaf spring 5 having an outer edge fixed to an inner wall of the housing 1a is provided.

In addition, an upper surface of the mass 6 is attached to the lower surface of the leaf spring 5 as an adhesive, and an opening 6a is formed in the center of the mass 6 so that the yoke 7 is inserted thereinto, At least two fastening protrusions 6b formed at the edge are disposed and fixed, and the yoke 7 having the magnet member 8 magnetized perpendicularly to the upper surface is fitted and fixed to the opening 6a. The upper plate 9 is attached to the upper surface of the magnet member 8 to form the mother portion 10 together with the yoke 7, the magnet member 8 and the upper plate.

On the other hand, a vibration generating coil 11 is attached to the upper surface of the shield plate 2 directly below the yoke 7, and the mother-of-pearl formed by the yoke 7, the magnet member 8 and the upper plate 9. The magnetic flux of the part 10 is used to generate vibration.

The actuator 1 uses a set resonance frequency in the vibration mode, and generates a large vibration by the resonance of the set by exciting the actuator 1 at the resonance frequency, which is provided inside the housing 1a. Vibration is generated using the rigidity k of the leaf spring 5 and the magnetic flux of the mother portion 10 composed of the yoke 7, the magnet member 8, and the upper plate 9.

The actuator 1 uses the set resonance frequency in the vibration mode, and causes the actuator 1 to be generated at the resonance frequency to generate a large vibration by the resonance of the set. The vibration is provided inside the housing 1a. The stiffness k of the leaf spring 5, and the mass m of the mass 6 including the magnetic field portion 10 composed of the yoke 7, the magnet member 8 and the upper plate 9, Only a certain amount of resonance occurs at the input frequency.

However, in order to maintain a constant resonant frequency of the mobile phone terminal, there is a problem in that the stiffness of the mass (m) and the spring (k) of each component in the process of manufacturing and assembling the parts of the product.

That is, the resonance frequency (fn) of the actuator (1) is proportional to the value of (k / m) ^1/2 , in order for the actuator (1) to perform a vibration function, the leaf spring (5) at a low frequency of 100 to 200 Hz The vibrational movement in the up and down direction is required. When the mass m of the mass 6 changes by approximately 0.03 g, the resonant frequency fn of about 1 Hz is changed, and the resonant frequency fn is 2 to 3 Hz. When changed, the vibration amount of the actuator 1 is drastically reduced.

However, in order to adjust the resonance frequency, it is difficult to precisely adjust the resonance frequency by adjusting the mass m of the real body 6.

In addition, the stiffness k of the leaf spring 5 directly affecting the resonance frequency f n is mainly used in a range of 100 to 200 gf / mm, and the stiffness of the leaf spring 5 is changed by 2 gf / mm. The resonance frequency f n varies by about 1 Hz.

Here, 2gf / mm leaf spring 5 stiffness is obtained every time the thickness of the leaf spring 5, which elastically supports the entire vibrator including the mass 6 and the magnetic field portion 10, changes by about 1 mu m. Since it corresponds to the value, it was difficult to strictly control the thickness of the leaf spring 5 and to keep the resonant frequency of the actuator constant.

In order to maintain a constant resonant frequency as described above, thorough management of the components of the actuator is required, and the proportion of parts is also increasing because it is difficult to control the mass and the plate thickness in proportion thereto.

In order to solve this problem, conventionally, a method of adjusting the resonance frequency by changing the stiffness (k) of the spring by drilling the hole 16 in the leaf spring 5 has been proposed.

However, there is a problem that the spring shape of the periphery of the hole is vulnerable to bending and impact, so that deformation such as disconnection and bending occurs.

The present invention provides a method of adjusting the rigidity of the leaf spring of the actuator which can adjust the rigidity of the leaf spring corresponding to the reference value without forming a hole in the leg of the spring.

One side of the present invention, the rigidity of the leaf spring of the actuator including a body, a support portion formed at the end of the body coupled to the housing, and a fixed portion formed in a portion of the body spaced a predetermined distance from the support portion As a method of adjustment,

(a) coupling a mass of a size corresponding to the size of the fixing portion at a position where the fixing portion is formed, (b) measuring a resonant frequency of the leaf spring coupled with the mass to generate a measurement value, and (c) measuring A method of adjusting the leaf spring stiffness of an actuator is provided that includes determining a position of a fixture by comparing a value with a preset reference value.

 Step (c) includes (d) adjusting the fixing part when the measured value exceeds a predetermined error range with respect to the reference value; And (e) repeating steps (a) to (d) so that the measured value is within an error range with respect to the reference value. This is to reach the reference value with repeated adjustments.

Step (d) may change the position of the fixing portion or the size of the fixing portion.

The mass may also be attached by welding or adhesive.

Hereinafter, an embodiment of the method for adjusting the plate spring stiffness of the actuator according to the present invention will be described in detail with reference to the accompanying drawings, and in the following description with reference to the accompanying drawings, the same or corresponding components are the same regardless of the reference numerals. Reference numerals will be given and duplicate description thereof will be omitted.

Figure 3 is a bottom view of the leaf spring according to an embodiment of the present invention, Figure 4a is an illustration showing a method of changing the position of the fixing portion, Figure 4b is an illustration showing a method of modifying the size of the fixing portion It is also. Referring to FIG. 3, the leaf spring 50, the support 51, the support force point 51a, the fixed portion 52, the fixed portion force point 52a, the body 53, and the leg portion 54 are illustrated. .

The leaf spring 50 of FIG. 3 is fixed by the inner circumferential surface of the housing 1a and the support 51 as shown in FIG. 1. In addition, a fixing portion 52 to which the mass 6 of FIG. 1 is attached is formed at the bottom of the body 53. The body 53 and the support part 51 are connected by the leg part 54. The structure of the leaf spring 50 can be changed in various forms.

The resonance frequency (fn) of the actuator (1) of Figure 1 is proportional to the value of (k ^/ m) ^1/2 is bayida already described. In this embodiment, the resonance frequency f n is changed by changing the stiffness k of the leaf spring 50 without changing the mass of the mass 6 in FIG.

As shown in FIG. 3, the rigidity of the leaf spring 50 is inversely proportional to the distance d between the support force point 51a and the fixed force point 52a. The support force point 51a is a point at which the weight of the leaf spring 50 and the mass 6 of FIG. 1 attached thereto is supported by the housing 1a. On the other hand, the fixing part force point 52a is an edge of the fixing part 52 which is the point where the weight of the mass 6 is supported by the leaf spring 50 and is the shortest distance from the supporting part point 51a.

The distance d between the supporting force point 51a and the fixing force point 52a is adjustable by changing the position of the fixing portion 52 or modifying the size of the fixing portion 52 itself.

4A shows an example in which the distance d between the supporting force point 51a and the fixing force point 52a is adjusted by changing the position of the fixing portion 52. When the fixing portion 52 is changed in the direction of the arrow, the moving direction of the fixing portion force point 52a becomes the direction of the supporting portion force point 51a. Therefore, the distance d between the supporting force point 51a and the fixing force point 52a is shortened, and the rigidity of the leaf spring 52 is increased. (Because the rigidity of the distance d and the leaf spring 52 is inversely proportional) As a result, the resonance frequency increases.

Table 1 below shows the change value of the resonant frequency when the initial resonance frequency and the position of the fixed part 52 are moved 0.1 mm in the direction of the support force point 51a with respect to the ten leaf springs 52 coupled to the mass 6. This chart shows the amount of change.

Table 1

 No. Initial value (Hz) Change value (Hz) Change One 209.3 211.1 1.8 2 208.2 209.7 1.5 3 209.6 211.8 2.2 4 210.0 211.8 1.8 5 208.7 210.1 1.4 6 207.5 209.1 1.6 7 207.9 209.5 1.6 8 208.6 209.9 1.3 9 209.9 212.0 2.1 10 210.8 212.4 1.6 Average 209.1 210.7 1.7 maximum 210.8 212.4 2.2 at least 207.5 209.1 1.3

As shown in the above table, even in the case of the leaf spring 50 of the same model, an initial value error of the resonant frequency occurs, and the resonant frequency of about 1.7 Hz is averaged when the fixing part 52 is moved 0.1 mm in the direction of the support force point 51a. Shows an increase. Therefore, the resonant frequency fluctuation amount of the movement of the fixing unit 52 is measured and data for each model, and the position of the fixing unit 52 is changed to adjust the resonant frequency having a different initial value to the reference value.

4B shows an example of adjusting the distance d between the supporting force point 51a and the fixing force point 52a by modifying the size of the fixing portion 52. As the size of the fixing unit 52 increases, the fixing unit force point 52a is closer to the supporting unit force point 51a. Therefore, the distance d between the supporting force point 51a and the fixing force point 52a is shortened, and the rigidity is increased. As a result, the resonance frequency increases.

Method for adjusting the resonant frequency of the actuator based on the embodiment described above with reference to the flow chart of Figure 5 as follows.

Basically, the actuator has an optimal resonant frequency reference value to suit the product's characteristics. Before the actuator is commercialized, the rigidity of the leaf spring 50 is attached to the initial fixing part 52, and then measured. (S51) After comparison with the reference value, the fixing part 52 is adjusted according to the changed data. Change or change the position of (S53).

For example, when the measured value is smaller than the reference value, the position of the fixing part 52 is moved in the direction of the supporting force point 51a to increase the rigidity of the leaf spring 50. As a result, the resonance frequency is increased. On the other hand, when the measured value is larger than the reference value, the rigidity of the leaf spring 50 is reduced by moving the position of the fixing part 52 in the direction opposite to the supporting force point 51a. As a result, the resonance frequency is reduced.

After repeating the steps to reduce this error, the process is completed if it is equal to the reference value.

Although the technical spirit of the present invention has been described in detail according to the above-described embodiments, the above-described embodiments are for the purpose of description and not of limitation, and a person of ordinary skill in the art of the present invention will appreciate the technical spirit of the present invention. It will be understood that various embodiments are possible within the scope.

According to the above configuration, the present invention can easily adjust the resonance frequency without hole processing in the leaf spring. Therefore, the actuator can be provided with a leaf spring having a stable resonance frequency without changing the material or dimensions of the leaf spring.

Claims (6)

A method of adjusting the rigidity of an actuator leaf spring comprising a body, a support portion formed at an end of the body and coupled to a housing, and a fixing portion formed at a portion of the body spaced apart from the support portion by a predetermined distance, (a) coupling a mass of a size corresponding to the size of the fixing part at a position where the fixing part is formed; (b) measuring a resonance frequency of the leaf spring coupled with the mass to generate a measurement value; And and (c) determining the position of the fixing part by comparing the measured value with a preset reference value. The method of claim 1, Step (c) is, (d) adjusting the fixing part when the measured value exceeds a predetermined error range with respect to the reference value; And (e) repeating the steps (a) to (d) so that the measured value is within the error range with respect to the reference value. The method of claim 2, The step (d) is a method of adjusting the leaf spring stiffness of the actuator comprising the change of position. The method of claim 2, The step (d) is the method of adjusting the leaf spring stiffness of the actuator comprising the size change. The method of claim 1, And the mass is coupled to the fixed part by welding. The method of claim 1, And said mass body is attached to said fixing part via an adhesive.

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