TWI585594B - The flexible element of the steady state system - Google Patents

Description

Flexible element of steady state constant force system

The present invention relates to a flexible element, and more particularly to a flexible element of a steady state constant force system.

Microelectromechanical systems (MEMS) are machines that are less than 1 mm in size and capable of performing precision and specific operations in a very small space. Flexible elements in MEMS that can change position in two steady-state positions are often used for switches, clamping configurations, valves, and the like.

For example, the invention patent case of the "active steady-state clamp release system" of the Republic of China Patent No. I515162 or the "bistable constant force system with protection mechanism" of the I465725 is mainly made of flexible components. The characteristics of the deflection at two steady-state positions achieve the purpose of the demand.

However, the flexible components used in the foregoing cases may have different design considerations due to space environment constraints or changes in the amount of actuation force required to be driven. However, in a limited space, depending on different conditions, determining the curve profile of the demand is a great problem in design.

Accordingly, it is an object of the present invention to provide a flexible element of a steady-state constant force system that achieves a contour profile that is optimal in performance and that effectively enhances design freedom.

Thus, a steady-state constant force system includes an actuating element and at least two flexible elements coupled to the actuating element and symmetrical to each other, each flexible element bearing an actuation force at a first steady state position and a second steady state The position of the state is flexed and deformed.

Each flexible element of the present invention is based on a function of the Bezier curve 0 t 1. Determining the Bezier curve profile, and defining a first control point P _B1 , a second control point P _B2 , a third control point P _B3 , and a fourth control point P _B4 , where t is a constant, Each flexible element has an X-axis length range and a Y-axis length range, the X-axis length range including a minimum value X _min and a maximum value X _max , the Y-axis length range including a minimum value Y _min and a The maximum value Y _max , the coordinate value of the first control point P _B1 is (X _min , Y _min ), the coordinate value of the fourth control point P _B4 is (X _max , Y _max ), and the second control point P _B2 is The coordinate value of the third control point P _B3 is a variable according to the actuation force required when the first steady state position and the second steady state position are respectively.

The utility model has the advantages that: by utilizing the characteristics of the Bezier curve, the invention can obtain the best performance curve profile by only controlling the second and third control points, and Improve the freedom of design.

1‧‧‧ Steady-state constant force system

11‧‧‧ actuation element

12‧‧‧Flexible components

X‧‧‧ axis

Y‧‧‧ axis

F‧‧‧ motivation

F‧‧‧ reaction

F1‧‧‧ limit value

F2‧‧‧ limit value

A‧‧‧ position

B‧‧‧ position

C‧‧‧ position

P _B1 ‧‧‧First Control Point

P _B2 ‧‧‧second control point

P _B3 ‧‧‧ third control point

P _B4 ‧‧‧fourth control point

Other features and advantages of the present invention will be apparent from the embodiments of the appended drawings, wherein: Figure 1 is a top view illustration of one embodiment of a flexible element of the steady state constant force system of the present invention; This embodiment is a reaction force-displacement amount graph of a first steady state position and a second steady state position, respectively; FIG. 3 is an X-axis length range - Y-axis length range of a flexible member in this embodiment. FIG. 4 is a flow chart of the embodiment; FIG. 5 is a comparison diagram of an X-axis length range-Y-axis length range of a contour of a Bezier curve, a cosine curve, and a linear curve, respectively; FIG. 6 is a comparison diagram of a reaction force-displacement amount curve of the design contour of the Bezier curve, the cosine curve, and the linear curve, respectively, in the embodiment.

Referring to Figure 1, a steady state constant force system 1 includes an actuating element 11 and four flexible elements 12 coupled to the actuating element 11 and symmetrical to one another. Each flexible element 12 is subjected to an actuation force f that is flexibly deformed between a first steady state position and a second steady state position. In this embodiment, each of the flexible elements 12 is a tantalum material. In the linear elastic and isotropic model, the Young's modulus E is 130 GPa, and the strain along a X-axis direction is along the line. The ratio of the strain in the Y-axis direction (Poisson's ratio) was 0.28.

Referring to FIG. 2, when the flexible elements 12 of the steady-state constant force system 1 are not subjected to the actuation force f, since the reaction force F is not generated, the reaction force F is 0 mN, and is stabilized at the first Steady position. When the flexible elements 12 are subjected to the action of the actuation force f and are flexibly deformed to the second steady-state position in the Y-axis direction, it can be found that the flexible elements 1 are produced as indicated by the solid lines in the figure. The reaction force F increases as the displacement increases. After the position a reaches a limit value F1, the generated reaction force F drops to 0 mN at the position b. At this time, the flexible members 12 are still in an unstable bomb. In the moving state, when the displacement amount is further increased, the generated reaction force F is decreased, and after reaching the other limit value F2, it is again increased to 0 mN of the position c. Thereby, by simply stopping the application of the actuation force f, the flexible elements 12 can be made to have a constant reaction force F (0 mN) and stabilized at the second steady state position.

It should be noted that the driving mode and the action mode of the driving force f generated by the present invention can be similar to the case of the Republic of China Patent No. I515162. Since the general knowledge in the art can infer the details of the expansion based on the above description, it will not be explained.

Referring to Figures 3 and 4, the flexibility of the steady state constant force system 1 of the present invention is combined below. An embodiment of the component 12 and the design steps are as follows:

Step 21: Define a first control point P _B1 , a second control point P _B2 , a third control point P _B3 , and a fourth control point P _B4 according to a function formula of the Bezier curve.

The function formula of the Bezier curve: 0 t 1 where t is a constant and P _B1 ~ P _B4 are vector positions.

Step 22: Determine the range of the X-axis length and the length of the Y-axis of the Bezier profile of each of the flexible elements 12. The X-axis length range includes a minimum value _Xmin and a maximum value _Xmax , the Y-axis length range including a minimum value _Ymin and a maximum value _Ymax .

For example, the X-axis length range and the Y-axis length range of the Bezier profile of each flexible element 12 can be determined in accordance with the limitation of the space environment. In this embodiment, X _min and Y _min are respectively 0, X. _Max is 20 um , Y _max is 600 um , and the width of each flexible element 12 along the Y-axis is 5 um .

Step 23: Given that the coordinate value of the first control point P _B1 is (X _min , Y _min ), the coordinate value of the fourth control point P _B4 is (X _max , Y _max ).

It should be noted that, in this embodiment, each of the flexible elements 12 includes two edges 121 spaced apart by a distance along the Y-axis direction, and the first control point P _B1 and the fourth control point P _B4 are respectively the same edge. The two endpoints of 121.

Step 24: The second control point P _B2 and the third control point P _B3 are variables, and the contour of the Bezier curve corresponding to each flexible component 12 is calculated, and the first steady state position and the second stable state are located. The actuation force F required for the position of the state.

In this embodiment, the minimum actuation force f is obtained as the best performance, and the variables of the second control point P _B2 and the third control point P _B3 are random numbers, and the number of random numbers can be given after setting the generation number. Determining the complex array variable for each generation, calculating the Bezier profile corresponding to each flexible element 12, and the minimum actuation force f required at the first steady state position and the second steady state position (ie, relative The resulting reaction force F), based on the variable array of the minimum actuation force f in each generation, determines the variable array of the next generation, and so on to calculate all the generations.

Step 25: Select the set of variables corresponding to the required actuation force f (ie, the relative reaction force F generated), and the corresponding Bezier curve profile. In the present embodiment, a Bezier curve profile capable of calculating the minimum actuation force f (i.e., the relatively generated minimum reaction force F) is selected.

It can be clearly seen from Fig. 5 and Fig. 6 that the length of the X-axis of the linear curve is proportional to the length of the Y-axis, and the length of the X-axis of the cosine curve is also proportional to the length of the Y-axis. Therefore, the length of the X-axis is limited. After the length of the Y-axis is determined, the actuation force is also determined, and the present invention only needs to control the second control point P _B2 and the third control point P _{B3 of the} Bezier curve, and can be in the required X-axis length range, Y. In the range of the length of the shaft, more changes are obtained than the cosine curve and the linear curve design, but a reaction force F which is more moderate than the linear curve and the cosine curve, or a more obvious displacement amount, and the like can be obtained.

Through the above description, the advantages of the foregoing embodiments can be summarized as follows: The present invention can utilize the characteristics of the Bezier curve, so that the present invention can obtain only the second control point P _B2 and the third control point P _B3 . The most efficient curve profile and effectively enhances the freedom of design.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the simple equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still Within the scope of the invention patent.

Claims (5)

A flexible element of a steady-state constant force system, the steady-state constant force system comprising an actuating element, and at least two flexible elements connected to the actuating element and symmetrical to each other, each flexible element bearing an actuation force in a A flexural deformation between a steady state position and a second steady state position, characterized in that each flexible element is a function formula according to a Bezier curve 0 t 1. Determining the Bezier curve profile, and defining a first control point P _B1 , a second control point P _B2 , a third control point P _B3 , and a fourth control point P _B4 , where t is a constant, Each flexible element has an X-axis length range and a Y-axis length range, the X-axis length range including a minimum value X _min and a maximum value X _max , the Y-axis length range including a minimum value Y _min and a The maximum value Y _max , the coordinate value of the first control point P _B1 is (X _min , Y _min ), the coordinate value of the fourth control point P _B4 is (X _max , Y _max ), and the second control point P _B2 The coordinate value with the third control point P _B3 is a variable according to the actuation force required at the first steady state position and the second steady state position, respectively. The flexible element of the steady-state constant force system of claim 1, wherein the variable is a random number. The flexible element of the steady-state constant-force system of claim 1, wherein X _min and Y _{min of} the first control point P _B1 are 0 respectively. The flexible element of the steady-state constant-force system according to claim 1, comprising two edges spaced apart by a distance along the Y-axis direction, wherein the first control point P _B1 and the fourth control point P _B4 are respectively the same The two endpoints of the edge. The flexible element of the steady-state constant force system of claim 1, wherein the coordinate value of the second control point P _B2 and the third control point P _B3 is determined by a required minimum actuation force.