TWI465725B - Bistable constant force system with protection mechanism - Google Patents

Description

Bi-stable constant force system with protection mechanism

The invention relates to a constant force system, in particular to a bistable constant force system with a protection mechanism.

The constant force mechanism can maintain two objects in contact with each other and contact with a stable force, thereby avoiding damage to objects and improving the precision of movement or processing, and is widely used in various types of machines, such as Detection systems, scrapers, robotic arms, printing presses, MEMS, etc.

As shown in FIG. 1 , a compliant constant-force compression mechanism 12 is used as an example, and mainly includes two swing arms 121 pivoted at a certain point, and connecting the swing arms 121 Two flexible elements 122 with the probe 11. When the probe 11 is in contact with the surface 21 of an object 2 and moves along the surface 21, the probe 11 receives a force with the height of the surface of the object 2, so that the probe 11 is at the flexibility. During the elastic deformation of the element 122, a constant force is applied to the object 2.

Referring to Fig. 1 and Fig. 2, by the formula N (force) = K (elastic system) × S (strain variable, corresponding to the displacement amount of the probe 11), it can be known that the aforementioned constant force refers to the probe. 11 In the case where the displacement amount is constant, a constant force can be output, but as long as the displacement amount changes, the output force will change accordingly, and therefore, in the case where the strain amount of the flexible members 122 has a limit, The surface 21 of the object 2 is excessively undulated, or foreign matter or impurities having a large particle size are retained, and when the strain amount of the flexible member 122 reaches the limit point A, the flexible member 122 may be deformed due to no deformation. The strain energy is getting bigger and bigger. At this time, the probe 11 that is still in contact with the object 2 is maintained, and the output force is getting larger and larger, which may damage the entire system, and seriously affect the accuracy and service life. Not practical.

Accordingly, it is an object of the present invention to provide a bistable constant force system having a protection mechanism capable of maintaining a constant force output and thereby improving safety and life.

Thus, the bistable constant force system of the present invention having a protection mechanism includes an actuating element and a flexible element set. The actuating element is used to transmit a force. The flexible element set has at least one first flexible element that acts on the actuating element, and at least one second flexible element that acts on the first flexible element, the first and second flexible elements are adapted to withstand The force is deformed such that the actuating element springs in a range of bounce and outputs a constant force as a constant at a critical value of the aforementioned force.

The function of the invention is that when the force does not exceed the critical value, the constant force output can be maintained without being affected by the aforementioned bounce range, and when the force exceeds the critical value, the protection mechanism can be activated to improve the safety and life of use.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to Figure 3, a preferred embodiment of the bistable constant force system of the present invention having a protective mechanism includes an actuating element 3, a carrier 4, a pair of supports 5, and a flexible element set 6.

The actuating element 3 is used to transmit a force.

This carrier 4 is used to mount the actuating element 3.

The pair of supports 5 are juxtaposed on both sides of the carrier 4 and are fixed at fixed points.

The flexible element group 6 has two first flexible elements 61 and two second flexible elements 62. The first flexible elements 61 are suspended in the carrier 4 and have a two-consolidated end 611 fixed to the carrier 4 and a flexure 612 coupled to the actuating element 3. The second flexible members 62 respectively have two fixed ends 621 fixed to the pair of supports 5 and a bending portion 622 coupled to the carrier 4. Referring to FIG. 3, and FIG. 7 and FIG. 8, when the actuating member 3 contacts an object (not shown) and receives a force F _a , and the displacement amount stays at the origin a and is 0, the first flexibility The element 61 and the second flexible element 62 are not deformed, and the strain and strain energy generated are also zero, and the force output by the actuating element 3 is zero.

Referring to FIG. 4, and FIG. 7, FIG. 8, as the movable member 3 contacts the object and subjected to the force F _a is greater than a force F _c, while when the former is displaced to the point a point C, the plurality of first flexible The element 61 and the second flexible element 62 are respectively elastically deformed, and at this time, the first flexible element 61 has a significantly larger deflection amplitude than the second flexible element 62, and the first flexibility The total strain energy of the element 61 and the second flexible element 62 will rise with a slope of the total strain, and the actuating element 3 will gradually stabilize with a constant force as the displacement increases.

Referring to FIG. 5, and FIG. 7 and FIG. 8, the first flexible element 61 and the actuating element 3 are in contact with the object and are subjected to a force F _d greater than the force F _c and continuously displaced to the point d. The total strain energy of the second flexible member 62 has approached the limit. At this time, the displacement of the actuating member 3 continues to increase, and the constant force of the output is increased again, whereby the force F _d can be regarded as To be a critical value, the origin a to point c can be regarded as the bounce range of the actuating element 3, and the force displaced between the point b and the point c can be regarded as a constant force whose output is approximately constant.

Referring to FIG. 6 , FIG. 7 and FIG. 8 , when the actuating element 3 receives a force F _e greater than the force F _d , the first flexible element 61 generates an irreversible deformation, and the actuating element 3 is caused. Jumping and stabilizing at a static position, i.e., point e, from the aforementioned bounce range. At this time, the strain energy of the first flexible members 61 is quickly returned to zero, and the strain states of the second retaining members 62 are stabilized. On a constant. Thereby, the total strain energy of the first flexible element 61 and the second flexible elements 62 is maintained at the constant.

In the preferred embodiment, when the actuating element 3 is stabilized at the static position, i.e., point e, the actuating element 3 will disengage from the object and, therefore, the output force will be zero.

According to the above description, the bistable constant force system with the protection mechanism of the present invention has the following advantages and effects: the present invention automatically activates the protection mechanism when the actuation element 3 is subjected to a force greater than a critical value. The actuating element 3 maintains a constant force output, thereby avoiding damage to the mechanism and improving safety and life. .

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

3. . . Actuating element

4. . . Carrier

5. . . supporting item

6. . . Flexible component group

61. . . First flexible element

611. . . Fixed end

612. . . Flexure

62. . . Second flexible element

621. . . Consolidation end

622. . . Twisting department

F _a ~F _e . . . Force

Figure 1 is a schematic view showing a general constant force system;

2 is a graph illustrating the relationship between the strain energy and the strain amount in the aforementioned constant force system;

Figure 3 is a front elevational view showing a preferred embodiment of a bistable constant force system having a protection mechanism of the present invention;

Figure 4 is a front elevational view of an actuating member at point c in the preferred embodiment;

Figure 5 is a front elevational view of the actuating member at point d in the preferred embodiment;

Figure 6 is a front elevational view of the actuating member at point e in the preferred embodiment;

Figure 7 is a graph showing the relationship between the force output and the displacement amount of the actuating member in the preferred embodiment; and

Figure 8 is a graph showing the relationship between strain energy and strain amount of a flexible component group in the preferred embodiment.

3. . . Actuating element

4. . . Carrier

5. . . supporting item

6. . . Flexible component group

61. . . First flexible element

611. . . Fixed end

612. . . Flexure

62. . . Second flexible element

621. . . Consolidation end

622. . . Twisting department

F _a . . . Force

Claims (4)

A bistable constant force system having a protection mechanism, comprising: an actuating element for transmitting a force; a carrier for mounting the actuating element; at least one support member fixed at a certain point; and a flexible element group Having at least one first flexible element coupled to the actuator element and suspended in the carrier to act on the actuating element, and at least one second flexible element acting on the first flexible element, the The second flexible member has two fixed ends fixed to the support member, and a flexible portion formed between the fixed ends and coupled to the carrier, the first and second flexible members for receiving the aforementioned force generation The deformation causes the actuating element to spring in a range of bounce, and outputs a constant force as a constant at a critical value of the aforementioned force. A bistable constant force system having a protection mechanism according to claim 1, wherein the first flexible element has a second consolidation end fixed to the carrier, and is formed between the consolidation ends a flexure coupled to the actuating element. A bistable constant-force system having a protection mechanism according to claim 1, wherein the first flexible member is bounced within the bounce range by a static origin from the static force. A bistable constant force system having a protection mechanism according to claim 3, wherein the first flexible member is subjected to a force greater than or equal to the aforementioned critical value, and an unrecoverable deformation is generated, so that the actuating member Stabilized in a static position away from the aforementioned bounce range.