Piezoelectric driving device and piezoelectric driving system having the same

Abstract

A piezoelectric drive device comprising: a case defining a cavity and having a closed end; a holder provided in the cavity and having a first end connected to the closed end of the case and a second end toward the open end of the case, the second end of the holder having a recess on its end surface, the recess including a first sidewall, a second sidewall, and a bottom connected between the first and second sidewalls, the first sidewall and the second sidewall extending at an angle outward from the bottom; a first piezoelectric element and a second piezoelectric element provided on the first sidewall and the second sidewall of the recess, respectively; and a first actuator and a second actuator fixed to the first piezoelectric element and the second piezoelectric element, respectively, facing each other.

Description

[Technical field]

[0001] TECHNICAL FIELD The present disclosure relates to the field of piezoelectric drive technology, and more particularly to piezoelectric drive devices and piezoelectric drive systems having the same. [Background technology]

[0002] In the related art, there are usually two types of piezoelectric drive systems. One is the USM type and the other is the SIDM type. The USM type piezoelectric drive system is complex and expensive, and the stroke generated is very small. Meanwhile, the SIDM type piezoelectric drive system requires a counterweight and a shaft, so the structure is complicated. In addition, the control method of the SIDM type piezoelectric drive system is very difficult because it needs to accurately control the deformation speed of the piezoelectric element. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, there is a need to propose a piezoelectric driving device and a piezoelectric driving system to solve at least one of the above technical problems in the related art. [Means for solving the problem]

[0004] Thus, an embodiment of a first aspect of the present disclosure provides a piezoelectric drive device, the device comprising: a case defining a cavity therein and having a closed end and an open end; and a holder disposed in the cavity and having a first end connected to the closed end of the case and a second end toward the open end of the case, the second end of the holder having a recess in an end surface, the recess including a first sidewall, a second sidewall, and a bottom connected between the first sidewall and the second sidewall, the first sidewall and the second sidewall extending at an angle outwardly from the bottom. the first piezoelectric element and the second piezoelectric element are respectively provided on a first side wall and a second side wall of the recess, wherein the first piezoelectric element is configured to expand or contract in a direction perpendicular to the first side wall of the recess when current is applied or a power outage occurs, and the second piezoelectric element is configured to expand or contract in a direction perpendicular to the second side wall of the recess when current is applied or a power outage occurs; and a first actuator and a second actuator fixed to the first piezoelectric element and the second piezoelectric element, respectively, and facing each other.

[0005] In some embodiments, the piezoelectric driver further includes a retaining member disposed in the cavity and having a first end abutting the closed end of the case and a second end opposite the first end, and a shaft disposed in the cavity and configured to engage the second end of the retaining member and move under the action of the retaining member, the first end of the holder being fixed to the shaft and abutting the second end of the retaining member.

[0006] In some embodiments, the case includes at least two opposing side walls, each side wall having an opening, the openings in the two opposing side walls of the case are aligned with each other, the two ends of the shaft are respectively received in the openings in the two opposing side walls of the case, and the shaft is configured to move within the openings under the action of the retaining member.

[0007] In some embodiments, end faces of the two ends of the shaft are flush with outer surfaces of two opposing side walls of the case, respectively.

[0008] In some embodiments, each aperture has two arcuate ends that match a shape of an end of the shaft, the arcuate ends being configured to engage the ends of the shaft.

[0009] In some embodiments, the second end of the retaining member has a first groove, the shaft at least partially engaging the first groove.

[0010] In some embodiments, the first end of the holder has a second groove, the shaft at least partially engaging the second groove.

[0011] In some embodiments, the first groove, the axis, and the second groove are aligned with one another in a direction from the closed end to the open end of the case, each of the first groove and the second groove has an arcuate cross-section that matches the axis, and the first groove and the second groove surround an outer periphery of the axis.

[0012] In some embodiments, the bottom of the recess includes a first section, a second section, and a third section, the first section connected to the first sidewall, the second section connected to the second sidewall, and the third section connected between the first section and the second section, the first section engaging the first piezoelectric element and the second section engaging the second piezoelectric element, the first piezoelectric element matching in shape and orientation to the first sidewall and the first section of the recess, respectively, and the second piezoelectric element matching in shape and orientation to the second sidewall and the second section of the recess, respectively.

[0013] In some embodiments, each of the first piezoelectric element and the second piezoelectric element has a rectangular parallelepiped shape, the third section of the recess is parallel to an end face of the first end of the holder, a direction perpendicular to a first side wall of the recess is perpendicular to a direction perpendicular to the first section of the recess, and a direction perpendicular to a second side wall of the recess is perpendicular to a direction perpendicular to the second section of the recess.

[0014] In some embodiments, a first transition portion is provided at a connection between the first side wall of the recess and the first section, and a second transition portion is provided at a connection between the second side wall of the recess and the second section.

[0015] In some embodiments, a direction perpendicular to the first sidewall of the recess and a plane on which an end face of the first end of the holder lies form a first angle, and a direction perpendicular to the first sidewall of the recess and a plane on which an end face of the first end of the holder lies form a second angle.

[0016] In some embodiments, the first angle ranges from 24 degrees to 25 degrees and the second angle ranges from 24 degrees to 26 degrees.

[0017] In some embodiments, the first piezoelectric element and the second piezoelectric element are symmetrical and the first angle is equal to the second angle.

[0018] In some embodiments, each of the first actuator and the second actuator has a first end adjacent to the holder and a second end away from the holder, the first end of the first actuator is spaced from the first end of the second actuator, the second end of the first actuator protrudes beyond the first piezoelectric element in a direction away from the holder, and the second end of the second actuator protrudes beyond the second piezoelectric element in a direction away from the holder.

[0019] In some embodiments, the piezoelectric drive device further includes a flexible printed circuit board electrically connected to the first piezoelectric element and the second piezoelectric element and configured to energize and de-energize the first piezoelectric element and the second piezoelectric element, the flexible printed circuit board being disposed within the cavity of the case and sandwiched between a sidewall of the case and the holder.

[0020] In some embodiments, the flexible printed circuit board has a first end and a second end, the first end of the flexible printed circuit board is accommodated within the cavity of the case, the second end of the flexible printed circuit board protrudes outside the cavity of the case, the first end of the flexible printed circuit board is flush with the first end of the holder and has a first notch that engages with the axis, and the second end of the flexible printed circuit board includes two legs spaced apart from each other to expose at least a portion of the recess.

[0021] In some embodiments, the piezoelectric driver further comprises a pad disposed within the cavity of the case and sandwiched between the flexible printed circuit board and a side wall of the case.

[0022] In some embodiments, the pad has an end that is flush with a first end of the holder, the end of the pad having a second notch that engages the shaft.

[0023] An embodiment of the second aspect of the present disclosure further provides a piezoelectric drive system, the system including a piezoelectric drive device according to any of the above embodiments, and a movable member disposed below the piezoelectric drive device and configured to engage a first actuator or a second actuator of the piezoelectric drive device, the holding member configured to abut against the movable member and hold the first actuator or the second actuator, and the movable member configured to move when driven by the first actuator or the second actuator.

[0024] In the piezoelectric drive device and the piezoelectric drive system according to the embodiment of the present disclosure, when the first piezoelectric element or the second piezoelectric element is energized, the first piezoelectric element or the second piezoelectric element expands in a direction perpendicular to the first sidewall or the second sidewall of the recess, driving the first actuator or the second actuator to move in the same direction, whereby the first actuator or the second actuator can engage with the movable member of the piezoelectric drive system and drive the movable member to move in a desired direction. Furthermore, when the first piezoelectric element or the second piezoelectric element is powered off, the first piezoelectric element or the second piezoelectric element contracts in a direction perpendicular to the first sidewall or the second sidewall of the recess, so that the movable member is not affected and the first actuator or the second actuator also returns to its initial position. By repeating this process, the movable member can be continuously moved in a desired direction.

[0025] Therefore, the piezoelectric driving device and the piezoelectric driving system according to the embodiments of the present disclosure have advantages such as simple structure, easy control, accurate driving stroke, strong driving force, and high energy conversion efficiency.

[0026] Described in this disclosure Piezoelectric drive device and piezoelectric drive system Other advantages, objects and features of the will be set forth in part in the description which follows, and in part will be learned by those skilled in the art based on study and practice of the present disclosure. [Brief description of the drawings]

[0027] The above and / or additional aspects and advantages of the present disclosure will become apparent and easier to understand from the following description of the exemplary embodiments taken in conjunction with the drawings. [Figure 1] 1 is a schematic diagram of a piezoelectric driving device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded view of a piezoelectric driving device according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a front view of a piezoelectric driving device according to an embodiment of the present disclosure. [Figure 4] 1 is a cross-sectional view of a piezoelectric driving device according to an embodiment of the present disclosure. [Diagram 5]FIG. 2 is a schematic diagram of a holder for a piezoelectric drive device according to an embodiment of the present disclosure. [Figure 6] 1 is a schematic diagram of a piezoelectric driving device according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a bottom view of a piezoelectric driving device according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a schematic diagram of a flexible printed circuit board of a piezoelectric driving device according to an embodiment of the present disclosure. [Figure 9] FIG. 1 is a schematic diagram of a piezoelectric drive system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments of the present disclosure will be described in detail, and examples of the embodiments are illustrated in the accompanying drawings, in which the same or similar reference numerals throughout indicate the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of illustrating the present application, and should not be understood as limitations on the present application.

[0029] In the description of the present disclosure, the orientations or positional relationships indicated by terms such as "center", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", and "circumferential" should be understood as orientations or positional relationships shown based on the drawings. These are merely for the purpose of explaining and simplifying the present disclosure, and are not intended to indicate or imply that the devices or elements shown necessarily have a specific orientation, or are constructed and operated according to a specific orientation. Therefore, they should not be understood as limitations on the present disclosure.

[0030] A piezoelectric driving device 100 and a piezoelectric driving system 1000 according to an embodiment of the present disclosure will be described with reference to the drawings. The piezoelectric driving device 100 can be used in the piezoelectric driving system 1000.

[0031] As shown in FIGS. 1 to 4, the piezoelectric driving device 100 includes a case 1, a holder 4, a first piezoelectric element 5, a second piezoelectric element 6, a first actuator 7, and a second actuator 8. The case 1 defines a cavity 13 therein, and the case 1 has a closed end and an open end. The holder 4 is provided in the cavity 13 and has a first end and a second end. The first end of the holder 4 is coupled to the closed end of the case 1, and the second end of the holder 4 faces the open end of the case 1, and the second end of the holder 4 has a recess on its end surface. The recess includes a first side wall 41, a second side wall 42, and a bottom portion 43 connected between the first side wall 41 and the second side wall 42. The first side wall 41 and the second side wall 42 extend inclined outward from the bottom portion 43. The first piezoelectric element 5 and the second piezoelectric element 6 are provided on a first side wall 41 and a second side wall 42 of the recess, respectively. The first piezoelectric element 5 is configured to expand or contract in a direction perpendicular to the first side wall 41 of the recess when electricity is applied or when there is a power outage, and the second piezoelectric element 6 is configured to expand or contract in a direction perpendicular to the second side wall 42 of the recess when electricity is applied or when there is a power outage. The first actuator 7 and the second actuator 8 are fixed to the first piezoelectric element 5 and the second piezoelectric element 6, respectively, and face each other.

[0032] In some embodiments of the present disclosure, as shown in FIG. 1 and FIG. 2, the upper end of the case 1 is closed and the lower end of the case 1 is open, so that other components can be mounted in the cavity 13 of the case 1 through the open lower end of the case 1. The upper end of the holder 4 is coupled to the upper end of the case 1, and the lower end of the holder 4 faces the lower end of the case 1 and has a recess on its end surface. The first side wall 41 is provided on the left side of the bottom 43, and the second side wall 42 is provided on the right side of the bottom 43. The first side wall 41 and the second side wall 42 extend outwardly from the bottom 43 at an incline. In other words, the first side wall 41 extends leftward and downward from the bottom 43, and the second side wall 42 extends rightward and downward from the bottom 43. Furthermore, the left end of the first piezoelectric element 5 is bonded to the first side wall 41 of the recess by a hard adhesive, and the right end of the second piezoelectric element 6 is bonded to the second side wall 42 of the recess by a hard adhesive. Thus, the first piezoelectric element 5 is configured to expand to the right and downward or contract to the left and upward when electricity is applied or power is lost, and the second piezoelectric element 6 is configured to expand to the left and downward or contract to the right and upward when electricity is applied or power is lost. The left end of the first actuator 7 is bonded to the right end of the first piezoelectric element 5 by a hard adhesive, and the right end of the second actuator 8 is bonded to the left end of the second piezoelectric element 6 by a hard adhesive, so that the right end of the first actuator 7 and the left end of the second actuator 8 face each other, whereby the right end of the first actuator 7 faces the right and downward direction, and the left end of the second actuator 8 faces the left and downward direction.

[0033] It should be noted that the terms "upper", "lower", "front", "rear", "left" and "right" used herein represent the orientation of the drawings and are intended to facilitate understanding of the present disclosure, but are not to be construed as limitations of the present disclosure.

[0034] In the piezoelectric driving device according to the embodiment of the present disclosure, when the first piezoelectric element 5 or the second piezoelectric element 6 is energized, the first piezoelectric element 5 or the second piezoelectric element 6 expands in a direction perpendicular to the first side wall 41 or the second side wall 42 of the recess, driving the first actuator 7 or the second actuator 8 to move in the same direction, whereby the first actuator 7 or the second actuator 8 engages with the movable member 200 of the piezoelectric driving system 1000 and drives the movable member 200 to move in a desired direction. Furthermore, when the first piezoelectric element 5 or the second piezoelectric element 6 is powered off, the first piezoelectric element 5 or the second piezoelectric element 6 contracts in a direction perpendicular to the first side wall 41 or the second side wall 42 of the recess, so that the movable member 200 is not affected, and the first actuator 7 or the second actuator 8 also returns to its initial position. By repeating this process, the movable member 200 can be continuously moved in a desired direction.

[0035] Therefore, the piezoelectric driving device 100 according to the embodiment of the present disclosure has the advantages of a simple structure, accurate driving stroke, strong driving force, and high energy conversion efficiency.

[0036] Furthermore, the first piezoelectric element 5 is adhered to the first side wall 41 of the recess and the first actuator 7 by a hard adhesive, and the second piezoelectric element 6 is adhered to the second side wall 42 of the recess and the second actuator 8 by a hard adhesive, so that the connections between the first piezoelectric element 5 and the first side wall 41 of the recess, the connection between the first piezoelectric element 5 and the first actuator 7, the connection between the second piezoelectric element 6 and the second side wall 42 of the recess, and the connection between the second piezoelectric element 6 and the second actuator 8 are strong and stable, and since the hard adhesive does not easily absorb the expansion of the first piezoelectric element 5 and the second piezoelectric element 6, the first piezoelectric element 5 and the second piezoelectric element 6 can expand to drive the first actuator 7 and the second actuator 8 to move reliably and efficiently.

[0037] In addition, since the first piezoelectric element 5 is bonded to the first sidewall 41 of the recess by a hard adhesive, and the second piezoelectric element 6 is bonded to the second sidewall 42 of the recess by a hard adhesive, when the first piezoelectric element 5 is energized and expands in a direction perpendicular to the first sidewall 41 of the recess, the first sidewall 41 of the recess restricts the movement of the left end of the first piezoelectric element 5, so that the right end of the first piezoelectric element 5 expands in a direction perpendicular to the first sidewall 41 of the recess, driving and moving the first actuator 7. Similarly, when the second piezoelectric element 6 is energized and expands in a direction perpendicular to the second sidewall 42 of the recess, the second sidewall 42 of the recess restricts the movement of the right end of the second piezoelectric element 6, so that the left end of the second piezoelectric element 6 expands in a direction perpendicular to the second sidewall 42 of the recess, driving and moving the second actuator 8.

[0038] In some embodiments of the present disclosure, the piezoelectric driving device 100 further includes a retaining member 2 and a shaft 3. The retaining member 2 is disposed within the cavity 13 and has a first end and a second end. The first end of the retaining member 2 abuts against the closed end of the case 1, and the second end of the retaining member 2 faces the first end. The shaft 3 is disposed within the cavity 13 and engages with the second end of the retaining member 2, such that the shaft 3 is configured to move under the action of the retaining member 2. The first end of the holder 4 is fixed to the shaft 3 and abuts against the second end of the retaining member 2.

[0039] 1 and 2, the upper end of the holding member 2 abuts against the closed upper end of the case 1, and the shaft 3 engages with the lower end of the holding member 2, so that the shaft 3 moves up and down due to the action of the holding member 2. The upper end of the holder 4 is bonded to the shaft 3 with a hard adhesive and abuts against the lower end of the holding member 2.

[0040] In some embodiments of the present disclosure, the case 1 includes at least two opposing side walls, each having an opening 11, the openings 11 in the two opposing side walls of the case 1 are aligned with each other, the two ends of the shaft 3 are respectively accommodated in the openings 11 in the two opposing side walls of the case 1, and the shaft 3 is configured to move within the openings 11 by the action of the retaining member 2.

[0041] 1 to 3, the front and rear walls of the case 1 have openings 11, which extend vertically. The openings 11 in the front and rear walls of the case 1 are aligned with each other, so that the shaft 3 can be inserted into the case 1 through the openings 11 after the holding member 2 is placed in the cavity 13 of the case 1. When the installation is completed, the front and rear ends of the shaft 3 are respectively engaged with and accommodated in the openings 11. Therefore, when the position of the movable member 200 changes vertically, the shaft 3 can move within the opening 11 due to the action of the holding member 2.

[0042] For example, the holding member 2 can be made of an elastic material such as rubber and can be mounted in a compressed state in the cavity 13 of the case 1, and when the shaft 3 is inserted into the case 1 through the opening 11 and engages with the holding member 2, the holding member 2 can apply an elastic force of about 200 mN to the shaft 3. Furthermore, since the holder 4 is fixed to the shaft 3 and the upper end of the holder 4 abuts against the lower end of the holding member 2, the holder 4 also receives the elastic force of the holding member 2. In this way, when the movable member 200 tries to move downward, the holding member 2 pushes the shaft 3 and the holder 4 to move downward along the opening 11, so that the first piezoelectric element 5 and the second piezoelectric element 6, the first actuator 7 and the second actuator 8 also move downward, and thus the first actuator 7 and the second actuator 8 can maintain contact and engagement with the movable member 200.

[0043] Similarly, since the holding member 2 has elasticity and can be further compressed, when the movable member 200 moves upward, the first piezoelectric element 5 and the second piezoelectric element 6, the first actuator 7 and the second actuator 8 are driven by the movable member 200 to move upward, and the shaft 3 and the holder 4 also move upward along the opening 11. During this process, the first actuator 7 and the second actuator 8 can maintain contact and engagement with the movable member 200.

[0044] Thus, the piezoelectric drive device 100 of the embodiment of the present disclosure can adapt to various changes in the vertical position of the movable member 200, thereby stably engaging the movable member 200, thereby driving the movable member 200 to move smoothly and reliably.

[0045] In addition, since the opening 11 can be positioned at the horizontal center, i.e., the horizontal center of the front wall or rear wall of the case 1, the axis 3 passing through the opening 11 and the holder 4 fixed to the axis 3 can also be positioned at the horizontal center.

[0046] Furthermore, the end faces of the two ends of the shaft 3 are flush with the outer surfaces of the two opposing side walls of the case 1. Specifically, as shown in Figures 1 and 2, the end faces of the front and rear ends of the shaft 3 are flush with the outer surfaces of the front and rear walls of the case 1. Therefore, when the shaft 3 is attached to the case 1, the case 1 has a flat surface, which provides a clean appearance and avoids interference with other external parts.

[0047] In some embodiments of the present disclosure, each opening 11 has two arcuate ends that match the end shape of the shaft 3, and the arcuate ends are configured to engage with the ends of the shaft 3. For example, as shown in Figures 1 and 2, both the upper and lower ends of the opening 11 have arcuate shapes that match the shape of the front or rear end of the shaft 3, such that when the shaft 3 moves to the upper or lower end of the opening 11, the front or rear end of the shaft 3 engages with the upper or lower end of the opening 11. Therefore, the shaft 3 can move smoothly and be stably positioned.

[0048] Also, the second end of the retaining member 2 has a first groove 21 parallel to the axis 3, and the axis 3 at least partially engages with the first groove 21. For example, as shown in Figures 1 and 2, the first groove 21 is formed at the lower end of the retaining member 2, and a portion of the axis 3 engages with the first groove 21.

[0049] Furthermore, the first end of the holder 4 has a second groove 46 parallel to the shaft 3, and the shaft 3 is at least partially engaged and fixed in the second groove 46. For example, as shown in combination of Figures 1-2 and Figure 5, the second groove 46 is formed in the upper end of the holder 4, and the other portion of the shaft 3 is engaged and fixed in the second groove 46.

[0050] The first groove 21, the axis 3, and the second groove 46 are aligned with one another in a direction from the closed end to the open end of the case 1, and each of the first groove 21 and the second groove 46 has an arc-shaped cross-section that matches the axis 3, and the first groove 21 and the second groove 46 surround the outer periphery of the axis 3.

[0051] Specifically, as shown in Figures 1-2 combined with Figures 4-5, the first groove 21, the shaft 3, and the second groove 46 are vertically aligned with each other, and both the first groove 21 and the second groove 46 have an arc-shaped cross-section that matches the shape of the arc-shaped cross-section of the shaft 3, so that the entire first groove 21 and the second groove 46 surround the outer periphery of the shaft 3.

[0052] In this way, the shaft 3 can be stably sandwiched between the holding member 2 and the holder 4, and the contact area between the holding member 2 and the holder 4 can be made relatively large, so that the holding member 2 can drive the shaft 3 and the holder 4 to move smoothly.

[0053] In some other embodiments of the present disclosure, the front wall and the rear wall of the case 1 may not be provided with the openings 11. Conversely, slits may be formed on the inner surfaces of the front wall and the rear wall of the case 1, respectively, and the slits may extend to the lower end of the case 1, and the shaft 3 may be attached to the case 1 through the slit, engage with the slit, and even move within the slit. Therefore, the holding member 2 can drive the shaft 3 and the holder 4 to move up and down within the slit, as described above.

[0054] In some other embodiments of the present disclosure, the shaft 3 and the opening 11 may be omitted, and only the retaining member 2 may be sandwiched between the upper end of the case 1 and the holder 4. In this case, the retaining member 2 may be a rubber block or a spring in a compressed state to drive the holder 4 to move up and down, as described above.

[0055] In some other embodiments of the present disclosure, the holding member 2, the shaft 3, and the opening 11 may not be provided, and the holder 4 may directly abut against the upper end of the case 1, and the case 1 itself may have a certain degree of elasticity. For example, as described above, the upper end of the case 1 is elastically deformed, which constantly applies a downward force to the holder 4, so that the holder 4 can be driven to move up and down.

[0056] In some embodiments of the present disclosure, the bottom 43 of the recess includes a first section 431, a second section 432, and a third section 433, where the first section 431 is connected to the first sidewall 41, the second section 432 is connected to the second sidewall 42, and the third section 433 is connected between the first section 431 and the second section 432. For example, as shown in Figures 2 and 5, the first section 431, the third section 433, and the second section 432 are connected in sequence, where the first section 431 is provided on the left side of the third section 433, and the second section 432 is provided on the right side of the third section 433.

[0057] Furthermore, the first section 431 engages with the first piezoelectric element 5, and the second section 432 engages with the second piezoelectric element 6. In other words, the first piezoelectric element 5 is in contact with the first section 431 but is not fixed to the first section 431, and the second piezoelectric element 6 is in contact with the second section 432 but is not fixed to the second section 432. In this way, when the first piezoelectric element 5 or the second piezoelectric element 6 expands or contracts, the first piezoelectric element 5 or the second piezoelectric element 6 does not interfere with the first section 431 or the second section 432, thereby allowing the first piezoelectric element 5 or the second piezoelectric element 6 to expand or contract smoothly.

[0058] Furthermore, the first piezoelectric element 5 matches the shape and orientation of the first sidewall 41 and the first section 431 of the recess, respectively, and the second piezoelectric element 6 matches the shape and orientation of the second sidewall 42 and the second section 432 of the recess, respectively. For example, the first piezoelectric element 5 has a flat surface parallel to the flat surface of the first sidewall 41 and another flat surface parallel to the flat surface of the first section 431, and the second piezoelectric element 6 has a flat surface parallel to the flat surface of the second sidewall 42 and another flat surface parallel to the flat surface of the second section 432.

[0059] In this manner, the first piezoelectric element 5 can be stably connected to the first side wall 41 and can also smoothly engage with the first section 431, and the second piezoelectric element 6 can be stably connected to the second side wall 42 and can also smoothly engage with the second section 432. Therefore, the first piezoelectric element 5 can expand or contract stably and smoothly in a direction perpendicular to the first side wall 41, and the second piezoelectric element 6 can expand or contract stably and smoothly in a direction perpendicular to the second side wall 42.

[0060] For example, as shown in Figures 1 to 4, each of the first piezoelectric element 5 and the second piezoelectric element 6 has a rectangular parallelepiped shape, the third section 433 of the recess is parallel to the end face of the first end (i.e., the upper end) of the holder 4, the direction perpendicular to the first side wall 41 of the recess is perpendicular to the direction perpendicular to the first section 431 of the recess, and the direction perpendicular to the second side wall 42 of the recess is perpendicular to the direction perpendicular to the second section 432 of the recess.

[0061] In other words, the first piezoelectric element 5 has two orthogonal surfaces, each of which is fixed to the first side wall 41 and engages with the first section 431, and the second piezoelectric element 6 has two orthogonal surfaces, each of which is fixed to the second side wall 42 and engages with the second section 432.

[0062] In this way, the first piezoelectric element 5 can expand or contract stably and smoothly in a direction perpendicular to the first side wall 41 with the guidance of the first section 431, and the second piezoelectric element 6 can expand or contract stably and smoothly in a direction perpendicular to the second side wall 42 with the guidance of the second section 432.

[0063] In some embodiments of the present disclosure, a first transition portion 44 is provided at a connection point between the first side wall 41 and the first section 431 of the recess, and a second transition portion 45 is provided at a connection point between the second side wall 42 and the second section 432 of the recess. For example, each of the first transition portion 44 and the second transition portion 45 may be a groove having an arc cross section to avoid local stress concentrations. Note that the groove extends in a direction perpendicular to the paper plane of FIG. 5, i.e., in the front-to-back direction of FIGS. 1 and 2.

[0064] Also, the holder 4 may be solid or hollow as long as it has the above-mentioned configuration and provides the necessary rigidity, and is not limited thereto. For example, in some embodiments of the present disclosure, the holder 4 is hollow, that is, the holder 4 is formed by folding a single sheet and connecting its head and tail, or by connecting the heads and tails of multiple sheets.

[0065] In some embodiments of the present disclosure, as shown in FIG. 3, a direction perpendicular to the first side wall 41 of the recess and a plane on which the end face of the first end (i.e., the upper end) of the holder 4 lies have a first angle α, and a direction perpendicular to the second side wall 42 of the recess and a plane on which the end face of the first end (i.e., the upper end) of the holder 4 lies have a second angle β.

[0066] Furthermore, the first angle α ranges from 24 degrees to 25 degrees, and the second angle β ranges from 24 degrees to 26 degrees.

[0067] For example, the first angle α may be 24 degrees, 24.5 degrees, 25 degrees, 25.5 degrees, or 26 degrees, and the second angle β may be 24 degrees, 24.5 degrees, 25 degrees, 25.5 degrees, or 26 degrees.

[0068] Preferably, the first angle α is 25 degrees and the second angle β is 25 degrees.

[0069] Since the first angle α and the second angle β are in the range of 24 degrees to 26 degrees, the movable member 200 of the piezoelectric drive system 1000 can move stably and smoothly, and the piezoelectric drive device 100 can achieve high drive efficiency.

[0070] Furthermore, the first piezoelectric element 5 is symmetrical to the second piezoelectric element 6, and the first angle α is equal to the second angle β.

[0071] This makes the overall configuration of the piezoelectric driving device 100 stable and strong, thereby enabling the movable member 200 of the piezoelectric driving system 1000 to be driven and moved stably and smoothly.

[0072] In some embodiments of the present disclosure, the first piezoelectric element 5 and the second piezoelectric element 6 are configured to operate in d33 mode to provide a large expansion force, such as about 500 mN. Here, d33 mode refers to the piezoelectric material having the same polarization direction and deformation direction. In other words, the polarization direction of the first piezoelectric element 5 coincides with the deformation direction of the first piezoelectric element 5, both directions being perpendicular to the first sidewall 41 of the recess. Similarly, the polarization direction of the second piezoelectric element 5 coincides with the deformation direction of the second piezoelectric element 5, both directions being perpendicular to the second sidewall 42 of the recess.

[0073] Furthermore, the first piezoelectric element 5 and the second piezoelectric element 6 operating in the d33 mode can have high energy conversion efficiency.

[0074] Optionally, in a direction perpendicular to the paper surface of FIGS. 3 and 4, i.e., in the front-to-back direction of FIGS. 1 and 2, the first piezoelectric element 5 includes multiple laminations, and the second piezoelectric element 6 includes multiple laminations. The number of laminations of the first piezoelectric element 5 is the same as the number of laminations of the second piezoelectric element 6. Each layer of the first piezoelectric element 5 is bonded to the first side wall 41 and the first actuator 7, and each layer of the second piezoelectric element 6 is bonded to the second side wall 42 and the second actuator 8. For example, the number of laminations of the first piezoelectric element 5 and the number of laminations of the second piezoelectric element 6 are 15. However, the present disclosure is not limited thereto.

[0075] In some embodiments of the present disclosure, the first actuator 7 and the second actuator 8 each have a first end adjacent to the holder 4 and a second end away from the holder 4. The first end of the first actuator 7 is spaced apart from the first end of the second actuator 8, the second end of the first actuator 7 protrudes beyond the first piezoelectric element 5 in a direction away from the holder 4, and the second end of the second actuator 8 protrudes beyond the second piezoelectric element 6 in a direction away from the holder 4.

[0076] For example, as shown in FIGS. 1 to 4, the first actuator 7 and the second actuator 8 each have an upper end adjacent to the holder 4 and a lower end away from the holder 4. The upper end of the first actuator 7 is spaced a certain distance from the upper end of the second actuator 8, so that the first actuator 7 does not interfere with the second actuator 8 when driven to move by the first piezoelectric element 5, and vice versa. The lower end of the first actuator 7 protrudes rightward and downward beyond the first piezoelectric element 5, and the lower end of the second actuator 8 protrudes leftward and downward beyond the second piezoelectric element 6, which makes it easy for the first actuator 7 and the second actuator 8 to engage with the movable member 200.

[0077] In some embodiments of the present disclosure, the lower end of the first actuator 7 and the lower end of the second actuator 8 both have a spherical notch shape, which allows the first actuator 7 and the second actuator 8 to stably contact the movable member 200 and ensures stable movement of the movable member 200.

[0078] In some embodiments of the present disclosure, the piezoelectric driving device 100 further includes a flexible printed circuit board 9 electrically connected to the first piezoelectric element 5 and the second piezoelectric element 6 and configured to energize or de-energize the first piezoelectric element 5 and the second piezoelectric element 6. Furthermore, the flexible printed circuit board 9 is provided in the cavity 13 of the case 1 and is sandwiched between the side wall of the case 1 and the holder 4.

[0079] 6 and 7, two flexible printed circuit boards 9 are provided, one of the two flexible printed circuit boards 9 is sandwiched between the front wall of the case 1 and the holder 4, and the other of the two flexible printed circuit boards 9 is sandwiched between the rear wall of the case 1 and the holder 4. However, the present disclosure is not limited thereto. In some other embodiments of the present disclosure, only one flexible printed circuit board 9 may be provided and sandwiched between the front wall or rear wall of the case 1 and the holder 4.

[0080] When two flexible printed circuit boards 9 are provided, the two flexible printed circuit boards 9 are configured to independently supply or cut off electricity to the first piezoelectric element 5 and the second piezoelectric element 6. When only one flexible printed circuit board 9 is provided, the flexible printed circuit board 9 is configured to independently supply or cut off electricity to the first piezoelectric element 5 and the second piezoelectric element 6.

[0081] Moreover, the flexible printed circuit board 9 has a first end and a second end, the first end of the flexible printed circuit board 9 is accommodated in the cavity 13 of the case 1, and the second end of the flexible printed circuit board 9 protrudes to the outside of the cavity 13 of the case 1. The first end of the flexible printed circuit board 9 is flush with the first end of the holder 4 and has a first notch 91 that engages with the shaft 3. The second end of the flexible printed circuit board 9 includes two legs spaced apart from each other to expose at least a portion of the recess.

[0082] For example, as shown in combination of FIG. 6 and FIG. 8, the upper end of the flexible printed circuit board 9 is accommodated in the cavity 13 of the case 1, and the lower end of the flexible printed circuit board 9 extends downward and protrudes outside the cavity 13 of the case 1. The upper end of the flexible printed circuit board 9 is flush with the upper end of the holder 4, and the first notch 91 is aligned with the second groove 46 of the holder 4, whereby the shaft 3 engages with the second groove 46 and the first notch 91. The lower end of the flexible printed circuit board 9 includes two legs 92 provided on both the left and right sides, spaced apart from each other to expose at least a part of the recess so that the lower end of the flexible printed circuit board 9 does not interfere with the piezoelectric element and the actuator. This makes it easy for the piezoelectric element and the actuator to operate.

[0083] In addition, the legs 92 of the flexible printed circuit board 9 protrude outside the cavity 13 of the case 1 and are then bent horizontally so as to be connected to an external power source, thereby enabling power to be supplied to the first piezoelectric element 5 and the second piezoelectric element 6.

[0084] In some embodiments of the present disclosure, the piezoelectric drive device 100 further includes a pad 10 disposed within the cavity 13 of the case 1 and sandwiched between the flexible printed circuit board 9 and a sidewall of the case 1 .

[0085] For example, as shown in Fig. 7 combined with Fig. 8, the pad 10 is sandwiched between the flexible printed circuit boards 9 and the front wall or rear wall of the case 1. Depending on the number of flexible printed circuit boards 9, one or two pads 10 may be provided. In other words, the pads 10 correspond one-to-one to the flexible printed circuit boards 9.

[0086] Furthermore, the pad 10 has an end that is flush with the first end of the holder 4 and the end of the pad 10 has a second notch 101 that engages with the shaft 3 .

[0087] For example, as shown in FIG. 8, the upper end of the pad 10 is flush with the upper end of the holder 4, and the second notch 101 is flush with the first notch 91 and the second groove 46 of the holder 4, thereby causing the shaft 3 to engage with the second groove 46, the first notch 91, and the second notch 101.

[0088] In some embodiments of the present disclosure, each of the first actuator 7 and the second actuator 8 may be formed from a ceramic material, which is highly resistant to wear and tear, thereby providing a long lifespan for the first actuator 7 and the second actuator 8.

[0089] In some embodiments of the present disclosure, the case 1 is fixed according to practical needs. For example, the case 1 is provided with a flange surrounding at least a part of its outer periphery, and the flange can be fixed to a fixed external part via a screw or a bolt.

[0090] An embodiment of the present disclosure further provides a piezoelectric drive system 1000, as shown in FIG. 9. The piezoelectric drive system 1000 includes a piezoelectric drive device 100 according to any of the above-described embodiments and a movable member 200. The movable member 200 is provided below the piezoelectric drive device 100 and configured to engage with the first actuator 7 or the second actuator 8 of the piezoelectric drive device 100. The holding member 2 is configured to abut against the movable member 200 and hold the first actuator 7 or the second actuator 8. The movable member 200 is configured to move when driven by the first actuator 7 or the second actuator 8.

[0091] In some embodiments of the present disclosure, when the outer circumferential surface of the movable member 200 is flat, the first actuator 7 and the second actuator 8 drive the movable member 200 to move horizontally, and when the outer circumferential surface of the movable member 200 is curved, the first actuator 7 and the second actuator 8 drive the movable member 200 to rotate.

[0092] Hereinafter, the operation process of the piezoelectric driving system 1000 will be briefly described using the first piezoelectric element 5 as an example.

[0093] When energized, the first piezoelectric element 5 expands in a direction perpendicular to the first sidewall 41 of the recess. During expansion, the left end of the first piezoelectric element 5 is restricted by the first sidewall 41 of the recess, so that the right end of the first piezoelectric element 5 expands to the right and downward, and drives the first actuator 7 to move to the right and downward. The first actuator 7 abuts against the movable member 200 and applies a driving force to the movable member 200. The driving force applied by the first actuator 7 has a right component and a downward component. Therefore, the movable member 200 is driven to move to the right. For example, the movable member 200 can be driven to accurately move 40 nm at a time.

[0094] In the event of a power failure, the first piezoelectric element 5 contracts, thereby driving the first actuator 7 to move leftward and upward. The direction perpendicular to the first side wall 41 of the recess has a first angle α of 24 degrees to 26 degrees with the plane on which the end face of the upper end of the holder 4 is located, and therefore the first actuator 7 moving leftward and upward cannot apply a driving force to the movable member 200. The first actuator 7 moving leftward and upward is even separated from the movable member 200 in a microscopic sense. Therefore, the movable member 200 does not move together with the first actuator 7 and remains in its position. In this way, the piezoelectric driving system 1000 completes one motion cycle. A periodic pulse signal can be applied to the first piezoelectric element 5, which allows the first piezoelectric element 5 to alternately complete the motion of expansion when current is applied and contraction when power is lost. As the motion cycle is repeated, the movable member 200 moves continuously to the right by the drive of the first actuator 7.

[0095] The operation process of the second piezoelectric element 5 is basically the same as the operation process of the first piezoelectric element 6, except that the moving direction of the movable member 200 when the first piezoelectric element 5 is operating is opposite to the moving direction of the movable member 200 when the second piezoelectric element 6 is operating. For example, the first piezoelectric element 5 drives the movable member 200 to move to the right, and the second piezoelectric element 6 drives the movable member 200 to move to the left. In some other embodiments of the present disclosure, the first piezoelectric element 5 can drive the movable member 200 to move clockwise, and the second piezoelectric element 6 can drive the movable member 200 to move counterclockwise. Also, only one of the first piezoelectric element 5 and the second piezoelectric element 6 operates during the same time period. In other words, the first piezoelectric element 5 and the second piezoelectric element 6 operate to repel each other.

[0096] According to the above embodiments of the present disclosure, the piezoelectric driving system 1000 has the advantages of simple structure, accurate driving stroke, strong driving force, high energy conversion efficiency, etc.

[0097] In the description of the present disclosure, unless otherwise specified and limited, the terms "attached", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a removable connection, or it may be integral. It may be a mechanical connection or an electrical connection. It may be a direct connection, an indirect connection through an intermediate medium, or an internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present disclosure according to the specific situation.

[0098] In this specification, a description that refers to terms such as "embodiment," "specific example," and "example" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, general descriptions of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, one of ordinary skill in the art can combine or combine different embodiments or examples described in this specification.

[0099] Although the embodiments of the present disclosure have been shown and described above, those skilled in the art may make changes, modifications, substitutions, and variations in the embodiments without departing from the principles and scope of the present disclosure. The scope of the present disclosure is limited by the claims and their equivalents.

Claims

1. A piezoelectric driving device, a case defining a cavity therein and having a closed end and an open end; a holder that is provided in the cavity via a retaining member and has a first end connected to the closed end of the case and a second end toward the open end of the case, the second end of the holder having a recess in its end surface, the recess including a first side wall, a second side wall, and a bottom portion connected between the first side wall and the second side wall, the first side wall and the second side wall extending at an angle in a direction away from each other; a first piezoelectric element and a second piezoelectric element bonded to a first side wall and a second side wall of the recess by a hard adhesive, respectively, the first piezoelectric element being configured to expand or contract in a direction perpendicular to the first side wall of the recess when a current is applied or a power outage occurs, and the second piezoelectric element being configured to expand or contract in a direction perpendicular to the second side wall of the recess when a current is applied or a power outage occurs; a first actuator and a second actuator fixed to the first piezoelectric element and the second piezoelectric element, respectively, and facing each other; the retaining member being provided in the cavity and having a first end abutting against the closed end of the case and a second end opposite the first end; a shaft disposed in the cavity and configured to engage a second end of the retaining member and move under the action of the retaining member; a first end of the holder fixed to the shaft and abutting a second end of the holding member; the case includes at least two opposing side walls, each side wall having an opening, the openings of the two opposing side walls of the case are aligned with each other, two ends of the shaft are accommodated in the openings of the two opposing side walls of the case, respectively, and the shaft is configured to move within the openings under the action of the retaining member; Piezoelectric drive.

2. The end faces of the two ends of the shaft are flush with the outer surfaces of the two opposing side walls of the case, respectively.

2. The piezoelectric drive device according to claim 1.

3. each opening has two arcuate ends that match the shape of the ends of the shaft, the arcuate ends being configured to engage the ends of the shaft; 2. The piezoelectric drive device according to claim 1.

4. The second end of the retaining member has a first groove, the shaft at least partially engaging the first groove.

2. The piezoelectric drive device according to claim 1.

5. The first end of the holder has a second groove, the shaft at least partially engaging the second groove.

5. The piezoelectric drive device according to claim 4.

6. the first groove, the shaft, and the second groove are aligned with one another in a direction from the closed end to the open end of the case; each of the first groove and the second groove has an arcuate cross section that matches the axis; the first groove and the second groove surround an outer periphery of the shaft; 6. The piezoelectric drive device according to claim 5.

7. A piezoelectric drive device, a case defining a cavity therein and having a closed end and an open end; a holder provided in the cavity and having a first end connected to the closed end of the case and a second end toward the open end of the case, the second end of the holder having a recess in its end surface, the recess including a first side wall, a second side wall, and a bottom portion connected between the first side wall and the second side wall, the first side wall and the second side wall extending at an angle away from each other from the bottom portion; a first piezoelectric element and a second piezoelectric element bonded to a first side wall and a second side wall of the recess by a hard adhesive, respectively, the first piezoelectric element being configured to expand or contract in a direction perpendicular to the first side wall of the recess when a current is applied or a power outage occurs, and the second piezoelectric element being configured to expand or contract in a direction perpendicular to the second side wall of the recess when a current is applied or a power outage occurs; a first actuator and a second actuator fixed to the first piezoelectric element and the second piezoelectric element, respectively, and facing each other; a bottom of the recess includes a first section, a second section, and a third section, the first section being connected to the first sidewall, the second section being connected to the second sidewall, and the third section being connected between the first section and the second section; the first section engages the first piezoelectric element and the second section engages the second piezoelectric element; the first piezoelectric element matches the first sidewall and the first section of the recess in shape and orientation, respectively, and the second piezoelectric element matches the second sidewall and the second section of the recess in shape and orientation, respectively. Piezoelectric drive.

8. each of the first piezoelectric element and the second piezoelectric element has a rectangular parallelepiped shape, the third section of the recess is parallel to an end face of the first end of the holder, a direction perpendicular to the first side wall of the recess is orthogonal to a direction perpendicular to the first section of the recess, and a direction perpendicular to the second side wall of the recess is orthogonal to a direction perpendicular to the second section of the recess; 8. The piezoelectric drive device according to claim 7.

9. a first transition portion is provided at a connection between the first sidewall of the recess and the first section, and a second transition portion is provided at a connection between the second sidewall of the recess and the second section.

8. The piezoelectric drive device according to claim 7.

10. a direction perpendicular to the first side wall of the recess and a plane on which an end face of the first end of the holder is located have a first angle, and a direction perpendicular to the second side wall of the recess and a plane on which an end face of the first end of the holder is located have a second angle. The piezoelectric driving device according to any one of claims 1 to 9.

11. the first angle ranges from 24 degrees to 25 degrees and the second angle ranges from 24 degrees to 26 degrees; 11. The piezoelectric drive device according to claim 10.

12. the first piezoelectric element is symmetrical to the second piezoelectric element, and the first angle is equal to the second angle; 11. The piezoelectric drive device according to claim 10.

13. each of the first actuator and the second actuator has a first end adjacent the holder and a second end remote from the holder; a first end of the first actuator is spaced apart from a first end of the second actuator, a second end of the first actuator protrudes beyond the first piezoelectric element in a direction away from the holder, and a second end of the second actuator protrudes beyond the second piezoelectric element in a direction away from the holder; The piezoelectric driving device according to any one of claims 1 to 9.

14. A piezoelectric drive device, comprising: a case defining a cavity therein and having a closed end and an open end; a holder provided in the cavity and having a first end connected to the closed end of the case and a second end toward the open end of the case, the second end of the holder having a recess in its end surface, the recess including a first side wall, a second side wall, and a bottom portion connected between the first side wall and the second side wall, the first side wall and the second side wall extending at an angle away from each other from the bottom portion; a first piezoelectric element and a second piezoelectric element bonded to a first side wall and a second side wall of the recess by a hard adhesive, respectively, the first piezoelectric element being configured to expand or contract in a direction perpendicular to the first side wall of the recess when a current is applied or a power outage occurs, and the second piezoelectric element being configured to expand or contract in a direction perpendicular to the second side wall of the recess when a current is applied or a power outage occurs; a first actuator and a second actuator fixed to the first piezoelectric element and the second piezoelectric element, respectively, and facing each other; a flexible printed circuit board electrically connected to the first piezoelectric element and the second piezoelectric element and configured to energize and de-energize the first piezoelectric element and the second piezoelectric element; The flexible printed circuit board is provided in the cavity of the case and is sandwiched between a side wall of the case and the holder. Piezoelectric drive.

15. A retaining member provided in the cavity and having a first end abutting the closed end of the case and a second end opposite the first end; a shaft disposed in the cavity and configured to engage a second end of the retaining member and move under the action of the retaining member; A first end of the holder is fixed to the shaft and abuts against a second end of the holding member.

15. A piezoelectric drive device according to claim 14.

16. the flexible printed circuit board has a first end and a second end, the first end of the flexible printed circuit board is accommodated in the cavity of the case, and the second end of the flexible printed circuit board protrudes outside the cavity of the case; a first end of the flexible printed circuit board is flush with a first end of the holder and has a first notch that engages with the shaft; a second end of the flexible printed circuit board including two legs spaced apart from each other to expose at least a portion of the recess; 16. A piezoelectric drive device according to claim 15.

17. a pad disposed in the cavity of the case and sandwiched between the flexible printed circuit board and a side wall of the case; 16. A piezoelectric drive device according to claim 15.

18. the pad has an end flush with a first end of the holder, the end of the pad having a second notch that engages the shaft; 18. A piezoelectric drive device according to claim 17.

19. 1. A piezoelectric drive system comprising: A piezoelectric driving device according to any one of claims 1 to 6, a movable member disposed below the piezoelectric drive device and configured to engage a first actuator or a second actuator of the piezoelectric drive device. the holding member is configured to hold the first actuator or the second actuator, and the movable member is configured to move by driving the first actuator or the second actuator. Piezoelectric drive system.

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